SH/T 0170-1992 Determination of Carbon Residue of Petroleum Products (Electric Furnace 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 title / English title / replacement relationship

• Standard number: SH/T 0170-92
• Chinese title: Determination of Carbon Residue of Petroleum Products (Electric Furnace Method)
• English title: not provided in the available source
• Replacement relationship: replaces ZB E30 011-88
• Other: the source text marks "(20q) year confirmation", suspected to be "(20XX) year confirmation", requires confirmation against the source standard (source-text extraction); approval date 1992-05-20, implementation date 1992-05-20

2. Scope of application and non-applicability

• Applicable to lubricating oils, heavy liquid fuels or other petroleum products.
• Not applicable: not provided in the available source.

3. Method principle

Under specified test conditions, an electric furnace is used to heat and evaporate a test portion of lubricating oil, heavy liquid fuel or other petroleum product, and the mass percentage of the charred black residue (carbon residue) formed after combustion is determined [%(m/m)].

4. Reagents and materials (purity / preparation)

• Fine sand: must be fully ignited beforehand. In the carbon residue test apparatus, fine sand 5～6 mL is placed in the bottom of each cavity holding a crucible.
• Other reagents: not provided in the available source.

5. Apparatus and equipment

• 4.1.1 Electric furnace carbon residue test apparatus: see Figure 1, including two parts: heating equipment and power distribution equipment.
• 4.1.2 High-temperature furnace.
• 4.1.3 Desiccator.
• 4.1.4 Crucible cover: dimensions see Figure 2 (source text "Figure 20", requires confirmation against the source standard (source-text extraction)).
• 4.1.5 Porcelain crucible: dimensions see Figure 3 (source text "Figure 3a", requires confirmation against the source standard (source-text extraction)).
• Figure 1 composition (source text): 1— heating wire (300W); 2— shell; 3— heating wire (100W) (the heating-wire power is unclear in the source transcription and remains unverified); 4— heating wire (1000W); 5— porcelain crucible; 6, 13— steel bath; 7— steel bath cover; 8— crucible cover; 9, 15— heating furnace cover; 10— thermocouple; 11— heating furnace bottom; 12— cavity; 14— thermocouple insertion hole.

6. Recommended operating conditions

• Furnace temperature: before determination, switch on the power supply so that the furnace temperature reaches the specified range 520 ℃ ± 5 ℃, and use an electronic automatic temperature controller to control the furnace temperature.
• Ignition temperature: maintain the furnace temperature at (520±5) ℃ to ignite the residue of the test portion.
• Total time: from the start of heating of the test portion, through combustion of vapors, to the end of ignition of the residue, a total of 30 min is required.
• High-temperature furnace ignition of porcelain crucible: 800 ℃ ± 20 ℃ (source text "800'C 1 20℃", requires confirmation against the source standard (source-text extraction)) ignite 1 h.
• Cold junction constant temperature: 0 ℃ (source text ".℃", requires confirmation against the source standard (source-text extraction)).

7. Sampling and test portion preparation

• 5.3 The test portion in the bottle must not exceed three quarters of the internal volume of the bottle. Shake the test portion uniformly 5 min. Viscous and wax-containing petroleum products must be preheated to 50～60 ℃ before shaking uniformly.
• 5.4 For petroleum products with a water content greater than 0.5%, dehydration must be carried out before determining the carbon residue.
• 5.5 When determining the carbon residue of diesel 10% residue, the test portion should be distilled no fewer than two times according to GB/T 255 or GB/T 6536. Collect the 10% residue of the test portion for use in determining the carbon residue of diesel 10% residue.
• 5.2 Porcelain crucible pretreatment: place a clean porcelain crucible in a high-temperature furnace at 800 ℃ ± 20 ℃ and ignite for 1 h, then remove it, first place it in air for 1～2 min, then transfer it into a desiccator. Cool in the desiccator for about 40 min, then weigh the mass of the porcelain crucible to the nearest 0.0002 g. When a new porcelain crucible is ignited in the high-temperature furnace for the first time, it must be for no less than 2 h, cooled in a desiccator for about 40 min, and then weighed to the nearest 0.0002 g. Then place it again in the high-temperature furnace and ignite for 1 h, and carry out accurate weighing as above; repeat ignition, cooling and weighing in this way until the difference between two consecutive weighings is not greater than 0.0004 g.

8. Analysis procedure

• 5.1 Install the apparatus: install and adjust the electric heating furnace and temperature measurement and control system of the apparatus according to the apparatus instructions. The thermocouple must be calibrated, and the cold junction must be led out with corresponding compensating wires, then the cold junction and the temperature indicating and regulating instrument must be connected with ordinary wires; the cold junction must be inserted into a glass tube containing transformer oil and placed in a vacuum flask containing ice water, so as to ensure the cold junction is kept at a constant temperature of 0 ℃; temperature measurement and control must be corrected using the thermocouple calibration results to ensure accurate measurement and control of the electric furnace temperature.
• 6.1 Weigh a test portion of the following amount into a pre-weighed porcelain crucible, to the nearest 0.01 g:
  • Lubricating oil or diesel 10% residue: 7～8 g
  • Heavy fuel oil: 1.5～2 g
  • Residual oil asphalt: 0.7～1 g
• 6.2 Use tongs to place the porcelain crucible containing the test portion into the cavity of the electric furnace, immediately cover with the crucible cover, and be sure not to tilt the porcelain crucible and cover against the wall. All unused cavities should be covered with steel bath covers. If four cavities are used at the same time, the furnace temperature will drop at this time. When the test portion is heated in the high-temperature furnace to the point where vapor begins to escape from the capillary of the crucible cover, immediately ignite the vapor to make it burn; at the end of combustion, cover the cavity of the high-temperature furnace with the cavity cover. Then maintain the furnace temperature at (520±5) ℃ to ignite the residue of the test portion. From the start of heating of the test portion, through combustion of vapors, to the end of ignition of the residue, a total of 30 min is required.
• 6.3 When ignition of the residue is finished, open the steel bath cover and crucible cover, and immediately remove the porcelain crucible from the electric furnace cavity, place it in air for 1～2 min, transfer it into a desiccator to cool for about 40 min, then weigh the mass of the porcelain crucible and residue to the nearest 0.0002 g.
• Note: When determining the test result, attention must be paid to the condition of the residue inside the porcelain crucible; it should be shiny; otherwise, repeat the determination. If the same residue is still obtained in the second analysis, the determination is considered correct.

9. Qualitative and quantitative determination and calculation formula

The carbon residue X[%(m/m)] of the test portion is calculated according to the following formula:

X = (M₁ / m) × 100

Where:

• M₁—mass of residue (carbon residue), g;
• m— mass of test portion, g.

The calculated result of carbon residue is accurate to 0.1%(m/m).

10. Precision

Repeatability: the difference between two results of repeated determinations by the same operator shall not be greater than the following values.

11. Report

Take the arithmetic mean of two results of repeated determinations as the carbon residue of the test portion.

12. Referenced documents

• GB/T 255 Determination of Distillation Range of Petroleum Products
• GB/T 6536 Determination of Distillation of Petroleum Products

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