Review: Sustainable production of hydroxymethylfurfural and levulinic acid: Challenges and opportunities

Hydroxymethylfurfural (HMF) and levulinic acid (LA) are two of the most promising chemicals derived from biomass owing to their convertibility into a large number of chemicals having applications in diverse industries. Their transition from niche products to mass-produced chemicals, however, requires their production from sustainable biomass feedstocks at low costs using environment-friendly techniques. In this review, the numerous reaction systems that have been developed to produce HMF and LA from various substrates have been looked at and their merits, demerits and requirements for commercialisation outlined. Special attention has been paid to microwave irradiation-heated systems due to their dual advantages of high product yields and low environmental footprint.