At present, the main denitrification methods in power plants are selective catalytic reduction (SCR) and non-selective catalytic reduction (SNCR). Both of these two flue gas denitrification technologies have their own advantages and disadvantages.
SCR technology is to arrange the SCR reactor between the boiler economizer and the air preheater of the thermal power unit, and the flue gas enters the SCR reactor vertically, and reduces NOx to harmless N2 and H2O through various layers of catalyst modules. The above reaction temperature can be carried out between 300 ° C and 400 ° C, and the denitration efficiency is greater than 90%, which has quite mature operation performance on large boilers and air volume equipment.
GRVNES has independently developed denitrification products applicable to power plants, glass kilns, cement kilns and other industrial furnaces and cracking furnaces incineration and other fields, and can recommend the use of dust removal and denitrification integrated products according to customer choice.
Selective catalytic reduction method (SCR) control of NOx in diesel exhaust, the use of NH3 or urea as a reducing substance, at a certain temperature and catalysis, the use of NH3 to reduce NOx to N2 and H2O, because NH3 highly selective preferential reduction of NOx, without first reacting with O2, it is called “selective catalytic reduction”.
For kiln denitrification, the nitrogen oxide generation pathway is mainly generated by the oxidation of nitrogen in the air at high temperatures, and the NOx generated in this way is called thermal NOx. Its production is a function of the temperature of the flame structure. SCR treatment does not need to modify the equipment body, only for tail gas treatment; The temperature range of the catalyst is greater than or equal to 175 degrees, and the sell-out efficiency is more than 85%. And the selection of 40-5O hole high-mesh compact SCR catalyst reduces the size of the equipment and the amount of catalyst used, and effectively saves the equipment and energy. By changing the flue sequence, the operation cost is reduced, the waste heat in the final exhaust of the boiler is further utilized, and part of the heat of the purified gas is recovered, which greatly reduces the movement cost of the post-treatment equipment while taking into account the SCR reaction.
NO concentration probe, temperature sensor and O concentration probe are set before and after the SCR catalyst, according to the real-time status of the exhaust gas, the injection amount of urea water (or ammonia water) is accurately controlled by the real-time ECU electronic control system, and the high purification rate of nitrogen oxides is achieved at the same time to prevent ammonia overflow. After the equipment is completed, only part of the pipeline needs to be modified and connected. The commissioning period is short and does not affect the normal use of the boiler.
Post time: Dec-19-2023