When this happens, some amount of liquid solvent gets converted to gas. Now, when this solvent + components mixture passes through the valve, it reduces a little pressure. But this time, in the extraction cell, we will have all the three compounds solubilized in the solvent mixture (carbon dioxide + acetic acid) The rest of the procedure will be the same. Let’s consider we have to extract 3 components having the following solubility profile with the solvent mixture: Let’s say we have to extract different components and all of them are soluble in this mixture. Since carbon dioxide is non-polar and acetic acid is polar, the mixture will be somewhere in the mid-polar region. Here, we have taken a mixture of carbon dioxide and acetic acid. We use the purified CO 2 gas again for next time.The gaseous CO 2 passes into a chamber for purification using activated charcoal.So, we will collect these compounds in the collection cell.But the constituents which were dissolved in the liquid CO 2 will no longer be soluble.It gets converted to gaseous carbon dioxide again.The same thing happens with liquid carbon dioxide.But we know that when we reduce the pressure in the supercritical state, the fluid turns into a gaseous state.This time the valve will reduce the pressure. But before that, we have another valve.This solution containing our desired compound flows into the collection cell.Based on the polarity, compounds keep on dissolving in carbon dioxide. The liquid CO 2 solubilizes the soluble part in it.Now, the extraction cell contains, let’s say, a plant material from which we need to separate/extract certain compounds.So, as soon as the CO 2 reaches the extraction cell, it becomes a supercritical fluid.We place the oven to create a temperature above 304.13K.From here the CO 2 gas passes into the extraction assembly which is placed inside an oven.By adding these two pressures, we get the pressure above 73.8 bar.The pump regulates the flow of CO 2 gas as well as it also applies some pressure on the gas.When CO 2 gas goes through the first pressure valve, it gets pressurized and flows into the pump.That means above these temperature and pressure conditions, carbon dioxide behaves as a supercritical fluid. For carbon dioxide, the supercritical temperature is 304.13K, and the supercritical pressure is 73.8 bar.So, now we are going to create such conditions so that our CO 2 gas will be in equilibrium as Liquid ⇔ Gas. We know that at a certain temperature and pressure, the compound acts as a supercritical liquid.A pipe connects this cylinder and a pressure valve. We have a cylinder containing CO 2 gas.

Fluid extractor