JP2000080385A - Method for thermally decomposing hydrocarbon gas and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for thermally decomposing hydrocarbon gases which does not necessitate heating at a high temperature and enables reduction of the cost of equipment as well as prevention of coking, and an apparatus therefor. SOLUTION: Hydrocarbon gases to be decomposed are let uniformly flow through the space among porous tubes 4 constituting a series of porous tubes installed extendingly in the perpendicular direction in a decomposition reactor column 1 and air or oxygen is homogeneously spouted outwards from the inside of the porous tubes in the direction perpendicular to the flow of the hydrocarbon gases to be decomposed followed by ignition, thereby forming a diffusion flame layer at the outside of the porous tube 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for pyrolyzing hydrocarbon gas.

[0002]

2. Description of the Related Art Gasoline, LP gas, kerosene, light oil and the like are refined by atmospheric distillation of crude oil, but a large amount of naphtha is generated at the same time. Usually, the main component of naphtha is a paraffinic organic compound (normal paraffin, isoparaffin, etc.) and used as a feedstock oil.

Conventionally, a desired olefinic organic compound (ethylene, acetylene,
In order to obtain propylene, butene, etc.), it is usually necessary to decompose a paraffinic organic compound having a long-chain chemical composition into an olefinic organic compound having a short-chain chemical composition via a thermal decomposition device or the like.

[0004] As a conventional pyrolysis apparatus, there is a type in which gaseous naphtha and steam are flowed into a tube in a heating furnace, and the naphtha is thermally decomposed by heating from the outer surface of the tube to produce an olefinic organic compound. It was mainstream.

[0005]

In a process using a conventional pyrolysis apparatus, high-temperature heating (about 700 to 900 ° C.) is required, so that an increase in equipment cost and a problem of coking in a tube cannot be avoided. . In order to prevent this caulking, it was necessary to flow steam together with naphtha into the tube as described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for pyrolyzing a hydrocarbon gas which does not require high-temperature heating, can reduce equipment costs, and can avoid coking.

[0007]

The present invention has solved the above-mentioned problems as follows. That is, the hydrocarbon gas to be decomposed is brought into direct contact with air or oxygen to form a diffusion flame layer, which is used as a heat source to cause a radical reaction in the hydrocarbon gas to be decomposed to generate an olefin-based organic compound gas.

In order to form the diffusion flame layer, the hydrocarbon gas to be decomposed is uniformly flowed between the porous tubes of the group of porous tubes extending vertically in the decomposition reaction tower,
Out of the porous tube, in a direction perpendicular to the flow of the hydrocarbon gas to be decomposed, air or oxygen is uniformly injected and ignited to form on the outer surface of the porous tube, or conversely, The air or oxygen is uniformly flowed between the porous tubes of the group of porous tubes extending vertically in the decomposition reaction tower, and the air or oxygen flows out of the porous tubes at right angles to the flow of the air or oxygen. In the direction, the hydrocarbon gas to be decomposed is uniformly jetted and ignited, and is formed on the outer surface of the porous tube.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 is a conceptual diagram of a hydrocarbon gas pyrolysis apparatus according to a first embodiment of the present invention. In the figure, what is indicated by reference numeral 1 is a decomposition reaction tower having a diffuser 2 at the upper part and a reducer 3 at the lower part, and a porous tube group extends in the inside thereof in the vertical direction.
The reaction tower 1 may be a circular type or a rectangular type.

Each porous tube 4 of the porous tube group is made of a porous metal or MF (Micro Filtration), U
It is composed of a metal film material having a pore size up to F (Ultra Filtration). SUS, tool steel, Inconel, titanium alloy, aluminum alloy or the like is used as the porous metal or metal film material.

The upper end of each porous tube 4 is closed, and the lower end is connected to the header 5. The header 5 has a hollow plate shape, and a non-porous tube 7 connected to the porous tube 3 via a joint 6 protrudes from an upper surface thereof.

At the lower end of the diffuser 2 and above the porous tube group, a distributor 8 is provided. An ignition system 9 is provided between the outer surfaces of the upper portions of the porous tubes 4.

The diffuser 2 has an inlet 2a for a hydrocarbon gas to be decomposed such as a paraffin-based gas, and the reducer 3 has an outlet 3a for a decomposed and purified gas such as an olefin-based gas.
Is provided. The header 5 is provided with a supply nozzle 5a for air or oxygen.

Next, the operation will be described.

The hydrocarbon gas to be decomposed obtained by evaporating naphtha and the like is supplied from the inlet 2a of the decomposition reaction tower 1, rectified by the distributor 8, and is uniformly distributed between the porous tubes 4 from the upper part of the reaction tower 1. Flows to

The air or oxygen supplied from the supply nozzle 5a flows perpendicularly to the flow of the hydrocarbon gas to be decomposed from the metal porous pores to the outside due to the pressure difference between the inside and outside of the porous tube wall. It is ejected in the direction and homogeneously.

When ignited by the ignition system 9 in this state, the diffusion flame layer B is formed on the outer surface of the porous tube 4 as shown in FIG.
Which is a heat source and causes a hydrocarbon reaction gas such as paraffin-based gas to undergo a radical reaction (free radical reaction) to generate a shorter-chain olefin-based organic compound gas.

FIG. 3 is a conceptual diagram of a hydrocarbon gas pyrolysis apparatus according to a second embodiment of the present invention. The present embodiment is different from the first embodiment only in that the non-porous tube 10 is provided concentrically with a gap surrounding the outer periphery of the porous tube 4, and thus the description of the other components will be omitted. Omitted. That is, as shown in FIG. 4, air is caused to flow through the inner tube of the porous tube 4 and the inner tube of the double tube constituted by the outer tube of the non-porous tube 10, and the space (double) divided by the inner and outer tubes By flowing gaseous hydrocarbon gas to be decomposed into the pipe section)
As in the first embodiment, the hydrocarbon gas to be decomposed undergoes a radical reaction to generate a shorter-chain olefin-based organic compound gas.

In the above-described embodiment, air or oxygen is supplied from the inside of the porous tube 4 to the outside, and the hydrocarbon gas to be decomposed is flown outside the porous tube 4. The hydrocarbon gas to be decomposed may be supplied to the outside, and air or oxygen may be supplied to the outside of the porous tube 4.

In the above-described embodiment, the hydrocarbon gas to be decomposed is supplied to the decomposition reaction column 1. However, as shown in FIG. It is also possible to decompose into a gas and a residue by the heating device 13 and supply the generated gas to the reaction tower 1 via the pipe 12 and the inlet 2a.

In the above-described embodiment, the decomposition reaction tower 1
Although the inlet 2a is provided on the upper side and the outlet 3a is provided on the lower side, the inlet 2a of the decomposition reaction column 1 may be provided on the lower side and the outlet 3a may be provided on the upper side.

[0023]

The pyrolysis method and apparatus according to the present invention include:
Unlike the conventional cracking method and apparatus described above, a hydrocarbon gas to be cracked obtained by evaporating naphtha etc. is brought into direct contact with air or oxygen to form a diffusion flame layer, which causes a radical reaction using this as a heat source. By using the present method and apparatus, it is possible to generate a target olefinic organic compound gas without going through a high-temperature and high-pressure process, thereby reducing capital investment and avoiding coking.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a hydrocarbon gas pyrolysis apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIGS. 1 and 3;

FIG. 3 is a conceptual diagram of a hydrocarbon gas pyrolysis apparatus according to a second embodiment of the present invention.

FIG. 4 is a partially cut-away enlarged view of the double pipe portion of FIG. 3;

FIG. 5 is a view showing an apparatus for gasifying a solid raw material connected to a pyrolysis apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decomposition reaction tower 2 Diffuser 2a Inlet 3 Reducer 3a Outlet 4 Porous tube 5 Header 5a Supply nozzle 6 Joint 7 Non-porous tube 8 Distributor 9 Ignition system 10 Non-porous tube 11 Gasifier 12 Pipe 13 Heating equipment

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuzo Matsumura London, England 8,4 Eichiwai, Gloucester Walk, 38 A (72) Inventor Shoji Yoneda 1-1-1 Nikkocho, Fuchu-shi, Tokyo Japan Steel Works (72) Inventor Rokuro Denda 1-1 Nikko-cho, Fuchu-shi, Tokyo Inside Japan Steel Works, Ltd.

Claims (9)

[Claims] 1. A cracked hydrocarbon gas is brought into direct contact with air or oxygen to form a diffusion flame layer (B), which is used as a heat source to cause a radical reaction in the cracked hydrocarbon gas.
A method for pyrolyzing a hydrocarbon gas, comprising generating an olefinic organic compound gas. 2. A gas to be cracked is uniformly flowed between porous tubes (4) of a group of porous tubes extending vertically in a cracking reaction tower (1), and the gas flows from inside the porous tube. In addition, it is preferable to form a diffusion flame layer (B) on the outer surface of the porous tube (4) by uniformly blowing air or oxygen in a direction perpendicular to the flow of the hydrocarbon gas to be cracked and igniting the same. The method of claim 1, wherein the hydrocarbon gas is pyrolyzed. 3. A uniform flow of air or oxygen between porous tubes (4) of a group of porous tubes extending vertically in a cracking reaction tower (1) so as to flow out of the porous tubes. At right angles to the air or oxygen flow,
The method for pyrolyzing hydrocarbon gas according to claim 1, wherein the hydrocarbon gas to be decomposed is uniformly jetted and ignited to form a diffusion flame layer (B) on the outer surface of the porous tube (4). 4. The method for thermally decomposing hydrocarbon gas according to claim 1, wherein a synthetic gas obtained by thermally decomposing waste plastic is used instead of the hydrocarbon gas to be decomposed. 5. A cracking reaction column (1) having an inlet (2a) for supplying a hydrocarbon gas to be cracked at one end and an outlet (3a) for discharging a generated olefinic organic compound gas at the other end.
And a group of porous tubes extending vertically in the reaction tower (1), and each of the porous tubes (4) are connected to each other;
And a header (5) for supplying air or oxygen. 6. A cracking reaction tower (1) having an inlet (2a) for supplying air or oxygen at one end and an outlet (3a) for discharging generated olefinic organic compound gas at the other end. 1) A carbonization method comprising: a group of porous tubes extending in the vertical direction; and a header (5) connected to each porous tube (4) and supplying a hydrocarbon gas to be decomposed. Thermal decomposition equipment for hydrogen gas. 7. The hydrocarbon gas pyrolysis apparatus according to claim 5, wherein a non-perforated tube (10) is provided concentrically around the outer periphery of each porous tube (4). . 8. The pyrolysis of hydrocarbon gas according to claim 5, wherein a distributor (8) is provided on the inlet (2a) side of the cracking reaction tower (1). apparatus. 9. The heat of a hydrocarbon gas according to claim 5, wherein a synthetic gas obtained by thermally decomposing waste plastic is used in place of the hydrocarbon gas to be decomposed. Disassembly method.