Recently, the denitrification systems of 5 biomass biogas generator sets designed for a company have been installed and operated in each project site and tested to meet the standards. After the customer's unit meets the original emission value of NOx 2000mg nm (standard dry basis, 5% oxygen content), the temperature meets the input conditions and the generator set works normally and stably, the flue gas meets the target emission requirements of NOx 150mg NM3 (standard dry basis, 5% oxygen content) after purification by denitrification equipment.
After the field investigation, the corresponding denitrification process and scheme were designed according to the site conditions and emission requirements, that is, the SCR denitrification purification system was adopted, and the system used urea solution as the reducing agent to reduce NOx to nitrogen and water under the reduction action of selective catalysts, and at the same time met the following requirements:
1) The reactor is installed at the rear end of the engine smoke exhaust pipe, and the control cabinet is placed near the unit room or mixing device
2) The flange connection of the reactor flue gas inlet and exhaust ends;
3) The gas, liquid and electric pipelines between the flue gas treatment equipment are firmly connected and there is no leakage
4) The outlet of the SCR denitrification system requires that the NOx content is not higher than 150mg NM (standard dry basis, 5% O2).
5) The denitrification reducing agent adopts a mass content of 325% finished urea solution.
6) The pressure drop of SCR equipment is not higher than 15kpa。
After the manufacturing of the SCR denitrification system of the biomass biogas unit is completed, the installation, commissioning, trial operation and technical guidance services will be carried outAfter the equipment installation and commissioning is completed, the trial operation will be carried out to normal operation and meet all the technical requirements and standards, until the equipment installation acceptance form is signed and delivered after passing the test. In addition, a 3-day training and guidance is available for equipment operation and maintenance personnel.
It is worth noting that in the process of equipment operation, due to the various inducements of denitrification catalyst inactivation, it is necessary to pay attention to the operation of the denitrification system according to the catalyst use conditions, for example: the emissions at the inlet of the catalytic reactor contain elements such as heavy metals, alkali metals, alkaline earth metals, halogens or halogen compounds and exceed the limit value;When the flue gas temperature exceeds the limit value for a long time;The amount of dust or particulate matter exceeds the limit and the catalyst is blocked. Due to the above reasons, the catalyst can be deactivated.