利用RUSKA公司无汞PVT装置,对辽河减压渣油-正戊烷体系的相行为进行了实验观察,测定了辽河渣油-正戊烷体系相态变化的边界线,如液-液相分界线、液-液-气三相区分界线等,绘制了体系的p-t相图;在140℃~190℃,1.0MPa~10.0MPa,溶剂质量比为3.0~6.0的条件下,对体系相特性的变化进行了分析和讨论。在实验条件下,辽河渣油-戊烷体系的p-t相图可以划分为四个区域:单一液相区、液-液两相区、液-液-气三相区、气-液两相区;溶剂质量比对由单一液相区转变为液-液两相分相压力的影响显著,溶剂质量比越大,分相压力越大;但溶剂质量比对液-液-气三相区影响不大。确定了辽河渣油-正戊烷体系溶剂脱沥青过程适宜的操作区域。
The phase behavior of Liaohe vacuum residue-n-pentane system was investigated with visual observation in a set of Hg-free PVT equipment with two cells and a sight window designated by RUSKA Co.Based on the observation,the p-t phase diagrams with the verging lines of phase transition such as liquid-liquid and liquid-liquid-vapor regions were protracted.The phase characteristics for such system were discussed at 140℃~190℃,1.0MPa~10.0MPa and the mass ratio of solvent to oil(ms/mo) of 3.0~6.0.Under the experimental conditions,the p-t phase diagram is divided into four regions of single liquid,liquid-liquid,liquid-liquid-vapor and liquid-vapor.The phase transition pressures from single liquid to liquid-liquid region are obviously affected by the ms/mo ratio;the phase transition pressure increases with the ms/mo ratio.However,the ms/mo ratio exhibits little effect on the range of liquid-liquid-vapor region.Based on these results,the operating region suitable for the Liaohe vacuum residue-n-pentane deasphalting process was determined.