Tricor Refining, LLC, a customer based in Kern County, California reached out to ClearSign to provide a solution to restart a heater that had been mothballed from service for over 20 years. This vertical cylindrical heater was originally designed for a single oil-fired burner with a 15MMBtu/hr heat release. In order to bring this unit back online, Tricor need to comply with current emissions regulations.
The small vertical cylindrical heater is used in the Tricor Asphalt plant located in Bakersfield, California. The first ClearSign Core™ process burner was installed in this heater in 2016. The heater function did not require the full name plate design rating and ClearSign had an 8 MMBtu/hr burner available at that time. ClearSign installed this burner with a guarantee to meet the emissions permit that put a limit at 6ppm NOx and 50 ppm CO corrected at 3% oxygen (all further emissions values will be corrected numbers).
Due to the service of the heater and availability of operators, the ClearSign Core™ burner is operated in batch service operating only during the day when operators are on site. To simplify the operation of the entire burner system, ClearSign assisted in automating the system from start up to shut down with a single button operation. Emissions performance was measured by a third party on behalf of the refiner with results well below the current permit emissions requirements even in conditions quite challenging for conventional burner technology. Since the heater operated at roughly half its original fired duty design, the radiant section was relatively cold with normal bridge wall temperatures between 700-800ºF.
In early 2019 Tricor requested ClearSign to deliver a solution for an increased firing duty to support future process demands. The previous generation burner was replaced with a new 15 MMBtu/hr ClearSign Core™ Ultra Low (Sub 5ppm) NOx burner. This was the first installation of the technology that capitalized on the addition of a new continuous pilot system that enabled rapid light off of the burner and elimination of the previous warm up stage required with previous generations of the technology. Upon removal of the 8MMBtu/hr burner, the ceramic components were removed and inspected. Both the tile and structural members appeared to be in great condition with the only sign of operation being a slight tint from the dust in combustion air, which is a normal expectation.
Similar to the original install, this larger burner was able to achieve <6ppm NOx and <10ppm CO emissions. The NOx levels achieved in this arrangement are a significant, because at this firing rate, the heater hearth intensity is ~470,000Btu/hr/ft2, roughly 1.5 times greater that the API guidelines for new heater designs. This means older heaters facing emissions reductions needs with limited floor areas can be retrofit with a burner technology in lieu of an SCR system and meet current NOx permit levels.
The development of the ClearSign Core™ technology allows ClearSign the ability to provide a combustion solution that delivers SCR competitive NOx emissions at a fraction of the cost. With the advancement of our technology, we provide superior emissions performance on a burner that operates similar to any other burner technology installed in the field.