JPS61287435A - Catalytic reaction apparatus - Google Patents

Abstract

PURPOSE:To enhance the heat transmissivity and to miniaturize the apparatus by inserting a catalyst whose base is a porous metallic body interposed between a larger diameter heat-transfer pipe and a smaller diameter heat-transfer pipe and by providing a combustion chamber at the upper part of each double heat- transfer pipe. CONSTITUTION:Air is introduced from an air-inlet 19 and fuel is introduced from a fuel-inlet 18, thus the combustion is carried out in the combustion chamber 12. On the other hand, steam and methane gas fed from an inlet 15 are introduced from a chamber 7 into the reaction chamber 6 placed in each double heat-transfer pipe. Steam and methane gas fed into the reaction chamber 6 are heated to ascend by the burned gas which is outside the double heat-transfer pipe, and the reaction is carried out by the catalyst 11 whose base is the porous metallic body. The resultant hydrogen is introduced into the inner part of the smaller diameter heat-transfer pipe, passes through the porous metallic body 10, then descends and is exhausted from the outlet 16 of a chamber 8. The burned gas used for heating steam and methane gas is exhausted from an outlet 17.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a catalytic reaction apparatus for use in producing a product gas from a feed fuel, such as producing hydrogen from a hydrocarbon fuel.

[Prior art] Conventionally, this type of catalytic reaction device and 1 No.
There is a structure as described in Japanese Patent No. 8983.

Now, to explain the above-mentioned known catalytic reaction device, the third
As shown in Figures 4 and 4, a plate b is provided at the lower part of the furnace a, and on the plate b, a number of cylindrical walls C are arranged parallel to the furnace axis. , the cylindrical wall C
A tubular reactor d, which has an outer diameter smaller than the inner diameter and whose upper end is closed, is placed upright, and a center tube e is placed inside the tubular reactor d with a required spacing, and further inside the center tube e. A cylindrical plug f is arranged concentrically in the cylindrical reactor d. The gap between them is an annular reaction chamber, and the inner surface of the center tube e and the cylindrical plug f
An annular regeneration chamber 1 is defined by the gap between the outer surface of the Further, at the lower end of the annular burner gas passage 9 is an outlet conduit j for high temperature gas, at the lower end of the annular reaction yh is a supply conduit k for a mixture of steam and hydrocarbon fuel, and at the lower end of the annular regeneration chamber i is a reaction conduit k. Product exit conduit! are connected to each other, the annular burner gas passage g is filled with alumina spheres m, and the annular reaction chamber is filled with catalyst particles n.

Furthermore, a burner combustion manifold 0 and an air manifold p are formed separately at the upper end of the furnace a, and the burner combustion manifold 0 is supplied with furnace fuel through a conduit q. At the same time, air is supplied to the air manifold p via a conduit r, combustion of fuel and air is performed in a burner cavity S, and the high temperature gas generated here passes through an annular burner gas passage 9. It's Nishide.

Thus, in the conventional catalytic reactor described above, a conduit supplies a mixture of steam and hydrocarbon fuel which enters the annular reaction chamber where it is heated by the hot gas descending in the annular burner gas passage g. The reaction begins in the presence of catalyst particles n. The reaction products that have moved upwards in the reaction chamber descend through the regeneration chamber i.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional catalytic reaction device, combustion is performed in the burner cavity S located at the - side of the tubular reactor d, but due to radiation heat transfer J: It is difficult to use low-heat-generating fuel due to the decrease in combustion moisture, ■ Due to the large heat capacity of the alumina bulbs 11, it takes time for the furnace to warm up, and the startup is a circling motion, ■ Catalyst particles There are problems such as fluidization of n occurs, ■ overall size increases, etc.

Therefore, the present invention is primarily aimed at achieving quick start-up and miniaturization.

[Means for Solving the Problems] The present invention provides a porous structure in which a plurality of double heat exchanger tubes are placed side by side in a furnace, and continuous holes are formed between each outer heat exchanger tube and inside the inner heat exchanger tube. a reaction chamber between the inner surface of the outer heat exchanger tube and the outer surface of the inner heat exchanger tube,
The base is made of a porous metal with continuous pores, and a catalyst is fitted in it, allowing a mixture of steam and hydrocarbons to be supplied to the lower part of each reaction chamber, and each double layer is made of a porous metal with continuous pores so that a mixture of steam and hydrocarbons can be supplied to the lower part of each reaction chamber, and combustion gas is guided to the outside of the outer heat exchanger tube. The combustion chamber is located above the heat exchanger tubes.

[Function] When the combustion gas is guided between the outer heat exchanger tubes, it flows through the numerous pores of the porous metal. On the other hand, when a mixture of water vapor and hydrocarbons is sent to the reaction chamber, the mixture is warmed by the surrounding high-temperature gas and rises. During this time, the mixture is reformed by a catalyst and converted into hydrogen and other gases. enters the inner heat transfer tube at the upper end of the reaction chamber, descends, and is taken out to the outside.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a double heat exchanger tube consisting of a large diameter heat exchanger tube 2 with its upper end closed and a small diameter heat exchanger tube 3 located at its axial center is installed inside a vertically elongated furnace 1. Multiple books (7 in the figure)
The lower ends of the large-diameter heat exchanger tubes 2 are supported by a plate 4, and the lower ends of the small-diameter heat exchanger tubes 3 are supported by a plate 5 that penetrates the plate 4 and is provided at the lower part of the furnace 1. The space between the large-diameter heat exchanger tube 2 and the small-diameter heat exchanger tube 3 is defined as a reaction chamber 6, and the lower end of the reaction chamber 6 is opened into the chamber 7 between the plates 4 and 5. The heat exchanger tube 3 has an upper end opened into a reaction chamber 6, and a lower end opened into a chamber 8 below the plate 5.

The space 9 formed between the outside of each large-diameter heat exchanger tube 2 constituting each of the double heat exchanger tubes and the furnace inner wall is made of a porous metal (mainly composed of copper or iron and having continuous pores). Spongy metal) 10 cut into appropriate sizes are stacked and fitted, and similarly cut porous metal 10 is fitted inside each small diameter heat exchanger tube 3. On the other hand, reaction chamber 6
Inside, a catalyst 11 based on a porous metal formed of nickel as a main component and formed to have continuous pores is incorporated.

A combustion chamber 12 is provided above each of the double heat transfer tubes, and an air jacket 13 is provided on the outer periphery of the combustion chamber 12, and a radiant air jacket made of porous ceramic (ceramic foam) is provided at the bottom of the combustion chamber 12. Install the converter 14.

Note that the porous metal-based catalyst is manufactured as follows.

That is, a solution is prepared by dissolving or suspending a compound containing both or one of alkaline earth metal elements such as aluminum, silicon, and magnesium, and transition metal elements such as titanium, zirconium, and vanadium in water or an organic solvent. . Next, the surface of the porous metal body mainly composed of nickel is cleaned by degreasing and pickling, and then the above solution is applied to the surface of the porous metal body to form a thin film of the compound. form,
Next, after drying the porous metal body on which a thin film of the above compound has been formed, it is oxidized in an oxygen-containing atmosphere at a high temperature of 1000° C. or higher for a long time, and then the oxidized nickel is formed as a main component. It is produced by reducing a porous metal body in a reducing gas stream of hydrogen or carbon monoxide.

In Fig. 1, 15 is an inlet for steam and hydrocarbon fuel provided in the chamber 7, 16 is an outlet for hydrogen gas, 17 is an outlet for combustion gas, 18 is an inlet for fuel into the combustion chamber 12, and 19 is an inlet for air. It is.

When air is introduced from the air inlet 19 and fuel is introduced from the fuel inlet 18, combustion occurs within the combustion chamber 12. Combustion chamber 1
If a radiation converter 14 made of porous ceramics is provided on the lower side of the combustion chamber 12 as shown in the figure, the radiation converter 14 can repel radiant heat and trap it in the combustion chamber 12.
The internal temperature can be raised to stabilize combustion, and as a result, even if low calorific value fuel is used, combustion can be stabilized and the low calorific value fuel can be used. Therefore, if the combustion in the combustion chamber 12 is stable, the radiation converter 14 may be omitted.

On the other hand, when steam and hydrocarbon fuel, such as methane gas (CH4), are supplied from the inlet 15, they enter the reaction chamber 6 in each double heat exchanger tube from the chamber 7.

The combustion gas generated by combustion in the combustion chamber 12 flows into the space 9 outside each double heat exchanger tube. A porous metal body 10 is fitted into the space 9, and the porous metal body 10 has a large surface area, so it has good heat transfer performance, and has a large number of pores, so the combustion gas can flow through it without any problem. Can pass.

The water vapor and methane gas that entered the reaction chamber 6 are heated by the combustion gas outside the double heat transfer tube and rise, and in the rising process, a catalyst 11 based on a porous metal body disposed inside the reaction chamber 6 causes Cto14 +H20-1Co
→-3112CO+[''2O-1CO2→-1''2 reaction is performed. Hydrogen that has completed the reaction in the reaction chamber 6 enters the inside of the small diameter heat exchanger tube 3 at the upper end of the reaction chamber 6.
It passes through the porous metal body 10 in the heat transfer tube 3 and descends, and is taken out from the chamber 8 and the outlet 1G. The combustion gas used to heat the steam and methane gas is discharged from the outlet 17.

[Effects of the invention] 10- or more
A plurality of double heat exchanger tubes are arranged C, and a porous metal body is fitted into the space between each double heat exchanger tube and the inner wall of the furnace and inside the small diameter heat exchanger tube of each double heat exchanger tube, and the large diameter heat exchanger tube of the double heat exchanger tube is fitted. Since the structure is such that a catalyst based on a porous metal body is fitted into the reaction chamber between the heat transfer tube and the small-diameter heat exchanger tube, the following excellent effects can be achieved.

ff) Since a porous metal body is fitted into the outer wall and the inner wall so as to sandwich the reaction chamber, and the high-pressure surface area of the porous metal body is utilized, (1) a high heat transfer rate is achieved; The device can be made smaller.

■) It has a small heat capacity and can be started up in a short time.

Oi9 The porosity of the porous metal body is large, making it suitable for ventilation.
The pressure loss is small.

00 The heat transfer tube can be a double tube, and one tube can be made thicker.
There is no need for a separate sealed tube installed in the center as in the conventional case, and it can be made up of 1 to 100 ml.

(II) Since a catalyst based on a porous metal body is used in the reaction chamber, the heat transfer f11 of the catalyst is good, and one can be thickened. That's great.

[Phase] In addition, by using a porous ceramic radiation converter in the downstream part of the combustion chamber, it is possible to trap the radiant heat in the furnace, increase the g, and stabilize combustion. Therefore, it becomes possible to use low calorific value fuel.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the catalytic reaction device of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, FIG. 3 is a cut side view of a conventional catalytic reaction device, and FIG. It is a sectional view in the B direction of the figure. 1 is a furnace, 2 is a large diameter heat exchanger tube, 3 is a small diameter heat exchanger tube, 6 is a reaction chamber, 7 and 8 are rooms, 9 is a space, 10 is a porous metal body, 11
12 is a combustion chamber, 13 is an air jacket, and 14 is a radiation converter.

Claims (1)

[Claims] 1) Stand a plurality of double heat exchanger tubes side by side in a furnace, fit a porous metal body into the outer wall of the large diameter heat exchanger tube and the inner wall of the small diameter heat exchanger tube of each double heat exchanger tube, and A catalyst made by fitting a catalyst based on a porous metal body into a reaction chamber between a heat exchanger tube and a small-diameter heat exchanger tube, and comprising a combustion chamber above each of the double heat exchanger tubes. Reactor.