JPH045419A - Exhaust gas treating device - Google Patents

Abstract

PURPOSE:To exactly clean exhaust gas by providing return passages in the upstream of exhaust gas passage in order to decompose carbon dioxide or nitrogen oxide of the exhaust gas by magnetites, and to re-treat the treated exhaust gas. CONSTITUTION:Cells 15 filled with magnetites 14 are inserted into exhaust cylinders 12, 13 connected to each of passages 10, 11. Carbon dioxide or nitrogen oxide in exhaust gas is decomposed by the magnetites 14 activated by the lack of oxygen atoms. Return passages 10a, 11a are provided in order to return a part of the exhaust gas to the passages 10, 11 for re-treating, which gas has been treated by exhaust gas treating units 7, 8. Carbon dioxide gas or nitrogen oxide of the exhaust gas can thus be exactly treated and decomposed in to carbon or nitrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust gas treatment device that reduces or eliminates carbon dioxide and nitrogen oxides in exhaust gas.

[Prior art]

As a conventional technique of this kind, Japanese Patent Application Laid-Open No. 63-113112
As shown in the publication, multiple catalysts such as platinum vanadium and platinum rhodium are arranged in series in the exhaust gas passage to oxidize carbon monoxide to carbon dioxide gas and convert nitrogen oxides NOx to nitrogen gas N2 for exhaust gas treatment. There is a device.

[Problem to be solved by the invention]

The conventional methods mentioned above are not only expensive, but also emit carbon oxide as carbon dioxide gas (despite the fact that the emission of carbon dioxide gas, which is currently a cause of global warming around the world, must be suppressed). , it is not a complete purification measure.

Furthermore, because the exhaust gases have to pass through different catalysts at multiple locations, the engine's output is reduced and more fuel is required, which in turn generates more exhaust gases. The problem was that it did not purify the exhaust gas.

[Means to solve problems]

In order to solve the above-mentioned problems, the present invention is an exhaust gas treatment device that decomposes carbon dioxide or nitrogen oxides in exhaust gas using magnetite activated by removing oxygen atoms, and processes the treated exhaust gas again. This exhaust gas treatment device is characterized in that a flow path is provided for returning the exhaust gas to the upstream side of the flow path.

[Effect]

The basic function of the exhaust gas treatment device is to make effective use of magnetite (ferrite).

In other words, the molecular structure of magnetite is composed of one divalent iron (Fe), which has two cations, and trivalent iron (Fe”), which has three cations.
There are two Fe"), resulting in a total of eight positive charges, which combine with four oxygen (0") containing anions to form Fe10. This magnetite is stable at 250℃ to 600℃ (the optimum temperature is 2
50℃~300℃) reacts with hydrogen (H7) to form oxygen (0
2) escapes as water (H20>), and oxygen-deficient active magnetite is obtained.In other words, active magnetite is hereinafter referred to as oxygen-deficient magnetite (de, 04-x), but this activation magnetite is heated to 250℃~6
It is in a state where chemical reactions requiring oxygen molecules can occur at 00°C (the temperature suitable for GT is 250°C to 300°C).

Therefore, when oxygen-deficient magnetite in this state is reacted with carbon dioxide gas, it becomes carbon and inactive magnetite, and then when hydrogen is reacted with this inactive magnetite, it rapidly becomes active magnetite and water. If we convert this into a chemical reaction formula, F e x 04 +y H2→Fe
, 04-x 1y H>0)' eqo4-x
+1/2yCO, → 1/2:yc+Fe,O.

It is.

Therefore, the magnetite provided in the middle of the exhaust passage of an internal combustion engine is converted into oxygen-deficient magnetite as described above, and the exhaust gas is brought into contact with this to decompose part of the carbon dioxide gas into carbon and water, which are then discharged and nitrogen oxides are removed. Discharge as nitrogen gas.

〔Example〕

Describing one embodiment of the present invention in detail, numeral 1 is a four-cylinder diesel engine, which is a type of internal combustion engine, and numeral 2 is its exhaust manifold.

3 is an oxygen separation device provided in the exhaust passage 2a of each cylinder of the exhaust manifold 2.

Reference numeral 4 denotes a gas cylinder containing an oxygen-free gas such as hydrogen or helium (hydrogen will be used in this embodiment).

5 is an oxygen-free gas extraction passage.

Reference numeral 6 designates a switching valve that transfers the exhaust gas that has passed through the oxygen separator 3 for each cylinder and collected in the collection pipe 3a and the oxygen-free gas from the gas cylinder 4 to the exhaust gas processing units 7 and 8, which will be described later. It is a two-way selection type valve that selectively allows the water to flow into either direction.

Reference numeral 9 denotes an on-off valve provided in the middle of the oxygen-free gas extraction passage 5.

Reference numerals 7 and 8 are exhaust gas processing units provided separately in flow paths 10 and 11 leading to the two outlet ports of the switching valve 6,
Cells 15 and 1 are filled with magnetite 14 (sintered and formed in a shape with a large number of holes 14a for ventilation) in exhaust pipes 12 and 13 connected to each flow path 10 and 11.
Further, a heater 16 is provided on the outer periphery of the exhaust pipes 12 and 13 in which the cells 15 and 15 are installed to keep the part where the magnetite 14 is installed at a temperature of 250°C to 300°C. (This heater 16 is not necessary if the magnetite 14 is kept at 250° C. to 300° C. by engine heat).

17 and 18 are exhaust gas stirring devices provided in the exhaust pipes 12 and 13, respectively, and stirring blades 7a and 18a are rotated by electric motors 17b and 18b to stir the exhaust gas throughout the magnetite 14 and 14. 6 10a and lla are return flow paths provided to
・A part of the exhaust gas treated in step 8 is returned to flow paths 10 and 11.
It is designed to be returned to the factory for reprocessing. Furthermore, 10b・
A suction fan llb is provided to forcibly return a portion of the treated exhaust gas to the flow paths 10 and 11.

Reference numeral 19 denotes a muffler, which discharges the exhaust gas from the exhaust pipes 12 and 13 into the atmosphere through its open port 20.

21... are bolts for attaching and detaching the exhaust manifold 2 to the diesel engine l, and 22... are bolts for attaching and detaching the cover portion 2b of the exhaust manifold 2 together with the muffler 19.

To explain the upper operation in detail, the exhaust gas from each cylinder of the diesel engine 1 flows into each oxygen separation device 3...
In each oxygen separator 3..., oxygen ○a is released into the air, producing carbon dioxide gas C○2 and nitrogen oxides N.

The exhaust gas mixed with X flows out toward the switching valve 6 through the collecting pipe 3a. Then, the exhaust gas is transferred to the switching valve 6
On the other hand, hydrogen H2 in the gas cylinder 4 passes through the passage 5 and the on-off valve 9, and flows into the flow passage 10 via the switching valve 6. Then, in the exhaust gas processing section 8 connected to the flow path 11 through which the exhaust gas flows, if the magnetite 14 is activated by passing hydrogen H2 in advance, the magnetite itself becomes oxygen-deficient magnetite Fe, 0. - Since it is transformed into x, 1 of carbon dioxide gas CO2! ! The oxygen-deficient magnetite takes in the oxygen OX of element 02 or NOx, and carbon C precipitates or escapes as nitrogen gas N2. At this time, the exhaust gas is stirred throughout the magnetite 14 by the exhaust gas stirring device 18.

The above exhaust gas is decomposed well.

On the other hand, in the exhaust gas treatment section 7 into which hydrogen H2 is sent,
Inert magnetite Fe, 0. Exhaust gas stirring device 1
The hydrogen H, stirred in step 7 acts, and this hydrogen H2 drives out the oxygen 02 in the magnetite, resulting in oxygen-deficient magnetite.

That is, on the exhaust gas treatment section 7 side,
, 0 chemical reaction takes place, and on the exhaust gas treatment section 8 side, )"e, 04-x+C○2 → C+ Fe,
, 04 or Fe, 04-x+2NOx-+N2+ )'e, +oa
A chemical reaction occurs.

Regarding nitrogen oxides (NOx), the reaction is extremely fast and purification of nitrogen oxides is carried out fairly quickly, but for carbon dioxide gas (C○2), the reaction is slow and it is necessary to pressurize the exhaust gas treatment section. is desirable.

After continuing the state shown in Fig. 2 for a predetermined period of time (approximately 1 to 3 minutes), the switching valve 6 is switched so that the exhaust gas flows into the flow path 10 and the hydrogen H2 flows into the flow path 11. When switched, the exhaust gas will be purified by the same effect as described above.

In the exhaust gas purification process, the exhaust gas treatment section 7.
A part of the exhaust gas treated in step 8 is returned to the flow path 10a/ll.
Since the exhaust gas is returned to the flow paths 10 and 11 at step a for reprocessing, the exhaust gas can be purified accurately.

The on-off valve 9 on the hydrogen H2 feed side is the switching valve 6.
By opening the opening for a predetermined period of time (approximately 10 seconds to 30 seconds) and then closing it in conjunction with switching, it is possible to eliminate waste of hydrogen H2.

In the above example, an example was shown in which an oxygen-free gas (hydrogen or helium) was used as a means to expel oxygen from magnetite to form oxygen-deficient magnetite. -2) Any means may be used, such as expelling the The larger the area, the better the decomposition efficiency, so it is better to make the contact area as wide as possible. In addition, the return flow path 1
Although an example is shown in which suction fans 10b and 11b are used for 0a and lla, any means may be used to return the exhaust gas. Furthermore, although a diesel engine is shown as an example of the internal combustion engine in the embodiment described above, any other internal combustion engine such as a gasoline engine, a gas engine, or a thermal power generator may be used.

[Effect]

This invention relates to an exhaust gas treatment device that decomposes carbon dioxide or nitrogen oxides in exhaust gas using magnetite activated by removing oxygen atoms, in which the treated exhaust gas is returned to the upstream side of the flow path for further treatment. Since the exhaust gas treatment device is equipped with a flow path, it is possible to accurately decompose carbon dioxide and nitrogen oxides in the exhaust gas into carbon and nitrogen, and successfully solve the above-mentioned conventional problems. .

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic plan view of the entire device, and FIG. 2 is a side view taken along the line A--A in cross section. In the figure, symbol 1 is a diesel engine, 2 is an exhaust manifold, 3 is an oxygen separator, 4 is a gas cylinder, 5 is an extraction passage, 6 is a switching valve, 7 and 8 are exhaust gas treatment parts, 9 is an on-off valve, 10- 1
1 is a channel, 10a and 11a are return channels, 12 and 13 are exhaust pipes, 14 is magnetite, 15 is a cell, 16 is a heater, 17 and 18 are exhaust gas stirring devices, and 19 is a muffler.

Claims (1)

[Claims] (1) In an exhaust gas treatment device that decomposes carbon dioxide or nitrogen oxides in exhaust gas using magnetite activated by removing oxygen atoms, the flow that returns the treated exhaust gas to the upstream side for reprocessing. An exhaust gas treatment device characterized by having a passage.