掺油浆渣油-轻烃体系的相特性

PHASE BEHAVIOR OF RESIDUE WITH DECANT OIL-LIGHT HYDROCARBON SYSTEMS

用RUSKA2 370 6 0 1型高压全自动无汞双釜PVT装置研究了大港减压渣油、澄清油和减压渣油混合油与轻烃体系 (分别为C3和iC4 )的相态特性。对丁烷在 10 0～ 15 0℃、丙烷在 6 0～ 90℃、压力在 15MPa以下 ,溶剂与油之比 1 0 0～ 4 0 0 ,澄清油质量分数在 0～ 40 %范围内的各体系相态变化的液 液两相分界线、液 液 气三相区分界线、相点和上临界终点进行了精确测定 ,得到了完整的P T相图。结果表明 ,随着溶剂比的增大 ,液 液分界线向压力增加方向移动 ;渣油中澄清油含量越高 ,分相压力越高 ;三相区分界线受溶剂与油之比、澄清油质量分数影响较小。讨论了相特性对溶剂脱沥青工业生产原料的预稀释、溶剂萃取及溶剂回收的指导意义。

Phase behavior characteristics of the systems, Dagang vacuum residue-isobutane and two mixed feed-isobutane, containing 20% and 40% FCC decant oil respectively, was observed in a RUSKA2370-601 Hg free high pressure PVT test unit. Liquid-liquid immiscible region (L-L), liquid-liquid-vapor region (L-L-V), liquid-vapor region (L-V) and upper critical end point (UCEP) were measured in the temperature range of 100-150°C, pressure up to 15 MPa and mass ratio of solvent to oil ms/Mo from 1 to 4 for isobutane-residue systems. The conditions adopted for a propane-residue system were similar to that for residue-isobutane system except the temperature was within the range of 60-90°. The P-T phase diagrams of these systems were worked out. With the increase of ms/mo, the L-L line shifts up to the higher pressure position while L-L-V region varies slightly. The more the FCC decant oil in residue with lower relative molecular mass but higher aromatic factor, the higher the pressure of L-L line located in phase diagram. The boundaries separating the three phases are less influenced by ms/mo and the content of decant oil added to residue. The influences of phase behavior on the operation of deasphalting process, the pre-dilution of feed, extraction and solvent recovery were discussed.