Organic compounds -- part of the class 532-570 series – Organic compounds – Halogen containing
Patent
1997-03-27
1999-06-22
Kight, John
Organic compounds -- part of the class 532-570 series
Organic compounds
Halogen containing
570181, 570261, 570175, 570101, 570177, C07C 1738, C07C 1908
Patent
active
059144327
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for hydrogenating a halogenated compound which contains one or more >C.dbd.O, olefinic and/or aromatic >C.dbd.C< groups.
There is an increasing demand for methods of processing halogenated organic compounds which are for example comprised in fractionation column bottoms in the production of allyl chloride, ethylene dichloride or trichloroethylene, or in used dielectric fluids containing polychlorinated biphenyls and chlorinated benzene. Several methods exist of converting saturated halogenated organic compounds by hydrodehalogenation techniques to hydrogen halide and hydrocarbonaceous organic compounds having a decreased halogen content which may be safely and usefully employed or recycled. Such hydrodehalogenating techniques are for example described in U.S. Pat. Nos. 5,316,663 and 4,899,001.
However, it is known from U.S. Pat. No.4,899,001 that unsaturated halogenated organic compounds present a greater challenge for subsequent processing, such as hydrodehalogenation, than the saturated halogenated organic compounds. For example, the presence of double bonds can interfere with the hydrodehalogenation reaction or polymerization may take place. Therefore, skilled artisans have searched for methods of converting unsaturated halogenated organic compounds to the corresponding saturated halogenated organic compounds.
U.S. Pat. No. 4,899,001 teaches a process wherein a) a first feedstock comprising unsaturated, halogenated organic compounds is reacted with hydrogen in a first hydrogenation reaction zone operated at mild hydrogenation conditions to produce a first hydrogenated stream comprising hydrocarbonaceous compounds, b) this first hydrogenated stream and a second feedstock comprising saturated, halogenated organic compounds are reacted with hydrogen in a second hydrogenation reaction zone operated at hydrogenation conditions selected to produce a stream comprising hydrocarbonaceous compounds and to generate at least one water-soluble inorganic halide compound. These two reaction steps are followed by several separation steps. The primary function of the hydrogenation reaction zone in step a) is the selective saturation of the unsaturated, halogenated compounds; however, dehalogenation, desulfurization, hydrocracking, may also take place.
Chemical Abstract No.116:255051 relates to studies on hydrogenation with nickel catalysts, particularly to catalytic properties of colloidal nickel for the hydrogenation of carbon--carbon double bonds.
Chemical Abstract No. 88:169335 relates to studies on hydrogenation of olefins catalyzed by polymer-bound palladium (II) complexes. It is disclosed that a polymer-bound PdCl.sub.2 complex under mild conditions catalyzes the hydrogenation of alkenes and alkynes.
Chemical Abstract No. 85:176349 discloses an active palladium catalyst for the hydrogenation of organic compounds, such as 1-hexene, cyclohexene, PhCHO and PhNO.sub.2, wherein Ph is phenyl.
However, hydrogenation of halogenated compounds which contain one or more >C.dbd.O, olefinic and/or aromatic >C.dbd.C< groups is an exothermic reaction. When the reaction is conducted on a large scale, the reaction temperature has to be carefully controlled.
GB-A-2,108,953 discloses a process for preparing 3-chloropropyl alcohol by hydrogenating 3-chloroallyl alcohol using palladium as a catalyst. The reaction is carried out in liquid phase, 3-chloroallyl alcohol is dissolved in a non-polar organic solvent, such as carbon tetrachloride, pentane, hexane, heptane, aromatic compounds, ketones or ethers. Preferred solvents are said to be cyclohexane and octane. By using such a solvent, the reaction temperature can be controlled, however, the solvent has to be separated from the product in an additional step after the reaction, which substantially increases the costs of the process.
Therefore, it would be desirable to provide a hydrogenation process which allows an efficient temperature control but which does not require subsequent separation of a solvent. It would be particul
REFERENCES:
patent: 2118662 (1938-05-01), Baumann et al.
patent: 4145367 (1979-03-01), Boozalis et al.
patent: 4899001 (1990-02-01), Kalnes et al.
patent: 5013424 (1991-05-01), James, Jr. et al.
patent: 5068484 (1991-11-01), James, Jr. et al.
patent: 5314614 (1994-05-01), Moser et al.
patent: 5316663 (1994-05-01), James, Jr.
patent: 5780695 (1998-07-01), Kalnes
Abstract of CA 116:255051, 1992.
Abstract of CA 88:169335, 1978.
Abstract of CA 85:176349, 1976.
Chemical Abstracts 116:255051; Studies on Hydrogenation with Nickel Catalysts; Sakai et al; 1992.
Chemical Abstracts 85:176349; Active Palladium Catalyst for Hydrogenation of Organic Compounds; Teleshev et al, 1976.
Chemical Abstracts 88:169335; Study of Hydrogenation of Olefins Catalyzed by Polymer-Bound Palladium (II) Complexes; Terasawa et al, 1978.
Kight John
M. Mach D. Margaret
The Dow Chemical Company
LandOfFree
Hydrogenation of halogenated compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrogenation of halogenated compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrogenation of halogenated compounds will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1709054