Effect of Amino-Desulphurization on the Concentration Retrieval of SO2

Amino-Desulphurization technology has been widely used to reduce the pollutant emission in coal-fired power plants. However, excessive amino sprayed, not only results in the waste of liquid amino, but also brings a great error of the concentration retrieval of SO₂ by Continuous Emission Monitoring System(CEMS) based on Differential Optical Absorption Spectroscopy(DOAS). To find an effective retrieving method to determine the excessive ammonia, a least-square algorithm simulation analysis on the effect of excessive ammonia is proposed. And the method is used to analyze the on-site spectrum data to improve the precision of the concentration retrieval of SO₂. The experimental result shows that the downward trend of the concentration retrieval of SO₂ is recognized. It confirms that the excessive ammonia gas affects the concentration retrieval of SO₂ during amino- desulphurization process. And if the excessive ammonia is considered, the change of concentration of SO₂ before and after the desulphurization can be fitted by least-square method, and the accuracy of the retrieved concentration is improved.