Abstract: Processes for producing acetic acid herein generally include contacting methanol and carbon monoxide in the presence of a reaction medium under carbonylation conditions sufficient to form acetic acid, the reaction medium including a carbonylation catalyst selected from rhodium catalysts, iridium catalysts and palladium catalysts; from 1 wt. % to 14 wt. % water; and a plurality of additives, in-situ generated derivatives of the plurality of additives or combinations thereof; the plurality of additives including a first additive including one or more phosphine oxides and a second additive selected from heteropolyacids, metal salts and combinations thereof, the heteropolyacids represented by the formula HnM12XO40, wherein H is hydrogen, M is selected from tungsten and molybdenum, X is selected from phosphorous and silicon and O is oxygen and n is 3 or 4, the metal salts are selected from transition metal salts, lanthanide metal salts and combinations thereof; and recovering acetic acid from the process.

Abstract: Processes for producing acetic acid and determining corrosion therein are described herein. The processes generally include contacting methanol and carbon monoxide in the presence of a liquid reaction medium under carbonylation conditions sufficient to form acetic acid, wherein the liquid reaction medium includes: a carbonylation catalyst selected from rhodium catalysts, iridium catalysts and palladium catalysts; from 1 wt. % to 14 wt. % water; and one or more, in-situ generated derivatives of the one or more additives and combinations thereof; wherein the one or more additives are independently selected from non-benzoyl containing pentavalent phosphine oxides, compound mixtures of at least four phosphine oxides and pentavalent aryl or alkaryl phosphine oxides including one or more benzoyl groups; and recovering acetic acid from the process.

Abstract: 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.

Abstract: The phase separation in the decanter of a process for producing acetic acid by carbonylating methanol in the presence of a catalyst under low water-high acid conditions is improved by forming a liquid mixture (D) which has a water content of at most 20% by weight, based on the weight of the liquid mixture, and a weight ratio of acetic acid to water of at least 1:1, and partitioning the liquid mixture by providing for an alkane(s) content of D of from 0.1 to 15% by weight, based on the weight of D, to obtain a light, aqueous phase and a heavy, organic phase.

Abstract: The phase separation in the decanter of a process for producing acetic acid by carbonylating methanol in the presence of a catalyst under low water-high acid conditions is facilitated and expedited by forming a liquid mixture (D) which has a water content of at most 10% by weight, based on the weight of the liquid mixture, an acetic acid content of at least 10% by weight, based on the weight of the liquid mixture, and a weight ratio of methyl iodide to methyl acetate of at least 1.5:1, and partitioning the liquid mixture at a temperature of from 0 to 35° C.

Abstract: A system and method for removing acetaldehyde from an acetic acid system, including providing a solution from the acetic acid system, the stream having methyl iodide and acetaldehyde, and contacting the solution with an ion-exchange resin and/or liquid catalyst.

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: 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 (BV) which comprises the acetic acid, water and methyl iodide, and a liquid stream (BL) which comprises the catalyst, the alkylimidazolium iodide and hydrogen iodide. The vapor stream (BV) is processed to purify the acetic acid, and the liquid stream (BL) is recycled to the reaction zone.

Abstract: A system and method for removing acetaldehyde from an acetic acid system, including providing a solution from the acetic acid system, the stream having methyl iodide and acetaldehyde, and contacting the solution with an ion-exchange resin and/or liquid catalyst.

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: 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.

Abstract: The phase separation in the decanter of a process for producing acetic acid by carbonylating methanol in the presence of a catalyst under low water-high acid conditions is improved by forming a liquid mixture (D) which has a water content of at most 20% by weight, based on the weight of the liquid mixture, and a weight ratio of acetic acid to water of at least 1:1, and partitioning the liquid mixture by providing for an alkane(s) content of D of from 0.1 to 15% by weight, based on the weight of D, to obtain a light, aqueous phase and a heavy, organic phase.

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: 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.

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 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 (BV) which comprises the acetic acid, water and methyl iodide, and a liquid stream (BL) which comprises the catalyst, the alkylimidazolium iodide and hydrogen iodide. The vapor stream (BV) is processed to purify the acetic acid, and the liquid stream (BL) is recycled to the reaction zone.

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 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.

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.