A selective catalytic reduction denitrification method and system thereof

Abstract

The invention discloses a selective catalytic reduction denitration method and a selective catalytic reduction denitration system. The method comprises the following steps: atomizing ammonia water (forming ammonia gas) by utilizing an ultrasonic generator, mixing the mist-type ammonia water (ammonia gas) with smoke containing nitric oxide, and reducing the mixed smoke to nitrogen and water in the existence of a catalyst. The selective catalytic reduction denitration system comprises a smoke inlet channel and a selective catalytic reduction denitration device, wherein the smoke inlet channel is provided with at least one ultrasonic generator, an ammonia water inlet of the ultrasonic generator is communicated with an ammonia water source through an ammonia water pump, and an ammonia water atomizing hole of the ultrasonic generator is arranged in the smoke inlet channel. According to the method and system, the ammonia water molecular structure can be scattered by utilizing electronic high-frequency vibration through the high-frequency resonance oscillation of an atomizing sheet in an ultrasonic atomizing way, the natural drifting mist is generated, no heating or chemical reagent is needed, ammonia gas can be formed without consumption of heat energy, and the ammonia gas and the smoke can be adequately mixed.

Description

technical field [0001] The invention relates to a denitrification method and system for flue gas containing nitrogen oxides, in particular to a selective catalytic reduction denitrification method and system. Background technique [0002] Cement manufacturing and thermal power generation are high-energy-consuming and high-polluting industries. In the process of cement clinker production, due to the use of coal as fuel, a large amount of dust and nitrogen oxides will be generated during the operation of the preheater and calciner. Mature denitrification technologies mainly include low nitrogen burner, staged combustion technology (SCC), SNCR (non-selective catalytic reduction technology) and SCR technology. Low-nitrogen burners, staged combustion and SNCR technologies have the problems of complex operation, low denitrification efficiency, high operating costs and high ammonia escape, making it difficult to meet the increasingly stringent requirements for nitrogen oxide emiss...

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Problems solved by technology

[0006] It can be seen that since the above-mentioned cement kiln low-temperature selective catalytic reduction denitrification system uses urea as the raw material of the reducing agent, it needs to use the urea pyrolyzer to pyrolyze the urea to generate ammonia gas, and also needs to dilute the ammonia gas through the mixer. Mixing the diluted ammonia gas with the flue gas through the ammonia injection grid consumes a lot of heat energy, and the system structure is relatively complicated

Even if liquid ammonia is used as the raw material of the reducing agent, it is necessary to vaporize the liquid ammonia through the liquid ammonia gasification device, dilute the ammonia gas through the dilution device and the mixing device, and mix the diluted ammonia gas with the flue gas through the ammonia spray grid , need to consume a lot of heat energy, and the system structure is more complex

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