Decarbonizaing Coal-Based Methanol Production: Energy and Environmental Assessment of a Novel Strategy Integrating with Co2 Utilization

Abstract

The chemical sector is a major contributor to climate change, and methanol production accounts for a considerable portion of these emissions. The production process, which relies on fossil fuels, generates substantial CO2, leading to initiatives aimed at cleaner and more sustainable alternatives. To improve the energy efficiency and reduce CO2 emission, a novel methanol production process was proposed by integrating indirect CO2 hydrogenation with coal-based methanol production. In this study, the energetic and environmental performance of the novel methanol production process was investigated and compared with traditional coal-to-methanol and direct CO2 hydrogenation to methanol process. Results showed that the proposed process has the highest energy efficiency of 57.38% compared with coal-to-methanol and direct CO2 hydrogenation to methanol. Additionally, a carbon conversion ratio of 95.68% and coal saving ratio of 27.38% can be achieved by combining CO2 utilization and hydrogen production from renewable electricity. Life cycle assessment was employed to evaluate the environmental impacts of three processes and the proposed process has the best performance. The GWP of the proposed process is 1.30 kg CO2. eq / kg methanol, which is lower than the other two reference processes. A multi-scenario analysis finds that the improvement of methanol production with a lower carbon footprint has a large dependence on green hydrogen, which plays a critical role in reducing the reliance on fossil fuels and achieving sustainable CO2 utilization.

Keywords: coal-based methanol production, indirect CO2 hydrogenation, Life cycle assessment, carbon footprint of methanol