China's new denitration catalyst technology: international leading level

Recently, the development of a wide-temperature structured denitration catalyst and its application in the deep purification of industrial furnace kiln flue gas by the Institute of Process Engineering of the Chinese Academy of Sciences, Shenyang University of Chemical Technology and Anhui Weida Environmental Protection Technology Co., Ltd. have passed China. Appraisal of scientific and technological achievements organized by the Petroleum and Chemical Industry Federation.

The appraisal committee composed of academicians of the Chinese Academy of Sciences and Duan Xue, Beijing University of Chemical Technology and others agreed that the technological achievements are highly innovative, and the preparation technology of its wide-temperature structured denitration catalyst has reached the international advanced level.

This technical result reveals the anti-sulfur ammonium salt poisoning mechanism of flue gas low-temperature denitration process. It is found that the deposition and decomposition balance of ammonium sulfide substances determines the mechanism of anti-sulfur poisoning performance, and the formation of high-strength primary nanoparticles by the thermal reaction of metatitanic acid solvent Mechanism, metatitanic acid retains the hydroxyl functional groups on the surface of the titanium carrier to achieve the reaction effect and mechanism of excellent molding performance of the slurry.

On this basis, the project team invented the one-step solvothermal preparation of high-activity catalyst slurry technology, and developed a short-term complete process of direct extrusion of aqueous slurry to prepare a large-size, porous-number structured denitration catalyst. The product is at 200 ℃ ~ 400 ℃ has high activity, wear resistance and excellent compressive strength. Taking the self-developed denitration catalyst as the core, they integrated the sodium bicarbonate dry injection desulfurization technology and developed an integrated set of processes and equipment for industrial flue gas deep purification "desulfurization + dust removal + denitration".

Relying on the technical achievements, the project team has built a 3000 m3 / year structured denitration catalyst production line, which has produced nearly 10,000 m3 of catalyst, which has been applied in more than 70 sets of coke ovens, sintering furnaces and other industrial furnaces and flue gas purification. The annual treatment of industrial combustion flue gas exceeds 350 billion cubic meters, accounting for more than one-third of the installed coke oven flue gas purification projects in China. In addition, this technical product has been rated as one of the top 10 brands of coking and denitrification in the steel industry for three consecutive years. It has also won 2 international patents and 21 Chinese invention patents, with significant economic and social benefits.

According to reports, nitrogen oxides (NOx) cause acid rain, photochemical smog, and ozone layer destruction, and are one of the main pollutants in the atmosphere. At present, the focus of atmospheric environmental governance is NOx governance in non-electricity industries such as coking and steel.

At present, the most mature and effective denitration technology is the SCR process, which has a broad application space in the non-electric field denitrification treatment. Its catalyst is the core of the SCR denitration technology. However, due to the complexity of the flue gas environment in the non-electric field, the temperature of the flue gas treated by the SCR process is often lower than 300 ℃, and usually contains a certain concentration of SO2. SO2 is susceptible to oxidation on the surface of flue gas or catalyst, and reacts with NH3 injected into the flue gas to form ammonium sulfate salt. Therefore, while improving the reaction activity of the catalyst, enhancing the anti-sulfur ammonium salt poisoning ability is of great significance to the application of the catalyst in the non-electric field.