Method for testing activity of denitration catalyst of selective catalytic reduction (SCR) system of thermal power plant on site

Abstract

The invention relates to a method for testing the activity of a denitration catalyst of a selective catalytic reduction (SCR) system of a thermal power plant on site. The method comprises the steps of (1) measuring average denitration efficiency, namely (1.1) measuring instant denitration efficiency eta 1, (1.2) measuring instant denitration efficiency eta 2, and (1.3) calculating the average denitration efficiency eta; (2) measuring an activity constant, namely (2.1) measuring the progressive decrease amount Mx of every layer of NOx, (2.2) measuring the consumption of ammonia, (2.3) measuring the molar ratio of ammonia to nitrogen, and (2.4) calculating the activity constant; (3) obtaining the field evaluation parameters of the activity of the denitration catalyst of the SCR system. The method has the advantages that the activity of the catalyst can be detected on site under the condition that a host machine does not stop running, the accuracy and the representativeness of test data can be guaranteed, the change situation can be mastered in real time and the operation working condition of the SCR system can be adjusted in time; an SCR reactor does not need to be reformed, and the method is simple and convenient to operate.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering, and in particular relates to a method for on-site testing of the denitrification catalyst activity of a thermal power plant SCR (English full name is "Selective Catalitic Reaction" abbreviation, Chinese translation is "flue gas selective catalytic reduction reaction") system, This method is suitable for on-site verification of the quality of denitrification catalysts in SCR systems of thermal power plants. Background technique [0002] NOx (abbreviation for "Nitrogen Oxide" in English, Chinese translation is "nitrogen oxide") in the flue gas of thermal power plants that use coal as energy. More than 90% of the denitrification project. The core technology of the SCR system is the catalyst, whose composition, structure, activity, life and related parameters directly affect the denitrification efficiency of the system. However, due to the complex types of coal in my country, larg...

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Problems solved by technology

However, due to the complex types of coal in my country, large fluctuations in coal quality, rapid changes in ash content, and poor operation and management, the activity of SCR catalysts changes rapidly, which affects the emission of NOx in the flue gas and the increase in ammonia slip rate. , the detection of catalyst activity is an important guarantee for the safe and economical operation of the SCR system

However, the known SCR catalyst activity detection method has the following defects: one is to regularly take out the catalyst test module from the SCR reactor for laboratory testing, and to implement this method requires that the main engine be shut down before sampling, the operation is complex, time-consuming, and subject to boiler operation limits

At the same time, due to the selective sampling test, the test data is not representative; the second is to use the online analysis instrument to directly measure the NOx concentration at the inlet and outlet of the SCR denitrification system to calculate the denitrification efficiency, and use the denitrification efficiency as a single evaluation parameter , at the same time, this method is limited by the position and number of test points at the inlet and outlet of the SCR reactor, and cannot reflect the activity changes of each catalyst layer; the third is to use CH 4 (methane) is added to the flue as a tracer gas, and the NOx concentration and CH 4 Concentration testing, the steps are cumbersome, and the operability is poor. At the same time, alkane is added as a tracer gas in the flue at 300-380 ° C, which has great potential safety hazards.

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