摘要:
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. It order to be able to implement the product-conserving mode of operation in the radiation zone of the dissociation furnace and simultaneously to maintain the function of the convection zone, the heat input to the dissociation furnace is divided such that a portion of the heat introduced by underfiring is introduced by burners in the radiation zone, and the other portion of the heat supplied by underfiring is introduced by burners arranged at the exit of the flue gas from the radiation zone.The partial decoupling of the heat input of the radiation zone and of the convection zone makes possible a particularly product-conserving mode of operation.
摘要:
The present invention relates to a device and a process for introducing gas into a fluidised bed reactor having at least one gas inlet pipe (2, 3) located underneath and/or above the fluidised bed for introducing gas into the fluidised bed, characterised in that the gas inlet pipe (2, 3) has gas-swirling means upstream of and/or at its mouth.
摘要:
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.
摘要:
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).
摘要:
Process and apparatus for producing ethylenically unsaturated halogenated hydrocarbonsThe 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.To be able to continue to operate the process economically despite the reduction in the reaction temperature, the process parameters have to be set so that at least 50% of the amount of feed used are vaporized by means of the sensible heat content of the reaction mixture leaving the reaction zone.
摘要:
The invention relates to a method for producing ethylenically unsaturated aliphatic halogenic hydrocarbons by the thermal cleavage of saturated aliphatic halogenic hydrocarbons. According to said method, an educt gas stream is introduced into a reactor, which comprises at least one supply conduit that opens into said reactor. The supply conduit feeds a heated gas formed from cleavage promoters and radicals into the reactor. The method permits an increase in the yield of the cleavage reaction.
摘要:
In the preparation of vinyl chloride by thermal cracking of 1,2-dichloroethane, three distillation stages are used to distill off first hydrogen chloride, then vinyl chloride and finally entrained hydrogen chloride with vinyl chloride. If, in the last stage, entrained water is not drawn off via the bottom, it is recirculated with the top product to the first stage and causes corrosion. Removal of the water at the top of the third distillation stage, advantageously by drying, prevents the corrosion.
摘要:
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).
摘要:
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.
摘要:
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.