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US 6,500,982 B1Granted
Process for preparing (meth) acrylic acid
AssigneeRohm and Haas Company
InventorsTimothy Allen Hale, Robert Michael Mason, Josefina Tseng Chapman, James Clarence Day, Chorng-Shyuan Tsay
Life of this patent
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Abstract
This invention relates to a process for preparing (meth)acrylic acid, whereby turndown control is utilized to maintain optimal distillation column performance in the dehydration of aqueous (meth)acrylic acid to provide a (meth)acrylic acid solution.
Claims20
A process for preparing (meth)acrylic acid, comprising the steps of:
- (A) feeding an aqueous (meth)acrylic acid stream comprising (meth)acrylic acid to a distillation column;
- (B) distilling the aqueous (meth)acrylic acid stream at a predetermined vapor rate, in the presence of at least one distillation solvent substantially insoluble in water, to form a crude (meth)acrylic acid stream;
- and
- (C) maintaining the predetermined vapor rate in response to aqueous (meth)acrylic acid fluctuation by
- (i) monitoring a distillation solvent to water ratio during distillation, and
- (ii) adjusting at least one of the amount of water and the amount of distillation solvent fed to the distillation column to maintain the predetermined vapor rate.
3 more elements
A process for preparing (meth)acrylic acid, comprising the steps of:
- (A) feeding an aqueous (meth)acrylic acid stream comprising (meth)acrylic acid and at least one polymerization inhibitor selected from 4-hydroxy-2,2,6,6-tetramethyl-piperidinyloxy and derivatives thereof to a distillation column;
- (B) distilling the aqueous (meth)acrylic acid stream at a predetermined vapor rate, in the presence of at least one distillation solvent, to form a crude (meth)acrylic acid stream;
- and
- (C) maintaining the predetermined vapor rate in response to aqueous (meth)acrylic acid feed rate fluctuation by
- (i) monitoring a distillation solvent to water ratio, and
- (ii) adjusting at least one of the amount water and the amount of distillation solvent fed to the distillation column to maintain the predetermined vapor rate.
3 more elements
Dependencies are inferred from the claim text.