Determination of Naphthenic Acids Concentration and Total Acidity and Investigation of the Impact of Their Nanoemulsions Structure on the Design of Oil Refinery

Naphthenic acids and TAN are one of the ever-increasing crucial problems in oil, shale oil and sand oil industry and also environment protection. Furtherer, they increases the corrosion of some parts of a refinery and transport pipelines and also can create nanoemulsions and make complicated the refining process especially in desalters. To prevent these problems it is important to first obtain a basic knowledge about the distribution/structure of Naphthenic acids and their relationship with TAN. This might be useful for troubleshooting of probable problems when the feed of refinery changes. In the present work, two fractions of Soroush-Norowz blend crude oil were analyzed to obtain their naphthenic acids concentration and TAN. At the second step, these two fractions were physically to sub-fractions by 25 °C intervals. After that, their naphthenic acids concentration and TAN was determined to obtain a detailed view about the distribution of naphthenic acids and TAN of each sub-fraction. In addition, the obtained results gave us a view point about the overall molecular structure of naphthenic acids presents in the Soroush-Norowz blend crude oil and can guide us toward better understanding of chemical structure of mentioned crude oil and consequently better designing of oil refinery in order to minimize the corrosion and also upper the performance of some special units such as desalters.