Quantitive investigation of the homogeneous decomposition of trimethylindium and ammonia by in situ Raman spectroscopy

2004·9.2 MB·English

by  Hwang, Jang Yeon

QUANTITATIVEINVESTIGATIONOFTHEHOMOGENEOUSDECOMPOSITION
OFTRIMETHYLINDIUMANDAMMONIABYINSITURAMANSPECTROSCOPY
By
JANG YEON HWANG
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOL
OFTHEUNIVERSITYOFFLORIDAINPARTIALFULFILLMENT
OFTHEREQUIREMENTSFORTHEDEGREEOF
DOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
2004
ACKNOWLEDGMENTS
TheauthorwouldliketothankDrs.Chang-WonPark,AdrianE.Roitberg,and
JamesD.Winefordnerforbeinghiscommitteemembers.Healsowishestopresenthis
sinceregratitudetohiscommitteechair,Dr.TimothyJ.Anderson.Hisencouragements
weregreatsupporttotheauthorthroughoutthiswork.
ItwasagreatpleasurefortheauthortohaveachancetolearnwithDr.Zemer.His
passionforteachingshouldbeappreciated.TheauthoralsothanksDr.Bartlettfor
encouraginghimtotakeadvantageofcomputationalchemistry.
Itwasalsoapleasurefortheauthortohavechancestoworkwithvisitingscholars
andcolleaguesinhisresearchgroup.
TheauthorwishestoexpresshisappreciationtoMr.D.VinceandMr.J.Hinnant
fortheirkindsupportforhisexperiments.Healsothinksthatthestaffmembersinthe
mainofficedeservehisgratitude.
Finally,theauthorshouldexpresshissinceregratitudetohisparentsfortheir
endlessloveandcareforhim.
u
1
TABLEOFCONTENTS
page
ACKNOWLEDGMENTS
ii
LISTOFTABLES vi
LISTOFFIGURES vii
ABSTRACT xi
CHAPTER
1 INTRODUCTION 1
2 REACTORANDMODELING 8
2.1Background 8
2.2ReactorSystem 10
2.2.1ReactorAssembly 1
2.2.2GasHandlingCircuit 12
2.3ReactorModel 14
2.3.1ModelDescription 14
2.3.2NumericalModel 16
2.3.3DerivationofMassDiffusionFluxEquation 21
2.3.4PropertyEstimationforSimulations 24
2.4PenaltyFiniteElementMethod 26
2.4.1TheGalerkinMethod 26
2.4.2PenaltyFormulation 29
2.4.3ASimpleTest 31
2.5Summary 32
3 RAMANSCATTERINGANDCOMPUTATIONALCHEMISTRY 34
3.1Introduction 34
3.2TheoreticalBackgroundofRamanScattering 38
3.2.1SelectionRulesforRamanScattering 39
3.2.2IntensityofRamanScattering 42
3.3ApplicationsofRamanScattering 45
3.3.1RamanSystem 45
3.3.2TemperatureDetermination 48
iii
3.3.2.1Formulation 48
3.3.33.3.2.2Applications 49
ConcentrationDetermination 52
3.3.3.1Formulation 52
3.3.3.2Applications 53
3.4ComputationalChemistry 56
3.4.1VibrationFrequency 58
3.4.1.1Harmonicvibration 58
3.4.1.2Hotbandtransition 59
3.4.2BasisSetSuperpositionError 62
3.4.3CalculationofThermodynamicProperties 64
4 MODELVALIDATIONFORHEATANDMASSTRANSPORT 66
4.1HeatTransport 66
4.1.1Background 66
4.1.2ValidationoftheHeatTransportModel 67
4.1.3GasPhaseDynamics 69
4.1.4Summary 79
4.2MassTransport 79
4.2.1Background 79
4.2.2FirstInletConfiguration 81
4.2.3NewInletConfigurationandFlowInstability 86
4.2.4MassTransportCharacteristicsintheReactor 97
4.2.5Conclusions 102
5 PARAMETERESTIMATIONPROCEDURE 103
5.1Background 103
5.2EstablishmentofParameterEstimationProcedure 104
5.2.1FundamentalFormulation 104
5.2.2OptimizationScheme 107
5.2.2.1Deterministicmethods 107
5.2.2.2Simplegeneticalgorithm 110
5.2.3ImplementationofaSimpleGeneticAlgorithm 112
5.2.3.1Parametersencoding 112
5.2.3.2Selection 114
5.2.3.3Reproduction 114
5.2.3.4Performancetests 115
5.2.3.5Crowdingmodel-anadvancedconcept 120
5.2.4Summary 121
5.3ApplicationtoMassTransport 122
5.3.1Introduction 122
5.3.2Experimental 123
5.3.3ProblemFormulation 125
5.3.4OptimizationScheme 127
5.3.5ApplicationsandDiscussion 128
IV
5.3.6Conclusions 135
6 BEHAVIOROFAMMONIAANDTRIMETHYLALUMINUM 137
6.1AmmoniaDecomposition 137
6.1.1Introduction 137
6.1.2Experimental 138
6.1.3ResultsandDiscussion 140
6.1.4Conclusions 149
6.2BehaviorofTrimethylaluminum 150
6.2.1Background 150
6.2.2Experimental 150
6.2.3Results 151
6.2.4Summary 155
7 DECOMPOSITIONOFTRIMETHYLINDIUM 157
7.1Introduction 157
7.2KineticsofTMInDecomposition 161
7.2.1Experimental 161
7.2.2NumericalDescription 163
7.2.3ResultsandDiscussion 164
7.2.4Conclusions 175
7.3ReactionIntermediates 176
7.3.1Experimental 176
7.3.2ComputationalChemistry 178
7.3.3ExperimentalResults 180
7.3.4ReactionIntermediates 183
7.3.5Conclusions 191
7.4InteractionbetweenTMInandAmmonia 191
7.4.1Experimental 191
7.4.2ResultsandDiscussion 192
7.4.3Conclusions 196
8 CONCLUSIONSANDRECOMMENDATIONS 197
LISTOFREFERENCES 202
BIOGRAPHICALSKETCH 215
v
2-
3- LISTOFTABLES
Table page
1.Calibrationresultsformassflowcontrollers 14
1.ElectronictransitionsofGroupIIIatoms 36
3-2.Calculatedspectralresolutions(cm’1) 47
5-
3-3.ApparentrelativeRamancross-sectionsforthreegasmixtures 54
6-
37--4.Experimentalandcalculatedvibrationalfrequencies(cm’1) 58
3-5.VibrationaltransitionsofMMIn 62
3-6.Ga-CbondenergiesinTMGadecomposition(kcal/mol) 65
5-1.Parameterestimationresultsfrommethanedispersionexperiments 132
2.Parameterestimationresultsfromammoniadispersionexperiments 132
1.ValuesofapparentrelativeRamancross-sectionofammoniaandactivation
energyforconcentrationandreactionratecalculations,respectively 143
1.NormalizedrelativeRamanintensitiesofTMIn,MMIn,andatomicindium 165
7-2.PresentandreportedreactionrateconstantsforTMIndecomposition 173
7-3.CalculatedAHandAGdependingonmodelchemistry(kcal/mol) 178
7-4.AverageAHandAGforReactions7-6athrough6cforthetemperature
range200to600°C(inkcal/mol) 184
7-5.AHandAGfortheselectedreactionsusingB3LYP/(6-311++G(2d,2p)+
SDB-aug-cc-pVTZ) 186
7-6.AH,AG,andreactionrateconstantsforReactions7-6dand7-6e 188
7-7.Calculatedvibrationsforselectedintermediates 188
7-8.Estimatedvs(In-C)oftheadduct 194
vi
1-
2- LISTOFFIGURES
Figure page
1.Methodologydevelopedinthisstudy 5
1.Apictureofthereactorusedinthiswork 10
2-
23--2.Schematicofthefirstreactorconfiguration 11
2-3.Gashandlingcircuit 13
2-4.Schematicoftheaxisymmetricreactormodel 15
2-5.Twofundamentalconfigurationsintheviewfactorcalculations 19
6.Velocityprofilesatx=0.5(V)andy=0.5(U)forRe=400 32
1.Observeddecompositionbehaviorofphospinedependingonprobingmethods 35
3-
34--2.SchematicoftheRamansystem 45
3-3.Temperaturedetermination 50
3-4.Overlapofspectrainthenitrogenrotationband 51
3-5.AgasflowcellusedintheRamancross-sectionstudy 54
3-6.Hypotheticalspectraltransmittanceofquartz 55
—
3-7.Curvefittingthecalculatedpotential( •)withtheMorsepotential(—) 61
3-8.Sizeoftheavailablebasissetin(a)isdifferentfromthatin(b) 63
9.AdductformationfromTMGaandammonia 64
1.Axialtemperatureprofilesfortwoinletvelocities 68
4-2.Temperatureprofilesalongthecenterlineofthereactor 70
4-3.CalculatedstreamlinesandisothermsinthereactorforN2carriergas 73
4-4.CalculatedstreamlinesandisothermsinthereactorforH2carriergas 75
vii
4-5.Calculated(a)streamlinesand(b)isothermsinthereactorwithH2carriergas 78
4-6.Thefirstinletconfigurationusedinthemodelvalidation 82
4-7.Axialconcentrationprofilesalongthecenterlineofthereactor 83
4-8.Axialconcentrationprofilesalongthecenterlineofthereactorforthegas
velocitiesof(•)1.5cm/sand( )2.5cm/s 84
4-9.Concentrationprofilewithpartiallyremovedglassbeads 86
4-10.Modifiedinletconfiguration 87
4-11.AxialconcentrationprofilesofCH4withthemodifiedinletconfiguration 89
4-12.AxialconcentrationprofilesofCH4atr=0mm(O,—)andr=10mm(•,—)...90
4-13.Streamlinesandconcentrationcontoursinthereactorwhen10%CH4/N2is
introducedthroughtheannulusinlet 92
4-14.AxialconcentrationprofilesofCH4forthreedifferentinletconcentrations 93
445---15.Sitnrteraomdluicneedstahnrdoucgohnctehnetarnantuilounscoinnlteotursinthereactorwhen5%CH4/N2is 94
4-16.AxialconcentrationprofilesofCH4withareducedgas-travellengthat23°C 95
4-17.Effectsoffillingtheannuluschannelonstreamlinesandconcentrationcontours..96
4-18.Methaneconcentrationprofilesat24°Calongthecenterline 98
4-19.RadialCH4concentrationprofilesatdifferentaxialpositions 99
4-20.CalculatedradialconcentrationprofilesofTMIn 100
21.CalculatedcenterlineconcentrationprofilesofNH3 101
1.TheshapeoftheobjectivefunctioninProblem1 116
5-2.PerformanceofthegeneticalgorithmforProblem1 117
5-3.TheshapeoftheobjectivefunctioninProblem2 118
5-4.Testresultsforthesecondproblem 119
5-5.Schematicofthereactorusedinparameterestimation 124
5-6.Measuredandsimulatedaxialconcentrationprofilesforthegasvelocity
of2.5(•),3.5(),and4.5(A)cm/s... 129
viii
5-7.Measuredandsimulatedaxialconcentrationprofilesforinlet
5- concentration4(•)and8(B)mole%ammoniainN2 129
56--8.Performanceoftheparameterestimationprocedure 130
9.Shapeoftheobjectivefunctionneartheestimatesfortheammoniacase 134
1.Schematicofthereactorforammoniastudy 139
6-2.Ammoniaconcentration(•)andgastemperature(O)profilesalongthe
centerlineofthereactoratdifferentheatertemperatures 141
6-3.Transmissioncharacteristicofthereactorwallsfortwotemperatures 146
6-4.Thesquare-rootterminEq.6-9evaluatedbyusingaW-lamp 146
6-5.Simulatedtemperaturedistributionsatthereactorwallfordifferentheater
6- temperature 147
7-
6-6.Ammoniaconcentration(•)andgastemperature(O)profilesalongthe
centerlineofthereactorwiththeheatertemperaturesetat500°C 149
6-7.ObservedRamanpeaksfor(TMA1)2at21°C 152
6-8.Measuredandsimulated(TMA1)2concentrationprofilesat21°C 152
6-9.Axialvelocitycomponentand(TMA1)2molefraction 154
10.Dissociationbehaviorof(TMA1)2intoTMA1atvarioustemperatureposition 155
1.Schematicofthereactor 161
—
7-2.Experimental(B)andsimulated( )gastemperatureprofiles 165
7-3.ExhaustivescanwiththeparametersdefinedinEq.7-3 167
7-4.Performanceofgenetic/Simplexapproach 168
7-5.ExhaustedscanwithafixedrelativeRamancross-section(SrMin-22.3) 169
7-6.Experimental(B)andsimulatedconcentrationprofilesofTMIn 170
7-7.ReportedreactionratesforTMIndecompositionwithdifferentcarriergases 172
7-8.Experimental()andcalculatedMMInconcentrationprofiles 174
7-9.Schematicofthereactorforthereactionintermediatestudy 177
IX
7-10.ObservedspectraintherangesofIn-Cvibrationsandtheatomicindium
transition 181
7-11.Spectratakeninthenitrogenrotationband 182
7-12.ReactionintermediatesduringTMIndecomposition 185
7-13.IRCcalculationforatransitionstateof(DMIn)2inReaction7-6e 187
7-14.RamanspectraintherangeofHInCH3vibrations 189
7-15.ChangesinTMIncharacteristicpeaksforthefollowingconditions 192
7-16.TMIndecompositioninthepresenceofNH3 195
x