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 ethyl acetate by reacting ethylene with acetic acid and water in the presence of a heteropolyacid catalyst in which the concentrations of reactants in the feed stream to the reactor are such that the mole ratio of ethylene to acetic acid lies in the range 6.0 to 12.2, the mole ratio of ethylene to water lies in the range 8.0 to 17.0 and the mole ratio of acetic acid to water lies in the range 1.25 to 1.40. It has been found that by careful control of the relative concentration of the reactants and of the process operating conditions the relative amounts of methyl ethyl ketone (MEK, 2-butanone) coproduced with the desired ethyl acetate can be reduced and the catalyst life can thereby be extended.

Abstract: Process for making lower aliphatic ester, especially ethyl acetate, by reacting a lower olefin with a saturated lower aliphatic mono-carboxylic acid in the vapor phase using a heteropolyacid catalyst, wherein the reaction pressure is 11 to 20 barg (1100 to 2000 KPa), more preferably 12 to 15 barg (1200 to 1500 KPa). The reaction temperature is 140 to 250° C., more preferably 160 to 195° C. The process reduces the level of by-products, for example methyl ethyl ketone and/or acetaldehyde.