Low-temperature smoke denitration SCR (silicon controlled rectifier) catalyst and preparation method

Abstract

The invention relates to a low-temperature smoke denitration SCR (silicon controlled rectifier) catalyst, which comprises a carrier, a manganese oxide, and composite oxide of one or more of Ce, Zr, Ti, Co, Fe and Cu, the mass content of manganese is 0.1-66 percent, and the total mass content of the Ce, Zr, Ti, Co, Fe or / and Cu is 0-50 percent; and glass fiber and / or kieselguhr is used as the carrier, wherein the glass fiber of the carrier is calcined for 2-4 hours at temperature of 400-600 DEG C, then placed in a nitric acid, sulfuric acid or hydrochloric acid solution with mass concentrationof 5-40 percent for acidizing for 1-8 hours, washed by distilled water to be neutered, dried at temperature of 80-120 DEG C, and crushed to have the fineness of 20-325 meshes. The catalyst uses the glass fiber and the kieselguhr as the carriers, so that the dispersion effect of nanoparticles and specific surface area of the catalyst are increased, the high adsorptive capacity and strong heat resistance and corrosion resistance capacity are achieved, stronger toxic resistance capacity to sulfur dioxide and stream contained in the smoke is realized, the invention can be used for 10-200 DEG C oflow temperature smoke denitration, and has strong water resisting and sulphur toxic resisting capacities.

Description

technical field [0001] The invention relates to the field of flue gas denitrification of coal-fired boilers, used for 3 The invention relates to a catalyst for selective catalytic reduction and removal of NOx in flue gas as a reducing agent, in particular to a low-temperature flue gas denitrification SCR catalyst with glass fiber and diatomite as a carrier and a preparation method thereof. Background technique [0002] With the continuous growth of energy consumption, stationary sources, mainly coal-fired boilers, emit more and more nitrogen oxides into the atmosphere. NOx is the main pollutant that causes air pollution problems such as acid rain, photochemical smog, and increased ozone concentration near the ground. Therefore, NOx emission reduction technology has always been the focus of attention of various countries. With the promulgation of the domestic "Nitrogen Oxide Prevention and Control Technology Policy for Thermal Power Plants" and the revision of GB13223 "Emiss...

AI Technical Summary

Problems solved by technology

[0003] At present, in the field of flue gas denitrification, ammonia NH 3 As the selective catalytic reduction (SCR) process of the reducing agent, the catalyst used is mainly V 2 o 5 / TiO 2 series, the catalyst has high catalytic activity, but there are still the following shortcomings in domestic applications: First, the reaction temperature is relatively high, and the general operating temperature is about 350 ° C. In order to meet the temperature requirements, the catalytic bed is generally arranged in the dust collector before, but on the one hand this arrangement will cause the SO of the catalyst 2 and alkali metal poisoning, as well as dust blockage, on the other hand, it requires a large space behind the furnace; second, the vanadium in the active component is poisonous, which is harmful to the ecological environment and human health; third, the core technology of the catalyst has been monopolized by foreign countries , it is necessary to pay higher technology royalties for domestic promotion and application, so the cost of engineering technology and catalysts is very high

However, when activated carbon fibers are used as the carrier, the catalyst has poor water resistance. In addition, the mechanical strength of activated carbon fibers is poor, and the prepared catalyst is not easy to shape.

[0007] In summary, the popularization and application of low-temperature SCR catalysts is limited by the carrier, especially the shape of the catalyst needs to be further developed