Effect of Crude Oil Quality on Properties of Hydrocracked Vacuum Residue and Its Blends with Cutter Stocks to Produce Fuel Oil

Abstract

The production of heavy fuel oil from hydrocracked vacuum residue requires dilution of the residue with cutter stocks to reduce viscosity. The hydrocracked residue obtained from different vacuum residue blends originating from diverse crude oils may have divergent properties and interact with the variant cutter stocks in a dissimilar way leading to changeable values of density, sediment content, and viscosity of the obtained fuel oil. H-Oil hydrocracked vacuum residues (VTBs) obtained from different crude blends (Urals, Siberian Light (LSCO), and Basrah Heavy) were diluted with the high aromatic fluid catalytic cracking (FCC) light cycle, heavy cycle, and slurry oil, and the low aromatic fluid catalytic cracking feed hydrotreater diesel cutter stocks and their densities, sediment content, and viscosity of the mixtures were investigated. Intercriteria analysis evaluation of the data generated in this study was performed. It was found that the densities of the blends H-Oil VTB/cutter stocks deviate from the regular solution behavior because of the presence of attractive and repulsive forces between the molecules of the H-Oil VTB and the cutter stocks. Urals and Basrah Heavy crude oils were found to enhance the attractive forces, while the LSCO increases the repulsive forces between the molecules of H-Oil VTBs and those of the FCC gas oils. The viscosity of the H-Oil VTB obtained during hydrocracking of straight run vacuum residue blend was established to linearly depend on the viscosity of the H-Oil vacuum residue feed blend. The applied equations to predict viscosity of blends containing straight run and hydrocracked vacuum residues and cutter stocks proved their good prediction ability with an average relative absolute deviation (%AAD) of 8.8%. While the viscosity was found possible to predict, the sediment content of the blends H-Oil VTBs/cutter stocks was recalcitrant to forecast.

Prediction of Viscosity of Blends of Heavy Oils with Diluents by Empirical Correlations and Artificial Neural Network

“…Kolev et al 41 (2023) 1), a new additional correlation was developed in this work using the computer algebra system (CAS) Maple and NLPSolve with Modified Newton Iterative Method, as described in ref 20 and employing the data in Tables 1 and 2, as well as Table S1 in the Supporting Information. It has the form of eq 31.…”

“…The data in Table 4 indicate an excellent fit of eq 30 to the experimental data of viscosity measurements of studied 17 heavy oil blends. This finding is consistent with the results reported in refs 3, 7, 11, 38, and 46−50, as well as in our recent research, 41 and suggests that the effect of diluent concentration variation on viscosity is similar to that of the temperature variation showing exponential dependence on temperature as reported in refs 49−52. Thus, the form of the correlation predicting the viscosity of the blend of heavy oils with diluents can be similar to that predicting the viscosity as a function of temperature.…”

“…Ssebadduka et al reported a % AAD value of 0.8272 for the ANN model versus a % AAD value of 3.86% for the best empirical correlation when the viscosity of blends of bitumen with light oil was investigated. Several empirical models to predict viscosity of oil blends have appeared in the literature, ,,− which will be discussed later in this work. Hernández et al .…”

Optimized Operation of Fluidized Catalytic Cracking Considering CO2 Fixation and Carbon Pricing

“…Second, achieving high operational efficiency and reducing environmental impact are paramount objectives. The FCC slurry is a byproduct of the FCC unit, which is commonly utilized as carbonaceous fuel oil in boilers because of its distinctive properties [11].…”

“…However, the slurry generated from FCC units yields low-value liquid products and high quantities of petroleum coke, resulting in adverse atmospheric pollution and diminished economic benefits [11]. To effectively mitigate the environmental impact of the FCC unit, alternative applications for the slurry must be explored beyond its current usage as a fuel.…”