Advanced Pygas Upgrading (APU) is a catalytic process technology developed by SK Corp. and is exclusively offered by Axens to convert pyrolysis (ex steam cracking) gasoline to a superior steam cracker feed (LPG), and benzene, toluene and xylene (BTX) aromatics.
Cuts originating from second-stage pygas hydrogenation units are used as feedstocks. The principal catalytic reactions are:
• Conversion of non-aromatics (especially C6 to C10 alkanes) into ethane and LPG.
• Conversion of C9+ aromatics into BTX, thereby increasing BTX yield.
The reaction section product delivers after standard distillation highpurity individual BTX cuts, and there is no need for further extraction.
In some locations, ethane and LPG are the desired products; they provide valuable cracking furnace feedstocks. Typical olefin yields based on the original pygas feed are:
Typical APU olefins yields