Fixed-bed pyrolysis of walnut shell: Parameter effects on yields and characterization of products

Abstract

Fixed-bed pyrolysis experiments of walnut shell have been conducted in a well-swept tubular reactor to investigate the effects of various process parameters on product yields. For this purpose, pyrolysis temperature, reaction time and sweeping gas (N-2) flow rate were set in the ranges of 350-650 degrees C, 10-50 min and 50-450 ml min(-1), respectively. The heating rate was fixed at 40 degrees C min(-1). Maximum liquid yield was obtained at 500 degrees C, 30 min and 150 ml min(-1) as 48.2%. The liquid product was characterized by FTIR and GC-MS analyses, and shown to be a highly oxygenated complex mixture with 32 identified compounds whose carbon distribution was between C-2-C-10. In addition, the solid product was analyzed by means of FTIR, SEM and BET surface area which showed that solid product, as produced, was not appropriate for activated carbon applications. However, the higher heating value of solid product was higher than that of sub-bituminous coal, indicating a valuable solid fuel. (C) 2017 Elsevier B.V. All rights reserved.