BioChem - DOS

Optimizing hydrogen production from a switchgrass steam exploded liquor using a mixed anaerobic culture in an upflow anaerobic sludge blanket reactor

International journal of hydrogen energy

Veeravalli, S.S.; Chaganti, S.R.; Lalman, J.A.; Heath, D.D.

In this study, the operation of an upflow anaerobic sludge blanket reactor (UASBR) producing hydrogen (H<SUB>2</SUB>) from a steam-exploded switchgrass (SWG) liquor was statistically optimized. The factors consider included pH, hydraulic retention time (HRT) and linoleic acid (LA) concentration. Under optimal operational conditions (pH 5.0, 10 h HRT and 1.75 g L<SUP>-1</SUP> LA), which were close to the predicted conditions using the D-optimality index, the maximum H<SUB>2</SUB> and methane yield observed were 99.86 +/- 5.6 mL g<SUP>-1</SUP> TVS and 0.5 +/- 0.1 mL g<SUP>-1</SUP> TVS, respectively. Under maximum H<SUB>2</SUB>-producing conditions, high levels of acetate plus butyrate were observed with low levels of ethanol and lactate. A principal component analysis revealed that clustering of the samples was based on the operating conditions and fermentation metabolites. The microbial profiles revealed that by lowering the HRT from 16 to 8 h or decreasing the pH from 7.0 to 5.0 in the controls caused a 50% reduction in the relative abundance of the terminal restriction fragments belonging to the methanogenic population (Methanobacteria, Methanomicrobia, Methanococci). With LA treatment, H<SUB>2</SUB> producers (Ruminococcaceae and Clostridiaceae) were dominant and methanogens were inhibited and/or washed-out from the UASBR.

2014

Pergamon Press ; Elsevier Science Ltd

0360-3199

1879-3487

39

7

pp.3160-3175

10.1016/j.ijhydene.2013.12.057

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART68595354

Switchgrass; Bio-hydrogen; Optimization; Mixed anaerobic culture; Microbial diversity; Upflow anaerobic sludge blanket reactor