PURPOSE: To solve problems of lowering in aromatic yield by the lowering in the activity of a catalyst by improving the flow process of a reactional product when 2-7C aliphatic hydrocarbons are converted to aromatic hydrocarbons.
CONSTITUTION: A mixture of an aliphatic hydrocarbon as a raw material with a light-weight hydrocarbon gas containing methane and/or ethane is passed through a conversion reaction zone 1 in which a catalyst consisting essentially of an aluminogallosilicate is retained, and then the reactional products are divided into a cracked gas and a separation liquid by the first separation zone 2, 3 and 4. The cracked gas is separated into a hydrogen-containing gas and a recycle gas having high methane and/or ethane contents in a hydrogen separating apparatus 6. On the one hand, a separated liquid from the first separation zone is separated to aromatic hydrocarbons and a low boiling hydrocarbon gas in the second separation zone 5. The low boiling hydrocarbon gas and the recycle gas as the light-weight hydrocarbon gas are mixed with the aliphatic hydrocarbon gas of the raw material. Then, in a conversion reaction zone 1, the reaction temperature is continuously or step by step raised to retain the aromatic yield in a definite range.
HIRABAYASHI KAZUO
SHIBATA SHUNJI
SAITO SHUNSUKE
KONDO TADAMI
IINO TADAAKI
