Hoechst Aktiengesellschaft

Dover Chemical Corporation

Hoechst Aktiengesellchaft

Walter Freyer

Detlef Kampmann

Manfred Schmidt

Karlheinz Miltenberger

Theo Olffers

Dietmar Bewart

Karl Bayer

The chlorination of paraffins is carried out in the presence of water and in the absence of an organic solvent. In this way, it is possible to prepare highly chlorinated paraffins in a simple manner. The presence of hydrochloric acid even at high temperatures, has no deleterious effect on the quality of the product. The separation of the chloroparaffin from the hydrochloric acid is very good. An emulsion layer which hinders the transport of the chloroparaffin into downstream equipment does not occur.

Process for preparing highly chlorinated paraffins

The invention relates to a process for the preparation of dichloroacetyl chloride by oxidation of trichloroethylene under pressure and at elevated temperature in the presence of a certain secondary aliphatic or cycloaliphatic amine of the formula HNR.sup.1 R.sup.2 in which R.sup.1 and R.sup.2 are identical or different and are an alkyl radical having 1 to 10 carbon atoms, where at least one of the radicals R.sup.1 and R.sup.2 has a tertiary structure, or R.sup.1 and R.sup.2 together with the nitrogen atom form a 5- to 10-membered ring, where at least one of the carbon atoms adjacent to the nitrogen is a tertiary carbon atom. Good yields of the acid chloride and low trichloroethylene oxide contents are obtained in one process step.

Process for the preparation of dichloroacetyl chloride

A process for producing a chlorine-free hydrochloric acid low in AOX from crude gases containing hydrogen chloride and organic impurities has been found. The crude gases wer subjected to a thermal treatment at 800.degree. to 1600.degree. in a reducing atmosphere. The hydrochloric acid obtained after absorption of the hydrogen chloride is chlorine-free and contains virtually no organic impurities. The waste gas is also chlorine-free.

Process for producing chlorine-free hydrochloric acid low in AOX

In the conversion of trichloroethene and tetrachloroethene into dichloroacetyl chloride (DAC) or trichloroacetyl chloride (TAC) by means of oxygen, the reaction mixture is passed several times as a thin film through the reaction zone. The reaction time for achieving a certain conversion is in this way reduced. In the preparation of DAC, a constant content of acid chloride is established in the reaction mixture by removing some of the mixture and working this up by distillation, while the circulating reaction mixture is simultaneously topped up with fresh trichloroethene.

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Stadtbergen, Germany

Walter Freyer