CS225148B2 - The production of dichloroethane - Google Patents

Abstract

1. A process for the production of 1,2-dichloroethane, in which ethylene is reacted with chlorine at 20 to 150 degrees C in at least one reaction chamber, if appropriate in the presence of a catalyst, and ethylene is reacted with hydrogen chloride and oxygen or inert gases containing oxygen at 180 to 300 degrees C in at least one further reaction chamber, in the presence of a catalyst, the reaction products which have been formed are removed from the reaction chambers and the bulk of the 1,2-dichloroethane formed is separated from them, characterized by introducing the mixture of gases remaining after separating the 1,2-dichloroethane from the reaction products of the reaction of ethylene with chlorine, optionally with addition of further gas strams, into the reaction chamber in which ethylene is reacted with hydrogen chloride and oxygen.

Description

The invention relates to a process for the preparation of 1,2-dichloroethane.

1,2-dichloroethene is produced on a large scale and is mainly used to produce vinyl chloride by thermal cleavage. In particular, a direct edition of chlorine to otylon in the presence of a taetelytic acid, such as Lewis acid, mostly iron (III) chloride, is used to obtain 1'-di-chloroethene. This reaction may be carried out in the gas phase or in a cepaine, which generally contains a permeability of 1,2-dichloroethane, with liquid phase reaction generally being preferred.

Since hydrogen chloride is formed in the thermal cleavage of 1,2-dichloroethane to vityl chloride, it is usually used in addition to the ethylene straightforward for reuse. Also, the use of oxygen or air and hydrogen chloride in the presence of a catalyst, usually containing the currency denoted by the catalyst. longer as the oxychloroacetyl.

Praying production equipment for the production of 1,2-dichloroethane, in which my hS-dichloroethane is not thermally cleaved. Accordingly, it preferably comprises at least one reactor in which direct chlorination of otylon is carried out and at least one reactor in which ethylene is carried out. From both reactors, after the 1,2-dichloroethene has been separated off, the off-gases containing environmental pollutants can only be discharged into the atmosphere after they have been removed.

The purpose of the present invention is to provide an economical and environmentally friendly environment for the use of off-gases from direct chlorine. In this regard, it is known, in particular from the older literature, to cool off gases from a direct chlorination reactor in heat exchangers downstream of this reactor to a temperature of about -20 ° C, such as condensation of 1'-dichloro-toluene. The non-condensed gases are then scrubbed in the scrubber first with water and then with a mixture to remove small amounts of undiluted chlorine. The remaining gas mixture can then be used as a fuel (see Bngneering 27, March 3, 1967, p. 28, right column, third paragraph). This procedure is age prone to failure. whereas the gases which are removed from the reactor for the direct chlorine obesahiuí so slight IMN ^é ^ ^y knows and vapor ^kt era when no cooling ⁰ -2 ° C is condensed in. solid form and clogs the heat exchangers. Therefore, more frequent shutdowns are required to remove these seals. At the same time, the water recovering is 1,2-dlchlorotane, which must be purified before it can be fed to the waste water.

This drawback can be removed if the gases from the direct chlorine reactor are only at a temperature of about +1 ° C to + 2 ° C. At this temperature, however, 1,2-dichloroethane is completely condensed to a deterioration in yield. The off-gas from the condensation contains a considerable amount of 1.2-1.0 g / h, which cannot be discharged into the environment due to environmental considerations, thus requiring additional cleaning costs, such as an activated carbon ebsorber.

Further cleaning of the exhaust gases in the scrubbers is expensive.

Recently, therefore, it has been moved to remove the waste gases from direct chlorine reactors, which have an excess of otylon, first from the large ones. parts of the 1,2-dichlorotate fed. under partial pressure condensing porn! cooling brine, whereupon the remaining gas is compressed to the initial pressure of fresh otylon e and returned to the direct chlorination reactor.

Instead of circulating otylon, another reactor can also be used in which dichloroethane is circulated through the filler bodies. A small amount of chlorine is introduced into the liquid at a suitable location. Free chlorine reacts with the remainder of the otylon to 1,2-dichlorotrotot. This additional liquid is combined with the main product. Remaining inert. the gases are discharged into the atmosphere via a purification device (absorption or scrubber) (see UHmonns Enzyklopadie der téchnischen Chemie, vol. 9 (1975), p. 427, right column, paragraphs 2 e 3). In particular, the process from the next reactor, which is used, is expensive, since returning the waste gases to the direct chlorination reactor is not a satisfactory solution. At the same time, our chlorate products are enriched! reactions that occur in the off-gas, such as acetyl chloride, vinyl chloride, hydrogen chloride, carbon monoxide, carbon monoxide, and lower saturated hydrocarbons in the system, thereby causing loss of chlorine, and by reaction with chlorine, further undesirable events are formed. products.

Njrní was started up method which enables less costly removal odpadiích ^ply Nu direct ehlorace of ethylene, wherein the legs preferably also include an even longer exhaust gases which come from the purification and storage of 1,2-dichloroethane.

The present invention is a process for producing 1,2-dichloroethane, wherein the reacting in at least one reaction space ethylene with chlorine, optionally in příoomnooti ketаlyz ^of toгu ^p ^ s temperature 20-15 ° C eva ^l ESPO ^least one meter ^d alSím. ethylene real-space 'в hydrogen chloride with oxygen in the presence of a catalyst and optionally in the presence ^of gas. which are inert under the reaction conditions, at temperatures of 18 DEG to ³⁰⁰ DEG C., the reaction products are discharged from the reaction compartments and the main moiety of the 1,2-dihydroeoethane formed is separated therefrom, characterized in that the gas mixture remains after separation. 2-dichloroethane from the reaction products of the reaction of ethylene with chlorine is introduced into a reaction space in which ethylene is reacted with hydrogen chloride and oxygen.

The reaction of ethylene with chlorine is conveniently carried out in known procedures, for example in chapters, which comprises compounding převato PoC ^ l steed teou at temperatures of ^{d and} CH 20-7 ° C in příoomnoosi kaSalySických mnosstí, for example from 0.05 to 0.01 % of mono-monohydric, based on the capsule, of one or more Lewis acids, such as ferric chloride.

This Ostu ^{p p} may emb ^ ive out of five flow ^{e p} s ^of EI ye ^{t h} e ^p Lot ^{E dp} la oapří ^to 83 s and ⁸⁵ ° C, whereby reaction heat is removed substantially boiling 1,2-dichloroethane. It is also possible to carry out the reaction of ethylene with chlorine in a gaseous phase under the action m.ir ^ i ^ i ^ £ ^ a ^ h ^ OOe of light or catalysts, o and ^p Rikli ^of my ^ previously listed. Dro this reaction are ^generally ob ^ ^d tragacanth temperature to about ¹⁵⁰ ° C tapioca.

From the gases resulting from the reaction of ethylene with chlorine, 1,2-dichloroethane is cooled by cooling to temperatures slightly above the freezing point. water, for example to +1 or +2 ° C, at normal air pressure. Pouužií lower temperatures would likely yield 1 ^ ·-dichloroethane, is somewhat of .Stě ^ ýšlo, but brings with it problems due to the fact that the lapsed gases obsethiui always marl ^ candle amount of ^water that ^p ^ s topLoto 0 ° C and at topliotoch ° ch umrzoa ^{width Lz, No.} COMES ^f may easily clog the cooling vessel and inlets. .

Drying the waste gases prior to the condensation of 1,2-dichloroethane would be difficult and costly. In the process according to the invention, the cooling of the waste gases from the direct chlorination of hen does not occur to only about. +1 and ^{M +2} DEG C. к no disadvantages due ^{to the} fact that below Ly ^{d 1, t 2} -dLchlora ane remaining in the exhaust gas, the reactor proiházeaí OX ^ <^ L ^ ^ i H, OR & obviously unchanged and thus increasing the yield of oxychlorination to 1,2-chloroethane in a reactive manner.

Reelkce ethylene with hydrogen chloride and kyslkkeí (oxychlorination) is also carried out suitably according to the known ^beta ostop ^of at toplotoch ¹⁸⁰ to ³⁰⁰ DEG C. The advantage ^d n ^of the ^'200 and ²⁵⁰ ° C in the presence of ^the atalyzátoru obese ^-enhancing sword, which moreover can contain alkali metal chlorides and longer additives. Men, mostly in the form sooi IIED., And optionally metals and chlorides alkaických longer effectively adsorbed ingredients are not inert, finely dispergonaoném matteiálu, ^d oapříkla not oxtou Linit ^h. The catalytic reader may be in the real space unstated as a so-called fixed bed or may be present in the form of a fluidized bed. In general, air can be used instead of oxygen to improve economy. This has a particular advantage when operating with the fluidized bed process in that nitrogen is available as an additional inert gas to maintain the catalyst particles in the fluidized bed.

The gases which are volatilized after reaction by atyllation with hydrogen chloride and oxygen, or possibly with air from the reaction space, are evacuated, for example by not spraying water containing alkali. ^Those m is removed from ^p lyn purposes ^of residual HCl ¹ is controlled ^to the smoothing, and ^the cooled gas, at vycHázeící atmosférckkém pressure MMI temperature OAD boiling point of 1,2-dichloro ethane (about 83 ° C). From the water used for cooling, the dissolved 1,2- &lt;&apos;&gt;&apos;&apos;&apos;&apos;&apos; The liquid 1,2-dichloroethane formed is first fed into the vessel and fed to the vessel to remove water from the 1,2-dichloroethane (a so-called dewatering column).

The major amount of oxychloride gases cooled, for example, to about 90 ° C, is now cooled, for example, by means of a condenser containing brine as the cooling medium, to a temperature which is only slightly above the freezing point of the water. Priom condenses the main ancdvv! 1,2-dichloroethane and collected in a collector. The non-condensed fractions are suitably absorbed. equipment to remove 1,22-dichloroethene from the off-gas from the exhaust gas. For this purpose, for example, absorbers from activated carbon or high-boiling, liquid, electrolytic, aromatic hydrocarbons known to the art may be used, called after the trade name Sooivseosoy (in Toobek Esso Chemie) or Sheiesss &apos;

Shhll). The off-gas that opposes the absorber (s) can now be US. lead again under pressure to the reactor for or not be subjected to additional chlorine! with the subsequent separation of the 1,2-dichloroethane formed, or can be fed under the bag. for combustion, or as such may be vented to the atmosphere.

The 1,2-fluorophenol, which is enriched in absorbent devices, is absorbed from time to time by heating the absorber, optionally under reduced pressure, condensed and also fed to the 1,2-dichloro-collecting tank,

According to the invention, the off-gas from direct chlorine styrene, which remains after cooling to a temperature close to the freezing point! of water, condensation and separation of the main mixture of 1,2-dichloroethane, return under the tank to the action area in which the stylin reacts with hydrogen chloride and oxygen, optionally with air. The soaking can be carried out together with styrene and / or with hydrogen chloride, however, the direct chlorine off-gases can be added to the reactor for the oxidation. also in another place. In any case, the pressurized gases should be supplied at a point from which the off-gas from the direct passage flows through all or part of the space containing the catalyst particles.

Before being pressurized into the reactor, the exhaust gases from the direct chlorate must be at a pressure which is somewhat higher than the pressure prevailing in the reactor at the point where For this purpose, a chamber may be used for this purpose.

The residual gases remaining from the reaction of styrene with chlorine after the separation of the main amount of 1,2-ethane are advantageously supplemented with off-gases which are obtained from the apparatus for the purification of 1,2 to 10-tents or / or and from storage containers for 1,2-ethoxyethane and which have been removed. after incomplete thermal cleavage of 1,2-trifluoromethylbenzyl to obtain a high-purity polymer after separation of the sulfonyl chloride.

Such storage containers are, for example, a container in which moist 1,2-chlorophthalene is collected from direct chlorine and oxychloride, a container in which a dehydrated 1,2-trichloride is stored and a container in which 1,2-trichloride is stored. calculated ρř.mtu chlorine stylene in the present !! % of the catalyst, for example chloride ^, water, is washed with water to remove catalyst residues.

The off-gases that are generated by other purification plants are those off-gases which, after condensation of the main night, are separated as products of the top of the column from the gas columns in question. 1,2-Dichloro-purification plants are, for example: an apparatus in which the 1,2-trichloride is freed of water and easily boiled fractions (three-column column), a device in which the 1,2-trichloride separates from the boiling height ( a high-conducting column) and an apparatus in which the 1,2-trichloro-stain contained in the high-boiling column is redistributed under a reduced vacuum (vacuum).

All of these off-gases have a nitrogen content of 1,2-g / l of gaseous gas at a partial pressure. The content of other gaseous substances, such as hydrogen chloride and styrene, is not disturbing. The admixture of all these waste gases to the residual gas from the direct gas is expediently carried out before being compressed and optionally heated to be fed to the oxychlorination reactor under pressure.

Po.kompresi residual gas from the direct chlorece, optionally mixed with the waste gases from a device that stalks described in the foregoing paragraphs, the exhaust plyny.výhodně ^p efore the advent of the reactor for the chlorination of alpha-heated to Ю0. ² to 00 ° C, especially 150 to

ISO ° C. For this purpose, ^p <oižívá oapří ^kl e ^{u '1} OB- klýc ^ t ^ Eple exchangers, ICEM ^{BC z} as it ^{eh P} n of ambience can vychézeeícího operating manual gas from reactor oKyc ^ -oraci.

In a further preferred embodiment of the process of the present invention, the gas mixture resulting from the reaction of ethylene with chlorine or with additional waste gases is analyzed for hydrogen chloride and ethylene content, for example by gas clrommaography, and the analysis result is used for automatic feed control. additional amounts of at least one of the gases represented by hydrogen chloride, air or ethylene, under the reaction zone, in which it reacts with hydrogen chloride and oxygen. In the latter oxychlorination reactor, 1 mole of ethylene is reacted with 2 mole of hydrogen chloride and 0.5 mole of oxygen (or 2.5 mole of air) to produce 1 mole of 1,2-diene chloride and 1 mole of water. If in the off-gas or in the off-gas mixture which is fed to the reactor under such conditions, the hydrogen chloride / ethylene ratio is less than 2, then a longer amount of hydrogen chloride is expediently added, if any. This molar ratio greater than 2 is then suitably fed to the oxychlorination reactor with an additional amount of ethylene so as to adhere to any gases that would be present. The hydrogen chloride / ethyl alcohol ratio was about 2 with a lower molar excess of oxygen and / or air in excess of the above-mentioned stearium trioxide moieties.

The new process is particularly suitable for the residual gases resulting from the reaction of ethylene with chlorine, which is carried out in the presence of liquid 1,2-ethane and the catalyst at a temperature of 20 to 95 ° C.

The process according to the invention makes it possible to inexpensively utilize the waste gases from the direct chlorine of ethylene and from the apparatuses and storage vessels which are used in the preparation of pure 1,2-diclioretane. In addition to this, an improvement in the yield of 1'-di-acetal is achieved. Another advantage is that since Kfrxí pl ^ ^{y y} n from the reaction of ethane with the chorus nevyžaduuí cooling below ⁰ ° C, if possible, to obtain a quantitative yield of 1,2-Uichlorztatu while cleaning OUP ^ Cu ^ gas now running, and avoid clogging condensation units with frozen water. In addition, the novel process has considerably less the effect of operating conditions fluctuations in direct ethylene chlorination, for example, fluctuations in catalyst concentration or fluctuations in the swrovio feed, as well as fluctuations in operating temperature, with respect to the quality and yield of 1,2-iodine produced.

The process of the present invention is illustrated in more detail by the following examples.

Retune

The quenchable reactor contains a large part of the 1,2-trifluoroacetate which is mainly present in the remainder, in addition to 1,1,2-trichloroethane in addition to other chlorinated hydrocarbons having 2 carbon atoms. The capsule also contains 0.02 to 0.04%. The concentration fluctuates during operation within the stated limits). The reactor was used tlakc ztylzo and chlorine fed in a continuous state in mmlárním ratio of 1: 1.02 and the liquid ^{BC No.} Zr e ^p temp topalioy sz c ^ assigning adjusted to ⁴⁵ ° C at this' sz udrfrujz temperature.

The pressure in the ^REA. at 110 kPa.

The liquid level in the reactor is maintained by weighing the liquid. The liquid drained from the spring in a conventional water wash container, separates from the wash water and stores it in the wash tank. the collecting container. The gas mixture from the reactor utkející sz cooled in a cooler, wherein the model as ^ ^^^ media Ιι ^p sing ^and brine, nz +3 ° C. КартИт, Zr ^{kt Z} přioom condensed, sz .'ovněž discharged Uo first collecting vessel. From the gas mixture, which cleans the brine-cooled cooler, it takes 300 milligrams of mono-mineral from 1 hour and treats as described below.

225146

The flue gas from the first collection vessel is fed to a distillation apparatus in which water and substances boiling at a temperature lower than the boiling point of 1,2-dichloroethane together with a small amount of 1,2-dichloroethane (via the top of the column) The stripped poles are condensed and fed to a second collection vessel and then treated in the usual manner to obtain a further portion of 1,2-chloroethane. The product remaining at the bottom of the column is also further processed by known methods to give pure 1,2-aichloroethene, and this is then fed to a vinyl cleavage apparatus. Washing the crude 1,2-dichloroethane from a reactor in which ethylene reacts with chlorine, collecting the liquid in the first and second collecting vessels, as well as collecting the liquid for the purpose of removing the liquid. More water and easily boiling fractions from 1,2-dlchloroethene are carried out under nitrogen as a shielding gas.

530 non-condensed waste gas from the above-described dessillation apparatus is withdrawn every hour. 20.1 parts by weight of the off-gas are taken each hour from the respective waste gases from the 1,2-carbohydrate scrubbing vessel and L from the first and second collection vessels. All exhaust gases collected shall be collected. In this way, 850.1 parts of hmoonoot waste gas per hour are analyzed, which is analyzed by gas-tar-gravity. The following values are achieved:

parts by weight / hour

hydrogen 5.2 oxygen 14.7 nitrogen 335,6 ' carbon monoxide 5.0 carbon dioxide 281.9 ethane 6.0 ethylene 38.0 1.5 1,2-ϋ ^ 1Θη ^ η 34.5 melty chloride 2.6 1, 1 -ϋ ^ ΙθηΐΜ 1.4 aty ^ h ^^ 106.1 1,1-dichloroethyl 0.3 1,2-dichloroethyl tetrenes 0.3 1,2-di-claretyl-is 0.3 tltrachlormitin 3.8 chloroform 11.9

850.1

The mixture ^of waste ^p Lyn is not compressed ^kp and ^360, warmed in heat exchanger t e ^p le not 175 ° C and introduced into a reactor in which ethylene is reacted, hydrogen chloride and air in the presence of catalyst particles in the fluidized bed. The catalyst particles are formed of aluminum oxide on which copper chloride and potassium chloride are absorbed. The exhaust gas mixture is fed into the reactor below a zone in which the catalyst particles are contained in the fluidized bed.

Based on the above analysis, 166.4 parts by weight per hour of air and 164 parts by weight of hydrogen chloride per hour are required to convert ethylene and ethylene chloride present in the off-gas to 1,2-dlchloroethane.

The reactor was fulfill air, hydrogen chloride and atylenem ks ^ Ri ^ cožit následají shown in Table ¹ d ^p from ^p říkldeem ^{first T} in the varnish is 35 reatooru ⁰ and ^kp, mp ²²⁰ ° C. A mixture of ^p lynů o ^ xi & T ^ .mu.Ci reactor was cooled shower ^alk ali-kt water and not 89 ° C, cooling water was then removed by β steam, the resulting gaseous mixture of water and crude 1,2-dichloroethane condensed by cooling no 5 The crude 1,2-aichlorine is removed from the water and passed to the first collection point described above.

The gas mixture cooled to ⁸⁹ ° C is cooled to ¹⁰ ° C in water chillers and brine-cooled chillers and the condensed 1,2-dichloroethane condensed therein is also fed to the first collection vessel described above. Nezkondenzovený gas scrubber is brought into contact with a mixture of harvested alk ^y tonzenů known under a ^b c ^h INTR designation Solvesao ™. L ^p · ^y n ^ ICI opcrnět scrubber was analyzed by gas ctaroemtogrefií. The values are given in Table 2 of Example 1. This waste gas is discharged into the atmosphere.

The scrubbing liquid enriched with the products from the gas mixture is heated under reduced pressure to a temperature above 100 ° C, the escaping gas is condensed and the crude 1'-dichloroethane thus obtained is fed to the first collecting vessel mentioned above several times. The treated liquid is returned to the scrubber.

In addition to the values already mentioned in the pre-heater paragraphs, the following values are given in Table 1 under Example 1: the total amount of crude 1,2-dichloroethane produced in the oxychlorination reactor, the content of pure. as determined by gas chromatography (see Table 3), calculated from this for the amount of pure 1,2-nitroacetate, the increase in this quantity compared to the comparative experiment A described above and the percentages of hydrogen chloride and otylene conversions.

In Table 3 below, Example 1 shows the analysis of crude 1,2-Uiclloret0uu carried out by gas chromatography.

Comparative experiment A of the ethylene froxychlorination was carried out as described above in Example 1, except that no waste gas was introduced into the reactor, the parameters listed in Tables 1, 2 and 3 under Experiment A were slaughtered and the results were are shown in Experiment A in Tables 1, 2 and 3 respectively.

Example 2

The procedure described in Example 1 is followed with the following differences:

a) Kappaim in a reactor in which tulle also reacts with chlorine contains from 0.001 to 0.003% by weight of iron chloride, based on the liquid (concentration varies during operation within the above ^b ) KapaHna reactor boils EPLL ^{r r} l ^NO IOI 84 ° C.

c) The temperature is kept at this temperature by withdrawing gaseous 1,2- οΜΜ ethane and condensation while maintaining a constant reactor volume.

d) The condensed n-discharged 1,2-dichloride is not washed with water. .

(i) The condensation described in (c) is carried out in a brine-cooled condenser of not more than +2 ° ^C; · From ^than ln ^d enelven pJ ^E mixture. ^ N ^of the tažtou Ludinou ⁴⁹⁰ AU ^ ^ ^ ο ο ^ β ^ Ι. The gas flow of this gas mixture was found to be as follows:

parts lololnolt / hlUioα nitrogen oxygen hydrogen carbon monoxide carbon dioxide ethane eГс1оо

43.8

10.0

3.1

4.4

133.4

4.7

229.3 ethyl chloride

I, 2-dichloroethene parts w / w no

10.1

46.2

490.0

This gas mixture is compressed to not more than 360 kPe without admixing additional waste gases, heated in a heat exchanger to 150 ° C and fed as described in Example 1 and fed to a reactor in which ethylene, hydrogen chloride and air react in the presence of catalyst particles in the fluidized bed.

Based on the above analysis, 665.6 parts by weight / hr are required to convert ethylene and ethyl chloride present in the off-gas into 1,2-dichloroethane. and 574 parts by weight / hour of air e 574 parts by weight / hour of hydrogen chloride.

f) The oxychlorination reactor is operated at a pressure of 350 kPa and a temperature of 230 ° C with the amounts of air, hydrogen chloride and ethylene listed in Table 1 under Example 2. The reaction products are processed as in Example 1. Observed values for crude 1.2 dichloroethene, pure 1,2-dichloroethane and conversions are also shown in Table 1 under Example 2.

The crude 1,2-dichloroethane analysis is shown in Table 3, the oxychlorination waste gases are shown in Table 2 under Example 2.

Comparative experiment В

The oxychlorination of ethylene is carried out as described in Example 2 above, except that no waste gas is introduced into the reactor and that the parameters given in Tables 1, 2 and 3 under Example B were used, and the values shown in Tables contained under Example B.

Example 3

The procedure described in Example 1 is followed with the following differences:

(a) The temperature of the liquid in the reactor, in which the ethylene reacts with chlorine, is 35 ° C and is maintained at this temperature by cooling.

(b) 422 parts by weight are taken from the gas mixture leaving the brine-cooled cooler. Analysis of the gas mixture by gas chromatography revealed the following values:

weight parts / hour

nitrogen 174.4 oxygen 11.9 hydrogen 3.5 carbon monoxide 4.1 carbon dioxide 148.5 hydrogen chloride 7.9 ethylene 15.0 ethyl chloride 8.2 1,2-dichloroethane 40.9

422.0

The gas mixture is compressed to 360 kPa without admixture of additional waste gases and without heating, and as described in Example 1, is fed at 30 ° C to a reactor in which ethylene, hydrogen chloride and air react in the presence of catalyst particles in the fluidized bed. . According to the above-mentioned gas chromatography analysis, the supply of hydrogen chloride and air to the oxychlorination reactor is automatically regulated.

(c) The oxychlorination reactor is operated at 350 kPe and 190 ° C with the amounts of air, hydrogen chloride and ethylene fed in the quantities shown in Table 1 under Example 1. The reaction products are operated as described in Example 1.

The observed values for crude 1,2-dichloroethane, pure 1H-dichloroethane and conversions are also shown in Table 1 under Example 3. Analysis of crude 1,2-dlchloroethene is given. in Table 3, the analysis of the waste gases from oxychlorination is shown in Table 2, in both cases - below. example 3.

Comparative experiment.

The ethylene chlorination is carried out as described in Example 3, with the difference that no waste gas is introduced into the reactor and the parameters listed in Tables 1, 2 and 3 under Example C are determined and the in Tables 1, 2 and 3 under Annex C.

Example 1

The procedure described in Example I is followed with the following procedure. differences?

e) the liquid in the reactor in which the ethylene reacts with chlorine contains 0.001 to 0.003% by weight of ferric chloride based on the liquid (the concentration varies during operation within these limits).

b) Kapplins boil in the reactor, the temperature is 145 ° C, the reactor is operating under pressure.

c) By withdrawing 1,2-dichloroethane gas and condensing while maintaining a constant reactor charge, the reactor temperature is maintained at 145 ° C.

(d) The condensed and drained 1,2-α-chloroacetyl sc does not wash with water.

e) Condensation described under c) is effected in a condenser chilled brine aS no gas temperature +2 ^C 'C, uncondensed gas mixture is released and mixed with other waste. The gases from the 1,2-dichloroethene storage tanks and the 1,2-dichloroethane aftertreatment apparatus are analyzed by gas chromatography for 842.5 parts of the hydrate / hr. The following values were found by this analysis:

parts nitrogen / h nitrogen oxygen hydrogen carbon monoxide carbon dioxide ethane ethylene ethyl chloride

1,2-dichloroethene

70.3

13.4

3.4

4.7

117.6

12.8

542.4

9.1

68.8

842.5

This gas mixture is pressurized to 360 kPa, heated to 190 ° C in a heat exchanger and as described in Example 1, fed to a reactor in which ethylene, hydrogen chloride and air are reacted in the presence of swollen catalyst particles. Based on the above analysis, 1,216 parts of air / air and 394 parts of air / air of hydrogen are required to convert the ethylene and ethyl chloride present in the off-gas to 1,2-dichloroethane.

f) for oxychloreci reactor is operated at ³⁵⁰ to ^P ea at ²⁸⁰ ° C with the amount of air, hydrogen chloride, ethylene and listed in Table 1 under the case 4. The reaction products is carried stejjýfa manner as described in Example 1. The determined values for ' crude 1,2-dichloroethane, pure 1,2-dichloroethane and conversions are also listed in Table 1 under Example 4. The analysis of crude 1,2-dichloroethane is given in Table 3, the analysis of the off-gas from oxychlorination is given in Table 2, both under Case 4.

Comparative experiment

The ethylene is carried out as described in Example 4 above, with the exception that no waste gas is introduced into the reactor and that the parameters given in Tables 1, 2 and 3 under D are used, or the values given in the Tables are determined. 1, 2 and 3 under O.

T eb u.lka 1

The process conditions and the product pH values were determined by ethylene chloride chlorination

Comparative example Example 1 Comparative example Example 2 Comparative Example Example 3 Comparative example Example 4 air parts l (note / l 46 920 47 086 46 920 47 586 46 850 46 882 47 042 48 258 HC1 parts hmoo- ПС81пХ / 1 CgH _A SUc mass- 31 240 31 404 31 650 32 224 31 158 31 200 31 158 32 552 П081п! / 1 12 580 12 580 12 580 12 580 12 310 12 310 12 310 12 310 temperature ° C 220 220 230 230 190 190 280 280 flue gas supply lmotnottní parts / l 850.1 - 490 422 842.5 Crude 1,2-dithltrotane, di- lyemnntni / l 41 965 42 270 42 570 43 400 41 000 41 095 41 435 42 885 1,2-dicloroethane content in% 99,119 99.065 98,969 98,960 99,225 99,201 97,053 96,954 Pure 1,2-dioltrotene parts ltDotnottní / l 41 595 41 870 42 130 42 950 40 680 40 765 40 310 41 575 increment of 1,2-dicHoronium in parts by mass _- 275 tm- 820 85 1 365 and% 0.66% 1,95% 0.2% 3.4% HCl conversion: 99.6% 99.6% 99.7% 99.7% 97.7% 97.8% 99.8% 99.8% C 3 H conversion. on raw * 1,2-11 µl ethane 94.2% 1) 95.3 ~ '' '% 1) 94.2% 1) 93.3% 1) to CO ₂ 2,3 * 1.95% , 1.9% 5.3% what for CjH. unchanged in waste 1.2% 0,90% 0.7% 0.2% gas 2.3% 1,85% 3.2% 1, 2% 100,00% 100,00% 100,00% 100,00%

1) The conversion is similar to that of Comparative Example A or Example A, respectively. B, C or D;

the determination is inaccurate due to admixtures from said waste gas.

Table 2

Analysis of waste gas from oxychlarec after scrubbing

Comparative example A vol% Example 1% by volume Comparative example В vol% Example 2 volume% Comparative example C vol% Example 3 volume% Comparative example D vol% Example 4 volume% ° 2 6.3 6.2 6.5 6.4 7.3 7.3 1,2 1.3 WHAT 0.76 0.76 0.56 0.57 0.46 0.48 0.2 0.25 co ₂ 1.45 1.86 1,25 1.46 1.15 1,28 4.0 4.4 ^C 2 ^H 4 0.72 0.71 0.58 0.58 1.01 1.05 0.44 0.41 ^C ? 6 <0.01 0.01 <0.01 0.01 <0.01 0.02 <0.01 0.01 vinyl chloride 0.0020 0,0024 0.0018 0.0020 0.0020 0,0021 0.0129 0.0099 g ₂ h ₅ ci 0.0045 0.0166 0.0040 0.0056 0.0045 0.0090 0.0081 0.0102 1,2-dichloro - 0,0001 0.0002 0.0002 0.0001 0.0001 0.0001 0.0001 0.0001

ethane

Table 3

Analysis of crude 1,2-dichloroethane produced by oxychlorination

Srovná- Srovná- Srovná- Srovná- vací vací vací vací example Example example Example example Example example ρίςγνΊ «л AND 1 В, 2 C 3 D 4 % wt. % wt. % wt. % wt. % wt. % wt. % wt. % wt.

и ₂ о 0.192 0.190 0.196 0.194 0.190 0.188 0.192 0.184 total ^ 2 ^ 2 '^ 2 ^ 4j ^C 2 ^H 6 0.009 0.009 0.007 0.007 0.008 0.009 0,002 0,002 vinyl chloride 0,002 0,002 0,002 0,002 0,002 0,002 0.024 0,028 c ₂ h ₅ ci 0.008 0,031 0.007 0.011 0.008 0.014 0,098 0,102 ethylene oxide 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 1,2-diohlorethylene-trans 0,002 0,002 0,002 0,002 0,002 0,002 0,056 0,054 1,1-Dicloroethane 0.004 0.007 0.005 0.005 0.005 0.005 0.008 0.007 CC1 ₄ 0.091 0,099 0,127 0.125 0,078 0,086 0,112 0.132 1,2-dichlorethylene-cis 0.008 0.008 0.010 0.011 0.008 0.006 0,103 0,098 I want ₃ 0-107 0.134 0,12.1 0,122 0,128 0.117 0,124 0.134 1,1,2-trichlorethylene 0.005 0.005 0.004 0.004 0,002 0.003 0.020 0.018

continuation of Table 3

Comparative Example A wt. Example i % wt. Comparative Example В% wt. Example 2 wt. Comparative Example C wt. Example 3 wt. Comparative Example D wt. Example 4 wt. 1,2-dichloroethane 99,119 99.065 98,969 98,960 99,225 99,201 97,053 96,954 tetrechlorethylene 0.018 0.018 0.018 0.019 0.014 <0.010 0,035 0,043 1,1,2-trichloroethane 0.397 0.394 0.498 0.496 0,307 0.335 1,386 1,669 ethylenchlorby drin 0.014 0.013 0.013 0.013 0.008 0.009 0,075 0,088 tetrachloretan 0,021 0.020 0,025 0,026 0.015 0,023 0.532 0.487

SUBJECT MATTER FROM U

Claims (5)

A process for the preparation of 1,2-dichloroethane, wherein at least one reaction space is reacted with ethylene 8 with chlorine, optionally in the presence of a catalyst, at a temperature of 20 to 150 ° C, and in at least one longer reaction space is reacted with ethylene with hydrogen chloride and oxygen in the presence of a catalyst and optionally gases inert under the reaction conditions, at temperatures of 180 to 300 [deg.] C., the resulting reaction products are removed from the reaction spaces and the major amount of 1,2-dichloroethane formed is separated therefrom; separation of 1,2-dichloroethane from the reaction products of the ethylene-chlorine reaction introduces the remaining gas mixture into the reaction space in which ethylene is reacted with hydrogen chloride and oxygen. 2. A process according to claim 1, characterized in that the gas mixture remaining after the 1,2-dichloroethane separation is admixed with waste gases from the distillation apparatus for 1,2-dichloroethene purification or from the 1,2-dichloroethane storage vessels. Process according to either of Claims 1 and 2, characterized in that waste gases originating from the distillation plant for the purification of 1,2-dichloroethane and / or storage vessels for ethylene-chlorine are admixed with the mixture of ethylene-chlorine gases. 1,2-dichloroethane, which use after incomplete thermal cleavage of 1,2-dichloroethane to obtain vinyl chloride after separation of vinyl chloride. Method according to one of Claims 1 to 3, characterized in that the mixture of gases from the reaction of ethylene with chlorine is heated to temperatures of 100 to 200 ° before being pressurized to the reaction space in which the reaction of ethylene with hydrogen chloride and oxygen is carried out. C. Method according to one of Claims 1 to 4, characterized in that the gas mixture from the reaction of ethylene with chlorine is analyzed for hydrogen chloride and ethylene and the result of the analysis is used to automatically control the supply of at least one of hydrogen, air or Ethyl to a reaction space in which ethylene 8 is reacted with hydrogen chloride and oxygen.