DEALKYLATION OF TOLUENE

Toluene is dealkylated to benzene over a hydrogenation-dehydrogenation catalyst such as nickel. The hydrodealkylation is essentially a hydrocracking reaction favored at higher temperatures and pressures. The reaction occurs at approximately 700°C and 40 atmospheres. A high benzene yield of about 96% or more can be achieved:

Dealkylation also can be effected by steam. The reaction occurs at 600 800°C over Y, La, Ce, Pr, Nd, Sm, or Th compounds, Ni-Cr₂O₃ catalysts, and Ni-Al₂O₃ catalysts at temperatures between 320–630°C.  Yields of about 90% are obtained. This process has the advantage of producing, rather than using, hydrogen.