Digital version: http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-6 ISBN 978-91-87525-73-5 (printed)
ISBN 978-91-87525-74-2 (pdf)
ISSN 0280-381X Skrifter från Högskolan i Borås, nr. 72
D O C TO R A L TH ESI S Re so ur ce R eco ve ry D O C TO R A L TH ESI S
The remarkable benefits associated with bringing to bear, the application of renewable energy carriers including fermentative hydrogen and methane, cannot be understated. Meanwhile, considering the tremendous benefits associated with the conver-sion of wastes to the two energy carriers (fermentative hydrogen and methane); people might be curious to know why the commer-cial application of the green technology, especommer-cially, fermenta-tive hydrogen, has not yet been widespread. The reason is not far-fetched; the current low yield of fermentative hydrogen makes large scale of the process to be unprofitable and uncompetitive with commercial hydrogen production processes from fossil fuels.
Low yields of fermentative hydrogen and methane productions could be attributed partly to substrate and product inhibitions which affect the metabolic pathways and thermodynamic conditions of the fermentative bacteria. The focus of this study was, therefore, on how to improve the yields of fermentative hydrogen and methane through the application of membrane techniques including encapsulation and membrane permeation of VFA. The encapsulation techniques were used to investigate the poten-tial of improved fermentative hydrogen and methane yields from encapsulated cells, when compared to free cells, during the anerobic fermentation of substrates with inhib-itory fruit flavour compounds (limonene, hexanal, myrcene and octanol). Similarly, the technique of membrane permeation of VFA was used to investigate the effects of the VFA extraction on bioreactor hydrodynamics in relation to fermentative hydrogen production.
The results from this thesis study indicate that application of the membrane techniques coupled with varying operational parameters could improve hydrogen and methane productions from fermentation media with substrate and product inhibitions. It is expected that applications of this research knowledge along with the government support will facilitate development of the commercial production of fermentative hydrogen and methane.
Keywords: Encapsulation, inhibition, hydrodynamics, hydrogen, methane, fruit flavour, membrane bioreactor.
FERMENTATIVE
HYDROGEN AND METHANE
PRODUCTIONS USING
MEMBRANE BIOREACTORS
Julius Gbenga Akinbomi
Jul iu s G be ng a A kin bo m i F ER ME N TA TIV E H YD RO GE N A N D ME TH AN E P RO DUC TIO N S U SIN G ME MB RA N E B IO RE AC TO RS
This thesis presents work that was done within the Swedish Centre for Resource Recovery (SCRR). Research and education performed within SCRR identifies new and improved methods to convert residuals into value-added products. SCRR covers technical, environmental and social aspects of sustainable resource recovery.
