Abstract: The invention relates to an improved process for making available the coproduct hydrogen chloride obtained in the preparation of an isocyanate by phosgenation of the corresponding amine for a desired subsequent use (i.e.

Abstract: The industrial scale preparation of isocyanates gives rise to distillation bottom streams that are in need of further workup. These distillation bottom streams still also contain, as well as a distillation residue consisting of compounds that can be evaporated without decomposition only with great difficulty if at all (also referred to as residue for short), proportions of the desired target product (i.e. isocyanate to be prepared). The present invention relates to a process that enables recovery, in an efficient manner, of this proportion of isocyanate to be prepared in a distillation bottom stream which is obtained in the workup of the crude liquid process product which contains the isocyanate to be prepared and is formed in an isocyanate preparation process. More particularly, the present invention relates to a drying step in which the isocyanate to be prepared is recovered to form a solid material that has been largely to completely freed of this isocyanate.

Abstract: The industrial scale preparation of isocyanates gives rise to distillation bottom streams that are in need of further workup. These distillation bottom streams still also contain, as well as a distillation residue consisting of compounds that can be evaporated without decomposition only with great difficulty if at all (also referred to as residue for short), proportions of the desired target product (i.e. isocyanate to be prepared). The present invention relates to a process that enables recovery, in an efficient manner, of this proportion of isocyanate to be prepared in a distillation bottom stream which is obtained in the workup of the crude liquid process product which contains the isocyanate to be prepared and is formed in an isocyanate preparation process. More particularly, the present invention relates to a drying step in which the isocyanate to be prepared is recovered to form a solid material that has been largely to completely freed of this isocyanate.

Abstract: The invention relates to a production process for di- and polyamines of the diphenylmethane series by the rearrangement of a condensation product of aniline and a methylene group-supplying agent preferably selected from the group consisting of aqueous formaldehyde solution, gaseous formaldehyde, para-formaldehyde, trioxane and mixtures thereof, wherein said condensation product is reacted in the presence of at least one silica-alumina catalyst, said catalyst having a surface area as determined by the BET method carried out according to ASTM D3663-03 (2015) of from 200 m2/g to 520 m2/g, preferably of from 350 m2/g to 495 m2/g, particularly preferably of from 400 m2/g to 490 m2/g, a molar ratio of silica/alumina on the catalyst surface of A, an overall (bulk) molar ratio of silica/alumina of C, and a quotient B=A/C; said catalyst being characterised in that “low” A values (i.e. equal to or lower than 8.0) are combined with “high” B values (i.e. of from 1.50 to 3.00), and “high” A values (i.e. larger than 8.

Abstract: The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent, or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

Abstract: The present invention relates to a continuous process for preparing a polyisocyanate, in which a polyamine and phosgene are first converted predominantly to carbamoyl chloride and amine hydrochloride and only in minor proportions to polyisocyanate, and a portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture thus obtained is recycled into the reaction with phosgene, wherein polyamine, phosgene and the carbamoyl chloride- and amine hydrochloride-containing reaction mixture are mixed intimately in a mixing unit. The portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture which is not recycled into the phosgenation is worked up to give the polyisocyanate.

Abstract: The invention relates to an improved process for making available the coproduct hydrogen chloride obtained in the preparation of an isocyanate by phosgenation of the corresponding amine for a desired subsequent use (i.e.

Abstract: The present invention relates to a continuous process for preparing a polyisocyanate, in which a polyamine and phosgene are first converted predominantly to carbamoyl chloride and amine hydrochloride and only in minor proportions to polyisocyanate, and a portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture thus obtained is recycled into the reaction with phosgene, wherein polyamine, phosgene and the carbamoyl chloride- and amine hydrochloride-containing reaction mixture are mixed intimately in a mixing unit. The portion of the carbamoyl chloride- and amine hydrochloride-containing reaction mixture which is not recycled into the phosgenation is worked up to give the polyisocyanate.

Abstract: The invention relates to a production process for di- and polyamines of the diphenylmethane series by the rearrangement of a condensation product of aniline and a methylene group-supplying agent preferably selected from the group consisting of aqueous formaldehyde solution, gaseous formaldehyde, para-formaldehyde, trioxane and mixtures thereof, wherein said condensation product is reacted in the presence of at least one silica-alumina catalyst, said catalyst having a surface area as determined by the BET method carried out according to ASTM D3663-03 (2015) of from 200 m2/g to 520 m2/g, preferably of from 350 m2/g to 495 m2/g, particularly preferably of from 400 m2/g to 490 m2/g, a molar ratio of silica/alumina on the catalyst surface of A, an overall (bulk) molar ratio of silica/alumina of C, and a quotient B=A/C; said catalyst being characterised in that “low” A values (i.e. equal to or lower than 8.0) are combined with “high” B values (i.e. of from 1.50 to 3.00), and “high” A values (i.e. larger than 8.

Abstract: The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent, or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.