HEGEL Pablo Ezequiel
congresos y reuniones científicas
Lubricant Oils Fractionation Using Liquefied Gases
Congreso; X Congresso Brasileiro de Termodinâmica Aplicada (CBTermo) e VI Escola de Termodinâmica; 2019
Institución organizadora:
IQ/UERJ (Universidade do Estado do Rio de Janeiro
Lubricantoils play an important role in different sectors from energy generation,metal-working and chemical production, to food/drink industry, andpharmaceutical laboratories. The elaboration of special lubricants forcompressors, turbines, electronic devices, or medical purpose applications hasstrict composition regulations regarding the presence of residual monomers andoligomers that alter the final product quality. However, the removal of thesenon-desired minor compounds from the oily lubricants by classical vacuumdistillation is difficult and expensive because of the high temperaturesgoverning the process. In this work we study the fractionation oflubricant oils using liquefied CO2 + propane solvent mixtures underliquid-liquid-vapor phase equilibrium. CO2+propane solvents haveshown interesting properties for extraction of viscous fluids regardingenvironmental aspects, high selectivity and non-flammability properties. Toevaluate the technical feasibility of the technology proposed in this work, asynthetic oil mixture prepared from two commercial silicone oils (MW: 8000 andMW: 38000) is used as a model lubricant. The liquid-liquid-vapor phase behaviorof the multicomponent system is studied in a high pressure view cell to setpreliminary operating conditions. The effect of the different variablesgoverning the separation process such as solvent composition (CO2/propane:60/40 to 90/10) and temperature (T: 298 K to 323 K) are being studied todetermine its effect on liquid partial miscibility. Then, a semi-batch liquid-liquidextraction process is carried out to evaluate the selectivity different CO2+ propane solvent mixtures. Results are pointing out liquefied gases with up to30 wt.% propane exhibit partial liquid miscibility between silicone oils +solvent at 313 K turning feasible a liquid-liquid fractionation process. Preliminaryextractions show liquefied gases with up to 30 wt.% propane are more suitableto fractionate silicone oils than pure CO2 or propane/CO2 liquified gases (18wt.% propane) due to the lower operating pressures observed in the system andmainly the higher solvent power to carry out the fractionation.