JPH0312302A - Methanol reformer - Google Patents

Abstract

PURPOSE:To simultaneously impart a catalytic function and a heat transfer function to the reformer by arranging a finned pipe coated with the titanium carrying a platinum-based catalyst in a reaction vessel for reforming methanol to produce a hydrogen-contg. gas. CONSTITUTION:A film of rutile-type titania (having 0.01-0.5mm thickness) is formed on the outer surface of a finned pipe, and the metal such as Pt and Pd is deposited on the film. The catalyst-coated finned pipe is arranged in the reaction vessel, a heating medium is passed through the pipe, and methanol or water-contg. methanol is brought into contact with the catalyst on the outside of the pipe to obtain a hydrogen-contg. gas (contg. >=50% H2, <=35% CO and <=25% CO2). The reaction temp. is preferably controlled to 300-600 deg.C, the pressure is adjusted to 0-15kg/cm<2>G, and the molar ratio of the supplied water to methanol is controlled to <=5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a methanol reformer, and more specifically, a methanol reformer for reforming methanol or a mixture of methanol and water into a hydrogen-containing gas by contacting it with a catalyst. Regarding a reformer.

[Conventional technology]

Currently, crude oil and petroleum products refined from it are used to produce liquid fuel, gaseous fuel, and reducing gas used in power generation boilers, internal combustion engines, etc., but due to the recent rise in crude oil prices, fuel Methanol, which can be synthesized from fossil fuels other than crude oil, is attracting attention due to diversification.

Furthermore, since methano-μ is decomposed into hydrogen-containing gas at a much lower temperature than naphtha, it has the advantage that waste heat can be used as a heat source for the methano-μ decomposition reaction and steam reforming reaction. The methano-μ decomposition reaction is as follows (1),
f2) is the result of the formula.

CH,OH+CO+2E[! Mu J! 25”(”=2t
7kcaA/mot...(1) CH, OH+n horse 0-+(2+n)H,+(1-n)CO+nCO,=1
2) Here, the methanol-μ steam reforming reaction is expressed by the following equation (3).

CH, OH+H, O-+COt+3H1" 2 da-11,
8 kcaA/mO2・-(3) The gas produced in the above reaction has the advantage that the calorific value of the produced gas increases by the amount of heat absorption (ΔH) of the reaction, and furthermore, this produced gas has a high octane number and is suitable for internal combustion with a high output design. When applied to engines, it has the advantages of increasing the compression ratio to improve thermal efficiency, and eliminating emissions of aldehydes and other substances during methanol combustion, resulting in clean combustion.It can also be used as a non-polluting fuel for automobiles and power generation. is available.

Furthermore, hydrogen can be separated from the gas produced by the above reactions (1) to (3) and used as a hydrogen source for petroleum refining, hydrogenation reactions of various organic compounds in the chemical industry, etc. , ! Carbon monoxide can be separated from the gas produced in 21 and used as a source of primary monoxide.

[Problem to be solved by the invention]

Conventionally, when the head heat of exhaust gas from an engine, gas turbine, etc. is used as a heat source and a mixture of methano-y or methano-μ and water is used as a raw material for decomposition or steam reforming reaction, the exhaust gas temperature is 200% as is well known. Since it changes from ℃ to 700℃, it can be reformed over a wide temperature range with a small amount of catalyst that can be installed in an internal combustion engine, and the reforming performance will not deteriorate even if it is exposed to high temperatures of about 700℃ as mentioned above. A reforming method and a stable catalyst are required.

Ammina (
Catalysts have been proposed in which platinum metal elements such as platinum, base metal elements such as copper, nickel, chromium, zinc, and their oxides are supported on carriers such as 40s, but these catalysts are At present, many problems remain, such as lack of activity and a tendency to deteriorate over time.

In addition to the above-mentioned catalyst preparation method using the metal support method, there is also a preparation method using the precipitation method.A typical example of a catalyst prepared by this method is one for the synthesis of methanol containing zinc, chromium, and copper. There is a catalyst. Although this catalyst for methanol synthesis is generally known to be effective in the reaction of reforming methanol-μ into a gas containing hydrogen and carbon monoxide, it is susceptible to thermal deterioration.

In addition, the reactor is a V-type μ-and-tube heat exchanger type, and the tube is filled with a catalyst, and the raw material methanol to steam or the mixed vapor of methanol and water is mixed with the catalyst. It is reformed into a hydrogen-containing gas through a catalytic reaction. This reforming reaction is a large endothermic reaction, and the necessary reaction heat is supplied from the heating medium on the V-section side, but since the heat transfer rate is not very high, the temperature in the catalyst layer is not affected by the reaction heat. There is a problem in that it is difficult to increase the low reaction rate.

[Means to solve the problem]

Therefore, in order to increase the heat transfer rate of the reactor, the present inventors used a finned pipe as a methanol-reforming reactor, carried a catalyst on the outer surface of the pipe, and attached it to the reaction vessel. The inventors have discovered that by arranging a plurality of scales within a container, it is possible to have both a catalytic function and a heat transfer function at the same time, and based on this knowledge, the present invention has been completed. That is, the present invention provides an apparatus for reforming methano-μ or a mixture of methano-μ and water into a hydrogen-containing gas by bringing it into contact with a catalyst.
This is a methano-reforming apparatus in which a finned pipe carrying a catalyst is disposed in a reaction vessel, on which a metal of at least one member of the group consisting of platinum and palladium is supported.

(Detailed Description of the Invention) The present invention will now be described in further detail with reference to the accompanying drawings.

FIG. 1 is a partially cutaway perspective view of a catalyst-carrying finned pipe, in which fins 2 are attached to the outside of the pipe 1, and the outer surface of the finned pipe is coated with a film containing μ-chill type titania. is formed, and a catalyst is further supported thereon to constitute the catalyst element of the catalyst-carrying finned pipe 3.

The titania used in particular has a chill-type crystal form, and unlike anatase-type titania, which has a solid acid, this titania has basic properties, so it is free from by-products such as water, ethers, and carbon formation. The reaction is suppressed and methanol
It can be preferably applied as a catalyst for reforming reactions.

This Nf-μ type titania can be easily obtained by calcining anatase type titanium oxide, which is usually used as a catalyst carrier, at 600°C or higher, preferably 800 to 1000°C.

This titania film is coated on the outer surface of the finned pipe.
It is coated to a thickness of 01 to α5-.

The method for forming the film is as described above.
A method is used in which milled-shaped titania is made into a fine slurry using a wet ball mill, the slurry is coated by dipping, and then dried and fired, or titania powder is thermally sprayed. Considering the heat conductivity, it is preferable that the thickness of the film be as thin as possible, but considering the function as a catalyst, there is an effective thickness range.As a result of various studies, it was found that a thickness in the range of 101 to [15] is suitable. understood. In addition, in order to obtain a good bond between the finned pipe and the titania coating, it is best to apply the coating after making the outer surface of the finned pipe uneven by sandblasting etc. It is possible to obtain an excellent and strong film.

Further, one or more metals from the group consisting of platinum and baodium are supported on the μ-chi μ-type titania film.

The supporting method is to immerse the finned pipe coated with μ-type titania obtained by the above method in an aqueous solution of platinum, palladium chloride, or ammine complex of platinum, then dry and sinter it to obtain K. I can do it.

A heat medium is passed through the thus obtained catalyst-carrying finned pipe 3 to control the catalyst to an active temperature. Such a catalyst element itself may be a continuous nine-piece piece, or it may be an assembly of several independent elements, and may be selected as appropriate in consideration of ease of temperature control, ease of processing, manufacturing, etc. Just use it properly.

FIG. 2 is a schematic view of a catalyst-carrying finned pipe 3 in which a catalyst element is incorporated, in which a plurality of catalyst-carrying finned pipes 3 are arranged in a reaction vessel 4.

Using such a reaction device, a heat medium is passed through the catalyst-carrying finned pipe 3, and the catalyst formed on the outside is brought into contact with methanol or a mixture of methanol μ and water to bring the catalyst to an activation temperature. Through control, the desired reforming reaction can be carried out.

Note that the hydrogen-containing gas in the present invention means a gas containing 50% or more of hydrogen, 35X or less of -carbon oxide, and 25X or less of carbon dioxide.

Further, preferred reaction conditions in the methano-p reforming method of the present invention are as follows.

Reaction temperature = 200-700°C, particularly preferably 300-700°C
600°C reaction pressure crab O~3 owaia, especially good! Preferably, the ratio of water supply to 0 to 15 μm methanol is 10 or less, particularly preferably 3 or less.The present invention will be specifically explained with reference to Examples.

[Example 1] A stainless steel pipe with an outer diameter of IAφIIIq) was previously sandblasted to a thickness of 1 t and a diameter of 10 m.

A pipe with fins was manufactured by attaching 16 strip-shaped fins with a length of 300 mm at equal pitches around the circumference of the pipe. After coating the entire outer surface of this finned pipe with ~C type titanium asfree to an average thickness of CL2■t, dry it and heat it to 500°.
It was baked at C for 3 hours. Next, it was immersed in an aqueous solution of tetraammineplatinum dichloride (chemical formula: Pt(N)4C4), dried, and then calcined at 500°C for 3 hours to form a catalyst-carrying fin with 5 wt% of platinum supported on it, as shown in Figure 1. Pipe 3 was prepared.

Five catalyst-carrying finned pipes 3 are installed in a reaction vessel 4 as shown in FIG.
4% hydrogen gas was flowed into the reaction vessel 4 in the direction of the arrow for 5 hours while a heating medium of 1 was flowed into the pipe for reduction treatment.

Next, methanol is preheated and vaporized at a supply rate of 200 CC/h, and this gas is flowed into the reaction vessel 4 from the direction of the arrow to perform a methanol decomposition reaction. The temperature difference can be maintained within 10℃, and the methanol reaction rate is almost the theoretical amount for a 90x1 cracked gas composition of 14: 66 moLN, Co: 33
motXco, :cL2 mOL N, CH4
: α2 mot%, others = α6 motN.

[Practical example 2] Palladium (L
A finned pipe 3 carrying 5vtX was prepared.

This was incorporated into the reaction vessel 4 in the same manner as in Example 1,
After the hydrogen reduction treatment, a methanol decomposition reaction similar to that in Example 1 was performed, and the methanol reaction rate was 88X, and the cracked gas composition was the same as when the platinum-supported finned pipe catalyst was used.

[Example 3] Using the reactor incorporating the platinum-carrying finned pipe of Example 1, the temperature of the heat medium flowing into the pipe was set to 520°C, and the reaction vessel 4 was charged with methanol 00 W/h and water 100 c.
A methanol-μ reforming reaction was carried out in the same manner as in Example 1, except that superheated steam of c/h was supplied. As a result, the heat g
The temperature difference between the temperature and the heating temperature can be maintained within 5°C, and the methanol reaction rate at this time is 85%.
74 rnoLN, Co: 5 moA%,
CH4: (jmoA%, Co, : 23 n0
Performance with a gas composition of 1% was obtained.

〔Effect of the invention〕

As described above, according to the present invention, both the heat transfer function and the catalytic function can be provided at the same time, so the reactor itself can be made compact, and furthermore, it becomes easy to control the catalyst at the optimum activation temperature.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a catalyst-supporting finned pipe, and FIG. 2 is a schematic diagram of a catalytic reaction apparatus in which the catalyst-supporting finned pipe of FIG. 1 is assembled into a reaction vessel.

Claims (1)

[Claims] A catalyst-supported finned pipe in which a film containing rutile-type titania is formed on the outer surface of the finned pipe and one or more metals from the group consisting of platinum and palladium is supported on the film is placed in a reaction vessel. A methanol reformer characterized by: