Waste oil characterization by XRF Analysis

Stefan Uhlig (Bruker AXS GmbH, Germany)

Workshop,2011 2

XRF analysis of Alternative Raw Materials and Fuels

• alternative fuels replacing natural fuels heating the kiln: used tyres, rubber scrap, paper waste, waste oils , residues from oil refineries, waste wood, textiles, paper sludge, sewage sludge, mineral oil sludge, plastics, used solvents, dye additives, dyes, paints, emulsions, electrodes from aluminium industry, agricultural waste including straw, waste from cotton production, animal meal, fuller´s earth, waste from raw sugar processing ...

• industrial waste materials replacing natural solid raw materials (in the raw meal and the cement): slags, fly ashes, foundary sands, desulfurication gypsum, ...

Workshop,2011 3

The advantage of XRF analysis:easy, fast sample preparation

Workshop,2011 4

X-ray Fluorescence Analysis Energy-dispersive XRF (EDX , ED-XRF)

The detector is usedto record both� the energy E and � the number N of X-ray

photons

X-ray

tube

Sample

Detector

E , N

Workshop,2011 5

X-ray Fluorescence Analysis Wavelength-dispersive XRF (WDX, WD-XRF )

� an analyzer crystalseparates the variouswavelengths λ(energies)

� the detector records onlythe number N of X-rayphotons at a givenwavelength (energy)

X-ray

tube

Sample

DetectorN

λλλλ

Workshop,2011 6

Θ= sin2dnλ

X-ray Fluorescence Analysis Wavelength-dispersive XRF (WDX, WD-XRF )

Bragg´s equation:λλλλ

d θθθθ

D2, D4, D8XRDΘΘΘΘd (structures)λλλλ

S4, S8XRFΘΘΘΘλ λ λ λ ((((elements)d

instrumentstechniquemeasuredwantedknown

Workshop,2011 7

A closer look at the Kβ – Lines; Spectrum: EDX (<150-200 eV) versus WDX

Element Energy DifferenceNi Kb1 8263 223 eVCu 8040 Co Kb1 7648 171 eVNi 7477Fe Kb1 7057 128 eVCo 6929Mn Kb1 6489 86 eFe 6403 Cr Kb1 5946 48 eVMn 5898

EDX

WDX

►Cu

►

►

►

►

Workshop,2011 8

Modern XRF analysis: safe, easy, and fast analysis of liquid samples

Preparation of liquid cups with 2,5µm Mylar-Foil

Filling of the Liquid cup with 7 g of the sample

Foil with a liquid cup

Workshop,2011 9

Selecting the most appropiate liquid cup foil:Resistance

Che m ica l P o lye ste r P o lypro- P o lyim ide P ro le ne UltraCla ssifica tion M yla r pyle ne Ka p ton P o lye ste r

A c ids , m ineral; s trong F-P G F-P G G -FA c ids , m ineral; weak G G -P G -F G GA c ids , ox idiz ing; c onc G G G -F G GA lc ohols G G G G GA lk alines ; s trong G G P G GA lk alines ; weak F-P G F-P G G -FE s ters G G G G GHy droc arbons , aliphatic G G G G GHy droc arbons , arom atic G G G G GK etones G G G G GO ils , m ineral, veg., anim al G G G G G

Workshop,2011 10

Selecting the most appropiate liquid cup foil:Transmission

heavy elements light elements

Workshop,2011 11

Analysed layer on the sample surface or within the sample(subsurface / penetration)

no excitation within the inner (upper) part of the sample

the lower parts (layers) of the sample can be excited (by short wavelengths) but emmitted radiation will be absorbed within the sample

fluorescence radiation to be measured comes from a layer near the sample (specimen) surface

Workshop,2011 12

Layer thickness and saturation depth

Sample

B KA1 (0,18 keV)

Sn LA1 (3,4 keV)Cr KA1 (5,4 keV)

Sn KA1 (25,2 keV)

tubeto soller slit

Workshop,2011 13

Layer thickness of 90% FRX radiation origin

Line Energy Graphite Glas Iron Lead Cd KA1 23,17 keV 14,46 cm 8,20 mm 0,70 mm 77,30 µm Mo KA1 17,48 6,06 3,60 0,31 36,70 Cu KA1 8,05 5,51 mm 0,38 36,40 µm 20,00 Ni KA1 7,48 4,39 0,31 29,80 16,60 Fe KA1 6,40 2,72 0,20 * 164,00 11,10 Cr KA1 5,41 1,62 0,12 104,00 7,23 S KA1 2,31 116,00 µm 14,80 µm 10,10 4,83 Mg KA1 1,25 20,00 7,08 1,92 1,13 F KA1 0,68 3,70 1,71 0,36 0,26 N KA1 0,39 0,83 1,11 0,08 0,07 C KA1 0,28 * 13,60 0,42 0,03 0,03 B KA1 0,18 4,19 0,13 0,01 0,01

Oils

Workshop,2011 14

X-ray tube

X-ray geometry: analysed layer and volume(solid or liquid samples)

Oil

Workshop,2011 15

Convenient, ergonomic and safe operation of liquid samples

Convenient and safe operation:

• sample changer with 75 positions:

• 40 positions on two trays (with 20 steel ring sample holders each)

• 35 fixed positions for sample holders

• Ergonomic sample loading with trays

• Fail-safe operation with

• automatic recognition of loose

• powders and liquid samples• Industry proven tough handles

and trays (no toys)

Workshop,2011 16

Safe, secure and economic analysis of liquid samples such as oils: unique Vacuum Seal

• reduced Helium consumption

• fast switching between modes (VAC/He/VAC)

• protected collimators and crystals

• shortest absorbent Helium path, rest under vacuum for highest precision

Workshop,2011 17

Optimized measurement parameters for XRF analysis of Oils and other liquid alternative fuels

2 Helium-Modes available:1. atmospheric pressure:

• normal Helium consumption

• necessary for extremely volatile liquids like gasoline, jet fuels

2. reduced pressure:• reduced Helium

consumption• works for diesel and all

oils etc.

Workshop,2011 18

S8 TIGER Superior Analytical Performance Analyser Crystals: XS-GE-C

Optimised sensitivity for the elements P, S, Cl:

• 20 % more intensity for S• 40 % more intensity for P• Improved resolution • Minimized line overlapping • Recommended for demanding

applications like low detection limits in

• P, S and Cl in petrochemicals• P, S and Mo in metals

Workshop,2011 19

ASTM 2622, norm compliant Sulphur analysis in mineral oils:LOD: 0,5 ppm (40s, 3s) LOD: 0,2 ppm (100s, 3s)

► Fast routine analysis of S in petrochemicals:

• High sample throughput• Reliable trace analysis

S8 TIGER Superior Analytical Performance Analyser Crystals: XS-GE-C

Workshop,2011 20

XRF analysis of Alternative Fuels such as Waste Oils, etc.

• Cement Plant specific calibrations for conventionalquantitative analyses:

• standard cement calibrations (8 – 11 routine elements) for materials such as raw meal, klinker, cement, etc.

• SPECTRAplus QUANT-EXPRESS standardless analyses:• all materials, all elements, all preparations,

good LLD´s, good accuracy• PETRO-QUANT (optimized standardless analysis for full

quantitative analyses):• materials with Carbon content >> 95% (plus H, O, etc.) • relevant elements and preparations• very good LLD´s and accuracy

Workshop,2011 21

QUANT-EXPRESS “Standardless” XRF method: a universal method for any totally unknown sample

• best Screening methodfor element range from Na to U

• analysis of completely unknown samples:accuracy +/- <1% rel. in fused beads and powders

• standardless analysis with different LLD levels:

• fast Monitoring in less than 2 minutes!

• full Quantitative Analysis: ~ 7 minutes

• best detection: ~ 14 minutes

• lower limits of detection: peak/background instead of scan measurements

Workshop,2011 22

Quality Control of Alternative fuels: for example Tyre Derived Fuel TDF

• TDF contain 1.5 - 2.0 % Zinc• the combined zinc content of the TDF and other fuels

may have an impact on cement quality• high total Zinc contents of all the fuels

(exceeding 0.4%) may increase the setting time• Solution: Quality Control by XRF analysis

sample C O Mg Si P S Cl K Ca Fe Zn Pb total1 88,1 3,01 0,021 0,86 0,006 5,25 0,013 0,007 0,71 0,016 1,98 0,011 99,992 87,6 3,87 0,025 0,91 4,9 0,007 0,74 0,016 1,92 99,98

Workshop,2011 23�23

Light Matrix Quantification based on the Rh-Compton Intensity

Determining a Compound using RhCompton Ratio:

• Oxygen cannot be measured directly (absorption of its intensity by the cup foil)

• Determining of additional matrix compounds using Compton optimization

In hydrocarbons as an example:

• the Oil matrix (CH2) is determined by the balance to 100%,

• the Oxygen content is determined by optimization of the Compton intensity

Workshop,2011 24December 8, 2010 24

• Using Compton peaks

• Measure the incoherent scatter from target tube lines

• Compton scatter is very sensitive to the average atomic number of a specimen

• Calculate a theoretical Compton scatter from the sample composition

• Compare theoretical Compton scatter to measured Compton scatter

• this ratio should be close to 1

Light Matrix Quantification based on the Rh Compton Intensity

Workshop,2011 25December 8, 2010 25

As average atomic number

decreases, Compton intensity

increases

• Water (H2O) has an average

atomic number of 3.3

• Ethanol (C2H6O) has an

average atomic number of 2.9

• Oil (CH2) has an average

atomic number of 2.7

Bruker Training25

Rh Compton

peak

Rh Kα1,2

Light Matrix Quantification based on the Rh-Compton Intensity

Workshop,2011 26

Influence of Matrix definition on calculated concentrations

ActualValues

Calculated Values

Matrix Oil Oil Ethanol Water CH2 CH2 C2H5OH H2O

Matrix (%) 98.9 98.9 98.3 97.3

Si (ppm) 300 280 430 660

Ni (ppm) 300 300 490 770

Cd (ppm) 300 290 350 430

Pb (ppm) 300 290 490 680

Workshop,2011 27�27

• example of Rh-Compton calibration in Oils without a Geometric Correction

• example of Rh-Compton calibration in Oils with Geometric Correction applied

Influence of Light Matrix:

Geometric Correction (“Wedge-Effect”)

Three new sample preparation options have been added to correct

• Diameter - Thickness - Density

• Diameter - Thickness - Mass

• Diameter - Mass - Density

Workshop,2011 28

Sample

Liquid Sample Cell

Film

Meniscus Effect Correction

Liquid samples often exhibit the Meniscus effect:

• top surface of the liquid is concave instead of flat

• this will introduce errors in the calculation of the composition (wrong sample height)

Meniscus Effect Correction for liquid samples:

Insert size of the Meniscus effect in the ApplicationWizard

Workshop,2011 29

Universal Calibration for petrochemicals based on SPECTRAplus:

• variable alpha (Fundamental Parameter) model for wide concentration ranges

• automatic selection of best line for high concentrations (S, Cl) and severe line overlaps (As, Tl, Pb, Bi)

• Quantification of light matrix

• Geometric Correction of Wedge Effect

• Meniscus-Correction

• Set for density measurement included

PETRO-QUANT Ultimate Analytical Performance

Workshop,2011 30ESMF 201030

Universal petrochemical calibration for up to 30 elements in hydrocarbon-based matrices– straight out of the box

Precalibrated PETRO-QUANT turn-key solution for analysis of Alternative Fuels

Workshop,2011 31

Precalibrated PETRO-QUANT turn-key solution for analysis of Alternative Fuels

(such as oils, fuels, plastics, coke, coals, animal meal, etc.)

Workshop,2011 32

XRF analysis of light elements in Oils (Fluorine)

• due to the liquid cup foil absorption the fluorescence radiation any light element (lighter than Na Sodium) cannot be determined in liquid cups

• an alternative is to prepare oil samples (minimum 100µl drops) on filter papers

Workshop,2011 33

Analysis of alternative fuels, such as Waste Oils (polymers, coke, etc.) by EDX

X-ray

tube

SampleDetectorN

λλλλ

Workshop,2011 3420.04.2011 34

Petrochemical Applications by EDXISO 8754: Sulfur in mineral oil

ISO 8754 requires for acceptance the test of the accuracy and reproducibility, running a sample several times on the system. The results must stay within defined limits:

Test Sample:• Concentration [S%] level

of 0.1000 %• 21 repetitions:

• mean value: 0.103 % +/- 0.0005 %

data measured with S2 RANGER with PETRO-QUANT

Workshop,2011 35

Small, compact benchtop EDX-ray spectrometers for fast qualitycontrol:

• first step into multi-element determination by XRF analysis• backup system for WD-XRF spectrometer• flexible element analyzer for non-routine samples• flexible element analyzer in Blending Terminals

EDX Solutions in the Cement PlantBack-up concept – the easy way !

Workshop,2011 36

Solutions forthe Cement

Industry