Direct catalytic conversion of biomass into glycols using tungsten- based catalysts

Introduction The world is currently facing two important issues in fossil energy consumption, i.e., depletion of fossil energy resources and climate warming caused by CO2 emission. Using renewable resources to obtain sustainable energy supplies and chemicals is required for a prosperous world in the future. Biomass originates from plants photosynthesis with huge annual production. The sugar polymers contained in biomass are suitable platforms for the production of renewable fuels and chemicals, and has gained much attention in their transformations [1-6]. Different from many works where cellulose is first hydrolyzed into glucose by mineral acids and then transformed into other chemicals by fermentation or catalysis, our group recently discovered that cellulose can be directly converted into ethylene glycol (EG) at yields of 60-75% by using tungsten-based catalysts under hydrothermal hydrogenation conditions [7-9]. Moreover, when the feed was changed to Jerusalem artichoke tuber (JAT), which contains 70-90 wt% fructan in the dried biomass, 1,2-propylene glycol (1,2-PG) was formed as the main product [10]. Ethylene glycol and propylene glycol are important bulk chemicals, which are dominantly produced from petroleum resources at present. Our work provides a novel way for biomass conversion to chemicals and thereby reduces the dependence on petroleum. In this contribution, we report our recent progress in the biomass conversion to EG and PG.Introduction The world is currently facing two important issues in fossil energy consumption, i.e., depletion of fossil energy resources and climate warming caused by CO2 emission. Using renewable resources to obtain sustainable energy supplies and chemicals is required for a prosperous world in the future. Biomass originates from plants photosynthesis with huge annual production. The sugar polymers contained in biomass are suitable platforms for the production of renewable fuels and chemicals, and has gained much attention in their transformations [1-6]. Different from many works where cellulose is first hydrolyzed into glucose by mineral acids and then transformed into other chemicals by fermentation or catalysis, our group recently discovered that cellulose can be directly converted into ethylene glycol (EG) at yields of 60-75% by using tungsten-based catalysts under hydrothermal hydrogenation conditions [7-9]. Moreover, when the feed was changed to Jerusalem artichoke tuber (JAT), which contains 70-90 wt% fructan in the dried biomass, 1,2-propylene glycol (1,2-PG) was formed as the main product [10]. Ethylene glycol and propylene glycol are important bulk chemicals, which are dominantly produced from petroleum resources at present. Our work provides a novel way for biomass conversion to chemicals and thereby reduces the dependence on petroleum. In this contribution, we report our recent progress in the biomass conversion to EG and PG