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Updated: May 9, 2025
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Published on: August 17, 2016
Consecutive coproduction of H2 and syngas from waste polyolefins derived pyrolysis gas via chemical looping
Jijiang Huang1, Andrei Veksha2, Grzegorz Lisak3
1State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China.
Abstract:
Upcycling waste plastics into H2 and syngas offers a sustainable strategy for mitigating their accumulation and addressing the global issue of plastic pollution. The deposition of coke during thermocatalytic reforming processes poses a significant challenge for efficient conversion. Here we report the consecutive coproduction of high-concentration H2 (up to 80.5 vol%) and hydrocarbon-free syngas with tunable H2/CO ratios of 1.1-4.8 via a stepwise chemical looping cracking-gasification (CLCG) process over equimolar NiFeAl catalyst. Optimal gas yields of 0.26 mol gcata-1 and 0.52 mol gcata-1 per redox cycle for H2 and syngas are obtained from the cracking and gasification reaction stages, respectively. The CLCG process is investigated at a reaction temperature range of 700-900 °C which significantly impacts the H2/syngas coproduction due to the promoted catalyst reduction and segregation of Ni and Fe phases. Furthermore, quantitative analysis of the metal distribution in the reduced NiFeAl catalysts by energy-dispersive X-ray spectroscopy reveals that the reaction temperature is essential in tuning the catalyst structure and performance. This work demonstrates the viable coproduction of separate H2 and syngas streams via the CLCG process which is promising for the circular management of waste plastics.
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