Grantee Research Project Results
Final Report: Ionic Liquids for Green Chemistry-Biphase Hydrogenation Catalysis
EPA Contract Number: 68D00232Title: Ionic Liquids for Green Chemistry-Biphase Hydrogenation Catalysis
Investigators: McEwen, Alan B.
Small Business: Covalent Associates Inc.
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text | Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:
Hydrogenation is a ubiquitous chemical transformation used in the petrochemical and specialty chemical industry. The hydrogenation of arenes is important for the generation of cleaner diesel fuels. The hydrogenation of isohexenes (a product of the Dimersol process) is important in gasoline reformulation. Development of biphase hydrogenation catalysts for these reactants will create a more efficient less polluting process to improve the cleanliness of fuels for internal combustion engines.We are developing biphase catalysts by immobilizing homogeneous catalysts in an ionic liquid phase. Transition metal homogeneous catalysts are highly efficient compared to heterogeneous catalysts. A shortcoming of homogeneous catalysis is the separation of catalysts from the products, which wastes a valuable resource and leads to contamination of the environment with heavy metals. Immobilizing homogenous catalysts into an immiscible phase will heterogenize the highly reactive and selective catalysts, thereby facilitating product separation and reuse of the catalyst. We are using ionic liquids to create biphase catalysts. We are developing biphase olefin hydrogenation with ionic liquids we have invented.
Product separation has been a major obstacle in the implementation of homogeneous catalysts in industrial processes. Biphase catalysis using water has been successful; however, these systems have a water contamination problem. The water must be cleaned of organic impurities before being discharged into the environment, an exceedingly difficult process. In addition, organic substrates have poor solubility in water limiting the reaction rate. Improved biphase catalytic systems are needed to overcome these limitations and provide an environmentally friendly, green, process.
Our technical objective in Phase I is to demonstrate the feasibility of using ionic liquids as an immobilizing phase in biphase hydrogenation catalysis. In contrast to Covalent's ionic liquids, haloaluminate and inorganic fluoride ionic liquids suffer from limited thermal stability. The ionic liquids we are using are non-flammable, non-volatile, with excellent thermal stability.
Summary/Accomplishments (Outputs/Outcomes):
We have shown that Covalent's thermally stable hydrophobic ionic liquids are highly effective as a solvent in biphase hydrogenation and in immobilizing the homogeneous catalyst for reuse. We have shown that hydrophobic ionic liquids such as EMIIm have excellent solubility characteristics for phase separating from hydrocarbon products and immobilizing highly active homogeneous catalysts. High conversions of olefins and aromatics in a true biphase hydrogenation system using three different homogenous catalysts immobilized in EMIIm were demonstrated. Over 10 batch cycles were run with no detectable metal catalyst (<1ppm) in the product hydrocarbon phase.Conclusions:
We have demonstrated repetitive biphase hydrogenation of alkenes and arenes using thermally stable ionic liquids to immobilize homogeneous catalysts.Supplemental Keywords:
Gasoline Reformulation, Dimersol Process, Pharmaceutical Industry, Decreased solvent use, Homogeneous catalyst immobilization., RFA, Scientific Discipline, Waste, Sustainable Industry/Business, Chemical Engineering, Sustainable Environment, cleaner production/pollution prevention, Environmental Chemistry, Chemistry, Technology for Sustainable Environment, Incineration/Combustion, Engineering, Environmental Engineering, biphase hydrogenation catalysis, hydrogenation catalysis, ionic liquids, fossil fuel combustion, catalysisThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.