GB/T 388-1964 Determination of sulfur content in petroleum products (oxygen bomb method)

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 name / English name / replacement relationship

• Standard number: GB 388-64
• Chinese full name: Determination of sulfur content in petroleum products (oxygen bomb method)
• English name: not provided in the available source
• Replacement relationship: From the date of implementation of this standard, the former ministerial standard SYB 2605-54 is void.
• Issuing body: Issued by the National Bureau of Standards and Metrology
• Implementation date: implemented on 1965 year 7 month 1 day

2. Scope of application and non-applicability

• Applicable to the determination of sulfur content in heavy petroleum products such as lubricating oils and heavy fuel oils.
• Not applicable: not provided in the available source.

3. Method principle

The sample is burned in an oxygen bomb, washed out with distilled water, and then precipitated with barium chloride to determine the sulfur content in the sample.

4. Reagents and materials (purity / preparation)

• Hydrochloric acid: chemically pure.
• Barium chloride: analytically pure, prepared as an aqueous solution of 10%.
• Silver nitrate: analytically pure, prepared as an aqueous solution of 3%.
• Methyl orange: prepared as an aqueous solution of 0.02%.
• 95% ethanol: chemically pure.
• Diethyl ether: chemically pure.
• Light gasoline (refined light gasoline, used for washing).
• Distilled water.
• Bottled compressed oxygen.
• Ignition wire: iron wire, nickel alloy wire, or copper wire, with a diameter not greater than 0.2 millimeters, cut into equal-length segments of length 60~120 millimeters (depending on the construction of the internal fittings of the oxygen bomb and the ignition method).
• Quantitative filter paper: slow speed, diameter 70~90 millimeters.
• Ashless filter paper (used for filtering barium sulfate precipitate).

5. Instruments and equipment

• Oxygen bomb for calorimeter and its accessories (see figure): the capacity of the oxygen bomb is 250~500 milliliters. Labels in the figure: 1— cylinder body; 2— protrusion; 3— male thread; 4— bomb cover; 5— conductive pin; 6, 7— needle valves; 8— gas inlet pipe; 9— small ring; 10— groove.
• Porcelain crucible: low form, size 4.
• Water bath for heating.
• Electric furnace.
• Beaker: 300~500 milliliters.
• Glass funnel: 60° angle, diameter 50~65 millimeters.
• Wash bottle: 500 or 1000 milliliters.
• Oxygen pressure gauge: operating pressure is 30–40 kilograms per square centimeter, indication range is 60–75 kilograms per square centimeter. When the bomb is filled with oxygen, it is used to indicate the pressure in the oxygen bomb. When using an oxygen cylinder with an oxygen pressure reducing valve, this pressure gauge should be installed on the oxygen pressure reducing valve. If there is no pressure reducing valve, a safety valve should be installed on the pressure gauge bracket, with a specified pressure of 40 kilograms per square centimeter.
• High-temperature furnace (controllable at 800±20°C).
• Drying oven.
• Desiccator.
• Double-arm wrench, wrench.
• Base (for fixing the oxygen bomb).

6. Recommended operating conditions

• Ignition voltage: ignite the sample by passing a voltage of 12~15 volts through the ignition wire. To observe ignition, it is best to connect a control lamp into the circuit.
• Oxygen filling pressure of the oxygen bomb: bring it to a pressure of 30~35 kilograms per square centimeter; if a bomb with a smaller capacity is used, a higher pressure is used.
• If carbonaceous deposits exist on the inner surface or accessories of the bomb, the test is considered invalid and should be repeated. In this case, when filling the bomb with oxygen, the pressure should be 5 kilograms per square centimeter higher than the previous time.
• The oxygen bomb, pressure gauge, and oxygen connecting pipe shall be subjected to a hydrostatic pressure check no less than once a year. At this time, the oxygen bomb should be tested at a pressure of 100 kilograms per square centimeter.
• Precipitate heating: place the beaker in a boiling water bath and heat for 2 hours, then let stand at 60–70°C for 2 hours, let stand at room temperature for 20–30 minutes, or let the beaker stand at room temperature for 12~16 hours.
• Calcination temperature: calcine and ash in a high-temperature furnace at 800±20°C until the precipitate is completely white.
• Cooling: take out the crucible, cool in air for 5 minutes, then cool in a desiccator for about 30 minutes, and weigh to the nearest 0.0002 grams. Then move it into the high-temperature furnace and calcine for 15 minutes, repeating the calcination, cooling, and weighing until the difference between consecutive weighings is not greater than 0.0004 grams.

7. Sampling and sample preparation

• Take 0.6~0.8 grams of sample and place it in a pre-weighed small cup, weighing to the nearest 0.0002 grams.
• Place this cup containing the sample into the ring inside the bomb, and insert the middle part of the ignition wire into the cup; the two ends of the wire should be fixed respectively to the conductive pin and the tube.

8. Analysis procedure

1. Check whether the connections are tight; if physical stress needs to be increased for tight connection and enhanced sealing, the gasket should be replaced.
2. Before the test, carefully wash the interior of the oxygen bomb and the grooves in the bomb cover with refined light gasoline, 95% ethanol, or diethyl ether, then dry and wash with hot distilled water.
3. Place the oxygen bomb in the base, and inject 20 milliliters of distilled water into the bottom of the oxygen bomb.
4. Take 0.6–0.8 grams of sample and place it in a pre-weighed small cup, weighing to the nearest 0.0002 grams. Place this cup containing the sample into the ring inside the bomb, and insert the middle part of the ignition wire into the cup; the two ends of the wire should be fixed respectively to the conductive pin and the tube. Screw on the bomb cover by hand, then tighten it with a double-arm wrench. Then connect it to the oxygen cylinder through the three-way pipe of the pressure gauge, and introduce oxygen into the bomb from the pipe of the inlet valve; care should be taken not to use a strong airflow, so as not to blow the sample. At this time, do not expel the air in the bomb; bring it to a pressure of 30–35 kilograms per square centimeter; if a bomb with a smaller capacity is used, a higher pressure is used.
5. After the bomb is filled with oxygen, disconnect the bomb from the oxygen cylinder, immerse it in water, and check whether it is sealed. Then place it in a water bath, connect the power supply wires to the conductive pin and one valve, and pass current. The heating of the cylinder body of the oxygen bomb is taken as a sign of combustion; leave the bomb in the water bath for 10 minutes to cool it. Then take it out of the water bath, wipe it dry, place it in the base fixed on the table, and carefully open the exhaust valve so that the time for the pressure in the bomb to drop to atmospheric pressure is not less than 5 minutes. Use a wrench to unscrew the bomb cover, and carefully check whether there are splashed sample or carbonaceous deposits on the inner surfaces of the small cup, bomb shell, and bomb cover and on the water surface.
   • If carbonaceous deposits exist on the inner surface or accessories of the bomb, the test is considered invalid and should be repeated. In this case, when filling the bomb with oxygen, the pressure should be 5 kilograms per square centimeter higher than the previous time.
   • If there are no deposits, carefully wash all parts inside the bomb, the small cup, and the valves with hot distilled water.
6. Collect all the washing water in a beaker; its volume should not exceed 350 milliliters, and care should be taken not to splash the washing water so as to avoid loss of liquid. Then filter the washing water through filter paper to remove possible mechanical impurities (slag particles and others). Then carefully wash the filter paper with distilled water, and add the washing water to the filtrate.
7. Add 2~3 drops of methyl orange solution to the filtrate, and pour in hydrochloric acid until a weakly acidic reaction is obtained; then heat this solution to nearly boiling. Stir the hot solution with a glass rod while adding 10 milliliters of hot barium chloride solution dropwise to form barium sulfate precipitate. Then place the beaker containing this solution on a boiling water bath. After the solution becomes clear, add a few more drops of barium chloride solution to this solution to check whether the barium sulfate precipitate is complete. If no turbidity occurs, the precipitation is considered complete. Otherwise, add more hot barium chloride solution until no turbidity appears.
8. Place the beaker in a boiling water bath and heat for 2 hours, then let stand at 60–70°C for 2 hours, let stand at room temperature for 20–30 minutes, or let the beaker stand at room temperature for 12~16 hours.
9. Filter the liquid that has been allowed to stand in the beaker through ashless filter paper, letting the liquid flow along a glass rod onto the filter paper; first wash the precipitate in the beaker by decantation with hot distilled water, then wash it on the filter paper until chloride ions are completely removed.
   • Note: Take 3–5 milliliters from the final washing liquid, place it in a test tube, and add 3–4 drops of silver nitrate solution to determine whether chloride ions have been completely removed; if no silver chloride precipitate appears, washing is considered complete.
10. Leave the wet filter paper with the barium sulfate precipitate in the funnel, place it in a drying oven to dry slightly, then take the filter paper out of the funnel, fold it into four folds, place it in a porcelain crucible weighed to constant weight, and press the filter paper slightly tight in the crucible. Carefully preheat the crucible (on an electric furnace or gas burner), then dry the filter paper, and then, under conditions without ignition, calcine and ash this crucible containing the precipitate in a high-temperature furnace at 800±20°C until the precipitate is completely white. Take out the crucible, cool in air for 5 minutes, then cool in a desiccator for about 30 minutes, and weigh to the nearest 0.0002 grams. Then move it into the high-temperature furnace and calcine for 15 minutes; repeat the calcination, cooling, and weighing in this way until the difference between consecutive weighings is not greater than 0.0004 grams.

9. Qualitative and quantitative determination and calculation formula

The sulfur content X (%) in the sample is calculated according to formula (1):

X = 32.06 × G₁ × 100 / (233.42 × G)

Where:

• 32.06—— atomic weight of sulfur;
• G₁——weight of barium sulfate precipitate, grams;
• 233.42—— molecular weight of barium sulfate;
• G—— sample weight, grams.

If sulfate is present in the reagents used for analysis, a blank test shall be carried out on these reagents. When the amounts of water, hydrochloric acid, and barium chloride solution used are the same as those used in analyzing the sample, the sulfur content X₁ (%) in the sample is calculated according to formula (2):

X₁ = 13.78 × (G₂ - G₁) / G

Where:

• G₂——weight of barium sulfate precipitate obtained when analyzing the sample, grams;
• G₁——weight of barium sulfate precipitate obtained in the blank test, grams;
• G—— sample weight, grams.

(Note: In the original text, formula (2) source-text extraction is displayed as "X:=-13.78×(G:-G1)", in which the symbols and denominator contain source-text extraction noise, requires confirmation against the source standard (source-text extraction).)

10. Precision

The difference between the results of two parallel determinations shall not exceed the following values:

Take the arithmetic mean of the results of two parallel determinations as the sulfur content of the sample.

11. Report

not provided in the available source.

12. Referenced documents

not 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 Q&A reference