Process for purifying terephthalic acid using ionic liquids

摘要

Methods of purifying crude or contaminated terephthalic acid using ionic liquids are described. Crude or contaminated terephthalic acid is contacted with a solvent in the absence of an oxidizing agent to form a purified product having at least 30 wt % less 4-carboxybenzaldehyde compared to the crude or contaminated terephthalic acid. The solvent consists essentially of an ionic liquid, optionally an ionic solid or a material capable of forming an ionic salt, and optionally an aqueous solvent. The ionic liquid is formed in situ from at least one ionic liquid precursor.

主权项

1. A process for purifying crude or contaminated terephthalic acid comprising:
contacting the crude or contaminated terephthalic acid with a solvent in the absence of an oxidizing agent to form a purified product having at least 30 wt % less 4-carboxybenzaldehyde compared to the crude or contaminated terephthalic acid, wherein the solvent consists essentially of an ionic liquid, optionally an ionic solid or a material capable of forming an ionic salt, and optionally an aqueous solvent; separating the purified product from the solvent, and wherein the ionic liquid is formed in situ from at least one ionic liquid precursor.