Efficient recycling and conversion of CO2 to methanol: Process design and environmental assessment

Abstract

Carbon capture and carbon reuse in the chemical plants is one of the attractive prospective approaches to decrease the concerns about global warming and climate change. In the present study, is focused on the synthesis gas production from carbon dioxide in a methanol synthesis plant. In this regard, two methanol processes are proposed based on CO2 separation, recycling, and reforming. In the first scenario, CO2 is separated and recycled to the conventional reformer, while the process is equipped by a CO2 separation unit and dry methane reformer in the second scenario. The proposed processes are simulated and a sensitivity analysis is performed to investigated the effect of inputs on methanol productivity and carbon conversion. The operational parameters of proposed processes are optimized to enhance methanol productivity and CO2 conversion. Then, the processes are compared from energy efficiency, carbon efficiency, CO2 emission rate and methanol productivity viewpoints. The results showed that, in the second proposed scenario, methanol production rate approach to 5367 tons per day in comparison to 5030 tons per day for industrial unit. In addition, modification of conventional methanol process based on the second scenario could decrease CO2 emission rate about 56 tons per day.