(339a) Cost-Effective Methanol Production from Vacuum Residue Gasification

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 dirty fossil fuels into clean and environmentally friendly fuels in an economical manner. In this study, vacuum residue, a heavy fraction of crude oil, 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 benchmarked with the conventional steam reforming to methanol (SRTM) process through energy, environmental, and economic analysis. The performance of the vacuum residue gasifier, natural gas reformer, and methanol synthesis reactor is validated against plant data, and the simulation results are found to be in good agreement. 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. Moreover, the VRTM process provides a viable option to utilize vacuum residue, which is a low-value residue, as a feedstock for the production of high-grade methanol, contributing to the reduction of waste and increasing resource utilization.

Furthermore, the study assesses the potential impact of varying process parameters such as gasification temperature, pressure, and oxygen/fuel ratio on the performance of the VRTM process. The results indicate that increasing the gasification temperature and oxygen/fuel ratio can improve the process efficiency and reduce the carbon emissions. This finding highlights the potential for further optimization of the VRTM process to achieve even better environmental and economic performance.