A Review on the conversion of levulinic acid and its esters to various useful chemicals

Abstract

Levulinic acid (LA), an important chemical produced from a bio-based resource for current petrochemical operation, the details of hydrogenation to gamma (γ)-valerolactone (GVL) is reviewed. Levulinic acid (LA) was listed among one of the top value-added chemicals by U.S. Department of Energy and also been identified as a promising sustainable material for the synthesis of other important chemicals. It can be synthesized via a process known as hydrolysis. Its synthetic hydrolysis can be carried out employing some kinds of saccharides (e.g. glucose), the major constituent unit composed in cellulose. Its production from cellulose, the most abundant and renewable natural resource on earth is advantageous; however, recalcitrance nature that holds components together in biomass prevents the easy accessibility to the utilization of cellulose therefore as a result of this, considerable pretreatment is required. This review elucidates the details of levulinic acid (LA) synthesis starting from γ-valerolactone (GVL), its derivatives and their useful applications in various fields, most especially in the biorefinery. We concentrate on derivatives such as methyltetranhydrofuran (MTHF) as gasoline additives, ethyl levulinate as a diesel additive, succinic acid, 2-Butanol (2-BO) and 2-pentanol (2-PO) mainly synthesized from Levulinic acid (LA). Likewise, catalysts and Catalytic system for the synthesis were also reviewed. Finally, Baeyer-Villiger (BV) oxidation of levulinates into succinates was also given brief consideration in this mini review.