全蒸发过程中加四溴化碳分离间、对二甲苯

The Separation of meta and para Xylene by Pervaporation in the Presence of CBr_4

四溴化碳（ＣＢｒ＿４）有选择性地和对位二甲苯形成一个固体复合分子，但在低于５℃下，进料中若加入２４％摩尔的ＣＢｒ＿４，便会产生一种对间二甲苯极具选择性的全蒸发过程。即使聚丙烯膜对对二甲苯具有选择性，也会发生这种全蒸发过程。在较高温度下，此过程在有ＣＢｒ＿４伴随下对对二甲苯具有选择性。依据温度、对二甲苯的浓度和ＣＢｒ＿４的添加量的不同，分离因子（αＰ／Ｍ）在１．２到０．０５之间波动。

CBr_4 selectively forms a solid molecular complex with p-xylene;at temperatures below about 5℃, the presence of 24mol%CBr_4 in the feed results in a rvaporation process very selective for m-xylene. This occurs even though the polypropylene membrane is selsctive for p-xylene. At higher temperatures,the process is selective for p-xylene At higher temperatures, the process is selective for p-xylene when CBr_4 is present.Separation factors(αp/m)varied form about 1.2-0.05 depending upon(1)temperature,(2)p-xylene concentration , and(3)the amount of CBr_4 pre-sent.