Source: China Chemical Industry News
总体排污水平与新型煤化工相当
On July 23, Gu Zongqin, Chairman of the China Nitrogen Fertilizer Industry Association, Cao Zhanggao, Chief Engineer, Liu Yu, Researcher from the Chinese Academy of Environmental Sciences, and representatives from member companies of the China Nitrogen Fertilizer Industry Association, visited and inspected the clean pressure-fixed-bed gasifier gas cooling project at Shanxi Jinneng Holding Equipment Manufacturing Group’s Jinfeng Company. They expressed their approval of the unit's operational performance.
Chen Zhiyun, the Production Technical Leader of Jinfeng Company, stated, "The operational results show that after the intermittent fixed-bed gasifier underwent cold recovery and ultra-low emission retrofits, all indicators meet or exceed the environmental standards for new clean coal gasification technologies. The overall pollution discharge level is on par with new coal chemical technologies, and the system remains highly competitive and sustainable in the long run."
The retrofit replaces the original water-washing spray tower with a dry purification system (bag filter), enabling the coal gas cooling and purification system to meet environmental standards. Compared to the original setup, the new system offers four key advantages:
Improved purification: The dust concentration in the coal gas at the original tower outlet was about 30mg/Nm³, while the dry retrofit reduced it to 10mg/Nm³.
Higher environmental performance: The cooling medium and coal gas do not directly contact each other, avoiding issues with polluted circulating water, leading to less pollution and better environmental benefits.
Reduced treatment difficulty: The bag filter separates dust from the coal gas, significantly reducing the dust content in the gas condensate and making treatment easier.
Better economic benefits: The ammonia solution produced by the ammonia system can be used for flue gas denitrification, yielding strong economic returns.
Sun Yongsheng, Chairman and General Manager of Jinfeng Company, commented, "There is still no final consensus in the industry on the future of traditional pressure-fixed-bed intermittent gasification processes. Based on our current situation, replacing the UGI furnace with advanced gasification technology would require eliminating the entire existing process, which involves high capital investment that the company cannot afford." The project team leveraged ZHGAS’extensive experience in dry cooling and purification technologies, along with the operational data from Jinfeng’s current production units, to develop a practical indirect cooling process. The project has achieved positive results after implementation.
The dry dust removal technology effectively removes dust from the coal gas condensate, resolving the environmental issues caused by wet sludge in the circulating water tank. The coal gas condensate undergoes a closed-loop cycle in both the gas cooler and the condensate cooler. Ammonia nitrogen and VOCs in the condensate are separated in the ammonia tower, with the ammonia water being resourcefully utilized and VOCs burned at the tower top, effectively solving VOCs pollution in the direct cooling system.
Gu Zongqin praised Jinfeng’s efforts in retrofitting the fixed-bed intermittent gasifier for environmental improvements. He suggested that Jinfeng address the incremental water treatment issue to make the technology even more comprehensive and environmentally friendly. He also mentioned that the Nitrogen Fertilizer Association would promptly communicate with government departments to advocate for policy support for traditional coal chemical enterprises.
