noun, noun or participle which takes 'suru'
Technical term in chemistry for purifying a liquid by repeated distillation, e.g. alcohol or petroleum.
エタノールを精留して純度を高める。
Rectify ethanol to increase its purity.
蒸留 is general distillation; 精留 specifically refers to fractional distillation for purification.
Compound of 精 (refine) and 留 (distill). The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning of fractional distillation.