Study on urea hydrolysis reaction mechanism is a premise for process design of ammonia production by urea hydrolysis in thermal power plants.In this paper

the nonlinear equations of mass balance

chemical equilibrium

thermal equilibrium and phase equilibrium for urea hydrolysis in an open system were established

according to the vapor-liquid equilibrium mechanism of ACWU system(NH3-CO2-H2O-(NH2)2CO).The thermodynamic and kinetics model of the urea hydrolysis reaction system were built

and the correctness of the established models were verified on a self-built pilot scale urea hydrolysis test system.Then

experiments were carried out on this pilot scale experimental system to investigate the effect of reaction temperature

pressure and urea concentration in feed on the urea hydrolysis.At last

the kinetic parameters of the urea hydrolysis reaction under condition for denitration in thermal power plants were obtained

through fitting the experimental data.The results show this phase-balance solution method's calculation result agrees well with the experimental result

indicating this method can be applied in the thermal power plants ammonia production by urea hydrolysis.With an increase in reaction temperature

the concentration of water

amine and CO2 in the reacted liquid decreased.As the urea concentration in feed increased

the concentration of amine and CO2 in the reacted liquid increased while that of the water decreased.When the pressure rose

the urea and its derivatives in the reacted liquid decreased.At 0.6 MPa and 150 ℃

the pre-exponential factor and activation energy of the urea hydrolysis reaction is 1.255×1012 s-1 and 107.24kJ/mol

respectively.