Pathways toward carbon-neutral coal to ethylene glycol processes by integrating with different renewable energy-based hydrogen production technologies

Many Belt and Road Countries are actively taking measures to achieve carbon peaking and carbon neutrality. It greatly promotes to transform and upgrade the coal based chemical industries. This study proposed a coal-to ethylene glycol process integrated with proton exchange membrane electrolyzer (PEM-CTEG) and a process integrated with solid oxide electrolysis electrolyzer (SOEC-CTEG) technologies to address the shortcomings of traditional process such as high carbon emissions and unreasonable process structure. The proposed processes are integrated with different renewable energy-based hydrogen production technologies to balance the hydrogen and carbon elements in the system to achieve carbon neutrality. Techno-economic performance of the two proposed processes is analyzed and compared with a traditional CTEG process based on the modeling and simulation of the processes. The results show the carbon utilization efficiency of the proposed processes are increased by 20.64%, and the CO2 emissions are reduced by 84.01%. The exergy efficiency of the PEM-CTEG and SOEC-CTEG processes is enhanced by 8.29% and 13.98%, and the internal rate of return is improved by 3.50% and 10.09%, respectively. In addition, the influence of the fluctuations of the key economic factors on the economic performance of the two proposed processes is studied through a sensitivity analysis. Results show that the proposed processes have better anti-risk ability of the fluctuations of coal and ethylene glycol prices. Thus, the proposed PEM-CTEG and SOEC-CTEG processes can effectively improve the techno-econo-environmental performance of traditional process, and have promising industrialization prospect.

Automated summary

Many Belt and Road Countries are taking measures to achieve carbon peaking and carbon neutrality, which promotes the transformation and upgrading of coal-based chemical industries. This study proposes two coal-to-ethylene glycol processes integrated with renewable energy-based hydrogen production technologies to achieve carbon neutrality. The techno-economic performance of these processes is analyzed and compared with a traditional process, showing significant improvements in carbon utilization efficiency, CO2 emissions reduction, and economic return.