Transport of catalytic particles immersed in fluid media through cylindrical geometries under heavy oil upgrading conditions

As light oil reserves diminish, extraction and processing of heavy crude oil and bitumen become increasingly important. The use of ultradispersed catalysts is considered to be a promising way to upgrade these materials. In order to simulate such processes, mass transfer of ultradispersed particles need to be estimated. However, an adequate mathematical expression that describes the behaviour of these particles immersed in fluid media is still missing. This thesis aims to study the separation and suspension of ultradispersed particles, based on their motion through diverse fluid media enclosed in cylindrical geometries. Two and three-dimensional convective-dispersive models that take into account pseudo-stationary and transient cases were developed in this thesis. Stagnant and flow scenarios during the mass transfer of particles immersed in diverse fluid media enclosed in cylindrical geometries were modeled in this work. These models were also successfully experimentally validated and their results unveiled the particle and fluid media properties that are necessary to control particle deposition in order to make a better use of the particle catalytic activity. The parameters that were not considered in the models were absorbed by a single parameter: the dispersion coefficient, which served as a proportionality constant to quantify the particle concentration due to convection and dispersion. The particle agglomeration effect was also taken into account by adding to the models a function of the variation of the particle diameter with time and temperature. The application of the convective-dispersive models to practical cases was also studied in this thesis. These cases consisted of systems where MoO3 catalytic particles were immersed in Athabasca bitumen. Simulations carried out for these cases showed that particles lower than 150 nm remain suspended either in a stagnant or a flow scenario. The comparison of the models performance employing a constant particle diameter and considering a particle agglomeration process, for systems where Fe 2O3 nanoparticles were immersed in base oil, was also part of the work for this thesis. These simulations demonstrated that the percentage of deposited particles at the bottom of the system is larger when the particle agglomeration process is taken into account.