The use of organic waste-derived volatile fatty acids as raw materials of C₄-C₅ bioalcohols

This study highlights a novel method for the production of bioalcohols, like 1-butanol, from organic waste-derived volatile fatty acids (VFAs) via non-biological pathways. A strategic two-step process was conducted to afford the bioalcohols. The process consists of esterification of VFAs to form VFA methyl esters (VFAMEs) followed by hydrogenation to bioalcohols. In the first step, carbon nanotubes was determined to be an effective carbon material to convert VFA to VFAME with high yields (>90%). In the second step, various metals (Pt, Pd, Rh, Ru, Ni, Co, and Cu) were tested and the inexpensive cobalt was the most active metal for hydrogenation of VFAMEs to their corresponding alcohols. The final yield of 1-butanol via the two-step process was 19 wt.%, which is comparable to that of conventional fermentation processes. Given the massive generation of organic waste, the two-step process to produce biobutanol has excellent potential for being developed in large scale.