Scaling down analysis of e-methane production: Advancing towards distributed manufacturing

Abstract

[EN]The reduction of CO2 emissions is crucial for controlling global warming. Within the carbon capture, utilization, and storage (CCUS) initiative, chemical production is appealing. Methane stands out due to its extended use and compatibility with the current natural gas infrastructure. Since CO2 emissions are highly distributed, a scale analysis of e-methane production is essential. This work presents a scale study of carbon capture and hydrogenation to produce methane. Three technologies for carbon capture (absorption, adsorption, and membrane separation) and two reactor designs (isothermal multitubular, and adiabatic multibed) are analyzed and three different scenarios are proposed: continuous, semi-modular, and modular. Module units are based on a 1.3 MW electrolyzer housed in a sea container. Adsorption is the most profitable carbon capture technology. The optimal operational scenario varies with the amount of CO2 treated. Prices for methane produced range from 40 to 60 $/million BTU for continuous scenario, from 40 to 55 $/million BTU for semi-modular scenario and from 50 to 70 $/million BTU for modular scenario. Although the prices are not competitive, they can be reduced considering the carbon credits and, in addition, these processes prevent CO2 emissions into the atmosphere and ensure methane availability for energy storage or as an energy carrier system.