Celanese International Corporation

Celanese Gmbh

Melchior A Meilchen

R Jay Warner

G Paull Torrence

George A Blay

Prashant Purushottam Barve

Ravindra William Shinde

Ilias S Kotsianis

Milind Yashwant Gupte

Barbara F M Kimmich

Sanjay Pandurang Kamble

Madan Singh

Michael L Karnilaw

Hang Wang

Robin Suzanne Tanke

Gopal Moreshwar Chaphekar

Bhaskar Datttraya Kulkarni

Satish N Shintre

Mark O Scates

Nathan Kirk Powell

Stefan Hess

Wayne David Picard

Valerie Santillan

Johann Stamm

Martin Wagner

Richard F Vogel, Jr

Michael O Streb

Rolf Soellner

Thomas Vernaleken

Michael Mark

A continuous process is provided for selective formation of a vinyl ester by reactive distillation from a corresponding carboxylic acid. Carboxylic acid, vinyl acetate, and a palladium acetate&#x2014;bidentate ligand catalyst complex are provided and reacted in a typical embodiment. Acetic acid and vinyl acetate are continuously removed from the reaction mixture and vinyl acetate is recycled to the reaction mixture. The vinyl ester product is separated from the vinyl acetate, residual carboxylic acid, residual acetic acid, and catalyst.

Process for the continuous transvinylation of carboxylic acids with vinyl acetate

A semi-continuous process is provided for selective formation of a vinyl ester by reactive distillation from a corresponding carboxylic acid. Carboxylic acid, vinyl acetate, and a palladium acetate&#x2014;bidentate ligand catalyst complex are provided and reacted in a typical embodiment. Acetic acid and vinyl acetate are continuously removed from the reaction mixture and vinyl acetate is recycled to the reaction mixture. The vinyl ester product is separated from the vinyl acetate, residual carboxylic acid, residual acetic acid, and catalyst.

Process for the semi-continuous transvinylation of carboxylic acids with vinyl acetate

There is shown a method of purifying glacial acetic acid containing terpene and terpenoid impurities. Substantially dry acetic acid containing terpene and terpenoid impurities is combined with water and a suitable organic solvent, which is substantially immiscible with acetic acid and water, to form a separating composite extraction medium having a weight ratio of acetic acid:water of at least 1:1. The components are separated into an organic phase and an aqueous acid phase, with the terpene and terpenoid impurities concentrated in the organic phase, and with the aqueous acid phase purified of terpene and terpenoid impurities. The purified aqueous acid phase is recovered, and the purified acetic acid is dried.

Purification of acetic acid from wood acetylation process using extraction

A method of purifying acetic acid containing terpene and terpenoid impurities, includes: (a) supplying acetic acid containing terpene or terpenoid impurities and water to a distillation column; (b) azeotropically removing terpene or terpenoid impurities from the mixture of acetic acid and water supplied to the column as distillate; and (c) withdrawing a product stream from the column comprising acetic acid purified of terpene or terpenoid impurities. The method is particularly effective for purifying acetic acid recovered from a wood purification process.

Purification of acetic acid from wood acetylation process

Removal or reduction of permanganate reducing compounds and alkyl iodides from a carbonylation process stream

A process for working up crude, liquid vinyl acetate feed containing acetic acid, water and ethyl acetate and optionally smaller amounts of other impurities by distillation, wherein there is introduced into the distillation column, above the feed point of the crude, liquid vinyl acetate, 0.1 to 5% by weight of water, based on the crude, liquid vinyl acetate feed, and 0.1 to 60% by weight of acetic acid, based on the crude, liquid vinyl acetate feed.

Process for working up crude, liquid vinyl acetate

Disclosed is a method to manufacture high purity acetic acid. Although described in relation to that produced by a low water carbonylation process the present invention is applicable to other mechanisms for production of acetic acid which results in formation of permanganate reducing compounds such as acetaldehyde, propionic acid, and alkyl iodide impurities in intermediate process streams. It has been found that permanganate reducing compounds and alkyl iodides may be conveniently removed from a light phase of an intermediate stream in the reaction process by employing a multiple distillation process coupled with an optional extraction of acetaldehyde. The distillation process involves first distilling a light phase to concentrate the permanganate reducing compounds, and in particular the acetaldehyde, and then separating the permanganate reducing compounds and alkyl iodides in a second distillation tower. The second distillation serves to remove the permanganate reducing compounds and alkyl iodides from methyl iodide, methyl acetate, and methanol mixture. As an optional third step, the twice distilled stream may be directed to an extractor to remove any remaining quantities of methyl iodide from the aqueous acetaldehyde stream to obtain acetic acid as a final product in greater than 99% purity. It has been found that this process removes at least 50% of the permanganate reducing compounds and alkyl iodides and at least 20% of the propionic acid impurity from the intermediate light phase stream, and results in lower alkyl iodide concentration in the carbonylation reaction process, and in particular in the carbonylation reactor. It has also been found that during shut down of the inventive process, polymers of acetaldehyde tend to form in the base of the second distillation tower. To avoid or minimize the formation of these polymers, a constant flow of solvent is passed through the base of the column.

Removal of permanganate reducing compounds and alkyl iodides from a

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Houston, TX, United States of America

Melchior A Meilchen