Optimization of biomass-to-methanol production pathways using P-graph approach.

The continuous growth of agricultural and food production results in substantial biomass waste generation. These biomass wastes present a promising and sustainable feedstock for the chemical industry. Methanol (MeOH) serves as a precursor for a wide array of commercial products. However, there is limited research on the systematic planning and optimization of biomass-to-methanol pathways considering the uncertainties of various conversion technologies. This study employs the P-graph framework to optimize biomass-to-methanol production pathways. Twenty-five scenarios are selected based on the design of experiments (DoE) techniques to facilitate the identification of optimal pathways that meet methanol demand. The results show that Anaerobic digestion (AD) pathway is the most cost-effective option, achieving the lowest methanol production cost (725 $/t MeOH). However, AD pathway has a CO2 emissions of 1.340 t CO2/t MeOH. Gasification pathway presents the lowest CO2 emissions (0.513 t CO2/t MeOH), while its cost is 805 $/t MeOH. The hybrid pathways may outperform standalone pathways under certain conditions. The findings identify economically competitive pathways and assess their corresponding environmental implications. It could provide valuable insights for decision-makers in the transition toward green methanol production.