ClearSign Technologies Corporation provides an update on operations for the second quarter ended on June 30, 2021.

"This last quarter has been a mix of great progress and encouragement as we move multiple product lines through the technical stages of commercialization and customer engagement," Jim Deller, Chief Executive Officer of ClearSign.

"Admittedly, the past days have not been without some frustration. What continues to bring me confidence are the developments in the strategic alliances we have made and the technical and commercial maturing of both our major product lines, both of which feed the strengthening of our proposal pipeline," concluded Deller.

Recent strategic and operational highlights during and subsequent to the second quarter of 2021 include: Advanced process burner performance capabilities to meet or exceed normal refinery requirements: On fuel gas blends ranging from natural gas to blends with 80% hydrogen content, including in extremely tight multi burner settings, the Company's burners operate over a turn-down range from 100% of design firing rate down to 20%. The burners can light off on any fuel in that range, including from a cold start when the furnace is full of fresh air. Depending on heater conditions, ClearSign can make NOx guarantees typically between 5ppm and 9ppm.

Performed witness test and shipped process burner to Super Major's refinery in Europe: The burner has been installed and awaits startup which is expected early in the fourth quarter this year. This project will be the first Super Major process burner installation, and the first in Europe.

Received, commissioned and held customer demonstrations with a newly fabricated 125hp ClearSign Core fire tube boiler burner: Burner demonstrates sub 2.5ppm NOx. This was the first product demonstration as part of the agreement with California Boiler for the sale and installation of "ClearSign Core enabled ultra-low NOx boiler burners into the U.S. market. The boiler has been deployed in recent days for use at a customer site.

500hp burner designed and delivered to California: Burner is being commissioned and readied for customer demonstrations.

Joined the Russell Microcap Index: The Company was added to the index at the conclusion of the 2021 Russell indexes annual reconstitution which became effective after the US market opened on June 28th.

Completed the Performance Testing and Application for Firetube Boiler Burner Certification in China and subsequently received certification: With this certification, the Company can produce, market and sell its 125hp fire tube boiler burners throughout China.

Cash, cash equivalents and short term investments were approximately $10,600,000 on June 30, 2021.