| 摘要 |
An improved technique is described for the recovery of aliphatic diol reaction solvent in a process wherein ethylene is oligomerized at elevated temperature and pressure by contact with a solution of a nickel complex catalyst in an aliphatic diol solvent to afford a reaction product made up of (a) a liquid solvent phase containing dissolved catalyst, (b) a liquid hydrocarbon phase comprising ethylene oligomers containing dissolved ethylene, catalyst and diol solvent and (c) gaseous ethylene, said reaction product being passed to a series of phase separation zones whereby gaseous ethylene and a substantial portion of the diol reaction solvent containing dissolved catalyst are separated and recycled to the oligomerization reaction zone with a minor portion of the separated reaction solvent being passed to a fractionation zone for removal of light ends and spent catalyst prior to reuse in the process. With this improved process, the formation of diol solvent degradation products, e.g., acetals and hemiacetals, are substantially avoided in the diol solvent fractionation step by adding a minor amount of an alkali metal hydroxide to the fractionation zone. |
