1、Designation: D8181 18D8181 18aStandard Specification forMicroemulsion Blendstock for Preparing MicroemulsionTest Fuel Oils1This standard is issued under the fixed designation D8181; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t
2、he 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. Scope Scope*1.1 This specification describes an alcohol-carboxylic acid blendstock which is to be blended with fuel
3、oils to produce amicroemulsion of inverse micelles that is to be used as a test fuel oil.NOTE 1Microemulsion blendstocks shall not include substances such as raw vegetable oil triglycerides. Refer to Appendix X2.1.2, Composition, fordetails.1.1.1 The microemulsion blendstock shall be stored in speci
4、al facilities and drums or tanks that are suited for low flashpointliquids and oxygenated products.1.2 The microemulsion blendstock is to be blended with fuel oils to produce a microemulsion test fuel oil that is intended fortesting and demonstration purposes in specialty applications such as compre
5、ssion-ignition engine and burner fuel applications.NOTE 2Typical fuel oils that could be used for blending with microemulsion blendstock are fuels that comply with Specifications D975 and D396and may contain up to 5 % by volume biodiesel.NOTE 3Testing with test fuels containing 10 % microemulsion bl
6、endstock using B5 as a base fuel did not show any detrimental changes to specifiedfuel properties relative to B0 base fuels, but can impair measurement of microemulsion blendstock concentration.1.2.1 The microemulsion test fuel oil (to be made from this blendstock) is to be used for demonstration pu
7、rposes only in specificequipment and vehicles that are suited for use with low flashpoint fuels and oxygenated fuels such as ethanol.NOTE 4The low flash point of this blendstock relative to conventional diesel fuel increases certain hazards during storage and distribution.1.3 Nothing in this specifi
8、cation shall preclude observance of federal, state, or local regulations, which may be more restrictive.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided forinformation only and are not considered standard.1.5 This standard
9、does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use.1.6 This internatio
10、nal standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee
11、.2. Referenced Documents2.1 ASTM Standards:2D97 Test Method for Pour Point of Petroleum ProductsD130 Test Method for Corrosiveness to Copper from Petroleum Products by Copper Strip TestD396 Specification for Fuel OilsD445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Cal
12、culation of Dynamic Viscosity)D664 Test Method for Acid Number of Petroleum Products by Potentiometric TitrationD665 Test Method for Rust-Preventing Characteristics of Inhibited Mineral Oil in the Presence of Water1 This specification is under the jurisdiction ofASTM Committee D02 on Petroleum Produ
13、cts, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.E0 on Burner, Diesel, Non-Aviation Gas Turbine, and Marine Fuels.Current edition approved July 1, 2018Oct. 1, 2018. Published July 2018October 2018. Originally approved in 2018. Last previous edition approved in 20
14、18 as D8181 18.DOI: 10.1520/D8181-18.10.1520/D8181-18A.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This d
15、ocument is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions
16、as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Uni
17、ted States1D974 Test Method for Acid and Base Number by Color-Indicator TitrationD975 Specification for Diesel Fuel OilsD3242 Test Method for Acidity in Aviation Turbine FuelD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4175 Terminology Relating to Petroleum Products, Liquid
18、 Fuels, and LubricantsD4625 Test Method for Middle Distillate Fuel Storage Stability at 43 C (110 F)D4806 Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use asAutomotive Spark-Ignition Engine FuelD6584 Test Method for Determination of Total Monoglycerides, Total Diglyceride
19、s, Total Triglycerides, and Free and TotalGlycerin in B-100 Biodiesel Methyl Esters by Gas ChromatographyD6751 Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate FuelsD7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of
20、 KinematicViscosity)D7545 Test Method for Oxidation Stability of Middle Distillate FuelsRapid Small Scale Oxidation Test (RSSOT)D7862 Specification for Butanol for Blending with Gasoline for Use as Automotive Spark-Ignition Engine Fuel3. Terminology3.1 For definitions of terms used in this test meth
21、od, refer to Terminology D4175.3.2 Definitions:3.2.1 biodiesel, nfuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats,designated B100.3.2.2 higher alcohols, naliphatic alcohols of the general formula CnH2n+1OH with n being 2 to 8.3.2.3 surfactants,
22、 nsurface active molecular species that exhibit both water-soluble and oil-soluble properties, and affect thephysical behavior at the interface between water and oil phases.3.3 Definitions of Terms Specific to This Standard:3.3.1 inverse micelle, nan aggregate of surfactant molecules dispersed in a
23、non-polar liquid where the hydrophilic head groupsare oriented at the center with the hydrophobic tails extending out.3.3.2 microemulsion blendstock, na mixture of aqueous solution and surfactant(s) that when blended into hydrocarbon dieselfuel oil forms an isotropic and thermodynamically stable sys
24、tem with dispersed droplet diameters varying from 1 nm to 100 nm.3.3.3 microemulsion test fuel oil, ndispersion made of microemulsion blendstock in a liquid hydrocarbon fuel that is anisotropic and thermodynamically stable system with dispersed droplet diameter varying from 1 nm to 100 nm.3.3.4 oxyg
25、enate, nan oxygen-containing, ashless, organic compound, such as an alcohol or ester, which can be used as a fuelor fuel supplement.3.3.4.1 DiscussionBoth alcohols such as ethanol and surfactants such as long-chain carboxylic acids are oxygenates.3.3.5 test fuel, na homogeneous mixture of blendstock
26、s and fuel additives meeting all specification and regulatoryrequirements for its intended use at the location where sold.4. Requirements4.1 Microemulsion blendstock shall be a mixture of aqueous alcohol solution and surfactants that conforms to the requirementsin Table 1.4.1.1 The alcohol component
27、 shall be alcohols containing two carbons and higher. Alcohols shall comply with existingstandards, if any exist. For example, ethanol shall comply with the requirements of denatured fuel ethanol in Specification D4806,and butanol shall comply with the requirements of fuel butanol in Specification D
28、7862.4.1.2 The surfactant component shall have total glycerin less than 0.48 % by mass and free glycerin less than 0.04 % by mass,as determined by Specification D6751D6584. See Appendix X2.1.2 for guidance.5. Workmanship, Finish, and Appearance5.1 The blendstock shall be visually free of undissolved
29、 water, sediment, and suspended matter. It shall be visually clear andbright.5.2 If sediment or phase separation appears, the blendstock shall not be used.6. Keywords6.1 biofuel; blendstock; diesel alternative; inverse micelle; micelle; microemulsion; oxygenated diesel; renewable fuel; test fueloils
30、D8181 18a2ANNEXES(Mandatory Information)A1. VERIFICATION OF FORMATION OF MICROEMULSION TEST FUELA1.1 ScopeA1.1.1 Annex A1 specifies a method to test that the blendstock was made correctly and will behave as expected when blendedinto a fuel at a concentration of 5 % to 45 %.A1.2 General RequirementsA
31、1.2.1 Microemulsion blendstock shall be at room temperature (20 C to 25 C) for at least 1 h before testing.A1.2.1.1 If microemulsion blendstock was at a reduced temperature prior to testing, the container shall be well mixed. Once anyair bubbles settle, the microemulsion blendstock shall be clear.A1
32、.2.1.2 Diesel used for testing shall conform to Specification D975.A1.3 Test ProcedureA1.3.1 Add 2 mL of microemulsion blendstock to a 50 mL conical tube.A1.3.2 Add 2.5 mL of diesel to the tube.A1.3.3 Agitate the tube to mix the sample.A1.3.4 Allow the sample to sit for 5 min.TABLE 1 Requirements fo
33、r Microemulsion BlendstockProperty Limit Test MethodKinematic Viscosity, 40 C, cSt 9.0 to 12.0 ASTM D7042ACopper strip corrosion, max No. 1 ASTM D130Iron Corrosion, max A ASTM D665Oxidation stability, 140 C, 700 kPa,minutesReport ASTM D7545Pour Point, C 13 to 15 ASTM D97Blending Requirement(1) Forma
34、tion of microemulsiontest fuelsize of inverse micelles,nm, max50 See Annex A1 andAnnex A2(1) Formation of microemulsiontest fuelsize of inverse micelles,nm, max50 See Annex A1 andAnnex A2(2) Stability of blendstock in certifi-cation fuel, days, min60 See Annex A3A Test Method D445 may also be used.
35、Test Method D7042 is the referee testmethod.D8181 18a3A1.3.5 Ensure the mixture is clear and bright. This represents blending at 44 %.A1.3.6 Add an additional 2 mL of diesel to the tube.A1.3.7 Agitate the tube to mix the sample.A1.3.8 Allow the sample to sit for 5 min.A1.3.9 Ensure the mixture is mo
36、nophasic and the clarity of diesel. This represents blending at 31 %.A1.3.10 Add an additional 6 mL of diesel to the tube.A1.3.11 Agitate the tube to mix the sample.A1.3.12 Allow the sample to sit for 5 min.A1.3.13 Ensure the mixture is monophasic and the clarity of diesel. This represents blending
37、at 16 %.A1.3.14 Add an additional 26.5 mL of diesel to the tube.A1.3.15 Agitate the tube to mix the sample.A1.3.16 Allow the sample to sit for 5 min.A1.3.17 Ensure the mixture is monophasic and the clarity of diesel. This represents blending at 5 %.A1.3.18 Retain the 5 % blended test fuel for 24 h a
38、t room temperature.A1.3.19 Ensure the mixture is monophasic and the clarity of diesel.A1.4 ResultsA1.4.1 If all of the above samples are monophasic and the clarity of diesel, the microemulsion blendstock passes and is confirmedto form micelles in a hydrocarbon solution.A1.4.2 Appendix X1 provides in
39、formation on correlating concentration of the blendstock to the inverse micelle size.A2. VERIFICATION OF MICELLE FORMATION BY DYNAMIC LIGHT SCATTERINGA2.1 ScopeA2.1.1 Annex A2 specifies a method to test that the blendstock forms micelles.A2.2 ApparatusA2.2.1 Any dynamic light scattering (DLS) instru
40、ment capable of measuring in the 2 nm to 200 nm range shall be sufficient.D8181 18a4A2.2.2 Cuvettes shall be made of a material that is compatible with all components of the test fuel.A2.3 ProcedureA2.3.1 A test fuel shall be made of 10 % microemulsion blendstock in diesel in sufficient quantity to
41、fill the cuvette.A2.3.2 Before adding the test fuel to the cuvette, add 0.5 % water by volume and mix well.A2.3.2.1 If the sample becomes cloudy, the test fails.A2.3.3 Sample shall retain the same clarity as the original test fuel.A2.3.4 Samples shall be measured in triplicate and average values tak
42、en.A2.4 ResultsA2.4.1 The average size of the inverse micelles shall be recorded.A2.4.2 Use Appendix X1 as guidance of typical sizes observed.A3. VERIFICATION OF STABILITY OF BLENDSTOCK IN CERTIFICATION FUELA3.1 ScopeA3.1.1 Annex A3 specifies a method to test that long-term stability of a blendstock
43、 in certification fuel.A3.2 ApparatusA3.2.1 Oven, of adequate size to fit the samples. The oven should be adequately vented.A3.2.2 ThermometerAny temperature-measuring device may be used, provided it can accurately indicate the temperature towithin 0.1 C or 0.2 F and properly be recorded.A3.3 Accele
44、rated Aging TheoryA3.3.1 Aging a sample at an elevated temperature is expected to expedite the aging process.A3.3.2 According to Test Method D4625, 14 days at 43 C should be equivalent to 60 days at room temperature.A3.3.3 To expedite aging more, the temperature shall be held at 55 C for 7 days.A3.4
45、 ProcedureA3.4.1 BaselineBefore the aging process is begun, the following should be measured:D8181 18a5A3.4.1.1 Acid NumberTest Method D664. Test Methods D3242 or D974 may also be used. Test Method D664 shall be thereferee test method.A3.4.1.2 Visual inspection of clarity.A3.4.2 Aging at 55 C:A3.4.2
46、.1 50 mL of test fuel shall be added to three glass vials whose caps provide adequate sealing at 55 C.(1) Glass vials should not be filled to the top and should be left with adequate headspace.A3.4.2.2 Record the temperature of the oven and verify it is within 1 C of 55 C.A3.4.2.3 Over the next 7 da
47、ys, verify that the oven has remained within 1 C of 55 C.A3.4.2.4 After 7 days at 55 C, remove the vials from the oven.A3.4.2.5 Allow to cool to room temperature before testing the aged samples.A3.4.3 Aged SamplesAfter the samples have been aged for 7 days, the following tests shall be completed:A3.
48、4.3.1 Acid NumberTest Method D664. Test Methods D3242 or D974 may also be used. Test Method D664 shall be thereferee test method.A3.4.3.2 Visual inspection of clarity.A3.4.4 Results:A3.4.4.1 Changes of more than 5 % in the acid number results in a failed age-stability test for the blendstock in cert
49、ification fuel.A3.4.4.2 Formation of a precipitate or a decrease in visual clarity also result in a failed age-stability test.APPENDIXES(Nonmandatory Information)X1. INVERSE MICELLE PROPERTIESX1.1 Micelle Structure and MorphologyWhen splash-blended into diesel fuel oil at volumes ranging from 5 % to 45 % byvolume, the resulting fuel blend forms a clear and thermodynamically stable homogeneous microemulsion consisting of ellipsoidmicelles with geometric diameters that average approximately 3 nanometers. The geometric diameter is the di
