Analysis of a double calcium loop process configuration for CO<inf>2</inf> capture in cement plants
This work analyses a novel calcium looping process for cement plants, based on a reactor configuration that uses a double calcium chemical loop for CO2 capture and the calcination of CaCO3. This novel scheme employs a number of state-of-the-art cyclonic preheaters, where the solids exiting the carbo...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/345584 |
| Acceso en línea: | http://hdl.handle.net/10261/345584 https://api.elsevier.com/content/abstract/scopus_id/84959286264 |
| Access Level: | acceso abierto |
| Palabra clave: | Post-combustion capture Calcium looping Cement Circulating fluidized bed combustors http://metadata.un.org/sdg/7 http://metadata.un.org/sdg/9 Ensure access to affordable, reliable, sustainable and modern energy for all Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Sumario: | This work analyses a novel calcium looping process for cement plants, based on a reactor configuration that uses a double calcium chemical loop for CO2 capture and the calcination of CaCO3. This novel scheme employs a number of state-of-the-art cyclonic preheaters, where the solids exiting the carbonator reactor are overheated by being brought into direct contact with high-temperature gas streams before they enter the calciner. This reduces the energy demand in the calciner, which is fed by solids from a second calcium solid loop where solids are overheated by an external air-fired combustor, thereby transferring the heat required for CaCO3 calcination and avoiding the need for oxy-fired combustion. Two different process schemes, with different ranges of capture efficiency and complexity, emerge when considering the option of feeding the flue gases from the new air-fired combustor to the carbonator. The results of the energy and mass balances performed on the proposed schemes reveal that as much as 94% of the total amount of CO2 generated can be captured (equivalent to 92% CO2 avoided) with an increase in the overall process heat demand of just 1.1 GJth/tcement. Moreover, this value could be as low as 0.3 GJth/tcement if a second configuration is used to capture only the CO2 derived from the calcination of the CaCO3 in the raw meal of the cement plant, resulting in a CO2 capture efficiency of 58%. A preliminary economic analysis of both configurations indicates that the cost of cement increases from 74 $/tcement typical of a reference cement plant to 106 and 85 $/tcement, respectively, while the calculated avoided costs are of the order of 42 and 27 $/tCO2 avoided, respectively. The results obtained show that the configurations proposed could be feasible and competitive within certain operating windows that are discussed in this work. |
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