Denitrification technology of melting furnace flue gas: a new chapter of industrial environmental protection


Release time:

2024-06-04

With the increase of global awareness of environmental protection, the emission control of pollutants in the industrial production process has become particularly important. As a key equipment in the process of metal processing and smelting, the emission of nitrogen oxides (NOx) from melting furnaces poses a threat to the environment and human health.

Melting furnaces play an important role in the metal smelting and recycling industry, and they produce large amounts of nitrogen oxides during operation, which are harmful to the environment and human health. Therefore, the development of effective denitrification technology is of great significance for the realization of cleaner production.

The nitrogen oxides generated in the production process of the melting furnace mainly include nitric oxide (NO) and nitrogen dioxide (NO₂). In the melting furnace, the generation of nitrogen oxides mainly comes from two processes: thermal NOx and fuel NOx. Thermal type NOx is generated by the reaction of nitrogen and oxygen in the air at high temperatures, while fuel type NOx is oxidized by nitrogen in the fuel during combustion.

The denitrification technology of melting furnace is widely used in many industrial fields. SCR denitrification technology has been successfully applied in power, steel, glass, cement, nonferrous metal metallurgy and various heat treatment industries. The melting furnace in these industries will produce pollutants such as nitrogen oxides during operation. Through the SCR denitration system, these harmful substances can be effectively converted into harmless nitrogen and water, which can meet the national environmental protection requirements at the same time, but also help industrial green development.

Denitration can be divided into three types: pre-combustion control, in-combustion control and post-combustion control.

1. Pre-combustion control requires the selection of low nitrogen or clean fuels to reduce the amount of nitrogen brought into the fuel. Fuel denitrification is the pre-removal of nitrogen from fuel by physical or chemical methods.

2, combustion control, by controlling the amount of air supply, reduce the oxygen concentration of the combustion area, inhibit NOx generation, reduce the air excess coefficient, reduce the combustion temperature, reduce the generation of thermal NOx.

3, after combustion control, through selective catalytic reduction (SCR) using a catalyst to reduce NOx to nitrogen and water.

Under the action of the catalyst, ammonia or urea is used as a reducing agent to reduce NOx to nitrogen and water. SCR denitrification technology has a high denitrification efficiency, up to 97%, but requires high investment and operating costs. With the increasingly strict environmental standards, the application of melting furnace denitrification can effectively reduce NOx emissions, reduce the negative impact on the environment, protect public health, and achieve sustainable development of industrial production.