Abstract: Process for producing acetic acid by carbonylating methanol and/or a reactive derivative thereof in a liquid reaction composition in which there exists in equilibrium, at least a first soluble catalytic species and a second soluble catalytic species. The first catalytic species is the least catalytically active or promotionally active of the species existing in the equilibrium. The process includes determining (i) the concentration of the first catalytic species and/or (ii) the ratio of the concentration of the first catalytic species to the concentration of the second catalytic species in equilibrium therewith, present in the liquid reaction composition and/or a present in a liquid fraction in a separation step, and maintaining (i) and/or (ii) below a pre-determined value.

Abstract: A process for the production of methyl acetate by reacting dimethyl ether with carbon monoxide into a carbonylation reactor containing a mordenite catalyst in the presence of added methyl acetate and/or acetic acid.

Abstract: A process for the production of methyl acetate by reacting dimethyl ether with carbon monoxide into a carbonylation reactor containing a mordenite catalyst in the presence of added methyl acetate and/or acetic acid.

Abstract: A process for the production of acetic acid which process comprises carbonylating methanol and/or a reactive derivative thereof in a liquid reaction composition in which there exists in equilibrium, at least a first soluble catalytic species and a second soluble catalytic species, wherein the first catalytic species is the least catalytically active or promotionally active of the species existing in the equilibrium, comprises determining (i) the concentration of the first catalytic species and/or (ii) the ratio of the concentration of the first catalytic species to the concentration of the second catalytic species in equilibrium therewith, present in the liquid reaction composition and/or a present in a liquid fraction in a separation step and maintaining (i) and/or (ii) below a pre-determined value, preferably by adjusting the concentration of at least the first catalytic species present in the liquid reaction composition and/or liquid fraction.

Abstract: A process for recovering tungsten from a spent catalyst comprising a supported heteropolytungstic acid characterised in that the process comprises: (a) contacting the spent catalyst with an extractant selected from water, methanol, ethanol or a mixture of any two or more thereof for sufficient time to extract at least part of the heteropolytungstic acid therefrom; (b) separating the extractant containing heteropolytungstic acid from the treated spent catalyst; (c) contacting the extractant containing heteropolytungstic acid with a strong acid ion exchange resin to remove corrosion metals contained therein and (d) recovering the treated extractant containing heteropolytungstic acid for subsequent use.

Abstract: A process for the production of acetic acid by carbonylating methanol and/or a reactive derivative thereof with carbon monoxide in at least one carbonylation reaction zone containing a liquid reaction composition comprising an iridium carbonylation catalyst, methyl iodide co-catalyst, a finite concentration of water, acetic acid, methyl acetate, at least one promoter selected from ruthenium, osmium and rhenium and at least one catalyst system stabiliser selected from indium, cadmium, mercury, gallium and zinc and wherein the molar ratio of iridium:promoter:stabiliser in the liquid reaction composition is maintained in the range 1:(>2 to 15):(0.25 to 12).

Abstract: A process for the production of acetic acid by reacting carbon monoxide with methanol and/or a reactive derivative thereof in a liquid reaction composition comprising an iridium carbonylation catalyst, methyl iodide, methyl acetate, water and acetic acid characterized in that there is also present in the reaction composition a polydentate phosphine oxide compound in an amount of less than 10 mol per gram atom of iridium.