关键词: 焦化, 溶解性, 选择性, 3, 4-苯并芘, 煤沥青

Abstract: The solubility selectivity for benzo[a]pyrene and dissolved amount for coal tar pitch of single solvent，mixed solvents were studied. Using maleic anhydride as modifying agent and sulfuric acid as catalyst，the solvent effect on reducing the concentration of benzo[a]pyrene in coal tar pitch was investigated. The mixed solvents，cyclohexane and toluene，cyclohexane and butyl acetate had appropriate benzo[a]pyrene solubility selectivity and coal tar pitch solubility. When using cyclohexane∶toluene = 2∶1（v/v），cyclohexane∶butyl acetate =2∶1（v/v）as reaction solvent，benzo[a]pyrene in coal tar pitch could be removed efficiently，with decreases of 88.26% and 90.83% for benzo[a]pyrene in coal tar pitch respectively. Using these kinds of solvent，benzo[a]pyrene wrapped in coal tar pitch could be released. In addition，a homogeneous system between modifying agent and benzo[a]pyrene was formed，with most non-carcinogenic high molecular weight PAHs and modifying agent forming a two phase system. As a result，the effective reaction between modifying agent and benzo[a]pyrene was greatly improved.

Key words: coking, solubility, selectivity, benzo[a] pyrene, coal tar pitch