US3844733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-stage downflow gasification of coal
Assignee: United States Department of the Interior
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Filing: 1972-03-23
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Granted: 1974-10-29
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Expires: 1992-03-23
Abstract
Abstract A process for the two-stage downflow gasification of coal to produce a methane rich fuel gas. In a first stage, partially gasified char recycled from a second stage is reacted with superheated steam and oxygen to produce a first stage synthesis gas. In the second stage, the first stage synthesis gas is mixed and reacted with coal and steam to produce partially gasified char and a hydrogen-rich product gas containing methane. Pressures in the first and second stages are maintained at at least 50 atmospheres. Slag formed in the first stage reaction is maintained in the molten state at temperatures in excess of 2,500* F. Gases, excess char and slag flow into the second stage in which coal, synthesis gas and steam react whereby the slag is cooled and solidified before it contacts the walls of the reactor in the second stage. After removal and separation of the partially gasified char and product gas from the second stage, the char is recycled to the first stage and the product gas is purified and methanated. The solidified slag is collected in the second stage and is thereafter elutriated with steam and quenched before disposal.
Inventors
- 👤 E Donath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:30
CPC Classifications
C; C10; C10J; C10J3/00; C10J3/46; C10J3/466; C07; C07C; C07C1/00; C07C1/02; C10J3/48; C10J3/485; C10J3/72; C10J3/74; C10J3/76; C10J3/78; C10J3/82; C10J3/84; C10J3/845; C10J2300/00; C10J2300/09; C10J2300/0913; C10J2300/093; C10J2300/0946; C10J2300/0953; C10J2300/0959; C10J2300/0973; C10J2300/0979; C10J2300/18; C10J2300/1807; C10J2300/1823
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
322 words
A PROCESS FOR GASIFYING COAL COMPRISING, INTRODUCING A PARTIALLY GASIFIED RECYCLE CHAR INTO A FIRST GASIFICATION ZONE, INTRODUCING OXYGEN AND STEAM INTO SAID FIRST GSIFICATION ZONE, REACTING SAID PARTIALLY GASIFIED CHAR, STEAM AND OXIDE IN SAID FIRST GASIFICATION ZONE AT A PRESSURE OF AT LEAST 50 ATMOSPHERES, OBTAINING AS PRODUCTS OF REACTION IN SAID FIRST GASIFICATION ZONE A FIRST ZONE SYNTHESIS GAS COMPRISING HYDROGEN AND OXIDES OF CARBON AND A MOLTEN SLAG, REACTING SAID STEAM, OXYGEN AND CHAR IN SAID FIRST GASIFICATION ZONE A TEMPERATURE SUFFICIENT HIGH TO MAINTAIN IN THE MOLTEN STATE SAID MOLTEN SLAG PRODUCED IN SAID FIRST GASIFICATION ZONE, MOVING SAID PRODUCTS OF REACTION DOWNWARDLY THROUGH SAID FIRST GASIFICATION ZONE TOWARD A SECOND GASIFICATION ZONE POSITIONED BELOW SAID FIRST GASIFICATION ZONE, INTRODUCING INTO SAID SECOND GASIFICATION ZONE AT A LOCATION ADJACENT SAID FIRST GASIFICATION ZONE COAL, STEAM SAID FIRST ZONE SYNTHESIS GAS SAID MOLTEN SLAG, REACTION SAID COAL, STEAM, MOLTEN SLAG AND FIRST zONE SYNTHESIS GAS IN THE SECOND ZONE AT A PRESSURE OF AT LEAST 50 ATMOSPHERES, AND AT A TEMPERATURE CONTROLLED TO ASSURE SOLIDIFCATION OF SAID MOLTEN SLAG, REACTING SAID COAL, STEAM, FIRST ZONE SYNTHESIS GAS AND MOLTEN SLAG AT A RATE SUFFICIENT TO SOLIDIFY SAID MOLTEN SLAG BEFORE SAID MOLTEN SLAG CONTACTS AND ADHERES TO THE WALLS IN SAID SECOND GASIFICATION ZONE, OBTAINING IN SAID SECOND ZONE A REACTION PRODUCT COMPRISING PARTIALLY GASIFIED CHAR ENTRAINED IN A SECOND ZONE PRODUCT GAS COMPRISING METHANE, HYDROGEN AND OXIDES OF CARBON, WITHDRAWING SAID SECOND ZONE PROUCT GAS AND SAID ENTRAINED PARTIALLY GASIFIED CHAR FROM SAID SECOND GASIFICATION ZONE, SEPARATING SAID PARTIALLY GASIFIED CHAR WITHDRAWN FROM SAID SECOND GASIFICATION ZONE FROM SAID SECOND ZONE PRODUCT GAS WITHDRAWN FROM SAID SECOND GASIFICATION ZONE, RECYCLING TO SAID FIRST GASIFICATION ZONE AT LEAST A PORTION OF SAID PARTIALY GASIFIED CHAR SEPARATED FROM SAID SECOND ZONE PRODUCT GAS, AND PURIFYING AND METHANATING SAID SECOND ZONE PRODUCT GAS TO YIELD A FUEL GAS CONTAINING METHANE.
Claim 2
Dependent Claim
322 words
A PROCESS FOR GASIFYING COAL COMPRISING, INTRODUCING A PARTIALLY GASIFIED RECYCLE CHAR INTO A FIRST GASIFICATION ZONE, INTRODUCING OXYGEN AND STEAM INTO SAID FIRST GSIFICATION ZONE, REACTING SAID PARTIALLY GASIFIED CHAR, STEAM AND OXIDE IN SAID FIRST GASIFICATION ZONE AT A PRESSURE OF AT LEAST 50 ATMOSPHERES, OBTAINING AS PRODUCTS OF REACTION IN SAID FIRST GASIFICATION ZONE A FIRST ZONE SYNTHESIS GAS COMPRISING HYDROGEN AND OXIDES OF CARBON AND A MOLTEN SLAG, REACTING SAID STEAM, OXYGEN AND CHAR IN SAID FIRST GASIFICATION ZONE A TEMPERATURE SUFFICIENT HIGH TO MAINTAIN IN THE MOLTEN STATE SAID MOLTEN SLAG PRODUCED IN SAID FIRST GASIFICATION ZONE, MOVING SAID PRODUCTS OF REACTION DOWNWARDLY THROUGH SAID FIRST GASIFICATION ZONE TOWARD A SECOND GASIFICATION ZONE POSITIONED BELOW SAID FIRST GASIFICATION ZONE, INTRODUCING INTO SAID SECOND GASIFICATION ZONE AT A LOCATION ADJACENT SAID FIRST GASIFICATION ZONE COAL, STEAM SAID FIRST ZONE SYNTHESIS GAS SAID MOLTEN SLAG, REACTION SAID COAL, STEAM, MOLTEN SLAG AND FIRST zONE SYNTHESIS GAS IN THE SECOND ZONE AT A PRESSURE OF AT LEAST 50 ATMOSPHERES, AND AT A TEMPERATURE CONTROLLED TO ASSURE SOLIDIFCATION OF SAID MOLTEN SLAG, REACTING SAID COAL, STEAM, FIRST ZONE SYNTHESIS GAS AND MOLTEN SLAG AT A RATE SUFFICIENT TO SOLIDIFY SAID MOLTEN SLAG BEFORE SAID MOLTEN SLAG CONTACTS AND ADHERES TO THE WALLS IN SAID SECOND GASIFICATION ZONE, OBTAINING IN SAID SECOND ZONE A REACTION PRODUCT COMPRISING PARTIALLY GASIFIED CHAR ENTRAINED IN A SECOND ZONE PRODUCT GAS COMPRISING METHANE, HYDROGEN AND OXIDES OF CARBON, WITHDRAWING SAID SECOND ZONE PROUCT GAS AND SAID ENTRAINED PARTIALLY GASIFIED CHAR FROM SAID SECOND GASIFICATION ZONE, SEPARATING SAID PARTIALLY GASIFIED CHAR WITHDRAWN FROM SAID SECOND GASIFICATION ZONE FROM SAID SECOND ZONE PRODUCT GAS WITHDRAWN FROM SAID SECOND GASIFICATION ZONE, RECYCLING TO SAID FIRST GASIFICATION ZONE AT LEAST A PORTION OF SAID PARTIALY GASIFIED CHAR SEPARATED FROM SAID SECOND ZONE PRODUCT GAS, AND PURIFYING AND METHANATING SAID SECOND ZONE PRODUCT GAS TO YIELD A FUEL GAS CONTAINING METHANE.
Claim 3
Dependent Claim
56 words
A process for gasifying coal as set forth in claim 1 which includes, collecting in a lower portion of said second gasification zone said slag solidified in said second gasification zone, introducing said solidified slag into a quenching zone, cooling said solidified slag in said quenching zone, and withdrawing said solidified slag from said quenching zone.
Claim 4
Dependent Claim
32 words
A process for gasifying coal as set forth in claim 1 which includes, reacting said steam, oxygen and char in said first gasification zone at a temperature of at least 2,500* F.
Claim 5
Dependent Claim
37 words
A process for gasifying coal as set forth in claim 1 which includes, reacting said coal, steam, first zone synthesis gas and slag in said second gasification zone at a temperature of at least 1, 600* F.
Claim 6
Dependent Claim
118 words
A process for gasifying coal as set forth in claim 1 which includes, passing said first zone synthesis gas and said molten slag from said first gasification zone through a mixing zone prior to introducing said molten slag and said first zone synthesis gas into said second gasification zone, introducing said first zone synthesis gas and said molten slag into an upper portion of said second gasification zone at a location adjacent said first gasification zone, and introducing said coal and said steam into said upper portion of said second gasification zone adjacent said first gasification zone to assure rapid mixing and reaction of said coal and steam with said molten slag and said first zone synthesis gas.
Claim 7
Dependent Claim
104 words
A process for gasifying coal as set forth in claim 1 which includes, collecting in a lower portion of said second gasification zone said slag solidiFied therein and partially gasified char entrained and collected with said solidified slag, removing from said second gasification zone said solidified slag and said partially gasified char collected in said lower portion thereof, elutriating with steam said solidified slag and said partially gasified char removed from said lower portion of said second gasification zone to remove said partially gasified char from said solidified slag, and returning to said second gasification zone said partially gasified char elutriated by said steam.
References Cited (Backward Citations)
US3463623A
Cited
US3746522A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |