Over the years, the U.S. Environmental Protection Agency ( EPA) has been actively involved in various flare enforcement initiatives. On June 30, 2014, the EPA proposed revisions to the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for petroleum refineries to include flare monitoring and operational requirements and mandate that flares serving as control devices at petroleum refineries achieve a minimum destruction efficiency of not less than 98 percent. The EPA then consolidated those efforts into a final rule known as 40 CFR Parts 60 and 63, with a compliance deadline of Jan. 31, 2019.
The known shortcomings of current indirect monitoring methods, combined with the new EPA standards and deadlines, drove the development of a new flare combustion efficiency (CE) measurement and monitoring method — a technology that can be used to directly, autonomously and continuously measure CE and smoke levels in real time.
This new method for flare monitoring was first proposed by Zeng, et al. In 2012 and has been proven through a series of large-scale validation tests. The technology, known as video imaging spectro-radiometry (VISR), is a real-time advanced multi-spectral infrared imager that directly and remotely monitors flare performance. VISR provides a high frame rate, high spectral selectivity and high spatial resolution. In addition to the measurement of CE, VISR also measures and reports the level of smoke in the flare flame, day or night, to provide the flare operator with a real-time tool to identify and operate at the “incipient smoking point” for optimized flare performance.
Zeeco Inc. has developed a patented new direct flare monitoring system using VISR named FlareGuardian™ (formerly known as FlareSentry). FlareGuardian eliminates the inaccuracies and delayed results inherent to indirect flare monitoring. Unlike a passive fourier transform infrared system, FlareGuardian’s VISR technology captures all the spectral bands for each pixel at the same time. The accuracy of the VISR technology removes the need for indirect surrogate parameters such as combustion zone net heating value and tip velocity. The FlareGuardian system can automatically adjust supplemental fuel additions as well as any assist source (gas, steam or air) via a closed-loop control system, lowering costs for supplemental fuel while maintaining required destruction efficiency.
FlareGuardian allows operators to eliminate tedious aiming, data reduction, and ongoing operation and maintenance costs associated with other flare monitoring methods, while staying in compliance with the Refinery Risk and Technology Review (RTR) rule under 40 CFR 63.670. Previously, flare operators have been limited to indirect flare monitoring options including gas chromatograph, calorimeters, flare gas flow meters and monitoring, and steam/air controls. Now, the maintenance and calibration-free Zeeco FlareGuardian offers an alternative direct monitoring system that eliminates ongoing maintenance and operational costs.
Cost savings vary depending on the current indirect monitoring method, but in many cases operators can save more than 50 percent of the capital, operation and maintenance costs over the life of the equipment.
For more information, visit www.Zeeco.com or call (918) 258-8551. •
