A.M.C. Uller

Optimization of the process of concentration of vitamin e from DDSO using supercritical CO2

The objective of this work was the scientific development of concentration of vitamin E from deodorizer distillate of soybean oil (DDSO) using supercritical CO2. Vitamins and sterols rare produced synthetically, but recently the interest in their extraction from natural sources has increased. Therefore, the motivation behind this work was to concentrate the tocopherols from deodorizer distillate of soybean oil, thereby increasing the value of this by-product, rich in fatty acids, sterols, tocopherols and squalene. The experimental step and the simulation of the process were done in a semi-batch mode using supercritical carbon dioxide. The operational conditions studied were temperatures of 40, 60 and 80oC and pressures from 90 to 350 bar. The best results for concentration factor and efficiency and pressures were achieved in a continuous process where the operational variables were optimized.

Simulation and thermodynamic modeling of the extraction of tocopherol from a synthetic mixture of tocopherol, squalene and CO2

Soybean oil is the most consumed vegetable oil in the world, representing 54% of the total world production. Brazil is the second country in the world that produces and export soybean seeds, almost 20%. One of the most important by-product of the soybean oil is the deodorizer distillate, commonly known as soybean sludge. This residue is rich in many high value compounds as tocopherols, squalene and sterols. Tocopherols are the major components in the deodorized distillated due to their characteristics as an antioxidant agent. So, the objective of this work is to study the concentration of tocopherols presented in this raw material, using the operational conditions obtained from the equilibrium data and using supercritical carbon dioxide as a solvent. The deodorizer distillate is a complex mixture of more than 200 components, so a synthetic mixture was chosen to represent the deodorizer distillate. The synthetic mixture used in this work is composed by tocopherols, fatty acids and squalene. The simulation was carried out using ASPEN+ simulator and the LCVM thermodynamic model was used to correlate the available equilibrium data.

HYBRID ARTIFICIAL NEURAL NETWORK APPLIEDTO MODELING SCFE OF BASIL AND ROSEMARY OILS

Neste trabalho sao apresentados os resultados obtidos na modelagem da extracao supercritica de oleo essencial de alfavaca e alecrim usando uma rede hibrida neuronal. Utilizou-se uma rede hibrida na configuracao em serie para estimar os parâmetros do modelo fenomenologico empregado para descrever o processo de extracao, o modelo de Sovova. Um pequeno conjunto de dados experimentais, para cada matriz vegetal, foi usado para gerar um conjunto estendido de dados, suficiente para a etapa de treinamento da rede. A validacao da presente proposta foi efetuada atraves da comparacao entre os resultados preditos e aqueles obtidos experimentalmente que nao constaram do processo de treinamento da rede. Demonstra-se que a rede hibrida neuronal correlaciona e prediz satisfatoriamente os dados experimentais, mostrando-se portanto promissora no campo da modelagem do processo de extracao supercritica.

ANÁLISE TERMODINÂMICA DA DESTERPENAÇÃO DO ÓLEO DA CASCA DE LARANJA COM CO2 SUPERCRÍTICO A PARTIR DE UMA MISTURA SINTÉTICA

Process design for supercritical CO2 deterpenation of orange peel oil requires accurate knowledge of phase behavior. This work is focused on modeling high-pressure vapor-liquid equilibrium for the ternary system CO2-limonene-linalool, owing to do a preliminary thermodynamics analysis of this process based on calculated selectivity values. A modification of Peng-Robinson equation of state was adopted to regress binary interaction parameters from experimental VLE data and its capacity for temperature extrapolating calculations was investigated. A comparison of ternary VLE obtained from the respective binary systems and that calculated using additionally ternary informations was done.

Solid–fluid phase equilibrium modeling for binary systems containing carbon dioxide

Abstract The excess function formalism was used to represent the solid–fluid equilibrium of binary systems formed by carbon dioxide and heavy hydrocarbons. The model is based on the Peng–Robinson equation of state, extended to represent the PVT properties of pure components, and the Peneloux excess function formalism to represent the solid–fluid equilibrium properties of mixtures. The results show that the effect of density on the excess term should be taken into consideration in the calculations for CO2/heavy hydrocarbons systems. This effect is particularly important in the vicinity of the gas critical point.

MODELAGEM E SIMULAÇÃO DA DESTERPENAÇÃO DO ÓLEO DA CASCA DE LARANJA COM CO2 SUPERCRÍTICO EM MODO SEMI-CONTÍNUO

A desterpenacao do oleo da casca de laranja com CO2 supercritico foi investigada atraves da modelagem e simulacao da separacao de uma mistura sintetica de limoneno (90 % em peso) e linalol (10 %), em um extrator operando em modo semi-continuo. A modelagem matematica da extracao supercritica foi realizada por analogia com a destilacao de uma mistura binaria, em batelada, expressando-se a composicao das fases em equilibrio numa base molar livre de CO2. O calculo das variaveis do processo foi feito por integracao numerica da equacao de Rayleigh empregando-se o metodo de Runge-Kutta de quarta ordem. Para a determinacao da relacao de equilibrio entre as fases, adotou-se a equacao de Peng-Robinson modificada, com os parâmetros de interacao obtidos de dados de ELV dos sistemas binarios CO2+limoneno e CO2+linalol e do ternario CO2+limoneno+linalol.