Optimal design, exergy and economic analyses of coal-to-ethylene glycol process coupling different shale gas reforming technologies

• Published in: Energy (Oxford) 2021-08, Vol.228, p.120535, Article 120535
• Main Authors: Yang, Qingchun, Yang, Qing, Xu, Simin, Zhang, Dawei, Liu, Chengling, Zhou, Huairong
• Format: Article
• Language: English
• Subjects: Capital; Carbon dioxide; Carbon dioxide emissions; Coal; Economic analysis; Economic models; Emissions; Energy consumption; Ethylene; Ethylene glycol; Exergy; Optimal design; Process parameters; Production costs; Reforming; Shale; Shale gas; Shales; Steam; Sustainable development; System analysis; Technology; Thermodynamics
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.120535

The large-scale sustainable development of the coal-to-ethylene glycol process is severely plagued by its shortcomings such as high CO2 emissions, investment cost, and energy consumption. To address these issues, three novel shale gas assisted coal to ethylene glycol (SCtEG) processes with different methane reforming technologies are proposed and compared: the SCtEG process integrated with dry reforming technology (D-SCtEG), the SCtEG process integrated with steam reforming technology (S-SCtEG), and the SCtEG process integrated with dry and steam reforming technologies (D + S-SCtEG) processes. The key operational parameters of these novel processes are optimized firstly based on the system modeling and simulation. Then a techno-economic analysis is conducted and compared with a conventional CtEG process. The results show that, the carbon utilization efficiency of the D-SCtEG, S-SCtEG, and D + S-SCtEG processes is increased from 21.09% to 59.47%, 58.51% and 59.33%, respectively. Their exergy efficiencies are increased by 17.70%, 20.66% and 13.66%, respectively. Among these processes, the D-SCtEG and D + S-SCtEG processes can achieve zero CO2 emission. Furthermore, the D-SCtEG, S-SCtEG, and D + S-SCtEG processes can greatly reduce the total capital investment and production cost, especially, their production costs are saved by 10.48%, 13.23%, and 9.09%, respectively. [Display omitted] •Three novel shale gas assisted coal to ethylene glycol processes are proposed and compared.•Key operational parameters of these processes are investigated and optimized in detailed.•Carbon and exergy efficiencies of these processes are increased by 37%–39% and 13%–21%.•Three proposed processes can greatly reduce the production cost of the conventional process by 9%–13%.•Proposed D-SCtEG and D + S-SCtEG processes can achieve zero CO2 emissions.