Recent advances in biomass-derived platform chemicals to valeric acid synthesis

Abstract

Biomass-derived carbohydrates are selectively converted into platform chemicals such as levulinic acid (LA) and 5-hydroxymethylfurfural (HMF). Among those platform chemicals, LA is one of the most promising and sustainable chemicals. LA can be upgraded into oxygenated fuels, chemicals, and polymers which is of tremendously significant interest for a decrease in dependence on fossil fuel resources and to resolve environmental issues. Biomass-derived alkyl valerate esters such as methyl, ethyl and pentyl valerate esters have potential applications in renewable additives for diesel fuels and gasoline. A previous review focused primarily on reports of the conversion of LA to γ-valerolactone (GVL) and valeric esters (VE). Here we have concentrated mainly on the direct transformation of LA to valeric acid (VA) and GVL to VA synthesis which is a significant pathway in biorefinery industrial development. VA is the most crucial platform molecule for the synthesis of valeric biofuels. This review can provide valuable information for the research and exploitation of LA to VA synthesis via a one-pot synthesis over noble and non-noble metal-supported catalysts and electrocatalytic systems. GVL to VA synthesis has been reported. Thus, this systematic review on the catalytic conversion of VA from LA and GVL will offer guidelines for designing efficient catalysts for biomass conversion.