Provided is a catalyst precursor containing a Keggin-type heteropolyacid used for the production of an ,-unsaturated carboxylic acid by oxidation of an ,-unsaturated aldehyde.

Provided is a catalyst precursor containing a Keggin-type heteropolyacid used for the production of an ,-unsaturated carboxylic acid by oxidation of an ,-unsaturated aldehyde.

The present disclosure relates to a method for preparing a crosslinker compound in which a crosslinker compound capable of using for the production of a super absorbent polymer can be obtained in a higher yield by a simple manner. The crosslinker compound obtained by the above method can be used as a thermally decomposable crosslinker in the process of producing a super absorbent polymer.

The present disclosure relates to a method for preparing a crosslinker compound in which a crosslinker compound capable of using for the production of a super absorbent polymer can be obtained in a higher yield by a simple manner. The crosslinker compound obtained by the above method can be used as a thermally decomposable crosslinker in the process of producing a super absorbent polymer.

A continuous flow process for the preparation of one or more esters of lactic acid and 2-hydroxy-3-butenoic acid or -hydroxy methionine analogs from a sugar in the presence of a solid Lewis acid catalyst and a solvent comprising an organic solvent and water. The invention facilitates Lewis acid catalyst stability in a continuous reaction process where the water is present in an amount of up to or equal to 10 vol. % of the organic solvent.

A continuous flow process for the preparation of one or more esters of lactic acid and 2-hydroxy-3-butenoic acid or -hydroxy methionine analogs from a sugar in the presence of a solid Lewis acid catalyst and a solvent comprising an organic solvent and water. The invention facilitates Lewis acid catalyst stability in a continuous reaction process where the water is present in an amount of up to or equal to 10 vol. % of the organic solvent.

A process can be used for preparing methyl methacrylate (MMA), by direct oxidative esterification of methacrolein. The MMA and polymers produced therefrom feature a very low yellowness index. A workup of the reactor output from the oxidative esterification of methacrolein allows for particularly discolouring by-products to be removed or degraded without significant MMA losses.

A process can be used for preparing methyl methacrylate (MMA), by direct oxidative esterification of methacrolein. The MMA and polymers produced therefrom feature a very low yellowness index. A workup of the reactor output from the oxidative esterification of methacrolein allows for particularly discolouring by-products to be removed or degraded without significant MMA losses.

A continuous production system for alcohol ester C-12 is provided, comprising: a feedstock tank, a reaction tower, an atmospheric distillation tower, a vacuum distillation tower, a condenser, a water washing tower, a dehydration tower, an evaporator, a light component removal tower, and a rectifying tower that are all connected with each other through pipelines. The continuous production system for alcohol ester C-12 replaces the traditional intermittent production process with the advantages of good batch stability, less by-products, and high yield.

A continuous production system for alcohol ester C-12 is provided, comprising: a feedstock tank, a reaction tower, an atmospheric distillation tower, a vacuum distillation tower, a condenser, a water washing tower, a dehydration tower, an evaporator, a light component removal tower, and a rectifying tower that are all connected with each other through pipelines. The continuous production system for alcohol ester C-12 replaces the traditional intermittent production process with the advantages of good batch stability, less by-products, and high yield.