(487al) Hydrogen Solubility and Mass Transfer Coefficient in Vacuum Residue Under Hydrocracking Conditions

Crude oil is the most common source of energy in the world; it has been used as a source of liquid fuels for more than a century. In the last years, the world's reserves of light crude oil have declined while the proportion of heavy oil reserves in some oil producing countries such as Canada, Venezuela and Mexico have increased; this heavy oil contains a lower amount of distillates and more residues. This new scenario in the oil producing field has led the petroleum refining industry into developing new technologies for heavy oil hydroprocessing. Therefore, maximizing products yield from various processes and valorization of residues is attention key task for refiners.

In the residue hydrotreating process, hydrogenation and various hydrogenolysis reactions consume hydrogen resulting in the reduction of the molecular weight of the starting material, the increase of hydrogen to carbon ratio, hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodemetallization (HDM). Therefore, not only the improved product selectivity is one characteristic of hydroprocessing but also we can obtain cleaner fuel specification with small coke yield. For upgrading residue processing, the most common type of reactors used are three phase ebullated bed and slurry reactors operated under high pressure and temperature. In this process the main reaction is thermal cracking, hydrogen and catalyst are used to inhibit the coke formation by hydrogenating the coke precursors and removing the heteroatoms. The design, modeling and scale-up of ebullated bed and slurry reactors for residue hydrotreating require precise knowledge of the kinetics and hydrodynamics, as well as heat and mass transfer characteristics of the gas-liquid-solid system used. Literature studies of these design criteria under hydrocracking conditions are very scarce especially on hydrodynamic and mass transfer.

Applications

? Residue hydroprocessing converts low value heavy residue in high valuable clean fuels;

? It is an alternative for the refiners in the new era of heavy crude;

? The crude oil feed in the refinery is going to be almost a hundred percent converted into useful products.

Technical Approach

? Measure the solubility and gas-liquid mass transfer coefficients in a stirred tank reactor operating under hydrocracking conditions (high pressure and high temperature);

? Statistically assess the effect of various operating variables (pressure, temperature, mixing speed, catalyst loading, etc.) on these parameters;

? Develop novel correlations for predicting the solubility and mass transfer parameters