Disclosed herein are methods of treating a hydroformylation catalyst solution wherein the solution comprises rhodium, polyphosphoramidite ligands, and polyphosphoramidite ligand degradation products and wherein the hydroformylation catalyst solution is used to hydroformylate an olefin in an operating hydroformylation unit. In some embodiments, such methods comprise contacting the catalyst solution with a peroxide in the operating hydroformylation unit.

The invention relates to a process for separating one or more components from a mixture by a membrane separation in whichdepending on the component to be separatedan acid or a base is added to the mixture before the membrane separation.

Provided is a method of reactivating a used titania catalyst for hydrogenation treatment, capable of improving the catalytic activity of the used titania catalyst for hydrogenation treatment that is obtained by supporting a catalyst component on a titania support and exhibits reduced catalytic activity after having been used for hydrogenation treatment of a hydrocarbon oil, to a level comparable to that of a newly prepared fresh titania catalyst before use. The method of reactivating a used titania catalyst for hydrogenation treatment, the used titania catalyst for hydrogenation treatment being obtained by supporting a catalyst component on a titania support and exhibiting reduced catalytic activity after having been used for hydrogenation treatment of a hydrocarbon oil, includes: a coke removal step of removing a carbonaceous component on a surface of the used catalyst by heating the catalyst in an oxygen-containing gas atmosphere; an impregnation step of impregnating the carbonaceous component-removed catalyst obtained by the coke removal step with a saccharide-containing solution; and a drying step of drying the saccharide-impregnated catalyst obtained by the impregnation step, to obtain a catalyst in which a saccharide is supported.

Disclosed herein are methods for recovering phosphorus-containing ligand from mixtures comprising organic mononitriles and organic dinitriles, using liquid-liquid extraction. Also disclosed are treatments to enhance extractability of the phosphorus-containing ligand.

The present disclosure relates generally to transition metal complex hydroformylation catalytic precursor compositions, to hydroformylation processes, and to processes for separating one or more heavies from a hydroformylation reaction product fluid in hydroformylation processes comprising a metal-monophosphite ligand complex catalyst.

Disclosed herein are methods for recovering phosphorus-containing ligand from mixtures comprising organic mononitriles and organic dinitriles, using liquid-liquid extraction. Also disclosed are treatments to enhance extractability of the phosphorus-containing ligand.

Disclosed herein are methods for recovering diphosphonite-containing compounds from mixtures comprising organic mononitriles and organic dinitriles, using multistage countercurrent liquid-liquid extraction. Recovery is enhanced with one or more method steps. In a first step, a portion of the heavy phase from the settling section of the first stage is recycled to the settling section of the first stage. In a second step, a portion of the light phase from the settling section of the first stage is recycled to the mixing section of the first stage. In a third step, the first stage takes place in a mixer-settler, a Lewis base is introduced into the settling section of the first stage, and a complex of Lewis acid and Lewis base is formed in this settling section. In a fourth step, a polyamine is added to the first stage.

A homogenous process for the hydrogenation of the carboxylic acids and/or derivatives thereof in the presence of a catalyst comprising ruthenium, rhodium, iron, osmium or palladium, and an organic phosphine is described in which the hydrogenation is carried out in the presence of at least about 1% by weight water. A process for regenerating a catalyst comprising ruthenium, rhodium, iron, osmium or palladium and an organic phosphine is also described in which the regeneration is carried out in the presence of hydrogen and water.

Provided is a method of preparing an acrylonitrile dimer including: supplying an acrylonitrile monomer, a phosphorus-based catalyst, and an alcohol solvent to a reactor to perform a dimerization reaction to produce dimerized reactants (S10); cooling the dimerized reactants to crystallize the phosphorus-based catalyst (S20); separating the crystallized phosphorus-based catalyst (S30); and supplying the dimerized reactants from which the phosphorus-based catalyst is separated to a distillation column to separate the acrylonitrile dimer (S40).