Comparative Study of Biogas Production from Cassava Pulp in a Sequencing Batch Reactor and a Continuous Stirred Tank Reactor

Abstract Thai cassava starch industry generates solid waste or pulp approximately of 9.5 Mt/y (with a moisture content 70–80%). Biogas production technology has been introduced for several decades in Thailand. However, the implementation biogas using as feedstock is still limited due to complex lignocellulosic structure, which diminishes hydrolysis. This work investigated from 50-m 3 pilot-scale sequencing batch reactor (SBR) and continuous stirred tank (CSTR). Both reactors were fed with pulp, under organic loading rate (OLR) 8 kg-COD/m -d average hydraulic retention time (HRT) 7 d. Under operation, more than 60% was utilized within first three days. The SBR achieved methane 1.87 m -CH 4 /ton-pulp fresh acids 2.19 kg-TVA/ton-pulp while CSTR had 0.22 7.07 -d. higher because settling process helped microorganisms remain system. In CSTR, rather produced washout methanogenic microorganisms. revealed that yielded production, intermediate acids, could be supplied biochemical industry.