This work presents a model to predict the behavior of velocity, gas holdup and local concentration fields in a pseudo-two-phase gas-liquid column reactor applied for thermal hydrocracking of petroleum heavy fractions. The model is based on the momentum and mass balances for the system, using an Eulerian-Eulerian approach. Using the k-epsilon model,fluid dynamics accounts for both laminar and turbulent flows, with discrete small bubbles (hydrogen) flowing in a continuous pseudohomogeneous liquid phase (oil and catalyst particles). The petroleum is assumed to be a mixture of pseudocomponents, grouped by similar chemical structural properties, and the thermal hydrocracking is taken into account using a kinetic network based on these pseudocomponents.

A model is presented for the description of the concentration behavior of organometallic and sulfurated compounds in hydrodemetallation and hydrodesulfurization catalytic processes, where catalyst effectiveness decreases with time. Due to the complexity of the mixture, an approach based on pseudocomponents was adopted. The system is modeled as an isothermal tubular reactor with axial dispersion, where the gas phase (hydrogen in excess) flows upward concurrently with the liquid phase (heavy oil) while the solid phase (catalyst) stays inside the reactor in an expanded (confined) bed regime. The catalyst particles are very small and are assumed to be uniformly distributed in the reactor. The heavy oil fractions contain organometallics and sulfurated compounds, from which the metals and sulfur are to be removed, the metals as deposits in the catalyst pores and the sulfur as gas products. Simulations were carried out where the concentration profile inside the reactor was calculated for several residence times.

This work presents a model to describe the behavior of the concentration of constituents of heavy fractions from petroleum during the hydrocracking process. An approximation based on pseudocomponents or lumps is adopted due to the complexity of the mixture. The system is modeled as an isothermal tubular reactor with an axial dispersion, where the hydrogen flows upward concurrently with the oil while the solid catalyst particles stay inside the reactor in an expanded bed regime. Simulations are carried out for different values of liquid superficial velocity, reactor length and degree of mixing (Peclet number).