Rapid on-line diagnosis method for deactivation condition of SCR (selective catalytic reduction) denitration catalyst

Abstract

The invention discloses a rapid on-line diagnosis method for the deactivation condition of an SCR denitration catalyst, which comprises the following steps: tapping test holes on the wall surfaces of SCR denitration reactors above and below a catalyst bed layer to be tested; adding tracer gas above the catalyst bed layer through the test hole; monitoring the outflow position of the tracer gas below the catalyst bed layer to obtain the path of the tracer gas flowing through the catalyst bed layer so as to indirectly determine the flowing trace of smoke; simultaneously, measuring the NOx concentration, the O2 concentration, the smoke temperature and the smoke pressure at the tracer gas injection position above the catalyst bed layer and the corresponding tracer gas outflow position below the catalyst bed layer to work out the NOx removing rate so as to judge the deactivation condition of each area of the catalyst bed layer and further determining the positions of deactivated catalysts caused by blocking, poisoning and the like so as to provide beneficial references for the operation management and maintenance of the catalyst. The invention can carry out on-line monitoring on the deactivation conditions of the catalysts of SCR denitration devices, such as coal-fired boilers, gas fired-boilers, oil burning boilers, biomass-fired boilers and the like and has convenient operation and very good environmental protection benefit.

Description

technical field [0001] The invention relates to a rapid on-line diagnosis method for deactivation of an SCR denitrification catalyst. Background technique [0002] SCR flue gas denitrification is currently one of the most effective and widely used technologies for NOx control, and has become the mainstream technology for NOx emission control in thermal power plants in the world. At present, more than 90% of the flue gas denitrification projects that have been built or are under construction in my country use the SCR process, basically using a complete set of imported or imported SCR key technologies and equipment, which not only has high investment and operating costs, but also has adaptability problems. Catalyst is the core technical equipment of SCR denitrification technology, and it is also one of the main consumables, which needs to be replaced regularly. During operation, if the deactivation speed of each part of the catalyst is inconsistent, it will lead to a decrease...

AI Technical Summary

Problems solved by technology

[0003] The current monitoring of catalyst deactivation has the following disadvantages: First, the operation is complicated by taking out the catalyst module for off-line detection, and the extraction of the module is limited by the operation of the boiler, especially when there is no SCR reactor bypass, the boiler must be shut down The second is to directly measure the NOx concentration above and below the catalyst layer through the flue gas analyzer, and then determine the denitrification efficiency according to the change of NOx concentration. The flue gas flow trajectory of the bed cannot reflect the deactivation of the catalyst in each area of ​​the catalyst bed

Images