Abstract:
In order to optimize the reaction rate of urea hydrolysis to ammonia, several commonly used urea hydrolysis catalysts were compared and tested in batch reaction system and pilot test bench.. The results show that the decomposition rate of urea with diammonium hydrogen phosphate or alumina is higher than that without catalyst, and the activation energy is in the order of: 73.6 kJ/mol, 65.3 kJ/mol, 52.9 kJ/mol, not only reduce the activation energy of hydrolysis reaction, but also increase the decomposition rate of urea, and the volume concentration of each component of the gas phase product of catalytic hydrolysis is consistent with the result without catalysis. The activity of the catalyst at 140℃ and 150 kPa remained stable after five cycles, and the concentration of liquid urea solution was smaller at higher reaction temperature. In the pilot test, due to the uneven distribution of solid alumina, the temperature of the reaction solution is higher than that of diammonium hydrogen phosphate under the same ammonia production.