A Seattle company says it has demonstrated a major reduction of NOX emissions using a proprietary system called Electrodynamic Combustion Control.

A Seattle company says it has demonstrated a major reduction of NOXemissions using a proprietary system called Electrodynamic Combustion Control. From ClearSign Combustion Corp., the technology introduces a computer-controlled electric field into the combustion zone to control flame shape and heat. According to the company, the electric field optimizes the chemical reactions that occur during combustion to minimize harmful emissions.

With the technology, ClearSign reported NOXemissions of 15 ppm in a system with thermal output of more than 400,000 BTU/hr. In many parts of the United States, NOXemissions levels must be below 20 ppm. California's South Coast Air Quality Management District, which includes the greater Los Angeles area, has introduced regulations that would require boiler operators in 2013 to reduce NOXemissions to 9 ppm initially, and below 5 ppm subsequently, ClearSign says.

According to Joe Colannino, ClearSign's chief technology officer, the California standards would be difficult to meet with conventional burner technology alone. He notes says that the company’s emissions-control demonstration validates burner design improvements, moving its ECC technology further along the path to commercialization.

"Our ECC technology allowed us to achieve [15 ppm] with a radically simplified burner design, requiring minimal excess air and without the use of any fans or blowers for flue gas recirculation," Colannino says.

According to Colannino, most low NOXburners use multiple gas jets to stage the introduction of fuel and air. In many cases, large fans are added to recirculate flue gas to reach emissions targets. ECC technology requires minimal excess air, optimizing fuel efficiency while eliminating the need for fans, Colannino says.

Colannino notes that the ClearSign system maintains flame stability across a wide operating range, which enables higher turndown ratios compared to other technologies. The effect, he says, is increased fuel efficiency in industrial settings in which boilers frequently are cycled to reflect changes in demand.

"Boiler operators are always focused on achieving NOXemissions standards at the lowest possible cost," says Rick Rutkowski, ClearSign CEO. "Our goal is to improve emissions performance to meet even the most stringent standards while at the same time simplifying burner design and eliminating the need for supplemental flue gas recirculation or costly SCR systems.

To download the white paper “Electrodynamic Combustion Control Technology,” go to http://tinyurl.com/97cenqe. For more information on ClearSign, go to www.clearsigncombustion.com.