Abstract Title: | A simultaneous CH4 and CO2 flux quantification method for industrial site onshore amp; offshore emissions from in-situ concentration measurements on-board an Unmanned Aircraft Vehicle |
Presenter Name: | Mr Ludovic Donnat |
Co-authors: | Dr Lilian Joly Dr Olivier Duclaux Dr Jean-Louis Bonne Mr Nicolas Galas Dr Nicolas Dumeli Dr Jrmie Burgalat Mr Nicolas Chauvin Dr Delphine Combaz Dr Julien Cousin Dr Thomas Decarpenterie |
Company/Organisation: | TotalEnergies |
Country: | France |
Abstract Information :
We developed an innovative tool quantify CO2 and CH4 to quantify emissions at the scale of an industrial site, based on a mass balance approach relying on a newly developed light-weight open path laser absorption spectrometer operable on-board Unmanned Aircraft Vehicles UAVs. This spectrometer simultaneously records in situ CO2 and CH4 concentration at high frequency typically 24 Hz. The large range of measurable concentrations, from 300 to 1000 ppm for CO2 and from 2 to 200 ppm for CH4, and the precision at 1s, 0.4 ppm for CO2 and 5 ppb for CH4 makes this analyzer suitable for operation directly on industrial sites, therefore avoiding many logistical and legal limits associated with most long-range airborne observations. To quantify the emissions, the mass balance approach uses the high spatial resolution, allowed by the high acquisition frequency, of atmospheric concentration measurements throughout a plume cross-section downwind of a source obtained within the limited UAV flight period. This high spatial resolution limits the use of horizontal interpolation, thus gaining in precision compared to current airborne alternative quantification techniques. rnA field validation campaign of this method, conducted on the TotalEnergies TADI test platform at Lacq, France, consisted in controlled CO2 and CH4 leak experiments to which several institutes participated with various measurement systems multispectral camera, infrared camera including concentrations and emissions quantification system, acoustic sensors, ground mobile and fixed CRDS analysers. The result of this campaign for our method led to high accuracy evaluations in comparison with alternative techniques, with 34 of estimated CH4 fluxes within the -20 and +20 errors, 86 within the -50 and +100 ranges. rnObservations across the plume of the two offshore oil and gas platforms in the North Sea were used to quantify the instantaneous greenhouse gases emissions of these facilities and are coherent with vent emissions estimates obtained by mass balance and combustion calculation for CO2. Operational deployment of such instruments and quantification methods, potentially based on autonomous UAV, will allow the quantification of the time dependent greenhouse gases emissions of industrial sites.rn