Reporting Emissions from NSPS Ja Flares -Are You Contemplating An On-Line Flare Gas Moisture Analyzer or TDLS to Determine Moisture Content

摘要

EPA's NSPS Ja Rule which affects almost all refineries in the U.S. is a perplexing Rule on many fronts, but in particular because it does not clearly distinguish whether flare gas volume, mass, or flare emission compliance data is to be reported on a wet or dry basis. Therefore, when a refinery is confronted with how to comply with Ja flare gas emission limits such as the 162 ppmv H2S limit, or 500 lb/day SO2 mass limit, or the 500,000 scf (above baseline) flare gas volume limit, is it a wet or dry basis? Flare gas mass flow meters and Total Sulfur analyzers all produce wet basis data. Depending on how well a flare knockout drum or water seal is functioning, refinery flare gas may contain anywhere from 0% to as high as 20% moisture content in some circumstances. If you are considering costly on-line moisture analyzers or TDLAS (Tunable Diode Laser Atomic Spectroscopy) systems for flare gas moisture measurement, there may be a viable alternative to determine moisture content and at virtually no cost. Sage Environmental Consulting has developed a unique empirical algorithm that can determine flare gas moisture content and which can be programmed into the refinery flare data acquisition system. The algorithm accurately determines moisture content with only a few simple input parameters and has been lab tested with accuracy comparable to TDLAS systems. So why spend up to $100,000 per flare on costly moisture analyzers or TDL's when a low cost alternative may be a viable option.