Methanation of Coke Oven Gas with Nickel-based Catalysts

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ABSTRACT

For a complete transition from fossil to CO2 neutral energy supply new energy storage concepts are needed that allow energy supply in times of absence of regenerative power production as during dark doldrums. A promising renewable energy storage approach is the power to gas (to power) technique based on the production of synthetic natural gas (also called e-methane) by methanation of CO2 with H2. The latter is usually produced by electrolysis. In any power to gas concept, electrolysis is a very critical part, due to its high costs, stability issues, or limited power of required electrolysers. As an alternative source of hydrogen, we investigate the methanation of coke oven gas (COG). COG is a byproduct of the carbon rich coke production from coal for the steel industry, with a high amount of hydrogen (~60vol%). Coke oven gas furthermore contains CH4 (~25vol%), CO (5-8vol%), and CO2 (1-3vol%), making it an attractive feedstock for the production of synthetic energy carriers like methane. In the present study, the authors investigate the direct conversion of CO and CO2 from COG into e-methane. Compared to stoichiometric conversion, the COG hydrogen content is too high for catalytic methanation of CO2. In order to achieve a higher methane yield, the addition of CO2 from air, flue gas, or coal gasification can compensate the surplus of hydrogen in the coke oven gas. The process is evaluated by the conversion of CO and CO2, the catalyst selectivity towards higher hydrocarbons for varying temperatures, and the CH4 yield.

KEYWORDS

Coke Oven Gas, CO2 recycling, Power to Gas (PtG), Synthetic Natural Gas (SNG), e-methane, Sabatier-Reaction

Cite this paper

Klaus Müller, Fabian Rachow, Vivien Günther, Dieter Schmeisser. (2019) Methanation of Coke Oven Gas with Nickel-based Catalysts. International Journal of Environmental Science, 4, 73-79