Abstract: A process for the preparation of predominantly non-cyclic polyalkylenepolyamines comprising contacting a difunctional aliphatic alcohol with ammonia or a primary or secondary aliphatic amine in the presence of a catalyst selected from the group consisting of Group VB metal oxides, niobium phosphates, tantalum phosphates, and mixtures thereof. For example, monoethanolamine is aminated by ethylenediamine to predominantly linear and branched polyethylenepolyamines in the presence of a catalyst containing niobium oxide supported on boehmite alumina.

Abstract: A method of removing color from crude triethylenetetramine (TETA) is disclosed. In the preferred procedure, acid treated clay or acidic form zeolite are mixed with the TETA at elevated temperatures. After several hours exposure, the TETA is distilled to obtain a decolored product. The decoloration can be a continuous or batch process. The distillation is performed in the presence or absence of the catalyst.

Abstract: A catalyst useful for dehydrating an alkanolamine to form an alkylenimine is prepared by providing an aqueous or hydrofluoric acid solution of a tantalum or niobium compound, neutralizing this solution with ammonium hydroxide to precipitate the metal hydroxide, washing the precipitated metal hydroxide with water and subsequently dissolving it in an aqueous solution of a lower carboxylic acid, e.g. oxalic acid, applying the acid solution to a catalyst support to impregnate it with the metal hydroxide and finally drying and calcining the impregnated support to form the desired metal oxide catalyst. An alkaline earth metal oxide is optionally employed by impregnating the support with an aqueous solution of the alkaline earth metal hydroxide, preferably prior to the application of the catalyst.

Abstract: An improved catalyst suitable for the dehydration of an alkanolamine in the vapor phase to produce an alkylenimine which catalyst contains an oxide of niobium or tantalum. Optionally an alkaline earth oxide is employed as a promoter. The catalyst is generally used on an inert low surface area support at a concentration of less than 5% of the tantalum or niobium oxide and less than 0.5% of the promoter oxide.

Abstract: An improved catalyst suitable for the dehydration of an alkanolamine in the vapor phase to produce an alkylenimine which catalyst contains an oxide of niobium or tantalum. Optionally an alkaline earth oxide is employed as a promoter. The catalyst is generally used on an inert low surface area support at a concentration of less than 5% of the tantalum or niobium oxide and less than 0.5% of the promoter oxide.