1、Designation: D7806 12Standard Test Method forDetermination of the Fatty Acid Methyl Ester (FAME)Content of a Blend of Biodiesel and Petroleum-Based DieselFuel Oil Using Mid-Infrared Spectroscopy1This standard is issued under the fixed designation D7806; the number immediately following the designati
2、on indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determi
3、nation of the contentof biodiesel (fatty acid methyl estersFAME) in diesel fueloils. It is applicable to concentrations from 1 to 30 volume %.This procedure is applicable only to FAME. This test methodis not appropriate for the determination of the concentration ofbiodiesel that is in the form of fa
4、tty acid ethyl esters (FAEE).1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of t
5、his standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D975 Specification for Diesel Fuel OilsD1298 Test Method for Density, Relative Density (SpecificGravity), or API Gravi
6、ty of Crude Petroleum and LiquidPetroleum Products by Hydrometer MethodD4052 Test Method for Density, Relative Density, and APIGravity of Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetrole
7、um ProductsD4307 Practice for Preparation of Liquid Blends for Use asAnalytical StandardsD5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasureme
8、nt System PerformanceD6751 Specification for Biodiesel Fuel Blend Stock (B100)for Middle Distillate FuelsE131 Terminology Relating to Molecular SpectroscopyE168 Practices for General Techniques of Infrared Quanti-tative AnalysisE1655 Practices for Infrared Multivariate QuantitativeAnalysisE2056 Prac
9、tice for Qualifying Spectrometers and Spectro-photometers for Use in Multivariate Analyses, CalibratedUsing Surrogate Mixtures3. Terminology3.1 Definitions:3.1.1 biodiesel, na fuel composed of mono-alkyl esters oflong chain fatty acids derived from vegetable oils or animalfats, designated B100 in Sp
10、ecification D6751.3.1.2 biodiesel blend, BXX, na blend of biodiesel fuelwith petroleum-based diesel fuel.3.1.2.1 DiscussionIn the abbreviation BXX, the XX rep-resents the percentage by volume of biodiesel fuel in the blend.3.1.3 diesel fuel oil, na petroleum-based diesel fuel, asdescribed in Specifi
11、cation D975.3.1.4 FAME, na biodiesel composed of long chain fattyacid methyl esters derived from vegetable or animal fats.3.1.5 Mid-Infrared Spectroscopy, nuses the mid-infraredregion of the electromagnetic spectrum, as described in Termi-nology E131.4. Summary of Test Method4.1 A sample of diesel f
12、uel or biodiesel blend is introducedinto a liquid sample cell having a specified path length.Abeamof infrared light is imaged through the sample onto a detector,and the detector response is determined. Wavelengths of theabsorption spectrum that correlate highly with biodiesel orinterferences are sel
13、ected for analysis. Mathematical analysis1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0F on Absorption Spectroscopic Methods.Current edition approved Sept. 1, 2012. Published November 2012
14、. DOI:10.1520/D7806-122For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr
15、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1converts the detector response for the selected areas or peaks ofthe spectrum of an unknown to a concentration of biodiesel.4.2 This test method can utilize two different types ofspectrometers.4.2.1 A Fourier Transform Mid-IR
16、 Spectrometer fitted witha transmission sample cell can be used. The absorbancespectrum is baseline corrected to eliminate linear and constantbackground from the spectrum. Linear regression calibration iscalculated without considering the influence of interferences.4.2.2 A filter-based Mid-IR spectr
17、ometer fitted with a trans-mission cell can be used. The absorbance values at specifiedwavenumbers are used to develop a multiple linear regressioncalibration.5. Significance and Use5.1 Biodiesel is a fuel commodity primarily used as avalue-added blending component with diesel fuel.5.2 This test met
18、hod is fast and simple to run.5.3 This test method is applicable for quality control in theproduction and distribution of diesel fuel and biodiesel blendscontaining FAME.6. Interferences6.1 The primary spectral interferences are vegetable oils, oranimal fats, or both.6.2 The hydrocarbon composition
19、of the diesel fuel has asignificant impact on the calibration model. Therefore, for arobust calibration model, it is important that the diesel fuel inthe biodiesel fuel blend is represented in the calibration set.6.3 Proper design of a calibration matrix, utilization ofmultivariate calibration techn
20、iques, and evaluation routines asdescribed in this standard can minimize interferences.6.4 This procedure is applicable only to FAME. The con-centration of fatty acid ethyl esters (FAEE) cannot be deter-mined using this test method.6.5 Undissolved WaterSamples containing undissolvedwater will result
21、 in erroneous results. Filter cloudy or watersaturated samples through a dry filter paper until clear prior totheir introduction into the instrument sample cell.7. Apparatus7.1 Mid-IR Spectrometric Analyzer:7.1.1 Fourier Transform Mid-IR Spectrometer (FT-IR)The type of apparatus suitable for use in
22、this test methodemploys an IR source, a liquid transmission cell, a scanninginterferometer, a deuterated triglycine sulfate detector, ananalog-to-digital converter, a microprocessor, and a method tointroduce the sample. The following performance specifica-tions must be met:scan range 4000 to 650 cm-
23、1spectral resolution 4 cm-1digital resolution 1 cm-1NOTE 1To obtain a digital resolution of 1 cm-1for a spectrumrecorded at 4 cm-1requires that the interferogram be zero filled prior toFourier transformation. Consult the FT-IR manufacturers instructions forthe appropriate zero fill parameter setting
24、s to achieve this digital resolu-tion.7.1.1.1 The noise level shall be established by taking andratioing two successive single beam spectra of dry air. Thesingle beam spectra obtained can be the average of multiple ofFTIR scans. The noise of the spectrum at 100 % transmissionshall be less than 0.3 %
25、 peak-to-peak in the region from 1765to 1725 cm-1.7.1.2 Filter-based Mid-IR Test ApparatusThe type ofapparatus suitable for use in this test method minimallyemploys an IR source, an infrared transmission cell, wave-length discriminating filters, a chopper wheel, a lithium tanta-late detector, an ana
26、log-to-digital converter, a microprocessor,and a method to introduce the sample. The frequencies andbandwidths of the filters are specified in Table 1.7.2 Transmission CellThe cell shall be a transmission cellmade from materials having a significant transmission in theappropriate IR wavelength regio
27、n. The nominal path length ofthe cell shall be 0.10 (6 0.01) mm, appropriate to measure thepeak regions (as defined in Table 1) of samples in scopewithout going into saturation. If path length information fromthe manufacturer is not available, use cyclohexane as a pathlength check sample (see A1.2).
28、8. Reagents and Materials8.1 Standards for Calibration, Qualification, and QualityControl Check StandardsAs this test method is intended toquantify FAME content in commercial biodiesel blends thereare no high purity standard chemical reference materials thatare appropriate for development of multiva
29、riate calibrationmodels.8.1.1 B100 (Neat Biodiesel) used for calibration, qualifica-tion and quality control standards must be Specification D6751compliant. The B100 shall be a methyl fatty acid ester derivedfrom soy. The B100 used to generate the precision of this testmethod was derived from soy. S
30、ee Annex A2 for furtherdiscussion.8.1.2 Middle distillate fuel used for calibration, qualificationand quality control standards must be Specification D975compliant, free of biodiesel or biodiesel oil precursor, or both,and so far as possible should be representative of petroleumbase stocks anticipat
31、ed for blends to be analyzed (that is, crudesource, 1D, 2D, blends, winter/summer cuts, etc). See AnnexA2 for calibration set.8.1.3 Diesel Cetane Check FuelLow (DCCF-Low).33The sole source of supply of the apparatus known to the committee at this timeis Chevron Phillips Chemical Company LP, 10001 Si
32、x Pines Drive, The Woodlands,TX 77380. If you are aware of alternative suppliers, please provide this informationto ASTM International Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee,1which you may attend.TABLE 1 Filter Frequencies
33、and BandwidthsCenter Wave Number(0.15 % of wave number)Bandwidth (in wavelength units)(full width at half height)1745 cm-11%oflc1605 cm-11%oflc1159 cm-11%oflc915 cm-11%oflc769 cm-11%oflc698 cm-11%oflcD7806 1228.1.4 Diesel Cetane Check FuelHigh (DCCF-High).38.1.5 n-Hexane 110-54-3Reagent grade. (Warn
34、ingFlammable.)8.1.6 Hexadecane 544-76-3With a minimum purity of99.0 volume percent.8.1.7 Acetone 67-64-1Reagent grade. (WarningFlammable.)8.1.8 Toluene 108-88-3Reagent grade. (WarningFlammable.)8.1.9 Cyclohexane 110-82-7Reagent grade.(WarningFlammable.)8.1.10 Methanol 67-56-1Reagent grade. (WarningF
35、lammable.)8.1.11 Triple SolventA mixture of equal parts by volumeof toluene, acetone, and methanol. (WarningFlammable.)9. Sampling and Sample Handling9.1 General Requirements:9.1.1 Fuel samples to be analyzed by the test method shallbe sampled using procedures outlined in Practices D4057 orD4177, wh
36、ere appropriate. Do not use the “Sampling by WaterDisplacement” procedure.9.1.2 Protect samples from excessive temperatures prior totesting.9.1.3 Do not test samples stored in leaking containers.Discard and obtain a new sample if leaks are detected.9.2 Sample Handling During Analysis:9.2.1 Equilibra
37、te all samples to the typical temperature ofthe laboratory (15 to 27C) prior to analysis by this testmethod.9.2.2 After analysis, if the sample is to be saved, reseal thecontainer before storing.10. Calibration and Qualification of the Apparatus10.1 Calibrate the instrument according to the procedur
38、edescribed in Annex A1. This calibration can be performed bythe instrument manufacturer prior to delivery of the instrumentto the end user. Perform this qualification procedure anytimethe instrument is calibrated.10.2 Perform this qualification procedure when an instru-ment is initially put into ope
39、ration, when it is recalibrated, orwhen it is repaired. The qualification procedure is described inAnnex A1.11. Quality Control Checks11.1 Each day it is to be used, confirm that the instrument isin statistical control by measuring the biodiesel concentrationusing the procedure outlined in Section 1
40、2 on at least onequality control sample of known biodiesel content. The prepa-ration of known biodiesel concentration is described in 11.1.1and 11.1.2. For details on quality control testing and controlcharting refer to Practice D6299.11.1.1 Standard(s) of known biodiesel concentration shallbe prepa
41、red by mass according to A1.1.1 and converted tovolume % using the measured density as outlined in Section13. At least one standard shall be prepared for each calibrationrange. For example, 2 volume % may be used for the lowcalibration range, 20 volume % for high calibration range.Additional standar
42、ds including 0 volume percent may also beprepared and used for quality control checks.11.1.2 Standard(s) should be prepared in sufficient volumeto allow for a minimum of 30 quality control measurements tobe made on one batch of material. Properly package and storethe quality control samples to ensur
43、e that all analyses of qualitycontrol samples from a given lot are performed on essentiallyidentical material.11.2 If the biodiesel volume % value estimated for thequality control sample exceeds the action limits describedspecified in Practice D6299 or equivalent, then the measure-ment system is out
44、-of-control and cannot be used to estimatebiodiesel concentrations until the cause of the out-of-controlbehavior is identified and corrected.11.3 If correction of out-of-control behavior requires repairto the instrument or recalibration of the instrument, thequalification of instrument performance d
45、escribed in A1.4 shallbe performed before the system is used to measure biodieselcontent on samples.12. Procedure12.1 FTIR Procedure:12.1.1 If the FTIR instrument is used, remove the fuel byflushing the cell and inlet-outlet lines with sufficient solvent,described in 8.1.11. Evaporate the residual s
46、olvent with dry air.12.1.2 Background SpectrumRecord a single beam infra-red spectrum of dry air. This spectrum can be used as abackground spectrum for 6 h.12.1.3 Prior to the analysis of unknown test samples,establish that the equipment is running properly by collectingthe spectrum of the quality c
47、ontrol standard(s) and comparingthe estimated biodiesel concentration to the known value forthe QC standard(s). Introduce enough standard to the cell toensure that the cell is washed by a volume of at least threetimes the dead volume of the sample introduction system.12.1.4 Equilibrate the unknown f
48、uel sample to the typicaltemperature of the laboratory (15 to 27C) before analysis.12.1.5 Introduce enough of the fuel sample to the cell toensure the cell is washed by a volume of at least three times thedead volume of the sample introduction system.12.1.6 Obtain the digitized spectral response of
49、the fuelsample over the frequency region from 4000 to 650 cm-1.12.1.7 Measure the absorption spectrum and note the maxi-mum absorption value of the peak in the region 1765 to1720 cm-1.12.1.8 Biodiesel and high concentrations of biodiesel inbiodiesel blends are difficult to remove from the cell surface.Flush several times with sample or use a solvent rinse betweensamples. When in doubt, repeat steps 12.1.6 through 12.1.8 andcompare result to ensure adequate rinsing occurred.12.1.9 For FTIR instruments using a baseline correctionstep and a li
