Disproportionation and trans-alkylation of aromatic hydrocarbon(s) - using a mordenite based catalyst contg. nickel, palladium or silver

摘要

In a process for disproportionation and trans-alkylation of alkylaromatic hydrocarbons, the catalyst used is based on mordenite with a pore dia. of 5-7 Angstroms and contg. 0.005-25 wt.% Na, Pd or Ag. The catalysts are made by introducing the metal by impregnation or ion exchange into a mordenite contg. at least 0.8 wt.% Na and with a mol. ratio SiO2/Al2O3 of 9-12 and a pore dia. of 5-7 Angstroms. Pref. starting material is small pore mordenite with a pore dia. of ca. 5 Angstroms, which takes up not more than 1 wt.% benzene or toluene in 2 hrs at 28 deg. C/25 mm Hg. Pref. during the prodn. of the catalyst or subsequently, the catalyst is calcined at 200-850 deg.C in the presence of water vapour, for 5 mins to 1 week at a partial press. of water of 0.02-5 atmos. The catalysts have high activity and stability during conversion of alkylaromatic hydrocarbons, esp. in the disproportionation of toluene and the transalkylation of toluene and trimethylbenzenes.