Catalytic hydrotreating, Oyama explained, is an important refining process used to remove S and N from hydrocarbon fuels. The removal of S and N is critical--they corrode engine components, pollute the air, cause gelling of untreated liquids and foul downstream reforming catalysts.
"Although hydroprocessing catalysts have been widely studied, their basic compositions have changed little for decades," Oyama noted. "They are typically sulfide-based."
The catalysts Oyama is developing "are completely different," he said. "These new materials are the phosphides of transition metals, a class of robust metallic substances. They have metallic--rather than insulating or semiconducting--properties. They also are more active than sulfide-based catalysts, resulting in much more efficient sulfur and nitrogen removal."
In addition, the new catalysts are physically strong and chemically stable, as well as inexpensive to produce and regenerate.
"The current research in our group at Virginia Tech involves understanding the mechanism of reaction of the catalysts as they remove the S and N pollutants," Oyama said. "This entails studying the molecular pathways of reaction."
The new catalysts will be employed in large-scale refineries that process hundreds of thousands of barrels of petroleum per day. "These new higher-activity catalysts are compatible with existing processing units at refineries," Oyama said. "This will help limit the need for installing new units to achieve the federally mandated reductions of S and N in the final product."
Oyama, the Fred W. Bull Professor of Chemical Engineering at Virginia Tech, completed his undergraduate work at Yale University and earned his graduate degrees at Stanford University.
Oyama will present his keynote address, "Transition metal phosphides: New catalysts for hydroprocessing (Fuel 82)," at 1:35 p.m. on Monday, March 24, in the Convention Center, Room 397. He also will present another paper, "Mechanism of permeation in hydrogen-selective silica membranes (Fuel 129)," at 4:30 p.m. on March 25 in the Convention Center, Room 398.
To contact Ted Oyama at Virginia Tech, call (540)231-5309 or email oyama@vt.edu .
PR CONTACT: Liz Crumbley (540)231-9772 lcrumb@vt.edu