DE1542132C - Process for the production of a catalyst containing copper silicate for oxychlorination, Deacon and dehydrochlorination reactions - Google Patents

Description

The invention relates to a method for producing a copper silicate-containing catalyst for Deacon, oxychlorination and elimination of hydrogen chloride reactions.

It is known to react hydrogen chloride with oxygen in the presence of a catalyst in a so-called Implement Deacon reaction, with the formation of free chlorine, which is suitable for chlorination reactions is. It is also known to chlorinate or hydrocarbons in so-called oxychlorination reactions further chlorinate partially chlorinated hydrocarbons; in these so-called oxychlorination reactions is chlorine, the z. B. obtained in the manner described above from hydrogen chloride, reacted with the hydrocarbon in the presence of an oxy-chlorination catalyst. Shall from saturated Hydrocarbon starting compounds, e.g. ethane, unsaturated hydrocarbons, z. B. trichlorethylene, this can be done by splitting off hydrogen chloride, the can also be catalyzed.

These reaction sequences are illustrated by the following equations, of which Equation I. the conversion of hydrogen chloride into free chlorine, equation II the oxychlorination of ethane with Hydrogen chloride and oxygen for the production of tetrachloroethane, equation III for oxychlorination of methane with chlorine and oxygen to produce carbon tetrachloride and equation IV the Reproduce elimination of hydrogen chloride from pentachloroethane for the production of perchlorethylene.

Equation I:

4HCl + O ₂ -> 2Cl ₂ + 2H ₂ O
Equation II:

C ₂ H ₆ + 4HCl + 2O ₂ -> C ₂ H ₂ Cl ₄ + 4 H ₂ O

Equation III:

CH ₄ + 2Cl ₂ + O ₂

CCl ₄ + 2H ₂ O

35

40

Equation IV:

C ₂ HCl ₅ -> C ₂ Cl ₄ + HCl

It is very desirable to use combinations of the above reactions in simple procedures to be carried out using simple catalysts. So z. B. the conversion of Hydrogen chloride to chlorine is useful in the same process as the oxychlorination of the hydrocarbons accomplished; the reactants are all fed to the reaction zone together, and both Reactions are catalyzed with the help of the same catalyst. In the production of unsaturated chlorinated Hydrocarbons from saturated hydrocarbons also include the elimination of hydrogen chloride in the reaction sequence, the hydrogen chloride released in this reaction in turn the catalyst is converted to release chlorine, which is used to chlorinate the hydrocarbons will.

The ability of a catalyst to catalyze all of these conversions depends on several Factors. First and foremost, the catalyst must be an effective promoter for all of these reactions. This is imperative not only in terms of yield, but also in terms of safety, because when using catalysts that have too little catalytic activity, excess Amounts of oxygen must be used, leading to the formation of both flammable and detonable Mixtures in the process leads.

It is also very important that the. Catalysts are resistant to deactivation as a result of loss on catalytically active substances that volatilize at the temperatures suitable for the reaction, can occur. Furthermore, the catalysts must not become sticky when heated. This latter condition is particularly important when the catalyst is used in a fluidized bed process which it must be in a finely divided and fluidized state. At the same time, the catalyst must be a have a selective effect and must not have any side reactions such as B. an oxidation of hydrocarbons with the formation of carbonyl groups, carbon monoxide, carbon dioxide, carbon and phosgene favor in a noteworthy way.

The most commonly used catalyst to date for Deacon and oxychlorination reactions is Copper (II) chloride, but it is known that a large number of other catalysts, such as. B. Iron (III) chloride, chromium oxide and copper (II) silicate, catalytic ones sufficient for these reactions Have activity (see, for example, Journal of Applied Chemistry, Vol. 12, No. 9, pp. 406 to 412 [1962]).

The German patent 869 052 already discloses a process for the preparation of hydrogenation catalysts known on the basis of copper, in which either freshly precipitated magnesium silicate with a Copper salt solution and then treated with a silicate salt solution, dried and reduced with hydrogen is, or where copper and magnesium are precipitated together as silicate and the resulting Precipitate is dried. The catalyst formed consists of the total mass of the precipitate and does not contain a carrier. It is reduced with hydrogen at an elevated temperature, with at least the copper component of the catalyst is converted into metallic copper.

However, none of these catalysts could meet the above conditions for all called reactions to be catalytically effective, so that the desired products are absent an excess and undesirable amount of oxygen can be obtained, and for these reactions to be selective, so that subsequently an undesired oxidation of the hydrocarbons to be converted is avoided, as well as under the reaction conditions, which also include elevated temperatures what counts are to be physically and chemically stable.

The aim of the present invention was therefore to develop catalysts for oxy-cloning reactions to produce all of the above requirements satisfy.

It has now been found that catalysts as catalytically active substances copper (II) silicate together with magnesium chloride or magnesium silicate, distributed on a porous and adsorbent Carriers, contain, effective, permanent and selective catalysts for deacon, oxychlorination and Represent hydrogen chloride elimination reactions. she may also contain didymium chloride or silicate. [The didymium is a mixture of rare earths, it consists essentially of lanthanum, neodymium and smaller amounts of praseodymium, Ccr and samarium;

3 4

the analysis of a typical didymic chloride sample that the catalyst becomes some wise at room temperature

in the examples described below, use hours, e.g. B. 24 hours at atmospheric

was det, had after the conversion of the chloride pressure or reduced pressure, dried, on it

the following composition in the oxides: 45% complete drying in one

La ₂ O ₃ ; 38 ° / ₀ Nd ₂ O ₃ ; 11% Pr ₆ On! 4% Sm ₂ O ₃ ; other 5 oven or in a fluid bed dryer, with the

Elements 2%]. Temperature gradually within a few hours of

The invention is now a process for _ 40 is increased to 120 ⁰ C.

Production of a kata containing copper silicate. Magnesium chloride and didymic chloride

lysators for Deacon, oxychlorination and dehydro are expediently removed from the carrier.

chlorination reactions, characterized in that io stores that solutions of these chlorides are produced

is that a porous, adsorptive carrier is used, these solutions separately or together with the

either one after the other, but mixed with the respective dry carrier loaded with copper silicate and that

tion, with the aqueous slurry, an obtained powder is dried. Will the application

Copper (II) silicate and magnesium compound treatment of magnesium and didymium silicates as catalytic

delt, or with the aqueous solution containing a copper (II) - 15 Iytische. If ingredients are desired, they will be soluble

and magnesium compound together contains, ver magnesium and didymium salts, such as. B. the chlorides

mixes and the product in the moist state the SiIi- by adding sodium silicate in the above

kat solution adds, the molar ratio of Mg to the production of copper silicate described manner

Ions to Cu (II) ions 0.1 to 4, preferably 0.5 to 3, converted into the silicates. If desired, can

should be. 20 the magnesium and. Didymesilicate catalysts

Those produced in the method according to the invention, used together with the copper silicate on the carrier

deten, catalytically active substances, above all that will.

Copper (II) silicate, the magnesium compounds and, the entire catalyst deposited on the carrier

If used, the didymium compounds are used in the analyzer amount between about 1 and about 15 Ge>

a total of about 1 to 15% or more, 25 percent by weight. The use of less than about ■

based on the weight of the carrier. 1% does not provide sufficient catalysis for the above

The copper (II) silicate and the magnesium compound described reactions during the use

gene are in molar ratios of 0.1 to 4 and more than about · 15% is unnecessary, since only the

preferably 0.5 to 3 moles of magnesium ions per mole of reactants presented catalyst upper

Copper (II) ions before, while in the catalysts, 30 area is important. A separation of more

the didymium chloride or silicate contain, the didymium as 15% of the catalytically active materials

compound (calculated as didymmetal ions) in one of the carriers has only the formation of thicker ones

Molar ratio of about 4 moles of didymium metal ions per layer result in no additional catalytic

MoI copper (II) ions is present. cause lytic effect, It is clear, however, that ge

If desired, the catalysts 35 prepared according to the invention also catalyze more than 15% on the support to a large extent the Deacon and Oxychlorie- can be separated.

approximately and hydrogen chloride elimination reactions, the copper (II) silicate and magnesium chloride or where they do not have any side reactions, such as. B. -silicate in amounts of 0.1 to 4 and prefer oxidations, favor in a noteworthy manner. wise 0.5 to 3 moles of magnesium ions per mole. Furthermore, they can be used at reaction temperatures of 4 ° copper (II) ions. Are, the Didymchlorid the order of about 420 comparable to 600 ⁰ C or silicate together with these other catalytically applies that used in particular for an effective acting substances, it may be up to 85% elimination of hydrogen chloride in reactions required the entire existing catalytic Substances are used with the help of which unsaturated chlorinated carbons make; it is to be produced in an amount from 0 to 4 moles of hydrogens. . 45 dymetal ions used per mole of copper ions.

Dar.in the process according to the invention, catalysts obtainable by the process according to the invention are used by precipitation (sealed porous, adsorptive carrier consists of pre-storage) of the catalytically active substances, i.e. preferably from diatomaceous earth, expediently from a Copper (II) silicate, magnesium chloride or Magne- Californian diatomaceous earth. Other suitable tresium silicate, and, if used, the didymic chloride 5 ° ger are infusor earths, silica clays, silica gels, pumice or pumice Didymesilicate, produced on a carrier. The stone and clay.

Copper (II) ion is expediently added to the carrier in the form. The particle size of the carrier used is varied a soluble copper salt supplied, for example depending on the type of implementation in which the Katalyin Form of copper (II) chloride dissolved in water is used. For fluidized bed reactions it is or copper (II) sulfate. It is then advisable to use an aqueous 55 catalyst gel Solution containing an appropriate amount of sodium silicate (a particle size between 10 and .600 microns, Amount corresponding to the amount of the copper salt chemically while for reactions in which the catalyst is equivalent) contains the loaded with copper in the form of a fixed bed and used by the reac catalyst support, which is flowed through before the addition of the sodium ion participant, such fine partial silicate can be dried if necessary, pulls are normally not required, but rather give, the concentration of the silicate solution so particles with a size of up to 1.3 cm irr. Through is that a thin slurry consisting of knives are quite suitable.

of carrier and adsorbed reactants, which are used for Deacon, oxychlorination and chlorinated water

arises. After a few minutes, the catalyst elimination reactions will come into consideration

product filtered, if desired with water 65 Reaction participants are hydrogen chloride, chlorine,

wash and dry thoroughly. Preferably oxygen and a hydrocarbon gas or a partial

the drying is done in such a way that only a wise chlorinated hydrocarbon gas. The relative

slow water evaporation takes place; example ratios of these reactants to one another

the various conversions depend on the reactions taking place in each case; they will voa the desired degree of chlorination of the hydrocarbon is determined. In the oxychlorination of Methane, ethane, ethylene, propylene and propane including the derivatives of these compounds vary the amounts of chlorine between 0.6 to 10.0 gram atom of chlorine (supplied as hydrogen chloride and / or Chlorine) and 0.2 to 6.0 moles of oxygen per mole of the in hydrocarbon introduced into the reactor.

The oxygen is either in the form of gaseous oxygen, with one or more inert gases, e.g. nitrogen, dilute gaseous oxygen, in the form of air or in the form of oxygen-enriched Air supplied.

Regarding the hydrocarbons and partially chlorinated hydrocarbon gases which are oxychlorinated, belong e.g. B. methane, ethane, ethylene, propylene, propane, dichloroethane, tetrachloroethane, vinyl chloride and Dichloroethylene. The term "gases" includes those that are gaseous under ambient conditions Hydrocarbons also include those hydrocarbons and chlorinated hydrocarbons that exist under ambient conditions are not gaseous but which evaporate under the oxychlorination reaction conditions will.

The products typically obtained in these reactions include e.g. B. chlorinated and partially chlorinated hydrocarbons, e.g. B. carbon tetrachloride, perchlorethylene, trichlorethylene, dichloroethane, Vinyl chloride, dichloroethylenes and methyl chloride, which, together with by-products, like z. B. water, carbon dioxide, carbon monoxide, accumulate. The products lie on leaving the reactor in a vaporous state. The desired products are obtained from the by-products through condensation separated and cleaned by means of conventional facilities. Normally the chlorinated hydrocarbon products fall as product mixtures, for example by fractional distillation, selective Adsorption and desorption, selective solution, can be separated. , '·

The reactions in which the catalysts prepared according to the invention can be used, are preferably carried out in a fluidized bed. The compound providing chlorine (hydrogen chloride and / or chlorine), air and the hydrocarbon gas to be converted are preferably added to the The bottom of the reactor is fed, which contains the catalyst in finely divided form. The fluidization of the catalyst is expediently introduced by nitrogen, after which the various reaction gases step by step are introduced until they have reached the appropriate proportions and the reaction begins. to This Zeilpunkt is with each discharge of reaction products started at the outlet end of the reactor.

The reaction of hydrogen chloride and / or chlorine and oxygen with a hydrocarbon or a partially chlorinated hydrocarbon gas to produce chlorinated hydrocarbons is best carried out at about 325 to 600 ° C. The elimination of hydrogen chloride normally takes place at about 420 to 600 ^° C.

The reactions can be carried out at atmospheric pressure or at elevated pressures. The chlorinated ones Hydrocarbon products, however, are often best obtained at elevated pressure, so that accordingly the implementation of the implementation in the case of the separation of the desired Appropriate pressure is appropriate for the product.

The following examples are intended to illustrate the process of the invention for preparing catalysts as well explain their use in typical oxychlorination reactions.

B is ρ ie 1 1
Manufacture of a catalyst

A solution of 10.8 g of copper (II) chloride in 120 ml of water was mixed with 65 g of Celite V particles (diatomaceous earth). The paste thus formed was dried at room temperature for 72 hours and then mixed with 120 ml of an aqueous solution containing 8.1 g of sodium silicate with a ratio of alkali to silicon dioxide of 1: 2.5. This mixture was dried at room temperature overnight and then at 100 to 30 ° C. for two hours. Then it was mixed with 116 ml of an aqueous solution containing 3.1 g of magnesium chloride. The final mixture was for 70 hours at room temperature and then dried for 40 minutes at 60 to 100 ⁰ C, followed by a 40 minute continuous heating joined at 100 to 1000 ⁰ C. The catalyst was slowly cooled to room temperature and placed in a desiccator before use.

B e i s ρ i e 1 2

. -. "'.y ---'--' Oxychlorination of ethane, '

Jv ^ A reactor consisting of a glass tube (Diameter: 4.0 cm, length 45.7 cm), which contained a perforated base for the catalyst, was installed in the vertical direction and charged with 74 g of the catalyst described in Example 1. The gases to be converted were in the lower part of the reactor at the following rates (mmol /

Minute): ethane 8.0, hydrogen chloride 25.5, air 42.0, oxygen 11.0. The total flow rate of the reactants was sufficient to keep the catalyst bed in a fluidized state. The reaction temperature in the tube was 409 ⁰ C, it was maintained at dieser.Temperatur by means of a tubular furnace 61.0 cm, which was controlled by means of a control transformer. The reaction products exiting the top of the reactor were collected, weighed and analyzed.

84 ° / ₀ of the total hydrogen chloride and 61 ° / "of the ethane introduced into the reactor was converted to chlorinated products. The ethane oxidation was 9%.

Example

Manufacture of a catalyst

1196 g of Celite particles were dissolved with 133 g of copper (II) chloride; in 2240 ml of distilled water, mixed. The mixture was allowed to stand for 48 hours at room temperature and then for 48 hours then dried at 74 ⁰ C and then for 3 hours at 115 ° C. The dry particles were then mixed with 2450 ml of an aqueous solution containing 99 g of sodium silicate for 2 hours. The solid particles were separated and dried overnight at room temperature, then for 48 hours at 80 to 100 ° C and finally for 3 hours at 110 ° C. After that, the dry particles were with

7 8

2250 ml of a 133 g didym chloride and 20.5 g Magne- Example 8
sium chloride-containing aqueous solution mixed. . ..
After a few hours the solid particles became oxychlorinated from athan
separately and for 70 hours at 85 ^° C. and then. In this experiment, a send made of glass was ^{dried at 105 °} C. for 4 hours. The part-5 reactor system used, which consisted of two in series, were sieved to remove fine catalyst particles to connected catalytic fluidized bed reactors. The produced stood up .these way that contained the reactor catalyst described in Example 2, 1.1% copper, 0.4 ° / ₀ resembled magnesium. The upper part of the first reactor was the latter as R ₂ O ₃ verist indicated above and 3.3 ° / ₀ didymium, a glass tube to the bottom of the second reactor. ίο bound. An Example 4 manifold was attached to the lower part of this joint. The bulk of the in that

Water formed in the first reactor condensed into this

Oxychlorination of ethylene manifold. The reaction gases were in the first

The reactor used in Example 2 was introduced with the reactor and passed through it,

40 g of the catalyst described in Example 3 on the product mixture through the connecting pipe

sends. The flow rate of the reaction part- was fed to the second reactor. Additional

participants (mmol / minute) was: ethylene 8.0, chlorine amounts of reactants could directly in

12.56, air 34.6 and nitrogen 20.0. The reaction is introduced into the second reactor. The first

temperature was 462 ⁹ C. The product mixture was ent- Reactor with 18 g and the second reactor with

held (in percent by weight: 48.8 ° / ₀ trichlorethylene, so '12.5 g of the catalyst described in Example 7

23.4% perchlorethylene and 20.0 ° / ₀ Dichloräthylene. loaded. The flow rates of the gases in the

The chlorine consumption was 74 ° / ₀ and the ethylene conversion first reactor (mmol / minute) were: ethane 9.6,

need 83%. 12% of the ethylene passed through oxychloride 10.0, hydrogen chloride 9.9 and air 49.9. the

dation losti flow velocities of the gases in the second reactor

35 tor were: chlorine 1.88 and oxygen 3.76. the

Example 5 was the reaction temperature in the first reactor

','. ·, 474 ° C and in the second reactor 476 ⁰ C. It was

Oxychlorination of ethylene _{consumes 65} o _{/ o chlorine and} 75 o / _o ethane. The ethane

In this experiment, the loss due to oxidation in Example 2 was 22%. The product

Dete reactor charged with 60 g of a catalyst, the mixture consisted of 45.2% trichlorethylene, 26%

from the same batch as that used in Example 4, perchlorethylene, 26.5% dichloroethylene and 2.3%

dete. came from. The flow rates of the reac- - other chlorine derivatives of hydrocarbons. on

tion participants in mmol / minute were: Ethylene both occurred in this way in this overall reaction

7.7, hydrogen chloride 6.7, hydrogen chloride 6.7, chlorine deacon, as well as oxychlorination and chlorinated water

8.65, air 35.5 and nitrogen 21.0. The reaction star- 35 splitting-off reactions, whereby the ethane

temperature was 457 ⁰ C. The product mixture consisted of unsaturated chlorinated compounds Trichloräthy-

obtained from 55.5% trichlorethylene, 13.3% perchlorethylene, len, perchlorethylene and dichloroethylene

25.4% dichloroethylenes, the rest were made up.

Vinyl chloride and chlorine derivatives of ethane together - B e i s ρ i e 1 9 (comparative example)

men. 79% chlorine and 91% ethylene were used. - ^{v K 5} * '

needs. In this example, an inventively produced

Example 6 provided catalyst (catalyst B) with a loaded

~ ,,. ., '' knew catalyst (catalyst A) with regard to the

Oxychlorination of ethylene catalytic activity when used for oxy,

In another experiment in which the same 45 compared chlorination of methane.
Catalyst in the same amount as in Example 5

was used, the rate of introduction was _a ) Preparation of the catalysts
diquities of the gases (mmol / minute): ethylene 15.0,

Hydrogen chloride 26.8, air 31.0, oxygen 4.0. The catalyst support: 100 g of Celite were mixed with 120 ml

The reaction temperature was 350 ^° C. 96% of an aqueous solution containing 8 g of copper (II) chloride was obtained

Chlorine and 76% ethylene consumed. Only 2% of the original solution mixed. The one obtained after drying

originally imported ethylene were turned into carbon paste was mixed with 5.04 g of sodium silicate in 150 ml of solution.

oxidized monoxide and carbon dioxide. The production mixed. This mixture was left for 48 hours

mixture contained 94% 1,2-dichloroethane. stand for a long time, and then a small amount was

55 standing liquid is decanted off. The lagging

B e ί s ρ i e 1 7 bende solid was for 36 hours at room

_TT ■ ". '' »,, ^ Temperature and then for 48 hours at 100 bis

Production of a catalyst dried at 400 ° C.

56 g of Celite particles were treated with Catalyst A (known) for 15 minutes: 107 g of the one obtained above

150 ml of 6.2 g of copper (II) chloride, 6.2 g of didymium 60 catalyst support were mixed with 10 g of didymium chloride in Chloride and Ig magnesium chloride containing Lo- '150 ml of water mixed. Then the catalyst was

sung mixed. The excess liquid was removed first at room temperature and then for 3 hours

decanted, and the wet particles with 170 ml of a dried at 4OQ to 600 ^0C.

25 g of sodium silicate containing solution mixed. Catalyst B (according to the invention): 109 g of the catalyst The solid particles were separated from the liquids. Lysator A was separated with 165 ml of an aqueous solution containing 2 g of magnesium and mixed four times with 150 ml of distilled water chloride. The paste, which was washed and then obtained overnight at room temperature, was first dried at room temperature. and then dried at 100 to 800 ^{° C. for 3 hours.}

b) Use of the catalysts for the oxychlorination of methane

The catalysts A and B were placed in a reaction tube and heated to 400 to 42O ⁰ C, while nitrogen was passed through the system. The fluidization properties of the catalysts were determined at varying nitrogen flow rates. The nitrogen flow rate which gave the optimal fluidization was used as the total gas flow rate in the subsequent oxychlorination. The reactor was ^{allowed to cool to about 380 °} C. and the experiment was started by introducing the diluent and reaction gases in the following order: nitrogen, methane, hydrogen chloride and oxygen. Great care has been taken to avoid explosive mixtures of oxygen and methane.

Table III

Effect of Magnesium
on the catalyst activity at 422 ° C

catalyst Consumed
° / "HCl Consumed
7o CH ₁ A.
B. 62
85 39
48

Table I.

Oxychlorination of methane using the catalyst A (CuCl _2, Didymchlorid and Na ₂ SiO ₃ on celite) at 422 ⁰ C.

ao

Introduced
crowd
g / min.

1.10
0.384
0.813
0.57

Molar ratio

related to

HCl

0.80 0.84 0.67

Consumption in ° / o

62 39 31

30th

Tables
Oxychlorination of methane using the

Catalyst B (CuCl ₂ , didym chloride,
Na ₂ SiO ₃ on Celite) at 422 ° C. Molar ratio
related to
HCl consumption
> 7o 1 85 HCl. 0.80
0.84
0.67 48
42 CH ₄
O ₂ ..
N, .. Introduced
crowd
g / min. 1.10 0.38
0.81
0.57

35

- From the above Table III show that when using the catalyst according to the invention B were consumed in the process for the oxychlorination of methane larger amounts of HCl and methane than when using the known catalyst A, that is, the catalyst B according to the invention produced a greater catalytic Activity.

Claims (2)

Patent claims: 1. Process for the production of a copper silicate containing catalyst for Deacon, oxychlorination and dehydrochlorination reactions, characterized in that one a porous, adsorptive carrier either one after the other, but after each drying, treated with the aqueous slurry of a copper (II) silicate and magnesium compound, or with the aqueous solution which has a copper (II) and magnesium compound in common contains, mixed and adds the silicate solution to the product in the moist state, the molar ratio from Mg ions to Cu (II) ions should be 0.1 to 4, preferably 0.5 to 3. 2. The method according to claim 1, characterized in that one with the solutions in addition introduces such amounts of didymium chloride or didymium silicate that to 1 mole of copper (II) ions up to 4 moles of didymions are omitted.