JPH0576723A - Method for reducing greenhouse-effect gas - Google Patents

Abstract

PURPOSE:To efficiently reduce, separate and remove the greenhouseeffect gas, especially carbon dioxide. CONSTITUTION:The greenhouse-effect gas is allowed to react with the gas or aerosol highly reactive to the greenhouse-effect gas to liquefy or solidify a part of the greenhouse-effect gas. The carbon dioxide is converted to urea by the reaction 2NH3+CO2 NH2CO2NH4. This conversion reaction is promoted by exciting the gaseous reactant in the discharge field such as a corona discharge, spark discharge, glow discharge, arc discharge, etc. The schematic diagram of a gas reactor 10 utilizing the discharge field is shown in the figure, an electrode rod 12 is arranged in the axial direction of a cylindrical reaction tube 11, and a coil 13 is wound on the tube 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing greenhouse gases such as carbon dioxide.

[0002]

[Prior art and its problems] It is feared that global warming will have the most serious impact on human society and ecosystem among various global environmental problems. In Japan, carbon dioxide that causes global warming It is planned to reduce emissions of greenhouse gases such as gas, freon and methane. Conventionally, physical and chemical absorption methods, adsorption methods, membrane separation methods, distillation methods, etc. are known as methods for reducing and removing exhaust gases such as carbon dioxide gas, which is the most exhausted of greenhouse gases. ..

Further, the exhaust gas often contains fine particles. For example, indoor polluting gas contains solid or liquid fine particles such as aldehydes and olefinic hydrocarbons produced by smoking. Fine particles of this type are conventionally separated and removed by a filtration separation method using various filters.

However, a technique for efficiently separating and removing greenhouse gases, particularly carbon dioxide, to reduce the emission amount thereof has not yet been established.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and an object thereof is to emit exhaust gas from thermal power plants, factories and other industrial facilities, or carbon dioxide emitted from heaters, gas appliances and the like. gas, carbon monoxide, indoor environmental pollution gas such as NO _X by aerosolization is to reduce greenhouse gases. Moreover, this invention aims at reducing the said greenhouse effect gas, and separating and removing.

[0006]

SUMMARY OF THE INVENTION The greenhouse gas reduction method according to the present invention reacts a greenhouse gas with a gas or an aerosol having a high reactivity with the gas to convert a part of the greenhouse gas into a liquid or a solid. It is characterized by Furthermore, the reaction is carried out in the excited state of the reaction gas, or the converted greenhouse gas is separated from the greenhouse gas by a filter.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a method for converting a gas which is a greenhouse effect gas into a solid or a liquid includes:
There are a method of reacting a gas to generate a substance having a boiling point higher than that of the gas, and a method of reacting a gas and an aerosol having high reactivity with the gas to generate a new stable substance.

For example, for carbon dioxide, the following reactions are specifically utilized. (1) Urea synthesis reaction 2NH ₃ + CO ₂ → NH ₂ CO ₂ NH ₄ NH ₂ CO ₂ NH ₄ → CO (NH ₂ ) ₂ + H ₂ O (2) Reaction with β-aminoethyl alcohol 2HOC ₂ H ₄ NH _{2 + H 2 O + CO 2 →} (HOC 2 H 4 NH 3) 2 CO 3

[0009] The following reaction is used for the above method. (3) Catalytic reaction of sprayed slaked lime aqueous solution and carbon dioxide Ca (OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O (4) Catalytic reaction of water glass and carbon dioxide H ₂ O + CO ₂ + Na ₂ O · nSiO ₂ → Na ₂ CO ₃ + nSiO ₂ + H ₂ O

In the above reaction, by increasing the activity of the reaction gas, the reaction can be promoted even at room temperature and near normal pressure. Specifically, a method of exciting the reaction gas to a chemically unstable state by a method such as corona discharge, spark discharge, glow discharge, self-sustaining discharge such as arc discharge, laser irradiation or ultraviolet irradiation is given. You can In particular, in the self-sustaining discharge, the reaction area can be increased by adopting a reactor as described later, while the laser and the ultraviolet rays make pinpoint reaction.

FIG. 1 is a schematic diagram of a gas reactor utilizing a discharge field. The gas reactor 10 has an electrode rod 12 arranged in the axial direction of a cylindrical reaction tube 11, a coil 13 is wound around the outer periphery of the reaction tube 11, and the electrode rod 12 generates a high voltage (not shown). It is connected to the device. By adjusting the voltage of the high voltage generator, self-sustaining discharge can be generated in the discharge field. The reaction tube 11 may be a normal electrode material, or the inner surface of the reaction tube 11 may be coated with a catalyst agent. Furthermore,
The material of the reaction tube 11 is a material highly reactive with greenhouse gases,
That is, if the greenhouse effect gas is carbon dioxide, quicklime or sodium salt may be used. If the material of the reaction tube 11 is made of such a reactive material, a storage device or a supply device for the reactive gas becomes unnecessary, and the gas conversion system can be simplified.

FIG. 2 is a schematic view of another gas reactor using a discharge field. Electrode nets 21, 21 are arranged at intervals in the gas reactor 20, and spheres 22 made of a reactive material are filled between them. The sphere 22 may be a high dielectric material whose surface is coated with a reactive material or a catalyst. Due to the discharge between the electrode nets 21, 21, the gas conversion reaction is promoted near the surface of the sphere 22.

If necessary in constructing the gas conversion reaction system, the reaction gas may be passed through a dryer and / or a gas mixer before being supplied to the reactor. An appropriate separator can be used to separate solid or liquid fine particles produced from the gas after the reaction. Examples of the separator include an electric dust collector, a HEPA filter, and an impactor.

[0014]

Example 1 A gas conversion reaction was carried out using carbon dioxide and ammonia gas as raw materials and using the gas reactor shown in FIG. Reaction vessel 1
The reaction temperature in 0 was 20 ° C., the reaction pressure was 1 Kgf / cm ² , and the discharge voltage was 5.0 KV. Carbon dioxide and ammonia gas were supplied at a theoretical ratio of 1: 2, and the residence time was 1 minute. The results of the conversion reaction are shown in Table 1. In addition, as a result of measuring the particle size in the generated aerosol with a particle size distribution analyzer, almost 0.01
It was less than μm.

In Examples 2 and 3 , the reaction was carried out by changing the concentration of the raw material carbon dioxide. The results of the conversion reaction are shown in Table 1.

Comparative Examples 1, 2, 3 In Examples 1 to 3, comparative experiments were conducted under the same conditions except that the discharge was not performed. However, no conversion reaction of carbon dioxide occurred at any concentration.

Reference Examples 1, 2 and 3 Using carbon dioxide and ammonia gas as raw materials, a gas conversion reaction was carried out using the same gas reactor as in FIG. No discharge was performed, reaction temperature was 190 ° C, reaction pressure was 175 Kgf / cm ²
And Carbon dioxide and ammonia gas were supplied at a theoretical ratio of 1: 2, and the residence time was 1 minute. The results of the conversion reaction are shown in Table 1.

[0018]

[Table 1]

[0019]

According to the method of the present invention, a greenhouse gas,
In particular, carbon dioxide gas can be efficiently reduced. Also,
By carrying out the conversion reaction in the excited state of gas, it becomes possible to promote the reaction even in a state close to normal temperature and pressure. Furthermore, by passing the converted product through a filter, there is an excellent effect that it can be reliably separated and removed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a gas reactor using a discharge field.

FIG. 2 is a schematic view of another gas reactor using a discharge field.

[Explanation of symbols]

 10, 20 Gas reactor 11 Reaction tube 12 Electrode rod 13 Coil 21 Electrode net 22 Sphere

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Mori No. 1 Tsukutocho, Shinjuku-ku, Tokyo Kumagai Gumi Tokyo Head Office Co., Ltd. (72) Masahiro Kobayashi No. 2 Tsukudo-cho, Shinjuku-ku, Tokyo Kumagai Gumi Tokyo Head Office

Claims (3)

[Claims] 1. A method for reducing a greenhouse effect gas, which comprises reacting a greenhouse effect gas with a gas or an aerosol highly reactive with the gas to convert a part of the greenhouse effect gas into a liquid or a solid. 2. The greenhouse gas reduction method according to claim 1, wherein the reaction is performed in an excited state of the reaction gas. 3. The greenhouse gas reduction method according to claim 1, wherein the converted greenhouse gas is separated from the greenhouse gas by a filter.