(422f) Thermodynamic and Economic Analysis of the Coal-to-Methanol Conversion Process System

Coal-to-methanol conversion through gasification has emerged as a crucial pathway for facilitating energy structure transformation. In this study, a process-wide simulation model for the coal-to-methanol process was developed using the Aspen Plus platform. Based on the simulation results, a thermodynamic evaluation of the model was conducted, and the impact of gasification conditions, particularly gasifier pressure, on methanol production was systematically investigated. To address the limitations of existing economic evaluation methods, a novel economic assessment framework based on the levelized cost of methanol (LCOM) was established. This study not only provides a theoretical foundation for optimizing coal-to-methanol processes but also establishes an economic evaluation standard for industrial applications. The results indicate that the total exergy efficiency of the system is 38.54%, with the gasifier exhibiting the highest exergy loss, accounting for 57.2% of the total exergy loss in the gasification unit. When the gasifier pressure is held constant, methanol production exhibits a positive correlation with the steam-to-oxygen mass ratio, reaching its maximum value at a ratio of 2.0, beyond which production gradually declines. Economic analysis reveals that the levelized cost of methanol is 666.23$/t, with fixed maintenance and operational costs representing the largest proportion of expenses. Furthermore, the study demonstrated that the project can achieve a positive return by the eighth year when the methanol price is 450$/t, providing valuable insights for market competitiveness assessment and investment decision-making.