KR101138183B1 - Method for cokes dry quenching using carbon dioxide - Google Patents

Abstract

By introducing carbon dioxide as a circulating gas into a CDQ (Coke Dry Quencher) facility, a coke dry extinguishing method using carbon dioxide that maximizes the heat of recovery through chemical endothermic reactions and further downsizes the CDQ facility is introduced.

Dry coke digestion method using carbon dioxide according to the present invention is charged charging step of injecting the coke to the prechamber formed on the CDQ body (S100); A reaction preparation process of moving the glowing coke to a cooling chamber positioned below the prechamber after a predetermined time (S200); A carbon dioxide injection process (S300) for injecting carbon dioxide into the cooling chamber at the same time as supplying the red coke; It includes; a reaction process (S500) to physically and chemically heat exchange while the coke and carbon dioxide react in the cooling chamber in the following reaction formula.

C (s) + CO _2- > 2CO △ H = 172.5KJ / MOL

Coke, dry, fire extinguishing, carbon dioxide, water, heat recovery

Description

Coke dry fire extinguishing method using carbon dioxide {METHOD FOR COKES DRY QUENCHING USING CARBON DIOXIDE}

The present invention relates to a coke dry fire extinguishing system, and more particularly, by using carbon dioxide as a circulating gas introduced into a cooling chamber in a CDQ system, heat recovery can be performed more efficiently by enabling physical heat exchange as well as chemical endothermic reaction. The present invention relates to a coke dry fire extinguishing system capable of enabling the compaction of a CDQ facility and recycling carbon monoxide generated during the reaction.

CDQ equipment, which is generally applied to the coke plant of steel mills, can be classified into wet and dry depending on the method of extinguishing the red coke supplied from the coke bucket.

As shown in FIG. 1, a Coke Dry Quencher generally comprises a CDQ body 1. That is, the CDQ main body (1) of the coke dry fire extinguishing system receives the high temperature red coke from the coke bucket (2) through the winch lift (3), and recovers high heat through the process of dry extinguishing such red coke, The dry extinguished coke in the CDQ body (1) is discharged to the coke discharge device (4). At this time, the coke dry fire extinguishing system of the prior art burns a gas that may cause an explosion such as hydrogen (H ₂ ) or carbon dioxide (CO ₂ ) generated in the process of dry extinguishing the red coke in the CDQ body (1). To this end, for this purpose, the combustion air necessary for burning hydrogen (H ₂ ) or carbon dioxide (CO ₂ ) is supplied through a combustion air supply device 5 installed on the upper side of the CDQ body 1.

As described above, the coke dry extinguishing facility is cooled and extinguished the coke using an inert gas, the red coke supplied to the prechamber 1a of the CDQ body 1 is introduced into the cooling chamber 1b and the gas supply pipe 6 By supplying the inert gas to the cooling chamber 1b through the heat sink), the inert gas and the red coke exchange heat, so that the heat recovered from the high temperature inert gas is generally used for a power generation system or the like.

However, such a coke dry fire extinguishing method has a problem that a large amount of inert gas must be circulated in order to sufficiently cool the red coke and recover a large amount of heat, thereby increasing the size of the CDQ facility.

The present invention recovers the heat generated in the endothermic process by reacting coke with carbon dioxide through a carbon dioxide injection process to solve the conventional problems, and improve the heat recovery efficiency, further miniaturizing the CDQ equipment by applying this efficient heat recovery method As well as providing a coke dry fire extinguishing method that can recycle the carbon monoxide produced during the chemical reaction.

Drying method for coke using carbon dioxide according to the present invention for achieving this object is a charging process for inputting the coke to the pre-chamber formed in the CDQ body; A reaction preparation process of moving the coke to the cooling chamber located below the prechamber after a predetermined time; A carbon dioxide injection process of injecting carbon dioxide into the cooling chamber at the same time as supplying the red coke; In the cooling chamber includes a reaction process of heat exchanged physically and chemically while the coke and carbon dioxide reacts in the following reaction formula.

C (s) + CO _2- > 2CO △ H = 172.5KJ / MOL

The coke dry fire extinguishing method using carbon dioxide according to the present invention preferably further includes a utilization process of recycling high temperature carbon monoxide generated in the reaction process.

Another feature of the present invention is that the water injection process for supplying water in the cooling chamber is performed at the same time as the carbon dioxide injection process, the reaction process includes the reaction according to the following reaction formula.

C (s) + H ₂ O-> CO + H ₂ △ H = 131.3KJ / MOL

In addition, the utilization process is characterized in that to produce power by heat exchange with the boiler using carbon monoxide produced in the reaction process.

In addition, the utilization process is characterized in that the carbon monoxide produced in the reaction process is introduced into the blast furnace.

Furthermore, the carbon dioxide generated in the blast furnace is preferably supplied to the cooling chamber through the carbon dioxide injection process.

The present invention can absorb the heat of the coke coke more efficiently only by injection of a small amount of carbon dioxide, the efficiency of heat recovery is improved. In addition, the CDQ facility can be downsized because a large amount of circulating gas is not required due to the improvement of the heat recovery efficiency. Furthermore, there is an effect that can improve the energy efficiency by recycling the carbon monoxide generated during the reaction of the coke and carbon dioxide.

Hereinafter, with reference to the accompanying drawings looks at the coke dry fire extinguishing method using carbon dioxide according to a preferred embodiment of the present invention.

2 is a flow chart illustrating a coke dry fire extinguishing method according to the present invention. The coke dry fire extinguishing method of the present invention includes a charging process (S100), a reaction preparation process (S200), a carbon dioxide injection process (S300), a reaction process (S500) and a utilization process (S600). The reaction process (S500) is a process of injecting coke into the prechamber formed in the CDQ main body. The red coke of about 1100 ° C. contained in the coke bucket is charged into a prechamber formed on the CDQ body using a winch lift. The prechamber in which the charging process (S100) is performed corresponds to a process of reducing the risk of work due to a decrease in reactivity with carbon dioxide and a sudden reaction with carbon dioxide, which will be described later, which occurs due to the time difference of the red coke input.

After the charging process (S100) is made, the reaction preparation process (S200) is performed. This process is the process of moving the charged red coke from the prechamber to the cooling chamber. That is, the cooling chamber corresponds to a reaction space with carbon dioxide for recovering heat of the red coke. Almost simultaneously with the reaction preparation process (S200), the carbon dioxide injection process (S300) is performed. After the carbon dioxide is injected, the reaction process (S500) is performed in the cooling chamber.

The reaction process S500 corresponds to a process of physically and chemically exchanging heat while the coke and carbon dioxide react. Carbon dioxide can be used as a heat exchange gas of coke in the low temperature range of less than about 300 ℃, such as nitrogen, which is a conventionally used inert gas, and can function as a heat exchange gas at a high temperature of about 300 ℃ or more. It has a function as a reactive gas. That is, the carbon dioxide can be physically heat exchanged as a heat exchange gas, as well as chemically heat exchanged as a reaction gas. After the carbon dioxide is injected, the reaction formula of the reaction process (S500) is as follows.

C (s) + CO _2- > 2CO △ H = 172.5KJ / MOL

The coke and carbon dioxide react to generate carbon monoxide. The reaction enthalpy (ΔH) of this reaction corresponds to 172.5 KJ / MOL. That is, the reaction in the cooling chamber system corresponds to an endothermic reaction in which the enthalpy of carbon monoxide (CO) corresponding to the product increases rather than the reaction enthalpy of reactant coke (C (s)) and carbon dioxide (CO ₂ ). . Therefore, if the temperature of the glowing coke supplied to the cooling chamber is about 300 ° C. or more, a rapid endothermic reaction occurs according to the above reaction formula, and thus the heat of the hot coke can be recovered as the hot carbon monoxide as a product.

After the reaction process (S500) is performed, the utilization process (S600) is performed.

Carbon monoxide generated by the reaction process (S500) is a high temperature carbon monoxide, in the utilization process (S600), as well as the thermal energy of carbon monoxide, carbon monoxide gas itself can be utilized.

On the other hand, in the cooling chamber it is preferable that the water injection process (S400) for supplying water proceeds simultaneously with the carbon dioxide injection process (S300). If the water injection process (S400) is carried out at the same time as the carbon dioxide injection process (S300) another reaction occurs in the cooling chamber, the reaction equation is as follows.

C (s) + H ₂ O-> CO + H ₂ △ H = 131.3KJ / MOL

That is, carbon monoxide and hydrogen gas are generated when water is injected into the cooling chamber supplied with the red coke. The reaction enthalpy (ΔH) of the reaction process (S500) corresponds to 131.3 KJ / MOL, and the value of the reaction enthalpy is the enthalpy of red coke (C (s)) and water (H ₂ O). This means that the endothermic reaction of increasing enthalpy of carbon monoxide (CO) and hydrogen (H ₂ ). Therefore, when using the water injection process (S400), as in the carbon dioxide injection process (S300) can effectively recover the heat of the red coke, the product of high heat carbon monoxide is recycled in the utilization process (S600).

In the utilization process (S600) it can be recycled carbon monoxide in various forms.

As shown in FIG. 3, the high temperature carbon monoxide produced in the cooling chamber 12 of the CDQ body 10 may supply heat to the power generation system 30 through the heat exchanger 20. That is, in the general power generation system 30 to replace the heat supplied to the boiler with the heat of carbon monoxide. Carbon monoxide heat from this can be recovered as electrical energy from the power generation system.

In addition, as shown in Figure 4, the utilization process (S600) may be made in the form of injecting carbon monoxide generated in the reaction process (S500) to the blast furnace (40). In general, the steelmaking process puts iron ore and raw coal bituminous coal into a blast furnace 40 having a height of about 100 m, and then blows hot winds of about 1,200 ° C., whereby iron ore is melted by heat from burning raw coal to make water. Since the iron ore is in the form of an oxygen-bonded oxide, a reducing agent is required. Carbon monoxide generated in the reaction process (S500) of the present invention may be directly injected into the blast furnace 40 and used as a reducing gas.

As described above, the carbon monoxide is supplied to the blast furnace 40 to reduce the iron ore which is in the form of oxygen-bonded oxide, the reaction schemes are as follows.

3Fe ₂ O ₃ + CO → 2Fe ₃ O ₄ + CO ₂

Fe ₃ O ₄ + CO → 3FeO + CO ₂

FeO + CO → Fe + CO ₂

That is, carbon dioxide is produced in the blast furnace 40 by the reduction of iron ore, such carbon dioxide is directly supplied to the cooling chamber 12 of the CDQ body 10 to which the coke dry fire extinguishing method using the carbon dioxide of the present invention is applied, or carbon dioxide Only the bay can be recovered, supplied and recycled.

5 is a thermodynamic equilibrium curve of carbon dioxide and carbon monoxide according to temperature and pressure in a coke dry fire extinguishing method using carbon dioxide according to the present invention.

That is, carbon dioxide does not react chemically with the coke at less than approximately 300 ° C. under 1 atmosphere (1 atm), and thus carbon monoxide is not produced. At this time, carbon dioxide functions only as a heat exchange gas. However, carbon dioxide starts to react chemically when the glowing coke becomes approximately 300 ° C or higher. When the coke reaches about 1030 ° C., all of the carbon dioxide supplied reacts with the coke, so that the amount of carbon monoxide produced is maximum. Therefore, the temperature of the red coke is preferably maintained at approximately 300 ° C or more, more preferably at 1030 ° C or more.

In addition, under 10 atmospheres (10 atm), the coke and carbon dioxide do not react below about 400 ° C. The carbon dioxide functions only as a heat exchange gas, but when it is higher than that, it also functions as a reaction gas. In particular, when the coke is 1300 ° C or higher, the amount of carbon monoxide produced is maximum.

Under 100 atmospheres (100 atm), carbon dioxide functions only as a heat exchange gas below about 430 ° C., but it also functions as a reaction gas above that. Particularly, if the temperature of the red coke is about 1500 ° C. or more, the amount of carbon monoxide produced is maximum. Becomes

While the invention has been shown and described with respect to particular embodiments, it will be appreciated that various changes and modifications can be made in the art without departing from the spirit of the invention provided by the following claims. It will be self-evident for those of ordinary knowledge.

1 shows a conventional coke dry fire extinguishing facility;

2 is a flow chart of a coke dry fire extinguishing method using carbon dioxide of the present invention;

3 is a view showing a process of utilizing the present invention;

4 is a view showing another utilization process of the present invention;

5 is a thermodynamic equilibrium curve of carbon dioxide and carbon monoxide according to temperature and pressure in a coke dry fire extinguishing method using carbon dioxide according to the present invention.

[Description of Reference Numerals]

S100: Charging Process S200: Reaction Preparation Process

S300: CO2 injection process S400: Water injection process

S500: Reaction Process S600: Application Process

Claims (6)

Charging step of injecting coke into the prechamber formed in the CDQ main body (S100); A reaction preparation process of moving the glowing coke to a cooling chamber positioned below the prechamber after a predetermined time (S200); A carbon dioxide injection process (S300) for injecting carbon dioxide into the cooling chamber at the same time as supplying the red coke; Drying coke and carbon dioxide reaction in the cooling chamber in the reaction scheme of physical and chemical heat exchange while the reaction (S500); coke dry fire extinguishing method using a carbon dioxide comprising a. C (s) + CO _2- > 2CO △ H = 172.5KJ / MOL The method of claim 1, wherein the coke dry fire extinguishing method using carbon dioxide further comprises a utilization process (S600) for recycling the high temperature carbon monoxide generated in the reaction process (S500). The method of claim 1, wherein in the cooling chamber, a water injection process (S400) for supplying water proceeds simultaneously with the carbon dioxide injection process (S300), and the reaction process (S500) includes a reaction according to the following reaction formula: Coke dry fire extinguishing method using carbon dioxide. C (s) + H ₂ O-> CO + H ₂ △ H = 131.3KJ / MOL The method according to claim 2, wherein the utilization process (S600) using the carbon monoxide produced in the reaction process (S500) coke dry fire extinguishing method using carbon dioxide, characterized in that to produce power by heat exchange with the boiler. The method of claim 2 or 3, wherein the utilization process (S600) is a coke dry fire extinguishing method using carbon dioxide, characterized in that the carbon monoxide generated in the reaction process (S500) is introduced into the blast furnace. The method of claim 5, wherein the carbon dioxide generated in the blast furnace is supplied to the cooling chamber through the carbon dioxide injection process (S300) coke dry fire extinguishing method using carbon dioxide.

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