What separation technique would most likely be used if a solvent were saved?

Distillation

Explanation:

If the solute is a solid or a liquid with a boiling point at least 30 °C different from that of the solvent, you can use the technique of distillation.

The solvent will boil before the solid or a higher-boiling liquid.

A liquid solute with a lower boiling point than the solvent will boil off first, and then you can distill off the solvent.

Distillation

Explanation:

Distillation is a process known long ago and according to some authors was created by the Alchemists at a time where Chemistry was not yet recognized as Science and was closely linked to religious precepts.

Basically the distillation process is a process of physical separation and is used to separate homogeneous mixtures from heating. To separate a solid-liquid type mixture we use simple distillation and to separate liquid-liquid mixtures we use fractional distillation.