KR20180105823A - Method for preparing synthetic natural gas having improved caloric value and application for the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a synthetic natural gas having increased calorific value by manufacturing synthetic natural gas by using synthetic gas obtained from coal, biomass, solid carbon fuel, etc., and separating a part of the synthetic gas to synthesize a hydrocarbon compound such as liquefied petroleum gas or dimethyl ether having high calorific values, and mixing the compounds with the synthetic natural gas. In the present invention, carbon dioxide generated in the course of manufacturing synthetic natural gas is collected and reacted to manufacture carbon monoxide, and the carbon monoxide is mixed with a part of the synthetic gas separated for synthesizing the hydrocarbon compounds, using a raw material favorable for synthesis of a desired hydrocarbon compounds.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for producing a natural gas,

The present invention relates to a method for producing a high caloric synthetic natural gas using a syngas obtained from coal, biomass, solid carbon fuel, etc., and an apparatus used therefor A part of the syngas is separated to synthesize a hydrocarbon compound such as liquefied petroleum gas (LPG), dimethyl ether (DME) or the like having a high calorific value and mixed with the synthetic natural gas to increase the calorific value 0002] The present invention relates to a method for producing a high-caloric synthetic gas (SNG) and an apparatus used therefor.

Among the fossil fuels, coal is rich in reserves and less localized than other resources, and research has recently been actively conducted to convert coal to synthetic natural gas (SNG) in the world.

Among them, Coal Gasification refers to the technology of making coal gas (H ₂ , CO) by gasification with high heat and using it for power generation. When high heat is applied to coal, it changes in the order of solid, liquid, and gas. Syngas made in this way can replace some of the natural gas, which is fuel for power generation.

However, synthesis gas (syngas) can not meet the calorific value of natural gas, so synthetic gas (syngas) is methanation reaction to produce synthetic natural gas (SNG). However, the calorific value of methane is 9,400 kcal / m ³ , which is below the standard calorific value of 10,400 kcal / m ³ of liquefied natural gas (LNG) supplied by KOGAS.

Accordingly, various attempts have been made to produce high quality synthetic natural gas (SNG) having a calorific value of LNG.

Korean Patent Laid-Open Publication No. 10-2014-0087254 (Patent Document 1) discloses a process in which a methanation reaction and a Fischer-Tropsch synthesis reaction proceed at the same time in order to produce a high calorific value synthetic natural gas, a process in which Fe, Co, Zr , Ce and Ga based catalysts and their production methods.

Korean Patent Registration No. 10-1508263 (Patent Document 2) discloses a process for producing a synthetic gas for producing synthetic natural gas by using energy efficiently by combining a fluidized bed reactor and a fixed bed reactor with a fuel such as low carbon or solid fuel, And the pyrolysis gasification system that manufactures it is proposed.

Korean Patent Laid-Open Publication No. 10-2010-0121423 (Patent Document 3) discloses a process for producing methane by using a molar ratio (H ₂ -CO ₂ ) / (CO + CO ₂ ) of synthesis gas required for the methanation process using water gas shift (WGS) ₂ ) was adjusted to be greater than 3.00, and a method for producing synthetic natural gas (SNG) was proposed.

As described above, most conventional methods are to produce synthesis gas from coal and solid fuel, and to convert the synthesis gas into methane to produce high-heat-producing synthetic natural gas. However, the synthesis gas produced from coal gasification has a molar ratio H ₂ / CO in the range of 0.5 to 0.8, which is far below the molar ratio H ₂ / CO of 3.0 for the methanation reaction.

Accordingly, a method of increasing the molar ratio H ₂ / CO of the synthesis gas through a water gas conversion (WGS) reaction as in Patent Document 3 has been developed. However, the water gas conversion reaction produces hydrogen and carbon dioxide Thereby significantly increasing the carbon dioxide emission of the process. According to the new climate regime derived from the recent COP21 agreement, it is necessary to achieve greenhouse gas emission reduction compared to 2030 (BAU, Business As Usual), which is also a suitable method for producing high calorific synthetic natural gas There is a limitation that it is not.

Patent Document 1: Korean Patent Publication No. 10-2014-0087254 Patent Document 2: Korean Patent Publication No. 10-1508263 Patent Document 3: Korean Patent Publication No. 10-2010-0121423

SUMMARY OF THE INVENTION The present invention has been made to overcome the above problems and limitations, and has the following purpose.

It is a first object of the present invention to provide a method for producing a synthetic natural gas having an increased calorific value using a synthesis gas produced through gasification such as coal, biomass and solid carbon fuel.

It is another object of the present invention to provide a method for converting a molar ratio of H ₂ / CO to 3 or more in a synthesis gas through an aqueous gas conversion reaction in order to use a synthesis gas produced through the gasification as a raw material for a methanation process The second purpose.

In the present invention, a part of the gas in which the molar ratio H ₂ / CO of the synthesis gas is converted to 3.0 or more through the above-mentioned water gas conversion reaction is separated, and this is subjected to a reverse reaction of the carbon dioxide A method of producing synthetic natural gas having a calorific value of a liquefied natural gas (LNG) level while remarkably reducing the amount of carbon dioxide emission by making it a raw material suitable for synthesizing a high-calorific hydrocarbon compound by mixing with carbon monoxide The third purpose is to provide.

The object of the present invention is not limited to the above-mentioned object. The objects of the present invention will become more apparent from the following description, which will be realized by means of the appended claims and their combinations.

In order to achieve the above object, the present invention provides a method for producing a synthetic natural gas having an increased calorific value including the following constitution.

The present invention provides a process for producing synthetic natural gas having an increased calorific value, comprising the steps of: gasifying a fuel to produce a synthesis gas; subjecting the synthesis gas to water gas shift; Separating the synthesis gas into a first stream and a second stream, and subjecting the synthesis gas of the first stream to a methanation reaction to produce a synthetic natural gas, before separating the converted synthesis gas into a first stream and a second stream, Separating the carbon dioxide from the carbon dioxide to produce carbon monoxide by a reverse boudouard reaction with the carbon material, mixing the carbon monoxide and the synthesis gas of the second flow to prepare a raw material, To produce a hydrocarbon compound, and mixing the hydrocarbon compound and the synthetic natural gas.

A preferred embodiment of the present invention may be such that, when separating the converted syngas into a first flow and a second flow, the volume ratio of the first flow and the second flow is 9: 1 to 6: 4.

In a preferred embodiment of the present invention, the reaction temperature of the reverse-boiling reaction may be 700 ° C to 2,000 ° C.

In a preferred embodiment of the present invention, the hydrocarbon compound is a liquefied petroleum gas (LPG), and the liquefied petroleum gas is fed to a fischer-tropsch synthesis reaction ).

[Reaction Scheme 4]

(2n + 1) H ₂ + nCO → C _n H _{2n +1} + nH ₂ O

And n may be from 1 to 20. [

In a preferred embodiment of the present invention, the carbon monoxide and the synthesis gas of the second flow are mixed to prepare a raw material having a molar ratio H ₂ / CO of 2.0 or more and less than 3.0, and reacting the raw material to produce a liquefied petroleum gas have.

In a preferred embodiment of the present invention, the hydrocarbon compound is dimethyl ether (DME), and the dimethyl ether can be prepared by reacting the starting material as shown in the following reaction formula (5).

[Reaction Scheme 5]

3H ₂ + 3CO -> CH ₃ OCH ₃ + CO ₂

In a preferred embodiment of the present invention, the carbon monoxide and the synthesis gas of the second flow are mixed to prepare a raw material having a molar ratio H ₂ / CO of 1.0 or more and less than 2.0, and reacting the raw material to produce dimethyl ether .

The present invention provides an apparatus for producing a synthetic natural gas having an increased calorific value, comprising a gasification unit for producing a synthesis gas by gasifying a fuel, a water gas conversion unit for supplying water to the synthesis gas, And a methanation unit for producing synthetic natural gas by methanation reaction of the syngas in the first stream, wherein the methanation unit is located between the separation unit and the water gas shift unit, A carbon dioxide separation unit for separating carbon dioxide from the gas, a reverse reaction unit for supplying carbon dioxide to the separated carbon dioxide to produce carbon monoxide, a raw material preparation unit for mixing the carbon monoxide and the synthesis gas of the second flow, A reaction unit for supplying a raw material from the unit and reacting to produce a hydrocarbon compound; And the composite may comprise a mixing unit for mixing the natural gas.

In a preferred embodiment of the present invention, the syngas separation unit may separate the syngas converted so that the volume ratio of the first stream and the second stream is 9: 1 to 6: 4.

In a preferred embodiment of the present invention, the inverse reaction unit may be a reaction of carbon dioxide with a carbon material at a reaction temperature of 700 ° C to 2,000 ° C.

In a preferred embodiment of the present invention, the reaction unit may be a reactor for producing liquefied petroleum gas by subjecting the raw material to a Fischer-Tropsch reaction as shown in Reaction Scheme 4.

In a preferred embodiment of the present invention, the feedstock preparation unit may be a mixture of carbon monoxide and a synthesis gas of the second stream such that the molar ratio H ₂ / CO of the feed is at least 2.0 and less than 3.0.

In a preferred embodiment of the present invention, the reaction unit may be a reactor for producing the dimethyl ether by reacting the raw materials as in the reaction formula (5).

In a preferred embodiment of the present invention, the feedstock preparation unit may be a mixture of carbon monoxide and a syngas of the second stream such that the molar ratio H ₂ / CO of the feed is at least 1.0 and less than 2.0.

Since the present invention includes the above-described configuration, the following effects can be obtained.

According to the present invention, synthetic natural gas having a calorific value of 10,400 kcal / m < 3 > or more can be produced from coal, biomass, and solid carbon fuel (waste, waste plastics, etc.) per unit volume, thereby making it economical and environmentally friendly.

Further, according to the present invention, it is possible to produce synthetic natural gas at a high heating rate without mixing liquefied petroleum gas (LPG) supplied from the outside with synthetic natural gas produced by the methanation reaction of the synthesis gas, It is possible to produce synthetic natural gas which is economically and reliably increased in calorific value without receiving it.

In addition, since the present invention uses carbon dioxide generated in the water gas conversion reaction of syngas as a fuel for producing high-calorific hydrocarbon compounds, it is possible to significantly reduce carbon dioxide emissions in the entire process, It can be very helpful to achieve.

The effects of the present invention are not limited to the effects mentioned above. It should be understood that the effects of the present invention include all reasonably possible effects in the following description.

FIG. 1 schematically shows a process for producing a conventional high-heat-amount synthetic natural gas.
FIG. 2 illustrates an exemplary method for producing synthetic natural gas having an increased calorific value according to the present invention.
Fig. 3 exemplarily illustrates an embodiment of a method for producing synthetic natural gas with an increased calorific value according to the present invention. The details of the embodiment are briefly shown in the embodiment when the hydrocarbonation reaction of FIG. 2 is an LPG synthesis reaction.
Fig. 4 exemplarily shows another embodiment of a method for producing a synthetic natural gas having an increased calorific value according to the present invention. 2 is a schematic view showing an embodiment of the DME synthesis reaction.

Hereinafter, the present invention will be described in detail by way of examples. The embodiments of the present invention can be modified into various forms as long as the gist of the invention is not changed. However, the scope of the present invention is not limited to the following embodiments.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention. As used herein, " comprising " means that other elements may be included unless otherwise specified.

The present invention relates to a method for producing a high caloric SNG with increased calorific value using syngas obtained from coal, biomass and solid carbon fuel. More specifically, a part of the syngas is separated to synthesize a hydrocarbon compound such as liquefied petroleum gas or dimethyl ether having a high calorific value and mix it with a synthetic natural gas (SNG) to produce a synthetic natural gas having a calorific value of a liquefied natural gas (LNG) (SNG), more specifically, carbon monoxide generated by a reverse boudouard reaction of a part of the synthesis gas and carbon dioxide generated in a water gas shift reaction of the synthesis gas; The present invention relates to a method for producing a synthetic high-caloric natural gas (SNG) having an increased calorific value while significantly reducing the emission amount of carbon dioxide by synthesizing the hydrocarbon compound as a raw material.

Before describing the technical features of the present invention in more detail, an embodiment of the prior art will be briefly described with reference to Fig.

A conventional method for producing synthetic natural gas with increased calorific value includes a step (S91) of producing a synthesis gas by gasifying a fuel such as coal, a step (S92) of converting the synthesis gas into an aqueous gas (S92) (S94), separating water and carbon dioxide from the synthetic natural gas (S95, S95 '), separating and discharging the synthesized natural gas, . Thereafter, a compound such as commercial liquefied petroleum gas (LPG) is supplied from the outside and mixed with the synthetic natural gas (S96), thereby producing high-caloric synthetic natural gas.

The conventional method has an advantage that it is possible to convert synthetic gas produced by gasification of coal or the like into natural gas and supply it as fuel. However, since the carbon dioxide generated in the process is discharged as it is and is not environmentally friendly, (LPG) from the outside is mixed with the synthetic natural gas (SNG) to produce synthetic natural gas having an increased calorific value, which is economically undesirable.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the conventional technology, and it is an object of the present invention to provide a method and apparatus for reducing the emission of carbon dioxide during a process without mixing with commercial liquefied petroleum gas We propose a method for the production of synthetic natural gas (high caloric SNG).

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIG. 2 through FIG. However, the embodiments of the present invention may be modified in other ways depending on the application, and the scope of the present invention is not limited to the embodiments described below.

FIG. 2 illustrates an exemplary method for producing synthetic natural gas having an increased calorific value according to the present invention.

The method for producing synthetic natural gas having increased calorific value according to the present invention includes the steps of producing a synthesis gas by gasifying fuel (S10), water gas shift the synthesis gas (S20) (S30), the synthetic gas of the first flow is subjected to a methanation reaction to produce a synthetic natural gas (S40), and the converted synthesis gas is separated into the first stream and the second stream Separating carbon dioxide from the converted syngas before separation into two streams (S30), performing a reverse boudouard reaction with the separated carbon dioxide to produce carbon monoxide (S60) Mixing the carbon monoxide and the synthesis gas of the second flow to prepare a raw material (S70), reacting the raw material to produce a hydrocarbon compound (S80), and mixing the hydrocarbon compound and the synthetic natural gas S90) .

Referring to FIG. 2, the method for producing synthetic natural gas with increased calorific value according to the present invention starts with coal gasification of fuel to produce syngas (S10).

The fuel may be coal, solid carbon, or the like, and coal or solid carbon obtained from biomass, waste, or the like may be used from the viewpoint of economy.

The method of coal gasification is not particularly limited, but a method of converting residual carbon into carbon monoxide (CO) and hydrogen (H ₂ ) by making thermal decomposition of coal such as coal or solid carbon into residual carbon (residual carbon) Lt; / RTI > The molar ratio H ₂ / CO of the synthesis gas (syngas) produced by the coal gasification is about 0.6-0.95.

The present invention may further include a step (not shown) of purifying the syngas. The purification of the synthesis gas may be a process such as dust collection, acid gas removal, sulfide separator, and the like.

Some carbon monoxide (CO) is the water in the purified synthesis gas according to the present invention is water gas shift reaction the synthesis gas as shown in Scheme 1 below go through a (water gas shift reaction, WGSR) (S20), through which (H ₂ O) and converted to hydrogen (H ₂ ) and carbon dioxide (CO ₂ ).

[Reaction Scheme 1]

CO + H ₂ O? CO ₂ + H ₂

The molar ratio H ₂ / CO of the syngas can be increased to about 3.0 by consuming some carbon monoxide (CO) of the synthesis gas through the water gas conversion reaction.

The present invention separates carbon dioxide (CO ₂ ) produced by the water gas shift reaction (WGSR) from the synthesis gas (S 50), synthesizes the hydrocarbon compound (S 80) without discharging the separated carbon dioxide (CO ₂ ) To significantly reduce the carbon dioxide emissions of the entire process. Details of this will be described later.

The method for separating the carbon dioxide is not particularly limited, but it can be separated by using a temperature sweep adsorption (TSA) method, a pressure swing adsorption (PSA) method, or a membrane .

The present invention separates carbon dioxide separated synthesis gas into a first stream (A) and a second stream (B) (S30), and the synthesis gas of the first stream (A) (S40), and the synthesis gas of the second flow (B) is used as a raw material for synthesizing the hydrocarbon compound (S70).

When the synthesis gas is separated into the first stream (A) and the second stream (B), the synthesis gas of the first flow and the synthesis gas of the second flow are separated to have a volume ratio of 9: 1 to 6: 4 May be preferred. If the volume ratio is more than 9: 1, the amount of the hydrocarbon compound synthesized by using the synthesis gas of the second flow is too small to increase the calorific value of the natural gas. On the other hand, if the synthesis gas of the first flow is too small and the volume ratio is less than 5: 4, the quantity of the synthetic natural gas (SNG) obtained by the methanation reaction of the synthesis gas of the first flow is insufficient, Lt; / RTI >

In the present invention, a synthesis natural gas (SNG) is produced by methanation reaction of the synthesis gas of the first flow (A) (S40). The synthesis gas of the first stream (A) is passed through an aqueous gas conversion reaction (WGSR), and has a molar ratio H ₂ / CO of about 3.0, which is suitable for carrying out the methanation reaction as shown in the following reaction formula (2).

[Reaction Scheme 2]

3H ₂ + CO - > CH ₄ + H ₂ O

The synthetic natural gas (SNG) refers to a gas having a composition similar to that of natural gas whose main component is methane. As described above, the present invention provides syngas from fuels such as coal, biomass, and solid carbon. And the synthesis gas is subjected to a methanation reaction as shown in Reaction Scheme 2 to obtain a methane-based product. In the present invention, the product is referred to as a synthetic natural gas (SNG).

Since the calorific value of the synthetic natural gas (SNG) is less than the standard calorific value of 10,400 kcal / m ³ of the liquefied natural gas (LNG) supplied by KOGAS, the present invention can be applied to carbon dioxide, Synthesizing a hydrocarbon compound having a high calorific value using the syngas of the second flow (B), mixing the hydrocarbon compound with the synthetic natural gas (SNG) to produce a synthetic natural gas having an LNG- high caloric SNG). This will be described in detail below.

The present invention separates carbon dioxide produced by the water gas conversion reaction from the synthesis gas as described above (S50). The technical feature of the present invention is that the carbon dioxide is used as a raw material for synthesizing a hydrocarbon compound without being discharged as it is.

In the present invention, a carbon material is supplied to the separated carbon dioxide, and carbon monoxide is produced by a reverse boudouard reaction as shown in the following reaction formula (3) (S60).

[Reaction Scheme 3]

C + CO _{2 -} > 2CO

The reaction temperature of the reaction of Reaction Scheme 3 may preferably be 700 ° C or higher, specifically 700 ° C to 2,000 ° C. When the reaction temperature is higher than 700 ° C, reverse reaction can proceed predominantly as compared to boudouard reaction (2CO → C + CO ₂ ).

In the present invention, a raw material (C) is prepared by mixing the carbon monoxide (CO) and the syngas of the second flow (B) (S70), and the raw material (C) is reacted to produce a high heating amount of hydrocarbon compound S80). Hereinafter, embodiments of the present invention for producing the hydrocarbon compound will be described in detail with reference to FIGS. 3 and 4. FIG.

3, the hydrocarbon compound may be a liquefied petroleum gas (LPG), and the liquefied petroleum gas (LPG) may be obtained by reacting the raw material (C) with the following reaction formula 4 (S81) by a fischer-tropsch synthesis reaction.

[Reaction Scheme 4]

(2n + 1) H ₂ + nCO → C _n H _{2n +1} + nH ₂ O

N may be from 1 to 20, more specifically from 2 to 5, still more preferably from 3 to 4.

In the present invention, the liquefied petroleum gas (LPG) may mean a hydrocarbon compound containing propane or butane as a main component having a high calorific value.

According to an embodiment of the present invention, the carbon monoxide (CO) is mixed with the syngas in the second flow (B) so that the raw material (C) has a molar ratio H ₂ / CO suitable for the Fischer- You can prepare.

Since the synthesis gas of the second flow (B) has a molar ratio H ₂ / CO of about 3.0, the hydrogen (H ₂ ) is somewhat larger than that of carbon monoxide (CO) in the Fischer-Tropsch reaction. Therefore, an embodiment of the present invention is a process for producing a carbon monoxide solution by mixing carbon monoxide (CO) produced by reacting carbon monoxide with the synthesis gas of the second flow (B) in such a manner that the molar ratio H ₂ / CO of the raw material (C) , More specifically 2.0 or more and less than 2.5, more specifically 2.0, and then the Fischer-Tropsch reaction is carried out.

According to another embodiment of the present invention shown in FIG. 4, the hydrocarbon compound may be dimethyl ether (DME), and the dimethyl ether (DME) may be prepared through the following reaction: (S82).

[Reaction Scheme 5]

3H ₂ + 3CO -> CH ₃ OCH ₃ + CO ₂

According to another embodiment of the present invention, the carbon monoxide (CO) is mixed with the syngas of the second flow (B), and the raw material (C) has a molar ratio H ₂ / CO suitable for the reaction You can prepare for this.

In another embodiment of the present invention for the same reason as the above-mentioned one embodiment, carbon monoxide (CO) produced by reacting the synthesis gas of the second flow (B) with carbon dioxide in reverse reaction is mixed to obtain a molar ratio H ₂ / CO is adjusted to 1.0 or more and less than 2.0, specifically 1.0 or more and less than 1.5, more specifically 1.0, and the reaction of Reaction Scheme 5 is proceeded.

The present invention relates to a process for separating and collecting carbon dioxide generated during a process of producing a high caloric SNG and converting the carbon dioxide into carbon monoxide through a reverse feed reaction and mixing the carbon monoxide with the syngas of the second flow A hydrocarbon compound capable of increasing the heating value of synthetic natural gas (SNG) is synthesized from the raw material. Therefore, as in the prior art, it is possible to produce a synthetic natural gas having an increased calorific value without supplying liquefied petroleum gas or the like from the outside, and the emission amount of carbon dioxide can be remarkably reduced.

(SNG) prepared by the methanation reaction of the syngas of the first flow and a hydrocarbon compound such as liquefied petroleum gas (LPG) or dimethyl ether (DME) to obtain a heat quantity of 9,500 kcal / m < 3 > or more, preferably 10,400 kcal / m < 3 > or more (S90).

The present invention can further carry out a step (S91) of separating water from the high-heat-produced synthetic natural gas (S91) and a step (S92) of separating the remaining minute amount of carbon dioxide. As a result, high-quality synthetic natural gas (SNG) having a calorific value of the liquefied natural gas (LNG) level can be finally obtained.

The present invention further provides a manufacturing apparatus that can be used in the above-described method for producing synthetic natural gas with an increased heating value.

The apparatus for producing synthetic natural gas according to the present invention comprises a gasification unit for gasifying a fuel to produce a synthesis gas, a water gas conversion unit for supplying water to the synthesis gas and reacting the synthesis gas, And a methanation unit for producing synthetic natural gas by methanation reaction of the synthesis gas of the first flow, wherein the methanation unit is located between the separation unit and the water gas conversion unit, A carbon dioxide separation unit for separating carbon dioxide from the synthesized gas, a reverse reaction unit for supplying carbon dioxide to the separated carbon dioxide to produce carbon monoxide, a raw material preparation unit for mixing the carbon monoxide and the synthesis gas of the second flow, A reaction unit for supplying a raw material from a raw material preparation unit and reacting to produce a hydrocarbon compound, It may include a mixing unit to mix the compound with the synthesis gas.

Specifically, the reaction unit is a reactor for producing liquefied petroleum gas (LPG) by a Fischer-Tropsch reaction of the raw material as in the above-mentioned Reaction Scheme 4, or reacting the raw material as shown in Reaction Scheme 5 to produce dimethyl ether (DME) Lt; / RTI >

The reaction occurring in each of the units and the reactors is the same as described in the above-mentioned method of producing a high caloric SNG in which the amount of generated heat is increased, so that a typical engineer can clearly understand the manufacturing apparatus , And will be omitted in order to avoid redundancy in the following description.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, these examples are for illustrating the present invention and the scope of the present invention is not limited thereto.

(Kcal / m < 3 >) per unit volume of the synthetic natural gas when the synthetic natural gas having an increased calorific value according to an embodiment of the present invention shown in Fig. 3 and another embodiment of the present invention shown in Fig. The process was simulated using PRO II, a process simulation program, to find out the amount of production per unit hour (kmol / hr) and the emission per unit hour (kmol / hr) of carbon dioxide emitted during the process.

Example 1  To Example 8

The process for producing the synthetic natural gas with the increased calorific value shown in Fig. 3 was simulated.

When separating the synthesis gas from the carbon dioxide into the first flow and the second flow, the volume ratio of the first flow and the second flow is 9: 1 (Examples 1 and 5), 8: 2 (Examples 2 and 6 ), 7: 3 (Examples 3 and 7), and 6: 5 (Examples 4 and 8).

As shown in FIG. 3, the synthesis gas of the second flow (B) and the carbon monoxide (CO) produced through the reverse feed reaction are mixed so that the molar ratio H ₂ / CO of the raw material (C) becomes 2.0, Liquefied petroleum gas (LPG) was produced by Fischer-Tropsch reaction of raw materials.

The conversion and the selectivity of the Fischer-Tropsch reaction are shown in Table 1 below. The reaction is shown in Qianwen Zhang, Direct synthesis of LPG fuel from syngas with modified catalyst based on modified Pd / SiO ₂ and zeolite, Catalysis (Catalyst A: Examples 1 to 4, Catalysts for B: Examples 5 to 8) disclosed in "Catalysts", "Catalysts, Catalysts and Catalysts", Today , 104, 30-36 (2005).

division A catalyst (Examples 1 to 4) B catalyst (Examples 5 to 8) Conversion rate of carbon monoxide [%] 43.5 74.1
Yield of product
hydrocarbon 23.7 40.7 Dimethyl ether 0.0 0.1 carbon dioxide 19.8 33.3

Composition of hydrocarbons
[C mol%]
C1 5.2 7.2 C2 6.5 4.3 C3 41.2 14.2 C4 35.8 8.2 C5 8.8 1.4 C6 + 2.5 0.3

Example 9  To Example 12

The process for producing the synthetic natural gas with the increased calorific value shown in FIG. 4 was simulated.

(Example 9), 8: 2 (Example 10), and 7: 2 (Example 10), respectively, when the synthesis gas from which the carbon dioxide was separated into the first flow and the second flow was 9: 3 (Example 11), and 6: 5 (Example 12).

As shown in FIG. 4, the synthesis gas of the second flow (B) and the carbon monoxide (CO) produced through the reverse feed reaction were mixed so that the molar ratio H ₂ / CO of the raw material C became 1.0, Dimethyl ether (DME) was prepared through synthesis reaction.

The conversion and selectivity of the DME synthesis reaction are shown in Table 2 below, and the reaction was performed by Andres Garcia-Trenco, Direct synthesis of DME from syngas on hybrid CuZnAl / ZSM-5 catalysts: New insights into the role of zeolite acidity, Applied catalysis A: General , 411-412, 170-179 (2012).

division C catalyst (Examples 9 to 12) Conversion rate of carbon monoxide [%] 93.0
Yield of product

hydrocarbon 0.5 Dimethyl ether 65.0 carbon dioxide 31.0 Methanol 3.5

Experiment result

(Kcal / m < 3 >), the amount of production per unit time (kmol / hr) and the amount of carbon dioxide discharged per unit time (kmol / hr) of the synthetic natural gas as the final product of the simulation process according to Examples 1 to 12 ) Were measured. The results are shown in Table 3 below.

division Volume ratio
[A: B] catalyst Synthetic natural gas
Per unit volume
calorie
[kcal / m 3] Synthetic natural gas
Per hour
output
[kcal / hr] carbon dioxide
Per hour
Emissions
[kmol / hr] Example 1 9: 1 A catalyst 9,548.7 6,188.4 11,536.1 Example 2 8: 2 A catalyst 10,081.5 6,277.6 11,501.2 Example 3 7: 3 A catalyst 10,379.8 6,367.1 11.466.3 Example 4 6: 4 A catalyst 11,447.0 6,456.7 11,431.4 Example 5 9: 1 B catalyst 9,806.9 6,090.0 11,653.8 Example 6 8: 2 B catalyst 10,595.3 6,040.4 11,736.6 Example 7 7: 3 B catalyst 11,464.7 6,011.3 11,819.5 Example 8 6: 4 B catalyst 12,428.5 5,982.3 11,902.3 Example 9 9: 1 C catalyst 9,918.9 6,274.9 11,282.1 Example 10 8: 2 C catalyst 10,685.6 6,450.4 10,993.5 Example 11 7: 3 C catalyst 11,411.5 6,626.4 10,704.7 Example 12 6: 4 C catalyst 12,099.8 6,802.5 10,416.1

Referring to Table 3, in Examples 1 to 12, the heat quantity per unit volume of the synthetic natural gas was 9,500 kcal / m 3 or more, and in all the examples except for Examples 1, 2, 5, Lt; 4 > kcal / m < 3 >

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. Various modifications and improvements of those skilled in the art are also within the scope of the present invention.

Claims (14)

A process for producing a syngas by gasifying at least one of coal, biomass and solid carbon, separating the syngas converted into a first stream and a second stream after water gas shifts the synthesis gas And the synthesis gas of the first flow is subjected to a methanation reaction to produce a synthetic natural gas,
Separating carbon dioxide from the converted syngas before separating the converted syngas into a first stream and a second stream;
A step of producing carbon monoxide by reverse boudouard reaction with the separated carbon dioxide;
Mixing the carbon monoxide and the synthesis gas of the second flow to prepare a raw material;
Reacting the raw material to produce a hydrocarbon compound; And
And mixing the hydrocarbon compound with the synthetic natural gas.
The method according to claim 1,
When separating the converted syngas into a first flow and a second flow,
Wherein a volume ratio of the first flow and the second flow is 9: 1 to 6: 4.
The method according to claim 1,
Wherein the reaction temperature of the reverse-boiling reaction is 700 ° C to 2,000 ° C.
The method according to claim 1,
The hydrocarbon compound is liquefied petroleum gas (LPG)
Wherein the liquefied petroleum gas is produced by a fischer-tropsch synthesis reaction of the raw material as shown in the following reaction formula (4).
[Reaction Scheme 4]
(2n + 1) H ₂ + nCO → C _n H _{2n +1} + nH ₂ O
And n is 1 to 20.
5. The method of claim 4,
The carbon monoxide and the synthesis gas of the second flow are mixed to prepare a raw material having a molar ratio H ₂ / CO of 2.0 or more and less than 3.0,
And reacting the raw material to produce a liquefied petroleum gas.
The method according to claim 1,
The hydrocarbon compound is dimethyl ether (DME)
Wherein the dimethyl ether is produced by reacting the raw material as shown in the following reaction formula (5).
[Reaction Scheme 5]
3H ₂ + 3CO -> CH ₃ OCH ₃ + CO ₂
The method according to claim 6,
The carbon monoxide and the synthesis gas of the second flow are mixed to prepare a raw material having a molar ratio H ₂ / CO of 1.0 or more and less than 2.0,
And then reacting the raw materials to produce dimethyl ether.
A gasification unit for gasifying at least one of coal, biomass, and solid carbon to produce a synthesis gas, a water gas conversion unit for supplying water to the synthesis gas and reacting the synthesis gas, And a methanation unit for producing synthetic natural gas by methanation reaction of the synthesis gas of the first flow,
A carbon dioxide separation unit located between the separation unit and the water gas conversion unit for separating carbon dioxide from the syngas converted;
A reverse reaction unit for supplying carbon material to the separated carbon dioxide to produce carbon monoxide;
A raw material preparation unit for mixing the carbon monoxide and the synthesis gas of the second flow;
A reaction unit for supplying a raw material from the raw material preparation unit and reacting to produce a hydrocarbon compound; And
And a mixing unit for mixing the hydrocarbon compound with the synthetic natural gas.
9. The method of claim 8,
Wherein the syngas separation unit separates the syngas converted so that the volume ratio of the first stream and the second stream is 9: 1 to 6: 4.
9. The method of claim 8,
Wherein the reverse reaction unit reacts carbon dioxide with a carbon material at a reaction temperature of 700 ° C to 2,000 ° C.
9. The method of claim 8,
Wherein the reaction unit is a reactor for producing liquefied petroleum gas by subjecting the raw material to a Fischer-Tropsch reaction as shown in the following reaction formula (4).
[Reaction Scheme 4]
(2n + 1) H ₂ + nCO → C _n H _{2n +1} + nH ₂ O
And n is 1 to 20.
12. The method of claim 11,
Wherein the raw material preparation unit mixes the carbon monoxide and the synthesis gas of the second flow such that the molar ratio H ₂ / CO of the raw material is 2.0 or more and less than 3.0.
9. The method of claim 8,
Wherein the reaction unit is a reactor for producing dimethyl ether by reacting the raw materials as shown in the following reaction formula (5).
[Reaction Scheme 5]
3H ₂ + 3CO -> CH ₃ OCH ₃ + CO ₂
14. The method of claim 13,
Wherein the raw material preparing unit mixes the carbon monoxide and the synthesis gas of the second flow such that the molar ratio H ₂ / CO of the raw material is 1.0 or more and less than 2.0.

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