Influence of Natural and H-Beta Zeolites on Yield and Composition of Non-Polar Fraction of Bio-Oil in Slow Co-Pyrolysis of Biomass and Polypropylene

Abstract

The non-oxygenated fraction of bio-oil is precursor of the formation of biofuel because it contains hydrocarbon only. Zeolite catalysts have been proved to improve the yields of non-polar fraction of bio-oil in case of fast co-pyrolysis. In the present work, the catalysts were applied to slow co-pyrolysis to investigate their effect on the yields and compositions of non-oxygenated fractions of bio-oil. The co-pyrolysis was conducted in a stirred tank reactor using non catalyst (thermal co-pyrolysis), natural zeolite and H-beta zeolite catalysts with heating rate of 5°C/minute from ambient temperature to 500°C and PP composition in combined feed varied 0, 50, and 100% weight of PP. As biomass, the present study used corn cobs. The results show that synergistic effect on the yield of non-oxygenated fraction in co-pyrolysis involving natural zeolite was lower than that in thermal co-pyrolysis and co-pyrolysis involving H-beta-zeolite exhibited negative synergistic effect. H-NMR analysis of the fraction from co-pyrolysis involving 50% weight of PP shows that the bio-oil contained approximately methyl H of about 55% by mol, methine H of 20% and methylene H of about 15% irrespective of catalysts used. This composition was closer to that of commercial gasoline rather than commercial diesel compositions.