| 摘要 |
The invention relates to a continuous method for producing polyamides by reacting at least one aminonitrile with water. The inventive method comprises the following steps: (10) reacting at least one aminonitrile with water at a temperature of 200 to 290 DEG C and a pressure of 40 to 70 bar in a stream tube which contains a Brönsted acid catalyst, selected from a beta zeolite, phyllosilicate or metal oxide catalyst in the form of a static catalyst, (11) addition of heat and expansion or adiabatic expansion of the reaction mixture of step (1) in a first deposition zone to a pressure of 20 to 40 bar, the pressure being at least 10 bar less than the pressure in step (1), and to a temperature in the range of from 220 to 290 DEG C, flash evaporation and removal of ammonia, water and optionally monomers and oligomers of the aminonitrile, (12) further reacting the reaction mixture of step (2) while adding water at a temperature of 200 to 290 DEG C and a pressure of 25 to 55 bar, said reaction being optionally carried out in the presence of a Brönsted acid catalyst, selected from a beta zeolite, phyllosilicate or metal oxide catalyst in the form of a static catalyst, (13) addition of heat and expansion or adiabatic expansion of the reaction mixture of step (3) in a second deposition zone to a pressure of 0.01 to 20 bar, with the pressure being at least 20 bar less than the pressure in step (3), and to a temperature in the range of from 200 to 290 DEG C, flash evaporation and removal of ammonia, water and optionally monomers and oligomers of the aminonitrile.
|
