Kinetic peculiarity of co-production of benzene and naphthalene from aromatic mixtures by thermal hydrodealkylation

The kinetic peculiarity of aromatic and non-aromatic hydrocarbons under co-production process conditions of benzene and naphthalene from pyrolysis gasoline or other industrial aromatic mixtures through thermal hydrodealkylation was experimentally investigated. In these experiments, various model mixtures of such pure hydrocarbons as benzene, toluene, naphthalene, 1-, 2-methylnaphtalenes and n-heptane were used as raw materials, and under thermal hydrodealkylation conditions, conversion kinetics of these hydrocarbons and their effects to each other were studied. According to the experimental results obtained, the conversion rates in descending order are as n-heptane > 1-methylnaphthalene (1-MN) > 2-methylnaphthalene (2-MN) > toluene. N-heptane considerably accelerates the hydrodealkylation reactions of both toluene and 1-MN and 2-MN. While 1- MN and 2-MN increase the rate of toluene's conversion to some extent, toluene can prevent their conversion. Furthermore, n-heptane has an increasing impact on the reaction rate of benzene's conversion into biphenyl. At temperature of 625degreesC and in a long contact time (60 s or more) almost all of n-heptane is converted into mostly alkanes, C1-C3 gases.