Evaluation of different cooling technologies for industrial methanol synthesis reactor in terms of energy efficiency and methanol yield: An economic-optimization

Abstract

In recent years, increasing demand for methanol, as a clean alternative to fossil fuels, necessitates analyzing the methanol synthesis reactor in terms of econometrics, methanol production, and energy efficiency. So, the aim of this work was to compare three kinds of industrial methanol synthesis reactor based on implemented cooling technologies, namely direct-cooling reactor (DCR), quench-cooling reactor (QCR), and indirect-cooling reactor (ICR) under the same feed-flow rate and catalyst weight. The performance of these reactors was evaluated in terms of energy efficiency and methanol yield under optimal conditions obtained through an economic-optimization. To identify decision variables for optimization procedure, a one-dimensional heterogeneous model was established to investigate the impact of different variables on the methanol yield. The results show that the DCR had the most profit value (i.e., 249,697 US$/day) and the highest methanol yield (i.e., 0.455) compared to other reactors. In addition, although no excess energy was required to provide products in all configurations due to the arrangement of equipment suggested for these processes, boiling-water was used to cool the catalyst-bed of DCR. In general, these configurations could be sorted from the most desirable one to the least in the following order: DCR > 5-bed ICR > 5-bed QCR.