Techno-Economic Exploitation Study

Transcript

1 BIOGAIA Development of Sustainable Biogas Strategies for Integrated Agroindustrial Waste ETCP Greece-Italy ΤΕΧΝΟΟΙΚΟΝΟΜΙΚΗ ΑΞΙΟΛΟΓΗΣΗ Techno-Economic Exploitation Study Achaia biogas potential Action 5.2 Development of Exploitation Business Plans Development Company of Region of Western Greece S.A. Patras, November 2015 Page 1

2 Contents 1. Introduction and deliverable scope Anaerobic digestion process for biogas production and other by-products Phases of Anaerobic Digestion Anaerobic Digestion parameters Operational parameters Waste type and sources for biogas production through anaerobic digestion Olive Mill Waste (OMW) Cheese Whey (CW) Wet Manure (WM) Other types of waste Agricultural and livestock waste exploitation model for biogas production Recording of liquid agricultural and livestock waste of the Achaia Regional Unity Elaboration of recorded data Estimated biogas production at Achaia Regional Unity level Anaerobic digestion biogas production plant equipment Substrate storage tank Feeding System Bio reactor (Digester) Stirring technology Heating systems Biogas Storage Biogas cleaning Internal Combustion Engine (CHP - Cogeneration of heat & electrical power) Processing of digestate Control and automation Biogas plant safety Anaerobic digestion biogas plant installation cost and basic assumptions SCENARIO 1 Central Unit SCENARIO 2 Two decentralized units Financial plan SCENARIO Page 2

3 SCENARIO Depreciation SCENARIO SCENARIO Employment SCENARIO SCENARIO Raw material Raw material quantities SCENARIO SCENARIO Raw material cost SCENARIO SCENARIO Total production cost SCENARIO SCENARIO Compost production SCENARIO SCENARIO Biogas production SCENARIO SCENARIO Electric and thermal power production SCENARIO SCENARIO Financial turnover SCENARIO SCENARIO and sales expenses SCENARIO SCENARIO Financial profile Working capital Page 3

4 SCENARIO SCENARIO Loan SCENARIO SCENARIO Trading account SCENARIO SCENARIO Cash flows Viability indicators SCENARIO SCENARIO Minimum viable biogas plant case (Scenario 3) Financial turnover Trading account Cash flows viability indicators Conclusions REFERENCES ANNEX Olive Mill Waste Data Cheese Whey data Wet Manure data Wineries data Agricultural production enterprises data Page 4

5 Images Image 1 - Anaerobic Digestion phases Image 2 - Olive mill waste polluting environment Image 3 - Cheese production process Image 4 - Open warehouse withmanure bedding Image 5 - Integrated AD plant process diagramm Image 6 - Provided data per production unit Image 7 - Achaia Map with all types of waste Image 8 - Olive Mills Waste locations Image 9 - Cheese Whey waste locations Image 10 - Wet Manure waste locations Image 11 - Agricultural and Wineries residues locations Image 12 - Visualization of waste volume per unit Image 13 - Over all map with Olive Mills, Dairies & Animal Farms waste volumes Image 14 - Olive Mills waste volumes & locations Image 15 - Dairies waste volumes & locations Image 16 - Animal Farms waste volumes & location Image 17 - Surveyed units Image 18 - Solid substrate storage examples Image 19 - Wet manure storage example Image 20 - Atermon screw and centrifugal pump Image 21 - Conventional two-stage anaerobic digestion [Kopsacheilis, 2009] Image 22 - Digestor stirring technologies Image 23 - Digester heating systems Image 24 - Different types of biogas storing facilities Image 25 - H 2 S water scrubbing Image 26 - CHP example Image 27 Centrifuge unit (decanter) Image 28 - Example of SCADA system for slurry management Image 29 - Biogas flare system Image 30 - Financial Plan Image 31 - Workforce structure in scenario Image 32 - Workforce structure in scenario Image 33 - Anticipated Quantitative Raw Materials Consumption Scenario Image 34 - Anticipated Quantitative Raw Materials Consumption Scenario Image 35 - Production Cost Scenario Image 36 - Production Cost Scenario Image 37- Sales for 1st Year Scenario Image 38 - Sales for 1st Year Scenario Image 39 - Οperation Expenses Pie Scenario Image 40 - Operation Expenses Pie Scenario Image 41 - Results Scenario Image 42 - Results before depreciation & taxes (Scenario 1) Image 43 - Revenues, expenses (Scenario 1) Page 5

6 Image 44 - Results Scenario Image 45 - Results before depreciation & taxes (Scenario 2) Image 46 - Revenues, expenses (Scenario 2) Image 47 - Results before depreciation & taxes Scenario Image 48 - Results (Scenario 3) Image 49 - Revenues, expenses (Scenario 3) Tables Table 1 - Physicochemical characteristics of OMW Table 2 - Physicochemical characteristics of CW Table 3 - Physicochemical characteristics of WM Table 4 - Seasonality of substrates Table 5 - Substrate recipe per period Table 6 - Surveyed units Table 7 - West Achaia group of units & waste Table 8 - East Achaia group of units & waste Table 9 - Achaia biogas estimated potential with no co-digestion Table 10 - Achaia biogas estimated potential with co-digestion Table 11 - West Achaia group biogas estimated potential with co-digestion Table 12 - East Achaia group biogas estimated potential with co-digestion Table 13 - Reactor size per scenario Table 14 - Feedin tariffs for biogas production Table 15 - Location and capacity of biogas plants Table 16 - Initial investment for central unit 2,5MW - Scenario Table 17 - Initial investment for West Achaia 1MW - Scenario 2A Table 18 - Initial investment for East Achaia 1,5MW - Scenario 2B Table 19 - Scenario 1 financial plan Table 20 - Scenario 2 financial plan Table 21 - Depreciation in scenario Table 22 - depreciation in scenario Table 23 - Employment cost for scenario Table 24 - Employment cost for scenario Table 25- Anticipated Quantitative Raw Materials Consumption Scenario Table 26 - Anticipated Quantitative Raw Materials Consumption Scenario 2A Table 27 - Anticipated Quantitative Raw Materials Consumption Scenario 2B Table 28 - Anticipated Values Of Raw Material Consumption Scenario Table 29 - Anticipated Values Of Raw Material Consumption Scenario 2A Table 30 - Anticipated Values Of Raw Material Consumption Scenario 2B Table 31 - Total Cost Of Production Scenario Table 32 - Total Cost Of Production for Scenario Table 33 - Compost Production Scenario Table 34 - Compost Production Scenario Table 35 - Anticipated Biogas Production Scenario Table 36 - Anticipated Biogas Production Scenario Page 6

7 Table 37 - Anticipated Production Of Electrical And Thermal Energy Scenario Table 38 - Anticipated Production Of Electrical And Thermal Energy Scenario Table 39 - Sales Revenues Scenario Table 40 - Sales Revenues Scenario Table 41 - Administrative - distribution expenses Scenario Table 42 - Administrative - distribution expenses Scenario Table 43 - Working Capital Scenario Table 44 - Working Capital Scenario Table 45 - Long Term Loan Scenario Table 46 - Long Term Loan Scenario Table 47 - Operating Income Scenario Table 48 - Operating Income Scenario Table 49 - Cash Flow Scenario Table 50 - Cash Flow Scenario Table 51 - Financial Plan (Scenario 3) Table 52 - Financial Turnover (Scenario 3) Table 53 - Trading Account (Scenario 3) Table 54 - Return on Investment (Scenario 3) Page 7

8 1. Introduction and deliverable scope The objective of this deliverable is to present indicative use solutions of waste potential exploitation of Achaia, for biogas and other sub-products production and to evaluate them from techno-economic perspective. To achieve this objective, the contractor analyzed initially the applicable biogas methodology of project BIOGAIA, which is that of Anaerobic Co-Digestion of agroindustrial and livestock waste. Then, the availability and spatial dispersion of the waste is examined in order to draw conclusions in relation to the size and geographical allocation of the biogas plants. In this context, the contractor company ProTeA - Project Technical Assistance conducted secondary research from public services, as well as primary research for verification purposes, in order to update the waste sources file, in terms of volume and their exact locations. The next step was to take into account the project Biogaia methodology in order to calculate the exploitable products volumes. This indicated a set of existing scenarios, from which two basic ones where considered. The first scenario foresees a central biogas plant, based in the industrial area of Patras, covering all Achaia and with a power 2.5 MW (approx.) The second scenario concerns two units, one in Eastern Achaia covering Aigialeia and Kalavryta municipality, based near Aigio, of 1,5 MW power (approx.) and a second in western Achaia covering the municipalities of Patra, Erymanthou and Western Achaia, located near Kato Achaia with power of 1 MW (aprox). For both scenarios, it is assumed that the plants operate throughout the year by applying different mix of waste per 4 months, depending on their seasonality. The three mixtures are: - 55% Olive Mill Waste, 40% Cheese Whey and 5% Wet Manure for the period November to February - 90% Cheese Whey and 10% Wet Manure for the period March to June - 100% Wet Manure for the period July to October Other mixtures with solid agricultural residues and energy crops are possible too. Page 8

9 The two proposed scenarios are discussed in terms of equipment and estimated investment costs, while there is a projection for investment inflows in order to assess their viability. According to the reached results, the investment's viability of Scenario 1 is satisfying and the investment is attractive given the fact that after the annual additional net cash flow calculation the internal rate of return (IRR) results to 11,29%. The Net Result of the investment is estimated at ,42. Regarding Scenario 2, again the viability is highly sacrificing and the invest is attractive given the fact that after the annual additional net cash flow calculation the internal rate of return (IRR) results to 7,9%. The Net Result of the investment is estimated at ,33. Consequently, Scenario 1 with the construction of 1 central unit for the entire Achaia prefecture, of 2,5 MW nominal power, seems to present higher IRR by 3,39%, while the net result of the investment is higher by ,09, compared with the construction of 2 decentralized units of 1MW and 1,5 MW. Additionally, a 3 rd scenario was examined in order to examine the possibility of establishing a biogas unit in smallest possible scale, which will be financed entirely by small investors. The aim of this alternative, was to determine the minimum capacity of the unit, the creation of which will have minimum capital requirement and simultaneously will be economically viable. To identify this case, it was chosen the investment with the Net Present Value that equals to zero in ten-year time. After a series of calculations presented above, it was estimated 1,7 MW and with an investment cost at The internal rate of return of the investment is calculated to be 4%. We should underline that given the fact that the current investment has a null defined net value, the creation of a unit with capacity greater than 1,7MW would have a net value greater than null and as a result, every investment with a capacity over 1,7MW is expected to be viable in terms of economy. Page 9

10 2. Anaerobic digestion process for biogas production and other by-products Modern western communities produce vast quantities of wastes. The rational for environment protection requires the adoption of a waste management method based on minimizing environmental impact and maximizing the utilization of these wastes. Recently and due to the growing demand for clean energy, there is great research mobility on energy production from biomass (biodegradable organic matter derived from plants, animals and microorganisms), focusing mainly on the treatment of: a) agricultural products and residues b) livestock products and waste c) industrial waste, d) and energy crops. Anaerobic Digestion is an appropriate technology for treating such waste, which within the frames of BioGAIA project, its application is investigated on the simultaneous treatment of both solid and liquid agroindustrial residues and wastes of Achaia. During Anaerobic Digestion process, bacterial degradation takes place, transforming complex organic molecules into smaller molecules like methane (CH4) and Carbon Dioxide (CO2), with oxygen absence and a temperature range of o C. Anaerobic Digestion results to biogas production with high methane (CH 4 ) content, which can be used as input to a Combined Heat and Power (CHP) system. While the produced heat can be used for raising the tank temperature to the desired levels (20-55 C), the produced electricity can cover part of the energy consumption costs of the facilities. Indeed, in cases of large waste treatment plants, the produced methane may outweigh the plants energy needs. Page 10

11 Organic matter + Η 2 Ο -> CH 4 + CO 2 + NH 3 + new cells 2.1 Phases of Anaerobic Digestion The process of biogas formation is a result of combination of steps, in which the starting material is continuously broken down into smaller components. Specific groups of micro-organisms are involved in each individual step. These organisms successively decompose the products of the previous steps. Anaerobic digestion is a purely bacterial process. The process works in the absence of air. The digestion process can be divided into four phases, namely: Hydrolysis, Acidogenesis, Acetogenesis and Methanogenesis. A simplified diagram of the AD process broken down to Phases is shown in the following figure. Image 1 - Anaerobic Digestion phases In the first phase (Hydrolysis) anaerobic bacteria use enzymes to decompose high molecular organic substances such as proteins, carbohydrates, cellulose and fats into low molecular compounds. Hydrolysis is a relatively slow process and may be hampered by factors such as the type of substrate, the value of ph, the particle size, the production of enzymes, the enzymes adsorption to the particle surface. Page 11

12 During the second phase (Acidogenesis) acid forming bacteria continue the decomposition process into organic acids, carbon dioxide, hydrogen sulphide and ammonia. Acidogenesis products vary depending on the type of microorganisms as well as the cultivation conditions (temperature, ph etc). The acidogenic population constitutes about 90% of the total microbial population in an anaerobic digester. Acid bacteria form acetate, carbon dioxide and hydrogen during the third phase (Acetogenesis). Under the high hydrogen partial pressure, acetogenic microorganisms are prevented to convert the volatile fatty acids, thus reducing the formation of acetic acid and the diversion of the process. The methanogenic microorganisms act collaboratively achieving a reduction in the hydrogen concentration. The fourth phase (Methanogenesis) involves methane forming bacteria producing methane, carbon dioxide and alkaline water. The methanogenesis is a critical step in the entire process of anaerobic digestion, since it is the slowest biochemical reaction process. The methanogenesis is severely influenced by operation conditions. The composition of the feedstock, the feed rate, the temperature and ph are examples of factors that influence the methanogenesis. Digester overloading, temperature changes or large entry of oxygen can result in termination of methane production. The bacteria can digest any kind of biological material except solid biofuels with a high quantity of lignin, such as wood. The bacteria in the methane phase need a longer reproduction time than the bacteria in the acid phase. Therefore the speed and scale of the fermentation depend on the metabolism of the methane bacteria. On the other hand the methane bacteria need the metabolism products from the acid bacteria. Thus, they are in symbiosis and the necessary conditions for both bacteria types are imperative for a smooth flow. 2.2 Anaerobic Digestion parameters The efficiency of AD is influenced by some critical parameters, so it is important to secure appropriate conditions for anaerobic microorganisms. Their growth and activity is significantly influenced by the exclusion of oxygen, the temperature, the value of ph, the supply with nutrients, the stirring intensity as well as the presence and amount of inhibitors (i.e. ammonia ). Methane Page 12

13 bacteria are sensitive anaerobes, so the presence of oxygen into the digestion process should be avoided. These influential parameters are presented below: TEMPERATURE The temperature is the major environmental factor that affects the growth of microorganisms. In literature, five temperature ranges for optimal growth of the microorganisms are idenitfied : a) hyperthermophilic T> 80 o C, thermophilic o C, mesophilic o C, psychroresistant o C, psychrophilic o C [Kopsacheilis, 2009]. The processing of waste in the anaerobic digestion is predominantly under mesophilic and thermophilic conditions because of their high performance. Even small temperature changes during the operation of a system of anaerobic digestion, can be fatal and this is mainly because the methanogenic microorganisms, which are very sensitive, enter a dormant phase to adapt to new conditions. In overall, thermophilic anaerobic digestion seems to outweigh the mesophilic since it presents advantages such as: a) a smaller number of required installations, b) greater rate of degradation of organic matter and therefore increased rate of biogas production, c) rapid hydrolysis and d) destruction of pathogenic microorganisms. However, high power requirements coupled with greater sensitivity to toxic compounds, and the reduced stability of these systems, usually make the thermophilic anaerobic digestion uneconomic and difficult to implement. PH VALUE RANGE In most cases the conversion of the organic material is achieved in a particular ph range (ph = ) [Zafeiri, 2013]. However, many types of bacteria can be satisfactorily developed at ph values ranging in a range between 6.0 and 9.0. For anaerobic fermentation, the ph values should range from 6.8 to 8.0. Acidity higher or lower than this range of ph, inhibits the fermentation. The influx of large amounts of untreated waste can cause excessive acidity and in that case gas producing bacteria are unable to digest the acid fast. The addition of a small amount of ammonia may increase the ph value, but if this value becomes too high (not acidic enough environment), Page 13

14 fermentation is retarded until the fermentation process forms sufficient hydrogen carbon oxide so as to restore the balance. Two important factors that affect the determination of the ph value of a digester is the concentration of volatile fatty acids (VFA) and alkalinity (expressed as CaCO 3 /l). The alkalinity is primarily due to HCO - 3 ions derived from the CO 2 production during degradation of organic compounds. Fatty acids produced during acidogenesis, tend to reduce the value of ph of the bioreactor, but under normal circumstances, this reduction is regulated by the HCO - 3 ions and consumption of acid during the stages of acetogenesis and methanogenesis. Under adverse conditions (e.g. inhibiting methanogenesis, extreme increase of fatty acids) buffering capacity of the system can be overturned, resulting in a price decrease of ph and eventual failure of the process, in the absence of a timely intervention in the system. A method of preserving the value of the ph in the desired range limits is the increase of alkalinity of the system by adding ammonia (NH 3 ), sodium hydroxide (NaOH) or sodium bicarbonate (NaHCO 3 ). TOXICITY The anaerobic microorganisms and especially methanogenic, are particularly sensitive to many substances [Zafeiri, 2013]. Inhibition of methanogenic microorganisms, results in reduced production of methane, and increase the concentration of volatile acids. Some of the compounds that inhibit or even stop the growth of the microorganisms are the following: Oxygen The methanogenic microorganisms are strictly anaerobic and therefore they are adversely affected by even traces of oxygen. Therefore during operation of the reactor it is required to ensure hermetically sealed lids that keep air out. Nitrite and Nitrate These compounds also have the ability to inhibit the anaerobic digestion and therefore should first be reduced before methanogenesis takes place. Ammonia (NH 3 ) Ammonia in its unionized form, is very toxic to methanogenic bacteria. Nevertheless low toxicity may be observed in ph values in the neutral range. Page 14

15 Higher Fatty Acids The higher fatty acids inhibit the activity of the acetic-utilitarian methanogenic bacteria. Heavy Metals Heavy metals such as Cu 2+, Pb 2+, Cd 2+, Ni 2+, Zn 2+, Cr 6+, which are contained mainly in the industrial waste, prevent the anaerobic digestion when their presence is in high concentrations, while in other cases they are required by the process as nutrients, but in low concentrations. Chlorinated hydrocarbons The chlorinated aliphatic hydrocarbons are toxic for methanogenic microorganisms. Especially chloroform (CHCl 3 ) is very toxic and results in complete inhibition of the metabolism of methanogenic bacteria when the concentration exceeds the value of 1 mg/l. Aromatic Compounds Pure cultivations of methanogens are prevented from aromatic compounds (such as benzene, toluene, phenols). Formaldehyde The methano-bacteria are significantly hampered when exposed to concentrations of formaldehyde (HCHO) of more 100mg/l. However their function is restored at lower formaldehyde concentrations. Sulfur and sulfate anion (HS -, S 2- ) Hydrogen sulphide (H 2 S) and generally sulphide anions (HS -, S 2- ) are among the most potent inhibitors of anaerobic treatment. Because diffusion through the cell membrane is more rapid for inseparably molecules, the toxicity of hydrogen sulfide depends on ph. Hydrogen sulfide is toxic to methanogens bacteria when the concentration is greater than mg/l. The acidogenic bacteria are less sensitive to hydrogen sulfide (H 2 S) in comparison to methanogenic. CHEMICAL COMPOSITION OF INPUT Page 15

16 The chemical composition of the substrate is the main factor shaping the characteristics of an anaerobic digester. The prevalence of microbial species, takes place by means of a natural selection, such as the adjustment of survival in a natural environment. This natural selection of microorganisms depends on their ability to grow in the medium, namely organic and inorganic constituents of the substrate. The formed metabolic products further enhance the culture of bacteria, which in turn lead the process into final products (such as methane and carbon dioxide). If any components of complex substrates are non-biodegradable then there is no complete removal of organic material. Knowing therefore the characteristics of the substrate is essential for understanding the behavior of a digester and for the design of processes of anaerobic treatment. The components of some composite substrates may be non-biodegradable, so when this is the case, the applicability of anaerobic digestion is reduced, resulting to insufficient removal of organic load. To achieve complete removal of the organic load high temperatures (T = 35 o C - 50 o C) have to be applied. For smooth and above all optimal operation of the anaerobic treatment, the bacteria need additional elements besides carbon, in order to meet their operational needs. Such elements are iron, cobalt, molybdenum, magnesium, calcium, sodium, barium, selenium and nickel. These nutrients are usually present in sufficient concentrations in most waste. The proposed ratio of C: N: P for anaerobic bacteria equal to 700: 5: 1. Other scientists argue that adequate C: N ratio is approximately equal to 25 ~ 30: 1, while Sanders and Bloobgood (1965) considered necessary a C: N ratio equal to 16: 1. The balancing of a waste in nitrogen may be done by adding either urea (NH 2 CONH 2 ), or NH + 4 ions, while the balance in phosphorus is mainly achieved by adding ion PO 3-4. Consequently the feeding of the anaerobic digestion should be: (1) rich in organic compounds, (2) non-toxic at desired anaerobic populations, and (3) contain sufficient amounts of nutrients. Of the above conditions, the condition (1) and (2) are particularly important [Georgiopoulou, 2007]. Page 16

17 2.3 Operational parameters ORGANIC LOAD The construction of a biogas plant is a combination of economical and technical considerations. The maximum biogas obtained by complete digestion of the substrate would require a large hydraulic retention time (HRT) and a corresponding size of the digester. In practice, the choice of the system (e.g., the size and type of the digester) is based on a compromise between the maximum biogas production and justifiable plant economy. In this respect, the organic load is an important operating parameter, which indicates how much organic dry matter can be fed into the digester, per m³ volume and unit time in accordance with the following equation: BR = m * c / V R Where, BR: organic load [kg /d*m³] m: mass of substrate fed per time unit [kg/d] c: concentration of organic matter [%] VR: digester volume [m³] HYDRAULIC RETENTION TIME An important parameter for dimensioning of the digester is the hydraulic retention time (HRT). The HRT is the average time interval when the substrate is kept inside the digester tank. The HRT is associated with the volume of the digester (VR), and the volume of substrate fed per unit time, according to the following equation: HRT = VR / Q Where, HRT: hydraulic retention time [days] VR: digester volume [m³] Q: volume of substrate fed per time unit [m³/d] Page 17

18 According to the above equation, increasing the organic load reduces the HRT. The retention time must be sufficiently long to ensure that the quantity of bacteria removed by the compost will not be higher than the amount of reproduced microorganisms (e.g. the duplication rate of anaerobic bacteria is 10 days or more). [Zafeiri, 2013] A short HRT provides a good substrate flow rate, but a lower gas yield. It is therefore important to adapt the HRT to the specific decomposition rate of the used substrates. Knowing the targeted HRT, the daily feedstock input and the decomposition rate of the substrate, it is possible to calculate the necessary digester volume. In general, Anaerobic Digestion can be seen as a method to treat the organic wastes but, in order to extract the maximum recovery value from these wastes, the digestate should have a useful purpose and benefit should be derived from its production. Its main advantage is that it has a high nutrient content. Its quality should be acceptable for purpose such as soil amendment or landscaping. In order to obtain a high quality product, with a higher value, the digestate can be processed into compost. It would ensure a complete breakdown of the organic components as well as fixing the mineral nitrogen onto humus-like fraction, which would reduce nitrogen loss. Finally, the liquid stream from the digestate, can be routed through a membrane system, in order to extract water that is either disposed to soil or used for irrigation purposes. Historically, Anaerobic Digestion was firstly observed during the 10th century, when the Assyrians used it to heat water. It reappeared in the 17th century, when Alessandro Volta observed gas emissions originating from the sediment bottom of a swamp lake, which were collected and proved to be flammable. This led to the biological production of methane and the first large-scale application, took place in 1890 in Britain, where it was used for wastewater treatment. Anaerobic Digestion has the following advantages: Produced biogas can either be cleaned from unwanted contaminants or be burned in special incinerators (CHP), producing heat and electricity, thus reducing the initial cost of the facility. Requires little energy expenditure for waste treatment. Achieves high removal of organic load. The process is suitable for treating heavy agro-wastes. Page 18

19 The produced anaerobic sludge can be used in other applications, such as for compost production. Major disadvantages are: - The long period of time required for the digestion procedure (up to 30 days). - The sensitivity of the equipment to fluctuations of organic load, which can be minimized though, by appropriate adjustment of the input mix. - The need for temperature and energy consumption, which is balanced though by the combustion of biogas and the re-insertion of the generated electricity and thermal energy to the facilities. - The sensitivity of methanogenic microorganisms to various toxic compounds, which may also be reduced by adjusting the input mix. - The bad odor arising from the process, especially when there are sulphates in the input. Page 19

20 3. Waste type and sources for biogas production through anaerobic digestion There are three main types of waste that can be used for biogas production through Anaerobic Digestion; 3.1 Olive Mill Waste (OMW) Image 2 - Olive mill waste polluting environment The main problem of olive mills is their liquid effluent, which presents high pollution indicators (BOD 5, COD, suspended solids) and contains natural pigments that are very difficult to remove by standard purification methods. The effluent is derived from the olive pressing step (when used as an oil extraction method), the stage of the final centrifugal separation and the step of washing the olives with clean water. Also, liquid waste is produced when the olive juices pass through water treatment (washing olives, olive paste dilution, additional water separators, cleaning mill etc.). This waste is dark in color with a characteristic odor and very high pollution indicators (BOD 5, COD, suspended solids). The volume of waste for small mills (e.g. with up to 3 presses), is estimated at 1 m 3 /ton of olives or up to 5 m 3 /ton of olive oil. 16% to 20% of waste from the washing step, 76%-80% of the step of pressing and separating and 4% is wastewater from the settling stage of the final separation. According to literature, the following values for the quality of waste apply: BOD 5 : 42 kg / ton olive or 210 kg/ton olive oil and TSS: 65 kg / ton olive or 325 kg / ton olive oil [Papadiamantopoulos, 2012]. For classical centrifugal systems (3-phase olive mills), waste is estimated at 1,4 m 3 /tons of olives or 7,5-8,2 m 3 /ton of olive oil because of the use of greater amount of water during treatment. More specifically, in this case, 10%-11% of waste water from the washing step, the 84%-85% of the step of centrifugal separation, and 4%-5% wet wastes settling. In the literature the following values are found regarding the quality of OMW that use centrifugal systems: BOD 5 : 19 kg/ton of olives or 95 kg/ton olive oil and TSS: 91 kg/ton olive or 455 kg/ton olive oil. Page 20

21 When the mills apply 2-phase centrifugation where there no water added in the decanters, the output consists only of oil and olive core and not olive juices. Therefore, the advantage of this technique is that the quantities of waste produced are much lower. However, a disadvantage is the high humidity of the resulting olive core (humidity: 62-70%), which needs special processing at an olive core plant. In any case, the OMW is among the most toxic agro-waste in terms of pollution load. Therefore it is easily understood that the pollution caused by the olive mills is one of the major environmental problems faced by the Mediterranean countries. In many cases these waste water is driven to nearby water bodies such as streams, rivers, lakes and seas, creating enormous groundwater contamination problems due to the toxicity of the waste and a general deterioration of the environment around the mill. The phenomenon of the destruction of the water body at the points of discharge of such waste is very common, due to the resulting lack of oxygen, because it is consumed for the oxidation of organic substances. Their physicochemical characteristics are presented in the following table [Kornaros 2010]: Page 21

22 Table 1 - Physicochemical characteristics of OMW Parameter Value ph 5 TSS VSS SOLUBLE C.O.D TOTAL C.O.D B.O.D TOTAL CARBOHYDRATES SOLUBLE CARBOHYDRATES TOTAL NITROGEN AMMONIACAL NITROGEN TOTAL PHOSPHORUS SOLUBLE PHOSPHORUS FATS-OILS PHENOLS 37 g/l 34,54 g/l 67,03 g/l 131,01 g/l 41 g/l 26,15 g/l 21,65 g/l 0,73 g/l 0,10 g/l 0,35 g/l 0,21 g/l 9,85 g/l 6,84 g/l 3.2 Cheese Whey (CW) Image 3 - Cheese production process Liquid waste from dairies mainly contain milk or milk products and various detergents and show a high organic load, high levels of nitrogen and phosphorus and variations in temperature and ph (due to the presence of basic and acidic detergent chemicals). The volume and concentration of dairy waste depends on many factors Page 22

23 such as the type and quantity of products, the process and the production equipment and the cleaning practices. The main sources of wastewater are: Washing water from the milk tanks, from the production lines, the machinery, floors, tank trucks or transporting milk containers milk losses during the production process (e.g. reception, storage, clarification, pasteurization, etc.) Disposal of whey, buttermilk in waste Milk losses The loss of milk in modern factories, is estimated to range between 0,5 to 2,5% (up to 4% in some cases) and the losses of whey is calculated between 5-15%. The reduction of raw material and product losses, allows both saving these materials and avoiding of additional pollution load. Milk contains water, fat, protein, sugar and mineral salts. Milk products may still contain sugar, salts, flavorings, emulsifiers and stabilizers. Due to the leaking milk entering the wastewater, there is a significant increase of the organic load of the wastewater. Disposal of whey & buttermilk The whey is a liquid byproduct of the cheese production process, is 80-90% of the total volume of milk used in cheese production, and contains more than 50% of milk solids. It is divided into sweet (ph 5,8 to 6,6), moderately acidic (ph 5 to 5,8) and acidic (ph <5). It contains 7,5% solids with high protein content etc. And rich organic load (COD ~ mg / L). The non-utilization of whey and its disposal to waste, results in a significant increase in organic load [Kornaros et al, 2008]. The physicochemical characteristics are presented in the following table [Kornaros 2010]: Page 23

24 Table 2 - Physicochemical characteristics of CW Parameter Value ph 6,33 TSS VSS SOLUBLE C.O.D TOTAL C.O.D B.O.D TOTAL CARBOHYDRATES SOLUBLE CARBOHYDRATES TOTAL NITROGEN AMMONIACAL NITROGEN TOTAL PHOSPHORUS SOLUBLE PHOSPHORUS FATS-OILS PHENOLS 9 g/l 7,96 g/l 53,51 g/l 72,12 g/l 36 g/l 40,94 g/l 35,68 g/l 0,92 g/l 0,12 g/l 0,30 g/l 0,22 g/l 0,09 g/l 0,09 g/l 3.3 Wet Manure (WM) Image 4 - Open warehouse withmanure bedding Animal farms also produce significant quantities of waste. For example a small cow farm produces 55 kg fresh manure per day and if the waste material is not managed properly can pollute the environment-particularly water. Incorrect storage or use may lead to pollution of rivers and groundwater, from which drinking water supplies are derived. Inadequate storage facilities allow the manure to Page 24

25 escape to the surroundings. Inadequate maintenance and unsuitable pens contribute to contamination of sites and hence the environment. Also in most cases, flood protection works on the premises of such units, are totally absent resulting in uncontrolled flow of waste from the units in the surrounding area and the stored manure flushed to nearby streams. Animal manures contain chemicals (e.g., nitrates, phosphates, ammonia), organic matter, sediments and pathogens (e.g., giardia, cryptosporidium), heavy metals, hormones and antibiotics. Beyond the problem of water quality, animal manure may contribute significantly to air problems. The livestock manure accounts for about 4% of all anthropogenic methane emissions. It is considered that developed countries are responsible for the largest percentage of total methane emissions due to their livestock farms. The rate of methane emissions from developing countries is expected to increase. Nevertheless, if properly stored and treated, manure can become a valuable source of raw material. The global trend led to more concentrated and usable form of manure to increase methane recovery and more appropriate management of waste from animal farms. The use of manure to crops may be environmentally friendly policy, as the processing in digesters, which decompose the manure and result in the emission of methane gas to generate electricity and other useful products such as ethanol. Page 25

26 The physicochemical characteristics are presented in the following table [Kornaros 2010]: Table 3 - Physicochemical characteristics of WM Parameter Value ph 7,07 TSS VSS SOLUBLE C.O.D TOTAL C.O.D B.O.D TOTAL CARBOHYDRATES SOLUBLE CARBOHYDRATES TOTAL NITROGEN AMMONIACAL NITROGEN 69,04 g/l 46,8 g/l 31,67 g/l 60,9 g/l 19,2 g/l 13,72 g/l 0,96 g/l 3,36 g/l 1,54 g/l TOTAL PHOSPHORUS 0.66 SOLUBLE PHOSPHORUS FATS-OILS PHENOLS n/a 3,24 g/l 1,54 g/l 3.4 Other types of waste Olive Mills Waste, Cheese Whey and Wet Manure are the basic substrates that can be used for biogas production, but there are also other sources of waste that can be utilized and even co digested in an Anaerobic Digestion process. Such waste is the following: Page 26

27 Livestock organic waste - animal by-products and derived products Organic animal slaughterhouse wastes, meat processing, packaging and canning finished product Organic waste from olive industries, olive mills, spore mills, oils and fats refining plants Organic waste from milk processing plants Organic waste from brewery - winery treatment facilities Organic waste from sugar processing plants Organic waste from canning vegetables and fruits Organic waste from edible fish, fish farms and their products Organic waste from juice processing Biodiesel processing waste, such as glycerin, methanol, vegetable and animal oils, and fatty acids Energy crops This waste can be utilized for co-digestion along with the basic proposed types (OMW, CW, WM), in order to enhance biogas production during periods that some of the waste types are not available due to seasonality. Page 27

28 4. Agricultural and livestock waste exploitation model for biogas production An integrated biogas plant using Anaerobic Digestion with various organic substrates is presented in schematic terms below. The Plant will have the ability to process both liquid agricultural and livestock waste, both liquid and solid, in order to maximize energy production through combustion of the produced biogas as well as the recovery of materials and particularly compost through aerobic composting and composting using worms (vermi-composting). Olive mill wastes Cow or pig manure Monitoring biogas and/or hydrogen quality Gas stream C.H.P. Electricity Heat Shredder Hydrolitic reactor ANAEROBIC PILOT PLANT Acidogenic reactor Excess sludge Methanogenic reactor Liquid stream Aerobic SBR Membrane system Liquid Fertilizer Disposal to soil or water body Reuse (irrigation) Grape Marcs Energy crops (sweet sorghum) Agricultural residues, potatoes, melons, tomatoes, etc. Other argoindustrial wastes Centrifuge Dry cake Aerobic composting Vermicomposting Mature compost Sweet sorghum cultivation Image 5 - Integrated AD plant process diagramm The integrated AD Biogas Plant has the ability to process different types of liquid and solid waste such as: Olive mills waste Cow or pig manure Cheese whey Wineries residues Residues of agricultural production Energy crops Page 28

29 The idea is to be able to operate the plant the entire year by being able to replace seasonal waste with others available. However, the need for tackling specific environmental problems of the area related to olive oil, dairy industry and animal farms, indicates that Olive Mills Waste (OMW), Cheese Whey (CW) and Wet Manure (WM) should processed by such a plant in order to minimize their environmental impact and at the same time to serve as feedstock substrates for energy and materials production. However there is seasonality in their availability according to the following table Table 4 - Seasonality of substrates JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC OMW OMW OMW OMW CW CW CW CW WM WM WM WM WM WM WM WM WM WM WM WM This means that there are three basic scenarios for the plant feedstock, related to the time of the year and the optimum recipes for the plant feedstock [Vavouraki 2011]. Table 5 - Substrate recipe per period TYPE PERIOD 1 NOV - FEB PERIOD 2 MAR - JUN PERIOD 3 JUL - OCT OMW 55% CW 40% 90% WM 5% 10% 100% However, the plant feedstock can be enhanced with other materials such as wineries residues during SEP-OCT, or agricultural residues during JUL - SEP, or ensilaged sweet sorghum all over the year. Page 29

30 In case solid waste e.g. agricultural residues or energy crops, then they are firstly passed through a shredder in order to create small particles which then are fed to the hydrolytic reactor. The mixed substrate is led to the hydrolytic reactor (for the hydrolysis of solid or semi-solid waste streams e.g agricultural residues, manures etc) and then to the Anaerobic Digester which operates two-stage anaerobic digestion of agro-industrial wastes through an acidogenic and a methanogenic reactor. The anaerobic co-digestion effluent (liquid stream) is further post treated in two settlers and an aerobic SBR reactor in order to either be used as liquid fertilizer or to be cleansed through a membrane system in order to be used for irrigation or process water. The gas stream of the AD is led to a H 2 S scrubber and the to the CHP where it is burned in order to produce electric and thermal power. The electric power is sold to public electricity grid and the thermal power is used for the AD process. Finally the sludge stream of the AD process is centrifuged in order to separate wastewater from the solids and this dry cake passes through aerobic composting or vermi-composting in order to produce mature compost. Page 30

31 5. Recording of liquid agricultural and livestock waste of the Achaia Regional Unity In order to be able to define the maximum biogas capacity of Achaia prefecture, as well as to provide proposals for suitable Biogas Plants locations, it is necessary to record both the location and the volume of the waste sources. Waste sources are enterprises such as Olive Mills, Dairy Industries, Animal Farms, Wineries Enterprises related to Agricultural products (Canning, Packing, Producers etc) The data gathered by the working team, which are provided in the Annex, were initially derived from public services. However, these data were not considered accurate or helpful for a number of reasons. In many cases these data are outdated and incomplete, containing in the best case name, address, type of enterprise, telephone, since they were recorded for other reasons such as permits issuing. Consequently, waste volumes and types of each unit were not initially recorded as this is not formally foreseen by the current legislation. Even more, in many cases the capacity of the units is not accurate since they are either fictitiously increased in cases of economic subsidies, or fictitiously decreased in cases of environmental permits. Consequently, the working team conducted a survey in order to verify the public data and to enhance them by collecting information regarding the exact location of the units and their waste production. More specifically, the data collected were related to: Page 31

32 Company Name Address, Municipal Unit, Municipality Type and units of production, Type and volume/weight of waste Geodata of their location Additionally, the collected data were represented on Google maps in order to visualize the location and the volume of waste sources. The following URL links to an online Google Map where all the waste locations are identified with additional information for each location. The map provides 5 layers of the recorded types of enterprises : Olive Mills, Animal Farms, Dairies, Wineries, Agricultural Enterprises. At each point of interest the user can receive additional data by left clicking on the mark. For instance, for Animal Farm No 36, additional information includes Latitude and Longitude values, and waste production per day, as depicted in the following picture. Page 32

33 Image 6 - Provided data per production unit Below, a set of Google Maps instances is provided and specifically: The entire Google Map with all layers activated Google map of Olive Mills Google map with Dairies Google map with Animal Farms Google map with Wineries and Agricultural Production farmlands. Page 33

34 34 Image 7 - Achaia Map with all types of waste

35 35 Image 8 - Olive Mills Waste locations

36 36 Image 9 - Cheese Whey waste locations

37 37 Image 10 - Wet Manure waste locations

38 38 Image 11 - Agricultural and Wineries residues locations

39 Additionally, the volume of the waste is visualized through Google Maps API, by representing the volume with the radius of a circle, centered at the LAT LON location of the unit. Again, further information is provided by left clicking on the center of the map. Provided information includes the name of the unit owner and the total waste produced per day, according to the recorded data. Image 12 - Visualization of waste volume per unit Again, respective maps are constructed by using Google Maps API (offline). Below, these maps are presented, but they are also available for downloading through the following URL: The listed maps are: The overall Map including Olive Mills, Dairies and Animal Farms Three maps, one for each category of Unit (Olive Mills, Dairies and Animal Farms) Page 39

40 40 Image 13 - Over all map with Olive Mills, Dairies & Animal Farms waste volumes

41 41 Image 14 - Olive Mills waste volumes & locations

42 42 Image 15 - Dairies waste volumes & locations

43 43 Image 16 - Animal Farms waste volumes & location

44 5.1 Elaboration of recorded data The findings of this survey are in short the following: Table 6 - Surveyed units Type of Unit Number of Units Waste production Olive Mills ,3 tn/day liquid wastes (OMW) Dairy Industries ,5 tn/day liquid wastes (CW) Animal Farms 48 95,66 tn/day wet manure (WM) Wineries 28 Agricultural production enterprises tn/season (15% of total capacity) 30 5% of production residues Waste Production Units Olive Mills Dairy Industries Animal Farms Wineries Agricultural production enterprises Image 17 - Surveyed units However, it should be noted once again that the verified and surveyed data are much less than the data provided by pubic services. This does not mean that other waste producing enterprises do not exist. Page 44

45 By examining the collected data and especially the location of the units, it is indicated that they can be distinguished geographically into two separate groups. The units located on the West of Achaia and the ones on the East. The Units at the West of Achaia are located within the limits of 2 municipalities: PATREON (PATRAS) DYTIKI ACHAIA (WESTERN ACHAIA) ERYMANTHOU The Units at the East of Achaia are located within the limits of 2 municipalities: AIGIALEIAS KALAVRYTON (KALAVRYTA) This geographic separation indicates the possibility for proposing alternatively, two separate Biogas Plants one in West and one in the East, instead of one Plant located centrally. In that case the allocation of units and waste is the following: Table 7 - West Achaia group of units & waste Group A Patras, Western Achaia, Erymanthos Type of Unit Number of Units Waste production Olive Mills ,9 tn/day liquid wastes (OMW) Dairy Industries 14 95,25 tn/day liquid wastes (CW) Animal Farms 30 64,77 tn/day wet manure (WM) Wineries tn/season (15% of capacity) Agricultural production enterprises 14 5% of production is residues Page 45

46 Table 8 - East Achaia group of units & waste Group B Aigialeia, Kalavryta Type of Unit Number of Units Waste production Olive Mills ,4 tn/day liquid wastes (OMW) Dairy Industries 7 137,25 tn/day liquid wastes (CW) Animal Farms 18 30,89 tn/day wet manure (WM) Wineries tn/season (15% of capacity) Agricultural production enterprises 16 5% of production is residues Subsequently, the two scenarios that are investigated from a technoeconomic point of view are the following: One (1) central Biogas Plant, operating on a yearly basis with three (3) different mixtures Two (2) decentralized Biogas Plants, operating on a yearly basis with three (3) different mixtures The three mixtures are: 1. Olive Mills Waste (OMW) 55% - Cheese Whey (CW) 40% - Wet Manure (WM) 5% for period: November February 2. Cheese Whey (CW) 90% - Wet Manure (WM) 10% for period: March June 3. Wet Manure (WM) 100% for period: July - October Page 46

47 5.2 Estimated biogas production at Achaia Regional Unity level The estimation of the power production potential for Achaia is performed based on three different sets of waste volumes. The 1 st set consists of the recorded waste volumes (three basic types OMW, CW, WM) which are evaluated separately without co-digesting them. Thus, it is assumed that three plants are constructed, one of each type. Two of them will have to operate seasonally i.e. the OMW plant and the CW plant. The WM can operate the entire year. The 2 nd set of data is based on the assumption of one central biogas plant using three different mixtures as described above. The quota of waste is then calculated according to the mixtures recipes. The plant will operate the entire year. The 3 rd set of data is based on the assumption that two decentralized plants will be build (at West and East Achaia), that will use again the three different mixtures. Again the quota of waste is calculated according to the mixtures recipes. The plants will operate the entire year. The following tables provide the respective data along with the prediction of biogas production. Bellow, the production calculation from OMW assumes approx. production of 32m 3 /tn of biogas [Zafiris, 2012]. The production calculation from CW assumes approx. production of 27,5m 3 /tn of biogas [Papazilakis, 2013]. The production calculation from WM assumes approx. production of 18,5m 3 /tn of biogas [Teodorita Al Seadi et al, 2008]. Table 9 - Achaia biogas estimated potential with no co-digestion Entire Achaia Plant, Anaerobic Digestion, no co-digestion 1 st Set Duration Waste type Waste exploitation Biogas production (est.) 4 months OMW 598,3 tn/day m 3 /year (season) 8 months CW 232,5 tn/day m 3 /year (season) 12 months WM 95,66 tn/day m 3 /year Page 47

48 For the 2 nd and 3 rd scenarios, (one central biogas plant or two decentralized ones), using three different mixtures, the biogas production yields taken into account are : 29,3 lt biogas / lt of Mixture 1 (OMW 55%, CW 40%, WM 5%) 34,3 lt biogas / lt of Mixture 2 (CW 90%, WM 10%) 18,5 lt biogas / lt of Mixture 3 (WM 100%) [Kornaros 2010] The results of the 2 nd scenario are shown in the following tables. Table 10 - Achaia biogas estimated potential with co-digestion Entire Achaia Plant, Anaerobic co-digestion 2 nd Set Waste type Waste exploitation Biogas production OMW (55%) 319 tn/day 4 months CW (40%) 232 tn/day 4 months WM (5%) CW (90%) WM (10%) 29 tn/day 232 tn/day 26 tn/day m 3 /year 4 months WM (100%) 96 tn/day The results of the 3 rd scenario are shown in the following tables. Table 11 - West Achaia group biogas estimated potential with co-digestion West Achaia Plant, Anaerobic co-digestion 3 rd Set case A Waste type Waste exploitation Biogas production OMW (55%) 132 tn/day 4 months CW (40%) 96 tn/day 4 months WM (5%) CW (90%) WM (10%) 12 tn/day 90 tn/day 10 tn/day m 3 /year 4 months WM (100%) 65 tn/day Page 48

49 Table 12 - East Achaia group biogas estimated potential with co-digestion East Achaia Plant, Anaerobic co-digestion 3 rd Set Case B Waste type Waste exploitation Biogas production OMW (55%) 187 tn/day 4 months CW (40%) 136 tn/day 4 months WM (5%) CW (90%) WM (10%) 17 tn/day 135 tn/day 15 tn/day m 3 /year 4 months WM (100%) 31 tn/day From the above scenarios, only Anaerobic co-digestion is evaluated, since it is considered much more economic and environmentally friendly. This is justified by comparing the scenario of one central co-digesting plant to the scenario of three mono-substrate digestion plants, in which case it is obvious that even though there is greater biogas production in the second case, however, it would require triple investment capital and triple transporting costs for the waste, than building one central co-digesting (multi-substrate) plant. Consequently, there are two basic scenarios that are evaluated techno-economically: One central AD Biogas Plant operating throughout the year. It should be located in the center of the prefecture in order to minimize transportation costs. One such location could be the Industrial zone of Patras. Two decentralized AD Biogas Plants operating the entire year. One could be located near Dytiki Achaia at the west of the prefecture and one near Aigion at the east of the prefecture. Page 49

50 6. Anaerobic digestion biogas production plant equipment 6.1 Substrate storage tank The storage of raw material serves primarily to compensate the seasonal fluctuations of supply of raw material. It also facilitates mixing different substrates for continuous application in the digester. The type of storage facilities depends on the feedstock and it is different when it is solid and liquid. In the second case, from the arrival of the liquid waste to the plant until its feed to the bioreactor, it should be stored in special water-proof tanks so that there are no leaks. The storage tank could ideally be placed at a higher level than the bioreactor, so that the hydraulic incline eliminates the need for transport pumps and thus achieve energy savings. Within the tank, water might need to be added so as to achieve the desired dry matter content for the substrate. The water may come from the grid or from the purified water produced at the end of the process. The dimensioning of the storage facilities is determined by the quantities to be stored, delivery intervals, and the daily amounts fed into the digester. Image 18 - Solid substrate storage examples Page 50

51 Image 19 - Wet manure storage example 6.2 Feeding System After storage and in some cases pre-processing, the feedstock is fed to the bioreactor. Pumpable feedstock can be conveyed by natural flow from the storage tanks to the digester or mechanically through the use of pumps, in order to achieve precise control. This method applies to wastewater and sludges. If the raw material is in solid form then it can be transferred with loader to the feeding system and then be fed into the digester (e.g. by an atermon screw system). Both feedstock types (liquid and solid) can be simultaneously fed into the digester. The ideal situation for a stable process of anaerobic digestion is a continuous flow of feedstock into the digester. In practice, however, the raw material is added to the digester, in several batches during the day without the feeding systems to operate continuously. Image 20 - Atermon screw and centrifugal pump Page 51

52 6.3 Bio reactor (Digester) The bioreactor is where the substrate (biomass) is deposited, so as with the help of heat and mixers to allow anaerobic digestion to take place and biogas to be produced. The choice of the bioreactor technology and the appropriate layout, is the most critical element for the correct operation of a biogas plant. For the selection of the system, the characteristics of the raw material (organic loading, solids concentration, possible presence of toxic substances) are taken into account as well as the economics of the plant. For the proposed plants, conventional anaerobic digestion will be applied with two separate digesters arranged in series. Conventional anaerobic digestion of two steps, takes place in two digesters, of which usually only the first is heated first. The main part of biological treatment takes place in the first reactor, while the second is for separating solids (biomass and suspended solids that have not hydrolyzed) from the liquid. The sludge that is concentrated returns to the first reactor, thus increasing the concentration of suspended solids and methanogenic microorganisms. [Kopsacheilis, 2009] Image 21 - Conventional two-stage anaerobic digestion [Kopsacheilis, 2009] Page 52

53 The average residence time of the substrate inside the digester is called hydraulic retention time HRT. The hydraulic retention time is related to the volume of the digester and the volume of substrate fed per unit time. HRT = VR / Q, where VR is the digester volume [m³] and Q volume of substrate fed per time unit [m³/d]. The HRT will be 30 days for wastewater treatment in an SBR for final production of biogas, without diluting the waste [Blika, 2009], and the feed rate of the substrate depends on the scenario, in each of which the maximum will be taken into consideration. The hydraulic residence time of a digester must be sufficiently large in order to allow anaerobic microorganisms to complete their cell cycle. So the calculated VR for each scenario is provided in the following table: Table 13 - Reactor size per scenario Scenario Q (m 3 /day) VR (m 3 ) 1. Entire Achaia Plant A.West Achaia Plant B.East Achaia Plant Stirring technology The minimum method of stirring of the biomass into the digester is passive. This occurs by insertion of fresh feedstock and the subsequent thermal convection streams as well as by the upflow of gas bubbles. Since passive stirring is not sufficient for optimal operation of the digester, active stirring is applied, using mechanical, hydraulic or pneumatic equipment. In 90% of biogas plants mechanical stirring equipment is used. The digester content must be stirred several times a day to mix the new feedstock with the existing substrate. Stirring prevents formation of upper layers and sediments and facilitates Page 53

54 the mixing of bacteria (microorganisms) with the fresh feedstock, the upward flow of gas bubbles and the homogenization of the distribution of heat and nutrients. Generally stirring equipment can operate continuously or intermittently. Experience shows that stirring sequences can be empirically optimized and adapted to a specific biogas production installation (tank size, feedstock quality, tendency to form floating layers). After initial loading and operation of the installation, experience and control will determine the optimal duration and frequency of stirring sequences, as well as adjustment of stirrers. Image 22 - Digestor stirring technologies The proposed bioreactor is equipped with stirring equipment, of which some is underwater. This option helps to better mix the substrate at the bottom and its fragmentation as the risk of creating large lumps must be minimized so as to avoid creating problems in circulation pumps, piping and warehouses. 6.5 Heating systems Achieving stable temperature during the process is one of the most important conditions for stable operation and high biogas production. Temperature fluctuations, including fluctuations in time, as determined by season and weather conditions and local variations in different areas of the digester, must be kept as low as possible. Large fluctuations of temperature lead to unbalanced AD process and at worst a complete failure of the process. The causes of temperature fluctuations are various: Page 54

55 The addition of new raw material with different temperature than the existing of the process. The formation of different temperature zones due to insufficient insulation, ineffective or incorrect dimensioning of heating system or insufficient stirring. Inadequate placement of heating elements. Extremely ambient temperatures during summer and winter. Failure of the power lines. In order to achieve and maintain stable temperature during the process and to compensate for heat losses, digesters must be insulated and heated by external heating sources. The most commonly used source is waste heat from the CHP plant's own biogas production plant. The heating of the feedstock can be done either during the feeding process (pre-heating), through heat exchangers, or into the digester by means of heating elements. Preheating the feedstock during feeding has the advantage of avoiding temperature fluctuations inside the digester. Several biogas plants use a combination of both types of feedstock heating. Image 23 - Digester heating systems Page 55

56 6.6 Biogas Storage The production of biogas must be kept as stable and constant as possible. Inside the digester, biogas is formed in fluctuating quantities and with performance peaks. To offset this, it is necessary to temporarily store the produced biogas, in appropriate storage facilities. The simplest solution being used, is the storage of biogas at the top of the digester by using a special film, which is also used as a cover of the digester. In larger facilities, separate biogas storage tanks are usually created. The biogas storage facilities can be operated at low, medium or high pressure. The correct selection and dimensioning of biogas storage facility brings substantial contribution to the efficiency, reliability and safety of the biogas plant while ensuring constant supply of biogas and minimizing biogas losses. All biogas storage facilities must be gas tight and pressure-resistant in the case of storage, not protected by buildings, they must be resistant to temperature, weathering and ultraviolet radiation (UV). Before starting operation, the gas storage tanks must be checked for leaks. For safety reasons, they must also be equipped with safety valves. Image 24 - Different types of biogas storing facilities 6.7 Biogas cleaning When the biogas is leaving the digester, it is saturated with water vapor and contains, apart from methane (CH 4 ) and carbon dioxide (CO 2 ), varying amounts of hydrogen sulfide (H 2 S). Hydrogen sulfide is toxic, with unpleasant odor similar to that of rotten eggs and generates sulfuric acid combined with the water vapor in the biogas. Sulfuric acid is corrosive and can Page 56

57 cause damage to the CHP engines, gas pipelines, chimneys, etc. Therefore, it is necessary to apply desulphurisation and drying of biogas. The manufacturers of CHP units have minimum requirements for the properties of the combustible gas. The properties of combustion must be guaranteed in order to prevent damage of machinery. This also applies to the use of biogas. Depending on the use of biogas (e.g. as vehicle fuel, fuel cells etc) further gas improvement measures are necessary. The removal of hydrogen sulfide (H 2 S) from biogas (desulfurization) is done with various methods, biological or chemical, taking place inside or outside the digester. Desulphurisation depends on the content of H 2 S and the throughput rate. The throughput rate can fluctuate significantly, depending on the process. Higher biogas production and thus high throughput rates can be observed after insertion of new feedstock into the digester and during stirring. Throughput rates higher than 50% of normal can occur for short periods. For this reason and in order to ensure complete desulphurization, it is necessary to use over-dimensioned desulphurization equipment, compared to average throughput rate. The biological oxidation is one of the most frequently used methods based on injection of a small amount of air (8.2%) in crude biogas. Thus, hydrogen sulfide is oxidized biologically either free (solid) sulfur or a (aqueous) sulfide acid, according to the following equations: 2H 2 S + O 2 -> 2H 2 O + 2S 2H 2 S + 3O 2 -> 2H 2 SO 3 Biological desulfurization often occurs in the digester, as an economically effective method. For this type of desulfurization, oxygen and oxidizing soulfobacteria must be present, for converting hydrogen sulfide to elemental sulfur in the presence of oxygen. Oxidants soulfobacteria are present inside the digester (no need to add) as the substrate of the AD contains the necessary nutrients for their metabolism. Oxygen is provided by injection of air at the top of the digester. This can be done with a small air compressor. Pouring air pipes inside the digester, should be positioned on the opposite side of the biogas in order to avoid blocking of the exhaust pipe. Another simple and cheap method for removing H 2 S from biogas, is the water scrubber. Water is fed into a cylinder in parallel to biogas. An aeration plate was placed in the bottom of the column and the biogas is pressurized into the column so as small bubbles get in Page 57

58 sufficient contact with water to remove the hydrogen sulfide in biogas. The biogas flow rate is measured by flow meter before biogas into the aeration plate. Upgraded biogas is collected on the top, while water after adsorption, needs to be replaced or regenerated before used again for scrubbing, since its absorption rate is significantly decreased. Image 25 - H 2 S water scrubbing The relative humidity of the biogas within the digester is 100%, so the gas is saturated with water vapor. To protect the energy conversion equipment from wear and from eventual damage, water must be removed from the produced biogas. The amount of water contained in the biogas is temperature dependent. A portion of the vapor may be condensed by cooling the gas. This is often done in the gas pipelines transporting biogas from digester to CHP unit. Water condenses on the walls of the sloping pipes and can be collected in a condensation separator, at the lowest point of the pipeline. A prerequisite for effective biogas cooling in the pipelines is a sufficient length of the respective tubes. If the gas pipelines are underground, the cooling effect is even superior. When underground pipes are used, it is very important to be placed in a fixed basis in order to guarantee the incline of the pipes, which may be affected by sinking or moving ground. The condensation separator must be kept frost-free and easily accessible in order to be emptied regularly. In addition to the removed water vapors, condensation also removes some of the undesirable substances such as water soluble gases and aerosols. Page 58

59 6.8 Internal Combustion Engine (CHP - Cogeneration of heat & electrical power) The biogas that is being produced by the process of anaerobic digestion after having been cleaned, it is channeled through pipes in the CHP. The size of CHP depends on the amount of biogas to be used as fuel. According to calculated biogas production the CHP, depending on the scenario has nominal value of 2500kW to 1000kW, with an average efficiency of 90%. Image 26 - CHP example The current produced by a CHP the generator is high and usually it cannot be directly integrated with the grid. Therefore a transformer (rectified voltage) is required. Burning the biogas, produces electricity, which is sold to the electricity grid with a value defined in Law.4254 / 2014 according to the following table: Table 14 - Feedin tariffs for biogas production Produced nominal power Biogas derived from biomass (fodder and agro-industrial organic residues and waste) installed capacity 3 MW Biogas derived from biomass (fodder and agro-industrial organic residues and waste) installed capacity > 3 MW Power tariff ( /MWh) With subsidy Power tariff ( /MWh) Without subsidy Page 59

60 6.9 Processing of digestate The digestate consists of two types: a liquid stream and excess sludge. The liquid stream can either be used a liquid fertilizer, or it is sent to an Anaerobic SBR (Sequential Batch Reactor). The SBR reactor treats the wastewater in batches. Oxygen is bubbled through the mixture of wastewater and activated sludge so as to reduce the organic matter (measured as biochemical oxygen demand (BOD) and chemical oxygen demand (COD)). The treated effluent may then either be safely discharged to surface waters or it is filtered through a membrane system in order to be used as process water within the plant facility or irrigation water. The excess sludge is pumped out of the digester and transported through pipelines to a centrifuge where dry cake is extracted so as to be treated through aerobic composting or vermi-composting in order to produce high quality compost, since it is rich Image 27 Centrifuge unit (decanter) in phosphorus content, nitrate, potassium and other minerals. The storage of the compost may be done in concrete tanks or ponds, which are covered by natural or artificial floating layers or membranes. Losses of methane and nutrients are probable, during storage and handling of digestate. Up to 20% of the total biogas production can take place outside the digester, in storage tanks for digestate. In order to prevent methane emissions and to collect the extra gas production, storage tanks should be covered with a gastight membrane for gas recovery Control and automation The biogas plant is a complex installation with interrelationships between all parts. The centralized, automated monitoring and centralized control are an important part of the overall operation of the unit. By using automatic control and data-logging it is possible to: Page 60

61 check the parameters of the facility in real time and immediately address any anomalies achieve optimum operation of the facility and thus to save resources and reduce costs The standardization and further development of the applied processes are only possible with systematic monitoring and recording of important data of the process of anaerobic digestion. The real time control shall include the collection and analysis of chemical and physical parameters, such as : The type and quantity of incoming feedstock Process temperature The value of ph The amount and composition of the gas The content of short chain fatty acids The filling level of the digester and the gas tank. The control of biogas plants is increasingly automated with the use of special process control systems via computer. Today control of the following processes is applied: Supply of raw materials Hygiene Heating the digester Volume and frequency of stirring Sediment removal Transfer of the raw material in the unit Separation of liquid and solid Page 61

62 Desulphurization Production of electricity and heat. All these parameters are logged by sensors and managed through SCADA systems, which allow precise supervision, control and management of the complete installation for producing of biogas, electricity and thermal energy. The control system has to provide permanent quality of biogas and electricity with reducing the influence of the personnel over the non-interruptible processes. The system of control and supervision is oriented at the minimization the personal faults. Image 28 - Example of SCADA system for slurry management 6.11 Biogas plant safety The construction and operation of a biogas plant is associated with a number of major safety issues that, if not taken into account, pose potential risks for both humans and the environment. Taking proper precautions and safety measures have the aim of avoiding any risks and hazardous situations and help to ensure reliable operation of the plant. The approval of the building permit and the environmental permit depends, inter alia, from the fulfillment of important safety issues and taking purely preventive measures and control of injuries such as: Prevention of explosion Page 62

63 Fire Prevention Mechanical hazards Construction static stability Electrical Safety Lightning protection Thermal safety Protection against noise emissions Protection against suffocation, poisoning Avoiding the emission of polluting gases Prevention of leaks in underground and surface waters Avoidance of pollutants release during waste disposal Flooding safety One very important safety component is the Biogas Flare. Each biogas plant is equipped with a biogas flare system. In situations where there is an excess of biogas, which cannot be stored or used, flaring is the ultimate solution, necessary to eliminate any safety hazards and environmental protection. In exceptional situations, flaring could be the solution for safe disposal of the biogas produced by AD processes, where it is not feasible to recover energy. The gas is burned because it would otherwise harm the atmosphere or increase gas pressure if not somehow eased. During combustion the gas is converted into carbon dioxide as part of the natural cycle. Page 63

64 Image 29 - Biogas flare system Page 64

65 7. Anaerobic digestion biogas plant installation cost and basic assumptions The initial investment includes the basic technological equipment required for Anaerobic Digestion, as listed below: Substrate Storage Tank Feeding System Bioreactor (Digester) Stirring and Heating System Biogas Storage Biogas cleaning (e.g. scrubber) Internal Combustion Engine (CHP) Digestate Storage (e.g. settler) Dry and Liquid Residue (fertilizer) Storage Measurement, Control and Automation Technology Biogas Unit Safety (e.g. biogas flare) The present study examines two alternative scenarios. The first one is about a centrally sited Unit of 2,5MW, working throughout the year, while the second one consists of two Units of 1MW and 1,5MW, sited in the Western and Eastern part of the region of Achaia respectively, and will also be working throughout the year. Table 15 - Location and capacity of biogas plants Scenario MW Location 1. Entire Achaia Plant 2,5 Patras industrial zone 2A.West Achaia Plant 1 Outside Kato Achagia 2B.East Achaia Plant 1,5 Outside Aigio Page 65

66 The first case indicates that the cost of the initial investment is way lower when there is only one production unit, but the raw material transportation costs needed for the biogas production is way higher. The second scenario is based upon the assumption that the facilities of the biogas production unit should be as close as possible to the raw material production unit, aiming to minimize the distance, the time and the expenses needed for the transportation of the raw material. The tables below provide information on the cost of the initial investment for each scenario. SCENARIO 1 Central Unit Table 16 - Initial investment for central unit 2,5MW - Scenario 1 Initial investment Scenario 1 (approx.) Substrate Storage Tank ,00 Feeding System ,00 Bioreactor (Digester) ,00 Stirring and Heating System ,00 Biogas Storage ,00 Biogas cleaning (e.g. scrubber) ,00 Internal Combustion Engine (CHP) ,00 Digestate Storage (e.g. settler) ,00 Dry and Liquid Residue (fertilizer) Storage ,00 Measurement, Control and Automation Technology ,00 Biogas Unit Safety (e.g. biogas flare) ,00 Basic technological equipment of the Anaerobic Digestion Unit ,00 Land ,00 Means of Transportation ,00 Building Facilities ,00 Other Equipment ,00 TOTAL ,00 As shown in the table above, the cost of plot and building facilities, amounts to and respectively. The cost of the basic technological equipment Anaerobic Digestion unit, sums to Conveyances include two freight-kegs useful volume of 20 tons of sewage, the total cost of which is approximately and the rest of the equipment is estimated at Thus, the total cost of the investment, amounts to Page 66

67 SCENARIO 2 Two decentralized units Table 17 - Initial investment for West Achaia 1MW - Scenario 2A Initial Investment Scenario 2A (West Achaia D. ACHAIA - ERYMANTHOS - PATRA) (approx.) Substrate Storage Tank ,00 Feeding System ,00 Bioreactor (Digester) ,00 Stirring and Heating System ,00 Biogas Storage ,00 Biogas cleaning (e.g. scrubber) ,00 Internal Combustion Engine (CHP) ,00 Digestate Storage (e.g. settler) ,00 Dry and Liquid Residue (fertilizer) Storage ,00 Measurement, Control and Automation Technology ,00 Biogas Unit Safety (e.g. biogas flare) ,00 Basic technological equipment of the Anaerobic Digestion Unit ,00 Land ,00 Means of Transportation ,00 Building Facilities ,00 Other Equipment ,00 TOTAL ,00 Table 18 - Initial investment for East Achaia 1,5MW - Scenario 2B Initial Investment Scenario 2B (East Achaia AIGIALEIA - KALABRYTA) (approx.) Substrate Storage Tank ,00 Feeding System ,00 Bioreactor (Digester) ,00 Stirring and Heating System ,00 Biogas Storage ,00 Biogas cleaning (e.g. scrubber) ,00 Internal Combustion Engine (CHP) ,00 Digestate Storage (e.g. settler) ,00 Dry and Liquid Residue (fertilizer) Storage ,00 Measurement, Control and Automation Technology ,00 Biogas Unit Safety (e.g. biogas flare) ,00 Basic technological equipment of the Anaerobic Digestion Unit ,00 Land ,00 Means of Transportation ,00 Building Facilities ,00 Other Equipment ,00 TOTAL ,00 Page 67

68 The table indicates that the plot and the building facilities cost for the biogas production unit with a capacity of 1,5 MW, amounts to and The respective costs of the unit with a capacity of 1 MW, amounts to and The cost, for the basic technology equipment of Anaerobic Digestion unit, sums to and for the units 1,5 MW and 1 MW respectively. The means of transportation costs (vehicles) is about for the 1,5 MW unit and for the 1 MW, while the cost for the rest of the equipment is and for the 1,5 MW and 1 MW unit respectively. As a result, the total investment cost for the second scenario amounts to Page 68

69 8. Financial plan The total cost of the investment project, consists of the equity by 35% and by a long-term bank loan by 25%. The provisions of the last law in force (Law. 3908/2011) states that, considering the implementation region of the investment and given the small size of the enterprise, a supporting financial package is offered. More specifically, this aid contains the 40% of the final investment. Image 30 - Financial Plan Next, we can see the funding resources of the investment for each scenario: SCENARIO 1 Table 19 - Scenario 1 financial plan Financial plan Equity ,00 Long-term borrowing ,00 Subsidy ,00 Page 69

70 It is estimated that creating the centrally sited power unit of 2,5MW capacity, will cost Therefore, the funding plan includes the equity , the long-term loan of and the State subsidiary which amounts to SCENARIO 2 Table 20 - Scenario 2 financial plan Financial plan Equity ,00 Long-term borrowing ,00 Subsidy ,00 As it is previously mentioned, the total investment scenario amounts to This will be covered with equity capitals which amount to , long-term bank loan which amounts to and subsidy which amounts to Depreciation The tax amortization, defined by the provisions of the Article 4 of the Law 4172/2013, are deducted from the total income of the business transactions in order to determine the final profit of the business activities. As far as the calculation of the amortizations and the depreciations is concerned, what is taken into account is the cost value of the assets to be purchased with the new investment. The depreciation method used is the straight-line method. At this point, it is crucial to mention that based on the paragraph 4, of the same Article, the tax depreciation rates are defined by fixed asset. The rates that define the final depreciation include the amount of 4% -for building facilities-, 10% -for the machinery-, 12% -for transport- and 10% -for other assets-. The amortization of the investment assets for each scenario, in a decade, is presented below: Page 70

71 SCENARIO 1 Table 21 - Depreciation in scenario 1 ASSET CATEGORY Main technological for anaerobic digestion unit Means of transportation DEPRECIATION RATE VALUE TO DEPRECIATION 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 10% % Building Facilities 4% Plot 0% Other fixed assets 10% TOTAL DEPRECIATION OF FIXED ASSETS DEPRECIATION OF EXISTING ASSETS TOTAL DEPRECIATION The total depreciation of the investment is estimated at for the first eight years of the unit operation, while this amount is configured to and during the ninth and tenth year of operation, respectively.

72 SCENARIO 2 Table 22 - depreciation in scenario 2 ASSET CATEGORY DEPRECIATION RATE VALUE TO DEPRECIATION 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th Main technological for anaerobic digestion unit Means of transportation Building Facilities 10% % % Plot 0% Other fixed assets TOTAL DEPRECIATION OF FIXED ASSETS DEPRECIATION OF EXISTING ASSETS TOTAL DEPRECIATION 10%

73 The total depreciation of the investment is estimated at for the first eight year of the unit operation, while this amount is configured to and during the ninth and tenth year of operation, respectively. 10. Employment The implementation of the investment, will mark the establishment of thirteen (13) new full- time jobs, which are necessary for the smooth operation of the company. The new job vacancies per specialty are showed below: Unit Manager Financial Manager of the Unit 1 Production Manager per shift (total of 3) 2 Workers per night (a total of 6) 2 Drivers- Vehicle Operator The selection of the personnel, is a matter of great importance when it comes to the success of the business activities. This is why, a skillful group of people will be able to attribute to the successful implementation of the business goals. The staff will cover the normal operation, as well as the operation during the holidays, the need for replacement during vacation, the regular and general maintenance. The Direction will be assigned on the Unit Manager, which is preferred to be an engineer with an MSc in Business Administration with an experience in managing Production Units of electricity waste management facilities of RES. The Production Line will occupy 3 engineers or technical engineers as Production Managers (one per shift) and six fill-time workers, two of which will be occupied in the morning shift, two in the afternoon shift and two in the night shift. The Accounting Department will be staffed by an employee with a University degree in Economics, with five year experience in double entry bookkeeping. This profile ensures an advanced user of accounting programs and commercial management packages. The employee of the accounting department will also be responsible for the administrative support.

74 This organizational model is structured in a way that coincides perfectly with the size of the company and makes the management, assignment of responsibilities and operation of the unit efficient, while facilitating the allocation of costs to individual functions. For the total number of jobs, it is calculated the 14 salaries and the relevant employer contributions. For the first year of business, the workers salary amounts to 800 a month and sums to during night shifts. Accordingly, the Production Manager salary is per month and the night shift yields to per month. The annual fees of the Unit Manager and the Financial Manager of the Unit amounts to and 15,000, respectively, for the first year of operation. Taking into consideration the assumption above, the annual cost of the personnel is analyzed for each scenario as follows:

75 SCENARIO 1 Table 23 - Employment cost for scenario PERMANENT Unit Manager , , , , , , , , , ,00 Production Manager (3) , , , , , , , , , ,00 Workers (6) , , , , , , , , , ,00 Drivers- Vehicle Operator (2) , , , , , , , , , ,00 Financial Manager of the Unit , , , , , , , , , ,00 TOTAL , , , , , , , , , ,00 The table of the first scenario, indicates that the total personnel cost amounts to annually. The diagram below shows the evolution of employment costs, as well as the participation cost for each different job in shaping the overall employment costs.

76 Image 31 - Workforce structure in scenario 1

77 SCENARIO 2 Table 24 - Employment cost for scenario 2 PERMANENT Unit Manager Production Manager (3) Workers (6) Drivers- Vehicle Operator (2) Financial Manager of the Unit TOTAL The table above shows the total personnel cost which amounts to annually.

78 Image 32 - Workforce structure in scenario 2

79 11. Raw material 11.1 Raw material quantities One of the company s basic goals, is the uninterrupted electricity production, with no production loss due to lack of supplies. This is the driving force for designing an effective plan that meets not only the raw materials and supplies requirements, but the ideal supply management as well. For the production of the combustion biogas, is estimated that the next list of raw materials will be necessary: Dairy Factory Residuals (CW) Olive Mill product Residuals (OMW) Cowshed waste (WM) Supplying the company with raw materials, is not subject to any time constrains as far as the part of the suppliers is concerned. However, there are and will be times when the animal farm activities will increase. There is no need for auxiliary material for the unit operation. Given the seasonality of the raw material availability and aiming the maximum biogas production throughout the year, raw material mixes will be used, changed and adjusted per season: Mix 1: It consists of residuals of 40% from dairy factory, 55% from olive mills and 5% from animal farms. This mixture will be used during November, December, January and February. Mix 2: It consists of residuals of 90% from dairy factory and 10% from animal farms. This mixture will be used during March, April, May and June. Mix 3: It consists exclusively of manure (100%). This mixture will be used in July, August, September and October In each scenario, an annual increase of raw material quantity consumption of 2% for the first five years of company's operation, has been assumed. Given the plant's capacity, it is decided that raw material quantity consumption remain stable from the fifth to tenth operating year. The quantitative raw material consumption, for a decade, is displayed, for each alternative scenario, on the following tables: Page 79

80 SCENARIO 1 Table 25- Anticipated Quantitative Raw Materials Consumption Scenario 1 DESCRIPTION MEASUREMENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year OLIVE MILL (OMW) tn , , , , , , , , , ,50 DAIRY FACTORY (CW) tn , , , , , , , , , ,91 MANURE (WM) tn 3.480, , , , , , , , , ,86 MIX 1 tn , , , , , , , , , ,28 DAIRY FACTORY tn , , , , , , , , , ,91 MANURE (WM) tn 3.120, , , , , , , , , ,19 MIX 2 tn , , , , , , , , , ,10 MANURE (WM) tn , , , , , , , , , ,62 MIX 3 tn , , , , , , , , , ,62 TOTAL , , , , , , , , , ,00 The following diagram shows the input for each raw material mix for estimated quantity consumption total in a ten year period.

81 Image 33 - Anticipated Quantitative Raw Materials Consumption Scenario 1

82 SCENARIO 2 Table 26 - Anticipated Quantitative Raw Materials Consumption Scenario 2A DESCRIPTION MEASUREMENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year OLIVE MILL (OMW) tn , , , , , , , , , ,78 DAIRY FACTORY (CW) tn , , , , , , , , , ,29 MANURE (WM) tn 2.040, , , , , , , , , ,16 MIX 1 tn , , , , , , , , , ,23 DAIRY FACTORY tn , , , , , , , , , ,40 MANURE (WM) tn 1.800, , , , , , , , , ,38 MIX 2 tn , , , , , , , , , ,78 MANURE (WM) tn 3.720, , , , , , , , , ,65 MIX 3 tn 3.720, , , , , , , , , ,65 TOTAL , , , , , , , , , ,66

83 Table 27 - Anticipated Quantitative Raw Materials Consumption Scenario 2B DESCRIPTION MEASURE MENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year OLIVE MILL (OMW) tn , , , , , , , , , ,73 DAIRY FACTORY (CW) tn , , , , , , , , , ,62 MANURE (WM) tn 1.440, , , , , , , , , ,70 MIX 1 tn , , , , , , , , , ,05 DAIRY FACTORY tn , , , , , , , , , ,27 MANURE (WM) tn 1.200, , , , , , , , , ,92 MIX 2 tn , , , , , , , , , ,19 MANURE (WM) tn 7.800, , , , , , , , , ,97 MIX 3 tn 7.800, , , , , , , , , ,97 TOTAL , , , , , , , , , ,20 TOTAL (1 AND 2) , , , , , , , , , ,86

84 The following diagram displays the input for each raw material mix for estimated quantity consumption total in a ten year period. Image 34 - Anticipated Quantitative Raw Materials Consumption Scenario 2

85 11.2 Raw material cost As far as the cost of the raw material needed for the smooth production process-; cowshed waste are free of charge and the only cost that emerges is the one for its transportation to the facilities. The dairy factory and olive mills residuals charge the company with purchasing and transportation fees. More specifically, the purchase cost of the dairy factory residuals amounts to 1,5 per ton and the cost for their relocation costs approximately 0,5 per ton. For the transportation of raw materials in wastewater receptacles of 20 tonnes useful volume (middle vehicle for traffic on rural roads), thus calculated cost of transporting raw materials 0,8 per kilometer. This includes the cost of fuel and maintenance of vehicles. Next, there are two scenarios, describing the different raw materials cost fluctuations through the decade: Page 85

86 SCENARIO 1 85 waste production units, around the wider region of Achaia, will supply the company with all the needed raw material. Taken into account that each transportation route will be 70 km, the raw material transportation cost amounts to 3,34 per ton. Table 28 - Anticipated Values Of Raw Material Consumption Scenario 1 DESCRIPTION PRICE VALUE 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year DAIRY FACTORY 4, , , , , , , , , , ,94 OLIVE MILL 3, , , , , , , , , , ,06 COWSHED 3, , , , , , , , , , ,66 TOTAL TOTAL , , , , , , , , ,66 Raw material cost amounts to ,60 for the first operating year and turns into ,66 in a ten year period. Same as in quantitative consumption, raw material cost has a 2% annual increase for the first five operating years, while it remains stable from the fifth to tenth year.

87 SCENARIO 2 The power unit of 1,5 MW will use the necessary raw materials of 49 different waste production units, located close to it. It is estimated that 40 km per transportation route is needed, the transportation cost amounts to 1,70 per ton. The power unit of 1 MW will use the necessary raw materials of 39 different waste production units, located close to it. Given the assumption that 50 km per transportation route is needed for each ton, the transportation cost amounts to 2,86 per ton. Table 29 - Anticipated Values Of Raw Material Consumption Scenario 2A DESCRIPTION PRICE VALUE 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year OLIVE MILL 3, , , , , , , , , , ,22 DAIRY FACTORY 2, , , , , , , , , , ,51 COWSHED 1, , , , , , , , , , ,42 TOTAL , , , , , , , , , ,15 Table 30 - Anticipated Values Of Raw Material Consumption Scenario 2B DESCRIPTION PRICE VALUE 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year OLIVE MILL 4, , , , , , , , , , ,10 DAIRY FACTORY 3, , , , , , , , , , ,64 COWSHED 2, , , , , , , , , , ,69 TOTAL , , , , , , , , , ,43 TOTAL (1 AND 2) , , , , , , , , , ,58 Raw material cost amounts to for the first operating year and turns into ,58 in a ten year period. Same as in quantitative consumption, raw material cost has a 2% annual increase for the first five operating years, while it remains stable from the fifth to tenth year.

88 12. Total production cost Calculating the annual total production cost of the investment project, is a holistic process, with a list of coefficients. The raw material cost, the energy required for the operation of the unit, as well as the wages of workers (all expenses included) and the third parties, employed in the production department, were all taken into account. As far as the cost of the energy required for the smooth operation of the factory, the electricity for the proper function of the unit, the liquid fuels for the transportation means, etc. are all included. At this point, it is crucial to mention that the generated thermal energy conducted from the biogas combustion, was used entirely for own consumption. As a result, in the production costs, the expenses of the thermal energy supply, was not included. In the tables below, there is a full display of the total production cost for each alternative scenarios, over a decade. Page 88

89 SCENARIO 1 Table 31 - Total Cost Of Production Scenario 1 TOTAL COST OF PRODUCTION AFTER THE INVESTMENT 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year Raw materials Production Labour wages (all expenses included) Third party tasks (facon) associated with the investment project ENERGY: Activityoperating expenses of the factory (electric power, liquid fuel, gas, etc.) TOTAL PRODUCTION COST OF THE INVESTMENT PLAN

90 The total production cost amounts to for the first year of operation and turns into in a decade, showing an average annual increase of 1.41% The diagram below shows the contribution of each cost category in the formation of total production costs for the first year of business operation. We observe that the higher cost is that of raw materials, participating with 70% in the total production costs. Image 35 - Production Cost Scenario 1 Page 90

91 SCENARIO 2 Table 32 - Total Cost Of Production for Scenario 2 TOTAL COST OF PRODUCTION AFTER THE INVESTMENT 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year Raw materials Production Labour wages (all expenses included) Third party tasks associated with the investment project ENERGY: Activityoperating expenses of the factory (electric power, liquid fuel, gas, etc.) OTHER EXPENSES TOTAL PRODUCTION COST OF THE INVESTMENT PLAN The total production cost amounts to for the first year of operation and turns into in a decade, showing an average annual increase of 1,04%. 10th year

92 The diagram below shows the contribution of each cost category in the formation of total production costs for the first year of business operation. We observe that, for the second scenario, the higher cost is that of raw materials, participating with more than 70% in the total production costs. Image 36 - Production Cost Scenario Compost production As it was mentioned before, the compost derived from the Anaerobic Digestion, is used as soil fertilizer. Compared to the crude manure, this type of compost, has a more improved fertilization efficiency (due to the higher homogeneity and nutrient availability), a better C / N ratio and significantly reduced odors. The quantity of compost produced, was estimated separately for each raw mix, using data reported in the literature. By using one ton of Mix 1 on a daily basis (40% of diary factory residuals, 55% of olive mill s residuals and 5 % of cowshed waste) it is estimated that 7,8 ton of compost is produced annually. In the case of Mix 2 the factor is 8,7 ton, while using one ton of Mix 3 on a daily basis, the estimated quantity produced is 14,2 tons, annually. Page 92

93 It is estimated that for the first five years of operation, the compost product will show an increase of 2% annually, while the next years, the production will remain steady, given the capacity of the unit. Taken into consideration the analysis above, the two different scenarios would result in the production of certain quantity of compost, as follows: Page 93

94 SCENARIO 1 Table 33 - Compost Production Scenario 1 DESCRIPTION MEASUREMENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year 10th year MIX 1 tn 1.508, , , , , , , , , ,31 MIX 2 tn 670,80 684,22 697,90 711,86 726,10 726,10 726,10 726,10 726,10 726,10 MIX 3 tn 454,40 463,49 472,76 482,21 491,86 491,86 491,86 491,86 491,86 491,86 TOTAL tn 2.633, , , , , , , , , ,26 The produced compost is estimated at 2.633,20tons during the first year of operation and turns into 2.850,26 tons in a decade.

95 SCENARIO 2 Table 34 - Compost Production Scenario 2 DESCRIPTION MEASUREMENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year MIX 1 tn 884,00 901,68 919,71 938,11 956,87 956,87 956,87 956,87 956,87 956,87 MIX 2 tn 390,00 397,80 405,76 413,87 422,15 422,15 422,15 422,15 422,15 422,15 MIX 3 tn 146,73 149,67 152,66 155,71 158,83 158,83 158,83 158,83 158,83 158,83 TOTAL 1 tn 1.420, , , , , , , , , ,85 COMPOST PRODUCTION FOR INVESTMENT 2 DESCRIPTION MEASUREMENT UNIT QUANTITY 1rst year 2nd year 3rd year 4th year 5th year 6th year 7th year 8th year 9th year MIX 1 tn 624,00 636,48 649,21 662,19 675,44 675,44 675,44 675,44 675,44 675,44 MIX 2 tn 260,00 265,20 270,50 275,91 281,43 281,43 281,43 281,43 281,43 281,43 MIX 3 tn 307,67 313,82 320,10 326,50 333,03 333,03 333,03 333,03 333,03 333,03 TOTAL 2 tn 1.191, , , , , , , , , ,90 TOTAL (1 AND 2) 2.612, , , , , , , , , ,75 10th year 10th year

96 During the first year of operation, 1.420,73 tons of compost will be produced in the unit of 1,5MW capacity unit and 1.191,67tons of compost in the unit of 1MW capacity. During the 5 th year of operation, both units will produce the maximum possible quantity of compost, which amounts to 1.537,85 tons for the unit of 1,5MW capacity and to 1.289,90tons of compost for the unit of 1 MW. Therefore, the company will produce 2.827,75tons of compost during the 5 th and the 10 th year of operation. 14. Biogas production The values used for the composition of the tables above, included the biogas rates per type of raw material, referred to literature. These rates derive from measurements in laboratories and other installed projects worldwide. The calculation of the biogas produced, is carried out by a combination of the percentage of total solids (TS), the percentage of fermentable solids contained in total solids (VS) and the biogas yield of fermentable solids, while the yield depends on the composition of the raw material (carbohydrates, proteins, sugars, fats, etc.). The amount of biogas produced, was calculated separately for each mix of raw materials, using the equation (Biogas = mx% TS x% VS xa). Using one ton of Mix 1, 29,3 m 3 of biogas with a content of 63% CH 4 is produced, while using Mix 2, the production level reaches the 34,3 m 3 of biogas containing 69% CH 4. Finally, the use of Mix 3 results in the production of 18,5 m 3 biogas, with 69% CH 4 content [Kornaros 2010] The following tables present the biogas produced per year. The data has been categorized in 3 raw material mixes, to represent the biogas production capacity for each scenario. Page 96

97 SCENARIO 1 Table 35 - Anticipated Biogas Production Scenario 1 DESCRIPTION MEASURMENT UNIT 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year MIX 1 m , , , , , , , , , ,26 MIX 2 m , , , , , , , , , ,02 MIX 3 m , , , , , , , , , ,94 TOTAL m , , , , , , , , , ,22 It was estimated that during the first year of operation, the plant will produce m 3 biogas. Up to the fifth year, this quantity will grow by 2% a year, when it will reach the maximum amount of ,22 m 3.

98 SCENARIO 2 Table 36 - Anticipated Biogas Production Scenario 2 DESCRIPTION MEASUREMEN T UNIT QUANTITY 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year MIX 1 m , , , , , , , , , ,70 MIX 2 m , , , , , , , , , ,62 MIX 3 m , , , , , , , , , ,98 TOTAL , , , , , , , , , ,30 DESCRIPTIO N MEASUREME NT UNIT QUANTITY 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year MIX 1 m , , , , , , , , , ,55 MIX 2 m , , , , , , , , , ,08 MIX 3 m , , , , , , , , , ,96 TOTAL , , , , , , , , , ,59 TOTAL (1 AND 2) , , , , , , , , , ,89

99 It was estimated that during the first year of operation, the units 1,5 MW and 1 MW, will produce m3 and m 3 of biogas, respectively. Up to the fifth year, this quantity will grow by 2% a year, when it will reach the overall amount of ,89 m3 ( ,30 m 3 for unit 1,5 MW and ,59 m 3 for unit 1 MW). 15. Electric and thermal power production The energy produced by the biogas, is a result of the equation [Biogas Energy = (V x LHV) / 1000 (MWh)], where V represent the volume of biogas in m 3 /year (calculated in biogas production table) and the LHV is the biogas calorific value in kwh/m 3, at a value of 5.95 kwh/m 3. Taking into consideration the established electric energy of the CHP is 2500 kw and the maximum annual operation hours amounts to 8760, we can calculate the maximum volume energy production (both electric and thermal). Also, given that the unit doesn t have the capability to operate ideally for 365 days per year (or 8760 hours/year), the electric energy available for sale, is calculated at 95% of the one produced. The unit is considered to function for 8322 hours/year and stops for 15 days for maintenance and repairs. Therefore the unit will reach 95% of efficiency. The amount produced is estimated based on the fact that the electric efficiency will be at the 35% and the thermal one to 65%. In the following table, we can examine each scenario based upon the projected volume of the electric and thermal energy production annually, in a decade. Page 99

100 SCENARIO 1 Table 37 - Anticipated Production Of Electrical And Thermal Energy Scenario 1 DESCRIPTION MEASUREMENT UNIT QUANTITY 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year ELECTRIC ENERGY ΜWh 6902, , , , , , , , , ,042 THERMAL ENERGY ΜWh 12818, , , , , , , , , ,79 TOTAL PRODUCTION (for 8760 operating hours) MWh 19720, , , , , , , , , ,83 The total energy produced, equals to ,25 MWh for the first year of operation (6902,09 MWh of electric and ,16 MWh of thermal energy) and turns into ,83 MWh in a decade (7.471,04 MWh of electric and ,79 MWh of thermal energy).

101 SCENARIO 2 Table 38 - Anticipated Production Of Electrical And Thermal Energy Scenario 2 DESCRIPTION MEASUREMENT UNIT QUANTITY 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year ELECTRIC ENERGY ΜWh 3918, , , , , , , , , ,57 THERMAL ENERGY ΜWh 7277, , , , , , , , , ,21 TOTAL 2 PRODUCTION (for 8760 operating hours) MWh 11195, , , , , , , , , ,78 DESCRIPTION MEASUREMENT UNIT QUANTITY 1 st Year 2 nd Year 3 rd Year 4 th Year 5 th Year 6 th Year 7 th Year 8 th Year 9 th Year 10 th Year ELECTRIC ENERGY ΜWh 2914, , , , , , , , , ,25 THERMAL ENERGY ΜWh 5413, , ,2 5744, , , , , , ,74 TOTAL 1 PRODUCTION (for 8760 operating hours) MWh 8328, , , , , , , , , ,99 The total energy produced by the unit of 1.5 MW capacity, equals to ,88 MWh for the first year of operation and to ,78 MWh for the next ten years. The relevant prices for the unit of 1 MW capacity are 8.328,45 MWh and 9.014,99 MWh. Both units produce 6.833,52 MWh of electric energy during the first year of operation and 7.396,82 MWh from the 5 th to the 10 th year.

102 16. Financial turnover The unit's revenue comes exclusively from sale of electric power and compost. The produced thermal energy was excluded as it is completely used for own consumption. According to Adjusting Energy Authority (AEA), if there is investment subsidy, the electricity price is 209 /MWh. Also in case when the investment is self-funded the electricity price is 230 /Mwh. The compost is available to markets in the price of 50 per ton. The following tables show the expected future revenue in ten-year depth for each option: SALES REVENUES SCENARIO 1 Table 39 - Sales Revenues Scenario 1 Price per Unit Electrical 209 Energy Thermal 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0 Energy Compost , , , , , , , , , ,02 Total Turnover , , , , , , , , , ,80

103 The total financial turnover of the company amounts to during the first year of operation and turns into in a decade. At this point, it is important to mention that for the next five years, the financial turnover will show an increase of 1,96%, annually. In case of sale of electricity without subsidy, the above figures might have been applied to ,25 and ,68, respectively. The diagram below shows the contribution of revenue from the sale of electricity (81%) and compost (19%) to the configuration of the total turnover, for the first year of business. Image 37- Sales for 1st Year Scenario 1 Page 103

104 SCENARIO 2 Table 40 - Sales Revenues Scenario 2 SALES REVENUES Price per Unit Electrical , , , , , , , , , ,74 Energy Thermal 0 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Energy Compost , , , , , , , , , ,29 Total Turnover The total of company's financial turnover amounts to for the first operating year and turns into in decade. There is a 2% financial turnover increase for the first five operating years. In case where there is electric power sale without subsidy, the previous amounts turn into ,10 and ,57, respectively.

105 The following diagram shows the income entry from electric power sale (92%) and compost (8%) for the configuration of financial turnover total for the first operating year. Image 38 - Sales for 1st Year Scenario and sales expenses The management-sales expenses consist of employee salaries (total surcharges included) and third-party fees. The maintenance expenses are calculated to be 1,5% of total investment's cost for the first year, while a 1% annual increase is also calculated. The maintenance vehicle expenses are calculated to be 10% of vehicle's cost. Energy expenses are also calculated. These consist of electricity, liquid fuel etc. The insurance is calculated to be 2% of total investment cost for the first year with a 1% annual increase. General operating costs are calculated based on the unit's financial turnover, while the consumables cost is estimated to be increasing by 2% annually. Other expenses consist of parcel's rent for the unit's operation, new equipment maintenance costs, fixed assets premiums and charges. The total cost of management-sales expenses for the first ten-years of unit's operation is shown on the following table: Page 105

106 SCENARIO 1 Table 41 - Administrative - distribution expenses Scenario 1 EXPENDITURE TYPES Total Labour (all expenses included) Maintenance costs Annual vehicle maintenance costs General operating expenses Insurance Consumables TOTAL COSTS WITHOUT DEPRECIATION The management-sales expenses amounts to for the first year of operation and turns into in a decade, showing an annual increase of 0,85 %.

107 The diagram below shows the contribution of each category to the formation expenses of the total administrative expenses - disposal of the business. Image 39 - Οperation Expenses Pie Scenario 1 Page 107

108 SCENARIO 2 Table 42 - Administrative - distribution expenses Scenario 2 EXPENDITURE TYPES Total Labour (all expenses included) Maintenance costs Annual vehicle maintenance costs General operating expenses Insurance Consumables TOTAL COSTS WITHOUT DEPRECIATION The management-sales expenses amounts to for the first year of operation and turns into in a decade, showing an annual increase of 0,82 %.

109 The diagram below shows the contribution of each category to the formation expenses of the total administrative expenses - disposal of the business. Image 40 - Operation Expenses Pie Scenario Financial profile 18.1 Working capital The working capital is the result of calculations which deal with the financial turnover, the cost of goods and the terms of goods sales, raw material merchant fee and stock management. The company saves raw material stock for 30 days and preserves mandatory stock for the same period. The customer s credit strategy reaches 90 days while the suppliers will be paid off in 30 days on average. A short-term bank load with an annual interest rate of 9%, is the way of covering the necessary working capital. Based on the assumptions formulated above, the following table shows the detailed working capital as well as the loan costs, for the two different scenarios: Page 109

110 SCENARIO 1 Table 43 - Working Capital Scenario 1 Α. Working Capital Commitments to: MONTHS OF COMMITMENT (1) Inventories of raw and auxiliary materials (2) Inventories semi-finished products (3) Inventories of goods (4) Appropriations to customers (open account & checks etc.) , (5) Necessary available Minus Appropriations of Procurement of Raw materials etc. 1, TOTAL WORKING CAPITAL ANNUAL VARIATION Funding working Capital after the investment ANNUAL REQUIREMENTS IN WORKING CAPITAL RATE ,00% Equity Capital 0,00% Dept Capital (short-term loan) 100,00% Interest rate 9,00% Interest on short-term loans

111 An annual increase of 2% during the first 5 years of the operation is included in the annual requirements for working capital. The interests of the short-term loan are calculated on for the first year and will amount to in a decade. From the fifth year onwards, the working capital requirements remain at per year.

112 SCENARIO 2 Table 44 - Working Capital Scenario 2 Α. Working Capital Commitments to: MONTHS OF COMMITMENT (1) Inventories of raw and auxiliary materials (2) Inventories semi-finished products (3) Inventories of goods (4) Appropriations to customers (open account & checks etc.) , (5) Necessary available Minus Appropriations of Procurement of Raw materials etc. 1, TOTAL WORKING CAPITAL ANNUAL VARIATION Funding working Capital after the investment ANNUAL REQUIREMENTS IN WORKING CAPITAL 100,00% Equity Capital 0,00% Dept Capital (short-term loan) 100,00% Interest rate 9,00% Interest on short-term loans

113 It is estimated that the annual increase in working capital will be around 2% during the first five years of operation of the business. From the fifth year onwards the working capital requirements remain at per year. The interests of the short-term loan are calculated on for the first year and will amount to in a decade Loan As mentioned before, a long term loan of 25% percentage of total cost will be used for the investment funding. The duration of the loan is estimated to last ten years and the annual rate is estimated to be 10% with fixed annuity payment. In the following table is shown the annuity table of the long term investment loan, for each scenario:

114 YEARS OF PAYMENTS SCENARIO 1 Table 45 - Long Term Loan Scenario 1 LOAN ,8 INTEREST RATE 10,0% DURATION Implementation year 10 YEARS 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th INTEREST RATE , , , , , , , , , ,2 INSTALLMENT , , , , , , , , , ,0 ANNUITY , , , , , , , , , ,2 REMAINING CAPITAL , , , , , , , ,0 0,0 YEARS OF PAYMENTS SCENARIO 2 Table 46 - Long Term Loan Scenario 2 LOAN ,0 INTEREST RATE 10,0% DURATION Implementation year 10 YEARS 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th INTEREST RATE , , , , , , , , , ,1 INSTALLMENT , , , , , , , , , ,7 ANNUITY , , , , , , , , , ,7 REMAINING CAPITAL , , , , , , , ,7 0,0

115 18.3 Trading account In the tables below, a trading account is shown for each alternative scenario: SCENARIO 1 Table 47 - Operating Income Scenario TOTAL TURNOVER Less: Cost of sales GROSS OPERATING PROFIT Less: Administrative Expenses - Distribution Less: Research & Development Expenses OPERATING RESULT Plus: Miscellaneous revenue Less: Other expenditure RESULTS BEFORE INTEREST, DEPRECIATION AND TAXES Less: interest on existing long-term loans Less: interest on short-term working capital loans Less: annual leasing rent Plus: leasing subsidy RESULTS BEFORE DEPRECIATION & TAXES Less: Depreciation RESULT BEFORE TAXES Less: Income tax Net result

116 According to the previous table, the company will present losses during the first four years of its operation. From the fifth year on wards, the company will record profits gradually increasing, which is estimatedto in the tenth year of operation. In the following chart shows the evolution of gross profit operating income before interest, depreciation and taxes and the net result in a decade: Image 41 - Results Scenario 1 The diagram below shows the diachronic evolution of the income before tax and depreciation of the business, which are expected to increase to in the first year of operation and changes to , in a decade. Page 116

117 Image 42 - Results before depreciation & taxes (Scenario 1) Page 117

118 In the next diagram, we can see the diachronic evolution of the elements that shape the results before interest, taxes and amortization of the business. Image 43 - Revenues, expenses (Scenario 1) Page 118

119 SCENARIO 2 Table 48 - Operating Income Scenario TOTAL TURNOVER Less: Cost of sales GROSS OPERATING PROFIT Less: Administrative Expenses - Distribution Less: Research & Development Expenses OPERATING RESULT Plus: Miscellaneous revenue Less: Other expenditure RESULTS BEFORE INTEREST, DEPRECIATION AND TAXES Less: interest on existing long-term loans Less: interest on short-term working capital loans Less: annual leasing rent Plus: leasing subsidy RESULTS BEFORE DEPRECIATION & TAXES Less: Depreciation RESULT BEFORE TAXES Less: Income tax Net result

120 As the table indicates, the company will present losses during the first eight years of operation, which will go gradually decreasing. In the ninth and tenth year of operation, will show profits o f6.460 and ,respectively. In the following chart shows the evolution of gross profit operating income before interest, depreciation and taxes and the net result in a decade: Image 44 - Results Scenario 2 The diagram below shows the diachronic evolution of the income before tax and amortization of the business, which are expected to increase to in the first year of operation and changes to , in a decade. Page 120

121 Image 45 - Results before depreciation & taxes (Scenario 2) In the next diagram, we can see the diachronic evolution of the elements that shape the results before interest, taxes and amortization of the business. Page 121

122 Image 46 - Revenues, expenses (Scenario 2) 18.4 Cash flows Viability indicators Basic factors for accepting the aim of the whole investment plan are net result and internal rate of return calculations. Net result method is based on a simple but fundamental principle which says that an investment is worth when the revenue of investment is positive. Basic factor of this method is that the candidate investor should accept an investment plan just when it comes with a positive net result. That means that the discounted liquidity flow of the revenue is bigger than the one of the revenue expenses. The internal rate of return is counted as the discounting interest rate which is used to set to zero the net present value, for discounting the whole program cash flow. The factor which provides the previously described method is the acceptance of an investment plan which has a greater rate of return than the minimum demanded rate which is defined by the investor. For the investment evaluation we have separated and evaluated the results of the new investment plan and we have also calculated the internal efficiency rate based on investment capitals total. For that purpose the cash flows of the new investing plan should Page 122

123 be calculated during the first ten-year working period after the implementation of the investment. The IRR indicator is calculated based on what is previously described. More specifically, the list of inputs includes: - Earnings before depreciation and taxes - Long-term loans and investment subsidiaries The list of outputs includes: - The investment costs - The repayment of the loan installment - Taxes - The working capital costs Finally, in order to complete the entire calculations, it is considered vital to add the inputs and the residual values of the investment. Since the calculations of residual value is very complex enough, the most objective specification is used; this is the net value of fixed investment. Below, there is a presentation of the relative tables for the two different scenarios which are examined. Page 123

124 SCENARIO 1 Table 49 - Cash Flow Scenario 1 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th INFLOWS (A1) RESULTS BEFORE DEPRECIATION & TAXES Subsidy Loan Total (Α) OUTPUTS (B1) Investment costs Installment Tax Working Capital Expenditure Total (B) Undepreciated Value CASH FLOWS (C1 = A1-B1) STATE CAPITAL The information provided by the table indicates that the investment's viability is satisfying, given the fact that after the annual additional net cash flow calculation the internal rate of return (IRR) results to 11,29%. The Net Result of the investment is estimated at ,42.

125 SCENARIO 2 Table 50 - Cash Flow Scenario 2 1rst 2nd 3rd 4th 5th 6th 7th 8th 9th 10th INFLOWS (A1) RESULTS BEFORE DEPRECIATION & TAXES Subsidy Loan Total (Α) OUTPUTS (B1) Investment costs Installment Tax Working Capital Expenditure Total (B) Undepreciated Value CASH FLOWS (C1 = A1-B1) STATE CAPITAL The information provided by the table indicates that the investment's viability is satisfying, given the fact that after the annual additional net cash flow calculation the internal rate of return (IRR) results to 7,90%. The Net Result of the investment is estimated at ,33.

126 19. Minimum viable biogas plant case (Scenario 3) In the present study, it was of crucial importance to examine the possibility of establishing a biogas unit in smallest possible scale, which will be financed entirely by small investors. The aim of this alternative, was to determine the minimum capacity of the unit, the creation of which will have minimum capital requirement and simultaneously will be economically viable. To identify this case, it was chosen the investment with the Net Present Value that equals to zero in ten-year time. After a series of calculations, it was estimated that the capacity of the unit is 1,7 MW and with an investment cost at As the next table displays, the financial plan of the investment consists of 35% equity, 25% long-term borrowed funds, and 40% grant. Table 51 - Financial Plan (Scenario 3) Financial plan Equity ,00 35,00% Long-term borrowing ,00 25,00% Subsidy ,00 40,00% TOTAL To determine the results of the investment, the assumptions of scenarios A and B were used, but the following differences were occurred: The unit will operate two shifts per day. For the biogas production, the 17% of the available Mix 1, 22% of the Mix 2 and 100% of the Mix 3, will be used. The values that shape the operating cost and the production cost of the business, will be changed, almost proportionally. Based on what we showed, we've reached on the following financial results for the 1,7 MW power unit: Page 126

127 19.1 Financial turnover Table 52 - Financial Turnover (Scenario 3) SALES REVENUES Price per Unit Electrical Energy 209 Thermal Energy 0 Compost 50 Total Turnover , , , , , , , , ,50 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0, , , , , , , , , , , , The total of financial turnover amounts to for the first operating year and turns into in decade. There is a 2% financial turnover annual increase for the first five operating years. In case where there is electric power sale without subsidy (buying price 253 ), the previously described amounts would turn into ,57 and ,98, respectively.

128 19.2 Trading account Table 53 - Trading Account (Scenario 3) TOTAL TURNOVER Less: Cost of sales GROSS OPERATING PROFIT Less: Administrative Expenses - Distribution Less: Research & Development Expenses OPERATING RESULT Plus: Miscellaneous revenue Less: Other expenditure RESULTS BEFORE INTEREST, DEPRECIATION AND TAXES Less: interest on existing long-term loans Less: interest on short-term working capital loans Less: annual leasing rent Plus: leasing subsidy RESULTS BEFORE DEPRECIATION & TAXES Less: Depreciation RESULT BEFORE TAXES Less: Income tax Net result

129 Based on the previous table, the company will have a result before amortization sums to for the first operating year. This sum will change into in a decade. The following diagram shows the future result before tax amounts and recoup amounts, which are estimated to turn into for the first operating year and to in decade. Image 47 - Results before depreciation & taxes Scenario 3 In the following chart shows the evolution of gross profit operating income before interest, depreciation and taxes and the net result in a decade: RESULTS GROSS OPERATING PROFIT RESULTS BEFORE INTEREST, DEPRECIATION & TAXES AND LEASING Net result Image 48 - Results (Scenario 3) Page 129

130 The following diagram shows the future evolution of the elements that form the before interest, taxes and amortization results of the company. Image 49 - Revenues, expenses (Scenario 3) Page 130