Production of hydrogen and hydrogen-rich syngas during thermal catalytic supported cracking of waste tyres in a bench-scale fixed bed reactor

There is much interest in producing hydrogen (H-2) and hydrogen carriers from various materials, including rubbery wastes to help in the fulfilment of the predicted H-2 economy. In this paper, simple and catalytic pyrolysis have been investigated for their suitability in producing gaseous fuels from waste tyres. Dihydrogen, alkane and alkene fuels production from tire wastes was carried out in a laboratory bench installation using a fixed bed reaction system at 500 degrees C and with a catalyst/waste ratio of 0.03. This last ratio is very low, which constitutes an interesting payoff in the plant costs. Investigations to valorise the three yielded by-products involved different combinations of four catalysts, three solid supports and three configurations of bed position. The results presented in this study concerned the gaseous phase, the yields of which varied from 17 to 32 wt%. The potential of H-2 production was significantly increased from 14 to 32 vol% by using MgO-based catalytic bed supported by a layer of oyster shells. It was also found that the low heating value of the pyrolytic gas was ameliorated from 10 to 44 MJ/Nm(3). The yield of H2S is focused on as it might increase the plant costs due to its relative post-treatment units. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.