Lifecycle assessment of methanol production from blast furnace gas.

A technological scenario configuration for producing methanol (MeOH) from blast furnace gas (BFG) with natural gas (NG)-based energy generation was evaluated by a rigorous life cycle assessment. The new BFG scenario was compared to a conventional BFG scenario-BFG energy generation with NG-based MeOH production. In all, 18 environmental impact categories were estimated for both technological BFG scenario configurations on a conceptual plant level. The results of a case study in South Korea indicated that the new BFG scenario performs better for 12 environmental impacts (20-97% lower), but fossil resource depletion is worse because NG is used for the displacement of energy generation. The robustness of the environmental impact results for the new BFG scenario was supported by a case study, which highlighted that the primary source for the displacement of energy generation is crucial.