KR20130048815A - Method for producing methane gas by use of by-product gas in the ironworks - Google Patents

Abstract

PURPOSE: A manufacturing method of methane gas by aqueous gas conversion reaction is provided to obtain methane gas by using carbon monoxide gas, to have effective aqueous gas conversion reaction, and to easily control an equivalent ratio between carbon monoxide gas and hydrogen gas. CONSTITUTION: A manufacturing method of methane gas comprises: a step of separating a carbon monoxide gas stream in a byproduct gas stream exhausted from an ironwork apparatus(10) using a carbon monoxide separator(110); a step of generating a hydrogen gas/carbon dioxide gas stream which includes hydrogen gas and carbon dioxide gas in a water-gas conversion reactor(120), by using carbon monoxide gas in the carbon monoxide gas stream; and a step of generating a methane gas stream in a methanation reactor(140) by using the carbon monoxide in the carbon monoxide stream and the hydrogen gas in the hydrogen gas/carbon dioxide gas stream. [Reference numerals] (10) Ironwork apparatus; (110) Carbon monoxide separator; (120) WGS reactor; (130) CO2 and acid gas remover; (140) Methanation reactor; (150) Condenser; (AA,DD) Water; (BB) CO2, N2, and others; (CC) CO2, acid gas, and others

Description

Method for producing methane gas using by-product gas in steel making facilities

The present invention relates to a methane gas production method using the by-product gas of the steelmaking facility, and more particularly to a method for producing methane gas through the water gas conversion reaction and methanation reaction using the by-product gas of the steelmaking facility.

In steel mills, by-product gases such as converter gas, blast furnace gas, and dry gas are produced. In particular, in blast furnace gas and converter gas, the composition of carbon monoxide reaches 20% and 64%, respectively. Carbon monoxide is a source of fuel that is not completely burned, and if it is simply discharged to the outside or discharged to the outside by burning completely, it ultimately wastes energy.

Korean Unexamined Patent Publication No. 2010-0121423 discloses a technique of providing a natural gas after gasification of a carbonaceous material and then using a water gas field and a methane generating reactor. However, the above technique has a problem that a separate fuel source such as coal and biomass is required for gasification. Moreover, in the above technology, only processes that do not consider the characteristics of by-product gas of the steel mill are disclosed, which is difficult to apply directly to the steel mill.

It is an object of the present invention to provide a method for producing methane gas through a water gas shift reaction and a methanation reaction using a by-product gas of an iron making facility.

The present invention provides a method of separating a carbon monoxide gas stream in a by-product gas stream discharged from an iron making facility in a carbon monoxide separator, and using hydrogen monoxide in a water gas shift (WGS) reactor using carbon monoxide gas in the carbon monoxide gas stream. Generating a hydrogen gas / carbon dioxide gas stream comprising carbon dioxide gas, and generating a methane gas stream in a methanation reactor using carbon monoxide in the carbon monoxide gas stream and hydrogen gas in the hydrogen gas / carbon dioxide gas stream. It provides a method for producing methane gas using by-product gas of the steel making facility.

According to another aspect of the present invention, the present invention provides a method of separating a carbon monoxide gas stream in a by-product gas stream discharged from a steelmaking plant in a carbon monoxide separator, by introducing a portion of the carbon monoxide gas stream into an aqueous gas shift reactor to produce hydrogen gas and Generating a hydrogen gas / carbon dioxide gas stream comprising carbon dioxide gas, mixing the stream bypassing the water gas conversion reactor of the carbon monoxide gas stream with the hydrogen gas / carbon dioxide gas stream, and from the mixed stream carbon dioxide gas And removing acid gas, generating a methane gas stream in a methanation reactor using carbon monoxide gas and hydrogen gas in the mixed mixed stream from which carbon dioxide gas and acid gas are removed. It provides a process for producing methane gas using the method of water vapor by-product gas of the steel plant, comprising the step of removing by condensation in a condenser in the rim.

According to another aspect of the present invention, the present invention, the carbon monoxide separator using the by-product gas stream from the carbon dioxide gas and acid gas is removed from the by-product gas stream discharged from the steelmaking facility Separating a carbon monoxide gas stream in a stream, introducing a portion of the carbon monoxide gas stream into a water gas shift reactor to generate a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas, and the hydrogen gas / carbon dioxide gas Introducing a stream into a carbon dioxide remover to remove carbon dioxide gas to produce a hydrogen gas stream, and using the carbon monoxide gas stream and the hydrogen gas stream bypassing the water gas shift reactor to methane in a methanation reactor. And generating a gas stream, it provides a process for producing methane gas using the method of water vapor by-product gas of the steel plant, comprising the step of removing by condensation in a condenser in the methane gas stream.

According to another aspect of the present invention, the present invention, the carbon monoxide separator using the by-product gas stream from the carbon dioxide gas and acid gas is removed from the by-product gas stream discharged from the steelmaking facility Separating the carbon monoxide gas stream in a stream; introducing a portion of the carbon monoxide gas stream into a water gas shift reactor to produce a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas; Using the bypassed carbon monoxide gas stream and the hydrogen gas / carbon dioxide gas stream to produce a methane gas stream in a methanation reactor and condensing and removing water vapor in the methane gas stream by condenser It provides a process for producing methane gas using a method of the non-product gas.

Methane gas production method using the by-product gas of the steelmaking facility according to the present invention has the following effects.

First, methane gas can be produced using carbon monoxide gas in the by-product gas of the steelmaking facility. If the by-product gas is discharged to the outside causes a pollution problem. In addition, even when the by-product gas is discharged to the outside in the combustion state, there is a loss of energy source. Moreover, when using the by-product gas as it is as a fuel source, there is a limit to become a low quality energy source. However, in the present invention, since the by-product gas of the steelmaking gas can be converted into a high quality methane gas, the generation of pollution problems can be reduced, and the efficient use of energy is possible.

Second, the process of implementing the manufacturing method is simple, it can be easily applied.

Third, since the carbon monoxide gas separated from the carbon monoxide separator flows into the water gas shift reactor, the water gas shift reaction is effective, and it is easy to match the equivalence ratio between carbon monoxide and hydrogen gas in the methanation reactor.

Fourth, when the acid gas is removed from the by-product gas flows into the carbon monoxide remover, the performance of the carbon monoxide remover is improved.

1 is a configuration diagram of a facility to which a methane gas production method using the by-product gas of the steelmaking facility according to the first embodiment of the present invention is applied.
2 is a configuration diagram of a facility to which a methane gas production method using the by-product gas of the steelmaking facility according to the second embodiment of the present invention is applied.
3 is a configuration diagram of a facility to which a methane gas production method using the by-product gas of the steelmaking facility according to the third embodiment of the present invention is applied.
4 is a configuration diagram of a facility to which a methane gas production method using the by-product gas of the steelmaking facility according to the fourth embodiment of the present invention is applied.

Hereinafter, terms such as a hydrogen gas stream, a methane gas stream, a carbon dioxide gas stream, and the like do not mean only a stream including only the corresponding gas, but are used as a term referring to a stream including the corresponding gas.

1 is a block diagram of a facility 100 to which a methane gas production method using the by-product gas of the steelmaking facility according to the first embodiment of the present invention is applied. In this embodiment, the steelmaking facility 10 is an electric furnace. When the steelmaking facility is an electric furnace, by-product gas is called converter gas, and the main components of the converter gas are carbon monoxide, carbon dioxide, and nitrogen. The molar ratios of the converter gas stream at the first location 11 are 64%, 18% and 16%, respectively. The converter gas stream also contains acid gases such as traces of sulfide gas, argon gas, and the like.

The converter gas stream enters the carbon monoxide separator 110. In the carbon monoxide separator 110, carbon monoxide gas is selectively separated from the converter gas stream. Thus, the carbon monoxide separator 110 removes nitrogen, carbon dioxide, and the like from the converter gas stream. The carbon monoxide separator 110 can be applied to a common carbon monoxide separator, a detailed description thereof will be omitted.

As above, a carbon monoxide gas stream is produced from the carbon monoxide separator 110. The components of the stream at the second position 12 are almost 100% carbon monoxide gas, and are mixed with trace impurities such as acidic gas. A portion of the carbon monoxide gas stream enters a Water Gas Shift (WGS) reactor 120. In the water gas shift reactor 120, the supplied water is converted into steam, and carbon monoxide is converted into hydrogen and carbon dioxide in the presence of the steam. Thus, the carbon monoxide gas stream is converted into a hydrogen gas / carbon dioxide gas stream of hydrogen and carbon dioxide. The molar ratios of hydrogen gas and carbon dioxide gas in the stream at the third position 13 are each nearly 50%.

The remainder of the carbon monoxide gas stream generated from the carbon monoxide separator 110 is mixed with the hydrogen gas / carbon dioxide gas stream after bypassing the water gas shift reactor 120. The molar ratios of carbon monoxide gas, carbon dioxide gas and hydrogen gas in the mixed stream are 14.2%, 42.9% and 42.9%, respectively (fourth position 14). The mixed stream enters the carbon dioxide gas and the acidic gas remover 130 where the carbon dioxide gas and the trace residual acidic gas are removed.

Almost a mixture of carbon monoxide gas and hydrogen gas in the mixed stream passed through the carbon dioxide gas and the acidic gas remover 130, and the ratio is almost 1: 3 (5th position 15). The mixed stream enters the methanation reactor 140. In the methanation reactor 140, a methanation reaction occurs, and one carbon monoxide and three hydrogen react to generate one methane and one steam. Therefore, the ratio (1: 3) of carbon monoxide gas and hydrogen gas in the mixed stream flowing into the methanation reactor 140 may be said to be ideal.

From the methanation reactor 140 a methane gas stream is produced (sixth location 16). The methane gas stream refers to a stream including methane gas, and is not limited to a stream in which only methane gas is present. In this embodiment, the methane gas stream contains both methane and water vapor produced through the methanation reaction.

The methane gas stream enters condenser 150. The condenser 150 condenses and discharges water vapor in the methane gas stream. Thus, the methane gas stream is converted into a pure methane gas stream as it passes through the condenser 150 (seventh location 17).

2 is a block diagram of a facility 200 to which a methane gas production method using the by-product gas of the steelmaking facility 20 according to the second embodiment of the present invention is applied. Also in this embodiment, the steelmaking facility 20 is an electric furnace. The molar ratios of the components of the converter gas stream at the first location 21 are 64%, 18% and 16%, respectively. As noted above, the converter gas stream also contains acid gases such as trace amounts of sulfide gas, argon gas, and the like.

The converter gas stream enters the carbon dioxide gas and the acidic gas remover 230. The carbon dioxide gas and acid gas remover 230 mainly removes carbon dioxide gas, acid gas, and the like from the converter gas stream. The molar ratio of carbon monoxide gas and nitrogen at the second position 22 is 4: 1.

The converter gas stream is then introduced into a carbon monoxide separator 210. In the carbon monoxide separator 210, carbon monoxide gas is selectively separated from the converter gas stream and nitrogen is removed. Thus, a carbon monoxide gas stream is produced from the carbon monoxide separator 210. When the ratio of the acidic gas in the stream flowing into the carbon monoxide separator 210 is high, carbon monoxide separation performance in the carbon monoxide separator 210 is generally reduced. However, in the present embodiment, the converter gas stream is introduced into the carbon monoxide separator 210 while the acid gas is removed, and thus the performance of the carbon monoxide separator 210 may be improved. The component of the stream at the third position 23 is almost 100% carbon monoxide gas.

A portion of the carbon monoxide gas stream enters the water gas shift reactor 220. In the water gas shift reactor 220, the carbon monoxide gas stream is converted into a hydrogen gas / carbon dioxide gas stream in the presence of steam. At the fourth position 24, the molar ratio of hydrogen gas and carbon dioxide gas is 50% each.

The hydrogen gas / carbon dioxide gas stream enters a carbon dioxide remover 235 where carbon dioxide gas is removed from the hydrogen gas / carbon dioxide gas stream and a hydrogen gas stream is produced. The hydrogen gas stream is almost all hydrogen. The hydrogen gas stream enters the methanation reactor. In addition, a bypass stream of the water gas shift reactor 220 in the carbon monoxide gas stream is also introduced into the methanation reactor. The ratio of carbon monoxide gas and hydrogen gas flowing into the methanation reactor 240 is about 1: 3.

In the methanation reactor 240, a methanation reaction occurs, and one carbon monoxide and three hydrogen react to generate one methane and one water vapor, resulting in a methane gas stream (7th position 27). ). The methane gas stream enters condenser 250. The condenser 250 condenses and discharges water vapor in the methane gas stream. Thus, the methane gas stream is converted into a pure methane gas stream as it passes through the condenser 250 (8th position 28).

3 is a block diagram of a facility 300 to which a methane gas production method using the by-product gas of the steelmaking facility 30 according to the third embodiment of the present invention is applied. Also in this embodiment, the steelmaking facility 30 is an electric furnace. The component molar ratios of the converter gas stream at the first location 31 are 64%, 18%, 16%. As noted above, the converter gas stream also contains an acidic gas, such as traces of sulfide gas.

The converter gas stream enters the carbon dioxide gas and the acidic gas remover 330. The carbon dioxide gas and acid gas remover 330 mainly removes carbon dioxide gas, acid gas, and the like from the converter gas stream. The molar ratio of carbon monoxide gas and nitrogen at the second position 32 is 4: 1.

The converter gas stream then enters a carbon monoxide separator 310. In the carbon monoxide separator 310, carbon monoxide gas is selectively separated from the converter gas stream and nitrogen is removed. Thus, a carbon monoxide gas stream is produced from the carbon monoxide separator 310. The component of the stream at the third position 33 is almost 100% carbon monoxide gas.

A portion of the carbon monoxide gas stream enters the water gas shift reactor 320. In the water gas shift reactor 320, the carbon monoxide gas stream is converted into a hydrogen gas / carbon dioxide gas stream in the presence of steam. At the fourth position 34, the molar ratio of hydrogen gas and carbon dioxide gas is 50% each.

The hydrogen gas / carbon dioxide gas stream enters the methanation reactor 340. In addition, a bypass stream (the fifth position 35) of the water gas shift reactor 320 in the carbon monoxide gas stream is also introduced into the methanation reactor 340. The relative ratio between the carbon monoxide gas and the hydrogen gas flowing into the methanation reactor 340 is almost 1: 3. In the methanation reactor 340, a methanation reaction occurs to generate methane gas. Accordingly, in the methanation reactor 340, a methane gas / carbon dioxide gas stream in which the newly generated methane gas and the carbon dioxide gas generated in the water gas shift reactor is mixed is discharged (sixth position 36). The methane gas stream / carbon dioxide gas stream contains water vapor in addition to methane gas and carbon dioxide gas.

The methane gas / carbon dioxide gas stream enters a carbon dioxide remover 335. Carbon dioxide gas is removed from the carbon dioxide remover 335 to produce a methane gas stream (seventh location 37).

The methane gas stream enters condenser 350. The condenser 350 condenses and discharges water vapor in the methane gas stream. Thus, the methane gas stream is converted to a pure methane gas stream as it passes through the condenser 350 (8th position 38).

4 is a block diagram of a facility 400 to which a methane gas production method using the by-product gas of the steelmaking facility 40 according to the fourth embodiment of the present invention is applied. Also in this embodiment, the steelmaking facility 40 is an electric furnace. The component molar ratios of the converter gas stream at the first location 31 are 64%, 18%, 16%. As noted above, the converter gas stream also contains an acidic gas, such as traces of sulfide gas.

The converter gas stream enters the carbon dioxide gas and the acidic gas remover 430. The carbon dioxide gas and acid gas remover 430 mainly removes carbon dioxide gas, acid gas, and the like from the converter gas stream. The molar ratio of carbon monoxide gas and nitrogen at the second position 42 is 4: 1.

The converter gas stream then enters a carbon monoxide separator 410. In the carbon monoxide separator 410, carbon monoxide is selectively separated from the converter gas stream and nitrogen is removed. Thus, a carbon monoxide gas stream is produced from the carbon monoxide separator 410. The component of the stream at the third position 43 is almost 100% carbon monoxide gas.

A portion of the carbon monoxide gas stream enters the water gas shift reactor 420. In the water gas shift reactor 420, the carbon monoxide gas stream is converted into a hydrogen gas / carbon dioxide gas stream in the presence of steam. At the fourth position 44, the molar ratios of hydrogen gas and carbon dioxide gas are 50% each.

The hydrogen gas / carbon dioxide gas stream enters the methanation reactor 440. In addition, a bypass stream (a fifth position 45) of the water gas shift reactor 420 in the carbon monoxide gas stream is also introduced into the methanation reactor 440. The relative ratio between carbon monoxide and hydrogen flowing into the methanation reactor 440 is about 1: 3. In the methanation reactor 440, a methanation reaction occurs to generate methane gas. Accordingly, in the methanation reactor 440, a methane gas stream in which the newly generated methane gas and the carbon dioxide gas generated in the water gas shift reactor is mixed is discharged (sixth position 36). The methane gas stream contains water vapor in addition to methane gas and carbon dioxide gas.

The methane gas stream enters condenser 450. The condenser 450 condenses and discharges water vapor in the methane gas stream. Accordingly, the methane gas stream is changed into a stream in which methane gas and carbon dioxide gas are mixed while passing through the condenser 450 (seventh position 47).

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100, 200, 300, 400: methane gas production facility
110, 210, 310, 410: carbon monoxide separator
120, 220, 320, 420: water gas shift reactor
130, 230, 330, 430: carbon dioxide gas and acid gas remover
140, 240, 340, 440: methanation reactor
150, 250, 350, 450: condenser

Claims (11)

Separating the carbon monoxide gas stream in the byproduct gas stream exiting the steelmaking plant in a carbon monoxide separator;
Generating a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas in a Water Gas Shift (WGS) reactor using carbon monoxide gas in the carbon monoxide gas stream; And
Producing a methane gas stream in a methanation reactor using carbon monoxide in the carbon monoxide gas stream and hydrogen gas in the hydrogen gas / carbon dioxide gas stream. The method according to claim 1,
Before separating the carbon monoxide gas stream, removing carbon dioxide gas and acidic gas from the by-product gas stream. The method according to claim 2,
Removing carbon dioxide gas from the hydrogen gas / carbon dioxide gas stream entering the methanation reactor. The method according to claim 2,
Removing the carbon dioxide gas from the methane gas stream. The method according to claim 1,
And removing carbon dioxide gas and acidic gas from the hydrogen gas / carbon dioxide gas stream flowing into the methanation reactor. The method according to claim 1,
And condensing the water vapor in the methane gas stream in a condenser to remove methane gas. The method according to any one of claims 1 to 6,
A portion of the carbon monoxide gas stream enters the water gas shift reactor to produce hydrogen gas, thereby supplying the generated hydrogen gas to the methanation reactor, and the remainder bypasses the water gas shift reactor to the methanation reactor. Methane gas production method for supplying carbon monoxide gas. Separating the carbon monoxide gas stream in the byproduct gas stream exiting the steelmaking plant in a carbon monoxide separator;
Introducing a portion of the carbon monoxide gas stream into a Water Gas Shift (WGS) reactor to produce a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas;
Mixing the hydrogen gas / carbon dioxide gas stream with the stream bypassing the water gas shift reactor in the carbon monoxide gas stream and removing carbon dioxide gas and acid gas from the mixed stream;
Generating a methane gas stream in a methanation reactor using carbon monoxide gas and hydrogen gas in the mixed mixed stream from which the carbon dioxide gas and the acid gas are removed; And
Condensation of the water vapor in the methane gas stream in the condenser to remove the methane gas production method using the by-product gas of the steel making facility. Removing carbon dioxide gas and acid gas from the by-product gas stream discharged from the steelmaking facility;
Separating the carbon monoxide gas stream in a carbon monoxide separator using the by-product gas stream from which the carbon dioxide gas and the acid gas are removed;
Introducing a portion of the carbon monoxide gas stream into a Water Gas Shift (WGS) reactor to produce a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas;
Introducing the hydrogen gas / carbon dioxide gas stream into a carbon dioxide remover to remove carbon dioxide gas to produce a hydrogen gas stream;
Generating a methane gas stream in a methanation reactor using the carbon monoxide gas stream and the hydrogen gas stream bypassing the water gas shift reactor; And
Condensation of the water vapor in the methane gas stream in the condenser to remove the methane gas production method using the by-product gas of the steel making facility. Removing carbon dioxide gas and acid gas from the by-product gas stream discharged from the steelmaking facility;
Separating the carbon monoxide gas stream in a carbon monoxide separator using the by-product gas stream from which the carbon dioxide gas and the acid gas are removed;
Introducing a portion of the carbon monoxide gas stream into a Water Gas Shift (WGS) reactor to produce a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas;
Generating a methane gas / carbon dioxide gas stream in a methanation reactor using the carbon monoxide gas stream and the hydrogen gas / carbon dioxide gas stream bypassing the water gas shift reactor;
Introducing the methane gas / carbon dioxide gas stream into a carbon dioxide remover to remove carbon dioxide gas to produce a methane gas stream; And
Condensation of the water vapor in the methane gas stream in the condenser to remove the methane gas production method using the by-product gas of the steel making facility. Removing carbon dioxide gas and acid gas from the by-product gas stream discharged from the steelmaking facility;
Separating the carbon monoxide gas stream in a carbon monoxide separator using the by-product gas stream from which the carbon dioxide gas and the acid gas are removed;
Introducing a portion of the carbon monoxide gas stream into a Water Gas Shift (WGS) reactor to produce a hydrogen gas / carbon dioxide gas stream comprising hydrogen gas and carbon dioxide gas;
Generating a methane gas stream in a methanation reactor using the carbon monoxide gas stream and the hydrogen gas / carbon dioxide gas stream bypassing the water gas shift reactor; And
Condensation of the water vapor in the methane gas stream in the condenser to remove the methane gas production method using the by-product gas of the steel making facility.

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