25 11 2005 11 Acta Scientiae Circumstantiae Vol. 25,No. 11 Nov., 2005,,,. [J ].,2005,25 (11) :1484-1490 DENG Na, ZHANG Yufeng, et al. Thermogravimetric study and kinetic model on pyrolysis of medical waste compositions[j ]. Acta Scientiae Circumstantiae,2005, 25 (11) :1484-1490, 3,,,, 300072 :2005204215 :2005209206 :2005209208 :,., 14,.,, 160 290, ;, 800.,1168 %,. : ; ; ; :025322468 (2005) 1121484207 :X705 :A Thermogravimetric study and kinetic model on pyrolysis of medical waste compositions DENG Na, ZHANG Yufeng 3, NIU Baolian, SUN Yuexia, CHEN Jing School of Environmental Engineering, Tianjin Uninversity,Tianjin, 300072, China Received 15 April 2005 ; received in revised form 6 September 2005 ; accepted 8 September 2005 Abstract : To obtain thermal decomposition and kinetic reaction mechanism of medical waste, thermogravimetric study of the 14 kinds of the typical medical waste compositions was carried out using the thermogravimetric analyser ( TGA) with N2. The mathematics model with two steps and four reactions was established to simulate the pyrolysis process. The results showed that : a) within the temperature range between 160 to 290, medicine, plastic, protein, biomass, synthetic fibre and rubber started to enter pyrolysis process in succession ; b) there was at least one or two decompositing stages for the these materials ; c) pyrolysis processes of all waste samples ended basically at about 800 ; d) the model could describe satisfactorily the weight loss and differential process of all waste samples within its maximum deviation 1168 %. The effect of the original waste compositions and all their product with different pyrolysis temperature in process could be estimated based on the model. Keywords :medical waste ; pyrolysis ; thermogravimetric analysis ; model,,,.,, (Lee et al.,1996 ;Mato et al.,1997 ;Lee et al., 2004).,,,,, (Zhang et al.,2003). ([ 2003 ]41 ).,,., ( Reina et al., 1998 ;, 2001 ; Raveendran et al., 1996 ;, 2003 ) ( Sgrum et al.,2001 ; Garc a et al.,1995 ;,1999) : (No. 50378062) ;(No. 013109611) ; (No. TD200111) : (1978 ),,,E2mail :denglouna @hotmail. com ; 3 ( ),E2mail :yufengfa @tju. edu. cn Foundation item : National Natural Science Foundation of CHINA ( No. 50378062), Key Technologies R&D Programme of Tianjin S&T Commission ( No. 013109611), Tianjin University and Nankai University Shared Research Item (No. TD200111). Biography :Deng Na (1978 ), female, Ph. D candidate, E2mail : denglouna @hotmail. com ; 3 Corresponding author,e2mail :yufengfa @tju. edu. cn
11 : 1485 (Conesa et al.,1996 ; Marcilla et al.,1995).,, (2003) (2004) 5 8,.,., : (1) :a) (Reina et al.,1998 ; Li et al.,2004) ;b) (,1999 ;,2004) ;c) (, 2003 ;Conesa et al.,1996). (2) : d) ( Sgrum et al., 2001 ; Garc a et al.,1995 ; Font et al.,1995).,a,,, ;b,,, ;c,,, ;d,,.,,,, ;,,,,,,., ;,,.,, 14 ;,. 1 ( Experiments) 111 14., 6 : ( ) ( ) ( ) ( ) ( ) () (). 1 (,,).,.,. 112 SHIMADZU DTG260H. 20 ml min - 1 N 2 ; Al 2 O 3 Al 2 O 3, ;, 20 min - 1, 2,;,, 2 9 mg,2 ; 015 mm, ;, (Antal et al.,1980). 2 ( Results) 1 14 20 min - 1 TG DTG, 14.,.,,. 150, ; 160 290,,, ; 600,, ;680 780, 800,.
1486 25 Table 1 1 Major constituent and ultimate analysis of typical medical waste compositions C H O 3 N S Cl Si 1 (PVC) 50. 87 % 7. 06 % 7. 56 % NA 0. 46 % 34. 05 % 2 (PVC) 42. 81 % 5. 95 % 3. 12 % NA 0. 73 % 47. 39 % 3 (LDPE) 86. 19 % 13. 41 % 0. 40 % NA NA 4 (NR) 86. 06 % 10. 27 % 2. 04 % 0. 42 % 1. 04 % 0. 17 % 5 (NR) 43. 86 % 5. 79 % 48. 45 % 0. 35 % 1. 23 % 0. 32 % 6 46. 26 % 6. 43 % 47. 09 % NA 0. 22 % 7 41. 63 % 5. 71 % 52. 35 % NA 0. 31 % 8 42. 51 % 6. 35 % 51. 01 % NA 0. 13 % 9 42. 90 % 6. 69 % 50. 19 % NA 0. 22 % 10 43. 16 % 7. 60 % 34. 85 % 13. 59 0. 80 % 11 (PVA) 54. 50 % 5. 18 % 40. 16 % NA 0. 16 % 12 13 14 O 3 : O,; NA : ; :; 1 TG( a)2dtg( b) (1.,2.,3.,4.,5., 6.,7.,8.,9.,10.,11.,12.,13.,14. ;m t, m 0 ) Fig. 1 TG(a)2DTG(b) curves of typical medical waste compositions(12tube for transfusion, 22sample collector for urine, 32one2off medical glove, 42operating glove, 52catheter, 62a cotton swabs, 72toilet paper, 82gauze, 92absorbent cotton, 102absorbable catgut suture, 112filling of dressing, 122adhesive plaster, 132dressing, 142medicine ; Annotation : m2sample weight at time t, m 0 2initial sample weight),1a,;, DTG( 1b),2,.,. PVC, HCl,,, (Marcilla et al.,1995 ; Varma et al.,1999). PE, PE,,,,(Conesa et al., 1996).,
11 : 1487.,40 % (,1999), 700.,,2. 1,3 DTG,, ;,DTG,.,,40 100, ;,,,,. 2 Table 2 Thermal analysis data of typical medical waste compositions 2,M, T, T onset, T endset, T max DTG, T. 2,,;. 800, 80 % 85 %90 %, 95 %,. d Πd t max, T max. 2, T max 300 470,.,,,. Πmg M T Π T T onset Π T endset Π T max Π d d t max Πs - 1 910 0. 1 510 0. 1 196 393 72. 40 % 288. 86 342. 86 320. 32 0. 43 % 428 541 14. 99 % 461. 92 491. 27 470. 41 3 0. 11 % 230 388 58. 21 % 295. 34 329. 97 309. 93 0. 55 % 403 568 24. 52 % 454. 58 493. 00 472. 31 3 0. 19 % 210 0. 1 272 513 95. 14 % 429. 40 493. 99 476. 81 0. 52 % 510 0. 1 267 495 92. 35 % 373. 42 422. 94 395. 88 0. 54 % 910 0. 1 257 501 46. 51 % 365. 72 430. 46 395. 80 0. 22 % 685 776 14. 03 % 717. 21 768. 13 755. 45 0. 08 % 210 0. 1 7. 01 % 201 421 69. 76 % 327. 12 394. 59 382. 50 3 0. 34 % 210 0. 1 4. 37 % 271 411 78. 94 % 344. 72 383. 81 372. 51 0. 66 % 210 0. 1 3. 00 % 265 424 81. 01 % 351. 41 397. 51 381. 75 0. 59 % 210 0. 1 2. 59 % 284 423 82. 89 % 353. 21 397. 2 382. 57 0. 63 % 510 0. 1 17. 89 % 227 482 48. 89 % 309. 30 382. 69 351. 28 0. 19 % 510 0. 1 3. 57 % 274 391 29. 16 % 329. 35 371. 26 358. 97 0. 21 % 391 511 48. 13 % 431. 49 475. 03 455. 50 0. 34 % 510 0. 1 1. 11 % 224 538 66. 59 % 365. 24 408. 49 384. 38 0. 39 % 510 0. 1 3. 30 % 258 390 52. 13 % 332. 23 376. 04 363. 67 0. 32 % 390 474 32. 39 % 440. 58 413. 25 0. 22 % 210 0. 1 5. 02 % 161 408 56. 01 % 260. 51 326. 15 300. 90 3 0. 19 % : 3,DTG() DTG. 3 ( Pyrolysis kinetic modeling) 311,, ;,,. 2, 2 ;,c,. (a),s,2
1488 25 ( k 1 k 2 ), :V 1 S 1, 1 ; S 1, ( k 3 k 4 ), V 2 S 2,S 2,, 2. S k 2 V 1 k 1 S 1 k 4 V 2 k 3 S 2 (a) (a) :1) ;2), ;3),. : : d SΠd t = - k 1 S n 1 - k 2 S n 2 (1) d S 1 Πd t = k 1 S n 1 - k 3 S n 3 1 - k 4 S n 4 1 (2) d S 2 Πd t = k 3 S n 3 1 (3) [ S, S 1, S 2 ] t = t0 = [1,0,0 ] ;, k i = A i exp ( - E i ΠRT), k i,a, E, n ;,: T = t + T 0 ; w,w cal = S + S 1 + S 2., x = [ A 1, A 2, A 3, A 4, E 1, E 2, E 3, E 4, n 1, n 2, n 3, n 4 ], : m OF = ( w cal ( t j, x) - w exp ( t j ) ) 2, (4) j = 1,OF, w cal ; w exp ; x ; m ; j j, t j j. 2 3, Levenberg2Marquardt,,.,,, : 5, 10, 30, 50 min - 1,Ozawa, ; ( Conesa et al., 1996 ; Marcilla et al.,1995 ; Kim et al.,1998 ; Williams et al., 1995 ; Dollimore et al.,1996 ; Rao et al.,1998),. 312 20 min - 1, 3 (, ). (4) D OF, gw exp VC(5). VC = OFΠ( D - P) gw exp 100 % (5), P,12. 3 Table 3 Kinetic parameters obtained by two2step, four2reaction, comprehensive model E A OF Π(kJ mol - 1 ) Πmin - 1 n D gw exp Π10-3 1 94. 14 7. 69 10 9 1. 03 2 119. 88 4. 52 1012 1. 12 3 232. 45 1. 18 10 18 1. 15 4 225. 28 1. 07 10 18 1. 46 1 110. 43 2. 13 10 11 1. 46 2 211. 52 7. 93 1020 2. 41 3 235. 69 2. 15 10 18 1. 38 4 248. 04 2. 42 10 19 1. 41 1 179. 93 4. 81 10 15 2. 08 VC 50 0. 463 1. 3 1. 26 % 90 0. 495 5. 4 1. 68 % 2 158. 41 9. 09 1013 1. 96 146 0. 639 8. 5 1. 25 % 3 384. 29 3. 60 10 20 1. 22 4 382. 32 2. 87 10 21 3. 42 1 184. 37 7. 24 10 14 0. 96 2 160. 05 7. 85 1014 0. 59 3 185. 02 6. 99 10 14 1. 01 4 184. 02 7. 40 10 14 0. 74 1 143. 63 1. 40 10 13 0. 52 2 105. 75 4. 85 1010 1. 98 3 137. 05 2. 03 10 13 2. 60 4 148. 63 1. 03 10 13 1. 67 1 136. 84 3. 59 10 12 0. 51 35 0. 692 1. 02 0. 96 % 42 0. 604 0. 55 0. 71 % 2 137. 07 3. 79 10 12 1. 60 155 0. 662 3. 8 0. 78 % 3 222. 40 8. 45 10 16 0. 64 4 215. 60 1. 17 10 17 0. 99 3,,,. 2 3 ( ) ( ),. 2 3
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