JPH10328555A - Double tube type reactor and degraded catalyst exchanging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double tube type reactor and a degraded catalyst exchanging method capable of easily performing the exchanging work of a catalyst without necessitating large scale work when a reforming catalyst is degraded and reaches the limit of the life. SOLUTION: The double tube type reactor is formed from a jacket 15 having a closed shaped tip part 47 and an inner tube 17 provided inside of the jacket 15 and a short pipe 49 having an outside diameter smaller than that of jacket 15 and formed to have a closed shaped tip part 53 is attached to the tip part 47 of the double tube type reactor 45 having communicating part 10 communicating the jacket 15 and the inner tube 17 with each other in the vicinity of the tip part 47 so as to enable to be connected to the communicating part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a reforming apparatus,
In particular, the present invention relates to a double tube type reaction tube which is suitable for use in a small reformer for a fuel cell and a method for replacing a deteriorated catalyst thereof.

[0002]

2. Description of the Related Art In general, a reforming apparatus is operated by a large-sized apparatus for producing hydrogen and the like by a reforming reaction from a hydrocarbon as a raw material in the field of petrochemicals. For this reason, a small reformer has been developed and is being tested.

Here, FIG. 2 shows a schematic system around a reformer using natural gas as a raw material, and description will be made based on this.
The area around the reforming apparatus mainly includes a reformer 1, a desulfurizer 3, a plurality of preheaters 11, 39, a plurality of pipelines 27, and the like. Based on these configurations, the natural gas 5 is first supplied to the desulfurizer 3, where the sulfur content in the natural gas 5 is removed, and the natural gas 5 becomes the raw material gas 7. Then, this raw material gas 7
Is mixed with the steam 9, preheated to a predetermined temperature by the raw material preheater 11 using the reformed gas 23 as a heat source, and supplied from the gas supply nozzle 13 of the reformer 1 to the inside of the reformer 1. The supplied raw material gas 7 passes through the reforming catalyst layer 19 filled in the gap between the outer tube 15 and the inner tube 17 of the reaction tube having a double tube structure from the lower part of the reaction tube to the upper end. At this time, the raw material gas 7 receives heat from the combustion portion 21 outside the outer tube 15 and is converted into a reformed gas 23 containing hydrogen by a reforming reaction. Then, the reformed gas 23 changes its direction by 180 ° toward the inside of the inner tube 17 at the tip of the reaction tube, and flows downward in the reaction tube. Then, heat is applied to the raw material gas 7 flowing through the reforming catalyst layer 19 between the inner pipe 17 and the outer pipe 15 to perform self-heat recovery, while being guided from the reformed gas outlet nozzle 25 to the reformed gas pipe 27. Then, the heat is recovered again in the raw material preheater 11 and supplied outside the system. As a heat source, a burner 29 is installed on the upper part of the reformer 1, and fuel is supplied to the burner 29 through a fuel supply pipe 31 and a valve 33. On the other hand, air
The air from the air blower 35 passes through the valve 37 and exchanges heat with the combustion exhaust gas 40 in the air preheater 39 to convert the burner 2 into preheated air 41.
9. Further, the combustion exhaust gas 40 used as a heat source of the reforming reaction is supplied again to the air preheater 39 from the combustion exhaust gas outlet nozzle 43 below the reformer 1, and after preheating the air, is discharged to the atmosphere.

Further, the structure of the tip of the double tube type reaction tube 45 inside the reformer 1 will be described in detail with reference to FIG. The double tube type reaction tube 45 has a structure in which the inner tube 17 of the reaction tube is arranged inside the outer tube 15 of the reaction tube.
Catalyst layer 1 filled with catalyst in the gap between the inner tube 17 and the reaction tube
9 are formed. A closing cap 47 is attached to the tip of the outer tube of the reaction tube 15, and the outer tube 15 has a double tube structure having a communicating portion 10 at which the outer tube 15 and the inner tube 17 communicate with each other. . In addition, the closing cap 47
Is integrally formed with the outer tube 15 of the reaction tube by welding or the like so that the reformed gas 23 does not leak outside.

[0005]

Since the performance of the reforming catalyst deteriorates with the operating time of the reformer and reaches its service life, it is necessary to replace the deteriorated reforming catalyst with a new catalyst. Therefore, before the reformer was installed on the base, the catalyst was filled upside down, that is, in a reversed state, so the reforming catalyst was replaced by removing the reformer from the base. After reversing, a method of extracting the reforming catalyst and filling it with a new catalyst is conceivable. However, many devices are provided around the reformer, and the replacement operation itself is not practical. In other words, the reformer of the prior art is in the test operation stage, and the operation time is within the life of the catalyst, so that the replacement work must be performed when the reforming catalyst has deteriorated and has reached the life. The structure is not considered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a double-tube reaction tube capable of easily performing a catalyst replacement operation without performing a large-scale operation when a reforming catalyst has deteriorated and reaches the end of its life. It is to provide a catalyst exchange method.

[0007]

In order to achieve the above-mentioned object, the present invention comprises an outer tube having a closed end and an inner tube provided inside the outer tube. In a double-tube reaction tube having a communication portion in the vicinity of a distal end portion for communicating the outer tube and the inner tube, a hollow tube having one end closed is attached so as to be connectable to the communication portion. In this case, if the hollow tube is cut at the time of replacement of the deteriorated catalyst, it is possible to take out the deteriorated catalyst filled in the gap between the outer tube and the inner tube from the cut portion through the communication portion, and thereafter,
It is possible to charge a fresh catalyst. As a result, it is possible to easily perform the catalyst replacement operation without performing a large-scale operation such as inverting the reformer.

Further, in the double tube type reaction tube according to the first aspect, the hollow tube is provided with a member for shutting off the communication portion with the hollow tube. In this case, the member can prevent the reformed gas from entering the inside of the hollow tube.

Further, in the double tube type reaction tube according to claim 1 or 2, the outer diameter of the hollow tube is smaller than the diameter of the outer tube. In this case, even when a plurality of double-tube reaction tubes are close to each other, the space is not limited by the hollow tube attached to another double-tube reaction tube in the catalyst replacement operation.

[0010] An outer tube having a closed end portion;
An inner tube provided inside the outer tube, wherein the outer tube and the inner tube of a double-tube reaction tube having a configuration in which the outer tube and the inner tube communicate with each other near the distal end. In the deteriorated catalyst replacement method of replacing the catalyst filled in the gap between the tubes, a hollow tube having one end closed is attached so as to be connectable to the communication portion,
This is a method for exchanging a deteriorated catalyst in which the hollow tube is cut at the time of catalyst replacement, the catalyst is taken out from the cut portion, and a new catalyst is filled. According to this method, if this hollow tube is cut at the time of replacement of the deteriorated catalyst, it is possible to take out the deteriorated catalyst filled in the gap between the outer tube and the inner tube from the cut portion through the communication portion, and then to remove the new catalyst. Can be filled.
As a result, it is possible to easily perform the catalyst replacement operation without performing a large-scale operation such as inverting the reformer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the inside of a tip portion of a double tube type reaction tube 45 in a reformer 1 according to the present invention, which will be described with reference to the drawings. That is, in the double tube type reaction tube 45, the reaction tube inner tube 17 is provided inside the reaction tube outer tube 15, the catalyst is filled in the gap between the reaction tube outer tube 15 and the reaction tube inner tube 17, and the reforming catalyst layer 19 is formed. It is configured such that a hollow tube 49 having a diameter smaller than the diameter of the reaction tube outer tube 15 and a cap 53 integrally formed by welding or the like is attached to the front end of the reaction tube outer tube 15. On the other hand, inside the hollow tube 49, a conical cone 51 that partitions the communicating portion 10 from the hollow tube 49 is arranged. The reformed gas 23 flows from the lower part to the upper part in the reforming catalyst layer 19, and does not enter the hollow tube 49 from the cone 51 and the double tube type reaction tube 4.
At the front end of the tube 5, the direction is changed by 180 ° toward the inside of the reaction tube inner tube 17, and flows downward of the double tube type reaction tube 45. Although the reforming catalyst 19 used here varies depending on the raw material, the operating conditions, and the like, the catalyst deteriorates in the operation time of about four years, and the performance of the reformer 1 deteriorates. And
When the reforming catalyst 19 has deteriorated, the catalyst must be replaced. At that time, the cutting portion 55 of the hollow tube 49 is cut along the entire circumference of the hollow tube 49. Then, the cap 53 integrally formed with the supporting portion 52 supporting the cone 51 is removed, and a hose (not shown) such as a vacuum pump is inserted through a cutting opening (not shown) to extract the deteriorated catalyst. Then, a new catalyst is refilled from the opening. Further, after filling, the cut portion 55 thus cut is re-welded.

[0012]

According to the present invention, when the reforming catalyst has deteriorated and has reached the end of its service life, the replacement of the catalyst can be easily performed without performing a large-scale operation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a tip portion of a double-tube reaction tube according to the present invention.

FIG. 2 is a system diagram of a conventional reformer.

FIG. 3 is a longitudinal sectional view of a tip portion of a conventional double tube reaction tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Communication part 15 Reaction tube outer tube (outer tube) 17 Reaction tube inner tube (inner tube) 19 Reforming catalyst (layer) 45 Double tube type reaction tube 49 Hollow tube 51 Member (cone) 55 Cutting part

Claims (4)

[Claims] 1. An outer tube having a closed end portion and an inner tube provided inside the outer tube, wherein the outer tube and the inner tube communicate with each other near the tip portion. A double tube type reaction tube having a communication portion, wherein a hollow tube having one end closed is attached so as to be connectable to the communication portion. 2. The double-tube reaction tube according to claim 1, wherein a member is provided in the hollow tube to block the communication between the hollow tube and the communicating portion. 3. The double-tube reaction tube according to claim 1, wherein an outer diameter of the hollow tube is smaller than a diameter of the outer tube. 4. An outer tube having a closed end portion and an inner tube provided inside the outer tube, wherein the outer tube and the inner tube communicate with each other near the tip portion. In the deteriorated catalyst exchange method for exchanging a catalyst filled in a gap between the outer tube and the inner tube of a double tube type reaction tube having a communication portion, a hollow tube having one end closed can be connected to the communication portion. A method for replacing a deteriorated catalyst, wherein the method comprises attaching the catalyst, replacing the hollow tube when replacing the catalyst, removing the catalyst from the cut portion, and filling the catalyst with a new catalyst.