Processes for Reducing the Mutagenicity of Refinery Streams and Coal Tars via °C3-Alkylation

Abstract

Processes for reducing the mutagenicity of refinery streams and coal tars containing polynuclear aromatic compounds (PAC) are described. The investigation was based on the supposition that the reduced mutagenic activity of some refinery streams (relative to cracked stocks and coal tars) was related to the degree of alkylation of the PAC stream components. Much of the development work was carried out using benzo[a]pyrene (BaP) as a model surrogate for the PAC responsible for the mutagenic potency of refinery streams and coal tars. Using Friedel-Crafts procedures, the mutagenic activity of a number of refinery streams and coal tar products was significantly reduced or completely eliminated when reacted with a C3-, C4-, or C5-alkylating agent. Recent work has turned toward adapting the laboratory-based chemistry to refinery-based chemistry using heterogeneous catalysis (acid clay/pillared catalysts/zeolites).

Key Words:

• petroleum streams
• coal tars
• PAH
• alkylation