While talking about co-solvent, it can be divided into two categories. The first type is miscible solvent on another side the smaller content is considered as an entertainer. The separation of heavy oils often uses two or more two C3 ~ C3 light hydrocarbon mixtures. Moreover, the interaction between the solvents makes the mixing solvent are far better than a single solvent. The second category of co-solvent is to add subcritical organic solvent in order to obtain pure supercritical fluids. Additionally, they may form a single-phase miscible mixed fluid, and it depends upon the amount of mixing and dragged by the supercritical fluid. Through this content journey, you may easily understand supercritical fluid extraction and the CO2 extraction process.
Two ways:
In supercritical gases, co-solvent can affect the solubility as well as selectivity in two ways:
First way: Solvent Density
Second Way: Interaction between trainer and interaction molecules.
In simple words, the mixing of the little amount of entrained gives little effect on the density of the solvent gas. Additionally, the defining factors affecting selectivity as solubility in the Van der Waals forces between the molecules of solute and the trainer. Or there is some definite intermolecular between the solute role and the trainer in order to form hydrogen bonds and some other chemical forces as well. In addition to this, the critical point of the mixed solvent will change accordingly after adding the trainer.
On the other side, other solvents are frequently used as co-solvent for carbon-dioxide research. Under moderate pressure and room temperature conditions, they can form a homogeneous miscible state with CO2.
To clear this point, let us take an example of a polar solvent with high solubility parameters. These polar solvents include methanol (CH3OH), ethanol (CH3CH2OH), and acetone (C3H6O) and are used as co-solvent and added to carbon dioxide. Not only the δ value of the mixture fluid is improved but also the continuous turnability of the fluid solubility parameter δ can be maintained. This is because, there is a special molecular force such as Lewis’s acid-base force, hydrogen bonding force, association force. And they are formed between the polar and the polar co-solvent, the selectivity and solubility of the solute enhance.
Importance of co-solvent in the CO2 extraction process:
It helps to increase the solubility of the separated components in supercritical fluids.
It helps to improve the selectivity of the solute when a suitable entertainer that plays a definite role when the solute is added.
Wrapping up
In the end, we can say non-polar carbon dioxide can effectively extract non-polar lipophilic substances of starch derivatives and selectivity as well. Add an appropriate amount of non-polar solvent to utilize co-solvent in order to improve the extraction process of CO2. Hopefully, the information shared through this post regarding supercritical fluid extraction and the role of co-solvent in the extraction process will help you a lot. Furthermore, you can clear your doubts and ask your questions in the below comment section box. To read more blogs and articles about the supercritical extraction process, feel free to visit https://tharprocess.com/. Thank you for reaching out!
