A kind of SCR monolithic honeycomb catalyst for low temperature flue gas denitrification and preparation method thereof

Abstract

The invention discloses an SCR (selective catalytic reduction) monolithic honeycombed catalyst for low-temperature flue gas de-nitrification and a preparation method thereof. The catalyst is prepared by using TiO2 and molecular sieve as carriers, MnO2 and Fe2O3 as main active ingredients, and one or more of ZrO2, NiO, WO3, CoO and CeO2 as auxiliary active ingredients through the following steps of: (1), preparing precursors of the carriers, main active gradients and auxiliary active ingredients, and the additives in proportion, and carrying out dry-mixing; (2), kneading to obtain plastic wet feed aggregates; (3), extruding the plastic wet feed aggregates successively through large sieve plates and small sieve plates or mixing in a vacuum pug mill to obtain compact and even degassed mud section; (4), carrying out extruding molding to the degassed mud section, so as to obtain a monolithic honeycombed catalyst blank; (5), drying the blank, carrying out microwave treatment and then baking. By adoption of the preparation method, the preparation process of the catalyst is simplified, the prepared catalyst does not need to be heated additionally, and the high catalysis activity and excellent waterproof property can be obtained only by heating the catalyst by tail end exhaust gas, therefore, the monolithic honeycombed catalyst is higher in engineering practical application value.

Description

technical field [0001] The invention relates to the preparation technology of a monolithic honeycomb catalyst, in particular to an SCR monolithic honeycomb catalyst used for low-temperature flue gas denitrification and a preparation method thereof. Background technique [0002] Nitrogen oxides (NOx) are the main factor of environmental pollution, endangering plant growth, destroying the ozone layer, and causing environmental problems such as acid rain, greenhouse effect, and photochemical smog. In recent years, the problem of ozone and fine particle pollution caused by NOx has become increasingly prominent, threatening human health. If control is not strengthened, our acid rain pollution and haze weather will develop and deteriorate rapidly in the future. In 2011, my country's nitrogen oxide emissions were 24.04 million tons, an increase of 5.73% compared with 2010, so the reduction of NOx pollution is imminent. SCR denitrification technology is currently the mainstream tec...

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Problems solved by technology

[0006] The above-mentioned microwave treatment has improved the performance of the catalyst to varying degrees, but there are also the following problems: (1) Most of them are powder catalysts with a large pressure drop, which is not suitable for treating large air volumes of polluted gases, and engineering applications are relatively difficult; (2) ) prepared catalysts are mostly placed in a microwave field, using the microwave-induced catalysis to selectively heat the catalyst active material, although the energy utilization rate and catalyst activity are improved, but due to the need for an external heat source, the engineering application cost increases

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