Simulation on hydrogen production from Mae-Moh lignite coal gasification

Hydrogen energy has attracted significant attention due to its cleanliness, efficiency, and sustainability. Gasification is considered one of the most promising thermochemical routes to convert coal into high-quality syngas, which can subsequently be utilized for hydrogen production. Mae-Moh lignite, a low-rank coal with low carbon content and high moisture and volatile matter, is selected as the feedstock for this study. This research aims to develop a comprehensive simulation model of a hydrogen production process, integrating gasification, water-gas shift (WGS), acid gas removal, and hydrogen purification using the software simulator. The model predicts hydrogen product gas composition from Mae-Moh lignite under varying operating conditions. Validation of the model is performed using the published experimental and simulation results. Sensitivity analyses are conducted to investigate the influence of the key operating parameters, including temperature, pressure, steam-to-coal ratio, oxygen-to-coal ratio, water-to-CO ratio, liquid-to-gas ratio, and MEA concentration. The product gas at each stage is evaluated using response parameters such as hydrogen purity, syngas composition, heat generation, methane formation, CO conversion, acid gas removal efficiency, and hydrogen recovery. The combined effects of these operating parameters are systematically analyzed, and the optimal conditions are determined to achieve target performance metrics. The optimized operational parameters are found to be: gasification pressure of 0.1 MPa, gasification temperature of 900 °C, steam-to-coal ratio of 0.5 kg/kg and oxygen-to-coal ratio of 0.3 kg/kg. The optimal water-gas shift conditions are 400 °C and a water-to-CO ratio of 2.5 kg/kg. For acid gas removal, the optimum conditions are a liquid-to-gas ratio of 16 kg/kg, MEA concentration of 27.5 wt%, and sour gas temperature of 40 °C. Under these conditions, the post-purification hydrogen product achieved a purity of 99.994% with a hydrogen recovery of 87.99%, resulting in an overall hydrogen yield of 0.049 kg H₂/kg coal. The findings provide a reliable simulation framework for hydrogen production from low-rank lignite coal and offer valuable insights for future development projects targeting sustainable hydrogen production from coal resources like Mae- Moh mine in Thailand while supporting the nation’s transition toward a low-carbon economy and energy security.