压力对碳氢氧超临界流体中碳的溶解度的影响

 采用统计热力学方法，利用CHEQ程序对5.5～7.7 GPa的压力和1 000～2 900 K温度下碳加水体系中碳的溶解度进行了计算。重点研究了石墨和金刚石在水中溶解度差与压力的关系，得出如下结果：（1）在一定压力下，使石墨和金刚石在水中的溶解度之差ΔX(C)为正值的温度有确定的下限和上限。（2）在高温高压下，对每一个压力，石墨和金刚石在水中的溶解度之差ΔX(C)都有一个极大值。使ΔX(C)为极大值的温度随着压力的升高而增大，同时，溶解度差的极大值本身也随压力的升高而增大。

Effect of Pressure on Carbon Concentration in C-H-O Supercritical-Fluid

By statistical thermodynamics methods and CHEQ code, the concentrations of carbon in the system of graphite-water were calculated at 5.5~7.7 GPa and 1 000~2 900 K. Relation between the concentration of carbon in water and the pressure was mainly studied. Results could be summarised as follows: (1) At a fixed pressure, there is a definite down-limit and a up-limit of temperature, between them the concentration difference of graphite and diamond in water ΔX(C) is positive; (2) Under a definite pressure, there is a maximum of the concentration difference of graphite and diamond in water. Both of the maximum of ΔX(C) and the temperature, which make ΔX(C) maximum, increase with the increase of the pressure remarkably.