(CLIR) Selected by Delek for Process Optimization

Company enters Texas market to support 75,000-barrel-per-day refinery operation

SEATTLE, Sept. 30, 2015  — ClearSign Combustion Corporation (NASDAQ: CLIR), an emerging leader in combustion and emissions control technology for industrial, commercial and utility markets, announced today it will install its Duplex™ technology at a Texas refinery owned by a subsidiary of Delek US Holdings, Inc. This agreement marks ClearSign’s entrance into the Texas market and the company’s fourth major refinery customer in recent months.

ClearSign will retrofit burners within a process heater at Delek’s 75,000-barrel-per-day refinery in Tyler, Texas. It is expected that ClearSign’s unique, patent-pending Duplex technology will eliminate potential flame impingement upon process tubes and reduce maintenance costs and downtime. Delek has expressed interest in retrofitting the Duplex technology into other process heaters if the initial installation proves the viability of ClearSign’s solution.

Lindale-based JLCC, Inc. will lead the contracting services for the project on behalf of ClearSign.

“The oil and gas industry has a need for practical, effective solutions that reduce impingement on process tubes which should improve utilization rates and operating conditions,” noted JLCC Founder Jerry Lang. “ClearSign’s Duplex technology offers the industry an economic, future-proof option to simultaneously remove operational bottlenecks while reducing NOx emissions.”

“We’ve gained considerable traction in recent months, and in two of the country’s leading oil and gas markets,” said Stephen Pirnat, CEO of ClearSign. “We look forward to demonstrating exceptional results in the field and further building on this momentum.”

About Delek US Holdings, Inc.

Delek US Holdings, Inc. is a diversified downstream energy company with assets in petroleum refining, logistics and convenience store retailing. The refining segment consists of refineries operated in Tyler, Texas and El Dorado, Arkansas with a combined nameplate production capacity of 155,000 barrels per day. Delek US Holdings, Inc. and its affiliates also own approximately 62 percent (including the 2 percent general partner interest) of Delek Logistics Partners, LP. Delek Logistics Partners, LP is a growth-oriented master limited partnership focused on owning and operating midstream energy infrastructure assets. The retail segment markets motor fuel and convenience merchandise through a network of approximately 360 company-operated convenience store locations operated under the MAPCO Express®, MAPCO Mart®, East Coast®, Fast Food and Fuel™, Favorite Markets®, Delta Express® and Discount Food Mart™ brand names. Delek US Holdings, Inc. also owns approximately 48 percent of the outstanding common stock of Alon USA Energy, Inc.

About ClearSign Combustion Corporation

ClearSign Combustion Corporation designs and develops technologies that aim to improve key performance characteristics of combustion systems including energy efficiency, emissions control, fuel flexibility and overall cost effectiveness. Our patent-pending Duplex™ and Electrodynamic Combustion Control™ platform technologies improve control of flame shape and heat transfer and optimize the complex chemical reactions that occur during combustion in order to minimize harmful emissions. For more information about the Company, please visit www.clearsign.com.

Cautionary note on forward-looking statements

This press release includes forward-looking information and statements within the meaning of the Private Securities Litigation Reform Act of 1995 and the provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Except for historical information contained in this release, statements in this release may constitute forward-looking statements regarding our assumptions, projections, expectations, targets, intentions or beliefs about future events that are based on management’s belief, as well as assumptions made by, and information currently available to, management. While we believe that our expectations are based upon reasonable assumptions, there can be no assurances that our goals and strategy will be realized. Numerous factors, including risks and uncertainties, may affect our actual results and may cause results to differ materially from those expressed in forward-looking statements made by us or on our behalf. Some of these factors include the acceptance of existing and future products, the impact of competitive products and pricing, general business and economic conditions, and other factors detailed in our Quarterly Report on Form 10-Q and other periodic reports filed with the SEC. We specifically disclaim any obligation to update or revise any forward-looking statement whether as a result of new information, future developments or otherwise.