Fixed-Bed Pyrolysis of Hazelnut Shell: A Study on Mass Transfer Limitations on Product Yields and Characterization of the Pyrolysis Oil

Abstract

Fixed-bed slow and fast pyrolysis experiments have been conducted on a sample of hazelnut shell. The experiments were performed in two different pyrolysis reactors, a fixed-bed Heinze and a well-swept fixed-bed tubular retort, to investigate the effects of fast pyrolysis on the mass transfer limitations. The effects of heating rate, pyrolysis temperature, particle size, and sweep gas velocity on the pyrolysis product yields and chemical compositions have been investigated. In a Heinze retort, the maximum oil yield of 22.5% was obtained in a sweeping gas atmosphere (100 cm3/min N2) at the particle size range of 0.85 < Dp < 1.8 mm, pyrolysis temperature of 550°C, and heating rate of 7°C/min. In a well-swept fixed-bed reactor, the maximum oil yield of 34% was obtained in a sweeping gas atmosphere, with a heating rate of 300°C/min. The chemical characterization has shown that the oil obtained from hazelnut shell can be used as a renewable fuel and chemical feedstock.