Method for NO oxidation and nitrogen oxide removal at room temperature through synergism of plasma and catalyst

Abstract

The present invention discloses a method for NO oxidation and nitrogen oxide removal at a room temperature through synergism of plasma and a catalyst. The method comprises that: a prepared catalyst is filled in a plasma reactor, and a mixing gas containing NO, O2 and N2 is introduced, such that the NO in the mixing gas is quantitively oxidized into NO2 at a room temperature through synergism of plasma and a catalyst, wherein a plasma voltage is 3.0-7.0 kV, and frequency is 8-10 kHz; and the treated gas enters an alkaline liquid absorption bottle to be absorbed, wherein a NO purification rate after absorption is up to more than 95%. According to the present invention, operation is performed at a room temperature, and heating equipment is not required, such that an operation cost is low; other gas components are not required to be added, such that an economic cost is substantially reduced, easy leakage caused by gas addition and other secondary pollution problems can be reduced; the method has characteristics of low equipment investment, low operating cost, simple process, no secondary pollution and the like; and adverse affects due to other impurity components in industrial flue gas are low, spreading use is easily performed, and high application values are provided.

Description

technical field [0001] The invention relates to the technical field of air pollution purification, in particular to a method for removing nitrogen oxides by oxidizing NO with a plasma co-catalyst under normal temperature conditions. Background technique [0002] Nitrogen oxide (NOx) is the main substance of air pollution, which not only endangers human health, but also is the main species and initiator of acid rain and photochemical smog, which will cause serious damage to the entire ecological environment. Now the world's NO emissions have reached 35-58Mt / a, more than 95% of which come from the combustion process of fossil fuels. my country's NOx mainly comes from industrial combustion processes and vehicle engines. Since my country's energy structure is still dominated by coal, and most of them are directly burned, NOx produced by combustion is an important polluting gas. [0003] At present, the ammonia selective catalytic reduction method is mostly used to purify the n...

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Problems solved by technology

[0004] Chinese patent CN 1803257A discloses a method for removing nitrogen oxides in coal-fired power plants using amino substances as reducing agents. Amino substances are sprayed into the upper part of the furnace to partially react with nitrogen oxides to remove 35-40% of nitrogen oxides in the flue gas. The unreacted amino substances enter the reactor with the flue gas. On the surface of the catalyst, the amino substances are oxidized with nitrogen again. The nitrogen oxide reduction rate can reach more than 90%, but the reaction temperature of this method is high, and the amino reducing agent is introduced, so there are problems of leakage and equipment corrosion

Chinese application CN 1613544A discloses a method for plasma-enhanced methane selective catalytic reduction of nitrogen oxides, which realizes the use of plasma synergistic catalytic reduction at room temperature to 350 ° C, and only uses catalytic reduction when the temperature exceeds 350 ° C. The reaction temperature of this method is relatively low. High, that is, the required energy consumption is high, and other gases need to be added, which not only increases the cost, but also makes the operation difficult to control

Chinese application CN 101773780A discloses a method for plasma synergistic catalytic oxidation of NO to remove nitrogen oxides. In this method, after the gas is activated by low-temperature plasma, it is passed into a fixed-bed reactor equipped with a catalyst to achieve Quantitative catalytic oxidation at ℃, this method uses highly active species generated by plasma to activate the gas, but the highly active species are not fully utilized, and the follow-up reactor still needs to be heated up, resulting in high energy consumption