Biodegradable fraction of municipal solid waste (BMSW) as a suitable feedstock for the production of biobutanol

The cost of raw material is one of the most important factors, affecting the economy of biobutanol production process. Municipal solid waste (MSW) is a low cost material, which has a high potential to convert to biobutanol. In this study, starch based materials was separated from MSW by hot water and subsequently dilute acid pretreatment was used to improve the enzymatic hydrolysis and fermentation of residual biodegradable municipal solid waste for butanol production via acetone-butanol-ethanol (ABE) fermentation. Hydrolysate with 17 g/L total sugar was obtained by using 0.75% w/w dilute sulphuric acid as a pretreatment reagent at 140 °C for 30 min, which was subsequently fermented to 6.84 g/L ABE. Dilute acid pretreatment increased the yield of enzymatic hydrolysis and butanol fermentation by 30.8% and 15%, respectively. At first step, the obtained liquid fraction containing the soluble starch of MSW was directly utilized by Clostridium acetobutylicum. However, phenolic components and tannic acid, which were presented in the liquid phase, had inhibiting effects on the amylolytic activity of C. acetobutylicum. After eliminating this phenolic component, C. acetobutylicum could directly use the starch fraction of BMSW and fermented it to ABE. Hence, the yield of ABE production from raw BMSW was significantly increased.

کلیدواژه ها:

ABE fermentation ، Municipal solid waste ، Biobutanol ، C. acetobutylicum ، Dilute acid pretreatment