Preparation process of renewable sulfur-resistant Fe-Mn-Ce magnetic adsorbent for flue gas demercuration

Abstract

The invention relates to a preparation process of a renewable sulfur-resistant Fe-Mn-Ce magnetic adsorbent for flue gas demercuration. The demercuration adsorbent prepared by a coprecipitation methodis an efficient demercuration adsorbent aiming at a coal-fired power plant flue gas demercuration technology, has the advantages of strong demercuration performance, separability in magnetism, renewability, SO2 poisoning resistance and the like, and can realize efficient demercuration and cyclic utilization of coal-fired flue gas.

Description

technical field [0001] The invention relates to a preparation process of a renewable anti-sulfur Fe-Mn-Ce magnetic adsorbent for demercuration of flue gas, belonging to the field of demercury of coal-fired flue gas. Background technique [0002] Heavy metal mercury is a very harmful and highly toxic pollutant to the ecological environment and human health, and has the characteristics of inter-regional migration, bio-enrichment, food chain toxicity transfer, and strong latency. In terms of man-made emissions and secondary releases, in addition to natural causes, man-made activities such as fossil fuel combustion, metal smelting, cement production, chlor-alkali industry, and municipal behavior have increasingly become important sources of mercury pollution in the atmosphere. [0003] Coal-fired power stations are currently the largest unit of mercury emissions, and China is the world's largest producer and consumer of coal. At present, my country is facing a very serious situ...

AI Technical Summary

Problems solved by technology

my country's coal-fired power plant flue gas mercury removal technology is mainly developing in two directions: one is to develop a new selective catalytic reduction (SCR) catalyst to achieve combined denitrification and mercury removal, but the Hg of the SCR catalyst 0 Oxidation performance is related to the chlorine content in the flue gas, and the use of SCR catalysts to remove mercury has certain limitations; the other direction is activated carbon injection (ACI), but ACI technology also has carbon-based adsorbents that are difficult to remove from fly ash after adsorbing mercury. The problem of separating out in the process leads to difficult recovery and reuse of the adsorbent, high cost, and low utilization rate; more importantly, the synergistic demercury removal of the SCR catalyst and the mercury removal by the ACI technology will decompose the more toxic HgCl 2 Introduced into coal combustion by-products (fly ash and desulfurization gypsum), and coal combustion by-products in my country are used for secondary use. After leaching or high temperature process, mercury in coal combustion by-products will be released again, causing secondary pollution

[0004] At present, iron-manganese (Fe-Mn) magnetic adsorbent has received extensive attention due to its advantages of recyclability, regeneration, low cost, and high activity, and is generally considered to have a good application prospect. However, Fe-Mn magnetic adsorbent Prone to SO 2 Poisoning defects limit its industrial application; a certain concentration of SO in coal-fired flue gas 2 It will lead to poisoning and inactivation of Fe-Mn magnetic adsorbent, especially when H 2 When O exists at the same time, SO 2 The poisoning is more serious, which will not only reduce its ability to remove mercury, but may even cause it to fail to return to its original state after regeneration, making the mercury adsorption capacity permanently damaged; therefore, Fe-Mn magnetic adsorbents can be modified with transition metals , to enhance its resistance to SO 2 Poisoning ability and mercury removal performance

Images