# US 6,296,739 B1 · Operation of heads column

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- Number: US 6,296,739 B1
- Document ID: US6296739B1
- Status: Granted
- Kind: B1
- Application number: 09/227,665
- Filed: 1999-01-08
- Granted: 2001-10-02
- Earliest claimed: 1999-01-08
- Assignees: The Standard Oil Company
- Inventors: Sanjay P. Godbole
- Web page: https://patentgrep.com/patent/US6296739B1

## CPC

- B01D 3/34: with one or more auxiliary substances
- C07C 253/34: Separation; Purification
- Y10S 203/11: Batch distillation
- Y10S 203/20: Power plant
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A process for the enhanced recovery and operation of hydrogen cyanide (HCN) / heads column obtained from the reactor effluent of an ammoxidation reaction of propane, propylene or isobutylene by reducing the polymer formation above the feed tray in the heads tower.

## Claims

### Claim 1

A process for the recovery of acrylonitrile, methacrylonitrile or hydrogen cyanide obtained from the reactor effluent of an ammoxidation reaction of propane, propylene or isobutylene comprising passing said reactor effluent through an absorber column, a recovery column and a heads column comprising a feed tray wherein the improvement comprises operating said heads column in a manner which inhibits the formation of an aqueous phase above the feed tray of said heads column;
wherein said operating manner of said heads column comprises feeding more hydrogen cyanide to said heads column to achieve conditions equivalent to higher reflux ratio and wherein said feeding is selected from the group consisting of (a) recycling purified HCN to the heads column and (b) operating the ammoxidation reactor in a manner to produce said reactor effluent with high concentration of HCN.

### Claim 2 (depends on 1)

The process of claim 1 wherein said feeding Is recycling purified HCN to the heads column.

### Claim 3 (depends on 1)

The process of claim 1 wherein said feeding is operating the ammoxidation reactor in a manner to produce said reactor effluent with high concentration of HCN.