AU7866798A

AU7866798A - Process for producing a catalyst construction and a catalyst construction

Info

Publication number: AU7866798A
Application number: AU78667/98A
Authority: AU
Inventors: Eric Killer
Original assignee: ABB Research Ltd Sweden
Current assignee: ABB Research Ltd Sweden
Priority date: 1997-08-18
Filing date: 1998-08-03
Publication date: 1999-02-25
Also published as: DE19735785C1; EP0899010A1

Description

USRALIA

AUSTRALIA

7 i j Patents Act 1990 ABB RESEARCH

LTD.

ORIGINAL

COMPLETE

SPECIFICATION

STANDARD

PATENT

Invention Title: Process for producing a catalyst construction and a catalyst construction The following statement is a full description of this invention including the best method of performing it known to us:i s g (1; r- 4 a: 8: a h~ -1J, BACKGROUND OF' THE INVENTTON Field of the Invention

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The invention starts out from a process for producing a catalyst construction and from a catalyst construction as set forth in the preamble of claims 1 and 7.

15 Discussion of Background In the preamble of claims 1 and 7, the invention makes reference to a prior art as is known from DE 4220865 Al. There, a process and an apparatus 20 for the hydrogenation of carbon dioxide by means of silent electric discharges in a reaction space containing a catalyst construction are described. The catalyst construction provided is a gas- and vaporpermeable catalyst support of glass, quartz or mineral wool, silica gel or granules which is -coated with catalyst materials and loosely fills part of the reaction space. The catalyst support may itself be catalytically active. Catalysts have a favorable influence on the reaction temperature and the selectivity of the reaction. No details are provided as to how the catalyst material is held in the catalyst support. If the catalyst is fixed to the catalyst support by means of a binder, the catalytic properties of the catalyst are adversely affected.

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SUMMARY OF THE IkENTION Accordingly, one object of the invention is to provide a novel process for producing a catalyst I -2 construction and a catalyst construction of the type mentioned at the outset, such that any catalyst powder becomes usable without being adversely affected by the catalyst support.

This object is achieved by the invention as defined in claims 1 and 7.

Advantageous embodiments of the invention are defined in the dependent claims.

An advantage of the invention is that commercial fiberglass nonwoven can be used as catalyst support without pretreatment.

BRIEF DESCRIPTION OF THE DRAWINGS 15 A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying 20 drawings, wherein: Fig. 1 shows a reactor having a catalyst construction in the reaction space and Fig. 2 shows a tube of dielectric around which a S.-fiberglass nonwoven is to be wound and also a fiberglass nonwoven whose right-hand half is sprinkled with catalyst grains.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, in Figure 1 input gases are fed from the left into a reaction space of a catalyst reactor or discharge reactor or reactor containing a dielectric tube of quartz, .arranged therein an inner electrode of corrosionresistant metal or of a metal alloy or of an electrically conductive layer, a grounded outer V 1 i ai o u i*,2 i ;r *c*

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Ics 'ft 3 electrode and a catalyst construction arranged in the reaction space between dielectric tube (2) and outer electrode Input gases used are, for example, CO2, H 2

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4 02 and other greenhouse gases, which are reacted in the reactor to form reaction gases or output gases e.g. methanol, CH 3 OH, and are passed out to the right in the direction of the arrow. The inner electrode is electrically connected at the end to a source of AC power having an AC voltage in the range of 5 kV-50 kV, preferably of kV, and a frequency in the range of 50 Hz-1 MHz, preferably of 30 kHz. The power of the AC source is in the range of 100 W-1 kW.

The catalyst construction has a chemically 15 inert, gas- and vapor-permeable support material or a catalyst support (10) of glass nonwoven or fiberglass nonwoven on the right-hand half of whose surface there is uniformly sprinkled a catalyst material or catalyst powder or catalyst grains (11) having a diameter of 20 less than 1 mm, cf. Fig. 2. This catalyst suppr- 5 -V is subsequently, starting with the part on which no catalyst is sprinkled, tightly wound around the quartz or dielectric tube so that afterwards at least two windings are superposed. This produces a package of windings in which catalyst support (10) and catalyst grains (11) alternate. Winding is carried out to the degree of tightness necessary for the catalyst grains (11) to be held firmly in place and the reaction gap in the reactor to be completely filled.

The input gas flows along the glass fibers of the fiberglass nonwoven (10) to the catalyst grains (Ii) at which the reaction occurs. The fiberglass nonwoven (10) has a favorable influence on the ignition voltage, which is advantageous particularly at an 35 elevated pressure, e.g. 10- Pa.

In operation, the catalyst (11) is also distributed into the interior of the nonwoven layer mm a;~mC~i~Bri~~- a~pa~lai~~ gc~ 4 Catalyst (11) used in this way displays the same properties as a normal bed.

Example: A fiberglass nonwcven having a weight per unit area of 27 g/cm 2 and dimensions of 30 cm x 31 cm and 8 g of catalyst grains commercially available under the trade name Haldor Topsoe MK 101, having a particle size in the range from 0.25 mm 0.5 mm were 1 d 6..

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Sif 'il i' 1 i The fiberglass nonwoven (10) was placed on a flat base and moistened with distilled water so as to reduce static charging. The catalyst (11) was homogeneously distributed on one half of the nonwoven 15 surface and fixed by spraying with distilled water. The fiberglass nonwoven (10) prepared in this way was rolled up, starting with the uncoated half, onto the dielectric tube so that the catalyst grains (11) were located between the two fiberglass nonwoven layers The ends of the catalyst construction were then fixed using distilled water. The dielectric tube prepared in this way was then inserted into the reaction space of the reactor and baked out at 1200C to remove the water. The reactor was then 25 ready to use.

A gas mixture comprising the greenhouse gases methane and carbon dioxide was passed at 2 x 105 Pa and a flow velocity of i i/min through the discharge gap The gap volume, without fiberglass nonwoven and catalyst grains was 50 ml. Using an electric power of 500 W at a frequency of 30 kHz, the greenhouse gases used were dissociated and new substances, including methanol, were formed from the dissociation products The catalyst (11) was selected so as to 35- influence methanol production in a targeted way and at the same timeto lower the optimum reaction temperature Sby about 100C to 100oC compared to purely thermal operation without a discharge. At this temperature,.the m Iii_ b a, factor of 10 and the methanol yield increases by a factor of 0 and he selectivity f the reaction by a factor of 10-20. t is obviously also possible to replace the fiberglass nonwoven (10) by another chemically inert and gaspermeable materia More than two windings of fiberglass nonwoven (10) and catalyst grains (11) can Slalso be present in the catalyst construction The catalyst support (10) does not necessarily have to be wound around a dielectric tube it could also be woun d arou"d a r e l s w ith c a ta ly st arranged in at least two flat layers with catalyst material (11) between the layers (not shown). It is advantageous if the grains of the catalyst material do not come into direct contact with the dielectric modifications and Obviously, numerous modifications variations of the present invention are possible in the variatio o e achings It is therefore to be llight of the above teach s pe understood that within the scpe of the appended claims, the invention may be practised otherwise than as specifically described herein.

IST OF L-DESIGNATIONS 1 Reactor, catalyst reactor, discharge reactor J- 25 2 Dielectric tube, quartz tube, tube 3 Inner electrode 4 Outer electrode, metal tube Catalyst construction 6 Reacton space, discharge gap, reaction gap 7 Input gases, greenhouse gases 8 Ouput gaes reaction gases, reaction products 9 Source of AC power 0 atalst support fiberglass nonwven Saterial catalyst grains, catalyst 11 Catalyst maeral, powder

Claims

6- i I I f i i *w S. c THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. A process for producing a catalyst construction comprising a) a chemically inert, gas- and vapor-permeable, fiber-containing catalyst support and b) a catalyst material wherein c) the catalyst construction is built up in at least two superposed layers of the catalyst support and d) grains of catalyst material are sprinkled onto at least one surface of one of the two or 15 more layers of the catalyst support before these layers are superposed, such chat e) the catalyst material is located between at least two layers of the catalyst support 2. The process as claimed in claim 1, wherein 20 a) grains of catalyst material are sprinkled onto only a part of a surface of a sheet-like catalyst support b) this catalyst support which has been sprinkled with the catalyst grains is subsequently 25 wound up around a tube c) starting with the part of the catalyst support which has not been sprinkled with the catalyst grains, in such a way that at least two windings of this catalyst support are superposed and the catalyst material is located inbetween- 3. The process as claimed in claim 1 or 2, wherein catalyst material having a diameter of less than 1 mm is sprinkled in a homogeneous distribution onto 3 part of the catalyst support 4. The process as claimed in any of the preceding claims, wherein the catalyst support is moistened -i z ss~ S. I- -7- with water before the cacalyst material is sprinkled onto it. S. The process as claimed in any of the preceding claims, wherein the catalyst support is moistened with water after the catalyst material has been sarinkled onto it. 6. The process as claimed in any of the preceding claims, wherein the ends of the catalyst construction are fixed using water-
7. A catalyst construction comprising a) a chemically inert gas- and vapor -permeable, 'iber-containing catalyst support and b) a catalyst material wherein C) the catalyst support has a sheet-like structure, d) grains or catalyst material are sprinkled onto at least one surface of a layer of the sheet- like catalyst support such that f) at eattwo laverS of this ca'Ltalyst, supp-ort are superposed and the catalyst material is located inbetween. A catalyst construction as claimed in claim. 7, wherein 25 a) graians or catalyst material are sprinkled onto only a Part of a surface of the sheet-like catalyst support b) s catalyst support onto which catalyst has been svrinkled is configured as a windilng, 3 0 c) the parz of the catalyst., support onto which cataivst has not- been sprinkled frrmS an inner laver a:f th'-is wind~ing and d) the zart onto wn-tch catalvst has been -=crinkled Zor-ms a Sunetno==d layer in such a wav that ar- le-ast t.wo win-cns of this catalysct suzuort ara-~su-:ernosed =nd the c_=aalst materia Ii located neten -8
9. A catalyst construction as claimed in any of claims 6 to 8, wherein catalyst material having a diameter of less than 1 mm is sprinkled in a homogeneous distribution onto part of the catalyst support DATED THIS-3 DAY OF AUGUST 1998 ABB RESEARCH LTD Patent Attorneys for the Applicant: F.B.RICE CO.