Test Method for Carbon Residue of Heavy Fuel Oil by Electric Furnace

Test Method for Carbon Residue of Heavy Fuel Oil by Electric Furnace

Heavy fuel oil, also known as fuel oil, is a straight-run residue, cracked residue, or a mixture of both obtained from petroleum processing. It is mainly composed of hydrocarbons, with small amounts of sulfur and trace inorganic compounds.

It is a viscous black liquid at ambient temperature and pressure, characterized by high molecular weight and high viscosity. Its specific gravity ranges from 0.90 to 1.07, boiling point from 300 to 350 °C, flash point from 50 to 158 °C, autoignition temperature from 380 to 420 °C, and explosion limit from 1.2% to 6%. It is widely used in power plants, marine propulsion, and industrial heating applications.

Experimental Purpose

In the chemical industry, carbon residue of petroleum products refers to the black carbonaceous residue formed after thermal evaporation and cracking of oil samples in the absence of air, expressed as a mass percentage. It is a key indicator for quality control of petroleum products.Measurement of carbon residue reflects the content of polycyclic aromatic hydrocarbons, resins, asphaltenes, and the refining degree of the oil, helping to evaluate purity, combustion efficiency, and carbon deposition tendency.

Experimental Apparatus

①SD-30011 Carbon Residue Tester by Electric Furnace

② Porcelain crucibles, fine sand, analytical balance with 0.0001 g readability, muffle furnace, and other accessories

Experimental Procedures

① Install and inspect the instrument according to the manual, ensuring it is clean, dry, and free of contamination.

② Calibrate the instrument.

③ Place the clean porcelain crucible in a muffle furnace, ignite at 800 °C ± 20 °C for 1 h, take it out, cool in air for 1–2 min, transfer to a desiccator, cool for 40 min, and weigh to the nearest 0.0002 g.

④ Weigh 1.5 g to 2 g of test sample into the crucible.

⑤ Preheat the electric furnace to 520 °C ± 5 °C, then place the crucible with the sample into the heating well.

⑥ When vapor evolves, ignite it. After combustion, cover the heating well and maintain the temperature at 520 °C ± 5 °C to ignite the residue.

⑦ Remove the crucible, cool in air for 1–2 min, transfer to a desiccator for 40 min, and weigh to the nearest 0.0002 g.

⑧ Repeat the test 1 to 3 times and calculate the results.Experimental Results and Analysis

After calculation and analysis, the carbon residue value of this product is 11.0 %, which meets the standard requirements.