Rethinking Fluorine Analysis in the Era of Petrochemical Circularity

The (petro-)chemical industry is in the midst of a monumental transformation. Crude oil is being replaced by oil derived from end-of-life plastics via chemical recycling. While this transition supports circularity, it also introduces new challenges: the recycled oil exhibits highly variable composition and contains new contaminants, making it a challenging feedstock for refineries.

Among these new contaminants, fluorine poses a significant concern. Currently, combustion ion chromatography (CIC) is the standard method. However, the petrochemical industry has been longing for a more efficient analytical method.

This led to the creation of a novel approach for determining fluorine in oil and other organic substances. The method involves high-temperature combustion of the waste plastic pyrolysis oil (WPPO) sample in the presence of water and subsequent capturing of fluorine in an aqueous solution. This sample pretreatment converts fluorine into a uniform and stable form while removing the complexity of an organic matrix. Gallium is then added to form Ga-fluoride molecules which are detected via High-Resolution-Continuum-Source Molecular Absorption Spectrometry. The instruments used in this process are called ICprep, which features self-optimizing combustion, and contrAA 800 G, which is also suitable for metal analysis and can handle smaller sample volumes than ICP-OES. 

Experiments show that the traditional CIC and the novel “ICprep + contrAA” approach have comparable limits of detection and find the same fluorine concentrations in WPPO samples, while the throughput increases significantly via the new approach