Techno-economic-environmental analysis of coal-based methanol and power poly-generation system integrated with biomass co-gasification and solar based hydrogen addition

Raising the share of renewable energy in energy structure is an essential approach to relieve global warming. The feasibility of the integration of renewable energy with fossil fuels for chemical production to reduce greenhouse gas (GHG) emission should be comprehensively evaluated before the project decision-making. In this study, a novel conceptual design is developed to reveal the effects of the addition of hydrogen-rich sources from biomass co-gasification and solar based hydrogen on the techno-economic-environmental performance of coal-based methanol and power poly-generation process. The results show that when the coal feeding is constant at 100 t/h and biomass is added from 0 to 40 t/h, the energy efficiency decreases from 53.56% to 51.64% while the unit GHG emission decreases by 24.34%. In the case of constant total feeding, even though the biomass addition benefits the decline of unit GHG emission, both energy efficiency and unit energy production cost show worse performance. Besides, the addition of solar based hydrogen from 600 kmol/h to 1000 kmol/h can enhance the carbon element utilization rate from 39.41% to 41.49% but deteriorate the performance of energy efficiency and economy. Hence the integration of renewable energy with fossil fuels for chemical production is not always beneficial for the overall performance. The process analysis in this study can provide some significant guidelines for the integration of renewable energy in coal-based methanol process.