Abstract: A process for reducing the mutagenicity of a coal-tar-based product containing polynuclear aromatic compounds. The process includes the step of contacting the coal-tar-based product in the presence of an alkylating agent with an acid catalyst under alkylation conditions sufficient to reduce the mutagenicity of the polynuclear aromatic containing coal-tar-based material to a level less than the initial mutagenicity index value. Also provided are non-carcinogenic coal-tar-derived products.

Abstract: Methods are provided for the remediation of sites containing coal tar compositions that contain polynuclear aromatic compounds. The remediation entails altering the coal tar compositions to substantially decrease the bioavailability of the polynuclear aromatic compounds. The process includes the contacting and blending of the coal tar with petroleum coke for a time sufficient to produce a uniform admixture. The weight ratio of the petroleum coke to coal tar is generally from about 1:1 to about 10:1. Processes are also disclosed for the determination of the proper blending ratio to achieve a necessary level of remediation.

Abstract: A process for reducing the mutagenicity of a polynuclear aromatic containing material containing from three to seven fused aromatic rings, especially a hydrocarbon refinery stream. The process reduces the initial mutagenicity index to a lower value by alkylating the compound with an alkylating agent which introduces an alkyl substituent having from three to five carbon atoms into the aromatic compound in the presence of an acid catalyst under alkylation conditions.

Abstract: Non-carcinogenic asphalts and asphalt blending stocks are produced from reduced hydrocarbon feedstocks. Such non-carcinogenic products are produced by establishing a functional relationship between mutagenicity index and a physical property correlative of hydrocarbon type for the asphalt or asphalt blending stock and determining a critical physical property level which, when achieved, results in a product having a mutagenicity index of less than about 1.0. Process conditions are established so that a product stream achieving the desired physical property level can be produced. Non-carcinogenic asphalts and asphalt blending stocks are then processed utilizing the conditions so established.