KR101964767B1 - Method of preparing syngas and method of preparing liquid fuel - Google Patents

Abstract

The present invention relates to a process for producing a steam reforming catalyst for use in a reactor including a noble metal catalyst in which a molar ratio of methane (CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) steam / CO ₂ reforming of methane).
[Equation 1]
0.97? (CO ₂ + H ₂ O) / CH ₄ ? 1.24

Description

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

The present invention relates to a process for producing syngas and a process for producing a liquid fuel.

Reducing the generation of carbon dioxide, which is the main cause of greenhouse gases, has become an important issue worldwide. The synthesis gas is reformed by reforming CH ₄ as well as the demand for reduction of CO ₂ by the restriction of the emission of carbon dioxide (CO ₂ ), and the synthesis of methanol as a chemical raw material or the synthesis of a liquid fuel by Fischer-Tropsch reaction And a method of producing carbon dioxide have been attracting attention as methods for efficiently utilizing carbon dioxide.

The reforming reaction for producing a synthesis gas using methane as a raw material, the steam reforming of methane (steam reforming of methane, SRM) , the methane CO ₂ reforming (CO ₂ reforming of methane, CDR) steam methane / CO ₂ and the like combined reforming _{(combined steam / CO 2 reforming of} methane), partial oxidation of methane (partial oxidation of methane, POM) .

In order to be used in the Fischer-Tropsch process for producing liquid fuel such as methanol, diesel, gasoline, dimethyl ether (DME) and the like, a synthesis gas having an H ₂ / CO molar ratio of about 2 is required.

There is provided a process for producing a syngas which has a low H ₂ / CO molar ratio of about 2 and a high conversion rate while exhibiting low carbon deposition, thereby exhibiting excellent efficiency and long life characteristics.

A method for producing a liquid fuel, polycarbonate or the like using the produced synthesis gas is provided.

An embodiment of the present invention is a method for supplying a vapor of methane (CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) to a reactor containing a noble metal catalyst so that the molar ratio of the methane / CO ₂ reforming of methane (CO ₂ reforming of methane).

[Equation 1]

1 < (CO ₂ + H ₂ O) / CH ₄ ? 1.24

The molar ratio of methane (CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) may satisfy the following condition:

&Quot; (2) &quot;

1 < (CO ₂ + H ₂ O) / CH ₄ ? 1.20

The molar ratio of carbon dioxide and water vapor may satisfy the condition of the following equation (3).

&Quot; (3) &quot;

1.1? H ₂ O / CO ₂ ? 2.49

The molar ratio of methane, carbon dioxide, and water vapor may range from about 1: 0.32: 0.65 to about 1: 0.4: 0.89.

The non-noble metal catalyst may include a metal selected from the group consisting of nickel (Ni), cobalt (Co), copper (Cu), iron (Fe) The non-noble metal catalyst may be supported on the porous oxide.

The steam / carbon dioxide complex reforming of the methane may be carried out at a temperature of about 500 ° C to about 1000 ° C.

The steam / carbon dioxide complex reforming of the methane may be conducted at a pressure of about 1 to about 25 atmospheres.

Another embodiment of the present invention provides a method for producing a liquid fuel using a synthesis gas produced according to the method for producing the synthesis gas.

The liquid fuel may be selected from methanol, diesel, gasoline, dimethyl ether (DME), and oxo alcohols.

According to the method of producing the syngas, it is possible to improve the efficiency and lifetime of the catalyst by lowering the carbon deposition while producing syngas at a high conversion rate, and by using a small amount of water vapor and carbon dioxide, the manufacturing and recycling / Can be reduced.

1 is a graph showing CO ₂ conversion rates in Example 1 and Comparative Examples 1 to 5.
2 is a graph showing carbon deposition rates (%) of Example 1 and Comparative Examples 1 to 5;
3 is a graph showing CO ₂ conversion rates in Examples 2 and 3 and Comparative Examples 6 to 8. FIG.
4 is a graph showing carbon deposition rates (%) in Examples 2 and 3 and Comparative Examples 6 to 8.

Hereinafter, exemplary embodiments of the present invention will be described in detail so as to enable those skilled in the art to easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In one embodiment of the present invention, the synthesis gas is produced through the steam / CO ₂ reforming of methane. The process for producing the synthesis gas in the steam / carbon dioxide complex reforming of methane can be represented by the following reaction formula.

[Reaction Scheme 1]

_{0.75CH 4 + 0.25CO 2 + 0.5H 2} O → 2H 2 + CO DH = 178 kJ / mol

When a CO ₂ reforming reaction is performed by injecting water vapor as in the above reaction formula 1, a synthesis gas having a H ₂ / CO molar ratio of about 2 suitable for the Fischer-Tropsch process can be produced. However, excessive use of water vapor may accelerate the sintering of the catalyst, adversely affect the lifetime of the catalyst by carbon deposition, and increase the cost of producing steam. Therefore, in one embodiment of the present invention, the steam / carbon dioxide complex reforming of methane is carried out while supplying the molar ratio of methane (CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) steam / CO ₂ reforming of methane).

[Equation 1]

0.97? (CO ₂ + H ₂ O) / CH ₄ ? 1.24

The molar ratio of methane (CH ₄ ), carbon dioxide (CO ₂ ), and water vapor (H ₂ O) may satisfy the following equation (2).

&Quot; (2) &quot;

0.97? (CO ₂ + H ₂ O) / CH ₄ ? 1.20

In the case of supplying methane, carbon dioxide and water vapor in the range of the above-mentioned formula (1) or (2), it is possible to produce a synthesis gas having a H ₂ / CO molar ratio of about 2 at high efficiency while preventing deterioration of the catalyst.

The molar ratio of carbon dioxide (CO ₂ ) and water vapor (H ₂ O) may satisfy the following condition (3).

&Quot; (3) &quot;

1.1? H ₂ O / CO ₂ ? 2.49.

If the molar ratio of carbon dioxide and water vapor is adjusted to a low value in the range of Equation (3), the yield of synthesis gas may be increased.

The molar ratio of methane, carbon dioxide, and water vapor may range from about 1: 0.32: 0.65 to about 1: 0.4: 0.89. When the methane, carbon dioxide, and steam are supplied, synthesis gas having a H ₂ / CO molar ratio of about 2 can be produced with high efficiency while preventing deterioration of the catalyst.

The synthesis gas production process can be carried out by charging a non-noble metal catalyst into the reactor. The non-noble metal catalyst may include a metal selected from the group consisting of nickel (Ni), cobalt (Co), copper (Cu), iron (Fe) The use of such a non-noble metal catalyst can reduce the process cost.

The non-noble metal catalyst may be supported on the porous oxide. Examples of the porous oxide include silica, alumina, clay, and zeolite.

The non-noble metal catalyst may be contained in an amount of about 2 wt% to about 15 wt% based on 100 wt% of the total amount of the noble metal catalyst and the porous oxide. When the non-noble metal catalyst is supported in the above range, the conversion and the yield during the catalytic reaction can be further improved.

The steam / carbon dioxide complex reforming of the methane can be carried out at a temperature of about 500 ° C to about 1000 ° C, specifically about 700 ° C to about 900 ° C.

The steam / carbon dioxide complex reforming of the methane may be conducted at a pressure of about 1 to about 25 atmospheres.

Steam / carbon dioxide reforming of the methane compound is approximately 3000h ^-1 or more, for example may be designed to reduce the size of the reactor can be carried out by increasing the space velocity of at least about 10000h ^-1 (GHSV, gas hourly specific velocity). This can also reduce the amount of catalyst used, thus reducing the cost of the process.

Another embodiment of the present invention provides a method for producing a liquid fuel using a synthesis gas produced according to the method for producing the synthesis gas.

The liquid fuel may be selected from methanol, diesel, gasoline, dimethyl ether (DME), and oxo alcohols.

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

Production Example 1: Preparation of Catalyst

Alumina (specific surface area: 150 m ² / g, Alfa) was immersed in an aqueous solution of Ni (NO ₃ ) ₂ .H ₂ O, dried in an oven at 120 ° C for 24 hours, Fired. The calcined catalyst was reduced in a nitrogen atmosphere while being heated (10 ° C / min), and then maintained in a hydrogen atmosphere at 850 ° C for one hour to prepare a 7 wt% Ni / γ-Al ₂ O ₃ catalyst.

Experimental Example 1: (CO ₂ + H ₂ O) / CH ₄ CO according to molar ratio ₂  Conversion rate and carbon deposition rate

The catalyst according to Production Example 1 is charged into a reactor, and CO ₂ reforming reaction is performed by injecting methane, carbon dioxide, and water vapor at the (CO ₂ + H ₂ O) / CH ₄ molar ratio shown in Table 1 below. The CO ₂ conversion (%) is measured while changing the temperature from 650 ° C to 1000 ° C, and the carbon deposition rate (%) is measured while changing the temperature from 500 ° C to 1000 ° C. The results are shown in Figs. 1 and 2, respectively. FIG. 1 is a graph showing CO ₂ conversion rates of Example 1 and Comparative Examples 1 to 5, and FIG. 2 is a graph showing carbon deposition rates (%) of Example 1 and Comparative Examples 1 to 5. The results of the measurements at 750 ° C are shown in Table 1 below .

(CO ₂ + H ₂ O) / CH ₄
Mole ratio CO ₂ conversion (%) Carbon deposition rate (%) H ₂ / CO mole ratio Comparative Example 1 0.9 78.6 14.5 2.45 Example 1 1.2 72.6 0 2.08 Comparative Example 2 1.4 62.7 0 2.09 Comparative Example 3 2 38.4 0 2.20 Comparative Example 4 2.5 24.7 0 2.40 Comparative Example 5 2.9 23.6 0 2.29

1 and Table 1, the CO ₂ conversion rate is calculated according to the following equation (4).

&Quot; (4) &quot;

CO ₂ conversion rate = (CO ₂ injection amount - CO ₂ emission amount) / (CO ₂ injection amount) X 100

1 and Table 1, the carbon deposition rate is calculated according to the following equation (5).

&Quot; (5) &quot;

Carbon deposition rate (%) = (Carbon deposition amount) / (CH ₄ injection amount + CO ₂ injection amount) X 100

As shown in FIG. 1, FIG. 2 and Table 1, when the molar ratio of (CO ₂ + H ₂ O) / CH ₄ is 0.9, the conversion of CO ₂ is excellent, but the carbon deposition is too much and (CO ₂ + H ₂ O) / CH ₄ is 1.4 or more, the CO ₂ conversion is low. On the other hand, if the molar ratio of (CO ₂ + H ₂ O) / CH ₄ is 1.2, if the CO ₂ reforming reaction is performed at 750 ° C or higher, CO ₂ conversion is low while exhibiting low carbon deposition.

Experimental Example 2: (CO ₂ + H ₂ O) / CH ₄ H ₂ / CO mole ratio

The catalyst according to Preparation Example 1 is charged into a reactor and CO ₂ reforming reaction is performed by injecting methane, carbon dioxide, and water vapor at the (CO ₂ + H ₂ O) / CH ₄ molar ratio shown in Table 1. When the CO ₂ reforming reaction of Example 1 and Comparative Examples 1 to 5 was carried out at 850 ° C, the H ₂ / CO molar ratio of the synthesis gas was measured and is shown in Table 1. As shown in Table 1, the H ₂ / CO molar ratio of Comparative Example 1, Example 1, and Comparative Example 2 is close to 2, but in Comparative Examples 4 and 5, it is far from 2.

Experimental Example 3: Preparation of H ₂ O / CO ₂ CO according to molar ratio ₂  Conversion rate, carbon deposition and H ₂ / CO mole ratio

The catalyst according to Preparation Example 1 was charged into a reactor, and methane, carbon dioxide, and steam were injected at a molar ratio of H ₂ O / CO ₂ shown in Table 2 below to perform a CO ₂ reforming reaction. The CO ₂ conversion (%) and the carbon deposition rate (%) are measured while changing the temperature from 650 ° C to 1000 ° C. The results are shown in Fig. 3 and Fig. FIG. 3 is a graph showing CO ₂ conversion rates in Examples 1 and 2 and Comparative Examples 6 to 8, and FIG. 4 is a graph showing carbon deposition rates (%) in Examples 1 and 2 and Comparative Examples 6 to 8. The results of the measurements at 750 占 폚 are shown in Table 2 below.

H ₂ O / CO ₂
Mole ratio CO ₂ conversion (%) Carbon deposition rate (%) H ₂ / CO mole ratio Comparative Example 6 One 84.6 24.2 2.33 Example 1 2.13 72.6 0 2.08 Example 2 1.58 79.6 10.65 2.16 Comparative Example 7 3 46.8 0 2.38 Comparative Example 8 4 19.4 0 2.71

3 and Table 2, the CO ₂ conversion rate is calculated according to Equation (4), and the carbon deposition rate in FIG. 4 and Table 2 is calculated according to Equation (5).

2, 4 and Table 2, when the molar ratio of H ₂ O / CO ₂ is 1, the conversion of CO ₂ is excellent but the carbon deposition is too much and the molar ratio of H ₂ O / CO ₂ is 3 or 4 The CO ₂ conversion rate is low. On the other hand, when the molar ratio of H ₂ O / CO ₂ is 1.58 or 2.13, CO ₂ reforming reaction at 700 ° C. or higher shows a low carbon deposition and a high CO ₂ conversion.

Experimental Example 4: CH due to pressure ₄  Conversion Rate

The catalyst according to Preparation Example 1 was charged into a reactor and methane, carbon dioxide, and steam were injected at a molar ratio of about 1: 0.38: 0.81, and a CO ₂ reforming reaction was performed at 900 ° C while changing the pressure as shown in Table 3 .

Pressure (atm) CH ₄ conversion (%) One 99.64 3 97.31 5 94.17 10 86.60 20 75.30

CH ₄ conversion of Table 3 is calculated according to the following equation (6)

&Quot; (6) &quot;

CH ₄ conversion rate = (CH ₄ injection amount - CH ₄ emission amount) / (CH ₄ injection amount) X 100

In Table 3, it can be seen that CH ₄ conversion rate is 75.30% or more at 1 to 20 atm.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

Claims (16)

(CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) were supplied to the reactor containing the non-noble metal catalyst so as to satisfy the following conditions to produce steam / CO ₂ complex reforming of methane Reforming of methane:
[Equation 1]
1.20? (CO ₂ + H ₂ O) / CH ₄ ? 1.24.
delete The method according to claim 1,
Wherein the molar ratio of carbon dioxide (CO ₂ ) and water vapor (H ₂ O) satisfies the following conditions:
&Quot; (3) &quot;
1.1? H ₂ O / CO ₂ ? 2.49.
The method according to claim 1,
Wherein the molar ratio of methane, carbon dioxide and water vapor is 1: 0.32: 0.65 to 1: 0.4: 0.89.
The method according to claim 1,
Wherein the non-noble metal catalyst is a catalyst comprising a metal selected from the group consisting of nickel (Ni), cobalt (Co), copper (Cu), iron (Fe) and combinations thereof.
The method according to claim 1,
Wherein the non-precious metal catalyst is supported on the porous oxide.
The method according to claim 1,
Wherein the steam / carbon dioxide complex reforming of the methane is carried out at a temperature of 500 ° C to 1000 ° C.
The method according to claim 1,
Wherein the steam / carbon dioxide complex reforming of the methane is carried out at a pressure of 1 to 25 atm.
(CH ₄ ), carbon dioxide (CO ₂ ) and water vapor (H ₂ O) were supplied to the reactor containing the non-noble metal catalyst so as to satisfy the following conditions to produce steam / CO ₂ complex reforming of methane the synthesis gas is produced through reforming of methane,
A method for producing a liquid fuel using the syngas:
[Equation 1]
1.20? (CO ₂ + H ₂ O) / CH ₄ ? 1.24.
delete 10. The method of claim 9,
Wherein said carbon dioxide (CO ₂ ) and water vapor (H ₂ O) satisfy the following conditions:
&Quot; (3) &quot;
1.1? H ₂ O / CO ₂ ? 2.49.
10. The method of claim 9,
Wherein the molar ratio of methane, carbon dioxide and water vapor is 1: 0.32: 0.65 to 1: 0.4: 0.89.
10. The method of claim 9,
Wherein the non-noble metal catalyst is a catalyst comprising a metal selected from nickel (Ni), cobalt (Co), copper (Cu), iron (Fe) and combinations thereof.
10. The method of claim 9,
Wherein the non-precious metal catalyst is supported on the porous oxide.
10. The method of claim 9,
Wherein the steam / carbon dioxide complex reforming of the methane is carried out at a temperature of 700 ° C to 900 ° C.
10. The method of claim 9,
Wherein the steam / carbon dioxide complex reforming of the methane is carried out at a pressure of 1 to 25 atm.

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