Techno-Economic and Carbon Footprint Analyses of a Coke Oven Gas Reuse Process for Methanol Production

Abstract

This paper focuses on the best way to produce methanol by Coke Oven Gas (COG) conversion and by carbon dioxide capture. The COG, produced in steelworks and coking plants, is an interesting source of hydrogen that can be used to hydrogenate carbon dioxide, recovered from flue gases, into methanol. The architecture of the reuse process is developed and the different process units are compared by considering a hierarchical decomposition. Two case studies are selected, process units are modelled, and flowsheets are simulated using computer-aided design software. A factorial techno-economic analysis is performed together with a preliminary carbon balance to evaluate the economic reliability and the environmental sustainability of the proposed solutions. The production costs of methanol are equal to 228 and 268 €/ton for process configurations involving, respectively, a combined methane reforming of COG and a direct COG separation to recover hydrogen. This cost is slightly higher than the current price of methanol on the market (about 204 €/ton for a process located in the USA in 2013). Besides, the second case study shows an interesting reduction of the carbon footprint with respect to reference scenarios. The carbon dioxide capture from flue gases together with COG utilization can lead to a competitive and sustainable methanol production process depending partly on a carbon tax.

Coal: exploration, reserves, and utilization

“…It is a mixture of different gases, such as CO, CO 2 , CH 4 , H 2 , N 2 , C 2 H 2 , C 2 H 4 , H 2 S, and HNO 3 . A portion of them can be reused [56,[58][59][60]. Effective recovery and utilization of coke oven gases for valuable fuel will be a future challenge.…”

Comparative Lifecycle Assessment of Methanol and Urea Produced from Steel Mill Gases

“…Methanol synthesis from SMG requires carbon dioxide and/or carbon monoxide and hydrogen as shown in reaction 1 [22]. Hydrogen is obtained from the electrolysis of water, as well as from the coke oven gas by pressure swing adsorption (PSA), since it contains considerable amount of hydrogen (14 wt % [8]).…”

Economic Evaluation of Renewable Hydrogen Integration into Steelworks for the Production of Methanol and Methane

“…There is a difference in the reported methanol production costs which is associated with the included processes, the different hydrogen and carbon sources as well as to the studied region of the publications. Due to the large content of hydrogen and the lower content of inerts, the majority of the publications use coke oven gas as the main feedstock [10][11][12][13] and/or in mixtures with other steelworks off-gases [14][15][16][17][18][19][20]. In most cases, hydrogen is derived from the coke oven gas itself, either through recovery by pressure swing adsorption [13][14][15]18,19] or by reforming of the COG [10][11][12]16].…”

“…Due to the large content of hydrogen and the lower content of inerts, the majority of the publications use coke oven gas as the main feedstock [10][11][12][13] and/or in mixtures with other steelworks off-gases [14][15][16][17][18][19][20]. In most cases, hydrogen is derived from the coke oven gas itself, either through recovery by pressure swing adsorption [13][14][15]18,19] or by reforming of the COG [10][11][12]16]. Only certain publications specify if the gaseous feedstock undergoes cleaning and/or if gas cleaning is included in the production cost estimation [10,13,16,20].…”

“…In most cases, hydrogen is derived from the coke oven gas itself, either through recovery by pressure swing adsorption [13][14][15]18,19] or by reforming of the COG [10][11][12]16]. Only certain publications specify if the gaseous feedstock undergoes cleaning and/or if gas cleaning is included in the production cost estimation [10,13,16,20]. The large number of recent publications indicate the increased interest in utilizing steelworks off-gases as a feedstock to produce methanol and simultaneously tackle an environmental issue.…”