Patent US3959115A successfully refreshed from Google Patents.
US3959115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of petroleum cokes
Assignee: Maruzen Petrochemical Co Ltd
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Filing: 1974-11-04
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Granted: 1976-05-25
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Expires: 1994-11-04
Abstract
Abstract Any kind of virgin, low-sulfur crude oil is directly treated in a two-stage delayed coking process for yielding non-crystalline coke in the first stage and high-crystalline coke in the second stage, which process comprises preheating the crude oil in a tube heater to 460 DEG - 520 DEG C under 5-20 kg/cm2G, maintaining the oil therein at that temperature for 30 - 500 seconds to allow the oil to be heat-soaked, subjecting the oil to first delayed coking under relatively mild conditions and subjecting the uncoked heavy residual oil to second delayed coking under relatively severe conditions.
Inventors
- 👤 Kiyoshige Hayashi
- 👤 Mikio Nakaniwa
- 👤 Minoru Yamamoto
- 👤 Kazuo Ozaki
- 👤 Arimasa Baba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:29
CPC Classifications
C; C10; C10B; C10B57/00; C10B57/04; C10B55/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
234 words
A process for the production of high crystalline coke from a virgin crude oil having a sulfur content of lower than 0.4% by weight and substantial amounts of non-crystalline substances which prevent the growth of coke crystals which comprises removing said non-crystalline substances by: preheating the virgin crude oil in a tube heater to a to a temperature of 460° - 520°C under a pressure of 5 - 20 kg/cm 2 G; maintaining the oil in the tube heater at that temperature for 30 - 500 seconds to effect cracking and heat-soaking thereof; flashing the oil thus heat-treated into a first coking drum, where the oil is subjected to a first delayed coking at a temperature of 410° - 430°C under a pressure of 2-10 kg/cm 2 G for a residence time of 3 - 5 hours to produce a non-crystalline coke; removing from the flashed product of the first coking drum cracked gases and light petroleum fractions including gasoline, kerosene and gas oil to provide a heavy residue substantially free of said non-crystalline substances; preheating said heavy residue of the flashed product to a temperature required for a second coking stage; and introducing the preheated heavy residue into a second coking drum, where it is subjected to a second delayed coking at a temperature of 430° - 460°C under a pressure of 4 - 20 kg/cm 2 G to produce said high-crystalline coke.
Claim 2
Dependent Claim
234 words
A process for the production of high crystalline coke from a virgin crude oil having a sulfur content of lower than 0.4% by weight and substantial amounts of non-crystalline substances which prevent the growth of coke crystals which comprises removing said non-crystalline substances by: preheating the virgin crude oil in a tube heater to a to a temperature of 460° - 520°C under a pressure of 5 - 20 kg/cm 2 G; maintaining the oil in the tube heater at that temperature for 30 - 500 seconds to effect cracking and heat-soaking thereof; flashing the oil thus heat-treated into a first coking drum, where the oil is subjected to a first delayed coking at a temperature of 410° - 430°C under a pressure of 2-10 kg/cm 2 G for a residence time of 3 - 5 hours to produce a non-crystalline coke; removing from the flashed product of the first coking drum cracked gases and light petroleum fractions including gasoline, kerosene and gas oil to provide a heavy residue substantially free of said non-crystalline substances; preheating said heavy residue of the flashed product to a temperature required for a second coking stage; and introducing the preheated heavy residue into a second coking drum, where it is subjected to a second delayed coking at a temperature of 430° - 460°C under a pressure of 4 - 20 kg/cm 2 G to produce said high-crystalline coke.
Claim 3
Dependent Claim
35 words
A process as claimed in claim 1 wherein the time to maintain the temperature of 460° - 520°C of the preheated virgin crude oil for effecting cracking and heat-soaking thereof is 200 - 500 seconds.
Claim 4
Dependent Claim
56 words
A process as claimed in claim 1 wherein the uncoked product of the first coking stage, after the cracked gases and light petroleum fractions have been removed therefrom, is subjected to vacuum distillation to recover a heavy gas oil fraction rich in paraffin wax and thereafter the vacuum residue is subjected to the second delayed coking.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |