On the issue of white smoke in catalytic flue gas desulfurization (wet method)
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Regarding the issue of white smoke in catalytic flue gas desulfurization (wet method): (1) How to understand white smoke, what substances are present in it, and what its hazards and consequences are. (2) What measures can be taken to effectively control white smoke?
The flue gas at 170 degrees coming out of the waste heat boiler enters the desulfurization tower, where it comes into countercurrent contact with an alkaline solution to remove sulfur; therefore, the white smoke is mainly water vapor!
It’s not white smoke; it’s all just water vapor, no problem
This post was last edited by humin on 2017-9-2 at 16:54. On June 6, 2017, the Shanghai Environmental Protection Bureau issued the “Notice on Issuing the ‘Technical Requirements for the Testing of Gypsum Rain and Colored Plumes from Coal-Fired Power Plants in Shanghai (Trial)’” (Hu Huan Bao Zong [2017] No. 203). The scope of application of these technical requirements is in accordance with the \"Emission Standards for Air Pollutants from Coal-Fired Power Plants\" (DB31/963-2016). Coal-fired power plants that employ flue gas heating or flue gas condensation reheating technologies are exempt from testing, but they must not shut down the relevant facilities without proper reason. In the case of plants using flue gas heating technology, the exhaust gas temperature under normal operating conditions must remain consistently above 75°C; during winter (from November to February each year) and when a severe pollution alert is in effect, the exhaust gas temperature must remain consistently above 78°C ； When the flue gas condensation reheating technology is employed to achieve the same effects as eliminating gypsum rain and white plumes, the exhaust gas temperature under normal operating conditions must remain consistently above 54°C; in winter and during periods of severe pollution alerts, this temperature must remain consistently above 56°C. For wet catalytic flue gas desulfurization, is it necessary to consider this issue?
On August 28, 2017, the Zhejiang Provincial Department of Environmental Protection issued the draft of Zhejiang Province’s mandatory local environmental protection standard, namely the \"Emission Standards for Air Pollutants from Coal-Fired Power Plants\" (for public comment). Among them, coal-fired power generation boilers located in the urban core areas and areas with sensitive ambient air conditions should adopt flue gas temperature control and other effective measures to eliminate phenomena such as gypsum rain and colored smoke plumes.
The flue gas temperature is low, resulting in water vapor generated upon counter-current contact.
White smoke is actually water mist; it’s not even water vapor, and it turns into small droplets that fall to the ground shortly after appearing. It contains alkaline components, which can corrode surrounding items over time. We have been in operation for over a year, and the metal sheets on the pipelines around us have all become rusty. There has been no effective solution to the water mist problem. It seems that CNPC’s WGS technology hasn’t been fully understood; many units suffer from the same issue, especially during winter in the north, when it turns into a real ice rink.