Provided is a method for producing purified acetic acid with a good hue. A method for producing purified acetic acid, including treating acetic acid having a poor hue with a synthetic adsorbent to obtain acetic acid with an improved hue. The acetic acid to be treated is, for example, acetic acid having an absorbance of 0.01 or greater at a wavelength of 430 nm. The acetic acid to be treated may be acetic acid recovered from an acetic acid-containing solution that is discharged in a cellulose acetate production process. The synthetic adsorbent may have a cation exchange group on a resin surface. The synthetic adsorbent may have a pore structure.

Provided is a method for producing purified acetic acid with a good hue. A method for producing purified acetic acid, including treating acetic acid having a poor hue with a synthetic adsorbent to obtain acetic acid with an improved hue. The acetic acid to be treated is, for example, acetic acid having an absorbance of 0.01 or greater at a wavelength of 430 nm. The acetic acid to be treated may be acetic acid recovered from an acetic acid-containing solution that is discharged in a cellulose acetate production process. The synthetic adsorbent may have a cation exchange group on a resin surface. The synthetic adsorbent may have a pore structure.

Compositions and methods are provided for producing crystalline forms of organic acids or salts or lactones thereof from an aqueous solution. More specifically, methods are provided for producing a crystalline form of a salt of mevalonic acid (also referred to as X-MVA) from an aqueous solution, comprising subjecting the aqueous solution comprising said X-MVA to a purification step to produce a purified solution and crystallizing said X-MVA from said purified solution by water solvent crystallization. Methods are also provided for producing mevalonolactone from an aqueous solution comprising X-MVA, comprising subjecting the aqueous solution comprising said X-MVA to cation exchange thereby converting said aqueous solution comprising X-MVA to an aqueous solution comprising mevalonolactone (MVL). Methods are also provided for producing mevalonolactone monohydrate crystals.

A monolithic organic porous ion exchanger having a continuous skeleton and continuous pores, wherein the continuous skeleton is formed of an organic polymer being a hydrolysate of a crosslinked polymer of a (meth)acrylic acid ester and divinylbenzene, the organic polymer having any one or both of a —COOH group and a —COONa group as ion-exchange groups, the continuous skeleton has a thickness of 0.1 to 100 μm, the continuous pores have an average diameter of 1.0 to 1000 μm, the monolithic organic porous ion exchanger has a total pore volume of 0.5 to 50.0 mL/g, and has a total ion-exchange capacity of the —COOH group and the —COONa group per weight in a dry state of 4.0 mg equivalent/g or more.

A monolithic organic porous ion exchanger having a continuous skeleton and continuous pores, wherein the continuous skeleton is formed of an organic polymer being a hydrolysate of a crosslinked polymer of a (meth)acrylic acid ester and divinylbenzene, the organic polymer having any one or both of a —COOH group and a —COONa group as ion-exchange groups, the continuous skeleton has a thickness of 0.1 to 100 μm, the continuous pores have an average diameter of 1.0 to 1000 μm, the monolithic organic porous ion exchanger has a total pore volume of 0.5 to 50.0 mL/g, and has a total ion-exchange capacity of the —COOH group and the —COONa group per weight in a dry state of 4.0 mg equivalent/g or more.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Method for lowering aldehyde content in a mixture comprising (i) diethylene glycol (DEG) and/or triethylene glycol (TEG) and (ii) aldehyde are disclosed. An ion exchange resin is soaked in monoethylene glycol. The mixture comprising 5 to 200 ppm aldehyde is then flowed to make contact with the soaked ion exchange resin to produce a product comprising DEG and/or TEG and less than 15 ppm aldehyde.

Precious metals such as those of the platinum group can be effectively recovered from crystalline aluminosilicate supports, for example from spent catalysts, without appreciable degradation of the crystal structure by ion-exchange using a base metal ion containing medium and subsequent sequestration of the precious metal in elemental form on a nonionic cross linked borane reducing resin.