JPH0375201A - Methanol reformer - Google Patents

Abstract

PURPOSE:To obtain hydrogen and carbon monoxide, etc., in excellent heat effect and a low cost by using a high-temperature gas generated by burning of a combustible gas such as hydrogen in contact with a burning catalyst as a heat source necessary for decomposing or modifying reaction of methanol. CONSTITUTION:Methanol or methanol and water as raw materials are supplied from a nozzle 6 to a preheating and transferring tube 7 and preheated by the waste gas for burning. Next, preheated raw materials are transferred to evaporating and superheating tube 8 and heated with a high-temperature gas generated by contact burning with a burning catalyst charged in the other periphery and a fuel such as hydrogen, etc., supplied from a nozzle 1, then subjected to evaporation and superheating. Thus, the evaporated and superheated raw materials are introduced into a decomposing or modifying reacting tube group 11 filled with a methanol decomposing or modifying catalyst and heated with a high- temperature gas generated by contact burning with burning catalyst charged in the outer periphery and a fuel from the nozzle 1 to be decomposed or modified. Next, a generated gas is gathered in a gas gathering part 13 filled with a impurity removing catalyst and impurities are removed, then a generated gas is recovered from a nozzle 14.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a methanol reformer that produces b or H3 and CO by decomposing or reforming methanol, and in particular,
The present invention relates to a methanol reformer that can be used in a manufacturing reaction device for fuel cells, a manufacturing reaction device for metal reduction, etc.

[Conventional technology]

Conventionally, a fixed bed reactor has been used as a catalyst for a methanol reforming reaction to produce H2 from methanol in view of its catalyst strength. This reaction is a large endothermic reaction,
The heat source is generally indirectly supplied using a high temperature heat medium obtained from a heat medium boiler or the like.

[Problem to be solved by the invention]

In a fixed bed reactor that absorbs heat, reaction efficiency is determined by how efficiently heat is supplied. Conventionally used heating medium systems require large costs for heating medium equipment and have problems such as being economically disadvantageous.

In view of the above-mentioned state of the art, the present invention aims to provide a methanol reformer that solves the problems of the prior art.

[Means to solve the problem]

The present invention consists of: (1) A raw material preheating transfer pipe that preheats raw material methanol or methanol and water using combustion exhaust gas; (2) A preheated raw material evaporation/superheating pipe connected to the raw material preheating transfer pipe and filled with a combustion catalyst on the outer periphery; A group of raw material decomposition or reforming reaction tubes that are connected to the evaporation/superheating tubes, the inside of which is filled with a methanol decomposition or reforming catalyst, and the outer periphery of which is filled with a combustion catalyst; The present invention is a methanol reformer characterized by comprising a gas collecting section filled with a catalyst for removing impurities from the produced gas.

The present invention is a methanol reformer that employs a direct heating method using a combustion catalyst instead of the conventional heat medium heating method.

That is, as a heat source necessary for the decomposition and reforming reaction of methanol, H2 or other combustible gas is used as fuel and is combusted in contact with a solid powder combustion catalyst to generate high-temperature gas, and the raw material methanol is evaporated with the gas. The predetermined reaction heat is directly applied to the methanol reaction tube group by heating it and guiding it to the outside of the methanol reaction tube group, which is also filled with solid powder combustion catalyst, while the inside of the methanol reaction tube group is heated. The led superheated methanol vapor is caused to undergo a catalytic reaction by a methanol decomposition or reforming catalyst filled inside the reaction tube group.

As mentioned above, the heat source necessary for this methanol catalytic reaction is supplied from the combustion gas led to the outside of the methanol reaction tube group. It is preferable that the methanol is introduced into the space of the outer cylinder surrounding the cylinder, and is preheated and evaporated in a raw methanol heat exchanger provided in the space, so that the methanol is discharged after being lowered in temperature.

On the other hand, methanol decomposed or reformed in the methanol reaction tube group is H2, Co mixed gas or H2, CD.

The mixed gas is collected and collected from the tube group.

In particular, H2. When C mixture gas is used as a hydrogen source for a hydrogen fuel cell, H, CQJ, which is obtained by reforming methanol, is used as a hydrogen source for a hydrogen fuel cell.
Contains %CO. This CO poisons the electrodes of hydrogen fuel cells and must be removed. This CO reacts with l'+20 by the CD shift catalyst filled in the space gathered from the methanol reaction tube group, becomes CO2, and most of it is reduced. In addition, the solid powder combustion catalyst is also filled outside the methanol reaction tube group, including the methanol evaporation and superheating section, to completely burn the unburned 1 hour, increasing safety and increasing the combustion gas flow rate outside the methanol reaction tube group. This reduces the membrane resistance outside the methanol reaction tube and improves the heat transfer coefficient into the methanol reaction tube group.

[Effect]

A solid powder combustion catalyst burns room temperature hydrogen without an ignition source such as a spark to generate high-temperature combustion gas, and secures the amount of heat necessary for preheating, vaporization, superheating, and reaction of raw methanol, and still produces solid powder. By filling the combustion catalyst outside the reaction tube group, unburned hydrogen is completely combusted, the film resistance outside the reaction tube group is lowered, the heat necessary for the reaction is efficiently supplied, and the reaction products are reacted. The target components can be efficiently recovered by collecting at the outlet of the tube group and filling the collecting part with a CD shift catalyst to reduce CO.

The methanol decomposition reaction and methanol reforming reaction as used in the present invention are as follows.

decomposition> C) IsOH-CD + 2H2 modification>
CHaOH+ nLO- (1-n)CO+ncO2+ (2+n)L(0<n<
l) Further preferred reaction conditions are as follows.

Note that the following catalysts are suitable as catalysts that can be used in the present invention.

(1) Methanol decomposition or reforming catalyst■ Pt,
Catalyst containing one or more elements of the group consisting of Pd, Rh, and Ni Catalyst containing one or more elements of the group consisting of Cu, Zn, and Cr (2) Combustion catalyst ■ One or more of the group consisting of Pt and Pd Catalyst containing the elements ■ Catalyst containing one or more elements of the group consisting of Fe, Ni, Co, Mn, and Cu r3) CD shift catalyst Catalyst containing Cu and Zn [Example] Hereinafter, one of the present invention will be described. Examples will be described with reference to the accompanying drawings.

In the figure, 1 is a supply nozzle for fuel (hydrogen and air), and 2 is a disperser that uniformly disperses the fuel, and also has a flashback prevention function for hydrogen combustion gas. 3 is a combustion gas discharge nozzle, and 4 is a rectangular inner cylinder that guides the combustion gas to a methanol evaporation, superheater 8, and methanol decomposition/reforming reaction tube 11. Reference numeral 5 designates an outer cylinder for guiding the combustion gas to the exhaust nozzle 3. Between this inner cylinder and the outer cylinder, a methanol raw material supply nozzle 6 leads the raw material, and the outer periphery of the inner cylinder 4 is coiled to preheat the raw material. A coil-shaped preheater 7 is provided, and this coil-shaped preheater 7 is connected to an evaporator/superheater 8 for raw methanol via the inside of the inner cylinder 4. The evaporator/superheater 8
The piping is coiled, and the outside of the piping is filled with solid powder combustion catalyst (not shown), and the fuel distributor 2
The fuel supplied from is ignited and burned by the combustion catalyst, and 4
It becomes a combustion gas with a temperature of 00 to 1000°C and evaporates and superheats the raw material methanol. This superheated methanol vapor is supplied from the header 9 through a rectifying orifice 10 to each cracking/reforming reaction tube 11 after being rectified. There is also a solid powder combustion catalyst between the outside of the reaction tube 11 and the inner tube 4 (No. 1118 shown in the figure).
is charged, the fuel hydrogen is completely combusted, the flow rate of the combustion gas is increased, the film resistance on the outer wall of the reaction tube 11 is reduced, and the reaction tube 11 is
This results in improved heat transfer inward.

On the other hand, the methanol vapor supplied into the reaction tube 11 catalytically reacts with the methanol decomposition/reforming catalyst filled in the reaction tube 11 . The amount of heat required for this reaction is supplied from the combustion gas on the outer wall of the reaction tube 11. Reference numeral 12 denotes a holding plate that holds the catalyst inside the reaction tube 11 and is made of punched metal. The reaction products are discharged from the punched metal openings and generated gas collection section 13
This collecting part is filled with a CD shift catalyst (not shown) to reduce CO as an impurity.

The produced gas from which the impurity CD has been removed is recovered from the produced gas recovery nozzle 14.

Next, a methanol reforming test was conducted using the methanol reformer shown in the drawing, and the results were as follows.

Raw material supply amount 5 kg/H■20/
Methanol ratio 1.5 mol/mol Fuel supply amount (H2) 1.5 m3/H Combustion air amount ? 'm3/H combustion catalyst (wt
%, Pd: 0.5. CeL: 9.5A12
0s: 90) Pd-containing catalyst 51 Methanol reforming catalyst [in wt%, Cub: 55. ZnQ:42A1203
:8 ] ZnO-containing catalyst 31 CO removal catalyst [in wt%, Cub: 50. ZnO: 4
0AtiOa:lO] ZnO-containing catalyst 0.51! Methanol conversion rate: 99.8wt% COW degree in generated gas (dry base): 1.0% [Effects of the invention] As explained above, the present invention can safely and reliably obtain high-temperature gas by using a combustion catalyst, Note that it is possible to obtain a target product gas with improved thermal efficiency and significantly reduced impurities by using an impurity removal catalyst. Further, by making the most effective use of the space, the scale of the device can be made more compact.

[Brief explanation of drawings]

The accompanying drawings illustrate a system that is an embodiment of the present invention. FIG. 2 is a schematic diagram of a Lureformer. the law of nature

Claims (4)

[Claims] (1) Raw material preheating transfer pipe that preheats raw material methanol or methanol and water using combustion exhaust gas (2) A preheated raw material evaporation/superheating pipe connected to the raw material preheating transfer pipe and whose outer periphery is filled with a combustion catalyst. (3) A group of raw material decomposition or reforming reaction tubes connected to the evaporation/superheating tubes, filled with a methanol decomposition or reforming catalyst inside, and surrounded by a combustion catalyst. (4) A methanol reformer comprising a gas collecting section that collects the produced gas of the reaction tube group and is filled with a catalyst for removing impurities from the produced gas.