Remote Sensing for Flaming Plume of Elevated Flares with Passive Fourier Transform Infrared Spectroscopy

 Elevated flare is the utter most significant exhaust source in chemical plants and as well as the best way to centralized disposal of combustible gases at high altitude. It is considerable to monitor the concentration of the exhaust plume of flares, however, flare research over the past decade has increasingly illustrated that there is likely no one effective method can accomplish the task. Passive Fourier Transform Infrared Spectroscopy (FTIR) remote sensing system is widely used in the field of hazardous chemicals park monitoring and warning, gas distribution monitoring at the scene of the explosion in the way of non-contact long-distance remote sensing. Compared to active FTIR absorption spectrometry, it is easier to install because the hot gas just has to be in the field of view of the telescope of the spectrometer and once there is equivalent radiation bright temperature difference between the measured plume and the background, IR radiation emitted by exhausts or gas plumes is detected and remote sensing by passive FTIR spectrometry allows the retrieval of column densities or concentrations of molecules in gas plumes such as exhaust plumes of aircraft, smoke stacks and flares. In the paper, the exhaust plumes of two elevated flare in a chemical plant in Shanghai is measured by passive FTIR remote sensing system and quantitative the concentrations of CO, N2O, HCN, NH3, C3H3N, C3H6 and C2H4 in the plumes. The theory and process relate with radiometric calibration and calculation of transmittance is presented as well as the factors caused the error of the concentrations of target gases is analysed. The passive FTIR remote sensing system makes up the inability of measure the exhaust plume of flares and provide the efficient and powerful date for estimate/evaluate the combustion process and efficiency of flare, building the list of emission index and so on