Low temperature chemical looping combustion of pyrolysis gases in a fixed bed reactor

This study presents an experimental investigation into the feasibility of oxidizing biomass pyrolysis gases at relatively low temperatures using a chemical looping combustion (CLC) approach. The application of this alternative method would enable the capture of carbon from the pyrolysis gas stream,...

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Detalhes bibliográficos
Autores: Gracia Monforte, César, Maldonado-Martín, Francisco, Atienza Martínez, María, Ábrego, Javier
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Recursos:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/54312
Acesso em linha:https://hdl.handle.net/2454/54312
Access Level:acceso abierto
Palavra-chave:Advanced combustion
Carbon capture
Chemical looping combustion (CLC)
Oxygen carrier (OC)
Pyrolysis gas
Descrição
Resumo:This study presents an experimental investigation into the feasibility of oxidizing biomass pyrolysis gases at relatively low temperatures using a chemical looping combustion (CLC) approach. The application of this alternative method would enable the capture of carbon from the pyrolysis gas stream, which is currently released into the atmosphere in most pyrolysis systems, as high-purity CO2. In a fixed bed reactor, the reduction behavior of three different Cu-based oxygen carriers (OC) - pure CuO pellets, carulite and Al2O3-supported CuO - was evaluated to determine whether pyrolysis gases could be completely oxidized to CO2 and H2O within a temperature range of 600–650 ◦C and at weight hourly space velocities (WHSV) of 0.06–0.10 h− 1 . Both CuO and carulite exhibited significant amounts of unconverted pyrolysis gases even during the initial stages of the reduction experiments. In contrast, Al2O3-supported CuO emerged as the most effective material, facilitating the complete oxidation of pyrolysis gases over extended reaction times. For this oxygen carrier, a decline in the combustion efficiency was only observed at very high (90 %) reduction conversions. Reduction/oxidation cycles for this most promising material were successfully demonstrated, with the oxygen carrier showing no signs of activity loss after 10 cycles. However, carbon deposition was detected under several experimental conditions, which could potentially reduce the carbon capture efficiency of the process.