CA1204287A - Method of generating a reducing gas - Google Patents
Method of generating a reducing gasInfo
- Publication number
- CA1204287A CA1204287A CA000428719A CA428719A CA1204287A CA 1204287 A CA1204287 A CA 1204287A CA 000428719 A CA000428719 A CA 000428719A CA 428719 A CA428719 A CA 428719A CA 1204287 A CA1204287 A CA 1204287A
- Authority
- CA
- Canada
- Prior art keywords
- gas
- molten metal
- bath
- metal bath
- iron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/57—Gasification using molten salts or metals
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/723—Controlling or regulating the gasification process
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/74—Construction of shells or jackets
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/82—Gas withdrawal means
- C10J3/84—Gas withdrawal means with means for removing dust or tar from the gas
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/86—Other features combined with waste-heat boilers
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0073—Selection or treatment of the reducing gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/02—Making spongy iron or liquid steel, by direct processes in shaft furnaces
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0913—Carbonaceous raw material
- C10J2300/093—Coal
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0913—Carbonaceous raw material
- C10J2300/0943—Coke
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0953—Gasifying agents
- C10J2300/0959—Oxygen
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0953—Gasifying agents
- C10J2300/0973—Water
- C10J2300/0976—Water as steam
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0983—Additives
- C10J2300/0996—Calcium-containing inorganic materials, e.g. lime
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/18—Details of the gasification process, e.g. loops, autothermal operation
- C10J2300/1846—Partial oxidation, i.e. injection of air or oxygen only
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/20—Increasing the gas reduction potential of recycled exhaust gases
- C21B2100/28—Increasing the gas reduction potential of recycled exhaust gases by separation
- C21B2100/282—Increasing the gas reduction potential of recycled exhaust gases by separation of carbon dioxide
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
- C21B2100/42—Sulphur removal
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
- C21B2100/44—Removing particles, e.g. by scrubbing, dedusting
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
- C21B2100/64—Controlling the physical properties of the gas, e.g. pressure or temperature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Combustion & Propulsion (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Manufacture Of Iron (AREA)
- Hydrogen, Water And Hydrids (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
ABSTRACT
A method for forming a reducing gas in a molten metal bath gasifier and simultaneously directly reducing iron oxide in a shaft furnace with the gas thus produced.
Apparatus for carrying out the method is also disclosed.
A method for forming a reducing gas in a molten metal bath gasifier and simultaneously directly reducing iron oxide in a shaft furnace with the gas thus produced.
Apparatus for carrying out the method is also disclosed.
Description
lZQ42~'7 This invention concerns ~ method and apparatus for generating a low-sul~ur reducing gas by the gasification of carbonaceous fuel in a molten iron bath. Fuel oxygen and a slag former are injected into the molten metal bath through the bottom of the bath-containing vessel. The reaction within the vessel is cooled by the injection of a gaseous coolant which is recycled, spent top gas from a direct reduction furnace, steam or a mixture thereof.
The present invention is an improvement to German OLS 27 50 725, which teaches the generation of a reducing gas in a molten metal bath. The known gasifier is noted for its refractory wear. The present invention alleviates the refractor~ wear problem by maintaining the bath temperature OL the gasifier at a lower level. This is achieved by lnjecting a coolant into the molten metal bath to cool the reaction.
The present invention also provides a well-balanced reducing gas for the direct reduction of iron.
This is achieved by maintaining the operating tempera-ture of the molten bath gasifier above the iron-car~on eutectic point.
In the direct reduction of iron oxide to metallized iron in a shaft furnace, the reacted top gas is superheated and must be cooled immediately upon removal from the furnace. The present invention utilizes this superheat to calcine lime for sulfur removal from the shaft furnace.
According to a method aspect of the invention there is provided a method for generating a reducing gas wherein sulfur-containing fuel, ox~gen and a flu~
are injected into a molten metal bath within a pressure-3~ :
12~)4287 tight vessel beneath the surface of the bath to produce a partially-desulfurized par-tial-oxidation gas having a h~drogen and carbon monoxide content of at least 80%, the molten metal bath consisting essentially of frorn one to 5 percent carbon, minor amounts of sulfur, phosphorus, and silicon, the balance substantially iron, the molten metal bath having a slag layer thereon, the improvement comprising: a) injecting a coolant into the molten metal bath beneath the surface of the bath, the coolant being a fuel-rich gas selected from the group consisting of hydrogen, carbon monoxide, methane, and any mixture thereof; and b) maintaining the temperature of the mo].ten metal bath between 1350C
and 1600C by monitoring the molten metal bath tempera-ture and increasing or decreasing the çoolant flow rate to lower or raise the bath temperature respectively as required.
According to an apparatus aspect of the invention there is provided an apparatus for generating a reducing gas and reducing iron oxide, the apparatus comprising: a) a molten bath gasifier for producing a gasifier gas; b) a generally vertical shaft furnace for the direct reduction of iron, the furnace having particle introducing means at the top thereof, particle removal means at the bottom thereof for establishing a descending burden therein, reducing gas introduction means between the particle introducing means and the particle removal means and a spent top gas outlet for removing spent top gas from the upper portion of the furnace; c) a first conduit communicating with the gasifier and the reducing gas introduction means for removing reducing gas from the gasifier and introducing
The present invention is an improvement to German OLS 27 50 725, which teaches the generation of a reducing gas in a molten metal bath. The known gasifier is noted for its refractory wear. The present invention alleviates the refractor~ wear problem by maintaining the bath temperature OL the gasifier at a lower level. This is achieved by lnjecting a coolant into the molten metal bath to cool the reaction.
The present invention also provides a well-balanced reducing gas for the direct reduction of iron.
This is achieved by maintaining the operating tempera-ture of the molten bath gasifier above the iron-car~on eutectic point.
In the direct reduction of iron oxide to metallized iron in a shaft furnace, the reacted top gas is superheated and must be cooled immediately upon removal from the furnace. The present invention utilizes this superheat to calcine lime for sulfur removal from the shaft furnace.
According to a method aspect of the invention there is provided a method for generating a reducing gas wherein sulfur-containing fuel, ox~gen and a flu~
are injected into a molten metal bath within a pressure-3~ :
12~)4287 tight vessel beneath the surface of the bath to produce a partially-desulfurized par-tial-oxidation gas having a h~drogen and carbon monoxide content of at least 80%, the molten metal bath consisting essentially of frorn one to 5 percent carbon, minor amounts of sulfur, phosphorus, and silicon, the balance substantially iron, the molten metal bath having a slag layer thereon, the improvement comprising: a) injecting a coolant into the molten metal bath beneath the surface of the bath, the coolant being a fuel-rich gas selected from the group consisting of hydrogen, carbon monoxide, methane, and any mixture thereof; and b) maintaining the temperature of the mo].ten metal bath between 1350C
and 1600C by monitoring the molten metal bath tempera-ture and increasing or decreasing the çoolant flow rate to lower or raise the bath temperature respectively as required.
According to an apparatus aspect of the invention there is provided an apparatus for generating a reducing gas and reducing iron oxide, the apparatus comprising: a) a molten bath gasifier for producing a gasifier gas; b) a generally vertical shaft furnace for the direct reduction of iron, the furnace having particle introducing means at the top thereof, particle removal means at the bottom thereof for establishing a descending burden therein, reducing gas introduction means between the particle introducing means and the particle removal means and a spent top gas outlet for removing spent top gas from the upper portion of the furnace; c) a first conduit communicating with the gasifier and the reducing gas introduction means for removing reducing gas from the gasifier and introducing
2 -mab/~l ~2~)~Z~7 reducing aas to the shaEt furnace; d) mean~ for cooling and cleaning the spent gas removed from the upper portion of the shaf-t furnace; e) a second conduit com-municating with the spen~ top gas outlet and the cooling and cleaning means; f) acid gas re~oval means for removing CO2 from the cleaned, cooled spen~ top gas;
g) a third conduit communicating with the top gas cooling and cleaning means and the acid gas removal system; h) a fourth conduit communicating between the acid gas removal system and the bo~tom of the gasifier;
i) a fifth conduit communicating between the acid gas removal system and the first conduit; j) a sixth conduit communicating between the acid gas removal system and the first conduit and having heating means therein; k) means for injecting solid fossil fuel into the bottom of the gasifier beneath the bath line; and .
1) means for injecting oxygen into the gasifier beneath the bath line.
This invention is better understood by referring to the following detailed description and the appended drawings in which:
Figure 1 is a schematic diagram of a pre-ferred embodiment of the invention showing a molten bath gasifier for supplying reducing gas to a shaft furnace and the necessary auxiliarv equipment.
mab/ `
"
12()4Z~7 }igure ~ is a schcn~ltic di~gr;lm simil;lr to Fi~lI`C 1 showillg ~n altcrnative flow shcet.
Figure 3 is yet another alternative flow sheet for achieving thc objects of the present invention.
Referring nol~ to ~igure l, a moltcn bath gasifier 10 contains a molten iron bath 12 and a fluid slag 14. Cooling coils 16 surround the gasifier; fuel such as coal from source 20 is injected into the bath through the bottom of the gasifier. A flu.~ such as lime from source 2~ is injected into the bath as needed to adjust the fluidity of the slag and to assist in sulfur removal.
lQ Oxygen from source 24 is also injected into the bath through the bottom of the gasifier to oxidize and gasify the fuel to carbon monoxide.
Suitable fuels are coal, a hydrocarbon, charcoal, coke oven gas, or any mixture thereof. The preferred fuel is powdered coal.
External cooling of the gasifier is provided by coils 16. I~ater from source 28 passes through the coils and emerges as steam from line 30. It is desired to maintain the operating temperature of the gasifier at about 1500~ C.
Steam ~rom source 32 or carbon dioxide-lean top gas from line 34 or a combination controlled by valve 36 are injected into the molten bath through line 38. The temperature of the bath is monitored by a device (not shown) which controls the operation of valve 36 and thus the injection of steam and/or cleaned top gas.
Mblten slag 14 is re ved from the gasifier at outlet 40 as required. Hot partial oxidation gas (reducing gas) is removed from gasifier 10 through line 42after which it is tempered or quenched to a temperature below slag fusion temperature by carbon dioxide-lean top gas from line 44 in quencher 46. Heated carbon dioxide-lean top gas from line 48 is added to the quenched reducing gas and the resulting mixture is intorduced to direct reduction furnace 50 through line 52. Iron oxide from bin 54 is fed into furnace 50 ~hrough line 56 to form a packed bed burden therein. The downwardly moving iron oxide burden is B
12~ 7 Teduced to mc~alli~ed iron by co~lterc-lrlellt flow of the reducing gas.
~talli~ed iron i~ rell~ved at outlct 58 from the furnace and spent top gas is remo~ed from the furnace via line 60. If desircd, lime or limestone nuy be fed to the furnace through line 56 to form a part of the descending burden.
The heat in the spent top g~s will calcine the lime. If there is any appreciable sulfur in the reducing gas, it will combine with the calcium as calcium sulfide .lhich is rel~oved ~ith the m~tallized iron along with any unreacted calcium oxide through discharge pipe 58. ~is will prevent contamination of the direct reduced iron with sulfide as well as preventing contamination of the spcnt top gas.
Because of ~lermodynan~c restrictions, not all of the hydrogen and carbon noxide in the reducing gas will react with the iron oxide, thus the spent top gas removed through line 60 contains valuable hydrogen and carbon monoxide.
The spent top gas is passed through cooler 62 and scrubber 64 to reduce the gas temperature and remove water and dust from the gas. A portion of the cleaned, cooled top gas passes through lines 66 and 68 to be used as fuel for burner 70.
Combustion air is provided from source 72 and additional fuel may be injected from source 74 if necessary for proper operation of burner 70. If it is desired to produce export fuel for other processes, such export fuel may be withdrawn Erom line ~6 through line 76 and stored in tank 78.
The major portion of the spent top gas from line 66 is compressed in compressor 80, then cleaned of carbon dioxide in an acid gas removal system 82.
Ihe resulting C02-lean top gas is used in three ways, first to cool the molten metal bath through lines 34 and 38; second, to temper the gasified reducing gas ~hrough line 44; and third, to be introduced to heater 84 through line 86 to be re-heated for controlling the temperature of the reducing gas in line 52.
In operation, the temperature of the mDlten metal bath is maintained at a desired operating temperature of between 1350 and 1600 C, preferably about 1500 C. The temperature of the reducing gas in line 52 is maintained between , ,,, .~ ..
~, ~
12~42~37 S00 and 900 C, and prefer~bly at a ten~elature of about 850 C to pro~ide a reducinx ~as ~hich will react with the iron oxide burdcn, but will not n~et e metallized iron product.
An alternative embodiment shown in Figure 2 includes a sulfur ren~al system 90 into which calcium oxide is fed througll line 92 and thc reaction product~ calcium sulfide is removed through line 94. ~luS a substantially sulfur-free reducing gas is introduced to furnace 50 through line 52.
In an alternative embodiment shown in Figure 3, the coolant injected intogasifier 10 through line 38 is cleaned, cooled, spent top gas having the same composition as in line 66. ~le carbon dioxide removal system 82 provides fuel - rich gas for line 44, a portion of which is injected into gasifier 10 above the molten metal bath through line 98. This provides a somewhat cooler reducing gas in line 42, being on the order of about 1500~ C. This reducing gas.is then reduced to a temperature of about 850 C in quencher 46 prior to its injection into the direct reduction furnace 50.
From the foregoing, it is readily apparent that we have developed a . method and apparatus for generating a reducing gas in a molten metal bath, in cooperation with a shaft furnace for the direct reduction of iron oxide to metallized iron. The process is highly efficient and results in a substantially sulfur-frèe ~etallized iron as well as a substantially sulfur-free spent top gas.
g) a third conduit communicating with the top gas cooling and cleaning means and the acid gas removal system; h) a fourth conduit communicating between the acid gas removal system and the bo~tom of the gasifier;
i) a fifth conduit communicating between the acid gas removal system and the first conduit; j) a sixth conduit communicating between the acid gas removal system and the first conduit and having heating means therein; k) means for injecting solid fossil fuel into the bottom of the gasifier beneath the bath line; and .
1) means for injecting oxygen into the gasifier beneath the bath line.
This invention is better understood by referring to the following detailed description and the appended drawings in which:
Figure 1 is a schematic diagram of a pre-ferred embodiment of the invention showing a molten bath gasifier for supplying reducing gas to a shaft furnace and the necessary auxiliarv equipment.
mab/ `
"
12()4Z~7 }igure ~ is a schcn~ltic di~gr;lm simil;lr to Fi~lI`C 1 showillg ~n altcrnative flow shcet.
Figure 3 is yet another alternative flow sheet for achieving thc objects of the present invention.
Referring nol~ to ~igure l, a moltcn bath gasifier 10 contains a molten iron bath 12 and a fluid slag 14. Cooling coils 16 surround the gasifier; fuel such as coal from source 20 is injected into the bath through the bottom of the gasifier. A flu.~ such as lime from source 2~ is injected into the bath as needed to adjust the fluidity of the slag and to assist in sulfur removal.
lQ Oxygen from source 24 is also injected into the bath through the bottom of the gasifier to oxidize and gasify the fuel to carbon monoxide.
Suitable fuels are coal, a hydrocarbon, charcoal, coke oven gas, or any mixture thereof. The preferred fuel is powdered coal.
External cooling of the gasifier is provided by coils 16. I~ater from source 28 passes through the coils and emerges as steam from line 30. It is desired to maintain the operating temperature of the gasifier at about 1500~ C.
Steam ~rom source 32 or carbon dioxide-lean top gas from line 34 or a combination controlled by valve 36 are injected into the molten bath through line 38. The temperature of the bath is monitored by a device (not shown) which controls the operation of valve 36 and thus the injection of steam and/or cleaned top gas.
Mblten slag 14 is re ved from the gasifier at outlet 40 as required. Hot partial oxidation gas (reducing gas) is removed from gasifier 10 through line 42after which it is tempered or quenched to a temperature below slag fusion temperature by carbon dioxide-lean top gas from line 44 in quencher 46. Heated carbon dioxide-lean top gas from line 48 is added to the quenched reducing gas and the resulting mixture is intorduced to direct reduction furnace 50 through line 52. Iron oxide from bin 54 is fed into furnace 50 ~hrough line 56 to form a packed bed burden therein. The downwardly moving iron oxide burden is B
12~ 7 Teduced to mc~alli~ed iron by co~lterc-lrlellt flow of the reducing gas.
~talli~ed iron i~ rell~ved at outlct 58 from the furnace and spent top gas is remo~ed from the furnace via line 60. If desircd, lime or limestone nuy be fed to the furnace through line 56 to form a part of the descending burden.
The heat in the spent top g~s will calcine the lime. If there is any appreciable sulfur in the reducing gas, it will combine with the calcium as calcium sulfide .lhich is rel~oved ~ith the m~tallized iron along with any unreacted calcium oxide through discharge pipe 58. ~is will prevent contamination of the direct reduced iron with sulfide as well as preventing contamination of the spcnt top gas.
Because of ~lermodynan~c restrictions, not all of the hydrogen and carbon noxide in the reducing gas will react with the iron oxide, thus the spent top gas removed through line 60 contains valuable hydrogen and carbon monoxide.
The spent top gas is passed through cooler 62 and scrubber 64 to reduce the gas temperature and remove water and dust from the gas. A portion of the cleaned, cooled top gas passes through lines 66 and 68 to be used as fuel for burner 70.
Combustion air is provided from source 72 and additional fuel may be injected from source 74 if necessary for proper operation of burner 70. If it is desired to produce export fuel for other processes, such export fuel may be withdrawn Erom line ~6 through line 76 and stored in tank 78.
The major portion of the spent top gas from line 66 is compressed in compressor 80, then cleaned of carbon dioxide in an acid gas removal system 82.
Ihe resulting C02-lean top gas is used in three ways, first to cool the molten metal bath through lines 34 and 38; second, to temper the gasified reducing gas ~hrough line 44; and third, to be introduced to heater 84 through line 86 to be re-heated for controlling the temperature of the reducing gas in line 52.
In operation, the temperature of the mDlten metal bath is maintained at a desired operating temperature of between 1350 and 1600 C, preferably about 1500 C. The temperature of the reducing gas in line 52 is maintained between , ,,, .~ ..
~, ~
12~42~37 S00 and 900 C, and prefer~bly at a ten~elature of about 850 C to pro~ide a reducinx ~as ~hich will react with the iron oxide burdcn, but will not n~et e metallized iron product.
An alternative embodiment shown in Figure 2 includes a sulfur ren~al system 90 into which calcium oxide is fed througll line 92 and thc reaction product~ calcium sulfide is removed through line 94. ~luS a substantially sulfur-free reducing gas is introduced to furnace 50 through line 52.
In an alternative embodiment shown in Figure 3, the coolant injected intogasifier 10 through line 38 is cleaned, cooled, spent top gas having the same composition as in line 66. ~le carbon dioxide removal system 82 provides fuel - rich gas for line 44, a portion of which is injected into gasifier 10 above the molten metal bath through line 98. This provides a somewhat cooler reducing gas in line 42, being on the order of about 1500~ C. This reducing gas.is then reduced to a temperature of about 850 C in quencher 46 prior to its injection into the direct reduction furnace 50.
From the foregoing, it is readily apparent that we have developed a . method and apparatus for generating a reducing gas in a molten metal bath, in cooperation with a shaft furnace for the direct reduction of iron oxide to metallized iron. The process is highly efficient and results in a substantially sulfur-frèe ~etallized iron as well as a substantially sulfur-free spent top gas.
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a method for generating a reducing gas wherein sulfur-containing fuel, oxygen and a flux are injected into a molten metal bath within a presssure-tight vessel beneath the surface of the bath to produce a partially-desulfurized partial-oxidation gas having a hydrogen and carbon monoxide content of at least 80%, the molten metal bath consisting essentially of from one lo 5 percent carbon, minor amounts of sulfur, phosphorus, and silicon, the balance substantially iron, the molten metal bath having a slag layer thereon, the improvement comprising:
a) injecting a coolant into the molten metal bath beneath the surface of the bath, said coolant being a fuel-rich gas selected from the group consisting of hydrogen, car-bon monoxide, methane, and any mixture thereof; and b) maintaining the temperature of the molten metal bath between 1350C and 1600C by monitoring the molten metal bath temperature and increasing or decreasing the coolant flow rate to lower or raise the bath temperature respectively as required.
a) injecting a coolant into the molten metal bath beneath the surface of the bath, said coolant being a fuel-rich gas selected from the group consisting of hydrogen, car-bon monoxide, methane, and any mixture thereof; and b) maintaining the temperature of the molten metal bath between 1350C and 1600C by monitoring the molten metal bath temperature and increasing or decreasing the coolant flow rate to lower or raise the bath temperature respectively as required.
2. A method according to claim 1 further comprising:
a) quenching the partial-oxidation gas with carbon dioxide lean gas to produce a reducing gas at a temperature between about 800 and 900° C;
b) introducing the tempered gas into a direct reduction furnace having an iron oxide burden therein to reduce the iron oxide to metallized iron and form a top gas;
c) removing the top gas from the furnace and removing a substantial portion of the carbon dioxide therefrom; and d) introducing CO2-lean top gas to the bottom of the molten metal bath as a coolant to cool the metal bath.
a) quenching the partial-oxidation gas with carbon dioxide lean gas to produce a reducing gas at a temperature between about 800 and 900° C;
b) introducing the tempered gas into a direct reduction furnace having an iron oxide burden therein to reduce the iron oxide to metallized iron and form a top gas;
c) removing the top gas from the furnace and removing a substantial portion of the carbon dioxide therefrom; and d) introducing CO2-lean top gas to the bottom of the molten metal bath as a coolant to cool the metal bath.
3. A method according to claim 1 wherein the flux is in the form of limestone, dolomite or calcined dolomite.
4. A method according to claim 1 further comprising injecting fuel rich gas into said vessel above the bath to maintain the temperature of the partial-oxidation gas between 1350 and 1600° C.
5. A method according to claim 4 wherein the fuel rich gas is directed downwardly toward the molten metal bath.
6. A method according to claim 1 wherein said coolant is CO2-lean spent reducing gas produced by the direct reduction of iron oxide to metallized iron.
7. A method according to claim 2 further comprising introducing a sulfur acceptor into said direct reduction furnace as a portion of said burden, whereby said sulfur acceptor will desulfurize both metallized iron product and the spent top gas.
8. A method according to claim 7 wherein said sulfur acceptor is selected from the group consisting of limestone, dolomite and calcined dolomite.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IN691/CAL/83A IN160813B (en) | 1982-03-22 | 1983-06-01 |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US36071382A | 1982-03-22 | 1982-03-22 | |
US55650283A | 1983-12-01 | 1983-12-01 | |
US06/659,109 US4553742A (en) | 1983-12-01 | 1984-10-09 | Apparatus for generating a reducing gas |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1204287A true CA1204287A (en) | 1986-05-13 |
Family
ID=27408476
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000428719A Expired CA1204287A (en) | 1982-03-22 | 1983-05-24 | Method of generating a reducing gas |
Country Status (6)
Country | Link |
---|---|
JP (1) | JPS59232172A (en) |
AU (1) | AU553896B2 (en) |
CA (1) | CA1204287A (en) |
DE (1) | DE3320669C3 (en) |
GB (1) | GB2140453B (en) |
ZA (1) | ZA833826B (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3438487A1 (en) * | 1984-10-17 | 1986-04-24 | Korf Engineering GmbH, 4000 Düsseldorf | METHOD FOR THE PRODUCTION OF RAW IRON |
DE3527532A1 (en) * | 1985-08-01 | 1987-02-12 | Teves Gmbh Alfred | METHOD AND BRAKE SYSTEM FOR DRIVE CONTROL |
AT394201B (en) * | 1989-02-16 | 1992-02-25 | Voest Alpine Ind Anlagen | METHOD FOR GENERATING COMBUSTIBLE GASES IN A MELT-UP CARBURETTOR |
CA2037860C (en) * | 1990-03-08 | 2001-07-31 | Paul Katona | Waste processing |
JPH06100917A (en) * | 1991-10-09 | 1994-04-12 | Cvg Siderurgica Del Orinoco Ca | Method for direct reduction of iron-containing metal oxide |
DE19622152A1 (en) * | 1996-06-01 | 1997-12-04 | Krupp Uhde Gmbh | Process for the production of gas |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3526478A (en) * | 1968-11-01 | 1970-09-01 | Black Sivalls & Bryson Inc | Generation of hydrogen from sulfurbearing carbonaceous fuel |
DE2401540B2 (en) * | 1974-01-14 | 1975-11-13 | Fried. Krupp Gmbh, 4300 Essen | Method for melting sponge iron |
DE2655813B2 (en) * | 1976-12-09 | 1980-10-23 | Kloeckner-Humboldt-Deutz Ag, 5000 Koeln | Process and plant for the direct and continuous extraction of iron |
DE2710106B2 (en) * | 1977-03-08 | 1980-08-14 | Eisenwerk-Gesellschaft Maximilianshuette Mbh, 8458 Sulzbach-Rosenberg | Process for the production of liquid pig iron |
DE2750725A1 (en) * | 1977-11-12 | 1979-05-17 | Kloeckner Humboldt Deutz Ag | Prodn. of sulphur-free synthesis gas in high-temp. melt - in presence of high-basicity solid slag-forming material |
US4188022A (en) * | 1978-09-08 | 1980-02-12 | Midrex Corporation | Hot discharge direct reduction furnace |
JPS5589395A (en) * | 1978-12-26 | 1980-07-05 | Sumitomo Metal Ind Ltd | Gasification of solid carbonaceous material and its device |
DE3024977A1 (en) * | 1980-07-02 | 1982-01-28 | Klöckner-Humboldt-Deutz AG, 5000 Köln | METHOD FOR PRODUCING REACTION GAS |
DE3034539C2 (en) * | 1980-09-12 | 1982-07-22 | Korf-Stahl Ag, 7570 Baden-Baden | Method and device for the direct production of liquid pig iron from lumpy iron ore |
SE426403B (en) * | 1981-05-20 | 1983-01-17 | Ips Interproject Service Ab | Carbon gasification process |
-
1983
- 1983-05-24 CA CA000428719A patent/CA1204287A/en not_active Expired
- 1983-05-26 ZA ZA00833826A patent/ZA833826B/en unknown
- 1983-05-27 GB GB08314821A patent/GB2140453B/en not_active Expired
- 1983-06-06 AU AU15385/83A patent/AU553896B2/en not_active Expired
- 1983-06-08 DE DE3320669A patent/DE3320669C3/en not_active Expired - Lifetime
- 1983-06-13 JP JP58105640A patent/JPS59232172A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS59232172A (en) | 1984-12-26 |
GB2140453B (en) | 1987-01-28 |
DE3320669A1 (en) | 1984-12-13 |
ZA833826B (en) | 1984-01-12 |
GB2140453A (en) | 1984-11-28 |
JPH0456081B2 (en) | 1992-09-07 |
AU553896B2 (en) | 1986-07-31 |
GB8314821D0 (en) | 1983-07-06 |
DE3320669C3 (en) | 1995-02-09 |
AU1538583A (en) | 1984-12-13 |
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