Reaction efficiency of industrial flares the perspective of the past

Dahm, Werner J. A. (2007). Scaling relations for flare interactions, flame lengths, and crosslighting requirements in large flare. American Flame Research Committee (AFRC).

Reaction Efficiency of Industrial Flares The Perspective of the Past Jim Seebold, ChevronTexaco(Ret); Bruce Davis, DuPont Engineering Technology; Peter Gogolek, Natural Resources Canada; Larry Kostiuk, University of Alberta; John Pohl, Virginia Polytechnic Institute and State University; Bob Schwartz, John Zink Company; Nick Soelberg, Idaho National Engineering and Environmental Laboratory; Mel Strosher, Alberta Research Council; Pete Walsh, University of Alabama at Birmingham Siegel, K. D., "Degree of Conversion of Flare Gas in Refinery Elevated Flares," PhD Thesis in Engineering Science, Feb, 1980, Chemical Engineering Department, University of Karlsruhe, Germany Siegel, K. D., "Degree of Conversion of Flare Gas in Refinery Elevated Flares," PhD Thesis in Engineering Science, Feb, 1980, Chemical Engineering Department, University of Karlsruhe, Germany Mid-80s USEPA Evaluation of the Efficiency of Industrial Flares Mixing buoyancydominated inertiadominated Industrial Pipe Flares EPA's Mid-80s Evaluation of the Efficiency of Industrial Flares  103 tests (3", 6", 12"D)  70 > 99%  87 > 98%  24 tests (3 12"D Commercial Tips)  21 > 99%  23 > 98%  Those that were lower were at the limit of stability … Broad Range of Normal Operation High Reaction Efficiency PERF Project 92-19 Demonstrated: Hydrocarbon Gaseous External Combustion is Extremely Robust  Dissociated elemental "soup"  highly reactive  HC emissions vanishingly small  near or below detection limits  Fuel composition doesn't matter  All possible molecular combinations of Cs and Hs and Os (Oh, My!) are produced regardless of fuel compositional details PERF Project 92-19 Example: a b c d e f g h i j k l m n o p T 1.E-02 1.E-03 1.E-04 1.E-05 process gas, lb/mmBtu natural gas, lb/mmBtu Process gas emissions are the same as natural gas emissions Key: a = acetaldehyde, b = formaldehyde, c = propyne, d = butadiene, e = ethane, 1.E-06 f = butane, g = propane, h = ethylene, i = propylene, 1.E-07 1.E-08 j = allene, k = acetylene, l = xylene, m = benzene, n = toluene, o = ethylbenzene, p = pah, T= total PERF Project 92-19: Trace Emissions from Gaseous Hydrocarbon External Combustion 10000 Concentration, ppb 1000 100 10 Required detection limit! 1 ethylene 0.1 propylene butadiene Broad Range of Normal Operation High Reaction Efficiency Limit of Stability "Stochastic" Efficiency] Walsh, P.M., D.K. Moyeda, W.S. Lanier, C.M. Booth, E.E. Folk, J. Maxwell, W.K. Whitcraft, R.K. Noble, J.M. Clopton, T. Rogers, C. Nicely, R.E. Rosensteel and C.A. Miller, Flame Stability Limits and Hydrocarbon Destruction Efficiencies of Flares Burning Waste Streams Containing Hydrogen and Inert Gases, American Flame Research Committee Fall Meeting, November 2002 Pohl, J.H., R. Payne & J. Lee, Evaluation of the Efficiency of Industrial Flares: Test Results, EPA-600/2-84-095, May 1984 Absence of Systematic Reaction Efficiency Variation IDEA OF "STOCHASTICNESS" Great Difficulties for Regulatory Interpretation‼ Stochastic, adj. 1. Of, relating to, or characterized by conjecture; conjectural; 2. Statistics: Involving or containing a random variable or variables; involving chance or probability; being or having a random variable. Limit of Stability "Stochastic" Efficiency] ? Pohl, J.H., R. Payne & J. Lee, Evaluation of the Efficiency of Industrial Flares: Test Results, EPA-600/2-84-095, May 1984 Walsh, P.M., D.K. Moyeda, W.S. Lanier, C.M. Booth, E.E. Folk, J. Maxwell, W.K. Whitcraft, R.K. Noble, J.M. Clopton, T. Rogers, C. Nicely, R.E. Rosensteel and C.A. Miller, Flame Stability Limits and Hydrocarbon Destruction Efficiencies of Flares Burning Waste Streams Containing Hydrogen and Inert Gases, American Flame Research Committee Fall Meeting, November 2002 Combustion Efficiencies of Smoking vs. Smokeless Flares  Smoking 99.20% (average of 45 tests)  Smokeless 98.09% (average of 55 tests) Many tests, researchers, years … The evidence amassed over 2½-decades suggests …  Jet-stabilized reacting flows are extremely robust, normally yielding combustion efficiencies »98%  The only way to produce marked inefficiency in a jet-stabilized reacting flow is to reduce the mixture's heating value well below that normally encountered in industrial practice Combustion Efficiency in Elevated Flares 1.00  inertia-dominated  buoyancy-dominated U. S. Petrochemical Flares Combustion Efficiency 0.95 Data of Pohl, J.H., et al, Evaluation of the Efficiency of Industrial Flares: Test Results, EPA-600 / 2-84-095, May 1984 0.90 0.85  wake-dominated Canadian Field Flares Data of Johnson, M.R., et al, Efficiency Measurements of Flares in a Cross Flow, Combustion Canada '99, May 1999 0.80 0.75 10-3 1.E03 10-2 1.E02 10-1 1.E+0 100 1.E+0 101 1.E+0 102 1.E+0 103 1.E+0 104 1.E+0 105 1.E+0 106 1.E01 (0V2)1jet/(V22)wind3 4 5 6 Questions?