Abstract: The present invention relates to a method for preparing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane, in which method the heat required for the thermal cracking is supplied via a liquid or condensing heat transfer medium. The present invention also relates to a plant for preparing vinyl chloride by catalytic thermal cracking of 1,2-dichloroethane, in which the heat required for the thermal cracking, as well as for the preceding preheating, evaporation and optionally overheating of the 1,2-dichloroethane, is supplied via a liquid or condensing heat transfer medium, said plant comprising at least one reactor in which the thermal cracking takes place and at least one first heating device by means of which heat is transported to the reaction medium in the reactor by means of the liquid or condensing heat transfer medium.

Abstract: The invention relates to a method for synthesizing 1.2-dichloroethane from ethylene and chlorine via low temperature direct chlorination of ethylene in the presence of a catalyst under conditions in which the synthesized 1.2-dichloroethane is condensed out, however, the ethylene and the chlorine are gaseous, in a reactor (3), wherein the stoichiometric ratio of ethylene to chlorine is adjusted in the reactor (3) such that there is an excess of ethylene. The invention further relates to a device for synthesizing 1.2-dichloroethane from ethylene and chlorine via low temperature direct chlorination of ethylene in the presence of a catalyst under conditions in which the synthesized 1.2-dichloroethane is condensed out, however, the ethylene and the chlorine are gaseous, in a reactor (3), wherein the stoichiometric ratio of ethylene to chlorine is adjustable in the reactor (3) such that there is an excess of ethylene.

Abstract: Method of concentrating aqueous alkali and apparatus suitable for this purpose. A very energy-saving method of concentrating aqueous alkali originating, for example, from a chloralkali electrolysis plant and an apparatus suitable for this purpose are described. The method/the apparatus utilizes heat of reaction from the formation of 1,2-dichloroethane and includes multistage concentration of the aqueous alkali, where at least part of the heat required for concentrating the aqueous alkali originates from the plant for preparing 1,2-dichloroethane and at least a further part of the heat required for concentrating the aqueous alkali originates from at least one of the higher stages of the plant for concentrating the aqueous alkali and is used for partial heating of the first stage. The apparatus can be used for retrofitting existing integrated plants made up of a DCE plant and chloralkali electrolysis or in the erection of new plants.

Abstract: An apparatus (1) and method for drying polymer powders is described. The apparatus has an inlet (2) and an outlet (3) for the polymer powder, heat registers (5) installed in the interior space (4) and lines (7) for a heated gas (6a) for drying the polymer powder. The lines open into the interior space (4) and are connected to heat exchangers (9) for heating gas (6). The heat exchangers (9) are connected to a plant for the preparation of 1,2-dichloroethane (15) and/or for the preparation of vinyl chloride from 1,2-dichloroethane so that thermal energy from the plant can be utilized for heating the gas (6). The method comprises treatment of a polymer powder with a heated gas (6a) in the drying apparatus (1).

Abstract: The invention relates to a method for synthesizing 1.2-dichloroethane from ethylene and chlorine via low temperature direct chlorination of ethylene in the presence of a catalyst under conditions in which the synthesized 1.2-dichloroethane is condensed out, however, the ethylene and the chlorine are gaseous, in a reactor (3), wherein the stoichiometric ratio of ethylene to chlorine is adjusted in the reactor (3) such that there is an excess of ethylene. The invention further relates to a device for synthesizing 1.2-dichloroethane from ethylene and chlorine via low temperature direct chlorination of ethylene in the presence of a catalyst under conditions in which the synthesized 1.2-dichloroethane is condensed out, however, the ethylene and the chlorine are gaseous, in a reactor (3), wherein the stoichiometric ratio of ethylene to chlorine is adjustable in the reactor (3) such that there is an excess of ethylene.

Abstract: Disclosed is a process and apparatus for heat recovery in vinyl chloride monomer manufacturing plants or in integrated vinyl chloride monomer/polyvinyl chloride manufacturing plants. A process for capture and use of excess heat recovered in the production of vinyl chloride includes distillatively purifying DCE in a high-boilers column, using a heat exchanger to capture thermal energy from a purified DCE vapor stream from the high-boilers column, generating low pressure steam from the captured thermal energy, returning condensed DCE vapors to the high-boilers column, and heating parts of the plant with the generated low pressure steam.

Abstract: Disclosed is a process and apparatus for heat recovery in vinyl chloride monomer manufacturing plants or in integrated vinyl chloride monomer/polyvinyl chloride manufacturing plants. A process for capture and use of excess heat recovered in the production of vinyl chloride includes distillatively purifying DCE in a high-boilers column, using a heat exchanger to capture thermal energy from a purified DCE vapor stream from the high-boilers column, generating low pressure steam from the captured thermal energy, returning condensed DCE vapors to the high-boilers column, and heating parts of the plant with the generated low pressure steam.

Abstract: Method of concentrating aqueous alkali and apparatus suitable for this purpose. A very energy-saving method of concentrating aqueous alkali originating, for example, from a chloralkali electrolysis plant and an apparatus suitable for this purpose are described. The method/the apparatus utilizes heat of reaction from the formation of 1,2-dichloroethane and includes multistage concentration of the aqueous alkali, where at least part of the heat required for concentrating the aqueous alkali originates from the plant for preparing 1,2-dichloroethane and at least a further part of the heat required for concentrating the aqueous alkali originates from at least one of the higher stages of the plant for concentrating the aqueous alkali and is used for partial heating of the first stage. The apparatus can be used for retrofitting existing integrated plants made up of a DCE plant and chloralkali electrolysis or in the erection of new plants.

Abstract: Process for operating a distillation column for the removal of water and lower-boiling components than 1,2-dichloroethane from 1,2-dichloroethane in which at least part of the heat from condensation of the aqueous vapors from the distillation column is used to concentrate caustic soda solution by evaporation; furthermore, at least part of the 1,2-dichloroethane formed when chlorine and ethylene react in a direct chlorination unit is used to heat said distillation column and can subsequently also be used as a heat transfer fluid to concentrate caustic soda solution by evaporation.

Abstract: An apparatus (1) and method for drying polymer powders is described. The apparatus has an inlet (2) and an outlet (3) for the polymer powder, heat registers (5) installed in the interior space (4) and lines (7) for a heated gas (6a) for drying the polymer powder. The lines open into the interior space (4) and are connected to heat exchangers (9) for heating gas (6). The heat exchangers (9) are connected to a plant for the preparation of 1,2-dichloroethane (15) and/or for the preparation of vinyl chloride from 1,2-dichloroethane so that thermal energy from the plant can be utilized for heating the gas (6). The method comprises treatment of a polymer powder with a heated gas (6a) in the drying apparatus (1).

Abstract: With a method for utilization of the reaction heat that occurs in the production of 1,2-dichloroethane from ethylene, by reaction with oxygen and hydrochloride (oxychlorination), in a fluidized bed reactor, with dissipation of this reaction heat through cooling pipe bundles situated within the reactor, positioned in the fluidized bed, utilization of the heat is supposed to be improved, while simultaneously reducing the size of the corresponding system elements. This is achieved in that part of the reaction heat is dissipated by heating boiler feed water, whereby the heated boiler feed water is used to heat heat sinks in the production process.

Abstract: The invention is directed to a process and to an apparatus for saving fuel in furnaces for thermal dissociation of halogenated aliphatic hydrocarbons, especially of 1,2-dichloroethane, using chemical dissociation promoters or physical measures which initiate the dissociation reaction. The initiation of the dissociation reaction lowers the temperature level in the reaction mixture with the same conversion. This can also lower the mean firing chamber temperature and save fuel. In a preferred process variant, flue gas leaving the convection zone of the dissociation oven is analyzed and its dew point is calculated. The dew point of the flue gas or the conversion of the dissociation reaction serves as command parameter for the intensity of the physical measure for initiation and/or for the amount of the chemical dissociation promoter added and/or for the amount of fuel. In a further preferred process variant, the latent heat content of the flue gas is used to preheat the burner air or other media.

Abstract: The invention relates to a process and an apparatus for product-conserving thermal dissociation of halogenated aliphatic hydrocarbons, preferably for thermal dissociation of 1,2-dichloroethane to vinyl chloride. This uses chemical dissociation promoters and/or physical measures which initiate the dissociation reaction. The initiation of the dissociation reaction, with the same conversion, lowers the temperature level in the reaction mixture and the temperature of the dissociation gas on exit from the dissociation furnace. The amount and the exit temperature of the flue gas from the radiation zone of the dissociation furnace likewise decrease at the same time.

Abstract: Process and apparatus for producing ethylenically unsaturated halogenated hydrocarbons The invention relates to a process and an apparatus for preparing ethylenically unsaturated halogenated hydrocarbons, preferably vinyl chloride by thermal dissociation of 1,2-dichloroethane, using physical or chemical measures which initiate the dissociation reaction. The process/apparatus described makes it possible to increase the amount produced using dissociation reactors of a given size considerably. Use is made here of initiating measures to increase the heat flux through the wall of the reaction tube and at the same time the feed stream and the heating power of the reaction furnace are increased so that the conversion of the reaction is not significantly increased compared to processes without use of initiating measures.

Abstract: With a method for utilization of the reaction heat that occurs in the production of 1,2-dichloroethane from ethylene, by reaction with oxygen and hydrochloride (oxychlorination), in a fluidized bed reactor, with dissipation of this reaction heat through cooling pipe bundles situated within the reactor, positioned in the fluidized bed, utilization of the heat is supposed to be improved, while simultaneously reducing the size of the corresponding system elements. This is achieved in that part of the reaction heat is dissipated by heating boiler feed water, whereby the heated boiler feed water is used to heat heat sinks in the production process.

Abstract: The invention relates to a falling film evaporator, which is fitted with a liquid distributor which is divided into segments, such that it is possible to charge only a limited number of evaporator tubes with liquid and the evaporator can be operated in an optimum manner even with a partial load. The invention also relates to a method for operating said falling film evaporator, the aim of which is to transfer heat, which is released when a gas-vapor mixture is condensed, to a liquid which is to be evaporated at least partially. It would be useful to use said falling film evaporator thus fitted in heat recuperation systems such as those used in the production of 1,2 dichloroethane.

Abstract: The invention relates to a method for producing high-purity 1,2-dichloroethane from dissolved chlorine and dissolved ethylene which are brought into contact with each other using a circulating liquid reaction medium which essentially consists of 1,2-dichloroethane and a catalyst and passes through at least one reaction loop. The two limbs of the loop are connected to a gas-phase stripping container which is arranged at the top and from which the reaction product is outwardly transferred either in a gaseous or liquid form or both in a gaseous form and in a liquid form. The addition points for the addition of chlorine and dissolved ethylene are arranged in the limb of the loop in which the liquid rises. The addition point for dissolved chlorine is always arranged downstream of the ethylene addition point.

Abstract: The invention relates to a method for using reaction heat produced by reaction during the production of 1,2-dichloroethane from ethylene and chlorine in a direct chlorination reactor. The chlorine is produced in a sodium chloride electrolysis and the reaction heat, during the formation of 1,2-dichloroethane is used at least partially for the evaporation of NaOH, which is produced during NaCl-electrolysis for producing the required chlorine for direct chlorination, as a coupling product. The invention also relates to a device for carrying out said method, comprising a multi-tube heat exchanger comprising two fixed tubular plates and a NaOH-liquid phase part, and the caustic soda passes through the inside of the tube and 1,2-dichloroethane passes the outside of the tube. The heat exchanger also comprises devices for feeding and distributing the caustic soda in the inside of the tube.

Abstract: The invention relates to a method for using reaction heat produced by reaction during the production of 1,2-dichloroethane from ethylene and chlorine in a direct chlorination reactor. The chlorine is produced in a sodium chloride electrolysis and the reaction heat, during the formation of 1,2-dichloroethane is used at least partially for the evaporation of NaOH, which is produced during NaCl-electrolysis for producing the required chlorine for direct chlorination, as a coupling product. The invention also relates to a device for carrying out said method, comprising a multi-tube heat exchanger comprising two fixed tubular plates and a NaOH-liquid phase part, and the caustic soda passes through the inside of the tube and 1,2-dichloroethane passes the outside of the tube. The heat exchanger also comprises devices for feeding and distributing the caustic soda in the inside of the tube.

Abstract: The invention refers to a process for the production of high-purity 1,2-dichloroethane from dissolved chlorine and dissolved ethylene, which are brought into contact with each other in a circulating liquid reaction fluid, which mainly consists of 1,2-dichlorethane and a catalyst and flows through at least one vertically arranged loop-type reaction section, both legs of the loop being connected to an overhead degassing vessel from where the reaction product is withdrawn either in gaseous or in liquid state or in both gaseous and liquid state, and numerous admixing sections being arranged in the leg of the loop in which the liquid rises, and each of these admixing sections having one upstream feed point for dissolved or gaseous ethylene and one downstream feed point for dissolved chlorine and, if required, the admixing sections featuring static mixers.