Wacker-Chemie Gmbh

Hoechst Aktiengesellschaft

Gerhard Dummer

Ludwig Schmidhammer

Rudolf Strasser

Klaus Haselwarter

Hermann Klaus

Peter Hirschmann

Gunter Roscher

Gunter Kratel

Gunter Stohr

Dominik Dempf

Burkhard Grune

Klaus-Peter Mohr

Karl-Heinz Schmidt

Franz Haunberger

Eduard Pichl

Ernst Selbertinger

Rudolf Straszer

Gerhard Stettner

Peter Niessner

A catalyst system for the preparation of 1,2-dichloroethane by reacting ethylene and chlorine in a solvent, if desired, in the presence of an inhibitor for reducing the formation of byproducts. The catalyst system comprises a phenolate/chlorine complex. The invention also relates to a process for the chlorination of ethylene using indicated catalyst system.

Catalyst system and use for the preparation of 1,2-dichloroethane

In a process for the purification of hydrogen chloride from the pyrolysis of 1,2-dichloroethane, optionally after a preceding step of acetylene removal by selective hydrogenation under specific conditions followed by rectification of the resulting mixture to obtain hydrogen chloride containing at most 5 ppm of unsaturated hydrocarbons and at most 5 ppm of chlorinated hydrocarbons.

Process for purification of HCl from pyrolysis of EDC

In a method of treating the reaction product of pyrolysis of 1,2-dichloroethane to form vinyl chloride and hydrogen chloride with multiple stage cooling and distillation separation of the reaction product and recycle of unreacted 1,2-dichloroethane to the pyrolysis step, the improvement comprising direct cooling of the reaction product immediately after leaving the pyrolysis step, within 1 sec from a temperature range of 480.degree. to 540.degree. C. down to 150.degree. to 250.degree. C., charging the cooled product into a quench column, recovering the vapors from the head of the quench column and indirectly cooling the same by heat exchange to at least its condensation point, the heat exchange media being at least one member of the group consisting of (a) 1,2-dichloroethane to be fed in heated condition to the pyrolysis unit, (b) air used as combustion air to fire the pyrolysis zone, (c) the sump of the hydrogen chloride column as defined above, (d) liquid hydrogene chloride to be evaporated and, (e) water, to dissipate heat not used within the measures according to the present invention.

Heat recovery in production of vinyl chloride by pyrolysis of

An improved method of producing vinyl chloride by pyrolysis of purified 1,2-dichloroethane at temperatures from 480.degree. C. to 540.degree. C. at a pressure of 10 to 36 bar absolute with partial utilization of the heat content of the flue gases from the pyrolysis furnace firing to preheat liquid 1,2-dichloroethane almost to its boiling temperature utilizing the flue gas waste heat to generate steam, cool the pyrolysis gas mixture in several stages and separate the hydrogen chloride from the pyrolysis gas mix in a hydrogen chloride column as well as separate vinyl chloride from the pyrolysis gas mix in a vinyl chloride monomer column.

Vinyl chloride production

An improved process for the preparation of vinyl chloride from 1,2-dichloroethane (EDC) wherein 0.10 to 0.15 % by weight of carbon tetrachloride based on EDC, is used as a cracking promoter and the CHCl.sub.3 content is limited to less than 200 ppm. Before being fed to the cracking zone, the EDC is brought almost to the boiling point at 15 to 31 bar and then expanded to 10 to 16 bar with flashing EDC vapors and the fraction which has remained liquid is vaporized externally, and the combined EDC gas streams are heated, after being fed into the cracking furnaces, so that the energy required for cracking is already supplied in the first 75 to 85% of the reaction zone, whereby a conversion of 60 to 70% is obtained at residence time from 10 to 25 seconds and the exit temperature from the reaction zone is 485.degree. to 510.degree. C.

Process for thermal cracking of 1,2-dichloroethane to form vinyl chloride

In a method of recovering heat from flue gas resulting from the combustion of chlorinated organic compounds at 900.degree. to 1300.degree. C. at a pressure of 0.9 to 1.5 bar absolute whereby the flue gas is cooled with the recovery of heat and hydrogen chloride is processed, the improvement comprising (a) cooling the flue gas in a first step to a temperature of 250.degree. to 350.degree. C. with a contact time of 0.05 to 0.15 seconds, (b) cooling the flue gas in a second step to a minimum of 140.degree. C. with a contact time of 1.3 to 2.0 seconds, the cooling medium in both stages being water flowing at an initial temperature of 100.degree. to 140.degree. C. in step (b) counter to the flue gas flow direction and added to cooling stage (a) at a temperature of 200.degree. to 220.degree. C. and (c) cooling the flue gas in a third stage to its dew point and scrubbing it with water to recover the hydrogen chloride therein in solution.

Novel heat recovery process

A process of upgrading hydrogen chloride which contains chlorine, iron-III-chloride, acetylene and/or ethylene, for use in an oxichlorination process, wherein water in a gaseous state is added to the hydrogen chloride at temperatures between 120.degree. and 180.degree. C. within a time period of maximally 0.9 seconds after the acetylene and/or ethylene is present in the hydrogen chloride, together with chlorine and iron-III-chloride.

Process for upgrading hydrogen chloride containing chlorine,

A process for the work-up of chlorination residues by dissolving the same at temperatures between 100.degree. and 180.degree. C. in chlorine- and oxygen-containing hydrocarbons having a ratio by weight of hydrogen to chlorine of 0.028-0.06:1, a ratio by weight of oxygen:carbon of 0.0038-0.0089:1, and an atomic ratio of carbon:hydrogen of 1:1.1-1.9 and/or in hydrocarbons, boiling between 160.degree. and 380.degree. C. at one bar abs. and having an atomic ratio carbon:hydrogen of 1:1.85-2.0 so as to obtain a liquid preparation having a ratio by weight of hydrogen:chlorine of 0.028-0.05:1.

Process for the work-up of residues of chlorination

A method for preparing hydrogen chloride resulting from chlorination reactions for use in the ethyleneoxichlorination process by reacting the chlorine contained in the hydrogen chloride with ethylene in the gaseous phase in the presence of carrier catalysts based on an iron-free transition metal chloride having an activity profile which increases in the flow direction, while maintaining the space-flow rates relatively high and the residence time of the gas in the reactor short. After discharge of the reaction product from the reactor the product is subjected to partial condensation advantageously performed in several steps.

Method for preparing hydrogen chloride for the ethyleneoxichlorination

The invention relates to a process for the manufacture of unsaturated carboxylic acid esters by the reaction of olefins or cyclo-olefins with oxygen and carboxylic acids in the gaseous phase, in the presence of a catalyst which contains elements of the subsidiary group VIII of the periodic system and/or compounds thereof, and an alkali metal acetate, at temperatures of from 100.degree. to 250.degree. C. and pressures of from 0.5 to 21 bar absolute, wherein from 1 to 8000 parts per million (by weight), calculated on the carboxylic acid used, of organic chlorine compounds are added to the reaction mixture.

Process for the manufacture of unsaturated carboxylic acid esters

The invention is a process for the purification of hydrogen chloride formed during the thermal cracking of 1,2-dichloroethane, by hydrogenating the acetylene impurities with excess hydrogen, at pressures of from 8 to 20 bar absolute and at temperatures of from 120.degree. to 180.degree. C., using platinum or palladium supported catalysts, wherein, according to the invention, carrier materials having a specific surface area of not more than 5 m.sup.2 /g are used, the hydrogen excess used is a function of the acetylene content, the gas mixture, after reaching a temperature of approximately 70.degree. C., is permitted a dwell time of not more than 0.8 second before it enters the catalyst, and the temperature, pressure and volume flow rates are dependent on one another within narrow limits. The purified hydrogen chloride is used for oxychlorination.

Purification by hydrogenation of hydrogen chloride containing acetylene

A method for increasing the bulk weight of silicon dioxide with a surface of at least 50m.sup.2 /g by means of sub-atmospheric pressure applied at a filter face, wherein the silicon dioxide is moved by means of a conveyor screw, whose longitudinal axis is arranged parallel with respect to the filter face and which preferably has a decreasing thread pitch in feeding direction. Furthermore, the invention relates to the use of the treated silicon dioxide as a filler material for polymeric masses, especially diorganopolysiloxane, which is storeable in the absence of water and when admixed with water at room temperature results in a hardened elastomer mass.

Growing community of inventors

Burgkirchen, Germany

Gerhard Dummer