Aromatics: From valuable base chemicals to surplus components?

With the advent of the second stage of the European Auto Oil Programme in the year 2005, the aromatics content of gasoline has to be reduced significantly, which could lead to an oversupply of aromatics. The sources of aromatic hydrocarbons and their petrochemical use are described. Options for avoiding a surplus of aromatics are discussed, i.e., diminishing the production of aromatics and intensifying their conversion into valuable products. Finally, a novel catalytic process for hydrogenative ring opening of aromatics is introduced which allows the conversion of pyrolysis gasoline from naphtha steamcrackers into a high-quality synthetic steamcracker feedstock composed of ethane, propane, and n-butane. There are two process variants, namely the direct conversion of aromatics on bifunctional zeolites or a two-stage process comprising a conventional ring hydrogenation to cycloalkanes followed by ring opening of the latter on acidic zeolites.