Catalytic wet oxidation method for flue gas desulfurization waste liquid

Abstract

The invention relates to a catalytic wet oxidation method for flue gas desulfurization waste liquid. In the presence of a catalyst, the flue gas desulfurization waste liquid is contacted with air to oxidize sulfite into sulfate. The catalyst uses nano-sized TiO2 as a carrier , the active component of the catalyst is one or more of noble metal elements Pt, Pd, Ru and Rh, the additive is one or more of rare earth metal elements La, Ce, Pr and Nd, each component element in the catalyst The weight percentages are: precious metal elements are 0.05%~0.5%, rare earth metal elements are 1%~10%, and the mass ratio of rare earth metal elements to precious metal elements is 10~200. The method of the invention adopts a suitable catalyst, reduces the cost of the catalyst while improving the reaction performance, has good stability of the catalyst, and does not produce secondary pollution.

Description

technical field [0001] The invention relates to a treatment method for flue gas desulfurization waste liquid, in particular to a method for treating flue gas desulfurization waste liquid by using a catalytic wet oxidation method. Background technique [0002] In the treatment process of flue gas desulfurization, wet flue gas desulfurization technology is mostly used at home and abroad. The principle is to use alkaline materials as absorbents to absorb SO in the absorption tower. 2 The flue gas is spray scrubbed to make SO 2 React with absorbent to generate sulfite and sulfate. In this process, the oxidation of sulfite is an important process in the treatment of desulfurization waste liquid. Due to the slow process of sulfite oxidation, after the waste liquid is directly oxidized by air Still containing too much sulfite ion makes it difficult for wastewater COD to meet the discharge standard. Improving the oxidation efficiency of sulfite through appropriate methods is of gr...

AI Technical Summary

Problems solved by technology

CN101185887 provides a catalyst for wet oxidation process, with γ-Al 2 o 3 As the carrier, transition metal Mn, rare earth oxide CeO 2 and La 2 o 3 As an active component, the catalyst can reduce the amount of expensive noble metal materials, and to a certain extent reduce the loss of transition metal elements such as copper and iron, but the carrier is prone to crystal transformation during the reaction, resulting in catalyst deactivation

U.S. Patent US5360552 adopts CuO / Al 2 o 3 , CuS / activated carbon, Cu / X molecular sieve as wet oxidation catalyst, COD removal rate is high, but still can not solve the problem of Cu loss

[0005] The above studies mainly focus on Cu 2+ , Fe 2+ , Mn 2+ Such metal ions are used as homogeneous catalysts to increase the oxidation rate of sulfite, and the catalytic activity is high, but it cannot overcome the problem of catalyst loss with wastewater discharge, resulting in secondary pollution, and the wastewater needs to be further treated before it can be discharged

For heterogeneous catalysts, the problem of loss of active components is not well resolved, so it will cause problems such as reduced catalyst activity and secondary pollution.