This standard specifies the tubular oven method for determining the sulphur content in dark petroleum products.
This standard is applicable to the dark petroleum products with sulphur content greater than 0.1% (m/m) such as lubricating oil, heavy petroleum products, crude oil, petroleum coke, paraffin wax and sulphur-containing additives, etc.
This standard is not applicable to additives containing metal, phosphorus and chlorine as well as the lubricating oil with such additives.
2 Normative References
GB 1790 Medicinal Vaseline
GB 6682 Water for Analytical Laboratory Use - Specification
SY 2001 Sampling Method of Solid and Semi-solid Petroleum Products
SY 2871 Method for Inspection of Petroleum Coke
SY 3302 Technical Provisions for the Acceptance of Porcelain Containers Used for Petroleum Products Test
3 Method Summary
When the sample is burning in airflow, the generated sulphurous acid anhydride is absorbed by hydrogen peroxide and sulfuric acid solution and the generated sulfuric acid will be titrated by standard sodium hydroxide volumetric solution.
4 Apparatus and Material
4.1 Apparatus
4.1.1 Tubular resistance oven: horizontal type, in a length no less than 130mm, the diameter of the oven chamber is about 22mm. A thermostat controller which ensures the temperature to be heated to 900~950 ℃ and a nickel chromium - nickel silicon (nickel chromium - nickel aluminum) thermocouple are included.
4.1.2 Porcelain boat: used for holding the sample for combustion and in accordance with the requirements for boat shaped porcelain boat used to determine the sulphur as specified in SY 3302. The new porcelain boat shall be combusted for 30min at 900~950 ℃ before use and then cool it at room temperature for standby.
4.1.3 Quartz tube: with quartz elbow (see Figure 1) and may be replaced by porcelain tube.
4.1.4 Flowmeter: used to measure the flow velocity of the supply air and with a measuring range of 0~800mL/min.
