US1936118A

US1936118A - Catalytic apparatus

Info

Publication number: US1936118A
Application number: US406437A
Authority: US
Inventors: Roka Koloman
Original assignee: FIRM DEUTSEHE GOLD und SILBER
Current assignee: FIRM DEUTSEHE GOLD und SILBER; FIRM DEUTSEHE GOLD- und SILBER-SCHEIDEANSTALT VORMALS ROESSLER
Priority date: 1928-11-28
Filing date: 1929-11-11
Publication date: 1933-11-21
Anticipated expiration: 1950-11-21

Description

Nov. 21, 19336 K. RoKA 1,936,118

CATALYTIC APPARATUS Fil ed Nov. 11, 1929 2 Sheets- Sheet 2 IN VEN TOR.'

A TTORNEYS.

Nov. 21, 1933. ROKA 1,936,118

CATALYTIC APPARATUS Filed NOV; 11, 1929 2 Sheets-Sheet l INVENTOR. KBo/ia A TTORNEYS.

UNITED STATES PATENT o1=1=1c1-:

In carrying out catalytic gas CATALYTIC Koloman Roka,

mesne assignments, Gold- 11ml Silber- APPARATUS Konstanz, Germany, assignor, by

to the firm Deutsche Scheideanstalt vormals Roessler, Frankfort-on-the-Main, Germany, a corporation of Germany Application November 11, 1929, Serial No. 406,437,

and in 5 Claims.

reactions which take place with the addition or evolution of heat care is taken to lead the vapour mixtures through 5 catalyst, cooled externally or heated by hot gases.

cross section and consequently gases or the gas and pipes packed with the for example by air the capability of such catalyst pipe to allow the gases to pass are placed within extremely narrow the fact that with increasing limits owing to diameter of the pipes the exchange of heat between the separate portions of the catalyst material and the outer wall becomes increasingly less effective. It is, therefore, necessary,

when working with large amounts of gas, to employ a correspondingly large number of pipes individually of relatively small diameter,

but connected up in-parallel.

It has been found that catalytic gas reactions, in particular such reactions as require an I exact maintenance of a particularly high degree, or which owing to specially temperatures to such reactions great absorption or definite evolution of 'heat require a specially energetic action of the cooling or heating means,

can be carried out considerably better and with greater certainty in reaction vessels that their inner space surfaces parallel with of such a fiat shape is mainly bounded by two one another or substantially parallel, the distance between which is small relatively to the other dimensions of the container so that the distance of the catalyst from the container wall does not exceed at any place the limits within which a sufficiently rapid heat exchange is possible, with the result that the containers so obtained, for example of pocket shape, are moreover S0 formed that the catalyst may be easily introduced and removed, and at the same time a good ing gas over the whole lyst is ensured.

distribution of the entercross section of the cata- With such containers, on accountv of the large containing space of which may amount to the individual containers,

about 100 litres, the furcontrast with sets that the catalyst can be filled into the containers and removed from the same very much more quickly owing to the smaller number of filling and emptying'openings and that furthermore any small irregularities in the thickness of the filling are very easily compensated over the whole cross section of pipes the resistance is never the same in with the result that the container while with a set of to the passage of the gases each of the separate pipes,

the gases in such cases The increase in the.

Germany November 28, 1928 will flow through the pipes of lower resistance in larger amounts than through those with greater resistance. Consequently for example in lower temperature limits permissible for thereaction.

The same is the case in the converse direction with endothermic reactions in which the desired reaction temperatures must be produced by uniform supply of external heat.

These drawbacks naturally are the more serious in proportion to the narrowness of the temperature limits for the gas reactions to be carried out or to the amounts of heat to be supplied or withdrawn, the result being that on the one hand not only incomplete conversion takes place in the cold pipes, and on the other hand the formation of decomposition products in the parts of the cata--' lysts which are too hot, but also the catalyst is injured by overheating.

By employing containers according to the invention the said drawbacks are largely avoided, and owing to the uniform flow of the gases throughthese containers it is possible to use them in larger numbers connected in parallel, because the relative differences in the capacity of the individual containers to allow the flow of gas becomes much smaller than between the individual small units when pipes are used.

A further advantage in contrast with such pipes is the avoidance of numerous connecting members, and of the corresponding number of points at which there are packed joints which easily give rise to losses of gas.

The described method of working has proved to be of particular advantage in the production of ketones, especially acetone from acetylene, alcohols, esters, aldehydes or other bodies capable of forming ketones by the treatment of these bodies with steam at high temperatures, for example temperatures between 250 and 650 C., in the presence of suitable catalysts, especially oxygen light metals in the presence or absence of metals, which latter when present preferably serve as the carrier for the oxygen compounds of metals, preferably in intimate contact therewith.

It has been found that in an oven assembly with pocket shaped reaction vessels for example constructed in the manner described hereinafter, all these reactions, whether they take place exothermically, endothermically or without substantially sensible heat effects, may be carried out in a particularly favorable manner and with a substantially decreased oven space and correspondingly simplified oven construction as contrasted with a set of pipes.

It is also possible without further steps to use one and the same oven assembly for example for the endothermic formation of ketones from alcohol, and also for the exothermic formation of ketones from acetylene.

The production of hydrogen from water gas as well as hydrogenation and dehydrogenation proc advantage in assemblies of reaction vessels of the kind described. The production of hydrogen takes place according to the equation:

CO+HzO. H2+CO2 10 kilocalories.

In order to have as complete as possible a conversion it is, asis known, important to keep the reaction temperature as low as possible, since it is only at low temperatures that the balance lies sufiiciently on the hydrogen side. This again requires the use of specially active catalysts, that is to say, catalysts which make possible a sufficient speed of reaction at low temperatures, and these again are sensitive in regard to high temperatures which may occur temporarily if the heat of reaction is insufiiciently led away. The sharp temperature regulation necessarily following from these considerations is easily made possible when carrying out the reaction according to the present invention.

While in the production of hydrogen the evolution of heat is not in itself too great and is partly taken up also by the steam which is present in excess, this is not the case in hydrogenation processes in which about 20 kilocalories are set free per molecule of the hydrogen obtained. On the other hand, in these reactions, the catalysts employed (such as nickel or copper reduced with special precautions, and on suitable carriers) are very specially sensitive to overheating so that if the heat is not removed sufliciently rapidly these catalysts become very quickly inactive.

It is known for example that for these reasons it is difiicult to hydrogenate acetaldehyde on a technical scale to form ethyl alcohol. This state of affairs is still more marked for example in the production of butyl alcohol from croton aldehyde in which for each molecule of butyl alcohol two molecules of hydrogen must be formed with the release of about 40 kilocalories. It has been found that these reactions also can be carried out with great advantage in pocket shaped reaction vessels according to the invention.

It has been found further that in carrying out such catalytic gas reactions,for example the above ed production of ketones, the preheating and prepurification of the gases, vapours or gasvapours mixtures to be supplied to the reaction vessels, may be carried out with good-results in same kind, for example the preheating may be carried out in a very uniform and well controlled manner in such vessels which a filled with a material of good heat conductivity and sufficient heat capacity, as for example scrap iron or other metallic bodies. Similarly, gases or vapours or gas-vapour mixtures from which tarry or other materials injurious to the catalyst may separate out at the commencement of heating,

may be purified by passing them through pocket shaped containers according to the invention which are packed for example with coke or another suitable filling material, before passing them through the main reaction vessels.

In this case also the purification occurs specially easily and thoroughly in consequence of the cooperation of the good temperature regulation and the uniform subdivision of the gas currents both over the cross section of the individual reaction vessels and over a plurality of such vessels connected in parallel.

A number of, embodiments of reaction vessels suitable for use in carrying out the method of working describedare illustrated in the annexed drawings wherein:

Figure l is an elevation of such a vessel from the side.

Figure 2 the same on Figure 3 is a cross of Figure 1, and

Figure 4 is a perspective view of a number of such vessels connected in parallel.

In these

drawings

1 and 2 indicate the parallel side walls which bound the greater part of the inner space of the container, and which are spaced a small distance apart relatively to the other dimensions of the vessel, which is provided on its outer surface wholly or partly with ribs 3 or similar members. 4 and 5 are end tubes for filling in and removing the catalyst or other filling material and for supplying and taking off gases, they are preferably located between the

side walls

1 and 2 at opposite ends of the container so that the change in cross section of the vessel from that of the tubes 4, 5, conveniently of the same diameter as the relative distance apart of the

walls

1 and 2, is effected by the oblique surfaces 6 to 9.

These tubes are conveniently provided with lateral subsidiary flanged

openings

10 and 11 which for example serve for supplying and taking off the gas and by means of which also a number of such containers may be connected in common to connecting pipes in the case of the parallel connection shown in Figure 4. The vessels in some instances may be built without ribs. Tubes 4 and 5 not employed for connecting purposes, but only for filling or emptying purposes could be closed in anysuitable manner for example as is shown in Figure 1 in connection with the tube 4 by means of a clamp closure 12 together with a cover 13 or in any other manner.

The filling and the removal of the catalyst or other filling bodies is substantially facilitated by the uniform narrowing of the cross section of the vessel for example by the inclined end walls 6 to 9 towards the inlet and outlet openings, and, moreover, a uniform distribution is ensured for inlet and outlet over the whole crosssection of the vessel. The union tubes mounted at the ends of the vessel preferably have a diameter which is equal to the distance between the

main boundary walls

1 and 2 of the vessel. One of the openings of the vessel, for example the upper opening, serves for filling in the catalyst and the other for removing the same. This takes place very easily and quickly, including any parthe line A-B of Figure 1, while section on the line C-D is a central longitudinal section of p. 3

faces

1 and 2 of the reaction vessel must not exceed ratio between the width and length of paratus of For example, the

stead of being made fiat as showncould be made internally with ribs ,ticlesadhering to are preferably selected the walls of the vessel, since these can be easily moved from the filling unions and all these operations are also easily carried out with the vessels built into the furnace.

The clear distance between-the two main sur- 200 millimeters in general. The width of the vessel is limited by the necessity of being able to distribute the catalyst from the filling opening over the whole cross section of the vessel. The width will generally lie between 500 and 1000 millimeters. The height ofthe pocket shaped unit depends upon'the details of the reaction to be .carried out. If it is carried out conveniently in relatively thin layers of catalyst the pocket shaped reaction vessel is relatively short. on the other hand if it is a question for example of a reaction which proceeds slowly and which requires a large volumeof catalyst, long pockets In a similar fashion the the pocket the existing special working millimeters and more.

is always adapted to conditions. a

The vessels according to the invention are with advantage provided on their outer surface with ribs, as shown at 3 in the drawings, which increase the surface of the pocket giving out or absorbing heat with respect to the heating or cooling medium, for example warm or cold gases, as well as conducting these gases in the desired paths. v

The preliminary treatment of the gases in apthis kind has essential working advantages because the control of a unit comprising apparatus of the same construction is much simpler and a preheating of the reaction gases is simultaneously attained with the preliminary treatment. The shape of the reaction vessels may naturally be varied within wide limits without departing from the scope of the present invention.

main boundary walls 1', 21nof other shapes, for example of wave shape whilst still being a substantially constant distance apart, and if desired could be provided arranged in any suitable mannerwhatever, or round on its narrow sides and so forth.

' In a similar way the reduction of cross-section of the vessel from the main part to the ends where according to the drawings the filling and emptying tubes are mounted, instead of being effected by oblique surfaces, could be effected by any other suitable guiding surfaces whatever. Also instead of providinga tube at each end of the vessel two or more of such at one or both ends, and, moreover tubes may be provided at other parts of the vessel, for exofi the reaction gases, for example in such a way that the supply of the reaction gases may take place through a tube mounted half way along the vessel; for example in.

the middle of one of surfaces from one or both sides of oil at the the boundary the vessel, and the gases may betaken ends of the vessel or conversely.

According to the invention a large number of such vessels may be connected in series with one another as well as in parallel. The parallel connection, as shown in w l, may be conveniently effected, for ex p ,"by' connecting the lateral auxiliary unions 0 the, necessary numbers of vessels at one and the same end to a corup to a length of 2000 the vessel may be made tubes may be mounted of introducing and leading responding number of tubes provided on cross pipes, so that upon passing from one set of vessels to the next connected behind it, only one connecting bend, or in the case number of pockets two, are necessary.

The'advantages of the above-described method of connecting together a series of vessels in parallel by means of cross connections arises particularly in the above described method of" work-- ing if the gases are passed, before their introduc vessel properpacked with tion into the reaction catalyst, through vessels of the same kind packed with suitable filling bodies with the object, for example, of preheating or separating injurious constituents, since for connecting the parallel series of vessels only one or at the most two pipes are necessary, so that without using a large number of pipe connections the perature afforded by the furnaceutilized in the manner heating can be form of connection.

The connection ofthe vessels in series is preferably arranged so that the reaction gases in the first vessel for example are allowed to fiow from the top towards the bottomin the-second, from the bottom towards the top and so the result that the length of the necessary pipe connections is very much reduced. As a result it is not necessary to connect the vessels in the series sequence according to their position in space, but they maybe connected in another furnace heatl heat and the like, and thus frequently a devious flow of the gases, in which individual vessels or groups of vessels are passed over, proves to be preferable. By assembling together pockets connected in parallel, it is possible with the help of cross pipes to connect together in any desired series sequence with a mi mum amount of connecting pipes the vessels of the assemblies increased by the parallel connection.

In order to produce a particularly uniform temperature or a particularly conveniently graded temperature distribution, this particular method of connection, for example that in which the gas passes first from the first parallel connec'ted series of pockets into the last i. e. the third and then only passes to the middle series, may be found of importance.

If for examplethe case of an endothermic reof a very large most favorable for car-., rying out the process by employing the desired forth, with temperature and amounts of distribution of temaction occurs as is illustrated by the production I of acetone from alcohol, wherein, moreover, in consequence of the excess of water vapour fairly large amounts of heat are necessary for the preheating, the method of connection may for example with-great advantage in certain cases be such that the vapour mixture is first led into the pre-heating pockets which lie the furnace in which the heating gases are already relatively cooled, and in fact preferably in counter-current to the heating gases, that is to say in such a way that the vapour mixture first passes into the last or coolest pocket, then into the one before that and so on. When in this way the vapour mixture is raised to the temperature at which the reaction commences, the mixture'is led into the foremost of the pockets packed "with the catalyst proper on which-the heating gas first strikes. In this pocket the greaterpart of'the conversion is consequently completed. In order to maintain the reaction temperature the most vigorous supply of heat is required from this foremost pocket. Then the mixture, already in that part of converted for the greater part, flows into the second and third pockets now in counter-current with the heating gases corresponding to the smaller heat requirements for completion of the 5 conversion. If the pockets according to their series sequence in the furnace gases are indicated as 1, 2, 3, 4,

5 and 6 in cases of the kind referred to, the

sequence of

connection

6, 5, 4, 1, 2, 3, or a simi- 10 lar sequence would be advantageous. Obviously a heat exchanger for exchanging heat between the gas or vapour mixture to be supplied and that flowing away may be provided outside the furnace assembly proper or the heat relations may be regulated in the desired fashion in any other desired manner.

In the case for example of exothermic reactions the connection will be made quite differently according to the amount of heat released during the reaction and according to the insulation of the furnace.- The most suitable method of. connection can, however, in each case be foretold with a certain probability, and the success ,is easily confirmed by the result of tests.

I claim:-

1. A reaction apparatus for ca rying out catalytic reaction with organic gaseous compounds, comprising a plurality of reaction-chambers being substantially filled withpowdery or lumpy catalysts or other filling material and having two of their walls substantially parallel to each other and forming between them an elongated zone of a cross section in which the thickness is small relative to the width, said reaction chambers having cylindrical portions at each end, the internal diameters of which are substantially the same as the thickness of said zone and tapered portions situated respectively between the body portion and the adjacent cylindrical portion, 40- said reaction-chambers being disposed with the aforesaid walls of adjacent chambers in register with, spaced apart from and substantially parallel to one another. a 2. A reaction apparatus for carrying out catalytic reaction with organic gaseous compounds,

comprising a plurality of reaction-chambers being substantially filled with powdery or lumpy catalysts or other filling material and having two of their walls substantially parallel to each other and forming between them an elongated zone of a cross section in which the thickness is small relative to the width, said reaction-chambers being disposed with the aforesaid walls of adjacent chambers in'register with, spaced apart from and substantially parallel to one another, and said walls havring projecting ribs on their external surfaces.

3. A reaction apparatus for carrying out catalytic reaction with organic gaseous compounds. comprising a plurality of reaction-chambers being substantially filled with powdery or lumpy catalysts or other filling material and having two of their, walls substantially parallel to each other and forming between them an elongated zone of a cross section in which the thickness is small relative to the width, said reaction-chambers being disposed with the aforesaid walls of adjacent chambers in register with, spaced apart from and substantially parallel to one another, and said walls having on their external surfaces projecting ribs extending perpendicularly to the length of the reaction-chambers.

4. A reaction apparatus for carrying out catalytic reaction with organic gaseous compounds, comprising a plurality of reaction-chambers being substantially filledlwith powdery or lumpy catalysts or other filling material and having two of their walls substantially parallel to each other and forming between them an elongated zone of a cross section in which the thickness is small relative to the width, said reaction-chambers being disposed with the aforesaid walls of adjacent chambers in register with, spaced apart from and substantially parallel to one another, and said walls having on their external surfaces projecting ribs extending perpendicularly to the length of the reaction-chambers, the ribs on each wall cooperating with the ribs on, the wall opposed thereto to provide flue-passages therebetween.

5. A reaction apparatus for carrying out catalytic reaction with organic gaseous compounds, comprising a plurality of reaction-chambers being substantially filled with powdery or lumpy 15 catalysts or other filling material and having two of their walls substantially parallel to each other and forming between them an elongated zone of a cross section in which the thickness is small relative to the width, said reaction-chambers being disposed side-by-side, with their aforesaid walls substantiallyparallel and provided with projecting ribs, an inlet pipe, an outlet pipe, and

pipe connections connecting the openings at one end oi the reaction-chambers in common to the inlet pipe and the opening at the other end in common to the outlet pipe.

KOLOMAN ROKA.