DE1260462B - Process for the production of tetrachlorethylene - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C07c

German class: 12 ο - 19/02

Number: 1260 462

File number: S 101747IV b / 12 ο

Filing date: February 1, 1966

Open date: February 8, 1968

It is known that in a number of technical processes, particularly in processes of manufacture of allyl chloride and / or epichlorohydrin, mixtures of organic compounds such as those used as starting material can be used for the process according to the invention, arise as by-products and, if at all possible, must be worked out into products with retail value. It has to be there Particular care should be taken to ensure that these commercial products make up a high proportion or even all of them Contain chlorine that was already present in the starting material or either during work-up in elemental form or in the form of chlorine-containing, gaseous, inorganic compounds, e.g. B. hydrogen chloride, has been introduced. Loss of other elements including hydrogen, oxygen and also carbon, are insignificant or Ms to some extent less important. Tetrachlorethylene is by far the most valuable commercial product and offers itself, so to speak Considerations of how the above-mentioned by-products can be exploited in an economically advantageous manner can be. Tetrachlorethylene is a well-known organic solvent and is particularly suitable for dry cleaning processes. Accordingly, it can even be economically advantageous to use compounds that are more valuable as starting materials to use as the above-mentioned mixtures of by-products. It is Z. B. It has previously been recommended to use pure propane or propene or mixtures that are essentially just propane or contain propene, "or 1,2-dichloroethane as Starting material for the production of tetrachlorethylene to use. However, product mixtures containing considerable amounts of chloroform were obtained or carbon tetrachloride or dichloroethylene. If such substances are used in the invention If the starting mixture is present, these are also converted very smoothly into tetrachlorethylene.

As a rule, 1,2,3-trichloropropane forms the main component of the process for the production of, which occurs as a by-product in the production of allyl chloride and / or epichlorohydrin
Tetrachlorethylene

Applicant:

Shell International Research

Maatschappij N.V., The Hague

Representative:

Dipl.-Chem. Dr. phil. E. Young

and Dipl.-Chem. Dr. rer. nat. V. Vossius,

Patent Attorneys, 8000 Munich 23, Siegesstr. 26th

Named as inventor:
Henk Johan Alkema,
Amsterdam, Netherlands)

Claimed priority:

Netherlands of February 3, 1965 (6 501 342)

Mixtures. It is of particular interest that these mixtures in the process according to the invention can be used as such without difficulty, since it would of course be uneconomical at first isolate the various compounds it contains in practically pure form. These Mixtures can also contain smaller proportions of such compounds, on the production of which the original procedure is directed, e.g. B. epichlorohydrin, dichlorohydrin or allyl chloride. This is especially when they are in such small quantities that their recovery is economical would be inexpedient. Furthermore, as starting material for the process according to the invention Mixtures used also contain by-products of this process itself, which are in the cycle be returned to the reaction zone, e.g. B. especially hexachloroethane. The following table gives an example of a feed mix.

. ,Link

Dichloropropene. Dichloropropane '.. isopropyl chloride allyl chloride "..".'. benzene

area
Weight percent

10.0 to 12.5

10.0 to 12.5

0.50 to 1.0

7.5 to 10.0

0.10 to 0.50

809 507/666

3 link 4th n-propyl chloride
1,2-dichloroethane
1,1-dichloroethane
Epichlorohydrin
Dichlorohydrin
1,2,3-trichloropropane
1,2,3-trichloropropyl ether
Hexachloroethane
Other chlorinated propanes area
Weight percent 0.10 to 0.50
0.10 to 0.50
0.10 to 0.50
1.0 to 2.5
0.05 to 0.10
40.0 to 50.0
7.5 to 10.0
5.0 to 10.0
1.5 to 2.5

So far, starting materials of the kind in which chlorine and hydrogen chloride are in principle also used can be used for the process according to the invention, but can be used in the can, in the presence of excess amounts of chlorine, usually cause substantial losses to be heated up in order to barely avoid tetrachlorethylene compounds from it.

to deliver. However, such processes are strongly exothermic. The process according to the invention makes the

and therefore difficult to control. This is disadvantageous, the formation of free carbon and tar completely

since it is necessary to avoid the temperature within one.

Relatively narrow range to keep the formation Preferably, substrates with a

less valuable by-products, such as trichloro-specific surface below 30 m ^a / g and in particular

ethylene, chloroform, carbon tetrachloride and others from 1 to 10 m ² / g are used. The average-

but tar and soot to prevent. This un- 25 liehe pore diameter is preferably between

Desired by-products are already below 600 and 3000 Å and in particular between 1000 and

relatively favorable conditions in such amounts 3000 Ä. The preferred carrier material is

made that it used to a frequent clogging of silica or alumina. Loading

Lead reaction system. For this reason, carriers made of a-aluminum oxide are particularly suitable

in general, frequent interruptions in the process, as well as Celite carrier masses (these are calcined di-

driving required to clean the system. atomic earth) or diatomaceous earth.

Furthermore, the production of tetrachlorethylene is the commercially available aluminum oxide in the by reacting tetrachloroethane with oxygen, the so-called α-form is already sufficient for the preferred in the presence of copper chloride on porous supports requirements for the support material with respect to as a catalyst, the catalyst in addition to copper 35 the specific surface and the pore diameter, also other metals in the form of chlorides If the manufactured or purchased contains aluminum, known. miniumoxide due to too large a specific

The process according to the invention is unsuitable for the production of a surface, so it can be modified accordingly by one or by tetrachlorethylene, several treatments, in particular heat treatments, that one lung mainly from 1,2,3-trichloropropane. For this existing chlorinated hydrocarbon mixture with acidic purpose, the aluminum oxide is either fabric in a vacuum or an oxygen-containing gas at 370 to or in a gas atmosphere that, for. B. consists of steam, 500 ⁰ C and a residence time of 1 to 100 seconds of air and / or nitrogen, 2 to 24 hours in the presence of a catalyst from the chlorides to temperatures between 1100 and 1700 ⁰ C, insdes copper, one or more Alkali metals, a 45 special one between 1200 and 1500 ° C, heated. Such or more rare earth metals and / or a treatment is generally required, zirconia, thorium and uranium on a porous support with a medium pore volume if alumina in the y-shape is to be used. For the method according to the invention of at least 300 Å and a specific surface, an ^{α-aluminum oxide obtained by sintering powdered aluminum surface of less than 100 m 2} / g, converts 50 minium oxide, is particularly suitable, the weight ratio of copper to rare die specific Surface area of silicon dioxide can be reduced earth metal in the catalyst between 0.2 and 3 and in the same way by heating, the alkali metal for copper between 0.3 and 1.5, however, the temperatures are lower, preferably. wise between 600 and 1100 ° C and in particular

Unreacted or only partially reacted components 55 between 700 and 1000 ° C.

of the starting material are preferably one with respect to the composition of the catalytic

fresh amount of the starting material added and active material are used for the invention

so circulated. according to processes such catalysts especially

Side reactions lead to the formation of various preferred, the copper content of which, calculated as metal,

Byproducts. If this is other chlorine derivatives from 60 0.3 to 10 percent by weight, based on the

Propane and propylene or chlorine derivatives of ethane Total weight of the catalyst, excluding that

or ethylene as the desired tetrachlorethylene chlorine contained in it. The atomic ratio of the

they can easily be recycled from the alkali metal (the alkali metals) to copper

will. However, losses of chlorine can be due to, preferably between 0.3: 1 and 1.5: 1. The best

Formation of elemental chlorine, hydrogen chloride 65 Results are generally achieved when the

and / or partially or fully chlorinated methane weight ratio of copper to the rare

occur, and these losses are as far as possible- earth metals, calculated as metals and not as

going to stop. Elemental chlorides can indeed be present in the catalytically active active material

5 6

0.2: 1 to 3.0: 1 and in particular 0.8: 1 to 1.2: 1 The carrier material is initially at 2 hours

amounts to. 500 ° C dried. After cooling down to room

The preferred temperature for the process according to the invention (about 2O ⁰ C), the support material with the catalysts used can also contain one or an aqueous solution of the catalytically active several additional promoters, eg. B. the 5 components, e.g. B. an aqueous solution of copper chlorides of iron, nickel, magnesium, calcium, fer (II) chloride, didymic chloride and potassium chloride, verBarium, palladium and zinc and mixtures of these mixes. The aqueous solution is in such a chloride. In particular the 'chlorides of iron and amount added that they are precisely from the carrier nickel have been found to be particularly effective. material can be absorbed. With constant stirring, the water from the impregnated carrier material is preferably in about the same weight ratio carrier material at a temperature of about 80 ° C. as the rare earth metals. However, have evaporated. The catalytically active ingredients are also suitable for lower ratios. In order to achieve a pacifying effect through several successive impregnations, it is not necessary to apply it to the particles. For example, it is absolutely necessary to incorporate separate solutions of copper (II) into the catalyst promoters. and / or copper (I) chloride, didymic chloride and potassium

The chloride used for the process according to the invention or solutions which are specific

th catalysts contain as alkali metal chlorides of these chlorides, in combination with one another

preferably potassium chloride, but can also be used. When using copper,

Sodium and lithium chloride give good results. 20 didymium and potassium chloride are the final ones

In case of a low melting point the catalytic proportions of these three components, calculated as metals

active material is desired, are appropriate and based on the total weight of the catalyst,

Moderately used mixtures of alkali metal chlorides. exclusively chlorine, expediently 2.5 or 2.5 or

The catalysts used according to the invention 1.55 percent by weight. After the impregnation is finished

preferably contain the rare earth metals with 25, the catalysts are expediently by heating

the atomic numbers between 59 and 64, either to about 150 ° C and finally by heating for

alone or in the form of a mixture. It is z. B. a few hours in an oven to about 450 ⁰ C on

the dried one commercially available under the name Didym,

technical mixture of lanthanides used. If a catalytically active ingredient is in

In general, catalyst compositions will only be insufficiently soluble in water.

tongues, which are in finely divided form, moderately dissolved in dilute hydrochloric acid, or the impregnation

d. H. which consists of particles with a diameter of gnation with an aqueous solution of this constituent

10 to 500 microns, preferably 35 to 300 microns, partly repeated a few times. In general

and especially 50 to 200 microns. Such solutions can also be aqueous instead of the chloride solutions

Catalysts containing the aforesaid prefer- 35 Solutions of nitrates of various metals

Drawn carrier material included, are particularly suitable to be used, which is advantageous in that the

for use in a fluidized catalyst nitrates are generally more soluble than that

bed and are characterized by their excellent chlorides. After drying, the impregnated

Activity and long life. Gnated carrier then suitably calcined to the

A suitable process to convert the 40 nitrates into oxides, from which by a

Catalysts consists in the impregnation of the carrier final treatment of the catalyst with an HCl air

particles are formed with solutions of the catalytically active mixture, the chlorides. Such a

Components. After impregnation, the final treatment is always beneficial. the

Catalysts dried. It is important that the catalysts are preferably fluidized

Drying takes place slowly. 45 state 1 to 4 hours at a temperature of

It is noted that the valence of the metals, 350 to 42O ⁰ C with a mixture of chlorine water

including copper, iron and nickel, in the substance and air in a volume ratio of 1: 1.2

Chlorides originally included in the treated according to the invention.

Catalysts used have been incorporated, although the inventive method by no Play a role as it can be performed during the process 50 without any other chlorine-containing changes. The metals can also be in the form of compounds other than those in the to be converted Compounds as chlorides are added to the material-containing compounds in the reaction then Introduced during the process or through a pre-zone, are preferably given little treatment with a chlorinating agent in chlorides at least 2, in particular at least 3.5 chlorine atoms in being transformed. Since the chlorine content of the catalysis 55 form of free chlorine and / or a chlorine-containing, is changeable, it becomes in contrast to gaseous, inorganic compound per molecule the content of metals and support materials before the organic feed. If only partially in the characterization of the catalyst, additional chlorine in the form of inorganic compounds composition not taken into account. is added, one generally leads chlorine

Before use in the inventive 60 hydrogen together with chlorine in a mole process the catalysts are usually in a ratio of 1: 0 to 10: 1. Useful except for chlorine treated with a gas mixture that uses hydrogen and elemental chlorine, Chlorine and / or hydrogen chloride as well as oxygen is the ratio of hydrogen chloride and possibly also one or more inert gases, such as for chlorine in general preferably 1: 1 to Nitrogen. 65 10: 1.

A particularly practical and useful method is the organic feed and oxygen

The method for preparing the catalysts is as follows - preferably in a molar ratio of 2: 1 to 3: 1

so carried out: introduced. As a rule, it is particularly useful

the organic feed, hydrogen chloride and order to have good heat dissipation during the reaction

To ensure oxygen in a molar ratio of about 1: 5: 2.5, the inventive method can

to introduce. driving in the presence of water,

The oxygen. is then expediently in the liquid state in the according to the invention

Process is generally only introduced into the reaction zone in the form of air, e.g. B. in the form of a

introduced the reaction zone. aqueous hydrochloric acid. The molar ratio of the added

The organic feed to be converted from water to the introduced feed is purposeful usually at least 60 mol percent 1,2,3-Tri- moderately between 1 and 10. However, since the addition of chlbrpropane and possibly consists of pure water can lead to losses of hydrogen chloride, !, ■ 2,3-trichloropropane. io is preferably used by other means for an

The method according to the invention is preferably provided with sufficient cooling.

carried out at 390 to 450 ° C. The residence time for the process according to the invention can be fixed

is 5 to 35 seconds. The catalyst beds according to the invention can be used. Preferably

Process can take place at atmospheric pressure or about the process according to the invention, however, under

Atmospheric pressure, desired 15 use of a fluidized bed carried out,

If, however, higher or lower levels of the reaction mixture obtained from the process can also be used

Pressures are applied. is worked up in the usual way.

1, example

A series of experiments is carried out with catalysts whose support materials are classified as A, B, C and D, respectively. The following carrier materials are used:

A. OC-Al ₂ O ₃

The specific surface area is less than 5 m ² / g and the average pore diameter is about 1600 Å. The carrier particles have an average diameter of 60 to 180 μ.

B. SiO ₈

A commercially available diatomaceous earth sold under the name Sil-O-Cel 22C; the specific surface is less than 5 m ² / g and the average pore diameter about 1300 Å. The carrier particles have an average diameter of 100 to 300 μ.

C. OC-Al ₂ O ₃

The specific surface area is about 5 m ² / g and the average pore diameter is 1300 Å. The carrier particles have an average diameter of 100 to 300 μ.

D. SiO ₁

Commercially available under the name "Silicagel"; the specific surface area is 270 m ² / g and the average pore diameter is 70 to 250 μ. This carrier material does not correspond to the conditions required according to the invention and is therefore only used for comparison.

In most cases, didymium-containing catalyst-converting organic material is used along with used. The didymium, referred to as Di, introduced further air and hydrogen chloride, is a hand ice product. In the case of the without addition of hydrogen chloride

The reactions are carried out in a tubular reactor. Experiment XIV is the one to be converted made of pyrex glass with an inner diameter of 55 organic material during preheating approx 10.5 mm and a length of 140 cm through- per-period, with the air being tracked during the. When trying the catalyst, the following reaction period to the feed gas Contains carrier material B, the gaseous stream is added.

Reaction mixture passed through the catalyst bed, After all experiments, the reaction

in the various experiments with the other 60 mixtures worked up by condensing and the Catalysts, the catalyst will be separated in fluidized organic and aqueous layers; Condition used. All experiments, with the exception of the organic layer, are washed with water, one that does not use hydrogen chloride, separated from the wash water and finally distilled, The various experimental conditions and the

brought to reaction temperature, with 65 results obtained in the following table just a mixture of air and hydrogen chloride. The organic feed consists to be led. After the desired reaction in these experiments from practically pure 1,2,3-trition conditions have set, the chlörpropane (abbreviated as TCP).

I. II III IV V VI VII 7.67 7.67 7.67 7.67 7.67 7.67 7.67 A. A. A. A. A. A. A. 2.5 2.5 2.5 2.5 2.5 2.5 2.5 1.55 1.55 1.55 1.55 1.55 1.55 1.55 Th4.15 Tue 5.0 Di2.5 Di 1.0 DiI ₅ O Di 1.0 DiI ₅ O - - - · - Fe0.56 Ni0.60 PdI, 06 60 60 60 60 60 60 60 420 420 420 420 420 420 420 1.1 1.1 1.1 1.1 1.1 1.1 1.1 13th 12.5 12.5 12.5 13.5 13.5 13.5 5: 1 5: 1 5: 1 5: 1 5: 1 5: 1 5: 1 2.5: 1 2.5: 1 2.5: 1 2.5: 1 2.5: 1 2.5: 1 2.5: 1 17th 15th 10 12th 12th 15th 0 81 84 93 80 96 83 107 15th 9 8th " 11 6th 11 5 113 108 111 103 114 109 112 7.3 5.5 5.6 3.6 17.3 4.3 12.2 5.1 2.5 1.9 2.3 2.5 1.9 4.6 12.5 6.8 3.2 7.6 1.0 6.8 0.1 51.4 72.1 78.6 69 67.5 73.0 57.9 76 87 89 83 88 86 75 5 4th 2 4th 1 4th 2

attempt
VIII

IX

X XI XII XIII XIV 7.67 7.67 22.5 7.67 5.75 A. A. B. C. A. 1.0 1.0 2.5 2.5 2.5 0.62 0.62 1.55 1.55 1.55 DiI ₅ O Di 1.0 Tue 2.5 Di2.5 Tue 2.5 60 60 20th 60 80 420 440 420 420 430 1.1 1.1 1.2 1.2 1.0 16 16 8th 8.5 20th 5: 1 5: 1 5: 1 5: 1 0: 1 2.5: 1 2.5: 1 2.5: 1 2.5: 1 2.75: 1 23 22nd 20th 1 0 78 80 80 41 140 8th 11 15th 31 13th 109 113 115 73 153 5.0 5.9 11.0 3.2 28.3 0.8 0.3 2.1 3 3.5 1.4 0.9 2.1 22nd 0 77.4 78.3 69.0 53.5 14.6 85 85 84 82. 46.5 1 1 0 11 20th

Amount of 1,2,3-trichloropropane (TCP) imported (1 kg / hour)

Support material in the catalyst

Cu in the catalyst (%, based on the total weight minus chlorine)

K in the catalyst (%> based on the total weight minus chlorine)

Rare earth metal in the catalyst (type and%, based on the total weight minus chlorine)

Promoter (type and%> based on the total weight minus chlorine)

Amount of catalyst (g)

Temperature ( ⁰ C)

Pressure (atm. Abs.)

Contact time (seconds)

HC1 / TCP molar ratio

_{O 2} / TCP molar ratio

Analysis of the product

Mole percent calculated on imported TCP

CO

CO ₂

CCl ₄

C ₁ overall

C2HCI3

C ₂ HCl ₅

C ₂ Cl ₆

C ₂ Cl ₄

C _{2 in} total

C _{3 in} total

7.67
A.

7.67
A.

1.0 1.0

0.62 0.62

1.6
12.3
15.9
41.4
71
14th

Di 1.0

60
400

1.1
16
5: 1
2.5: 1

24

75
8th

107
2.9
5.0
7.0

73.1

Di 1.25

20 370

1.1 15 5: 1 2.5: 1

132

Claims (7)

ii Claims: 1. A process for the preparation of tetrachlorethylene, characterized in that a chlorinated hydrocarbon mixture consisting mainly of 1,2,3-trichloropropane is mixed with oxygen or an oxygen-containing gas at 370 to 500 ° C and a residence time of 1 to 100 seconds in the presence of a catalyst, that of the chlorides of copper, one or more alkali metals, one or more rare earth metals and / or zirconium, thorium and uranium on a porous support with an average pore volume of at least 300 Å and a specific surface area of less than 100 m ² / g, where the weight ratio of copper to rare "" earth metal in the catalyst is between 0.2 and 3 and the alkali metal to copper is between 0.3 and 1.5. ... 2. The method according to claim 1, characterized in "that the reaction is carried out in the presence of hydrogen chloride. 3. The method according to claim 1 or 2, characterized in that the reaction is carried out with a chlorinated hydrocarbon mixture containing at least 60 mol percent 1,2,3-trichloropropane, performs. 4. The method according to claim 1 to 3, characterized in that the reaction is carried out in Presence of a catalyst, the copper and the rare earth metals in a weight ratio between 0.8 and 1.2, based on the weight of the metals concerned and the carrier material contains, performs. 5. The method according to claim 1 to 4, characterized in that the reaction is carried out in the presence of a catalyst which additionally contains iron and / or contains nickel chloride. 6. The method according to claim 1 to 5, characterized in that the reaction is carried out in the presence a catalyst; whose carrier material has a mean pore diameter * of 1000 Å has, performs. 7. The method according to claim 1 to 6, characterized in that the reaction is carried out in the presence of a catalyst whose support material has a specific surface area of at most 30 nt ^a / g. 809 507/666 1. bd ® Bundesdruckerei Berlin