Abstract: A process for extracting a phosgene compound, comprising providing a membrane extracting unit comprising at least one extracting cell that comprises at least one membrane contactor module having at least two sides, a gas side and a liquid side; letting an initial gas stream comprising a phosgene compound flow on the gas side of the membrane contactor module; and letting an extractant liquid stream, suitable for dissolving a phosgene compound, flow on the liquid side of the membrane contactor module so that the extractant liquid stream absorbs the phosgene compound from the initial gas stream and provides a second extractant liquid stream enriched with the phosgene compound.

Abstract: A process for extracting a phosgene compound, comprising providing a membrane extracting unit comprising at least one extracting cell that comprises at least one membrane contactor module having at least two sides, a gas side and a liquid side; letting an initial gas stream comprising a phosgene compound flow on the gas side of the membrane contactor module; and letting an extractant liquid stream, suitable for dissolving a phosgene compound, flow on the liquid side of the membrane contactor module so that the extractant liquid stream absorbs the phosgene compound from the initial gas stream and provides a second extractant liquid stream enriched with the phosgene compound.

Abstract: A process according to the invention is a process to separate an initial fluid stream comprising phosgene and hydrogen chloride in at least a first and a second fluid stream, said first fluid stream being a hydrogen chloride enriched and phosgene depleted gaseous stream, said second fluid stream being a hydrogen chloride depleted and phosgene enriched stream. The separation is performed by feeding said initial fluid stream to a membrane separation unit, said membrane separation unit separating said initial fluid stream in a first and a second fluid stream.

Abstract: A method for removing methylene-bridged polyphenyl polyamines from an aqueous stream comprising said methylene-bridged polyphenyl polyamines according to the invention comprises the steps of Providing a pertraction equipment comprising a membrane with a first side and a second side opposite to said first side; Bringing an aqueous stream comprising methylene-bridged polyphenyl polyamines into contact with the first side of the membrane and bringing an organic stream into contact with the second side of the membrane, thereby causing the methylene-bridged polyphenyl polyamines to transfer from the aqueous stream through the membrane to the organic stream. The method further comprises, before bringing the aqueous stream and organic stream in contact with the membrane, the step of wetting the membrane with a liquid having a surface tension of less than 40 mN/m.

Abstract: A process according to the invention is a process to separate an initial fluid stream comprising phosgene and hydrogen chloride in at least a first and a second fluid stream, said first fluid stream being a hydrogen chloride enriched and phosgene depleted gaseous stream, said second fluid stream being a hydrogen chloride depleted and phosgene enriched stream.

Abstract: Method of fractionating a mixture of polyisocyanates in the liquid phase, optionally in the presence of a suitable solvent or mixture of two or more solvents, by means of a selectively permeable membrane into a permeate stream and a retentate stream of polyisocyanate compositions different to each other and different to the original mixture.

Abstract: The present invention relates to a process for the preparation of di- and polyamines of the diphenylmethane series, and to the preparation of di- and polyisocyanates of the diphenylmethane series from these di- and polyamines. The di- and polyamines of the diphenylmethane series are prepared by the reaction of aniline and formaldehyde in the presence of hydrochloric acid. In the present invention, the formaldehyde employed is used as an aqueous solution which contains less than 0.001 wt % of metal ions which are divalent and/or more than divalent.

Abstract: A method for removing methylene-bridged polyphenyl polyamines from an aqueous stream comprising said methylene-bridged polyphenyl polyamines according to the invention comprises the steps of Providing a pertraction equipment comprising a membrane with a first side and a second side opposite to said first side; Bringing an aqueous stream comprising methylene-bridged polyphenyl polyamines into contact with the first side of the membrane and bringing an organic stream into contact with the second side of the membrane, thereby causing the methylene-bridged polyphenyl polyamines to transfer from the aqueous stream through the membrane to the organic stream. The method further comprises, before bringing the aqueous stream and organic stream in contact with the membrane, the step of wetting the membrane with a liquid having a surface tension of less than 40 mN/m.

Abstract: Process for the preparation of polyaromatic polyamines comprising the step of reacting formaldehyde with at least one monoaromatic monoamine and at least one monoaromatic compound containing at least two amino functions in the presence of an acidic catalyst where a) the total amount of di-aromatic compounds in the polyaromatic polyamine mixture is in the range from about 25 wt % to about 50 wt % and b) the amount of monoaromatic compound containing at least two amine functions is in the range 5 to 30 mole % relative to 100 mole % of the total amount of monoaromatic monoamines and c) the amount of acidic catalyst used in the preparation of the polyaromatic polyamine mixture is less than about 0.4 moles per mole of formaldehyde or formaldehyde equivalents.

Abstract: Method of fractionating a mixture of polyisocyanates in the liquid phase, optionally in the presence of a suitable solvent or mixture of two or more solvents, by means of a selectively permeable membrane into a permeate stream and a retentate stream of polyisocyanate compositions different to each other and different to the original mixture.

Abstract: The present invention relates to a process for the preparation of di- and polyamines of the diphenylmethane series, and to the preparation of di- and polyisocyanates of the diphenylmethane series from these di- and polyamines. The di- and polyamines of the diphenylmethane series are prepared by the reaction of aniline and formaldehyde in the presence of hydrochloric acid. In the present invention, the formaldehyde employed is used as an aqueous solution which contains less than 0.001 wt % of metal ions which are divalent and/or more than divalent.