To extract desired components from plant material, CO$2$ extraction is used. Plants and CO$2$ are mixed together $($unit $1).$ The mixture is transferred to a new vessel where solid plantmaterial is separated from the CO$2$ stream now also containing desired components. The plantmaterial retains $10\%$ of the CO$2.$ The stream of CO$2$ and product are brougt up to atmospheric pressure and the evaporated CO$2$ is recycled to unit $1.$

Draw the system and label the streams.

Explain what balances could be set up and give an example of such a balance.