Fuji Oil Company Limited

Chiyoda Chemical Engineering Construction Co., Ltd.

Fuji Standard Research, Inc.

Research Association for Residual Oil Processing

Ryuzo Watari

Toru Takatsuka

Shimpei Gomi

Tomomitsu Takeuchi

Itaru Matsuo

Tomio Arai

Masaki Fujii

Shigeru Miwa

Hideo Hashimoto

Yoshihiko Shohji

Tamotsu Ito

Hitoshi Maekawa

Takeru Iimori

Yuzo Takahashi

A process of thermally cracking a heavy petroleum oil wherein the heavy petroleum oil is treated successively in a cracking furnace and then in a perfect mixing type tank reactor. The thermal cracking in the cracking furnace is performed at a temperature at the outlet of the cracking furnace of 450.degree.-520.degree. C. with a conversion of at least 60-75% of the overall conversion rate while the thermal cracking in the tank reactor is performed at a temperature of 400.degree.-450.degree. C. a pressure of from ambient pressure to 1 kg/cm.sup.2 for a period of time of less than 30 minutes but not less than 10 minutes while feeding steam having a temperature of 435.degree.-700.degree. C. to the tank reactor in an amount of 8-20% by weight of the heavy petroleum oil fed to the cracking furnace.

Process of thermally cracking heavy petroleum oil

A heavy hydrocarbon feed stock is, after being heat-treated in a first cracking zone, is introduced into a second thermal cracking zone for obtaining a thermally cracked product and a pitch product. The second cracking zone has a plurality of cracking reactors which are connected in series, through which is successively passed the treated feed stock and to each of which is supplied a gaseous heat transfer medium to maintain the liquid phase therein at a temperature sufficient for effecting the thermal cracking and to strip the resulting distillable, cracked components from the liquid phase. The thermal cracking temperature in one reactor is so controlled as to become higher than that in its adjacent upstream-side reactor. The distillable, cracked components in respective reactors are removed overhead therefrom and separated into a heavy fraction and a light fraction, while the liquid phase in the downstream-end reactor is discharged therefrom for recovery as the pitch product. The light fraction is recovered as a light product oil, while the heavy fraction is fed to a third thermal cracking zone for obtaining a tar-containing product which is recycled to at least one of the reactors of the second thermal cracking zone together with a naphthene base heavy hydrocarbon oil.

Process of thermally cracking heavy hydrocarbon oils

A heavy hydrocarbon feed stock is, after being heat-treated in a first cracking zone, introduced into a second thermal cracking zone for obtaining a thermally cracked product and a pitch product. The second cracking zone has a plurality of cracking reactors which are connected in series, through which is successively passed the treated feed stock and to each of which is supplied a gaseous heat transfer medium to maintain the liquid phase therein at a temperature sufficient for effecting the thermal cracking and to strip the resulting distillable, cracked components from the liquid phase. The thermal cracking temperature in one reactor is so controlled as to become higher than that in its adjacent upstream-side reactor. The distillable, cracked components in respective reactors are removed overhead therefrom and separated into a heavy fraction and a light fraction, while the liquid phase in the downstream-end reactor is discharged therefrom for recovery as the pitch product. The light fraction is recovered as a light product oil, while the heavy fraction is fed to a third thermal cracking zone for obtaining a tar-containing product which is recycled to at least one of the reactors of the second thermal cracking zone.

Thermal cracking of heavy hydrocarbon oils

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Yamato, Japan

Ryuzo Watari