The current climatic situation requires the implementation of important changes already in the short term: the capture of carbon dioxide and the use of hydrogen are considered among the main solutions. Hydrogen, thanks to the possibility of storing energy, especially from renewable sources, is the basis of the main national and international development plans, while Carbon Capture and Utilization approaches are increasingly at the center of research to optimize the already numerous solutions available and to limit the damage of this pollutant to the environment. The present work, therefore, after an analysis of the current technological solutions for CO2 capture, has focused on the analysis of a cogeneration plant fed by methane in dynamic regime, foreseeing the capture of carbon dioxide from the engine exhaust gases in order to be able to use it later in one of the Power-to-gas solutions: the methanation process with green hydrogen produced through electrolysis and electricity obtained from a photovoltaic field. Using the TRNSYS software, the main components of the system were modeled (eg cogenerator, photovoltaic system, electrolyser) thus allowing an hourly analysis of the hypothesized configuration to be carried out; in particular, for a 20 kWe cogenerator at the service of a small company, the capture of different percentages of CO2 from the exhaust gases and the subsequent reuse in a methanation process with green hydrogen produced by the excess electricity of the photovoltaic field was simulated. The simulations carried out have shown the significant advantage in terms of both CO2 emissions avoided and economic benefits obtained by exploiting the potential of all the cogeneration plant components, while a blind adoption of carbon capture and methanation is difficult to implement due to the too large amount of green solar energy required. This case study shows the need to optimize some of the components needs (e.g. the electricity requests for the electrolysis process) by identifying alternative solutions, such as the use of hydromethane, to cope with the pollution problem.
Carbon Capture and Power-to-gas: a dynamic analysis of the use of hydrogen in a cogeneration plant
M Costa;F S Marra;M V Prati
2022
Abstract
The current climatic situation requires the implementation of important changes already in the short term: the capture of carbon dioxide and the use of hydrogen are considered among the main solutions. Hydrogen, thanks to the possibility of storing energy, especially from renewable sources, is the basis of the main national and international development plans, while Carbon Capture and Utilization approaches are increasingly at the center of research to optimize the already numerous solutions available and to limit the damage of this pollutant to the environment. The present work, therefore, after an analysis of the current technological solutions for CO2 capture, has focused on the analysis of a cogeneration plant fed by methane in dynamic regime, foreseeing the capture of carbon dioxide from the engine exhaust gases in order to be able to use it later in one of the Power-to-gas solutions: the methanation process with green hydrogen produced through electrolysis and electricity obtained from a photovoltaic field. Using the TRNSYS software, the main components of the system were modeled (eg cogenerator, photovoltaic system, electrolyser) thus allowing an hourly analysis of the hypothesized configuration to be carried out; in particular, for a 20 kWe cogenerator at the service of a small company, the capture of different percentages of CO2 from the exhaust gases and the subsequent reuse in a methanation process with green hydrogen produced by the excess electricity of the photovoltaic field was simulated. The simulations carried out have shown the significant advantage in terms of both CO2 emissions avoided and economic benefits obtained by exploiting the potential of all the cogeneration plant components, while a blind adoption of carbon capture and methanation is difficult to implement due to the too large amount of green solar energy required. This case study shows the need to optimize some of the components needs (e.g. the electricity requests for the electrolysis process) by identifying alternative solutions, such as the use of hydromethane, to cope with the pollution problem.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
