Studying Patterns of Synthesis of Low Freezing Distillates from Atmospheric Gasoil by Means of Mathematical Modelling

Background: Physical-chemical regularities of diesel fuel catalytic hydrodewaxing process were studied. Objective: The objective of this work is to develop mathematical model of hydrodewaxing for numerical studying patterns of the process. Methods: The method of mathematical modelling was used in the current research. Results: In summer regime, when the required target product is summer grade diesel fuel, the temperature in the reactor should be at the lowest value of 345 ºC in order to prevent catalyst deactivation and expand its service life, the feedstock flow rate should be the highest at 290 m3/h to increase the productivity of the plant. In winter regime, when high conversion of high molecular weight n-paraffins is needed to achieve required loetemperature characteristics, the process is to be carried out at high temperature. So, the temperature 355 ºC is optimal for studied feedstock composition as it allows achieving required selectivity towards high molecular weight n-paraffins. The feedstock flow rate is to be maintained at low level (210 m3/h) to provide high residence time in the reactor. Conclusion: On the base of thermodynamic analysis, which was performed using the method of quantum chemistry, the influence of hydrocarbon structure and length of the carbon chain on the reactiveness was investigated. By solving the reverse kinetic problem, using the experimental data from the industrial plant, kinetic dependences of stages of diesel fuel synthesis were established. Using the developed model, the effect of process parameters on the composition of the product was investigated.