Investigation of the Techno-Economical Feasibility of the Power-to-Methane Process Based on Molten Carbonate Electrolyzer

Abstract

High-temperature steam/CO2 electrolysis process has been the scope of study for the last decades. This study confers a feasible and environmental approach to convert low-carbon electrical energy into chemical energy, stored in the form of synthetic gas (H2 and CO) to be further processed in line with the final use target. It focuses on the Power-to-Methane technology using a high-temperature molten carbonates electrolyzer (MCEC). A large-scale process composed of the built-in MCEC model and the Balance of Plant (BOP) equipment is proposed and simulated with AspenPLUS software, taking into consideration the possible heat integration in the system for saving energy consumption. The proposed full-based process system shows an overall efficiency of 72%. The employment of this carbon neutral process relies on its economic competitiveness. For this reason, an economic assessment is conducted to investigate the economic feasibility of the proposed process. Indeed, the current methane production cost resulting from this process is not as competitive as market prices induced by other technologies. However, a parametric study demonstrating the impact factors on the methane selling price reveals that amelioration in the lifespan of the electrolyzer, accompanied by a reduction in its cost, can be an attractive solution, given the current market technology. This overall analysis sheds light on the role of the proposed process as an environmental-friendly and cost feasible solution for synthetic methane production.

Electrolysis Assisted Biomass Gasification for Liquid Fuels Production

“…Power-to-gas and power-to-liquid technologies, based on electrolysis, to store intermittent renewable energy in the form of chemical fuels are progressively evaluated (Hulteberg and Karlsson 2009;Clausen et al, 2010;Chen et al, 2014;Giglio et al, 2015;Koytsoumpa et al, 2016;Mesfun et al, 2017;Mesfun et al,2019), including, for example, the techno-economics of hydrogen (Hulteberg and Karlsson 2009), methanol (Clausen et al, 2010) and methane (Mesfun et al, 2019;Monzer et al, 2021) production (Ferrario et al, 2021). investigated MCEC application for offgas recovery system in a steam-reforming process at oil refinery.…”

“…Electrolysis at high temperature has several advantages, generally less energy intensive since part of the electrical energy needed to decompose the water molecule is replaced by the heat (Hu 2016), processing of hydrocarbon fuels with minor degradation of catalyst (Giulio and Nam, 2012), and the possibility to operate in reverse mode producing electricity (Mcphail et al, 2015). Neither the SOEC nor the MCEC technology is commercial today and heavily relies on R&D efforts to commercialize solid oxide fuel cell (SOFC) (Küngas 2020) and MCFC (Barckholtz et al, 2021;Ferguson and Tarrant 2021;Monzer et al, 2021;Shikhar et al, 2021) where MCFC units of up to 3.7 MW are sold on the market and used in several power plants (10-60 MW) worldwide (Bove et al, 2008). In view of using high temperature electrolysis technology in applications utilizing CO 2 for co-electrolysis of CO 2 and H 2 O in CO 2 -rich streams, the MCEC technology is favored due to the highly solubility of CO 2 in the molten carbonate electrolytes (Chery et al, 2015).…”