Greyrock Energy, Inc., which transforms natural gas into premium transportation fuels, added George Couvaras and Glenn McGinnis to its team as director of international projects and vice president of engineering, respectively, the company said Jan. 6.

Couvaras is a chemical engineer who has worked in the petrochemical industry, particularly gas to liquids (GTL). He has been an executive at Sasol--including CEO of Sasol-Chevron (London), executive vice president of U.S. megaprojects, vice president of technology, president of GTL business development (Canada), and country president for Sasol (Qatar).

McGinnis is a chemical engineer with more than 35 years of refining experience. He previously held senior positions with Aux Sable Liquid Products, El Paso Corp., Imperial Oil Ltd., Exxon International, Orion Refining Corp. and TransAmerican Refining Corp.