Lyondell Chemical Technology, L.p.

Millennium Petrochemicals Inc.

Equistar Chemicals, LP

Lyondellbasell Acetyls, LLC

Wayne Joseph Brtko

Brian A Salisbury

Noel C Hallinan

Michael E Fitzpatrick

Ronnie M Hanes

Gary A Sawyer

Noel Hallinan

Chuc Tu Nguyen

A process for producing acetic acid includes: obtaining hydrogen iodide in an acetic acid production system; and continually introducing a complexing agent into the system, wherein the complexing agent and hydrogen iodide interact to form a complex.

Process for the production of acetic acid

The disclosure relates to a process in which methanol is carbonylated in a reaction zone in the presence of a catalyst to obtain a reaction mixture (A) comprising acetic acid, hydrogen iodide, methyl iodide, water and the catalyst. At least a part of the reaction mixture (A) is withdrawn from the reaction zone. The withdrawn part of the reaction mixture (A) is introduced into a flash zone where it is brought into contact with an alkylimidazolium iodide to form a secondary mixture (B), and where the secondary mixture (B) is separated to obtain a vapor stream (B) which comprises the acetic acid, water and methyl iodide, and a liquid stream (B) which comprises the catalyst, the alkylimidazolium iodide and hydrogen iodide. The vapor stream (B) is processed to purify the acetic acid, and the liquid stream (B) is recycled to the reaction zone. The reaction mixture (A) is brought into contact with the alkylimidazolium iodide in the flash zone

The disclosure relates to a process in which methanol is carbonylated in a reaction zone in the presence of a catalyst to obtain a reaction mixture (A) comprising acetic acid, hydrogen iodide, methyl iodide, water and the catalyst. At least a part of the reaction mixture (A) is separated in a flash zone to obtain a vapor stream (B) which comprises acetic acid, hydrogen iodide, methyl iodide and water. The vapor stream (B) is withdrawn from the flash zone, and the withdrawn vapor stream is then reacted with at least one alkylimidazole to obtain a composition (C) from which acetic acid is separated. By reacting the vapor stream (B) with the alkylimidazole at least parts of the hydrogen iodide and methyl iodide contained in (B) are bound in form of iodide salts which significantly facilitates the separation of crude acetic acid from the vapor stream (B) and the further purification of the crude acetic acid.

Process for the manufacture of acetic acid

A process is disclosed for the production of vinyl acetate where a mixture of ethylene, acetic acid, and oxygen is reacted in the presence of a catalyst to produce a product mixture of vinyl acetate, ethylene, carbon dioxide, acetic acid, water, ethyl acetate, and ethylene glycol diacetate. The product mixture contains both a gaseous phase and a liquid phase, which are separated. The gas phase contains at least carbon dioxide, which is removed via gas stream. The crude vinyl acetate stream is removed via a liquid stream. The crude vinyl acetate is then further separated to isolate a stream containing at the majority of the ethylene glycol diacetate. The ethylene glycol diacetate stream is then methanolyzed in the presence of a methanolyzing catalyst, to recover methyl acetate, which can be optionally recycled as a feed stock to an acetic acid plant.

Vinyl acetate production process

The invention is a method of removing methyl iodide from an alkane distillation bottoms stream of an acetic acid production process. The method comprises contacting the alkane distillation bottoms stream in the liquid phase with a phosphine or a phosphine-functionalized support, and recovering a treated alkane distillation bottoms stream having a reduced methyl iodide content.

Methyl iodide removal from acetic acid waste stream

A process for producing acetic acid is disclosed. The process comprises carbonylating methanol to form a reaction mixture and flashing the reaction mixture to form a vapor stream and a liquid stream. The flash tank is equipped with a distillation column. The vapor stream comprises acetic acid and other volatile components but essentially no catalyst. The liquid stream comprises the catalyst and sufficient amounts of water and acetic acid to carry and stabilize the catalyst. The liquid stream is recycled to the carbonylation and the vapor stream is subjected to further separation to produce essentially pure acetic acid.

Preparation of acetic acid

A method for reducing aldehydes in an acetic acid production process is disclosed. The acetic acid is produced by reacting methanol and carbon monoxide in the presence of a carbonylation catalyst. The method comprises reacting an aldehyde-containing stream with an alcohol to form an acetal-containing stream. An acetal-enriched stream is separated from the acetal-containing stream and then hydrolyzed to form a hydrolysis mixture comprising the alcohol and the aldehydes. The alcohol is isolated from the hydrolysis mixture and used to react with the aldehyde-containing stream to form the acetal-containing stream. The invention reduces aldehydes in the acetic acid produced.

A process for producing acetic acid is disclosed. The process comprises carbonylating methanol to form a reaction mixture comprising a catalyst, catalyst stabilizer, acetic acid, methanol, methyl iodide, methyl acetate, water, and carbon monoxide and introducing at least a portion of the reaction mixture to a distillation column to separate into a bottom steam comprising the catalyst and catalyst stabilizer, a sidedraw stream comprising acetic acid and water, and an overhead stream comprising methanol, methyl acetate, methyl iodide, and water. The process of the invention eliminates the use of flash tank.

A method for removing aldehyde impurities from an acetic acid stream is disclosed. The method comprises reacting aldehyde impurities with a hydroxyl compound in a drying distillation column or a combined column to form corresponding acetals. The acetals are subsequently removed as heavy impurities from acetic acid by distillation.

A method of real time process control in a reaction system for the production of vinyl acetate from the oxidation of ethylene and acetic acid. Reaction system samples are collected from the reactor vessel feed and/or effluent and/or from columns and/or transfer lines downstream of the reactor vessel, and the concentration of one or more components in the sample is measured by an infrared analyzer. The concentration measurements are then used to make adjustments in the concentration of components in the reaction system, directly or indirectly, such as by adjusting the temperature profile in a particular column, the flow rate of solution in to or out of a column, or the addition or extraction of a component to or from the solution. For optimum process control, the measurements are transmitted to a control unit for real time analysis, and the adjustments are made almost instantly after the infrared analysis.

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Glen Mills, PA, United States of America

Wayne Joseph Brtko