Tests sur l’essence et les distillats légers

BS EN 228 specifies the requirements and test methods for unleaded motor gasoline sold in the UK. Two grades of unleaded petrol are specified, one with a maximum oxygen content of 3.7 % (m/m), corresponding to a maximum ethanol* content of 10.0 % (v/v) and another with a maximum oxygen content of 2.7 % (m/m), corresponding to a maximum ethanol content of 5.0 % (v/v). * refers to ethanol derived from a biomass (bioethanol) and conforming to BS EN 15376, Ethanol as a blending component for petrol - Requirements and test methods. The INEOS Laboratory can test petrol product with an ethanol content from 0 to 5% to BS EN 228. The INEOS laboarory can also test petrol components.

Gas chromatography (GC) method for ethanol, to measure higher alcohols (propan-1-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol (isobutanol), 2-methylbutan-1-ol, and 3-methylbutan-1-ol) from 0.1 to 2.5% (m/m); methanol from 0.1 to 3% (m/m) and other components from 0.1 to 2% (m/m). BS EN 15376 (Ethanol as a blending component for petrol) sets a limit for the combined result of ethanol + higher alcohols, not the ethanol content itself. Due to possible interferences, the method is not applicable to denatured ethanol samples. Water, will not be detected by this method and needs to be considered separately in the calculations.

This test method covers the determination of the corrosiveness to silver of automotive gasoline. A polished silver strip is immersed in the sample and heated. The level of tarnish on the strip is assessed and rated as a number from 0 - 4.

This standard specifies a method for the determination of the corrosiveness to copper of liquid petroleum products and certain solvents. Volatile products, having a maximum vapour pressure of 124 kPa at 37.8°C are included.

A UKAS ISO17025 accredited method for the determination of the density of crude petroleum and related products within the range 600 to 1100 kg/m3 by oscillating U-tube density meter. Suitable for liquids of any vapour pressure, that can be kept a single phase with light end evaporation. The density value measured at one temperature can be converted to the density at another temperature using petroleum measurement tables.

Determination of the distillation characteristics of light and middle distillates derived from petroleum and having initial boiling points above 0°C and end point below approximately 400°C.

Determination of water in ethanol to be used in gasoline blends, for water content in the range 0.039 to 0.500% (m/m).

Procedure 1 provides a rapid pass/fail method for estimating the presence of suspended free water and solid particulate contamination in distillate fuels having distillation end points below 400°C and an ASTM colour of 5 or less.

Determination of the existent gum content of aviation fuels, gum content of motor gasoline or other volatile distillates in their finished form. For non-aviation fuels, a procedure for the determination of the heptane-insoluble portion of the residue is also described.

Method for the determination of saturated, olefinic and aromatic hydrocarbons in motor gasoline (petrol) and ethanol (E85) automotive fuel by gas chromatography (GC) Additionally, the benzene content, oxygenate compounds and the total oxygen content can be determined.

Fluorescent indicator adsorption method for the determination of hydrocarbon types over the concentration ranges: 5 to 99% (v/v) aromatic hydrocarbons; 0.3 to 55% (v/v) olefinic hydrocarbons; 1 to 95% (v/v) saturated hydrocarbons in petroleum fractions that distil below 315°C. May be applicable to concentrations outside these ranges, but the precision has not been determined. This test method is for use with full boiling range products, however precision statement does not apply to fractions with narrow boiling ranges near the 315°C limit, which will give unreliable results. Samples containing dark coloured components that interfere with reading the chromatographic bands cannot be analysed. Oxygenated blending components are not detected, but do not interfere with the determination of the hydrocarbon types at normal concentrations.

This test method is to quantify viable aerobic microorganisms present as contaminants in middle distillate fuels, gasolines, biofuel blends and residual fuels and associated water. The procedure quantitatively assess the viable aerobic microbial content as microbial colony forming units (cfu) and determines whether the microbial contamination in samples drawn from fuel tanks and systems is absent or present at light, moderate and heavy levels.

Motor octane number (MON) of motor gasoline (petrol) using a standard single cylinder, four stroke cycle, variable compression ratio, carburetted, CFR engine, operated at constant speed. MON is a measure of the knock characteristics of the fuel under severe operating conditions. This method covers entire scale range from 0 MON to 120 MON, but the working range is 40 MON to 120 MON. Typical motor fuel testing is in the range of 80 MON to 90 MON. This method covers gasoline containing up to 25% (V/V) ethanol.

This method measures the stability of motor gasoline under accelerated oxidation conditions. The result is an indication of gum formation in the gasoline over time, but cannot account for different storage conditions. The method is not suitable for gasoline components.

Determination of water in petroleum products boiling below 390°C. It covers the mass fraction range 0.003% (m/m) to 0.100% (m/m). It is not applicable to products containing ketones or residual fuel oils. It may be applicable to lubricating base oils; however the precision has not been established for these materials.

Method for the determination of saturated, olefinic and aromatic hydrocarbons in motor gasoline (petrol) and ethanol (E85) automotive fuel by gas chromatography (GC) Additionally, the benzene content, oxygenate compounds and the total oxygen content can be determined.

Research octane number (RON) of motor gasoline (petrol) using a standard single cylinder, four stroke cycle, variable compression ratio, carburetted, CFR engine, operated at constant speed. RON is a measure of the knock characteristics of the fuel under mild operating conditions. This method covers entire scale range from 0 RON to 120 RON, but the working range is 40 RON to 120 RON. Typical motor fuel testing is in the range of 88 RON to 101 RON. This method covers gasoline containing up to 25% (V/V) ethanol. This can be used for oxygenate-containing fuels containing up to 4.0 % (m/m) oxygen.

Test method for the determination of sulphur content in the range 3 to 500 mg/kg by ultraviolet (UV) fluorescence. This method is suitable for motor gasoline (petrol) containing up to 3.7% (m/m) oxygen - including those blended with ethanol up to about 10% (BS EN 228) and diesel fuels, including those containing up to about 30% (V/V) fatty acid methyl ester (FAME), (BS EN590) and other products and feed streams. Halogens >3500 mg/kg interfere with this measurement. For diesel containing cetane improver, the sample should be checked for nitrogen interference. The sulphur content is measured by pyrolysis of the sample followed by detection by UV fluorescence. For sulphur content <3ppm, ASTM D5453 is used.

Determination of the total pressure exerted in a vacuum by volatile, low viscosity petroleum products, components, and feedstocks containing air. A dry vapour pressure equivalent (DVPE) can be calculated from the air containing vapour pressure (ASVP) measurement. The conditions used in the test described in this standard are a vapour to liquid ratio of 4:1 and a test temperature of 37.8°C. This standard has precision for both 1 l and 250 ml sample containers. This method described is suitable for testing air-saturated samples that exert an air-saturated vapour pressure of between 9.0 and 150.0 kPa at 37.8°C. This document is applicable to fuels containing oxygenated compounds.