Sub-Product

Benzene, Toluene and Xylenes can be made by various processes.

However, most BTX Production is based on the Recovery of Aromatics derived from the Catalytic Reforming of Naphtha in a Petroleum Refinery. Catalytic Reforming usually utilizes a Feedstock Naphtha that contains Non-Aromatic Hydrocarbons with 6 to 12 Carbon Atoms and typically produces a Reformate product containing C₆ to C₈ Aromatics (Benzene, Toluene, Xylenes) as well as Paraffins and Heavier Aromatics containing 9 to 12 carbon atoms.

Another process for producing BTX Aromatics involves the Steam Cracking of Hydrocarbons which typically produces a Cracked Naphtha product commonly referred to as Pyrolysis Gasoline, Pyrolysis Gas or Pygas. The Pyrolysis Gasoline typically consists of C₆ to C₈ Aromatics, heavier Aromatics containing 9 to 12 Carbon atoms, and Non-Aromatic Cyclic Hydrocarbons (Naphthenes) containing 6 or more Carbon Atoms.

Tab. 1 compares the BTX content of pyrolysis gasoline produced at standard cracking severity or at medium cracking severity with the BTX content of catalytic reformate produced by either a continuous catalytic regenerative (CCR) reformer or by a semi-regenerative catalytic reformer. About 70 percent of the global production of benzene is by extraction from either reformate or pyrolysis gasoline.

Table 1 - BTX content of Pyrolysis Gasoline and Reformate.

Source: Wikipedia, BTX (chemistry)