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US 12,459,887 B2Granted
Acetonitrile separation process
AssigneeAscend Performance Materials Operations LLC
InventorsKyle Kissell, Basil Michaels
Life of this patent
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Abstract
Provided herein are processes for the separation of acetonitrile from low-purity feedstock streams. The provided processes are particularly useful for isolating acetonitrile at high purity from chemical manufacturing waste streams that include methanol, water, and allyl alcohol.
Claims16
A process for producing acetonitrile, the process comprising:
- distilling a feedstock stream in a dehydration distillation column to yield a dehydration distillate stream and a dehydration bottoms stream, wherein the feedstock stream comprises acetonitrile, acrylonitrile, allyl alcohol, and water and the dehydration distillate stream is collected as the top stream from the dehydration distillation column;
- extracting the dehydration distillate stream with a caustic to hydrolyze acrylonitrile and yield an extract stream comprising water and from 0.01 wt % to 5.0 wt % of hydroxypropionitrile and a raffinate stream comprising allyl alcohol and less than 1 wt % water;
- reacting allyl alcohol in the raffinate stream with a strong acid in a reactor to yield a reactor output stream;
- distilling the reactor output stream in a lights removal distillation column to yield a lights removal distillate stream and a lights removal bottoms stream;
- and
- distilling the lights removal bottoms stream in a heavies removal distillation column to yield a product acetonitrile stream containing more than 98 wt % acetonitrile.
3 more elements
A process for producing acetonitrile, the process comprising:
- distilling a feedstock stream comprising acetonitrile, acrylonitrile, allyl alcohol, and water in a dehydration distillation column to yield a dehydration distillate stream and a dehydration bottoms stream, the dehydration distillate stream being collected as the top stream from the dehydration distillation column;
- extracting the dehydration distillate stream with a caustic to hydrolyze acrylonitrile to yield an extract stream comprising water and from 0.01 wt % to 5.0 wt % of hydroxypropionitrile and a raffinate stream comprising allyl alcohol and less than 1 wt % water;
- distilling the raffinate stream in a lights removal distillation column to yield a lights removal distillate stream and a lights removal bottoms stream comprising allyl alcohol and less than 1 wt % water;
- reacting allyl alcohol from the lights removal bottoms stream with a strong acid in a reactor to yield a reactor output stream comprising less than 7 ppm allyl alcohol;
- and distilling the reactor output stream in a heavies removal distillation column purifying the reactor output stream to yield a product acetonitrile stream comprising greater than 98 wt % acetonitrile.
2 more elements
Dependencies are inferred from the claim text.