US4477334A
Expired / Lapsed
US
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Thermal cracking of heavy hydrocarbon oils
Assignee: Fuji Standard Research Inc
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Filing: 1984-02-24
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Granted: 1984-10-16
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Expires: 2004-02-24
Abstract
Abstract 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.
Inventors
- 👤 Shimpei Gomi
- 👤 Tomomitsu Takeuchi
- 👤 Itaru Matsuo
- 👤 Masaki Fujii
- 👤 Toru Takatsuka
- 👤 Ryuzo Watari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:11
CPC Classifications
C; C10; C10G; C10G51/00; C10G51/02; C10G51/023
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
250 words
A process for thermally cracking a heavy hydrocarbon oil, comprising the steps of: (a) feeding the heavy hydrocarbon oil into a first thermal cracking zone for thermally cracking the heavy hydrocarbon oil and for obtaining a first, thermally cracked product; (b) introducing said first product into a second thermal cracking zone for thermally cracking said first product and for obtaining a second, thermally cracked product and a pitch product, said second cracking zone having a plurality of cracking reactors which are connected in series, through which is successively passed said first product and to each of which is supplied a gaseous heat transfer medium to maintain the liquid phase therein, including said first product, 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 being so controlled as to become higher than that in its adjacent upstream-side reactor, the distillable, cracked components in respective reactors being removed overhead therefrom as said second product, the liquid phase in the downstream-end reactor being discharged therefrom for recovery as said pitch product; (c) separating said second product into a heavy fraction and a light fraction; (d) recovering said light fraction as a light product oil; (e) introducing said heavy fraction into a third thermal cracking zone for thermally cracking same and for obtaining a tar-containing product; and (f) recycling said tar-containing product to at least one of said reactors of said second thermal cracking zone.
Claim 2
Dependent Claim
250 words
A process for thermally cracking a heavy hydrocarbon oil, comprising the steps of: (a) feeding the heavy hydrocarbon oil into a first thermal cracking zone for thermally cracking the heavy hydrocarbon oil and for obtaining a first, thermally cracked product; (b) introducing said first product into a second thermal cracking zone for thermally cracking said first product and for obtaining a second, thermally cracked product and a pitch product, said second cracking zone having a plurality of cracking reactors which are connected in series, through which is successively passed said first product and to each of which is supplied a gaseous heat transfer medium to maintain the liquid phase therein, including said first product, 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 being so controlled as to become higher than that in its adjacent upstream-side reactor, the distillable, cracked components in respective reactors being removed overhead therefrom as said second product, the liquid phase in the downstream-end reactor being discharged therefrom for recovery as said pitch product; (c) separating said second product into a heavy fraction and a light fraction; (d) recovering said light fraction as a light product oil; (e) introducing said heavy fraction into a third thermal cracking zone for thermally cracking same and for obtaining a tar-containing product; and (f) recycling said tar-containing product to at least one of said reactors of said second thermal cracking zone.
Claim 3
Dependent Claim
50 words
A process as claimed in claim 1, wherein step (a) is performed at a temperature of between 450° and 500° C. and a pressure of between normal pressure and 20 Kg/cm 2 G for a period of between 0.5 and 5 min while substantially preventing the formation of toluene insolubles.
Claim 4
Dependent Claim
25 words
A process as claimed in claim 1, wherein the number of the cracking reactors of said second thermal cracking zone is between 2 and 4.
Claim 5
Dependent Claim
24 words
A process as claimed in claim 1, wherein the thermal cracking of step (b) is performed at temperatures of between 400° and 440° C.
Claim 6
Dependent Claim
32 words
A process as claimed in claim 1, wherein the thermal cracking in one cracking reactor is performed at a temperature at least 5° C. higher than that in its adjacent upstream-side reactor.
Claim 7
Dependent Claim
64 words
A process as claimed in claim 1, wherein the second thermal cracking zone includes first, second and third cracking reactors and wherein the thermal cracking in the first cracking reactor is performed at a temperature of between 400° and 420° C., that in the second reactor is between 410° and 430° C. and that in the third reactor is between 420° and 440° C.
Claim 8
Dependent Claim
16 words
A process as claimed in claim 1, wherein said gaseous heat transfer medium is superheated steam.
Claim 9
Dependent Claim
39 words
A process as claimed in claim 1, wherein step (b) is performed so that the pitch product has a volatile matter content of between 25 and 40 weight % and a softening point of between 200° and 300° C.
Claim 10
Dependent Claim
20 words
A process as claimed in claim 1, wherein said heavy fraction has a boiling point of 370° C. or more.
Claim 11
Dependent Claim
59 words
A process as claimed in claim 1, wherein step (e) includes introducing said heavy fraction into a cracking furnace for thermally treating same, and feeding the thus treated heavy fraction to a soaker for soaking same and for forming a tar, the tar-containing liquid in the soaker being discharged from the bottom of the soaker as said tar-containing product.
Claim 12
Dependent Claim
86 words
A process as claimed in claim 10, wherein said thermal treatment in the cracking furnace is performed at a temperature of between 450° and 520° C. and a pressure of between 0.3 and 150 Kg/cm 2 G and for a period of between 0.5 and 20 min and said soaking treatment in said soaker is performed at a temperature of between 400° and 460° C. and a pressure of between 0.1 and 50 Kg/cm 2 G and for a period of between 0.1 and 8 hours.
Claim 13
Dependent Claim
20 words
A process as claimed in claim 10, wherein the tar-containing liquid has a boiling point of 370° C. or more.
Claim 14
Dependent Claim
27 words
A process as claimed in claim 10, further comprising removing volatile components in the soaker overhead from the soaker and recycling the overhead components to step (c).
Claim 15
Dependent Claim
24 words
A process as claimed in claim 1, wherein said tar-containing product is fed to one or more reactors located downstream of the upstream-end reactor.
Claim 16
Dependent Claim
32 words
A process as claimed in claim 1, wherein the amount of said tar-containing product supplied to each reactor is between 5 and 50 weight % of the liquid phase in each reactor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |