Process for purifying terephthalic acid using ionic liquids
AssigneeUop LLC
InventorsSusie C. Martins, Kaitlin DeSalvo, Alakananda Bhattacharyya
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Abstract
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.
Claims19
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.
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 60 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, and wherein the solvent is at a temperature in a range of about 50° C. to about 200° C.;
- separating the purified product from the solvent;
- recovering the purified product, and
- wherein the ionic liquid is formed in situ from at least one ionic liquid precursor.
Dependencies are inferred from the claim text.