DE102006062331A1 - Production of vinyl chloride - Google Patents

Abstract

A supported, base and halogenated catalyst prepared by impregnation techniques on a support material containing metal salts with at least one platinum metal, further at least one metal capable of changing its oxidation number by +1, and further exactly one alkali metal, wherein a support material having a specific surface area is less than 10 m <SUP> 2 </ SUP> / g, the catalyst is obtained by first drying the metal salt-impregnated support material and calcining the impregnated and dried catalyst precursor at 300 to 500 ° C.

Description

The invention is directed to a catalytic process and an apparatus for the production of monomeric vinyl chloride, hereinafter referred to as VCM, from which ultimately polyvinyl chloride, PVC, is prepared, and the catalyst required for this purpose. In the catalytic reaction of 1,2-dichloroethane, hereinafter referred to as EDC, to VCM, hydrogen chloride HCl is formed. EDC is therefore preferably prepared from ethylene C ₂ H ₄ and chlorine Cl _{2 in} such a way that a balanced balance is achieved with respect to the hydrogen chloride HCl produced and consumed during the reactions in accordance with the following reaction equations: Cl ₂ + C ₂ H ₄ → C ₂ H ₄ Cl ₂ (pure EDC) +182 kJ / mol (1) C ₂ H ₄ Cl ₂ (cleavage EDC) → C ₂ H ₃ Cl (VCM) + HCl - 71 kJ / mol (2) C ₂ H ₄ + 2 HCl + ½ O ₂ → C ₂ H ₄ Cl ₂ (crude EDC) + H ₂ O + 238 kJ / mol (3)

• – eine Direktchlorierung, in der aus Ethylen C₂H₄ und Chlor Cl₂ der eine Teil des benötigten EDC erzeugt wird und als sogenanntes Rein-EDC abgegeben wird.
• – eine Oxichlorierung, in der aus Ethylen C₂H₄, Chlorwasserstoff HCl und Sauerstoff O₂ der andere Teil des EDC erzeugt wird und als sogenanntes Roh-EDC abgegeben wird.
• – eine fraktionierende EDC-Reinigung, in der das Roh-EDC zusammen mit dem aus der VCM-Fraktionierung rezirkulierten Rück-EDC von den in der Oxichlorierung und von den in der EDC-Pyrolyse gebildeten Nebenprodukten befreit wird, um ein für den Einsatz in der EDC-Pyrolyse geeignetes, sogenanntes Feed-EDC zu gewinnen.
• – eine EDC-Pyrolyse, in der das Rein-EDC mit dem Feed-EDC zusammengeführt und in der das dann Spalt-EDC genannte Gemisch thermisch gespalten wird; das erhaltene Spaltgas enthält VCM, Chlorwasserstoff HCl und nichtumgesetztes EDC sowie Nebenprodukte.
• – eine VCM-Fraktionierung, in der das als Produkt gewünschte Rein-VCM aus dem Spaltgas abgetrennt und die anderen wesentlichen Spaltgasbestandteile Chlorwasserstoff HCl und nichtumgesetztes EDC als Wertstoffe gesondert zurückgewonnen und als wiederverwertbarer Einsatz als Rück-HCl bzw. Rück-EDC im ausgewogenen VCM-Verfahren rezirkuliert werden.

The conventional method for producing VCM with balanced HCl balance, hereinafter referred to as "balanced VCM method", has:

• - A direct chlorination in which from ethylene C ₂ H ₄ and chlorine Cl ₂ of a part of the required EDC is generated and is discharged as a so-called pure EDC.
• - An oxychlorination in which from ethylene C ₂ H ₄ , hydrogen chloride HCl and oxygen O _2, the other part of the EDC is produced and is discharged as a so-called crude EDC.
• A fractional EDC purification in which the crude EDC, together with the recycle EDC recirculated from the VCM fractionation, is freed from the by-products formed in the oxychlorination and the by-products formed in the EDC pyrolysis, for use in the EDC pyrolysis suitable to win so-called feed EDC.
• - An EDC pyrolysis, in which the pure EDC merges with the feed EDC and in which the mixture then called gap EDC is thermally cleaved; the resulting cracked gas contains VCM, hydrogen chloride HCl and unreacted EDC, as well as by-products.
• A VCM fractionation in which the pure VCM desired as product is separated from the cracked gas and the other essential cracked gas constituents hydrochloric acid HCl and unconverted EDC are recovered separately as recyclables and recycled as reusable use as back HCl or reverse EDC in the balanced VCM Procedures are recirculated.

adversely This process has a relatively high investment cost and resource costs through the complex reaction system. Furthermore become in the pyrolytic EDC cleavage unwanted polychlorinated by-products formed as precursors for serve a coking. About that In addition, the EDC cracking furnace must still by supplying z. B. natural gas externally fired, although the exothermic nature of the two steps Direct chlorination and oxychlorination would be sufficient for the EDC cleavage with sufficient heat to supply. Further disadvantages are also familiar to the person skilled in the art.

By the strongly endothermic nature of pyrolytic dehydrochlorination, which is a thermal cracking reaction the difficulty of feeding additional Heat too the reactant mixture to the cleavage at the necessary high Temperature to perform. In the direct chlorination of ethylene and oxychlorination of Ethylene to EDC theoretically fall sufficient amounts of heat to pyrolytic Cleavage of EDC to form VCM. You would like to therefore carry out all the reactions involved simultaneously. there could the heat generated by the exothermic reactions for the endothermic pyrolytic Cleavage of EDC can be used.

Examples of common direct chlorination and pyrolytic cleavage reactions are those in the US 2,838,577 and the DE 2 629 461 been described. In the in US 2,838,577 described method, the heat transfer between an exothermic Direktchlorierungszone and an endothermic pyrolytic dichloroethane cleavage zone by the use of a common solid fluidized bed, which serves as a catalyst for the cleavage of dichloroethane. This in US 2,838,577 However, the method described has the disadvantage that ethyl chloride is formed in larger quantities. If the fluidized bed solid serves as a catalyst for the cleavage of dichloroethane, although more vinyl chloride than ethyl chloride is formed, but at the expense of an increase in the molar ratio of chlorine to ethane and an increase in the amount of dichloroethane supplied. In addition, the conversions of dichloroethane are relatively low and there are undesirable higher chlorinated hydrocarbons as by-products. The formation of by-products increases the yield of VCM as well as coking. The method described is suitable is therefore not for the commercial production of vinyl chloride, as it has a low vinyl chloride yield and selectivity.

In the DE 2 629 461 describes a method and a reaction apparatus for producing halogenated hydrocarbons, in particular vinyl chloride, by simultaneous chlorination and dehydrochlorination in a fluidized bed. The solids contained in the fluidized bed are non-catalytic and are circulated through both and between the two reaction zones to remove heat from the exothermic chlorination reaction and to supply the dehydrochlorination reaction. The hydrogen chloride produced by the dehydrochlorination reaction is used as a chlorinating agent for oxychlorination, so that substantially no hydrogen chloride is obtained as a by-product. This in DE 2 629 461 However, the process described has the disadvantage that the feed additionally a chlorinated hydrocarbon (eg., CCl ₄ ) must be added for initiation. In addition, the process is very complex in that it is operated non-catalysed.

Moreover, it is already known that metal mixed oxide or metal mixed halide catalysts can be used to produce halogenated hydrocarbons, especially vinyl chloride, by combined oxychlorination and dehydrochlorination. In the US 3,670,037 For example, supported, base, halogenated noble metal / transition metal catalysts are described as being active for vinyl chloride synthesis. The carriers preferably have small surfaces. The best catalysts contain as active components Pd, Fe and Na. At a temperature between 180-350 ° C VCM is formed as the main product of this catalyst from an ethylene, HCl, oxygen mixture. At about 290 ° C, ethylene conversions of 88% and a selectivity to VCM of 60% are described. The major byproduct is EDC, which is formed with a selectivity of 25%.

The GB 2 003 740 describes the production of VCM with a similar combination of catalytically active metals consisting of Pd, Cu, Fe, Na (K), Ce. The reaction temperatures are between 250 and 400 ° C. Based on 80-90% HCl conversions VCM is formed in a selectivity of up to about 58%. EDC is the major byproduct. The total oxidation is 10%, depending on the catalyst and the reaction conditions used.

In the US 4,115,323 For VCM synthesis, a catalyst system consisting of Rh (Pt), Fe (Cu), Zn and supported alkali metals (TiO ₂ , Al ₂ O ₃ , ZrO ₂ , SiO ₂ or AlSiO _x ) is claimed. Best reaction results were achieved at 400 ° C with a selectivity of 70% for VCM with an ethylene conversion of 22%.

A disadvantage of the described inventions is the formation of oxygenates ( US 3,670,037 ), the high level of total oxidation ( GB 2 003 740 ) and low ethylene sales ( US 4,115,323 ), low yields of vinyl chloride and coking of the catalyst. This prevents commercial use of the catalysts.

The The object of the invention is therefore to provide a catalyst for the production from VCM, with the use of which the known difficulties no longer occur, as well as the appropriate procedures to his Production and its use according to the invention.

• – ein Trägermaterial mit einer spezifischen Oberfläche, welche kleiner ist als 10 m²/g, eingesetzt wird,
• – der Katalysator erhalten wird, indem das mit dem Metallsalz imprägnierte Trägermaterial zunächst getrocknet wird, und
• – das imprägnierte und getrocknete Katalysatorvormaterial bei 300 bis 500°C calciniert wird.

The invention solves this problem by a supported, base and halogen-containing catalyst, prepared by impregnation techniques, on a support material containing metal salts with at least one platinum metal, further at least one metal which can change its oxidation number by +1, and further exactly one alkali metal, wherein

• A support material having a specific surface area which is less than 10 m ² / g is used,
• - The catalyst is obtained by the metal salt impregnated carrier material is first dried, and
• - The impregnated and dried catalyst precursor is calcined at 300 to 500 ° C.

The support material used may be TiO ₂ , α-Al ₂ O ₃ , γ-Al ₂ O ₃ , ZrO ₂ , SiO ₂ , activated carbon or AlSiO _x .

• – dass die Calcinierung unter reduzierender Atmosphäre, vorzugsweise unter Wasserstoff-Atmosphäre, durchgeführt wird,

oder alternativ

• – dass die Calcinierung unter inerter Atmosphäre durchgeführt wird, wobei insbesondere Stickstoff-Atmosphäre oder Edelgas-Atmosphäre zum Einsatz kommen.

In embodiments of the invention, it is provided with regard to the calcination of the catalyst,

• That the calcination is carried out under a reducing atmosphere, preferably under a hydrogen atmosphere,

or alternatively

• - That the calcination is carried out under an inert atmosphere, in particular nitrogen atmos phased or inert gas atmosphere are used.

• – dass die Konzentration des Platinmetalls zwischen 0,1 und 2 Gewichtsprozent beträgt,
• – dass die Konzentration des Metalls, welches seine Oxidationszahl um +1 ändern kann, zwischen 0,5 und 10 Gewichtsprozent beträgt,
• – dass die Konzentration des Alkalimetalls zwischen 0,5 und 10 Gewichtsprozent beträgt,
• – dass als Metall, welches seine Oxidationszahl um +1 ändern kann, ein Metall oder mehrere Metalle aus einer aus Eisen, Kupfer, Cer und Lanthan gebildeten Gruppe ausgewählt wird,
• – dass als Platinmetall Palladium, als Metall, welches seine Oxidationszahl um +1 ändern kann Eisen, und als Alkalimetall Natrium ausgewählt werden, wobei vorzugsweise Palladium, Eisen und Natrium jeweils eine Konzentration von 1 Gewichtsprozent aufweisen,

wobei jede der Ausgestaltungen einzeln oder in Kombination miteinander genutzt werden können.In further embodiments of the invention is provided with regard to the metals used,

• That the concentration of the platinum metal is between 0.1 and 2 percent by weight,
• That the concentration of the metal, which can change its oxidation number by +1, is between 0.5 and 10% by weight,
• That the concentration of the alkali metal is between 0.5 and 10% by weight,
• That as metal which can change its oxidation number by +1, one or more metals are selected from a group formed from iron, copper, cerium and lanthanum,
• That as platinum metal palladium, as metal, which can change its oxidation number by +1 iron, and be selected as alkali metal sodium, wherein preferably palladium, iron and sodium each have a concentration of 1 weight percent,

wherein each of the embodiments can be used individually or in combination with each other.

• a) Herstellung je einer Lösung von 1-Masse% PdCl₂ in ca. 5%iger wässriger HCl und einer wässrigen Lösung, die 5%ig an FeCl₃ und 4,3%ig an NaCl ist,
• b) Hinzugabe von 17 kg α-Al₂O₃ pro 30 Liter der PdCl₂-Lösung und 10 Liter der FeCl₃/NaCl-Lösung,
• c) 45 Minuten intensives Rühren, um eine möglichst vollständige und gleichmäßige Imprägnierung des Trägers zu gewährleisten,
• d) Abzug des überschüssige Lösungsmittel in einem bewegten System bei 100°C durch Anlegen eines leichten Vakuums,
• e) Vollständige Trocknung der erhaltenen Pellets über 12 Stunden bei 110°C,
• f) Calcinierung der trockenen Pellets unter reiner H₂-Atmosphäre zunächst für 1 Minute bei 50°C, danach Aufheizung während 30 Minuten auf 375°C und anschließendem halten dieser Temperatur während 5 Stunden,
• g) Entfernung des Katalysators aus dem Ofen mit unmittelbar anschließender Abkühlung auf Raumtemperatur innerhalb von 1 Minute.

In a particular embodiment of the catalyst, this is obtained by carrying out the following working steps for its production:

• a) Preparation of a solution of 1 mass% PdCl ₂ in about 5% aqueous HCl and an aqueous solution which is 5% FeCl ₃ and 4.3% NaCl,
• b) addition of 17 kg of α-Al ₂ O ₃ per 30 liters of the PdCl ₂ solution and 10 liters of the FeCl ₃ / NaCl solution,
• c) 45 minutes of intensive stirring to ensure the most complete and uniform impregnation of the carrier,
• d) removal of the excess solvent in a moving system at 100 ° C by applying a slight vacuum,
• e) complete drying of the pellets obtained over 12 hours at 110 ° C,
• f) calcination of the dry pellets under pure H ₂ atmosphere first for 1 minute at 50 ° C, then heating for 30 minutes at 375 ° C and then keep this temperature for 5 hours,
• g) removal of the catalyst from the oven with immediate cooling to room temperature within 1 minute.

Further Embodiments of the invention relate to the use of the catalyst for the production of VCM or, alternatively, for simultaneous production of EDC and VCM, each together with water from ethylene, hydrogen chloride and oxygen. The catalyst is in this case preferably as a fluidized bed material in a Fluidized bed reactor, as it corresponds to the conventional oxychlorination, used, but can also be used in a flow or fixed bed reactor become.

By such a procedure is used in the reaction of ethylene with a chlorine source and a oxygen-containing gas at temperatures between 200 and 400 ° C VCM with formed a high yield as the main product. The product gas is free of oxygenates and the total oxidation is suppressed as much as possible. Of Further, no coking of the catalyst is observed and the Formation of unwanted By-products is low, which benefits the catalytic Procedure are. As a chlorine source can also EDC from a serve upstream direct chlorination.

As an example, catalysts containing as active components Pd, Fe and Na, at a temperature of 330 ° C ethylene conversions of about 90%. The selectivity to vinyl chloride is between 55% and 60% and the selectivity to EDC is between 30% and 35%. As by-products are formed ethyl chloride with a selectivity of 2-4%, 1,1,2-trichloroethane with a selectivity of 1-2% and CO ₂ with a selectivity of 3-6%.

The The invention is explained in more detail below with reference to further examples. Under Use of supported Noble metal / transition metal-supported catalysts For example, oxychlorination with VCM formation with ethylene became a source of chlorine (HCl, chlorine, EDC) and an oxygen-containing gas (oxygen, Air) was investigated as starting material.

Palladium, iron and sodium, which have been applied to various supports in the form of their chlorides (incipient wetness method and excess solvent method), have generally been chosen as the active components of the catalysts. The metal contents were within the limits Pd: 0.1-2% by weight; Fe: 0.5-10% by weight; Na: 0.5-10% by weight varies. The metal mixed chloride catalysts were applied to various support materials TiO ₂ , γ-Al ₂ O ₃ , α-Al ₂ O ₃ and SiO ₂ . The carrier materials used differ by their aci dität and surface (TiO _2: about 320 m ² / g, γ-Al ₂ O _3: about 200 m ² / g, SiO _2: about 150 m ² / g, α-Al ₂ O _3: ca. 5-35 m ² / g). The catalysts prepared were calcined under various atmospheres (air, argon, hydrogen) between 350 and 400 ° C. It was found that the calcination atmosphere has a significant influence on the catalytic properties. Carrier variation assays revealed that small surfaces (5-35 m ² / g) and the avoidance of residual acidity lead to very good catalytic results. On a metal mixed chloride catalyst on α-Al ₂ O ₃ as a carrier were ethylene conversions at reaction temperatures of 330 ° C at about 90%. The main products were VCM and EDC. Both products achieved a summary selectivity of about 85-90%. Selectivities of ethyl chloride and 1,1,2-trichloroethane did not together exceed 4-5%.

In a variation of the calcining conditions was found that Calcination under hydrogen is the best catalytic result he brings. It seems as if calcining under air and to a lower part also lower argon generates increased oxidic particles, especially at the beginning of the reaction to greater total oxidation or led to the formation of coke. The calcination under hydrogen atmosphere also led to a better Controllability of the reaction.

All for the Catalysts used in the following series of experiments were impregnation technique (incipient wetness and excess solvent method). The metal chlorides served as a precursor. In a typical synthesis, the corresponding Amount of metal chlorides dissolved in hydrochloric acid. To this solution was the carrier given and the solution adsorbed within 30 minutes to 2 hours. The unadsorbed solution was carefully separated and the catalyst then for 3-4 hours dried at room temperature. This was followed by drying for 12 Hours in an oven at 110 ° C followed by calcination under different atmospheres 300-500 ° C for 3-5 hours.

A typical synthesis approach for the catalyst system is carried out according to the invention as follows. First, a solution of 1 mass% PdCl ₂ in about 5% aqueous HCl and an aqueous solution which is 5% FeCl ₃ and 4.3% NaCl, prepared separately. Then, to 17 g of α-Al ₂ O _3, 30 ml of the PdCl ₂ solution and 10 ml of the FeCl ₃ / NaCl solution are added. This system is then stirred intensively for about 45 minutes to ensure the most complete and uniform impregnation of the carrier. In order to obtain a complete and at the same time uniform loading with the active components PdCl ₂ , FeCl ₃ and NaCl, the excess solvent is removed in a moving system at 100 ° C. by applying a slight vacuum (rotary evaporator). As a result of this drying process, pre-dried, uniformly loaded, catalyst pellets are obtained, which are completely dried for about 12 hours at 110 ° C. These dry catalysts are finally calcined under pure H ₂ - atmosphere according to the following temperature program. First, the temperature is kept at 50 ° C for 1 minute, then heated to 375 ° C over 30 minutes and then held for 5 hours. After switching off the H ₂ gas stream, the catalyst is immediately removed from the oven, the cooling time to room temperature is about 1 minute.

Table 1 below gives a summary of characteristics of the carriers used. description BET-OF m ² / g Particle size mm Bulk weight g / cm ³ α-Al ₂ O ₃ 1 5.0 1.3 1.11 α-Al ₂ O ₃ 2 9.3 2 0.84 α-Al ₂ O ₃ 3 34.2 3-4 0.68 γ-Al ₂ O ₃ 200 1-2 TiO ₂ 320 1-2 SiO ₂ 150 1-2

Table 2 below shows an overview of the catalysts used. description Composition / treatment calcining α-1 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 1 350 ° C, 5 h, air α-2 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 2 350 ° C, 5 h, air α-3 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 3 350 ° C, 5 h, air α-4 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 1 350 ° C, 5 h, H ₂ α-5 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 1 400 ° C, 5 h, H ₂ α-6 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 1 350 ° C, 5 h, Ar α-7 1% by weight of Pd, Fe, Na / α-Al ₂ O ₃ 1 400 ° C, 5 h, Ar γ-Al ₂ O ₃ 1% by weight of Pd, Fe, Na / γ-Al ₂ O ₃ 300 ° C, 3 h, air TiO ₂ 1% by weight of Pd, Fe, Na / TiO ₂ 300 ° C, 3 h, air SiO ₂ 1 wt% Pd, Fe, Na / SiO ₂ 300 ° C, 3 h, air

The catalytic tests were carried out in a fixed bed reactor (glass) between 240 and 370 ° C, which was electrically heated with a furnace. The catalyst volume was 5 ml and was diluted 1: 1 with inert material. The apparatus constructed for the experiments had metering possibilities for ethylene, O ₂ , HCl, Cl ₂ , O ₂ / N ₂ and 1,2-dichloroethane (EDC). The reaction of ethylene with HCl and oxygen proceeds under volume contraction. To avoid condensation of higher-boiling chlorinated hydrocarbons, the reactor effluent was heated and the volume of product gas after leaving the reactor was increased with a stream of nitrogen. The gas stream was then passed through a gas collection vessel used for sampling for the GC.

• GHSV = 1000 h^–1;. τ = 3,6 s; C₂H₄:HCl:O₂ = 1:3:1,
• DCE: Dichlorethylen, HOAC: Essigsäure
• Auffällig ist die zwischen 5 und 7% liegende Selektivität zu Essigsäure.

Table 3 shows the results of Comparative Examples 1-3 for the oxychlorination of ethylene over a catalyst containing as active components 1% by weight of Pd, Fe and Na on α-Al ₂ O ₃ having a surface area of 5.5 m ² / g Carrier is used and heated at 260 ° C for 2-3 hours under air before use. Ex. ^T bed (° C) XC ₂ H ₄ (%) S-VCM (%) S-EC (%) S-EDC (%) S-CO / CO ₂ (%) DCE (%) HOAc (%) 1 260 49.4 52.8 14.7 21.6 0.5 5.0 5.4 2 275 66.8 56.1 8.4 24.4 0.7 3.2 7.2 3 290 88.1 60.2 3.1 25.2 2.8 2.3 6.4

• GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1,
• DCE: dichloroethylene, HOAC: acetic acid
• Striking is the between 5 and 7% lying selectivity to acetic acid.

For the following Examples 4-15, the following experimental conditions were set: The feed gas used was ethylene, hydrogen chloride and oxygen in a molar ratio of ethylene / hydrogen chloride / oxygen of 1/3/1. The space velocity was 1000 h ^-1 corresponding to a residence time of τ = 3.6 s. The use of an inert gas was not necessary. The reaction temperature was varied between 270 ° C and 330 ° C. The reaction results using the catalysts α-1, α-2, α-3, γ-Al ₂ O ₃ , TiO ₂ and SiO ₂ are summarized in Tables 4-7.

• α-1; GHSV = 1000 h^–1;. τ = 3,6 s; C₂H₄:HCl:O₂ = 1:3:1

Table 4 shows the results of Examples 4-6 for Catalyst α-1: (350 ° C air, 5 h). Ex. T _bed (° C) XC ₂ H ₄ (%) S-VCM (%) SEC (%) S-EDC (%) S-TCE (%) S-CO / CO ₂ (%) 4 270 32.4 40.4 22.2 20.6 0.0 16.8 5 300 56.7 53.1 11.7 24.4 0.4 10.4 6 334 82.3 52.3 3.2 27.0 1.1 27.0

• α-1; GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1

The ethylene conversions of this catalyst are in the investigated temperature range between about 30 and 80%. The main products in the upper temperature range VCM and EDC are observed. Insbeson At 270 ° C reaction temperature surprisingly much EC is formed (S to 22.2%). VCM and EDC achieve a total selectivity of about 61-79%. At 330 ° C the selectivities are highest. Here, the formation of EC also clearly decreases in favor of the two main products (S-EC approx. 3%). The selectivity to TCE increases slightly with increasing temperature. Probably here is that with increasing temperature the possibility of adding chlorine to VCM increasingly occurs.

• α-2; GHSV = 1000 h^–1;. τ = 3,6 s; C₂H₄:HCl:O₂ = 1:3:1

Table 5 shows the results of Examples 7-9 for Catalyst α-2: (350 ° C air, 5 h) Ex. T _bed (° C) XC ₂ H ₄ (%) S-VCM (%) S-EC (%) S-EDC (%) S-TCE (%) S-CO / CO ₂ / Coke (%) 7 270 22.4 45.1 26.9 16.2 0.3 11.5 8th 299 48.5 52.3 10.0 25.3 0.5 11.9 9 328 58.1 38.9 4.0 19.4 0.6 37.1

• α-2; GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1

Catalytic studies with the higher surface area catalyst of 9.3 m ² / g performed similarly well as the previously described experiments, but not the high ethylene conversions and VCM selectivities are achieved.

Table 6 shows the results of Examples 10-12 for Catalyst α-3: (350 ° C air, 5 h) Ex. T _bed (° C) XC ₂ H ₄ (%) S-VCM (%) S-EC (%) S-EDC (%) S-TCE (%) S-CO / CO ₂ / Coke (%) 10 269 12.4 63.5 35.5 2.7 0.6 - 11 300 17.0 49.0 17.9 2.7 0.8 29.6 12 326 9.8 35.1 11.3 3.1 0.0 5.05

• α-3; GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1

The catalyst α-3 shows a significantly different behavior with a significantly higher surface area (about 35 m ² / g). In addition to a significantly lower initial activity outweighs the EC by-products, EDC is formed only in small amounts. When the temperature increased, it was found that the activity collapsed completely; after removal of the catalyst, a black covering coated the catalyst particles (coke formation).

• GHSV = 1000 h^–1;. τ = 3,6 s; C₂H₄:HCl:O₂ = 1:3:1

Table 7 shows the results of Examples 13-15 for the oxychlorination of ethylene over the catalysts γ-Al ₂ O ₃ , TiO ₂ , SiO ₂ : Ex. Cat. T _bed (° C) XC ₂ H ₄ (%) S-VCM (%) 13 γ-Al ₂ O ₃ 300 32 28 14 TiO ₂ 300 45 15 15 SiO ₂ 300 50 39

• GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1

When using γ-Al ₂ O ₃ , TiO ₂ , SiO ₂ as a carrier showed a strong coke formation. After removal of the catalyst, a black cover coated the catalyst particles.

In summary, it can be stated that very good results could be achieved with the catalysts α-1. Furthermore, the test series showed that residual acidities and BET surface areas> 10 m ² / g of carriers have negative consequences for activity and selectivity. The following ranking of the carrier quality, in particular with regard to the VCM selectivity, results from the tests: α-Al ₂ O ₃ (<10 m ² / g)> α-Al ₂ O ₃ (> 10 m ² / g)> SiO ₂ > γ-Al ₂ O ₃ > TiO ₂

• GHSV = 1000 h^–1;. τ = 3,6 s; C₂H₄:HCl:O₂ = 1:3:1

Table 8 shows the results of the further experiments 16-23, in which various calcination Table 2, and the resulting catalysts α-4, α-5, α-6, and α-7 were compared with catalyst α-1 as listed in Table 4 in Examples 4-6 , The rest of the experimental procedure corresponds to that of experiments 1-15. Ex. Cat. T _bed (° C) XC ₂ H ₄ (%) S-VCM (%) SEC (%) S-EDC (%) S-TCE (%) S-CO / CO ₂ (%) 16 α-4 300 60.3 50.8 7.8 28.3 0.5 12.6 17 α-4 332 84.5 54.7 2.8 33.8 1.6 7.1 18 α-5 301 67.3 51.5 6.2 33.5 0.7 8.1 19 α-5 331 85.7 54.6 2.5 33.9 1.5 7.5 20 α-6 300 60.4 51.3 9.0 29.2 0.6 9.9 21 α-6 331 82.4 52.0 3.0 32.6 1.4 11.0 22 α-7 299 60.4 47.9 8.7 27.7 0.6 15.1 23 α-7 333 80.8 56.1 3.5 34.6 1.4 4.4

• GHSV = 1000 h ^-1 ;. τ = 3.6 s; C ₂ H ₄ : HCl: O ₂ = 1: 3: 1

The Experiments with the catalysts calcined under hydrogen show Ethylene sales up to approx. 85%. The selectivities The main products VCM and EDC show a summary selectivity of almost 90%. The results on the catalysts, which calcined under argon were are similar to those with catalysts which were calcined under hydrogen. In no case was a disturbing Formation of acetic acid observed.

The following embodiments relate to the use of the catalyst in production processes of VCM, in particular the integration into the "balanced VCM process" but the use is not limited thereto. Simplified by 2 Process block flow diagrams the application is clarified:

1 shows the balanced VCM process with formation of EDC and VCM in the oxychlorination

2 shows the formation of EDC and VCM in the oxychlorination with upstream direct chlorination

1 The starting material used for the direct chlorination reactor I is chlorine via compound 1 and ethylene via compound 2. EDC as product of the direct chlorination is transferred via compound 5 without further work-up into an EDC cracking furnace II, in which EDC is thermally split into VCM and HCl. The product gas from the EDC cracking furnace is fed via compound 6 to a column for VCM distillation III. In the column, VCM is separated from unreacted EDC and hydrogen chloride formed by a known method. VCM is discharged via compound 7 and stored for the polymerization to PVC or transferred directly into a polymerization reactor. In the EDC cleavage unreacted EDC and formed hydrogen chloride are fed via the compounds 8 and 9 to the VCM / EDC reactor IV. Via compound 3, ethylene is fed to the VCM / EDC reactor IV and oxygen (air) is supplied via the compound 4.

The product gas leaving the VCM / EDC reactor IV via compound 10 consists predominantly of VCM and EDC (as well as ethyl chloride, trichloroethane, CO _x , water and unreacted hydrogen chloride and ethylene). After condensation of the product gas in a heat exchanger V, if necessary, the aqueous phase is conveyed via compound 21 to the phase separation unit VI. Here a separation of organic and aqueous phase takes place. The uncondensed gases are transferred via compound 11 in the column VII.

The aqueous phase of the phase separation unit VI is conveyed via compound 22 for HCl treatment, where separation of water and hydrogen chloride is carried out by known methods. The organic phase is transferred via compound 23 into the columns for the separation of the low boilers VII. In the column, the low boilers (including CO _x , ethylene, and traces of hydrogen chloride). separated via compound 17. Hydrogen chloride and ethylene can be recovered from this stream. The product stream leaves the column VII via compound 12 and is transferred to a drying column VIII. After removal of the water via compound 14, the product is transferred via compound 13 into a further column IX. By known methods, a separation of VCM takes place. VCM is over verbin tion 15 and temporarily stored for the polymerization to PVC or transferred directly into a polymerization reactor.

ethyl will over Compound 16 is recycled to the VCM / EDC reactor IV. About connection 18 reaches the residual product stream consisting mainly of EDC in the column X in which a cleaning of the EDC according to known methods is performed. Separated EDC can over Compound 19 can be recycled to the VCM / EDC reactor IV. High boilers are going through connection 20 separated and can for HCl recovery be sent to a burn.

2 : Chlorine via compound 1 and ethylene via compound 2 are used as feed for the direct chlorination reactor I. EDC as product of the direct chlorination is converted via the compounds 5 and 6 into VCM / EDC reactor II without further workup. Via compound 3, ethylene is fed to the VCM / EDC reactor II and oxygen (air) is supplied via the compound 4.

The product gas leaving the VCM / EDC reactor II via compound 7 consists predominantly of VCM and EDC (as well as ethyl chloride, trichloroethane, CO _x , water and unreacted hydrogen chloride and ethylene). After condensation of the product gas in a heat exchanger III, the aqueous phase is conveyed via compound 14 to the phase separation unit IV. Here a separation of organic and aqueous phase takes place. The non-condensed gases are transferred via compound 8 in the column V.

The aqueous phase of the phase separation unit IV is conveyed as required via compound 15 for HCl treatment, where a separation of water and hydrogen chloride is carried out by known methods. The organic phase is transferred via compound 16 in the columns for the separation of the low boilers V. In the column, the low boilers (including CO _x , ethylene, and traces of hydrogen chloride) are separated via compound 12. Hydrogen chloride and ethylene can be recovered from this stream. The product stream leaves the column V via compound 9 and is transferred to a drying column VI. After removal of the water via compound 13, the product is transferred via compound 10 into a further column VII. By known methods, a separation of VCM takes place. VCM is discharged via compound 11 and stored for the polymerization to PVC or transferred directly into a polymerization reactor.

ethyl will over Compound 17 returned to the VCM / EDC reactor II. About connection 18 reaches the residual product stream consisting mainly of EDC in the column VIII in which a cleaning of the EDC by known methods is performed. Separated EDC can over Compounds 19 and 6 are recycled to the VCM / EDC reactor II. High boilers are about Compound 20 separated and can for HCl recovery be sent to a burn.

Claims (16)

A supported, base-containing and halogen-containing catalyst, prepared by impregnation techniques, on a support material containing metal salts with at least one platinum metal, furthermore at least one metal which can change its oxidation number by +1, and furthermore exactly one alkali metal, characterized in that - a support material with a specific surface area, which is less than 10 m ² / g, the catalyst is obtained by first drying the metal salt-impregnated support material, and calcining the impregnated and dried catalyst precursor at 300 to 500 ° C. Catalyst according to claim 1, characterized in that that the calcination is carried out under reducing atmosphere. Catalyst according to claim 2, characterized in that that the calcination is carried out under hydrogen atmosphere. Catalyst according to claim 1, characterized in that that the calcination is carried out in an inert atmosphere. Catalyst according to claim 4, characterized in that that the calcination is carried out under a nitrogen atmosphere. Catalyst according to claim 4, characterized in that that the calcination is carried out under inert gas atmosphere. Catalyst according to one of claims 1 to 6, characterized that the concentration of platinum metal between 0.1 and 2 percent by weight is. Catalyst according to one of claims 1 to 6, characterized that the concentration of the metal, which is its oxidation number change by +1 can be between 0.5 and 10 percent by weight. Catalyst according to one of claims 1 to 6, characterized that the concentration of the alkali metal is between 0.5 and 10% by weight is. Catalyst according to one of claims 1 to 9, characterized that as metal, which can change its oxidation number by +1, one or more metals of one of iron, copper, cerium and lanthanum-forming group is selected. Catalyst according to one of claims 1 to 10, characterized that as platinum metal palladium, as metal, which its oxidation number change by +1 can be selected iron, and as the alkali metal sodium. Catalyst according to claim 11, characterized in that that palladium, iron and sodium each have a concentration of 1 percent by weight. Catalyst according to one of claims 1 to 12, characterized in that the following working steps are carried out for its preparation: h) Preparation of a solution of 1 mass% PdCl ₂ in about 5% aqueous HCl and an aqueous solution containing 5 % of FeCl ₃ and 4.3% NaCl, i) add 17 kg of α-Al ₂ O ₃ per 30 liters of the PdCl ₂ solution and 10 liters of the FeCl ₃ / NaCl solution, j) 45 minutes intensive stirring in order to ensure the most complete and uniform impregnation of the support, k) removal of the excess solvent in a moving system at 100 ° C. by applying a slight vacuum, l) complete drying of the pellets obtained at 110 ° C. for 12 hours, m) calcination of the dry pellets under pure H ₂ atmosphere first for 1 minute at 50 ° C, then heating for 30 minutes at 375 ° C and then keep this temperature for 5 hours, n) removal of the catalyst from the Ofe n with immediately subsequent cooling to room temperature within 1 minute. Use of the catalyst according to one of claims 1 to 13 for the simultaneous production of 1,2-dichloroethane and vinyl chloride monomer together with water from ethylene, hydrogen chloride and oxygen. Use of the catalyst according to one of claims 1 to 13 for the preparation of vinyl chloride monomer with water from ethylene, Hydrogen chloride and oxygen. Use of the catalyst according to one of claims 14 or 15 as a fluidized bed material in a fluidized bed reactor.