Optimization of biomass-to-green methanol production: Techno-economic and environmental analysis

To address the problem of global warming, environmental pollution, and energy source depletion, the transition to renewable and sustainable energy source from fossil fuels is so critical. Biomass is one of promising renewable and sustainable energy sources that can replace existing fossil fuels. In the chemical industry, methanol is used as an important intermediate for producing synthetic hydrocarbons and regarded as a future energy carrier. Recently, green methanol production from biomass is a promising alternative for green and sustainable methanol production compared to traditional methanol synthesis from fossil fuels. Since the syngas derived from biomass gasification does not meet the optimal syngas composition for methanol synthesis, the syngas composition needs to be adjusted by injecting hydrogen into the syngas. This study aims to identify the optimal design and operation strategy of green methanol production system. To achieve this goal, we developed process simulation model for green methanol production from biomass by using commercial process simulator Aspen plus to obtain the sizing and equipment costing data, and mass and energy flow data. Then, we developed sequential quadratic programming optimization model implemented in Aspen plus based on these data. The objective function of the optimization model is to minimize the unit production cost of the produced green methanol considering various constraints such as hydrogen price, and biomass price. As a result, we identified the optimal system configuration and operation strategy for green methanol production from biomass. In addition, the identified optimal system by optimization model is analyzed with technical, environmental, and economic metrics.