Method for Real-Time Estimation of the Emission Characteristics of Natural Gas Flaring

Abstract The global problem presented by the flaring of associated gas in petroleum production facilities is made worse by the absence of efficient methods to quantify the volume and mass of pollutants emitted during flaring activities. Operators have argued that flaring is done for safety reasons; however, it has serious environmental implications and is a waste of monetisable resources. In this work, a model is developed for the estimation of the non-hydrocarbon {Carbon dioxide (CO2, Carbon monoxide (CO), Nitric oxide (NO), Nitrous dioxide (NO2) and Sulphur dioxide (SO2)} emissions from gas flaring in real time. Six different flare gas samples consisting of different mole compositions have been analysed. These gas samples comprise four sweet gas samples and two sour gas samples. Different reaction conditions were considered; three different combustion temperature conditions of 2500°F, 2000°F and 1500°F were used to model the emission products depending on the conditions of the reaction. Air availability of 120% and 95%, and combustion efficiency of 90% and 70% were investigated during the simulation of the model, respectively. MATLAB software was used in the simulation of the model. The result reveals that the best temperature of the combustion system would be that which does not favour the formation of NO and NO2 species, which is a temperature of 1500°F. Furthermore, it was realised that a decrease in combustion efficiency decreases the mass of CO2 emission and increases the mass of CO, NO and NO2 emissions from each mole composition of the flare gas sample used. Air availability does not have any effect on the formation of CO2 and CO emissions; its excess increases the mass of NO and NO2, while its deficiency decreases the mass of NO and NO2 formed. It was discovered that rich gases have a tendency to emit more of the gaseous pollutants than lean gases. The model provides a good real-time estimate of the emissions released from the flaring of natural gas.