Low temperature purification of naphthalene dicarboxylic acids
AssigneeBP Corporation North America Inc.
InventorBruce I. Rosen
Life of this patent
Estimating the term…
Abstract
A process for purifying a naphthalenic carboxylic acid comprising contacting at a temperature below about 575° F. a mixture comprising an impure naphthalenic carboxylic acid and a solvent in the presence of hydrogen gas with a noble metal on carbon catalyst. The process results in reduced amounts of organic impurities in the purified acid when compared to other purification processes.
Claims19
A process for purifying a naphthalenic carboxylic acid selected from the group consisting of 2,6-naphthalenedicarboxylic acid and 1.5-naphthalenedicarboxylic acid comprising contacting an impure naphthalenic acid and a purification solvent selected from the group consisting of water or mixtures of acetic acid and water in the presence of hydrogen with a catalyst comprising, in combination, a Group VIII noble metal selected from the group consisting of palladium, platinum, and ruthenium, with a Group IVB metal selected from the group consisting of silicon, germanium, tin, or lead, at a purification temperature of from about 520 to 575° F.
Dependencies are inferred from the claim text.