Modeling of crystallization processes of aviation fuel with different content of aromatic hydrocarbons

The influence of additives of some organic substances on the crystallization onset temperatures of kerosene fractions (KF) obtained from crude oil (straight-run or SRKF) and in the process of catalytic cracking of heavy oil residues (HKF) is studied by the method of thermodynamic modeling. Normal paraffins CnH2n+2 (n = 9, 11, 16) are used as additives to the KFs, and m-ethylbutylbenzene is used as an aromatic hydrocarbon. It is shown that using the UNIFAC and UNIQUAC models, one can reproduce the experimental data presented in publications and indicating that the addition of normal paraffins to HKF noticeably increases the freezing point when n is 11 and greater. For SRKF, a similar increase occurs starting from n = 16. According to the calculation results, the addition of m-ethylbutylbenzene practically does not affect the crystallization onset temperature.