| 摘要 |
The present invention provides a process for preparing 3,3,3-trifluoropropene (1243zf), the process comprising: (a) fluorinating CCI3CH2CH2Cl (250fb) to produce a reaction product comprising CF3CH2CH2Cl (253fb) in the liquid phase in a first reactor, using HF as the fluorinating agent; and (b)(i) dehydrohalogenating 253fb to produce 1243y1 in the vapour phase in the present of a catalyst in a second reactor; or (b)(ii) dehydrohalogenating 253fb to produce 1243zf in a second reactor, wherein the reaction product comprising 253fb produced in step (a) has subjected to one or more purification steps before step (b). Step (a) may be conducted in the presence of a polymerisation inhibitor and/or retarder, preferably a cyclic ketone such as cyclobutanone or cyclohexanone. Preferred catalysts for step (b) comprise activated carbon, alumina, chromia, zinc/chromia, Pd/carbon, Pt/carbon, Au/carbon, Pd/alumina, Ni/alumina, Pt/alumina, Cr/alumina or Zn/chromia. The present invention also provides an azeotropic or near-azeotropic composition comprising HF and 253fb. |
