| 摘要 |
PURPOSE:To crack a nonaromatic hydrocarbon, by treating a raw material containing a xylene isomer mixture and a small amount of a nonaromatic hydrocarbon of reaction mixture with hydrogen in the presence of a catalyst in isomerizing the material, isolating a specific isomer and recirculating the rest. CONSTITUTION:A raw material containing a xylene isomer mixture and a small amount of a nonaromatic hydrocarbon is isomerized to isolate a specific isomer, particularly p-xylene and the rest is recirculated through the isomerization reaction. In the process, the raw material or reaction mixture is treated with hydrogen in the presence of a cracking catalyst consisting of specific zeolite and refractory inorganic oxide, preferably gamma-alumina carried by platinum under condition simultaneously satisfying 300-425 deg.C, 5-200/hr weight unit hourly space velocity (V) and formulas I and II IT is temperature) to crack the nonaromatic hydrocarbon. Thereby deterioration in efficiency of the isomerization reaction by deposition thereof is prevented to enable continuous isomerization for a long period. |
