RECOVERY OF POLYMERIZATION INHIBITOR

摘要

A process is provided for recovery and re-use of dinitrophenols employed as inhibitors of polymerization in the distillation and purification of styrene. The styrene still residues commonly referred to as tar or tars are treated with an aqueous hydroxide at a controlled pH, the phases are separated, the aqueous phase is treated with an acid and an organic solvent at a controlled pH and the resulting organic phase is recycled to a suitable point in the styrene purification system. The recycled solution is a more effective inhibitor than the dinitrophenol originally employed.