Catalytic preparation of linear polyethylenepolyamines

In a method wherein monoethanolamine is reacted with ethylenediamine in a reaction zone in the presence of a phosphorus-containing catalyst to provide an essentially noncyclic product comprising polyethylenepolyamines, the improvement for conducting said process on a continuous basis which comprises:

• a. using, as a catalyst, a composition prepared by treating pellets of a group IVb metal oxide with a liquid containing a liquid or liquefiable phosphorus compound at a temperature within the range of about 100.degree. to about 150.degree. C. for about 0.5 to about 5 hours to thermally chemically bond to at least the surface of said pellets from about 0.5 wt. % to about 10 wt. % of phosphorus and thereafter water washing, recovering and drying the thus treated pellets,
• b. continuously contacting a mixture of ethylenediamine and monoethanolamine in a molar ratio of about 1 to 5 moles of ethylenediamine per mole of monoethanolamine with said pelleted catalyst at a temperature of about 250.degree. to about 400.degree. C. and a pressure of about 500 to about 3000 psig. to obtain an essentially noncyclic reaction product.