GB/T 6536-2010 English PDF (GBT6536-2010)
GB/T 6536-2010 English PDF (GBT6536-2010)
GB/T 6536-2010: Standard test method for distillation of petroleum products at atmospheric pressure
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
Replacing GB/T 6536-1997
Standard test method for distillation of petroleum
products at atmospheric pressure
ISSUED ON: JANUARY 10, 2011
IMPLEMENTED ON: MAY 01, 2011
Issued by: General Administration of Quality Supervision, Inspection and Quarantine;
Standardization Administration of the People's Republic of
Table of Contents
Foreword ... 4
Introduction ... 8
1 Scope ... 9
2 Normative references ... 9
3 Terms and definitions ... 10
4 Method summary ... 13
5 Instruments ... 13
6 Sampling, sample storage and sample handling ... 19
7 Instrument preparation ... 22
8 Calibration and standardization ... 23
9 Test steps ... 25
10 Calculation ... 31
11 Report ... 34
12 Precision and deviation ... 36
Annex A (normative) Details of instruments ... 42
Annex B (normative) Determination of the difference in temperature lag time between electronic temperature measurement system and glass mercury
Annex C (informative) Steps to simulate the influence of the exposed liquid column of a glass mercury thermometer ... 49
Annex D (normative) Measurement steps and precision calculation examples for the evaporation percentage or recovery percentage at the specified
temperature reading ... 51
Annex E (informative) Determination of the corrected loss data table based on observed loss and atmospheric pressure ... 55
Annex F (informative) Calculation examples of report data ... 58
Annex G (informative) Report format description ... 60
Annex H (informative) Instructions for determination of repeatability and reproducibility ... 62
Annex I (normative) Determination of repeatability of Group 0 samples ... 63 Standard test method for distillation of petroleum
products at atmospheric pressure
WARNING - This standard does not intend to make recommendations for
all safety issues related to its use. Before applying this Standard, users are responsible for establishing appropriate safety and protection
measures, and determining the applicability of relevant regulatory
This Standard specifies the method that uses laboratory batch distillation equipment to quantitatively determine the distillation characteristics of petroleum products at atmospheric pressure. This Standard includes
measurement methods for manual instruments and automatic instruments.
This Standard is applicable to distillate fuels such as natural gasoline (stabilized light hydrocarbons), light and middle distillates, automotive spark-ignition engine fuels, aviation gasoline, jet fuel, diesel and kerosene, as well as naphtha and white spirit products. This Standard does not apply to products that contain more residues.
NOTE: The residual volume fraction of samples used to establish the precision of this method is not more than 2%.
2 Normative references
The provisions in following documents become the provisions of this Standard through reference in this Standard. For dated references, the subsequent amendments (excluding corrigendum) or revisions do not apply to this Standard, however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies. GB/T 514, Specification for Liquid-In-Glass Thermometers for Testing of Petroleum Products
GB/T 3535, Petroleum products - Determination of pour point (GB/T 3535- 2006, ISO 3016:1994, MOD)
GB/T 4756, Method for manual sampling of petroleum liquids (GB/T 4756-
NOTE: In use, the final boiling point is generally used instead of the dry point. For some naphtha with special uses, such as naphtha used in the paint industry, the dry point can be reported. When the final boiling point determination precision of some samples does not always meet the specified requirements, the dry point can also be used instead of the final boiling point.
3.5 dynamic holdup
The materials that appear in the neck of the distillation flask, branch pipes and condenser tubes during the distillation process.
3.6 emergent stem effect
The deviation of the thermometer reading produced when using the fully
immersed glass mercury thermometer under partial immersion conditions.
NOTE: Under local immersion conditions, part of the mercury column, that is, the exposed part of the mercury column, is at a lower temperature than the immersed part, which causes the mercury column to shrink and causes the thermometer to read lower.
3.7 final boiling point; FBP
end point; EP
The highest calibrated thermometer reading obtained during the test.
NOTE: The final boiling point or end point usually occurs after all the liquid at the bottom of the distillation flask has evaporated, and is often referred to as the maximum temperature.
3.8 front end loss
It refers to the volatilization loss of the specimen transferred from the receiving cylinder to the distillation flask, the evaporation loss of the specimen during the distillation process, and the uncondensed specimen vapor loss in the distillation flask at the end of the distillation.
3.9 initial boiling point; IBP
The corrected thermometer reading observed when the first drop of condensate is dripped from the end of the condenser tube.
3.10 percent evaporated
The sum of the percent recovery and the loss percentage.
The temperature obtained by a temperature measurement device or system
and equivalent to the thermometer reading described in 3.19
3.18.1 corrected temperature reading
The temperature of the temperature reading described in 3.18 after being corrected by atmospheric pressure.
3.19 thermometer reading; thermometer result
Under the test conditions of this method, the saturated vapor temperature at the neck below the branch pipe of the distillation flask measured with a prescribed thermometer.
3.19.1 corrected thermometer reading
The temperature after the thermometer reading described in 3.19 is corrected by atmospheric pressure.
4 Method summary
According to the specimen composition, vapor pressure, expected initial boiling point and expected final boiling point, classify the specimen into one of the five specified groups. Put the 100mL of specimen under the conditions specified by the corresponding group, under the ambient atmospheric pressure and the design that is about a theoretical fractionation tray. Use the laboratory batch distillation equipment to distill. According to the requirements of test results, systematically observe and record temperature readings and condensate
volume, distillation residue and loss volume. The observed temperature
readings need to be corrected for atmospheric pressure. The test result is expressed as a table or graph of the evaporation percentage or percent
recovery to the corresponding temperature.
5.1 Basic components of the instrument
5.1.1 The basic components of the distillation instrument are the distillation flask, the condenser and the connected condensation bath, the metal protective cover or enclosure for the distillation flask, the heater, the distillation flask holder and support plate, the temperature measurement device and the receiving cylinder for collecting the distillate.
5.1.2 The manual distillation apparatus is shown in Figure 1 and Figure 2. 14 - Distillation flask stand;
15 - Ground wire;
16 - Electric heater;
17 - Operation hole for adjusting the level of stand platform;
18 - Power cable;
19 - Receiving cylinder;
20 - Cooling bath of receiving cylinder;
21 - Cover of receiving cylinder.
Figure 2 -- Diagram of electric heating type distillation apparatus
5.2 Instrument details
The specific regulations of the instrument are detailed in Annex A.
5.3 Temperature measurement device
5.3.1 Glass mercury thermometer: shall meet the specifications of GB-46 and GB-47 thermometers in GB/T 514. The GB-46 thermometer is a low
temperature range thermometer. The temperature measurement range is -
2??C~300??C. The graduation value is 1??C. The GB-47 thermometer is a high temperature range thermometer. The temperature measurement range is -
2??C~400??C. The graduation value is 1??C.
When the thermometer is continuously exposed to a temperature higher than 370??C for a long time, the thermometer shall be zero-calibrated or verified in accordance with the provisions of GB/T 514 and JJG 50. Otherwise, the
thermometer cannot be used again.
NOTE: When the observed thermometer reading is higher than 370??C, the temperature of the thermometer bulb is close to the stable limit range of the bulb glass. The calibration of the thermometer may be invalid.
5.3.2 Except for the glass mercury thermometer specified in 5.3.1, another temperature measurement system can also be used in this method, as long as it is confirmed that it has the same temperature hysteresis, exposed liquid column influence and accuracy as the glass mercury thermometer.
18.104.22.168 The circuits and/or algorithms used in other temperature measurement systems shall have the ability to simulate the temperature hysteresis of a glass mercury thermometer.
22.214.171.124 The temperature sensor can also be placed in the casing, so that the tip is covered. In this way, the temperature sensor system has a temperature lag time similar to that of a glass mercury thermometer due to its thermal quality and thermal conductivity have been adjusted.
126.96.36.199 If the temperature reading measured in the relevant instrument used does not reach the value specified in Table 4 (see 188.8.131.52 Note and Table 4), then it is considered that this temperature measurement device is
nonconforming and cannot be used in this method.
NOTE: Use toluene as calibration solution. It cannot give any information on the degree of temperature hysteresis of the electronic temperature measurement system simulating a glass liquid thermometer.
184.108.40.206 Use analytically pure toluene and hexadecane as the calibration fluid. However, as long as it can ensure that the measurement accuracy of this method will not be reduced, other grades of reagents can also be used.
NOTE: When measuring with a local immersion thermometer, the reference boiling point of toluene at 101.3kPa is 110.6??C. The reference boiling point of hexadecane at 101.3kPa is 287.0??C. Since the thermometer used in this method is calibrated under full immersion conditions, the measurement results will generally be low. Affected by the type of thermometer and measurement conditions, the measurement results of different thermometers will be different.
8.1.3 Refer to Annex B for the steps to determine the temperature hysteresis. 8.1.4 Refer to Annex C for the steps to estimate the impact of the exposed liquid column.
8.1.5 Use hexadecane to verify the high temperature calibration of the
temperature measurement system. At 50% recovery volume, the temperature measurement system shall display a temperature result equivalent to the distillation conditions of Group 4 in Table 4 and the corresponding temperature of the relevant instrument.
NOTE: Due to the high melting point of hexadecane, the Group 4 verification distillation process needs to be carried out under the condition that the condensation temperature is greater than 20??C.
8.2 Automatic method
8.2.1 Level tracker: The level tracker or recording device in the automatic distillation tester shall have a resolution of 0.1mL or better for each volume between 5mL and 100mL. The maximum error is 0.3mL. The calibration of the instrument shall be verified at an interval of no more than 3 months according to the instrument manual. Calibration is also required after the system has been replaced and repaired.
NOTE: The typical calibration procedure shall include the calibration of the output value when there are 5mL and 100mL of samples in the receiving cylinder, respectively. 9.5 Position the temperature sensor at the center of the neck of the distillation flask through the close-fitting device specified in 5.4. If a thermometer is used, use a silicone rubber stopper or a stopper made of other equivalent polymer materials, so that the thermometer bubble is located in the center of the bottleneck. The bottom end of the thermometer capillary shall be flush with the highest point at the bottom of the inner wall of the distillation flask branch pipe (see Figure 4). If a thermocouple or resistance thermometer is used, it shall be assembled according to the instrument manual (see Figure 5).
NOTE: If vacuum grease is used on the surface that matches the center positioning device, its amount shall be as small as possible.
9.6 Use a close-fitting cork stopper, silicone rubber stopper or stopper made of other equivalent polymer materials to tightly connect the branch tube of the distillation flask to the condenser tube. Adjust the distillation flask to an upright position. Make the branch pipe of the distillation flask extend into the condenser tube by 25mm~50mm. Raise and adjust the distillation flask support plate to tightly contact the bottom of the distillation flask.
9.7 Put the previously measured specimen and the undried receiving cylinder into the temperature-controlled cooling bath below the end of the condenser. The end of the condenser tube shall be located in the center of the receiving cylinder, and extend into the cylinder at least 25mm, but not below the 100mL graduation line of the cylinder.
9.8 Determination of initial boiling point
9.8.1 Manual method: Use a piece of absorbent paper or similar material to cover the receiving cylinder, so as to reduce evaporation loss in distillation. The paper or material used for covering shall be cut close to the condenser tube so that the cylinder can be tightly covered. If a receiving deflector is used, make the tip of the deflector just touch the inner wall of the receiving cylinder. If the receiving deflector is not used, the drip tip of the condenser tube shall not touch the inner wall of the receiving cylinder. Start distilling. Indicate the start time of distillation. Observe and record the initial boiling point, to the nearest of 0.5??C. If the receiving deflector is not used, when the initial boiling point is observed, the receiving cylinder shall be moved immediately so that the drip tip of the condenser tube touches the inner wall of the cylinder.
9.8.2 Automatic method: Use the device provided by the instrument
manufacturer to reduce the evaporation loss during the distillation process. Make the tip of the receiving deflector just touch the inner wall of the receiving cylinder. Start heating the distillation flask and specimen. Indicate the start time of distillation. Record the initial boiling point, to the nearest of 0.1??C. 9.9 Adjust the heating so that the time interval from the start of heating to the WARNING: Due to the structure and test conditions of the distillation flask, if the vapor and liquid around the temperature sensor do not reach
thermodynamic equilibrium, the distillation rate will affect the measured vapor temperature. Therefore, the distillation rate shall be kept as uniform as possible throughout the test.
NOTE: When measuring gasoline specimens, when the steam temperature reaches 160??C, sometimes it is found that the condensate suddenly forms an insoluble liquid phase and accumulates (bubbles) on the temperature measurement device and the neck of the distillation flask. This phenomenon will be accompanied by a rapid drop in steam temperature (about 3??C) and a drop in recovery rate. This phenomenon may be caused by traces of water in the specimen. Generally, it lasts about 10s~30s. Then the temperature rises again and the condensate starts to flow smoothly again. This point is commonly referred to as the "pause point".
9.12 If the distillation process fails to meet the requirements of 9.9, 9.10 and 9.11, the distillation shall be repeated.
9.13 If the decomposition point as described in 3.3 is observed, the heating shall be stopped and the step 9.17 shall be followed.
9.14 Between the initial boiling point and the final boiling point, observe and record the calculation and report the data required by the specifications or the test results determined in advance. These observed data can include
temperature readings at specified percent recovery and/or percent recovery at specified temperature readings.
9.14.1 Manual method: Record the volume reading of the receiving cylinder, to the nearest of 0.5mL. Record the temperature reading, to the nearest 0.5??C. 9.14.2 Automatic method: Record the volume reading of the receiving cylinder, to the nearest of 0.1mL. Record the temperature reading, to the nearest 0.1??C. 9.14.3 Group 0: If no special data requirements are specified, record the initial boiling point, final boiling point and the temperature readings at every 10% recovery volume multiple between 10%~90% recovery volume.
9.14.4 Group 1, Group 2, Group 3 and Group 4: If no special data requirements are specified, record initial boiling point, final boiling point and/or dry point, temperature readings at 5%, 15%, 85% and 95% recovery volume, as well as the temperature reading at every 10% recovery volume multiple between
10%~90% recovery volume.
Group 4: When measuring jet fuel or similar products with a high temperature range thermometer, the relevant thermometer readings may be obscured by the central positioning device. If these data are needed, another distillation test shall be done according to the regulations of If these data are needed, another If the actual front end loss differs from the estimated value by more than 2mL, the test shall be repeated.
9.16 Observe and record the final boiling point and/or dry point as needed. Stop heating.
9.17 After the heating is stopped, the distillate is completely dropped into the receiving cylinder.
9.17.1 Manual method: When there are continuous drops in the condenser tube dripping into the receiving cylinder, observe and record the condensate volume every 2min, to the nearest of 0.5mL, until the volume of two consecutive observations is the same. Accurately measure the volume of liquid in the receiving cylinder. Record it to the nearest of 0.5mL.
9.17.2 Automatic method: The instrument will continuously monitor the recovery volume until the change in the recovery volume is less than 0.1mL within 2min. Accurately record the volume of liquid in the receiving cylinder to the nearest 0.1mL.
9.18 Record the percent recovery corresponding to the volume of liquid in the receiving cylinder. If the distillation is terminated prematurely due to the occurrence of a decomposition point, then subtract the percent recovery from 100%. Report this difference as the sum of the percent residue and the percent loss, and omit step 9.19.
9.19 After the distillation flask is cooled, and no more steam is observed, remove the distillation flask from the condenser. Pour its contents (except zeolite) into a 5mL graduated cylinder. Hang the distillation flask upside down on the cylinder. Let the liquid in the distillation flask drip until the volume of the liquid in the cylinder does not increase significantly. Measure the volume of the liquid in the cylinder to the nearest 0.1mL. Record it as the percent residue. 9.19.1 If the 5mL cylinder has no scale below 1mL, and the liquid volume is ...