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All of these things have forced the textile industry to look at how much water it uses and how dangerous its effluents are. Two very promising ways to save water are to use supercritical carbon dioxide (SC-CO 2) to dye without water and low liquor ratio machines in textile wet processing. Both options have challenges, including cost and the ...
Supercritical carbon dioxide can be used as a solvent in dry cleaning. [4] Supercritical carbon dioxide is used as the extraction solvent for creation of essential oils and other herbal distillates. [5] Its main advantages over solvents such as hexane and acetone in this process are that it is non-flammable and does not leave toxic residue.
Carbon dioxide (CO 2) is the most used supercritical fluid, sometimes modified by co-solvents such as ethanol or methanol. Extraction conditions for supercritical carbon dioxide are above the critical temperature of 31 °C and critical pressure of 74 bar. Addition of modifiers may slightly alter this.
Dyeing, which is readily carried out on polymer fibres such as polyester using disperse (non-ionic) dyes, is a special case of this. Carbon dioxide also dissolves in many polymers, considerably swelling and plasticising them and further accelerating the diffusion process.
A variant on this process involves the direct injection of supercritical carbon dioxide into the pressure vessel containing the aerogel. The result of either process exchanges the initial liquid from the gel with carbon dioxide, without allowing the gel structure to collapse or lose volume. [24]
A third process, supercritical carbon dioxide extraction, combines the best aspects of the other two methods. When carbon dioxide is put under at least 72.9 atm (73.9 bar) of pressure and at a temperature of at least 31.1 °C (88.0 °F) (the critical point ), it becomes a supercritical fluid with the permeation properties of a gas and the ...
Beck missed the second half of the game, and backup quarterback Gunner Stockton took over and led the Bulldogs to the win in overtime. That secured them a spot in the College Football Playoff and ...
Efficient supercritical CO 2 power cycles requires that the compressor inlet temperature is close to, or even lower than, the critical temperature of the fluid (31 °C for pure carbon dioxide). When this target is reached, and the heat source is higher than 600–650 °C, then the sCO 2 cycle outperforms any Rankine cycle running on water ...