CN114807485A - Coal gas treatment method and system for producing direct reduced iron - Google Patents
Coal gas treatment method and system for producing direct reduced iron Download PDFInfo
- Publication number
- CN114807485A CN114807485A CN202210223835.8A CN202210223835A CN114807485A CN 114807485 A CN114807485 A CN 114807485A CN 202210223835 A CN202210223835 A CN 202210223835A CN 114807485 A CN114807485 A CN 114807485A
- Authority
- CN
- China
- Prior art keywords
- gas
- heat exchange
- temperature
- furnace
- reduced 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.)
- Pending
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 46
- 239000003034 coal gas Substances 0.000 title claims abstract description 12
- 238000000034 method Methods 0.000 title claims abstract description 11
- 239000007789 gas Substances 0.000 claims abstract description 229
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 58
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 44
- 239000001257 hydrogen Substances 0.000 claims abstract description 38
- 238000000926 separation method Methods 0.000 claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 claims abstract description 17
- 239000002994 raw material Substances 0.000 claims abstract description 16
- 238000006243 chemical reaction Methods 0.000 claims abstract description 15
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 44
- 238000005262 decarbonization Methods 0.000 claims description 31
- 238000010438 heat treatment Methods 0.000 claims description 26
- 239000000428 dust Substances 0.000 claims description 22
- 238000005261 decarburization Methods 0.000 claims description 19
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 17
- 239000001301 oxygen Substances 0.000 claims description 17
- 229910052760 oxygen Inorganic materials 0.000 claims description 17
- 239000002737 fuel gas Substances 0.000 claims description 12
- 238000002407 reforming Methods 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 6
- 229910001882 dioxygen Inorganic materials 0.000 claims description 4
- 238000004064 recycling Methods 0.000 abstract description 4
- 230000009467 reduction Effects 0.000 abstract description 4
- 238000005272 metallurgy Methods 0.000 abstract description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 abstract 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 12
- 239000004215 Carbon black (E152) Substances 0.000 description 8
- 229930195733 hydrocarbon Natural products 0.000 description 8
- 150000002430 hydrocarbons Chemical class 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 8
- 230000008901 benefit Effects 0.000 description 7
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000003723 Smelting Methods 0.000 description 3
- 239000003345 natural gas Substances 0.000 description 3
- 238000011946 reduction process Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 206010021143 Hypoxia Diseases 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 239000002826 coolant Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- 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
- 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
-
- 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
- C21B2100/66—Heat exchange
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
The invention relates to a coal gas treatment method and a coal gas treatment system for producing direct reduced iron, belongs to the technical field of metallurgy, and relates to a method for producing direct reduced iron by using H 2 And methane-rich gas as raw material gas to produce direct reduced iron and CO produced from top gas of shaft furnace 2 By using CO 2 After the separation step, by means of a reverse water-gas shift reaction, with H 2 Reacting CO with 2 After reduction to CO, is recirculated back to the shaft furnace as reducing gas. Therefore, in the whole shaft furnace reaction process, the raw material gas uses the methane-rich gas and the supplemented raw material hydrogen, and the CO generated in the production process is realized 2 The maximum recycling is realized, and the consumption of methane-rich gas in the raw material gas is reduced.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and relates to a coal gas treatment method and a coal gas treatment system for producing direct reduced iron.
Background
Direct reduction iron making is a production process for directly reducing iron oxide in iron ore into iron without melting below the softening temperature of the iron ore by using a gas or solid reducing agent; the produced product is direct reduced iron, also called sponge iron (DRI), has the advantages of stable components, low harmful impurities, uniform granularity and the like, is an indispensable impurity diluent for smelting pure steel and high-quality steel by an electric furnace, and is also the best coolant for converter steelmaking. The process for producing the direct reduction iron-making by adopting the gas-based shaft furnace has the technical advantages of short flow, no need of coking coal and obvious energy-saving and emission-reducing effects, and is an important development direction for realizing low-carbon green smelting.
At present, corresponding technical routes are provided for the direct reduction process of the gas-based shaft furnace in China, and the direct reduction process mainly comprises the following steps:
1) utilizing hydrocarbon-rich gas and CO-rich 2 The furnace top gas is heated to about 900 ℃ in a reforming furnace, and CO is simultaneously added under the action of a catalyst 2 +CH 4 Reaction to CO + H 2 Reducing gas is supplied to the shaft furnace for production and use.
2) The hydrocarbon-rich gas and the purified and decarbonized top gas of the shaft furnace are heated to about 950 ℃ in a high-temperature heating furnace, then oxygen is sprayed to continuously raise the temperature to 1050 ℃, and the high-temperature hydrocarbon-rich gas at about 1050 ℃ enters the shaft furnace to reduce the iron ore. The reaction principle is that under the catalysis of high-temperature thermal state iron, CH 4 Reaction to CO + H 2 Reducing gas and supplying gas for shaft furnace production.
3) The hydrocarbon-rich gas and the purified and decarbonized top gas of the shaft furnace are heated to about 850 ℃ in a pure oxygen converter and then enter the shaft furnace to reduce the iron ore. The reaction principle is that pure oxygen is blown into hydrocarbon-rich gas, and CH is sprayed into hydrocarbon-rich gas under the condition of oxygen deficiency 4 And O 2 Reacting to produce CO + H 2 Reducing gas is supplied to the shaft furnace for production and use.
However, the above technical route for the gas-based shaft furnace direct reduction process has large consumption of hydrocarbon-rich gas and high CO content 2 The utilization rate is low.
Disclosure of Invention
In view of the above, the present invention is directed to a method and a system for processing coal gas to produce direct reduced iron to increase CO 2 The recycling of the process reduces the consumption of the methane-rich gas of the raw material gas.
In order to achieve the purpose, the invention provides the following technical scheme:
a coal gas treatment method for producing direct reduced iron comprises the following steps: after dedusting and heat exchange, part of the top gas discharged from the top of the shaft furnace enters a decarburization separation system, part of the top gas is used as fuel gas, and part of the top gas is used as exhaust gas and is sent to a whole plant pipe network; CO formed after decarburization 2 Mixing the gas with hydrogen to perform a reverse water gas shift reaction to produce H 2 CO, CO2 and H 2 Primary high-temperature reducing gas with O as a main component; pressurizing and exchanging heat of decarbonized gas to form medium temperature decarbonized gas, mixing partial medium temperature decarbonized gas with preheated rich methane gas, reacting in converter with oxygen introduced into converter to produce CO and H 2 A secondary high-temperature reducing gas as a main component; the other part of the medium-temperature decarbonization gas is mixed with the primary high-temperature reducing gas, the secondary high-temperature reducing gas and the preheated hydrogen to form CO and H 2 And the third-level high-temperature reducing gas is a main component and has the temperature matched with the reduced iron ore, and enters the shaft furnace from the middle part or the bottom part of the shaft furnace for producing the direct reduced iron by the shaft furnace.
Optionally, pressurizing the CO2 gas formed after decarburization, mixing the pressurized CO2 gas with hydrogen according to the molar ratio of H2 to CO2 of 1-3 to form a mixed gas, preheating the mixed gas to 400-500 ℃ through a tubular heating furnace, and then performing a reverse water-gas shift reaction to generate H2, CO and CO 2 And H2O as the main component, and the fuel gas preheated by the mixed gas is the top gas after dust removal and heat exchange.
Optionally, the temperature of the medium-temperature decarbonization gas is 120-160 ℃, part of the medium-temperature decarbonization gas is mixed with methane-rich gas preheated to 120-160 ℃ and enters the converter, and oxygen preheated to 120-160 ℃ injected from the top of the converter generates secondary high-temperature reducing gas at 1100-1300 ℃.
Optionally, CO and H in the three-stage high-temperature reducing gas 2 Is greater than or equal to 85 percent, H 2 And CO in a volume ratio of 3-5, (H) 2 +CO)/(H 2 O+CO 2 )≥10。
Optionally, the heat source used for the decarbonization gas heat exchange is furnace top gas subjected to dust removal and heat exchange.
Optionally, the hydrogen is preheated by a hydrogen heating furnace, and the fuel gas preheated by the hydrogen is furnace top gas subjected to dust removal and heat exchange.
Optionally, the oxygen enters the reformer after being preheated by an oxygen heater, which uses steam as a heating medium.
Optionally CO formed after decarbonation 2 The purity of the gas is more than or equal to 95 percent, and the temperature is 30-40 ℃.
A gas treatment system for producing direct reduced iron comprises a dust removal heat exchange pipeline for dust removal and heat exchange of furnace top gas, wherein the dust removal heat exchange pipeline is connected with a decarburization separation system, a fuel gas pipeline and a gas pipeline connected with a whole plant pipe network, and the decarburization separation system is connected with CO 2 A treatment branch and a decarbonization gas treatment branch, CO 2 The treatment branch comprises a first pressurizer, a first mixing device, a tubular heating furnace and a reverse water gas shift reactor which are sequentially arranged along the airflow direction, the first mixing device is connected with a hydrogen gas supply pipeline to provide hydrogen gas for the first mixing device, the decarbonization gas treatment branch comprises a second pressurizer, a heat exchange device and a reforming furnace which are sequentially arranged along the airflow direction, a methane-rich gas supply pipeline is connected on a pipeline between the heat exchange device and the reforming furnace, the reforming furnace is connected with an oxygen gas supply pipeline to provide oxygen gas for the reforming furnace, the reforming furnace and the reverse water gas shift reactor are both connected with the second mixing device, the hydrogen gas supply pipeline is connected with a hydrogen heating furnace connected with the fuel gas pipeline, the hydrogen heating furnace is connected with the second mixing device, a medium-temperature decarbonization branch is connected on a pipeline between the heat exchange device and the methane-rich gas supply pipeline, the medium-temperature decarbonization branch is connected with the second mixing device, the second mixing device is connected to the shaft furnace.
Optionally, the dedusting heat exchange pipeline comprises a coarse dedusting device, a fine dedusting device and a heat exchange device which are sequentially arranged along the airflow direction, the fine dedusting device is a dry dedusting device, the heat exchange device is a multi-stage heat exchange device, and the furnace top gas subjected to dedusting exchanges heat with the decarbonization gas after passing through the decarbonization separation system in a primary heat exchanger of the heat exchange device; and exchanging heat between the methane-rich gas and the dedusted high-temperature furnace top gas in a secondary heat exchanger of the heat exchange device.
Optionally, the decarbonization separation system is a wet decarbonization separation system.
The invention has the beneficial effects that:
1. the invention takes methane-rich gas and hydrogen as raw material gas to produce direct reduced iron and CO produced by furnace top gas on the upper part of the shaft furnace 2 By using CO 2 After the separation measure, CO is converted by 'green hydrogen' by reverse water-gas shift reaction 2 The gas is recycled back to the shaft furnace as reducing gas after being reduced into CO, therefore, the raw material gas uses methane-rich gas and supplemented raw material 'green hydrogen' in the whole reaction process of the shaft furnace, and CO generated in the production process is recycled 2 The maximum recycling is realized.
2. Because the hydrogen is added into the raw material gas, the consumption of the methane-rich gas in the raw material gas is saved by about 8 to 45 percent.
3. The invention utilizes the heat of the top gas to preheat the methane-rich gas and the decarbonized gas at normal temperature in the heat exchange device, recovers part of the heat of the top gas and realizes the reasonable application and recovery of the heat energy.
4. The invention utilizes the reformer to produce CO + H 2 Mainly high-temperature reducing gas, and avoids H in the prior art 2 S caused catalyst failure and for H in hydrocarbon-rich gas 2 The S content is not critical.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.
Drawings
For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic view of a gas treatment system of the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.
Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.
Referring to fig. 1, a coal gas processing method for producing direct reduced iron by using methane-rich gas and hydrogen as gas sources includes the following steps: after the furnace top gas discharged from the top of the shaft furnace is subjected to a coarse dust removal device, a fine dust removal device, a heat exchange device and heat energy utilization, one part of the furnace top gas is used as fuel gas of the tubular heating furnace and the hydrogen heating furnace, the other part of the furnace top gas enters a decarburization separation system, and the last part of the furnace top gas is used as external exhaust gas and sent to a whole plant pipe network. CO formed after the top gas entering the decarburization separation system is subjected to decarburization 2 The gas is pressurized by a pressurizer and then mixed with hydrogen in a primary mixing device, the mixed gas is heated to 400-500 ℃ in a tubular heating furnace and then enters a reverse water-gas shift reactor to generate H 2 CO, CO2 and H 2 O is primary high-temperature reducing gas with the main component. And the other part of hydrogen enters a secondary mixing device after passing through a hydrogen heating furnace. The oxygen enters the reformer after being preheated by the oxygen heater and is used as reaction gas of the reformer. And pressurizing the decarbonized gas from the decarbonization separation system by a second pressurizing machine, and exchanging heat by a heat exchange device to generate medium-temperature decarbonized gas. And mixing a part of medium-temperature decarbonized gas with the methane-rich gas preheated by the heat exchange device, and then feeding the mixture into a converter to generate a secondary high-temperature reducing gas. And the other part of the medium-temperature decarburization gas enters a mixing device, and is mixed with the primary high-temperature reducing gas, the secondary high-temperature reducing gas and the hydrogen preheated by the hydrogen heating furnace in the mixing device to form a third-level high-temperature reducing gas, and the third-level high-temperature reducing gas enters the shaft furnace from the bottom of the shaft furnace for producing the direct reduced iron by the shaft furnace.
Optionally, the furnace top gas is subjected to coarse dust removal, and gravity dust removal or cyclone dust removal is adopted; fine dust removal, namely, dry dust removal is adopted; the heat exchange device is a multi-stage heat exchange device and is matched with the dry dedusting, and the high-temperature furnace top gas subjected to the dry dedusting exchanges heat with the decarbonized gas subjected to the decarbonization separation system in a primary heat exchanger of the heat exchange device; the methane-rich gas and the high-temperature furnace top gas subjected to dry dedusting exchange heat in a secondary heat exchanger of the heat exchange device; the preheating temperature of the methane-rich gas in the heat exchange device is not more than 200 ℃.
Optionally, the preheating temperature of oxygen in the oxygen heater does not exceed 300 ℃, and steam is used as a heating medium;
optionally, the top gas of the shaft furnace adopts a wet decarburization process.
Optionally, CO formed after the top gas entering the decarburization separation system is subjected to decarburization 2 Pressurizing the gas by a first pressurizer, and then boosting the pressure to 1.0MPa and CO 2 The gas is pressurized and then mixed with hydrogen according to H 2 With CO 2 Mixing the raw materials in a molar ratio of 1-3 to form mixed gas, heating the mixed gas to 450 ℃ in a tubular heating furnace, and then feeding the mixed gas into a reverse water gas shift reaction device to generate H 2 、CO、CO 2 And H 2 O is primary high-temperature reducing gas with the main component.
Optionally, a part of the medium-temperature decarbonized gas is mixed with the methane-rich gas preheated by the heat exchange device and enters the converter, and H is generated in the converter 2 And a secondary high-temperature reducing gas containing CO as a main component.
Optionally, the temperature of the three-stage high-temperature reducing gas is 850-950 ℃ (adjustable according to ore types), and the reducing gas contains (CO + H) 2 )/(CO 2 +H 2 O) is greater than 10, H 2 /CO＝3～5。
The invention takes H as 2 And methane-rich gas as raw material gas to produce direct reduced iron and CO produced from top gas of shaft furnace 2 By using CO 2 After the separation measure, CO is converted by 'green hydrogen' by reverse water gas conversion reaction 2 After reduction to CO, is recirculated back to the shaft furnace as reducing gas. Therefore, in the whole shaft furnace reaction process, the raw material gas uses the methane-rich gas and the supplemented raw material is 'green hydrogen', and CO generated in the production process 2 The maximum recycling is realized, and the consumption of the methane-rich gas of the raw material gas is reduced.
Examples
The research is carried out by taking natural gas and hydrogen as gas sources, using a 0.3MPa gas-based shaft furnace and matching a coal gas treatment process with a direct reduced iron hydrogen-rich shaft furnace producing 100 ten thousand tons per year.
The gas amount of the top gas discharged from the top of the shaft furnace is 254300Nm3/h and 400 ℃, and after coarse dust removal and fine dust removal, the dust content is reduced to 5mg/m3, and then the gas enters a heat exchange device to exchange heat with the decarbonization gas of the furnace top gas. After passing through the heat exchange device, the temperature of the top gas is reduced by 40 ℃, then most of the top gas (92600 Nm3/h) enters a decarburization separation system, a small part of the top gas (15200 Nm3/h) is used as fuel gas of the tubular heating furnace and the hydrogen heating furnace, and the last part of the top gas (95200 Nm3/h) is used as external exhaust gas and sent to a whole plant pipe network. CO formed after the furnace top gas entering the decarburization separation system is decarburized 2 Pressurizing the gas (-4600 Nm3/H) to 1.0MPa, mixing the gas with hydrogen (4100Nm3/H, 1.0MPa) in a first mixing device to form mixed gas, heating the mixed gas to 450 ℃ in a tubular heating furnace, and then feeding the mixed gas into a reverse water-gas shift reactor to generate H 2 、CO、CO 2 And H 2 O is primary high-temperature reducing gas with the main component.
Hydrogen with the flow rate of 14600Nm3/h and the pressure of 0.32MPa enters a hydrogen heating furnace, is heated to 850 ℃ and then enters a second mixing device.
The decarbonization gas from the decarbonization separation system is pressurized to 0.34MPa and preheated to 160 ℃ in a heat exchange device to form medium-temperature decarbonization gas, and a part of the medium-temperature decarbonization gas enters a second mixing device. The other part of the medium-temperature decarbonization gas enters a converter.
The natural gas with the flow of 15800Nm3/h is pressurized to 0.34MPa, preheated to 160 ℃ in a heat exchange device, mixed with part of medium-temperature decarbonization gas and then enters a converter. Meanwhile, oxygen is heated to 160 ℃ by an oxygen heater and is sprayed into the converter from the top of the converter. Natural gas and oxygen are in the converter to generate 1250 ℃ secondary high-temperature reducing gas.
The medium-temperature decarbonization gas, the hydrogen gas, the primary high-temperature reducing gas and the secondary high-temperature reducing gas are mixed in a second mixing device to form a third-level high-temperature reducing gas with the temperature of 850 ℃ (CO + H) 2 )/(CO 2 +H 2 O)＝19，H 2 and/CO is 5. And the third-stage high-temperature reducing gas enters the shaft furnace from the bottom of the shaft furnace and is used for producing direct reduced iron by the shaft furnace.
The invention realizes the conversion and cyclic utilization of carbon in the shaft furnace flow system by adopting the reverse water-gas conversion reaction of hydrogen and carbon dioxide, has simple process flow arrangement and lower energy consumption, effectively reduces carbon emission, has obvious environmental protection benefit and is a green low-carbon smelting gas treatment technology.
Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.
Claims (10)
1. A coal gas treatment method for producing direct reduced iron is characterized by comprising the following steps: the method comprises the following steps: after dedusting and heat exchange, part of top gas discharged from the shaft furnace enters a decarburization separation system, part of top gas serves as fuel gas, and part of top gas serves as exhaust gas and is sent to a whole plant pipe network; CO formed after decarburization 2 Mixing the gas with hydrogen to perform a reverse water gas shift reaction to produce H 2 、CO、CO 2 And H 2 Primary high-temperature reducing gas with O as a main component; pressurizing and exchanging heat of decarbonized gas to form medium temperature decarbonized gas, mixing partial medium temperature decarbonized gas with preheated rich methane gas, reacting in converter with oxygen introduced into converter to produce CO and H 2 A secondary high-temperature reducing gas as a main component; the other part of the medium-temperature decarbonization gas is mixed with the primary high-temperature reducing gas, the secondary high-temperature reducing gas and the preheated hydrogen to form CO and H 2 And the third-level high-temperature reducing gas is a main component and has the temperature matched with that of the reduced iron ore, and the third-level high-temperature reducing gas enters the shaft furnace to be used for producing the direct reduced iron by the shaft furnace.
2. The gas treatment method for producing direct reduced iron according to claim 1, wherein: CO formed after decarbonation 2 The gas is pressurized and then mixed with hydrogen according to H 2 With CO 2 Mixing the raw materials in a molar ratio of 1-3 to form mixed gas, preheating the mixed gas to 400-500 ℃ by using a tube-type heating furnaceEntering reverse water gas shift reaction to generate H 2 、CO、CO 2 And H 2 O is primary high-temperature reducing gas with the main component, and fuel gas preheated by the mixed gas is furnace top gas subjected to dust removal and heat exchange.
3. The gas treatment method for producing direct reduced iron according to claim 1, wherein: the temperature of the medium-temperature decarbonization gas is 120-160 ℃, part of the medium-temperature decarbonization gas is mixed with methane-rich gas preheated to 120-160 ℃ and enters a converter, and oxygen which is blown from the top of the converter and preheated to 120-160 ℃ generates secondary high-temperature reducing gas at 1100-1300 ℃.
4. The gas treatment method for producing direct reduced iron according to claim 1, wherein: CO and H in the three-stage high-temperature reducing gas 2 Is greater than or equal to 85 percent, H 2 And CO in a volume ratio of 3-5, (H) 2 +CO)/(H 2 O+CO 2 )≥10。
5. The gas treatment method for producing direct reduced iron according to claim 1, wherein: the heat source used for the decarburization gas heat exchange is furnace top gas subjected to dust removal and heat exchange.
6. The gas treatment method for producing direct reduced iron according to claim 1, wherein: the hydrogen is preheated by a hydrogen heating furnace, and the fuel gas preheated by the hydrogen is furnace top gas subjected to dust removal and heat exchange.
7. The gas treatment method for producing direct reduced iron according to claim 1, wherein: the oxygen enters the reformer after being preheated by the oxygen heater, and the oxygen heater adopts steam as a heating medium.
8. The gas treatment method for producing direct reduced iron according to claim 1, wherein: CO formed after decarbonation 2 The purity of the gas is more than or equal to 95 percent, and the temperature is 30-40 ℃.
9. A coal gas treatment system for producing direct reduced iron is characterized in that: comprises a dust removal heat exchange pipeline for dust removal and heat exchange of furnace top gas, the dust removal heat exchange pipeline is connected with a decarburization separation system, a fuel gas pipeline and a gas pipeline connected with a whole plant pipe network, and the decarburization separation system is connected with CO 2 A treatment branch and a decarbonization gas treatment branch, CO 2 The treatment branch comprises a first pressurizer, a first mixing device, a tubular heating furnace and a reverse water gas shift reactor which are sequentially arranged along the airflow direction, the first mixing device is connected with a hydrogen gas supply pipeline to provide hydrogen gas for the first mixing device, the decarbonization gas treatment branch comprises a second pressurizer, a heat exchange device and a reforming furnace which are sequentially arranged along the airflow direction, a methane-rich gas supply pipeline is connected on a pipeline between the heat exchange device and the reforming furnace, the reforming furnace is connected with an oxygen gas supply pipeline to provide oxygen gas for the reforming furnace, the reforming furnace and the reverse water gas shift reactor are both connected with the second mixing device, the hydrogen gas supply pipeline is connected with a hydrogen heating furnace connected with the fuel gas pipeline, the hydrogen heating furnace is connected with the second mixing device, a medium-temperature decarbonization branch is connected on a pipeline between the heat exchange device and the methane-rich gas supply pipeline, the medium-temperature decarbonization branch is connected with the second mixing device, the second mixing device is connected to the shaft furnace.
10. The gas treatment system for producing direct reduced iron according to claim 9, wherein: the dedusting heat exchange pipeline comprises a coarse dedusting device, a fine dedusting device and a heat exchange device which are sequentially arranged along the direction of airflow, the fine dedusting device is a dry dedusting device, the heat exchange device is a multi-stage heat exchange device, and the furnace top gas subjected to dedusting exchanges heat with the decarbonization gas after passing through the decarbonization separation system in a first-stage heat exchanger of the heat exchange device; and exchanging heat between the methane-rich gas and the dedusted high-temperature furnace top gas in a secondary heat exchanger of the heat exchange device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210223835.8A CN114807485A (en) | 2022-03-09 | 2022-03-09 | Coal gas treatment method and system for producing direct reduced iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210223835.8A CN114807485A (en) | 2022-03-09 | 2022-03-09 | Coal gas treatment method and system for producing direct reduced iron |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114807485A true CN114807485A (en) | 2022-07-29 |
Family
ID=82529768
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210223835.8A Pending CN114807485A (en) | 2022-03-09 | 2022-03-09 | Coal gas treatment method and system for producing direct reduced iron |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114807485A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117344076A (en) * | 2023-10-27 | 2024-01-05 | 攀钢集团西昌钢钒有限公司 | Progressive direct reduction method and device for iron ore |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090013828A1 (en) * | 2006-01-31 | 2009-01-15 | Danieli & C. Officine Meccaniche S.P.A. | Reduction Process and Plant |
| CN101643809A (en) * | 2009-05-14 | 2010-02-10 | 中冶赛迪工程技术股份有限公司 | Sponge iron production technology by coal gasification |
| CN102851426A (en) * | 2012-10-09 | 2013-01-02 | 中冶赛迪工程技术股份有限公司 | Direct reduction process for producing spongy iron from CH4-rich coal gas |
| CN106521073A (en) * | 2016-12-16 | 2017-03-22 | 江苏省冶金设计院有限公司 | System and method for preparing direct reduced iron through top gas |
| CN113736943A (en) * | 2021-08-20 | 2021-12-03 | 中冶赛迪工程技术股份有限公司 | Direct reduction method for producing sponge iron by converting hydrocarbon-rich gas |
-
2022
- 2022-03-09 CN CN202210223835.8A patent/CN114807485A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090013828A1 (en) * | 2006-01-31 | 2009-01-15 | Danieli & C. Officine Meccaniche S.P.A. | Reduction Process and Plant |
| CN101643809A (en) * | 2009-05-14 | 2010-02-10 | 中冶赛迪工程技术股份有限公司 | Sponge iron production technology by coal gasification |
| CN102851426A (en) * | 2012-10-09 | 2013-01-02 | 中冶赛迪工程技术股份有限公司 | Direct reduction process for producing spongy iron from CH4-rich coal gas |
| CN106521073A (en) * | 2016-12-16 | 2017-03-22 | 江苏省冶金设计院有限公司 | System and method for preparing direct reduced iron through top gas |
| CN113736943A (en) * | 2021-08-20 | 2021-12-03 | 中冶赛迪工程技术股份有限公司 | Direct reduction method for producing sponge iron by converting hydrocarbon-rich gas |
Non-Patent Citations (1)
| Title |
|---|
| 梁仁杰: "化工工艺学", 重庆大学出版社, pages: 6 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117344076A (en) * | 2023-10-27 | 2024-01-05 | 攀钢集团西昌钢钒有限公司 | Progressive direct reduction method and device for iron ore |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2022535446A (en) | Method and system for producing steel or molten iron containing material with reduced emissions | |
| US8926729B2 (en) | Method and apparatus for direct reduction ironmaking | |
| CN107337179B (en) | Preparation system and method of reducing gas of gas-based shaft furnace | |
| CN102037145B (en) | Method for melting raw iron while recirculating blast furnace gas by adding hydrocarbons | |
| CN111979371B (en) | Method for distributed utilization of heat in process of producing direct reduced iron by dry quenching coupled shaft furnace | |
| CN113736943A (en) | Direct reduction method for producing sponge iron by converting hydrocarbon-rich gas | |
| CN114574650A (en) | Method and device for producing direct reduced iron by using hydrogen-based shaft furnace | |
| CN112813219A (en) | System and process for realizing near-zero emission of ammonia direct reduced iron | |
| KR20230119202A (en) | Smart Hydrogen Production for DRI Manufacturing | |
| CN114686633A (en) | Method for pre-heat exchanging hydrogen by utilizing direct reduction iron furnace top gas | |
| CN114807485A (en) | Coal gas treatment method and system for producing direct reduced iron | |
| CN103805728A (en) | Method and device for producing reduced iron through synthetic gas prepared from high-nitrogen content retort gas | |
| TW201333212A (en) | Method and system for the production of direct reduced iron using a synthesis gas with a high carbon monoxide content | |
| CN108315523B (en) | Method and system for producing direct reduced iron by autothermal reforming of carbon dioxide-methane | |
| CN114729407A (en) | Carbon monoxide production method and application thereof | |
| CN107164594B (en) | System and method for producing direct reduced iron by double reforming and conversion of BGL gasification gas | |
| CN113373274B (en) | Coal gas treatment process for full hydrogen shaft furnace | |
| CN206607251U (en) | The system that laterite nickel ore pellet is reduced after gas water steam reformation | |
| CN114574642A (en) | Gas making process and equipment for reducing solid fuel for molten iron production in blast furnace | |
| CN212102909U (en) | System for producing sponge iron by direct reduction of hydrogen energy | |
| CN112662824A (en) | Blast furnace hydrogen-rich smelting process for efficiently utilizing metallurgical waste gas | |
| CN207121422U (en) | Preparation system of gas-based shaft furnace reducing gas | |
| CN221681135U (en) | Gas-based shaft furnace reducing gas preparation system based on natural gas steam reforming | |
| CN109868335B (en) | System and method for closed-loop utilization of tail gas in iron ore reduction process | |
| JP2003261301A (en) | Method of producing hydrogen by steel making co- production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220729 |