DE1768453A1 - Process for the production of 1-2-dichloroethane - Google Patents

Description

Priority: 17th quay 1967, the Netherlands Registration number: 67 - 06807

From the German Auslegeschrift 1 229 999 as well as the corresponding French patent specification 1 421 903 and Dutch Auslegeschrift 65.01.192 a process for the production of 1,2-I) chloroethane is known, with ethylene in such a V / ice in a first stage is oxychlorinated that it is not completely converted, while in a second mah anechliessend Stufo chlorine, which is added as a so Chee, the remaining unreacted ethylene can act to also convert it to the desired 1,2-Dichioräthan.

The object of the invention is to improve this known method and to be aware of the oxychlorination stage.

17/1825

INSPECTED

176S453

The invention thus provides a process aur Preparation of 1 _F 2-dichloroethane _y wherein oxychlorinated in a first Stufi ethylene in such a manner that it is not completely converted, while subsequently, in a second step, chlorine that is added as such to the remaining unreacted ethylene deposits, as it is characterized in that the oxychlorination is carried out in the presence of an oxychlorination catalyst which is already known per se and has a content of

a) one or more copper halos,

b) one or more chlorides of the rare earths or of scandium, yttrium, zirconium, thor and uranium,

o) one or more alkali chlorides "where the atom the ratio of rare earth metals to copper is at least 0.1.

The oxychlorination catalyst is in German Ausle document 1 195 726 described. These catalysts are also known as deaoon catalysts.

Component (a) of the catalyst preferably contains lanthanum and / or one or more elements with atomic numbers 59 to 64. The mixture sold under the name "Didym" is particularly recommended. Such mixtures not only contain praseodymium and meodymium, according to the definition of "Didym ¹¹ in scientific textbooks. A typical analysis of technical" Didymoxide 1st as. B .: La ₂ O ₃ : 45 $; Nd ₂ O ₃ 1 38 5 *; Pr ^ O _n 1 11 Pt. ^ Cj t $ 4? Miscellaneous j 2 ji.

> y., ■ -> · ■■■ '■ 109812/1825 ^0RIGINA1 -

The alkali metal to copper atomic ratio is preferably »Between 0.6 and 3, Jim most preferred is an atomic ratio Alkali metal to copper · between 0.8 and 1.2. potassium

is most preferred as the alkali metal. While c In use, the mixture of chlorides is preferably gax ζ or partially in molten form. Preferably the catalytically active mixture on a table

germmaterial · Silica gel is preferred as the carrier, insbea < others with a specific surface area of at least 200 st / g and an average forum size of at least 60 mix

It is known that Deacon catalyst pots are generally suitable also as a chlorine carrier in oxychlorination reactions

A mixture of chlorine can cause oxychlorination reactions

hydrogen gas, a gas containing free oxygen, such as air, and the organic compound to be chlorinated can be brought into contact with catalyst Xn. During these reactions, HCl is consumed and the organic compound is:

chlorinated. If this method is modified, suitable For substitutive chlorination, elemental chlorine (Cig) is used as the feed gas in place of hydrogen chloride gas used. This latter method works in a similar way In the same way as the previous procedure with the exception * that an initial chlorination of the organic compound

takes place. Kreies chlorine, a containing free oxygen Gas and the organic compound to be chlorinated are brought into contact with the catalyst. Chlorine sets

t 0 9 8 1 7.1 1 8 2 E ° ^mm H- INSPECTED

■ - 4 -

reacts with the organic compound to form hydrogen chloride and a chlorination product. The hydrogen chloride produced in this way is consumed and its chlorine content is used with the result that additional chlorination of the organic feed takes place. According to another known method, the oxychlorination is carried out in two stages. In the first stage, the Deacon catalyst is treated with HCl and Og, optionally also with Cl ₂ or with mixtures of Cl ₂ , HCl and O ₂ , the catalyst taking up chlorine while in FIG.

second stage the organic compound through the deacon catalyst, whose chlorine content is reduced in the process, is chlorinated (see e.g. the German Auslegeschriften 1 079 020, 1 137 424 and 1 249 246).

The main claim of the German interpretative document 1 195 726

f ... is looking for catalyst systems for the production of chlorine turned off a gas mixture of hydrogen chloride and oxygen. One can now admittedly what has been expressed above Believed that this description, which with the

■ ■> ι

The designation "Deacon catalysts" is equivalent for the catalysts the composition specified in the claim is granted patent protection, which does not apply to the case is limited that such a catalyst for the production of chlorine from a gas mixture of chlorine water · = substance and oxygen is to be used, but also includes such cases, the use of such Catalyst in an oxychlorination reaction is intended will. But because the exact limitation of the protection

109817/1825 ~~

ORIGINAL INSPECTED

uia is still debatable at the beginning is also a precautionary measure another special focus on oxychlorination catalysts corresponding composition filed patent application S 74 143 IVa / ^ g «, (In many countries.

already published, e.g. in France as a patent specification No. 1 290 062.

The patent application S 90 455 IVa / 12g (published in France as supplementary patent specification no.85 871; supplement to the main patent 1 290 062 already mentioned) concerns a special class of oxychlorination catalysts according to patent applications S 72 111 IVa / 12i (Auslegeschrift 1 195 726) and S 74 143 IVa / 12g “namely those which are characterized by the fact that the carrier for the chlorine mixture has a specific surface area of 0.1 to 40 m / g and an average pore diameter of at least 300 % . These special oxychlorination catalysts are particularly suitable for the oxychlorination of conjugated diolefins if one wishes to obtain products from them exclusively or at least mainly dichloromonoolefins as reaction products.

Catalysts that match the oxychlorination catalysts according to the earlier patent application S 90 455 IVa / 12g (or French supplementary patent specification 85 871) with regard to the metals contained therein are very similar, but which do not contain any halogen, only oxygen, have themselves in accordance with the Dutch patent specification 110 374 shown particularly suitable in procedures in which wel (

T Ü U 81 7 I 1 H 2 ι. ^{0RIQ |} NAJ-INSPECTED

aromatic carboxylic acids by, exposure to molecular Oxygen in the gas phase can be converted into phenolic compounds and / or into aryl esters of aromatic carboxylic acids.

t ■

They German Auslegeschrift 1 36O 462 and the corresponding French Patent 1 466 846 describe oxychlorolysis processes. It is a novel reaction involving cracking, oxidation and oxychlorination take place simultaneously in the presence of an oxychlorination catalyst. Such a procedure can be used ZeBo a compound containing three carbon atoms in the molecule or a mixture of such compounds with optionally also one or more compounds, which contain two carbon atoms in the molecule, convert into tetrahydrofuran, also called perchlorethylene, wobiei the yield can optionally be increased by recycling the by-products

Of course, in the Oxychlorolyse in principle, all Ox y can chlorination catalysts are used. According to de French patent 1,466,846 is used, however in addition an oxychlorination catalyst from the Chlorides of copper, one or more alkali metals, one or more rare earth metals and / or of Zirconia, of thorium and uranium on a porous support with eLnem mean pore volume of at least 300 pounds and an epezi fisohen surface of less than 100 m / g consists, wöbe

the weight ratio of copper to rare earth metal in the

^{1 ?} ' ^{1 H:} - - original inspected

Catalyst between 0.2 and 3 and the alkali metal for Copper is between 0.3 and 1.5. These oxychlorination catalysts are therefore those according to the earlier patent application S 90 455 IVa / 12ß (or the French supplementary patent specification 85 871) very similar.

In the process of the present invention, oxychlorination catalysts according to the earlier patent application S 90 455 IVa / 12g (or the French supplementary patent font 85 871) are not preferred, but rather those according to the earlier patent application S 74 143 IVa / lÜg (or the French Patent specification 1 290 062) are the most favorable, namely oxychlorination catalysts, which are characterized by a combination of a) one or more copper chlorides, b) one or more chlorides of lanthanum and / or lanthanides and c) one or more alkali chlorides, applied to an inert support material »Ih, the ratio of copper: lanthanum and / or lanthiinides between 3: 1 and 1: 3 and the ratio of alkali metal: copper between 0.3 to 3, preferably 0.8 to 1, while the mixture of metal chlorides is on a "rager in the form of silica gel is applied, which has a specific: .- fish surface of at least 200 m / g and a through-ßchnit daily pore size of at least 60 % .

Suitable processes for the preparation of the oxychlorination catalysts to be used according to the invention are, for example, in d Belgian patent specification 615 035 and in patent application S 113 819 IVa / 12g filed on January 22, 1968.

10 9 8 1 // ftalu & hitic IjNSPECTSJ

17664B3

A preferred Auaführungsform of erfindungsgemäesen fahreno beeteht in _P that the oxychlorination of ethylene in a verv / irbelten bed of the catalyst is carried out, wherein the catalyst chlorides from a containing or more rare earth metals, copper, and one or more alkali metals, and wherein the atomic ratio of rare earth metals (or rare earth metals) to copper is in the range of 0/3: 1 to 3.0: 1 and the atomic ratio of potassium metal (s) to copper is also in the range of 0.3: L to 3.0: 1 lies by keeping at a temperature in the range

Λ O

from 200 to 300 C through the catalyst bed a gas mixture conducts, fins rubbed hydrogen chloride ethylene in a 50 b:

150 5 & ~ igon excess and oxygen in a ratio which between a 5 yrs-igen deficit and a 20! # ~ igen excess varies, contains, and dao ethylene in one

Auninaso from 30 to 65 ^r ß> urnsetzt _r 30 daas 35 Ms 70 ■ # des _; Ethylene are to be implemented in the second stage.

The erfindungsgemäsoe method is particularly advantageous in that when the Oxychlorierungastufe easily Aehr high selectivities to the formation of I _1, 2-dichloroethane he aim blank, in particular selectivities \ oii over 9b ·, £. "

Bas er.findun ^ agemrini-i? Verfaliren lä.'iol ni oh good (einpaafen irojstufiges üiJHrimtvoifnhren that gebildM π 1,2-dichloroethane is pyrolysed in oiner third stage to vinyl chloride at the ¹ and dor this Iroi v / t; rdei) in a de Chlorwani; r ntoff in the first Hufe to the Oxyohloriereu of A'thylou before.

1 V

BATH ORIGINAL

«7

It has been found that, in the present invention oxychlorination process, d _o h. i.e. using a special oxychlorination catalyst, as described above, ethylene excess with respect to hydrogen chloride in the

rich from 70 to 130 mol-56 are very cheap; is preferred but the range from 85 to 115 M0I - 56 and most will the range from 95 to 105 moles is preferred. The results in oxychlorination the better the ethy ~ oil excess approaches the value of 100 mol / l.

Oxygen quantities of a 0.5 J ^ igen molar deficit ^ up to a $ 10 surplus in relation to chlorinated water ~ fabric are very cheap; An oxygen excess is preferred in the range from 0.1 to 5 $ and particularly preferred is the range from 0.2 to 2.5

Temperatures in the range from 230 to 270 0 are very favorable, but temperatures in the range from are most preferred 240 to 255 ° C.

The conversion of the ethylene in the oxychlorination stage is preferably within the above range of 30 to 65 Φ with the size of the ethylene excess used

It varies according to the general rule that the change which has the most favorable coefficients is no smaller the greater the excess. Thus, in the case of ethylene excesses of £ 100 or £ 150, the Äfchylenumwarjdlun & tiri are preferred below 52.5 or below 40 '/> salary ·, · ί ^ c ί. cha η cases, where the Athyienuawaridlurig üwl.oohen 4 ^Vir '-' ■: '> ■■■ ': '5 ¹ ^ remains in the era tan; Jtufe sfiv / a fii a ΙΙ'& Ί f \ ^; : * yes granted-

'J J "> I ' i i (

1766453

beneath ethylene unchanged and therefore converted in the second stage. »The chlorine contained in the product 1,2-dichloroethane then comes approximately half from hydrogen chloride and approximately half from the Cl ₂ introduced in the second stage. This is very beneficial for a three-stage process for the production of vinyl chloride.

With oxychlorination, the conversion of the ethylene becomes proportional kept low, because at higher conversion, the selectivity of the reaction and also the fluidity are reduced the catalysts adversely affected. For the same reason, the retention of the. ! Temperature over-

half of the limits given above are recommended. The amount of oxygen influences the selectivity and the conversion of the hydrogen chloride, so that retention of the relevant limits given above is advantageous.

The contact time of the charge with the catalyst is usually best between 20 and 100 seconds, preferably between 40 and 80 seconds. The pressure can be atmospheric, but a slight overpressure, z.Bo of 5-10 atm _p is harmless

The addition of chlorine to ethylene in the second stage is preferably carried out in the liquid phase. One came gügebonenfi.'Ll3 previously accumulated 1,2-dichlo cut off ethai, but not necessary int this. Instead of Chlorination ωit CL ^ in the second stage one could do that svich * - umiywHruUilte ethylene to the Oxyohlorierungsreaktor recycle, ö ;; he the addition of chlorine in a second

^v ' ^v ■■■■■''■ · "'""^, 1 CJ ¹ JM lv / 1 μ ') f <

ORIGINAL INSPECTED

Stage has proven to be cheaper. The execution of this chlorination in the liquid phase is in terms did selective and heat dissipation asphase favorable than the embodiments -in * Daboi it is also advantageous that Äthylenme dasa in unit volume "in the Plüssigkeitsphasenchlorieriin _is higher than in the Gasphasenchlcrierung.

The production of 1 _f 2-dichloroethane by chlorination of ethylene in the liquid phase is known per se (cf., for example, British patent 553 959 and USA -.- patents: 2 099 231ι 2 601 322 and 2 929 852). In general, an iron-containing catalyst is preferably used. this

this is also the case in the process according to the invention. rid is very suitable for this purpose,

Example 1 ].

At the preparation of the catalyst s' i

A silica carrier material with a specific surface area of 430 m / g and a specific pore volume of O 72 ml / g was impregnated in a fluidized state at a temperature of 25 ° C with an aqueous solution of copper chloride, lidym chloride and potassium chloride (referred to as Didym here a metal mixture like .obnn circumscribed). In the impregnation much Wüssigkfi.t was used dasn dan pore volume dos carrier 90 'ß> has been filled. Eating in the solute, the carrier, also in a swirled mouth, was dried at a temperature of 120-100 ° C, until it was still 10 Gow. Then wiu <»the carrier material" iederuni in vorwirlxO 1. "m state and! Uem"

176845?

impregnated with such an amount of water that 90% of the pore volume was filled with liquid. Finally, the icatelysator mass thus obtained was completely dried in a swirling stand. The finished catalyst had the following composition: 5% by weight of copper, 5% by weight of didymium, 3% by weight of potassium and 87% by weight of SiO ₂ . The weight quantities of the anions associated with the metal parts (carbon dioxide and oxygen) are not included in this.

In a series of experiments ethylene was m in property Heides catalyst obtained in a fluidized bed: an inner diameter of 20 cm and a height of 450 pm at a temperature of 230 - 27O ^ü C _f a pressure of 3i5 ata, a linear gas velocity of 7 cra / Sec .:

and a contact time of 60 seconds oxychlorinated. The duration of the experiment was 15 hours in each case. The ÄthylenUberschuse with respect to hydrogen chloride was kept between 99 and 101 i>. Oxygen was added in the form of air. The excess of oxygen with respect to hydrogen chloride was 1-10 # varied "The obtained reaction dee ethylene was always zwinchen 4 ') _r 5 and 50.5 #», the reaction of the hydrogen chloride betruß in 5 Si at 27O ⁰ C, .99, 7 1> at 250 ⁰ C and 99.9 f> at 23O ⁰ C. The selectivities achieved are given in the table below

I \) W'- 1

BAD ORJGINAL

Temperature "C

Excess oxygen, Vol.-5 »

Ethylene selectivity, jß

Hydrogen chloride selectivity t $

230

2-5

[99.2-99.4

99.3

10

97.4

98 _r 9

250

99.0-98.4

99.4

10

97.1

99.1

270

2-5

97.2-97.6

99.2

30th

$ 8.9

In all of the experiments, the catalysts were very fluidizable. The top of the swirled bed varies only over a distance of about 10 cm.

C. Chlorination

The dichloroethane in the gas mixture which left the oxychlorination reactor was removed therefrom by condensation. The remaining ethylene-containing Gaegemisoh was then passed through a washing tower, in which traces of unconverted hydrogen chloride were neutralized with sodium hydroxide solution. Subsequently, the gas was led to a Chlprierungsreaktor and in countercurrent with a chlorine solution in 1,2-Dichioräthan at a temperature of 40 ⁰ C and in the presence of traces Ferriehlorid as a catalyst in Bert

H-

tion broke L-. The chlorine was used in the amount required fetoichiometrically. Dao Uichloriifchan was continually returned to the Kealctor and was re-formed to separate the same amount as in the chlorination, so that the total volume of liquid in the system remained unchanged.

1 Ü Ά U I '? I 1 H \> fj

-U-

The chlorination proceeded with a selectivity of 97.1 based on converted ethylene, and of 97.0 # based on converted chlorine. The added ethylene was fully implemented. ../

Example 2

An experiment according to Example 1 was carried out · In the 1,2-dichloroethane obtained was added to a third stage Vinyl chloride thermally decomposes during this third Stage formed hydrogen chloride for oxychlorination. fe was returned.

The conditions in the oxychlorination stage were as indicated in Example 1. With regard to the conditions which were varied, the following choice was made: Te; temperature 270 ⁰ C, molecular excess of oxygen with train on hydrochloric 10 # <. Only hydrogen chloride from the pyrolysis stage was added.

The total consumption of chlorine, added in iOr.m of CJL «* ^{η in} the ^second stage, was 1.45 kg per kg of ethylene, added in the first stage. The total amount of vinyl chlorine was 2.05 kg per kg of ethylene. These results were not significantly changed when using technically pure oxygen instead of air from the oxychlorination stage.

ORIGINAL INSPECTED 1 0 Y) 8 Y? / 1 H 2 E

d i in

Claims (6)

1. Process for the preparation of l _r 2 ~ dichloroethane _t where in a first stage, ethylene is oxychlorinated in this way • 'ti v / ird that it is not fully implemented, while then in a second stage, chlorine, which is added as such, is added to the unreacted ethylene still present, characterized in that the oxychlorination is started in the presence of one already known Oxyehlorierungskatalyaators with a content of a) one or more copper cavities _p , " b) one or more chlorides of the rare earths or of scandium, yttrium, zirconium, thor and ο) one or more alkali chlorides, where the The atomic ratio of rare earth metals to copper is at least 0.1. 2. The method according to claim 1, characterized in that an oxychlorination catalyst is used which is composed of a combination of a) one or more copper chlorides, b) one or more chlorides of lanthanum and / or of the lanthanides, and c ) one or more alkali metal chlorides _r wherein the Verhältnin of copper: LanUwm and / or Lunthruiiden between 3: 1 and 1: 3 and the ratio alkali metal: copper ebonfiOls between 3: 3 m 1: 3, the Trägermai wnlrond r.rj; .1. oine Speziljnrho "" λ ... "■ - 16 - Has a surface of at least 200 m / g and an average pore size of at least 60 X « 3. The method according to claim 1 and 2, characterized g , dasa one the Oxychlorierung'deo ethylene in a swirled. Bed of the catalyst is carried out, wherein passing a gas mixture at a temperature in the range of 200 300 ⁰ C by the Katalj ^r 8atorbett, the _f next hydrochloric ethylene in a 50 to 150 excess and oxygen in a ratio of the jS-strength between a 5 Deficiency and a 20% excess varies, contains, and the ethylene converts to an extent of up to 65 $. 4. The method according to claim 3? characterized by the fact that oxygen is used in an excess of 0.1 to 5 mol # _f ', preferably from 0.2 to 2.5 Μο1- #, 5 · The method of claim 1 to 4, characterized in that, 'preferably performs the oxychlorination at a temperature in the range 230-270 ⁰ C in the range of 240 to 255 ° C. 6. The method according to claim 1 to 5, characterized in that ethylene is used in the oxychlorination stage in an excess of 70 to 130, preferably from 85 to 115 mol? » and especially from 95 up to 105 mol-j6 used. 1 0981 7/1825 ORIGfNAL / NSPECTEO 7 «Process according to claim 1 to 6, characterized in that the ethylene is converted in the oxychlorination stage to an extent of 45 and 55 Ί» . 8 β process according to claim 1, to 7 _f characterized in that chlorine is added to the non-converted ethylene in the second stage in liquid phakic, preferably using an iron-containing catalyst, in particular ferric chloride. 1098 17/1825 ORIGiNAL iNSPECTED