Mass and energy flows of a new process for CO₂ capture from flue gas using ionic liquids and catalytic hydrogenation to produce methanol in a 400 MW natural gas power station

CO₂ emissions from the combustion of fossil fuels contribute to global warming. Industrial processes that recycle CO₂ would decrease the demand for fossil carbon resources and consequently reduce new CO₂ emissions. This article describes and evaluates the mass and energy flows of a new process that can be used to capture CO₂ and produce renewable methanol in a large power station. The process includes CO₂ capture on novel ionic liquids, desorption and compression of CO₂, a catalytic process to hydrogenate CO₂ under mild conditions of temperature and pressure and distillation steps to obtain the final product. Values obtained at the laboratory scale or from literature sources were used in Aspen Plus and spreadsheet models to predict the mass and energy flows at the industrial scale. Excluding the supply of hydrogen, we estimate the heat and electricity demand of the new process if it were installed in a 400 MW electric power station. The calorific value of the methanol product is compared to the calorific value of the natural gas consumed by the power station. The process has the potential for wide application to exploit CO₂ streams in industry and in polluted urban environments.