Patent US4309272A successfully refreshed from Google Patents.
US4309272A
Expired / Lapsed
US
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Sequential thermal cracking process
Assignee: Stone and Webster Engineering Corp
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Filing: 1980-08-15
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Granted: 1982-01-05
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Expires: 2000-08-15
Abstract
Abstract A process and system for sequentially cracking hydrocarbons in a TRC system. A first hydrocarbon feed is cracked at high severity low residence times and the cracked effluent is quenched by a second hydrocarbon feed which is coincidentally cracked at low severity.
Inventors
- 👤 Axel R. Johnson
- 👤 Herman N. Woebcke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:09
CPC Classifications
C; C10; C10G; C10G9/00; C10G9/28; C10G9/32; B; B01; B01J; B01J8/00; B01J8/0015; B01J8/003; C10G2400/00; C10G2400/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
153 words
In a TRC process wherein the temperature in the reaction chamber is between 1300° and 2500° F. and wherein the hydrocarbon fluid feed or the hydrosulfurized residual oil along with the entrained inert solids and the diluent gas are passed through the reaction chamber for a residence time of 0.5 to 2 seconds, the improvement wherein the step of cracking hydrocarbon feed to produce olefins comprises: a. delivering hydrocarbon feed to a first zone; b. thermally cracking the hydrocarbons in the first zone at temperatures above 1,500° F.; c. discharging the cracked effluent from the first zone to a second zone; d. delivering a second hydrocarbon feed to the entry of the second zone; and e. mixing the cracked effluent from the first zone and the second hydrocarbon feed in the second zone; whereby the cracked effluent from the first zone is quenched and the second hydrocarbon feed is cracked at low severity.
Claim 2
Dependent Claim
153 words
In a TRC process wherein the temperature in the reaction chamber is between 1300° and 2500° F. and wherein the hydrocarbon fluid feed or the hydrosulfurized residual oil along with the entrained inert solids and the diluent gas are passed through the reaction chamber for a residence time of 0.5 to 2 seconds, the improvement wherein the step of cracking hydrocarbon feed to produce olefins comprises: a. delivering hydrocarbon feed to a first zone; b. thermally cracking the hydrocarbons in the first zone at temperatures above 1,500° F.; c. discharging the cracked effluent from the first zone to a second zone; d. delivering a second hydrocarbon feed to the entry of the second zone; and e. mixing the cracked effluent from the first zone and the second hydrocarbon feed in the second zone; whereby the cracked effluent from the first zone is quenched and the second hydrocarbon feed is cracked at low severity.
Claim 3
Dependent Claim
41 words
A process as in claim 1 further comprising the steps of passing the composite quenched effluent from the second zone through the hot side of an indirect heat exchanger and passing steam through the cold side of the indirect heat exchanger.
Claim 4
Dependent Claim
28 words
A process as in claim 1 further comprising the steps of fractionating the cracked effluent and returning a portion of the fractionated cracked effluent to the first zone.
Claim 5
Dependent Claim
19 words
A process as in claim 1 wherein the first zone is operated at high severity short residence cracking conditions.
Claim 6
Dependent Claim
22 words
A process as in claim 1 wherein the feed delivered to the second zone is virgin gas oil 400° to 650° F.
Claim 7
Dependent Claim
22 words
A process as in claim 3 wherein the fraction returned to the first zone is light paraffinic gases of ethane and propane.
Claim 8
Dependent Claim
24 words
A process as in claim 1 wherein the hydrocarbon delivered to the first zone is pre-heated to a temperature between 600° and 1,200° F.
Claim 9
Dependent Claim
24 words
A process as in claim 1 wherein the hydrocarbon delivered to the second zone is pre-heated to a temperature between 600° and 1,200° F.
Claim 10
Dependent Claim
18 words
A process as in claim 4 wherein the kinetic severity function in the first zone is about 3.5.
Claim 11
Dependent Claim
20 words
A process as in claim 4 wherein the kinetic severity factor is about 0.5 at about 300 to 400 milliseconds.
Claim 12
Dependent Claim
30 words
A process as in claim 1 wherein 100 pounds of hydrocarbon are delivered to the second reaction zone as quench for every 60 pounds of effluent from the primary zone.
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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) | 1985-01-04 | 1985-07-06 | 1986-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-04 | 1989-07-06 | 1990-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-04 | 1993-07-06 | 1994-01-05 | $7700.00 | Window Closed / Lapsed |