CN104838019A - Device for manufacturing direct-reduced iron and method for manufacturing direct-reduced iron - Google Patents

Device for manufacturing direct-reduced iron and method for manufacturing direct-reduced iron Download PDF

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Publication number
CN104838019A
CN104838019A CN201380063455.1A CN201380063455A CN104838019A CN 104838019 A CN104838019 A CN 104838019A CN 201380063455 A CN201380063455 A CN 201380063455A CN 104838019 A CN104838019 A CN 104838019A
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China
Prior art keywords
gas
mentioned
direct
coal
reduced iron
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CN201380063455.1A
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Chinese (zh)
Inventor
市川宏
中山俊孝
大泽靖之
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Nippon Steel Engineering Co Ltd
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Nippon Steel Engineering Co Ltd
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Publication of CN104838019A publication Critical patent/CN104838019A/en
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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K3/00—Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide
    • C10K3/02—Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide by catalytic treatment
    • C10K3/04—Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide by catalytic treatment reducing the carbon monoxide content, e.g. water-gas shift [WGS]
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10K—PURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K1/00—Purifying combustible gases containing carbon monoxide
    • C10K1/002—Removal of contaminants
    • C10K1/003—Removal of contaminants of acid contaminants, e.g. acid gas removal
    • C10K1/005—Carbon dioxide
    • 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
    • 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
    • C21B2100/24—Increasing the gas reduction potential of recycled exhaust gases by shift reactions
    • 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
    • C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
    • 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
    • Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
    • 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
    • Y02P10/20—Recycling

Abstract

A device (100) for manufacturing direct-reduced iron has the following: a shift reactor (25) that uses the water-gas shift reaction to obtain, from an exhaust gas from a direct reduction furnace (30), a reaction gas that has a higher hydrogen concentration than the exhaust gas; CO2-removal equipment (28) that reduces the amount of carbon dioxide in the reaction gas, yielding a hydrogen-containing circulation gas; a heater (29) that heats the circulation gas, which is supplied to the direct reduction furnace (30); a junction part (51), in a gas channel (21) between the heater (29) and the direct reduction furnace (30), that mixes the circulation gas with coal gas; and a pressure-reduction part (19) in a coal-gas channel between a coal gasification furnace (10) and the junction part (51).

Description

The manufacturing installation of direct-reduced iron and the manufacture method of direct-reduced iron
Technical field
The present invention relates to the manufacturing installation of direct-reduced iron and the manufacture method of direct-reduced iron.
Background technology
Be known to following method: in direct-reduction stove, the ferric oxide that iron ore is comprised contacts with the reducing gas such as carbon monoxide or hydrogen and reduces, thus manufactures direct-reduced iron.Reducing gas used in such method can gasify to generate by making coal in coal gasifier.Such as vertical direct-reduction stove is adopted as direct-reduction stove.In the Exhaust Gas gone out from direct-reduction fire grate, except containing except the carbonic acid gas produced due to the reduction reaction of ferric oxide and moisture, also containing unreacted composition, i.e. carbon monoxide and hydrogen.Therefore, the Exhaust Gas gone out from direct-reduction fire grate is reused after eliminating carbonic acid gas, moisture utilizing the coolings such as wet type dust-collecting equipment and cleaning in direct-reduction stove.
Such as, in patent documentation 1, the Exhaust Gas gone out from direct-reduction fire grate is carried out recycle as follows.After the Exhaust Gas gone out from direct-reduction fire grate is cooled in interchanger, contact with water in the washers and be cooled and clean.After gas after cooling and cleaning is boosted in gas compressor, the synthesis gas supplied with the gasification installation by hydrocarbon converges.At this, the synthesis gas supplied by the gasification installation of hydrocarbon, before converging with recycle gas, utilizes water cooler, washer and shift-converter and carries out the adjustment of the cooling of gas, cleaning and composition.
After gas after converging has been removed carbonic acid gas in the removal device of carbonic acid gas, after being heated to more than 800 DEG C in the heater, be supplied to direct-reduction stove.So, recycle the Exhaust Gas from direct-reduction stove, realize effectively applying flexibly of reducing gas composition.
Prior art document
Patent documentation
Patent documentation 1: the U.S. speciallys permit out hope and discloses No. 2010/0162852 specification sheets
Summary of the invention
the problem that invention will solve
, the bulk of molecule of hydrogen is less than the bulk of molecule of carbon monoxide, therefore, it is possible to be easily impregnated into the inside of iron ore.Thus, think that the ratio of the hydrogen improved in reducing gas is the effective means of the speed of response of the reduction reaction improved in direct-reduction stove.
The carbon monoxide of the reducing gas generated in coal gasifier and the volume ratio of hydrogen the chances are 2:1.As the means of the ratio of the hydrogen improved in such reducing gas, utilize and carry out being effective for the shift-converter that carries out water gas shift reaction to improve the ratio of the hydrogen in reducing gas shown in following formula (1).
CO+H 2O→CO 2+H 2(1)
On the other hand, due in shift-converter, use catalyzer to carry out water gas shift reaction, therefore, need the temperature of the gas supplied to shift-converter to be adjusted to the temperature being suitable for reacting.If from the view point of the damage of catalyzer preventing water gas shift reaction, then the temperature of supply gas needs to be adjusted to such as 200 DEG C ~ 350 DEG C.Therefore, in the method for patent documentation 1, synthesis gas is cooled to the temperature being suitable for transformationreation.Further, the CO at the back segment being positioned at shift-converter is needed 2in removal device, synthesis gas is cooled further.The synthesis gas that temperature reduces like this needs to heat before importing direct-reduction stove.Thus, need operation synthesis gas being cooled and heats, the loss of result generate energy.
The present invention makes in view of the foregoing, object is the manufacturing installation providing a kind of following direct-reduced iron: when employing coal gasifier at the supply source as reducing gas, fully accelerate by making the speed of the reduction reaction of ferric oxide and effectively utilize the energy that coal gas has, thus direct-reduced iron can be manufactured with the energy efficiency of excellence.In addition, the object of the present invention is to provide a kind of by making the speed of the reduction reaction of ferric oxide fully accelerate and the energy effectively utilizing coal gas to have thus the manufacture method of the direct-reduced iron of energy efficiency excellence.
for the scheme of dealing with problems
The invention provides a kind of manufacturing installation of direct-reduced iron, it is used in and makes gasification in coal gasifier and the coal gas obtained, direct-reduction raw iron oxide material in direct-reduction stove, wherein,
The manufacturing installation of this direct-reduced iron comprises:
Shift-converter, it utilizes water gas shift reaction and obtains the hydrogen concentration reactant gases higher than the hydrogen concentration of Exhaust Gas by the Exhaust Gas of direct-reduction stove;
De-CO 2equipment, it is for reducing the carbonic acid gas that reactant gases comprises and the recycle gas obtained containing hydrogen;
Well heater, it is for heating the recycle gas to the supply of direct-reduction stove;
Linking part, it converges in the gas flow path between well heater and direct-reduction stove for making recycle gas and coal gas; And
Relief portion, in the gas flow path of its coal gas between coal gasifier and linking part.
In the manufacturing installation of the direct-reduced iron of the invention described above, except reducing the carbonic acid gas that comprises from the Exhaust Gas of direct-reduction stove, also in shift-converter, generate hydrogen.The hydrogen concentration improving recycle gas comprise therefore, it is possible to abundant.Thus, even if the hydrogen concentration of coal gas is lower, also can improve the hydrogen concentration of coal gas and the reducing gas of recycle gas after linking part place converges, the speed of response of reduction reaction can be made fully to accelerate.
In addition, in the manufacturing installation of direct-reduced iron of the present invention, the temperature of the coal gas from coal gasifier can be maintained high temperature.Therefore, it is possible to make the coal gas from coal gasifier not supply to direct-reduction stove via well heater.Thereby, it is possible to effectively utilize the sensible heat of the coal gas obtained in coal gasifier, direct-reduced iron can be manufactured with the energy efficiency of excellence.That is, the manufacturing installation of direct-reduced iron of the present invention is set to the hydrogen concentration that fully can improve recycle gas and the device that can effectively utilize the sensible heat of coal gas such formation, thus can manufacture direct-reduced iron with high energy efficiency.
Relief portion also can be decompression turbine.In this case, also can comprise interchanger, its for above-mentioned gas stream be positioned at the decompression part of inlet side of turbine and the part being positioned at the outlet side of the turbine that reduces pressure of above-mentioned gas stream carries out heat exchange.By comprising decompression turbine, thus the pressure energy of coal gas can be applied flexibly effectively and make electric energy.That is, by being set to the hydrogen concentration that fully can improve recycle gas and the device effectively utilizing the pressure energy of coal gas such formation, thus direct-reduced iron can be manufactured with high energy efficiency.In addition, by arranging interchanger, thus the temperature of the coal gas when linking part place and recycle gas converge can be improved.Its result, effectively can utilize the sensible heat of the coal gas obtained in coal gasifier, can manufacture direct-reduced iron with more excellent energy efficiency.Relief portion also can be reducing valve.
The manufacturing installation of direct-reduced iron of the present invention also can be provided with the fly-ash separator of the dedusting for carrying out coal gas in the gas flow path of coal gas between coal gasifier and relief portion.By arranging fly-ash separator, the dust fractions of the coal gas entrained with generated in coal gasifier fully can be removed.On the stream of the coal gas between coal gasifier and linking part, also can set gradually fly-ash separator and interchanger from gasification furnace side, this fly-ash separator is for carrying out the dedusting of coal gas; This interchanger be used in the gas flow path of coal gas being arranged in decompression the part of inlet side of turbine and the part being positioned at the outlet side of the turbine that reduces pressure of the gas flow path of coal gas carry out heat exchange.
Also the 1st particle collector for removing the solids component that coal gas comprises with dry type from coal gas can be provided with between coal gasifier and relief portion.Thereby, it is possible to suppress solids component to be brought into relief portion, steady running can be proceeded chronically.In addition, owing to being dry type, the sensible heat of coal gas can more effectively be utilized.
Also the 2nd particle collector for removing the solids component that coal gas comprises with wet type from coal gas can be provided with between coal gasifier and relief portion.Thereby, it is possible to make a kind of ammonium chloride (NH of the solids component comprised as coal gas 4cl) dissolve, ammonium chloride can be removed from coal gas.
Preferably, between direct-reduction stove and shift-converter, be provided with the 3rd particle collector for removing the solids component that Exhaust Gas comprises from Exhaust Gas.Thereby, it is possible to suppress solids component to flow into shift-converter, the further stabilization operated can be realized.
The manufacturing installation of direct-reduced iron of the present invention preferably, has the temperature adjustment part for the temperature of coal gas when converging with recycle gas being adjusted to 500 DEG C ~ 900 DEG C in the stream of coal gasifier or the coal gas between coal gasifier and linking part.Can effectively utilize in the scope of the sensible heat of coal gas, by the temperature with temperature adjustment part adjustment coal gas, thus the cinder that coal gas can be suppressed to comprise and ash grade and are attached to the inwall of the various equipment such as stream, fly-ash separator, interchanger and particle collector.
The manufacturing installation of direct-reduced iron of the present invention preferably, for being provided with for for recycle gas autospasy CO to coal gasifier for the supply unit of coal supply 2equipment or de-CO 2carry out the gas flow path circulated in the downstream side of equipment.In the past, in order to supply coal supply to coal gasifier, the non-active gas such as carbonic acid gas or nitrogen was employed.Above-mentioned non-active gas not only reduces the concentration of the reducing gas (carbon monoxide, hydrogen) in coal gas, but also needs the device of these non-active gas removed in coal gas.Contain by de-CO in contrast, use 2equipment decreases the recycle gas of the hydrogen of carbonic acid gas, to coal gasifier for coal supply, thus the gas concentration lwevel that can fully reduce in coal gas and improve hydrogen concentration.Thus, the speed of response of the reduction reaction of the ferric oxide in direct-reduction stove can be improved further, and energy efficiency can be improved further.
Another technical scheme of the present invention provides a kind of manufacture method of direct-reduced iron, in the manufacture method of this direct-reduced iron, is used in and makes gasification in coal gasifier and the coal gas obtained, direct-reduction raw iron oxide material in direct-reduction stove, wherein,
The manufacture method of this direct-reduced iron comprises following operation:
Reaction process, in this reaction process, utilizes water gas shift reaction to obtain the hydrogen concentration reactant gases higher than the hydrogen concentration of Exhaust Gas from the Exhaust Gas of direct-reduction stove;
De-CO 2operation, at this de-CO 2in operation, reduce the carbonic acid gas that comprises of reactant gases and the recycle gas that obtains containing hydrogen;
Heating process, in this heating process, heats the recycle gas to the supply of direct-reduction stove;
Decompression operation, in this decompression operation, reduces pressure to coal gas by relief portion; And
Supply step, it, after heating process and decompression operation, in this supply step, makes recycle gas and coal gas converge, and contains the reducing gas of recycle gas and coal gas to the supply of direct-reduction stove.
In the manufacture method of the direct-reduced iron of the invention described above, except reducing the carbonic acid gas that comprises from the Exhaust Gas of direct-reduction stove, also in reaction process, generate hydrogen.Therefore, it is possible to fully improve the hydrogen concentration of recycle gas.Thus, even if the hydrogen concentration of coal gas is lower, also can improves the hydrogen concentration of the reducing gas after coal gas and recycle gas converge, and the speed of response of reduction reaction can be made fully rapid.
In the manufacture method of direct-reduced iron of the present invention, the temperature of the coal gas produced in coal gasifier can be maintained high temperature.Therefore, it is possible to make the coal gas from coal gasifier not supply to direct-reduction stove via well heater.Thereby, it is possible to effectively utilize the sensible heat of the coal gas obtained in coal gasifier, direct-reduced iron can be manufactured with the energy efficiency of excellence.That is, adopt the manufacture method of direct-reduced iron of the present invention, fully can improve the hydrogen concentration of recycle gas, and, effectively can utilize the sensible heat of coal gas, thus direct-reduced iron can be manufactured with the energy efficiency of excellence.
In the manufacture method of direct-reduced iron of the present invention, preferably, the hydrogen in reducing gas is more than 1 relative to the volume ratio of carbon monoxide.Thereby, it is possible to improve the speed of response of the reduction reaction of ferric oxide further.In addition, the density of the density ratio carbon monoxide of hydrogen is little, therefore, by improving the volumetric ratio of hydrogen, can reduce the pressure-losses of direct-reduction stove.In addition, from the view point of the reaction efficiency of the water gas shift reaction in reaction process, the hydrogen of reducing gas is preferably less than 2 relative to the volumetric ratio of carbon monoxide.
In decompression operation, use decompression turbine reduce pressure to coal gas and generate electricity, also can have the heat exchange operation that the coal gas making to supply to relief portion and the coal gas of discharging from relief portion carry out heat exchange between decompression operation and supply step.
Use decompression turbine to generate electricity, thus effectively can utilize the pressure energy of the coal gas obtained in coal gasifier, direct-reduced iron can be manufactured with the energy efficiency of excellence.In heat exchange operation, by heat exchange, and the temperature of the coal gas when linking part place converges can be improved.Thereby, it is possible to make the coal gas from coal gasifier not supply to direct-reduction stove via well heater.Its result, effectively can utilize the sensible heat of the coal gas obtained in coal gasifier, can manufacture direct-reduced iron with more excellent energy efficiency.
In the manufacture method of direct-reduced iron of the present invention, preferably, before decompression operation, dust-removing process coal gas being carried out to dedusting is comprised.
In dust-removing process, fully remove the dust fractions of coal gas entrained with, thus the cinder that coal gas can be suppressed to comprise and ash grade and are attached to the inwall of pipe arrangement, various equipment.Further, fully remove ash content, dust fractions that coal gas comprises, thus more stable manufacture can be continued for a long time.
Also the 1st control of dust operation removing the solids component that coal gas comprises from coal gas with dry type can be comprised before decompression operation.Thereby, it is possible to suppress solids component to be brought into relief portion, steady running can be continued for a long time.In addition, owing to being dry type, the sensible heat of coal gas can more effectively be utilized.
Also the 2nd control of dust operation removing the solids component that coal gas comprises from coal gas with wet type can be comprised before decompression operation.Thereby, it is possible to make a kind of ammonium chloride (NH of the solids component comprised as coal gas 4cl) dissolve, ammonium chloride can be got rid of from coal gas.
Preferably, before reaction process, comprise the 3rd control of dust operation removing the solids component that Exhaust Gas comprises from Exhaust Gas.Thereby, it is possible to suppress solids component to flow into reaction process, the further stabilization operated can be realized.
In the manufacture method of direct-reduced iron of the present invention, preferably, in supply step, when converging with recycle gas the temperature of coal gas is 500 DEG C ~ 900 DEG C.By becoming such temperature range, effectively can utilize the sensible heat of coal gas, and the cinder that coal gas can be suppressed to comprise and ash grade and are attached to the inwall of the various equipment such as stream, fly-ash separator.
The manufacture method of direct-reduced iron of the present invention also can comprise use recycle gas and supply the coal supply step of coal supply to coal gasifier.In the past, in order to supply coal supply to coal gasifier, the non-active gas such as carbonic acid gas or nitrogen was employed.Above-mentioned non-active gas not only reduces the concentration of the reducing gas (carbon monoxide, hydrogen) in coal gas, but also needs the device of the non-active gas removed in coal gas.In contrast, use by de-CO 2equipment decreases the recycle gas of carbonic acid gas, to coal gasifier for coal supply, thus fully can reduce the concentration of the carbonic acid gas in coal gas and improve hydrogen concentration.Thus, the speed of response of the reduction reaction of the ferric oxide in direct-reduction stove can be improved further, and energy efficiency can be improved further.
the effect of invention
Adopt the present invention, a kind of manufacturing installation of following direct-reduced iron can be provided: when using coal gasifier at the supply source as reducing gas, fully accelerate by making the speed of the reduction reaction of ferric oxide and effectively utilize the energy of coal gas, thus direct-reduced iron can be manufactured with the energy efficiency of excellence.In addition, the present invention can provide a kind of by making the speed of the reduction reaction of ferric oxide fully accelerate and effectively utilizing the energy of coal gas thus the manufacture method of the direct-reduced iron of energy efficiency excellence.
Accompanying drawing explanation
Fig. 1 is the figure of the overview of the formation of an embodiment of the manufacturing installation representing direct-reduced iron of the present invention.
Fig. 2 is the figure of the overview of the formation of another embodiment of the manufacturing installation representing direct-reduced iron of the present invention.
Fig. 3 is the figure of the overview of the formation of the another embodiment of the manufacturing installation representing direct-reduced iron of the present invention.
Fig. 4 is the figure of the manufacturing installation overview of the formation of an embodiment again representing direct-reduced iron of the present invention.
Fig. 5 is the figure of the overview of the formation of an embodiment of the manufacturing installation representing direct-reduced iron of the present invention.
Fig. 6 is the H representing reactant gases 2the chart of the relation between the value of/CO and the equilibrium temperature of catalytic amount required in shift-converter and water gas shift reaction.
Fig. 7 is the H representing reactant gases 2the chart of the relation between the value of/CO and the equilibrium temperature of catalytic amount required in shift-converter and water gas shift reaction.
Fig. 8 is the figure representing the overview that the device of comparative example 1 is formed.
Embodiment
Below according to circumstances while with reference to accompanying drawing while illustrate preferred embodiment of the present invention.In addition, in the drawings and in which, for the Reference numeral that identical or equal element annotation is identical, the repetitive description thereof will be omitted.
Fig. 1 is the figure of the overview of the formation of the manufacturing installation 100 of the direct-reduced iron represented in present embodiment.The manufacturing installation 100 of the direct-reduced iron of present embodiment comprises: coal gasifier 10, and it produces the coal gas containing carbon monoxide and hydrogen for making gasification; Direct-reduction stove 30, it utilizes the reducing gas containing coal gas and recycle gas carry out reduction-oxidation iron material 32 and generate direct-reduced iron 34, and, discharge the Exhaust Gas containing carbonic acid gas, carbon monoxide and water; Shift-converter 25, it is by water gas shift reaction, generates the hydrogen concentration reactant gases higher than the hydrogen concentration of Exhaust Gas from Exhaust Gas; De-CO 2equipment 28, it is for the carbonic acid gas contained by absorption reaction gas, and generates the recycle gas that gas concentration lwevel reduces than the gas concentration lwevel of reactant gases; Well heater 29, it is for heating cycle gas.
In coal gasifier 10, be linked with the supply unit as coal and supply the stream 12 of coal supply and the gas flow path 13 for oxygen-containing gass such as air supplies.Delivering gas is used to supply coal supply via stream 12 to coal gasifier 10.The coal gas that the coal being supplied to coal gasifier 10 from stream 12 is vaporized and generates with carbon monoxide and hydrogen is principal constituent.This coal gas, except above-mentioned principal constituent, can also contain carbonic acid gas and water etc.In addition, when the non-active gas such as nitrogen are used for delivering gas, in coal gas, containing this non-active gas.As the stream in this specification sheets and gas flow path, use common pipe or bushing pipe.
The coal gas generated in coal gasifier 10 has the such as 950 DEG C ~ temperature of 1200 DEG C and the pressure of 2MPa ~ 6MPa in the exit of coal gasifier 10.In order to effectively utilize the sensible heat of coal gas, be provided with the temperature adjustment part 14 of coal gas in the downstream side of coal gasifier 10.Boiler can be listed as temperature adjustment part 14.Temperature adjustment part 14 is not limited to boiler.The temperature adjustment of coal gas also can by autospasy CO in future 2the recycle gas of equipment imports coal gasifier 10 to carry out.
The part between coal gasifier 10 and fly-ash separator 15 of the gas flow path of coal gas is located in temperature adjustment part 14.The cinder that coal gas is cooled to coal gas entrained with in temperature adjustment part 14 can not be attached to the temperature of the degree of the fly-ash separator 15 of back segment and the inwall of interchanger 16.As such temperature, be preferably less than 1000 DEG C.On the other hand, from the view point of the sensible heat effectively utilizing coal gas, the temperature of coal gas is preferably more than 600 DEG C.
The coal gas generated in coal gasifier 10 to grade entrainment containing cinder and ash usually.Such entrainment can be removed in the fly-ash separator 15 in downstream side being located at temperature adjustment part 14.In temperature adjustment part 14, coal gas is cooled, so, cinder can be suppressed to adhere to the inwall of fly-ash separator 15.Thereby, it is possible to remove the entrainment of coal gas in fly-ash separator 15 efficiently.By removing the entrainment in coal gas at fly-ash separator 15, thus fully can suppress the obturation of the interchanger 16 in the downstream side being located at fly-ash separator 15, particle collector 18 and relief portion 19.As fly-ash separator 15, such as cyclone separator, porcelain filter or metal sintered filter etc. can be used.Interchanger 16 is preferably from heat exchange type interchanger.Relief portion 19 is decompression turbine 19A.
In fly-ash separator 15, in interchanger 16 with from the turbine 19A coal gas out that reduces pressure, carried out heat exchange by the coal gas after dedusting, and be cooled to such as less than 300 DEG C.Preferably, consider the concentration of the ammonium chloride that the efficiency of decompression turbine 19A and coal gas comprise etc. and suitably carry out selecting the cooling temperature of coal gas.The coal gas having carried out heat exchange in interchanger 16 in particle collector 18 further by dedusting.So, particle collector 18 is set at the upstream side of decompression turbine 19A, thus fully can suppresses that the decompression turbine 19A's caused because of being mixed into of dust etc. is in poor shape.The solids component of the less size that particle collector 18 cannot catch for the fly-ash separator 15 removed in coal gas.As particle collector 18, electric dust precipitator and porcelain filter etc. can be used.
Be directed into decompression turbine 19A by the coal gas after particle collector 18 dedusting, such as, be decompressed to 1MPa from 3MPa.In decompression turbine 19A, the pressure energy of coal gas is converted into electric power.Be depressurized the post-decompression coal gas of turbine 19A and carry out heat exchange with the coal gas flowed at the upstream side of the turbine 19A that reduces pressure in interchanger 16.So, carry out coal gas from recovery of heat.By this from recovery of heat, the coal gas of the outlet side of interchanger 16 is heated to such as 500 DEG C ~ 900 DEG C.
So by the coal gas after heating via gas flow path 17 with heated by well heater 29 after recycle gas converge at linking part 51 place.At linking part 51 place, the gas flow path 17 of the coal gas after being heated by interchanger 16 and the gas flow path 21 between well heater 29 and direct-reduction stove 30 are can the mode that circulates of supplied gas be connected.After converging, coal gas is fed into direct-reduction stove 30 as reducing gas together with recycle gas.The method that coal gas and recycle gas converge is not particularly limited, as long as the gas flow path 21 making gas circulate to direct-reduction stove 30 from well heater 29 is connected in the mode be communicated with the gas flow path 17 circulated that gives gas.As gas flow path 17,21, common pipe or bushing pipe can be used.
Coal gas and recycle gas when linking part 51 place converges, coal gas relative to the volume ratio of recycle gas as being 0.5 ~ 1.5.In addition, the volume of the gas in this specification sheets and volume ratio are all the values of standard state (0 DEG C, 1 air pressure) benchmark.The temperature of coal gas when coal gas and recycle gas converge is preferably 500 DEG C ~ 900 DEG C, more preferably 600 DEG C ~ 800 DEG C.By being set to such temperature range, effectively can utilize the sensible heat of coal gas, and can fully suppress cinder to be attached to be respectively used to link the inwall of gas flow path of fly-ash separator 15 and temperature adjustment part 14, reducing valve 19B and linking part 51.
When supplying to direct-reduction stove 30 reducing gas being converged by coal gas and recycle gas and obtained, the temperature of the reducing gas that coal gas and recycle gas converge and obtain is preferably 800 DEG C ~ 1100 DEG C, more preferably 850 DEG C ~ 1050 DEG C.By being set to such temperature range, thus the reduction reaction in direct-reduction stove 30 can be made to carry out more swimmingly.
In the gas flow path 21 for reducing gas circulation, also can arrange in the downstream side of linking part 51 and be used for measuring the temperature of reducing gas and the analyzer of composition continuously, and, the oxygen ingress pipe being used for importing oxygen to gas flow path 21 is set.By monitoring that the composition of reducing gas and temperature are while import oxygen to reducing gas, thus a part for reducing gas can be made to burn and adjust temperature and the composition of reducing gas.
Supply to direct-reduction stove 30 via the loading pipe being linked to direct-reduction stove 30 from raw iron oxide material 32 such as the iron ores that hopper transports.In direct-reduction stove 30, raw iron oxide material 32 is heated to 750 DEG C ~ 1050 DEG C and contacts with the reducing gas imported from gas flow path 21.Thus, ferric oxide is reduced and obtains direct-reduced iron.The direct-reduced iron 34 of acquisition like this is discharged from the bottom of direct-reduction stove 30.
Because the hydrogen concentration of the recycle gas forming reducing gas is fully high, therefore, the reducing gas imported to direct-reduction stove 30 can make the reduction reaction of raw iron oxide material 32 fully promptly carry out.From the view point of making reduction reaction fully promptly carry out, the hydrogen concentration of reducing gas is preferably 40 more than volume %, is more preferably 45 more than volume %.From the same viewpoint, the hydrogen in reducing gas is relative to the volume ratio preferably more than 1 of carbon monoxide.
The Exhaust Gas of discharging from direct-reduction stove 30 imports interchanger 23 via gas flow path 22.This Exhaust Gas contains the carbonic acid gas, carbon monoxide and the water that produce due to the reduction of ferric oxide and the unreacted carbon monoxide deriving from reducing gas and hydrogen.The temperature of the Exhaust Gas in the exit of direct-reduction stove 30 is such as 300 DEG C ~ 500 DEG C.This Exhaust Gas is cooled to such as 200 DEG C ~ 350 DEG C by interchanger 23.Particle collector 24 is provided with in the downstream side of interchanger 23.Thereby, it is possible to make the shift-converter 25 being positioned at downstream side run steadily in the long term.Electric dust precipitator and porcelain filter etc. can be used as particle collector 24.The solids component utilizing this particle collector 24 to remove Exhaust Gas to comprise.
Shift-converter 25 is provided with in the downstream side of particle collector 24.The dust content of the gas of shift-converter 25 ingress is preferably 5mg/m 3below.In shift-converter 25, catalyzer is utilized to carry out the water gas shift reaction shown in following formula (1).Thus, the carbon monoxide comprised by Exhaust Gas and water generate carbonic acid gas and hydrogen.Utilize this reaction, hydrogen concentration in gas and the hydrogen volume ratio relative to carbon monoxide can be improved.Specifically, be 1 ~ 2 relative to the hydrogen of the Exhaust Gas be imported into before shift-converter 25 relative to the volume ratio of carbon monoxide, can utilize that water gas shift reaction obtains, the hydrogen of the reactant gases in the exit of shift-converter 25 is 3 ~ 6 relative to the volume ratio of carbon monoxide.
CO+H 2O→CO 2+H 2(1)
At the upstream side of shift-converter 25, the water vapour introduction part 60 for water vapour being imported recycle gas also can be set.By importing water vapour to recycle gas, and the equilibrium temperature of the water gas shift reaction of formula (1) can be improved, therefore, it is possible to improve the temperature of the Exhaust Gas imported to shift-converter 25.Thus, the speed of response of the water gas shift reaction of formula (1) accelerates, therefore, it is possible to reduce the catalytic amount of shift-converter 25.
The reactant gases obtained in shift-converter 25 contains the carbonic acid gas produced due to the reduction reaction in direct-reduction stove 30 and water gas shift reaction.Therefore, the gas concentration lwevel of reactant gases is higher than the gas concentration lwevel of Exhaust Gas.The de-CO being located at the downstream side of shift-converter 25 at least partially of the carbonic acid gas that reactant gases comprises 2equipment 28 is removed.So, the de-CO for removing carbonic acid gas is provided with in the downstream side of shift-converter 25 2equipment 28, therefore, it is possible to effectively remove carbonic acid gas.
At shift-converter 25 and de-CO 2on gas flow path between equipment 28, transformation into itself's reactor 25 side is provided with cooling cleanser 26 and gas compressor 27 successively.In cooling cleanser 26, cool reactant gases and remove the moisture and dust that reactant gases comprises.As such cooling cleanser 26, such as Venturi scrubber etc. can be used.Utilize cooling cleanser 26 and gas compressor 27, the pressure of reactant gases and temperature are adjusted to and are adapted at de-CO 2the scope processed is carried out in equipment 28.
As de-CO 2equipment 28, can use the equipment of the common co 2 removal being removed carbonic acid gas by gas-to-liquid contact.As the absorption liquid that such equipment uses, the organic system alkaline absorption solutions such as such as MEA (monoethanolamine) can be used.In this case, de-CO 2the temperature of the reactant gases of the ingress of equipment 28 is such as about 40 DEG C.
By de-CO 2the gas (recycle gas) that equipment 28 eliminates carbonic acid gas is heated to such as 800 DEG C ~ 1100 DEG C in well heater 29.As well heater 29, heating unit burner and high-temperature heat-exchanging combined can be used.Recycle gas, after being heated by well heater 29 via gas flow path 20, converges at linking part 51 place that the gas flow path 21 for making gas circulate between well heater 29 and direct-reduction stove 30 and the gas flow path 17 of coal gas are connected and coal gas.The reducing gas containing recycle gas and coal gas of acquisition like this imports direct-reduction stove 30 through gas flow path 21.
Supplying recycle gas at de-CO 2gas flow path 42 is linked with in the mode be communicated with the stream 12 that coal supplies in the gas flow path 20 circulated between equipment 28 with well heater 29.By de-CO 2the supplying to stream 12 via this gas flow path 42 at least partially of recycle gas that equipment 28 obtains, thus as carrying the delivering gas of coal to play a role.Gas compressor 40 is provided with at gas flow path 42.Thereby, it is possible to make the pressure of recycle gas boost to the pressure of the conveying being suitable for coal.
At cooling cleanser 26, shift-converter 25 and de-CO 2in equipment 28, the concentration of carbonic acid gas and water to be reduced and the recycle gas that the concentration of hydrogen increases is used as the delivering gas of conveying coal, thus coal gas comprises, the circulation of the gaseous constituent that is helpless to reduction reaction reduces, and, can the reduction reaction of accelerating oxidation iron, and improve the energy efficiency of the operation of manufacturing installation 100 entirety of direct-reduced iron further.In addition, each device miniaturization of purification cycle gas can be used in.
Adopt the manufacturing installation 100 of the direct-reduced iron of present embodiment, except utilizing de-CO 2beyond the carbonic acid gas that the gas that equipment 28 reduces generation in direct-reduction stove 30 comprises, in shift-converter 25, hydrogen can also be generated by carbon monoxide and water.Therefore, it is possible to fully improve the ratio of the hydrogen that recycle gas comprises.Thus, even if the hydrogen concentration of coal gas is lower, also can improves the hydrogen concentration of coal gas and the reducing gas of recycle gas after linking part 51 place converges, and reduction reaction can be made fully promptly to carry out in direct-reduction stove 30.
In the manufacturing installation 100 of the direct-reduced iron of present embodiment, make the gas stream produced in direct-reduction stove 30 pass to shift-converter 25, thus improve the hydrogen concentration in recycle gas.On the other hand, as the supply source of the gas for reducing iron oxides, use coal gasifier 10.The coal gas generated in this coal gasifier 10 can be made not to be circulated to shift-converter and de-CO 2equipment, but converge with recycle gas and import direct-reduction stove 30.The coal gas produced by coal gasifier 10 can be maintained high temperature, therefore, it is possible to make coal gas not supply to direct-reduction stove 30 via well heater 29.Thereby, it is possible to realize the miniaturization of well heater 29, and effectively can utilize the sensible heat of coal gas, direct-reduced iron can be manufactured with the energy efficiency of excellence.
At de-CO 2in equipment 28, in order to reduce the concentration of the carbonic acid gas in gas, and the temperature of gas is cooled to the temperature of certain degree.In the manufacturing installation 100 of direct-reduced iron, at this de-CO 2the upstream side of equipment 28 is provided with shift-converter 25.Therefore, the manufacturing installation as direct-reduced iron is overall, can reduce the heating of gas and the multiplicity of cooling, and, effectively can apply flexibly the pressure energy of coal gas, and manufacture direct-reduced iron with the energy efficiency of excellence.
The coal gas generated in coal gasifier 10 contains the NH of the concentration of such as hundreds of ppm 4cl.NH 4cl is decomposed into gas (NH sometimes more than 340 DEG C 3and HCl), but separate out as solid being less than at the temperature of 340 DEG C.NH 4the Precipitation Temperature of Cl depends on NH 4the concentration of Cl.Such as, at NH 4when the concentration of Cl is 500ppm, NH 4cl in about 205 DEG C of precipitations, at NH 4when the concentration of Cl is 100ppm, NH 4cl is in about 165 DEG C of precipitations.
From minimizing NH 4the viewpoint of the amount of precipitation of Cl is set out, and preferably, the temperature of the coal gas in interchanger 16, particle collector 18 and decompression turbine 19A maintains more than 170 DEG C, more preferably maintains more than 210 DEG C.
Particle collector 18 also can be electric dust precipitator and porcelain filter etc., the dry dust collector removing solids component with dry type.Thereby, it is possible to maintain the temperature of coal gas higher, the NH with the decline of temperature can be suppressed 4cl separates out.
Fig. 2 is the figure of the overview of the formation of the manufacturing installation 200 of the direct-reduced iron representing another embodiment.The manufacturing installation 200 of direct-reduced iron comprises the wet collector 18A of the particle collector as the downstream side being located at fly-ash separator 15.Formation beyond dehumidification type particle collector 18A is identical with the manufacturing installation 100 of direct-reduced iron.The coal gas that have passed fly-ash separator 15 in interchanger 16A be imported into the coal gas of the turbine 19A that reduce pressure and oneself reduces pressure after turbine 19A coal gas out carried out heat exchange, be imported into wet collector 18A.
Be connected with for supplying the water supply portion 62 of feedwater and the water discharge portion 64 for self-wetted particle collector 18A discharge water to wet collector 18A at wet collector 18A.In wet collector 18A, the temperature of coal gas drops to such as 100 DEG C ~ 150 DEG C, and NH 4cl separates out.At this, in wet collector 18A, can dissolve with supplying from water supply portion 62 water of coming the NH separated out 4cl also removes NH 4cl.NH 4the Cl aqueous solution is externally discharged from water discharge portion 64.
Fig. 3 is the figure of the overview of the formation of the manufacturing installation 300 of the direct-reduced iron representing another embodiment.The manufacturing installation 300 of direct-reduced iron comprises interchanger 23B in order to the Exhaust Gas cooled from direct-reduction stove 30 discharge.At this, Exhaust Gas with carry out heat exchange from gas compressor 27 Exhaust Gas out, and be cooled to such as 200 DEG C ~ 300 DEG C.Interchanger 23B is preferably from heat exchange type interchanger.
The manufacturing installation 300 of direct-reduced iron comprises wet collector 24B.Exhaust Gas after cooled in interchanger 23B imports wet collector 24B.Be connected with for supplying the water supply portion 62 of feedwater and the water discharge portion 64 for self-wetted particle collector 24B discharge water to wet collector 24B at wet collector 24B.In wet collector 24B, the temperature of Exhaust Gas drops to such as 100 DEG C ~ 150 DEG C, and NH 4cl separates out.At this, in wet collector 24B, can dissolve with supplying from water supply portion 62 water of coming the NH separated out 4cl also removes NH 4cl.NH 4the Cl aqueous solution is externally discharged from water discharge portion 64.By having wet collector 24B in this wise, thus the NH that can will be brought into by coal gas in the manufacturing installation 300 of direct-reduced iron 4cl is discharged to the outside of manufacturing installation 300.
NH has been removed in wet collector 24B 4the Exhaust Gas of Cl imports gas compressor 27.Exhaust Gas by such as after 0.6MPa boosts to 1MPa, is directed into interchanger 23B in gas compressor 27, and carries out heat exchange with the Exhaust Gas of discharging from direct-reduction stove 30.By heat exchange, be warming up to such as 220 DEG C ~ 350 DEG C by the Exhaust Gas after gas compressor 27 boosts.That is, Exhaust Gas utilizes interchanger 23B and gas compressor 27 and is adjusted to temperature range and the pressure range of the process being suitable for shift-converter 25.The formation than that described above of the manufacturing installation 300 of direct-reduced iron is same with the manufacturing installation 100 of direct-reduced iron.
Fig. 4 is the figure of the overview of the formation of the manufacturing installation 400 of the direct-reduced iron representing an embodiment again.The manufacturing installation 400 of the direct-reduced iron of present embodiment make coal gas different from the manufacturing installation 100 of direct-reduced iron to the formation between linking part 51 from coal gasifier 10.The manufacturing installation 400 of direct-reduced iron, in the same manner as the manufacturing installation 100 of direct-reduced iron, the gas flow path of the coal gas between coal gasifier 10 and fly-ash separator 15 is provided with temperature adjustment part 14.In temperature adjustment part 14, the cinder that coal gas is cooled to coal gas entrained with can not be attached to the temperature of the degree of the inwall of the fly-ash separator 15 of back segment.
The manufacturing installation 400 of direct-reduced iron has the reducing valve 19B as relief portion 19.Utilize fly-ash separator 15 to remove entrainment in coal gas, thus fully can suppress the obturation of the reducing valve 19B in the downstream side being located at fly-ash separator 15.Gas utilize reducing valve 19B and be such as depressurized to 1MPa from 3MPa.Recycle gas after being depressurized the post-decompression coal gas of valve 19B and being heated by well heater 29 converges at linking part 51 place.By being set to such formation, the sensible heat that coal gas has fully effectively can be applied flexibly.Other formation is same with the manufacturing installation 100 of direct-reduced iron.
One embodiment of the manufacture method of direct-reduced iron of the present invention can adopt the manufacturing installation 100,200,300,400 of above-mentioned direct-reduced iron to carry out.The manufacture method of the direct-reduced iron of present embodiment comprises following operation:
Gasification operation, wherein, in coal gasifier 10, adds hot coal and oxygen-containing gas and makes gasification, obtains the coal gas containing carbon monoxide and hydrogen as principal constituent;
Reduction operation, wherein, in direct-reduction stove 30, utilizes the reducing gas reduction-oxidation iron material 32 containing recycle gas and coal gas, and generates direct-reduced iron 34, and, obtain the Exhaust Gas containing carbonic acid gas, carbon monoxide and water;
Reaction process, wherein, utilizes water gas shift reaction, and the carbon monoxide comprised by above-mentioned Exhaust Gas and water are to generate hydrogen and carbonic acid gas and to obtain reactant gases;
De-CO 2operation, wherein, reduces the carbonic acid gas that reactant gases comprises, and the recycle gas that the concentration generating the carbonic acid gas of the concentration ratio reactant gases of carbonic acid gas is low;
Heating process, wherein, with well heater 29 heating cycle gas;
Decompression operation, wherein, reduces pressure with relief portion 19 pairs of coal gas;
Supply step, wherein, makes to be merged as reducing gas at linking part 51 place by the recycle gas after heating and coal gas in heating process, and supplies the reducing gas containing recycle gas and coal gas to direct-reduction stove 30.
From the view point of the reduction reaction of fully promptly carrying out ferric oxide, in supply step, be preferably more than 1 to the hydrogen of the reducing gas of direct-reduction stove 30 supply relative to the volume ratio of carbon monoxide.If consider the energy efficiency of manufacturing installation 100 entirety of direct-reduced iron, then in reducing gas, hydrogen is preferably less than 2 relative to the volume ratio of carbon monoxide.Decompression operation also can be use decompression turbine 19A be used as relief portion 19 and reduce pressure to coal gas and the generating operation generated electricity.
Also can arrange between gasification operation and supply step and utilize fly-ash separator 15 pairs of coal gas carry out the dust-removing process of dedusting and make the coal gas supplied to the turbine 19A that reduces pressure and the coal gas of discharging from the turbine that reduces pressure carry out the heat exchange operation of heat exchange.Thereby, it is possible to fully remove ash content, the dust of the coal gas entrained with generated in coal gasifier 10, and by carrying out the sensible heat effectively utilizing coal gas from recovery of heat of coal gas.Thus, direct-reduced iron can be manufactured with higher energy efficiency.
Preferably, in decompression operation (generating operation), before importing coal gas to decompression turbine 19A, carry out the dust-removing process of the solids component removed in coal gas and use particle collector 18 or wet collector 18A to carry out the control of dust operation A of the solids component removing coal gas.Thereby, it is possible to the generation suppressing the obturation in decompression turbine 19A etc. in poor shape, can continue steadily in the long term to run.In control of dust operation A, the solids component that cannot catch such less size in dust-removing process in coal gas can be removed.As long as utilize wet collector 18A to carry out control of dust operation A as the manufacturing installation 200 of direct-reduced iron, just the NH of coal gas can be derived from 4cl is rejected to outside from manufacturing installation 200.
Preferably, between reduction operation and reaction process, there is the control of dust process B using particle collector 24 or wet collector 24B to remove the solids component that Exhaust Gas comprises.Thereby, it is possible to the generation suppressing the obturation in shift-converter 25 etc. in poor shape, can continue steadily in the long term to run.Adopt wet collector 24B, the NH deriving from coal gas can be got rid of 4cl.
Preferably, there is utilization at de-CO 2the recycle gas obtained in operation carries the coal supply step of coal to coal gasifier 10.So, to the concentration of carbonic acid gas and water be decreased and improve the concentration of hydrogen recycle gas be used as conveying coal delivering gas, thus the circulation of the gaseous constituent being helpless to reduction reaction can be reduced, and, can the reduction reaction of accelerating oxidation iron, make the operational efficiency of manufacturing installation 100,200,300,400 entirety of direct-reduced iron.In addition, each device miniaturization of purification cycle gas can be used in.
In table 1 and table 2, represent an example of the running status in the manufacture method of the direct-reduced iron of present embodiment.Table 1 and the Position Number shown in table 2 consistent with the Reference numeral of Fig. 5.Table 1 and the gas flow shown in table 2 are the values of the standard state when manufacturing 1 ton direct-reduced iron 34 with direct-reduction stove 30.
Table 1
As shown in table 1, in this example embodiment, in the front and back of decompression turbine 19A, the pressure of coal gas is changed to 1MPa from 3MPa, effectively can utilize the pressure energy (position 10-3 and position 10-4) of coal gas.In addition, the coal gas of discharging from decompression turbine carries out recovery of heat in interchanger 16, and temperature rises to 700 DEG C.(position 10-5).So, the coal gas converged at linking part 51 place and recycle gas has higher temperature.Therefore, it is possible to do not utilize heating process to heat coal gas, and in supply step, coal gas is supplied as reducing gas to direct-reduction stove 30 together with recycle gas.
Table 2
At the outlet side (position 20-3) of shift-converter 25, the hydrogen concentration of reactant gases becomes abundant height.By fully improving hydrogen concentration in this wise, thus fully promptly can carry out the reduction reaction of ferric oxide.
As shown in table 2, utilize de-CO 2equipment 28, fully reduces the concentration (position 20-4,20-5,40-1) of the carbonic acid gas in recycle gas.So, carbonic acid gas fully to be reduced and the recycle gas that hydrogen concentration has uprised is used for the reduction of ferric oxide, thus the speed of reduction reaction can be made fully to accelerate.In addition, a part for this recycle gas is used as the gas of coal conveying, thus the operational efficiency of manufacturing installation 100 entirety of direct-reduced iron can be made.
The H of the reducing gas produced in coal gasifier 10 2the volume ratio of/CO is 0.71 (the position 10-1 etc. with reference to table 1).At this, from the view point of raising reaction efficiency, preferably, to the H of the reducing gas that direct-reduction stove 30 imports 2the value (volume reference) of/CO is higher.In order to improve H 2the value of/CO, needs the H improving the reactant gases obtained at outlet (position 20-3) place of shift-converter 25 2the value of/CO., along with the H of reactant gases 2the value of/CO becomes large, and the equilibrium temperature that there is the water gas shift reaction shown in formula (1) declines and the slack-off trend of speed of response.
Fig. 6 is the figure being expressed as follows content: when manufacturing direct-reduced iron with 250 tons/hour, transverse axis represents the H of the reactant gases obtained at outlet (position 20-3) place of shift-converter 25 2the value of/CO, the left longitudinal axis represents catalytic amount required in shift-converter 25, the equilibrium temperature of the water gas shift reaction shown in right longitudinal axis expression (1).In Fig. 6, curve 1 represents the H of reactant gases 2relation between the equilibrium temperature of the reaction of the value of/CO and formula (1).In Fig. 6, curve 2 represents the H of reactant gases under the operational conditions shown in table 1,2 2relation between the value of/CO and catalytic amount required in shift-converter 25.
As shown in Figure 6, as the H of the reactant gases at outlet (position 20-3) place of raising shift-converter 25 2during the value of/CO, there is the trend increased in required catalytic amount.From the view point of minimizing catalytic amount, by the H of the reactant gases at outlet (position 20-3) place of shift-converter 25 2the value of/CO is set to such as less than 3.5, thus can reduce catalytic amount.
Preferably, water vapour is added in the front of shift-converter 25 or inlet side to Exhaust Gas.Thus, the equilibrium temperature of water gas shift reaction rises, therefore, it is possible to improve the temperature of the Exhaust Gas imported to shift-converter 25.By improving the temperature of Exhaust Gas, thus accelerate the speed of response of water gas shift reaction, therefore, it is possible to reduce the catalytic amount of shift-converter 25.
Fig. 7 is the figure being expressed as follows content: when manufacturing direct-reduced iron with 250 tons/hour, transverse axis represents the H of the reactant gases obtained at outlet (position 20-3) place of shift-converter 25 2the value of/CO, the left longitudinal axis represents catalytic amount required in shift-converter 25, the equilibrium temperature of the water gas shift reaction shown in right longitudinal axis expression (1).In Fig. 7, curve 1 except the water vapour introduction part 60 that represents autogamy and be placed in the upstream side of shift-converter 25 to add except water vapour with the flow of 10ton/ hour, also represent the operational conditions identical with Fig. 6, the H of reactant gases 2relation between the equilibrium temperature of the reaction of the value of/CO and formula (1).In Fig. 7, curve 2 except the water vapour introduction part 60 that represents autogamy and be placed in the upstream side of shift-converter 25 to add except water vapour with the flow of 10ton/ hour, also represent the operational conditions identical with Fig. 6, the H of reactant gases 2relation between the value of/CO and catalytic amount required in shift-converter 25.
Result according to Fig. 6,7 can be clear and definite, at outlet (position 20-3) place of shift-converter 25, at acquisition H 2when the value of/CO is the reactant gases of 3.5, add water vapour to Exhaust Gas, thus can by the catalytic amount of shift-converter 25 from 630m 3be reduced to 410m 3.
Above, describe preferred embodiment of the present invention, but the present invention is not had any restriction by above-mentioned embodiment.Such as, in the manufacturing installation 100 of direct-reduced iron, the coal gas generated in coal gasifier 10 is cooled as the thermal source of the temperature adjustment part 14 be located between coal gasifier 10 and fly-ash separator 15.The temperature adjustment of coal gas is not limited to temperature adjustment part 14, such as, also can blow the gas of cooling to carry out the temperature adjustment of coal gas to coal gasifier 10.As the gas of cooling, de-CO can be used 2recycle gas afterwards.
Embodiment
Further describe content of the present invention with reference to embodiment and comparative example, but the present invention is not limited to following embodiment.
(embodiment 1)
When using the manufacturing installation of the direct-reduced iron shown in Fig. 5 to manufacture direct-reduced iron, obtained the amount of required coal by simulation.The iron ore used as iron oxide-containing materials and the proterties of coal as shown in table 3.By simulating the temperature of each gas, proterties and the coal consumption rate of trying to achieve as shown in table 3 summarizes.
(embodiment 2,3)
Except the temperature of the coal gas at the 10-5 place, position in Fig. 5 has been carried out except simulation in the mode becoming the value of table 3, carry out the simulation manufacturing direct-reduced iron similarly to Example 1.By simulating the temperature of gas, proterties and the coal consumption rate of trying to achieve as shown in table 3 summarizes.
(comparative example 1)
When using the manufacturing installation of the direct-reduced iron in the past shown in Fig. 8 to manufacture direct-reduced iron, obtained the amount of required coal by simulation.The iron ore used as iron oxide-containing materials and the proterties of coal as shown in table 3.By simulating the temperature of each gas, proterties and the coal consumption rate of trying to achieve as shown in table 3 summarizes.The step of the manufacture method of the direct-reduced iron undertaken by the manufacturing installation of this direct-reduced iron as shown below.
In the manufacturing installation of the direct-reduced iron of Fig. 8, supply to give coal and air to coal gasifier 110 from gas flow path 112 and gas flow path 113 respectively.The coal gas containing carbon monoxide and hydrogen generated in coal gasifier 110 after cooled cleaning, is directed into shift-converter 125 in washer 150.In shift-converter 125, carry out water gas shift reaction, generated hydrogen and carbonic acid gas by carbon monoxide and water.Transformation into itself's reactor coal gas is out directed into de-CO via gas flow path 54 after being cooled again in washer 152 and having cleaned 2equipment 80.At de-CO 2in equipment 80, eliminate a part for carbonic acid gas.Thereafter, autospasy CO 2after equipment 80 reducing gas is out boosted in gas compressor 146, via gas flow path 148 and interchanger 123, be directed into well heater 158.The reducing gas being heated to predetermined temperature in well heater 158 is directed into direct-reduction stove 130 via gas flow path 160.
In direct-reduction stove 130, import iron ore 132 from top.In direct-reduction stove 130, iron ore is heated while contact with reducing gas.Thus, the ferric oxide that iron ore comprises is reduced, and obtains direct-reduced iron 134.After the carbonic acid gas produced from direct-reduction stove 130 and water, Exhaust Gas containing unreacted carbon monoxide and hydrogen have carried out heat exchange with reducing gas via gas flow path 122 in interchanger 123, cooled and cleaning in washer 124.After Exhaust Gas after cooling and cleaning is boosted in gas compressor 138 and gas compressor 142 via gas flow path 136, converge with the coal gas from shift-converter 125 in gas flow path 144.Gas after converging is directed into de-CO 2equipment 80.
Table 3
" coal consumption rate " in table 3 is the amount (kg) manufacturing the coal required for 1 ton of direct-reduced iron (DRI) with direct-reduction stove, and " generated energy " is the generated energy of decompression turbine 19A." pressure 1 of coal gas " and " pressure 2 of coal gas " in table 3 is the pressure at " position 10-3 " and " position 10-4 " place in Fig. 5 respectively.In addition, " temperature of coal gas " is the temperature at the 60-1 place, position in position 10-5 and Fig. 3 in Fig. 5.The temperature of the position 10-5 in Fig. 5 equals the temperature of coal gas when coal gas meets at recycle gas." the H of coal gas in table 3 2/ CO " be the volume ratio of hydrogen relative to carbon monoxide of coal gas in above-mentioned position.
" temperature of recycle gas " in table 3 is the temperature at the 60-3 place, position in position 20-5 and Fig. 8 in Fig. 5." temperature of reducing gas " in table 3 is the temperature at the 60-4 place, position in position 30-1 and Fig. 8 in Fig. 5." the H of reducing gas in table 3 2/ CO " be the volume ratio of hydrogen relative to carbon monoxide of reducing gas in above-mentioned position.
Arrive according to the results verification shown in table 3: the manufacture method adopting the direct-reduced iron shown in embodiment 1 ~ 3, compared with comparative example 1, coal consumption rate can have been cut down about 7% ~ 16%.In addition, confirmed: the manufacture method adopting the direct-reduced iron shown in embodiment 1 ~ 3, used decompression turbine, thus effectively can utilize the pressure energy of coal gas.
utilizability in industry
Adopt the present invention, can provide a kind of and make the speed of response of the reduction reaction of ferric oxide fully rapidly and effectively utilize the energy of coal gas thus can with the energy efficiency of excellence to manufacture the manufacturing installation of the direct-reduced iron of direct-reduced iron.In addition, adopt the present invention, can provide a kind of and make the speed of response of the reduction reaction of ferric oxide fully rapidly and effectively utilize the energy of coal gas and the manufacture method of the direct-reduced iron of energy efficiency excellence.
description of reference numerals
10,110 ... coal gasifier, 16 ... interchanger, 18,24 ... particle collector, 19 ... relief portion, 19A ... decompression turbine, 19B ... reducing valve, 20,21,42 ... gas flow path, 14 ... temperature adjustment part, 15 ... fly-ash separator, 23,23B ... interchanger, 25 ... shift-converter, 26 ... cooling cleanser, 27,40 ... gas compressor, 28,80 ... de-CO 2equipment, 29,158 ... well heater, 30,130 ... direct-reduction stove, 32,132 ... raw iron oxide material, 34,134 ... direct-reduced iron, 51 ... linking part, 60 ... water vapour introduction part, 62 ... water supply portion, 64 ... water discharge portion, 100,200,300,400 ... the manufacturing installation of direct-reduced iron.

Claims (18)

1. a manufacturing installation for direct-reduced iron, it is used in and makes gasification in coal gasifier and the coal gas obtained, direct-reduction raw iron oxide material in direct-reduction stove, wherein,
The manufacturing installation of this direct-reduced iron comprises:
Shift-converter, it utilizes water gas shift reaction and obtains the hydrogen concentration reactant gases higher than the hydrogen concentration of above-mentioned Exhaust Gas by the Exhaust Gas of above-mentioned direct-reduction stove;
De-CO 2equipment, it is for reducing the carbonic acid gas that above-mentioned reactant gases comprises and the recycle gas obtained containing hydrogen;
Well heater, it is for heating the above-mentioned recycle gas to above-mentioned direct-reduction stove supply;
Linking part, it converges in the gas flow path between above-mentioned well heater and above-mentioned direct-reduction stove for making above-mentioned recycle gas and above-mentioned coal gas; And
Relief portion, the gas flow path of its above-mentioned coal gas between above-mentioned coal gasifier and above-mentioned linking part.
2. the manufacturing installation of direct-reduced iron according to claim 1, wherein,
Above-mentioned relief portion is decompression turbine,
The manufacturing installation of this direct-reduced iron also comprises interchanger, and this interchanger carries out heat exchange for making the part being positioned at the inlet side of above-mentioned decompression turbine in above-mentioned gas stream with the part being positioned at the outlet side of above-mentioned decompression turbine of above-mentioned gas stream.
3. the manufacturing installation of direct-reduced iron according to claim 1, wherein,
Above-mentioned relief portion is reducing valve.
4. the manufacturing installation of the direct-reduced iron according to any one of claims 1 to 3, wherein,
The fly-ash separator for carrying out dedusting to above-mentioned coal gas is provided with in the gas flow path of the above-mentioned coal gas of manufacturing installation between above-mentioned coal gasifier and above-mentioned relief portion of this direct-reduced iron.
5. the manufacturing installation of the direct-reduced iron according to any one of Claims 1 to 4, wherein,
The manufacturing installation of this direct-reduced iron is provided with the 1st particle collector for removing the solids component that above-mentioned coal gas comprises with dry type from above-mentioned coal gas between above-mentioned coal gasifier and above-mentioned relief portion.
6. the manufacturing installation of the direct-reduced iron according to any one of Claims 1 to 5, wherein,
The manufacturing installation of this direct-reduced iron is provided with the 2nd particle collector for removing the solids component that above-mentioned coal gas comprises with wet type from above-mentioned coal gas between above-mentioned coal gasifier and above-mentioned relief portion.
7. the manufacturing installation of the direct-reduced iron according to any one of claim 1 ~ 6, wherein,
The manufacturing installation of this direct-reduced iron is provided with the 3rd particle collector for removing the solids component that above-mentioned Exhaust Gas comprises from above-mentioned Exhaust Gas between above-mentioned direct-reduction stove and above-mentioned shift-converter.
8. the manufacturing installation of the direct-reduced iron according to any one of claim 1 ~ 7, wherein,
The manufacturing installation of this direct-reduced iron has the temperature adjustment part for the temperature of above-mentioned coal gas when converging with above-mentioned recycle gas being adjusted to 500 DEG C ~ 900 DEG C in the gas flow path of above-mentioned coal gasifier or the above-mentioned coal gas between above-mentioned coal gasifier and above-mentioned linking part.
9. the manufacturing installation of the direct-reduced iron according to any one of claim 1 ~ 8, wherein,
The manufacturing installation of this direct-reduced iron is provided with for supplying above-mentioned recycle gas from above-mentioned de-CO at the supply unit supplying above-mentioned coal to above-mentioned coal gasifier 2equipment or above-mentioned de-CO 2carry out the gas flow path circulated in the downstream side of equipment.
10. a manufacture method for direct-reduced iron,
In the manufacture method of this direct-reduced iron, be used in and make gasification in coal gasifier and the coal gas obtained, direct-reduction raw iron oxide material in direct-reduction stove, wherein,
The manufacture method of this direct-reduced iron comprises following operation:
Reaction process, in this reaction process, utilizes water gas shift reaction and obtains the hydrogen concentration reactant gases higher than the hydrogen concentration of above-mentioned Exhaust Gas by the Exhaust Gas of above-mentioned direct-reduction stove;
De-CO 2operation, at this de-CO 2in operation, reduce the carbonic acid gas that above-mentioned reactant gases comprises and the recycle gas obtained containing hydrogen;
Heating process, in this heating process, heats the above-mentioned recycle gas to above-mentioned direct-reduction stove supply;
Decompression operation, in this decompression operation, reduces pressure to above-mentioned coal gas by relief portion; And
Supply step, it is after above-mentioned heating process and above-mentioned decompression operation, in this supply step, above-mentioned recycle gas and above-mentioned coal gas is converged, and contains the reducing gas of above-mentioned recycle gas and above-mentioned coal gas to above-mentioned direct-reduction stove supply.
The manufacture method of 11. direct-reduced irons according to claim 10, wherein,
Hydrogen in above-mentioned reducing gas is more than 1 relative to the volume ratio of carbon monoxide.
The manufacture method of 12. direct-reduced irons according to claim 10 or 11, wherein,
In above-mentioned decompression operation, decompression turbine is used to reduce pressure to above-mentioned coal gas and generate electricity,
The manufacture method of this direct-reduced iron also comprises heat exchange operation between above-mentioned decompression operation and above-mentioned supply step, in this heat exchange operation, makes the coal gas supplied to above-mentioned relief portion carry out heat exchange with the coal gas of discharging from above-mentioned relief portion.
The manufacture method of 13. direct-reduced irons according to any one of claim 10 ~ 12, wherein,
The manufacture method of this direct-reduced iron comprised the dust-removing process above-mentioned coal gas being carried out to dedusting before above-mentioned decompression operation.
The manufacture method of 14. direct-reduced irons according to any one of claim 10 ~ 13, wherein,
The manufacture method of this direct-reduced iron comprised the 1st control of dust operation removing the solids component that above-mentioned coal gas comprises from above-mentioned coal gas with dry type before above-mentioned decompression operation.
The manufacture method of 15. direct-reduced irons according to any one of claim 10 ~ 13, wherein,
The manufacture method of this direct-reduced iron comprised the 2nd control of dust operation removing the solids component that above-mentioned coal gas comprises from above-mentioned coal gas with wet type before above-mentioned decompression operation.
The manufacture method of 16. direct-reduced irons according to any one of claim 10 ~ 15, wherein,
The manufacture method of this direct-reduced iron comprised the 3rd control of dust operation removing the solids component that above-mentioned Exhaust Gas comprises from above-mentioned Exhaust Gas before above-mentioned reaction process.
The manufacture method of 17. direct-reduced irons according to any one of claim 10 ~ 16, wherein,
In above-mentioned supply step, when converging with above-mentioned recycle gas the temperature of above-mentioned coal gas is 500 DEG C ~ 900 DEG C.
The manufacture method of 18. direct-reduced irons according to any one of claim 10 ~ 17, wherein,
The manufacture method of this direct-reduced iron also comprises coal supply step, in this coal supply step, uses above-mentioned recycle gas to supply above-mentioned coal to above-mentioned coal gasifier.
CN201380063455.1A 2012-12-07 2013-12-05 Device for manufacturing direct-reduced iron and method for manufacturing direct-reduced iron Pending CN104838019A (en)

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CN104046714B (en) * 2014-06-13 2016-03-02 江苏大学 A kind of reduction reaction shaft furnace waste heat recovery cyclic utilization system
CN105733689A (en) * 2016-04-26 2016-07-06 北京神雾环境能源科技集团股份有限公司 Preparation system and method for reducing gas for gas-based shaft kiln

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JP2000212620A (en) * 1999-01-28 2000-08-02 Nippon Steel Corp Production of reduced iron
US20020078795A1 (en) * 2000-11-08 2002-06-27 Kabushiki Kaisha Kobe Seiko Sho Method of producing direct reduced iron with use of coal-derived gas
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JPS5286914A (en) * 1976-01-14 1977-07-20 Mitsubishi Heavy Ind Ltd Gas reduction of iron ore
JP2000212620A (en) * 1999-01-28 2000-08-02 Nippon Steel Corp Production of reduced iron
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