The present invention relates to a process for treating a composition comprising natural vanillin by separating a compound of formula (I).

##STR00001##

Provided is a method of separating carbon and oxygen isotopes by using a laser. In one preferred embodiment, the method includes performing a photolysis process on formaldehyde including a carbon or oxygen isotope by irradiation with ultraviolet light having a wavelength ranging from 340 nm to 360 nm to generate carbon monoxide having a carbon or oxygen isotope enriched therein and hydrogen, performing a catalytic reaction on the carbon monoxide having a carbon or oxygen isotope enriched therein and the hydrogen to synthesize carbon dioxide (CO.sub.2) and water (H.sub.2O) having a carbon or oxygen isotope enriched therein, and cooling the H.sub.2O to recover CO.sub.2 having a carbon isotope enriched therein or H.sub.2O having an oxygen isotope enriched therein.

Provided is a method of separating carbon and oxygen isotopes by using a laser. In one preferred embodiment, the method includes performing a photolysis process on formaldehyde including a carbon or oxygen isotope by irradiation with ultraviolet light having a wavelength ranging from 340 nm to 360 nm to generate carbon monoxide having a carbon or oxygen isotope enriched therein and hydrogen, performing a catalytic reaction on the carbon monoxide having a carbon or oxygen isotope enriched therein and the hydrogen to synthesize carbon dioxide (CO.sub.2) and water (H.sub.2O) having a carbon or oxygen isotope enriched therein, and cooling the H.sub.2O to recover CO.sub.2 having a carbon isotope enriched therein or H.sub.2O having an oxygen isotope enriched therein.

The present invention provides a process for preparing aldehydes from C2 to C20 olefins using a subsequent membrane separation to separate the homogeneously dissolved catalyst system, wherein prior to the membrane separation a gas exchange that increases the partial pressure fraction of carbon monoxide or hydrogen is carried out in order to boost catalyst retention by the membrane.

The presence of certain impurities in diphenyl sulfone have a deleterious effect on the properties of the poly(aryletherketone)s produced therein, including one or more of color, melt stability, molecular weight, crystallinity, etc. and here identify those impurities and provide processes for the recovery of the diphenyl sulfone.

The presence of certain impurities in diphenyl sulfone have a deleterious effect on the properties of the poly(aryletherketone)s produced therein, including one or more of color, melt stability, molecular weight, crystallinity, etc. and here identify those impurities and provide processes for the recovery of the diphenyl sulfone.

Provided is a process for preparing dry methacrolein which maximizes capture of methanol. Also provided is a process for producing methyl methacrylate.

Provided is a process for preparing dry methacrolein which maximizes capture of methanol. Also provided is a process for producing methyl methacrylate.

The present invention provides a process for preparing aldehydes from C2 to C20 olefins using a subsequent membrane separation to separate the homogeneously dissolved catalyst system, wherein prior to the membrane separation a gas exchange that increases the partial pressure fraction of carbon monoxide or hydrogen is carried out in order to boost catalyst retention by the membrane.

The present disclosure is directed to methods and systems of purifying solvents. The purified solvents can be used, e.g., as pre-wet liquids, solution developers, and cleaners in a multistep semiconductor manufacturing process.