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US4351976A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for purifying 1,2-dichloroethane

Assignee: Kanegafuchi Chemical Industry Co Ltd
•
Filing: 1981-03-23
•
Granted: 1982-09-28
•
Expires: 2001-03-23
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Abstract

Abstract An improvement of a method for purifying 1,2-dichloroethane by passing through a distillation column a crude 1,2-dichloroethane produced by oxychlorination of ethylene with at least one of a crude 1,2-dichloroethane produced by direct chlorination of ethylene and a crude uncracked 1,2-dichloroethane recovered in thermal cracking of 1,2-dichloroethane, the improvement which comprises feeding the oxychlorination-produced 1,2-dichloroethane to an upper plate of the distillation column than a plate of the column to which at least one of the direct chlorination-produced 1,2-dichloroethane and the uncracked 1,2-dichloroethane is fed, and recovering 1,2-dichloroethane as a bottom product. The purification method is very useful in the production of vinyl chloride by thermal cracking of 1,2-dichloroethane, since carbon tetrachloride effective as a thermal cracking catalyst is stably recovered in high concentrations with 1,2-dichloroethane, while removing other low boiling impurities, and the method is economically practiced.

Inventors

  • 👤 Yusaku Ariki
  • 👤 Takio Hino
  • 👤 Noboru Yoshida

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 16:30
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C07C17/383; Y; Y02; Y02P; Y02P20/00; Y02P20/50

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 127 words
In a method for purifying, 1,2-dichloroethane by passing through a distillation column a crude 1,2-dichloroethane produced by oxychlorination of ethylene with at least one of a crude 1,2-dichloroethane produced by direct chlorination of ethylene and a crude uncracked 1,2-dichloroethane recovered in thermal cracking of 1,2-dichloroethane, the improvement which comprises feeding a crude, 1,2-dichloroethane produced by the oxychlorination to an upper plate of a distillation column, feeding to a plate sufficiently below said upper plate at least one crude 1,2-dichloroethane of a crude 1,2-dichloroethane produced by the direct chlorination and a crude uncracked 1,2-dichloroethane recovered in thermal cracking, and recovering 1,2-dichloroethane as a bottom product having a substantially non-varying concentration of carbon tetrachloride over a time duration of said method sufficient to catalyze a thermal cracking of dichloroethane.
Claim 2
Dependent Claim 127 words
In a method for purifying, 1,2-dichloroethane by passing through a distillation column a crude 1,2-dichloroethane produced by oxychlorination of ethylene with at least one of a crude 1,2-dichloroethane produced by direct chlorination of ethylene and a crude uncracked 1,2-dichloroethane recovered in thermal cracking of 1,2-dichloroethane, the improvement which comprises feeding a crude, 1,2-dichloroethane produced by the oxychlorination to an upper plate of a distillation column, feeding to a plate sufficiently below said upper plate at least one crude 1,2-dichloroethane of a crude 1,2-dichloroethane produced by the direct chlorination and a crude uncracked 1,2-dichloroethane recovered in thermal cracking, and recovering 1,2-dichloroethane as a bottom product having a substantially non-varying concentration of carbon tetrachloride over a time duration of said method sufficient to catalyze a thermal cracking of dichloroethane.
Claim 3
Dependent Claim 42 words
The method of claim 1, wherein the crude 1,2-dichloroethane fed to the upper plate further contains as a minor component at least one of a crude 1,2-dichloroethane produced by the direct chlorination and a crude uncracked 1,2-dichloroethane recovered in the thermal cracking.
Claim 4
Dependent Claim 25 words
The method of claim 1, wherein said at least one crude 1,2-dichloroethane further contains as a minor component a crude 1,2-dichloroethane produced by the oxychlorination.
Claim 5
Dependent Claim 39 words
The method of claim 1, wherein carbon tetrachloride included in the crude 1,2-dichloroethane fed is recovered together with 1,2-dichloroethane as a bottom product, while other compounds having a lower boiling point than carbon tetrachloride are removed as a distillate.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-09-27 1986-03-29 1986-09-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-09-27 1990-03-29 1990-09-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-09-27 1994-03-29 1994-09-28 $7700.00 Window Closed / Lapsed

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