The gravimetric separator is the first separator (S1). It applies the gravimetric effect to separate the extract in fractions. This separator is heated at a set-point temperature.
When the mixture of CO2 and chemical compounds extracted are directed in this separation, the solvent’s temperature and pressure goes down thanks to the lamination valve. With this operation, the supercritical CO2 becomes a gas and it loses its solvent properties and so it releases the solutes that, due to the effect of gravity, sink to the bottom of the separator, ready to be collected.
In this separator the operator will collect all the heavier compounds. To remove the remaining compounds, water included, other separation operations have to be conducted with other separators.