Fast pyrolysis of sesame stalk: yields and structural analysis of bio-oil

Abstract

Sesame stalk pyrolysis experiments were conducted in a fixed-bed reactor in an attempt to determine the effects of pyrolysis temperature, particle size, heating rate and sweeping gas (N 2) flow rate on the product yields and their chemical compositions. Variables investigated were pyrolysis temperature between 400 and 700 °C, particle sizes between 0.224 and 1.8 mm diameter, heating rates between 100 and 700 °C min −1 and nitrogen-flow rates between 50 and 800 cm 3 min −1. The maximum oil yield of 37.20 wt.% was obtained at a pyrolysis temperature of 550 °C, heating rate of 500 °C min −1 and sweeping gas-flow rate of 200 cm 3 min −1. The differences observed on yields for the four particle-size ranges are practically negligible. The oil product was characterised by elemental analysis, IR and 1 H -NMR spectroscopy. While all subfractions of oil were analysed by elemental analysed and IR spectroscopy, only the n-pentane subfraction of oil was analysed by GC in order to determine the distribution of hydrocarbons in oil. The chemical characterisation results showed that the oil obtained from sesame stalk can be used as a potential source of renewable fuel.