Abstract: An improved process for the manufacture of technical grade (meth)acrylic acid, e.g., acrylic acid, the process comprising producing a hydrated reaction product from the gas-phase oxidation of at least one (meth)acrylic acid precursor, e.g., propylene, followed by first dehydrating and then concentrating the reaction product, the improvement comprising controlling at least one of the water, acetic acid and (meth)acrylic acid content of the reaction product during the purification of the reaction product using on-line, near IR spectroscopy.

Abstract: An improved process for the manufacture of technical grade (meth)acrylic acid, e.g., acrylic acid, the process comprising producing a hydrated reaction product from the gas-phase oxidation of at least one (meth)acrylic acid precursor, e.g., propylene, followed by first dehydrating and then concentrating the reaction product, the improvement comprising controlling at least one of the water, acetic acid and (meth)acrylic acid content of the reaction product during the purification of the reaction product using on-line, near IR spectroscopy.

Abstract: An improved process for the manufacture of technical grade (meth)acrylic acid, e.g., acrylic acid, the process comprising producing a hydrated reaction product from the gas-phase oxidation of at least one (meth)acrylic acid precursor, e.g., propylene, followed by first dehydrating and then concentrating the reaction product, the improvement comprising controlling at least one of the water, acetic acid and (meth)acrylic acid content of the reaction product during the purification of the reaction product using on-line, near IR spectroscopy.

Abstract: The process for the distillation of a gas mixture comprising (meth)acrylic acid obtained from the gas-phase oxidation of at least one (meth)acrylic acid precursors is improved through the use of coupled distillation columns. In a first column, the gaseous mixture is dehydrated while in a second column, the dehydrated gaseous mixture is distilled into product, overhead and bottoms streams.

Abstract: The process for the distillation of a gas mixture comprising (meth)acrylic acid obtained from the gas-phase oxidation of at least one (meth)acrylic acid precursors is improved through the use of coupled distillation columns. In a first column, the gaseous mixture is dehydrated while in a second column, the dehydrated gaseous mixture is distilled into product, overhead and bottoms streams.

Abstract: The process for the distillation of a gas mixture comprising (meth)acrylic acid obtained from the gas-phase oxidation of at least one (meth)acrylic acid precursors is improved through the use of coupled distillation columns. In a first column, the gaseous mixture is dehydrated while in a second column, the dehydrated gaseous mixture is distilled into product, overhead and bottoms streams.

Abstract: An improved process for the manufacture of technical grade (meth)acrylic acid, e.g., acrylic acid, the process comprising producing a hydrated reaction product from the gas-phase oxidation of at least one (meth)acrylic acid precursor, e.g., propylene, followed by first dehydrating and then concentrating the reaction product, the improvement comprising controlling at least one of the water, acetic acid and (meth)acrylic acid content of the reaction product during the purification of the reaction product using on-line, near IR spectroscopy.

Abstract: The process for the distillation of a gas mixture comprising (meth)acrylic acid obtained from the gas-phase oxidation of at least one (meth)acrylic acid precursors is improved through the use of coupled distillation columns. In a first column, the gaseous mixture is dehydrated while in a second column, the dehydrated gaseous mixture is distilled into product, overhead and bottoms streams.

Abstract: Processes are disclosed for the oxidation of alkanes such as, for example, propane, to form unsaturated carboxylic aldehydes and acids such as, for example, acrolein and acrylic acid. The processes utilize oxygen and recycle alkanes, e.g. propane, to the aldehyde reactor. The presence of the alkane-to-aldehyde reaction can enhance the efficiency of the processes.

Abstract: Processes are disclosed for the conversion of propylene to methylmercaptopropanal by converting propylene to acrolein and converting acrolein to methylmercaptopropanal. The processes utilize oxygen and recycle propane to the acrolein reactor. Process feeds can comprise, propane, propylene or mixtures thereof. The presence of propane in the propylene-to-acrolein reaction can enhance the efficiency of the processes.

Abstract: Acrolein is prepared by the heating of 3,4-dihydro-2H-pyran-2-carboxaldehyde. The process provides acrolein in very high yields and with few impurities. The process is advantageously employed to produce acrolein at the point of use.

Abstract: The processes for oxidation of propylene to acrolein and the oxidation of propylene to acrylic acid in two stages with acrolein as an intermediate are improved by use of essentially inert essentially anhydrous diluent gases to replace steam in the reaction streams. In particular, the use of essentially inert essentially anhydrous diluents which raise the composite heat capacity of the diluent gaas mixture to at least about 6.5 calories/(gram-mole) (.degree.C.) will improve selectivity to desired products and will reduce both the waste water load on the system and by-product formation.

Abstract: The process for oxidation of propylene to acrolein and the oxidation of propylene to acrylic acid in two stages with acrolein as an intermediate are improved by use of essentially inert essentially anhydrous diluent gases to replace steam in the reaction streams. In particular, the use of essentially inert essentially anhydrous diluents which raise the composite heat capacity of the diluent gas mixture to at least about 6.5 calories/(gram-mole) (.degree.C.) will improve selectively to desired products and will reduce both the waste water load on the system and by-product formation. Reduction in second-stage catalyst efficiency is compensated for by introducing steam to the feed to the second-stage, and/or by increasing the operating temperature of the second-stage, and/or by increasing the active surface area of the second-stage catalyst.

Abstract: The processes for oxidation of isobutylene to methacrolein and the oxidation of isobutylene to methacrylic acid in two stages with methacrolein as an intermediate are improved by use of essentially inert essentially anhydrous diluent gases to replace steam in the reaction streams. In particular, the uses of essentially inert essentially anhydrous diluents which raise the composite heat capacity of the diluent gas mixture to at least about 6.5 calories/(gram-mole) (.degree.C.) will improve selectivity to desired products and will reduce both the waste water load on the system and by-product formation.

Abstract: A process for producing acrylic ester by the catalytic esterification of a crude liquid stream of enriched acrylic acid recovered by the partial condensation of the reaction gas effluent from the catalytic oxidation of propylene and/or acrolein. The partial condensation allows a significant proportion of volatile aldehydes and water to pass through the first recovery stage to a second stage for conventional recovery, along with uncondensed acrylic acid vapors and the remainder of the uncondensed reaction gases.