Simulação do processo de desasfaltação de petroleo pesado para obtenção de asfaltenos e oleo lubrificante / Simulation of a heavy oil deasphalting process to obtain asphaltenes and lube oil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Petroleum deasphalting is one of the major primary processes in crude oil refining. The study of deasphalting has gained considerable attention in the last few decades due to the increase in heavy crude oil reserves. In Brazil, the majority of the explored reserves produce heavy oils. The increasing reduction in the processing of light oils, added to the increasing demand for fuels and lube oils of better quality, force the Brazilian oil industry to develop new and upgraded processes for the refining of crude oil and their residues. Asphaltenes, which are found in large amount in heavy oils, must be removed from the oil in order to get higher yields in the fluid catalytic cracking process (FCC) and to produce lighter deasphalted oil (DAO). The extraction of asphaltenes from petroleum residues though supercritical fluid is presented as a viable alternative for the vacuum-residue deasphalting, in the lube oil production. In this work, a deasphalting process of heavy crude oil through supercritical fluid extraction was studied. All the problematic of the system phase equilibrium was evaluated through the computational construction of phase ternary diagrams for the asphalt-oil-solvent mixture. A thermodynamic model capable to predict the phase behavior in the deasphalting process for the supercritical conditions of the solvent was selected. A propane deasphalting unit was simulated using a commercial process simulator, in order to remove asphaltenes, resins and heavy components from the crude. Simulations were carried out considering liquid-liquid extraction and supercritical separation. A sensitivity analysis was carried out in order to evaluate the influence of the main operational variables on this process. The efficiency of the extraction and the product quality was verified with systematic variations in the independent variables, in order to obtain higher yields in asphaltene removal and in light oil fractions recovery, aiming the process optimization. The establishment of this kind of simulation as well as the obtained results was very important because they are not easily found in the open literature. The computational evaluation of the deasphalting plant will serve as basis for operation and design of a pilot plant, which can validate the simulation data.

ASSUNTO(S)

supercritical fluid extraction propano extração com fluido supercritico asfalteno petróleo petroleum propane asphaltenes

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