Abstract: A new thermodynamic model for ammonia-carbon dioxide-water-urea system at the condition of urea synthesis (T=438.15-478.15K, P=6.87-24.5 MPa, NH3/CO2 = 2.6-5.0, H2O/CO2= 0.2-1.2) is established on the basis of experimental data. Perturbed-hard-sphere equation of state and Wilson equation are use to treat the non-idealities of vapor and liquid phases. Correlations of the experimental data at 433.15K,438.15K,448.15K, 458.15K, 468.15K and 478.15K are made with this model. The mean relative deviation of molar fraction of ammonia and carbon dioxide in vapor phase is 3.05% and 8.27% respectively, and the mean relative deviation of total pressure is 3.31%. The calculated values of pressure with this mode] are in agreement with those of industrial synthesis of urea.

摘要： 提出了一个适用于尿素合成条件下(T=438.15～478.15K,P=6.87～24.5MPa,NH_3/CO_2=2.6～5.0,H_2O/CO_2=0.2～1.2)NH_3-CO_2-H_2O-NH_2CONH_2体系的热力学模型,该模型用PHS状态方程和Wilson方程来分别修正气液两相的非理想行为,用本模型可对尿素合成体系进行有效的汽液平衡计算.