Thermal hydrodealkylation adapted to heavy aromatics feeds

Studies have demonstrated that processing C/sub 9/ and heavier monoaromatics in a conventional hydrodealkylation (HDA) reactor system can produce benzene yields nearly equal to yields from toluene HDA. Economics are viable for grassroots installations where the C/sub 9/+ aromatics are not a feasible octane premium gasoline additive, and where the material is considered to be no more than distillate value. Increased flexibility may be available in existing HDA facilities processing C/sub 7/-C/sub 8/ aromatics to respond to the swing-market characteristics of the aromatics market. When toluene is in demand, the refiner can divert toluene to satisfy that market and maintain benzene production using site-available C/sub 8/ and heavier feeds. But when the market for C/sub 9/+ aromatics is sufficiently profitable, the lighter HDA feeds can be utilized, with less hydrogen consumption, to produce benzene.