To provide a process for fractionating crude oil whereby the amount of an off-gas produced can be reduced, and the yields of LPG, light gasoline or heavy gasoline can be increased.
The overhead fraction 6 from an atmospheric distillation tower 3 is separated into a gas fraction 15 and a mixture 21 containing LPG and full-range gasoline by means of a separation drum 13. In a stabilizer 22, the mixture is separated into LPG 23 and a full-range gasoline fraction 24, and the fraction 24 is separated into light gasoline 26 and heavy gasoline 27 by means of a splitter 25. At least portions of the gasoline 26, the gasoline 27 and the fraction 24 are added to the overhead fraction 6 from the tower 3 through lines 30, 31 and 35. Thus, the gas fraction (off-gas) leaving from the drum 13 can be decreased.
NAGAI HIROHISA
INOUE YUBUN
MITSUBISHI SEKIYU ENG KK
MITSUBISHI HEAVY IND LTD