Investigation of supercritical drying methods and a reactor design

In the last two decades, supercritical fluid dryings (SCFD) or supercritical dryings (SCD) has attracted growing interests for its increasing applications in various fields. Because of it's effective and any other outstanding properties SCD has a lot of advantage compare to other dryings tecniques. There are different physical and chemical properties of each and in this respect they have different phase diagram. Any substance discussed in the pressure-temperature phase diagram of the states of solid-liquid-gas boundary curves with each other, they are in balance. At balanced between gas and liquid states of the substance which we move forward curve in the case of temperature and pressure are increased. Due to thermal expansion as a result, decrease of viscosity of the liquid, density of the gas is increasing. After a while the density of the liquid and gas phases obtain in the same value by approaching to each other. That point indicates the critical point which the density of the two phases to have a common point. If the temperature or the pressure increase over the critical points then it becomes the supercritical fluids (SCF) which has average properties between gas and liquid phases. The features of the supercritical fluid, viscosity at low rates, high-value propagation, density and resolving powers are similar to both gas and liquid. Because of the drying process is actually a supercritical fluid extraction, the high resolving power of supercritical fluid is very important at this point. SCF extraction conventionally high-pressure pump for achieving critical conditions, is achieved by a system with the extractor and separator. SCF decided to be use a predetermined pressure value sent to the system passed through a heater at this time is transferred to the extractor. Here SCF interacting with sample which desired to be dried gains the components which can be solved. After that the fluid passing through the separator under reduced below critical conditions of temperature and pressure of the drying cycle is completed. Up to the present the developing polymeric materials which are used for different purposes and different areas, forces scientific world to find other modern and effective solutions. Among known materials on Earth lightest and lowest density aerogels with presents itself as a solution to humanity at this point. Because of the easily controlled pore structure, carbon aerogels which has features such as huge surface area, low electric resistance, high electrical conductivity, and its thermal and mechanic aspects, are produced by supercritical drying with the help of supercritical fluids. Carbon aerogels (CA) have many features to make our lives easier in many sectors such as textile, health, food, agriculture, medicine, materials .