Modeling and Simulation of a Pyrolysis Reactor for Slurry Feed
Luiz Fernando Gallo1, Arilza de Castilho Pickler1, Christine Althoff2, Carlos Eduardo Fontes3, Jaime Neiva Miranda3, Alexarder Clausbruch3, and Alessandro Alle3. (1) CENPES/Petrobras, Rio de Janeiro, Brazil, (2) Albrecht Equipamentos Industriais, Joinvile, Brazil, (3) Chemtech – A Siemens Company, Rio de Janeiro, Brazil
Over the past years, the petroleum extracted throughout the world has become heavier. Many refineries are already adapting their processes so that they can cope with such viscous oils. An immediate consequence of the use of ultra-heavy oils is the generation of an increasing amount of residues. Although a number of process technical advances (like FCC and hydrocracking) increase the conversion of heavy cuts into light and valuable derivatives, it is also true that this is not a equilibrated conflict: the amount of residue formed increases much faster than the technology has advanced. The logistic and ecological problems that arise from this situation are evident and the potential gains of oil industry in the processing of these residues are very large. Based on this situation, many research centers throughout the world are trying to find a solution for the logistic and ecological problems regaining the potential profits inside these oils. Computational simulation can be a very powerful and useful tool for the development of new processes, and therefore should be used in order to reduce the costs and reduce the risks associated with this task. Having these aspects in mind, CENPES/PETROBRAS and ALBRECHT developed a brand new process to treat slurries (very high weight oils that remain after traditional processing operations). Since they successfully operated a pilot plant, CHEMTECH has been invited to assist them during the scale-up of the reactor. In this work, CENPES/PETROBRAS, ALBRECHT and CHEMTECH present the simulation-based scale-up analysis applied to the new reactor. The idea was to model the pyrolysis kinetics that takes place inside the reactor and then use it as a base for a CFD (Computational Fluid Dynamics) model. The latter model will be able to predict the best position for side outlet streams, maximizing the production of interesting petroleum fractions. Figures 1, 2 and 3 show some results. The kinetic model has been validated against experimental and field data. The simulations allowed the anticipation of potential problems during operation and the design of the necessary inertization system, what certainly reduced the cost and the necessary time for the equipment development and increased the safety of the reactor operation.