HollyFrontier Corporation, an independent petroleum refiner and marketer, has appointed J.W. Gann as controller and vice president, effective as of June 25. Gann also will serve as principal accounting officer.

Gann joins HollyFrontier with more than 20 years of public accounting experience. For the last year, he has served as chief financial officer at Energy Water Solutions, a clean water treatment and transformation technology company. From 2004 to 2010, he served as chief accounting officer at KBR, a global engineering, construction and service company. He was previously a partner at both Ernst & Young and Arthur Anderson.