A progress insight of the formation of hydrogen rich syngas from coal gasification

This review paper aims to explore the research progress in the formation of hydrogen rich gas from different innovative coal gasification parameters. Promotion effects of parameters such as pressure, temperature, catalyst, coal type, reactor setup, and gasification agents (H 2 O, O 2 , supercritical water) were extensively analysed. The formation of hydrogen gas through coal gasification was sub-divided into H 2 production from fixed bed gasification system, fluidised bed system, and entrained flow system. The advantages of coal and biomass co-gasification towards clean energy formation was also reviewed. Co-gasification and Elevated temperatures, pressures, and steam-carbon ratios were reported to positively influence the yields of H 2 gas by facilitating steam reforming and water gas shift reactions. The presence of different catalyst and sorbents in the gasification reaction systems was also noticed to enhance the concentration of hydrogen in the gaseous products. Production of hydrogen rich syngas from fixed bed and fluidized bed gasifiers was assessed, and both methods were found to favour the formation of hydrogen gas. The polygeneration of hydrogen gas, electricity and carbon dioxide capture was discovered to be feasible via coal gasification techniques. • Higher temperatures, pressures, and steam-carbon ratio were reported to enhance the yields of H 2 gas. • Presence of Na, K, Ca, and Fe derived catalysts favoured H 2 gas production reactions. • The use of sorbents like CaO have facilitated the yields of hydrogen gas. • Co-gasification of coal with biomass has a positive influence on hydrogen gas formation. • Both fluidised bed and fixed bed reactors were efficient in producing hydrogen gas. • Lower CO 2 gas emission.