Process for purifying crude gaseous hydrogen chloride
First Claim
1. A process for the purification of crude gaseous hydrogen chloride which contains as impurities silanes containing chlorine and/or organic radical, alkanols, water, chlorinated hydrocarbons, hydrocarbons, and organic acids, by condensation, compression and fractional distillation, which comprises (1) passing the crude gas through a heat exchanger, in which it is cooled to -15°
- C. to -35°
C.;
(2) subsequently heating the crude gas which has been at least partially freed from condensable products to 0°
to -40°
C., compressing it in a screw compressor with oil injection to a pressure of 0.6 to 1.5 MPa, separating off the hydrogen chloride from the oil through a separator having a filter, cooling the oil which has been separated off in a heat exchanger, freeing it from residues through a filter web, and recycling it to the compressor; and
(3) subsequently fractionating the compressed hydrogen chloride which has been separated from the oil in a distillation column under pressure and discharging the purified hydrogen chloride at the top of the column. PG,12
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Accused Products
Abstract
The invention relates to a process for purifyng crude gaseous hydrogen chloride originating from plants producing silane or siloxane and containing as impurities silanes which contain chlorine and/or organic radicals, water, alkanols, hydrocarbons, chlorinated hydrocarbons, organic acids and derivatives thereof, by condensation, compression and fractional distillation. In this process, the crude gas is at least partially freed from condensable products by cooling to -35° C., then compressed in a screw compressor with oil injection to 1.5 MPa, the oil is separated off, freed from gel-containing residues through a filter web and again recycled into the compressor. The compressed hydrogen chloride gas is fractionated in a distillation column under pressure and hydrogen chloride having a purity of 99.999 percent is recovered.
57 Citations
5 Claims
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1. A process for the purification of crude gaseous hydrogen chloride which contains as impurities silanes containing chlorine and/or organic radical, alkanols, water, chlorinated hydrocarbons, hydrocarbons, and organic acids, by condensation, compression and fractional distillation, which comprises (1) passing the crude gas through a heat exchanger, in which it is cooled to -15°
- C. to -35°
C.;
(2) subsequently heating the crude gas which has been at least partially freed from condensable products to 0°
to -40°
C., compressing it in a screw compressor with oil injection to a pressure of 0.6 to 1.5 MPa, separating off the hydrogen chloride from the oil through a separator having a filter, cooling the oil which has been separated off in a heat exchanger, freeing it from residues through a filter web, and recycling it to the compressor; and
(3) subsequently fractionating the compressed hydrogen chloride which has been separated from the oil in a distillation column under pressure and discharging the purified hydrogen chloride at the top of the column. PG,12 - View Dependent Claims (2, 3, 4, 5)
- C. to -35°
Specification