JPS60200802A - Co converter - Google Patents

Abstract

PURPOSE:To simplify a converter and to reduce the cost by incorporating an inner tube packed with a catalyst for high temp. use and an outer tube packed with a catalyst for low temp. use into a single apparatus and by combining the apparatus with a heat exchanger for cooling. CONSTITUTION:Gas for conversion contg. gaseous CO, together with steam, is fed into an inner tube 31 from a gas inlet 37, and it is exchaused from a gas outlet 37' through an outer tube 32. In the inner tube 31, a cooling medium is fed into a group of cooling ipes from the bottom to cool catalyst 34 for the conversion reaction of CO at a high temp., and it is discharged from the top. In the outer tube 32, a cooling medium is fed into a group of cooling pipes from the top to cool a catalyst 35 for the conversion reaction of CO at a low temp., and it is discharged from the bottom. The outer tube 32 is kept at a lower temp. than the inner tube 31.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CO shift converter (also commonly referred to as a CO converter) used in a hydrocarbon steam reformer in hydrogen production.

FIG. 1 shows the flow of a conventional steam reformer. 1st
In the figure, 1 is a hydrocarbon reformer, 2 is a heat exchanger (cooler), 3 is a high-temperature CO shift device, 4 is a cooling heat exchanger,
5 is a low temperature CO converter. The reaction within the steam reformer is expressed by the following formulas (1) and (2), and is usually 65
It is carried out at a temperature range of 0 to 850°C.

OH4+H20-Co+! lH2・・・・・・(1
)00-1- H, O≠=co2+a2 -・・・・・・
(2) In the hydrocarbon reformer 1, the reaction mainly expressed by equation (1) is carried out, and in the high temperature CO shift equipment 3 and low temperature OO shift equipment 5, the reaction mainly expressed by equation (2) is carried out. It happens.

In the case where methane is used as a raw material, an example of the gas composition, temperature, and pressure of each line shown in FIG. 1 is shown in the table below.

The CO conversion (shift) reaction in the CO shift converter expressed by the above equation (2) is an exothermic reaction69, and the reaction proceeds further at low temperatures, so cooling is required.

For this reason, in the conventional equipment, high temperature and low temperature 00 shift equipment 3,
A heat exchanger 2.4 is provided in front of 5 for cooling.

When each device is separated in this way, piping, shutoff valves, control valves, etc. are added, and as a result, the entire device becomes complicated.

Conventional CO conversion equipment is used in steam reforming equipment for chemical plants, but in particular, it requires a small amount of hydrogen generation, such as distributed fuel cells, and is characterized by restrictions on CO concentration. In small-sized plants that place great emphasis on thermal economy, conventional methods tend to be complicated and thermally uneconomical, and are also costly.

The present invention provides a CO metamorphosis device that completely eliminates the drawbacks of the conventional devices.

That is, the present invention consists of a cylinder filled with a high-temperature CO conversion catalyst and an outer cylinder filled with a low-temperature CO conversion catalyst.
The present invention relates to a CO converter characterized in that a mixed gas consisting of shoulder gas and water vapor is made to flow through the inner cylinder and the outer cylinder in this order.

The device of the present invention is characterized by the following points.

(1) Omit an intermediate cooling device and provide a cooling function inside the CO converter.

(2) It must have high temperature and low temperature 00 shift devices in the same device, and a cooling function in the CO conversion catalyst layer.

(3) The inner cylinder is fully filled with a high-temperature CO conversion catalyst, and the outer cylinder is fully filled with a low-temperature 00 conversion catalyst.

The device of the present invention having such characteristics can be applied to a hydrogen backing device and a fuel reformer for a fuel cell power generation system.

The entire apparatus of the present invention will be explained below based on FIG. 2.

FIG. 2 shows an outline of the configuration of the CO converter of the present invention.

In the device shown in FIG. 2, a common end plate 33 is attached as a bottom plate to the double cylindrical tube consisting of the inner tube 31 and the outer tube 32.
It forms the main body container of the metamorphic device. The inner cylinder 31 contains a catalyst 34 for high-temperature CO conversion reaction, and the outer cylinder 32 contains a catalyst 35 for low-temperature CO conversion reaction, both of which are supported by perforated plates 36. . The raw material gas to be metamorphosed is supplied from the gas population 37 and descends inside the cylinder 31,
The gas rises inside the outer cylinder 32 through the bottom space 38 and is discharged from the system through the gas outlet 37' in a hydrogen-enriched state.

Further, cooling pipe groups 39 and 39' are provided penetrating the insides of the inner cylinder 31 and the outer cylinder 32, so that the heat generated in the catalyst layer can be absorbed and cooled. As the cooling medium, gases, liquids, and other materials that can be easily recovered and used as hot metals are used.

Converting gas containing CO gas enters the gas inlet 3 together with water vapor.
7 into the inner cylinder 31 9 and the perforated plate 36 via the bottom space 38
The gas passes through 32 outer cylinders and is discharged from the gas outlet 37'. - In the inner cylinder 31, the cooling medium enters the cooling pipe group 39 from the lower part, cools the high temperature CO conversion reaction catalyst 34, and is discharged to the upper cooling pipe group 39'. Further, in the outer cylinder 32, the cooling medium is cooled from the upper part to the cooling pipe group 39, and is then cooled to the low-temperature CO conversion reaction catalyst 35', and then discharged to the lower cooling pipe group 39'. In this case, cooling pipe group 39.3
9' is arranged so that the outer cylinder 32 side is kept at a lower temperature than the inner cylinder 31 side.

That is, an iron-chromium catalyst is used for the high-temperature CO conversion reaction in the inner cylinder 31, and a cooling system is installed at 250 to 350°C at the inlet and 400 to 500°C at the outlet. For the low-temperature CO conversion reaction, 0u-Zn system, 0u-Eli system,
A catalyst such as 0uO-ZnO-At203 system is used, and a cooling system is set up at 100 to 150°C at the inlet and at 250 to 300°C at the outlet.

After completing the conversion reaction in this way, the phosphorus gas is converted to c.

The residual concentration is usually reduced to 1% or less, and the resulting gas is mainly composed of CO2, H2, and excess water vapor, and is discharged from the system through the outlet 37' of the outer cylinder 32. The CO conversion reaction catalyst can be replaced by taking it out from the top using a suction method and refilling it.

In addition to reforming with LNG (methane), the device of the present invention
Modification using PG (propane) or methanol is also possible.

The present invention also provides the following effects.

(The heat generated in the reconversion reaction is transferred to the cooling medium,
By using this cooling medium for the t-V effect, heat recovery is possible and black loss in conventional piping can be prevented.

(2) Since the high-temperature/low-temperature aO shift device is incorporated into a single device, and the cooling heat exchangers for each previous stage are combined, piping, valves, etc. can be completely omitted, resulting in low cost. Equipment can be supplied.

(3) The cylinder is filled with a CO conversion catalyst for high temperatures and the outer cylinder is filled with a CO conversion catalyst for low temperatures, and each aOK formation device is filled with a different cooling medium,
Alternatively, since cooling media with different conditions can be introduced, reaction control becomes easier.

[Brief explanation of the drawing]

FIG. 1 shows the flow of a conventional steam reformer. Second
The figure is a schematic diagram of the configuration of a CO metamorphosis device of the present invention. Sub-agents 1) Meifuku agent Ryo Hagiwara -

Claims (1)

[Claims] It consists of a cylinder fully filled with a CO conversion catalyst for high temperatures and an outer cylinder fully filled with a CO conversion catalyst for low temperatures.Each catalyst light filling layer is equipped with a cooling means that can be adjusted individually, and a mixed gas consisting of 00-containing gas and steam is provided. A CO conversion device characterized in that a gill is used to cause the flow to flow through the inner cylinder and the outer cylinder in this order.