The APU process, developed by SK, enables the reduction of low valued pyrolysis gasoline by converting it into additional purified aromatics and into LPG, a steam cracker feedstock.

This selective catalytic technology increases BTX (benzene, toluene and xylenes) production via the hydrodealkylation of C9+ aromatics. In addition, LPG (liquefied petroleum gas: propane and butanes) production is increased through selective cracking and hydrogenation of non-aromatic compounds into light paraffinic products. Through the recycling of the light ends to the steam cracker, additional ethylene and propylene are produced. Due to these reactions, the BTX stream does not require solvent extraction treatment. Benzene can be used as-is for the production of other building blocks, such as ethylbenzene-styrene. Toluene purity is ideal as a transalkylation feedstock, and the xylenes fraction does not require further extraction before separation to recover paraxylene.