SH/T 0238-1992 Determination of Storage Stability of Diesel Fuels

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: SH/T 0238-92 (confirmed in 2004)
• Chinese title: Determination of Storage Stability of Diesel Fuels
• English title: not provided in the available source
• Replacement relationship: replaces SY 2125-84
• First issued: 1978
• Technical committee: Technical committee of the Research Institute of Petroleum Processing
• Drafting organization: Refining Research Institute of Luoyang Petrochemical Engineering Company
• Main drafter: Zhang Guanglin

2. Scope of application and exclusions

• Applicable: all types of diesel fuel except hydrotreated diesel; also applicable for evaluating and screening diesel antioxidant additives.
• Not applicable: hydrotreated diesel (explicitly excluded in the source text).

3. Method principle

After a 700 mL sample is subjected to accelerated storage under specified conditions (100℃, 16 h; or 50℃, 4 weeks), its sediment amount and light transmittance are measured to determine the storage stability of the diesel fuel. The sediment is filtered with glass fiber filter paper.

4. Reagents and materials (purity / preparation)

• 4.1 Petroleum ether: 60～90℃, analytical reagent, tested with sulfuric acid-formaldehyde reagent to be free of aromatic hydrocarbons.
• 4.2 Benzene: analytical reagent.
• 4.3 Anhydrous ethanol: analytical reagent. Benzene and anhydrous ethanol are mixed in a volume ratio of 1:1 to prepare benzene-ethanol solution.
• 4.4 Anhydrous calcium chloride: chemical reagent.
• 4.5 Sulfuric acid: chemical reagent.
• 4.6 Potassium dichromate: chemical reagent, prepared into chromic acid cleaning solution.
• 3.2.1 CY type glass fiber filter paper (Note: complies with enterprise standard QB/BX Y 04-830 of the Glass Fiber Research and Design Institute of the State Bureau of Building Materials Industry, requires confirmation against the source standard (source-text extraction)).
• 3.2.2 Industrial filter paper.
• 3.2.3 Industrial glycerol (industrial glycerin).

5. Apparatus and equipment

• 3.1.1 Test flask: volume 1000 mL, with a five-bulb condenser connected to the test flask by a ground joint (see figure below).
• 3.1.2 Oil bath: with electric heating equipment and stirring device, capable of automatically controlling a constant temperature at 100℃±0.5℃ (or 50℃±0.5℃) during the test. The volume of industrial glycerol (glycerin) filled should be sufficient to completely immerse the round-bottom part of the test flask, and the distance from the flask to the bottom of the oil bath shall not exceed 4 cm.
• 3.1.3 Thermometer: 0～150℃, scale division 0.5℃.
• 3.1.4 Contact thermometer: 0～150℃.
• 3.1.5 Nickel filter crucible: volume 30 mL, with small holes arranged in a concentric circle at the bottom, 91 holes, hole diameter 0.7 (unit not provided in the available source, requires confirmation against the source standard (source-text extraction)). Note: can be obtained from Nanjing Glass Fiber Research and Design Institute.
• 3.1.6 Vacuum pump: displacement 30 L/min, with a vacuum pressure gauge.
• 3.1.7 Suction filter flask: 1000 mL (original text “1[unreadable character])On[unreadable character]” requires confirmation against the source standard (source-text extraction)).
• 3.1.8 Suction filtration pad.
• 3.1.9 Water bath: contains distilled water, used for evaporating solvent.
• 3.1.10 Graduated cylinder: 1000 mL.
• 3.1.11 Conical flask: 100 mL.
• 3.1.12 Wash bottle: 250 or 500 mL, three in total, respectively containing distilled water, petroleum ether, and benzene-ethanol solution.
• 3.1.13 Analytical balance: sensitivity 0.0001 g.
• 3.1.14 Drying oven.
• 3.1.15 72 type photoelectric spectrophotometer.

6. Recommended operating conditions

• Accelerated storage temperature and time: 100℃, 16 h; or 50℃, 4 weeks.
• Oil bath constant temperature: 100℃±0.5℃ (or 50℃±0.5℃).
• Suction filtration vacuum degree: 26.7～40.0 kPa (200～300 mmHg); when there is much sediment, it may be appropriately increased to 60.0～66.7 kPa (450～500 mmHg) (original text “60.[unreadable characters]66.7kPa” requires confirmation against the source standard (source-text extraction)).
• Drying temperature: 105℃±3℃.
• Light transmittance measurement wavelength: 460 nm, 1 cm cuvette, distilled water as reference liquid.

7. Sampling and sample preparation

• 5.1 Sample preparation: filter the sample with industrial filter paper. If the sample contains obvious traces of water, anhydrous calcium chloride should first be added to the sample, shaken for 10～15 min, until there are no obvious traces of water, and then filtered; if the filtered sample is not tested immediately, it may be stored in a dark room.
• 5.2 Washing of test flask: soak a new test flask in chromic acid cleaning solution overnight, pour out the solution, wash off the cleaning solution with tap water, then scrub with benzene-ethanol solution, finally rinse clean with distilled water, dry in an oven, and cool to room temperature before use. A used test flask may be washed directly with tap water without soaking in cleaning solution, rinsed with distilled water, dried in an oven, and set aside for use. The conical flasks used for weighing are also washed in the same way.
• 5.3 Treatment of nickel filter crucible: after carefully cleaning a new nickel filter crucible with detergent powder, wash it three times each with petroleum ether and benzene-ethanol solution in sequence, finally rinse clean with distilled water, dry, and set aside for use.
• 5.4 Several hours before the test, start heating the oil bath; when the temperature rises to about 80℃, start stirring so that the oil bath maintains a constant temperature at 100℃±0.5℃; when performing the 50℃, 4 week test, the oil bath is kept at a constant temperature of 50℃±0.5℃.

8. Analytical procedure

• 6.1 Accurately measure 700 mL of the filtered sample with a graduated cylinder, and pour it into a test flask treated according to the requirements of clause 5.2. Stop stirring the oil bath, place the test flask containing the sample into the constant-temperature oil bath so that the round-bottom part is completely immersed in glycerin. Resume stirring, and at the same time record the test start time.
• 6.2 After accelerated storage at 100℃ for 16 h (for 50℃, 4 weeks), stop stirring and heating, remove the test flask, rinse with tap water while shaking to cool for 5 min, then place in a dark box to cool naturally to room temperature (20～40℃).
• 6.3 The cooled sample is suction-filtered through a nickel filter crucible lined with two layers of CY type glass fiber filter paper into a 1000 mL suction filter flask; during suction filtration, the vacuum degree is controlled at 26.7～40.0 kPa (200～300 mmHg); when there is much sediment, the pressure difference may be appropriately increased to 60.0～66.7 kPa (450～500 mmHg); pour the filtered sample into a clean reagent bottle.
• 6.4 Wash the oil traces on the inner wall of the test flask clean with petroleum ether, three times in total, using about 30 mL of petroleum ether each time, and pour all into the nickel filter crucible for suction filtration. Finally, use a wash bottle containing petroleum ether to spray-wash the inner wall of the nickel filter crucible once or twice until there is no oil.
• 6.5 After washing with petroleum ether, replace with a suction filter flask and directly suction-filter into a pre-weighed conical flask. First use benzene-ethanol solution to wash and dissolve the sediment adhering to the inner wall of the test flask three times, about 20 mL each time, and pour all into the nickel filter crucible for suction filtration. Finally, use a benzene-ethanol wash bottle to wash the inner wall of the nickel filter crucible and the filter paper once or twice until the filter paper is as white as before the test (or although colored, the filtrate is colorless).
• 6.6 After evaporating the benzene-ethanol solution in the conical flask to dryness on a water bath, place it in an oven and dry at 105℃±3℃ for at least half an hour, take it out, cool in a desiccator for 30 min, and weigh. Repeat drying, cooling, and weighing until the difference between two consecutive weighings does not exceed 0.0004 g.
• 6.7 Combine the samples filtered according to clause 6.3 from two replicate determinations, and measure their light transmittance with a 72 type photoelectric spectrophotometer. Use a wavelength of 460 nm, a 1 cm cuvette, and distilled water as reference liquid.

9. Qualitative and quantitative determination and calculation formula

The milligrams of sediment contained in a 100 mL sample, X (mg/100 mL), is calculated according to the following formula:

X = (m2 − m1) / 700 × 100

Where:

• m1 — mass of conical flask, mg;
• m2 — total mass of sediment and conical flask, mg;
• 700 — sample volume, mL.

(The original formula source-text extraction appears as “‘=[unreadable characters](/100 = m2[unreadable character]m”, which has been organized according to context and symbol meaning, requires confirmation against the source standard (source-text extraction).)

10. Precision

In sediment determination, the difference between two replicate results shall not exceed the following values:

11. Report

• Take the arithmetic mean of two replicate results as the determination result of the sample sediment amount.
• Express the light transmittance measured according to clause 6.7 as a percentage (%), as the determination result of the sample light transmittance.

12. Referenced documents

• QB/BX Y 04-830 (CY type glass fiber filter paper, enterprise standard of the Glass Fiber Research and Design Institute of the State Bureau of Building Materials Industry, requires confirmation against the source standard (source-text extraction))
• No other normative referenced documents are provided in the available source.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick reference Q&A