Life cycle assessment and economic analysis of methanol production from coke oven gas compared with coal and natural gas routes

Abstract

Abstract Coke oven gas (COG), a considerable byproduct in coke production, has been utilized as the feedstock for methanol production. A “cradle-to-gate” life cycle assessment (LCA) of COG-based methanol production (COG route) was conducted and compared with the coal and natural gas routes by applying CML 2001 method with GaBi 6.0 software. Besides, the economic analysis of the three methanol routes were performed. The results indicate that COG route shows lower impacts than coal route to all the selected environmental categories. Moreover, the average methanol production cost of COG route is lower than that of coal and natural gas routes by 25.1% and 19.8%, respectively. In COG route, 82.1% of the overall normalized environmental burden occurs at methanol production stage dominated by electricity and steam consumption. The environmental impact of COG route could be reduced by supplying medium-pressure steam from coke dry quenching system for methanol production. This work intends to provide useful insights on the sustainability development of COG utilization in coke industry.