Understanding “Fouling” in Extremely Complex Petroleum Mixtures

“Fouling”, the unwanted deposition of solids, causes significant operational difficulties in petroleum producing and processing industries and is considered a billion dollar problem. There are two routes of petroleum fouling: physical fouling, where material of low-solubility precipitates, and chemical fouling, where a chemical reaction produces insoluble material, often on the surface of heat exchangers. By implementing laboratory-scale experimental simulations of the industrial process using a petroleum derived light crude oil fraction, it is shown that chemical fouling proceeds via multistep pathways involving dehydrogenation and radical formation reactions on PAHs, resulting in the formation of carbonaceous deposits.