Efficient catalytic conversion of biomass derived cellulose to short chain polyols

In efforts to replace petro-derived polyethylene terephthalate (PET) with a 'green' equivalent, technologies are being developed and scaled up for biobased production of the two components of PET viz. monoethylene glycol (MEG) and terephthalic acid. Herein, we report work on single-pot catalytic hydrogenolysis of cellulose isolated from lignocellulosic biomass into polyols with the major fraction being monoethylene glycol. A combination of silica-alumina-supported nickel (NSA) and bulk tungsten-based catalyst (HW) was investigated for selective conversion of cellulose to MEG. While raw rice straw showed negligible conversion, the two-step pretreated rice straw performed similar to pure cellulose. Ethylene glycol in up to 60 % yield was obtained over 0.15%NSA-0.2% HW within minutes at a hydrogen pressure lower than reported thus far for similar catalysts. Product buildup was seen to have no effect on the catalyst activity and a fed-batch approach could generate product stream in high concentrations with MEG as a single major product.