Optimization of the Oxidative Coupling of Methane Process for Ethylene Production

Abstract

The oxidative coupling of methane (OCM) process is considered an intriguing route for the production of ethylene, one of the most demanded petrochemical products on the market. Ethylene can be produced by various methods, but the most widely used is the steam cracking process. However, due to the current instability of the crude oil market and the shale gas revolution, the production of olefins from natural gas has opened a new path for companies to mitigate the high demand for crude oil while utilizing an abundant amount of natural gas. In this work, the OCM process was compared with other existing processes, and the process was simulated using Aspen HYSYS. The flowsheet was divided into four sections, namely (i) the reaction section, (ii) the water removal section, (iii) the carbon dioxide capture section, and (iv) the ethylene purification section. Each section was thoroughly discussed, and the heat integration of the process was performed to ensure maximum energy utilization. The heat exchanger network was constructed, and the results show that the heating utility can be reduced by more than 95% (from 76567 kW to 2107.5 kW) and the cooling utility can be reduced by more than 60% (from 116398 kW to 41939.2 kW) at an optimum minimum temperature difference of 25 °C. In addition, a case study on the recovery of the high exothermic heat of reaction for power production shows that 16.68 MW can be produced through the cycle, which can cover the total cost of compression.