Catalytic Cascade Transformations of Biomass into Polyols

Abstract

mong the many oxygen-rich chemicals that can be obtained from biomass, polyols, such as ethylene glycol and propylene glycol, are widely used in industry. Liquid polyols have been used in polyurethane foam preparation and as components of adhesives. Hydrolysis, coupled with hydrogenation and hydrogenolysis allows transformation of biomass or its constituents into polyols. Liquefaction is another approach which is efficient for converting biomass into liquid polyols that have high content of reactive hydroxyl groups. The cascade transformation of biomass to polyols is widely used. In some cases, fractionation of biomass into its main components (cellulose, hemicelluloses and lignin) is accomplished to facilitate its further conversion. Production of polyols from cellulose can be conducted in a two-step process with suitable catalysts or in an one-step process with bifunctional catalysts. Polyol production depends on the material used as feedstock, catalyst employed and reaction conditions. This chapter reviews key strategies used to convert biomass into polyols. Special emphasis is given to emerging processes aimed to valorize biomass through a cascade approach.