Abstract: Alkyl halides can be effectively scrubbed from gas streams containing them by passing the gas streams through dispersers having a very small pore size into an aqueous scrubbing liquid containing a nucleophile such as thiosulfate. Optionally, the addition of a water-soluble organic compound to the scrubbing liquid may increase the rate of destruction of the alkyl halide. Alkyl halides such as methyl bromide can be effectively scrubbed from enclosed spaces containing the halide, for example in enclosures used for fumigation.
Abstract: An alkyl halide such as methyl bromide can be effectively removed from a gas stream by passing the gas stream through a bed of adsorbent at a relatively low temperature to adsorb the alkyl halide onto the adsorbent, desorbing the alkyl halide at a higher temperature to produce a smaller volume of gas containing the alkyl halide in more concentrated form, and then reacting the alkyl halide with a nucleophile contained in a liquid phase by contacting this smaller gas volume with such liquid phase.
Abstract: Alkyl halides can be effectively scrubbed from gas streams containing them by passing the gas streams through dispersers having a very small pore size into an aqueous scrubbing liquid containing a nucleophile such as thiosulfate. Optionally, the addition of a water-soluble organic compound to the scrubbing liquid may increase the rate of destruction of the alkyl halide. Alkyl halides such as methyl bromide can be effectively scrubbed from enclosed spaces containing the halide, for example in enclosures used for fumigation.
Abstract: A method and system for reactively destroying alkyl halides in volume or stream of gas. The method and device employ nucleophilic reaction of the alkyl halide under phase transfer catalysis conditions. The method and system are useful for scrubbing applications requiring the reduction of alkyl halide concentrations to very low levels.
Type:
Grant
Filed:
May 27, 2003
Date of Patent:
August 15, 2006
Assignee:
Value Recovery, Inc.
Inventors:
Peter J. Joyce, Roman Bielski, Terrence P. Buckmaster, Marc Halpern
Abstract: A method for preparing organic products from aqueous solutions, such as waste or byproduct liquid streams and waste or byproduct gas or vapor streams, uses phase transfer catalysis to transfer a chemical species in low concentration from the aqueous solution to the organic phase or the aqueous-organic interface. The system has little or no organic solvent, and the organic phase contains an electrophile which participates in the reaction. In one embodiment, the aqueous solution is contacted with the electrophile and a phase transfer catalyst and, optionally, a pH adjusting agent in the event that the chemical species in the aqueous solution is not sufficiently ionized to react with the electrophile, and optionally an organic solvent. A method for continuously converting a chemical species involves this contacting step, separating the phases, then dividing the organic phase into the product, the phase transfer catalyst, and the optional organic solvent.
Type:
Grant
Filed:
September 6, 2002
Date of Patent:
January 25, 2005
Assignee:
Value Recovery, Inc.
Inventors:
Peter J. Joyce, Roman Bielski, Marc Halpern