DE2827934A1 - METHOD AND DEVICE FOR ISOTHERMAL CATALYTIC REACTION - Google Patents

Description

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1A-50 994

Patent application

Applicant: MINNESOTA MINING AND MANUFACTURING COMPANY 3M Center, Saint Paul, Minnesota 55101, USA

Title: Process and device for isothermal catalytic analysis reaction

809882/0933

I) If. INC. F. WTICSTIIf) FK h'MM M O NC II IC .V ί) Ο I) Il. K. ν. I ¹ HC-IIM Λ Ν.V sc: ii .ν ki «m: h.ntii.vsni ·: ο

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ΤΚΙ.ΚΠΠΛΜΜΚ:

1 · ΔΪΚΝϊΛ.νη-ΛΙ.ΤΒ

1-50 994

description

The invention relates to a method and a reactor for catalytic, essentially isothermal reactions with simultaneous heat exchange.

There are a large number of catalytic reactions which are associated with a large amount of emitted or required thermal energy. Of great importance is e.g. the conversion of CO and Hp to methane and water in one Nickel catalyst or the conversion of Np and Hp to NH ^ over an iron catalyst. Reactions in which large amounts of heat occur are relatively difficult to control. A lack of regulation can lead to high temperatures, which in turn lead to damage to the reaction vessel Formation of unwanted by-products, to destroy the catalyst or to shift the thermodynamic Equilibrium from optimal areas result köfi ^ S · For optimal Process control should avoid a temperature increase and a substantially uniform or isothermal temperature are maintained or at most there is a slight drop in temperature.

There are at least four measures to avoid extremely exothermic plants To regulate reactions, namely

1) dilution of the reactants with an inert medium,

2) stepwise reaction, with cooling between the steps,

809832/0933

1A-50 994

3) Use of a boiling heat exchange medium and

4) at least partial cooling of ¹ reaction partner.

All of these measures have disadvantages such as multiple recirculation and complexity of the system. It would therefore be desirable To have reactors in which highly exothermic reactions proceed smoothly under essentially isothermal conditions can. The object of the invention is to determine the operating conditions for such reactors.

If a material to be cooled flows through a reactor, then generally consider countercurrent flow of reaction mass and coolant to be most effective in practice. However, it can can be shown mathematically that it is not possible by countercurrent heat exchange, for example by cooling essentially to achieve isothermal conditions.

Various considerations have been made regarding the use of direct current in reactors, but not with regard to the need for isothermal operation.

Surprisingly, it was found that essentially isothermal conditions with direct current heat exchange, for example cooling, can be achieved and that the parameters for the reactor for a heterogeneous or homogeneous reaction with

ι -, j- j -i · -urichtune; of reaction mass with same or pseudo-equal flow γ cooling or heating medium Through the heat exchanger can be expressed by the mathematical relationship for an exothermic or an endothermic Reaction:

(t _h -t _c ) u _c r _c s _c J _{H (1. 1}}

Therein mean:

8 09882/0933

1A-50 994

T "inlet temperature of the reactants in C T _n inlet temperature of the coolant in C

3.827934

Heat of reaction in cal./gMol
C ₀ initial concentration of the reactants in g mol / cm U "heat transfer coefficient on the reaction side in

cal
s.cm ^ grd.

U _c heat transfer coefficient on the cooling side in

s.cm .grd Ttt throughput on the reaction side in s

γ _η throughput on the coolant side in s

S _n heat transfer surface on the reaction side

2 S _n Heat transfer area on the cooling side, cm

> i "free volume on the reaction side excluding the fine catalyst in cm ^J

O- free volume on the cooling side in cm ^u cal

9 _n C _n density χ heat capacity of the cooling gas in

This applies to a chemical reaction over a catalyst under such conditions that the heat release is essentially in a direct relationship to the concentration of the reactants and this relationship is a function of IL, and the ratio ΐρ / ΐττ ^ ^s ^ ·

"Throughput" is the time it takes for the gas to to flow through the rooms without fine-grained substances such as Catalyst pellets. The heat exchange area on each side is defined as the areas common to the currents are on the respective sides, and the surfaces that extend between the common surfaces like bumps.

It is obvious that these relationships are a whole group of reactors from which a certain selection can be made by fixing certain values for a certain Reaction, such as inlet temperatures, concentrations or the like.

809882/0933

1-50 994

■ τ

ise the reaction

The definition of the reaction normally determines the heat of the reaction and usually also the density and the heat capacity or the heat content. The remaining factors are influenced by the level of response and design details. It has been found that the specific conditions are met in a satisfactory manner by reactors, a series of cross-flow reactors or heat exchangers are each of which have passages for reactant and coolant at right angles to each other and through have heat exchanging materials separated from one another. Preferably, each cross-flow reactor is unitary or monolithic, the for very high temperatures or corrosive materials, preferably made of ceramic. The exact dimensions and variations in such cross-flow reactors result from the requirements of the above mathematical relationship and can easily be calculated using the usual methods of process engineering. Somewhat surprisingly, however, it was found that only a relatively narrow range of certain parameters is able to maintain isothermal conditions of a reaction. This range of parameters can be compared with the "windows" for calculating a flight into space and can be determined in a similar way.

The part of a reactor in which the reaction takes place is also sometimes referred to as the reaction zone. It should be noted that that various configurations are possible according to the invention, however, cross-flow reactors are particularly preferred .

Examples of reactions that are either first order or can be considered first order and which are after the Method according to the invention in the device provided for this purpose can be carried out are the following:

Exothermic reactions

1. Methanation, ie CO + 3H ₂ - * CH4 + H ₂ O.

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1A-50 994

2nd oxidation, 2 CH ₀ -CH ₀ + O ₀ ^ 2 CH ₀ -CH ₀ .

2 2 2 \ ^2/2

0 3- Production of hydrocarbons from methanol.

4. Oxidation of naphthalene to phthalic anhydride.

5. Chlorination of hydrocarbons.

6. Elimination of hydrogen sulfide, for example from thiophene ₍ by reaction with H ₂ to form butadiene + HpS.

7. Production of methanol, ie CO + 2H ₂ »CH ^ OH.

Endothermic reactions

1 _O dehydrogenative cyclization, eg n-heptane to toluene. 2. Catalytic cracking of petroleum or petroleum products.

The invention will now be further explained using the accompanying drawings.

Fig. 1 shows schematically a cross-flow heat exchanger of about 7 cm with catalyst impregnated pellets of about 2 mm in diameter and 3 mm in height in one group of the passages .

FIG. 2 shows an arrangement of 4 heat exchangers from FIG in a housing to form a pseudocurrent reactor according to the invention.

3 shows in a diagram the sequence of the calculations as they are used to determine the parameters of the reactor according to the invention can serve.

4 shows schematically a small reactor with associated control and supply, which in the context of example 2 is explained in more detail.

FIGS. 5 to 10 show various isotherms and conversions at certain reaction temperatures.

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2827834

Fig.11 is a diagram from which the temperature conditions emerge within the reactor according to the invention with pseudocurrent.

Fig. 12 shows schematically a plant for methanol synthesis from CO + Hp with a heat exchanger stack in the reactor.

13 is a diagram from which the catalyst loading in a device according to FIG. 12 is compared with a conventional one isothermal reaction.

The Kr ^ uzstrom heat exchanger shown in Fig. 1 is suitable for the method according to the invention, if several of them in series can be applied so that a pseudo direct current is present. From this schematic representation one can see four groups of Passages 10 and 12 connected to and separated by level Sheets 14 and sinusoidally curved sheets 16 and 18 and closed on the sides by sheets 20 and 22. The passages 10 and 12 are not the same height. In terms of height pan can make variations as desired. Passages 12 are filled with pellets 30 which are impregnated with catalyst, some missing, around the inner parts of the passageways to show. For the further description of such structures it is useful to designate two axes for each segment, which contains a corrugated sheet between two flat sheets. These axes are called q in the direction of the corrugations of the corrugated sheet and denoted as χ at right angles to it. The direction of flow follows the waves of the corrugated sheet. The corners 34 are filled with ceramic material, which the lateral Passages blocked in any direction.

In FIG. 2, four heat exchangers 40 from FIG. 1 are now arranged in series within the housing 42 with feed lines 44 for reactants and 46 for coolant and discharges 50 for reaction mass and 52 for coolant. Details of the insulation and sealing of the heat exchangers are not shown «

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809882/0933

1A-50 994

The assembly is carried out with lugs or supports 54 within the housing or with a sealant between the inner and exterior of the heat exchangers and at points where the heat exchangers abut the housing 42. the Paths of the reaction mass are indicated in solid lines and those of the coolant in broken lines. the The end faces of the housing are held together with the aid of the bolts 56. The catalyst within the passages of the Heat exchanger 40 is held in place by nets 58, which are advantageously made of corrosion-resistant steel.

FIG. 3 now shows a flow chart for a method of calculating the dimensions of the device according to the invention according to FIG. 2 for a specific gas reaction. You can see that different boxes are numbered. In the following description the math operations or reasoning for each box is reasonably detailed. the Operations can be done by any measure as with normal computers "for numerical calculations, with slide rules or appropriate computer programs are carried out. The selection of a particular method for a desired goal can be done in the usual way. There are also other sequences of operations that produce the same or similar results to lead.

Some simplifying assumptions are made for the following calculations in order to avoid unnecessary complications. It is assumed that neither reactants nor reaction products are forward or backward along the flow path diffuse and no heat conduction takes place along the flow path, i.e. axially. It is also assumed that the only one Resistance to radial heat transfer takes place on the walls. Finally, it is believed that there is no heat transfer occurs by radiation in any direction within the reactor. It is believed that the front of the reaction mass or coolant moves at the same speed over the entire cross-section ("plug flow") ·

809882/0933

2827S34

The most important assumption, however, is that there is co-current flow, which is generally true when two or more cross-flow reactors are used are arranged in series «, In the case of cross-flow units, this means that the implementation is not abrupt in of the first unit, but only partially in each cross-flow unit At first glance it may seem insignificant, but if excessive reaction takes place in any part of the cross-flow reactor In some cases, a deviation from the isothermal reaction can occur, which in turn leads to deactivation of the catalyst or excessive side reactions in part of the reactor and can lead to a general deterioration in performance or malfunction at all.

Boxes 120, 130, 140 and 150 request specification the input values, kinetic parameters, properties of the gases (reactants, reaction products, coolants) and certain predetermined physical dimensions of the interior of the reactor. For the following treatment, the required Quantities indicated as follows:

For box 120 determine:

C = initial concentration of the reactants (g-mol / cnr Total use), determined on the basis of the required dilution, to avoid local overheating, explosions or the like to avoid.

C = final concentration of the reactants (dimension as C ₀ )

z = 1 - -TT- conversion ratio (as a fraction) selected in terms of reactant and product cost, difficulty of separation, and the like. And with regard to the selected temperature in V (box 16O),

8G9882 / 0933

_ 2827834

F = feed rate of the reaction mass in kg.mol / d on the catalyst side, determined by the process conditions;

Mrr = mean molecular weight of the gases on the reaction side (in daltons, i.e. g / g-mol);

-AH molar heat of reaction in cal / g-mol. This is characteristic of the reaction and the numerical value is positive for an exothermic reaction, even if this term is negative. The heat losses are estimated as part of the heat of reaction and reduce this Z ₀ B ₀ by a third. The heat losses are generally lower in larger reactors.

For box 130 determine the kinetic and catalytic parameters:

Previous year Density of the catalyst (g / cnr), determined experimentally on the solid catalyst;

£ free space of the catalyst bed (dimensionless), calculated from the bulk density and the specific weight of the catalyst 9- ·

k ^ pre-exponential factor from the Arrhenius equation (rate) for the reaction system and the applied catalyst (s);

D diameter of the catalyst pellets, for the spherical shape is assumed on the basis of statistical determinations on a sample (cm);

809882/0933

2827234

E / R activation energy broken down by the gas constant, determined from the rate equation as the slope of the curve ln (k) (reaction rate constant) against the reciprocal absolute temperature ( ⁰ K)

For box 140 determine the gas properties:

C _TT heat content of the gaseous reaction mixture at the ptl

Catalyst side assuming constant temperature and average composition in cal / g.grd

C ρ heat content of the cooling gas assuming average Temperature in cal / g

λ. Gas viscosity, means of reaction gases and cooling gases,

K thermal conductivity of gas, agent from reaction and cooling gases,

cal grd
s * cm ² * cm

M _n molecular weight of the cooling gas in daltons <? ti density of the reaction _{gases in g / cm 9 n} density of the cooling gas in g / cm.

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8098 8 2/0933

- ■ »._ 2827824

For box 150, some characteristics of the heat exchangers or reactors without a catalyst must be specified, The reactors are cross-flow heat exchangers in which, in use, a group of passages is filled with pellets impregnated with catalyst _o The calculation of the heat exchange area varies somewhat with the Geometry of the passages _o The following applies to passages that are formed by two flat plates separated by a corrugated sheet, a powder or the like, but without a catalyst filling. This is illustrative but not limiting. The geometric terms that can be directly measured or calculated are listed below. The specified lengths or distances are listed in cm, the indices C and H respectively relate to the coolant side and the reaction side (hot side) in the sense of the following example 1.

ψ Ratio of the height of the exchanger blocks to the distance via the flow path

J length of a sine wave
λ wavelength over the a-axis
a = amplitude = 1/2 height of the elevations

f Overlap factor = fraction of the sine length of the plane

Surfaces is bound.
2j Height between two flat surfaces 0 Thickness of the corrugated sheet in cm
c Thickness of the flat panels in cm

K ^r Thermal conductivity of the reactor material including the flat sheets, corrugated sheets and elevations

J is calculated from the relationship:

J = I j / 1 + (from cos bqj dq (lV-1)

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809882/0933

28279-U

optionally using a computer program, where q is the distance along the q-axis, as in above The framework of FIG. 1 is defined. Certain functions of the above terms are commonly performed by computer programs accessible.

The heat transfer area S for the unit area (x _o q) of the passages (including the common surface for the reaction and cooling side) is calculated as the sum of the two sinusoidal areas + the area of the flat sheets minus the overlap factor "f".

S = ψ + Z- ^ ψ- = (1-f) ^ +2

The heat transfer surface on the reaction side St _T and

on the cooling side Sp are calculated on the unit area of the common area of the reaction and cooling side using the corresponding values for J, λ and f _o

The volume of space per unit length and width (x. Q) is the range of height between the flat sheets, i.e.

The open unit volume "ν" is the total volume minus the volume of the ceramic corrugated body:

V = 2d- -Y (IV-3)

This is calculated for the cooling side \) ~ and for the reaction side \? "♦

n.

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8098B2 / 0333

The relation of the heat transfer area to the empty volume S / u is calculated in cm "for the reaction and cooling side",

It was found that the hydraulic diameter of the passages D, (in cm) is given by the expression

The part of the open area is the part of the flat the unit length of the passage for flow "G", includes a blind row and an open row, and is calculated after

Γ -

2 j + 2 j

This is calculated for Gtt and Gp with the corresponding values in the counter "

The part of the total heat transfer area, Ω due to the area of the sine body results from the equation

I ⁽⁾ 1-f, c, η = Λ ₌ (iv-6)

(-l_f) M +2 1- ^{f +} j ^

The ratio of the heat transfer areas on the reaction side to that on the cooling side is

³ E.

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and the ratio of the volumes on the reaction side, too the cooling side is

The isothermal temperature T ^ ( ⁰ C) at which the reaction is to be carried out is selected in accordance with box 160 on the basis of known or experimentally determined data of the catalyst system “This temperature

will have a very strong influence on the degree of conversion ^u z "/ _o Im

in general, the highest temperature is chosen at which

a) the catalyst has not yet sintered,

b) the catalyst is not poisoned quickly,

d) unwanted side reactions do not occur,

e) the reaction does not proceed so quickly that it leads to a Damage to the reactor is coming.

For box 170, the reaction side throughput ^ jT is calculated for a first order reaction or a Re action that can be simulated as the first order with Help the relationship

§- = exp (-p) (VI-1)

wherein Γ is the catalytic activity

so that the above equation takes the form:

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80 98 82/0333

τ ^ CL. - Xr T p-srn ί - - I ( VT ^ I

- ± n "- K ₀₃ L exp - pm ^ v ± -j;

- η - V RT _H

from which all values with the exception of T _TT "are known.

ti

The throughput is given in s

For box 180, the total amount of catalyst required ¥ in kg is determined by the following relationship:

^z o

where F is the flow rate of the reaction mass on the catalyst side and is determined from the Annual output in kg, ζ the implementation is as defined under I, 'z "is a numerical value of O and ζ the for The final degree of conversion j r is the rate of reaction According to the function

r = k = *, exp f- ~ | - \ .C (VII-2)

for first-order reactions.

The total volume which is taken up by the total required catalyst when the passages on the reaction side are filled according to the above conditions is V “ and results from box 190 from the relationship

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in'

where f>> - is defined as the specific weight of the catalyst and W is calculated as under VII.

The number of transfer units on the cooling side N ^ is calculated for box 200 from the relationship

The number of transfer units N is a dimensionless expression for the "cooling or heating quantity ^{11 of} a heat exchanger ο If N is small, then the exchanger efficiency is low and if N is large, the efficiency asymptotically approaches the limit value that is derived from the Flow mode and the thermodynamic conditions results (Kays and London, Compact Heat Exchangers, 2nd ed (1964), pages 15-16).

For the box 210, the inlet temperature of the cooling gas Tp is assumed to be ^{in 0 C.} This determines the driving force of the heat transfer from the reaction side to the cooling side. Some factors that seem particularly important are the following:
Ao ambient temperature;

Bo temperature of available gas flow;

such
Co a / temperature that - when the reaction gases first

_,,, ., Ί., After leaving, the. are used as cooling gases - have this / iCuhlseite at the appropriate temperature for entry to the reaction side.

For box 220, the value for Γ is determined from the following relationship:

809882/0933

- 16 -

- ~ T6 *

r = k., t

., t _H exp (-

All terms are known from the above, eg "B _e VI", the value is dimensionless ο

For box 230, the number of transfer units on the catalyst side N _{fI is} calculated from

where I after XI and after

_{Q =}

(-AH) C ₀

results, whereby all terms are known.

For box 240, the total heat transfer coefficient on the catalyst side in cal / s _o degrees, UVr, is calculated from

u ₌ (%) (f _H ) (c _pH ) (v _H ) (xin-1)

■ Π τ * Q /

^u H ^b H

of which all terms from the above are known, e.g. the ratio Stt / Vtj from IV.
rl π.

For box 250, the ratio of the number of transfer units on the catalytic converter side to the number of transfer units on the cooling side Y is determined from Y = i. This fact is used to calculate the ratio of the gas velocity (cm / s) on the cooling side to that on the catalyst side νί _o

809882/0933

(XIV-1)

From this relationship all terms except for nL "known ,,

From the relationships from I to XIV it follows that the relation between the rate of heat development and the concentration of the reactants k _{R is} a function of H _n and the ratio C is.

υ. ■ ^ ~

H-This gives a heat balance for a volume differential

dv "according to the following equation, where Q ₁ . the speed ti - 'L ^ _n

the heat development over the entire flow path, cal / s

and C is the concentration in volume dv> _TT . X ri

k _R du _H (XIV-2)

If this equation is integrated, the result is

Q _L ■ "= (-AH) k _R / ₀ ^H C _x di> _H. (XIV-3)

kp is a constant of proportionality, i.e. _{e is} a reaction rate constant which, using the above terms, shows the following dependency:

k _D = k <x, exp (- = S-), (XIV-4)

- H

where -ΔΗ is a characteristic of the reaction. Of course, there is a relationship between the rate of heat release and the concentration \ md of the reactants in the volume dv ^, due to the equivalence of J \ U and Γ.

- 18 € 09-882 / 0933

^{= N} c (xiv-5)

pCTC ^ü

⁽ ) (XIV-6)

^J CpC ^V C

The values for / ^ C ν depend on the type of cooling

'CTpC C

medium and the geometry of the system and can be considered to be constant insofar _f are selected as the reaction partner such that k _{D n} a Eunkton of U and C is "

¹ p

For box 260, the length of the flow path on the cooling side X for a reactor is corresponding to ΐψ. The value of X is selected based on the scope of the implementation or

applied
commercial systems · «It is particularly useful to use a large number of cube-shaped or cubic reactors, but it is also possible to use reactors in which the flow path on the cooling side = X and on the reaction side j · X. and the reactor = ψΧ perpendicular to the directions of flow ,, For the purposes of this description it is assumed that the catalyst is deposited on pellets, but it can also be deposited on the walls

QAJ. 37 C ti

his or both. But you can also use the coolant ducts Provide pellets without a catalyst.

For box 270, calculate the flow rate on each side necessary to obtain the total heat transfer coefficient Utt, calculated according to XIII, to result. The calculation is done step by step by adding the heat transfer coefficients to the cooling and reaction

S-Q 9 8 8 2/0933

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Sides "are calculated and combined in the usual way. The speed on the cooling side Y _n is assumed and in practice is, for example," at 80 cm / s _e

The mean film coefficient for laminar flow

the cooling side h "in cal / s _o cm _o deg results from the following relationship

Ta.,

3.65K _n / ■ (1 + 0.078-RPj ^{J J} , _v C = D _H /

(XVI-1)

K _n is the thermal conductivity of the cooling gas in

cal ₂ . grd
s.cm cm

Dp. is the hydraulic diameter,

R. Reynold's number for an assumed speed; P _{r is} the Prandtl number of the mean; X is the length of the flow path on the cooling side of a reactor;

3.65 is the Nusselt number for fully developed laminar flow in the effective passages of commercially available ceramic body according to Figure _e 1 matched the average value is used as the laminar flow does not stop _f before the cooling gas is passed through a part of the passages.

is
This is known as the "bottom line". With the help of a computer program, ZoBo with Simpson's rule, the above equation can be integrated.

B. The five coefficient on the reaction side is filled with Catalyst pellets is calculated from

Κ _π D Vpf »0.75

"= 0.125— ( ^? (XVI-2)

Dp ^μ Η

809882/0933 - ²⁰ -

where the bracket term is the Reynolds number for a flow, in which D is the particle diameter. The above expression can be used for ü between about 0.2 to 0.8 times the hydraulic diameter of the passages (see calculation in IV).
Κ ,, is the thermal conductivity of the gases at the reaction

page in cal ^ · ^ rd
s.cm cm

g>" is the gas density on the reaction side, u" is the gas viscosity on the reaction side, V ^ is the linear gas velocity at the reaction side, based on the passages without finely divided material according to the expression

from XIV.

C. To combine the two film coefficients from A and B, it is necessary to ctie total surface temperature effectiveness to determine the flat transfer surfaces on the cooling and reaction side because of a reduction in effectiveness through the sinusoidal elevations.

The value m results from:

for
where h is the film coefficient on the corresponding sides of A or B, K ^{1 is} the thermal conductivity of the material of the elevations and θ is their thickness.

If 2 j is the distance between the flat sheets or parts, i.e. the amplitude of the elevations, the effectiveness of the rising surfaces, η, results. _ν , from the relationship

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This expression is required for the calculation of the total effectiveness of the surfaces * on the corresponding sides, namely r ^ for the coolant side and r \, for the reaction

Hc ^{= 1} - "Έ ⁽¹ ~ ν ^} (xvi-6)

S is the entire heat exchanging surface on one side, thus Sp on the cooling side and S "on the reaction side, · correspondingly IV and Sp is the total area of the elevations on the side to be calculated.

D. Now the two film coefficients from A and. B combined v / er den, where IL, the total heat exchange coefficient, based on the reaction side, taking into account the area of the surveys, and is out of the relationship

.J- = -4- ■ + & - + "(xvi-7)

results. S _w is the area of the common area of the flows of reaction medium and coolant. This expression can be simplified because the mean expression relating to the Y / arm transition through the walls _{1 is} relatively very small, since the walls are thin and can therefore be neglected. This results in

"L ₌ —jL- ₊ 1 ■ (XVI-8)

rl in. π O _n

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809882/0933

In this equation, all values, with the exception of U _H , are calculated or known.

υ ,,, v.'ie calculated above can now be compared with the value calculated in XIII. If you find a deviation of more than 0.1 % , you should make changes in the assumed speeds for a better match, e.g. B. by increasing the speeds according to box 280.

For box 290 is now. to calculate the reactor length L on the basis of the above parameters

L = T _fl V _n , (XVII-1)

where 7 _[{has been calculated in VI and V "means the linear velocity on the reaction side which was assumed and confirmed according to XVI.

XVIII.

For box 300, the cross section of the passages on the reaction side A 1 is determined from the following relationship

^A XH = ² X ( ^XVI11 - ¹ )

L results from XVII and \> "from VIII.

Total surface area of the reaction side Α _{φυ is} calculated according to box 310 from the relationship

δ ₌
IH

- 23 ß09832 / Ö933

where Α _{χΗ is obtained} from XVIII and G _H from IV.

For box 320, the parameters on the cooling side are calculated

The ratio ^ _H / ^ _c results from IV and ^ from VIII.

The mean cross section of the passages on the cooling side A ″ results from

= ^ (XX-2)

and the entire area of the cooling side A, “ _c from

_ ^A xC
^A TC ~ "g ~. (XX-3)

Gp is obtained from IV.

For box 330, the length, X, of the flow path is calculated. Assuming that the base is a square, that is, either a cube with the X side or a prism with the X base. X and -ψΧ perpendicular to the flow passages, d. h, the height, the following relationships result

or X -Η ~ (XXI-D

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8 0 9882/0933

For box 340, the values for X from XV and XXI are compared. If the length calculated in this way differs from the assumed length according to XV, XVI to XXI become accordingly Repeatedly boxes 350-260 using the calculated Values for X and repeated until agreement is reached. Then it continues:

XXIII.

For box 360, the outlet temperature of the cooling gas Ti is calculated. For an adiabatic reaction temperature, ΔT ₁ is first obtained from the relationship

(XXIII-1)

calculated, C, p ", C" and - AH result from I or III The V / ert for Δι is required for the calculation of the outlet temperature according to

(k

J ^ L * ⁰ ^ H

Ί 'is obtained from V and A is the ratio .K / R i ^{n den eri} "t

speaking units as determined in II.

For box 370, the flow rate of the cooling gas in Hol / d (d = 86400 s), £ _c , is derived from the relationship

_r _ 864UOVpA-P _n

te - —r— (xxiv-1)

^w c

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9882/0933

calculated, M _c and i < _c are available from III, V _c from XVI and A _xC from XX.

XXV. ...

For box 380, the number of individual reactors of the assumed dimensions is derived from the relationship

W _n = -j (XXV-1)

calculated, where L results from XVII and X from XXI.

Isothermal conditions on the catalyst side can only be maintained if the rate of heat release is essentially directly proportional to the concentration ete-3? the reaction partner. As mentioned, it must be taken into account that the rate of heat development includes cases in which this rate is a positive number, that is, exothermic Reaction, or a negative number, so endothermic reaction. If the reaction kinetics are not of the first order or the reaction is irreversible, the physical Characteristics of the system are modified so that there is a direct relationship between the rate of heat release and the concentration of the reactants. For reactions of the second order between A and B results in the reaction rate r ″ according to

r »= Ic ₀₀ exp (-— f) C _A .C _Ü , (S-1)

where the last two expressions mean concentrations of the two reactants. The modification of the reaction • conditions adapts the reaction to the kinetics of a reaction of the first order (pseudo-first order) according to the equations

809882/0933 - 26 -

in which the rate constants kooCg and k ^ C. are. Similar considerations are applicable to reactions of other orders and reaction constants which, under consideration of the above calculations, e.g. B. VI, VII, XI, XIV have been accepted.

The above modification for the apparent order of the reactions can be completed by the following method.

1. The catalyst concentration can be determined over the course of the reaction vary.

2. The throughput on the reaction side can be varied by varying the O-size and / or the number of passes in the reactor the reaction side can be regulated.

The first option is more practical because it only uses the catalyst must be diluted with an inert material.

It has been shown that

P = exp / Xn-1) N _c ^ J _{ (S-3)

where P is the ratio of the amount of catalyst W (g / cnr) in one any point χ in the reactor for the amount of catalyst W at x = 0: η denotes the order of the reaction; N ^ the number the heat transfer units on the cooling side, the -In (1-z) is equivalent to; χ is the specific length of the course of the reaction and L is the total amount of the reaction history.

Are several, i.e. H. four or more, single heat exchangers , Reactors arranged in series, as shown for example in Figures 2 and 12, and assuming that the speed the catalytic reaction per unit volume is directly proportional to the amount of catalyst that can dilute the The catalyst with good food is achieved by the catalyst

- 27 809882/0933

sator in the passages of each heat exchanging reactor or each stage is poured in, with the appropriate concentration, to an average ratio P over the entire Length of the block. These concentrations can be calculated from the values for P at x, accordingly the entry and exit of the successive heat exchanging reactors, d. H. for four heat exchangers are the calculations for the ratio | j 0, 0.25, 0.50, 0.75 and 1 should be taken as a basis. These values for P become the mean in calculated for each reactor and the amount of diluent, based on the volume, is easy to determine by assuming that the highest catalyst concentration is used in the last stage and the most dilute catalyst is used

is

located in the earlier stages. The inert material / preferably the same, e.g. B. in terms of particle size and shape of heat capacity, etc., such as the catalyst support.

The procedure for correcting the amount of catalyst to be used for the adsorption-hindered or reversible one can proceed in a completely analogous manner Reactions.

Although here in the description and in the examples primarily heterogeneous reactions are discussed, some of which are catalyzed the invention also encompasses homogeneous reactions under isothermal relationships in cocurrent or pseudocurrent through corresponding simple procedural modifications. It is recognized that it is extremely difficult to find investments to plan where there is only direct current because of the problems of the connections. Pseudo direct current is easier to use because of the straight passages in cross-flow heat exchangers the introduction of the catalyst is relatively simple.

The invention is further illustrated by the following examples.

- 28 -

809882/0933

3Ψ

example 1

A reactor as shown schematically in FIG. 4 was used for the conversion of CO into COp; by lifting the cover one can see four cross-flow heat exchangers 400, similarly constructed as shown in FIG. 1, but with special dimensions and fixed with the bolts 418. The heat exchangers 400 consist of C. _o rdierit and are between the lugs 414 in de. Housing 402 fixed. The cover 404 is provided. Between the heat exchangers 400 and all contact surfaces, such as the fixings 414 and the covers, there is a sealing material (not shown) for high temperatures, as is known, for example, from US Pat. No. 3,916,057. The bolts (not shown) are used to fix the cover (not shown). The passages in each heat exchanger correspond to those of Fig. 1, the passages being filled in one direction with a copper-chromium catalyst. This catalyst can be pelletized, e.g. B.

for cylinders 2 mm in diameter, 1 mm in height and 1.44 % Cu and 0.97 %

filled
Cr contain up to about 6 mm of the area and then quartz pieces of about the same size. The bits and catalyst are held in place by means of the stainless steel net 416. Air is introduced through 410 to provide oxygen and act as a cooling gas. CO is fed in via 412. The air flow serving as coolant enters the reactor via valve 406 and flow meter 408 at 420, leaves it via 422. The part of the air fed in, which is intended to provide oxygen, goes via the throttle valve 430, the air filter 432, the flow meter 436 and the heater 436 in which a small amount of copper-chromium catalyst is introduced at 438. The CO stream 412 is regulated by valves in the feed line (not shown). The main flow passes through the rotameter 440 and mixes with the air flow coming from the heater 436. To the air in the heating

- 29 -

809882/0933

2827834

One can bring 436 to the appropriate temperature Introduce small partial stream of CO via valve 442 at 444 into the air stream, which in an exothermic reaction on Catalyst 438 is oxidized. The combined stream of air and CO enters the reactor at 450 and enters the Pseudo co-current with the coolant through a number of Reactors, v / o above the copper-chromium catalyst in the passageways the oxidation of CO to COp takes place, which is discharged at 452. To now experimentally implement the isothermal and to determine the degree of conversion, there are temperature sensors and tubes for sampling in chambers 474 intended. Finally, there is a temperature meter 476 for the reaction flow in the heat exchanging reactor intended. The temperature measuring device 460 is for the chambers and the tube 462 for sampling the cooling gas therefrom Chambers are provided to determine diffusion through the reactor walls or leakage from one stream into the other. With the aid of 466, the temperature of the cooling stream is determined. Thermocouples and the analysis of gases by chromatography are generally used as temperature measuring devices.

The determinable parameters of the system, as under I, II, III and IV are summarized in Table 1 below.

Table 1 C _n 5.19 x 10 ~ ⁷ g-moles / cm ⁵ O
C. 7.21. 10 ~ ⁸ g-mol / cm ³ Z 0.86 F. 20.6 g-moles / d M.
H 29.0 g / g-hol -Ali 45,600 cal / g mol

809882/0933

II. P _r 1.19 g / cm ³

£ 0.564

Ic ^ 1.75. 10 ~ ⁸ sec " ¹

D _p 0.317 cm

iS / R 8944 ° K

III. C _pH 0.254 cal / g. grd

C ^ p 0.256 cal / g. grd

^p -4 ,

λχ 2.38. 10 g / cm. s

K 8.39. 10 "^ cal ο grd

s. cm ¹ "* cm

li _c 29.0 g / g-mol

P _n 7.53. 10 " ⁴ g / cm ³

P ₀ 7.93. 10 " ⁴ g / cm ³

IV. Ψ 1.0

J ₁₁ 1.93 cm

J ₀ 0.99 cm

A _n 0.95 cm

λ ₀ 0.71 cm

a ,, 0.40 cm

a ,, 0.16 cm

w _r 6.60 cm "

b _c 8.80 cm " ¹

f 0.10

2j, _D 0.83 cm

2J ₀ 0.348 cm

θ 0.0305 cm

k '3.44. 10 ~ ³ c al ο

s.cm * cm

& ¹ 0.061 cm

809882/0933

F is given above for an initial concentration of 2 % CO in air. The actual daily amount of CO + air is therefore about 50 times as large as the value given for F.

Using the above calculations and data, it is possible to find all the terms in the relationship

V ^T C ^U C ^T C ^S C ° H _M. .,

to calculate · ppC ρ can also be written as (^ C ) “ . The figures in Table 2 come from the values above.

Table 2

T _H 2A'9 ° C

T _c 199 ° C

U _c 3.37 x 10 ~ ^{/ +} cal / s. cm ² . grd

U _H 4.28. 10 cal / s. cm ² . grd

'r _H 0.308 s

r _c 0.0476 s

S _C / S _H 0.787

^ _H / 0 _c 2.68

There are various methods to show that the reaction conditions described are in fact precisely defined. According to one method, the temperatures are measured by the measuring devices 460, 466, 470, 476 along the reaction path and plotted in a diagram _{one after the other as a function of the entire path, ie from 0 to 1 f.} The results of such an experiment, described by the above parameters, are given in the diagram of FIG. 11, the symbols χ, Λ , + and O referring to meters 460, 466, 470 and 476, respectively. The temperature of the cooling gas rises from 199 to about 251 ⁰ C and that of CO from

- 31 809882/0933

3 '2827S34

the feed ^{temperature 249 0} C to a maximum of about 255 ° C. The excellent isothermal conditions result from the small fluctuation range of 252 - 3 ° C. The degree of implementation was 85.4% compared to 86 % according to the calculations (z = 0.86).

To further confirm the relationships as described above it is possible to determine the number of V / heat exchangers required to calculate as well as their dimensions and the cooling flow required for the results obtained. Additional Data relating to the experimental conditions are summarized in Table 3.

Table 3

0 _H ^{3 by} 5.8 cm 3

0 _c 113.3 cm ³

L 20.32 cm

X 5.08 cm

A _xH 15.05 cm ²

A _xC 5.593 cm ²

e _r 5.670 g-mol / d

^ 4

W 158 g

The terms and values used in the calculations are summarized in Table 4 for three significant values.

Table 4

iM _H 5.04

W _c 1.97

r 1.97

(K 2.56

Q 0.390

- 32 809882/0933

oil
—3a. - cal / s. 2827934 . grd 4.28 . 10 ~ ⁴ cm 4.34 cm / s 67.1 cm / s 375 67.4 0.867 0.695 cal / s. . grd 7.77 . ΙΟ " ⁴ cal / s. cm . grd 1.88 . 10 " ³ cm

^U H ^V C ^V H ^R eC ^R eH

^h H

With the values also in Tables 1, 2 and 4, the designations from Table 3 (which are determined experimentally) can be calculated, as shown in Table 5, including the approximate deviation in % from the values given in Table 3 .

Table 5 deviation 1.85 311.5 cm 2.50 116.1 cm 1.75 20.69 cm 1.92 5.188 cm 0.62 15.143 cm 0.0 5,574 cm 6.08 6.014 g-moles / d 0 4th 3.07 162.7 G

^A xH ^A XC

You can see that in all cases there is a very good match consists. It should be noted that the above figures have been rounded up to three or four significant figures from values obtained from computer calculations. It can therefore be said that the deviations calculated above in all cases are immaterial.

- 33 809882/0 9

2527934

Example 2

The variations of ⁷ Zj. in the form of maximum deviation from isothermal relationships in ⁰ C and C / C _Q left and right on the Urdinaten versus the feed temperature in ⁰ C on the abscissa. For the sake of simplicity, N ₁ , = U _n and

»Fe P ^H _ -ι-] -1-1 (2-1)

the calculations are based on. The cooling gas was fed in at ⁰ ° C., the reaction gas contained 5.48% CO.

The deviations from the i so the rmi see conditions v / earth as + 4T "or - ÄT" indicated, k ^ f "results from table 6, in which the variables from the diagrams of FIGS can be found.

Table 6 ^N H = ^left C 0.983 162Ü 0.983 250U 0.983 1000 ο, ουυ 1620 2.00 1620 25.00 1620

figure

5 6 7 8

9 10

The above variation ranges for T ^ and N ^ are relatively wide around the optimal values from FIG. 5 after each side. To ensure that the conditions are exactly isothermal, the curves for + Δ T ^ and - Λ T must show a deviation from 0 at the same time. this

- 34 809882/0933

is the case at the intersection of the curves in FIG. 5 at about 550 ° C. It is obvious that somewhat higher inlet temperatures favor higher yields because of the steep negative slope of the conversion curve at this temperature. The range of the working capacity of the isothermal point may be selected at any Seito, as indicated by the arrows, the isothermal conditions - indicate 100 ⁰ C. The range can also be set to -ü and + 1üO ° C or other values if this is desirable. The diagram then shows the impact on the implementation. Isothermal conditions with - correspond! Example 1 allow a relatively narrow range of working conditions.

Of course, other factors than implementation can also be important, such as coking during methanation, that occurs at excessive temperatures for any given Response, a group of such curves can be formed, which serves as a reference point for the manual control or a computer can be programmed precisely for variations, which it automatically and continuously monitors.

The B'ig. 6 to 10 show that no other conditions lead to the isothermal reaction or allow a deviation by small values with good conversions as under the conditions shown in FIG. Fig. Shows that without cooling the reaction temperature is only increased and although good conversion is achieved in this particular system, the temperature rises to the reaction side auf'1000 ⁰ C8. Such a considerable increase in temperature is only possible because the selected model system is relatively free from side reactions, catalyst poisoning and other disadvantageous phenomena. In other systems, such as methanation, this is not necessarily the case. FIGS. 9 and 10 show greater fluctuations in terms of temperature. These calculations were made assuming that the reaction was only partial in any part of the reactor

- 35 8Q9882 / 0933

take place and that the flow takes place in the same direction.

Example 5

In a reactor should 231 kg / h of methanol from CO + 2H _? getting produced. Langmuir's adsorption kinetics can be used for this conversion (F. Daniels and R. Alberty, Physical Chemistry, 3rd edition, 288 (1966, John Wiley)). For such reactions in general and using the above terms as extensively as possible, the rate r results from

where C _{0 is} the entry concentration IxRF. Reaction partners, the speed of which can be regulated and K means the adsorption constant in equilibrium at 1 'for the adsorption of the reaction partner regulating the speed on the catalyst.

Hit above math methods and assuming that IL = top, the following relationship results:

^w c ^x i ¹

The ratio results for Langrauir's adsorption kinetics the amount of catalyst P at each point of the reactor to the amount of catalyst at the beginning of the reactor

el T)

P - κ + _1 (3-3) _ 36 -

a Q ₁

809 8 82/0933

7934

Assume that the rate of any catalytic reaction per unit volume is directly proportional to the amount of catalyst, so the material balance follows quite generally during the Relationship reaction

L dz _β ! Ih _(r) . ₍₃ _ ").

dx · C ₀

The heat balance on the reaction and cooling side of the heat exchanger results from the following relationships:

_dT (-ΔΉ) Ρτ _Η

dx HH ü ^p h pH

dx

(3-5) = μ (T -T) (3-υ)

If these three equations are solved at the same time, the following equation is obtained:

(-AH) C _n (-ΔΗ) Ρτ,

VVV ²¹ Tr- ⁹ ^. ³ τϊ— · ^{(r) (3} " ⁷⁾

HHCP _H L _pH Ρ _ιΓρΗ

and

Z (-AH) C ₀ Λ

¹ CC ⁽ⁱ H ¹ C ^ H ⁰ PH

⁽³ ~ ⁸⁾

from which P is calculated as a function of the length from the values Nr ,, C _n ti and Z at any point γ · Iäf3t.

- 37 -

8098 82/0933

This procedure is applicable to the methanol synthesis accordingly Fig. 12.

A gas mixture (synthesis gas) of 12% by volume of CO, 80% by volume of H ₂ and 8% by volume of inert substances was fed in at 500, the first stage 512 of a two-stage compressor 510 and passed into the scrubber 515 Washer is introduced at 516 cold water and discharged at 518, which was used to take up the CO ₂ and other impurities. If necessary, parts of the gas mixture can be returned to the first stage 512 of the compressor 510 via the connecting line 514. The gas reaches the second stage 517 of the compressor 510, v / o it is brought to the desired working pressure and is then fed via 522 to the trap 520 and discharged from this at 524 after removal of oil and other suspended matter. The materials of the system up to this point must be resistant to CO and H ₀ . So there is no reaction with the CO and no embrittlement due to Hp. Copper-lined systems for the direct current reactor 530 can be advantageous, particularly at elevated temperatures. Although only one cocurrent reactor is shown and described in detail, it is obvious that several such reactors can operate in parallel.

The DC actuator 530 is essentially cylindrical Tower with a row of six cross-flow heat exchangers arranged one above the other according to FIG. 1, the elevations 540, 542 and in which the catalyst (not shown) is located on the reaction side 540, as in FIG. 1. In this example it is assumed that there are six cubic units with an edge length of 60.8 cm in a 3.68 m high tower intended. The bumps in these units should have the same shape (i.e. the ratios of the parameters) as in the above examples, but with thinner walls, but with regard to mechanical strength sufficient. It should be noted that a plurality of such towers are combined

809882/0933

2827834

can and that corresponding connection lines for larger Production capacities are to be provided. The tower is insulated because heat losses are not taken into account for the following calculations are.

The units are fixed at the edges where they touch the reactor vessel to prevent leakage. In between there are baffles 537, 538, the direct current reactor 530 is equipped with a cooling gas supply 532, a reactant supply 534 and a coolant discharge 533 with the supply 534 via an auxiliary heater 535. In the secondary circuit 539 there is the valve 541 for further reactant supply _f than it is used for coolant.

When the coolant at 532 and the reaction mixture at 534 enters, they reach the via lines 542 and 540, respectively Lowest heat exchanger unit I through the baffles 537, 538; Above the unit I, the currents are directed upwards into the unit II out, where they then enter through the baffles 537, 538. This continues until the currents reach the top unit - here VI - have flowed through. The cooling stream, which has absorbed a substantial proportion of the heat from the reaction on the reaction side, then reaches the reaction side, where it is begins to react on the catalyst in passages 544. To get the reaction going, the auxiliary heater is used 535 heat is supplied until the temperature of the synthesis gas is sufficient is high, so that the conversion on the catalyst begins in the passages 540 of the unit I and possibly also in the Units I to VI takes place.

The reaction mixture mainly contains CO, H ₂ and CIUOH and leaves the reactor 530 at 531 to be condensed in the condenser 560 with the aid of the cooling coil 525, to which cooling water is supplied at 564 and from which the cooling water is removed at 562. The cooling flow of gaseous and liquid phase leaves the condenser at 56e and enters the separating

809882/0933

- 39 -

vessel 570 at 572, from which the gases are discharged at 574 and returned via 610. The valve 578 is used to parts Discharge of the return gas if there are impurities have already enriched. The condensate is crude methyl alcohol and leaves separation vessel 570 at 578 and is in 580 relaxed. The gaseous substances leave the tension vessel 580 at 5Ö2 via valve 584 and unite with the purge gas from valve 578 to vent at 586.

Raw methanol, from which most of the dissolved gases are removed is now in the distillation column 590, which is equipped with the heating coil 592, introduced and stripped there. It passes through the reflux condenser 600 and from this again via 594 back :: ur distillation. Pure methanol 608 is discharged via 602 and residual impurities, like v / ater, are removed at 595.

The DC reactor 530 is packed in units I to VI with different concentrations of ZnO-Cr ₂ O ₃ - or ZiD-CuO-CroO ^ catalyst, the concentrations based on the kinetics and thermodynamic data for ZnO-Cr ₂ O ₇ catalyst from liatta are calculated ("Catalysis", PH iSmmett, Vol. 3, p. 345 ff. (1955)) or for Znü-CuO-Cr ^ catalysts by Pasquon and Dente (J. Catal. Vol. 1, p. 508 ff. (1962)). Optimal working conditions are 395 ° C and 280 atmospheres.

The equation according to Pasquon and üente is

(A + Ba ₀₀ + Ca ^ + ^

Reaction rate for the formation of methanol kg-mol / h

Catalyst efficiency 0.67

- 40 809882/0933

a _co = thermodynamic activity of CO =

a _M = thermodynamic activity of H _Q = “ p _u

rip c. rip U

^a rH OH ⁼ thermodynamic activity of methanol =

= Activity coefficient of CO = 1 fa = activity coefficient of H ₂ = 1 / CH OH ⁼ activity coefficient of CH, OH = 0.52

ρ = ■ partial pressure (product of the mole fraction of the ■ components and 280 atm)

K = equilibrium constant of the homogeneous reaction y κ-?

for the methanol synthesis = 2.67. Λ0 atm * ~

Ae - -24.45 kcal / g-mole

AT = 386 ° C

C = 7.6 cal / g mol. grd

A = 125

B = .1.0 (. Empirical constants, determined according to

C = 0.125 I Natta.

"D = 4.63 J

Assuming 7 \ r = 0.011 b and a cooling gas temperature .Tp of 9 ° C when entering the unit I can be the equations 3-7, 3-8 and 3-9 dissolving NP = N "= 0.357. the equation 3-7 can be converted to the solution for the ratio of the catalyst weight P to that point of the reactor after

Pr _ Pr ,, _{Λ 1} ν

¹ O 0 0 ^χ

where P _{Q is} the ratio of the amount of catalyst on entry into unit I and numerically represents the unit; r ^ is the reaction rate and Z ^ the degree of conversion when entering the unit I. It is clear that, although P _{Q is numeric}

■ - 41 -

8 09 88 2/0 933

2827S34

is moderately 1, the actual catalyst concentration in pure catalyst pellets as a catalyst on a carrier or as a catalyst + can be any carrier. The concentration of inert diluent can be any. the end these relationships can be the fourth for Z, P and r (g-mol) CH, OH per g-ii catalyst and hour (on leaving the units (6 i-'units) according to box 530 in FIG. 12 is determined the values in Table 7 as well as the

Ί
calculated values for R are combined.

Z Tabc P. lie 7 R ¹ unit 0 1.0 r. 10 ² 1.90 0 0.0578 1.07 0.22 1.78 I. 0.112 1.21 0.180 1.57 II 0.164 1.36 0.150 1.40 II 0.212 1.53 0.126 1.24 IV 0.257 1.70 0.106 1.12 V 0.300 1.90 0.090 1.0 VI 0.076

The above information was provided with six V / heat exchanger units based on certain dimensions. This leads to the value N in box 380 of FIG. 3 as well as to the dimensions and Values of box 120 and 150 of Figure 3 and permits the calculations, the values of which are summarized in Table 7 for Box 180 of Fig. 3 · The data for the construction of the heat exchanger units, such as wall thickness (box 150 in Fig. 3) | must be calculated in order to get to the results and other .parameters. The assumed values are given in Table 8 in relation to the symbols given in Table 1. The reaction partner regulating the rate of conversion is CO and values for C, - / dH etc. relate to it.

- 42 -

809882/0933

2327234

Table 8

C ₀ 6.12. 1Ο " ⁴ g-mol / cm ³

G 4.61. 10 "" ⁴ g-mol / cm ³

Z 0.30

F 5.77. 10 ⁵ g-moles / d

% 7.52 g / g-mol

-idH 24,450 cal / g-mole

/ 5 _T 1.31 g / cm ³

£ 0.50

Dp 0.95 cm

k _R 0.129 s ~ ¹

C _pH 7.60 cal / g. grd

C _pC 7.60 cal / g. grd

fj-g 3.46. 10 "g / cm. S

/; _c 2.18. 10 g / cm. s

K _H 5.95. 10 ~ ⁴ cal ₂ deg

- - cm

K _c 2.57. 10 ^ cal ₂ grd

s. cm "cm

M ₀ 7.52 g / g-mol

p _H 2.85. 10 " ² g / cm ³

p _c 7.22. 10 " ² g / cm ³

On the assumption given above that the wavy Elevations in each heat exchanger unit have the same proportions have than in the previous examples, the dimensions of the elevations are determined by repeated calculations determined according to Table 9.

Table 9 cm 1.0 cm 9.73 cm 5.05 4.70

809882 / 0S33

3.58 cm 3.93 cm 1.57
1.34
1.76 cm
cm"
cm" 0.111 0.163 4.05 1.68 0.11
3.44 _1n -3 cal
* ^IU s.cm

"cm

The values given in Table 10 for the symbols as described in Table 2 can be calculated from this data are.

Tabel

% 195 ° C

T _r 9 ° C

U "6.37. 10 cal / s. cm. grd

U _c 8.36. 10 cal / s. cm. grd

T _H 39.6 s

r _c 38.4 s

S _C / S _H 0.762

\) _H / 0 _c 2.61

In the sense of Example 1 for carrying out the calculations according to the invention, the values are corresponding to those of Table 4 determined and summarized in Table 11.

809882/0933

2027934

SA 2
. cm. grd Table 11 0.357 0.357 0.357 1.031 1.0 39.6 s 2
. cm. grd 6.37. 10 ~ ⁴ cal / s 2
. cm grd 4.75 cm / s 4.63 cm / s 2062 361 0.68 0.41 6.50. 10 "x ⁵ cal / s 1.82. 10 ~ ³ cal / s

■% ■

r a

GL

^U H ^V C ^V H ^R eC ^R eH

Using the data from Tables 9, 10 and 11 will be Calculations made to show that the originally given dimensions in terms of yield, size of the tower and number of units actually result from these calculations. This is described in Example 1 and Table 5. The data are summarized in Table 12.

L X

^A XH ^A XC

Tabel 12th 8.67. 10 ⁵ cm ³ 3.32. 10 ⁵ cm ³ 365 cm 60.9 cm 2369 cm 2 907 cm ² 2.00. 10 ⁵ g-moles / d 6th 569 kg

809882/0933 - 45 -

2027S34

It follows that the plant for the production of methanol from carbon monoxide and hydrogen at the desired rate be able to.

The advantages of the plant according to the invention result from a comparison with a plant when the catalyst concentration is varied using tube bundles surrounded by a boiling heat exchanger liquid (P. H. Calderbank, A. Caldwell and G. Ross, Chimie et Industrie-Genie Chimique, Vol. 101, pp. 215-230 (196g)). The comparison can be carried out are with the total catalyst volume, i. H. the volume of the catalyst including the diluent. The bigger this total volume is, d. H. the more dilute the catalyst, the greater the volume required for it Power. The results according to Calderbank et al. are expressed by the catalyst dilution factor R, which is in relation lags behind the values of P.

^p t

| T ι (3-12)

where P ₁ - is the value of P at the exit end of the reactor. the

1
Values for R in the present example are calculated and are summarized in Table 7. According to Calderbank et al. are 2.6 at on the inlet side, 1.8 at in the middle and 1 at on the outlet side. In the diagram of FIG. 13, the values from Table 7 are entered as curve A and those according to Calderbank as curve B, and in a diagram with the units in the example or the

dimensionless distance, which is 1, at the end of the unit against VI

1 are applied, "

the values of R on the ordinate /. The curve A shows the gradual Change of the dilution factor R, since it is assumed for each unit that the same amount of catalyst is present. The curve B shows a straight line since it appears that Calderbank et al. intended a more gradual change in the amount of the catalyst. Of the

- 46 809882/0933

2827S34

lower part of curve A shows that sufficient catalyst for the desired degree of conversion in a lower Volume than in the comparison device is included. This is believed because of the greater effectiveness of the Heat exchanger units and the possibility of regulation by the method according to the invention.

0 9 8 8 2/0933

e e r s e ι ϊ e

Claims (1)

Claims (-.AH) C H ΔΗ ^J c 'Η S ₁ S, Entry temperature of the reactants Inlet temperature of the coolant heat of reaction Initial concentration (des) of the reactant (s) total heat transfer coefficient at the Response page total heat transfer coefficient on the cooling side, throughput on the reaction side Throughput on the cooling side ■ heat-transferring surface on the reaction side heat-transferring surface on the cooling side, free volume on the reaction side -2- 809882/0933 Often GINAL INSPECTED 2927834 excluding the finely divided catalyst D _c = free volume on the cooling side -, C _n = density. Heat capacity of the coolant and the relationship between the rate of heat release and the concentration of the reactants is a direct function of U _n and the ratio T _n / V " , O L rl 2. Device for performing the method according to claim 1 with feed lines and discharge lines for the reactants, Reaction mass and cooling medium, characterized by one or more heat exchanger units with two groups of passages, one group of passages for the reaction zone and the other group of passages for the cooling medium is provided and these two groups of passages are arranged so that the direction of flow in them are in direct current or pseudo direct current. 3 ο device according to claim 2, characterized in that the heat exchanger units are cross-flow heat exchangers. 4 _O device according to claim 2 or 3, characterized in that pellets impregnated with catalyst or the catalyst are located on the walls of the first group of passages in the reaction zone. 5. Apparatus according to claim 2 to 4, characterized in that in the first group of Runs through different catalyst concentrations to change the reaction kinetics for reactions first In order. - 3 8 0 9882/0933 6ο device according to claim 5, characterized in that the catalyst concentration increases in the direction of flow. 7c apparatus according to claim 2 Ms 6, characterized in that at least four cross-flow heat exchanger units are arranged in succession with increasing catalyst concentrations ₀ 8ο Device according to claim 2 to 7 for the catalytic conversion of at least one reaction component at a rate constant k _R , characterized by a reaction zone in the form of at least one group of passages within at least two cross-flow heat exchangers, in which the catalyst is located, and in a second group of passages for the coolant _o 9. The device according to claim 8, characterized geke η η ζ e ichnet that at least two heat exchanger units are arranged one above the other, the groups of passages are perpendicular to each other and between the units there are guide elements for the entry of the emerging from one unit and the other aee unit incoming flow are provided _o 10c application of the method and the device according to Claims 1 to 9 for the production of methanol from CO + Hg, the controlled variable being the initial concentration of CO, especially with at least two cross-flow heat exchanger units. .11 «, = device according to claim 10, characterized in that the catalyst is pellets 809882/0933 of ZnO-Cr ₂ O-, or ZnO-CuO-Cr ₂ O-, with diluent and the concentration of diluent decreases in the direction of flow " 12 ₀ device according to claim 11, characterized in that the cooling takes place at least partially with the aid of the reaction gases. 809882/0933