Operation of the Pilot Plant Prototype

LIFE08 ENV/GR/000578 INTEGRASTE «Development of integrated agroindustrial waste management politics maximizing materials recovery and energy exploitation» Operation of the Pilot Plant Prototype Author: Dr. Aikaterini Vavouraki Scientific Responsible for the project : Assist. Professor Michael Kornaros Responsible Partner: University of Patras PATRAS, SEPTEMBER, 2013

LIFE08 ENV/GR/000578 INTEGRASTE «Development of integrated agroindustrial waste management politics maximizing materials recovery and energy exploitation» Λειτουργία της Πιλοτικής Mονάδας Συντάκτης: Δρ. Αικατερίνη Βαβουράκη Επιστημονικός Υπεύθυνος Εργου : Επίκ. Καθηγητής Μιχάλης Κορνάρος Υπεύθυνος δικαιούχος: Πανεπιστήμιο Πατρών ΠΑΤΡΑ, ΣΕΠΤΕΜΒΡΙΟΣ, 2013

LIFE PROJECT NAME INTEGRASTE Project location Data Project Patras, Greece Project start date: 01/01/2010 Project end date: 30/09/2013 Total Project duration (in months) 45 months Total budget 1.156.325 Eligible 1.087.325 EC contribution: 543.662 (%) of total costs 47 (%) of eligible costs 50 Name Beneficiary Contact person Postal address Visit address Data Beneficiary University of Patras Dr. Michael Kornaros 1 Karatheodori Str., 26500, Patras, GR 1 Karatheodori Str., 26500, Patras, GR Telephone 0030 2610 997418 Fax: 0030 2610 969556 E-mail Project Website kornaros@chemeng.upatras.gr http://www.achaia.gr/integraste/index.php

ΠΕΡΙΕΧΟΜΕΝΑ ABSTRACT... 9 ΠΕΡΙΛΗΨΗ... 11 1. ΕΙΣΑΓΩΓΗ... 13 2. ΣΕΝΑΡΙΑ ΛΕΙΤΟΥΡΓΙΑΣ ΠΙΛΟΤΙΚΗΣ ΜΟΝΑΔΑΣ... 24 2.1 ΕΚΚΙΝΗΣΗ ΤΗΣ ΑΝΑΕΡΟΒΙΑΣ ΜΟΝΑΔΑΣ ΣΕΝΑΡΙΟ 1... 25 2.1.1 Γενικά... 25 2.1.2 Οξεογόνος αντιδραστήρας... 27 2.1.3 Μεθανογόνος αντιδραστήρας... 31 2.2 ΣΕΝΑΡΙΟ 2: 55% ενσιρωμένο σόργο, 40% τυροκομείο και 5%βουστάσιο... 36 2.2.1 Γενικά... 36 2.2.1 Οξεογόνος αντιδραστήρας... 38 2.2.2 Μεθανογόνος αντιδραστήρας... 42 2.3 ΣΕΝΑΡΙΟ 3: 95% ενσιρωμένο σόργο και 5%βουστάσιο... 45 2.3.1 Γενικά... 45 2.3.1 Οξεογόνος αντιδραστήρας... 46 2.3.3 Μεθανογόνος αντιδραστήρας... 51 3. ΕΠΕΞΕΡΓΑΣΙΑ ΤΗΣ ΑΠΟΡΡΟΗΣ ΜΕΘΑΝΟΓΟΝΟΥ ΑΝΤΙΔΡΑΣΤΗΡΑ (ΣΕΝΑΡΙΟ 2) ΜΕ ΧΡΗΣΗ ΜΕΜΒΡΑΝΩΝ... 52 3.1 ΕΙΣΑΓΩΓΗ... 52 3.1.1 Υπερδιήθηση... 52 3.1.2 Νανοδιήθηση... 53 3.1.3 Κροκίδωση-καθίζηση... 53 3.2 ΠΕΙΡΑΜΑ ΚΡΟΚΙΔΩΣΗΣ - ΚΑΘΙΖΗΣΗΣ... 54 3.3 ΛΕΙΤΟΥΡΓΙΑ ΣΥΣΤΗΜΑΤΟΣ ΥΠΕΡΔΙΗΘΗΣΗΣ... 57 3.4 ΛΕΙΤΟΥΡΓΙΑ ΣΥΣΤΗΜΑΤΟΣ ΝΑΝΟΔΙΗΘΗΣΗΣ... 58 Page 1 of 79

4. VERMICOMPOST ΜΕ ΧΡΗΣΗ ΓΑΙΟΣΚΩΛΗΚΩΝ EISENIA FOETIDA... 60 4.1 ΥΛΙΚΑ ΚΑΙ ΜΕΘΟΔΟΙ... 60 4.2 ΠΕΙΡΑΜΑΤΙΚΗ ΔΙΑΤΑΞΗ... 61 4.3 ΑΠΟΤΕΛΕΣΜΑΤΑ - ΣΥΖΗΤΗΣΗ... 61 5. ΑΕΡΟΒΙΑ ΚΟΜΠΟΣΤΟΠΟΙΗΣΗ... 65 5.1 ΕΙΣΑΓΩΓΗ... 65 5.2 ΛΕΙΤΟΥΡΓΙΚΕΣ ΠΑΡΑΜΕΤΡΟΙ... 68 5.2 ΑΠΟΤΕΛΕΣΜΑΤΑ ΛΕΙΤΟΥΡΓΙΑΣ ΤΗΣ ΠΙΛΟΤΙΚΗΣ ΜΟΝΑΔΑΣ ΑΕΡΟΒΙΑΣ ΛΙΠΑΣΜΑΤΟΠΟΙΗΣΗΣ... 70 6. ΕΝΕΡΓΕΙΑΚΗ ΑΝΑΛΥΣΗ ΤΗΣ ΠΙΛΟΤΙΚΗΣ ΜΟΝΑΔΑΣ... 74 6.1 ΕΙΣΑΓΩΓΗ... 74 6.2 ΣΥΜΠΕΡΑΣΜΑΤΑ... 79 Page 2 of 79

Abstract Co-digestion of organic wastes is a technology that is increasingly being applied for simultaneous treatment of several solid and liquid organic wastes, in which the content of nutrients can thereby be balanced, and the negative effect of toxic compounds on the digestion process may be decreased giving an increased gas yield from the biomass. Moreover, co-digestion contributes to a more efficient use of AD reactors and cost-sharing by processing multiple waste streams in a single facility. In this work, efficient biodegradation of three different mixtures (3 scenarios) using a twostage process were examined at pilot-scale. Two continuously stirred tank reactors (CSTRs) were used under mesophilic conditions (35 0 C) in order to enhance acidogenesis and methanogenesis. Initially, a mixture composed of 55% OMW (olive mill wastewater), 40% CW (cheese whey) and 5% LCM (liquid cow manure) was studied. The overall process was designed with a hydraulic retention time (HRT) of 19 days. The methanogenic digester was fed with the acidified mixture from the effluent of the acidogenic reactor. The average removal of soluble COD was 50% and methane production rate at the steady state reached to 0.75 L CH 4 / L R / d. Following the system upgrade, another feeding mixture was tested. In this case the mixture was changed to 55% PSS (pretreated ensiled sorghum), 40% CW and 5% LCM. The ensiled sorghum was used to replace olive mill wastewater in the mixture because of its seasonal availability. The acidogenic reactor was operated at three different HRTs of 2, 1, and 0.75 d, under controlled ph 5.5 providing optimum operating conditions for acidogenic bacteria. A significant production of biogas and H 2 was observed when shorter HRTs were applied: in particular H 2 productivity increased to 0.84 L/ L R / d by decreasing the HRT to 0.75 d. On the other hand, the methanogenic reactor was operated at three different HRTs of 24, 16 and 12 d under uncontrolled ph conditions. The higher productivity was achieved at HRT of 16 d with maximum CH 4 production rate of 0.96 L/ L R / d, whereas at lower HRT the process appeared to be inhibited and/or overloaded, as indicated by the accumulation of volatile fatty acids and the decline in the CH 4 productivity. Finally, the 3 rd scenario tested was based on a feeding mixture containing 95% PSS and 5% LCM in order to replace cheese whey in the mixture. The acidogenic reactor was operated at two different HRTs of 3 and 5 d, under controlled ph 5.0, whereas the methanogenic reactor was operated at two different HRTs of 20 and 25 d under uncontrolled ph conditions. The maximum production of biogas (0.46 L/ L R / d) and H 2 (0.13 L/ L R / d) in the acidogenic reactor was observed at HRT of 5 d. Τhe higher productivity during methanogenesis was achieved at the HRT of 25 d with maximum CH 4 production rate of 0.48 L/ L R / d, whereas at the lower HRT of 20 d the process appeared to be inhibited by the accumulation of volatile fatty acids. Page 9 of 79

The application of pilot-scale membrane separation system in the effluent of the methanogenic digester fed with a mixture of 55% PSS, 40% CW and 5% LCM resulted in a final permeate of 2.46 g COD/ L. Vermicomposting was studied at pilot-scale using two mixtures consisting of cow manure (90%) and anaerobic sludge (10%) produced in the Wastewater Treatment Plant of Patras and in the Pilot Plant (solid part of anaerobic effluent from scenario 2). At the end of experimentation period using anaerobic sludge from the pilot plant, an increase of phosphorus and potassium concentration at about 30% and 50% respectively was observed, while the mean weight of each individual worm of Eisenia foetida increased about 33%, whereas the nitrogen concentration of the mixture remained practically constant. The pilot-scale configuration of composting was used for conducting experiments utilizing the solid fraction of anaerobic effluents from scenario 2 in combination with other organic wastes and residues. The prepared compost after 32 days proved to contain adequate amounts of macro-nutrients and properties that may be used for characterizing the product as compost. Based on the results of energetic analysis of all scenarios realized in the pilot plant it can be concluded that the obtained electrical energy yields per liter of fed wastes are almost equivalent in all scenarios proving that the project s initial objective has been fulfilled i.e. to design a plant that can be operational on annual basis at the maximum efficiency. Moreover, the initial project design and assumption that sweet sorghum may be used as an alternative substitute of liquid organic wastes in cases that a full-scale plant lacks feeding from liquid wastes has also been confirmed. Page 10 of 79