Supercritical fluid extraction
AssigneeIdaho Research Foundation, Inc.
InventorsChien M. Wai, Kenneth Laintz
Life of this patent
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Abstract
A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
Claims32
A method of extracting a metalloid or metal species from a solid or liquid, comprising the steps of:
- exposing the solid or liquid to a supercritical fluid solvent containing a fluorinated chelating agent, for a sufficient period of time to form chelates between the agent and species that are solubilized in the supercritical fluid solvent.
A method of extracting metalloid or metal species from a solid or liquid, comprising the step of:
- exposing the solid or liquid to supercritical carbon dioxide and a fluorinated chelating agent which forms chelates with the species that are soluble in the supercritical carbon dioxide.
A method of extracting a metalloid or metal species from a solid or liquid, comprising the steps of:
- exposing the solid or liquid to supercritical fluid carbon dioxide containing a fluorinated chelating agent for a sufficient period of time to form chelates between the agent and species that are solubilized in the supercritical carbon dioxide.
The method according to 23 wherein the step of exposing the waste material to the supercritical fluid comprises exposing the material to supercritical carbon dioxide.
The method according to 30 further comprising the step of providing a chelating agent in the supercritical fluid that forms chelates with the metalloid, metal, lanthanide or actinide species, wherein the chelates are soluble in supercritical carbon dioxide.
Dependencies are inferred from the claim text.