Development and techno-economic study of methanol production from coke-oven gas blended with Linz Donawitz gas

Coke-oven gas and Linz Donawitz gas are pollutive by-product gases generated from steel plants. The gases are currently combusted or released to atmosphere, but those can be economically utilized as chemical product. Thus, this study proposes improved methanol production process from the gases, by considering two different strategies: efficiency (Case 1) and productivity (Case 2). Both processes are rigorously integrated using Aspen Plus V10 and evaluated from the perspectives of productivity, thermodynamic efficiency, environmental impact, and techno-economics. Compared to Case 1, Case 2 had 2.1 times the productivity but required 3 times natural gas. As a result, Case 1 showed better efficiencies of 58-68% (46-56% in Case 2), reduced larger carbon emission of 425 kmol/h (123 kmol/h in Case 2), and had lower minimum selling price of 371 $/tonne (398 $/tonne in Case 2). Two proposed processes are also economically superior than similar previous processes (550-712 $/tonne). This study confirms that both presented novel processes are sustainable and economically viable, and also improves the understanding of methanol production from the waste gases of steel production. (C) 2020 Elsevier Ltd. All rights reserved.