Environmental load evaluation and monitoring method for selective catalytic reduction of NOx in cement plant

Abstract

The invention belongs to the technical field of cement production environmental safety, and provides an environmental load evaluation and monitoring method for selective catalytic reduction of NOx in a cement plant. The environmental load evaluation and monitoring method is characterized in that under the control of a center control computer, sensors are used for measuring environmental load indexes, in one period, including NOx average discharging amount, NOx discharging amount peak value times, SCR system electricity consumption, extra coal consumption increasing amount, SO2 discharging amount, CO discharging amount, smoke discharging amount, ammonia escape amount at an ammonia discharging point and an outlet and an ammonia spraying opening of an SCR reactor, the SCR denitration rate, catalyst service life and efficient using time and the smallest value of the ammonia nitrogen ratio, the environmental load indexes are divided into three grades of A, B and C according to set thresholds, when environmental load is evaluated to be in the C grade, an alarm is given, the center control computer builds a raw material source tracing system of an SCR system, and an environmental load evaluation feedback system with the SCR technology is implemented. By means of the environmental load evaluation and monitoring method, environmental load indexes are effectively monitored, and through adjustment of the ammonia nitrogen ratio, the corrosion problem of reactors and downstream devices caused by excessive ammonia concentration can be solved.

Description

technical field [0001] The invention belongs to the technical field of cement production environment safety, and in particular relates to an environmental load evaluation and monitoring method for selective catalytic reduction of NOx in cement plants. Background technique [0002] The invention discloses an environmental load evaluation and monitoring method for selective catalytic reduction of NOx in a cement plant, and belongs to the technical field of cement production environment safety. [0003] Nitrogen oxides (NOx) are nitrogen monoxide (NO) and nitrogen dioxide (NO 2 ) is a common air pollutant that is extremely harmful to the environment, stimulates the human lungs, causes respiratory diseases, and induces urban photochemical smog. According to the data of the first national survey of pollution sources in 2007, NOx produced in the cement production process, of which NO accounts for 90% to 95%, for the domestic mainstream new dry process cement kiln, the average emi...

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Problems solved by technology

[0012] Although SCR technology has high denitrification efficiency compared with other technologies, there are the following problems in practical application: the operation of the SCR reactor installed separately under the preheater of the cement plant requires additional power consumption; the SCR reactor is installed after the dust collector , the temperature of the flue gas decreases after dust removal, and the flue gas needs to be reheated, which increases the coal consumption; if the dust collector fails, the catalyst is easy to block, and the treatment of the invalid and toxic catalyst will have a great impact on the environment; strict real-time control of the reduction is required The injection amount of ammonia agent is used to prevent corrosion of downstream equipment caused by excessive ammonia concentration; the equipment of SCR technology is relatively complicated, it is difficult to control accurately manually, and the cost of implementing SCR is high. If the technology fails, the economic and economic losses will be large. To ensure The normal operation of the cement production system and the effective implementation of SCR technology require sophisticated automatic monitoring equipment and emergency treatment systems; although the implementation of SCR technology can reduce NOx emissions, it will bring other additional impacts on the environment, such as gas pollutants NH 3 Emissions and coal consumption, electricity consumption increase

However, these documents and patents only focus on how to reduce NOx emissions by controlling combustion methods and technologies in the cement production process, and have not conducted an overall study on the NOx control technology produced in the cement production process from the perspective of the cement production cycle. Propose detailed solutions for the technology and other environmental problems caused by the actual application of SCR technology

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