ASTM D3238-95(2015)
(Test Method)Standard Test Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n-d-M Method
Standard Test Method for Calculation of Carbon Distribution and Structural Group Analysis of Petroleum Oils by the n-d-M Method
SIGNIFICANCE AND USE
4.1 The carbon distribution and ring content serve to express the gross composition of the heavier fractions of petroleum. These data can be used as an adjunct to the bulk properties in monitoring the manufacture of lubricating oil base stocks by distillation, solvent refining or hydrogenation, or both, and in comparing the composition of stocks from different crude sources. Furthermore, the data can often be correlated with critical product performance properties.
SCOPE
1.1 This test method covers the calculation of the carbon distribution and ring content (Note 1) of olefin-free petroleum oils from measurements of refractive index, density, and molecular weight (n-d-M).2 This test method should not be applied to oils whose compositions are outside the following ranges:
1.1.1 In terms of carbon distribution—up to 75 % carbon atoms in ring structure; percentage in aromatic rings not larger than 1.5 times the percentage in naphthenic rings.
1.1.2 In terms of ring content—up to four rings per molecule with not more than half of them aromatic. A correction must be applied for oils containing significant quantities of sulfur.
Note 1: The composition of complex petroleum fractions is often expressed in terms of the proportions of aromatic rings (RA), naphthene rings (RN), and paraffin chains (CP) that would comprise a hypothetical mean molecule. Alternatively, the composition may be expressed in terms of a carbon distribution, that is, the percentage of the total number of carbon atoms that are present in aromatic ring structures (% CA), naphthene ring structures (% CN), and paraffin chains (% Cp ).
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D3238 − 95 (Reapproved 2015)
Standard Test Method for
Calculation of Carbon Distribution and Structural Group
1
Analysis of Petroleum Oils by the n-d-M Method
This standard is issued under the fixed designation D3238; 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 in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Dispersion of Hydrocarbon Liquids
D1480 Test Method for Density and Relative Density (Spe-
1.1 This test method covers the calculation of the carbon
cific Gravity) of Viscous Materials by Bingham Pycnom-
distribution and ring content (Note 1) of olefin-free petroleum
eter
oils from measurements of refractive index, density, and
2 D1481 Test Method for Density and Relative Density (Spe-
molecular weight (n-d-M). This test method should not be
cific Gravity) of Viscous Materials by Lipkin Bicapillary
applied to oils whose compositions are outside the following
Pycnometer
ranges:
D1552 Test Method for Sulfur in Petroleum Products by
1.1.1 In terms of carbon distribution—up to 75 % carbon
High Temperature Combustion and IR Detection
atoms in ring structure; percentage in aromatic rings not larger
D2502 Test Method for Estimation of Mean Relative Mo-
than 1.5 times the percentage in naphthenic rings.
lecular Mass of Petroleum Oils from Viscosity Measure-
1.1.2 Intermsofringcontent—uptofourringspermolecule
ments
with not more than half of them aromatic.Acorrection must be
D2503 TestMethodforRelativeMolecularMass(Molecular
applied for oils containing significant quantities of sulfur.
Weight) of Hydrocarbons by Thermoelectric Measure-
NOTE 1—The composition of complex petroleum fractions is often
ment of Vapor Pressure
expressed in terms of the proportions of aromatic rings (R ), naphthene
A
D2622 Test Method for Sulfur in Petroleum Products by
rings (R ), and paraffin chains (C ) that would comprise a hypothetical
N P
Wavelength Dispersive X-ray Fluorescence Spectrometry
mean molecule.Alternatively, the composition may be expressed in terms
of a carbon distribution, that is, the percentage of the total number of
3. Summary of Test Method
carbon atoms that are present in aromatic ring structures (% C ),
A
naphthene ring structures (% C ), and paraffin chains (% C ).
N p
3.1 The refractive index and density of the oil are deter-
1.2 The values stated in SI units are to be regarded as the
mined at 20 °C. The molecular weight is determined experi-
standard. The values in parentheses are for information only.
mentally or estimated from measurements of viscosity at
1.3 This standard does not purport to address all of the 37.8 °C and 98.89 °C (100 °F and 210 °F). These data are then
used to calculate the carbon distribution (% C ,% C ,% C )
safety concerns, if any, associated with its use. It is the
A N P
responsibility of the user of this standard to establish appro- or the ring analysis (R , R ) using the appropriate set of
A N
equations.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4. Significance and Use
2. Referenced Documents
4.1 The carbon distribution and ring content serve to ex-
3
press the gross composition of the heavier fractions of petro-
2.1 ASTM Standards:
leum. These data can be used as an adjunct to the bulk
D1218 Test Method for Refractive Index and Refractive
propertiesinmonitoringthemanufactureoflubricatingoilbase
stocks by distillation, solvent refining or hydrogenation, or
1
This test method is under the jurisdiction of ASTM Committee D02 on
both, and in comparing the composition of stocks from
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
different crude sources. Furthermore, the data can often be
Subcommittee D02.04.0K on Correlative Methods.
correlated with critical product performance properties.
Current edition approved Oct. 1, 2015. Published December 2015. Originally
approved in 1973. Last previous edition approved in 2010 as D3238 – 95 (2010).
DOI: 10.1520/D3238-95R15. 5. Measurement of Physical Properties
2
Van Nes, K., and van Westen, H. A., Aspects of the Constitution of Mineral
5.1 Determine the refractive index of the oil at 20 °C using
Oils, Elsevier, New York, 1951.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Test Method D1218.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
5.2 Determine the density at 20 °C using Test Method
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. D1480 or Test Method D1481.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 194
...
This document 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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3238 − 95 (Reapproved 2010) D3238 − 95 (Reapproved 2015)
Standard Test Method for
Calculation of Carbon Distribution and Structural Group
1
Analysis of Petroleum Oils by the n-d-M Method
This standard is issued under the fixed designation D3238; 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 in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the calculation of the carbon distribution and ring content (Note 1) of olefin-free petroleum oils from
2
measurements of refractive index, density, and molecular weight (n-d-M). This test method should not be applied to oils whose
compositions are outside the following ranges:
1.1.1 In terms of carbon distribution—up to 75 % carbon atoms in ring structure; percentage in aromatic rings not larger than
1.5 times the percentage in naphthenic rings.
1.1.2 In terms of ring content—up to four rings per molecule with not more than half of them aromatic. A correction must be
applied for oils containing significant quantities of sulfur.
NOTE 1—The composition of complex petroleum fractions is often expressed in terms of the proportions of aromatic rings (R ), naphthene rings (R ),
A N
and paraffin chains (C ) that would comprise a hypothetical mean molecule. Alternatively, the composition may be expressed in terms of a carbon
P
distribution, that is, the percentage of the total number of carbon atoms that are present in aromatic ring structures (% C ), naphthene ring structures (%
A
C ), and paraffin chains (% C ).
N p
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
3
2.1 ASTM Standards:
D1218 Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquids
D1480 Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Bingham Pycnometer
D1481 Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Lipkin Bicapillary Pycnometer
D1552 Test Method for Sulfur in Petroleum Products by High Temperature Combustion and IR Detection
D2502 Test Method for Estimation of Mean Relative Molecular Mass of Petroleum Oils from Viscosity Measurements
D2503 Test Method for Relative Molecular Mass (Molecular Weight) of Hydrocarbons by Thermoelectric Measurement of
Vapor Pressure
D2622 Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry
3. Summary of Test Method
3.1 The refractive index and density of the oil are determined at 20°C.20 °C. The molecular weight is determined
experimentally or estimated from measurements of viscosity at 37.837.8 °C and 98.89°C (10098.89 °C (100 °F and
210°F).210 °F). These data are then used to calculate the carbon distribution (% C , % C , % C ) or the ring analysis (R , R )
A N P A N
using the appropriate set of equations.
4. Significance and Use
4.1 The carbon distribution and ring content serve to express the gross composition of the heavier fractions of petroleum. These
data can be used as an adjunct to the bulk properties in monitoring the manufacture of lubricating oil base stocks by distillation,
1
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.04.0K on Correlative Methods.
Current edition approved Oct. 1, 2010Oct. 1, 2015. Published November 2010December 2015. Originally approved in 1973. Last previous edition approved in 20052010
as D3238–95(2005).D3238 – 95 (2010). DOI: 10.1520/D3238-95R10.10.1520/D3238-95R15.
2
Van Nes, K., and van Westen, H. A., Aspects of the Constitution of Mineral Oils, Elsevier, New York, 1951.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.