1、Designation: F3045 15Standard Test Method forEvaluation of the Type and Viscoelastic Stability of Water-in-oil Mixtures Formed from Crude Oil and Petroleum ProductsMixed with Water1This standard is issued under the fixed designation F3045; the number immediately following the designation indicates t
2、he 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 a procedure to determine
3、thewater-in-oil emulsification tendencies and stabilities in thelaboratory. The results of this test method can provide oilbehavior data for input into oil spill models.1.2 This test method covers a specific method of determin-ing emulsion tendencies and does not cover other procedureswhich may be a
4、pplicable to determining emulsion tendencies.1.3 The test results obtained using this test method areintended to provide baseline data for the behavior of oil andpetroleum products at sea and input to oil spill models.1.4 The test results obtained using this test method can beused directly to predic
5、t certain facets of oil spill behavior or asinput to oil spill models.1.5 The accuracy of the test method depends very much onthe representative nature of the oil sample used. Certain oilscan form a variety of water-in-oil types depending on theirchemical contents at the moment a sample is taken. Ot
6、her oilsare relatively stable with respect to the type formed1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the
7、responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Summary of Test Method2.1 Oil is mixed with 33 (3.3%) saline water for 12 h ina standard rotating apparatus. The resulting mixt
8、ure is charac-terized after this shaking period.2.2 The resulting mixture as created in step 2.1, is charac-terized visually, by measuring water content and by rheologicalmeasurements. The mixture is then classified as a stable,meso-stable, unstable emulsion or an entrained water mixture.Each of the
9、se four types of mixtures has different characteris-tics affecting the oils behavior once spilled.3. Terminology3.1 Definitions:3.1.1 complex modulusOne of the results of viscoelasticmeasurement, a measure of the resistance of a viscoelasticsubstance to flow under an applied dynamic stress, combinin
10、gboth the non-reversible (viscous) flow of the test substance andthe reversible (elastic) deformation of the test substance.3.1.2 emulsionA type of colloid, specifically, a dispersionof small droplets of one liquid in another.3.1.2.1 meso-stable emulsionsEmulsions which lack oneor more of the compos
11、itional factors necessary to form a stableemulsion, but which are sufficiently stable to persist for shortperiods, typically a few days.3.1.2.2 stable emulsionsEmulsions that persistindefinitely, consisting of fine droplets with a rigid filminterface which resists coalescence.3.1.2.3 unstable emulsi
12、onsMixtures of water and oilwhich resolve rapidly into two phases, usually within a fewminutes to hours. There may be residual water remaining inlow percentages.3.1.2.4 water-in-oil emulsionAn emulsion consisting of acontinuous phase of oil containing a dispersed phase of water.3.1.3 entrained water
13、This is not an emulsion but a me-chanical mixture of oil and water which has not separated dueto the physical properties of the water and oil.3.1.3.1 DiscussionTypically, the oil and water have simi-lar densities and the oil phase has a high viscosity.ragTheremnant of a broken water-in-oil emulsion.
14、3.1.3.1 DiscussionRag will not reform an emulsion. Ragis thought to consist of tightly bound asphaltenes and resins.3.1.4 stability indexAn index describing the stability of anemulsion.1This test method is under the jurisdiction of ASTM Committee F20 onHazardous Substances and Oil Spill Response and
15、 is the direct responsibility ofSubcommittee F20.16 on Surveillance and Tracking.Current edition approved Oct. 1, 2015. Published December 2015. DOI:10.1520/F304515Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.4.1 DiscussionIn t
16、his standard, it is calculated usingdata derived from rheological measurements.3.1.5 storage modulusOne of the results of viscoelasticmeasurement, a measure of the elastic (reversible) deformationbehavior of a viscoelastic substance under an applied dynamicstress.4. Significance and Use4.1 A standar
17、d test is necessary to establish a behaviorpattern for spilled oils or petroleum products at different oilweathering stages.4.2 Water-in-oil mixtures vary with oil type and oil condi-tions such as weathering. Results from this test method form abaseline, and usually are a measure of behavior at sea.
18、4.3 This test has been developed over many years usingstandardized equipment, test procedures, and to overcomedifficulties noted in other test procedures.4.4 This test should be performed at the temperatures anddegrees of weathering corresponding to the spill conditions ofinterest.5. Interferences a
19、nd Sources of Error5.1 Interferences can be caused by contaminants, particu-larly residual oil or surfactants on labware, and other samplehandling supplies and apparatus that lead to irregular results.All glassware must be thoroughly cleaned. The cleaningprocess includes rinsing with dichloromethane
20、 to remove theoil, followed by rinsing three times each with tap water,purified water (reverse osmosis), and acetone. Once cleaned,precautions must be taken to minimize contact of the labwarewith contaminants to prevent interferences.5.2 Emulsion formation is somewhat susceptible to energylevels. Th
21、e rotational speed of the shaker should be checkedwith a tachometer every day. The specified direction of rotationshould be followed (vessel cap leads rotation on start-up).5.3 The specified fill volumes of the test vessels must beobserved as the energy level varies with the amount of fill.5.4 Tempe
22、rature is a factor in emulsification, so it isimportant that all components (salt water, pre-mix, and tem-perature controlled chamber) are stable at 15C or the selectedtest temperature, before starting.5.5 The handling of the samples after the mixtures areformed is important. Care must be taken to t
23、ake a representa-tive sample. Excess water should be avoided when sampling.5.6 Since the test results may be affected by salinity,thorough mixing of the salt water is required. Salinity shouldbe verified using a salinity meter before use.5.7 Oils sources, especially crude oil sources, vary muchwith
24、production time and conditions. Oil samples must betreated as unique and are not necessarily representative of thesource. Some oils are near the threshold of two differentwater-in-oil types. Depending on the actual conditions underwhich this oil was sampled, different results may occur. Otheroils ar
25、e not as sensitive.5.8 Additives introduced in the production and transport ofoils can change their emulsification behavior. Some oils haveadded asphaltene suspenders or emulsion inhibitors. Thesemay significantly alter the outcome of this test. Information onthe oil treatment should be obtained bef
26、ore making the test.6. Apparatus6.1 2.2-litre fluorinated HDPE wide-mouth bottles, approxi-mately 24 cm in height and 6 cm in radius (Nalgene orequivalent), used as the test vessel. These vessels match theshaker as described below.6.2 Variable speed end-over-end rotary mixer capable ofmaintaining 55
27、 RPM, with a radius of rotation of 15 cm (7.5cm from center of vessel) (Associated Design or equivalent).26.3 Automated Karl Fischer titration analyser, This deviceis used to measure the water content of the resulting water-in-oil mixture.6.4 Rheometer, with a 35 mm parallel-plate geometry, ca-pable
28、 of functioning in forced-oscillation mode. This device isused to measure the rheological properties of the resultingwater-in-oil mixture.6.5 Circulating bath with a range from 0 to 25 C (60.1).6.6 Salinometer or water quality meter, SensIon 745 orequivalent.6.7 Oil mixing devices including a shaker
29、 for mixing thesmall samples prior to use and devices to mix the oil containedin drums.6.8 The following is a list of other necessary supplies.Equivalent supplies are acceptable.6.8.1 Disposable 30- and 1-mL plastic syringes,6.8.2 20-L plastic carboy, stirring plate and stir bar.6.8.3 Spatulas and w
30、ide-mouth bottles for sample handlingand storage,7. Reagents37.1 ReagentsWater purified by reverse osmosis or equiva-lent means is used for the test water. Fine granular sodiumchloride or table salt, non-iodized, is used for making the saltwater. The brine solution of 33 (3.3%) NaCl prepared fromsal
31、t and purified water, is stored in a 20-L carboy at ambienttemperatures until needed. Fresh water may also be used forthe test to mimic non-saline conditions.7.1.1 Oilis used as received, but is shaken for 30 minutesprior to use and is maintained at the test temperature of 15C.2These devices are des
32、cribed in EPA standards for use in extraction tests: EPAMethod 1310 Extraction Procedure (EP) Toxicity Test Method And StructuralIntegrity Test, EPA Method 1311 Toxicity Characteristic Leaching Procedure(TCLP), and EPA 1312 Synthetic Precipitation Leaching Procedure (SPLP).Environmental Protection A
33、gency 1200 Pennsylvania Avenue, N.W. Washington,DC 20460. http:/www3.epa.gov/3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for Laborat
34、oryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.F3045 1527.1.2 Karl Fischer reagent, 5 mg/mL H2O, singlecomponent, pyridine free.7.1.3 Toluene, methanol and chloroform, reagent grade, asso
35、lvent for the Karl-Fischer titration.7.1.4 Dichloromethane and acetone, as clean-up solvents,and RO purified water8. Procedure8.1 Crude Oil Sample Collection and StorageThe bulk oilis mechanically mixed for 1 to 2 h prior to obtaining a workingsample. Working samples are stored in 2-L high-densitypo
36、lyethylene bottles with polypropylene screw closures. Theworking sample is mechanically shaken for 30 min at 15C orthe selected operating temperature prior to removing a sub-sample for testing. When not in use, all samples should bestored in a temperature controlled room at 5C.8.2 Generating the wat
37、er-in-oil mixtureIn summary,water-in-oil mixtures are formed in 2.2-litre fluorinated vesselson an end-over-end rotary mixer (Associated Design, VA orequivalent) at a rotational speed of 55 RPM.8.2.1 Each 2.2 L mixing vessel is filled with 600 mL ofwater, either salt or fresh water as selected for t
38、he test. Thewater should be at the test temperature at the time of addition.8.2.2 Oil is introduced at a ratio of 1:20 oil:water by adding30 mL of the test oil to the vessel.8.2.3 The vessels are sealed and mounted in the rotary mixersuch that the cap of each mixing vessel leads the direction ofrota
39、tion to maximize the turbulence of mixing.8.2.4 The rotary mixer and vessels are held at 15C or theselected operating temperature in a temperature controlled coldroom for the duration of the experiment. This temperature(15C) or the selected operating temperature is the standardtemperature for measur
40、ing oil properties, If the predictedtemperatures the time of a spill are different the test should beperformed at those predicted temperatures as well. Testing atdifferent temperatures necessitate that the entire study beperformed at the new chosen temperature.8.2.5 The vessels and their contents ar
41、e allowed to stand for4 h to thermally equilibrate.8.2.6 The mixing is initiated using an electronic timerswitch. The vessels are mixed continuously for 12 h at arotation speed of 55 RPM.8.2.7 After 12 h mixing, the water-in-oil mixtures arecollected from the vessels and transferred to appropriately
42、sized glass wide-mouthed jars for observation and analysis.8.2.8 The emulsions are stored in the cold room at 15C orthe selected operating temperature for one week, followed byadditional observation and analysis.8.2.9 Each oil is tested in triplicate.8.2.10 The visual observations, viscosity, viscoe
43、lastic prop-erties and water content of the starting oil and the resultingwater-in-oil mixture are measured for comparison as outlinedin the procedures described below.8.3 Sampling and analysisA small sample is withdrawnfrom each wide-mouth jar for further analysis as describedbelow. Analysis is per
44、formed twice, immediately after mixingand after one week.8.4 Sample Analysis for Water ContentWater content ismeasured using a Metrohm 784 KFP Titrino Karl Fischervolumetric titrator (or equivalent) and Metrohm 703 Ti Stand(or equivalent). The titre reagent is Aquastar Comp 5 (orequivalent) and the
45、solvent is 1:1:2 methanol:chloroform:tolu-ene. A set of three measurements are made for each sample.8.5 Viscosity Measurement of oilsDynamic viscosities ofthe oils are measured at 15C using a VT550 with viscometerusing concentric cylinder geometry. The appropriate cup andspindle combination is selec
46、ted on the basis of the validviscosity range for each type, as provided by the manufacturer.The highest suitable shear rate is selected from the manufac-turers guidance manual. The measurement protocol follows aone minute ramp up to the target shear rate, holding for fiveminutes, then ramping back d
47、own to zero to evaluate thixot-ropy. The reported value for the oil is the average viscosityover the five minutes hold period. Triplicates are performed foreach sample.8.6 Viscoelastic Measurements of the water-in-oilmixturesThe viscoelastic properties are determined on aThermoHaake RheoStress RS600
48、0 rheometer with RheoWinsoftware (or equivalent) using 35 mm plate-plate geometry inforced oscillation mode. The sample stage height is set for a2.00-mm gap. The sample is measured at 15C in forcedoscillation mode using a stress sweep from 0.100 to 10.0 Pa ata frequency of one reciprocal second. Val
49、ues of the complexmodulus, storage modulus, loss modulus, and tan () areobtained in the linear viscoelastic range (stress independentregion of the stress response curve). Samples are measured induplicate.8.7 Data recording of the measurementsThe visual obser-vations and the data on the water content and the viscoelasticmeasurements are recorded for the water-in-oil mixtures on thetest day following the 12-h mixing and again after one week.The water content and viscosity measurements are taken of thestarting oil. All values are recorded to 3-signific
