Low-temperature selective catalytic reduction denitration catalyst and preparation method thereof

Abstract

The invention discloses a low-temperature selective catalytic reduction denitration catalyst and a preparation method thereof, wherein the catalyst takes an attapulgite as a carrier to load nano-composite materials of manganese oxide nano-particles; the structure thereof is as follows: manganese oxide particles with the particle diameter of less than 20nm are loaded on the rod-shaped crystal surface of the attapulgite with the diameter of 40-50nm; one or more types from iron, copper and nickel are added as an additive; and calculated according to the mass percentage of manganese, the content of the manganese oxide in the catalyst is 0.1-20. The preparation method comprises the steps of: firstly extruding, drying and crushing the attapulgite clay, and then preparing attapulgite clay powderinto suspension liquid; adding acid solution to wash and remove carbonate impurities, adding manganese salt, and then adding alkali solution for stirring so as to lead the manganese ion to be hydrolyzed and precipitated and loaded onto the crystal surface of the attapulgite, and finally obtaining the product after centrifugal washing, dewatering, drying and calcinations. The catalyst takes ammonia as a reducing agent, and has higher activity of catalyzing NH3 and reducing NO reaction within the scope of 120 DEG C to 350 DEG C.

Description

technical field [0001] The invention relates to the field of air pollution control engineering, in particular to a low-temperature selective catalytic reduction denitrification catalyst and a preparation method thereof. Background technique [0002] Thermal power plants produce a large amount of CO during high-temperature combustion 2 , SO 2 , NOx, until acid rain occurs in 81.6% of cities across the country. The emission of nitrogen oxides can also cause regional environmental pollution problems such as photochemical smog and ozone layer destruction. As a large-scale source of NOx emission point pollution, thermal power plants have become the main source of NOx pollution control. There are two main types of technologies for reducing nitrogen oxides in power plants today: the first type is combustion process control, that is, improving the combustion method to reduce the formation of nitrogen oxides during the combustion process (including low-oxygen combustion technology...

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Problems solved by technology

The disadvantages are: first, the cost of catalytic preparation is high, and the toxicity is strong; second, the catalyst preparation conditions are relatively strict and difficult to control; third, the operating temperature is high at 350-400 ° C, and the control is strict, which is not suitable for the existing power plants in my country. The actual situation that the temperature is low after gas desulfurization and dust removal; the fourth is V 2 o 5 for SO 2 Oxidation to SO 3 The reaction is catalytic, and the resulting SO 3 with escaped NH 3 React with water vapor in the flue gas to form NH 4 HSO 4 , below its dew point (300-330°C), it condenses on equipment and pipelines causing blockage and corrosion

The advantage of the catalyst prepared with activated carbon as the carrier is that the rich specific surface area of ​​the activated carbon carrier is conducive to the dispersion of the active components, and it has a certain anti-SO2 performance, but the activated carbon is ablated at high temperature during the activation and regeneration process. Too serious, resulting in excessive catalyst loss

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