To make decaffeinated coffee one option is to first soak the beans in water. The moist beans are then filtered from the excess liquid and transferred to a pressure vessel where supercritical CO$2$ is added. After several hours, the CO$2$ and caffeine is separated from the product beans.

$1.$ Draw the system and label the streams.

$2.$ Explain what balances could be set up and give an example of such a balance.