Standards Development

Scope

This test method is a standard procedure for the determination of group type totals of aromatic, polyaromatic, and FAME content in diesel fuel using gas chromatography and vacuum ultraviolet detection (GC-VUV).

Polyaromatic totals are the result of the summation of diaromatic and tri-plus aromatic group types. Aromatics are the summation of monoaromatic and polyaromatic group types. FAME content is the result of summation of individual fatty acid methyl esters.

This test method is applicable for renewable diesel fuels from hydrotreated vegetable oil (HVO) or animal fat, gas to liquid (GTL) diesel, light cycle oil, wide boiling range aromatic solvents and biodiesel blends.

Concentrations of compound classes and certain individual compounds are determined by mass fraction % (m/m) or volume fraction % (V/V). The concentration ranges for which the method is applicable are given in Table 1.

NOTE For the purposes of this document, the terms “% (m/m)” and “% (V/V)” are used to represent respectively the mass fraction and the volume fraction, respectively.

This test method has been tested for diesel according EN 590 [1] and paraffinic diesel fuel EN 15940 [2]

Diesel fuel containing biodiesel, (FAME, that is, fatty acid methyl esters including soy methyl esters, rapeseed methylesters, tallow methylesters and canola methylesters) can be analyzed by this test method. The FAME component completely elutes from the analytical column independent of feedstock.

Individual hydrocarbon components are not reported by this test method; however, any individual component determinations are included in the appropriate summation of the totals of aromatic, polyaromatic, monoaromatic, diaromatic, tri-plus aromatic, or FAME groups.

This test method may apply to other hydrocarbon streams boiling between heptane (98 °C) and triacontane (450 °C), but has not been extensively tested for such applications. 

Table 1 —Application ranges

Compound or group      Units   Concentration range
Total Aromatics          % (V/V)    0,088 to 77,000
Total Aromatics          % (m/m)   0,104 to 79,451
MonoAromatics         % (m/m)   0,080 to 67,848
Diaromatics               % (m/m)   0,027 to 34,812
Tri-plus aromatics      % (m/m)   0,82 to 6,77
PAH                           % (m/m)   0,028 to 41,586
FAME                        % (V/V)    1,08 to 21,67

Individual hydrocarbon components are typically not baseline-separated by the procedure described in this test method. The coelutions are resolved at the detector using VUV absorbance spectra (Annex A) and deconvolution algorithms.

Purpose

An alternative method for regulatory compliance, commercial commodity exchange, quality evaluation, performance and process control is provided. The technique is versatile and multi-purpose offering routine diesel and biodiesel blend parameter determinations. The determination of class group composition of compression ignition fuels fuels is useful for evaluating quality and expected performance, as well as compliance with various governmental regulations.

European users (Contract laboratories as well as company laboratories) of GC-VUV are requesting CEN test method standard to cover diesel using methodology similar to ASTM D8368.