Supercritical WaterOxidation TOC AnalysisKeith McLeroyAssociate Training SpecialistTEEX-Water & EnvironmentalWater&EnvironmentalTraining ProgramC ll St ti TXCollegeStation,TX.TOC Analyses•When measuring Total OrganicWhenmeasuringTotalOrganicCarbon (TOC), several techniquesare used to oxidize the organicareusedtooxidizetheorganiccarbon in the sample to form carbondioxide.• Once theCO2is formed it can bed t t d d tifi ddetectedandquantified.TOCCon’t.• The main problem facing TOC analysis isensuring efficient oxidation of the organiccarbon.• The GE InnovOx TOC Analyzer uses theStandard Methods wet chemical oxidationtechnique (5310D )technique.(5310-.• The InnovOx is currently being utilized byTEEX Global Petroleum ResearchTEEX,GlobalPetroleumResearchInstitute in a wide variety of research andapplicationsprojects.p jSuper Wet-CriticalOxidation Method•Supercritical Water Oxidation (SCWO)SupercriticalWaterOxidation(SCWO)was originally developed to treat largevolumes of aqueous waste streams,,sludges and highly concentratedbrine/mineralized waters• SCWO destroys organic wastes using anoxidant in water and temperatures andb th iti l i t fpressures abovethe criticalpointofwater, 375 °C, and 3,200 psi.SWCO Description•TheInnovOxemploys a 30%employsa30%weight/volume solution of sodiumpersulphateas the oxidizer It thenastheoxidizer.Itthenheats the sample and oxidizer in al d t t th iti l i tsealedreactor pastthe criticalpointand Supercritical Water Oxidation(SCWO) is achieved.Why SWCO ?• Research performed in the 1970’s foundthe SCWO technique to have manycharacteristics that were ideal for ananalytical technique relying on efficientanalyticaltechniquerelyingonefficientsample oxidation and accounting fordifficult sample matricesdifficultsamplematrices.• Numerous studies have demonstratedthat the process achieves oxidationthattheprocessachievesoxidationefficiencies of > 99% for residence timesof 10 to 30 seconds.SWCO Chemistry•When water reaches a supercriticalWhenwaterreachesasupercriticalstate, organic material and gasesbecome highly soluble whilebecomehighlysoluble,whileinorganic salts become insoluble.S lt ill t i ll th•Salts willtypically scavengetheoxidizer, resulting in an incompletei b t b di idorganic carbonto carbondioxideconversion.SWCO Chemistry Cont’dSWCO Chemistry Cont d.•TheInnovOxtakes thetakestheenvironmental sample to asupercritical state by increasing thesupercriticalstatebyincreasingthetemperature and subsequently thepressure within the reactorpressurewithinthereactor.• The InnovOx uses a titaniumid ti h b bl foxidation chamber capable ofwithstanding excessive pressures.SWCO Is In Short:SWCO Is...In Short:•The properties of supercritical waterThepropertiesofsupercriticalwaterenable the ultra-efficient, rapidoxidation of organic carbon to CO2oxidationoforganiccarbontoCO2,even in the presence of chloride andother inorganic species thatotherinorganicspeciesthatnegatively interfere with non-SCWOwet chemical oxidationwetchemicaloxidation.Meaning•Environmental samples of variousEnvironmentalsamplesofvariousmatrices can be analyzed withoutinterferences.• This application is an importantt l f th iti l l fprotocolforthe criticalanalyses ofabroad range of very difficult samples.• i.e.: oil-field wastewaters, frac-flowback and brine waste ponds.TOC Detection inEnvironmental Matrices•When testing for TOC in the detectionWhentestingforTOCinthedetectionrange of 0.5 to 50,000 ppm, it is verycommon to have a complicated samplepmatrix.• Specifically, in a UV- Nondispersiveyinfrared (NDIR) type system, theaggressive sample matrix attacks thel d d ti ll d itlamp anddramatically reducesitssensitivity to detection of TOC.Detector•TheInnovOxuses a highly stableusesahighlystable,nondispersive infrared (NDIR)detector.• Unlike other NDIR detectors theI ONDIR h i tnnovxNDIRhas no moving parts,and features tight temperaturet l f th IR dcontroloftheIRsource anddetector.EnvironmentalApplications•Flowback waters in wellfracing-backwatersinwellfracing• Brine retention ponds• Wastewaters from petro,chemicalproduction & gas condensatemanagement sites.• Groundwater monitoringCurrent Research atTEEX & GPRI•Fracwater analyses protocol-wateranalysesprotocoldevelopmentsLi l ti hi f k•Linear relationships ofknown“difficult” to analyze sample matricesi tk t d dagainstknown standards• Oil/gas produced wastewatersclean-up technology, organicmonitoringSamples Analyzed SoFar•Evaluations of a wide range of oilEvaluationsofawiderangeofoilfield waters in diverse matrices ofsludges liquids and glycolsludges,liquidsandglycoldehydrator condensates.B i t t t d/ t t d fl•Brine waters,treated/untreatedflowback & groundwater• From these studies, protocols andmethodologies can be designed forthese applications.Questions??Thank you!Thankyou!Keith McLeroy979-458-0912keith.mcleroy@teexmail.tamu.eduTexas Engineering Extension Serv.The Texas A&M University SystemTheTexasA&MUniversitySystem