Method of carrying out heterogeneous catalytic chemical processes

A catalytic chemical process is carried out non-adiabatically using as a catalyst a body with two sets of channels throughout the body. One set of channels leads the process fluid towards one of two parallel walls of the catalyst chamber, the other set towards the outer wall, In slits between walls and catalyst heat is exchanged between process fluid and at least one of these walls upon reflecting the process fluid leaving channels of one set and entering channels of the other. The body may be made of alternatingly corrugated and plane sheets using in turn two different orientations for the corrugated sheets. It is preferred that the sheets are arranged orthogonal to the heat transmitting wall(s) and parallel to the overall direction of flow. The method is preferred for endothermic processes, especially steam reforming of hydrocarbon(s).

FIELD OF THE INVENTION 
The present invention relates to a method of carrying out catalytic 
chemical processes at non-adiabatic conditions. 
In a heterogeneous catalytic chemical process, a process fluid is contacted 
with a solid catalyst or a supported liquid phase catalyst which catalyses 
one or more reactions to form part of the process, the catalyst usually 
being arranged in one or more beds in one or more catalyst chambers in a 
catalytic reactor Throughout this specification is by catalytic processes 
meant processes of this kind. 
Carrying out a catalytic process at non-adiabatic conditions implies that 
during passage of the process fluid through the catalyst bed or beds heat 
is exchanged between the process fluid and some agent for heating or 
cooling, usually by convective heat exchange with a heat transmitting wall 
separating the process fluid from said agent. 
By catalyst throughout this specification any solid catalyst or supported 
liquid phase catalyst is meant, whether in one or more monolithic blocks 
or in the form of particles. Similarly by catalyst bed a bed is meant in 
which any such catalyst is placed. By catalyst support body a body is 
meant which is usable for being transformed into a catalyst, e.g. by 
impregnation or coating, whether or not the body such treated must undergo 
one or more further special treatments before reaching an active catalytic 
state, e.g. calcining or reduction. Similarly, a catalyst as above defined 
may need a special treatment after being loaded into a catalyst chamber in 
order to reach an active state 
By the term fluid both liquids and gaseous substances are aimed at. 
Chemical processes may be classified either as endothermic processes, which 
consume heat, or as exothermic ones, which produce heat. 
Among the endothermic catalytic processes of industrial importance and 
carried out at non-adiabatic conditions, steam reforming of hydrocarbons 
may be mentioned as an example. It is usually performed at 
400.degree.-950.degree. C. The process is often performed in tubes 
containing a catalyst promoting the reaction(s). The tubes may be arranged 
in a radiant furnace chamber in which the combustion of a fuel supplies 
the necessary heat. The process may as an alternative be performed in a 
heat exchange reformer, e.g. as disclosed in European Patent Application 
No. 195,688. 
Exothermic catalytic processes are often performed at 
200.degree.-600.degree. C. As examples of exothermic processes of 
industrial importance carried out at non-adiabatic conditions, partial 
oxidations may be mentioned, e.g. the manufacture of ethylene oxide, 
formaldehyde, or phthalic anhydride. Another example is methanation of 
carbonoxides. These processes are often performed in cooled tubular 
reactors. 
Some industrially important catalytic processes are reversible and 
exothermic, e.g. manufacture of ammonia or methanol. These processes are 
often performed while recirculating a part of the process gas through the 
catalyst beds as the conversion per pass is often fairly small. A number 
of different concepts are used among which some are non-adiabatic. 
A combination of pressure drop in the process fluid passing through the 
catalyst bed and heat transfer coefficient between the process fluid and 
the heat transmitting walls of the catalytic chambers will often represent 
the limiting process condition for throughput and yield with a given 
amount of catalyst as well as for process economy. A low pressure drop and 
a high heat transfer coefficient represent the desired process conditions. 
A low pressure drop will reduce the power required by the process plant 
irrespective of type of catalytic process. A high heat transfer 
coefficient is desirable for all types of non-adiabatic catalytic 
processes. For endothermic catalytic processes, a high heat transfer 
coefficient will increase the amount of heat supplied to the process fluid 
and, therefore, the reaction rate and the degree of conversion for a given 
amount of catalyst. For exothermic catalytic processes, a high heat 
transfer coefficient will reduce the temperature of the process fluid and, 
therefore, the reaction rate. Thus catalyst temperatures are more easily 
controlled and excess temperatures resulting in catalyst damage are more 
readily averted. Likewise, undesired reactions, e.g. total oxidations are 
more easily avoided. 
For reversible exothermic catalytic processes, a high heat transfer 
coefficient between process fluid and cooling surfaces will result in (1) 
the temperature of the process fluid being reduced and (2) the equilibrium 
being shifted towards a higher degree of conversion. The total effect will 
frequently be a higher yield. 
Using common commercial catalysts in the form of pellets, rings, or any 
other particulate form it is not possible to increase the heat transfer 
coefficient between the walls of the catalyst chamber and the process 
fluid substantially without simultaneously increasing the pressure drop. 
Especially for the steam reforming process, this restriction has been felt. 
For some time, therefore, various methods using catalyst having 
non-particulate form have been described, aiming at obtaining 
simultaneously a low pressure drop and a high heat transfer coefficient. 
In the steam reforming process, the highest degree of conversion for a 
given amount of catalyst is obtained when operating at the highest 
temperature. For that reason the operation temperature often approaches 
the upper limit temperature for the tube material. A uniform temperature 
distribution along the heat transmitting walls will permit the highest 
average temperature for a given maximum temperature and is, therefore, 
highly desirable 
BACKGROUND OF THE INVENTION 
Methods of obtaining some of these features have been described in the 
literature. Some of these methods utilize bodies which might be used as a 
catalyst or a catalyst support body if made from a suitable material but 
which, according to the description in the literature, are used otherwise. 
Below, references will be given to literature describing catalysts as well 
as bodies having some of the above features without being catalysts. 
U.S. Pat. No. 3,785,620 describes bodies consisting of corrugated lamellae 
which are proposed used as static mixers. 
U.S. Pat. No. 4,296,050 describes packing elements for an exchange column 
made from a plurality of corrugated plates. 
Sales pamphlets from Sulzer Brothers Ltd. describe bodies of similar form 
as the bodies of the U.S. Patents mentioned above, but in ceramic 
material, and propose to use them i.a. as catalyst support bodies. 
U.S. Pat. No. 3,112,184 describes a method of making ceramic articles some 
of which have such characteristics as to fulfill the above features if 
made from a catalytic active material or used as support bodies. Such use 
is not, however, proposed in the description although it is stated that 
bodies of a somewhat similar configuration are used in such a way. It is 
proposed to use the articles for making heat exchangers transferring heat 
from streams flowing through some channels into streams flowing through 
others, but not to effect the heat transfer through a vessel wall. 
EP Patent Specification No. 0 025 308 discloses a process and an apparatus 
for endothermic steam reforming of hydrocarbons. A catalyst in the form of 
a structure comprising a stack of profiled plates is described. The 
structure is spaced from the walls of the catalyst chamber and has 
passages angled to the overall direction of flow in the catalyst chamber 
causing a process fluid to flow alternatively through the catalyst and for 
a significant length through a space between the structure and the heated 
walls of the catalyst chamber. Due to this flow pattern, the heated walls 
will show exended and successive areas of high temperature and low 
temperature caused by prolonged heating of some of the fluid, and 
decreasing flow rate in different areas along the reactor walls resulting 
in low heat transmission, followed by massive flow of the process fluid 
leaving the catalyst with a reduced temperature due to the reaction inside 
the catalyst channels. 
Thus, since the flow pattern according to the above mentioned EP-patent 
will not result in a uniform temperature distribution in the fluid 
entering the catalyst channels at a given level at the catalyst chamber, 
it is not possible to obtain a uniform catalyst utilization. 
A very high transmission of heat from the walls of the catalyst chamber 
into the process fluid is particularly important when providing some of 
the heat for steam reforming of hydrocarbons by convective heat exchange 
between the process fluid and a flue gas in a heat exchange reformer. An 
essentially even temperature distribution along the heat transmitting 
walls is also of paramount importance for this process concept. 
None of the previously proposed methods has fully overcome the problem of 
simultaneously obtaining (1) a very low pressure drop in the process fluid 
passing through the catalyst bed, and (2) a high heat transfer coefficient 
between the wall(s) of the catalyst chamber and the process fluid, and 
further (3) having uniform or essentially uniform temperature distribution 
along the heat transmitting wall(s), and (4) efficient utilization of the 
total amount of catalyst. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide a method which combines a 
very low pressure drop in the process fluid passing through the catalyst 
bed and a high and essentially uniform heat transfer coefficient between 
the wall or walls of the catalyst chamber and the process fluid, combined 
with an efficient utilization of the catalyst. 
Accordingly, the invention relates to a method of carrying out a 
heterogenous catalytic chemical process at non-adiabatic conditions by 
passing a stream of a process fluid in one overall flow direction through 
a catalyst contained in a catalyst chamber defined by walls two of which 
are substantially uniformly spaced, and transmitting heat through at least 
one of the two substantially uniformly spaced walls between the process 
fluids inside the catalyst chamber and a fluid outside the catalyst 
chamber, said catalyst having a structure of channels arranged in groups 
of substantially parallel channels causing the process fluid to be 
subdivided into a plurality of sub-streams having actual flow directions 
angled to the two uniformly spaced walls and to the overall flow 
direction, and changing direction whenever reaching one of the walls. The 
characteristic feature of this method is that the mass flow towards one of 
the two substantially uniformly spaced walls, at any cross section 
orthogonal to the overall flow direction, is approximately equal to the 
mass flow towards the other of said two walls, the flow direction of the 
sub-streams in one group of channels being different from that in the 
neighbouring group or groups of channels, and that the actual flow 
direction of any sub-stream is reflected whenever it reaches one of the 
two substantially uniformly spaced walls. In this manner there is obtained 
an essentially uniform temperature distribution along the heat 
transmitting wall or walls and an efficient utilization of the total 
amount of catalyst is thus made possible, i.e. that the amount of catalyst 
necessary for reaching a desired degree of conversion is diminished. 
The efficiency of the method according to the present invention results 
from the immediate reversion of flow of any of the sub-streams whenever 
such a sub-stream reaches one of the heat transferring walls. No or only a 
minor flow of the fluid outside the channels and along the heat 
transferring walls is obtained. This flow pattern provides the least 
possible distance between cold spots caused by the fluid from the channels 
outlet and hot spots at the channel inlet. The structure of the catalyst 
chamber ensures uniform heating of the process fluid due to the frequent 
and close contact of said process fluid to the heat transferring wall or 
walls at the points of reflection. 
Another feature of the above mentioned catalyst chamber is the continuous 
and prolonged contact of the process fluid to the catalyst surface 
obtained by forced angular movement through the catalyst chamber, 
interrupted only by the reflection points at the heat transferring wall or 
walls. 
DETAILED EXPLANATION OF THE INVENTION 
The ratio between the number of sub-streams directed towards each of the 
two walls can be between 1:100 and 100:1 It is, however, preferred that 
the ratio is between 1:10 and 10:1. Especially, it is preferred that the 
number of substreams directed towards one of the substantially uniformly 
spaced walls are approximately the same as the number of sub-streams 
directed towards the other of said walls. 
It is preferred that the angles between the directions of actual flow 
through the catalyst and the direction of the overall flow through the 
catalyst bed are from 5.degree. to 85.degree., preferably from 15.degree. 
to 75.degree., and especially it is preferred that the angles are 
approximately 45.degree.. 
It is preferred to use a catalyst wherein the channels are arranged in 
layers which are not orthogonal to the overall direction of flow. 
Especially, it is preferred to use a catalyst wherein the channels are 
arranged in layers which are approximately parallel to the overall 
direction of flow. 
The manufacture of the catalyst is particularly simple when the layers are 
angled from 5.degree. to 90.degree. to the heat transmitting wall(s). It 
is especially preferred that the channels are arranged in layers which are 
approximately orthogonal to the heat transmitting walls. 
An optimum combination of pressure drop and rate of heat transfer results 
when the streaming process fluid, when reaching whichever of the two 
uniformly spaced walls, is reflected or thrown back towards the opposite 
wall in a slit between the wall in question and the catalyst, the width of 
said slit being less than one fifth of the distance between the two 
uniformly spaced walls. 
In one embodiment of a catalyst chamber complying with the method of the 
invention, the two substantially uniformly spaced walls are coaxial 
cylindrical walls, the catalyst chamber being annular and the overall flow 
direction of the process fluid being parallel to the common axis of the 
cylindrical walls. 
In another embodiment of a catalyst chamber complying with the method of 
the invention, the two substantially uniformly spaced walls are parallel 
and plane, the catalyst having the form of a prism with at least one pair 
of parallel sides 
The manufacture of a catalyst which may be used in the method of the 
invention, and the later loading thereof into a catalyst chamber is 
facilitated when using a catalyst wherein the catalyst is in the form of 
essentially identical bodies placed in the catalyst chamber in a 
systematic way. 
Complying with the method of the invention, a process fluid can be brought 
to flow in sub-streams being arranged in sets of layers, the direction of 
the flow in one set of layers being essentially parallel and different 
from the direction in the neighbouring set or sets of layers, each set of 
layers comprising a small number of layers, preferably one or two. 
A simple way of obtaining such a flow is by means of a catalyst or catalyst 
support body comprising layers of sheets defining channels. 
The described flow pattern may e.g. be obtained by using as a catalyst or 
catalyst support body a stack composed of corrugated sheets, preferably 
alternating with plane sheets. Both types of sheet may, e.g.,be made in a 
manner known per se and from a material compatible with the catalytic 
material and the chemical process. The stack may comprise one layer of 
channels in each set of either streaming direction and take the following 
form: 
a. a corrugated sheet, orientation A 
b. a plane sheet 
c. a corrugated sheet, orientation B 
d. a plane sheet 
this sequence being repeated until the desired size is obtained. It is not 
mandatory that all sheets have the same size nor are cut to size along 
straight lines. Actually, it may often be preferable to cut the plane 
sheets to a size slightly less than the overall size of the corrugated 
sheets and/or give them a pair of serrated edges at the sides to become 
mounted against said walls of essentially constant spacing. 
It is suitable to pass the process fluid through a catalyst bed wherein the 
channels are substantially straight, the angles between the actual 
directions of the sub-streams and the overall flow direction being 
5.degree. to 85.degree., preferably 15.degree. to 75.degree. and notably 
approximately 45.degree.. 
The flow pattern characteristic for the method of the invention may also be 
obtained using only corrugated sheets and stacking them using alternately 
sheets of orientations A and B. 
In one of the above mentioned embodiments of a catalyst chamber complying 
with the method of the invention said two walls are coaxial cylindrical 
walls. This requires a catalyst in the form of a hollow cylindrical body. 
A catalyst or catalyst support body of such form producing the flow 
pattern and heat transmission characterizing the method of the invention 
may as an example be manufactured by cutting stacks of sheets as described 
above and placing these stacks within two walls forming an annular mould. 
The stacks may e.g. be deformed sufficiently for them to attain the form 
of segments of a hollow cylindrical body and thus fit into the mould. It 
should be borne in mind that the diameter of the two walls of the mould 
(corresponding to inner and outer wall, respectively, of a catalyst 
chamber) usually must differ slightly from the actual diameter of the 
corresponding walls of the catalyst chamber in order to allow for a 
possible different thermal expansion for catalyst or catalyst support body 
and the material of the catalyst chamber and to allow for desired slits 
between catalyst and walls. 
It is especially preferred to stack the sheets defining the stream pattern 
in the above said mould in such a manner that all flow directions become 
arranged in planes essentially parallel to the overall direction of flow 
when the catalyst has been loaded into a catalyst chamber. 
The sheets can be stacked orthogonally or obliquely relative to the walls 
of the above said mould and thus obliquely relative to the heat 
transmitting walls when the catalyst has become loaded into a catalyst 
chamber. 
The method of the invention is not restricted to the use of bodies prepared 
from stacks of sheets comprising corrugated sheets or, when using 
corrugated sheets, to use a special form of corrugation or to use the same 
form or size of corrugation for all corrugated sheets. Any other means of 
obtaining said flow pattern while obtaining a transmission of heat between 
the process fluid and the heat transmitting wall(s) is considered part of 
the invention when used in carrying out non-adiabatic catalytic processes. 
The flow pattern and heat transmission characterizing the method of the 
invention may e.g. be obtained using instead of sheets a great number of 
essentially identical pipes placed between two walls of approximately 
constant spacing of which at least one is heat transmitting. Stacking 
pipes of e.g. rectangular cross section and having length exeeding the 
distance between said two walls in such way as to obtain consecutive piles 
of pipes of alternating orientatiOn, one leading towards one wall, the 
other towards the other wall, will provide for the desired flow pattern 
and give rise to only a small pressure drop. Each partial stream leaving a 
pipe will, when reaching one of the walls reverts towards the other wall 
through neighbouring pipes of opposite orientation. If the wall is heat 
transmitting, this reversion causes a high heat transfer coefficient 
between process fluid and wall. 
The flow pattern and heat transfer characterizing the method of the 
invention may also be obtained e.g. using (instead of pipes) cylinders 
having two or more fluid passages extending axially therethrough from one 
end to the other. 
In order to transform a catalyst support body providing the desired flow 
pattern and producing the desired heat transmission into a catalyst usable 
for carrying out the method of the invention such body may e.g. be 
impregnated or coated using an impregnation or coating technique and 
active materials known per se. 
The method of the invention may be utilized when carrying out a 
heterogeneous catalytic chemical process at non-adiabatic conditions and 
it is not restricted to any particular process. 
The process carried out can be an exothermic process, especially partial 
oxidation of hydrocarbons or alcohols, or hydrocarbon synthesis from 
carbon oxides and hydrogen. 
For partial oxidation of hydrocarbons or alcohols one can, e.g. use a 
coated catalyst support consisting of for instance glass wool paper, the 
coating consisting of e.g., approximately 80% (w/w) molybdenum oxide and 
20% (w/w) iron oxide promoted with chromium oxide. 
Synthesis of hydrocarbons from carbon oxides may be carried out by use of a 
coated catalyst support body consisting of, e.g. ceramic paper based on 
alumina fibers, 15 the coating consisting of, e.g 25-50% (w/w) Ni and the 
balance alumina. 
The process carried out can also be an endothermic process, especially 
steam reforming of hydrocarbons, preferably carried out in a heat exchange 
reformer. 
Such steam reforming may be carried out for instance by use of a coated 
catalyst support body consisting of, e.g., ceramic paper based on alumina 
fibers the coating consisting of, e.g., 25% (w/w) Ni, the other main 
components being magnesia and alumina.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 shows a horizontal section of a reactor. The reactor has an annular 
catalyst chamber loaded with a catalyst suitable for carrying out the 
method of the invention. The process fluid flows down towards the catalyst 
The catalyst body consists of corrugated sheets 14, 15 and plane sheets 
16. The corrugated sheets have alternating orientations. The fluid 
channels 17 defined by the corrugated sheets 14 and the plane sheets 16 at 
either side lead fluid flowing down onto the catalyst body towards the 
outer wall 20 of the catalyst chamber, whereas the fluid channels 18 
defined by the corrugated sheets 15 and the plane sheets 16 at either side 
lead the fluid towards the inner wall 19. In the catalyst shown in the 
figure, all sheets are essentially orthogonal to the surface of both walls 
19, 20. 
The slits between catalyst and walls are not shown in FIG. 1. 
FIG. 2 shows a vertical section of the top part of the reactor and the 
catalyst body of FIG. 1 along the line a--a. The overall direction of flow 
is indicated by the arrows C. All layers of sub-streams and of the 
channels in which they flow are parallel to the overall direction of flow, 
C, and being orthogonal to the walls, the plane of a layer will coincide 
with the cut. The left part of the figure shows a section through a 
corrugated sheet 14 having sub-streams in channels 17 leading the 
sub-streams in the direction of the outer wall 20 whereas the right part 
of the figure shows a section through a corrugated sheet 15 having 
sub-streams in channels 18 leading the sub-streams in the direction of the 
inner wall 19. The flow directions of the sub-streams are indicated by 
arrows. The corrugated sheet lying beneath the sheet being sectioned and 
the plane sheet in between these sheets is indicated by dashed lines. The 
flow at this lower level has been indicated by dashed arrows. The flow 
reflection or "throwing back" upon reaching either of the walls is 
indicated by shifting from full to dashed arrows at the reversal 
corresponding to the shifting from the plane of the figure to an 
underlying plane or vice versa. 
The slits between catalyst and walls are not shown in FIG. 2. 
The annular catalyst chamber shown in FIGS. 1 and 2 may, e.g., be the 
catalyst chamber of a heat exchange reformer of the kind disclosed in 
published European Patent Application No. 195,688. 
At or near the edges of sheets against the inner and outer walls zones will 
occur with little net flow and locally small coefficient of heat transfer. 
Due to the turbulence caused by the reversal of flow at each or every two 
sheets or channels these zones will be very narrow and will be situated at 
distances corresponding to the height of one or two channels, typically a 
few mm each. The heat conductance in the wall or walls will effectively 
level out any temperature difference caused by such zones and no uneven 
temperature distribution will be noticeable. 
FIG. 3 shows a section of a catalyst or catalyst support body which may be 
used in accordance with the invention. The section consists of a stack of 
essentially parallel sheets 14, 15, 16, the sheets 14 having a corrugation 
of orientation A, the sheets 15 having corrugations of orientations B, and 
the sheets 16 being plane. The stack has been made stacking the sheets in 
the following order (from below): 
one plane sheet 16 
one corrugated sheet 14, orientation A 
one plane sheet 16 
one corrugated sheet 15, orientation B 
this sequence being continued throughout the stack 
The corrugated sheets 14 define together with the plane sheets 16 below and 
on top of it essentially straight channels 17 and the corrugated sheets 15 
define together with the plane sheets 16 below and on top of it 
essentially straight channels 18 the directions of the two systems of 
channels 17, 18 being different. The channels of either direction are 
arranged in essentially parallel layers. 
A section as shown in this figure may be made in the catalyst shown in 
FIGS. 1 and 2, the overall flow direction being indicated by an arrow C 
e.g. one of the bisectors of the angles formed by the directions of the 
channels 17, 18. No deformation to accommodate to the loading in an 
annular catalyst chamber is shown. 
FIG. 4 shows an end view of a corrugated sheet seen along the corrugations. 
The figure indicates the dimensions E and L being characteristic for the 
corrugation. 
FIG. 5 shows a perspective view of another embodiment of a catalyst or 
catalyst support body suitable for carrying out the method of the 
invention, a part of the body having been taken away. This body consists 
of pipes 21, 22 having rectangular cross section. The pipes are stacked in 
piles 23, 24 with alternating orientation of the pipes, the piles 23 
consisting of pipes 21 having an orientation different from that of the 
pipes 22 of the piles 24, providing for the flow pattern and heat transfer 
characteristic of the invention. Some of the piles 26 are indicated by 
dashed lines only, whereas only some of the pipes are shown in the 
foremost of the piles 27. Although the pipes of different piles are shown 
reaching the same level, this is not mandatory. 
As explained with reference to FIGS. 1 and 2, no uneven temperature 
distribution will be noticeable at the wall or walls when this embodiment 
is used for the process. 
FIG. 6. shows a vertical section of the body of FIG. 5. The body is placed 
between two walls 25 cutting one pile of pipes 21 and seen orthogonal to 
the plane of this pile. The pipes of the pile of pipes 22 laying just 
beneath the layer shown is indicated by dashed lines and the fluid flows 
are indicated by solid arrows and dashed arrows, respectively The two 
walls 25 have essentially constant spacing. The reflection of the flows 
upon reaching these walls is indicated by the arrows. 
FIG. 7 shows a sketch of the experimental set-up used to determine pressure 
drops and heat transfer coefficients for different models of catalyst 
bodies and catalyst particle beds. 
The reference numbers of FIG. 7 refer to the following items 
(1) an air compressor, suction capacity .ltoreq.250 m.sup.3 /hr. 
(2) an air vessel 
(3) a closing valve 
(4) a reduction valve 
(5) a precision pressure gauge, 0-15 kg/cm.sup.2 g 
(6) a flowmeter 0-101 Nm.sup.3 /hr. at 5 kg/cm.sup.2 g, 15.degree. C. 
(7) a manually operated regulating valve 
(8) a model of a catalytic reactor having two heat transmitting walls 11, 
12 at essentially constant distance. These two walls being plane steel 
radiators were fitted with wooden laths one at each end, the whole 
assemble was clamped together. The bottom consisted of a wiremesh screen 
and the top of an air distributing piece fitted tightly. 
The distance between the radiators could be modified placing sheets of 
cardboard between one of the radiators and the laths. 
(9) a catalyst body or catalyst bed 
(10) a U-tube manometer 
The invention and the advantages obtained are explained in more detail in 
the Example below. 
EXAMPLE 
In an experimental set-up, models of catalysts providing the 
characteristics of the invention were compared with specimens of standard 
catalysts for steam reforming of hydrocarbons. 
Three models of cross-arranged corrugated catalyst support bodies were 
prepared from corrugated cardboard. Models 1 and 2 consisted of 
cross-arranged corrugated cardboard having a wave height, E, of 2.5 and 
4.4 mm and having a plane sheet (a liner), i.e. made up like the body 
shown in FIG. 3. Model 3 consisted of cross-arranged corrugated cardboard 
having a wave height, E, of 2.1 mm and not having a liner. For comparison, 
corresponding experiments were carried out using specimens of standard 
catalyst rings with OD/ID.times.H=16.7/7.8.times.10.4 mm and standard 
catalyst cylinders with OD.times.H=5.3.times.5.1 mm. 
The data of the tested catalyst models and catalyst particles are stated in 
Table 1. 
TABLE 1 
______________________________________ 
Model Model Model 
Filling 1 2 3 Rings Cylinders 
______________________________________ 
Material Card- Card- Card- Ceramic Ceramic 
board board board magnesium 
magnesium 
aluminate 
aluminate 
spinel spinel 
E, mm 2.5 4.4 2.1 -- -- 
L, mm 7.1 8.3 6.4 -- -- 
Corrugation 
1.3 1.5 1.3 -- -- 
Factor 
OD, mm -- -- -- 16.7 5.3 
ID, mm -- -- -- 7.8 -- 
H, mm -- -- -- 10.4 5.1 
VOID, % 82 95 91 52.2 34.6 
S/V, m.sup.2 /m.sup.3 
1840 1140 1240 306 757 
______________________________________ 
The dimensions E and L are indicated in FIG. 4. The corrugation factor is 
defined as the ratio between the actual upper outer area of the corrugated 
sheet and the projected area of this sheet on a plane at which the 
corrugated sheet is brought to rest. S/V is the outer surface (m.sup.2) 
per volume (m.sup.3). 
It is noted that the outer surface per volume (S/V) is 1.5-2.5 times larger 
for the cross-arranged cardboard models than for the 5.3.times.5.1 mm 
cylinders. Thus, for the reforming process it is expected that the 
catalyst activity per volume will be higher when using a cross-arranged 
catalyst than when using 5.3.times.5.1 mm catalyst cylinders, since the 
effectiveness factor of the reforming reaction is very low, typically less 
than 5%, in the bottom 80% of an ordinary tubular reformer and decreasing 
to less than 1% at the bottom, cf. J. R. Rostrup-Nielsen, Catalytic Steam 
Reforming, Springer Verlag, Berlin (1984), p. 69. 
The heat transfer and pressure drop properties of the models and of the 
catalyst cylinders and rings were determined in a 1000 mm long vertical 
channel having 55.times.300 mm rectangular horizontal cross section. The 
two walls of 300.times.1000 mm were two parallel plane radiators wherein 
hot water at 80.degree. C. was circulated. The cardboard models of 
dimensions 55.times.300.times.1000 mm were arranged having the planes of 
the sheet orthogonal to the heating surfaces and parallel to the direction 
of overall flow. The distance between the radiators could be increased at 
will as above said. 
FIG. 7 shows a sketch of the experimental set-up. When carrying out an 
experiment, a stream of air was passed down through the channel containing 
a cardboard model or catalyst cylinders or rings. The pressure drop across 
the "catalyst filling" and the heat transfer were determined. Valve (3) 
was opened and the reduction valve (4) and the control valve (7) were 
adjusted to obtain a reading on the pressure gauge (5) of 6 kg/cm.sup.2 g 
and the flowmeter (6) showed a predetermined reading. The pressure drop 
across the catalyst filling (9) indicated by the U-tube manometer (10) was 
read 
The temperatures of the catalyst or cardboard model and the hot water were 
recorded at 5-10 minute intervals until the recorded temperatures were 
stable. The difference between the hot water temperature at inlet and 
outlet was less than 2.degree. C. in all experiments. In the 
interpretation of the measurements it was assumed that the temperature was 
the same in all positions on the radiator walls. 
The physical properties of the gas flow of the experiments are stated in 
the below Table 2. 
TABLE 2 
______________________________________ 
G, Mass Flux, kg/m.sup.2 /h 
7.2 .times. 10.sup.3 
Viscosity, kg/m/h 0.070 
k, Conductivity, kcal/m/h/.degree.C. 
0.023 
C.sub.p, 
Heat Capacity, kcal/kg/.degree.C. 
0.24 
Gas Density, kg/m.sup.3 
1.09 
______________________________________ 
Thirteen thermocouples were placed in the catalyst or models. 
In the experiments using catalyst rings or cylinders, the distance between 
the radiator walls was 60 mm and all the thermocouples were placed in the 
centre plane between the two radiator walls. One thermocouple was placed 
on the centre line 10 mm from the bottom (gas outlet) and the remaining 12 
were placed 10, 125, 250, and 500 mm from the top and in three different 
lateral positions: On the centre line 95 mm to the left, and 95 mm to the 
right. 
In the experiments testing the cardboard models, all thermocouples - except 
two - were placed in the centre plane orthogonal to the radiator walls. 
Five thermocouples were placed on the centre line 10 mm from the bottom 
(gas outlet) and 10, 125, 250, and 500 mm from the top. Six thermocouples 
were placed 19.5 mm from the centre line 125, 250, and 500 mm from the 
top, three on the near side of the centre plane between the two radiator 
walls and three on the far side. The remaining two thermocouples were 
placed in the centre plane between the two radiator walls 250 mm from the 
top and 105 mm from the centre line, one to the left and one to the right. 
The results obtained in the various experiments are summarized in Table 3. 
TABLE 3 
______________________________________ 
Determinations of Heat Transfer Coefficient, h, and Pressure 
##STR1## 
Slit 
Filling mmfilling,wall andbetween 
##STR2## 
##STR3## 
______________________________________ 
Model 1 1.2 163 81 
2.4 117 72 
Model 2 0.6 230 182 
1.2 187 49 
2.4 122 34 
Model 3 0 193 133 
0.6 196 107 
1.2 161 93 
Standard Catalyst 
0 152 245 
Ring, 
16.7/7.8 .times. 10.4 mm 
Standard Catalyst 
0 152 1441 
Cylinder, 
5.3 .times. 5.1 mm 
______________________________________ 
The pressure drops found for the cardboard models are lower, in some cases 
an order of magnitude lower than those found for the catalyst particles. 
The heat transfer coefficients found for the cardboard models are higher 
than those found for the catalyst particles, provided that the slit width 
between the specimen and the wall does not exceed 1.2 mm. 
Comparing the experimental results found using models 1 and 2, it is seen 
that reducing the channel width leads to superior heat transfer and 
pressure drop properties. 
Comparing the experimental results found for models 2 and 3, it is seen 
that the pressure drop may be halved by replacing a catalyst or catalyst 
support body (model 3) having no liner by a catalyst or a catalyst support 
body (model 2) having a liner, having the same outer surface per volume 
(S/V) and yielding the same heat transfer coefficient when using the same 
slit width. 
In the above explanations referring to the figures and in the above 
Example, a number of embodiments of a catalyst complying with the method 
of the invention have been described in detail and the experimental 
results found when comparing three of these embodiments with a standard 
catalyst in a model experiment are stated. However, the results are 
considered illustrating only and not restricting the method of the 
invention to the specifically described embodiments. Any means of 
realizing the flow pattern and heat transferring characteristic of the 
invention and usable for carrying out a heterogeneous catalytic chemical 
process at non-adiabatic conditions is considered part of the invention 
only being restricted by the scope of the appended claims. 
Using stacks of corrugated sheets having undulating corrugations will fully 
comply with the method of the invention. 
Also corrugated sheets (having straight or undulating corrugations) may be 
given a secondary corrugation, optionally having other form or size and an 
orientation different from the primary corrugation may be used according 
to the invention. 
Further possibilities comprise apertured sheets or sheets having surface 
projections.