ALEXANDRIA, Va., July 16 -- United States Patent no. 12,667,820, issued on June 30, was assigned to UOP LLC (Rosemont, Ill.).

"Process and apparatus for contacting feed and catalyst with improved fluid dynamics" was invented by Wolfgang A. Spieker (Glenview, Ill.) and Richard A. Johnson II (Algonquin, Ill.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A process and apparatus comprise a reaction chamber that includes an aspect ratio between about 0.7 and 1.3 for establishing a dense catalyst bed in the reaction chamber while minimizing hot residence time of the product gas in a range that will not deteriorate product selectivity. We have found the dense catalyst bed is necessary to ensure sufficient contact ...