Environmental Impact and Environmental Cost Assessment of Methanol Production from wood biomass

Increasing demand for biofuel production and global competition for the use of natural resources are key factors in finding new and environmentally safe routes for methanol production. In the present study, life cycle assessment was used to analyse the potential environmental impact and environmental cost of a novel methanol production process from wood compared to a conventional processes. Both the novel and the conventional process were divided into three stages: pre-treatment, gasification, and syngas cleaning and methanol synthesis. The environmental impacts were assessed and compared using Simapro 9 (ecoinvent 3.5 database) and the ReCiPe 2016 (World-H) midpoint method. The results, expressed per tonne methanol, showed that the impact categories of global warming potential (GWP) and marine ecotoxicity potential were lower in the novel process in comparison to the conventional process (48.2 kg CO₂ eq. vs. 63.1 kg CO₂ eq., and 4.55 kg 1,4-DCB vs. 6.35 kg 1,4-DCB respectively). However, the novel process had a higher environmental impact in the pre-treatment stage. The results of the sensitivity analysis showed that the GWP of the novel process increased from 48.2 kg CO₂ eq. to 216 kg CO₂ eq. due to the replacement of Na₂CO₃ by K₂CO₃. The human toxicity impact categories showed significant impact on environmental cost. These findings will help relevant industries to reduce their environmental impact and improve the production efficiency of methanol from wood.