The development of renewable energy makes it possible to produce abundant hydrogen as the energy carrier. For reducing the hydrogen storage and transportation cost, methanol synthesis via reverse water gas shift (RWGS) reaction can provide significant environmental benefits through a carbon capture and utilization pathway. There have been researches in the past to determine the most effective catalysts and related technologies in process development. However, a remaining question has been whether it should be run at a temperature above 900 °C where problematic by-products and coke might be an issue, or below 500 °C where it is not kinetically favored, but heavy catalyst use could compensate.

This paper investigated the tradeoff between running the RWGS process at the higher or the lower temperature range as part of a methanol (MeOH) production plant. The plant had a basis of 80 kmol/hour of methanol product. A process flowsheet for each route was developed and optimized using ASPEN Plus as well as heat integration methods. The carbon footprint was then calculated to assess the environmental performances of both processes. Finally, an economic analysis was conducted to assess the overall feasibility for implementing either process.

It was found that while running the process at a lower temperature of 450 °C requires a lower energy consumption, however it comes with a higher cost due to the heavy reliance on the catalytic reaction. The higher temperature reaction running at 940 °C performed similarly to the lower temperature reaction but with a better environmental performance and lower cost of production. Moreover, using a higher production capacity for the plant proved a higher promise of eliminating economic issues due to economies of scale.

可再生能源的发展使得可以生产丰富的氢作为能量载体。为了降低氢气的存储和运输成本，通过逆水煤气变换（RWGS）反应合成甲醇可以通过碳捕获和利用途径提供重大的环境效益。过去已经进行了研究以确定工艺开发中最有效的催化剂和相关技术。但是，还有一个问题是，是否应在可能会产生问题的副产物和焦炭的900℃以上的温度下运行，还是在动力学上不希望使用但可以大量使用催化剂的情况下，在低于500℃的温度下运行。

本文研究了在较高或较低温度范围内运行RWGS工艺作为甲醇（MeOH）生产厂的一部分之间的权衡。该工厂的甲醇产品基准为80 kmol /小时。使用ASPEN Plus以及热集成方法，开发并优化了每种路线的工艺流程图。然后计算碳足迹，以评估两个过程的环境绩效。最后，进行了经济分析，以评估实施任一流程的总体可行性。

已经发现，在450℃的较低温度下运行该方法需要较低的能量消耗，但是由于严重依赖于催化反应，因此具有较高的成本。在940℃下进行的高温反应与低温反应相似，但是具有更好的环境性能和较低的生产成本。此外，利用工厂更高的生产能力被证明具有消除规模经济带来的经济问题的更大希望。