7/27/2019 Methane Generation by Anaerobic Digestion of Cellulose Containing Wastes One Page

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Methane Generation by Anaerobic Digestionof Cellulose-Containing Wastes

J . M. Scharer, M. Moo-YoungB iochem ica l En g i n e e ri ng Gro u p , Dep t . o f Chemica l Eng inee r i ng ,U n iv e r s i t y o f Wa te r l oo , Wa te r l oo , O n ta r i o , Canada , N 2L 3G 1

1 In tro du ctio n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

2 Cellu lose Hydro lys is and Acidogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 873 M ethanogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 894 Substra te -Microbe Interac tions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 925 Process E co no mic s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 996 Concluding R em ark s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1007 R eferen ces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

The a naerob ic digestion of cellulose-containing wastes, bo th m unicip al and ag ricultural, hold s promiseas a dual method of energy (methane) generation and waste treatment. Advances regarding the tech-nical bio chem istry and mi crobi olog y of this anaerobic-digestion process are reviewed. Ex perim enta lresults concerning the kine tics of methan e generatio n from various substances and t he de pend enceof methanogenesis on operatin g parame ters are assessed. Deficiencies in our presen t know ledge andareas of futur e research needs are iden tified. The fe asibility of the process for farm-scale app licatio nsare examined.

1 I n t r o d u c t i o n

M i crob i a l con ve r s io n o f o rgan ic m a t t e r t o me th ane i s i nd igeneous t o na tu r a l anae rob i cec osys t e ms . Th i s p ro c e s s , kn o wn a s a nae rob i c d ige s t i on , ha s been w ide ly adap t ed fo r s ta -b i l i zi ng p r im a ry an d s eco n d a r y was t e s l udge i n mun ic ipa l was t ewa te r po l l u t i on con t ro lp l an t s. I n d e e d , m u c h o f t h e p r a c t i c a l k n o w l e d g e a n d m o s t o f t h e t e c h n o l o g y c o n c e r n i n gm e t h a n e g e n e r a t io n b y a n a e r o b i c d i ge s t io n h as b e e n t h e o u t g r o w t h o f t h is p r a c ti c e . I th a s beco me c l ea r, ho weve r, t ha t t h e m e than e gen e ra t i on capa c i t y f r om w as t ewa te r s l udgei s n o t s i gn i fi c an t i n a l l ev i a t i n g na t i on a l en e rgy sho r t ages. I n No r th Am er i ca , a s e l s ewhe r e ,t h e ene rgy c r i si s ( e sp ec i a l l y t h e exhau s t i on o f n a tu r a l ga s r e se rve s) ha s p rov ided t he

r ece n t i mpe t u s f o r re s ea r c h i n to me t h a ne gene ra t i on by anae rob i c d ige s t i on o f o the rr en e wab le r e sou rce s , pa r t i c u l a r l y c e l l u lo se - con t a in ing ag r i cu l t u ra l and mun ic ip a l was t eresidu es 14, 17, 45, 46, 4a, s s). Th e ensuin g discus sion is an eva lua t io n o f t he adv ance s and

un s o lved p rob l em s p e r t a i n i n g t o a n a e r ob i c d ige s t i on o f c e l l u lo s i c ma t e r i a l s t o me tha ne .