Optimized Asphaltene DeterminatorTM and Waxphaltene DeterminatorTM Separations for

Rapid Characterization of Asphalt Binders

John F. SchabronJoseph F. Rovani

Mark M. Sanderson

Pavement Performance and Prediction SymposiumPavement Performance and Prediction SymposiumJuly 15, 2010

Fund Sources

• U S Department of Energy National• U.S. Department of Energy, National Energy Technology Laboratory (NETL)

• BP• Chevron• ConocoPhillipsp• ExxonMobil• Shell• UW School of Energy Resources• FHWA

Outline of Presentation

• Background• Heavy Oil Structure Continuum• Asphaltenes: Suspended Particle Solution Model• Solubility Parameter

• Prior Work• Free Solvent Volume: Heat-Induced Deposition and Coke

Formation Induction Period• WRI Coking Index

• Recent Work Update• Asphaltene Determinator Optimizationp p

• Applications• Preparative Work

• Waxphaltene Determinator OptimizationWaxphaltene Determinator Optimization• Applications

Polarity / Aromatic Continuum

SARA SEPARATION FRACTIONS

Pre-coke MesophaseMaltenes / Petrolenes Subfractions Asphaltenes

The particular methods used define the fraction chemistry

Saturates, Naphthenes

Polars / Resins, Pericondensed

Asphaltenes: Pericondensed AromaticsNaphthenes Structures with

Side ChainsAromatic Structures

Precipitation / SolubilityAdsorption Chromatography Fractions p yp g p y

Waxes can be present in Maltenes or Asphaltenes

Gravimetric Separations

• The term “Asphaltenes” is a catch-all for things that i it t hi hl i t d l th t i l dprecipitate as highly associated complexes that include

pericondensed aromatic molecules and various types of hydrocarbon structures including waxesy g

• Different gravimetric precipitation procedures provide different results

• The new on-column precipitation and re-dissolution methods provide chemically meaningful profiles of pericondensed aromatic and wax componentpericondensed aromatic and wax component distributions

• Asphaltene Determinator data can measure totalAsphaltene Determinator data can measure total pericondensed aromatic material without gravimetric separations

Many Different Asphaltene Methods Yield Different ResultsMethods Yield Different Results

Solvent to Stirring TemperatureMethod Solvent Oil Ratio and Settling Time Filter Media

ASTM D-3279-07 Heptane 100:1 Reflux 30 min., Settle Ambient Fiberglass1 hr., Filter at 38-49 °C 1.5 micron

ASTM D-4124-01 Heptane 100:1 Heat on Steam Bath 30 min., Slow / MedS OSettle Ambient Overnight Paper ~ 10 micron

ASTM D-4124-09 Isooctane 100:1 Reflux 2 hours, Ambient 2 hr., Med. GlassSettle Ambient 2 hr. Frit, 10 micron

WRI Heptane 40:1 Heat to 80 °C for 5 min., Stir Med. GlassAmbient 16 hr., Settle 30 min. Frit, 10 micron

ASTM D-6560-00 Heptane 30:1 Reflux 60 min., Settle at Whatman 42p ,Ambient 90-150 min. Paper 2.5 micron

ASTM D-2007-03 Pentane 10:1 Ambient 30 min Rapid Paper20 micron

IFP 9313 Heptane 20:1 to Heat to 80 °C 5 min. Cellulose EsterAbsorbance vs. 200:1 Filter Ambient Filter 0.45 micronMaltenes at 750 nm

Petroleum Asphaltene Component Moleculesp

• 4 - 10 pericondensed aromatic ring systems• 4 - 6 alkyl carbon chains4 6 alkyl carbon chains • 20 - 40 aliphatic carbons • 60 - 90 hydrogens• Average H/C atomic ratio 1.2• Number average molecular weights near

700 g/molg• Heteroatoms Sulfur: aromatic thiophene, aliphatic

sulfidesulfide Nitrogen: aromatic pyrrole or pyridine,

and metal (Ni, V) chelating structures Oxygen: naphthenic (carboxylic) acidsOxygen: naphthenic (carboxylic) acids

Component molecules self-associate

Asphaltenes Can Contain Waxy ComponentsWaxy Components

Size Exclusion Chromatography of 0.5 mg SARA Fraction Portions

Size Exclusion Chromatography of Asphaltenesof Asphaltenes

Apparent Molecular Weight is Concentration Dependent

Dilute Size Exclusion Chromatography(0 01 t %)(0.01 wt. %)Mn 388 - 772 g/molM /M 1 8 – 4 0Mw/Mn 1.8 – 4.0

Vapor Pressure pOsmometry(2 - 5 wt.%)Mn 474 - 23,000 g/mol

Heavy Oils and Residua

Suspended Particle Solution Model

System Free Energy is Minimized by Alignment of Components

Experimental Estimation of Model Parameters

Core particle volume fractionФ X / 1 2ФP = Xa / 1.2

Solvation factor/ ( )KS = 1 / (1 – ΧCy)

Flocculation factorKS = 1 / (1 – pa)

Effective particle volume fractionФEFF = KS *KF *ФP = K ФP

η = η / η = 1 + 2 5 * Фηrel = ηdisp / ηsol = 1 + 2.5 ФEFFA. Einstein 1904

Solubility Parameter Basics

ΔG = ΔH – TΔSΔG = Free Energy ChangeΔH = Heat of MixingΔS = Entropy Change

H = V((E1/V1) ½ - (E2/V2) ½ )2* Φ1Φ2

V = Total VolumeEX = Molar Energy of VaporizationVX = Molar VolumeΦX = Volume Fraction

Hildebrand Solubility Parameter

δ = (ΔE / V)1/2

ΔE = Molar energy of vaporizationV = Molar volume

Solvent Mixtures δmixture = ∑ δiΦi

Solvent (cal/cc)½ δ, MPa½( ) ,Isooctane 6.9 14.1Pentane 7.0 14.3Heptane 7.4 15.1pCyclohexane 8.2 16.8Toluene 8.9 18.2Carbon disulfide 10.0 20.4Ethanol 12.7 26.0

Hansen Components of Solubility Parametery

δ

δ

δ

δ

δd = Dispersion Component δp = Polarity Component δ = Hydrogen Bonding Componentδh = Hydrogen Bonding Component

Solubility Parameter Component MPa½Solvents used in the automated solubility separations

Solubility Parameter Component MPa½

Solvent δd δp δh Hildebrandn-Heptane 15.3 0.0 0.0 15.3Cyclohexane 16 8 0 0 0 2 16 8Cyclohexane 16.8 0.0 0.2 16.8Toluene 18.0 1.4 2.0 18.2Methylene Chloride 18.2 6.3 6.1 20.2Chlorobenzene 19 0 4 3 2 0 19 6Chlorobenzene 19.0 4.3 2.0 19.6Methyl Ethyl Ketone 16.0 9.0 5.1 19.1Methanol 15.1 12.3 22.3 24.0

Solubility of Asphaltenes:Scatchard-Hildebrand Equationq

ln xa = - (Ma / RTρa) * ((δa – δs)2)a a a a sWhere

x = Mole Fraction Solubilityx = Mole Fraction SolubilityM = Molecular WeightR = Gas ConstantT = TemperatureΡ = Density Partial Solubility Zoneδ = Solubility Parametera = Solute (Asphaltenes)s = Solvent (Excess)

T.F. Turners = Solvent (Excess)

Solubility is a function of molecular weight, density, and solubility parameter

Solubility as a Function of Molecular Weight and Solubility Parameter g y

Components of Solubility ParameterSolubility Parameter

δTOT2 = δd

2 + δp2 + δh

2

δd = Dispersion Component δp = Polarity Component δ = Hydrogen Bonding Componentδh = Hydrogen Bonding Component

Solubility Parameter Component MPa½Solvents used in the automated solubility separations

Solubility Parameter Component MPa½

Solvent δd δp δh Hildebrandn-Heptane 15.3 0.0 0.0 15.3Cyclohexane 16 8 0 0 0 2 16 8Cyclohexane 16.8 0.0 0.2 16.8Toluene 18.0 1.4 2.0 18.2Methylene Chloride 18.2 6.3 6.1 20.2Chlorobenzene 19 0 4 3 2 0 19 6Chlorobenzene 19.0 4.3 2.0 19.6Methyl Ethyl Ketone 16.0 9.0 5.1 19.1Methanol 15.1 12.3 22.3 24.0

Solubility Sphere Model

The solubility parameter of the solvent is not the same as the solubility parameter of the asphaltenes

Solvents1. Heptane

2. Cyclohexane

3. Toluene

4. MethyleneChlorideChloride

TF Turner and Per Redelius, Nynas Oil, private communication 2007

Heat-induced Deposition

• One model is of a protective shell around asphaltene cores that is partially removed by heating

• Solvation shell energy ~ 1,000 cal/molAt t t < 340°C thi i ibl• At temperatures < 340°C, this is reversible

Deposition Experiment

50 g Residuum in Weighing Pan Argon Inert Gas Flow

Heat Induced Deposition

Boscan Vacuum Residuum on Aluminum Weighing Pan Surface

Porphyrins and Metals

BOSCAN RESIDUUM DEPOSITION, mg/kg

Porphyrin ICP AnalysisPorphyrin ICP AnalysisMaterial (Ni+V) Ni V (Ni+V)

Original Residuum 490 126 1300 1430250 ºC Deposits 520 155 1430 1580p300 ºC Deposits 590 203 1640 1840

The Deposits Are Enriched in Metals (Asphaltenes)

More Highly Ordered Systems Are More Readily Disruptedy p

Pyrolysis Reactors

Heated Fluidized S d B th fSand Bath for Heated Tubes

Stirred Vessel Reactor

5-gram 50-gram 500-gram

Effects of Pyrolysis

• Pyrolysis bond cleavage occurs > 340 °CPyrolysis bond cleavage occurs > 340 C• Intermediate polarity material decreases during

the coke formation induction periodp• Asphaltenes become more aromatic• Polar / highly aromatic particles agglomeratePolar / highly aromatic particles agglomerate

and grow larger• Coke formation is coincidental with the Co e o at o s co c de ta t t e

disappearance of intermediate polarity material and the formation of a bimodal or multi-phase system

Coke Formation Induction Period

Depletion of intermediate polarity material in the continuum

Original ResiduumOriginal Residuum

Pyrolysis Induction Period Coke Formation

Thermal Bond Cleavage Reactions

400 ºC

H/C 1.3

OLEFINSVOLATILES

FREE RADICAL RECOMBINATION REACTIONS

OLEFINS

H/C 0.8

Thermal Bond Cleavage

• Free radicalsFree radicals • Hydrogen sulfide• Light hydrocarbon gasesg y g• Unsaturated hydrocarbons• More polar pericondensed ring systems

P h i d d• Porphyrin structures destroyed• Metals (Ni,V) concentrate in polar / aromatic• material• material• Ring condensation reactions – coke• Two liquid phases – polar / aromatic andTwo liquid phases polar / aromatic and

non-polar

Atomic Force Microscopy

Lloydminster Residuum Pyrolyzed at 400°C

30 MIN, <0.03 wt.% COKE 60 MIN, 4.2 wt.% COKE

Tapping Mode AFM

TWO LIQUID PHASES

Proton NMR Images

Residua Pyrolyzed at 400°C for 90 Minutes

CONCURRENT WITH COKE FORMATION, TWOCONCURRENT WITH COKE FORMATION, TWO IMMISCIBLE LIQUID PHASES ARE EVIDENT IN

VISBROKEN OILS

Coke Formation Induction Period at 400 °C

Coke formation occurs sooner for more highly ordered systems (small free solvent volume fraction)

KS and KF Decrease Irreversibly During Pyrolysis

WRI Coking IndexesUniversal for All Oils for Any Pyrolytic Processy y y

Threshold: KS < 1.2 Threshold: KF < 1.5

Asphaltene Solubility in Cyclohexane

Flocculation Titration

Recent Work Update

A h lt D t i t• Asphaltene Determinator• Optimized Conditions• Applications• Preparative Workp

• Waxphaltene Determinator• Optimized Conditions• Optimized Conditions• Applications

WRI Asphaltene DeterminatorSOLUBILITY BASED SEPARATION – NOT

CHROMATOGRAPHYC O OG

Separation of Asphaltene Solubility Subfractions

Re-dissolutionSolvent

PrecipitationSolvent

Detector

Signal Output

Solubility Subfractions

Solubility of Individual Components

WasteSolventColumn

Packing

PTFE-Packed Column

Column SolventSelection

Valve

Injector Pump

SampleSolution

Asphaltene Determinator

• Separation of oil into heptane soluble maltenesSeparation of oil into heptane soluble maltenes and subfractions of heptane insolubles

• ELSD detector measures relative amounts of material in the various fractions

• Optical absorbance at 500 nm and 700 nm profiles pericondensed aromatic component distribution and is an indicator of total

i d d ti itpericondensed aromaticity

Asphaltene Determinator SeparationSeparation

STEP GRADIENT TIMESLloydminster Residuum 2 mg

Solvent at 2 mL/minHeptane: 0 minC l h 15 iCyclohexane: 15 minToluene: 25 min CH2Cl2:MeOH: 35 min

10 uL 20% Solution (2 mg)

250 x 7 mm column250 x 7 mm column40-60 mesh PTFE

ELSD and 500 / 700 nm Absorbance Detectors

Asphaltene Determinator Multiple Uses

• Monitor pyrolysis severity / optimize y y ydistillation efficiency (universal for all oils)

• Determine the amount of and distribution of resin/polar and asphaltene pericondensed aromatics

• Study asphaltene component contributions in emulsion chemistry

• Monitor oxidative aging of asphalts• Replace the use of gravimetric asphaltenes• Replace the use of gravimetric asphaltenes

Pyrolysis: Peak Areas Change With Pyrolysis Severityy y y

Four solvent separation with methylene chlorideCyclohexane soluble pericondensed aromatics decrease, methylene chloride soluble pre-coke mesophase increases

60

70

Toluenenm

40

50

rcen

t at 5

00

20

30Heptane

eak

Are

a Pe

r

0

10CyclohexanePe

COKE

00 10 20 30 40 50 60

Pyrolysis Time at 400 °C, minutes

Universal Coking Index Ratio

Coking Index RatioApplies to Any Oil From Any Source with Thermal Treatment

= Cy500 / CH2Cl2 500whereC A P t C l h k t 500Cy = Area Percent Cyclohexane peak at 500 nmCH2Cl2 = Area Percent Methylene Chloride:Methanol (98:2 v:v) at 500 nmv:v) at 500 nm

Ratios near 1 Instability due to Pyrolysis, Ratios <1 Indicate Coke

Determination of Asphaltenes: Two ApproachesTwo Approaches

A P t M th d• Area Percent Method• Measure relative areas of maltenes

and asphaltenes peaks• Weight percent = (M * Area%) + B

• Asphaltene Peak Area Method• Measure area of asphaltene

peak(s)• log mass = (D * log area) + Eg ( g )

• Neither approach is satisfactory since gravimetric methods precipitate associated complexes with entrainedassociated complexes with entrained species, with little chemical meaning.

Correlating Gravimetric Data with Asphaltene Determinator Peak Areasp

• Gravimetric methods are bulk separations that form and precipitate associated complexes

• Heptane insoluble components are found in maltenes, and heptane soluble components are found in asphaltenes

• Correlations with gravimetric data are empirical at best, since pericondensed aromatic components can “hide” in other fractions

• Asphaltene Determinator can measure all of the pericondensed aromatic material without gravimetric separations

Determination of Total Pericondensed Aromatics (TPA)( )

Determination of Total Pericondensed Aromatic Content

wt.% Total Pericondensed Aromatics (TPA)( )

= ((100-HELSD) x H500 / (100-H500)) + (100-HELSD)(( ELSD) 500 ( 500)) ( ELSD)

whereHELSD = Area Percent Heptane ELSD PeakH500 = Area Percent Heptane 500 nm Peak

Sample-specific internal calibration of 500 nm absorbance areas using ELSD peak areasabsorbance areas using ELSD peak areas

Gravimetric Asphaltenes vs. TPA

RELATIONSHIP WITH GRAVIMETRIC ASPHALTENESWEIGHT PERCENT SHRP‐A‐645                           WEIGHT PERCENT SHRP‐A‐645

AD PERICONDENSED GRAVIMETRIC  GRAVIMETRIC

RESIDUUM  AROMATICS % HEPTANE INSOLUBLES ISOOCTANE INSOLUBLES

Lloydminster 19.90 15.80 19.20WY Sour 19.88 17.30 19.30Redwater 12.72 9.90 13.20CA Coastal 24.37 20.20 23.60W TX Sour 18.57 13.40 16.50CA Valley 11.53 5.00 8.40Boscan 23.18 20.10 22.90

W TX Intermedite 14.47 3.70 9.30

AD Pericondensed Value Correlates with Isooctane Asphaltenes

Asphaltenes and SARA Resins / Polars

500 nm

CONTINUUMCONTINUUMMinnelusa Oil Asphaltenes

CONTINUUMCONTINUUM

Emulsion Studies:Asphaltenes in Emulsions areAsphaltenes in Emulsions are Different than Asphaltenes in the Original Oil

Air Blown vs. Original BinderOriginal Binder

  Asphaltene Determinator Area Percent Total Coke Index Aging Index Percentp g gBinder Sample Detector Heptane CyC6 Toluene CH2Cl2:MeOH Area Ratio Cy/CCl Ratio T/H TPA

Lloydminster  ELSD 86.95 5.36 7.37 0.32 ‐ 16.8 19.9AAA‐1 500 nm 34.42 26.14 37.40 2.05 83.46 12.8 1.09

Lloydminster ELSD 77.95 6.32 14.79 0.95 ‐ 6.7 28.1Air Blown  (AAE) 500 nm 21.64 20.66 53.85 3.86 102.30 5.4 2.49

Toluene 500 nm Peal Area Increases, Heptane 500 nm

P k A DPeak Area Decreases

Asphaltene DeterminatorAsphaltene Determinator Separation can Track Aging ??

Extent of Oxidative Asphalt Aging

Universal AD Asphalt Aging Index RatioUniversal AD Asphalt Aging Index Ratio (ADAIR) (proposed)

= T500 / Cy500whereT = Area Percent Toluene peak at 500 nmCy = Area Percent Cyclohexane Peak at 500 nm

Unaged: <1.5A d 1 5Aged: >1.5

Evaluation of 8 SHRP Core AsphaltsCore Asphalts

  Asphaltene Determinator Area Percent Total Coke Index Aging Index PercentBinder Sample Detector Heptane CyC6 Toluene CH2Cl2:MeOH Area Ratio Cy/CCl Ratio T/H TPA

Lloydminster  ELSD 86.95 5.36 7.37 0.32 ‐ 16.8 19.9AAA‐1 500 nm 34.42 26.14 37.40 2.05 83.46 12.8 1.09

Lloydminster ELSD 77.95 6.32 14.79 0.95 ‐ 6.7 28.1Air Blown (AAE) 500 nm 21 64 20 66 53 85 3 86 102 30 5 4 2 49Air Blown  (AAE) 500 nm 21.64 20.66 53.85 3.86 102.30 5.4 2.49

WY Sour ELSD 86.83 4.10 8.60 0.47 ‐ 8.7 19.9AAB‐1 500 nm 33.74 17.42 45.15 3.70 122.33 4.7 1.34

Redwater ELSD 93.84 2.45 3.50 0.21 ‐ 11.7 12.7AAC 1 500 51 59 17 65 28 17 2 49 86 92 7 1 0 55AAC‐1 500 nm 51.59 17.65 28.17 2.49 86.92 7.1 0.55

CA Coastal ELSD 82.10 6.80 10.71 0.39 ‐ 17.4 24.5AAD‐1 500 nm 26.98 25.56 44.88 2.58 70.21 9.9 1.66

W TX Sour ELSD 89.18 3.98 6.56 0.28 ‐ 14.2 18.6AAF‐1 500 nm 41.73 18.68 37.44 2.14 95.80 8.7 0.90

CA Valley ELSD 96.21 1.36 2.26 0.18 ‐ 7.6 11.5AAG‐1 500 nm 67.13 11.50 19.20 2.18 62.31 5.3 0.29

Boscan ELSD 84.08 5.72 9.67 0.53 ‐ 10.8 23.2AAK‐1 500 nm 31.31 21.81 43.53 3.34 111.66 6.5 1.39

W TX Intermediate ELSD 96.96 1.28 1.56 0.20 ‐ 6.4 14.5AAM‐1 500 nm 78.99 9.12 9.92 1.97 115.06 4.6 0.13

Evaluation of Minnesota Paving Validation Site AsphaltsValidation Site Asphalts

  Asphaltene Determinator Area Percent Total Coke Index Aging Index PercentBinder Sample Detector Heptane CyC6 Toluene CH2Cl2:MeOH Area Ratio Cy/CCl Ratio T/H TPA

Elvaloy MN1‐2 ELSD 87.94 3.90 7.24 0.92 ‐ 4.2 17.9y500 nm 32.71 16.53 41.97 8.79 88.41 1.9 1.28

RTFO MN1‐2 ELSD 86.96 4.18 8.07 0.78 ‐ 5.4 18.9

500 nm 30.95 17.24 44.74 7.07 93.91 2.4 1.45RTFO PAV MN1‐2 ELSD 83.83 4.15 10.98 1.04 ‐ 4.0 21.6

500 nm 25.27 14.89 53.07 6.77 98.11 2.2 2.10500 nm 5. 7 4.89 53.07 6.77 98. . . 0

MN1‐3 ELSD 86.95 4.72 8.05 0.38 ‐ 12.4 19.5

500 nm 33.11 21.31 42.19 3.39 96.37 6.3 1.27RTFO MN1‐3 ELSD 86.03 5.08 8.57 0.33 ‐ 15.4 19.8

500 nm 29.48 25.33 42.54 2.65 106.41 9.6 1.44RTFOPAV MN1 3 ELSD 81 96 6 47 11 07 0 50 12 9 23 8RTFOPAV MN1‐3 ELSD 81.96 6.47 11.07 0.50 ‐ 12.9 23.8

500 nm 24.33 25.87 47.06 2.74 117.14 9.4 1.93

MN1‐4 ELSD 87.09 5.02 7.47 0.42 ‐ 12.0 19.4

500 nm 33.33 22.46 40.28 3.93 101.26 5.7 1.21RTFO MN1‐4 ELSD 86.18 4.80 8.62 0.39 ‐ 12.3 19.7

500 nm 29.76 21.80 45.06 3.38 104.86 6.4 1.51RTFOPAVMN1‐4 ELSD 82.86 5.45 11.23 0.47 ‐ 11.6 22.7

500 nm 24.60 21.75 50.77 2.87 116.35 7.6 2.06

MN1‐5 ELSD 89.16 3.89 6.52 0.44 ‐ 8.8 17.6500 nm 38.47 18.44 38.80 4.30 103.11 4.3 1.01500 nm 38.47 18.44 38.80 4.30 103.11 4.3 1.01

RTFO MN1‐5 ELSD 88.33 4.18 7.12 0.37 ‐ 11.3 18.1500 nm 35.54 20.50 40.71 3.25 107.99 6.3 1.15

RTFOPAV MN1‐5 ELSD 85.21 4.88 9.49 0.42 ‐ 11.6 20.7

500 nm 28.70 21.17 47.34 2.79 115.88 7.6 1.65

Evaluation of Arizona Paving Validation Site AsphaltsValidation Site Asphalts

  Asphaltene Determinator Area Percent Total Coke Index Aging Index PercentBinder Sample Detector Heptane CyC6 Toluene CH2Cl2:MeOH Area Ratio Cy/CCl Ratio T/H TPA

AZ‐1 Neat ELSD 90.11 5.04 4.67 0.19 ‐ 26.5 21.7500 nm 54.44 21.40 22.94 1.22 110.68 17.5 0.42

RTFO AZ‐1 ELSD 89.54 5.43 4.86 0.17 ‐ 31.9 22.3500 nm 53.08 22.16 23.43 1.34 114.61 16.5 0.44500 nm 53.08 22.16 23.43 1.34 114.61 16.5 0.44

AZ‐2 Neat ELSD 83.05 6.23 10.30 0.42 ‐ 14.8 25.0500 nm 32.27 22.26 42.78 2.69 109.40 8.3 1.33

RTFO AZ‐2 ELSD 81.12 6.87 11.62 0.39 ‐ 17.6 26.8500 nm 29.61 22.63 45.32 2.44 116.31 9.3 1.53

AZ‐3 Neat ELSD 86.65 4.31 8.31 0.72 ‐ 6.0 20.7500 nm 35.59 17.54 41.65 5.22 123.43 3.4 1.17

RTFO AZ‐3 ELSD 84.53 5.21 9.62 0.63 8.3 23.0500 nm 32.81 18.72 43.93 4.54 131.21 4.1 1.34

AZ‐4 Neat ELSD 84.76 5.56 9.17 0.51 ‐ 10.9 23.8500 nm 36 07 20 55 40 00 3 37 131 96 6 1 1 11500 nm 36.07 20.55 40.00 3.37 131.96 6.1 1.11

RTFO AZ‐4 ELSD 83.68 6.14 9.76 0.42 ‐ 14.6 24.6500 nm 33.76 21.53 41.76 2.95 141.12 7.3 1.24

Aging / Oxidation Effects

• Pericondensed Aromatics in the Resins / PolarsPericondensed Aromatics in the Resins / Polars (Heptane Soluble) Decrease

T l S l bl P i d d A ti• Toluene Soluble Pericondensed Aromatics Increase

• Total 500 nm Absorbance Increases (More Pericondensed Structures)

• Aromatization of Naphthenes in the Resins/Polars?

• No Pyrolytic Bond Cleavage

Preparative Asphaltene Determinator SeparationDeterminator Separation

• Heptane3 g Heptane AsphaltenesHeptane

• Cyclohexane• Toluene

M th l hl id th l• Methylene chloride:methanol (95:5 v:v)

Asphaltene Samples Separated by Preparative Asphaltene Determinatorp p

• Asphaltenes contain heptaneheptane, cyclohexane, toluene, and methylene chloride:methanol (98:2 v:v) soluble ( )subfractions

• Original and pyrolyzed whole asphaltenes are both fully soluble inboth fully soluble in methylene chloride

Preparative Separation of Lloydminster Heptane Asphaltenesy p p

Original PyrolyzedF ti U l d 35 i 400 °CFraction Unpyrolyzed, g 35 min 400 °C, gHeptane 0.181 0.113Cyclohexane 0 594 0 178Cyclohexane 0.594 0.178Toluene 2.048 1.773CH2Cl2:MeOH 0.143 0.2062 2

CH2Cl2 Insoluble - 0.300

• Fractions characterized at Florida State University

• Asphaltenes from the pyrolyzed residuum are fully soluble in methylene chloride (99.7% through 0.45 micron filter for 2% (w/v) solution)

Cross Polarization 13C NMR Results (W. Schuster, F. Miknis)

A Asphaltenes fromA. Asphaltenes from unpyrolyzed Lloydminster vacuum residuumresiduum

B. Asphaltenes from Lloydminster vacuum residuum pyrolyzed atresiduum pyrolyzed at 400 °C for 25 min.

C. Methylene chloride insolubles frominsolubles from preparative Asphaltene Determinator separation of pyrolyzed p py yresidua asphaltenes

Pericondensed Aromatic Structures Have High Surface Energyg gy

Pauli A. T., A. G. Beemer, and J. J. Miller, 2005 (San Diego CA) , An Assessment of Physical Property Prediction Based on Asphalt Average Molecular Structures. American Chemical Society Division of Petroleum Chemistry Preprints, 50 (2).

Lloydminster AsphaltenesAbsorptivity at 600 nmAbsorptivity at 600 nm

Absorptivity Fractional MaterialFraction AU per mg/mL x Amount = Balance

UNPYROLYZEDHeptane 0.973 0.0324 0.0315CyC6 1 51 0 177 0 267CyC6 1.51 0.177 0.267Toluene 2.66 0.782 2.08CH2Cl2 2.48 0.0088 0.022

Total: 2.40Whole Asphaltenes: 2.34

PYROLYZEDHeptane 0.840 0.0409 0.0364CyC6 1.57 0.103 0.107Toluene 4.13 0.626 2.80CH2Cl2 5.85 0.0786 0.460

0 0462 i l bl0.0462 insoluble -Total: 3.21

Whole Asphaltenes: 3.91

Lloydminster AsphaltenesPorphyrin ContentPorphyrin Content

Porphyrin Content Fractional MaterialFraction (Ni + V), mg/kg x Amount = Balance

UNPYROLYZEDHeptane 311 0.0324 10.1CyC6 145 0 177 25 7CyC6 145 0.177 25.7Toluene 55.1 0.782 29.7CH2Cl2 28.2 0.0088 0.25

Total: 65.8Whole Asphaltenes: 68.6

PYROLYZEDHeptane 231 0.0433 9.45CyC6 194 0.0680 20.0Toluene 62.8 0.678 39.3CH2Cl2 28.2 0.0787 2.22

0 132 i l bl0.132 insoluble -Total: 71.0

Whole Asphaltenes: 65.2Quantitation limit is ~20 mg/kg

Boscan AsphaltenesInfrared AbsorbanceInfrared Absorbance

Fraction Infrared wave Number, cm-1

3060 1660 1600 1510

Heptane 0.334 0.0468 0.0769 0.0401CyC6 0.340 0.0544 0.0884 0.0476yToluene 0.458 0.0802 0.130 0.0763CH2Cl2 0.485 0.0896 0.112 0.112

Aromaticity

Whole Asphaltenes 0.404 0.0717 0.121 0.0717

y

Absorbance Values Relative to 2930 cm-1 Aliphatic C-H Peak

Asphaltene Determinator Fractions R

R l ti t f i d d ti• Relative amount of pericondensed aromatic structures increases from heptane to cyclohexane to toluene to methylenecyclohexane to toluene to methylene chloride:methanol (98:2) fractions.

• SARA Resins / Polars pericondensed aromatic• SARA Resins / Polars pericondensed aromatic material elutes primarily with heptane.

• Characterization of preparative AD conducted• Characterization of preparative AD conducted by Amy McKenna at the FSU High Magnetic Field Laboratory (Ryan Rodgers). y ( y g )

Characterization at FSU by High Resolution APPI FT-ICR MSResolution APPI FT ICR MS

Amy McKenna, Ryan Rodgers

Characterization at FSU by High Resolution FT-ICR MSResolution FT ICR MS

Fractions From Preparative Asphaltene Determinator Separations of Lloydminster Asphaltenes

DBE = c – h/2 + n/2 + 1From the formula C H N O SFrom the formula CcHhNnOoSs

Amy McKenna, Ryan Rodgers

Characterization at FSU by High Resolution FT-ICR MSResolution FT ICR MS

Petroleum Waxes

• Complex mixtures of branched and normal alkanes ~ C18 - C70 • Paraffin waxes contain mainly n-paraffins and have a typical

melting range of 25-75 °C• Microcrystalline waxes contain mainly branched paraffins and have

a typical melting range of 55-100 °CP t l t i l t d t i l ith l i f• Petrolatum is a related material with a complex mix of hydrocarbons and a gelled appearance

IGI 5788Amp 60 C

d:\hpchem\3\DATA\aug06\18f50004 IGI 1245A mp 60 C 8/18/2006 9:45:34 AM

3.5

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NORMALS

ISOMERS

6

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NORMALS

ISOMERS

IGI 5788AMicrocrystalline Wax

IGI 1245AMP 60° C

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2.5

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Area

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IGI 1245AParaffin Wax

0

0.5

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15 20 25 30 35 40 45 50 55 60 65

Carbon Number

0

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15 20 25 30 35 40 45 50 55 60 65

Carbon Number

GC Profiles from IGI, Inc.

Isolation of Petroleum Waxes

• Typically a two step procedure involving an initial isolation of an alkane-rich fraction Aliphatic fraction from silica or alumina separation Urea adduction Size exclusion chromatography Size exclusion chromatography Distillation

• Determination of waxes from alkane-rich fraction Gas chromatography Differential scanning calorimetry (DSC) Precipitate in a polar solvent at sub ambient

temperature with sub ambient filtration• Diethyl ether : ethanol (1:1) at -20 °Cy ( )• Methyl ethyl ketone at -20 °C

Waxphaltene Determinator Optimization Updatep p

SIMULTANEOUS DETERMINATION OF WAXES AND ASPHALTENES

250 mm x 7 mm i d250 mm x 7 mm i.d. stainless steel column packed with 40-60 mesh (0 25 0 42 mm) PTFE(0.25 -0.42 mm) PTFE

0 min, MEK -24 °C10 min. heptane -24 °Cp20 min, heptane 60 °C30 min, heptane 30 °C35 i t l 30 °C35 min, toluene 30 °C45 min, methylene chloride:methanol(98:2 v:v) 30 °C

Rapid Column Temperature Changes: -24, +60, +30 °CChanges: 24, 60, 30 C

ELSD DetectabilityELSD Detectability

Octadecane (n-C18) is not detected( 18)• Completely lost in vacuum oven at 200 °C

and full vacuum (bp 317 °C ) Octacosane (n-C28) is detected

• 48% loss in vacuum oven at 200 °C and full vacuum

Volatile oils must be devolatilized to allow detection of all components

(0.5 g heated to 200 °C then cooled under full vacuum)

Waxphaltene Determinator

• Methyl Ethyl Ketone -24 °CR l ti l l l l i ht h d b / MEK lt• Relatively low molecular weight hydrocarbons / MEK maltenes

• Highly branched iso-paraffins• Heptane -24 °C

• Alkyl substituted pericondensed polars / resins• Alkyl substituted pericondensed polars / resins• Branched iso-paraffins

• Heptane 60 °C• n-Paraffins > ~C• n-Paraffins > ~C24• Slightly branched iso-paraffins

• Toluene 30 °C• Pericondensed asphaltenesPericondensed asphaltenes

• Methylene chloride 30 °C• Highly pericondensed condensed pre-coke asphaltenes

Paraffinic, branched, naphthenic and heteroatom structures can be present in any fraction, depending on other molecular components

Standards with ELS Detector

n-Paraffin Cutoff Near C24

ELSD and 500 nm Absorbance DetectorsAbsorbance Detectors

Pericondensed ring systems absorb 500 nm radiation

Waxphaltene Determinator Separation of Waxy West Texas AAM Bindery

ELSD Separation Profiles for SHRP Core AsphaltsSHRP Core Asphalts

ELSD Separation Profiles for SHRP Core AsphaltsSHRP Core Asphalts

WD Evaluation of 8 SHRP Core AsphaltsCore Asphalts

                   WRI WAXPHALTENE DETERMINATOR                Evaporative Light Scattering Detector Area Percent

SHRP ‐24 °C ‐24 °C 60 °C 30 °C 30 °C  Dichloromethane:

Sample MEK Heptane Heptane Toluene Methanol (98:2)Sample MEK Heptane Heptane Toluene  Methanol (98:2)

AAA‐1 79.99 8.00 0.71 9.61 1.71AAB‐1 78.64 10.22 1.79 7.58 1.78AAC 1 83 52 9 90 2 24 3 27 1 09AAC‐1 83.52 9.90 2.24 3.27 1.09AAD‐1 77.49 7.68 0.83 10.44 3.56AAF‐1 82.91 8.68 1.93 5.45 1.03AAG‐1 93 39 4 16 0 27 1 04 1 15AAG 1 93.39 4.16 0.27 1.04 1.15AAK‐1 76.11 9.25 1.18 10.81 2.64AAM‐1 54.73 34.09 6.90 3.29 1.00

WD Evaluation of Minnesota Validation Site RTFO Asphaltsp

                   WRI WAXPHALTENE DETERMINATOR               Evaporative Light Scattering Detector Area Percent

‐24 °C ‐24 °C 60 °C 30 °C 30 °C  Dichloromethane:Sample MEK Heptane Heptane Toluene  Methanol (98:2)

Original MN1‐2  81.51 6.67 1.13 6.66 4.03Original MN 8 .5 6.67 . 3 6.66 4.03Elvaloy RTFO MN1‐2 79.73 7.62 1.05 7.96 3.64

Elvaloy RTFOPAV MN1‐2 78.24 6.78 0.83 9.26 4.87Original MN1‐3  80.93 7.07 0.90 9.06 2.04RTFO MN1‐3 77.53 8.90 1.02 10.65 1.91

RTFOPAV MN1‐3 76.22 7.69 0.92 12.43 2.74Original MN1‐4  78.90 8.74 1.62 8.69 2.28RTFOMN1‐4 76 19 9 70 1 68 10 15 2 29RTFO MN1 4 76.19 9.70 1.68 10.15 2.29

RTFOPAV MN1‐4 74.64 9.02 1.62 11.98 2.76Original MN1‐5  83.16 7.47 0.57 6.76 2.04RTFO MN1‐5 81.39 8.36 0.53 7.66 2.06

• MN1-4 sample solutions contain some chlorobenzene insoluble material• RTFO increases toluene solubles content

RTFOPAV MN1‐5 80.06 7.79 0.52 9.47 2.16

WD Evaluation of Arizona Validation Site RTFO Asphaltsp

                   WRI WAXPHALTENE DETERMINATOR                Evaporative Light Scattering Detector Area Percent

‐24 °C ‐24 °C 60 °C 30 °C 30 °C  Dichloromethane:Sample MEK Heptane Heptane Toluene  Methanol (98:2)

Original AZ‐1 69.89 19.12 2.23 7.53 1.22RTFO AZ1‐1 67.96 20.08 2.29 8.57 1.12Original AZ‐2 71.05 9.92 2.43 13.19 3.40RTFO AZ1‐2 70.28 9.95 2.16 14.81 2.80Original AZ‐3 77.03 9.58 1.36 8.14 3.89RTFO AZ1‐3 76.22 9.40 1.16 9.33 3.89Original AZ‐4 75 57 10 35 1 28 9 71 3 18

• RTFO increases toluene solubles content with RTFO

Original AZ‐4 75.57 10.35 1.28 9.71 3.18RTFO AZ1‐4 74.18 10.44 1.09 11.64 2.65

• RTFO increases toluene solubles content with RTFO• n-Paraffins are not affected• Dichloromethane:methanol fraction is not affected significantly

WD Correlations with SHRP A-645 Gravimetric AsphaltenesA 645 Gravimetric Asphaltenes

        RELATIONSHIP WITH GRAVIMETRIC ASPHALTENESELSDAREA PERCENT WEIGHT PERCENT             ELSD AREA PERCENT                            WEIGHT PERCENT

SHRP AD HEPTANE  WD MEK ‐24 °C GRAVIMETRIC  GRAVIMETRICSample INSOLUBLES INSOLUBLES HEPTANE INSOLUBLES ISOOCTANE INSOLUBLES

AAA 1 13 05 20 01 15 80 19 20AAA‐1 13.05 20.01 15.80 19.20AAB‐1 13.17 21.36 17.30 19.30AAC‐1 6.16 16.48 9.90 13.20AAD‐1 22.51 22.51 20.20 23.60AAF‐1 10.82 17.09 13.40 16.50AAG‐1 3.79 6.61 5.00 8.40AAK‐1 15.92 23.89 20.10 22.90AAM‐1 3 04 45 27 3 70 9 30AAM‐1 3.04 45.27 3.70 9.30

Correlation is good except for waxy materials AAC and AAM

Dakota Crude Oil and Waxy Dakota Field DepositsDakota Field Deposits

Potential for predictability for wax fouling by crude oilsp y g y

80“On-column Separation of Wax and Asphaltenes in Petroleum Fluids”, L. Goual, J.F. Schabron, T.F. Turner, and B. Towler, Energy and Fuels, 22, 4019-4028, 2008.

Wyoming Crude Oils

Contributors

• Joseph Rovani• Joseph Rovani• Mark Sanderson• William Schuster• Fran Miknis• Fred Turner• Mark PoolerMark Pooler• Pam Coles

T M i• Tony Munari