ClearSign Combustion Corporation (NASDAQ: CLIR) announced today that it has entered into an agreement with Tesoro Refining & Marketing Company LLC to evaluate the performance of ClearSign's low emissions Duplex™ technology in Tesoro's refinery heaters.

In the initial stage of the agreement, ClearSign will retrofit Duplex technology within a selected multiple-burner process heater at Tesoro's Los Angeles refinery. Several performance criteria will be evaluated, including NOx emissions that meet or exceed the California South Coast Air Quality Management District's (SCAQMD) ambitious NOx Reclaim Program's goal of reducing refinery NOx emissions to half of their current level of (tons NOx or PPM) by 2020.

About Tesoro Refining & Marketing Company LLC

Tesoro Refining & Marketing Company LLC is a subsidiary of Tesoro Corporation.  Tesoro Corporation, a Fortune 100 company, is an independent refiner and marketer of petroleum products. Tesoro, through its subsidiaries, operates six refineries in the western United States with a combined capacity of over 850,000 barrels per day and ownership in a logistics business which includes a 35% interest in Tesoro Logistics LP and ownership of its general partner. Tesoro's retail-marketing system includes over 2,200 retail stations under the ARCO®, Shell®, Exxon®, Mobil®, USA Gasoline™ and Tesoro® brands.

About ClearSign Combustion Corporation

ClearSign Combustion Corporation designs, develops and markets technologies that drive to improve key performance characteristics of combustion systems, including emissions and operational performance, energy efficiency and overall cost-effectiveness. Our patent-pending Duplex™ and Electrodynamic Combustion Control™ platform technologies enhance the performance of combustion systems in a broad range of markets, including the chemical, petrochemical, refinery, power and commercial boiler industries.