| 摘要 |
1,170,661. Cycloparaffins. GULF RESEARCH & DEVELOPMENT CO. 30 Jan., 1967 [10 Feb., 1966], No. 4362/67. Heading C5E. Alkylaromatics are converted to corresponding cycloparaffins by thermally hydrodealkylating to produce an effluent containing gaseous dealkylated aromatic, and then subjecting said effluent, while said dealkylated aromatic is still gaseous, to hydrogenation conditions to produce an effluent containing dealkylated cycloparaffin. Suitable hydrodealkylation conditions are: preheat to 621-982‹ C., outlet temperature 677-1038‹ C., hydrogen: alkylaromatic ratio from 1.5: 1 to 20: 1, pressure 7-70 kg./sq. cm. gauge, residence time 1-400 seconds. Suitable hydrogenation conditions include: temperature 38-316‹ C., pressure 1À75-70 kg./sq. cm. gauge, and a catalyst comprising any of Ni, Co, Mo, W, Pt or Pd on a support of silica, alumina, silica-alumina, silica-magnesia, silicon carbide, clay or kieselguhr; nickel on kieselguhr being preferred. If the original feed contains sulphur, either as impurity or as added mercaptan to inhibit coke formation, the hydrodealkylation effluent can be treated for H 2 S removal, before hydrogenation, by passage through an absorber containing a metal which is sulphidable by H 2 S, e.g. Ni, Co, Fe, Mo or W supported on one of the catalyst supports listed above. |
