DE2629461A1 - Halogenated unsaturated hydrocarbons esp. vinyl chloride prodn. - using fluidised bed to transfer heat from exothermic to endothermic zones - Google Patents

Abstract

Prodn. of halogenated, unsaturated hydrocarbon is effected by simultaneous and common halogen substitution of a hydrocarbon and thermal decomposition of an alkyl halide. An exothermic reaction of a halogen with a selected hydrocarbon in the vapour phase is carried out in a first reaction zone (I) in the presence of fine particulate solids, so that a selected alkyl halide comprising >=2 halogen atoms in the molecule is formed, accompanied by heat production; this heat is absorbed by the solid particles; Simultaneously, an additional quantity of the selected alkyl halide is introduced into a second reaction zone (II) the solid particles are transported from (I) to (II) where they give up their heat to promote dehydrohalogenisation of the additional alkyl halide in this zone, thus producing a halogenated, unsaturated hydrocarbon with the same number of carbon atoms in the molecule as the alkyl halide. Used partic, for the prodn. of vinyl chloride. Effective transfer of the considerably heat produced (I) to (II) where it is required, is attained.

Description

Process and reaction apparatus for the production of

halogenated unsaturated hydrocarbons, especially vinyl chloride The invention relates generally to the production of halogenated hydrocarbons and in particular the production of vinyl chloride.

Vinyl chloride is an important and valuable commodity product, which is used in many ways in the manufacture of polymer materials. It will usually by pyrolytic dehydrochlorination of dichloroethanes (1,2 or 1,1-dichloroethane) manufactured according to one of different processes 8 For example, 1,2-dichloroethane, which is also known as ethylene chloride (EDC) by direct chlorination of ethylene in a gas phase reaction with chlorine or by the reaction of ethylene and chlorine in a liquid medium getting produced; 1,1-dichloroethane can be produced by chlorinating ethane, Vinyl chloride monomer (VCM) is mostly produced by the dehydrochlorination of 1,2-dichloroethane The state of the art relating to the preparation of the 1,1- and 1,2-dichloroctane isomers and for the pyrolytic dehydrochlorination of these isomers to obtain Vinyl chloride monomer (VOM) is exemplified by U.S. Patent 2,838,577 and British Patents 1,146,706, 1,184,778, 1,218,417 and 1 225 210 illustrated the additive chlorination reactions of ethylene and Ethane are highly exothermic and are usually in the near temperature range the ambient temperature. The reverse is the case with the dehydrochlorination of dichloroethane an endothermic reaction for which a large amount of heat and a relative one high temperature is required to achieve the desired reaction with the desired Achieve speed of response. This applies in particular to the 1,1-dichloroethane isomer, for the one to achieve a sufficient dehydrochlorination rate higher temperature is required than for the corresponding 1,2-isomer. Through the strongly Andothersian character of pyrolytic dehydrochlorination, in which it when it is a thermal cracking reaction, a serious problem arises in terms of adding additional heat to the reactant mixture when necessary applied higher temperature.

In the direct chlorination of ethylene or ethane for production of dichloroethanes theoretically sufficient heat falls to thermal cracking of the Dichloroethane for the generation of monochlorinated hydrocarbons. One has therefore already recognized that it would be desirable to direct the two reactions Succession, d. H. in series one behind the other, to be carried out in this Process the heat released in the exothermic chlorination addition reaction is used to at least part of the heat demand of the endothermic Bring cracking reaction on, while at the same time an internal cooling device for excess heat from the chlorination reaction is provided. Such a thing Process with joint chlorination and dehydrochlorination reaction is in the U.S. Patent 2,838,577; the heat transfer takes place within and between an exithermal ithan-chlorine reaction zone and an endothermic one 1,1-dichloroethane cracking reaction zone using a common reaction bed of fluidized solid particles for both zones. The reactants come out the chlorination zone to the dehydrochlorination zone and become during this transition enriched with additionally supplied 1,1-dichloroethane, preferably by recycling unconverted dichloroethanes from the product stream.

A certain dehydrochlorination catalyst is preferably used as the fluidized bed solid material used. However, this method of US Pat. No. 2,838,577 has one Number of disadvantages. On the one hand, there is a substantial proportion of the process product from ethyl chloride.

If the fluidized or fluidized bed solids have a dehydrochlorination catalyst it is possible to produce more vinyl chloride than ethyl chloride, however only by increasing the molar ratio of chlorine to ithan, as well as by increasing it that of the reaction vessel supplied relative amount of dichloroethane. If the flow or. Fluidized bed solids do not have a dehydrochlorination catalyst contain, the product stream contains significantly more ethyl chloride than vinyl chloride. Another disadvantage is that the product is relatively large in size Contains proportion of unreacted dichloroethane It was also found5 that the production of dichloroethane through a chlorine addition reaction in the gas phase, as described in US Pat. No. 2,838,577, difficult to control is, with the result that there is a tendency towards the formation of undesirable polychlorinated soles hydrogen by-products through direct chlorine substitution of the hydrocarbon used It also favors the presence of chlorine in the dehydrochlorination reaction zone tends to form by-products, which not only reduce the yield of vinyl chloride mono mer (VCM), but can also be subject to gumming and coking. Thus, this method is not suitable as a basis for a commercial vinyl chloride monomer complex, as it is characterized by unsatisfactory vinyl chloride yield and insufficient selectivity is.

In British patent specification 1 218 417 it is indicated that the simultaneous production of vinyl chloride and dichloroethanes without occurrence A disruptive chlorine-ethylene reaction can be achieved if 1,1,2-trichloroethane in a mixing zone at a temperature of 800C to 3000C in certain molar ratios mixed with ethylene, chlorine and dichloroethanes and then this mixture into one Reaction zone is introduced, which is free of any filling and on a Temperature from 370 ° O to 5000G is maintained. In the same British patent 1 218 417 it is noted that the interfering chlorination of ethylene possibly can be avoided in several ways, for example by reducing the pressure works, you dilute or chlorine with an ethylene overshot or with an inert gas Stir in chlorine at various points in the reactor; However, this brings a reduction the productivity of the reaction vessel.

Much more satisfactory for the production of vinyl chloride monomer is that of Joseph A. Buckley in an article "Vinyl Chloride via Direct Chlorination and Oxychlorination ", Chemical Engineering, Nov. 21, 1966, SB.

102-104, described method (see also US Pat 2 724 006). A plant embodying the Buckley process essentially consists of three units One unit is a direct chlorination unit, in which ethylene dichloride by direct addition of 1 mole of chlorine to 1 mole of ethylene is generated in the second unit, commonly referred to as the cracking unit thermally 1 mole of HCL and 1 mole of vinyl chloride monomer (VCM) per mole of ethylene dichloride generated.

Commonly referred to as the oxyhydrochlorination unit (OECl unit) Unit is used to convert HCl and Xthylene into ethylene dichloride by catalytic Oxidation, d. H.

2 Nol HCl and 1 mol of ethylene are mixed with air to 1 Nol of ethylene dichloride oxidized (the oxyhydrochlorination process is sometimes also called oxychlorination or called oxidative chlorination). Theoretically, in a balanced, in equilibrium half of the ethylene dichloride fed into the cracking unit generated in the direct chlorination unit and the other half in the OHCl unit. The ethylene supply for the entire system is divided equally between the The direct chioring unit and the OHCl unit are divided. In the practice However, the direct chlorination unit produces due to losses in the overall cycle more ethylene dichloride than the OHCl unit.

A conventional vinyl chloride monomer system of that described by Buckley Art offers the advantage of eliminating the by-product generation of HOl. However, this system also suffers from a number of disadvantages, including relative high investment costs, excessive formation of undesirable polychlorinated By-products and relatively high operating costs. Other disadvantages are also known to the person skilled in the art. The invention is therefore an object to provide a method and reaction apparatus for producing halogenated Hydrocarbon open, in particular for the production of vinyl chloride based on the free from the disadvantages of the methods described above and otherwise known for the production of vinyl chloride monomer are particularly intended by the invention a process for the production of vinyl chloride with simultaneous chlorination and Dehydrochlorination can be created, in which the chlorination and dehydrochlorination processes be carried out under such conditions that the formation of carbonaceous Deposits and residues as well as the formation of undesirable chlorinated hydrocarbon by-products as well as non-chlorinated hydrocarbons, such as gumming or coking are subject to, is reduced as much as possible. The inventive method is to carry out the simultaneous chlorination and dehydrochlorination reactions in a fluidized bed or fluidized bed apparatus with a high effective heat transfer within and between the two Enable reaction zones. Included should preferably have the same fluidized bed or fluidized bed solids for both reaction zones used and the need to use Kat alysatorfe materials The invention is also intended to provide a method for production of vinyl chloride, which is produced by the dehydrochlorination reaction produced hydrogen chloride (hydrogen chloride) as a chlorinating agent in an oxychlorination stage dichloride can be used to produce ethylene, so that in effect essentially no HCl is obtained as a by-product. For the method according to the invention should be a separate he reaction vessel for the direct chlorination with accordingly unnecessary large cooling water requirements. The inventive method for production of vinyl chloride monomer (VCM) is said to have high selectivity and good efficiency own and at relatively high temperatures and within a relatively wide Pressure range be feasible.

For this purpose, according to the basic idea of the invention in a Process of the general type mentioned at the outset provided that the chlorination and debydrochlorination reactions concurrently with each other in one reaction apparatus which contains fluidized non-catalytic solids * the be circulated through and between the two reaction zones to Removing heat from the exothermic reaction and supplying it to the dehydrochlorination reaction.

A vinyl chloride monomer B system in the equilibrium state according to the invention comprises an oxyhydrochlorination carried out in a first reaction zone in accordance with the following reaction equation (1), and associated therewith at the same time a direct chlorination and dehydrochlorination carried out in a second reaction zone in accordance with the following reaction equations (2) and ( 3): However, as explained above, when EDC (ethylene dichloride) is produced by a direct chlorine addition reaction carried out at high temperature in the gas phase, there is a tendency towards the formation of undesirable mono- and polychlorinated hydrocarbons. In addition, the chlorination reaction can downright destroy the hydrocarbon used, in such a way that carbon-containing by-products are formed. To further explain the importance and difficulty of the problem of reaction control and regulation posed by this, it should be mentioned that in a process for the production of vinyl chloride monomer which works with ethylene and chlorine as starting materials and with ethylene dichloride (EDC) as intermediate product, the reactants and the reaction products with one another come into contact, a number of secondary reactions can occur (some of which may also be desirable depending on the desired product mixture).

Below are some examples of such possible secondary reactions: Vinyl chloride + chlorine "trichloroethane (4) Trichloroethane heat; Dichloroethylenes + Hydrogen chloride (5) Dichloroethylenes + chlorine> tetrachloroethanes (6) Tetrachloroethane Heat, Trichlorethylene | Hydrogen chloride (7) Trichlorethylene + chlorine -7 pentachloroethane (8) Pentachloroethane heat perchlorethylene + Hydrogen chloride (9) Perchlorethylene + chlorine - + hexachloroethane (10) The following reactions are also possible: The reaction (10) is a final reaction, since hexachloroethane cannot be chlorinated any further. A main object of the invention is therefore to ensure sufficient reaction guidance or control, such that only reactions (2) and (3) take place in the reaction apparatus, and to stop these reactions in such a way that reactions (4) to ( 12) cannot occur.

Reactions (11) and (12) are particularly troublesome because they are carbon is formed, which can contaminate the reaction vessel. In addition, the Reaction (11) the generation of excess HCl in the system, an excess However, the presence of HCl disrupts the equilibrium of heat as well as the equilibrium of materials or substances the reaction. In this context it should be noted that the problem of Formation of excess HCl in certain commercial vinyl chloride monomer processes occurs, in which case the HCl is used to produce other products, such as Perchlorethylene is used. However, this is not entirely satisfactory Solution, there such other products are of less value as a vinyl chloride monomer. It should also be noted that the conversion of too much oil in EDC (ethylene dichloride.

Dichloroethane) has the consequence that the heat requirement for the implementation the dehydrochlorination reaction, the heat available from the direct chlorination reaction exceeds. It can be seen that reactions (4) to (10) cannot occur, when no chlorine is present, as in the cracking furnace of the one described above Buckley system is the case. Therefore, in the method according to the invention is a precise control of the reaction conditions is provided so that undesirable reactions of EDC and vinyl chloride monomer (VCM) and in particular reactions (4) to (12) avoided or suppressed, while at the same time the directed formation of EDC and the conversion of EDC to VCM (vinyl chloride monomer) supported and promoted will.

In detail, it is provided in the method according to the invention that Chlorine from the chlorination reaction zone in a number of locations and in a controlled manner Manner is fed so that the direct chlorination and dehydrochlorination reactions positively terminated, such that the formation of carbonaceous deposits and undesirable chlorinated hydrocarbons as by-products are largely reduced will. Another feature of the invention is the recycling of by-products accruing chlorinated hydrocarbons into the fluidized bed reaction apparatus for thermal dehydrochlorination to increase the vinyl chloride monomer yield Another feature or a further embodiment of the invention consists in the Feeding carbon tetrachloride to the fluidized bed reaction apparatus; this carbon tetrachloride feed serves (a) as a controlled chlorine supply, (b) for stabilization the ethylene supply and (c) to improve the rate of conversion of EDC to VOM.

In the following, embodiments of the invention are based on the Drawing described; 1 shows a preferred one in the form of a flow chart Embodiment of a balanced, in equilibrium plant for generation of vinyl chloride by the process according to the invention, FIG. 2 shows a preferred embodiment of a flow or

Fluidized bed reactor for the simultaneous implementation of the chlorination and dehydrogenation reactions according to the invention, FIG. 3 to 8 further embodiments of flow or

Fluidized bed reactors and modifications of certain parts for implementation the invention.

It should be emphasized at this point that the fluidized bed process according to the invention and the apparatus according to the invention do not apply to the in 1 are limited and not necessary must be used in conjunction with an oxyhydrochlorination rejection unit, albeit this common application for the sake of desirability and the obvious Advantages of having a balanced system in which the conversion of EDC HCl formed in VON is used to form additional EDC is.

The system illustrated in FIG. 1 has a first Oxyhydrochlorination reaction vessel 1 for the formation of EDC (ethylene dichloride, dichloroethane) and a second reaction vessel 2 for the generation of VCM (vinyl chloride monomer). The reactor 1 will be used as reactants Ethylene, air and hydrogen chloride supplied via lines 6, 8 and 10 respectively; the in Reactor 1 running process is the oxidative chlorination of ethylene according to the above Reaction (1). The reactor 1 contains a highly reactive oxyhydrochlorination catalyst.

The oxyhydrohalogenation reaction can take place in various ways Ways known to those skilled in the art can be carried out, for example, according to the in U.S. Patents 3,214,481 and 3,214,482 Use of an aqueous catalyst can be carried out, which consists of a cupric halide or a ferric halide catalyst component and a promoter component.

which is a halide of bismuth, copper, chromium, Cobalt, iron, mercury, molybdenum, nickel, tin, titanium, vanadium or nangan The preferred catalyst systems are cupric cuprose chloride and ferric chloride for oxyhydrochlorination according to the processes of US patent steps 3,214 481 and 3 214 482. The oxyhydrochlorination reaction can also be carried out according to that in the UB patent 3,488,398 using a copper halide catalyst be performed.

The oxidative chlorination reaction is preferably used in the system according to FIG in the reactor 1 according to the method of US Pat. No. 3,448,398 a fluidized bed carried out on a catalyst which is essentially Contains cupric chloride on an aluminum oxide carrier. The response is in the Vapor phase at moderate pressure, typically in the range of about 10 to 50 peig (US pounds per square inch), as well as at a temperature in Range from about 19000 to 2500C. To dissipate the heat of reaction a liquid coolant guided in a closed circuit, which (not shown) Cooling coils in the reactor and a heat exchanger 12 comprises. The coolant is generated in the heat exchanger 12 by indirect heat exchange with water cooled by steam. The reactant product mixture is withdrawn from the reactor via conduit 14 withdrawn and fed to an adiabatic quenching column 16, where it is through adiabatic Quenching into a gaseous fraction enriched with EDC and into a second, liquid fraction is separated from an aqueous HCl solution. This liquid fraction The gaseous EDC-containing fraction is recovered via a line 18 passed through a heat exchanger 20 for cooling and then an EDC recovery unit fed to a decanter 22, where it is converted into a gaseous fraction, which is unreacted Ethylene and any gaseous by-products such as oxygen, nitrogen, Contains water vapor, carbon dioxide and carbon monoxide, which have a Line 24 are drained and separated into a liquid or wet crude EDC fraction This wet raw EDC reaction is transferred to a drying column 28 via a line 26 suppliedO It can also be considered the effluent from the reactor 1 to subject to a multi-stage condensation and extraction treatment, such as this in US Pat. No. 3,488,398 for obtaining dry EDC friction is described. Although this is not shown in the drawing, it could be related to this Purpose of the decanter 22 to be replaced by an EDC recovery unit, which is so designed is that (a) the top fraction from the quench column 16 initially through an or several stages each from (1) a cooling condenser, in which EDC, some water vapor and low-boiling by-products, such as Ethyl chloride, trichlorethylene, carbon tetrachloride and chloroform condensed are, and (2) a sedimentation tank in which these condensed substances from separated from the non-condensed vapor, there is that (b) the non-condensed Steam in an absorber column with a selected liquid absorption medium (such as toluene) is brought into contact to absorb any residue EDC and C1-C3 chlorinated hydrocarbons and for overhead fraction separation of water vapor and condensed by-product gases, and that (c) the enriched Absorbent medium is fed to a scraper, where the absorbed EDC and the otherwise separated chlorinated hydrocarbons from the absorption medium you will be returned to the absorber column. The EDC and the others chlorinated hydrocarbons obtained by this condensation and absorption treatment are combined with one another and fed to the drying column 28. In the drying column 28 the crude EDC fraction is dried to form an overhead fraction from water and a moisture-free, EDC-containing soil fraction. The water head fraction is withdrawn via a line 30, the dry EDC soil fraction is recovered and as introduced into the reaction vessel 2 via a line 32 as an insert will be described in detail further below, the reaction vessel 2 has a Bed of certain non-catalytic solids that are in the fluid or fluidized state are held and act as a heat transfer medium. The line 32 leads directly into a reaction chamber of the reactor. A second reaction chamber of the Reactor are also certain amounts of chlorine and ethylene via lines 34 and 36 These last-mentioned reactants supplied react in the reactor 2 with formation of EDC after the above-mentioned direct chlorination reaction (2). As below still in detail in connection with Figs. 2 and 3 are described EDC formed according to reaction (2) and the EDC fed in via line 32 thermally cracked in reactor 2 to produce vinyl chloride monomer the above-mentioned thermal cracking reaction (3). A substantial part of the heat energy requirement for reaction (3), the heat given off during reaction (2) is applied.

The reaction product flow from reactor 2 is via a conduit 38 is fed to a quenching column 40, where it is quenched into a liquid Soil fraction, which contains EDC and other heavy components, as well as a gaseous one Top fraction, which is rich in ethylene, HCl and VCM * separated. The soil fraction is fed to a distillation column 44 via a line 42. The head faction from the column 40 is cooled in a heat exchanger 46 and via a line 50 leads to the head section of the distillation column 44. This distillation column 44 is operated so that a top fraction consisting of HCl and ethylene gas, which Binding via a line reactor 1 is recycled, and a bottom fraction of crude vinyl chloride be generated. This crude vinyl chloride fraction is fed via line 52 to a vinyl chloride distillation column 54 which is operated to be one of at least 98 Xigem VCM Creates top fraction and a bottom fraction which is any unreacted EDC as well as any by-products such as other chlorinated hydrocarbons with a higher boiling point than vinyl chloride monomer. These Bottom fraction is preferably returned to reactor 2 via line 56. It can enter the reactor 2 together with the raw EDC fed in via line 32 are introduced, or with the ethylene supplied through line 36, or possibly also separately via a line 37. They can finally also together are introduced with the ethylene via line 35. This recirculation of by-products @ acts to improve the VCM yield in reactor 2. The one at the top the acid 54 recovered VCM product stream is via line 58 to a storage tank fed.

To further improve the conversion of EDC to VCM is preferred Carbon tetrachloride in controlled quantities via a line 60 together with the EDC fed in via line 32 into reactor 2, optionally Carbon tetrachloride can be used as an additional control measure also fed to the reactor via a line 62 together with the feed ethylene will.

As will be explained in more detail below with reference to FIGS. 3 to 8, the reactor 2 consists of three interconnected reaction chambers or zones, namely (1) an EDC cracking section, in which EDC from the reactor 1 with a high degree of conversion per throughput is thermally cracked to VCM, (2) an ethylene-chlorine reaction section, in which C2H4 and C12 are reacted in a controlled manner primarily EDC and VCM su generate, as well as (3) a post-cracking section in which the outlet flows from the first and the second section are combined and the thermal Cracking of the EDC is completed. The exothermic Heat of reaction from the ethylene-chlorine section is made by a continuously circulating stream of fluidized or fluidized solids into the two cracking sections transferred and there to generate the endothermic heat requirement for the EDC cracking reaction used.

In the course of the development of the present invention it was recognized that that the chlorine addition reaction is not particularly specific as to the question is which of the double bonds in a mixture of ethylene and unsaturated Chlorinated hydrocarbons (for example according to reactions 2, 4, 6, 8 and 10) Is attacked in each case. The chlorine addition reaction is also very fast in comparison to the debydrochlorination reactions (e.g. reactions 3, 5, 7 and 9) and chlorine is a powerful catalyst for dehydrochlorination. on the other hand Ethylene is a powerful inhibitor of dehydrochlorination and a mild catalyst for EDC decomposition (reaction 11), which is relatively slow compared with the dehydrochlorination reaction is, furthermore, in the course of the development of the present invention recognized that it can be achieved in a direct chlorination reactor a chlorine selectivity to EDC and VCM of about 90% is required Maintain ethylene: chlorine molar ratio greater than 4: 1. At a molar ratio of 1s1 the chlorine selectivity with respect to EDC and VCM is less than 40% o for a conventional balanced EDC-VCM system of the type with both an oxyhydrochlorination unit like a direct chlorination unit (compare for example the Buckley system described above) 2 moles of ethylene per mole of chlorine are required, with about half of the ethylene is fed to the oxyhydrochlorination unit. When using a fluidized bed reactor according to the invention could use all of ithylene for the ethylene chlorine section can be used so that any unreacted Ethylene is then separated off and the oxyhydrochlorination reactor 1 in admixture with HCl could be fed. However, it was found that at an ethylene: chlorine feed ratio of 2: 1, such a process has an chlorine selectivity with respect to EDC and VCM of would be less than 65%. Furthermore, the HCl / VCM ratio would be much greater than 1.0. From a strictly commercial point of view, one is chlorine Selectivity for EDC and VCM of about 65 * unsatisfactory. aside from that When the ethylene / chlorine feed ratio is high, the heat equilibrium becomes a very high temperature level for heat supply around the fluidized bed reactor require an external source. This would be a major concern right now of the invention, namely the complete redundancy or at least extensive reduction of fuel requirements for the reactor, negated the problem of achievement the greatest possible chlorine selectivity with regard to EDC and VCM with simultaneous The greatest possible reduction in the fuel requirement for the reactor is according to the Invention solved by the fact that the ethylene-chlorine reaction section of the fluidized bed reactor Chlorine added gradually through several chlorine inlet openings. The ethylene / chlorine ratios the total feed ratio is intentionally kept high at the individual insertion openings however, ethylene / chlorine is kept below the value of about 2: 1. To this Way is the formation of by-products through undesired chlorination reactions largely reduced and at the same time the EDC generation maximized - by very narrow gaps between the chlorine filling openings result in a very short Residence time which is sufficient that the chlorine addition reaction with ethylene is essentially can fully expire, while at the same time the extent of any accompanying Dehydrochlorination reactions can be reduced. This short dwell time contributes helps to keep the decomposition reactions at a low level.

In addition, the inhibiting effect of ethylene compensates for the catalytic one Effect of chlorine on debydrochlorination. In a balanced system as illustrated in Figure 1, about one-half of the total ethylene feed is used fed to the ethylene-chlorine section of the fluidized bed reactor, the remaining part is the Oxybydro chlorination reactor 1 fed. In this way, the heat requirement is increased of the fluidized bed reactor largely reduced.

A flow or flow rate that meets the requirements of the invention

Fluidized bed reactor unit can be designed in various forms; be. A preferred reactor design is illustrated in FIG. Here points the reactor unit designated as a whole by 2A has a bottom 66, which is preferably is provided with a solid grid or grate 68 as a support for a non-catalytic Solid bed of certain selected particle size and composition.

A riser unit is attached inside the vessel, which is a open at both ends and by means of suitable devices, such as (not shown) struts, on the vessel walls attached riser pipe 70. At its lower end, the riser has, as a precaution, a widening one Hopper 71 for easier entry of the solids. A feed pipe 72 also protrudes one end up into the funnel, with its other end up it was stirred out of the side of the vessel and connected to the ethylene supply line 36. The top of the riser is well below that upper Level 80 of the fluidized solid vortex or

Fluidized bed. The riser pipe 70 has a plurality of side openings which are connected to the chlorine supply line 34 by means of separate supply pipes 74 sind0 The EDC supply line 32 is connected to a further inlet opening of the vessel 66 connected, which is arranged directly above the grating 68 and with a Distribution unit 76 is connected, which is a uniform introduction of the supplied EDC in the bed of solids, but guaranteed outside of the riser arrangement. In a separating cyclo 82 is arranged in the solids separation zone above the solids bed; a dip tube 84 of the cyclone extends downwardly into the bed of solids. The dip tube 84 is preferably provided with a flap valve 86 at its lower end (or some other guiding device). An exit pipe 88 of the cyclone The product flow is connected to line 38. The cyclone serves as a matter of course to separate the wines from the reactor outlet flow and feed them into the Solid bed back.

The solids are removed from the riser through that of the manifold 76 supplied EDC and within the riser by the supplied via line 36 Xthylene is fluidized or made to flow or vortex. The solids flow in a circuit through the climbing device upwards and outside the climbing device the one down, in the manner indicated by the dashed arrow line; this Cycle is achieved by the pumping action of the ethylene. In one of those The reactor forms the interior of the riser device the aforementioned ethylene / chlorine reaction section. The post-crack section in the sense of the above extends approximately from upper end of the riser pipe to the top of the fluidized bed, the EDC cracking section from the post-cracking section down to about the point the introduction of the employed EDC into vessel 66. The post-cracking section is so obsessed that he has a large car lounge for complete completion the thermal dehydrochlorination of the EDC to VCM.

Heating coils (not shown) can be provided for the reactor be to the bed of solids to a suitable temperature level to initiate the Bring dehydrochlorination of the EDC and, if necessary, depending on the heat losses of the reactor from the direct ethylene chlorination reaction into the dehydrochlorination reaction to supplement the amount of heat transferred. However, thermal equilibrium is preferred maintained in the reactor by supplying heat in Borm a preheating of the feedstock.

At the low feed ratios used, in conjunction with The high degree of conversion of the EDC. Depending on the throughput, this can be preheated using high-pressure steam or by process heat exchange, whereby fuel gas supply or Eliminate other external sources of heat for heat supply at a high temperature level.

The mode of operation of the reactor 2A takes place in the practical experience of the invention as follows: (1) Ethylene and chlorine are gradually added to the riser reacted, producing EDC and heat, (2) the exothermic Heat of reaction in the riser is generated by a continuous recycle stream of fluidized solids in the post-cracking section and also in the EDC cracking section transferred, (3) fed from the reactor 1, it is EDC in the EDC cracking section thermally cracked, whereby the endothermic heat requirement for this cracking reaction through the one from the riser transferred heat is applied, and finally (4) those from the ethylene-chlorine reaction section and the Product exiting the EDC cracking section flows into the post-cracking section unites where the thermal cracking of the EDC under the influence of that from the riser pipe transferred heat is essentially conducted until it is completely closed, In practice, there is some tendency for something to sit in the ethylene-chlorine reaction section EDC generated in the top of the riser is cracked to VCM as a result of the build-up of heat generated by the direct chlorination reaction. However, since ethylene is an inhibitor for debydrochlorination is and there the ethylene: chlorine ratio at the different Chlorine injection points is deliberately kept high, the relative EDC amount remains, which is cracked in this way in the riser pipe, quite small.

It should be noted that the total ratio of ethylene: chlorine must be kept low in the riser, eo that the in the post-cracking chamber the amount of ethylene entering is kept to a minimum. Otherwise it would EDC in the post-cracking section strongly causes carbon formation, for example according to the reaction equation (11) from above. The reaction (11) shines through Ethylene to be promoted heavily and even at temperatures as low as 500 0F to occur to a significant extent. This EDC decomposition reaction is thereby largely minimized that one each at the individual inlets of the riser arrangement The amount of chlorine fed in is controlled so that essentially all of the reacted in the riser pipe Ethylene is converted to EDC0 The solids only serve as a heat transfer medium and should not have any catalytic properties.

In fact, it has been found that when using solids with catalyst properties, de h. of solids with active sites, these the Accelerate carbon-forming reactions. Therefore, for the ZwEC: k "der Invention solids with few or almost no active sites used. In order to ensure satisfactory operation, the solids are reserved delt to any possible active positions. neutralize. this happens in such a way that the solids are coated with carbon in order to do this to clog the active sites, as it were. This pretreatment takes place in such that the reactor is allowed to operate under normal operating conditions. In doing so, carbon is generated and accumulated during the initial phase of operation Die deposited from the solid particles for equilibration, d. H. Conditioning The amount of time required for solids is a function of surface area of solids. Conditioning pretreatment can be used for solids with a high surface area ratio require one or more days, while for solids with low surface areas achieving equilibration can be a matter of hours. It was further also found that the molar ratio of HCl to that produced in the fluidized bed reactor VCM (vinyl chloride monomer) increases with solids with a higher surface area and that to achieve the best results, the surface proportion of the solid materials about Should not exceed 50 qm / g. Therefore they are solids with a low surface area preferable. Under the name "Best materials with a low surface area" should in the sense used here solid materials with a surface area of less can be understood as about 50 qmXg. For the purposes of the invention can be manifold Solids are used, for example (but in no way limited to this ) Silicon oxide (quartz), aluminum oxide (alumina), silicon oxide-aluminum oxide, Glass powder and carbon. As a precaution, but not necessarily, you can the solids have a particle size of about 50 to 70 microns mean diameter own.

A significant advantage of the method according to the invention is that that the fluidized bed reactor at high temperatures up to, for example, 10000F and at Pressures up to about 300 psig (pounds per square inch) can be operated. The minimum temperature of the reactor for satisfactory operation is about 700 ° F. The best results will be with a temperature in the range of about Achieved 840 ° F to about 9250F. The reaction vessel can also come down when printing operated at ambient pressure, however, it is preferred when printing between worked about 50 psig and about 50 psig.

The container vessel of the reactor 2 is preferably made of nickel or a nickel alloy (e.g. type 304 stainless steel) to protect against Attack by the chlorine at the elevated temperatures maintained in the reactor. However, one lined with nickel, a nickel alloy, ceramic or brick can also be used Containers made of carbon steel can be used. The riser unit (or the used outer reaction chamber or transfer line) is made of an erosion-resistant Material, for example a nickel-containing alloy such as stainless steel from Type 304. The riser device preferably consists of a ceramic one Material. For example, but without any limitation) the climbing device made of aluminum oxide (xonerdem material) 0 The speed the upward flow of gas through the bed outside the climbing device as well as within the riser unit is set so that the solid materials be kept in a sealed phase in both chambers. Alternatively, the Solids within the riser are kept in a dilute phase0 For the purposes of the invention, a distribution of the fluidized solids is of about 10 to 40 FS pounds per cubic foot of a dense phase successful even with a dilute phase in the riser between 0.02 and 0.5 pounds per cubic foot. For the bluidization of the solid particles gas velocities between 0.7 to about 3.0 feet / second application while generating the upward flow of the solids in the riser as a dense phase gas velocities between about 5 to 40 feet / second are required. A feature of the invention is that relatively short residence times, especially in the Climbing unit, can be used The length of stay in the climbing unit is kept short enough to prevent the formation of -EDC, but not of VOM in the lower part To allow part of the riser, otherwise the VCM with formation of undesirable By-products can be chlorinated.

The chlorine inlet openings provided in the riser arrangement can vary in terms of number and spacing, and each can also be specific to each Place more than one opening along the climbing unit at least two and preferably about four insertion openings along the crate aggregate intended. Preferably between about six to nine insertion openings can be along the riser unit can be provided. Even more than nine entry openings can be attached, but this is because of the large number of supply lines required not preferable. Depending on the distance between the openings, the chlorine can be delivered to the various Insertion openings supplied with the same or with different throughput rates will. Also for the sake of example it should be mentioned that the inlet openings and the Flow rates at the inlet openings can be adjusted so that equal residence times for the gas flow between an inlet opening and the next surrender. Since each additional chlorine supply, the gas flow increased in the climbing device, it is to maintain the same length of stay required that the distances between the insertion openings with increasing distance from the lower end of the riser unit or with increasing distance along the direction of flow of solids in the transmission length in the case of a reactor as shown in FIG. 3 to 5, increase. Alternatively the riser pipe diameter can also be used to maintain a constant gas velocity be variable in the riser.

The total ratio (in moles) of ethylene fed to chlorine in the riser is maintained at a value between about 0.8: 1 and about 2.0: 1. However, the chlorine supply from the various supply openings is carried out with such Throughput that in the riser unit at the lowermost inlet opening an ethylene : Chlorine to mol ratio greater than about 2: 1, and preferably at least about 4: 1, and at the highest inlet opening a molar ratio of at least about 1: 1 and preferably at least about 2: 1 is maintained. In practice does not like the ethylene / chlorine ratio at the highest inlet opening 2: 1 or above and will be below the value at the previous or previous Feed opening (s) due to the fact that the overall feed ratio is less than about 2.0: 1 and because it is also a major part of the ethylene introduced into the riser unit by reaction with chlorine supplied upstream of the highest supply point is converted into EDC. Nevertheless, through appropriate control of the Total ethylene / chlorine feed ratio and feed rate to the individual feed openings proved to be possible in the manner just described, to ensure a selectivity of ethylene with respect to EDC and VCM of more than 90%. The molar ratio of directly into the bed of solids outside of the riser unit EDC introduced to the ethylene fed into the riser unit is preferred adjusted so that the amount of heat released by the conversion of ethylene to EDC slightly larger than that for the thermal cracking of the fed to the reactor as well of the EDC generated in the riser unit is the required amount of heat. In practice if ethylene is fed to 1 mol of EDC per mol of the riser unit. However, an EDC / ethylene ratio less than or greater than 1 can also be used if appropriate measures are taken to maintain the correct thermal equilibrium are provided.

The inner riser assembly is not essential to the invention and can be replaced with an outer transfer tube. This modification will illustrated by the reactor 43 shown in FIG. In this case it is Reactor vessel 66 is provided with a transfer tube 90 which extends from an outlet opening on the underside of the vessel to an inlet opening in the vessel side wall below the level 80, up to which the bed of solids is fluidized. The transfer tube 90 has a first insertion opening with an inlet tube 92 on, which is connected to the ethylene supply line, as well as several spaced apart Inlet ports with inlet pipes 94 connected to the chlorine supply line are. The grate 68 is omitted and the solids in the vessel are transported through the Fluidized via the distributor 76 supplied for the EDC. In this reactor design the supplied ethylene fluidizes the solids in the transmission line and also ensures the necessary pumping action to remove the solids exit at the bottom of the reactor vessel and up along the transfer line and flow back into the vessel.

This cycle is shown in the drawing by the dashed arrow line indicated. The reactor according to this modified embodiment operates in the same way Way like a previously described reactor with an internal riser. That Transfer tube forms the direct chlorination reaction section, and the solid volume above the point where the transfer line returns the solids to the vessel, forms the post-cracking section or the post-cracking zone.

Fig. 4 illustrates a modification of the apparatus of Fig. 3 which also operated in the same way as an internal riser reactor will. In this modification, the transfer line 90 is formed so that it the solids into the reactor at a point above level 80 of the fluidized bed returns. In this case the post-cracking section of the vessel 66 is that top of the bed of solids in the vessel, and the section for the direct chlorination reaction is the part of the transfer line between the last chlorine inlet opening and the vessel 66.

Fig. 5 shows a further modification. In this case is equivalent to the reactor unit from Fig0 4, with the difference that two separation cyclones 82A and 82B are provided. The inlet of the separation cyclone 82A is arranged so that he is the reaction product flow exiting upwardly from the bed of solids in vessel 66 while the inlet of the separation cyclone 82B with the transfer line 90 is connected and picks up the product flow from the direct chlorination reaction. The output lines 88A and 88B of the two separators are with that to the column 40 leading line 38 connected. The post cracking section is the same as in the case of the reactor according to FIG. 43 FIG. 6 shows a further possible modification of a inner riser unit. In this case, the riser pipe 70 in its lower Part of an enlarged hollow Eduktorabschnitt 98, which in turn on his closed bottom wall 100 is provided with an inlet opening, which with the äthylenztufuhrleitung 72 is connected.

There are one or more in the side wall of the eductor section enlarged openings 102 are provided through which the solid materials from the vessel 66 can flow into the riser. The through the bottom of the eductor section supplied ethylene flow induces a solid-state flow through the opening 102 and leads it up through the riser unit. Of course that shows Riser unit on several chlorine inlet openings, just like the riser unit according to Fig. 2.

It can also be provided according to FIG. 7 that the riser pipe 70 at its lower end with a Venturi mixing nozzle in the form of a constriction section 104 with a tapered diameter and with an open funnel-shaped widening end piece 106 is provided. The ethylene supply line 72 protrudes into the funnel-shaped lower End 106 upwards into the funnel-shaped End 106 is designed with a large enough diameter that solids around the Feed pipe 72 around can enter the riser. The one from the supply line 72 supplied ethylene flow provides the necessary pumping action to remove the solids to be drawn from the surrounding bed of solids into the lower end of the riser pipe, and leads the solids through the riser up to the top according to Fig. 2 to ensure the cycle described. The nozzle portion 104 functions as one Venturi mixing nozzle such that the solids in the ethylene feed stream are uniform be dispersed. Alternatively, the nozzle section 104 can be spaced from the lower End of the riser are provided such that the solids through the Gap between the nozzle section 104 and the actual riser pipe through in the riser pipe must be pulled in.

Figure 8 illustrates a modification at the top of the riser 70o In this case the riser pipe 70 ends at the upper end in a hollow 2-piece 108, the two horizontally running and oppositely directed outlet openings 110 and 112 form0 These openings cause the solids and the Reaction product flow in lateral instead of vertical direction into the reactor vessel 66 The tee 108 is normally submerged in the bed of solids; through the Exit in the lateral direction from the 2-piece is the period of time during which the direct chlorination reaction product flow is in the post-cracking section is as large as possible.

It can be seen that the outer transfer line 90 is in a sense acts as a separate reactor, and one therefore into consideration pull the transfer line through a second vertical elongated reaction vessel to replace, with a first lower conduit the lower end of this second vessel connects to the lower end of the reaction vessel 66 and a second upper conduit the upper end of the second vessel with a side opening in the vessel 66 connects either below or above the surface 80 of the bed of solids is ethylene, which is either in the first connection line or directly on the lower The end of the second vessel is introduced, the required pumping action would be Creation of a flow of pesticides from the lower end of the vessel 66 into the lower one Ensure the end of the second vessel, and those located in the second vessel Solids would be driven by the second connecting line Reaction product flow from the second reactor vessel is returned to vessel 66.

As mentioned earlier, the overall conversion rate will be from EDC to VON improved by adding carbon tetrachloride to the EDC cracking section. Such addition of CCl4 inhibits the formation of carbon from the EDC via reaction (3) and also provides chlorine, which causes the dehydrochlorination of the EDC catalyzes the formation of VOM. However, it was found that the CCl4 to to aid the conversion of EDC to VCM, put in the reactor vessel in an amount between about 0.7 and 3.3 moles per 100 moles of EDC must be introduced. A value above 3.3 mol should be avoided for reasons of economy. The required amount of CCl4 addition decreases with increasing reactor temperature. It was determined, that with the addition of CC14 the total conversion of EDC to VCM to a value of over 90% can be increased and that the selectivity is over 90%. It was furthermore also found that the addition of chlorine instead of hollow material tetrachloride in the reactor does not produce comparably favorable results.

Provision can also be made to add CCl4 to the ethylene feed line, if this feed line is made of nickel or a nickel-containing alloy and the ethylene fed in is heated to around 3000F. This has turned out to be Proven to be advantageous that this stabilizes the ethylene, so that it does not form carbon and methane in the supply line. The amount to CCl4, which is fed to the riser unit or the outer transfer line, should be maintained between about 0.5 and about 4.0 moles per 100 moles of ethylene will.

The following are specific examples to illustrate the Method according to the invention and certain aspects of this method described. Unless expressly stated otherwise, in the following examples In each case a reactor of the type with an internal riser assembly as shown in Fig. 2 used. The reaction vessel was made of nickel, the riser assembly was made of fired Made from 99% pure aluminum oxide. The reaction vessel was six in height Feet and an inside diameter of about 2 inches. The vessel contained a bed of solids of alumina silicate, the height of the bed of solids was about 2.5 feet. The solids possessed a particle size in the range of about 44e to about 150, with an average average surface area of 4 qm / g. The chemical composition of the solids was about 60% by weight SiO2 and 40% by weight Al2O3. The climbing unit had a length 18 inches, an inner diameter of about 3/8 inches, and eight Shlor injection ports in the following arrangement: opening No. layer 8 3 inches below the top 7 2 3/4 Inches under No. 8 6 2 1/2 inches under KrO 7 5 2 1/4 inches under NrO 6 4 2 inches under NrO 5 3 1 3/4 inches under No. 4 2 1 1/2 inches under NrO 3 1 1 1/4 inches under No. 2 The reactor vessel was from a bath of molten salt in one between Surrounding the vessel and an outer jacket formed chamber. Was around the coat an electrical heating coil is provided.

Example I (test runs No. 168-177) In the reactor was EDC at 4.71 g-moles per hour and at a temperature of about 400 ° F fed.

0.10 g-Nol per hour were also fed in together with the EDC CCl4, 0.28 g-mol / hour trans-1,2-dichloroethylene, 0.03 g-mol / hour chloroform and 0.05 g-mol / hour perchlorethylene. Ethylene and chlorine were put in the riser in amounts of 3.55 and 2.44 g-mol / hour and at a temperature of about 250 ° F The reactor was operated at about atmospheric pressure and at about 8900F. The chlorine flow was divided equally between the eight openings. That ethylene contained 0.19 g-Xol CCl4. Together with the EDC, the reactor was further developed even 1.33 g-moles / hour of nitrogen supplied. The experiment lasted 60 hours. The product outlet flow was removed from the reactor and analyzed. An initial sample of the product exit flow was removed about 1 hour after the start of the experiment, further samples were each taken at intervals of about 5 to 8 hours. The input and output product compositions Table I (g-mol / hour) compiled in Table I below are product output flow start- end- through-use sample sample cut EDC 4.71 0.15 0.31 0.15 nitrogen 1.33 1.57 1.18 1.33 ethylene 3s55 1.35 1.59 1.55 chlorine 2.44 VCM (vinyl chloride monomer) - 7.52 6.13 6.96 carbon tetrachloride 0.29 0.21 0.47 0.34 cis- and rans-1,2-dichloroethylenes 0.28 0.23 0.32 0.32 vinylidene chloride - 0.11 0.14 0.16 Hydrogen chloride - 8.99 7.34 8.48 Chloroform 0.03 0.03 0.06 0.05 Trichlorethylene - - - NIL perchlorethylene and others 0.05 0.04 0.07 0.05 Total 12.68 20.20 17.61 19.39 The average of the samples taken became determined that the EDC conversion rate was 97.3% and the C2 selectivity for VCM Was 94.5%.

Example II (Run # 145) The reactor and solids were in this example the same as in example 1. EDC and carbon tetrachloride were fed together into the main part of the reactor in amounts of 7.67 and 0.21 g-mol / hour, respectively introduced. At the same time, ethylene and carbon tetrachloride were on the lower end of the riser in amounts of 8.75 and 0.39 g-mol / hour, respectively; at the eight Openings along the riser unit were chlorine in equal amounts (with a total supply amount of 7.68 g4 mol / hour). The EDC, the ethylene and you chlorine were on the preheated to the same temperature as in Example 1 and the reactor was at about 890 ° F and a pressure of about 1.5 atmospheres (absolute). The attempt lasted about 44 hours.

The product outlet flow became a sample about 1 hour later At the beginning of the experiment, further samples were taken at periodic intervals taken.

Test Sample No. 145 was removed approximately 33 hours after the start of the experiment. The composition of Sample No. 145 is shown in Table II.

Table II (g-mol / hour) product starting flow (test no. 145) EDC 0.3658 ethylene 3.5279 chlorine -VCM (vinyl chloride monomer) 13.4812 carbon tetrachloride 0.3459 cis and trans 1,2-di-0.0912 chlorethylene vinylidene chloride 0.1496 hydrogen chloride 17.8000 chloroform 0.0422 perchlorethylene and other 0.0643 from the test sample No. 145, the EDC conversion rate became about 95.2% and the C2 selectivity with respect to FROM determined to be about 97.9%.

Examples III to V are intended to demonstrate the pronounced superiority of Carbon tetrachloride over chlorine as an additive to improve EDC conversion To be shown per round.

In these three examples the reactor was of the same construction as the reactor used for the previous examples, but was Inside diameter only 1 1/4 inches. The climbing unit was not used. The solids were of the same type as in the previous examples, however only about 600 cc Solids used.

Example III (Test No. 348) The reactor was preheated to about 400 ° F EDC fed at a rate of 2.82 g-mol / hour. The reactor was at a temperature heated to 900 ° F. The product outlet flow from the reactor was recovered and analy value, the EDC conversion was 57% and the C2 selectivity from the test sample No. 348 determined with respect to VCM to be 93.5%.

Example IV (Test Sample No. 410) The reactor was heated to about 400 ° F preheated EDC supplied in an amount of 3.41 g-Nol / hour. The reactor was heated to 8750F. Chlorine was added to the EDC at a rate of 0.007 g-mol / hour. Samples were taken from the reaction product exit stream and analyzed of Test Sample No. 410, the EDC conversion became 85% and the C2 selectivity became VCM was determined to be 94.0%. Example V (test experiments No. 897-898) was EDC preheated to about 400 ° F is fed in at a rate of 2.91 g-mol / hour The reactor was heated to 905 ° F. Along with the EDC became carbon tetrachloride Introduced in an amount of 0.076 g-mole / hour From the resection product exit stream samples were taken; from the test samples Er. 897 and No. 898 the EDC conversion was 99.7% and the C2 selectivity for VCM was 94% In Examples VI and VII below, the reactor and solids were the same as in Examples III to V. A riser unit was not provided0 The ethylene feed line was made of 316 stainless steel.

The purpose of these tests is to illustrate the cheap Effect of carbon tetrachloride in reducing the tendency to Carbon formation, which would lead to a blockage of the system.

Example VI (Test Sample No. 434) Ethylene was used in an amount of 2.54 g-moles / hour and at about 2000F into the reactor heated to 8900F.

Chlorine was separated in an amount of 1.31 g-mol / hour and at about 2000F is fed into the reactor. Within about 8 hours the reactor was overturned Carbon congestion shut down.

Example VII (Test Sample No. 462) was used in an amount of 1.49 g-moles / hour and at about 2000F into the reactor heated to 9000F.

Together with the ethylene input, carbon tetrachloride became in one Amount of 0.037 g-mol / hour of chlorine supplied was separately in an amount of 0.85 g-mole / hour and fed to the reactor at about 2000F. An increase in pressure due to carbon deposition, it took 48 hours to become fully clogged However, nothing came of it Example VTIX (Test Sample No. 1984-1984A) In this example, the same reactor and solids as in Example 1 used. The EDC was fed into the reactor at the temperature of 4000F. The reactor temperature was 900 ° F. Ethylene and chlorine were at one temperature of about 2500B introduced into the riser. The chlorine flow was the same Parts split between the eight openings in the riser unit. The feed rates for EDC, ethylene and chlorine were 3.378, 3.390 and 3.263 g-mol / hour, respectively. The attempt took 20 hours. The product exit stream from the reactor was recovered and analyzed at intervals. The composition of the product output stream for the Test samples 1984 and 1984A are shown on average in Table III.

Table III (g-mol / hour) 1,2-dichloroethane 0.655 1,1-dichloroethane 0.0 ethylene 1.590 hydrogen chloride 7.876 nitrogen 0.324 vinyl chloride 4.198 dichloroethylene 0.162 methane 0.0 chloroform 0.005} carbon tetrachloride 0.0 trichlorethylene 0.187 Perchlorethylene and others 0.015 The conversion of EDC was about 80.6%, the selectivity of C2 with respect to VCM about 90%.

Examples 1 and II illustrate (a) the addition of both CCl4 to the ethylene feed and the EDC feed for reactor 2, and (b) the non-uniform Clearances of the chlorine injection openings. Example I also simulates the recycling of by-products from the VCM column 54 via line 56 in reactor 2, since this example includes compounds of the type which are by-products can occur during the formation of EDC and the conversion of EDC to VCM. Example I also illustrates that O1-C3 chlorinated by-products as well as not it reacted ethylene and EDC in the reactor output product flow up to the complete Consumption can be recycled and this increases the overall VCM yield. In practice, as illustrated in FIG. 1, that recovered from the fluidized bed reactor Treated reaction product exit stream to recover VCM, HOl and ethylene and then the remaining fraction of the product exit stream into the reactor recycled, for introduction into the solid fluid bed together with fresh EDC.Eß Treatment of the bottom fraction from vinyl chloride column 54 can also be provided to remove any tarry residue or polymerized vinyl chloride to be separated from the return to the fluidized bed tank. Although preferably essentially pure EDC is fed to the fluidized bed reactor from the oxyhydrochlorination reactor, it can also be provided that the EDC from this source small amounts of other contains chlorinated ethylene compounds as impurities.

The examples Til to V show that the addition of carbon tetrachloride cheaper in terms of EDC conversion to VCM is as the encore von Chlor0 Examples VI and VII show that the addition of carbon tetrachloride to ethylene the extent of the hollow material clogging of the plant is reduced.

Example VIII shows (by comparison with Example I) that the EDC conversion is lower if there is no carbon tetrachloride in the material input for reactor 2 is added and if recovered from the starting product flow of the reactor 2 By-products are not returned to the reactor via line 56.

Of course, the invention is also suitable for use in the production of other alkyl halides and for simultaneous debydrohalogenization such other alkyl halides to a corresponding halogenated unsaturated hydrocarbon. The halogen substituent on the alkyl halide can be for example chlorine, bromine or iodine, the inventive method is suitable can also be used to treat tri- and di-halide-substituted hydrocarbons. By way of example, the following halogenated hydrocarbons, all of which can be used (as known to the person skilled in the art) can be dehydrohalogenized in a pyrolytic way, instead of EDC to produce a corresponding halogenated unsaturated Hydrocarbons are used: 1,1-dichloroethane, trichloroethane, di- and trichloropropane, Di- and trichlorobutanes, di-bromoethanes, di- and tribromopropanes, di- and tribromobutanes as well as higher-boiling saturated alkyl chlorides and bromides with at least two halogen atoms in the molecule.

It can also generate more than one alkyl halide at the same time be dehydrohalogenized. The production of halogenated unsaturated hydrocarbons above is pyrolytic dehydrohalogenization of alkyl halides in British Patent 1,218,417 and in U.S. Patent 2,569 923, 2,378,859, 2,379,372 and 2,838,577 and in the references cited therein described.

In addition to the advantages already mentioned, the invention has the advantage lower capital investment costs and space requirements than a matched one Plant of the type described by Buckley The invention also provides an essential feature Reduction in operating costs and water consumption. Indeed made possible the use of the Fleißbettreaktors that a system of the type shown in Fig. 1 Steam generates instead of consumed. As a result of the recycling of by-products, the The problem of waste disposal is significantly reduced a whole series of modificationsa For example, in the reactor 2, if necessary more than one riser (or transfer line) can be used. Further Modifications are readily apparent to those skilled in the art.

Patent claims:

Claims (1)

Claims 1. A method for producing a halogenated unsaturated hydrocarbon by simultaneous common halogen substitution of a hydrocarbon and thermal decomposition of an alkyl halide through the following process steps. (a) Exothermic reaction of a halogen with a selected one Hydrocarbon in the vapor phase in a first reaction zone in the presence of fine broken solids in such a way that, with the generation of heat, a selected allyl halide is formed with at least two halogen atoms in the molecule, (b) absorption of heat in the solids, (c) simultaneous incorporation of an additional amount of the selected Alkyl halide in a second reaction zone, (d) removal of heated solids from the first reaction zone and introducing these heated solids into the second Resction zone, (e) dehydrohelogenization of this additional alkyl halide in the second reaction zone with heat added from the solids, with formation of a halogenated unsaturated hydrocarbon with the same number of Hollow atoms in the molecule such as the alkyl halide O 2 * process mentioned Claim 1 characterized in that the selected hydrocarbon is an olefin is. 3. The method according to claim 1 or 2, characterized in that one the alkyl halide generated in the first reaction zone in a third, of the finely divided solids a free reaction zone Dehydrohalogeni si erungereaktion in the vapor phase e undergoes to generate an additional Amount of said halogenated unsaturated hydrocarbon 4o process according to claim 3, characterized in that the dehydrohalogenization reaction is carried out in the third reaction zone using heat, which is supplied by product gases from the first or the second reaction zone. 5 * method according to one or more of the preceding claims, characterized in that the second reaction zone surrounds the first reaction zone. 6. The method according to one or more of the preceding claims, characterized in that solids are separated from the second reaction zone and these withdrawn solids are returned to the first reaction zone. 7. The method according to claim 6, characterized in that the solids from the top of the first reaction zone to the introduction into the second reaction zone are withdrawn and from the second reaction zone to the lower end of the first reaction zone to be led back. 8. The method according to one or more of the preceding claims, characterized in that the second reaction zone is in a reaction vessel (66, Figg. 3 to 5) and the first reaction zone (gO, Fig. 3 to 5) outside the reaction vessel is arranged. 9. The method according to one or more of the preceding claims especially for the production of vinyl chloride, characterized in that it is ethylene (at 36, Fig. 1; 72, Fig. 2; 92, Pigg. 3 to 5) and chlorine (at 34, Fig. 1; 74, Fig. 2; 94, Fig. 3 to 5) into a first reaction zone (71, 70, Fig. 2; 90, Fig. 3 to 5) initiates which finely divided solids in a fluidized or Vortex state includes that you put the ethylene and chlorine in contact with these solids brings to reaction with the generation of heat and ethylene dichloride that one simultaneously additional Ltbylendiohlorid (at 32, Fig. 1 to 5) in a second reaction zone which introduces finely divided solids in a fluidized or vortex state contains that the heat generated in the first reaction zone for dehydrochlorination of the additional ethylene dichloride in the second reaction zone to form Vinyl chloride is used by putting fluidized solids in the loop from the first Reaction zone into the second zone and from the second reaction zone into the first Reaction zone leads, and that the reaction products from the first and from the second reaction zone withdraws. 10. The method according to claim 9, characterized in that the solids in the circuit from the top of the first reaction zone to the top of the second Reaction zone and lom the lower end of the second reaction zone to the lower end of the first reaction zone are performed. 11. The method according to claim 9 or 10, characterized in that one part of the heat generated in the first reaction zone for dehydrochlorination of in the first reaction zone generated ethylene dichloride under Formation of vinyl chloride used. 12. The method according to any one of claims 9 to 11 and in particular according to Claim 11, characterized in that at least part of the in the first reaction zone generated ethylene dichloride is debydrochlorinated in the first reaction zone. 13. The method according to one or more of claims 9 to 12, characterized characterized in that the chlorine of the first reaction zone in a number of different, at a distance from one another along the flow path of the ethylene in this reaction zone arranged locations (34, Fig. 1; 74, Fig. 2; 94, Fig. 3 to 5) is supplied. 14. The method according to one or more of claims 9 to 13, characterized characterized in that the first reaction zone is in a first vertical reaction chamber (70, 71, Fig. 2; 90, Fig. 3 to 5) and that chlorine of this first reaction zone at a number of locations at different levels (74, Fig. 2; 94, Fig. 3 to 5) is accessed in this first chamber. 15. The method according to claim 14, characterized in that the second The reaction zone is located in a wide reaction chamber and that the fluidized Solids circulated from the first chamber to the top of the second chamber and fed from the lower end of the second chamber to the first chamber. 16. The method according to one or more of claims 9 to 15, characterized in that the first reaction zone is in a first vertical Reaction chamber (70, 71, Fig. 2) and the second reaction zone are in a die second vertical reaction chamber (66, 2A) surrounding the first chamber and that the fluidized solids in the circuit from the top (70, Fig. 2) of the first Chamber to the top of the second chamber and from the bottom of the second chamber to the lower end of the first chamber. 17. The method according to one or more of claims 9 to 16, characterized characterized in that the solids from the first reaction zone (70, 71) in the second Zone introduced in countercurrent direction to the flow of reactants in the second zone will. 18. The method according to one or more of claims 9 to 17, characterized characterized in that ethylene of the first reaction zone in an amount of about 0.8 until about 2.0 moles per mole of chlorine is supplied. 19 The method according to claim 13, characterized in that the chlorine supply flow in the first reaction zone is adjusted so that at each of the different feed points (34, Fig. 1; 74, Fig. 2; 94, Fig. 3 to 5) the ratio of not implemented Ethylene to unreacted chlorine receives a maximum value. 20. The method according to one or more of claims 9 to 19 thereby characterized in that the second reaction zone carbon tetrachloride in a Amount from about 0.7 to about 3.3 moles of carbon tetrachloride per 100 moles of ethylene dichloride feeds. 21. The method according to one or more of claims 9 to 20, characterized characterized in that one of the first reaction zone carbon tetrachloride in a Amount of about 0.5 to about 4.0 moles of carbon tetrachloride per 100 moles of ethylene supplied. 22. The method according to one or more of claims 9 to 21, characterized characterized in that there is also ethylene, oxygen and hydrogen chloride in one third reaction zone in the presence of an oxyhydrochlorination catalyst for reaction causes ethylene dichloride and water to be formed by removing the reaction product flow the oxyhydrochlorination reaction wins ethylene dichloride and this ethylene dichloride feeds as use of the second reaction zone. 23t method according to claim 22, characterized in that as Use hydrogen chloride for the third reaction zone used hydrogen chloride, which is obtained as a by-product of the dehydrochlorination of ethylene dichloride. 24o method according to one or more of the preceding claims, for the production of vinyl chloride, characterized in that ethylene and chlorine are used in gaseous form at the lower end of a first reaction chamber which is fed through a Gas flow in the first chamber in a fluidized or vortex state finely divided solids contains that one the ethylene and chlorine in this first Reacts the chamber with the generation of heat and the formation of ethylene dichloride, that at least part of the ethylene dichloride produced here in the first Chamber using some of this heat to form vinyl chloride dehydrochlorinated, that one withdraws the converted gases at the lower end of the first chamber that one at the same time additional ethylene dichloride at the lower end of a second reaction chamber supplies, which by a gas flow in the second chamber in a fluidized or fluidized state contains finely divided solids that one in the first Chamber generated heat is transferred to the second chamber that one the ethylene dichloride in the second chamber with de * on the first chamber in the second chamber Heat dehydrochlorinated to form vinyl chloride and the product gases at the bottom At the end of the second chamber, the heat transfer fluidized by circulation Solids from the top of the first chamber to the top of the second chamber as well as from the lower end of the second chamber to the lower end of the first chamber. 25. The method according to claim 24, characterized in that the conducts gases withdrawn from the first chamber into the upper end of the second chamber and that in the gases from the first chamber contained ethylene dichloride in the upper End of the second chamber using from the first chamber to the second Chamber transferred heat is dehydrochlorinated. 26. The method according to claim 24 or 25, characterized in that is the molar ratio of ethylene introduced at the lower end of the first reaction chamber to chlorine is greater than 1: 1 and that one more chlorine on several in the first chamber introduces different levels and thereby this introduction of chlorine on the different Adjusts levels so that the greatest possible chlorination of the in the first chamber contained ethylene; and the lowest possible chlorination of the vinyl chloride present in the first chamber is guaranteed. 27. Reaction apparatus for the production of vinyl chloride monomer according to the method according to one or more of the preceding claims, characterized by devices (2, Fig. 1; 66, 2A, Fig. 2; 66, 2B, Fig. 3 to 5), which. one form the first reaction chamber, through a bed of solids in this chamber, through a Device (32, 76) by means of which ethylene dichloride is introduced into the first chamber is1 that the bed of solids is fluidized or put into the vortex state, by devices (70, 71, Fig, 2; 90, Fig. 3 to 5), which at least one form additional reaction chamber, which at one end with the lower end of the solid fluid bed is connected and at its opposite end with the connected to the first chamber at a location above the bottom of the fluidized bed is, by devices (34, Fig. 1; 74, Fig. 2; 94, Fig. 3 to 5), by means of which in this additional Reaktlonskammer (70, 71; 90) chlorine at different intervals arranged along the additional reaction chamber between the two ends Places can be fed, as well as devices (36, Fig. 1; 72, Fig. 2; 92, Fig. 3 to 5) for the supply of ethylene at one end of the additional reaction chamber, such that a solids cycle from the lower end of the fluidized bed to the one End of the additional reaction chamber and from the opposite end of the additional Reaction chamber is generated back into the first reaction chamber in such a way that (a) the ethylene and chlorine in the additional reaction chamber (70, 71, Fig. 2; 90, Figg0 3 to 5) with the formation of ethylene dichloride and heat generation can react and (b) the circulated solids in the ethylene-chlorine reaction absorb generated heat and this heat to that in the additional reaction chamber generated ethylene dichloride and the ethylene dichloride introduced into the first chamber able to deliver, for the production of vinyl chloride by dehydrochlorination of the Ethylene dichloride and devices (82, 88, 38) for removing the reaction products from the first reaction chamber (66). 28. Apparatus according to claim 27, characterized in that the first Reaction chamber is formed by a reaction container (66) and that the at least an additional reaction chamber through one arranged in the first chamber (66) hollow climbing unit (70, Fig. 2, Figg. 6 to 8) is formed. 29. Apparatus according to claim 27 or 28, characterized in that the device for ethylene supply in the additional reaction chamber one in the lower end (71) of the riser unit (70) leading into the supply line (72, Figg. 2 and 6). 30. Apparatus according to claim 28 or 29, characterized in that the climbing unit (70) consists of a ceramic material. 31. Apparatus according to one of claims 28 to 30, characterized in that that the lower end of the riser unit has a Venturi mixing nozzle (104, Fig. 7). 32. Apparatus according to one of claims 28 to 30, characterized in that that the climbing unit (70, Sigo 6) at its lower end (98) through an end plate (100) is closed and that the ethylene supply line (72) with an inlet opening is connected in this end wall and that the riser unit has a lateral opening (102) in the vicinity of the front-side closure plate (100) through which Know solids entering the riser. 33. Apparatus according to one or more of claims 28 to 32, characterized characterized in that the climbing unit (70, Fig. 8) at its upper end (108) for lateral exit (at 110, 112) of solids and gases into the reaction vessel (66) is formed. 34. Apparatus according to one or more of claims 28 to 33, characterized characterized in that the riser assembly (70) is immersed in the BlieB- or eddy current bed is. 35 * Apparatus according to one or more of claims 27 to 34, characterized characterized in that the additional reaction chamber (70) is within the first chamber (66) is arranged. 36. Apparatus according to claim 27, characterized in that the first Reaction chamber is formed by a reaction vessel (66, 2B, Fig. 3 to 5) and that the devices for forming the at least one additional chamber at least a solids transfer line (90, Fig. 3 to 5), which at its one end with a solids outlet opening in the lower part of the reaction vessel (66) forming the first reaction chamber and on its other End with a solids re-entry opening in the side wall of the rector vessel (66) connected 37. Apparatus according to claim 36, characterized in that the solids re-entry opening is arranged above the level (80) of the fluidized bed is (Figs. 4 and 5). 38. Apparatus according to claim 36, characterized in that the solids re-entry opening arranged at a level between the top and bottom of the fluidized bed is (Fig. 3). 39. Apparatus according to claim 36, characterized by devices (82A, 88A; 82B, 883, Fig. 5) for the separate production of hydrogen chloride and vinyl chloride from the product gases of the reactor vessel. 40. Apparatus according to one or more of claims 27 to 39, characterized through an oxyhydrochlorination reaction vessel (1, Fig. 1) with an oxyhydrochlorination catalyst, Devices (6, 8, 10) for supplying ethylene, oxygen and hydrogen chloride into the oxyhydrochlorination reaction vessel For contact with the oxyhydrochlorination catalyst for the production of ethylene dichloride, devices (14) for removing the product flow the oxyhydrochlorination reaction from the oxyhydrochlorination reaction vessel, as well as devices (16, 20, 22, 26, 28) for the recovery of ethylene dichloride from the oxyhydrochloride reaction vessel withdrawn product flow and feed this ethylene dichloride to the ethylene dichloride feed device (32) of the first reaction chamber (2, 66). 41. Apparatus according to claim 40 in conjunction with claim 39, characterized by means (10) for supplying that withdrawn from the first reactor (2, 66) Product flow of recovered hydrogen chloride to the hydrogen chloride supply device (10) of the oxyhydrochlorination reaction vessel (1).