Preparation of polysuccinimide

In a process for the continuous production of polysuccinimide in high yield comprising continuously depositing an aspartic acid on a plurality of trays at different levels in a tray dryer wherein the material is forced from trays in upper levels to trays in lower levels, heating the alpha amino acid to a temperature in the range of from about 200.degree. C. to about 300.degree. C. and continuously withdrawing anhydropolyamino acid from said dryer, the improvement which comprises contacting the aspartic acid with a gas containing a catalytic amount of carbon dioxide whereby the rate of reaction is increased.

In a process for producing polysuccinimide in relatively high yields comprising the steps of:

• a) providing an agitated, fluid bed constituted by freely flowing, solid, particulate aspartic acid;
• b) heating the fluid bed to a temperature of at least about 180.degree. C. and maintaining the heated bed at a temperature in the range of from about 180.degree. C. to about 250.degree. C. for a time sufficient to polymerize the aspartic acid and to drive off water from the heated bed whereby the degree of agitation is sufficient to maintain the particles in a substantially free-flowing state throughout the time period, and
• c) recovering the polysuccinimide from the fluid bed, the improvement which comprises contacting the aspartic acid in the fluid bed with a catalytic amount of carbon dioxide whereby the reaction rate is increased.