PURPOSE: To continuously produce a pitch suitable for use as a raw material of a carbon fiber with high efficiency, by heat treating a raw aromatic oil to convert it into a pitch, subjecting the pitch to thermal decomposition to form a geseous component and a liquid component, subjecting the gaseous component to fractional distillation to get a heavy oil which, in turn, is returened to the heat treatment furnace and subjecting the liquid component to solid-liquid separation.
CONSTITUTION: A raw aromatic oil is introduced into the first tubular heat-treating furnace 1 and heat treated therein to convert it into a pitch. The pitch is introduced into a continuous single reaction tank 2 and brought into contact with a heat medium 15 to effect thermal decomposition of the pitch, thereby forming a gaseous component 16 and a liquid component 20 comprising a pitch containing mesophase dispersed therein. The gaseous component 16 is separated and subjected to fractional distillation using a fractional distillation column 3, 4 to obtain a heavy oil 11, 12, middle oil 19, light oil and pyrolysis gas 18. The heavy oil 11 is returned to the heat-treating furnace 1. The liquid component 20 is introduced into a separation apparatus 5 to separate it into a mesophase pitch component 25 containing mesophase in a large amount and a matrix pitch component 21 containing mesophase in a small amount. A part of the latter is returned to the reaction tank 2.
UEDA TAKUYA
NAKAGAWA TAKAO
TACHIBANA MASAHARU
