Techno-economic-environmental evaluation of a combined tri and dry reforming of methane for methanol synthesis with a high efficiency CO2 utilization

Abstract

Production of methanol, as a green energy, from syngas is coming into focus. However, natural gas based methanol plants, which are used steam reforming of methane for syngas production, have a high CO 2 emission resulting in the global warming. In this study, a novel process for methanol synthesis is proposed to reduce CO 2 emission. In this regard, natural gas and flue gas are fed to a parallel-series system with tri and dry reforming of methane for syngas production with the optimized stoichiometric number. Then, the produced syngas is converted to methanol in a reactor. Finally, the produced methanol is purified by two distillation towers. The proposed method is compared to a referenced method in the view of technological, economic and environmental metrics. The techno-economic-environmental analysis of the processes reveals that not only the proposed method, as compared to the referenced one, increases CO 2 conversion from 20.93% to 99.22%, but also it is more economical and environmentally friendly. In addition, the global warming potential of the proposed method is almost 60% lower than that for the referenced method due to the lower CO 2 emission. Therefore, the proposed method can save above MUS$ 8 a year by CO 2 capture. • Combination of tri and dry reforming of methane to produce syngas for methanol synthesis. • Utilization of flue gas, instead of pure CO 2 , as a raw material to reduce CO 2 purification cost. • Reduction of CO 2 emission of a natural gas based methanol plant. • A techno-economic-environmental analysis of the proposed and referenced processes. • Investigation of the effect of the processes on the global warming potential (GWP).