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 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 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: Disclosed is a method for controlling the decanter phase separation of an acetic acid production by methanol carbonylation. The method comprises measuring the methyl acetate concentration of the reactor mixture, calculating the density of the decanter heavy, organic phase according to the measured methyl acetate concentration, and adjusting the conditions in the reactor or in the decanter to ensure phase separation of the decanter.

Abstract: A method for quantifying the permanganate-reducing compounds (PRCs) in an acetic acid sample is disclosed. The method comprises establishing a correlation between permanganate absorbances of standard samples and their PRC contents and determining the PRC content of the acetic acid sample by measuring its permanganate absorbance of a reaction mixture containing a standard permanganate solution and the acetic acid sample. The permanganate absorbance is obtained by subtracting the manganese dioxide absorbance from the absorbance of the mixture.

Abstract: A method for quantifying the permanganate-reducing compounds (PRCs) in an acetic acid sample is disclosed. The method comprises establishing a correlation between permanganate absorbances of standard samples and their PRC contents and determining the PRC content of the acetic acid sample by measuring its permanganate absorbance of a reaction mixture containing a standard permanganate solution and the acetic acid sample. The permanganate absorbance is obtained by subtracting the manganese dioxide absorbance from the absorbance of the mixture.

Abstract: Disclosed is a method for controlling the decanter phase separation of an acetic acid production by methanol carbonylation. The method comprises measuring the methyl acetate concentration of the reactor mixture, calculating the density of the decanter heavy, organic phase according to the measured methyl acetate concentration, and adjusting the conditions in the reactor or in the decanter to ensure phase separation of the decanter.

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: 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 method for quantifying the permanganate-reducing compounds (PRCs) in an acetic acid sample is disclosed. The method comprises establishing a correlation between permanganate absorbances of standard samples and their PRC contents and determining the PRC content of the acetic acid sample by measuring its permanganate absorbance of a reaction mixture containing a standard permanganate solution and the acetic acid sample. The permanganate absorbance is obtained by subtracting the manganese dioxide absorbance from the absorbance of the mixture.

Abstract: A method for quantifying the permanganate-reducing compounds (PRCs) in an acetic acid sample is disclosed. The method comprises establishing a correlation between permanganate absorbances of standard samples and their PRC contents and determining the PRC content of the acetic acid sample by measuring its permanganate absorbance of a reaction mixture containing a standard permanganate solution and the acetic acid sample. The permanganate absorbance is obtained by subtracting the manganese dioxide absorbance from the absorbance of the mixture.

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 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 method of real time process control in a reaction system for the production of acetic acid from the carbonylation of methanol. Reaction system samples are collected from columns and/or transfer lines downstream of a 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, the vent gas rate out of the reactor or 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 substantially instantly after the infrared analysis.

Abstract: 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.

Abstract: There is provided a process control method for the production of acetic acid by the catalyzed carbonylation of methanol and a process for the manufacture of acetic acid using the process control method. The process control method comprises measuring various reactor component concentrations, specifically the active catalyst species, methyl iodide, water and methyl acetate by means of an infrared analyzer, and adjusting in response thereto the concentrations of at least the catalyst species, methyl iodide and water to optimize the acetic acid reaction.

Abstract: There is provided a process control method for the production of acetic acid by the catalyzed carbonylation of methanol and a process for the manufacture of acetic acid using the process control method. The process control method comprises measuring various reactor component concentrations, specifically the active catalyst species, methyl iodide, water and methyl acetate by means of an infrared analyzer, and adjusting in response thereto the concentrations of at least the catalyst species, methyl iodide and water to optimize the acetic acid reaction.

Abstract: Methanol is converted to acetic acid by reaction with carbon monoxide in the presence of an improved carbonylation system which comprises a rhodium catalyst component and a liquid reaction medium containing water in low levels, acetic acid, methyl iodide, methyl acetate, and at least one pentavalent Group VA oxide wherein the concentration of pentavalent Group VA oxide to rhodium is greater than about 60:1. The present carbonylation system not only increases the yields and reaction rates but also serves to stabilize the rhodium catalyst component in an active form.

Abstract: Methanol is converted to acetic acid by reaction with carbon monoxide in the presence of an carbonylation system which comprises a rhodium catalyst component and a liquid reaction medium containing acetic acid, methyl iodide, methyl acetate, and at least one pentavalent Group VA oxide and water in specific concentrations. The present carbonylation system not only increases the yields and reaction rates but also serves to stabilize the rhodium catalyst component in an active form.