Process Alternatives for the Co-Production of Hydrogen and Methanol using Fuel Switch and Energy Mix Systems

With the increase in the global energy requirements, the utilization of fossil fuels have been also increased which not only increased greenhouse gas (GHG) emissions but also caused global warming. The sharp reduction in the GHG emissions demands for utilizing the energy mix and fuel switch technologies to develop the cleaner fuels. In this study, process simulation framework has been proposed to simultaneously produce two fuels (methanol and H₂₎ in the co-generation process integration framework. Two process models have been developed in Aspen Plus ® V12 followed by the techno-economic assessment to analyze the process feasibility. Case 1 is considered as the base case process, where the process initiates with the coal-biomass gasification to produce the synthesis gas. The synthesis gas is then treated in the acid gas removal units to remove the CO₂ and H₂S. The synthesis gas is then fed to the methanol synthesis unit to produce methanol, whereas, the unconverted CO is treated in the water-gas shift (WGS) reactors to convert CO into the H₂ and CO₂ followed by CO₂ removal in the AGR section. Case 2 design represents the novel process for co-production of methanol and H₂, where the coal- biomass gasification technology is sequentially integrated with the methane reforming technology to maximize the heat utilization without any energy penalties. Both the models are techno-economically compared in terms of methanol and H₂ production rates, specific energy requirements, carbon conversion, CO₂ specific emissions, overall process efficiencies, fuel production costs and project feasibilities. The results showed that the case 2 design offers higher methanol and H₂ production rates with the low energy requirements. Also, the process efficiency of case 2 is 3.8% higher than the case 1 design, where, the specific energy requirements of case 2 is almost 16% less compared to the case 1 design. While performing some sensitivity studies, it has been analyzed that the case 2 process offers better process feasibility in terms of process performance and economics.