Solution process for the production of EP(D)M elastomers and polymerisation reactor for use in said process

A process for the production of EP(D)M elastomers in solution, comprising the polymerisation reaction of monomers in which ethylene, propylene, optionally a diene, catalytic system, hydrogen and a hydrocarbon solvent for said EP(D)M are fed continuously to a stirred reactor (CSTR) with formation of a reaction bath in which the EP(D)M elastomer dissolves in said hydrocarbon solvent, characterized in that:

• i) said reaction bath is kept at a boiling condition at a temperature from 40 to 60° C. and at a pressure from 0.6 MPa to 1.3 MPa, whereby partial vaporization of said reaction bath occurs;
• ii) from 40% to 80% of the heat generated by the polymerisation reaction is removed by said partial vaporization of the reaction bath;
• iii) the monomers, solvent and other fluids formed by said partial vaporization of the reaction bath are withdrawn from said reactor, compressed, condensed and, after joining with other recycle and fresh feed streams, subcooled to a temperature below the temperature of the reaction bath and recycled to the reactor;
• iv) from 20% to 60% of said reaction heat is removed by introducing in said reactor said monomers, solvent and fluids that have been subcooled according to step iii);
• wherein said reactor is a substantially cylindrical CSTR reactor with a ratio between height (h) and diameter (d) of between 1 and 6, and comprising a distributor of recycled gases having a circular or polygonal shape placed on the bottom of the reactor, a stirring device comprising un upper, an intermediate and a lower impeller, all mounted spaced apart on a motorized vertical shaft, and an array of inlet ports for fluids, said ports being placed in the proximity of one of said intermediate impeller, the reactor further comprising a gamma ray control device for the level of said bath.