enzyme efficiency was investigated in the lipase-catalyzed hydrolysis of canola oil in supercritical carbon dioxide (scco2). immobilized lipase from mucor miehie (lipozyme im) was used as the catalyst and the results showed that enzyme efficiency dropped at high pressures indicating a possible change in enzyme microstructure. therefore, scanning electron microscopy (sem) was used as a supplemen...

Recently, Supercritical fluids have been used in material synthesis and processing because of their special properties such as high diffusivity, low viscosity, and low surface tension. Supercritical carbon dioxide is the most attractive because it is non-toxic, non-flammable, and has moderate critical temperature and critical pressure. Moreover, and can also swell most polymers. In this study, ...

The objective of the study is the development of a new technique based on supercritical technology for the production of bioabsorbable polymeric microparticles containing pharmaceutical principles, for their use in the controlled release of medicines. For this purpose, the ring-opening copolymerization of D,L-lactide and glycolide in supercritical carbon dioxide, using zinc(II) 2-ethylhexanoate...

The objective of the study was to prepare vinblastine microparticles by supercritical antisolvent process using N-methyl-2-pyrrolidone as solvent and carbon dioxide as antisolvent and evaluate its physicochemical properties. The effects of four process variables, pressure, temperature, drug concentration and drug solution flow rate, on drug particle formation during the supercritical antisolven...

Supercritical fluid extraction represents an efficient and environmentally friendly technique for isolation of phytosterols from different plant sources. Sea buckthorn (Hippophae rhamnoides L.) seeds were extracted with supercritical carbon dioxide at pressures ranging from 15-60 MPa and temperatures of 40-80 degrees C. Oil and β-sitosterol yields were measured in the extraction course and comp...

Use of conventional organic solvents often leads to the formation of hazardous waste, the disposal of which is a matter of environmental concern. Carbon dioxide is considered to be a green reaction medium and a good replacement for conventional organic solvents as it is benign and leads to elimination/reduction of hazardous wastes. Use of CO2 at near/above critical conditions has several additi...

Nanometric titanium dioxide (TiO2) powder has been treated on the surface with octyltriethoxysilane in a supercritical carbon dioxide (scCO2) medium. The surface silanization conferred water repellency to the TiO2 powder. The effect of operating variables of the supercritical silanization process (pressure, temperature) on the surface characteristics of the material was analyzed. Finally, the e...

Wheat germ oil was obtained by mechanical pressing using a small-scale screw press and by supercritical extraction in a pilot plant. With this last method, different pressures and temperatures were tested and the tocopherol concentration in the extract was monitored during extraction. Then supercritical extracted oil as well as commercial pressed oil were deacidified in a countercurrent column ...

The purpose of this evaluation was to provide an objective evaluation of the use of supercritical carbon dioxide (CO,) as an alternative technology for spray applied in wood finishing processes using reduced solvent formulations. Union Carbide has pioneered this technology under the UNICARBTM trademark. In the UNICARBTM process, the solvent-like properties of supercritical CO, are employed to r...

Supercritical fluid extraction was used to extract the alkaloid N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl]pyrrolidine from leaves of Piper amalago L. A three-level orthogonal array design matrix, OAD OA9(34), was used for optimization of the parameters of supercritical extraction of the alkaloid, employing supercritical carbon dioxide: extraction time (20, 40, and 60 min), temper...