Kerosene & Jet Fuel

TAN Determination in Fuel as per ASTM D 3242

The acid and base number may be determined by photometric titration with color indication of the equivalence point. Metrohm offers the Optrode, a new sensor for photometric titration. Its glass shaft makes the Optrode 100% solvent resistant. Another key advantage of the Optrode is its capacity for automation.

Link to App Note TAN in Jet Fuel ASTM D3242

Product Link: Titrando or Titrotherm Landing Page

Hydrogen Sulfide and Mercaptan Determination as per ASTM D3227

Sulfur compounds in petroleum products not only have an unpleasant odor, they are also environmentally damaging and promote corrosion. To determine hydrogen sulfide and mercaptans in liquid hydrocarbons (gasoline, kerosene, naphtha, and similar distillates), the sample is titrated with silver nitrate solution, whereby silver sulfide (Ag2S) and silver mercaptide are produced. Two pronounced potential jumps occur. The first endpoint corresponds to hydrogen sulfide (H2S), the second to the mercaptans. The indicator electrode for the titration is the Ag-Titrode with Ag2S coating. Since both H2S and mercaptans are oxidized by atmospheric oxygen and the arising oxidation products cannot be determined titrimetrically, the sample must be run in a nitrogen atmosphere.

Application Links: AN-T-152; AN-T-028, AB135

Product Page: Titrando

Moisture Determination in Fuels

Fuels contain mercaptans which are oxidized by iodine and thus falsely indicate a water content that is too high. This problem is solved by adding N-ethylmaleimide, which causes the SH groups of the mercaptan to add to the double bond of the N-ethylmaleimide. 

Water content in fuels is usually determined by coulometric titration. With volumetric titration, a solubility promoter must be added to the methanol.

Application Link: An-K-014

Product Link: KF Titrando

Organically Bound Chlorine in Fuels by Combustion IC

The burning of sulfur-containing fuels leads to the emission of air-polluting sulfur oxides into the atmosphere. Furthermore, high sulfur concentrations have an adverse effect on the ease of ignition of fuels and their stability during storage. Halogen concentrations in the refinery process must also be analyzed due to the corrosion risk.

As a result, a fast and reliable method for determining the halogen and sulfur contents is required. Combustion IC enables the sulfur and halogen content in combustible solids, liquids, and gases to be determined by combining combustion digestion (pyrolysis) with subsequent ion chromatography. It can be fully automated and excels in its high sample throughput, large measuring range, and excellent precision and accuracy. 

<< AN-CIC-013>> & << AN-CIC-018 >>; <<TA021>>& << TA041>>