KR200264419Y1 - Device for Desulfurizing Exhausted Gas Using Aqueous Hydrogen Peroxide - Google Patents

Abstract

The present invention relates to a desulfurization apparatus for exhaust gas using hydrogen peroxide water,

A reactor (1) having an inlet (21) and an outlet (22) through which the exhaust gas passes; At least one slurry feeder (3) for sprinkling a lime (CaO) slurry or a limestone (CaCO ₃ ) slurry in the middle or the rear of the exhaust gas flow direction at an upper portion of the reactor (1); At least one spray nozzle 5 for spraying hydrogen peroxide (H ₂ O ₂ ) is additionally installed at the front of the reactor (1), so that the desulfurization apparatus having high desulfurization performance and excellent economic efficiency is provided. You can get it.

Description

Device for Desulfurizing Exhausted Gas Using Aqueous Hydrogen Peroxide

The present invention relates to a desulfurization apparatus for exhaust gas using hydrogen peroxide water, and more particularly, to a desulfurization apparatus for exhaust gas by semi-dry desulfurization.

Since most fossil fuels contain sulfur (S), sulfur oxides such as SO ₂ are present in the exhaust gas discharged after combustion, and if it is discharged to the atmosphere as it is, serious environmental problems such as acid rain or building corrosion are caused. do. Accordingly, various types of desulfurization apparatuses have been developed to reduce SO ₂ in exhaust gas emitted from boilers such as power plants. As a representative example, a desulfurization apparatus according to a wet desulfurization method and a semi-dry desulfurization method is currently mainly used. Hereinafter, the principle and configuration of these devices will be described.

In the wet desulfurization method, most limestone (Limestone, CaCO ₃ ) is made into a slurry and sprayed to absorb SO ₂ in the exhaust gas, and then the absorbing liquid is treated. Specifically, the SO ₂ in the exhaust gas is contacted with the limestone slurry to be sprayed to be absorbed in the form of liquid sulfur, sulfuric acid, or the like, or partially oxidized to CaSO ₃ and CaSO ₄ . At this time, the main reaction formula is shown in the following equations (1) and (2).

Liquid H ₂ SO ₃ is collected in a reaction tank, forcedly oxidized by injection of compressed air, converted into H ₂ SO ₄ , and gypsum (calcium sulfate, Gypsum, (CaSO ₄ ) · 2H ₂ O). Used to generate CaSO ₃ 2H ₂ O is also oxidized to produce gypsum. The main oxidation reaction at this time is shown in the following equation.

Wet desulfurization is known to have a high desulfurization rate (more than 90%) and a stable desulfurization reaction. However, this method has the disadvantages of high initial investment cost, large installation space (especially floor area), difficult maintenance, and generation of secondary pollutant wastewater.

On the other hand, the most common semi-dry desulfurization method is a lime desulfurization method in which a lime (CaO) slurry is sprayed and dried, which is similar to a limestone wet desulfurization method except that lime is much more reactive than limestone, and thus the apparatus and process Similarly, FIG. 1 shows a desulfurization apparatus according to the semi-dry desulfurization method, in which (a) represents a horizontal type and (b) represents a vertical type desulfurization apparatus. Referring to the drawings, a conventional semi-dry desulfurization apparatus will be described.

First, the exhaust gas 2 in the range of 150 to 350 ° C. is introduced into the reactor 1 of the desulfurization apparatus. When the lime slurry is sprayed through the slurry feeder 3 installed above the reactor 1, a flow of the slurry spray particles 4 as shown in the drawing is generated. The lime slurry spray particles 4 are dried while absorbing SO ₂ in the exhaust gas to form CaSO ₃ · 2H ₂ O, gypsum (CaSO ₄ · 2H ₂ O), and the like, and CaSO ₃ · 2H ₂ O or gypsum (CaSO). _It is discharged as a by-product containing ₄ 2H ₂ O), or contained in the exhaust gas 2 to exit the reactor outlet and collected in the dust collecting facility. The formation reaction of CaSO ₃ .2H ₂ O and gypsum is shown in the following Equation 3.

As in the reaction, the resulting CaSO ₃ .2H ₂ O is converted to gypsum after the oxidation reaction. However, since the oxidation reaction rate is lower than that of the wet desulfurization method, the amount of gypsum produced is low, and it is accumulated in the reactor hopper 7 together with the impurities such as ash and discharged or contained in the exhaust gas and collected in the dust collector (not shown) together with the ash. In addition, there was a problem that the purity is too low to use the by-product (8) produced again for industrial use. In addition, the semi-dry desulfurization method has the advantages of simple structure, low maintenance cost, low installation cost, and no waste water compared to wet desulfurization method, but requires a large amount of lime that is low in desulfurization performance and higher than limestone. There was also a disadvantage.

The present invention is devised to solve the above problems, and the object of the present invention is to provide a desulfurization apparatus having high desulfurization performance and excellent economic efficiency.

1 is a conventional semi-dry desulfurization apparatus, (a) is a horizontal desulfurization apparatus, (b) is a vertical desulfurization apparatus.

2 is a desulfurization apparatus according to the present invention, (a) is a horizontal desulfurization apparatus, (b) is a vertical desulfurization apparatus.

※ Explanation of Major Drawings

1 ... reactor

2 ... exhaust gas

3. Slurry Feeder

4 ... slurry spray particles

5 ... spray nozzle

6 ... Hydrogen Peroxide (Aqueous H ₂ O ₂ ) Spray Particles

7 ... Hopper

8 ... Byproduct

21 ... Reactor Inlet

22 ... Reactor Outlet

In order to achieve the above object, the present invention, a reactor having an inlet and an outlet for the exhaust gas passes through; In the desulfurization device consisting of one or more slurry feeder for spraying the lime (CaO) slurry or limestone (CaCO ₃ ) slurry in the middle or back of the exhaust gas flow direction in the upper portion of the reactor,

At least one spray nozzle for spraying hydrogen peroxide (H ₂ O ₂ ) is additionally installed at the front of the reactor.

In addition, in order to receive the by-products from the reaction, it is preferred that an additional hopper is installed at the bottom of the reactor.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

Figure 2 shows a semi-dry desulfurization apparatus according to the present invention, (a) is a horizontal desulfurization apparatus, (b) is shown a vertical desulfurization apparatus, respectively.

As shown in the drawing, in the desulfurization apparatus according to the present invention, one or more spray nozzles 5 for spraying hydrogen peroxide (H ₂ O ₂ ) 6 in the front of the reactor 1 are installed. . The arrangement configuration of the spray nozzle 5 can be arbitrarily determined, but considering the flow direction of the exhaust gas, in the horizontal type is arranged in the vertical direction and sprayed sideways, in the vertical type is disposed in the horizontal direction and sprayed from the top to the bottom It is preferable. However, as shown in Fig. 2 (b), the injection direction of the nozzle 5 can be freely determined vertically and horizontally according to the shape of the reactor 1 and the flow direction of the exhaust gas 2.

On the other hand, when the exhaust gas (2) in the temperature range of 150 ~ 350 ℃ is introduced into the reactor (1), the hydrogen peroxide (H ₂ O) of 10 to 50% concentration through the spray nozzle (5) installed in front of the reactor (1) ₂ ) is sprayed and sprayed to form hydrogen peroxide spray particles 6, and the hydrogen peroxide spray particles 6 react with SO ₂ in the exhaust gas to produce H ₂ SO ₄ . The reaction formula at this time is shown in Equation 4 below.

On the other hand, lime (CaO) slurry or limestone (CaCO ₃ ) slurry 4 is ejected from the upper portion of the reactor 1 through the slurry supply device 3 installed in the middle or the rear portion in the flow direction of the exhaust gas 2, This slurry 4 reacts with the H ₂ SO ₄ produced by the supply of hydrogen peroxide water to produce gypsum (CaSO ₄ ) .2H ₂ O. This reaction is represented by the following equation 5, in which the supply of the lime slurry and the supply of the limestone slurry are separated.

Limestone slurry reaction:

As described above, after the oxidation reaction, such as the conventional wet and semi-dry desulfurization reaction in the process of gypsum is produced and the expression 2 or the expression 3, but plaster is produced, the subject innovation in the H ₂ SO ₄ by the supply of H ₂ O ₂ After the production, since the gypsum is produced without the oxidation reaction, the desulfurization reaction time is greatly shortened.

On the other hand, the remaining SO ₂ that does not react with the H ₂ O ₂ supplied to the front of the reactor reacts with the slurry spray particles as in the prior art to finally produce gypsum. That is, in the process of forming gypsum, CaSO ₃ 2H ₂ O reacts with oxygen in the exhaust gas as in Equation 3 to oxidize gypsum (CaSO ₄ 2H ₂ O). At this time, since oxygen molecules are generated from the hydrogen peroxide spray particles sprayed at the front of the reactor, the oxygen molecules participate in the oxidation reaction of CaSO ₃ .2H ₂ O and the reaction rate is further improved. Equation 6 below shows the production of oxygen molecules by hydrogen peroxide supply, and the reaction process in which gypsum is formed after the oxidation reaction by the generated oxygen molecules.

The gypsum produced by the slurry dispersing particles 4 reacting with H ₂ SO ₄ , SO _2, and the like is slowly dried during the reaction process and accumulated in the hopper 7 under the reactor 1 to be discharged as a by-product 8, or exhaust gas. It is included in the discharger and collected in the dust collector. In the hopper 7 below the reactor 1, not only gypsum generated during the desulfurization reaction, ash in the exhaust gas, dried slurry, other sulfur oxides, etc. accumulate and are discharged to the outside as a by-product 8.

According to the present invention of the configuration as described above, since H ₂ SO ₄ generated by supplying H ₂ O ₂ reacts with the lime or limestone slurry spray particles to produce gypsum immediately without oxidation, the reaction time is shortened to desulfurization rate This has the advantage of being improved.

In addition, when SO ₂ and slurry spray particles passed without reacting with H ₂ O ₂ react to form gypsum, the supplied H ₂ O ₂ spray particles are decomposed to promote this oxidation reaction, and thus desulfurization rate. It is effective to further improve.

In addition, in the conventional semi-dry desulfurization apparatus, the lime slurry having high reactivity and high cost must be used. However, in the desulfurization apparatus according to the present invention, a low reactivity but inexpensive limestone slurry can be used, thereby achieving economic efficiency.

In addition, the purity of gypsum contained in the by-products produced by the reaction with SO ₂ can be applied again to the industrial field.

Claims (2)

A reactor (1) having an inlet (21) and an outlet (22) through which the exhaust gas passes; In the desulfurization device consisting of one or more slurry feeder (3) for spraying the lime (CaO) slurry or limestone (CaCO ₃ ) slurry in the middle or the rear of the exhaust gas flow direction in the upper portion of the reactor (1), The desulfurization apparatus of the exhaust gas using hydrogen peroxide water, characterized in that at least one spray nozzle (5) for spraying hydrogen peroxide water (H ₂ O ₂ ) is additionally installed at the front of the reactor (1). The method of claim 1, Desulfurization apparatus of the exhaust gas using hydrogen peroxide, characterized in that the hopper (7) for receiving the reaction by-products are additionally installed in the bottom portion of the reactor (1).