JPH01264904A - Apparatus for reforming hydrocarbon - Google Patents

Abstract

PURPOSE:To effectively utilize the heat of combustion gas and to make the whole apparatus compact by forming a reaction tube with coaxially arranged tubes, and heating the catalyst beds in the inner and outer passages of the reaction tube from both the inner and outer peripheries. CONSTITUTION:A fuel such as methane and air are supplied to a burner 3 to generate combustion gas. The combustion gas is sent upward through the inside of a sleeve 31, and discharged to the upper end of a first passage 41 through penetrating holes 311. A part of the discharged combustion gas descends in the passage 41, reverses at the lower end, and is discharged from an outlet pipe 45 through a second passage 42. The residual combustion gas is passed through a communicating passage 112, and sent downward in a third passage 43, reversed at the lower end, sent upward in a fourth passage 44, and discharged from an outlet pipe 45 through a communicating passage 145. Meanwhile, the raw gas consisting of gaseous hydrocarbons such as natural gas, etc., and steam. Is supplied to the inner passage 21 from a supply pipe 20 through the upper space 50 of a furnace body, and catalytically converted to H2 and CO while being sent upward in the outer passage 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydrocarbon reforming apparatus for producing hydrogen for use in fuel cells, for example, by steam reforming of hydrocarbons.

[Conventional technology]

Conventionally, as a hydrocarbon reformer, for example,
The one proposed in -102801@publication is known. This consists of a reaction tube in which an inner layer passage and an outer layer passage are formed that communicate with each other due to a triple tube structure, a fuel supply tube arranged on the outside of this reaction tube, and a combustion exhaust gas formed in the center of the reaction tube. The raw material gas passed from the inner layer passage to the outer layer passage and the combustion gas passed from the outer peripheral surface side to the inner peripheral surface side of the reaction tube and first discharged from the exhaust path flow in opposite directions. It is structured as follows.

While passing through the reaction tube, the raw material gas is supplied with heat from the combustion gas and reformed into reformed gas.

[Problem to be solved by the invention]

In the conventional hydrocarbon reformer described above, heat transfer from the combustion gas to the inner layer passage is performed from the inner peripheral surface of the reaction tube, and heat transfer from the combustion gas to the outer layer passage is performed from the outer peripheral surface of the reaction tube, In either passage, the catalytic reaction is carried out by supplying heat from only one side.

For this reason, it cannot be said that the heat of the combustion gas is fully utilized, and since the reactor II is determined in correspondence with the heat supply tank, the volume of the reaction tube is also relatively large.

This invention was made to solve these conventional problems, and provides a hydrocarbon reforming device that can fully utilize the heat of combustion gas and can be made more compact than conventional ones. is intended to provide.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a reaction tube filled with a catalyst, a combustion gas guide path, and a heat supply means for supplying combustion gas, and the reaction tube has a plurality of coaxially arranged cylinders. An annular inner layer passage and an annular outer layer passage are formed between the shaped bodies, and these passages are formed to communicate with each other at one end thereof, and the combustion gas guide path is constituted by two guide paths, one of which The guide path is formed so that the combustion gas supplied from the heat supply means is guided along the inner circumferential surface of the inner layer passage and the outer circumferential surface of the outer layer passage. It was formed so as to be guided along the outer circumferential surface of the inner layer passage and the inner circumferential surface of the outer layer passage.

Further, in claim 2, the reaction tube has a reaction tube filled with a catalyst, a combustion gas guiding path, and a heat supply means for supplying combustion gas, and the reaction tube is arranged in an annular shape between a plurality of coaxially arranged cylindrical bodies. An inner layer passage and an outer layer passage are formed, and these passages are formed so as to communicate with each other at one end thereof, and the combustion gas guide path is constituted by two guide paths, one of which is connected to the above-mentioned supply passage. The combustion gas supplied from the heating means is formed so as to be guided along the inner circumferential surface of the inner layer passage and the outer circumferential surface of the outer layer passage, and the other guide path is formed so that the combustion gas is guided along the outer circumferential surface of the inner layer passage. The raw material gas is supplied to the other end of the inner layer passage, and the raw material gas and the combustion gas flow in parallel with each other.

(Function) According to the structure of claim 1, both the inner and outer peripheral surfaces of the inner and outer passages of the reaction tube are in contact with the combustion gas guide path, so that the catalyst layer in the passages is in contact with the combustion gas guide path. receives heat transfer from both sides of this passage.

Therefore, compared to the conventional case where heat is transferred only from one side, the heat transfer area is approximately twice, and the amount of heat absorbed increases accordingly. As a result, the amount of catalyst can be reduced, the volume of the reaction tube can also be reduced, and the entire fruiting apparatus can be made compact.

According to the structure of claim 2, since the combustion gas and the raw material gas flow in parallel to each other, the temperature difference between the combustion gas in the high temperature section and the raw material gas in the inlet section to which heat is supplied by this combustion gas is relatively large. Therefore, a relatively large amount of heat can be transferred from the combustion gas in the high temperature section.

〔Example〕

In FIG. 1, the reformer basically consists of a reaction tube 1, a combustion burner (heat supply means) 3, a combustion gas guide path 4, and a furnace body 5.

The reaction tube 1 includes five cylindrical bodies 11. each having a different diameter.
By arranging 12.13 and 14.15 coaxially,
It is formed integrally with the combustion gas guide path 4. An annular inner layer passage 21 is formed between the innermost first cylinder 11 and the second cylinder 12, and an annular outer layer passage 22 is formed between the fourth cylinder 14 and the fifth cylinder 15, and A third annular guide path 43 is formed between the second cylinder 12 and the third cylinder 13, and a fourth annular guide path 44 is formed between the third cylinder 13 and the fourth cylinder 14, respectively. has been done.

The third guide path 43 is arranged so that the inner layer passage 21 and the outer layer passage 22 communicate with each other at their lower ends, and the first cylinder 11 passage 43 and the fourth guiding path 44 communicate with each other at their lower ends. The lower end of the tube 13 is spaced upwardly by a predetermined distance from the closed bottom portion.

At the upper end of each of the first cylinder 11 and the second cylinder 12,
A plurality of communication passages 112 are formed radially through the inner side of the first cylinder 11 and the third guide passage 43 to communicate with each other, and similarly, the upper ends of the fourth cylinder 14 and the fifth cylinder 15 are respectively Also, a plurality of communicating passages 145 are formed radially through the fourth guiding passage 44 and the outside of the fifth cylinder 15 to communicate with each other.

The inner space between the inner layer passage 21 and the outer layer passage 22 is filled with an alumina-nickel-based reforming catalyst S, and a pair of passages 21 and 22 are formed inside and outside of this, and the height of the reaction tube 1 is approximately 2 times the height of the reaction tube 1.
A reforming catalyst layer with twice the quality is formed. The upper end 211 of the inner layer passage 21 is opened upward, and the lid 5 of the furnace body 5
Raw material gas supplied from raw material gas supply pipes 20 arranged once per furnace flows through an upper space 50 of the furnace body 5. Further, one end 61 of a coil heat exchanger 6 provided in the upper space 50 of the furnace body 5 is connected to the upper end 221 of the outer layer passage 22. It is connected to the port 63.

As a result, the raw material gas supplied from the raw material gas supply pipe 20 passes through the inner layer passage 21 and the outer layer passage 22 and is reformed into reformed gas, and this reformed gas is passed through the reformed gas outlet 63 through the heat exchanger i56. It is made so that it can be taken out from.

The reaction tube 1 is attached to the furnace body 5 at a predetermined distance from the bottom surface 52 and inner surface 53 thereof. Further, a cylindrical sleeve 31 of the combustion burner 3 is disposed in the center of the reaction tube 1, and an annular first guide path 41 is provided between the outer peripheral surface of the sleeve 31 and the inner peripheral surface of the first n11. It is attached to the bottom surface 52 of the furnace body 5 so as to be formed therein. There is a combustion burner 3 inside this sleeve 31.
is provided with its tip facing upward, and when the fuel and air supplied to this combustion burner 3 are combusted, the combustion gas is released into the internal space of the sleeve 31,
This combustion gas is released to the upper end of the first guide path 41 from a large number of through holes 311 formed at the upper end of the sleeve 31.

The annular space between the outer peripheral surface of the reaction tube 1, that is, the outer peripheral surface of the fifth fi 115, and the inner surface 53 of the furnace body 5 constitutes a second guide path 42, and this second guide path 42 and the second The guide passages 41 of 1 and 1 communicate with each other via the bottom surface of the reaction tube 1 and the bottom surface 52 of the furnace body 5.

Further, the first to fourth mutually communicating guideways 41.4
The upper end surfaces of 2.43 and 44 are opened respectively, and the second
The upper end of the guide path 42 communicates with four combustion gas exhaust pipes 45 provided through the furnace body 5. As a result, one continuous taxiway is composed of the first taxiway 41 and the second taxiway 42, and the other continuous taxiway is composed of the third taxiway and the fourth taxiway 44. Ru.

And the first to fourth taxiways 41, 42゜43.4
The internal space of 4 is filled with a filler B such as alumina balls or Raschig rings, which adjusts the residence time of the combustion gas to be relatively long and promotes heat transfer.

Note that P in the figure indicates a heat insulating material.

In the reformer having the above configuration, combustion gas is generated by supplying a fuel such as methane and air to the combustion burner 3 and combusting them. This combustion gas rises inside the sleeve 31 and passes through the through hole 311 to the first guide path 4.
1 is released at the upper end. A part of the released combustion gas descends through the first guide path 41, turns back at the lower end thereof, passes through the second guide path 42, and is discharged from the combustion gas exhaust pipe 45. Further, the remaining part of the combustion gas released into the upper end of the first guideway 41 flows down through the communication path 112 to the third guideway 43, turns back at the lower end thereof, and returns to the fourth guideway. 44, is guided to the upper end of the second guiding path 42 via the communication path 145, and is discharged from the combustion gas exhaust pipe 45.

On the other hand, a raw material gas consisting of gaseous hydrocarbons such as natural gas and water vapor is supplied from the raw material gas supply pipe 20 to the inner layer passage 21 through the upper space 50 of the furnace body 5.

Then, the raw material gas descends along the inner layer passage 21, turns back at the lower end, and ascends the outer layer passage 22, and while passing through the catalyst layers in these passages 21 and 22, the raw material gas becomes mainly hydrogen due to a catalytic reaction. and carbon monoxide. By passing through the heat exchanger 6, this reformed gas exchanges heat with the raw material gas passing through the upper space 50, whereby the reformed gas is lowered to a predetermined temperature and taken out from the reformed gas outlet 63. At the same time, the raw material gas is preheated.

The combustion gas is transferred from the combustion burner 3 to the combustion gas outlet pipe 43
The catalyst layer of the inner layer passage 21 is guided to the first
The combustion gas flowing through the guide path 41 and the third guide path 43 causes damage from both the inner and outer peripheral surfaces (the first cylinder 11 and the second cylinder 12), and the contact The combustion gas flowing through the guide path 44 and the second guide path 42 transfers the heat necessary for the catalytic reaction from both the inner and outer peripheral surfaces (the fourth cylinder 14 and the fiftieth cylinder 15) through radiation heat transfer and filling. Heat is supplied by heat conduction through object B.

As a result, the heat transfer area of the catalyst layer in the inner layer passage 21 and the outer layer passage 22 is approximately twice that of the conventional heat supply from one side, and correspondingly, the heat transfer area of the catalyst layer in the inner layer passage 21 and the outer layer passage 22 is approximately twice that of the conventional heat supply from one side. Therefore, the required amount of catalyst can be reduced compared to the conventional method, and this can contribute to making the device more compact. For example, the amount of hydrogen generated is several thousand N11t/h.
As a small-sized reformer, it can be constructed compactly with only one reaction tube 1 shown in FIG.

In addition, during the above heat supply, the combustion gas in the guide passages 41, 42, 43, 44 and the raw material gas or reformed gas in the outer layer passage 21, 22 of the reaction tube 1 are connected to the first, which is the heat transfer surface. Second
, the fourth and fifth cylinders 11, 12, 14, and 15 are configured to flow in parallel to each other, so that the combustion gas flows at the inlet portion of the combustion gas, that is, at the upper end of the first guiding path 41. , the temperature difference between the combustion gas and the source gas or reformed gas becomes relatively large. Therefore, on the upper end 21] side of the inner layer passage 21, which is the inlet portion of the raw material gas, the amount of heat transferred is large due to the large temperature difference, and the heat of the relatively high temperature combustion gas immediately after combustion in the combustion burner 3 is effectively used. can be used.

Furthermore, since the combustion gas and the raw material gas flow in parallel, the raw material gas that has not yet received heat from the combustion gas is supplied from the upper end portion 211 of the inner layer passage at the inlet portion of the combustion gas. As a result, the wall surfaces of the first and second cylinders 11 and 12 are cooled, thereby making it possible to suppress the rise in the wall temperature W of the reaction tube 1 to a relatively low level.

Therefore, a lower grade material can be used for the reaction tube 1 than in the case where the reaction tube 1 is configured to have counterflow, and a reduction in cost can be expected.

Furthermore, since the combustion burner 3 is disposed in the center of the reaction tube 1, which would normally be an extra space, it is possible to save space and contribute to the compactness of the entire apparatus.

In addition, by changing the quality or type of the filling B filled in the guideways 41, 42, 43, 44, it is possible to change the residence time of the combustion gas, and thereby adjust the degree of heat supply. can do. Therefore, the filling material B may not be filled at all.

In the above embodiment, the combustion gas and the raw material gas or the reformed gas are configured to flow in parallel, but the configuration is not limited to this, and as shown in FIG. You may drive as you like.

That is, in FIG. 2, the raw material gas is supplied from the reformed gas outlet 63 to the upper end 221 of the outer layer passage 22 via the heat exchanger 6, contrary to the case shown in FIG. The reformed gas is reformed by descending, turning back at the lower end, and ascending the inner layer passage 21, and the reformed gas is passed from the inner layer passage upper end 211 through the upper space 50 to the raw material gas supply pipe 2.
It is sufficient to start from 0.

In this case as well, since heat is supplied to the catalyst layers in the passages 21 and 22 of the reaction tube 1 from both their circumferential surfaces, the heat transfer area can be increased as in the case of parallel flow shown in FIG.

Furthermore, in the embodiment shown in FIG. 1, the combustion burner 3 is provided penetrating the furnace body 5 from below, but for example, as shown in FIG. Good too. In FIG. 3, the sleeve 31a of the combustion burner 3a is provided so as to communicate with the upper end of the center of the reaction tube 1, that is, the upper end of the first guide path 41, and the upper end surface A cylinder 5 having a fireproof layer 501 on
5 is fixed on the bottom surface 52 of the furnace body 5.

As a result, the combustion gas from the combustion burner 3 descends within the sleeve 31a and is discharged to the upper end of the first guide path 41. Then, this combustion gas flows into the third guide path 43 via the first guide path 41 and the communication path 112, so that the catalyst layers in the inner layer path 21 and the outer layer path 22 are similar to the device shown in FIG. is heated from both sides. Note that the flow directions of the combustion gas and the raw material gas or the reformed gas are not limited to parallel flows, but may be counterflows.

Note that the reforming apparatus shown in FIGS. 1 to 3 can obtain the same effect even if its vertical arrangement is completely reversed.

〔Effect of the invention〕

According to the hydrocarbon reforming apparatus of claim 1 of the present invention, the catalyst layers in the inner passage and the outer passage of the reaction tube receive heat from both the inner and outer sides of the passage. Therefore, the heat of the combustion gas can be fully utilized, and the heat transfer area is almost double compared to the conventional case where heat is transferred only from one side, and the corresponding amount of heat per unit volume of the catalyst is increased. The amount of heat absorbed can be increased. As a result, the required amount of catalyst can be reduced, so the volume of the reaction tube can also be reduced, and the entire fruiting apparatus can be made compact.

According to the structure of claim 2, in addition to the effect of the invention of claim 1, since the combustion gas and the raw material gas flow in parallel to each other, heat is supplied by the combustion gas on the upstream side of the high temperature section and this combustion gas. The temperature difference with the raw material gas at the inlet section becomes relatively large, and a relatively large amount of heat corresponding to this temperature difference can be obtained from the combustion gas at the high temperature section, and the heat of this combustion gas can be used effectively. be able to.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram of an embodiment of this invention, and FIG.
FIG. 3 is an explanatory cross-sectional view showing the case where the direction of supply of raw material gas to the reaction tube in the apparatus shown in the figure is reversed, and FIG. 3 is an explanatory cross-sectional view showing the case where the combustion burner is disposed at the upper part. 1... Reaction tube, 3... Combustion burner (heat supply means),
4... Combustion gas guide path, 5... Furnace body, 11... First cylinder, 12... Second cylinder, 13... Third cylinder, 1
4... Fourth cylinder, 15... Fifth cylinder, 21... Inner layer passage, 22... Outer layer passage, 41... First guideway (one guideway), 42... ...Second taxiway (one taxiway), 43...Third taxiway (other taxiway), 4
4...Fourth guideway (the other guideway), S...catalyst. Patent applicant: Representative of Kobe Steel, Ltd. Patent attorney: Etsushi Kotani
Patent Attorney 1) Masamukai Patent Attorney Takao Ito Figure 1 Figure 2

Claims (1)

[Claims] 1. It has a reaction tube filled with a catalyst, a combustion gas guide path, and a heat supply means for supplying combustion gas, and the reaction tube is composed of a plurality of coaxially arranged cylindrical bodies. An annular inner layer passage and an outer layer passage are formed in between, and these passages are formed to communicate with each other at one end thereof, and the combustion gas guide path is constituted by two guide paths, one of which The guide path is formed so that the combustion gas supplied from the heat supply means is guided along the inner circumferential surface of the inner layer passage and the outer circumferential surface of the outer layer passage, and the other guide path is formed so that the combustion gas is guided along the inner circumferential surface of the inner layer passage. A hydrocarbon reforming device characterized in that it is formed so as to be guided along the outer peripheral surface of the passage and the inner peripheral surface of the outer layer passage. 2. It has a reaction tube filled with a catalyst, a combustion gas guide path, and a heat supply means for supplying combustion gas, and the reaction tube has an annular inner layer passage between a plurality of coaxially arranged cylindrical bodies. and an outer layer passage are formed, and these passages are formed so as to communicate with each other at one end thereof, and the combustion gas guide passage is constituted by two guide passages, one of which is the heat supply passage. The combustion gas supplied from the means is formed so as to be guided along the inner circumferential surface of the inner layer passage and the outer circumferential surface of the outer layer passage, and the other guiding path is formed so that the combustion gas is guided along the outer circumferential surface of the inner layer passage and the outer circumferential surface of the outer layer passage. and the raw material gas is supplied to the other end of the inner layer passage,
A hydrocarbon reformer characterized in that the raw material gas and the combustion gas are configured to flow in parallel with each other.