초록
<P><B>Abstract</B></P> <P>The performance of a novel biofilm plug flow reactor containing a mixed anaerobic microbial culture was investigated for the conversion of CO<SUB>2</SUB>/H<SUB>2</SUB> to CH<SUB>4</SUB>. Unlike conventional gas-liquid contactors that depend on agitation, gas diffusion was decoupled from power consumption for mixing by increasing the gas phase inside the reaction space whilst increasing the gas residence time. The mixed mesophilic culture exhibited good biofilm formation and metabolic activity. Within 82days of operation, 99% and 90% CH<SUB>4</SUB> conversion efficiencies were achieved at total gas throughputs of 100 and 150v/v/d, respectively. At a gas input rate of 230v/v/d, methane evolution rates reached 40v/v/d, which are the highest to date achieved by fixed film biomethanation systems. Significant gas transfer related parasitic energy savings can be achieved when using the novel plug flow design as compared to a CSTR. The results and modelling parameters of the study can aid the development of high rate, low parasitic energy biological methanation technologies for biogas upgrading and renewable power conversion and storage systems. The study has also established a reactor system which has the potential of accelerating biotechnology developments and deployment of other novel C1 gas routes to low carbon products.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel bio-methanation reactor was designed and evaluated. </LI> <LI> A biofilm consisting of mixed anaerobic consortia served as the biocatalyst. </LI> <LI> High rate methanogenesis was observed without gas-liquid agitation. </LI> <LI> Gas conversion was successfully de-coupled from energy consumption. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>