If the emission of particulate matter from catalytic cracking flue gas is controlled to less than 30 mg/m3n

It is best to give thorough consideration when selecting the process; generally, wet dust removal is safer and more effective than electrostatic dust removal. The downside is that the catalyst in the wastewater needs to be treated.

Are these the parameters before entering the smoke extractor? After the first and second stage centrifugation, the third and fourth stages are almost done. More can also be removed through flue gas desulfurization!

I’d like to ask the original poster: why do you want to control this indicator?

I wonder too; our levels are stable during the day, but exceed the limit at night, and it seems to be related to humidity!

①Increase the amount of make-up water injected, boost the discharge volume from the bottom of the tower, and improve the dust removal efficiency through water washing in the desulfurization tower； ②It has a certain relationship with temperature. Since the flow rate of flue gas from the desulfurization tower to the exhaust point remains relatively constant, when the temperature is low, liquid droplets adhere to the surface of dust particles, forming aerosols and resulting in an increase in the dust content in the exhaust gas.

First, I won’t go into detail about the three-spin operation mode; nowadays, dust removal processes are generally available. We use a dual-circulation slurry reverse injection method

This must be the indicator for the dust content in the flue gas emitted by the chimney. The dust content in the flue gas entering the flue gas extractor is several times, or even a dozen times, higher than this value. The dust content in the flue gas emitted from chimneys is 30 mg/Nm^3, which poses a significant challenge for many FCCUs.

These are the internal control standards for the FCCU desulfurization and denitrification units in many petrochemical enterprises located in areas with strict regulations on environmental emissions.

This post was last edited by luoli519 on 2017-8-13 09:46. The dust content in the flue gas emitted from chimneys is not greatly affected by weather and humidity. The main reason for the fluctuations in the levels of flue gas and dust emissions during the day and at night is operational factors. Most FCCUs include main desulfurization and denitration pipelines as well as bypass pipelines; after the mixture from these pipelines meets the required standards, it is emitted through the chimney. During the day, the flue gas processed by the main desulfurization and denitration systems has very low levels of sulfur oxides, nitrogen oxides, and dust. Managers often monitor the DCS data, and from time to time they look up at the chimney to observe the shape of the smoke plume. Thanks to the attention paid by all staff during the day, the emission parameters of the flue gas after treatment in the main desulfurization and denitration systems are excellent. Although the bypass valves are kept at a high opening degree (to reduce sodium alkali consumption, water consumption, and electricity consumption), the emission parameters of the mixed flue gas still meet the required standards. But there may be problems at night. Because the operators lost their vigilance (the leaders and residents who were watching the chimney also fell asleep). Problems can arise due to negligence in areas such as catalyst regeneration, flue gas washing, and dust and foam removal, which can lead to a deterioration in the parameters related to flue gas treatment. In addition, the workshop also needs to be evaluated based on indicators such as sodium-alkali consumption, water consumption, and electricity consumption – these are precisely the key consumption factors that affect the performance of flue gas purification. The unity of opposing contradictions may deviate between day and night. Intentionally or unintentionally, the indicators change throughout the day and night. Today, environmental protection agencies have installed online real-time monitoring and data transmission systems at chimney exhaust outlets; regardless of day or night, efforts must be made to ensure that emission standards are met. Otherwise, administrative penalties will be imposed immediately.