1、ASTM DZL59 93 I 0759530 0522759 978 m Designation:D 2159-93 AMERICAN SOCIE-W H)R TESTING AND MATERIALS 1916 Race St Philadelphia,Pa 19103 Reprinted from the Annual Book of ASTM Standards.Copyright ASTM If not lited in the current combined index will appear in the neti edition.AnArmfkan National Stan
2、dard Standard Test Method for Naphthenes in Saturates Fractions by Refractivity Intercept This standard is issued under the fixed designation D 2 159;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number
3、 in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope 1.1 This test method covers the determination of naphthenes or“equivalent naphthenes”in saturates fractions obtained by Test Methods D 2002 or Tes
4、t Method D 2003 from naphthas or depentanized gasolines which have end points that do not exceed 221C(43oF)as determined by Test Method D 86.1.2 Polycyclic naphthenes,if present,will cause a high value for total naphthenes to be indicated.Although the basic data for this correlation compensate in pa
5、rt for the presence of dicyclic naphthenes,results may be high by as much as 1 volume%for each 1 volume%dicyclic naphthenes present.Thus the naphthene content indicated for stocks with end points greater than 163C(325F)should be considered“equivalent naphthenes.”1.3 The preferred unit of measure is
6、volume percent.1.4 This standard does not purport to address all of the safety problems,if any,associated with its use.It is the 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
7、.Referenced Documents 2.1 ASTM Standards:D 86 Test Method for Distillation of Petroleum Products*D 941 Test Method for Density and Relative Density(Specific Gravity)of Liquids by Lipkin Bicapillary Pyconometel.2 D 12 18 Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquid
8、s2 D2002 Test Methods for Isolation of Representative Saturates Fraction from Low-Olefinic Petroleum Naphthas2 D 2003 Test Method for Isolation of Representative Satu-rates Fraction from High-Olefinic Petroleum Naphthas2 3.Summary of Test Method 3.1 The refractive index and density of the saturates
9、fraction are determined.The refractivity intercept,calculated from these data,and the density are used with Fig.1 to obtain the volume percent naphthenes or volume percent“equivalent naphthenes.”This test method is under the jurisdiction of ASTM Committee D-2 on Petroleum Products and Lubricants and
10、 is the direct responsibility of Subcom-mittee DO2.04 on Hydrocarbon Analysis.Current edition approved Feb.IS,1993.Published May 1993.Originally published as D 2 IS9-63 T.Last previous edition D 2 159-88.2 Annual Book of ASTM Standards,Vol OS.0 1.1 4.Siguikance and Use 4.1 This test method provides
11、information on the total volume percent of naphthenes in saturate petroleum frac-tions.This information is important in characterizing the quality of petroleum fractions as feeds to catalytic reforming processes and as gasoline blending components.5.Test Methods 5.1 The apparatus and procedures desc
12、ribed in the test methods listed in 5.1.1 and 5.1.2 are recommended;other equipment that will give comparative accuracy and precision is permitted.5.1.1 Dens&-Test Method D 941 Pycnometers should be calibrated at 2oC.NOTE I-Methylcyclohexane or 2,2,4-trimcthylpentane are recom-mended and certified s
13、amples may be obtained from the National Institute of Standards and Technology.Secondary reference samples of known refractive index and density may be established for future reference,tier standardization of the tests has been accomplished with the primary standard.5.1.2 Refractive Index-Test Metho
14、d D 1218.The refractometer should be calibrated to give data accurate to six units in the fXh decimal of refractive index for the D line of sodium at 2oC(Note 1).5.1.3 Standardization of Equipment-The refractive index and density tests must be standardized to give the correct refractive index and de
15、nsity values for a pure hydrocarbon primary reference standard.6.Procedure 6.1 Determine the density and the refractive index,for the D line of sodium,at 2oC of the saturates fraction after standardizing these tests.It is preferable to complete the density and refractive index determinations within
16、an 8-h period to reduce the possibility of a change in composition.7.Calculation 7.1 Calculate the refractivity intercept as follows:Refractivity intercept=n-(d/2)where:n=refractive index at 2o”C,and d=density at 2oC.7.2 Enter Fig.l3(Note 2)with the refractivity intercept and density values and read the volume percent naphthenes for the saturates fraction at the point of intersection.3 From the data shown in Table 1,a nomograph has been prepared for reading the percent naphthenes.This nomograph
