Removal of aldehydes in acetic acid production
AssigneeLyondellBasell Acetyls, LLC
InventorsShane J. Weber, Noel C. Hallinan, Ryan J. Mathews
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Abstract
A system and method for removing acetaldehyde from an acetic acid system, including providing a solution from the acetic acid system, the stream having methyl iodide and acetaldehyde, distilling the solution to produce an overhead stream having a higher concentration of acetaldehyde, contacting the overhead stream, and optionally a hydroxyl compound, with an acid catalyst to convert the acetaldehyde to an aldehyde derivative having a higher boiling point than acetaldehyde.
Claims11
A method for removing acetaldehyde from an acetic acid system, wherein the acetic acid system comprises a light-ends column and a decanter, the method comprising:
- feeding a light-ends overhead stream from the light-ends column to the decanter;
- withdrawing from the decanter:
- (i) a heavy organic phase stream, comprising methyl iodide, acetaldehyde, water, methyl acetate, and acetic acid;
- and (ii) a light aqueous phase stream comprising methyl iodide, acetaldehyde, water, methyl acetate, and acetic acid;
- and
- providing as a solution a portion of the heavy organic phase stream and/or a portion of the light aqueous phase stream,
- wherein the solution comprises acetic acid, water, methyl acetate, methyl iodide, and acetaldehyde, wherein the acetaldehyde is present in a first concentration based on the total weight of the solution;
- distilling the solution to form a first distillation overhead stream, comprising methyl iodide and acetaldehyde, wherein the acetaldehyde is present in a second concentration based on the total weight of the first distillation overhead stream, and the second concentration is greater than the first concentration;
- and
- contacting a reactive feed stream, comprising the first distillation overhead stream, and optionally a hydroxyl compound, with an acid catalyst to form a reacted stream, wherein contacting the reactive feed stream with the acid catalyst converts at least a portion of the acetaldehyde to an aldehyde derivative having a higher boiling point than acetaldehyde.
Dependencies are inferred from the claim text.