A process is useful for producing optical molding materials on the basis of methyl methacrylate (MMA), wherein this MMA has been produced by an optimized method and the molding materials feature in particular a very low yellowness index. This MMA has been produced by direct oxidative esterification of methacrolein. In particular, an optimized workup of the reactor output from the oxidative esterification of methacrolein is useful for removing particularly discoloring byproducts. This process moreover has the advantage that fewer demands than described in related art are placed on plant apparatus configuration.

A process is useful for producing optical molding materials on the basis of methyl methacrylate (MMA), wherein this MMA has been produced by an optimized method and the molding materials feature in particular a very low yellowness index. This MMA has been produced by direct oxidative esterification of methacrolein. In particular, an optimized workup of the reactor output from the oxidative esterification of methacrolein is useful for removing particularly discoloring byproducts. This process moreover has the advantage that fewer demands than described in related art are placed on plant apparatus configuration.

A process for the preparation of MMA via oxidative esterification in the presence of a catalyst comprising palladium, bismuth, and antimony.

A process for the preparation of MMA via oxidative esterification in the presence of a catalyst comprising palladium, bismuth, and antimony.

This invention relates to a method for the conversion of lignocellulosic biomass into ethyl esters of carboxylic acids. Said method consists of treating the biomass material with an oxidizing agent that is incorporated in an solution comprising one or more acids, one or more alcohols and water, and subsequently performing a catalytic reaction at a higher temperature using the same acidic solution into which a larger volume of alcohol is added, in such a way that the catalytic conversion occurs in a medium with a much higher concentration of alcohol, i.e. with a much higher alcohol-to-water wt ratio. Such a method results in relatively high yields of ethyl esters, such as ethyl esters of formic, acetic, and levulinic acids, while producing a low yield of dialkyl ethers, which are unwanted by-products. The concentration of the oxidizing agent in the pre-treatment step is preferably higher than 6.0 wt %. The oxidizing agent is preferably a Fenton or Fenton-type reagent, and most preferably hydrogen peroxide activated by Fe (II), and/or Ti (IV) ions. The alcohol is preferably ethanol, and when ethanol is used, diethyl ether is formed as the unwanted dialkyl ether by-product. Preferably, the biomass material is pelleted before treatment.

This invention relates to a method for the conversion of lignocellulosic biomass into ethyl esters of carboxylic acids. Said method consists of treating the biomass material with an oxidizing agent that is incorporated in an solution comprising one or more acids, one or more alcohols and water, and subsequently performing a catalytic reaction at a higher temperature using the same acidic solution into which a larger volume of alcohol is added, in such a way that the catalytic conversion occurs in a medium with a much higher concentration of alcohol, i.e. with a much higher alcohol-to-water wt ratio. Such a method results in relatively high yields of ethyl esters, such as ethyl esters of formic, acetic, and levulinic acids, while producing a low yield of dialkyl ethers, which are unwanted by-products. The concentration of the oxidizing agent in the pre-treatment step is preferably higher than 6.0 wt %. The oxidizing agent is preferably a Fenton or Fenton-type reagent, and most preferably hydrogen peroxide activated by Fe (II), and/or Ti (IV) ions. The alcohol is preferably ethanol, and when ethanol is used, diethyl ether is formed as the unwanted dialkyl ether by-product. Preferably, the biomass material is pelleted before treatment.

A compound is provided of Formula (I), wherein R.sup.1 represents a C.sub.3 to C.sub.20 hydrocarbon group derived from an alcohol of formula R.sup.1OH, from a formate of formula R.sup.1OCH═O, or a cinnamyl aldehyde of Formula (II) wherein a compound of Formula I is capable of releasing a compound, when oxidized, selected from the group consisting of a fragrant alcohol of formula R.sup.1OH, a fragrant formate ester of formula R.sup.1OCH=0 and aryl aldehyde of Formula (III), wherein R.sup.2 is, independently, hydrogen atom, hydroxyl group, optionally substituted C.sub.1-C.sub.6 alkyl group, C.sub.1-C.sub.6 alkoxy group, or -0(C=0)CH(CH3).sub.2 wherein any two of R.sup.2 may form an optionally substituted 5 or 6 membered ring. The compounds are useful for example as a precursor for the prolonged delivery or release of fragrant compounds such as fragrant alcohols, fragrant aldehydes or fragrant formates. ##STR00001##

A compound is provided of Formula (I), wherein R.sup.1 represents a C.sub.3 to C.sub.20 hydrocarbon group derived from an alcohol of formula R.sup.1OH, from a formate of formula R.sup.1OCH═O, or a cinnamyl aldehyde of Formula (II) wherein a compound of Formula I is capable of releasing a compound, when oxidized, selected from the group consisting of a fragrant alcohol of formula R.sup.1OH, a fragrant formate ester of formula R.sup.1OCH=0 and aryl aldehyde of Formula (III), wherein R.sup.2 is, independently, hydrogen atom, hydroxyl group, optionally substituted C.sub.1-C.sub.6 alkyl group, C.sub.1-C.sub.6 alkoxy group, or -0(C=0)CH(CH3).sub.2 wherein any two of R.sup.2 may form an optionally substituted 5 or 6 membered ring. The compounds are useful for example as a precursor for the prolonged delivery or release of fragrant compounds such as fragrant alcohols, fragrant aldehydes or fragrant formates. ##STR00001##

A catalyst comprising palladium, bismuth, and at least one third element X selected from the group consisting of P, S, Sc, V, Ga, Se, Y, Nb, Mo, La, Ce, and Nd, wherein the catalyst further comprises a support.

A catalyst comprising palladium, bismuth, and at least one third element X selected from the group consisting of P, S, Sc, V, Ga, Se, Y, Nb, Mo, La, Ce, and Nd, wherein the catalyst further comprises a support.