KR102267746B1 - Catalyst for methanation, method for preparing the same and method for preparing synthetic natural gas using the same - Google Patents

Abstract

The present invention relates to 100 parts by weight of the total catalyst, 10 to 70 parts by weight of Ni, 0.5 to 7 parts by weight of one type of cocatalyst selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca, and a metal It relates to a methanation catalyst having excellent hydrothermal reforming reaction including a support residue. According to the present invention, using syngas containing C5 or more hydrocarbons larger than LPG (C2, C3 and C4 hydrocarbons) reduces carbon precipitation generated in the methanation reaction during synthetic natural gas production, and suppresses the _{CO 2 generation reaction.} A methanation catalyst capable of being used is provided. In addition, by using the methanation reaction catalyst to produce the synthetic natural gas, there is an effect that can increase the yield of the synthetic natural gas.

Description

Methanation catalyst, manufacturing method thereof, and manufacturing method of synthetic natural gas using the same

The present invention is obtained through gasification of coal or biomass, or using synthesis gas (CO and H ₂ mixed gas) generated from by-gas such as petrochemical industry to produce high-calorie synthetic natural gas (Synthetic natural gas). It relates to a methanation catalyst having excellent hydrothermal reforming reaction used, a method for preparing the same, and a method for producing high-calorie synthetic natural gas using the catalyst.

With the recent rise in oil prices, the price of natural gas also rises, and interest in converting cheap coal into a clean fuel is increasing. According to the development of coal gasification technology, the production of synthetic natural gas (SNG), which can economically utilize synthetic gas, is being actively commercialized in the United States, China, and the like.

In the case of synthetic natural gas synthesized from coal, methane is the main component and the calorific value is about 9300 ~ 9500 kcal/Nm ³ , which is lower than the calorific value of general natural gas. In particular, in the case of LNG used as domestic city gas, the standard calorific value is 10,200 kcal/Nm ³ , which is higher than that of synthetic natural gas. Therefore, in order to use synthetic natural gas as city gas, a fuel gas with a high calorific value such as LPG must be mixed and used. However, since the price of LPG is generally linked to the international oil price, the price is higher than that of natural gas or coal, so the cost competitiveness of synthetic natural gas manufactured from coal is lowered.

On the other hand, a catalyst for producing synthetic natural gas by gasifying carbon-containing materials such as coal and biomass _{to produce synthesis gas, which is a mixture of hydrogen (H 2} ) and carbon monoxide (CO), and methanating the synthesis gas in the presence of a catalyst Ni-based catalysts are generally used in methanation reaction techniques.

However, when the synthesis gas supplied to the methanation reactor contains a large amount of hydrocarbons of C5 or more, carbon precipitation or CO ₂ production reaction occurs predominantly, thereby limiting the production of synthetic natural gas.

The present invention has been devised to solve the above problems, and in the methanation reaction, methanation with excellent hydrothermal reforming reaction capable of producing more synthetic natural gas _{by reducing carbon deposition and suppressing the CO 2 production reaction} An object of the present invention is to provide a reaction catalyst and a preparation method thereof.

Another object of the present invention is to provide a method for generating synthetic natural gas using the methanation catalyst.

According to an aspect of the present invention, based on 100 parts by weight of the total catalyst, 10 to 70 parts by weight of Ni, 0.5 to one kind of cocatalyst selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca There is provided a methanation catalyst having excellent hydrothermal reforming reaction comprising 7 parts by weight and the remainder of the metal support.

The promoter may be Ba.

The metal support may be one selected from the group consisting _{of Al 2} O ₃ , TiO ₂ , ZrO ₂ and SiO _{2 .}

The metal support may be Al ₂ O ₃ .

According to another aspect of the present invention, preparing a first solution comprising a Ni precursor and one metal precursor selected from the group consisting of Al, Ti, Zr and Si; Preparing a second solution containing one kind of precursor selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca; mixing the first solution, the second solution and the precipitant and heat-treating to produce a precipitate; There is provided a method for preparing a methanation catalyst having excellent hydrothermal reforming reaction, including the step of calcining the precipitate.

In the first solution, a molar ratio of Ni and one metal selected from the group consisting of Al, Ti, Zr, and Si may be 1:1 to 2.

The one selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca is 1 to 20 mol% compared to the one selected from the group consisting of Ni and Al, Ti, Zr and Si. may be included.

The step of mixing the first solution, the second solution, and the precipitant may have a pH of 7 or more, and may be performed at a temperature of about 40 to 70°C.

The heat treatment to generate a precipitate may be performed at a temperature of 80 to 120° C. for 1 to 3 hours.

The calcining of the precipitate may be performed at a temperature of 600 to 800° C., in an oxygen atmosphere for 1 to 3 hours, and in a hydrogen atmosphere for 30 minutes to 2 hours.

According to another aspect of the present invention, carbon monoxide, and the step of supplying the synthesis gas containing hydrogen to the hydrocarbon synthesis reactor and the first methanation reactor separately;

supplying C5 or more hydrocarbon compounds discharged from the hydrocarbon synthesis reactor to a first methanation reactor, and generating methane in the presence of the methanation catalyst; and supplying the gas discharged from the first methanation reactor and the C1-C4 hydrocarbon compound discharged from the hydrocarbon synthesis reactor to the second methanation reactor to generate methane.

According to the present invention, using syngas containing C5 or more hydrocarbons larger than LPG (C2, C3 and C4 hydrocarbons) reduces carbon precipitation generated in the methanation reaction during synthetic natural gas production, and suppresses the _{CO 2 generation reaction.} A methanation catalyst with excellent hydrothermal reforming reaction is provided.

In addition, by using the methanation reaction catalyst to produce the synthetic natural gas, there is an effect that can increase the yield of the synthetic natural gas.

1 is a flowchart schematically illustrating a synthetic natural gas manufacturing method according to an embodiment of the present invention.
Figure 2 schematically shows the process performed in the first methanation reactor according to an embodiment of the present invention.
3 schematically shows a method for preparing a methanation catalyst according to an embodiment of the present invention.
4 is a photograph of the surface shape observed using a scanning electron microscope (SEM) after the reaction of the catalyst according to Example 1 and Comparative Example 3 is finished.
5 is a result of evaluating the degree of carbon precipitation by performing thermogravimetric analysis (TGA) in an oxygen atmosphere after the reaction of the catalysts according to Example 1 and Comparative Example 3 is finished.
6 is a result of evaluating the CO conversion rate of the catalysts of Examples 5 to 7 and Comparative Example 4.
7 is a result of evaluating _{the CH 4} selectivity of the catalysts of Examples 5 to 7 and Comparative Example 4.

Hereinafter, preferred embodiments of the present invention will be described with reference to various examples. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

The present invention relates to a methanation catalyst having excellent hydrothermal reforming reaction, a method for preparing the same, and a method for producing methane using the same.

According to an aspect of the present invention, the step of supplying a synthesis gas containing carbon monoxide and hydrogen to a hydrocarbon synthesis reactor and a first methanation reactor separately; supplying C5 or more hydrocarbon compounds discharged from the hydrocarbon synthesis reactor to a first methanation reactor, and generating methane in the presence of the methanation catalyst according to the present invention; and supplying the gas discharged from the first methanation reactor and the C1-C4 hydrocarbon compound discharged from the hydrocarbon synthesis reactor to the second methanation reactor to generate methane.

The synthesis gas containing carbon monoxide and hydrogen may be prepared by reacting coal or biomass with oxygen, hydrogen, or a mixed gas thereof. In this case, the volume ratio of hydrogen and carbon monoxide in the synthesis gas is preferably 2.0 to 3.5, and more preferably 2.6 to 3.0.

If the volume ratio is less than 2, in the case of methanation reaction, whisker carbon is doped on the Ni surface, which is an active metal, due to lack of stoichiometric hydrogen, and inactivation occurs. hydrocarbons are formed. On the other hand, when it exceeds 3.5, unreacted hydrogen remains in the final product after the methanation reaction and the Fischer-Tropsch reaction, which causes hydrogen embrittlement, causing damage to the gas pipe network.

The synthesis gas may be separated and supplied to the hydrocarbon synthesis reactor and the first methanation reactor through the separator. In this case, the hydrocarbon synthesis reactor may be, for example, an isothermal reactor, and the amount of synthesis gas supplied to the hydrocarbon synthesis reactor may be 10 to 70% by volume of the total synthesis gas. If it is less than 10, the amount of LPG synthesis of C2~C4 hydrocarbon compounds is small, so the calorific value of the final gas after mixing with synthetic natural gas (SNG) may be lower than ^{10,200kcal/Nm 3} It may not be economical because the amount of synthesis is high, and the absolute amount of generated gas is unnecessarily high.

In the hydrocarbon synthesis reactor, a hydrocarbon compound-containing gas is prepared by a Fischer-Tropsch reaction (LPG synthesis reaction). This is an exothermic reaction, and it is advantageous to maintain a low temperature because it induces a coking phenomenon by causing a decomposition reaction when exposed to high temperature, and is preferably performed at 200 to 400°C.

The hydrocarbon synthesis reaction step may be performed in the presence of a hydrocarbon compound synthesis catalyst, and the hydrocarbon compound synthesis catalyst may use a Co-based catalyst, a Mn-based catalyst, or the like, and it is also possible to use two types of catalysts. In the case of using a Co-based or Mn-based catalyst, the reaction proceeds at a relatively low temperature, which is advantageous for the production of paraffin-based hydrocarbons such as liquids or waxes.

The hydrocarbon compound-containing gas discharged from the hydrocarbon synthesis reactor passes through a heat exchanger and a condenser installed at the lower end of the hydrocarbon synthesis reactor, heat is recovered, and moisture is condensed and removed. At this time, among the hydrocarbon compounds, C5 or higher hydrocarbon compounds are supplied to the first methanation reactor, and C1-C4 hydrocarbon compounds are supplied to the second methanation reactor as described below to perform methanation.

A portion of the C5 or higher hydrocarbon compound discharged from the hydrocarbon synthesis reactor and the synthesis gas supplied from the separator is supplied to the first methanation reactor to perform methanation. A gas containing methane may be synthesized through the above reaction. The methanation reaction is an extremely exothermic reaction, and heat can be recovered by passing through a heat exchanger provided at the lower end of the first methanation reactor to generate high-temperature and high-pressure steam.

FIG. 2 schematically shows a reaction occurring in the first methanation reactor. Referring to FIG. 5, hydrocarbons of C5 or higher supplied to the first methanation reactor are used as effective gases CO, H ₂ , CH ₄ and C2. There are cracking reactions and reforming reactions for conversion to ~C4 hydrocarbons. This reaction is an endothermic reaction and ^{requires a heat source of 500 o} C or higher, and in the case of reforming reaction, steam must be additionally supplied. Since the methanation reaction generates severe exotherm, it is an appropriate temperature for cracking or reforming at a high temperature of ^{700 o} C in the region below the upper layer where the reaction takes place, and the reforming reaction can be easily performed using _{H 2 O generated in the methanation reaction.} can induce In the first methanation reactor, the following reaction proceeds.

The methane synthesis step may be performed in a temperature range of 280 to 720 °C. 280 ^o If C is less than a yen low temperature to cause a catalytic reaction, causing an incomplete methanation reaction may be a whisker carbon blossomed in the active metal Ni lead to catalyst deactivation, 720 ^o C deactivated catalyst at a sintering phenomenon of the high-temperature exposure or more can cause

Meanwhile, in the first methanation reactor, the following reaction proceeds.

Methanation: CO + H ₂ →CH ₄ + H ₂ O

Cracking: LPG→CO + CO ₂ + H ₂

Steam reforming: LPG + H ₂ O→CO + CO ₂ + H ₂ + HC

Dry reforming: LPG + CO ₂ →CO + CO ₂ + H ₂ + HC + C

As a catalyst used in this methanation reaction, a Ni-based catalyst is generally used. However, when a large amount of C5 or more hydrocarbons is included in the synthesis gas supplied to the methanation reaction, carbon precipitation occurs on the surface of the catalyst and the catalyst is As the activity is lowered and the dry reforming reaction prevails over the hydrothermal reforming, the CO ₂ generation reaction occurs actively, thereby limiting the production of synthetic natural gas.

According to the present invention, based on 100 parts by weight of the total catalyst, 10 to 70 parts by weight of Ni, 0.5 to 7 parts by weight of one type of cocatalyst selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca and a methanation catalyst having excellent hydrothermal reforming reaction including the remainder of the metal support.

Ni, as a main catalyst, is added to induce methanation and reforming reactions, and is preferably included in an amount of 10 to 70 parts by weight based on 100 parts by weight of the total catalyst. If it is less than 10 parts by weight, the methanation reaction may not occur, and if it is more than 70 parts by weight, it is difficult to secure a specific surface area of the catalyst, and the reactivity may be lowered.

The methanation catalyst of the present invention includes one type of cocatalyst selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca, and it is more preferable to use Ba as the cocatalyst. _{The cocatalyst can suppress dry reforming that occurs in Ni metal by adsorbing or occluding CO 2} generated in the reforming reaction or cracking reaction, and induces the hydrothermal reforming reaction to occur predominantly, furthermore, deactivation of the catalyst according to carbon deposition can be suppressed.

The content of the cocatalyst is preferably included in an amount of 0.5 to 7 parts by weight based on 100 parts by weight of the total catalyst. If it is less than 0.5 parts by weight, _{the amount that can occlude or adsorb the generated CO 2} may be insufficient, and if it exceeds 7 parts by weight, the dispersibility of the co-catalyst is lowered to form large particles, and the reactivity can be lowered as well as the co-catalyst. It may be difficult to control the side reaction because the surface and the inside state are different.

The remainder of the methanation catalyst of the present invention may consist of a metal support, and the metal support may be one selected from the group consisting _{of Al 2} O ₃ , TiO ₂ , ZrO ₂ and SiO _{2 , preferably Al 2} It may be _{O 3 . When Al 2} O ₃ is used as the metal support, Al in the catalyst may be included in an amount of 30 to 90 parts by weight based on 100 parts by weight of the total catalyst.

On the other hand, the gas discharged from the first methanation reactor is supplied to the second methanation reactor after passing through the heat exchanger, and the C1-C4 hydrocarbon compound discharged from the hydrocarbon synthesis reactor is also supplied to the second methanation reactor, and has a high concentration of gas containing methane.

Since the exothermic reaction is not severe in the second methanation reactor due to the low concentration of synthesis gas, the methane synthesis step may be performed in the presence of at least one methane synthesis catalyst selected from Ni and Al, preferably Ni Can be used. As the gas discharged from the second methanation reactor passes through a heat exchanger and a condenser installed at the bottom, heat is recovered, and moisture is condensed and removed. According to this process, it is possible to obtain a high-calorie synthetic natural gas composed of 97% or more of C1 to C5.

Hereinafter, a method for preparing the methanation catalyst of the present invention will be described. According to another aspect of the present invention, preparing a first solution comprising a Ni precursor and one metal precursor selected from the group consisting of Al, Ti, Zr and Si; Preparing a second solution containing one kind of precursor selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca; mixing the first solution, the second solution and the precipitant and heat-treating to produce a precipitate; And there is provided a method for producing a methanation reaction catalyst comprising the step of calcining the precipitate.

First, a first solution including a Ni precursor and one metal precursor selected from the group consisting of Al, Ti, Zr, and Si is prepared. Nickel precursors include, for example, nickel nitrate hydrate (Ni(NO ₃ ) ₂ .4H ₂ O), nickel acetate (Ni(CO ₂ CH ₃ ) ₂ .4H ₂ O), nickel oxalate (NiC ₂ O _{4 )} ), nickel acetate (Ni(CH ₃ COO) ₂ ), and nickel chloride (NiCl ₂ .6H ₂ O) may be used.

One metal precursor selected from the group consisting of Al, Ti, Zr and Si is also not particularly limited, and for example, Nitrate (NO ₃ ⁻ ) containing Al, Ti, Zr and Si, Acetate (CH ₃ COO ^- ), Chloride (Cl ^- ), Sulfate (SO ₄ ^2- ), etc. can be used.

In the first solution, the molar ratio of Ni and one metal selected from the group consisting of Al, Ti, Zr and Si is preferably 1:1 to 2. If it is less than 1:1, it is difficult to form a catalyst because the amount of the precursor is small, and if it exceeds 1:2, there is a problem in that it is difficult to make a solution state.

Next, a second solution including one kind of precursor selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca is prepared. One kind of metal precursor selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca is also not particularly limited, for example, Nitrate (NO ₃ ^- ) containing the metal, Acetate (CH ₃ COO ^- ), Chloride (Cl ^- ), Sulfate (SO ₄ ^2- ), etc. can be used.

On the other hand, the content of one selected from the group consisting of Ba, Sr, Na, K, Rb, Cs, Mg and Ca is 1 to 20 mol% based on the total weight of the metal in the group consisting of Ni and Al, Ti, Zr and Si It is preferable to include If it is less than 1 mol%, _{the amount to occlude or adsorb the generated CO 2} may be insufficient, and if it exceeds 20 mol%, the dispersibility of the promoter may be lowered to form large particles, and the reactivity may be lowered, and the reactivity of the promoter may be lowered. Since the state of the surface and the inside are different, it may be difficult to control the side reaction.

Next, the first solution, the second solution and the precipitating agent are mixed and heat-treated to produce a precipitate. As the precipitating agent, for example, aqueous ammonia can be used. The step of mixing the first solution, the second solution and the precipitating agent is preferably carried out at a pH of 6 or more and a temperature condition of about 40 to 90°C. If the temperature of the precipitant solution exceeds 90° C. before injection of the metal precursor, the water in the solution is highly likely to evaporate, and the formation of particles is accelerated, making it difficult to synthesize a uniformly dispersed catalyst. Furthermore, when the temperature is less than 40 ℃, there is a problem that it takes a long time to prepare the catalyst because the precipitation reaction does not occur. In addition, when the pH is less than 6, there is a problem in that a precipitate is not formed.

The heat treatment is preferably performed at a temperature of 80 to 120 °C for 1 to 3 hours. The precipitate is injected into the solution containing the precursor, and the temperature is partially increased due to the time for each metal to react and sufficiently precipitate and the exothermic reaction.

The precipitate after the heat treatment may be dried at a temperature of 100 to 120° C. for 10 to 14 hours after removing unnecessary ions through filtration and washing, if necessary.

Next, the precipitate is calcined at a temperature of 500 to 700° C. to prepare a methanation catalyst. The step is preferably carried out at a temperature of 600 to 800° C., in an oxygen atmosphere for 1 to 3 hours, and in a hydrogen atmosphere for 30 minutes to 2 hours.

More specifically, it is first subjected to sintering in an oxygen atmosphere for 1 to 3 hours. If the temperature is less than 500 ℃, the transformation in the form of an oxide is not sufficiently made, which may cause a problem of stability of the catalyst after activation, and if it is more than 700 ℃, there is a problem that the oxidized particles due to the high temperature become large.

Thereafter, it is preferably carried out for 30 minutes to 3 hours in a temperature range of 700° C. or higher, more preferably 700 to 800° C., and in a hydrogen atmosphere. When the temperature is low, it takes a long time to sinter, so hydrogen and energy consumption are high, and when the temperature is high, there is a problem in that the particles become large due to the high temperature.

As described above, the methanation catalyst prepared by the production method of the present invention is generated in the methanation reaction during the production of synthetic natural gas using a synthesis gas containing C5 or more hydrocarbons larger than LPG (C2, C3 and C4 hydrocarbons). It can reduce carbon precipitation and suppress the _{CO 2 production reaction.} Accordingly, there is an effect of increasing the yield of the synthetic natural gas by producing the synthetic natural gas using the methanation reaction catalyst.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. The following examples are provided to explain the present invention in more detail, and the present invention is not limited thereto.

A metal precursor solution in which Ni and Al are mixed and a metal precursor solution used as a co-catalyst were prepared, respectively. Specifically, the molar ratio of Ni and Al was 40:60, and the molar ratio of the promoter was 5% of the total metal ions. The concentration of the metal precursor was 1.2 M, and Nitrate or Acetate was used for the anion portion of each metal precursor.

For precipitation, an aqueous solution having a concentration of 0.1 M was prepared using basic aqueous ammonia. The temperature of the solution and ammonia water was set to about 50° C., and the first stirring was performed, and the pH was set to 8. Thereafter, the temperature was raised to 90° C., and synthesis and aging were performed for 2 hours.

The aged precipitate was dried in an oven set at 105° C. for about 12 hours after removing unnecessary ions through filtration and washing. The dried sample was calcined at a temperature of 700° C. in an oxygen atmosphere for 2 hours and in a hydrogen atmosphere for 1 hour to prepare a catalyst.

Table 1 shows the CO conversion rate (%) for each reactor inlet temperature during the methanation reaction of the prepared catalyst, and the CO conversion rate (%), CH ₄ concentration (%) and CO ₂ concentration (%) at the reactor inlet temperature of 600°C (%) is shown in Table 2.

division catalyst CO conversion rate (%) by reactor inlet temperature 300℃ 350℃ 400℃ 450℃ 500℃ 550℃ 600℃ 650℃ Comparative Example 1 Ni-based commercial catalyst 100 100 100 100 100 coking coking coking Example 1 40%Ni-5%Ba-Al 100 100 100 100 100 100 92 75 Comparative Example 2 40%Ni-5%Ce-Al 100 100 100 100 100 coking coking coking Example 2 40%Ni-5%Al-Al 100 100 100 100 100 98.2 83.6 67.9 Example 3 40%Ni-5%Mg-Al 100 100 100 100 100 100 87.4 65.1 Example 4 40%Ni-5%W-Al 100 100 100 100 100 100 83.9 55.8 Comparative Example 3 40%Ni-5%Fe-Al 100 100 100 100 100 coking coking coking

division catalyst CO conversion (%) CH ₄ concentration (%) CO ₂ Concentration (%) Comparative Example 1 Ni-based commercial catalyst caulking caulking caulking Example 1 40%Ni-5%Ba-Al 92 73.7 0.9 Comparative Example 2 40%Ni-5%Ce-Al caulking caulking caulking Example 2 40%Ni-5%Mg-Al 83.6 73.2 2 Example 3 40%Ni-5%Al-Al 87.4 46.9 3.2 Example 4 40%Ni-5%W-Al 83.9 47.5 3.2 Comparative Example 3 40%Ni-5%Fe-Al caulking caulking caulking

In Comparative Examples 1 to 3, as the reaction temperature increased, the reaction did not proceed due to coking. In the case of Examples 1 to 4, coking did not occur even at a high temperature of 650 ° C. As shown in Table 2, it can be seen that not only the CO conversion rate is excellent, but also the methane selectivity is high and the CO ₂ production is suppressed. That is, CO ₂ production is suppressed and CO production is increased, so that the _{CO methanation reaction takes place predominantly rather than the CO 2} methanation reaction, so that the amount of hydrogen used is lowered and more methane is generated, thereby increasing the selectivity.

4 is a photograph of the surface morphology of the catalyst after the reaction was observed using a scanning electron microscope (SEM). (a) and (b) are the catalyst according to Example 1, (c) and (d) are the catalyst according to Comparative Example 3 ((a) and (c) magnification is X5000, (b) and (d) ) magnification is X20,000). As shown in the photo, in the catalyst of Example 1, no coking occurred, so carbon filaments did not occur on the catalyst surface, and only the catalyst surface shape was present, whereas in Comparative Example 3, a lot of coking occurred and the carbon filaments covered all the surface. shape can be observed.

Meanwhile, FIG. 5 is a result of evaluating the degree of carbon precipitation by performing thermogravimetric analysis (TGA) on the catalysts of Example 1 and Comparative Example 3 in an oxygen atmosphere after the reaction has been completed. It can be seen that the carbon precipitation catalyst exhibits a weight reduction phenomenon in the vicinity of 600 to 700° C. that occurs during thermogravimetric analysis, but in Example 1, the weight reduction phenomenon does not occur, thereby improving carbon precipitation resistance. Rather, there is a shape in which the weight slightly increases due to oxidation of the reduced catalyst. However, in the case of Comparative Example 3 in which caulking occurred, it can be seen that the weight loss in the vicinity of 600 to 700° C. was very severe. This is a phenomenon in which the weight loss occurs as the carbon filament is oxidized.

In the case of using Ba as a co-catalyst, in order to confirm the effect according to the content, the CO conversion and CH ₄ selectivity were measured in the same manner as above and shown in FIGS. 6 and 7, respectively, and the composition of the catalyst was controlled as follows. (Example 5: 40%Ni-1%Ba-Al, Example 6: 40%Ni-3%Ba-Al, Example 7: 40%Ni-5%Ba-Al, Comparative Example 4: 40%Ni -10% Ba-Al). Referring to FIG. 7 , it can be seen _{that the CO conversion rate and CH 4} selectivity are excellent when Ba is 1 to 5 wt%.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.

Claims (11)

Separating and supplying a synthesis gas containing carbon monoxide and hydrogen to a hydrocarbon synthesis reactor and a first methanation reactor;
C5 or more hydrocarbon compounds discharged from the hydrocarbon synthesis reactor are supplied to the first methanation reactor, and based on 100 parts by weight of the total catalyst, 10 to 70 parts by weight of Ni, Ba, Sr, Na, K, Rb, Cs, Mg and generating methane in the presence of a methanation catalyst comprising 0.5 to 7 parts by weight of one cocatalyst selected from the group consisting of Ca and the remainder of the support; and
A synthetic natural gas production method comprising the step of supplying the gas discharged from the first methanation reactor and the C1-C4 hydrocarbon compound discharged from the hydrocarbon synthesis reactor to the second methanation reactor to generate methane.
According to claim 1,
The method for producing synthetic natural gas, characterized in that the co-catalyst is Ba.
According to claim 1,
The support is Al ₂ O ₃ , TiO ₂ , ZrO ₂ and SiO ₂ Synthetic natural gas production method, characterized in that one selected from the group consisting of.
delete delete delete delete delete delete delete delete

Images