Biomass combustion with in situ CO2 capture by CaO in a 300 kWth circulating fluidized bed facility
This paper reports experimental results from a new 300 kWth calcium looping pilot plant designed to capture CO2 “in situ” during the combustion of biomass in a fluidized bed. This novel concept relies on the high reactivity of biomass as a fuel, which allows for effective combustion around 700 °C in...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/107919 |
| Acceso en línea: | http://hdl.handle.net/10261/107919 |
| Access Level: | acceso abierto |
| Palabra clave: | Biomass combustion CO2 capture Negative emissions Calcium looping BECCS |
| Sumario: | This paper reports experimental results from a new 300 kWth calcium looping pilot plant designed to capture CO2 “in situ” during the combustion of biomass in a fluidized bed. This novel concept relies on the high reactivity of biomass as a fuel, which allows for effective combustion around 700 °C in air at atmospheric pressure. In these conditions, CaO particles fed into the fluidized bed combustor react with the CO2 generated during biomass combustion, allowing for an effective CO2 capture. A subsequent step of regeneration of CaCO3 in an oxy-fired calciner is also needed to release a concentrated stream of CO2. This regeneration step is assumed to be integrated in a large scale oxyfired power plant and/or a larger scale post-combustion calcium looping system. The combustor-carbonator is the key reactor in this novel concept, and this work presents experimental results from a 300 kWth pilot to test such a reactor. The pilot involves two 12 m height interconnected circulating fluidized bed reactors. Several series of experiments to investigate the combustor-carbonator reactor have been carried out achieving combustion efficiencies close to 100% and CO2 capture efficiencies between 70 and 95% in dynamic and stationary state conditions, using wood pellets as a fuel. Different superficial gas velocities, excess air ratios above stoichiometric requirements, and solid circulating rates between combustor-carbonator and combustor-calciner have been tested during the experiments. Closure of the carbon and oxygen balances during the combustion and carbonation trials has been successful. A simple reactor model for combustion and CO2 capture in the combustor-carbonator has been applied to aid in the interpretation of results, which should facilitate the future scaling up of this process concept. |
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