Use of reverse osmosis membranes for the separation of lemongrass essential oil and supercritical CO2

Abstract

-Although it is still used very little by industry, the process of essential oil extraction from vegetable matrices with supercritical CO 2 is regarded as a potentially viable technique. The operation of separating the extract from the solvent is carried out by reducing the pressure in the system. Separation by membranes is an alternative that offers lower energy consumption and easier operation than traditional methods of separation. Combining the processes essential oil extraction with supercritical CO 2 and separation by membranes permits the separation of solvent and oil without the need for large variations in extraction conditions. This results in a large energy savings in the case of solvent repressurisation and reuse. In this study, the effectiveness of reverse osmosis membranes in separating lemongrass essential oil from mixtures with supercritical CO 2 was tested. The effects of feed oil concentration and transmembrane pressure on CO 2 permeate flux and oil retention were studied for three membrane models.

Solvent recovery from soybean oil/n-hexane mixtures using hollow fiber membrane

“…Membrane technology has been increasingly adopted by the food industry, mainly for the clarification of juices, wines and beers and the concentration of milk proteins. The interest in the application of membrane separations in the processing of vegetable oils to replace some of the traditional steps has also been growing in the last decade (Baker, 2004;Coutinho et al, 2009;Sarmento et al, 2004;Shahidi, 2005) Membrane separation processes have advantages over conventional separation processes, including energy savings, the selectivity of the compounds obtained, the possibility of separation of thermolabile compounds, the simplicity of operating the system and a relatively easy scale up from lab to industrial scale (Faria et al, 2002;Shahidi, 2005). In contrast to the conventional refining process, the membrane process can be conducted at low temperatures, preserving the heat sensitive components of technological interest of the oil, such as natural antioxidants.…”

Obtenção de ingrediente lacteo enriquecido em lipideos polares a partir de leitelho de soro

“…As opções de uso da extração supercrítica em alimentos, especialmente utilizando CO 2 supercrítico como solvente, são variadas. A extração de óleos essenciais e outras substâncias de frutas, sementes, castanhas e outras partes de plantas, como citros (Mendes et al, 1997), capim-limão (Sarmento et al, 2004), pupunha (Araújo et al, 2000), macadâmia (Silva et al, 2008), castanha de caju (Lameira et al, 1997), café (Lucas e Cocero, 2006), folhas de chá mate (Saldaña et al, 2000), gengibre (Nobrega et al, 1997), soja (Araujo et al, 2000) e alecrim (Coelho et al, 1997), dentre outros, tem sido o campo de maior estudo dessa técnica. Recentemente, a extração supercrítica foi utilizada por Astaire et al (2003) para remover lipídeos não-polares de leitelho em pó com o objetivo de concentrar lipídeos polares.…”

Obtenção de extratos vegetais por diferentes metodos de extração

“…A sua pressão e temperatura críticas, respectivamente, 73,8 bar e 31,2 °C são facilmente atingíveis (LEAL et al, 2003). Adicionalmente, o dióxido de carbono tem ainda as vantagens da sua natureza inerte, não tóxica e não inflamável (HERRERO et al, 2006;SARMENTO et al, 2004;GRIGONIS et al, 2005), e do seu baixo custo (YANG e ZHONG, 2005). Geralmente é adotado no processamento de produtos naturais com aplicação na indústria alimentícia, de fármacos, cosmética e nutracêutica.…”