Dual Catalyst for Alkane Metathesis
Dr. Maurice Brookhart
Department of Chemistry
The University of North Carolina at Chapel Hill.
Dr. Alan Goldman
Department of Chemistry
Pending U.S. and PCT patent application
We are seeking a commercial partner to evaluate, develop and commercialize the dual catalysts system for alkane metathesis developed by researchers at The University of North Carolina at Chapel Hill and Rutgers. The UNC/Rutgers technology involves a pair of catalytic chemical reactions that can be used on the products of the Fischer-Tropsch (FT) process to more efficiently convert carbon sources, such as coal, natural gas, or biomass, to diesel fuel. The catalyst duo increases the efficiency of coal-to-liquid (CTL) conversion, and conversion of other carbon-containing materials such as biomass to liquids (BTL), whereby coal or biomass, respectively, is converted to petroleum-like liquids in a three-step process: 1) gasification (heating with controlled oxygen addition) to produce syngas, a mixture of carbon monoxide and hydrogen; 2) conversion of the gas to a liquid syncrude by synthesis over a catalyst in a Fischer-Tropsch process; and 3) this dual catalyst reaction system. The FT process often creates a mixture of low- and high-molecular weight products, only some of which are useful for diesel fuel. The dual-catalyst system can augment the method by converting the less useful low-molecular weight alkanes (with between four and nine carbons in the chain) to diesel fuel-range alkanes (10 to 19 carbons) and ethane. The dual catalyst reaction system can also be used to upgrade the low-molecular weight alkanes in existing refinery or petrochemical waste streams, or to increase the diesel yield in existing gas-to-liquids (GTL) plants.
The dual-catalyst system utilizes two types of catalysts: a hydrogen transfer catalyst, preferably a "pincer"-ligated iridium complex catalyst, and an olefin metathesis catalyst. The first catalyst removes hydrogen, converting the alkane to a new material with carbon-carbon double bonds. The second catalyst scrambles the carbon bonds, creating compounds with higher molecular weights. The first catalyst then returns the hydrogen atoms to the rearranged compounds, yielding alkanes usable as fuel. The next step is to continue research to improve catalyst stability: the catalyst currently decays after approximately 2,000 turnovers. Although the technology is exciting and potentially very useful; to be viable in commercial production it needs to be improved to several million turnovers. Drs. Brookhart and Goldman continue to make progress and are available to discuss the technical details of their research