Generación de energía y captura de CO2 en plantas térmicas con incorporación de celdas de combustible.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
En el presente informe se estudia la integración de celdas de combustible de carbonato fundido en plantas termoeléctricas, con el objetivo de evaluar su impacto en la eficiencia global del sistema y su potencial en la mitigación de gases de efecto invernadero, particularmente el dióxido de carbono. Se analiza el efecto de diversos parámetros técnicos involucrados en la integración, tales como factores de utilización, condiciones de operación, tipo de combustible de alimentación y su sinergia con tecnologías de captura de carbono. Asimismo, se identifican las principales causas que limitan la vida útil de las celdas en la actualidad.
Como alternativa para la modernización de plantas existentes, se propone la instalación de una celda de carbonato fundido a la salida del generador de vapor de recuperación en un ciclo combinado. Adicionalmente, se incorpora una cámara de combustión alimentada con oxígeno puro, con el objetivo de obtener una corriente de gases a la salida de la planta compuesta principalmente por vapor de agua y dióxido de carbono, facilitando así el almacenamiento de carbono. Esta configuración permite una captura de carbono del 79.2%, sin modificar el ciclo térmico original. Además, resultados muestran una reducción de aproximadamente 5 puntos porcentuales en la eficiencia neta respecto al caso base y un consumo de energía para la captura de carbono de 2.1 MJ/ kg de 𝐶𝑂2 capturado. Estos resultados evidencian una competitividad energética superior frente a tecnologías de captura convencionales, las cuales presentan mayores penalizaciones en la eficiencia total de la planta.
Finalmente, se llevó a cabo una evaluación económica mediante un enfoque bottom-up para estimar el costo de la electricidad (COE) y el costo de carbono evitado (CCA). La solución propuesta obtuvo como resultados un COE de 63.56 $/MWh y un CCA de 81.59 $/Tonelada de 𝐶𝑂2, posicionando a la celda MCFC como una alternativa tecnológicamente viable y económicamente atractiva, sujeta a mejoras en su grado de madurez y confiabilidad operacional.
This report examines the integration of molten carbonate fuel cells (MCFC) in thermal power plants, with the objective of assessing their impact on overall system efficiency and their potential in mitigating greenhouse gas emissions, particularly carbon dioxide. The analysis considers the effect of various technical parameters involved in integration, such as utilization factors, operating conditions, type of feed fuel, and its synergy with carbon capture technologies. Additionally, the main factors currently limiting the service life of these cells are identified. As an alternative for the modernization of existing plants, the installation of a molten carbonate fuel cell at the outlet of the heat recovery steam generator in a combined cycle is proposed. Furthermore, an oxygen-fired combustion chamber is integrated to achieve an exhaust gas stream mainly composed of water vapor and carbon dioxide, thereby facilitating carbon storage. This configuration enables a carbon capture rate of 79.2% without modifying the original thermal cycle. Moreover, the results indicate a reduction of approximately 5 percentage points in net efficiency compared to the base case and an energy consumption for carbon capture of 2.1 MJ/kg of captured 𝐶𝑂2. These results demonstrate superior energy competitiveness compared to conventional capture technologies, which typically impose greater penalties on overall plant efficiency. Finally, an economic evaluation was carried out using a bottom-up approach to estimate the cost of electricity (COE) and the cost of carbon avoided (CCA). The proposed solution yielded a COE of $63.56/MWh and a CCA of $81.59 per ton of 𝐶𝑂2, positioning the MCFC as a technologically feasible and economically attractive alternative, provided improvements in its maturity and operational reliability are achieved.
This report examines the integration of molten carbonate fuel cells (MCFC) in thermal power plants, with the objective of assessing their impact on overall system efficiency and their potential in mitigating greenhouse gas emissions, particularly carbon dioxide. The analysis considers the effect of various technical parameters involved in integration, such as utilization factors, operating conditions, type of feed fuel, and its synergy with carbon capture technologies. Additionally, the main factors currently limiting the service life of these cells are identified. As an alternative for the modernization of existing plants, the installation of a molten carbonate fuel cell at the outlet of the heat recovery steam generator in a combined cycle is proposed. Furthermore, an oxygen-fired combustion chamber is integrated to achieve an exhaust gas stream mainly composed of water vapor and carbon dioxide, thereby facilitating carbon storage. This configuration enables a carbon capture rate of 79.2% without modifying the original thermal cycle. Moreover, the results indicate a reduction of approximately 5 percentage points in net efficiency compared to the base case and an energy consumption for carbon capture of 2.1 MJ/kg of captured 𝐶𝑂2. These results demonstrate superior energy competitiveness compared to conventional capture technologies, which typically impose greater penalties on overall plant efficiency. Finally, an economic evaluation was carried out using a bottom-up approach to estimate the cost of electricity (COE) and the cost of carbon avoided (CCA). The proposed solution yielded a COE of $63.56/MWh and a CCA of $81.59 per ton of 𝐶𝑂2, positioning the MCFC as a technologically feasible and economically attractive alternative, provided improvements in its maturity and operational reliability are achieved.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Mecánico/a.
Keywords
Energía eléctrica, Termoelectricidad, Combustibles Investigaciones, Efecto invernadero