KR101234557B1 - Method for Increasing Heating Value and Flammable Gas Using Linz Dowawiz Gas and Organic Resources and Apparatus Therefor - Google Patents

Abstract

The present invention relates to a method for not only improving the efficiency of the converter by-product gas, specifically the calorific value by the reaction of the converter by-product gas and the organic resources, but also recycling the organic waste resources to the combustible gas. According to one embodiment of the present invention, a calorific value and flammable gas increasing method for reacting converter byproduct gas (LDG) and organic resources in a high temperature reducing atmosphere; And a flue extending upward from the converter; An organic resource input unit connected to an upper end of the flue unit; An unreacted organic resource recovery unit extending downward from the flue section between the converter and the organic resource input unit; And a gasifier inlet provided in the flue section adjacent to the converter. According to the present invention, the relatively low temperature converter by-product gas and the conventionally discarded organic resources are recycled in the reaction between the LDG and the organic resources. In addition, the calorific value and the combustible gas of the converter by-product gas are increased.

Description

Method for Increasing Heating Value and Flammable Gas Using Linz Dowawiz Gas and Organic Resources and Apparatus Therefor}

The present invention relates to a method for increasing calorific value and flammable gas using converter by-product gas and organic resources, and an apparatus used therein. More specifically, the present invention relates to a method for not only improving the efficiency of the converter by-product gas, specifically the calorific value by the reaction of the converter by-product gas and the organic resources, but also recycling the organic waste resources to the combustible gas.

The function of the converter during the steelmaking process is the oxidation and deoxidation of carbon in the molten iron, and the Linz Donawiz Converter Gas (LDG) generated in this converter operation is a large amount of carbon monoxide (for example, approximately 20% to 80% by volume). , Carbon dioxide and nitrogen, trace hydrogen, and the like. LDG having such a composition has been used as an energy source because it releases heat of oxidation reaction by oxidation to CO ₂ of CO ₂ . That is, a method of recovering the heat generated by burning the LDG and converting the furnace furnace flue into a boiler (using the combustion method) or a method of recovering the LDG as a gas and using it as a fuel (non-combustion method) has been used. . In particular, the non-combustion method can utilize LDG as a fuel or a raw material, making the mainstream of the LDG recovery method.

Recently, in the converter operation, the CO content is lowered and the CO ₂ fraction is increased according to the operation method to burn as much CO as possible to CO ₂ and use the generated heat as melting heat, and the quality of LDG is deteriorated. This low LDG gas is burned away without energy recovery through combustion.

In the related art, research has been carried out to gasify coal by using carbon dioxide and sensible heat in LDG as in Reaction (1) by reacting LDG with coal. However, this reaction requires high temperature and long contact time due to the nature of the Boudouard reaction.

C + CO ₂ → 2CO ΔH = + 172.5 kj / mol (1)

On the other hand, LDG is a high temperature of about 1500 ° C in the furnace furnace of the converter and the sensible heat of such a high temperature LDG is difficult to recover, and there is also a problem that the recovery facilities are expensive. Therefore, most of the sensible heat recovery of LGD is a relatively low temperature part called radiant part of the flue gas flue. Therefore, there is a need for a method of increasing the calorific value of such relatively low temperature LDG gas and efficiently recycling it.

On the other hand, useful plastic products are being discarded due to increased use of disposable plastic products, and recycling and recycling of waste plastics are required.

According to one embodiment of the present invention, a method of increasing the calorific value of converter byproduct gas (LDG) is provided.

According to another embodiment of the present invention, a method of increasing the flammable component content of converter byproduct gas (LDG) is provided.

According to another embodiment of the present invention, a method of increasing the combustible gas is provided.

Furthermore, another embodiment of the present invention provides an apparatus for use in the reaction of converter by-product gas and organic resources.

According to one aspect of the invention,

Provided are a calorific value and flammable gas increasing method for reacting converter byproduct gas (LDG) with organic resources in a high temperature reducing atmosphere.

According to another aspect of the present invention,

A flue extending upward from the converter; An organic resource input unit connected to an upper end of the flue unit; An unreacted organic resource recovery unit extending downward from the flue section between the converter and the organic resource input unit; And a calorific value and a combustible gas increasing apparatus for reacting the converter by-product gas (LDG) including the gasification agent input unit provided in the flue part adjacent to the converter and the organic resources.

In the reaction between the converter by-product gas (LDG) and the organic resource according to the present invention, the converter by-product gas of a relatively low temperature to a high temperature range, for example, 300 ° C to 1200 ° C, and the organic resources that have been conventionally disposed of are recycled.

By the method according to one embodiment of the present invention, the calorific value and the flammable gas content of the low-temperature converter by-product gas are increased. In addition, in addition to the combustible gas contained in the converter by-product gas, the combustible gas is increased by using an organic resource, which is efficient and economical. Furthermore, it is possible to selectively recover and use a desired component among the components contained in the combustible gas generated by reprocessing the combustible gas generated by the reaction. For example, since hydrogen is produced by reforming hydrocarbons contained in a gas product, hydrogen recovery can be improved and used as a new energy source.

Further, by using the apparatus according to the present invention, the rising LDG and the falling organic resources come into contact with each other in counter current with each other while passing through the flue of a certain length, so that they react efficiently. In addition, since unreacted organic resources fall and are recovered and removed by the unreacted organic resource recovery unit, the incorporation of impurities into the product gas or the converter is largely prevented. Furthermore, by selectively adding the desired gasifier through the gasifier inlet located near the LDG gas introduction unit, the type and amount of the gas to be increased can be properly adjusted and the reaction temperature can also be controlled.

1 is a schematic diagram of an apparatus used for the reaction of converter by-product gas and organic resources according to the present invention.

According to one embodiment of the present invention, there is provided a method of increasing the calorific value and the flammable gas by the reaction of converter byproduct gas (LDG) and organic resources in a reducing atmosphere.

Reaction of the organic resources with LDG in a relatively low to high temperature range, in particular about 300 ° C. to 1200 ° C., in a reducing atmosphere results in the reaction of LDG, organic resources, water contained therein, and optionally a gasifier added as needed. The calorific value increases the calorific value and the flammable gas. The gas generating reaction by the above reaction takes place, for example, by the reactions of the following reaction formulas (2) to (13), and may be accompanied by other incidental reactions. As described above, the LDG includes CO, CO ₂ and N ₂ , and the organic resources mainly consist of hydrocarbons (represented by -CH ₂ -in the following scheme). The reaction is also a catalystless gasification process.

On the other hand, the LDG and the organic resources are preferably reacted by inputting so as to meet each other in a counter current (count current). Preferably, the LDG rises and the organic resources are added in a falling direction to react. In this way, the LDG rises and the organic resources fall in the direction of falling, so that the organic resources are not only preheated to the high temperature atmosphere of the LDG, but also the mixing of the unreacted organic resources into the reaction product gas is prevented.

The reaction is preferably performed by bringing LDG into contact with an organic resource for 1 second to 10 minutes. If the reaction time is less than 1 second, the conversion rate of pyrolysis of organic resources into gaseous phases such as CH ₄ , CO, H _2, etc. is not preferable. If the reaction time is greater than 10 minutes, the reaction apparatus becomes large, which is uneconomical. On the other hand, the organic resources are preferably added in an amount of 0.1 kg / h to 100 kg / h with respect to LDG 100 Nm ³ / h in terms of the calorific value and the reaction conversion rate is suitable.

-CH _2- + H ₂ → CH ₄ (2)

-CH _2- + H ₂ O → CO + 2H ₂ (3)

CH _2- + CO ₂ → 2CO + H ₂ (4)

-CH _2- → C + H ₂ (5)

-CH _2- + H ₂ O → CO + 2H ₂ (6)

-CH _2- + 0.5 O ₂ → CO + H ₂ (7)

C + CO ₂ → 2CO (8)

C + H ₂ O → H ₂ + CO (9)

C + 0.5 O ₂ → CO (10)

CO + 0.5 O ₂ → CO ₂ (11)

H ₂ + 0.5 O ₂ → H ₂ O (12)

CO + 3 H ₂ → CH ₄ + H ₂ O (13)

In the method according to one embodiment of the present invention, as described above, LDG having a high temperature, specifically 300 ° C. to 1200 ° C., may be used. In particular, LDG of 300 ° C. to 550 ° C., which has not been conventionally recycled, is used, and the calorific value of the LDG and the content of flammable gas are increased to be recycled into high quality LDG.

Due to the low pyrolysis temperature of organic resources containing hydrogen sources compared to the boudouard reaction of coal and CO _2, the constituents and organic resources of LDG react at a temperature of 300 ° C. to 550 ° C. and therefore relatively low temperatures, for example, 300 ° C. to Not only LDG at 550 ° C. is efficiently recycled, but also the calorific value, the flammable component content and the total flammable gas amount are increased by the reaction of the LDG and the organic resources. Further, the reaction product may be retreated to recover desired components.

The organic resource is preferably waste plastic or biomass in terms of organic decomposition efficiency and cost. Waste plastics are high molecular hydrocarbons, which have high conversion efficiency to flammable gas when decomposed and can increase a large amount of flammable gas at low cost. Biomass is an energy source that is abundant in the surroundings such as trees, grains, plants, food residues, livestock manure, etc., and it is excellent in energy efficiency because a large amount of combustible gas such as methane is produced during combustion.

Furthermore, a gasifying agent may be added to the reaction as necessary. In the present invention, it is preferable to add a gasifier in order to promote the gasification by the reaction of the LDG and organic resources.

A gasifier is a gaseous substance that is blown with fuel to gasify a solid fuel or a liquid fuel. As the gasifier, at least one selected from the group consisting of H ₂ O, CO _2, O _2, and H ₂ may be used. The gasifier may be added in a desired amount in consideration of the reaction of LDG, organic resources, and gasifier types according to the type and amount of gas to be increased and the calorific value.

In this way, the amount of heat and the type and amount of gas obtained by adjusting the type and amount of the gasifier can be suitably adjusted. The gasifier is added in an amount of 1 part by weight or less (for example, 100 g or less of a gasification agent when 100 g of an organic resource is added) with respect to 1 part by weight of an organic resource to be introduced from the viewpoint of treatment of the gasification agent and reaction conversion rate. desirable.

By the method according to one embodiment of the present invention, a gas having an increased calorific value and / or a content of flammable gas is obtained, which can be recycled to a high quality LDG gas. In addition, the reaction product obtained in the reaction according to the embodiment of the present invention may be reprocessed to recover and use a desired specific component contained in the reaction product. Although not limited to this, for example, the hydrocarbon component can be reprocessed to recover hydrogen gas, and the hydrogen gas thus obtained can also be used as a reducing agent and a heat source.

The reprocessing of combustible gas for obtaining the hydrogen gas can be carried out by any method generally known in the art. For example, but not limited thereto, the impurities contained in the combustible gas obtained are purified, and hydrocarbons contained in the purified combustible gas are catalyzed by at least one gas selected from H ₂ O, CO ₂ , and O ₂ . Reaction by reforming and carbon monoxide obtained in the reforming step can be greatly reduced by aqueous reaction to obtain pure hydrogen.

Specifically, the purification step is a step for purifying various impurities included in the combustible gas, but not limited thereto, for example, H ₂ S, HCN, NH ₃ , and the like. In particular, H ₂ S must be removed by ppm because it acts as a toxic component of the catalyst in the next reforming step. In addition, impurities such as HCN and NH ₃ should be removed because they corrode pipes or form deposits. Purification can be carried out by any method generally known in the art, and the purification can be carried out by, for example, adsorption or absorption, without being limited thereto.

Hydrocarbon (C _n H _m ) contained in the combustible gas purified in the purification step is reacted with one or more gases selected from H ₂ O, CO ₂ and O ₂ under a catalyst to be reformed to obtain carbon monoxide and hydrogen. In the reforming step after the purification step, for example, when using H ₂ O, the hydrocarbons react with water to produce carbon monoxide and hydrogen.

As the catalyst, it is preferable to use a Ni-based metal catalyst having high activity against decomposition and reforming reactions and high poisoning resistance to sulfur compounds. In addition, the reforming step is preferably reacted at a temperature range of 600 ° C to 1000 ° C, since the reforming efficiency is low below 600 ° C, and a large amount of energy is consumed above 1000 ° C.

The reforming step is followed by an aqueous reaction step (WGS). In the aqueous reaction step, the carbon monoxide contained in the reformed gas is greatly reduced through the aqueous reaction of the following Reaction Formula (14), thereby generating hydrogen in the equimolar. Unconverted carbon monoxide is preferably reduced to ppm units in a selective carbon monoxide remover.

CO + H ₂ O → CO ₂ + H ₂ (14)

Finally, hydrogen gas is obtained by removing gases such as CO, CO ₂ and H ₂ O through PSA (Pressure Swing Absorption).

According to another embodiment of the present invention, an apparatus for use in the method according to the present invention is provided. 1 schematically shows the apparatus provided by another implementation of the present invention. Hereinafter, an apparatus according to another embodiment of the present invention will be described with reference to the drawings.

As shown in Fig. 1, the apparatus according to another embodiment of the present invention comprises a flue portion 2 extending upward from the converter 1; An organic resource input unit 3 connected to the top of the flue section; An unreacted organic resource recovery unit 4 extending downward from the flue section between the converter and the organic resource input unit; And a gasifying agent inlet 5 provided in the flue section adjacent to the converter.

Converter by-product gas (LDG) is discharged from the converter (1) is introduced into the flue (2) extending to the upper portion and rises along the flue (2). On the other hand, the organic resources are introduced below the flue section 2 from the organic resource input section 5 above the flue section. In FIG. 1, the flow of LDG is indicated by arrow 7 and the flow of organic resources is indicated by arrow 8.

Specifically, the organic resources are introduced into the flue section 2 by the storage tank 11 and the organic resource input device 12 and fall. The flue portion 2 may be formed to be inclined as shown in FIG. 1 so that the rise of the LDG and the fall of the organic resources are smoothly progressed. In addition, the diameter and length of the flue (2) can be appropriately adjusted in consideration of the contact time and reaction time of the LDG and organic resources, and the input flow rate and input amount of the LDG and organic resources.

The LDG rising in the flue section 2 and the falling organic resources are brought into contact with each other by a reverse flow, and the gasification reaction proceeds by a high temperature in the flue section, for example, 300 ° C. to 1200 ° C. atmosphere. In addition, since the LDG and the organic resources are in contact with each other in a reverse flow, the organic resources are preheated by the sensible heat of the LDG. Furthermore, the organic resources are introduced to fall, thereby preventing the incorporation of unreacted organic resources into the reaction product gas. Furthermore, the apparatus is provided with an unreacted organic resource recovery unit 4 extending downward from the flue section between the converter 1 and the organic resource input unit 3, and the unreacted organic resources that fall fall into the organic resources. Recovered through the recovery unit (4).

On the other hand, the gasification agent inlet portion 5 provided in the flue portion adjacent to the converter (1) is provided, and optionally composed of any gasification agent, specifically H ₂ O, CO ₂ , O ₂ and H ₂ At least one or more selected from the group to be added may be introduced into the flue section 2 through the gasifier input section 5.

The gas formed by the reaction is discharged through the flue 2. Dust in the gas produced by the reaction can be removed by the dust removal device 9 at the rear of the device. As the dust removing apparatus 9, any known in the art can be used, but is not particularly limited. The gas product obtained by removing the dust may be retreated 10 as necessary to selectively recover the component to be recovered from the components contained in the gas product. Although not limited to this in FIG. 1, the process of recovering the hydrogen component in the generated gas is shown as an example.

Hereinafter, the present invention will be described in detail with reference to Examples. The following examples illustrate the invention but do not limit the invention.

Example

A mixed gas containing 20% by volume of CO _2, 20% by volume of nitrogen, and residual CO and having a temperature of 400 ° C., similar to the composition of converter by-product gas (LDG), is lowered in the flue portion 4 of the apparatus as shown in FIG. 1. Injection at a flow rate of 1 Nm ³ / h. The polyester (PE) plastic was introduced at 0.5 kg / Nm ³ -LDG per hour from the organic resource input unit 3 through the storage tank 11 and the organic resource input device 12. 1 kg per kg of PE was introduced through the gasifier input unit 5 as a gasifier. The mixed gas, steam and PE plastics were brought into contact with each other for 30 seconds to 2 minutes in an atmosphere in the flue section 2 at about 400 ° C. On the other hand, as the reaction proceeded, the unreacted PE was recovered by the unreacted organic resource recovery unit 4.

After completion of the reaction, the composition analysis was confirmed to increase the gas flow rate of 20% by volume, the composition of the product was confirmed to be 11% methane, 4% hydrogen, 53% carbon monoxide, 18% carbon dioxide and the balance nitrogen. . It was confirmed that the calorific value increased from 1,800 kcal / N㎥ to 2,600 kcal / N㎥.

From the above results, it can be seen that the flow rate of the combustible gas is increased by 20% and the amount of heat is increased by 40% or more by injecting the plastic.

1 ... converter 2 ... year
3 ... organic resource input 4 ... unreacted organic resource recovery
5 ... gasifier input part 6 ... oxygen blowing nozzle
7 ... LDG Flow Direction 8 ... Organic Resource Flow Direction
9 ... dust removal device 10 ... reprocessing process (hydrogen production / separation process)
11 ... storage tank 12 ... organic resource input device

Claims (7)

The converter by-product gas (LDG) and organic resources are reacted with each other in such a way as to contact the converter by-product gas (LDG) and the organic resources in a reverse flow direction in a high temperature reducing atmosphere. Calorific value and flammable gas increasing method, wherein the organic resources are added in an amount of 0.1 kg / h to 100 kg / h based on LDG 100 Nm ³ / h.
The method of claim 1, wherein the high temperature is 300 ° C. to 1200 ° C., and a calorific value and flammable gas increasing method using LDG.
The method of claim 1, wherein the organic resource is at least one selected from the group consisting of waste plastics and biomass.
delete The calorific value and flammable gas increasing method according to any one of claims 1 to 3, further comprising at least one gasifier selected from the group consisting of H ₂ O, CO ₂ , O _2, and H ₂ .
A flue part inclined upwardly from the converter so that the rise of the converter by-product gas (LDG) and the drop of the organic resources proceed smoothly; An organic resource input unit connected to an upper end of the flue unit; An unreacted plastic recovery part extending downward from the flue part between the converter and the organic resource input part; And a gasifier input unit provided in the flue part adjacent to the converter, wherein the flue part converts the converter by-product gas (LDG) and the organic resource into contact with the organic resource for 1 second to 10 minutes. A calorific value and flammable gas increasing device to react. delete

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