Abstract: 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 (BV) which comprises acetic acid, hydrogen iodide, methyl iodide and water. The vapor stream (BV) is withdrawn from the flash zone, and the withdrawn vapor stream is then reacted with at least one alkylimidazole to obtain a composition (C) from which acetic acid is separated.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 (BV) with the alkylimidazole at least parts of the hydrogen iodide and methyl iodide contained in (BV) are bound in form of iodide salts which significantly facilitates the separation of crude acetic acid from the vapor stream (BV) and the further purification of the crude acetic acid.

Abstract: A method for determining the characteristic of one or more components in a step of an acetic acid production process using Raman spectroscopy. The process includes providing a feed stream comprising multiple components to a separations unit, one of the components being acetic acid, the separations unit separating the feed stream into two or more exit streams having a different composition from one another, and measuring a characteristic of one or more of the components by Raman spectroscopic analysis.

Abstract: Disclosed is a method for controlling a vinyl acetate production process. The method comprises reacting ethylene, acetic acid, and an oxygen-containing gas in the presence of a catalyst in a reactor to produce vinyl acetate, measuring the concentration of a component involved in or associated with the reaction and/or any of the subsequent steps by Raman spectroscopic analysis, and adjusting the conditions in the reactor or in any of the subsequent steps in response to the measured concentration of the component to achieve a proper control of the reaction or any of the subsequent steps.

Abstract: Disclosed is a method for controlling an acetic acid production process. The method comprises: (i) reacting methanol and carbon monoxide in the presence of a carbonylation catalyst, a catalyst stabilizer, methyl iodide, water, and methyl acetate to produce a reactor mixture which comprises the catalyst, the catalyst stabilizer, methanol, carbon monoxide, carbon dioxide, methyl iodide, methyl acetate, water, and acetic acid; (ii) measuring the concentration of a component of the reactor mixture by Raman spectroscopic analysis; and (iii) adjusting the component concentration in the reactor mixture in response to the measured concentration. The method of the invention is particularly useful for measuring and controlling the concentration of carbon monoxide in the reactor liquid mixture.

Abstract: 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.

Abstract: The invention is a method of purifying acetic acid containing 15 to 100 ppb iodide compounds. The method comprises contacting the acetic acid in the liquid phase with a phosphine-functionalized support, and recovering a purified acetic acid product having 10 ppb, or less, iodide compounds.

Abstract: The invention is a method of purifying propylene oxide containing 25-100 ppm aldehyde impurities. The method comprises contacting the propylene oxide in the liquid phase with an amine-functionalized ion exchange resin, and recovering a purified propylene oxide product containing 10 ppm, or less, aldehydes.

Abstract: 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.

Abstract: Disclosed is a process for the preparation of acetic acid and acetic anhydride. The process comprises carbonylating dimethyl carbonate. The carbonylation reaction for producing acetic acid is performed in the presence of water, while the carbonylation for producing acetic anhydride is performed essentially in the absence of water.

Abstract: The disclosure relates to a process for the preparation of acetic acid. The process comprises reacting a decanter heavy, organic phase of an acetic acid production process with acetic anhydride to convert acetaldehyde in the decanter heavy, organic phase to ethylidene diacetate and separating it from the decanter heavy, organic phase. Ethylidene diacetate can be hydrolyzed to recover acetic acid.

Abstract: The invention is a method of purifying propylene oxide containing 25-100 ppm aldehyde impurities. The method comprises contacting the propylene oxide in the liquid phase with an amine-functionalized ion exchange resin, and recovering a purified propylene oxide product containing 10 ppm, or less, aldehydes.

Abstract: A process for the production of vinyl acetate is disclosed. The process comprises reacting ethylene, acetic acid, and oxygen in the presence of a catalyst to produce a reaction mixture comprising vinyl acetate, ethylene, carbon dioxide, acetic acid, water and ethylene glycol diacetate. The reaction mixture is separated to a gas stream comprising ethylene, and carbon dioxide and a crude vinyl acetate stream comprising vinyl acetate, acetic acid, water and ethylene glycol diacetate. An ethylene glycol diacetate stream is isolated from the crude vinyl acetate stream and subjected to a reactive distillation to recover acetic acid.

Abstract: A process for the production of vinyl acetate is disclosed. The process comprises reacting ethylene, acetic acid, and oxygen in the presence of a catalyst to produce a reaction mixture comprising vinyl acetate, ethylene, carbon dioxide, acetic acid and ethylene glycol diacetate. The reaction mixture is separated to a gas stream comprising ethylene, oxygen, and carbon dioxide and a crude vinyl acetate stream comprising vinyl acetate, acetic acid and ethylene glycol diacetate. An ethylene glycol diacetate stream, which comprises at least 50 wt % of ethylene glycol diacetate, is isolated from the crude vinyl acetate stream and hydrolyzed to recover acetic acid. Recovered acetic acid may be recycled to the acetoxidation reaction.

Abstract: 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.

Abstract: A method for removing hydrocarbon impurities from acetic acid is disclosed. The method comprises extracting acetic acid with a hydrophilic imidazolium salt. The imidazolium salt preferably has the general structure of wherein X? is a counter ion and R1, R2, R3, R4, and R5 are independently selected from the group consisting of C1-C6 hydrocarbon substitutes. The method is useful for removing hydrocarbon impurities from the alkane distillation bottoms stream of a methanol carbonylation process.

Abstract: A method for removing hydrocarbon impurities from acetic acid is disclosed. The method comprises extracting acetic acid with a hydrophilic imidazolium salt. The imidazolium salt preferably has the general structure of wherein X? is a counter ion and R1, R2, R3, R4, and R5 are independently selected from the group consisting of C1-C6 hydrocarbon substitutes. The method is useful for removing hydrocarbon impurities from the alkane distillation bottoms stream of a methanol carbonylation process.

Abstract: A method for removing hydrocarbon impurities from an acetic acid production intermediate is disclosed. The method comprises extracting the intermediate with a hydrocarbon extracting agent. The extraction is preferably performed with the alkane distillation bottom stream which comprises methyl iodide, acetic acid, and hydrocarbon impurities. The extraction forms a light phase which comprises the hydrocarbon impurity and the extracting agent and a heavy phase which comprises methyl iodide and acetic acid. The extraction heavy phase is optionally recycled to the alkane distillation or to the carbonylation reaction.

Abstract: 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.

Abstract: A method for removing hydrocarbon impurities from an acetic acid production process is disclosed. The method comprises distilling at least a portion of the heavy organic phase from the decanter of the acetic acid production process into a vapor stream comprising the majority of methyl iodide (i.e., over 50% of the methyl iodide from the heavy organic phase) and a bottoms stream comprising the majority of acetic acid, methyl acetate, methyl iodide and the hydrocarbon impurity (i.e., over 50% of each of the components from the heavy organic phase); extracting the bottoms stream with water, an acetic acid aqueous solution, or with a methanol aqueous solution to form an organic phase comprising the majority of the hydrocarbon impurity (over 50% of the hydrocarbon impurity from the bottom stream) and an aqueous phase comprising the majority of methyl iodide (over 50% of the methyl iodide from the bottoms stream); and recycling the aqueous phase to the carbonylation reaction.

Abstract: 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.