A novel process for the simultaneous production of methanol, oxygen, and electricity using a PEM electrolyzer and agricultural-based landfill gas-fed oxyfuel combustion power plant

Abstract

This paper presents a novel process for the simultaneous production of methanol, oxygen, and electricity through oxyfuel-combustion of landfill gas (LFG) produced from the agricultural residues and proton exchange membrane (PEM) electrolyzer. Among the most important advantages of the proposed process, one can mention high thermodynamic efficiency and negative CO2 emission. The proposed process includes a PEM electrolyzer, oxyfuel combustion power plant (OFCPP), and methanol synthesis unit (MSU). According to the analyses, this process has energy and exergy efficiency of 75.58% and 86.1%, respectively. In addition, based on the conducted analyses, the total exergy destruction of the process equals 54.21 MW, in which the OFCPP unit with a 76% share has the highest exergy destruction and lowest exergy efficiency. In addition, it is demonstrated that the proposed process converts liquefied natural gas to natural gas. Using oxygen for LFG combustion reduces energy consumption in gas compressors and raises energy efficiency. According to the environmental analysis, it is deduced that the CO2 emission of this process is negative and equals −0.97 kgCO2/kgMeOH, to which the contribution of indirect emission is zero. In addition, economic analysis illustrated that the total annual cost of the process and total methanol cost are 21.6 M$ and 0.62 $/ kgMeOH respectively.