The Dow Chemical Company

Dow Agrosciences LLC

Terrence McCabe

Daniel A Hickman

Timothy Charles Frank

Patrick H Au-Yeung

Bruce S Holden

Paul L Morabito

Mukund R Patel

Jason Lee Bronkema

Joseph F Hiller

Michael Lee Trippeer

Robin K Johnston

Richard G Melcher

Thomas L Peters

Patrick Ho Sing Au-Yeung

Robin Keith Johnston

Bruce Stephen Holden

Daniel Alan Hickman

A process for converting tertiary halogenated hydrocarbons in a tertiary halogenated hydrocarbon-containing stream to a corresponding unhalogenated or less-halogenated unsaturated hydrocarbon product with the release of hydrogen halide involves contacting the tertiary halogenated hydrocarbon with a sorbent-type dehydrohalogenation catalyst in a reaction zone and optionally passing a stripping gas through the reaction zone to remove vapor phase reaction products from the reaction zone. A process for removing a tertiary chlorinated hydrocarbon impurity from 1,3-dichloro-1-propene involves contacting a mixture containing the 1,3-dichloro-1-propene and the tertiary chlorinated hydrocarbon impurity with a dehydrochlorination catalyst effective to catalyze a conversion of the tertiary chlorinated hydrocarbon impurity to a corresponding unchlorinated or less-chlorinated unsaturated hydrocarbon and hydrogen chloride and distilling the 1,3-dichloro-1-propene to produce a purified cis-1,3-dichloro-1-propene fraction and a purified trans-1,3-dichloro-1-propene fraction.

Selective dehydrohalogenation of tertiary halogenated hydrocarbons and removal of tertiary halogenated hydrocarbon impurities from a halogenated hydrocarbon product

A process for converting a tertiary halogenated hydrocarbons in a tertiary halogenated hydrocarbon-containing stream to a corresponding unhalogenated or less-halogenated unsaturated hydrocarbon product with the release of hydrogen halide involves contacting the tertiary halogenated hydrocarbon with a sorbent-type dehydrohalogenation catalyst in a reaction zone and optionally passing a stripping gas through the reaction zone to remove vapor phase reaction products from the reaction zone. A process for removing a tertiary chlorinated hydrocarbon impurity from 1,3-dichloro-1-propene involves contacting a mixture containing the 1,3-dichloro-1-propene and the tertiary chlorinated hydrocarbon impurity with a dehydrochlorination catalyst effective to catalyze a conversion of the tertiary chlorinated hydrocarbon impurity to a corresponding unchlorinated or less-chlorinated unsaturated hydrocarbon and hydrogen chloride and distilling the 1,3-dichloro-1-propene to produce a purified cis-1,3-dichloro-1-propene fraction and a purified trans-1,3-dichloro-1-propene fraction.

Method and apparatus for gas chromatography/mass spectroscopy including a retention gap, a capillary gas chromatography column and a mass spectrometer, the improvement being a valve that facilitates temporarily venting the carrier gas from between the retention gap and the capillary gas chromatography column immediately after the injection of a sample. The valve also facilitates an alternate flow of carrier gas into the mass spectrometer during the venting operation.

Vented capillary gas chromatography apparatus

The invention describes a large volume on-column gas chromatographic method for analyzing trace levels of high molecular weight and polar compounds in a sample and an apparatus for performing the method. A column inlet coupled to an analytical column is heated rapidly to concentrate difficult to chromatograph compounds onto the analytical column resulting in an increase in the detectability of the compounds.

Heated column inlet gas chromatography method and apparatus

A method for on-column injection of large sample volumes using the retention gap technique in capillary gas chromatography for sample components of interest that would be obscured by the large solvent peak otherwise inherent in the technique. This interference from the large solvent peak is removed by venting carrier flow from the retention gap to waste for a limited time, long enough to discard much of the solvent without serious loss of the sample component of interest.

Vented retention gap capillary gas chromatography method

In one embodiment the invention is a method for on-column valved injection gas chromatography by on-column injecting more than 5 microliters and less than one milliliter of sample consisting of a solvent and a component of interest into a retention gap/capiliary column system with an injection valve at a first carrier gas flow rate, followed by a substantially higher carrier gas flow rate to blow the solvent of the sample out of the system at a rapidly increased rate and then a return to a lower flow rate to chromatograph the component of interest. In another embodiment, less than 5 microliters of sample consisting of a solvent and a component of interest is on-column injected into a capillary column using an injection valve and a relatively high column inlet pressure of gas to move the sample from the injection valve into the colunm rapidly and with reduced carryover. Then, the pressure of carrier gas is reduced to a normal pressure for chromatography of the component of interest.

Method for on-column injection gas chromatography

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Midland, MI, United States of America

Terrence McCabe