Brief description of technology

In view of the problems that conventional SNCR technology has low denitrification efficiency, introduced water vapor affects furnace life, and SCR technology cannot operate normally in the process of low-temperature, tar-containing flue gas treatment, through research on the high-efficiency solid denitrification agent reaction system and simulation and optimization of the mixed reaction of denitrification agent and flue gas based on the carbon calciner/Calciner simulation model, a special denitrification agent for carbon furnaces and a high-efficiency integrated denitrification equipment for carbon calciner and a special tracking mobile denitrification equipment for carbon calciner have been developed. A complete set of key technologies for carbon kiln flue gas denitrification has been formed, and the nitrogen oxide emission concentration can reach below 40mg/Nm3, which is better than the national ultra-low emission standard.

technical information

The nitrogen oxide emission concentration shall not exceed 40mg/Nm3.

Commercial applications

Since 2017, this technology has been applied in nearly 20 carbon companies such as Henan Xinxin Carbon Co., Ltd., Henan Zhongfu Aluminum Carbon Branch, Shandong Haiyun Energy Technology Co., Ltd., and Suotong Qili Carbon Materials Co., Ltd., and has reduced nitrogen oxides by more than 4000 tons.① Henan Xinxin Carbon Co., Ltd. has one set of 68 calciners and one set of 72 calciners each, all using this technology for denitrification. The total equipment investment is 2 million yuan, and the nitrogen oxide emission concentration has been maintained at 40-50mg/Nm3.② Chinalco Shanxi New Materials Co., Ltd. has 2 sets of three-flame system roasting units with 7 feed boxes, 8 fire channels and 54 rooms, and 1 set of three-flame system with 15 feed boxes, 16 fire channels and 54 rooms. All of them use this technology for denitrification. The total investment in equipment is 8 million yuan, and the nitrogen oxide emission concentration has been maintained at 35-40mg/Nm3.

Help/support you hope to receive during the technology transfer process

This technology is of great significance to the implementation of the national ecological civilization development strategy. It is recommended that relevant departments issue relevant policies, increase publicity and recommendation of this technology, and provide relevant preferential treatment to using companies so that this technology can be fully applied and make due contributions to the country's green development and environmental protection.

equipment investment

Taking the carbon roasting furnace for aluminum with an annual production capacity of 100,000 tons as an example, one open-type roasting furnace with 7 feed boxes, 8 fire channels and 54 rooms is equipped. A total of 3 denitrification systems (complete sets of equipment) are equipped. The project investment is about 3 million yuan, including equipment The cost is about 2.7 million yuan, the construction cost is about 100,000 yuan, and other expenses are about 200,000 yuan. The technical service life is 15 years.

Annual operation and maintenance fee

A 54-room open roaster with 7 feed boxes, 8 fire channels, and the roaster is equipped with 3 sets of combustion systems. The flue gas volume is about 110000 Nm3/h, and the preliminary NOx concentration is 150mg/Nm3. After the implementation of the project, flue gas NOx stably reaches ultra-low emission requirements (≤50mg/Nm3), and the denitrification efficiency is ≥67%. During normal use, the cost of denitrification agent per unit product is about 26.5 yuan/t-product, the cost of compressed air is about 25 yuan/t-product, the power consumption is about 0.1 yuan/t-product, the repair cost is about 0.1 yuan/t-product, the management fee is about 0.5 yuan/t-product, and the depreciation fee is about 2 yuan/t-product.

investment recovery period

Taking the carbon roasting furnace for aluminum with an annual production capacity of 100,000 tons as an example, one open-type roasting furnace with 7 feed boxes, 8 fire channels and 54 rooms is equipped. A total of 3 sets of denitrification systems (complete sets of equipment) are equipped. The project investment is about 3 million yuan, which is for the enterprise. The economic benefits are approximately 138,000 yuan and the investment payback period is approximately 21.7 years.

added benefit

Taking the carbon roasting furnace for aluminum with an annual production capacity of 100,000 tons as an example, after adopting this technology, flue gas NOx stably reaches ultra-low emission requirements (≤50mg/Nm3), the denitrification efficiency is ≥67%, and the annual NOx emission reduction is about 110t/a, environmental protection tax is levied at 1.2 yuan/kg-equivalent pollutant, saving environmental protection tax of about 138,000 yuan/a (pollutant equivalent coefficient is 0.95). Compared with conventional denitrification technology, the project investment is saved by more than 2 million yuan.

comprehensive benefits

This technology is suitable for denitrification of flue gas from carbon furnaces and other characteristic furnaces. It can be promoted and applied in carbon enterprises that have not yet built denitrification facilities or cannot meet environmental protection requirements. After the technology is used, it can ensure that the nitrogen oxide emission concentration in the flue gas of carbon kiln for aluminum is ≤50mg/Nm3 (ultra-low emission standard). At the same time, investment in environmental protection is reduced, and investment in denitrification systems can be saved by more than 40% compared with conventional technologies. It is conducive to the realization of green development of enterprises and is in line with the comprehensive implementation of the new development concept of "innovation, coordination, green, openness, and sharing".

Level of impact of obstacles on technology transfer

no

technology maturity

Since 2017, carbon kiln flue gas denitrification technology has been applied in nearly 20 carbon companies such as Henan Zhongfu Aluminum Carbon Branch, Shandong Haiyun Energy Technology Co., Ltd., and Suotong Qili Carbon Materials Co., Ltd. After treatment, the nitrogen oxide emission concentration of flue gas has been maintained at no more than 40~Stable operation within the range of 45mg/Nm3, which is better than ultra-low emission standards.

technical applicability

This technology can be applied to calciners and roasting furnace systems of all carbon enterprises. The denitrification process of the calciner is mainly between the outlet of the calciner flue and the heat transfer oil boiler (850 - 1000℃). According to the actual scale, each furnace is equipped with at least 2 denitrification systems (including denitrification agent storage device, denitrification agent transportation and spraying device), covering an area of about 10m2. During denitrification of the roasting furnace, the denitrification system is mainly designed according to the furnace chamber, hopper, roasting curve, etc. of the roasting furnace. Each combustion system is equipped with 1 denitrification device, covering an area of about 8m2.

technical stability

The denitrification efficiency of the carbon kiln flue gas denitrification technology reaches more than 75%, which can stably achieve that the flue gas nitrogen oxide emission concentration does not exceed 50mg/Nm3, and has no adverse impact on the production system.

technical safety

This technology belongs to air pollution control technology. It mainly solves the problem that nitrogen oxide emissions from carbon enterprises affect the atmospheric environment. It can significantly improve air quality and is conducive to environmental protection and sustainable development of the aluminum industry. During the implementation process of this technology, solid denitrification agents are used to replace denitrification agents such as ammonia water and liquid ammonia in traditional denitrification technologies, with low safety risks; no denitrification catalyst is used and there is no secondary pollution.

Barriers to technology transfer and promotion

no