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Exhibit 99.1 ClearSign ClearSign Technologies Corporation Provides Third Quarter 2021 Update SEATTLE , November 23 , 2021 -- ClearSign Technologies Corporation ( Nasdaq : CLIR ) ( " ClearSign " or the " Company " ) , an emerging leader in industrial combustion and sensing technologies that improve energy , operational efficiency and safety while dramatically reducing emissions , today provides an update on operations for the third quarter ended September 30 , 2021 . " We made progress in the commercialization of our products , including the recent receipt of a process burner order for a multi heater project , ” said Jim Deller , Ph.D. , Chief Executive Officer of ClearSign . “ We fabricated and demonstrated our products in full scale installations and have received interest from our customers . As a result , we are seeing greater customer inquiries and proposal opportunities , and have developed a robust proposal pipeline in both our process burner and boiler burner technologies , " concluded Dr. Deller . Recent strategic and operational highlights during and subsequent to the third quarter of 2021 include : Announced Multi Heater Project for Major National Refiner : The Company received a purchase order from a Fortune 500 national refiner in connection with the first phase of the project to retrofit two process heaters with eight ClearSign Core ™ burners each to be installed in their Midwest refinery . Fabricated redesigned 2500hp water tube boiler burner in Tulsa and twin in China : The ClearSign Core ™ water tube boiler burner has been redesigned and is now configured as a continuation of our fire tube boiler burner technology , and has been tested and proven to operate with results consistent with the fire tube size burners . One is ready to install in China and the Company is in process of negotiating arrangements for the demonstration and certification of that burner there . 500hp boiler burner demonstration and product launch at California Boiler : Following a successful demonstration , the ClearSign Core fire tube burner technology is operating and delivering sub 2.5ppm NOx , and is being offered for sale in retrofit or new boiler applications through ClearSign and partner California Boiler . Announced the hiring of Brent Hinds as VP and Controller : Mr. Hinds was appointed by the board of ClearSign as the Company's VP and controller in October . Mr. Hinds joined ClearSign from Enovation Controls , Inc. a stand alone subsidiary of Helios Technologies , where he served as VP of Finance focused on global sales , manufacturing , and application engineering operations , working directly with original equipment manufacturers . His responsibilities there included consolidation of reporting across four legal entities totaling $ 120 million in revenues , $ 600 million in assets and $ 70 million in net - working capital . Cash and cash equivalents were $ 8,841,000 on September 30 , 2021 . There were 31,574,704 shares of our common stock issued and outstanding as of September 30 , 2021 .