Analysing total fluorine, chlorine, and sulphur in aromatic hydrocarbons and petroleum products by automated C-IC analysis

The amount of fluorine, chlorine, and sulphur present in aromatic hydrocarbon matrices can contribute to emissions, be harmful to many catalytic chemical processes and may even lead to corrosion. Refining and petrochemical companies need to monitor these elements to determine whether their refining process optimisation measures are effective. The ASTM D7359 and UOP 1001 test methods cover the determination of these analytes in aromatic hydrocarbons and their mixtures by combustion IC.

Combustion IC enables the determination of speciated halides and sulphur compounds by a single analysis. TE Instruments have developed a fully automated, extremely compact sample preparation system covering the pyrohydrolytic combustion, fraction collection, and sample injection towards the IC. The XPREP C-IC is the only configuration capable of introducing samples both via direct injection (liquids module) and boat-inlet (boat module) into a horizontal furnace.

Sample introduction by direct injection has multiple benefits compared to boat-inlet. XPREP C-IC is temperature controlled (500 °C) and can dispense samples up to 1 µL p/s by automated syringe. This means that there is a controlled evaporation of liquid sample into the gas phase, transferred by the inert carrier gas into the combustion zone. Controlled sample combustion also prevents soot or coke formation, a result of incomplete combustion. This also improves the repeatability for automated C-IC analysis and eliminates the need for a boat program, decreases time of analysis. XPREP C-IC enables a larger sample volume up to 100 µL. This Improves IC-detection limit compared with boat introduction (limited sample volume). Moreover, multiple injections from the same sample can be introduced, combusted and absorbed for a single IC analysis

The liquids module is specifically designed for the direct injection of liquid samples with a final boiling point up to 420 °C, which corresponds with the boiling ranges of ASTM D7359 and UOP 1001. Test methods focusing on the analysis of total sulphur (e.g. ASTM D7183) and total chloride (e.g. ASTM D7457) in aromatic hydrocarbons, stipulate direct injection as a viable sample introduction technique.

Switching between introduction modules and sampling systems can be achieved within minutes, which gives the operator a high degree of flexibility in the analysis of different matrices. XPREP C-IC is the ideal solution to cover the increasing demand for simultaneous analysis of corrosive halogens and sulfur in a wide range of sample matrices, like organic solvents, fuels, and polymers.

The XPREP C-IC has a small footprint; it is half the size compared to existing C-IC configurations. It features fully automated sample introduction by means of robust sampling systems, oxidative pyrohydrolitic combustion of solids, liquids, gas, and LPG, a 65 position fraction collection unit for immediate or later analysis, an integrated sampling system which fully controls the dosing of reagents and performs speciated halide and sulphur analysis by any renowned IC.

TE Instruments will be exhibiting at PEFTEC, in Rotterdam from 22- 23 May 2019, where you can see the XPREP C-IC for yourself and get advice on how combustion IC could enhance your productivity. Application note are also available via TE Instruments’ website.