KR100499860B1 - Process for high performance synthetic gas generation using the catalysts - Google Patents

Abstract

The present invention relates to a process for producing a synthesis gas using a catalyst for producing a high-efficiency synthesis gas, the reaction temperature can be lowered by 200 ℃ or more compared to a conventional synthesis gas production process using a dual function composite catalyst capable of producing synthesis gas at low temperature It relates to a process for producing a synthesis gas with high efficiency. The process according to the present invention comprises supplying a reactant consisting of hydrocarbon and / or alcohol, water, and oxygen to a heat exchanger to heat it to a constant temperature, and supplying the heated reactant to a catalytic reactor for direct partial oxidation and continuous reforming reaction. The step of carrying out, and the synthesis gas produced by the direct partial oxidation and reforming reaction is cooled through the heat exchanger and then transferred to a post-stage process.

Description

Process for high performance synthetic gas generation using the catalysts

The present invention relates to a process for producing a synthesis gas using a catalyst for producing a high-efficiency synthesis gas, the reaction temperature can be lowered by 200 ℃ or more compared to a conventional synthesis gas production process using a dual function composite catalyst capable of producing synthesis gas at low temperature It relates to a process for producing a synthesis gas with high efficiency.

Steam reforming of hydrocarbons among commercially available synthesis gas production techniques is widely used because of the high hydrogen content. For example, in the case of methane, the reaction proceeds as in Scheme 1 below. Since the reaction is a very large endothermic reaction, transferring the reaction heat into the catalyst layer determines the overall reaction rate. In this method, a Ni-based catalyst is used and is still commercially available. In addition, the reaction can obtain a high conversion of methane in the temperature range of 750 ~ 850 ℃. In the process using the same, as shown in FIG. 1, the system is configured in such a manner as to indirectly heat the outer surface of the catalyst layer to supply reaction heat. Detailed description of Figure 1 will be described later.

Therefore, in order to solve the heat transfer problem, which is pointed out as the biggest problem in the steam reforming reaction, a part of oxygen is mixed in a hydrocarbon as a reactant as shown in FIG. 2 and an oxidation reaction proceeds as shown in Scheme 2 below. It is used as a heat source for the secondary reaction of carbon dioxide, water, and hydrocarbons produced by using the following reaction schemes (3, 4 in the case of methane) (AM O'Connor and JRH Ross, "The effect of O ₂ addition"). on the dioxide reforming of methane over Pt / ZrO ₂ catalysts ", Catal. Today, 46, 203-210 (1998)).

Korean Laid-Open Patent Publication No. 99-49702 has proposed an improved process to compensate for the problem of conventional steam reforming using the process as shown in FIG. In other words, by using a method of using the heat, water, and carbon dioxide generated during the oxidation reaction in the primary reactor as a reactant of the secondary reactor, the problem of efficiency deterioration due to heat transfer due to direct heating from the outside of the reactor as shown in FIG. . In particular, a noble metal with excellent thermal stability was used as the catalyst for oxidation reaction, and the post-modification catalyst used Ni-based to improve the durability of the system.

However, the reaction temperature still needs to be maintained at a high state of 750 to 850 ° C. The main reason for this is due to the equilibrium conversion of each substance. That is, methane, a reactant, can obtain a high conversion rate of 95% by volume or more at around 800 ° C.

On the other hand, in the partial oxidation reaction, a part of the hydrocarbon is converted into carbon dioxide and water as described above, and then, on the surface of a specific noble metal, the hydrocarbon is partially partially oxidized to obtain a synthesis gas as shown in Scheme 5 below. (K. Takehira et al., “Direct partial oxidation of methane into synthesis gas over Rh | YSZ | Ag”, Catal. Toady, 29, 397-402 (1996)). In other words, the reaction proceeds through a path that is directly decomposed into carbon monoxide and hydrogen, instead of being converted into carbon monoxide and hydrogen again through an intermediate of carbon dioxide and water as shown in Scheme 2 (Scheme 3 and 4). )can do. Therefore, unlike carbon dioxide reforming of methane and steam reforming of methane, the reaction can proceed at a lower temperature than the conventional reaction by passing through a reaction path that does not require a large amount of reaction heat. Moreover, when the direct decomposition reaction proceeds, it is very easy in terms of temperature control of the reactor with a weak exothermic reaction (-36 kJ / mol).

On the other hand, the reaction schemes 3 and 4 are equilibrium reactions, and since the decomposition rate of methane can be increased when removing hydrogen and / or carbon monoxide from the reactor, the methane reforming reaction can be performed at a lower temperature. As a representative method, various research results can be seen. As a representative method, a research result of lowering the reaction temperature as hydrogen is removed using a hydrogen separation membrane in a synthesis gas manufacturing process using CH ₄ and CO ₂ can be seen. "Study on the Development of High Selective Membrane Catalysts for the Improvement of Dehydrogenation Process," Research Institute of Chemical Research, 1995-E-IDO2-P-01 (1998). As the reaction / separation proceeds at the same time, the reaction temperature is lowered and it is evaluated as an attractive process because it has the advantage of obtaining a high concentration of hydrogen incidentally.

Representative findings indicate that nickel-based reforming catalysts and palladium separators can be used to reduce the reactor temperature by increasing the equilibrium conversion of methane (A. Bsile, et al., “The partial oxidation of methane to syngas in a palladium membrane reactor: simulation and experimental studies ", Catal. Toady , 67 , 65-75 (2001)). However, nickel-based catalysts are limited in lowering the temperature of the system because of their low activity for hydrocarbon oxidation, and as described above, the possibility of syngas production at low temperatures has been reported using the direct partial oxidation method. The process development used is not complete.

In addition, due to the increased awareness of the possibility of fuel cells, a lot of researches have been conducted on the production of syngas by reforming reactions of hydrocarbons and alcohols, in particular, a process using hydrogen as a target material. In particular, in transportation and mobile fuel cell systems, a method of producing hydrogen through reforming of liquefied hydrocarbons and alcohols has been adopted due to fuel storage convenience, safety, and hydrogen production per unit mass.

In general, alcohol is used as methanol, and in the case of the reforming reaction using methanol, unlike the hydrocarbon described above, the reforming is performed using a Cu-based catalyst under the reaction conditions of 250 to 350 ° C. and GHSV (1000 to 4000 hr ⁻¹ ). Proceed the reaction [PJ de Wild et al. "Catalytic production of hydrogen from methanol", Catal. Today , 60 , 3 (2000)]. However, due to the low GHSV, a large amount of catalyst is required, and since the catalyst used is Cu-based, when the reaction temperature is maintained at a high temperature, the catalyst has a disadvantage of shortening the life of the catalyst.

In order to make up for the disadvantages of the conventional methanol reforming process and to produce hydrogen with higher purity, J. Han et al. Performed a wet reforming reaction using Pd-Cu and Pd-Ag separation membranes, but were considerably more expensive than conventional processes. Configuration is inevitable (J. Han et al., “Purifier-integrated methanol reformer for fuel cell vehicles, J. Power Sources , 86 , 223 (2000)).

Accordingly, the present inventors have developed a synthesis gas production process using a catalyst capable of improving the equilibrium conversion rate by performing direct partial oxidation of hydrocarbons and / or alcohols at a low temperature and converting / removing products.

Accordingly, an object of the present invention is to provide a synthesis gas by using a carbon monoxide reforming catalyst which is excellent in converting carbon dioxide and hydrogen by an CO shift reaction to carbon monoxide together with a catalyst having excellent direct partial oxidation of hydrocarbons and / or alcohols. To provide a process for producing a synthesis gas that can significantly lower the manufacturing temperature of the.

Synthetic gas production process according to the present invention for achieving the above object, the step of supplying a reactant consisting of a hydrocarbon and / or alcohol, water, and oxygen to a heat exchanger to heat to a constant temperature; Supplying the heated reactant to a catalytic reactor to perform direct partial oxidation and continuous reforming reaction; And syngas produced by the direct partial oxidation and reforming reaction is cooled through the heat exchanger and then transferred to a post stage process.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram of a process for producing a synthesis gas by a conventional steam reforming method, a conceptual diagram of a process for producing a synthesis gas using natural gas and / or alcohol currently in use. The reactants (hydrocarbon and water) are preheated to a constant temperature (about 105 to 700 ° C. for natural gas, about 105 to 250 ° C. when methanol is a raw material) in the heat exchanger 101 using waste gas, and then the supply line ( 11) is supplied to the reactor (100). The reactor 100 is equipped with a plurality of pipes therein, for example, in the case of methane, a nickel-based reforming catalyst 200 is mounted in the case of the methane, a copper-based reforming catalyst 200 in the case of methanol Is equipped. The preheated reactant is converted into syngas as it comes into contact with the catalyst in the reactor and the resulting syngas is fed to the downstream process via discharge line 12. Steam reforming is an endothermic reaction (Scheme 1), the amount of heat required for the reactor 100 is supplied through the line 1 from the external heat source (drawing gas is a heating gas) and the waste gas discharged through the waste gas discharge line (2) In order to improve the thermal efficiency, the heat exchanger 101 is cooled to a lower temperature (about 105 to 300 ° C) and then discharged into the atmosphere. The biggest problem in the synthesis gas production reactor according to this configuration is that the reaction heat transfer from the outside is evaluated as the most important element technology, and this research is being promoted even now.

In addition, Figure 2 is a schematic diagram showing a process for producing a synthesis gas by a conventional partial oxidation reaction, in particular, the process of complementing the problem of heat transfer that is pointed out as the biggest problem in the process of Figure 1 of the hydrocarbon reforming reaction. That is, in FIG. 1, since the catalyst layer 200 and the heating gas in which the reactants flow are separated to flow in separate spaces, a part of the reactants is partially oxidized to compensate for the problem of efficiency of heat exchange. Looking at the construction of the process, the heat of reaction is obtained by burning a portion of the hydrocarbons (combustion reactor, 99) to form CO ₂ and H ₂ O, the resulting gas being discharged via line (9), where the hydrocarbons and water The mixture is supplied to the reforming reactor (102). The reforming reactor 102 is filled with a Ni-based catalyst 200, hydrocarbon gas and water proceed in accordance with Scheme 1 above, and hydrocarbon and carbon dioxide proceed in accordance with Scheme 3 above. Thus, the synthesis gas is formed and supplied to the heat exchanger 101 through the line 13, cooled to a predetermined temperature, and then supplied to the subsequent process through the line 14. In this case, the reforming reactor 102 is usually maintained at 750 to 850 ° C in consideration of the equilibrium conversion rate of hydrocarbons, for example, methane, and a conversion rate of 95% or more can be obtained.

In addition, as shown in FIG. 3, the partial oxidation system of the initial model can be seen that the same effect can be obtained by mounting the oxidation catalyst layer and the reforming catalyst layer in one reactor, but this reactor has a high concentration of CH ₄ initially introduced. The chance of coke formation is high. Therefore, as shown in FIG. 2, it is common to supply CH ₄ separately for generation of reaction heat and synthesis gas. The catalytic combustion device for the purpose of generating the reaction gas of FIG. 2 may also be configured in a modified form using a general combustor (Pionier et al., "Oxygen-fuel boost reformer process and apparatus", Korean Laid-Open Patent Publication , 2001-23652).

As described above, in the synthesis gas production process using the partial oxidation reaction using a conventional nickel-based catalyst, the hydrocarbon is subjected to a complete oxidation reaction according to Scheme 2 to generate carbon dioxide and water, and the carbon monoxide and The reaction proceeds through a path to form hydrogen.

However, in the present invention, as shown in Scheme 5, low-temperature reaction was possible using a noble metal catalyst capable of directly oxidizing methane and / or methanol to carbon monoxide and hydrogen at low temperature. At this time, the carbon monoxide and hydrogen generated through the reaction scheme 5 generates methane through the following reaction scheme 6. In other words, as the concentration of carbon monoxide and hydrogen increases, the rate of hydrocarbon (methane) production increases. Therefore, the decomposition reaction temperature of hydrocarbons and / or alcohols is preferably carried out at low temperatures, and the carbon monoxide, which is a product, is converted into hydrogen and carbon dioxide to suppress the regeneration of hydrocarbons. At this time, the reforming of the carbon monoxide used can be rapidly performed using a commercially available nickel-based catalyst or an iron-chromium-based catalyst. Such carbon monoxide reforming catalysts are already well known in the art (J. M. Thomas and W. J. Thomas, "Principles and practice of Heterogeneous Catalysis", VCH, 545-546 (1997)).

Therefore, if the direct decomposition catalyst and carbon monoxide reforming catalyst are uniformly mixed without separating the layers, the carbon monoxide decomposed on the surface of the catalyst of the noble metal can be quickly converted into carbon dioxide and hydrogen on the surface of the neighboring aqueous reaction catalyst. It was possible to improve the equilibrium conversion of hydrocarbons (for example methane) by using (see FIG. 4).

In addition, as another method for improving the equilibrium conversion of hydrocarbons and / or alcohols, the progress of the hydrocarbonation reaction of carbon monoxide can be further suppressed when selectively removing the produced hydrogen from the reactor and the hydrogen production by conversion of carbon monoxide. There is a way to use that the process can proceed more quickly. Therefore, when the mixed catalyst is mounted in a membrane reactor, a higher conversion rate of hydrocarbon and / or alcohol may be achieved.

As mentioned above, the manufacturing process of the syngas according to the present invention

Supplying a reactant consisting of hydrocarbon and / or alcohol, water, and oxygen to a heat exchanger to heat to a constant temperature;

Supplying the heated reactant to a catalytic reactor to perform direct partial oxidation and continuous reforming reaction; And

Synthetic gas produced by the direct partial oxidation and reforming reaction is cooled through the heat exchanger and then transferred to a subsequent step.

The catalyst reactor is equipped with a catalyst formed by uniformly mixing a supported noble metal catalyst and a catalyst for carbon monoxide aqueous reaction, pulverizing to 10 μm or less, processing into a granular or monolithic material, or coating a metal plate, a metal net or a metal web.

At this time, the noble metal supported catalyst is at least one noble metal selected from the group consisting of Rh, Ru, Pd and Pt decomposed hydrocarbon supported on at least one porous support selected from the group consisting of Al, Si, Zr, Ti and oxides thereof. Is a catalyst. In addition, the content of the noble metal is 0.01 to 5.0% by weight based on the weight of the support.

The carbon monoxide aqueous reaction catalyst is at least one selected from the group consisting of Cu, Ni, Fe, Cr, Al, and metals of Groups 1A and 2A of the periodic table.

In addition, the hydrocarbon usable in the present invention is selected from the group consisting of aliphatic hydrocarbons having 1 to 32 carbon atoms, aromatic hydrocarbons, and olefins, preferably natural gas (LNG), carbon number containing mainly methane, ethane, propane, butane It is selected from the group consisting of 2-7 liquefied petroleum gas (LPG), gasoline, white kerosene, light hydrocarbons, the liquid hydrocarbon is used by vaporization.

Alcohols usable in the present invention are preferably methanol and / or ethanol.

In addition, the catalyst bed temperature in the catalytic reactor according to the present invention is 250 ~ 800 ℃, the gas space velocity (GHSV) of the reactants is 5,000 ~ 200,000hr ^-1 .

The content of the reactant consisting of hydrocarbon, water and oxygen is 0.3 to 1.0 times the oxygen to mole ratio of the constituent carbon in the hydrocarbon and 0.5 to 3.0 times the water to the molar ratio of the constituent carbon in the hydrocarbon.

In the catalytic reactor, a hydrogen and / or carbon monoxide passivation membrane is installed to increase the equilibrium conversion rate of the hydrocarbon and at the same time increase the concentration of hydrogen in the synthesis gas. The separation membrane is formed of Rh, Ru, Pd and Pt on the porous support. At least one metal selected from the group consisting of at least one precious metal selected from the group, Ni, Cu and Ag, is prepared by chemical vapor deposition or sputtering. The porous support of the separator is Al, Si, at least one ceramic porous support selected from the group consisting of periodic table 1A and 2A, and oxides thereof, or Fe, Co, Ni, Mn, Cr, W, Mo, Sn and oxides thereof At least one porous metal selected from the group consisting of may be used. However, it is possible to joint by welding, which may be more advantageous in system configuration when using a metal that is convenient for forming a structure. At this time, the heating temperature of the reactants is 105 ~ 700 ℃, the cooling temperature of the synthesis gas is 105 ~ 300 ℃.

Looking at the present invention in more detail with reference to the drawings, Figure 5 is an example of a high-efficiency syngas production process according to the present invention, Figure 6 is an example of another high-efficiency syngas production process according to the present invention.

As described above, the biggest factor affecting the durability in the oxidation catalyst may be degradation. In the process of FIGS. 2 and 3 using the conventional partial oxidation reaction, the inlet portion of the reactor in which the oxidation reaction proceeds in the catalyst bed is performed. Represents a temperature range of about 80 to 100 ° C. higher than the middle region of the reactor by oxidation of hydrocarbons (Scheme 2) and a temperature distribution ranging from the middle to the rear end of the reactor (MES Hegarty et al., "Syngas production from natural gas"). using ZrO ₂ -supported metals ", Catal. Today , 42 , 225-232 (1998). Therefore, the temperature of the inlet is very high (900 ~ 1000 ℃), it is necessary to pay attention to ensure the thermal stability of the oxidation catalyst. Therefore, in the present invention, the temperature of the reforming reactor is lowered by more than 250 ° C. using the method of improving the equilibrium reaction, thereby reducing the durability of the catalyst and the durability of the system, the convenience of selecting materials in the system configuration, and the time required at the start and end of operation. I could do it.

That is, in Figure 5, hydrocarbon and / or alcohol, water and oxygen is heated to a constant temperature in the heat exchanger 101 for waste heat recovery and then supplied to the catalytic reactor 400 through the line (11). The reactant supplied is subjected to a direct partial oxidation reaction according to Scheme 5 at the surface of the catalyst 210 to form carbon monoxide and hydrogen. At this time, the carbon monoxide is converted into carbon dioxide and hydrogen by continuously undergoing a reforming reaction according to Scheme 7 (see FIG. 4). Therefore, the conversion of the hydrocarbon is increased, so that the reaction temperature can be significantly lowered compared to the process according to FIGS. 1 to 3. The resulting syngas is lowered while preheating the reactants in the heat exchanger 101 via line 15 and then transferred to the subsequent process via line 16.

Since the temperature of the heat exchanger 101 is very low at the beginning of operation, supply of more heat is required from a separate preheater (not shown in the drawing). When the temperature of the reactor 400 reaches a steady state, the temperature of the heat exchanger 101 is reached. Increasingly, the preheater power supply is gradually reduced and the final steady state is operated without the preheater running.

In the catalytic reactor 400, the catalyst 201 is nickel or iron, which is a catalyst for carbon monoxide aqueous reaction which is excellent in high temperature aqueous reaction in the case of reforming reaction between a noble metal catalyst and a hydrocarbon supported on a high surface area support having direct partial oxidation power. -The chromium-based catalyst may be mixed and pulverized to 10 μm or less and then processed into a particle or monolithic form, or coated on a metal plate, a metal net or a metal web to promote heat transfer, and may be decomposed at a lower temperature than a general hydrocarbon. If possible methanol can be used by processing or coating the same copper-based catalysts excellent in low-temperature aqueous reaction. Synthetic gas output can be used in the form of particles in small size of 2000Nm ³ / day or less, but in the production scale of 2000Nm ³ / day or more, the type of reactor coated and mounted on a metal plate, a metal net or a metal web is suitable for maintaining a uniform temperature.

By following this process configuration, as the concentration of carbon monoxide in the product is rapidly removed, the equilibrium conversion can be increased, thereby lowering the operating temperature of the reactor.

On the other hand, as shown in FIG. 6, when the catalytic reactor 400 of FIG. 5 is replaced with the catalytic reactor 500 of FIG. 6 in a way to further increase the efficiency of the process as shown in FIG. have. Separation membranes through which hydrogen and / or carbon monoxide produced in the reactor can pass are used to separate them from the reactants. As a result, the equilibrium conversion of hydrocarbons and / or alcohols can be improved and efficiency can be improved over existing reaction systems. In addition, the biggest drawback when producing the synthesis gas using the partial oxidation reaction is to supply air to supply the oxygen for the oxidation reaction, when nitrogen also shows the effect of diluting the synthesis gas produced. Therefore, when the process configuration according to the present invention, by minimizing the concentration of nitrogen and water contained in the reactants it is possible to maintain a very high concentration of hydrogen in the gas passing through the separator. Of course, the concentration of carbon monoxide, hydrocarbons and / or alcohols, water, and nitrogen in addition to hydrogen, which are the main components, is determined depending on the type of separator used, but the permeation selectivity for hydrogen (H ₂ / N ₂ ) is secured. Even more than 90% hydrogen and unreacted hydrocarbons and / or alcohol, carbon monoxide, water, carbon dioxide can be obtained a synthesis gas containing about 1% and 5% nitrogen, respectively. Therefore, the synthesis gas produced using such a process is more competitive when used in a process requiring a high concentration of hydrogen because the concentration of hydrogen is very high.

In the present invention, the synthesis gas is aimed at improving the efficiency of the reactor at a lower temperature. Therefore, the separator used in the present invention is described above in the porous support described above rather than a method of manufacturing a conventional foil-type or electroless plating (hereinafter referred to as EP) having high selectivity for hydrogen. It is preferable to use a separator prepared by chemical vapor deposition (CVD) or sputtering of at least one precious metal, Ni, Ag, and Cu group (M. Kajiwara et al., “Rhodium-and iridium-dispersed porous alumina membranes and their hydrogen perameation properties ", Catal. Today , 56 , 83-87 (2000), E. Kikuchi et al.," Steam reforming of methane in membrane reactors: comparision of electroless-plating and CVD membrane and catalyst packing modes ", Catal. Today , 56 , 75-81 (2000). The hydrogen separation membrane thus prepared has a slightly low permeation selectivity of 200 to 300 (H ₂ / N ₂ ), but is intended to maximize the conversion of hydrocarbons and / or alcohols as in the present invention. Use in the system yields the best results (YS Cheng et al., "Performance of alumina, zeolite, palladium, Pd-Ag alloy membrane for hydrogen separation from Towngas mixture", J. Membr. Sci. , 204 , 329-340 ( 2002)). In addition, conventional membranes manufactured by the thin film type or EP method are expensive because they use a lot of precious metals, and thus they cannot be used except for high value-added devices for special purposes to obtain ultra-high purity hydrogen. However, the use of expensive separators having infinite selectivity for hydrogen is not competitive in a system having compatibility, even though other materials are included in 90% or more of hydrogen while lowering the reaction temperature as in the present invention.

Details of the technical configuration and specific effects of the high-efficiency syngas production process of the present invention will be clearly understood by the following description of the preferred embodiment of the present invention.

Example 1

Preparation of Rh / Al ₂ O ₃ and Nickel-based Mixed Catalysts:

The catalyst was prepared by Rh / Al ₂ O ₃ and then used as a commercial catalyst, a nickel-based catalyst (57I of ICI, 18% by weight of Ni, 0.1% by weight of SiO ₂ , 0.05% by weight of SO ₃ , support Ca, Al oxide mixture ) Was physically mixed with the catalyst. First, the manufacturing method of Rh / Al ₂ O ₃ will be described.

A metal precursor (manufactured by Kojima Co., Ltd.) was dissolved in distilled water so that the content of rhodium was 0.1% by weight of activated alumina as a support. The prepared solution was supported on activated alumina (Aldrich 19996-6, hereinafter Al ₂ O ₃ ) by incipient wetness method three times. In order to obtain uniformity, a solution corresponding to the alumina pore volume as a support was added and mixed, so that a solution remaining without being absorbed was not present. After mixing the solution, the stirred alumina was dried in a 60 ° C. dryer for 30 minutes, and the impregnation of the precursor was repeated in the same manner as described above. After repeating three times, dried for 24 hours and completed by firing for 3 hours in a 400 ℃ kiln.

After mixing the prepared Rh / Al ₂ O ₃ catalyst with the same content as ICI 57-7, the slurry was molten for 12 hours, dried in an 80-105 ° C. dryer, calcined at 400 ° C. for 4 hours, and then 100-140 mesh. It was prepared by milling into a mesh.

Example 2

Preparation of Rh / SA and Nickel-based Mixed Catalysts:

A catalyst was prepared in the same manner as in Example 1, except that silica alumina (Aldrich, 22,883-4) was used as the support for rhodium.

In addition, a mixed catalyst was prepared in the same manner as in Example 1 using the Rh / SA catalyst.

The activity of the catalysts prepared in Examples 1 and 2 and ICI 57-7, which is a commercial catalyst for aqueous reaction, was measured using CH ₄ in a hydrocarbon as a model reactant.

Example 3

The methane decomposition activity of the catalyst prepared in Example 1 was measured using a quartz fixed bed reactor having an inner diameter of 4 mm. The composition of the reaction gas was methane 10.0% by volume, 5.0% by volume of O ₂ , 10% by volume of water, and nitrogen was used as a balance gas. The volume of the reaction gas was supplied at 50 ml / min and the weight of the catalyst was filled with 0.05 g. The space velocity (GHSV) of the reaction gas in the catalyst bed was 60,000 ^{hr −1} . The conversion of methane was measured 3 hours after the reaction feed to reach steady state. The conversion of methane at the inlet side of the reactor was determined using Equation 1 below. The conversion of oxygen was also determined in the same way as methane.

The concentrations of H ₂ and CO in the catalyst bed exhaust gas were quantified using 1% by volume of standard gas. They were analyzed using Hewlett-Packard's HP-6890 gas chromatography equipped with a thermal conductivity detector (TCD) detector and a flame ionization detector (FID). Hydrogen, oxygen, and carbon monoxide were separated into a molecular sieve 13x, and methane was separated into an HP-1 capillary column (30 m, ID 250 µm), and gas chromatography used helium. Catalytic activity was measured at 700 ° C and 500 ° C.

As a result of activity measurement, the conversion of methane and oxygen and the concentration of hydrogen and carbon monoxide are shown in Table 1 below. According to the results, the conversion rate of methane in the mixed catalyst was 59.9% by volume, which was about 11% increase compared to 48.8% when the nickel-based reforming catalyst was not mixed, and the ratio of hydrogen and carbon monoxide was also 3.69% by volume. Was very high at 12.36% by volume. From this point of view, the produced carbon monoxide can be seen to have been converted to carbon dioxide and hydrogen by an aqueous reforming reaction with water (Scheme 7), thereby increasing the conversion of methane.

Example 4

Except for changing the presence or absence of water supply at the reaction temperature 500 ℃ was carried out in the same manner as in Example 3, the experimental results are shown in Table 1. As summarized in Table 1, when no water was supplied, the conversion rate of methane was 53.7%, and when water was supplied, the conversion rate was increased to 61.5%. That is, as moisture was supplied, the conversion rate of methane was increased by about 14.5% ([61.5-53.7] /53.7×100) compared to the drying condition by the conversion of CO, and the concentration of hydrogen was also greatly increased. The hydrogen / carbon monoxide ratio was then increased to 10.02.

Reference Example 1

The decomposition reaction of methane was carried out under the same conditions as in Example 3. The charge amount of the catalyst was doubled to keep the SV at 30,000 hr ⁻¹ . Experimental results As summarized in Table 1 below, the conversion rate of methane at 500 ° C. was found to be an amazing effect. This point, despite the same noble metal catalyst input compared with Comparative Example 2 was able to obtain a conversion rate of 60% compared to noble metal alone from 48.8% by volume to 81.0%. From this point of view, the removal of carbon monoxide, that is, the removal of the product, means absolute conversion of methane. As shown in FIG. 5, a higher conversion rate is expected to be obtained when the product gas is removed from the reactor.

Comparative Example 1

The same process as in Example 4 was carried out except that only a 57-4 nickel-based catalyst of ICI Corporation was used without using a noble metal catalyst. As a result, hydrogen and carbon monoxide could not be obtained at 500 ℃ and no consumption of methane and oxygen was observed. However, the conversion of methane was 99.1% by volume at 700 ℃. Therefore, it can be seen that it is an effective method for lowering the reaction temperature when using a mixture of a noble metal and a carbon monoxide transition metal easy to convert according to the present invention.

Comparative Example 2

The same procedure as in Example 3 was carried out except that the methane decomposition activity of the Rh / Al ₂ O ₃ catalyst alone was measured without mixing the nickel-based ICI 57-7 catalyst.

Experimental results are shown in Table 1, as shown in Table 1, the conversion of methane was found to be 48.8% by volume. This showed a relatively low conversion rate even when the amount of the Rh / Al ₂ O ₃ catalyst was doubled. In this regard, it can be seen that the role of the nickel-based catalyst is important. This is even more apparent in terms of the ratio of H ₂ / CO. In the case of Example 3, the ratio of H ₂ / CO was 12.36, but in the experiment conducted with noble metal alone, the ratio of H ₂ / CO was 3.69, which was low as 25%.

Comparative Example 3

It was carried out in the same manner as in Comparative Example 2, except that the direct decomposition of the hydrocarbon was not included, the results are shown in Table 1 below.

According to Table 1 below, the conversion of methane was 48.8%, showing similar results to the reaction of Comparative Example 2. On the other hand, it can be seen that the direct decomposition reaction according to Scheme 5 was performed at a ratio of carbon monoxide and hydrogen of 2.10. Another point is that the Rh / Al ₂ O ₃ catalyst does not play a role in the conversion of CO and can be seen that the decomposition reaction is suppressed by water. Therefore, in order to effectively remove CO, it can be seen that a mixture of a nickel-based or iron-chromium-based catalyst having excellent aqueous reactivity of carbon monoxide is required.

Item catalyst Reaction temperature (℃) Reactant product Composition ratio Remarks ^* CH ₄ O ₂ H ₂ CO H ₂ / CO % Conversion % Conversion density(%) density(%) Example 3 Rh [0.1] / Al ₂ O ₃ + ICI 57-7 (catalyst weight ratio 1: 1) 500 59.9 99.5 9.77 0.79 12.36 Water 10% SV 60,000 / hr 700 99.1 99.8 18.2 4.89 3.72 Example 4 Rh [0.1] / SA + ICI 57-7 (catalyst weight ratio 1: 1) 500 53.7 99.5 7.00 1.93 3.61 SV 30,000 / hr 500 61.5 99.5 9.67 0.96 10.02 10% water, SV 30,000 / hr Reference Example 1 Rh [0.1] / Al ₂ O ₃ + ICI 57-7 (catalyst weight ratio 1: 1) 500 81.0 99.8 14.7 2.14 6.88 Water 10% SV 30,000 / hr 700 99.8 99.8 18.1 5.23 3.46 Comparative Example 1 ICI 57-7 500 0.0 0.0 0.0 00 0.00 Water 10% SV 60,000 / hr 700 99.1 99.8 18.1 5.01 3.61 Comparative Example 2 Rh [0.1] / Al ₂ O ₃ 500 48.8 99.5 5.88 1.59 3.69 Water 10% SV 60,000 / hr 700 87.9 99.8 15.0 4.59 3.26 Comparative Example 3 Rh [0.1] / Al ₂ O ₃ 500 49.8 99.5 4.89 2.32 2.10 SV 60,000 / hr 700 93.9 99.5 15.0 7.41 2.02

* Reaction condition: CH ₄ 10%, O ₂ 5%, balanced gas uses nitrogen and water.

By lowering the temperature of the synthesis gas to a low temperature around 500 ° C using hydrocarbons, it is possible to enhance the competitiveness of the synthesis gas process compared to the existing synthesis gas process in terms of catalyst life, process configuration and operation. In particular, due to the characteristics of the system, the reformed gas has a very high hydrogen content, and thus economical efficiency is expected when used in ammonia synthesis and fuel cell hydrogen production.

As can be seen from the above examples and comparative examples, as the production temperature of the synthesis gas is lowered to a low temperature around 500 ° C. using hydrocarbons, water, and oxygen, the catalyst life, process configuration and operation of the conventional Competitiveness can be improved compared to the synthesis gas process, and since the content of hydrogen is very high in the reformed gas, it is expected to be economical when used in the ammonia synthesis process and the hydrogen production process for fuel cells.

1 is a schematic configuration diagram of a synthesis gas production process by a conventional steam reforming method.

2 is a schematic configuration diagram of a conventional synthesis gas production process by a partial oxidation reaction.

3 is a schematic configuration diagram of another syngas production process using a conventional partial oxidation reaction.

Figure 4 shows a syngas production reactor through the decomposition of hydrocarbons and / or alcohols and carbon monoxide transfer reaction on the catalyst surface of the present invention.

5 is one embodiment of a high-efficiency syngas production process according to the present invention.

6 is one embodiment of another high-efficiency syngas production process according to the present invention.

Claims (12)

(Iii) feeding a reactant consisting of hydrocarbon, alcohol or mixtures thereof, (ii) water, and (iii) oxygen to a heat exchanger and heating to 105-700 ° C .; Feeding the heated reactant to a catalytic reactor to perform direct partial oxidation and continuous reforming reactions; And Cooling the synthesis gas generated by the direct partial oxidation and reforming reaction through the heat exchanger and then transferring the synthesis gas to a post-stage process; Synthesis gas production process comprising a. The method of claim 1, wherein in the catalytic reactor The noble metal supported catalyst for the direct partial oxidation and the carbon monoxide aqueous reaction catalyst for the reforming reaction are uniformly mixed and pulverized to 10 μm or less and processed into a granular or monolithic material, or coated on a metal plate, a metal net or a metal web. A process for producing a syngas, wherein the catalyst is mounted. The porous support according to claim 2, wherein the precious metal supported catalyst is one or two or more precious metals selected from the group consisting of Rh, Ru, Pd, and Pt selected from the group consisting of Al, Si, Zr, Ti, and oxides thereof. A catalyst for decomposing hydrocarbons, wherein the content of the noble metal is 0.01 to 5.0% by weight based on the weight of the support. The process of claim 2, wherein the carbon monoxide aqueous reaction catalyst is selected from the group consisting of Cu, Ni, Fe, Cr, Al, and metals of Groups 1A and 2A on the periodic table. . The process according to claim 1, wherein the hydrocarbon is selected from the group consisting of aliphatic hydrocarbons having 1 to 32 carbon atoms, aromatic hydrocarbons, and olefins. The process according to claim 5, wherein the hydrocarbon is selected from the group consisting of gaseous hydrocarbons of methane, ethane, propane, butane and liquid hydrocarbons of petroleum, gasoline and diesel. The method of claim 1, wherein the alcohol is methanol, ethanol or a mixture thereof. The process of claim 1, wherein the catalyst bed temperature in the catalytic reactor is 250-800 ° C., and the gas space velocity (GHSV) of the reactants is 5,000-200,000 hr ⁻¹ . The process according to claim 1, wherein the reactant comprises 0.3 to 1.0 times oxygen to mole ratio of constituent carbon in hydrocarbon and 0.5 to 3.0 times water to molar ratio of constituent carbon in hydrocarbon. The method of claim 1, wherein the catalytic reactor is hydrogen, carbon monoxide, or a mixture of these mixtures are installed through the production of syngas, characterized in that the equilibrium conversion rate of the hydrocarbon increases and the concentration of hydrogen in the synthesis gas increases at the same time. fair. The method of claim 10, wherein the separator is Al, Si, a ceramic porous support or at least one selected from the group consisting of metals and oxides of the periodic table 1A and 2A metal or Fe, Co, Ni, Mn, Cr, W, Mo, In the porous metal support selected from the group consisting of Sn and oxides thereof, at least one metal selected from the group consisting of noble metals selected from the group consisting of Rh, Ru, Pd and Pt, Ni, Cu and Ag, 1 or 2 or more chemical vapor deposition or sputtering process for producing a synthesis gas, characterized in that the production. The process for producing syngas according to claim 1, wherein the syngas is cooled at 105 to 300 deg.