RU99117537A

RU99117537A - IMPROVED METHOD FOR PRODUCING VINYL ACETATE

Info

Publication number: RU99117537A
Application number: RU99117537/04A
Authority: RU
Inventors: Брюс Лео УИЛЛЬЯМС; Роберт Уилльям КЛАРК; Тимоти Криспин БРИСТОУ; Майкл Джеймс БЕЙКЕР
Original assignee: Бп Кемикэлз Лимитед
Priority date: 1998-08-11
Filing date: 1999-08-10
Publication date: 2001-06-27

Claims

1. A method of producing vinyl acetate, including:
(a) introducing into the reactor ethylene, acetic acid and oxygen-containing gas,
(b) the interaction in this reactor of ethylene, acetic acid and oxygen-containing gas in the presence of a catalytic material with obtaining vinyl acetate at a pressure greater than atmospheric,
(c) removal of gases from the reactor, including unreacted ethylene, vinyl acetate, carbon dioxide as a by-product, and inert gases, such as nitrogen and / or argon,
(d) separating unreacted ethylene from the gases withdrawn from the reactor, optionally together with small amounts of carbon dioxide and inert gases, and
(e) introducing the ethylene recovered from step (d) and an additional amount of ethylene into the reactor in step (a), with the amount of ethylene in the combined feedstock for the reactor being at least 60 mol%.

2. The method according to claim 1, wherein ethylene is separated from the gases withdrawn from the reactor, (I) separating condensable products from gases and (II) treating the gases from step (I) in order to isolate ethylene by membrane separation or chemical treatment.

3. The method according to claim 2, wherein the condensable products are isolated using a heat exchanger or by quenching the gases due to the outflow of countercurrent to the direction of flow of the liquid acetic acid and / or condensed products that absorb the resulting vinyl acetate.

4. A method according to claim 2 or 3, in which the chemical treatment involves (a ′) bringing the gases from step (i) into contact with acetic acid in a scrubber to remove the residual amount of vinyl acetate obtained, (b ′) treating the product from step (a ') with water in a scrubber to remove acetic acid and (c') removing carbon dioxide from ethylene in the product from step (b ') by contacting with potassium carbonate.

5. The method according to any one of the preceding claims, wherein the amount of ethylene in the combined feedstock for the reactor is from at least 60 to 85 mol.%, Preferably from at least 60 to 80 mol.%.

6. The method according to any of the preceding paragraphs, in which the amount of oxygen in the combined feedstock for the reactor is 4-15 mol.%.

7. The method according to any one of the preceding claims, wherein the amount of acetic acid in the combined feedstock for the reactor is 10-20 mol%.

8. The method according to any of the preceding paragraphs, in which the reaction of ethylene, acetic acid and oxygen-containing gas in the reactor is carried out under gauge pressure ranging from 5x10 ⁴ Pa (0.5 bar) to 2x10 ⁶ Pa (20 bar), preferably from 6x10 ⁵ Pa (6 bar) to 1.4x10 ⁶ Pa (14 bar), most preferably in the range of 7x10 ⁵ Pa (7 bar) to 1.2x10 ⁶ Pa (12 bar).

9. The method according to any one of the preceding claims, wherein the catalytic material comprises a metal of group VIII, preferably palladium, a promoter selected from the group comprising gold, copper, nickel and mixtures thereof, and an optional co-promoter selected from the group comprising elements of group I, group II, lanthanides and transition metals.

10. The method according to any one of the preceding claims, wherein the reactor is a fluidized bed reactor and the catalyst is a fluidized bed catalyst.