Abstract: A depolymerization reaction of a polyester input with an organocatalyst and an alcohol solvent produces (i) a recycled monomeric or oligomeric diester from the polyester, (ii) the organocatalyst for reuse, and (iii) the alcohol solvent, which may also be reused. The presence of volatile impurities, such as water, acetyl aldehyde, and organic solvents can interfere with the success of the depolymerization reaction. A pre-reaction distillation step removes volatile impurities from the polyester input resulting in an efficient depolymerization reaction with consistency among batches. The polyester input may be further treated with a water azeotrope to remove water from the polyester input prior to the pre-reaction distillation.