Abstract: The partial molar volumes of components in a supercritical ammonia synthesis system were calculated under different conditions with the calculation formula of partial molar volume derived from R-K equation of state.The objectives were to comprehend phase behavior of components and to provide the theoretical explanation and guidance for developing novel processes of ammonia synthesis under supercritical conditions. The conditions of calculation were H₂/N₂=3, concentration of NH₃ in synthesis gas ranging from 2% to 15%, concentration of medium in supercritical ammonia synthesis system ranging from 20% to 50%,temperature ranging from 243 K to 699 K and pressure ranging from 0.1 MPa to 187 MPa.The results showed that the ammonia synthesis system could reach supercritical state by adding a suitable supercritical medium and then controlling the reaction conditions.It was good for supercritical ammonia synthesis that medium reached supercritical state under the corresponding total pressure and composition,and at a temperature near the normal temperature or near the critical temperature of medium or in the range of temperature of commercial ammonia synthesis.

Key words: 偏摩尔体积, 氮气, 氢气, 氨气, 超临界, 介质, 氨合成

摘要： 结合R-K方程推导出偏摩尔体积计算公式，计算了超临界氨合成体系的组分偏摩尔体积，以期进一步了解各组分的相行为，为探索超临界相氨合成新工艺提供理论依据和指导.计算的条件为：H₂/N₂=3，合成气中NH₃浓度为2％～15％，超临界体系中介质浓度为20％～50％，温度为243～699 K，压力为0.1～187 MPa.结果表明：在合成气中加入合适的超临界介质并控制反应条件，体系可以达到超临界状态；在常温下或介质的临界温度附近或工业氨合成温度范围内，在各自相应的总压和组成条件下，使介质处于超临界状态，对超临界氨合成才是有利的.

关键词: 偏摩尔体积, 氮气, 氢气, 氨气, 超临界, 介质, 氨合成