Aromatic hydrocarbons (BTEX & PAH) are usually present in natural gas to some degree. BTEX – Benzene, Toluene, Ethyl Benzene and Xylene are aromatic compounds usually present in natural gas streams in small quantities.

These quantities are not usually so high that they affect the gas specification or that recovery of them is commercially viable. The significance of these components is that they have a high level of solubility in water and often form a contaminant that may require removal from produced water streams.

Poly-Aromatic Hydrocarbon (PAH) components are higher non-volatile aromatic hydrocarbons that consist of more than one aromatic ring. These are usually present in minute quantities in natural gas and as with BTEX components the problem lies with their solubility in produced water. These components can also be removed from produced water by polymer adsorbents, or alternatively disposed of using biological treatment (although due to large equipment this technology is not applied offshore).