CO2 recycling plant for decarbonizing hard-to-abate industries: empirical modelling and process design of a CCU plant- a case study

Abstract

Climate change, driven by increasing CO2 emissions, necessitates innovative mitigation strategies, particularly for hard-to-abate industries. Carbon Capture and Utilization technologies offer promising solutions by capturing CO2 from industrial flue gases and converting it into value-added products. Among capture methods, membrane separation stands out for its compact design, energy efficiency, and scalability. Following capture, CO2 can be converted into chemicals like formic acid using electrocatalytic processes, enabling energy storage from renewable sources. This study proposes the design of an industrial demonstrator for a CO2 recycling plant targeting hard-to-abate sectors such as textile and cement industries. The system integrates polymeric membranes for CO2 capture and a 100 cm² electrochemical reactor for CO2 electroreduction into formic acid. Experimental data from both stages are used to develop predictive models based on artificial neural networks (ANN), optimizing system performance. Case studies reveal that CO2 concentration at the capture inlet significantly impacts plant design. For a textile plant with 3.5% CO2 emissions, a four-stage membrane system is required, resulting in higher CAPEX and OPEX. Conversely, a cement plant with 12% CO2 emissions requires only two stages to achieve the target CO2 concentration of >75 %, reducing costs by over 60%. Sensitivity analysis highlights the critical role of inlet CO2 concentration on the membrane area and system stages. The findings underscore the feasibility of modular membrane systems tailored to emission characteristics, paving the way for sustainable CO2 recycling processes adaptable to various industries. This integrated approach offers a pathway to mitigate emissions while generating valuable chemical products.