Design and simulation of methanol synthesis using heavy residues with carbon utilization

Global carbon emissions are continuously increasing, clean and sustainable technologies are needed to utilize fossil fuels. Methanol is a clean fuel that can enable a smooth transition between fossil fuels and renewables. This work explored the production of methanol through two different fossil fuels, i.e., natural gas (case I) and vacuum residue (case II). Aspen Plus has been utilized to simulate the two processes for the methanol production capacity of 90 t/h with 99.9 wt. % purity. The two methanol production processes are compared in terms of energy, environmental and economic factors. The important reactive sections of the two processes are validated with the design data to ascertain the accuracy of the results. The results show that case II has a process efficiency of 49.5 % which is 1.6 % higher compared to the case I. From an economics point of view, case II design can produce methanol at a unit cost of $317/t CH₃OH, which is 14% less than the case I design. As a result of the environmental analysis, the case I design releases fewer carbon emissions than case II. Despite this, the case II design offers CO₂ captured with high purity that can be used for another application which can further reduce the production cost of methanol.