BioChem - DOS

Simultaneous production of acetate and methane from glycerol by selective enrichment of hydrogenotrophic methanogens in extreme-thermophilic (70 °C) mixed culture fermentation

Applied energy

Zhang, Fang; Zhang, Yan; Chen, Yun; Dai, Kun; van Loosdrecht, Mark C.M.; Zeng, Raymond J.

<P><B>Abstract</B></P> <P>The feasibility of simultaneous production of acetate and methane from glycerol was investigated by selective enrichment of hydrogenotrophic methanogens in an extreme-thermophilic (70&deg;C) fermentation. Fed-batch experiments showed acetate was produced at the concentration up to 13.0g/L. A stable operation of the continuous stirred tank reactor (CSTR) was reached within 100days. Acetate accounted for more than 90 w/w% of metabolites in the fermentation liquid. The yields of methane and acetate were close to the theoretical yields with 0.74&ndash;0.80mol-methane/mol-glycerol and 0.63&ndash;0.70mol-acetate/mol-glycerol. The obtained microbial community was characterized. Hydrogenotrophic methanogens, mainly <I>Methanothermobacter thermautotrophicus</I> formed 93% of the methanogenogenic community. This confirms that a high temperature (70&deg;C) could effectively select for hydrogenotrophic methanogenic archaea. <I>Thermoanaerobacter</I> spp. was the main bacterium forming 91.5% of the bacterial population. This work demonstrated the conversion of the byproduct of biodiesel production, glycerol, to acetate as a chemical and biogas for energy generation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simultaneous production of acetate and methane from glycerol was investigated. </LI> <LI> Acetate accounted for more than 90% of metabolites in liquid solutions. </LI> <LI> The maximum concentration of acetate was above 13g/L. </LI> <LI> 93% of archaea were hydrogenotrophic methanogens. </LI> <LI> <I>Thermoanaerobacter</I> was main bacterium and its percentage was 92%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

2015

Elsevier

0306-2619

1872-9118

148

pp.326-333

10.1016/j.apenergy.2015.03.104

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART72043311

Extreme thermophilic; Mixed culture fermentation; Glycerol; Acetate; Methane; Hydrogenotrophic methanogens