ASTM D5236-03(2007)
(Test Method)Standard Test Method for Distillation of Heavy Hydrocarbon Mixtures (Vacuum Potstill Method)
Standard Test Method for Distillation of Heavy Hydrocarbon Mixtures (Vacuum Potstill Method)
SIGNIFICANCE AND USE
This test method is one of a number of tests conducted on heavy hydrocarbon mixtures to characterize these materials for a refiner or a purchaser. It provides an estimate of the yields of fractions of various boiling ranges.
The fractions made by this test method can be used alone or in combination with other fractions to produce samples for analytical studies and quality evaluations.
Residues to be used in the manufacture of asphalt can also be made but may not always be suitable. The long heat soaking that occurs in this test method may alter some of the properties.
Note 1— While the practice of reblending distillates with residue can be done to produce a lighter residue, it is not recommended because it produces blends with irregular properties.
Details of cutpoints must be mutually agreed upon before the test begins.
This is a complex procedure involving many interacting variables. It is most important that at the time of first use of a new apparatus, its components be checked as detailed in Annex A1 and Annex A2 and that the location of the vapor temperature sensor be verified as detailed in 6.5.3 and Fig. 1.
SCOPE
1.1 This test method covers the procedure for distillation of heavy hydrocarbon mixtures having initial boiling points greater than 150°C (300°F), such as heavy crude oils, petroleum distillates, residues, and synthetic mixtures. It employs a potstill with a low pressure drop entrainment separator operated under total takeoff conditions. Distillation conditions and equipment performance criteria are specified and typical apparatus is illustrated.
1.2 This test method details the procedures for the production of distillate fractions of standardized quality in the gas oil and lubricating oil range as well as the production of standard residue. In addition, it provides for the determination of standard distillation curves to the highest atmospheric equivalent temperature possible by conventional distillation.
1.3 The maximum achievable atmospheric equivalent temperature (AET) is dependent upon the heat tolerance of the charge. For most samples, a temperature up to 565°C (1050°F) can be attained. This maximum will be significantly lower for heat sensitive samples (for example, heavy residues) and might be somewhat higher for nonheat sensitive samples.
1.4 The recommended distillation method for crude oils up to cutpoint 400°C (752°F) AET is Test Method D 2892. This test method can be used for heavy crude oils with initial boiling points greater than 150°C (302°F). However, distillation curves and fraction qualities obtained by these methods are not comparable.
1.5 This test method contains the following annexes:
1.5.1 Annex A1—Test Method for Determination of Temperature Response Time,
1.5.2 Annex A2—Practice for Calibration of Sensors,
1.5.3 Annex A3—Test Method for Dehydration of a Wet Sample of Oil,
1.5.4 Annex A4—Practice for Conversion of Observed Vapor Temperature to Atmospheric Equivalent Temperature (AET), and
1.5.5 Annex A5—Test Method for Determination of Wettage.
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.7 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. For specific warnings, see 6.5.4.2, 6.5.6.3, 6.9.3, 9.5, 9.7, and A2.3.1.3.
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Designation:D5236–03 (Reapproved 2007)
Standard Test Method for
Distillation of Heavy Hydrocarbon Mixtures (Vacuum Potstill
Method)
This standard is issued under the fixed designation D5236; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.5.5 Annex A5—Test Method for Determination of Wet-
tage.
1.1 This test method covers the procedure for distillation of
1.6 The values stated in SI units are to be regarded as the
heavy hydrocarbon mixtures having initial boiling points
standard. The values given in parentheses are for information
greater than 150°C (300°F), such as heavy crude oils, petro-
only.
leum distillates, residues, and synthetic mixtures. It employs a
1.7 This standard does not purport to address all of the
potstill with a low pressure drop entrainment separator oper-
safety concerns, if any, associated with its use. It is the
ated under total takeoff conditions. Distillation conditions and
responsibility of the user of this standard to establish appro-
equipment performance criteria are specified and typical appa-
priate safety and health practices and determine the applica-
ratus is illustrated.
bility of regulatory limitations prior to use. For specific
1.2 This test method details the procedures for the produc-
warnings, see 6.5.4.2, 6.5.6.3, 6.9.3, 9.5, 9.7, and A2.3.1.3.
tion of distillate fractions of standardized quality in the gas oil
and lubricating oil range as well as the production of standard
2. Referenced Documents
residue. In addition, it provides for the determination of
2.1 ASTM Standards:
standard distillation curves to the highest atmospheric equiva-
D941 Test Method for Density and Relative Density (Spe-
lent temperature possible by conventional distillation.
cific Gravity) of Liquids by Lipkin Bicapillary Pycnom-
1.3 The maximum achievable atmospheric equivalent tem-
eter
perature (AET) is dependent upon the heat tolerance of the
D1217 Test Method for Density and Relative Density (Spe-
charge.Formostsamples,atemperatureupto565°C(1050°F)
cific Gravity) of Liquids by Bingham Pycnometer
can be attained. This maximum will be significantly lower for
D1250 GuideforUseofthePetroleumMeasurementTables
heatsensitivesamples(forexample,heavyresidues)andmight
D1298 Test Method for Density, Relative Density (Specific
be somewhat higher for nonheat sensitive samples.
Gravity), or API Gravity of Crude Petroleum and Liquid
1.4 The recommended distillation method for crude oils up
Petroleum Products by Hydrometer Method
to cutpoint 400°C (752°F) AET is Test Method D2892. This
D1480 Test Method for Density and Relative Density (Spe-
testmethodcanbeusedforheavycrudeoilswithinitialboiling
cific Gravity) of Viscous Materials by Bingham Pycnom-
pointsgreaterthan150°C(302°F).However,distillationcurves
eter
and fraction qualities obtained by these methods are not
D2892 Test Method for Distillation of Crude Petroleum
comparable.
(15-Theoretical Plate Column)
1.5 This test method contains the following annexes:
D4057 Practice for Manual Sampling of Petroleum and
1.5.1 Annex A1—Test Method for Determination of Tem-
Petroleum Products
perature Response Time,
D4177 Practice for Automatic Sampling of Petroleum and
1.5.2 Annex A2—Practice for Calibration of Sensors,
Petroleum Products
1.5.3 Annex A3—Test Method for Dehydration of a Wet
D5002 Test Method for Density and Relative Density of
Sample of Oil,
Crude Oils by Digital Density Analyzer
1.5.4 Annex A4—Practice for Conversion of Observed Va-
por Temperature to Atmospheric Equivalent Temperature
3. Terminology
(AET), and
3.1 Definitions of Terms Specific to This Standard:
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
D02.08 on Volatility. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Dec. 1, 2007. Published January 2008. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1992. Last previous edition approved in 2003 as D5236–03. DOI: the ASTM website.
10.1520/D5236-03R07. Withdrawn.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5236–03 (2007)
3.1.1 boil-up rate, n—the quantity of vapor entering the 4.4 Distillation curves of temperature versus mass or vol-
distillation head per unit time. ume percent, or both, are drawn using the data from 4.2 and
4.3.
3.1.1.1 Discussion—It is approximately equal to the takeoff
rate, differing only by the parasitic heat losses. It is expressed
5. Significance and Use
in millilitres per hour for a head of any given internal diameter
5.1 This test method is one of a number of tests conducted
or millilitres per hour per square centimetre of cross-sectional
on heavy hydrocarbon mixtures to characterize these materials
area of the throat for comparative purposes.
forarefinerorapurchaser.Itprovidesanestimateoftheyields
3.1.2 condenser, n—theapparatusconnectedtotheoutletof
of fractions of various boiling ranges.
the distillation head in which condensation of the product
5.2 The fractions made by this test method can be used
occurs.
alone or in combination with other fractions to produce
3.1.3 distillation flask, n—the flask, of glass or metal, in
samples for analytical studies and quality evaluations.
which the charge is boiled.
5.3 Residues to be used in the manufacture of asphalt can
3.1.3.1 Discussion—The flask is sometimes called a kettle
also be made but may not always be suitable. The long heat
or pot.
soaking that occurs in this test method may alter some of the
3.1.4 distillation head, n—the section immediately above
properties.
the distillation flask containing the entrainment separator.
NOTE 1—While the practice of reblending distillates with residue can
3.1.5 distillation pressure (or operating pressure), n—the
be done to produce a lighter residue, it is not recommended because it
pressure measured in the distillation head just before the outlet
produces blends with irregular properties.
to the recovery system.
5.4 Details of cutpoints must be mutually agreed upon
3.1.6 distillation temperature (or vapor temperature),
before the test begins.
n—the temperature of the vapors in the distillation head at the
5.5 This is a complex procedure involving many interacting
point of measurement.
variables. It is most important that at the time of first use of a
3.1.7 loading, n—the volume of charge relative to the
newapparatus,itscomponentsbecheckedasdetailedinAnnex
cross-sectional area of the neck.
A1 and Annex A2 and that the location of the vapor tempera-
3.1.8 pressure drop, n—the difference between the operat-
ture sensor be verified as detailed in 6.5.3 and Fig. 1.
ing pressure and the pressure measured in the distillation flask.
3.1.8.1 Discussion—It is a result of the friction developed
6. Apparatus
by driving the vapors through the system expressed in kilopas-
6.1 Four sizes of apparatus, based upon the internal diam-
cals (mm Hg).
eter of the distillation head (25, 36, 50, and 70 mm), are
3.1.9 spillover point, n—the lowest point in the head above
allowed. The apparatus (see Fig. 2) consists of a flask with
theentrainmentseparatoroverwhichthevaporscanflowtothe
heating mantles, an upper compensator, and a head containing
condensing region.
an entrainment separator. Attached to the head are the vapor
3.1.10 static hold-up (or wettage), n—the amount of liquid
temperature sensor, a connection for the vacuum gage, a
material remaining on the inside of the walls of the apparatus
condenser,arundownline,aproductreceiver(s),andavacuum
after the distillation has been completed.
pumping line with pump. The parts are connected by vacuum-
3.1.10.1 Discussion—In this test method, it includes wet-
tight joints to facilitate servicing.
tage of the distillation flask in the case of the steel flasks, but
6.2 Distillation Flask:
not in the case of glass flasks that are removed for weighing
6.2.1 The sizes specified for flasks are at least 50% larger
after the distillation is completed.
than the size of the charge to provide space for suppression of
3.1.11 takeoff rate, n—the quantity of product removed per
foam and for bubble breaking. The size of the charge for each
unit time.
size of still is determined from the loading factor. The
3.1.11.1 Discussion—It is approximately equal to the
recommended loading factor is between 200 and 400 mL of
boil-up rate differing only by parasitic heat losses.
chargepersquarecentimetreofcrosssectionalareaintheneck
of the head. Table 1 shows the range of charge volume that is
4. Summary of Test Method
recommended with each size of apparatus.
6.2.2 Flasks are made of borosilicate glass except those
4.1 A weighed volume of sample is distilled at absolute
larger than 10 L, which are made of stainless steel for reasons
pressures between 6.6 and 0.013 kPa (50 and 0.1 mm Hg) at
of safety.
specified distillation rates. Cuts are taken at preselected tem-
6.2.3 Theflaskisfittedwithathermowellreachingtowithin
peratures. Records of vapor temperature, operating pressure,
6 mm of the bottom and offset from the center to avoid a
and other variables are made at intervals, including at each
stirring bar. In the case of glass flasks, the bottom shall be
cutpoint.
slightly flattened or slightly concave, but not perfectly flat to
4.2 Themassofeachfractionisobtained.Distillationyields
facilitate the rotation of the magnetic stirrer. Steel flasks can
by mass are calculated from the mass of each fraction relative
have a cooling coil for rapid quenching of the distillation in an
to the total mass recovery.
emergency. Fig. 3 shows a typical example.
4.3 The density of each fraction is obtained. Distillation
yieldsbyvolumearecalculatedfromthevolumecomputedfor
each fraction at 15°C (59°F) relative to the total recovery. Cooke, Industrial and Engineering Chemistry, Vol 55, 1963, p. 36.
D5236–03 (2007)
STILL HEAD DIMENSION CHART
Size A B C D E F G H I
25 mm 85 mm 75 mm 64 mm 47 mm ID 40 mm OD 4–5 mm 35/25 28/15 35 mm
36 mm 90 mm 75 mm 64 mm 68 mm ID 57 mm OD 5–6 mm 65/40 35/25 35 mm
50 mm 110 mm 100 mm 75 mm 94 mm ID 79 mm OD 7–9 mm 75/50 35/25 45 mm
70 mm 140 mm 100 mm 100 mm 131 mm ID 111 mm OD 10–11 mm 102/75 50/30 70 mm
FIG. 1 Distillation Head
6.3 Stirring System—A magnetically driven stirring bar 6.4.3 The upper half of the flask shall be covered with a
approximately 3-mm diameter and 20-mm long shall be mantle to compensate for heat losses. A heat density of 0.2
providedfortheglassflasks,or6-mmdiameterby50-mmlong W/cm is adequate.
for the steel flasks. The edges shall be rounded to minimize 6.5 Distilling Head:
grindingthewalloftheflask.Theexternalmagneticdrivemust 6.5.1 The head shall conform to the details shown in Fig. 1.
becapableofrotatingthebarintheflaskwhenlocateddirectly It shall be made of borosilicate glass and be totally enclosed in
below and touching the mantle. The drive can be used to a silvered glass vacuum jacket having a permanent vacuum of
supporttheapparatusabove.Anadjustablejackingmechanism less than 0.0001 kPa (0.00075 mm Hg).
is recommended for raising and lowering the stirrer. 6.5.2 The head shall be enclosed in a heat insulating system
6.4 Heating System: such as a glass fabric mantle capable of maintaining the outer
6.4.1 The flask shall be heated by means of a nickel walloftheglassvacuumjacketatatemperature5°Cbelowthe
reinforced quartz fabric heating mantle on the lower half so internal vapor temperature in the head. For this purpose the
that boiling rates of up to 150 mL/h per cm of the cross vacuum jacket shall have a temperature sensor fastened to the
sectional area of the neck can be maintained.Aheat density of outer wall of the jacket at a point level with the vapor
0.5 W/cm is adequate. Usually two or more circuits are used temperature sensor and opposite to the outlet arm of the head.
to improve heat control by applying automatic heat to the 6.5.3 The head shall be fitted with an adapter to support the
bottom circuit. vapor temperature sensor so that it is held centered in the neck
6.4.2 Atemperaturesensorshallbelocatedbetweenthewall with the top of the sensing tip 3 6 1 mm below the spillover
of the flask and the mantle for control of the skin temperature. point. This dimension can be checked by removing the
D5236–03 (2007)
FIG. 2 Apparatus
TABLE 1 Standard Charge and Flask Size
and at least once per year thereafter as described in A2.2.2.
Throat Alternatively, certified sensors may be used, provided the
Inside
Cross-Sectional Charge, L Flask, L
calibration of the sensor and its associated recording instru-
Diameter, mm
Area, cm
ment can be traced back to a primary temperature standard.
25 5 1–2 2–3
Recalibratewheneitherthesensorortheinstrumentisrepaired
36 10 2–4 3–6
or serviced. (Warning—Vapor temperature measurement is
50 20 4–8 6–12
70 40 8–16 12–24
one of the two major sources of error in distillation data.)
6.5.4.3 Verification of the calibration of the vapor tempera-
ture measuring devices is to be made on a regular basis.
Verificationatleastonceamonthisrecommended.Verification
temperature sensor and inserting in its place a copper wire
of the calibration of the sensors can be accomplished poten-
havingashortrightanglebendatthebottom.Byfeelingforthe
tiometrically by the use of standard precision resistance or by
spillover point, the distance from the top joint of the adaptor
distilling a pure compound with accurately known boiling
can be found. Laying the wire on the temperature sensor will
point, as described in A2.2.3.
then permit checking of this dimension.
6.5.5 AheadtrapasillustratedinFig.4shallbefittedtothe
6.5.4 The vapor temperature sensor shall be either a plati-
adapterdescribedin6.5.3forconnectiontothevacuumsensor.
num resistance thermometer, a thermocouple with the junction
It shall be kept filled with crushed dry ice at all times while in
head fused to the lower tip of the well or any other device
service.
whichmeetstherequirementsin6.5.4and6.5.4.1.Itshallhave
a response time of less than 60 s as described in Annex A1. 6.5.6 Avacuum sensor shall be connected to the sidearm of
6.5.4.1 The vapor temperature measuring device shall have the trap. The sensor shall be capable of reading the pressure
an accuracy of 0.5°C or better and be measured with a with a precis
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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.
An American National Standard
Designation:D5236–02 Designation:D5236–03 (Reapproved 2007)
Standard Test Method for
Distillation of Heavy Hydrocarbon Mixtures (Vacuum Potstill
Method)
This standard is issued under the fixed designation D5236; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber 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 procedure for distillation of heavy hydrocarbon mixtures having initial boiling points greater
than 150°C (300°F), such as heavy crude oils, petroleum distillates, residues, and synthetic mixtures. It employs a potstill with a
low pressure drop entrainment separator operated under total takeoff conditions. Distillation conditions and equipment
performance criteria are specified and typical apparatus is illustrated.
1.2 This test method details the procedures for the production of distillate fractions of standardized quality in the gas oil and
lubricating oil range as well as the production of standard residue. In addition, it provides for the determination of standard
distillation curves to the highest atmospheric equivalent temperature possible by conventional distillation.
1.3 The maximum achievable atmospheric equivalent temperature (AET) is dependent upon the heat tolerance of the charge.
For most samples, a temperature up to 565°C (10570°F)(1050°F) can be attained. This maximum will be significantly lower for
heat sensitive samples (for example, heavy residues) and might be somewhat higher for nonheat sensitive samples.
1.4 The recommended distillation method for crude oils up to cutpoint 400°C (752°F) AET is Test Method D2892. This test
method can be used for heavy crude oils with initial boiling points greater than 150°C (302°F). However, distillation curves and
fraction qualities obtained by these methods are not comparable.
1.5 This test method contains the following annexes:
1.5.1 Annex A1—Test Method for Determination of Temperature Response Time,
1.5.2 Annex A2—Practice for Calibration of Sensors,
1.5.3 Annex A3—Test Method for Dehydration of a Wet Sample of Oil,
1.5.4 Annex A4—Practice for Conversion of ObservedVaporTemperature toAtmospheric EquivalentTemperature (AET), and
1.5.5 Annex A5—Test Method for Determination of Wettage.
1.6 The values stated in SI units are to be regarded as the standard. The inch-pound units values given in parentheses are
provided for information purposes only.
1.7 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. For specific warnings, see 6.5.4.2, 6.5.6.3, 6.9.3, 9.5, 9.7, and A2.3.1.3.
2. Referenced Documents
2.1 ASTM Standards:
D941 Test Method for Density and Relative Density (Specific Gravity) of Liquids by Lipkin Bicapillary Pycnometer
D1160Test Method for Distillation of Petroleum Products at Reduced Pressure
D1217 Test Method for Density and Relative Density (Specific Gravity) of Liquids by Bingham Pycnometer
,
D1250Guide for Petroleum Measurement Tables Guide for Use of the Petroleum Measurement Tables
D1298 TestMethodforDensity,RelativeDensity(SpecificGravity),orAPIGravityofCrudePetroleumandLiquidPetroleum
Products by Hydrometer Method
This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.08.0C
on Crude Distillation.
Current edition approved April 10, 2002. Published July 2002. Originally published as D5236–92. Last previous edition D5236–01.
This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.08 on
Volatility.
Current edition approved Dec. 1, 2007. Published January 2008. Originally approved in 1992. Last previous edition approved in 2003 as D5236–03.
Discontinued; see 1993 Annual Book of ASTM Standards , Vol 05.01.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Annual Book of ASTM Standards, Vol 05.01.
Withdrawn.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5236–03 (2007)
D1480 Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Bingham Pycnometer
D2892 Test Method for Distillation of Crude Petroleum (15-Theoretical Plate Column)
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D5002 Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 boil-up rate, n—the quantity of vapor entering the distillation head per unit time.
3.1.1.1 Discussion—It is approximately equal to the takeoff rate, differing only by the parasitic heat losses. It is expressed in
millilitres per hour for a head of any given internal diameter or millilitres per hour per square centimetre of cross-sectional area
of the throat for comparative purposes.
3.1.2 condenser, n—the apparatus connected to the outlet of the distillation head in which condensation of the product occurs.
3.1.3 distillation flask, n—the flask, of glass or metal, in which the charge is boiled.
3.1.3.1 Discussion—The flask is sometimes called a kettle or pot.
3.1.4 distillation head, n—the section immediately above the distillation flask containing the entrainment separator.
3.1.5 distillation pressure (or operating pressure), n—thepressuremeasuredinthedistillationheadjustbeforetheoutlettothe
recovery system.
3.1.6 distillation temperature (or vapor temperature ), n—the temperature of the vapors in the distillation head at the point of
measurement.
3.1.7 loading, n—the volume of charge relative to the cross-sectional area of the neck.
3.1.8 pressure drop, n—the difference between the operating pressure and the pressure measured in the distillation flask.
3.1.8.1 Discussion—It is a result of the friction developed by driving the vapors through the system expressed in kilopascals
(mm Hg).
3.1.9 spillover point, n—the lowest point in the head above the entrainment separator over which the vapors can flow to the
condensing region.
3.1.10 static hold-up (or wettage), n—the amount of liquid material remaining on the inside of the walls of the apparatus after
the distillation has been completed.
3.1.10.1 Discussion—In this test method, it includes wettage of the distillation flask in the case of the steel flasks, but not in
the case of glass flasks that are removed for weighing after the distillation is completed.
3.1.11 takeoff rate, n—the quantity of product removed per unit time.
3.1.11.1 Discussion—It is approximately equal to the boil-up rate differing only by parasitic heat losses.
4. Summary of Test Method
4.1 Aweighed volume of sample is distilled at absolute pressures between 6.6 and 0.013 kPa (50 and 0.1 mm Hg) at specified
distillationrates.Cutsaretakenatpreselectedtemperatures.Recordsofvaportemperature,operatingpressure,andothervariables
are made at intervals, including at each cutpoint.
4.2 The mass of each fraction is obtained. Distillation yields by mass are calculated from the mass of each fraction relative to
the total mass recovery.
4.3 The density of each fraction is obtained. Distillation yields by volume are calculated from the volume computed for each
fraction at 15°C (59°F) relative to the total recovery.
4.4 Distillation curves of temperature versus mass or volume percent, or both, are drawn using the data from 4.2 and 4.3.
5. Significance and Use
5.1 This test method is one of a number of tests conducted on heavy hydrocarbon mixtures to characterize these materials for
a refiner or a purchaser. It provides an estimate of the yields of fractions of various boiling ranges.
5.2 The fractions made by this test method can be used alone or in combination with other fractions to produce samples for
analytical studies and quality evaluations.
5.3 Residues to be used in the manufacture of asphalt can also be made but may not always be suitable. The long heat soaking
that occurs in this test method may alter some of the properties.
NOTE 1—While the practice of reblending distillates with residue can be done to produce a lighter residue, it is not recommended because it produces
blends with irregular properties.
5.4 Details of cutpoints must be mutually agreed upon before the test begins.
5.5 This is a complex procedure involving many interacting variables. It is most important that at the time of first use of a new
apparatus,itscomponentsbecheckedasdetailedinAnnexA1andAnnexA2andthatthelocationofthevaportemperaturesensor
be verified as detailed in 6.5.3 and Fig. 1.
D5236–03 (2007)
STILL HEAD DIMENSION CHART
Size A B C D E F G H I
25 mm 85 mm 75 mm 64 mm 47 mm ID 40 mm OD 4–5 mm 35/25 28/15 35 mm
36 mm 90 mm 75 mm 64 mm 68 mm ID 57 mm OD 5–6 mm 65/40 35/25 35 mm
50 mm 110 mm 100 mm 75 mm 94 mm ID 79 mm OD 7–9 mm 75/50 35/25 45 mm
70 mm 140 mm 100 mm 100 mm 131 mm ID 111 mm OD 10–11 mm 102/75 50/30 70 mm
FIG. 1 Distillation Head
6. Apparatus
6.1 Foursizesofapparatus,basedupontheinternaldiameterofthedistillationhead(25,36,50,and70mm),areallowed. The
apparatus (see Fig. 2) consists of a flask with heating mantles, and upper compensator, and a head containing an entrainment
separator.Attached to the head are the vapor temperature sensor, a connection for the vacuum gage, a condenser, a rundown line,
aproductreceiver(s),andavacuumpumpinglinewithpump.Thepartsareconnectedbyvacuum-tightjointstofacilitateservicing.
6.2 Distillation Flask:
6.2.1 The sizes specified for flasks are at least 50% larger than the size of the charge to provide space for suppression of foam
and for bubble breaking. The size of the charge for each size of still is determined from the loading factor. The recommended
loading factor is between 200 and 400 mL of charge per square centimetre of cross sectional area in the neck of the head. Table
1 shows the range of charge volume that is recommended with each size of apparatus.
6.2.2 Flasksaremadeofborosilicateglassexceptthoselargerthan10L,whicharemadeofstainlesssteelforreasonsofsafety.
6.2.3 The flask is fitted with a thermowell reaching to within 6 mm of the bottom and offset from the center to avoid a stirring
bar. In the case of glass flasks, the bottom shall be slightly flattened or slightly concave, but not perfectly flat to facilitate the
rotation of the magnetic stirrer. Steel flasks can have a cooling coil for rapid quenching of the distillation in an emergency. Fig.
3 shows a typical example.
6.3 Stirring System—A magnetically driven stirring bar approximately 3-mm diameter and 20-mm long shall be provided for
the glass flasks, or 6-mm diameter by 50-mm long for the steel flasks. The edges shall be rounded to minimize grinding the wall
Description only. Tables are published separately in 12 volumes.
Cooke, Industrial and Engineering Chemistry, Vol 55, 1963, p. 36.
D5236–03 (2007)
FIG. 2 Apparatus
TABLE 1 Standard Charge and Flask Size
Throat
Inside
Cross-Sectional Charge, L Flask, L
Diameter, mm
Area, cm
25 5 1–2 2–3
36 10 2–4 3–6
50 20 4–8 6–12
70 40 8–16 12–24
of the flask.The external magnetic drive must be capable of rotating the bar in the flask when located directly below and touching
the mantle. The drive can be used to support the apparatus above.An adjustable jacking mechanism is recommended for raising
and lowering the stirrer.
6.4 Heating System:
6.4.1 The flask shall be heated by means of a nickel reinforced quartz fabric heating mantle on the lower half so that boiling
2 2
ratesofupto150mL/hpercm ofthecrosssectionalareaoftheneckcanbemaintained.Aheatdensityof0.5W/cm isadequate.
Usually two or more circuits are used to improve heat control by applying automatic heat to the bottom circuit.
6.4.2 A temperature sensor shall be located between the wall of the flask and the mantle for control of the skin temperature.
6.4.3 The upper half of the flask shall be covered with a mantle to compensate for heat losses.Aheat density of 0.2 W/cm is
adequate.
6.5 Distilling Head:
6.5.1 The head shall conform to the details shown in Fig. 1. It shall be made of borosilicate glass and be totally enclosed in a
silvered glass vacuum jacket having a permanent vacuum of less than 0.0001 kPa (0.00075 mm Hg).
6.5.2 The head shall be enclosed in a heat insulating system such as a glass fabric mantle capable of maintaining the outer wall
of the glass vacuum jacket at a temperature 5°C below the internal vapor temperature in the head. For this purpose the vacuum
jacket shall have a temperature sensor fastened to the outer wall of the jacket at a point level with the vapor temperature sensor
and opposite to the outlet arm of the head.
D5236–03 (2007)
SYSTEM SIZE A B
25 mm 35/25 3 L
36 mm 65/40 6 L
50 mm 75/50 12 L
70 mm 102/75 24 L
FIG. 3 Distillation Flask
6.5.3 Theheadshallbefittedwithanadaptertosupportthevaportemperaturesensorsothatitisheldcenteredintheneckwith
thetopofthesensingtip3 61mmbelowthespilloverpoint.Thisdimensioncanbecheckedbyremovingthetemperaturesensor
andinsertinginitsplaceacopperwirehavingashortrightanglebendatthebottom.Byfeelingforthespilloverpoint,thedistance
from the top joint of the adaptor can be found. Laying the wire on the temperature sensor will then permit checking of this
dimension.
6.5.4 The vapor temperature sensor shall be either a platinum resistance thermometer, a thermocouple with the junction head
fused to the lower tip of the well or any other device which meets the requirements in 6.5.4 and 6.5.4.1. It shall have a response
time of less than 60 s as described in Annex A1.
6.5.4.1 The vapor temperature measuring device shall have an accuracy of 0.5°C or better and be measured
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