JP2787773B2 - Apparatus and method suitable for producing hydrogen - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for producing hydrogen and a method for producing a hydrogen-containing gas.

[Conventional technology]

Syngas (hydrogen and carbon monoxide, and, in addition,
It is well known to prepare hydrogen-containing gases such as carbon dioxide, nitrogen and hydrocarbons (mainly composed of unconverted) hydrocarbons and steam by endothermic steam reforming of the hydrocarbon feedstock in the unit. In this system, heat is exchanged between the flue gas and the product gas, and the heat required to maintain a proper reaction temperature is recovered.
However, in such devices, no heat is recovered where heat is most needed, i.e., within the reaction section where normally high endothermic reactions take place.

In addition, a reaction section consisting of two concentric tubes is used, which forms an annular space for accommodating the catalyst particles, and the product gas is withdrawn through the central tube, whereby the hot product gas and the catalyst are separated. It is also known to take advantage of the heat content of the product gas exiting the reaction zone by exchanging heat directly at the reactor.

[Problems to be solved by the invention]

A major problem with the use of reaction sections consisting of concentric tubes is the degree of heat exchange that can be achieved, especially when the product gas having a temperature of 800 ° C. or 1000 ° C. is cooled.

[Means for solving the problem]

Surprisingly, the helically wound tube disposed inside the catalyst vessel has a hot product gas withdrawn through the tube and surrounding catalyst particles that are further heated by convective heat transfer. Has been found to provide excellent heat transfer between

Accordingly, the present invention is directed to an apparatus suitable for producing hydrogen, comprising: (i) a housing including a convection section having inlet and outlet means for a heating medium; and (ii) a convection section within the convection section. One or more catalyst containers extend;
Each of the catalyst containers contains a plurality of spiral, open-ended tubes, each of which extends axially spaced apart and in parallel with each other in the catalyst container and further entangled with each other. The convection section relates to an apparatus comprising inlet and outlet means for the process fluid, the inlet means for the process fluid communicating with the catalyst vessel and the outlet means for the process fluid communicating with the upper end of the tube.

Further, the present invention relates to a process for producing a hydrogen-containing gas, comprising contacting a hydrocarbon feedstock with a reforming catalyst heated by convective heat transfer in the presence of high-temperature and high-pressure steam. Extending into the catalyst,
A plurality of tubes that are spiral and open at both ends,
The present invention relates to a method for extracting a hydrogen-containing product gas through tubes that extend axially spaced apart from each other and parallel to each other, each tangling with each other.

〔Example〕

The apparatus and method according to the present invention will be described below with reference to the drawings showing various preferred embodiments. Note that the present invention is not limited to the specific embodiments shown in the drawings. Reference numerals for corresponding parts are the same throughout FIGS. 1 to 3.

The apparatus shown in FIG. 1 comprises a housing 1 containing a convection section 2, which is a heating medium, such as a hot liquid or a hot gas or a hot particulate solid.
It preferably has inlet means 3 and outlet means 4 for the combustion gas.

The housing further comprises a reaction section comprising one or more catalyst vessels 8 and a distribution section 5, the distribution section comprising a feed of steam and a hydrocarbon-containing gas, preferably natural gas or methane. It has inlet means 6 for a process fluid, such as a mixture, and outlet means 7, for a process fluid such as a mixture of a hydrogen-containing product gas and unconverted feed gas.

The catalyst container 8 is preferably tubular in shape and surrounds at least a major part of the plurality of open tubes 9 that are at least partially helically wound.

A plurality of tube-shaped catalyst vessels 8, suitably arranged (concentrically) in a circle (as shown in FIG. 2) within the housing 1, preferably extend downwardly into the convection section 2. Is out.

The distribution section 5 is separated from the convection section 2 by a tubesheet 10 so that contamination of the product gas flowing out through the outlet means 11 by the heated gas is avoided. In addition, suspending the tube-like catalyst container by the tube sheet 10 causes problems such as cracking of the tube or tube connection which can easily occur when the tube is connected at both ends to the inlet or outlet means. Without causing the catalyst container to expand freely during startup of the device according to the invention.

To ensure uniform heating of the catalyst vessel as much as possible,
It preferably includes means 12 for preventing the transfer of radiant heat, such as the insulating means shown in FIGS. 1 and 3 in the form of a disc made of a refractory material, for example.

The process feed gas is supplied to the inlet opening 13 at the upper end.
Through the particulate catalyst only through the granular catalyst. The granular catalyst is preferably used in the reaction section 5 so that it can be operated at a relatively low temperature of 400 to 1200 ° C. and a pressure of 2 to 200 bar.

The catalyst container 8 is preferably provided with catalyst support means 14 at its closed lower end, whereby the two spiral coil tubes suitably present in each catalyst container are inserted into the open lower end 15 thereof. Entrainment of catalyst particles is prevented. Catalyst support means
14 also serves as support means for the lower end 15 of the spiral coil tube.

During operation, the hot process gas enters the tube 9 through the end 15 shown in FIGS. 1 and 3 and flows upward, so that the best heat exchange with the surrounding catalyst is achieved. It is definitely done.

The heat-exchanged process gas (which may still have a temperature of, for example, 500-1000 ° C.) is present at the upper end 29 of the catalyst vessel 8 and with a pair of spirally wound tubes. Enter the communicating annular channel 16. The annular channel 16 is in communication with the product outlet means 7 via a manifold tube 17.

As mentioned above, the upper part of each pair of spirally wound tubes 9 is connected to a single outlet manifold for the process fluid, which is arranged approximately in the middle of the upper part of the housing 1. . Such an arrangement, from a structural point of view,
Very advantageous. This has the associated sealing and swelling problems. This is because the use of a plurality of separate outlet means for each catalyst tube can be avoided, and furthermore, the pressure in all the manifold tubes 17 is substantially equal and thus the process gas to all the catalyst vessels This is because the best distribution is ensured.

The bottom part 18 of the housing 1 functions as an inlet means 3 for a heat medium as shown in FIGS. There may be one or more combustor outlet means. In a preferred embodiment of the device according to the invention, a plurality (eg 3
Outlet means for the combustors are arranged rotationally symmetrically (not shown) in the housing (e.g., tangentially) so as to ensure the highest distribution of the combustion gases throughout the combustion section 2. become.

The combustion means shown in FIGS. 1 and 3 comprises an inlet means 19 for (eg oxygen-enriched) air, an inlet means for combustible fluids (eg hydrocarbon gas, hydrocarbon liquid and / or coal). 20 and, optionally, an inlet means 21 for the recycle gas, which is separated from the hydrogen and carbon monoxide-containing product gas by, for example, pressure swing adsorption (not shown). Carbon monoxide-containing gas, or recirculated flue gas.

FIG. 3 shows a more complex, but more thermally efficient embodiment of the device according to the invention, in which the outlet manifold 7 forms at least one annular space 22, It comprises a plurality of tubes arranged concentrically, said annular space being provided with a heat exchange fluid (e.g. a relatively cold, expanded and / or heat exchanged flue gas) extending outside the housing 1. ) Are in communication with the inlet means (23) and the outlet means (24).

The product outlet means 7 comprises a tube-like housing 24 extending through the tubesheet 10 and into the convection zone 2.
It has. The closed bottom end 25 of the housing 24 is connected to the heat exchange fluid inlet means 23, preferably by a telescopic bellows (not shown in FIG. 3). The product manifold tube 17 is in communication with a tube-shaped heat exchange means 26 having a closed lower end 27, and during operation an annular space 28
The downward flow of product gas passing through the manifold tube 17 penetrates the manifold tube 17 and into the open tube product outlet means 11 extending into the tube heat exchange means 26 in the opposite direction.

The product outlet means described above allows a significant portion of the thermal energy present in the product gas exiting the manifold tube 17 to be recovered.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the device according to the present invention. FIG. 2 is a cross-sectional view of the device shown in FIG. 1 along the line AA '. FIG. 3 is a longitudinal sectional view of the device including additional heat exchange means as compared to the device shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Convection section 3 ... Inlet means 4 ... Outlet means 5 ... Reaction section 6 ... Inlet means 7 ... Outlet means 8 ... Catalyst container 9 ... Opening tube

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-248230 (JP, A) JP-A-50-129604 (JP, A) JP-B-47-41881 (JP, B1)

Claims (7)

(57) [Claims] 1. An apparatus suitable for producing hydrogen, comprising: (i) a housing including a convection section having inlet and outlet means for a heating medium; and (ii) one housing in the convection section. Or more catalyst vessels extend, each of which contains a plurality of spiral, open-ended tubes, each of which is axially spaced and parallel within the catalyst vessel. And the convective section further comprises inlet and outlet means for a process fluid, wherein the inlet means for the process fluid communicates with the catalyst vessel and the outlet means for the process fluid comprises the tube. Device in communication with the upper end of the 2. The apparatus of claim 1 wherein said convection section includes means for preventing radiant heat transfer to said catalyst vessel. 3. Apparatus according to claim 1, wherein said convection section and said reaction section are separated by a tubesheet. 4. The apparatus of claim 3 wherein a plurality of tubular catalyst vessels extend down through said tubesheet and into said convection section. 5. The upper end of each pair of said helically wound open tubes is connected to a single outlet manifold for process fluid located approximately in the center of the upper end of said housing. An apparatus according to any one of the preceding claims. 6. An outlet manifold comprising a plurality of concentrically arranged tubes forming at least one annular space, said annular space for a heat exchange fluid extending outside said housing. An apparatus according to claim 5, in communication with the inlet means and the outlet means. 7. A method for producing a hydrogen-containing gas, comprising contacting a hydrocarbon feedstock with a reforming catalyst heated by convective heat transfer in the presence of high-temperature and high-pressure steam. Extracting the hydrogen-containing product gas through a plurality of helical, open-ended tubes extending through the tubes, each of which extends axially spaced apart and in parallel with each other. Method.