Methanol is a clean fuel and an important feedstock for the petrochemical industry. Conventionally, the coal-to-methanol process generates a substantial amount of CO₂ emissions with a low yield of methanol. In this study, we propose the conceptual design development of coal-to-methanol process using captured CO₂ from the gasification plant by implying process intensification. The base case and three alternative designs have been developed using the Aspen Plus to analyze the process performance. The four designs have been compared in terms of their energy consumption, economics, methanol production rate, and carbon emissions while maintaining the gasifier operation conditions, sulfur content in the syngas, and stoichiometric number at the methanol synthesis reactor. Among the developed designs, the most feasible design requires an energy requirement and product cost of 21.9 GJ and $142.5 per ton of methanol product. The study also showed that the coal-to-methanol process assisted with external hydrogen from electrolysis plant for achieving higher production rates and low CO₂ emissions is currently not economical due to the high H₂ cost.

The continuous rise of global carbon emissions demands the utilization of fossil fuels in a sustainable way. Owing to various forms of emissions, our environment conditions might be affected, necessitating more focus of scientists and researchers to upgrade oil processing to more efficient manner. Gasification is a potential technology that can convert fossil fuels to produce clean and environmentally friendly hydrogen fuel in an economical manner. Therefore, this study analyzed and examined it critically. In this study, two different routes for the produc-tion of high-purity hydrogen from vacuum residue while minimizing the carbon emissions were proposed. The first route (Case I) studied the gasification of heavy vacuum residue (VR) in series with dry methane reforming (DMR). The second route studied the gasification of VR in parallel integration with DMR (Case II). After investigating both processes, a brief comparison was made between the two routes of hydrogen production in terms of their CO₂ emissions, en-ergy efficiency, energy consumption, and environmental and economic impacts. In this study, the two vacuum-residue-to-hydrogen (VRTH) processes were simulated using Aspen Plus for a hydrogen production capacity of 50 t/h with 99.9 wt.% purity. The results showed that Case II offered a process energy efficiency of 57.8%, which was slightly higher than that of Case I. The unit cost of the hydrogen product for Case II was USD 15.95 per metric ton of hydrogen, which was almost 9% lower than that of Case I. In terms of the environmental analysis, both cases had comparably low carbon emissions of around 8.3 kg of CO₂/kg of hydrogen produced; with such high purity, the hydrogen could be used for production of other products further downstream or for industrial applications.