(481d) Catalytic Steam Reforming of Water Extracted Bio-Oil Fractions

Steam reforming of bio-oil over a Ni-catalyst mainly generates syngas which can further be converted into a range of fuels and chemicals. Moreover, under suitable conditions and through catalyst modifications, product selectivity toward highly desirable hydrogen can be significantly improved by promoting water-gas shift reaction. Production of syngas from bio-oil is highly endothermic requiring higher temperatures while water-gas shift reaction that produces hydrogen is exothermic preferring lower temperatures. Thus optimum reaction conditions are required for improving yield toward syngas/hydrogen. Although steam reforming of petroleum-derived feedstocks is well established but because of the higher reactivity and thermal instability of bio-oil several challenges are faced in the fixed bed reformer wherein catalyst deactivation is rapid with bio-oils. Typically this condition is minimized by the utilization of higher steam to carbon ratios. The focus of this work is to study the catalytic conversion efficiency of different fractions of bio-oil that were obtained during the fast pyrolysis of biomass mainly in terms of the yield of syngas/hydrogen from wheat straw bio-oil. One of the main goals of this work is to identify the most desirable bio-oil fraction for the reforming step. A commercial Ni/Al2O3 catalyst is employed for testing. High steam to carbon ratios of 10 or higher are maintained by selectively extracting water soluble compounds from the four different bio-oil fractions produced during fast pyrolysis of wheat straw. The temperature range studied is between 350°C and 550°C at atmospheric pressure. Effluent gases are analyzed on a Micro-GC.