Photochemical advanced oxygenation-based simultaneous desulfuration and denitration system

Abstract

The invention discloses a photochemical advanced oxygenation-based simultaneous desulfuration and denitration system. The system is provided with a burning and exhausting system consisting of a burner, an electrostatic dust collector, a heat exchanger, a spray tower, a liquid adding tower and a chimney, wherein fume generated by the burner enters the electrostatic dust collector, fume particles are removed from the fume by the electrostatic dust collector, the fume enters the heat exchanger and is cooled by the heat exchanger, and then the fume enters the spray tower; an UV light tube is arranged in the spray tower; hydrogen peroxide solution from the liquid adding tower is pumped by a circulating pump, sprayed into the spray tower through an atomizing nozzle and is activated by ultraviolet light to decompose hydrogen peroxide and then generate hydroxyl radicals (.OH) with strong oxidizing property; after being contacted with the fume in the spray tower, the hydroxyl radicals undergoes a gas-liquid absorption reaction with the fume to oxidize and remove NOx and SO2 in the fume; the fume, after being absorbed and washed, enters the chimney from the top of the spray tower and is exhausted; and sulfuric acid solution and salpeter solution generated in the spray tower are pumped into the separating column by the circulating pump and are reacted with added ammonia water to generate agricultural fertilizers including ammonium sulfate and ammonium nitrate.

Description

technical field [0001] The present invention relates to SO in flue gases including power plant boilers, industrial kilns and waste incinerators 2 and NO x Emission pollution control technology, especially related to a simultaneous desulfurization and denitrification system based on photochemical advanced oxidation. Background technique [0002] SO produced during combustion 2 and NO x It can cause acid rain and photochemical smog, which has brought great harm to human health and the ecological environment. Therefore, developing effective desulfurization and denitrification methods is one of the important tasks of environmental protection scientists in various countries. In recent years, although people have developed a large number of desulfurization and denitrification technologies, the most widely used flue gas desulfurization and denitrification technologies are mainly wet limestone-gypsum flue gas desulfurization technology (Ca-WFGD) and ammonia selective catalytic re...

AI Technical Summary

Problems solved by technology

In recent years, although people have developed a large number of desulfurization and denitrification technologies, the most widely used flue gas desulfurization and denitrification technologies are mainly wet limestone-gypsum flue gas desulfurization technology (Ca-WFGD) and ammonia selective catalytic reduction (NH 3 -SCR), the combined use of the two processes can achieve simultaneous desulfurization and denitrification, but the simple superposition of the two systems results in complex process and system, large floor area, high investment and operating costs, and a large amount of gypsum by-products. Poor, resulting in difficulties in post-processing, it is difficult to promote and apply on a large scale in developing countries

[0003] Wet flue gas desulfurization and denitrification technology is a traditional flue gas purification technology, which has the characteristics of small initial investment and simple process flow. However, the research progress of traditional wet simultaneous desulfurization and denitrification technology has been relatively slow. The main reason is that NO x Contains more than 90% of insoluble NO in water, and the Henry constant of NO at room temperature (25°C) is only 1.94×10 -8 mol / L·Pa, than SO 2 3 orders of magnitude lower

It can be seen from the double-membrane theory that NO must first be transferred from the gaseous state to the liquid phase through mass transfer and diffusion processes, and then it can undergo a chemical reaction and be fixed in the absorption liquid. The insoluble characteristics of NO greatly increase the resistance of its liquid phase absorption. It is difficult to significantly increase the solubility of NO in the liquid phase by adjusting pH and temperature. This characteristic has caused the problem of high desulfurization efficiency but low denitrification efficiency in traditional wet desulfurization and denitrification technologies. In fact, it is difficult to achieve simultaneous desulfurization and denitrification. , ultimately hindering its industrial application

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