DE102008022940A1 - New catalyst with catalytic core and a mat wrapping the catalytic core for damping the catalytic core influencing shocks and vibrations, useful in a reformer - Google Patents

Abstract

Catalyst (10) with catalytically active catalytic core (14) and a mat (18) wrapping the catalytic core for damping the catalytic core influencing shocks and vibrations, is new, where the mat wrap releases free notches by directly passing heat at the catalyst core.

Description

The Invention relates to a catalyst for a reformer, with a catalytically active catalyst core and a catalyst core enveloping mat for damping of acting on the catalyst core Bumps and vibrations.

The The invention further relates to a process for the preparation of a Catalyst for a reformer, with a catalytic active catalyst core and an enveloping the catalyst core Mat for damping of acting on the catalyst core Bumps and vibrations.

catalysts with a monolithic catalyst core containing a catalytically active Surface provides are widespread. The monolithic catalyst core often includes a ceramic carrier matrix, the is very brittle and therefore especially for mobile Applications a corresponding vibration and shockproof Storage required.

It is for example from the DE 102 47 582 A1 known to wrap a catalyst core with a bearing mat and insert both together into a housing, which is firmly fixed. In this way, the catalyst core is protected from shocks and vibrations transmitted to the housing. At the same time, the catalyst core is thermally isolated from the environment to minimize the heat losses caused by thermal bridges between the catalyst core and the housing.

For However, the application in a reformer, this is disadvantageous because the the catalyst core flowing around the fuel gas due to the thermal insulation through the mat no heat in the reforming zones of the Enter catalyst core can. But there she is needed to drive the soot gasification reaction. Instead, will the heat is passed into the oxidation zone or is on the Way there partly radiated to the fuel cell system, so that they can no longer be used in the reformer.

Of the The invention is therefore based on the object, the storage of known Catalysts for heat transfer reformers to improve without the vibration and shockproof storage of the catalyst core.

These The object is achieved with the features of the independent claims solved.

advantageous Embodiments of the invention are described in the attached Claims specified.

The Invention is based on the generic catalyst in that the enveloping mat leaves recesses over transfer the heat directly to the catalyst core can. The word "direct" refers in particular to a bypass of the catalyst core enveloping Mat with the help of the recesses, the heat transferring Medium can flow to the catalyst core and his Transfer heat by direct contact to the catalyst core. This allows in particular the introduction of a larger one Amount of additional heat energy in the catalyst core, as for example for driving an endothermic partial reaction is necessary in a reformer. For a reformer is this is advantageous because with increasing catalyst temperatures of a reduced soot formation is assumed, what the life elevated. Furthermore, higher conversion levels and the Operation at a lower air ratio possible, what the efficiency the reformer or the associated fuel cell stack elevated. The mechanical provided by the mat Breakpoints for attachment of the catalyst core can completely preserved.

Especially it is preferred that a cladding receiving the catalyst core is provided, via which the catalyst core together with the mat is fixable. With the cladding, the catalyst core can be fixed more easily, in particular solid compounds, For example, screw or welded joints, provided could be.

Preferably is provided that the recesses in the enveloping Matte are incorporated. Are the recesses incorporated into the mat, so the mat can envelop the catalyst core in a known manner and still leaves recesses for direct transfer of heat on the catalyst core free. The recesses For example, breakthroughs may occur in the mat will be cut. The exact shape of the breakthroughs, that is their dimensions, their arrangement and shape are in addition to the desired heat transfer properties to match the method used, in which the catalyst core with the mat enveloping him in a housing is introduced. For example, small dimensions of the breakthroughs transverse to shear forces necessary to rupture To prevent the mat on the recesses, creating a slot shape or triangular shape of the recesses results. Due to lower occurring shear forces during assembly of the catalyst core with the mat enveloping him in a housing, In particular, the half-shell technique or are suitable The Tourniquettechnik for a mounting of the catalyst core in a housing.

It is preferably provided that the off Savings are offset from each other. Due to the staggered arrangement of the recesses, at least one recess may be present over the entire circumference of the catalyst core in order to ensure heat input into each channel along the circumference of the catalyst core.

Usefully it is provided that the mat is composed of several mat parts, where recesses remain free. The use of several mat parts, which are put together to a larger mat, allows a reduction of waste. In contrast, the introduction is of recesses in the mat associated with a high waste, by assembling the mat of several items is reducible.

Especially can be provided that the mat parts have the same shape. Identical mat parts allow flexible adjustment of the mat size without causing additional waste.

Farther can be provided that the mat helically the catalyst core is wound. The helical Wrapping the catalyst core with the mat allows especially with a multi-part mat one opposite a slipping safer placing the mat on the catalyst core. If at least one complete turn is provided around the catalyst core, so the arrangement is particularly well secured against slipping and the recesses are evenly over distributed over the catalyst core.

Especially it is preferred that a pitch of the mat winding larger than a width of the mat is. Is the pitch the mat wrap is greater than the width of the mat itself, this creates a helical recess in the Placing the mat on the catalyst core. In this arrangement the mat is no waste necessary because the recess only can arise when placing the mat on the catalyst core.

Farther can be provided that in the flow direction of the Catalyst supplied reaction gas before the recesses a mat area is provided in which there are no recesses are to a flow of reaction gas around the catalyst core to prevent. By a flow in front of the Recesses lying mat area, which no recesses has an undesirable flow around the Catalyst core supplied from the catalyst core Reaction gas avoided. Especially when the mat winding is helical around the catalyst core, this is advantageous.

The generic method is further developed by that the catalyst core is wrapped with the mat, wherein Recesses are provided in the wrapping of the catalyst core. In this way, the advantages and special features of the invention Catalyst also in the context of a method for producing a Catalyst implemented.

This also applies to the following particularly preferred Embodiments of the invention Process.

This is advantageously developed by the fact that the wrapped Catalyst core is absorbed by a sheath.

Prefers is that the recesses before wrapping the catalyst core cut into the mat and / or punched.

It can also be provided that the mat of several mat parts is assembled, wherein the recesses in the assembly result.

Preferably is provided that the recesses offset from each other become.

Farther can be provided that the mat helically the catalyst core is wound.

Especially it is preferred that the pitch of the winding is greater as the width of the mat is selected.

According to one Another preferred embodiment provides that in the flow direction of a catalyst supplied Reaction gas provided in front of the recesses a mat area is, which has no recesses to a flow around of reaction gas to prevent the catalyst core.

The Invention will now be described with reference to the accompanying drawings particularly preferred embodiments exemplified.

It demonstrate:

1 a first embodiment of a mat with recesses;

2 a second embodiment of a mat with recesses;

3 a third embodiment of a mat with recesses;

4 a fourth embodiment of a mat with recesses;

5 a mat composed of equal parts with recesses;

6 a first embodiment of a reformer according to the invention and

7 a second embodiment of a reformer according to the invention.

In In the following drawings, like reference characters designate the same or similar parts.

In the 1 to 4 a mat with recesses is shown in each case. The illustrated mat 18 each has recesses 20 different shape. 1 shows symmetrically arranged circular recesses,

2 shows rectangular recesses 20 in a mat 18 . 3 also shows rectangular recesses 20 , which, however, offset each other in the mat 18 are arranged, and 4 shows triangular recesses 20 in a mat 18 , as they are useful due to an adaptation to shear forces occurring during assembly. As a material for the production of the mat 18 In particular, ceramic materials come into question.

5 shows a mat composed of equal parts with recesses. The illustrated mat is made of individual parts 18 ' composed of the same shape. The mat 18 can, as indicated by the oblique boundary line, helically wound around a catalyst core, not shown. This results in the gaps between the mat parts 18 ' the recesses 20 , as in 5 indicated.

6 shows a first embodiment of a reformer according to the invention. The reformer of the invention 12 gets air 22 and fuel 24 fed, both components at the latest in a mixing zone 28 before entering a catalyst core 14 Mix. The catalyst core 14 is from a recessed mat 18 surrounded him, the vibration and shockproof in a cladding 16 fixed. The catalyst core 14 forms together with the mat 18 and the serving 16 a catalyst 10 , In one of the mixing zone 28 facing the front of the mat 18 No recesses are provided, so that an undesirable flow around the catalyst core 14 prevented by the mixing zone gases is prevented. After passing through the supplied gas mixture through the catalyst core 14 leaves part of the converted gas stream as a reformate 30 the reformer 12 , However, a part of the converted gas mixture becomes via breakthroughs 32 in the serving 16 branched off and as exhaust 26 again the mixing zone 28 fed. This is the hot exhaust gas 26 at the catalyst core 14 fixing cladding 16 passed along, with the hot exhaust gas 26 about in the mat 18 provided recesses with the catalyst core 14 comes into contact and transfers heat. For this purpose, the cladding 16 have not shown breakthroughs. The catalyst 10 with the catalyst core 14 is thus in countercurrent to the hot exhaust gases 26 flows around, wherein in the catalyst core 14 expiring endothermic partial reaction of transmitted heat is driven.

7 shows a second embodiment of a catalyst according to the invention. In this embodiment, the reformer 12 air 22 and fuel 24 one a catalyst 10 enveloping area supplied. There is an exothermic at least partial reaction of air 22 and fuel 24 to an exhaust 26 which is a mixed zone 28 along with more air 22 ' is supplied. From the mixing zone 28 the gas mixture enters the catalyst 10 one, wherein one is a catalyst core 14 enveloping mat 18 on the mixing zone 28 facing side has no recesses, whereby an undesirable flow around the catalyst core 14 is prevented by the supplied gas mixture. The in the catalyst core 14 The ongoing reaction is at least partially endothermic and is partly due to the heat input through the apertures in the mat 18 driven. There are at the possibly provided with openings enclosure 16 passing exhaust gas 26 thermal energy bypassing the mat 18 directly to the catalyst core 14 from.

The in the above description, in the drawings and in the Claims disclosed features of the invention can both individually and in any combination for the To be essential to the realization of the invention.

10

catalyst

12

reformer

14

catalyst core

16

wrapping

18

mat

18 '

Matt part

20

recess

22

air

22 '

air

24

fuel

26

exhaust

28

mixing zone

30

reformate

32

breakthrough

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 10247582 A1 [0004]

Claims (17)

Catalyst ( 10 ) for a reformer ( 12 ), with - a catalytically active catalyst core ( 14 ) and - one the catalyst core ( 14 ) enveloping mat ( 18 ) for damping on the catalyst core ( 14 ) impacting and vibration, characterized in that the enveloping mat ( 18 ) Recesses ( 20 ), via the heat directly to the catalyst core ( 14 ) can go over. Catalyst ( 10 ) according to claim 1, characterized in that a catalyst core ( 14 ) receiving envelope ( 16 ) is provided, via which the catalyst core ( 14 ) together with the mat ( 18 ) is fixable. Catalyst ( 10 ) according to claim 1 or 2, characterized in that the recesses ( 20 ) into the enveloping mat ( 18 ) are incorporated. Catalyst ( 10 ) according to one of the preceding claims, characterized in that the recesses ( 20 ) are arranged offset from each other. Catalyst ( 10 ) according to one of the preceding claims, characterized in that the mat ( 18 ) of several mat parts ( 18 ' ), wherein recesses ( 20 ) remain free. Catalyst ( 10 ) according to claim 5, characterized in that the mat parts ( 18 ' ) have the same shape. Catalyst ( 10 ) according to one of the preceding claims, characterized in that the mat ( 18 ) helically around the catalyst core ( 14 ) is wound. Catalyst ( 10 ) according to claim 7, characterized in that a pitch of the mat winding is greater than a width of the mat ( 18 ). Catalyst ( 10 ) according to one of the preceding claims, characterized in that in the flow direction of the catalyst ( 10 ) supplied reaction gas in front of the recesses ( 20 ) a mat area is provided in which no recesses ( 20 ) are present in order to circulate reaction gas around the catalyst core ( 14 ) to prevent. Process for the preparation of a catalyst ( 10 ) for a reformer ( 12 ), with - a catalytically active catalyst core ( 14 ) and - one the catalyst core ( 14 ) enveloping mat ( 18 ) for damping on the catalyst core ( 14 ) impact and vibration, characterized in that the catalyst core ( 14 ) with the mat ( 18 ), wherein in the winding of the catalyst core ( 14 ) Recesses ( 20 ). A method according to claim 10, characterized in that the wrapped catalyst core ( 14 ) of an envelope ( 16 ) is recorded. Method according to claim 10 or 11, characterized in that the recesses ( 20 ) before wrapping the catalyst core ( 14 ) in the mat ( 18 ) are cut and / or punched. Method according to one of claims 10 to 12, characterized in that the mat ( 18 ) of several mat parts ( 18 ' ), wherein the recesses ( 20 ) when assembled. Method according to one of claims 10 to 13, characterized in that the recesses ( 20 ) are arranged offset from each other. Method according to one of claims 10 to 14, characterized in that the mat ( 18 ) helically around the catalyst core ( 14 ) is wound. A method according to claim 15, characterized in that the pitch of the winding is greater than the width of the mat ( 18 ) is selected. Method according to one of claims 10 to 16, characterized in that in the flow direction of the catalyst ( 10 ) supplied reaction gas in front of the recesses ( 20 ) a mat area is provided which does not have recesses ( 20 ) in order to prevent a flow of reaction gas around the catalyst core ( 14 ) to prevent.