The supercritical carbon dioxide is applied in many separation processes as solvent. Due to this applicability of carbon dioxide, in this study, it is applied to oil refinery. In order to find the maximum efficiency, the experiment was conducted in the ranges of 150-210 bar of pressure, and 35-65oC of temperature. Based on this study, the changes in pressure show strong effect on the efficiency, and when it increases the efficiency increases, too. Despite of the pressure, when the temperature increases at a constant pressure, the density of supercritical carbon dioxide decreases. As a results, its solubility in decreases and the oil viscosity and mass transfer rate from oil increases. According to the results, the optimized operational condition to get the highest efficiency is investigated as 21 Obar of pressure and 45oC of temperature.

Separation techniques, effective use of supercritical gases in the food industry has become so large several large companies already in supercritical separation methods employ purification and food production. The fields of the food industry in Germany has made considerable progress. For example, the extraction of the coffee and herbal tea Kafyny chewing tobacco extract using carbon dioxide under supercritical conditions is performed. In recent years, foods containing cholesterol have created many problems for human health. Cholesterol is easily soluble in supercritical carbon dioxide, and this promise is the separation of cholesterol from foods of animal origin.

This paper reports a study to find optimum conditions for oil extraction from vetiver root. For this purpose, the influence of temperature and pressure on the extraction yield is investigated. In addition, the effects of supercritical fluid flow rate and particle diameter on optimum temperature and pressure have been studied. The results show that optimum pressure is a strong function of particle diameter and solvent flow rate. However, the results reveal that the optimum temperature is independent from particle diameter and solvent flow rate.

Synthesis and processing of polymer-based materials through green friendly methods involving supercritical fluids particularly supercritical carbon dioxide (SCC) has recently received substantial technological importance because of the commercial and industrial benefits involved. In the present work, a SCC assisted green and sustainable process has been developed to synthesize polypyrrole/polythiophene copolymers (PPCs). The process of synthesis has been conducted through ferric chloride-initiated chemical oxidative polymerization in the presence of various molar proportions of pyrrole to thiophene 0: 1.0, 1.0: 0, 1.0: 1.0 and 1.0: 2.0 at temperature ranging from 50 to 90oC, 1, 200 psi over 12 h in SCC. Polymerization below 90 °C afforded PPCs in semi-solid products, whereas polymerizations conducted at 90 °C under identical conditions have afforded the end products in complete solid state. The structure and properties of PPCs have been evaluated through ultraviolet–visible absorption and Fourier transform infrared spectra, elemental analysis, atomic force microscopy, simultaneous thermogravimetric–differential thermal analysis–differential thermogravimetry and four-point probe electrical conductivity methods. With molar proportion of thiophene, time and temperature, all the polymerization reactions have been conducted to completion resulting in PPCs with enhanced polymerization yield, rheoviscosity, dispersion of polypyrrole into polythiophene matrix and thermal stability. This has contributed a simultaneous loss in the electrical conductivity of PPCs.

In the present investigation efforts have been made to synthesis polyvinyl pyridine (PvPy) /C60 conjugates through 2, 2-azobisisobutyronitrile (AIBN) initiated insitu polymerization of PvPy in scCO2.The process of synthesis was monitored under different reaction conditions ranging 1200-1800psi, 60-90°C over 6 hours. The progress of polymerization was monitored rheoviscometrically. The concentration of PvPy and AIBN ranging 6.95-20.85*10-3 and 304.50-931.50*10-3 afforded PvPy/C60 conjugates in the yield (%) ranging 10.30-48.8. Selected PvPy/C60 conjugates were characterized through UV-VIS spectra, scanning electron microscopy, gel permeation chromatography and solution rheoviscometery.