Real-time Compliance Flare Emissions Monitoring and Reporting

摘要

Real-time flare emissions monitoring and reporting must include input data qualification,rnsubstitution, limit testing, alerts, annotations and auditing, and data visualization andrnreports. Calculating and storing emissions data rolled up to hourly, daily, year-to-daternand/or 12-month rolling totals is crucial to eco-friendly operations. Equally important isrnthe ability to identify “flaring events” in real-time and to calculate event-based metricsrnsuch as start and end timestamps, speciated and total emissions, and excess emissions.rnCalculation of Flare Emissions based on Measured or Estimated Flare Gas Compositionrnunder US EPA rules must be operated within certain limits: minimum heating value ofrnthe flare gas and maximum tip exit velocity. In some cases, maximum tip exit velocity isrncalculated as a function of the net heat content of the flare gas: the higher heat content,rnthe higher the allowable exit velocity. The rules for heat content and exit velocity differrnfor different types of flares (steam- or air-assisted vs. non-assisted).rnCalculation of Flare Emissions Based on Emission Factors using AP-42 provides thernfollowing emission factors for flares: total hydrocarbons, carbon monoxide, nitrousrnoxides and soot.rnThe AP-42 emission factors are in units of lb/MMBtu. Heat flow rate must be inrnMMBtu/hr to calculate mass emissions and can be determined by calorimeter and flowrnmeter, composition analysis and flow meter, process knowledge and vent valve position,rnetc.