Reduced Combustion Mechanism for C<sub>1</sub>-C<sub>4</sub> Hydrocarbons and its Application in CFD Flare Modeling
Creators: name: Damodara, Vijaya
name: Chen, Daniel H.
name: Lou, Helen H.
name: Rasel, Kader M.A.
name: Richmond, Peyton
name: Wang, Anan
name: Xianchang Li
Publisher: name: Taylor & Francis
Year: 2016
Subjects: subject: Biophysics
subject: Genetics
subject: FOS: Biological sciences
subject: FOS: Biological sciences
subject: Physiology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: 80699 Information Systems not elsewhere classified
subject: FOS: Computer and information sciences
subject: FOS: Computer and information sciences
subject: Inorganic Chemistry
subject: Science Policy

description: Emissions from flares constitute unburned hydrocarbons, CO, soot, and other partially burned and altered hydrocarbons along with CO<sub>2</sub> and water. Soot or visible smoke is of particular concern for flare operators /regulatory agencies. The goal of the study is to develop a computational fluid dynamics (CFD) model capable of predicting flare combustion efficiency (CE) and soot emission. Since detailed combustion mechanisms are too complicated for (CFD) application, a 50-species reduced mechanism, LU 3.0.1, was developed. LU 3.0.1 is capable of handling C<sub>4</sub> hydrocarbons and soot precursor species (C<sub>2</sub>H<sub>2</sub>, C<sub>2</sub>H<sub>4</sub>, C<sub>6</sub>H<sub>6</sub>). The new reduced mechanism LU 3.0.1 was first validated against experimental performance indicators: laminar flame speed, adiabatic flame temperature, and ignition delay. Further, CFD simulations using LU 3.0.1 were run to predict soot emission and CE of air-assisted flare tests conducted in 2010 in Tulsa, Oklahoma using ANSYS FLUENT software. Non-premixed Probability Density Function (PDF) model and Eddy Dissipation Concept (EDC) model results are discussed. It is also noteworthy that, when used in conjunction with the EDC turbulence-chemistry model, LU 3.0.1 can reasonably predict volatile organic compound (VOC) emissions as well. Implication statementA reduced combustion mechanism containing 50 C1-C4 species and soot precursors has been developed and validated against experimental data. The combustion mechanism is then employed in the computational fluid dynamics (CFD) of modeling of soot emission and combustion efficiency (CE) of controlled flares for which experimental soot and CE data are available. The validated CFD modeling tools are useful for oil, gas, and chemical industries to comply with EPA’s mandate to achieve smokeless flaring with a high CE. Implication statement A reduced combustion mechanism containing 50 C1-C4 species and soot precursors has been developed and validated against experimental data. The combustion mechanism is then employed in the computational fluid dynamics (CFD) of modeling of soot emission and combustion efficiency (CE) of controlled flares for which experimental soot and CE data are available. The validated CFD modeling tools are useful for oil, gas, and chemical industries to comply with EPA’s mandate to achieve smokeless flaring with a high CE.