Abstract: The present invention relates to a process for the working up of a product stream from the epoxidation of olefins that contains olefin, olefin oxide, water-miscible organic solvent and water, by separating this product stream into an overhead product containing olefin, olefin oxide and organic solvent, and into a bottom product containing organic solvent and water, wherein the separation takes place in a pre-evaporator with at most 5 theoretical separation stages, and 20 to 60% of the total amount of organic solvent introduced with the product stream is removed with the overhead product and the residue remains in the bottom product, as well as a process for the epoxidation of olefins that includes this working up stage.

Abstract: The present invention relates to a process for the catalytic epoxidation of olefins in which in one reaction stage the olefin is reacted with aqueous hydrogen peroxide in an organic, water-miscible solvent in the presence of a titanium silicalite catalyst, wherein an exit gas stream is obtained which contains olefin oxide, unreacted olefin and oxygen and this exit gas stream is brought into contact in an absorption unit with the same solvent as used in the reaction stage and a solvent stream loaded with olefin and olefin oxide is drawn off from the absorption unit and an exit gas stream containing oxygen is discharged.

Abstract: A process and a device are for the methanol synthesis from hydrogen, carbon monoxide and carbon dioxide under pressure, in particular for increasing the yield of processes already in use. Desulphurized natural gas is charged in a reformer and the synthesis gas is subsequently admitted to a methanol synthesis. There are the advantages that a favorable possibility for refitting existing plants is provided, and synthesis gas from external sources can be used. This is accomplished in the process in that after passing through the reformer, a side stream from the synthesis gas stream is supplied to a methanol pre-reactor. The methanol produced in the pre-reactor is supplied to the methanol stream exiting from the methanol synthesis of the main stream. A stream of synthesis gas non-reacted in the methanol pre-reactor is recycled into the main stream upstream of the methanol synthesis.

Abstract: A process for the catalytic epoxidation of olefins with hydrogen peroxide in a multiphase reaction mixture comprising a liquid aqueous hydrogen peroxide rich phase containing an organic solvent having a solubility in water of at least 10% by weight at 25° C. and a liquid organic olefin rich phase.

Abstract: A process for the catalytic epoxidation of olefins with hydrogen peroxide in a continuous flow reaction system, wherein the reaction mixture is passed through a fixed catalyst bed within a reactor equipped with cooling means while maintaining a temperature profile within the reactor such that the cooling medium temperature of the cooling means is at least 40° C. and the maximum temperature within the catalyst bed is 60° C. at most.

Abstract: A process for the catalytic epoxidation of olefins with hydrogen peroxide in a continuous flow reaction system, wherein the reaction mixture is passed through a fixed catalyst bed in down-flow operation mode and the reaction heat is at least partially removed during the course of the reaction.

Abstract: The invention relates to a rectifying column for extractive distillation, comprising a column main section (204) and a raffinate section (205) above said main section, an evaporator (208) situated on the lower end of the column, an inlet (214) disposed between the main section of the column and the raffinate section and a solvent inlet (215) arranged on the top side of the raffinate section (205) for feeding an extracting agent. According to the invention, the main section (204) has two chambers (216, 217) connected in parallel. A stripping section (222) is disposed between the bottom of the column (221) and the main section (204), in which concentration of the extracting agent occurs from the top down. The bottom (221) is connected to the solvent inflow (215) by a device (223) for recycling the extracting agent.

Abstract: An electrolysis apparatus for producing halogen gases from aqueous alkali halide solution, having a number of plate-like electrolysis cells which are arranged beside one another in a stack and are in electrical contact and which each have a housing comprising two half-shells of electrically conductive material with external contact strips on at least one housing rear wall, and in each case having two essentially flat electrodes (anode and cathode) and the anode and cathode being provided with apertures like venetian blinds for the electrolysis starting materials and the electrolysis products to flow through, being separated from one another by a dividing wall and arranged parallel to one another and being electrically conductively connected to the respective associated rear wall of the housing by means of metal reinforcements, is intended to provide a solution with which, even at current densities above 4 kA/m2 and correspondingly increased production of gas in the boundary layer, it is possible to operate wh

Abstract: In a process for the treatment of a cracking gas formed by pyrolysis of 1,2-dichloroethane (EDC), in which the cracking gas is split into its principal components hydrogen chloride (HCl), vinyl chloride (VCM) and unreacted 1,2-dichloroethane (EDC), and these are formed in substantially pure form, where, in the first step of the treatment of the cracking gas, the solids are separated therefrom in a quench zone, the disadvantages of the prior art are intended to be reduced at least partly and in particular the energy losses which usually arise due to the substantial condensation of the quench gas and its re-heating for the purposes of distillative separation are avoided and, due to the circulation of the unreacted EDC at a higher temperature level, the original conversion in the pyrolytic cracking of EDC is intended to be subsequently increased.

Abstract: In a process for the production of VCM, the gaseous reactants and an inert carrier gas are fed into an adiabatic reaction zone in the oxychlorination section, both reaction zones being associated with an integral fluidised bed, the cooled reaction zone containing a vertically coaxial hollow cooling rod bundle forming a passage. A balanced production of VCM is to be achieved, this being done by selecting a ratio of 1 to 6 inclusive between the equivalent diameter of the passage cross-sectional area and the mean gas bubble pocket diameter of the fluidised bed.

Abstract: A process for the removal of carbon dioxide, sulphur compounds, water and aromatic and higher aliphatic hydrocarbons from industrial gases. The sour gas components, water and hydrocarbons are removed from the gas to be treated by absorption at elevated operating pressure. At least one morpholine derivative is used as the absorbent. The absorbent laden with absorbed components is regenerated with the aid of a stripping gas. The stripping gas is generated by partial evaporation of the laden absorbent.

Abstract: When applied to an electrolyser for producing halogen gases from aqueous alkali halogenide solution using several plate-like electrolysis cells arranged side by side in a stack whilst electrically connected, each cell being encased in two semi-shells made from electroconductive material with contact strips on the outer side of at least one of the casing's rear walls, the anode and the cathode being separated from one another by a partition, arranged parallel to one another and electrically connected to the rear wall of the respective casing via metal reinforcements, the current-carrying surface should be as large as possible to avoid uneven current distribution. This is achieved by the fact that the metal reinforcements are in the form of solid plates (10) which are flush with the contact strips (7) and whose side edges run up the entire height of the rear wall (3A, 4A) and the anode (8) or cathode (9).

Abstract: A process for the production of nitric acid using the dual-pressure process in which the ammonia is burnt at an initial low pressure with the aid of compressed process air and the nitrous gases formed during combustion are at least partly absorbed by water at a second pressure which is higher than the first. This causes nitric acid to be produced and the pressure of the residual gas, which is not absorbed, is reduced to atmospheric pressure in a residual gas expander for the purpose of winning compression potential. Said process provides a solution aimed at optimising the production of nitric acid whilst improving the production parameters and the materials and energy balances. This is achieved by supplying a multishaft geared centrifugal compressor separately with process air and nitrous gas, the process air being compressed to the initial pressure and the nitrous gas being compressed to a second pressure.

Abstract: By a process for the production of 1,2-dichloroethane (EDC) by reaction of ethylene with chlorine in the liquid phase (direct chlorination), the heavy ends being separated from the obtained 1,2-dichloroethane in a heavy-ends column and in a downstream vacuum column and, for the purpose of heat recovery and heating of the column bottoms, a 1,2-dichloroethane part-stream from the direct chlorination passing through a heat exchanger (one attributed to each column) for indirect heat exchange with the bottom product of each column, the aim of the invention is to provide a solution in which the reaction enthalpy of the direct chlorination can be used in a variable manner, thus precluding the above-described disadvantages. This is achieved by using at least one falling-film evaporator for heating the column bottoms, the bottom product of the respective column being routed to the distributor at the head of the column.

Abstract: Using a process for the production of 1,2-dichloroethane by reacting ethylene and chlorine in the liquid phase in the presence of a catalyst, the 1,2-dichloroethane produced being drawn off in the gaseous phase, the high-boilers being separated from the 1,2-dichloroethane in a heavy-ends column and in a downstream vacuum column and the light-boilers and gases, such as ethylene and hydrogen, being separated in an EDC stripping column or in a light-ends column, a commercial-scale solution should be created to effectively remove the hydrogen chloride at the head of the stripping column or light-boiling column to avoid corrosion occurring there. This is achieved in that the cleaned 1,2-dichloroethane leaving the heavy-ends column is cleaned in the EDC stripping column or in the light-ends column by separating the light-boilers and the gases.

Abstract: Besides a synthesis gas, a metallurgical raw material is to be produced from an oil containing heavy metals. To do this, the oil is partially oxidized and the heavy metal-containing soot is separated and burnt and the heavy metals thus occurring as ash can be taken to further processing, e.g. washing from the synthesis gas produced, using an aqueous washing solution.

Abstract: A process for specific energy saving, especially in processes involving the oxychlorination of ethylene, facilitates recovery of as much sensible heat to be used for other purposes. In the process the gas mixture leaving the oxychlorination reactor is cooled before it enters the quenching column and the heat recovered is then used to preheat the ethylene recycle gas feed stream.

Abstract: A process for evaporating 1, 2-dichloroethane (EDC) prior to its thermal decomposition (pyrolysis) is provided so that it facilitates the heating of the liquid-phase EDC at temperatures below 100.degree. C. to meet the inlet conditions for the pyrolysis zone, while dispensing with the need for an evaporation zone and exploiting sensible heat recovery at the same time. This is achieved in that the liquid-phase EDC is first pressurized to attain a value above its critical pressure (5.36 MPa) and then heated to attain at least its critical temperature (approx. 288.degree. C.).

Abstract: Polyester yarn is made by melt spinning the polyester filaments which are then cooled at least to solidification and heated by counterflow with prestretching to a crystallinity in excess of 24%. The prestretched filaments are gathered and stretched to after-stretching at a temperature of 80.degree. C. to 250.degree. C. to a final titer of 1.0 dtex to 7.5 dtex with a stretching ratio of 1:1.5 to 1:1.15. The yarn is then wound up at a rate of 5000 to 8000 m/min.

Abstract: A process is disclosed for generating pure aromatic compounds from a reformed gasoline which contains aromatic compounds, olefins, diolefin, and triolefins, which comprises the steps of:(a) selectively hydrogenating the olefins, diolefins and triolefins in the reformed gasoline to obtain a mixture of hydrogenated, non-aromatic compounds and aromatic compounds; and(b) separating the aromatic compounds from the hydrogenated, non-aromatic compounds in the mixture formed during step (a) by either extractive distillation, liquid--liquid extraction or both to obtain the pure aromatic compounds.