DE2040501B - Process for carrying out exothermic reactions between a gas and a liquid - Google Patents

Description

Carbon dioxide, carbon monoxide, ethylene. Hydrogen is acetylene, oxygen, usually pure or passed through the reaction vessel containing the packing. As Tvir have found, technically pure gas is used.Although a transition from trickle flow to transition dilution of the flow to be used as starting material is possible through a sudden increase in the pressure gas with inert gases such as nitrogen, there is, however, a difference Δ ρ marked (see. Fig. 1). The excess amounts to the amount of inert gas in the supplied passage from the area of the transition flow to the admixture of reaction gas and inert gas at most rich in pulsations due to the occurrence of the pul-20 percent by volume. sizing flow, the exemplary

The liquid can be displayed in pure form or as a mole by pressure surges in the apparatus

schung with inert to under the reaction conditions.

Liquids, e.g. B. organic solvents or The adjustment of the transition flow can now be applied to the reaction product itself. For example, in a visual way and / or by measurement, the liquid can also solve a solution of the pressure difference Δ ρ . The setting of solid or gaseous starting material in one of the transition flow can be by measuring the pressure-inert solvent. 15 difference Ap takes place z. B. in such a way that the

The exothermic reaction between gas and liquid is carried out in the presence of solid catalysts through the reaction vessel with gas, measured in normal volume. The catalyst can be set as such or according to parts per unit of time and, beginning with application to an inert support material, be used as a load F of the reaction vessel with liquid catalyst. In general ao speed, measured in parts by volume per unit time, of about the catalyst also serves as a packing. There zero increasing amounts of liquid through which travels, however, possible in addition to the catalytically active action vessel passes. In this case, initially fillers will be filled with inert packing. The trickle area that runs through a near-filler body can, for example, have the shape from Ku to a linear slow increase in the pressure difference Δ ρ gem, rings, cylinders or tablets, as is characterized by increasing load F. If spherical bodies are used to further increase the liquid load F, the balls generally have a diameter of the beginning of the region of the transition flow between 2 and 8 mm. Cylinders with a pressure difference A ρ are generally displayed as cylindrical packing bodies due to a sudden and increasingly steep rise. In general, a length of 2 to 15 mm and a diameter between the range of the transition flow is reached, see 2 and 6 mm. Not spherical or zy- if the increase in the pressure difference Δ ρ with ascending linder-shaped packing bodies generally have ad _{load expressed} as ^ f , to a minimum volume that of the spherical packing bodies ⁵ ' ^ö SF
is equivalent to. at least a factor of 2, preferably a factor of 3,

The procedure is especially for such exo- 35 is greater than the average increase in the Rieselthermen reactions between a gas and an area. With a further increase in the liquid-liquid load F in the presence of solid catalytic converters, the increase is linear again, but it is suitable if a narrow temperature must now be maintained at a much steeper rate than in the trickle flow area, i.e. for reactions in which mung (cf. Fig. 1). With a further increase in the temperature fluctuations the occurrence of temperature fluctuations, the area of transition during the reaction or the occurrence of local flow is finally passed through and the temperature peaks are found to be unfavorable. Reached the range of the pulsating flow, the narrow temperature range is generally to be understood by the fluctuations caused by the pulsations, a fluctuation range of ± 20 ° C, preferably fluctuations in the pressure difference Δ ρ of ± 5 ° C. The procedure is therefore 45 net. The fluctuations occur approximately with the Frez. B. advantageously suitable for the catalytic hydration rate of the pulsation. The transition disorder and for the ethynylation reaction become visible. Further mung, for example, in the AI Ch. E. Journal, suitable reactions are, for. B. the oxidation of Vol. 10 (1964), pp. 952 to 953, described manner hydrocarbons such as cyclohexane, p-xylene with adjusted. One observes in the reaction vessel, molecular oxygen, the halogenation of carbon, that the initial part of the reaction vessel after the hydrogen. With the application of the new supply of gas and liquid from an intimate drive to the individual reactions, the general mixture of gas and liquid becomes turbulent in general and the general flow usual for the reaction. Since the gas is constantly consumed during the reaction to reaction conditions, such as solid catalysts, the number of the gas temperature is not affected. The bubbles in the reaction mixture caused by the new process a 55 when passing through the conditional, faster and more intensive mixing of the reaction vessel, and to the corresponding extent of gas and liquid, however, the fact that the consumption of the gas is released can influence the reaction rate, whereby it ends Volume filled by the liquid. If necessary, it is advisable to observe the process parameters of the discharge of the reaction vessel, the mean residence time, temperature and ca- 60 then finally, depending on the degree of conversion, the amount of catalyst that is required for a technical working of the gas or the content of inert gas, that practically wise have proven to be optimal, because no more gas escapes or only a fraction of the new, higher reaction rate used gas in the form of gas bubbles in the optimization. Liquid leaves the reaction vessel.

It is an essential feature of the new method

driving that gas and liquid in the form of the over-conversion of the gas is the use of a long-

transition flow, as required in A. I. Ch. E. elongated reaction vessel. The Rea-

Journal, Vol. 10 (1964), pp. 952 to 953, described tion vessels can have a cross section in any

Have shape, for example in the form of a square or an ellipse. Generally used one cylindrical reaction vessels. The ratio of the diameter to the length of the reaction vessel is generally 1: 5 to 1: 300, preferably 1:10 to 1: 150, in particular 1:20 to 1: 100. On Place an elongated reaction vessel with the specified ratio of diameter to length however, two or more individual reaction vessels connected in series can also be used, each of which has a greater ratio of diameter to length than in the case of the elongated reaction vessel, but which in the effect of the elongated one Correspond to the reaction vessel. As a rule, two or more are connected in series Use single reaction vessels instead of an elongated reaction vessel if a single one elongated reaction vessel would cause technical difficulties because of its length. Accordingly the number of reaction vessels connected in series is usually two to ten.

The reaction vessels can be aligned vertically or horizontally and also take intermediate layers. However, vertical reaction vessels are preferably used. The vertical Standing reaction vessels can move from top to bottom or from bottom to top of gas and liquid flowed through in direct current. In general, the reaction vessels are upright Pass gas and liquid from top to bottom.

In the case of gas-liquid reactions with a particularly high conversion rate for the gas it may be advantageous not to put the total amount of gas to be supplied as a total amount in the initial part of the elongated reaction vessel, because this easily moves into the area of the pulsating Flow, but the total amount of gas to be supplied in two or more Subsets in the direction of the axis of the reaction vessel segments of the one behind the other Reaction vessel feeds. In this way of working, you will usually add 2 to about 5 partial amounts, where, when several reaction vessels are connected in series, the partial quantities expediently in each case supplied to the initial part of the individual reaction vessels. In this embodiment can through the interposition of "heat exchangers" a particularly uniform temperature control is achieved will.

The process of the invention can be carried out batchwise and continuously. The procedure is z. B. continuously carried out in such a way that the reaction mixture in a circle through, the packed vessel passes through it, the starting materials being added to the circulating reaction mixture before it enters the reaction vessel and the reaction product of the circulating reaction mixture after leaving the reaction zone The continuous process can also be carried out in such a way that the Run the reaction mixture through several, e.g. 3 to 5, circulation apparatuses connected in series leaves

In applying the new method to the ethynylation reaction, i. H. the manufacture of Alkynols and / or alkynediols by reacting acetylenes with aldehydes in the presence of heavy metal acetylides and optionally in the presence of basic agents, are in the Usually acetylides of heavy metals of the first or second group of the periodic table as solid catalysts used. The heavy metal acetylides can be used as such for the reaction. However, it is also possible to use the heavy metals themselves or their salts, which are then used at the beginning

ίο the implementation converted into the corresponding acetylides will. Suitable heavy metals are, for example, silver, gold, and mercury in particular Copper. When using heavy metal salts, the type of anion is not critical. When Heavy metal salts come, for example, copper phosphate, copper acetate, copper (I) chloride, copper (II) chloride, Copper acetate, copper formate. Silver nitrate or mercury chloride into consideration. The heavy metal acetylides are preferably after application

on shaped carrier material, which also serves as a filler body. Suitable carrier materials are for example aluminum oxide, animal charcoal, kieselguhr and especially silica gel. The ethynylation is expedient in the presence of an inert solvent or diluent, such as Alcohols, ethers, esters, carbonamides, aromatic and aliphatic, hydrocarbons or water executed. Examples include ethanol, isobutanol, n-butanol, eth / glycol, dioxane, Tetrahydrofuran, dimethylformamide, N-methylpyrrolidone. You can also use the end product itself or excess liquid starting material as a diluent use.

For the ethynylation, alkylacetylenes, preferably those with 3 to 6 carbon atoms, are used. Arylacetylenes, preferably those with up to 12 carbon atoms, as well as alkenyl and alkynyl acetylenes with preferably 4 to 6 carbon atoms and in particular acetylene itself is used. For example called methylacetylene, ethylacetylene, phenylacetylene, vinyl acetylene, diacetylene.

For the ethynylation, aromatic aldehydes with preferably up to 11 carbon atoms are used and in particular aliphatic aldehydes are used.

The aliphatic aldehydes generally have 1 to 12, preferably 1 to 6, carbon atoms. Suitable aldehydes are, for example, acetaldehyde. Butyraldehyde, n-caproaldehyde, benzaldehyde and preferably formaldehyde. The formaldehyde can be in monomeric form, e.g. as technical aqueous Formaldehyde solution, for example as a 20 to 50 percent by weight solution or in polymer form, z. B. as trioxane and especially paraformaldehyde can be used. Technical aqueous formaldehyde solutions are preferred

In general, the reaction is carried out without the addition of basic agents. However, it is also possible to carry out the ethynylation in the presence of basic agents. As a basic agent For example, carboxylic acid salts, carbonates, hydroxides of the alkaline earth or alkali metals come into consideration. Examples include potassium formate sodium acetate sodium carbonate potassium carbonate Magnesium carbonate calchim hydroxide.

The basic agents can be dissolved, for example

Form can be applied in the reaction mixture.

In the process, the starting material with the

lower boiling point gaseous and the initial

ki H di z \ B η d

d d ti d

P ο S g

η Ii ti

f P d T

L ν ei 5 s t

substance with the higher boiling point than liquid to- Differential pressure between feed to the column and guided. The ethynylations are generally removed from the column via the difference in Temperatures between -10 and 120 ° C, measured pressure gauge 8 and is 0.3 atm. at especially between -10 and 100 ° C. an acetylene pressure of 5 atmospheres, the reac-

In general, the starting materials are reacted at a molar temperature of 105 ° C. in the packed column. From a ratio of about 1: 1. The separator is 1.17 liters of reactant per hour, but it is also possible to discharge one of the two starting products 15 which use a formaldehyde substance in excess, with an expedient content of 15 percent by weight. The molar ratio of the starting materials between the amount of butynediol, based on converted 1: 1 and 1:10, in particular between 1: 1 and 1: 3 w formaldehyde, is 97% of theory. Sales at is maintained. Formaldehyde is 6O ⁰ Z ₀ .

When applying the new procedure to the _R. .

catalytic hydrogenation can use the usual solid Example 2

Hydrogenation catalysts such as platinum, palladium, rho five vertical packed columns of each

dium, ruthenium, nickel or cobalt metals, the 15 8 m length and a diameter of 140 mm are practical on carrier materials such as animal charcoal, which are connected in series through tubes in such a way that Barium sulfate, calcium carbonate, silica gel, Ahimi- the lower end of the first reactor with the upper one Nium oxide are applied, can be used. After the end of the second reactor, the lower end of the two new processes can use the usual catalyti- t with the upper end of the third reactor and see hydrogenations being carried out, e.g. B. the Hy- ao is immediately connected.

dration of carbon-carbon triple bonds The one reactor at the lower end is

The formation of the corresponding double bond or the gas-liquid mixture that leaves a seed thus becomes without tied bond, hydrogenation of the double bond, further separation at the head of the next reaction Hydrogenation of aromatic to cycloaliphatic vessels added. At the end of the last reactor see hydrocarbons, from carbonyl groups to 25 there is a separation vessel. The five packing hydroxyl groups, from nitro groups to amino groups are filled with a hydrogenation catalyst, pen, from nitrile compounds to amines, from amines from strands of 6 mm in diameter and 4 to oxide groups to amines, the hydrogenolysis of 10 mm in length and each 20% nickel Protective groups such as benzyl ester or benzyl ether silica gel contains.

groups, the hydrogenolysis of acid chlorides to 30 Duch the five columns are now 960 liters each Aldehydes. Hour 2-ethylhexanol-l pumped in a circle and

The hydrogenation can be carried out in the absence of solution 160 liters per hour of 2-ethylhexane-2-al-l at the head means. However, it is also possible to meter it into the first contact column. The temperature borrowed the hydrogenation in the presence of the mixture entering the catalyst is 90 ° C. In addition, liquids commonly used for hydrogenation, such as 35, 44 Nm ³ per hour of ethers are at the top of the first column. Esters, lower aliphatic carboxylic acids, hydrogen injected under a pressure of 27 atmospheres. Carry out alcohols or water. For the inven- gas and liquid pass through the five towers in the proper catalytic hydrogenation can, for. B. the direction in each case from top to bottom and who temperatures between 10 and 300 ° C and pressures that applied after passing through the fifth tower such as between atmospheric pressure and 325 at 4 ° of the separated. Become out of the fluid cycle. However, it is also possible, at a reduced pressure of 162 liters per hour as the reaction product, e.g. B. 600 Torr to work. men. The amount of gas escaping is 5.5 Nm ³ each

. Hour and is discharged as exhaust gas. The last one

Example 1 Product leaving column has a temperature of

A pressure-resistant filling 45 170 ° C was used for the implementation. The body column 1 made of stainless steel with a mixer, which is returned to the first tower, is cooled to 120 ° C. The 2-ethylhexanol-1 leaving the last length of 6 m and a diameter of 45 mm tower has a pure used (cf. FIG. 2). The packed column had a unit of 96 ⁰ Zo. The yield is 97.7%. one in strands of 3 mm in diameter and 2.5 to

5 mm length shaped supported catalyst filled, des- 50 Example 3

sen analysis a content of 85 percent by weight

Silica gel, 12 percent by weight CuO and 3 Ge A glass tube of 30 mm internal width and 2 π

weight percent bismuth. Through line 11a length was with a hydrogenation catalyst from strands 1 liter per hour was 37 percent by weight genes 2 mm in diameter and 2 to 6 mm in length aqueous formaldehyde solution 11 and filled through line 9 α 55, the analysis of which has a content of 0.4Ge 120 normal liters of acetylene 9 per hour are supplied. By weight percent palladium and 99.6 weight percent Feed 12 was the circulated reaction silica gel. At the head of the vertical one! liquid fed to the packed column. After passing through a line, 1.2 liters per hour the packed column was running in the separator! a 20 weight percent solution of trimethyl a separation into gas phase and liquid reaction- 60 p-benzoquinone in isobutanol pumped in and durci mixture. 92 liters per hour of the liquid reaction - another line 50 normal liters per hour of what Mixtures are added from the separator through the discharge material. The lower end of the pipe wa tion 16 connected via circulation pump 3 and flow meter 6 with a vessel in which there is and passed through the circulating cooler 5 in a circle. Gas-liquid mixture leaving a pipe separated Part of the liquid reaction mixture from the waste 65 The liquid was circulated by a pump separator 2 is conveyed back to the top of the reaction tube through discharge 14 as a reaction product 15 removed. About discharge 10 a and one of the quinone solution supplied accordingly 30 normal liters of exhaust gas 10 taken per hour. Taken from the amount from the separator. The Meng

the liquid pumped in a circle was 56 liters per hour. Between the top and bottom the column found a differential pressure of 55 toners. The temperature of the liquid being pumped was 85 ° C. At the lower end of the tube, 1.5 standard liters of exhaust gas per hour were passed through the separating vessel escape. 1.2 liters of reaction solution were discharged per hour from the separator, which had a content of trimethylhydrochnon of 20 percent by weight. Conversion and yield were practically 100% the theory.

Dependent wedge of the pressure difference Δ ρ
on the liquid loading F of the packed column

The following apparatus (cf. FIG. 3) was used to measure the dependence of the pressure difference Δ ρ on the liquid load on the packed column F: A 130 cm long glass tube 1 ml. a clear width of 45 mm is over a length of

10

120 cm filled with glass balls 3 mm in diameter. The glass balls are at the bottom of the Column held by a sieve with a mesh size of 1.5 mm. The outflow opening has a Cross-section that is larger than the free cross-section available between the balls, see above that no additional pressure builds up due to the accumulation of gas and liquid in the outflow opening can. The measurement of the incoming gas and liquid

The flow rate is determined by the rotameters 7 and 6. The pressure difference Δ ρ is measured in the manometer ». To measure the pressure difference Δ ρ , the amount of hydrogen (9) was kept constant and the liquid load F was slowly increased, with as

Liquid water was used. The dependence of the pressure difference Δ ρ on the amount of liquid F for different amounts of gas, which are kept constant for each series of experiments, is shown in FIG.

1 sheet of drawings

Claims (3)

According to the invention, exothermic react Claims between a gas and a liquid in Presence of solid catalysts by pass-through process for carrying out exothermic th of the gas and the liquid in cocurrent Reactions between a gas and a liquid 5 through a packing containing elongated sigkeit in the presence of solid catalysts through reaction vessel advantageously carry out if one Passing through the gas and the liquid in the gas and liquid in the form of the transition flow Direct current through a packing containing (transition flow), as it is from A. I. Ch. E. Journal, elongated reaction vessel or several hin- Vol. 10 (1964), pp. 952 to 953, is known by the Single reaction vessels connected one behind the other, through which reaction vessels containing filler bodies a pressure difference-dp conducts between the ends and ensures that a significant part of the of the reaction vessel, which indicates the amount of gas supplied during the reaction, that the burden of the disappears. Reaction vessel selected by the liquid, It has now been found that exothermic redass with constant gas loading of the reaction 15 actions between a gas and a liquid vessel, the increase in the pressure difference Ap with in the presence of solid catalysts by increasing the liquid load at least two conduct the gas and the liquid in cocurrent is times as large as in the area of the pure trickle through an elongated flow of the liquid containing a packing, but the fluctuations in the pressure-reduced individual reaction vessels caused by pulsed reaction vessels or several successive single reaction vessels, whereby a pressure difference-dp is not yet occur, and thereby a renz Ap between the Euden of the reaction vessel ratio of the fed to the reaction vessel occurs, can be carried out advantageously if the amount of gas leaving this is maintained from 4: 1 to the loading of the reaction vessel by the liquid 100: 1. is chosen so that with constant gas loading of the reac- as tion vessel the increase in the pressure difference Ap with increasing liquid load is at least twice as large as in the area of pure trickle flow It is known that exothermic reactions between the liquid, however, caused by pulsations gases and liquids in the presence of fixed fluctuations in the pressure difference Ap catalysts, z. B. the reaction of acetylene and 30 does not yet occur, and a ratio of formaldehyde to butynediol (cf. Ulimann's Encyc- the reaction vessel supplied to the gas quantity of 4: 1 that allows this Verklopadie der technischen Chemie, Vol. 3 [1953]) up to 100: 1.
P. 109 to 119), to be carried out in such a way that in the new process a very intimate liquid is achieved in packed columns over the catalyst used as a mixture of gas and liquid and the packed catalyst can trickle down 35 at the same time, while causing a much higher load on the at the same time the gas is reached in cocurrent as a packed column with gas and liquid leads. In this so-called trickle method after the trickle method. Therefore, the reaction will only have a poor space-time yield and will essentially target the products of gas and liquid. Because of the difficult heat dissipation, a higher space-time yield is obtained than with the herds because of the occurrence of local temperature settings according to the trickle method. The reaction peaks very easily formed by-products and or heat can be dissipated very easily without causing local damage or damage to the catalyst. lent temperature peaks occur. It is the object of the invention to provide a process or the formation of by-products largely preventing a single mode of operation for carrying out exothermic reactions, so that the reaction products are obtained in a higher purity than the known ones on fixed, fixed catalysts Ren propose, with the reactants partly gas process. in the form and partly in liquid form, which shows the avoids the disadvantages. nis of supplied to the reaction vessel left- From the A. I. Ch. E. Journal, Vol. 10 (1964), p. 951 the amount of gas maintained from 4: 1 to 100: 1. to 957, it is now known that when passing through 50 this can occur during the implementation of a gas and a liquid in cocurrent to avoid a pulsating flow that occurs in the causes harmful pressure surges through a column filled with random packings, depending on the apparatus, and the loading of the column by gas and liquid at the same time the conversion rate considerably the following types of flow occur: lowers. In addition, this way of working has the τ n · iu u · 1 j · n- · 1 · »u j- 55 Advantage that a relatively small amount of gas * · * ^M * i. ^eselbere l ^{ch nesel} * ^d \ ^e liquid through the _{action tube so leaves} 3 _ate f _{n of the} r ^ _o f a Fullkorperpackung and the gas flows continu- _{Rückfünrung of the gas in the} circuit waived advertising ü ^Uie ™ · Sf i ^ ^S ^ ^h ! ⁿ . ^ra " ^m ^""« Chen _{den can} if _ien i _urch will result in considerable savings den FJrtUcorpern The liquid flows as noisy _{at ate achieved} . Narrow film about the individual packing. _{6o D} ⁶ _{as erfi} ^ _ungsgemaß to be observed ratio of 1: 2. The so-called transition flow (supplied leaving the transmitter to the reaction vessel for a walk ion trän- flow) moves the fluid in a _men ge of from 4: 1 to 100: 1 to type turbulent flow through the packed column 20: 1, preferably from 5 . can be set in a simple manner, e.g. B. in ^bed by which the reaction gas is passed through without dilution 3. In the pulsating flow, pulverulent inert gas is passed through to such an extent that the station of the invention becomes in the form of waves of higher density according to the ratio of supplied to adjusts the amount of gas discharged from the packing body with a certain frequency. Accordingly pillar. is the gas to be used as a starting material, such as