Desulfurization and denitrification system and method

Abstract

The invention provides a desulfurization and denitrification system comprising a smoke generating device, a dust collector and an absorption tower connected with the dust collector through a second flue, wherein the top of the absorption tower is connected with a chimney, and the bottom of the absorption tower is connected with a circulating pump; the second flue is internally provided with a hydrogen peroxide high-temperature decomposition system comprising a gas mixing device and a heating device, wherein the gas mixing device is composed of at least three layers of pipe fittings, each layer of pipe fittings includes a plurality of pipe fittings, and the plurality of pipe fittings are arranged horizontally; based on the smoke entering direction, the heating device is arranged inside all the pipe fittings at the even layer of the gas mixing device; and the hydrogen peroxide high-temperature decomposition system is connected with a hydrogen peroxide storage tank through a pipeline, and an inlet of the hydrogen peroxide high-temperature decomposition system is arranged between the pipe fittings at the odd layer and the even layer of the gas mixing device. According to the invention, the second flue is internally provided with the hydrogen peroxide high-temperature decomposition system, so that the activity and utilization ratio of hydrogen peroxide are increased, and the desulfurization and denitrification efficiencies are high.

Description

technical field [0001] The invention relates to the technical field of desulfurization and denitrification, in particular to a desulfurization and denitrification system and method. Background technique [0002] The combustion of fossil fuels and the nitrogen oxides and sulfur oxides produced in chemical production have caused serious harm to the atmospheric environment. At present, there are several types of desulfurization technologies commonly used for air pollution control, such as dry method, semi-dry method and wet method. However, these technologies are powerless in terms of denitrification. At present, the most widely used denitrification technology in industry is selective catalytic reduction (SCR). However, this method has the following problems: high investment and operating costs, and a large floor area; the used reducing agent liquid ammonia is a national second-class dangerous product, and the management and maintenance requirements are strict; the generated s...

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Problems solved by technology

However, this method has the following problems: high investment and operating costs, and a large floor area; the used reducing agent liquid ammonia is a national second-class dangerous product, and the management and maintenance requirements are strict; the generated solid catalyst waste is difficult to deal with; when the old boiler is transformed, Need to modify the flue and air preheater, resulting in difficult and expensive problems

Among the many oxidants, hydrogen peroxide is popular because of its low price; however, hydrogen peroxide is not active at low temperatures, and it is not enough to oxidize the low-valence nitrogen oxides in the flue gas into a high-valence state that is easily soluble in water. Nitrogen oxides, which need to be excited by heating to generate oxidative free radicals

However, due to the extremely short survival time of oxidative free radicals generated after high-temperature excitation of hydrogen peroxide, they need to react immediately after generation to be effectively used

[0005] Publication No. US6793903B1 discloses a hydrogen peroxide pyrolysis system and method, which preheats before hydrogen peroxide enters the decomposition device, and then uses a special heating plate to excite it in the decomposition device; The difference between the above US patents is that there is no hydrogen peroxide preheating device, and the hydrogen peroxide pyrolysis system of the present application introduces the Venturi design concept. During the process of heating and exciting hydrogen peroxide, the system itself has a flue gas mixing effect , which solves the problem of oxidative free radical generation and reaction

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