Techno-economic evaluation of methanol production via gasification of vacuum residue and conventional reforming routes

Abstract

The continuous rise of global carbon emissions demands the utilization of fossil fuels in a cleaner and sustainable way. Gasification is a potential technology that can convert the dirty fossil fuels for the production of clean and environment friendly fuels in an economical manner. In this study, vacuum residue is employed as a feedstock to produce high grade methanol. A vacuum residue to methanol (VRTM) process is simulated using Aspen Plus for a methanol production capacity of 90 t/h with 99.9 wt.% purity. The developed VRTM process is bench-marked with the conventional steam reforming to methanol (SRTM) process through energy, environmental and economic analysis. The performance of vacuum residue gasifier, natural gas reformer and the methanol synthesis reactor are validated against the plant data and the simulation results are found to be in good agreement. The results showed that the VRTM process offers a process energy efficiency of 49.5% which is 1.6% higher than the SRTM process. The unit cost of methanol product from the VRTM process is $ 317/tCH3OH which is 14% lower compared to the SRTM process. In terms of environmental analysis, SRTM process emits less carbon emissions than the VRTM process. However, the VRTM process offers a high purity captured CO2 stream that can be utilized for another application that can further offset the methanol production cost.