1. Exergy analysis of hydrogen-reduction based steel production with coal gasification-shaft furnace-electric furnace process
- Author
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Mansheng Chu, Zhou Yusheng, Wang Jiaxin, Jue Tang, Zhenggen Liu, and Li Feng
- Subjects
Exergy ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,Energy Engineering and Power Technology ,Condensed Matter Physics ,Pelletizing ,Steelmaking ,Fuel Technology ,Volume (thermodynamics) ,Heat recovery ventilation ,Exergy efficiency ,Environmental science ,Coal gasification ,Coal ,business - Abstract
Carbon-free energy utilization in steel production is an effective way for China's iron and steel industry to achieve low carbon development. Thus, coal gasification-shaft furnace-electric furnace (CSE) technology, which use hydrogen-enriched gas for steel production, has recently become a sustainable topic of great concern. In the current study, the material flow analysis (MFA) and exergy assessment of the CSE process are conducted to investigate the material consumption and energy efficiency of this new steelmaking process. The exergy efficiency of the CSE process is calculated to be 50.11%, indicating a great potential for energy-saving. The results indicate that the coal gasification & gas purification that responsible for hydrogen-enriched gas production is the system with the largest exergy loss (account for 23.13% of the total exergy input), while the pelletizing system has the lowest efficiency (13.33%) due to heat loss. The key to further improve the thermal performance of this process lies in the heat recovery of the coal gasifier and pelletizing. It is also found that when the H2 content in reducing gas rise from 57.00% to 100.00%, the exergy efficiency of the shaft furnace is only increased by 1.58%, while the demand volume of reducing gas significantly increases from 1326.30 Nm3/t to 2201.50 Nm3/t. The environmental benefits of hydrogen reduction based steelmaking must be considered together with energy utilization and production cost. The present work should do helpful effort for the application and further improvement of the CSE process in China.
- Published
- 2021