	US 11,939,281 B2
	Process for the purification of hydrogen cyanide
Martin Körfer, Kahl (DE); Michael Eicker, Bergisch Gladbach (DE); Catrin Dorothee Becker, Frankfurt (DE); Thorsten Merker, Erftstadt (DE); and Marko Bussmann, Bornheim (DE)
Assigned to Evonik Operations GmbH, Essen (DE)
Appl. No. 17/256,861
Filed by Evonik Operations GmbH, Essen (DE)
PCT Filed Jul. 17, 2019, PCT No. PCT/EP2019/069235 § 371(c)(1), (2) Date Dec. 29, 2020, PCT Pub. No. WO2020/025322, PCT Pub. Date Feb. 6, 2020.
Claims priority of application No. 18186212 (EP), filed on Jul. 30, 2018.
Prior Publication US 2021/0269396 A1, Sep. 2, 2021
Int. Cl. C07C 319/20 (2006.01); B01D 3/00 (2006.01); C01C 3/02 (2006.01); C07C 319/28 (2006.01)

CPC C07C 319/20 (2013.01) [B01D 3/007 (2013.01); B01D 3/008 (2013.01); C01C 3/0295 (2013.01); C07C 319/28 (2013.01)]

15 Claims

1. A process for the purification of hydrogen cyanide, comprising:

a) splitting a liquid feed stream comprising hydrogen cyanide into at least a first liquid stream and a second liquid stream,

b) introducing the first liquid stream with a temperature T1 into a distillation column at a point between the top and the bottom of the distillation column,

c) introducing the second liquid stream with a temperature T2 into the distillation column at the top of the distillation column,

d) withdrawing an overhead vapor stream enriched in hydrogen cyanide from the distillation column, and

e) withdrawing a bottom stream (6) depleted in hydrogen cyanide from the distillation column,

wherein the temperature T2 of the second liquid stream in step c) is lower than the temperature T1 of the first liquid stream in step b).