| 摘要 |
PURPOSE:To efficiently separate m-dichlorobenzene(DCB) in high purity from a DCB isomer mixture comprising o, m and p-DCBs using specific zeolite as adsorbent. CONSTITUTION:When a DCB isomer mixture comprising o, m and p-DCBs is put to adsorptive separation, the m-DCB is separated and recovered through e.g. chromatographic fractination techinque or adsorptive separation technique with pseudo moving bed using, as adsorbent, a zeolite, pref. a crystalline aluminosilicate belonging to faujasite-type zeolite containing K<+> and Pb<2+> at the molar ratio Pb<2+>/(Pb<2+>+2K<+>)=0.1-0.8 (pref. 0.2-0.5) as the essential components, thus markably improving the adsorptive separation efficiency. For a desorbing agent, 3,4-dichlorotoluene is esp. preferable, and as the operational conditions for the adsorptive separation, it is preferable that the operation be carried out in a liquid phase at room temperature to 350 deg.C (pref. 50-250 deg.C) under a pressure of the atmospheric pressure to 50kg/cm<2>G (pref. the atmospheric pressure to 40kg/cm<2>G). |
