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(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)

(19) World Intellectual Property Organization

International Bureau §IJ ~

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(10) International Publication Number

WO 2012/131318 A1 (43) International Publication Date 4 October 2012 (04.10.2012) WI PO I PCT

(51) International Patent Classification: COIB 3138 (2006.01) COIB 3140 (2006.01)

(21) International Application Number:

(22) International Filing Date:

(25) Filing Language:

(26) Publication Language:

PCT /GB20 12/050493

6 March 2012 (06.03.2012)

English

English

(81) Designated States (unless otherwise indicated, for every kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ, CA,CH,CL,CN,CO,CR,CU,CZ,DE,DK,DM,DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP, KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, VA, UG, US, UZ, VC, VN, ZA, ZM, ZW.

(30) Priority Data: 1105131.5 28 March 2011 (28.03.2011) GB (84) Designated States (unless otherwise indicated, for every

kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR, NE, SN, TD, TG).

(71) Applicant (for all designated States except US): JOHN­SON MATTHEY PUBLIC LIMITED COMPANY [GB/GB]; 5th floor, 25 Farringdon Street, London EC4A 4AB (GB).

(72) (75)

Inventors; and Inventors/Applicants (for US only): FARNELL, Peter William [GB/GB]; 36 Tanton Road, Stokesley, North Yorkshire TS9 5HR (GB). FOWLES, Martin [GB/GB]; 9 Bridge Green, Danby, Nr. Whitby, North Yorkshire Y02l 2JQ (GB). SENGELOW, William Maurice [GB/GB]; 2 Brandon Close, Billingham, Cleveland TS23 2TH (GB).

(74) Agent: RIDLAND, John; Johnson Matthey Catalysts, In­tellectual Property Department, PO Box I, Belasis Avenue, Billingham Cleveland TS23 ILB (GB).

Published:

with international search report (Art. 21(3))

::: -------------------------------------------------------------------------------------------{54) Title: STEAM REFORMING

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(57) Abstract: A process for the steam reforming of hydrocarbons in an autothermal or secondary reformer is described comprising (i) non-catalytically partially combusting a feedgas comprising a hydrocarbon with an oxygen-containing gas in the presence of steam to form a partially oxidised hydrocarbon gas mixture at a temperature 2::1200°C and (ii) passing the partially oxidised hydro­carbon gas mixture through a first particulate layer of steam reforming catalyst, a second particulate layer of steam reforming catalyst and a third particulate layer of steam reforming catalyst, wherein the first layer comprises a catalytically active metal selected from platinum, palladium, iridium, ruthenium or rhodium supported on a zirconia, and the second and third layers comprise nickel on a refractory support selected from alumina, calcium aluminate, magnesium aluminate, titania, zirconia, magnesia or mixtures thereof, wherein the second layer has a voidage 2::0.5 and a higher equivalent passage diameter than the third layer.

wo 2012/131318 PCT/GB2012/050493

Steam Reforming

This invention relates to a process and apparatus for the catalytic steam reforming of a partially

combusted hydrocarbon feedstock for the preparation of synthesis gas.

Steam reforming is widely practised and is used to produce hydrogen streams and synthesis

gas comprising hydrogen and carbon oxides for a number of processes such as ammonia and

methanol synthesis and the Fischer-Tropsch process. In order to obtain a synthesis gas more

suited to Fischer-Tropsch or other downstream processes, a primary or pre-reformed gas

containing methane is typically subjected to secondary or autothermal reforming in an adiabatic

refractory lined reformer by partially combusting the primary-reformed or pre-reformed gas in a

combustion zone using a suitable oxidant, e.g. air, oxygen or oxygen-enriched air using burner

apparatus mounted usually near the top of the reformer. The process of partially combusting

the primary-reformed or pre-reformed gas produces a partially oxidised gas mixture. The

refractory lining typically contains multiple layers and is designed to protect the pressure vessel

from the hot gases in the reformer and to provide insulation to minimise heat losses. One or

more layers of low thermal conductivity materials containing alumina may be used to provide

the thermal insulation. The hot face material is typically made from dense high purity alpha

alumina bricks that are chemically inert to the hot gases and resist physical attrition due the

high gas velocities employed. These blocks are cemented in place to prevent the hot process

gas contacting the more reactive insulating layers beneath.

The partial combustion reactions are exothermic and the partial oxidation increases the

temperature of the partially oxidised gas to between 1200 and 1500°C. The partially oxidised

reformed gas is then passed from the combustion zone through a bed of a steam reforming

catalyst disposed below the burner apparatus, to bring the gas composition towards

equilibrium. Heat for the endothermic steam reforming reaction is supplied by the hot, partially

oxidised reformed gas. As the partially oxidised reformed gas contacts the steam reforming

catalyst it is cooled adiabatically by the endothermic steam reforming reaction to temperatures

in the range 900-1100°C.

Typically the steam reforming catalyst in the secondary or autothermal reformer is a nickel

catalyst supported on an alpha alumina or a magnesium-, or calcium-aluminate support.

W02006/126018 discloses a process for the steam reforming of hydrocarbons in an

autothermal or secondary reformer, wherein in order to prevent volatilisation of the catalyst

support, the steam reforming catalyst bed comprises a first layer and a second layer, wherein

the oxidic support for the first layer is a zirconia. Preferably the catalytic activity of the first

layer is higher than the second layer so that the endothermic steam reforming reactions act to

reduce the gas temperature quickly and so prevent volatilisation of the catalyst. This may be

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achieved by using a more catalytically active metal in the first layer such as platinum,

palladium, iridium, ruthenium or rhodium.

Volatilisation of the dense alpha-alumina bricks used to line the adiabatic reformer, can occur

when the refractory lining in the vessel is new or when the dense alpha alumina bricks have

been replaced or repaired. This is a particular problem in the burner region and combustion

zone of the reformer where the gas temperatures are hottest. Volatilisation occurs until the

bricks and the cement used to hold the blocks together have aged in-situ. We have found

surprisingly that, where volatilised alumina is formed, it does not condense on the first zirconia­

supported catalyst layer, despite the fact that it is cooled by the endothermic steam reforming

reactions, and is deposited instead in the second layer. In extreme cases, this can increase

the pressure drop though the bed of steam reforming catalyst causing the plant to reduce

throughput, and/or result in the non-uniform flow of gas through the catalyst bed resulting in

the apparent poor performance of the catalyst. Therefore we have devised an arrangement

that overcomes these problems.

Accordingly, the invention provides a process for the steam reforming of hydrocarbons in an

autothermal or secondary reformer comprising (i) non-catalytically partially com busting a

feedgas comprising a hydrocarbon with an oxygen-containing gas in the presence of steam to

form a partially oxidised hydrocarbon gas mixture at a temperature ~1200°C and (ii) passing

the partially oxidised hydrocarbon gas mixture through a first particulate layer of steam

reforming catalyst, a second particulate layer of steam reforming catalyst and a third particulate

layer of steam reforming catalyst, wherein the first layer comprises a catalytically active metal

selected from platinum, palladium, iridium, ruthenium or rhodium supported on a zirconia, and

the second and third layers comprise nickel on a refractory support selected from alumina,

calcium aluminate, magnesium aluminate, titania, zirconia, magnesia or mixtures thereof,

wherein the second layer has a voidage ~ 0.5 and a higher equivalent passage diameter than

the third layer.

The invention further provides a bed of steam reforming catalyst disposed below burner

apparatus in an autothermal or secondary reformer, wherein the bed comprises a first

particulate layer, a second particulate layer and a third particulate layer, wherein the first layer

comprises a catalytically active metal selected from platinum, palladium, iridium, ruthenium or

rhodium supported on a zirconia, and the second and third layers comprise nickel on a

refractory support selected from alumina, calcium aluminate, magnesium aluminate, titania,

zirconia, magnesia or mixtures thereof, and wherein the second layer has a voidage ~ 0.5 and

a higher equivalent passage diameter than the third layer.

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In the process, the feed gas may comprise a desulphurised hydrocarbon feedstock, such as

methane or a natural gas, which may further comprise recycled gas streams from downstream

processes comprising one or more of methanol, hydrocarbons, carbon oxides or hydrogen, or

may be a pre-reformed or primary reformed gas stream comprising methane, steam, hydrogen

and carbon oxides. The latter are preferable as it may be desirable to ensure that the feed to

the secondary reformer or autothermal reformer contains no hydrocarbons higher than

methane and also contains a significant amount of hydrogen, as these factors reduce the risk

of carbon or soot formation above or on the steam reforming catalyst.

The oxygen containing gas may be substantially pure oxygen, air or an oxygen enriched air.

The oxygen:carbon molar ratio may be in the range 0.4 to 0.7:1. Steam is preferably present at

a steam:carbon ratio between 0.5 and 3.5. Steam may be provided by adding it directly to the

combustion zone or by mixing, either with the feedgas or the oxygen-containing gas.

Alternatively, if the feedgas is a pre- or primary-reformed gas, no additional steam may be

necessary. Furthermore, if the feedgas contains hydrogen, its combustion with oxygen will

generate steam under the reaction conditions. The hydrocarbon in the feedgas is non­

catalytically partially com busted by the oxygen in the oxygen-containing gas in the combustion

zone of a secondary or autothermal reformer. The combustion zone is generally formed

beneath a burner disposed near the top of the reformer to which the feed gas and oxygen­

containing gas are fed.

The partially oxidised hydrocarbon/steam mixture then passes from the combustion zone to the

surface of the first layer of steam reforming catalyst at a temperature ~1200°C and preferably in

the range 1200-1500°C. When the partially oxidised feedgas/steam mixture, e.g. a partially

combusted pre- or primary reformed gas, contacts the steam reforming catalyst, the steam

reforming reaction, which is endothermic, cools the gas and the surface of the catalyst. The

surface temperature of the catalyst may therefore, depending upon the conditions and activity

of the catalyst, be in the range about 900-1400°C. In particular, we have found alumina or

metal aluminate volatilisation to occur when the catalyst temperature is above about 1150°C,

particularly about 1200°C. Thus, preferably the first layer reduces the catalyst temperature

below about 1200°C, more preferably below about 1100°C.

The pressures at which the process may be operated are preferably ~20 bar abs, more

preferably in the range 20 to 80 bar abs. The gas-hourly space velocity in the catalyst layers

may be ~5000h-1 , preferably 5000 to 30000h-1, more preferably 5000 to 20000h-1

.

In the present invention, the first layer catalyst support is a zirconia. Preferred zirconia

supports are stabilised zirconias, such as magnesia-, calcia-, lanthana-, yttria- or ceria­

stabilised zirconias, which are most preferably in the cubic form. Such zirconias are known and

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are commercially available. Yttria-stabilised cubic zirconia is most preferred, e.g. a 16% wt

yttria-stabilised cubic zirconia. Typically such stabilised zirconias have been fired to

temperatures above 1200°C. We have found zirconia-containing supports to have lower

volatility than supports comprising alumina or magnesium- or calcium-aluminate and so the

presence in the first layer of alumina or magnesium- or calcium-aluminate is undesirable.

The catalytically active metal in the first layer of steam reforming catalyst may platinum,

palladium, iridium, ruthenium or rhodium, preferably platinum and/or rhodium. These metals

have a higher catalytic activity/g and greater stability than the conventional nickel steam

reforming catalysts, which has the further advantage or reducing catalyst volatilisation. By

increasing the catalytic activity of the first layer, the endothermic steam reforming reactions

take place to a greater extent and thereby act to cool the gas stream passing through the bed

more rapidly than in the case where the layer of increased activity is absent. Rhodium is

particularly preferred as it has a lower vapour pressure than nickel under typical reaction

conditions. Suitably active rhodium catalysts comprise 0.01-1.00%, preferably 0.05 to 0.5%,

more preferably 0.1 to 0.25% Rh by weight. A particularly preferred first layer catalyst therefore

consists of a rhodium impregnated zirconia catalyst, particularly a 0.05 to 0.5%wt rhodium­

impregnated stabilised zirconia.

The partially reformed gas mixture passes from the first layer to the second and third layers

respectively. The second and third layers comprise a nickel catalyst on a suitable refractory

support. The refractory catalyst support for the second layer preferably comprises alumina,

calcium aluminate, magnesium aluminate, titania, zirconia or magnesia or mixtures thereof.

More preferably, the second layer catalyst and third layer catalyst comprise nickel on alumina,

magnesium aluminate or calcium aluminate.

Steam reforming catalysts may be made using a variety of methods. Impregnation methods

are particularly suitable and are well known to those skilled in the art of catalyst manufacture.

For example, rhodium may be provided in the first layer steam reforming catalyst by

impregnation of the zirconia support with a solution of a suitable rhodium compound, followed

by heating in air to convert the compound to rhodium oxide. If desired, the rhodium oxide may

then be reduced to elemental form by treatment with a reducing gas such as hydrogen at

elevated temperature, although it is generally more convenient to install the catalyst in the un­

reduced oxidic form and perform the reduction immediately prior to use in-situ by reaction with

a reducing gas (hydrogen and/or carbon monoxide). For example, a rhodium catalyst may be

prepared by impregnating a stabilised cubic zirconia with an aqueous solution of rhodium

nitrate, if necessary separating the impregnated material from the solution, drying and calcining

to 400-500°C. The rhodium oxide, Rh20 3 , is subsequently reduced in-situ. In a preferred

embodiment, the rhodium is provided on the support as a so-called "eggshell" catalyst in which

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the rhodium is concentrated in the surface layers of the catalyst support rather than being

distributed evenly throughout the support. This provides a more efficient use of the rhodium,

which is relatively expensive, compared to e.g. nickel.

Nickel catalysts may similarly be formed by impregnation of the refractory oxide support with

nickel acetate or nickel nitrate, followed by calcination, or by precipitation of nickel compounds

by combining a solution of a nickel salt such as nickel nitrate with a base, followed by washing,

drying, and calcining. Again prior to use the nickel may be reduced with a reducing gas

stream.

Whereas impregnation of soluble salts is a particularly suitable method for preparing the

catalysts, other techniques whereby sols or suspensions of catalytic metals are applied to the

support material may also be used.

The first, second and third layer reforming catalysts are particulate, i.e. in the form of shaped

units such as pellets, rings or extrudates, which may be lobed or fluted and/or which may

contain one or more through holes. Such catalysts are commercially available or may be made

using conventional techniques.

In the present invention, the second layer has a voidage ~ 0.5, preferably~ 0.55 and the

equivalent passage diameter (Dep) is higher in the second layer, in which the volatilised alumina

condenses, than in the third. In this way the condensation of volatilised alumina will have a

reduced effect on the pressure drop of the catalyst bed and is less likely to result in non­

uniform flow through the bed. However, it is still desirable that the second layer catalyst activity

is sufficient, and this may be achieved by using catalysts with a suitable geometric surface area

(GSA).

Voidage (s) is a dimensionless number related to the interstitial "empty" volume between and

within the catalyst particles present in the layers. Voidage is described, for example, in The

Catalyst Handbook, 2nd Edition, Manson Publishing, 1989, pages 101-5. The shape of the

catalyst particle can be used to determine the voidage of the catalyst layer- generally the more

eccentric the shape, the greater the voidage. Thus higher voidages may be achieved using

particles with an aspect ratio, i.e. a length/diameter value, other than 1.0. Solid cylinders

generally have a low voidage, typically <0.4. Voidage may also be increased by providing the

catalyst particles with one or more through holes, preferably 1 to 10 through holes. Whereas

rings with adequate strength can provide increased voidage, their GSA may not be suitable.

Accordingly preferred catalysts have 2-10 through holes. Voidage may also be increased by

providing the catalyst particles with lobes or flutes. Particularly preferred catalyst particles are

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4 to 10 holed cylindrical pellets, optionally with lobes or flutes arranged around their periphery,

and which may be domed or flat ended.

The second layer may have the same or different voidage to the first or third layers. Preferably

the voidage in the second layer will be the same or higher than that in the third layer. The

voidage of the second layer may also be the same or higher than that of the first layer. A high

voidage of the second layer allows the volatilised alumina to be captured without adversely

increasing the pressure drop through the bed.

The equivalent passage diameter, or hydraulic diameter, Dep, is given in the Chemical

Engineer's Handbook, 51h Edition, Table 5-11 as 4 x RH, where RH is the area of the fluid stream

cross-section/wetted perimeter. In a particulate catalyst bed Dep (in metres) may be expressed

as 4 x voidage/geometric surface area in m2/m 3, i.e. Dep = 4s/GSA.

The Geometric Surface Area (GSA) may be calculated from the dimensions of the catalyst

particles using known methods. For example, GSA may be calculated for ring or multi-hole

cylindrical catalysts using the expression, GSA= S.(1-s)N, where Sis the surface area of the

catalyst, s is the voidage and V is the volume of the catalyst particle.

S = rc.L.(D0 +(Nh.D;))+0.5.rc.(D02-(Nh.D;2

)) and V = 0.25.rc.L.(D02-(Nh.D;2

) where Lis the length of

the catalyst particle, Do is the outside diameter, D; is the inside diameter, and Nh is the number

of holes.

The second layer has a higher equivalent passage diameter than third layer. It may also have

a higher equivalent passage diameter than the first layer. This may be achieved by using

larger particles of the same voidage (as a result of their lower GSA) or by increasing the

voidage of the catalyst particles in the second layer as described above.

The equivalent passage diameter of the second layer is preferably~ 6mm, more preferably

~ 7mm, most preferably~ 8mm, especially~ 9mm. A suitable upper limit for the equivalent

passage diameter in the second layer may be 15mm. The equivalent passage diameter in the

first or third layers is preferably smaller by 1 or more millimetres, i.e. the difference between the

Dep of the second and first or third layers is preferably ~ 1 mm, with a minimum value of the Dep

in the first and third layers preferably of 2 mm.

The second layer therefore preferably has a combination of sufficient volume to capture the

volatilised alumina without adversely affecting the pressure drop or flow distribution and

sufficient GSA to catalyse the reaction to further reduce gas temperature thereby promoting

complete condensation of the volatilised alumina in the second layer and at the same time

contributing towards the approach to equilibrium for the reformed gas. This is achieved by

selecting catalyst particles with the appropriate voidage and equivalent passage diameter. The

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geometric surface area of the second layer is preferably ~150m2/m3 , more preferably

~200m2/m3 , up to about 350m 2/m3. The GSA of the third layer is preferably higher than that of

the second layer so that the reacting gasses may be brought towards equilibrium in the

autothermal reformer. The geometric surface area of the first layer may also be higher than

that of the second layer for the same reason. The GSA of the first layer and the third layer is

preferably ~300m2/m3 , more preferably ~400m2/m3 , with an upper limit preferably about

650m 2/m 3. Preferably, there is a difference in GSA between the first or third layers and the

second layer of at least 50 m2/m 3.

In a preferred embodiment, the bed of steam reforming catalyst comprises a first layer

comprising 0.05 to 0.5% wt Rh on a stabilised zirconia, in the form of multi-holed cylindrical

pellets, which may be lobed or fluted, with a voidage ~ 0.5, over a second layer comprising 5-

20% wt Ni on alumina in the form of rings or multi-holed cylindrical pellets having voidage ~ 0.5

and a Dep ~ 6mm, over a third layer comprising a 5- 20% wt Ni on alumina in the form of multi­

holed pellets, which may be lobed or fluted, with a voidage ~ 0.5 and Dep ~ 1 mm smaller than

that of the second layer.

The thickness of the bed of the steam reforming catalyst will depend upon the feed rate, the

activity of the catalytically active metals, the conditions under which it is operated and whether

the feedgas is a hydrocarbon/steam mixture or a pre- or primary-reformed gas. The thickness

of the bed of steam reforming catalyst may be in the range 1-10 metres, preferably 2-5 metres

with the first and second layers each preferably comprising between 3 and 25%, most

preferably 5 and 15% of the thickness of the bed.

If desired, a layer of zirconia balls, pellets or perforate tiles may be placed on top of the first

layer of reforming catalyst to protect the surface of the steam reforming catalyst from

irregularities in the combusting gas flow. A benefit of providing this layer is to prevent

disturbance of the surface of the particulate catalyst bed.

It will be understood by those skilled in the art that it may be useful to graduate the activity of

the steam reforming catalyst through the bed. Therefore the third layer may comprise two or

more successive layers of a steam reforming catalyst, the fourth or further layers having a

higher catalytic activity than that preceding it.

The invention will now be further described by reference to the figures in which;

Figure 1 is depiction of an autothermal reformer containing a catalyst bed according to one

embodiment of the invention.

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In Figure 1 and autothermal reformer vessel 1 comprises an upper section comprising a burner

tube 10 to which an oxygen-containing gas may be fed and an inlet 12 to which a feedgas

comprising a hydrocarbon may be fed. The hydrocarbon-containing feedgas passes from the

inlet and though a perforate diffuser 14 to a lower combustion zone 16 to which the burner tube

10 extends. The walls of the vessel are lined with multi-layer alumina-containing refractory

liner 18. The oxygen-containing gas from the burner tube mixes with the hydrocarbon­

containing feedgas and partially combusts in the combustion zone 16. The hot, partially

oxidised gas then passes through a layer of perforate refractory oxide target tiles 20 and a

catalyst bed 22, 24, 26 disposed beneath the combustion zone 16. The catalyst bed comprises

three layers 22, 24, and 26. The first layer 22 comprises a catalytically active metal selected

from platinum, palladium, iridium, ruthenium or rhodium supported on a zirconia, and the

second 24 and third 26 layers comprise nickel on a refractory support selected from the group

consisting of alumina, calcium aluminate, magnesium aluminate, titania, zirconia, magnesia or

mixtures thereof. The second layer has a voidage ~0.5 and a higher equivalent passage

diameter than the third layer. The partially oxidised gas is steam reformed by the steam

reforming catalysts 22, 24, 26 and the resulting gas mixture brought towards equilibrium as it

passes down through the bed. The catalyst bed is supported within the vessel by refractory

oxide units 28, such as alumina spheres, which allow the reformed gas to pass from the

catalyst bed to a perforate end-member 30 and thence from the vessel via a reformed gas

outlet 32.

The alumina volatilised from refractory liner 18 passes though the tiles 20 (which are at the

same temperature as the hot gasses in the combustion zone), and surprisingly also through the

first layer 22 despite the cooling effect of the endothermic stream reforming reactions. The

volatilised alumina condenses in the second layer. Because the second layer has a voidage

~0.5 and a higher equivalent passage diameter, the deposited alumina does not negatively

affect the pressure drop through the bed compared to the case where the second layer is

absent.

In a specific embodiment an autothermal reformer was loaded with a catalyst bed comprising a

0.1-0.3 m thick layer of perforate zirconia tiles and lumps on top of a 0.1-0.2 m thick first layer

of a Rh/Zr02 steam reforming catalyst (KATALCOJM TM 89-6GQ) on a 0.2-0.3m thick second

layer of a large diameter 4-holed cylindrical Ni/AI20 3 steam reforming catalyst (KATALCOJM 23-

8E) on a 1-2m thick third layer of a smaller diameter 4-hole quadralobe Ni/AI20 3 steam

reforming catalyst (KATALCOJM 28-40).

In an alternative specific embodiment, an autothermal reformer was loaded with a catalyst bed

comprising a layer of perforate zirconia tiles on top of a 0.1-0.3 m thick first layer of a Rh/Zr02

steam reforming catalyst (KATALCOJMTM 89-6GQ or KATALCOJMTM 89-6EQ) on a 0.2-0.3m

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thick second layer of a large diameter 4-holed cylindrical Ni/AI20 3 steam reforming catalyst

(KATALCOJM 23-8E) on a 2-3m thick third layer of a smaller diameter 4-holed cylindrical

Ni/AI20 3 steam reforming catalyst (KATALCOJM 28-4GQ).

In both cases, the catalysts are commercially available from Johnson Matthey Catalysts.

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1. A process for the steam reforming of hydrocarbons in an autothermal or secondary

reformer comprising (i) non-catalytically partially com busting a feedgas comprising a

hydrocarbon with an oxygen-containing gas in the presence of steam to form a partially

oxidised hydrocarbon gas mixture at a temperature ~1200°C and (ii) passing the

partially oxidised hydrocarbon gas mixture through a first particulate layer of steam

reforming catalyst, a second particulate layer of steam reforming catalyst and a third

particulate layer of steam reforming catalyst, wherein the first layer comprises a

catalytically active metal selected from platinum, palladium, iridium, ruthenium or

rhodium supported on a zirconia, and the second and third layers comprise nickel on a

refractory support selected from alumina, calcium aluminate, magnesium aluminate,

titania, zirconia, magnesia or mixtures thereof, wherein the second layer has a voidage

~ 0.5 and a higher equivalent passage diameter than the third layer.

2. A process according to claim 1 wherein the catalytically active metal in the first layer of

steam reforming catalyst comprises rhodium and/or platinum, preferably rhodium.

3. A process according to claim 1 or claim 2 wherein the refractory support for the second

layer is selected from the group consisting of alumina, calcium-aluminate, magnesium­

aluminate or mixtures thereof.

4. A process according to any one of claims 1 to 3 wherein the refractory support for the

third layer is selected from the group consisting of alumina, calcium-aluminate,

magnesium-aluminate or mixtures thereof.

5. A process according to any one of claims 1 to 4 wherein the equivalent passage

diameter of the second layer is~ 6mm, preferably~ 7mm, more preferably~ 8mm,

especially~ 9mm.

6. A process according to any one of claims 1 to 5 wherein the second layer has a

voidage ~ 0.55.

7. A process according to any one of claims 1 to 6 wherein the third layer has a geometric

surface area higher than that of the second layer.

8. A process according to any one of claims 1 to 7 wherein the third layer has a geometric

surface area~ 300m 2/m 3, preferably~ 400m 2/m 3

.

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9. A process according to any one of claims 1 to 8 wherein a layer of zirconia balls,

pellets or tiles is placed on top of the first layer of reforming catalyst.

10. A process according to any one of claims 1 to 9 wherein the third layer comprises two

or more successive layers of a steam reforming catalyst, the fourth or further layers

having a higher catalytic activity than that preceding it.

11. A bed of steam reforming catalyst disposed below burner apparatus in an autothermal

or secondary reformer, wherein the bed comprises a first particulate layer, a second

particulate layer and a third particulate layer, each layer comprising a catalytically

active metal and an oxidic support wherein the first layer comprises a catalytically

active metal selected from platinum, palladium, iridium, ruthenium or rhodium

supported on a zirconia, the second and third layers comprise nickel on a refractory

support selected from alumina, calcium aluminate, magnesium aluminate, titania,

zirconia, magnesia or mixtures thereof, and wherein the second layer has a voidage

~0.5 and a higher equivalent passage diameter than the third layer.

12. A catalyst bed according to claim 11 wherein the first layer comprises rhodium on a

zirconia and the second and third layers comprises nickel on an alumina or

magnesium-aluminate or calcium-aluminate support.

13. A catalyst bed according to claim 11 or claim 12 wherein the first and second layers are

each between 5 and 25% of the thickness of the bed.

14. A catalyst bed according to any one of claims 11 to 13 wherein an inert layer of zirconia

balls, pellets or tiles is placed on top of the first layer of reforming catalyst.

15. A catalyst bed according to any one of claims 11 to 14 wherein the third layer

comprises two or more successive layers of a steam reforming catalyst, the fourth or

further layers having a higher catalytic activity than that preceding it.

wo 2012/131318 PCT/GB2012/050493

1/1

10

12

u---....L.----L...---u.-- 14

18

20

t:~~~;::t-22 24

26

28

Figure 1

INTERNATIONAL SEARCH REPORT International application No

PCT/GB2012/050493 A. CLASSIFICATION OF SUBJECT MATTER

INV. C01B3/38 C01B3/40 ADD.

According to International Patent Classification (I PC) or to both national classification and IPC

B. FIELDS SEARCHED

Minimum documentation searched (classification system followed by classification symbols)

C01B

Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched

Electronic data base consulted during the international search (name of data base and, where practicable, search terms used)

EPO-Internal, WPI Data, COMPENDEX

C. DOCUMENTS CONSIDERED TO BE RELEVANT

Category• Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No.

X,P wo 2011/113611 A2 (TOPSOE HALDOR AS [DK]; 1-15 SKJOETH-RASMUSSEN MARTIN SKOV [DK]; MORALES CAN) 22 September 2011 (2011-09-22) the whole document

-----X wo 2006/126018 A1 (JOHNSON MATTHEY PLC 1-15

[GB]; FARNELL PETER WILLIAM [GB]; FOWLES MARTIN [G) 30 November 2006 (2006-11-30) cited in the application page 5, last paragraph claims 1,2,5,6,7,10

------!--

[]] Further documents are listed in the continuation of Box C. lRJ See patent family annex.

• Special categories of cited documents : "T" later document published after the international filing date or priority

"A" document defining the general state of the art which is not considered date and not in conflict with the application but cited to understand

to be of particular relevance the principle or theory underlying the invention

"E" earlier application or patent but published on or after the international "X" document of particular relevance; the claimed invention cannot be filing date considered novel or cannot be considered to involve an inventive

"L" document which may throw doubts on priority claim(s) or which is step when the document is taken alone cited to establish the publication date of another citation or other "Y" document of particular relevance; the claimed invention cannot be special reason (as spec~ied) considered to involve an inventive step when the document is

"0" document referring to an oral disclosure, use, exhibition or other combined with one or more other such documents, such combination means being obvious to a person skilled in the art

"P" document published prior to the international filing date but later than the priority date claimed "&" document member of the same patent family

Date of the actual completion of the international search Date of mailing of the international search report

30 May 2012 19/06/2012 Name and mailing address of the ISAI Authorized officer

European Patent Office, P.B. 5818 Patentlaan 2 NL- 2280 HV Rijswijk

Tel. (+31-70) 340-2040, Harf-Bapin, E Fax: (+31-70) 340-3016 2

Form PCT/ISA/21 0 (second sheet) (April 2005)

page 1 of 2

2

INTERNATIONAL SEARCH REPORT

C(Continuation). DOCUMENTS CONSIDERED TO BE RELEVANT

Category• Citation of document, with indication, where appropriate, of the relevant passages

A F. BENYAHIA ET AL: "Enhanced Voidage Correlations for Packed Beds of Various Particle Shapes and Sizes".

A

PARTICULATE SCIENCE AND TECHNOLOGY. vol. 23. no. 2. 1 April 2005 (2005-04-01). pages 169-177. XP55028273. ISSN: 0272-6351. DOl: 10.1080/02726350590922242 the whole document

US 2003/083198 A1 (XU BANG CHEN [US] ET AL) 1 May 2003 (2003-05-01) the whole document

Form PCT/ISA/21 0 (continuation of second sheet) (April 2005)

International application No

PCT/GB2012/050493

Relevant to claim No.

1-15

1-15

page 2 of 2

INTERNATIONAL SEARCH REPORT International application No

Information on patent family members PCT/GB2012/050493

Patent document

I Publication

I Patent family

I Publication

cited in search report date member(s) date

wo 2011113611 A2 22-09-2011 NONE -----------------------------------------------------------------------wo 2006126018 A1 30-11-2006 AU 2006250933 A1 30-11-2006

BR PI0611199 A2 24-08-2010 CN 101180237 A 14-05-2008 EA 200702597 A1 28-04-2008 EP 1883604 A1 06-02-2008 NZ 563419 A 30-09-2010 us 2008197323 A1 21-08-2008 wo 2006126018 A1 30-11-2006 ZA 200709562 A 29-10-2008

-----------------------------------------------------------------------us 2003083198 A1 01-05-2003 us 2003083198 A1 01-05-2003

us 2005181939 A1 18-08-2005 -----------------------------------------------------------------------

Form PCT/ISA/21 0 (pa1en1 family annex) (April2005)