Change of existing circulating fluidized bed boilers to oxy-firing conditions for CO2 capture

This work investigates a circulating fluidized bed boiler, originally designed for air-firing, retrofitted to oxy-firing with the purpose of removing the CO2 emission from coal combustion. Previous studies have shown that the heat balance on the gas-particle side can be satisfied without changes in...

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Detalles Bibliográficos
Autores: Leckner, Bo, Gómez Barea, Alberto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/135076
Acceso en línea:https://hdl.handle.net/11441/135076
https://doi.org/10.1016/j.jaecs.2021.100042
Access Level:acceso abierto
Palabra clave:Oxy-combustion
Circulating fluidized bed
Boiler
Coal
CO2 reduction
Carbon capture
Descripción
Sumario:This work investigates a circulating fluidized bed boiler, originally designed for air-firing, retrofitted to oxy-firing with the purpose of removing the CO2 emission from coal combustion. Previous studies have shown that the heat balance on the gas-particle side can be satisfied without changes in the boiler, but then the volume flow of gas is reduced. To retain the operation like that during air-firing, the volume flow, that is the fluidization velocity, in oxy-firing should be equal to that in air-firing. It is the main purpose of this work to determine the conditions for the transition from air to oxy-firing, while the heat transfer conditions are maintained at a constant fluidization velocity. Measures to achieve this, such as adjusting the supply of additional gas and the heat transfer surface, are analysed. The fulfilment of the furnace's heat balance requires extra fuel or reduction of the heat-transfer surface in the furnace. These changes affect the performance of the back pass, which must be modified to accommodate the change in gas composition and the higher sensible heat content of the flue gas. Strategies to deal with these circumstances in CFB boilers are discussed.