KR20190057186A - High-yield synthesizing method of Synthetic-Natural-Gas with higher heating level in a reactor containing Fe-based catalytic bed and Ni-based catalytic bed - Google Patents

Abstract

The present invention relates to a method for producing synthetic natural gas (SNG) containing methane and C2-C4 paraffin having a composition exhibiting a high heating value of 10,000 to 13,000 Kcal/Nm^3, and to a reactor for producing SNG used therein. The reactor for producing SNG is stacked with an iron-based catalyst layer for FT synthesis in upper stream and a nickel-based catalyst for a methanation reaction in down stream in order of a reaction to allow a Fischer-Troshsh (FT) synthesis reaction and a methanation reaction to sequentially proceed, and adjusts the amount of a stacked nickel-based catalyst to be in 10 to 50 parts by weight with respect to 100 parts by weight of the sum of an iron-based catalyst for FT synthesis and the nickel-based catalyst for the methanation reaction to form synthetic natural gas of a composition exhibiting a high heating value of 10,000 to 13,000 Kcal/Nm^3 while increasing the yield of SNG by lowering the amount of generation of CO_2.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-yield synthetic natural gas producing method using high-yield synthetic natural gas in a reactor having an iron-based catalyst layer and a nickel- catalytic bed}

The present invention relates to a reactor for producing synthetic natural gas in which an iron-based catalyst layer for FT synthesis and a nickel-based catalyst layer for methanation catalysis are laminated upstream in the order of reaction, and a method for producing high yield calorific synthetic natural gas in the reactor.

Natural gas is a major component of CH ₄ , and it is a clean fuel that generates less SO _{2 and} less NOx, dust, and CO ₂ than coal or oil during combustion, and its demand is continuously increasing worldwide. However, it is anticipated that the supply of natural gas will not follow the increase in demand. Therefore, the carbon-containing material such as coal and biomass is gasified to produce a synthesis gas which is a mixture of H ₂ and CO, (SNG: synthetic natural gas) have attracted new interest worldwide.

Coal is more than 200 years old and has the longest current fossil fuel, relatively low price per calorie, distributed in various regions around the world, and is advantageous in terms of supply and energy security.

Coal gasification technology converts most of the energy of coal into chemical energy, which reduces the efficiency of the entire process due to the temperature change in the downstream purification process. The main products of the coal gasification reaction are carbon monoxide (CO) and hydrogen (H ₂ ). These gases give a large calorific value when burned. That is, a large part of energy in the sample is converted into gas containing chemical energy such as carbon monoxide or hydrogen by the gasification reaction, and even if the gas is rapidly cooled, the chemical energy of the gas is kept as it is. The energy can be reacquired.

Coal prices have been on a downward trend due to rising oil prices and the recent decline in demand for coal due to the development of shale gas due to the indiscreet consumption of petroleum resources. In addition, according to the development plan of coal chemical industry in China, energy and chemical production technology using coal, which is relatively long and cheap in price, is attracting attention. Among them, the technology to produce synthetic natural gas from coal began with the development of methane conversion process of coal due to the surge of natural gas demand in the United States in the 1960s.

Coal gasification technology is a process of producing synthesis gas (Syngas) composed mainly of CO and H ₂ by incompletely burning coal by injecting coal into a gasifier and then producing a mixture of sulfur compounds such as COS and H ₂ S (SNG), Coal to Liquid (CTL), chemical products (methanol, DME, etc.) and power using synthetic / power generation processes.

The coal gasification system consists of a gasifier, an air separation unit as an oxygen supply unit, and a gas purification unit.

IGCC, one of the most widely known coal gasification technologies, is an eco-friendly next generation power generation technology that drives a gas turbine and a steam turbine after refining the synthesis gas by incomplete combustion and gasification reaction of low fuel at high temperature and high pressure condition to be.

Synthetic natural gas (SNG) may be natural gas obtained from coal. The method of obtaining SNG from coal includes a method of obtaining synthesis gas obtained through coal gasification through methane synthesis reaction, a method of obtaining SNG by reacting coal directly with hydrogen (Hydrogasification), a method of using coal to steam coal at low temperature To obtain SNG (catalytic gasification).

The process of producing synthetic natural gas by the gasification of coal developed so far consists of the gasification process of coal and the methanation process of synthesis gas produced by coal gasification. Although the gasification process of coal itself is complicated, the syngas methanation process to date is composed of two or three methanation reactors, or the methanation process and the C2-C4 paraffin production process are linked, and the process configuration is complicated There are difficulties in securing the operation of the process and securing facilities.

The catalyst technology, which is the core technology of the synthetic natural gas production process, was mainly developed by Ni-based catalysts such as Haldor-Topsoe, BASF, Johson & Metthey and Sud-Chemie.

The Ni-based catalyst produces 1 mole of methane and 1 mole of water from 2 moles of carbon monoxide, and the product composition is mostly composed of methane. As a result, the calorific value of the synthetic natural gas produced from the Ni-based catalyst is about 8500 Kcal / Nm ^{3, which} is much lower than that of LNG (about 10,500 Kcal / Nm ³ ) and LPG (about 12,000 Kcal / Nm ³ ) The process is complicated by linking the C2-C4 paraffin production process. Therefore, efforts have been made to develop a catalyst capable of simultaneous production of methane and C2-C4 paraffin, and to simplify the process thereof.

The present invention relates to an iron-based catalyst layer for FT synthesis and an iron-based catalyst layer for upstream reaction, in which the FT synthesis reaction and the methanation reaction are sequentially performed in a single reactor using hydrogen (H ₂ ) and carbon monoxide (CO) (SNG) containing methane and C2-C4 paraffins from hydrogen and carbon monoxide in a reactor in which a nickel-based catalyst layer is coated with a methane-based flame.

A first aspect of the present invention is a process for the production of methane and C2-C4 paraffin-containing synthetic natural gas (SNG) having a composition that exhibits a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ , FT) synthesis reaction and methanation reaction are successively carried out in a single reactor, a reactor in which an iron-based catalyst layer for FT synthesis and a nickel-based catalyst layer for methanation reaction are laminated upstream in the order of reaction, and methane and C2 -C4 paraffin-containing synthetic natural gas, wherein the amount of the nickel-based catalyst is 10 to 50 parts by weight based on 100 parts by weight of the iron-based catalyst for FT synthesis and the nickel-based catalyst for methanation reaction, lowering the _second generation while increasing the yield SNG ^{10,000Kcal / Nm 3 ~ 13,000 Kcal /} Nm 3 SNG of the charged amount of heat is characterized by containing a step of forming a synthetic gas of the following composition exhibiting calorific the manufacturing room It provides.

A second aspect of the present invention is a reactor for producing methane and C2-C4 paraffin-containing synthetic natural gas (SNG) from a hydrogen and carbon monoxide composition having a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ , -Tropsh (FT) synthesis reaction and the methanation reaction to take place in sequence in a single reactor, in accordance with the reaction sequence and is a nickel-based catalyst layer for the methanation reaction laminated on an iron-based catalyst for the FT synthesis and the downstream to the upstream, the CO ₂ generation amount 100 parts by weight of a total amount of an iron-based catalyst for FT synthesis and a nickel-based catalyst for methanation reaction so as to form a synthetic natural gas having a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ while lowering the SNG yield Wherein the amount of the deposited nickel-based catalyst is controlled to 10 to 50 parts by weight.

The process for producing the SNG of the first aspect of the present invention can be carried out in the reactor for producing the SNG of the second embodiment.

Hereinafter, the present invention will be described in detail.

The present invention relates to an iron-based catalyst layer for FT synthesis and an iron-based catalyst layer for upstream reaction, in which the FT synthesis reaction and the methanation reaction are sequentially performed in a single reactor using hydrogen (H ₂ ) and carbon monoxide (CO) methane hwaban Ni-based catalyst is in the stacked reactor containing methane and C2-C4 paraffins from hydrogen and carbon monoxide synthesis result of the production of natural gas (SNG), methane (CH ₄₎ as mainly is C2-C4 paraffin content is high It is possible to produce high-caloric synthetic natural gas, and since the conversion rate from hydrogen and carbon monoxide-containing syngas to C2-C4 hydrocarbon is higher than when the same amount of iron-based catalyst and nickel-based catalyst are physically mixed, And that the total amount of the iron-based catalyst for FT synthesis and the nickel-based catalyst for methanation is 100 Based on the weight of the nickel catalyst, the amount of the nickel-based catalyst was adjusted to 10 to 50 parts by weight to lower the amount of generated CO _2, thereby increasing SNG yield, and synthesizing a composition exhibiting a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ It is possible to form natural gas. The present invention is based on this.

<Fischer-Tropsch synthesis reaction>

n CO + 2n H ₂ - - (CH ₂ ) n + nH ₂ O

<Water Gas Conversion Reaction>

CO + H ₂ O ↔ CO ₂ + H ₂

<Methanation reaction>

n CO + 3n H ₂ ↔ nCH ₄ + nH ₂ O

Through experiments, the present inventors have found through experimentation that Fe catalysts for FT synthesis reaction and / or Fe catalysts for performing FT synthesis reaction and / or methanation reaction in which hydrogen and carbon monoxide (for example, synthesis gas) are used as a common reaction gas in one reactor The following results were identified and / or found for the first time according to the loading method of the Ni-based catalyst for the methanation reaction:

(i) When the Fe-based catalyst alone is used for the SNG synthesis reaction, the amount of heat generated by the SNG is very high, but since the SNG yield is low due to the high water gas conversion reaction activity (CO to CO ₂ conversion) When using only Ni-based catalyst, it is not suitable because of low SNG heating value due to low C2-C4 selection.

(ii) a low water gas conversion reaction activity (low CO ₂ production amount), and a high C2 (low CO conversion efficiency) when the Fe-based catalyst and the Ni-based catalyst are laminated upstream -C4 hydrocarbon selectivity, and found that SNG yield and calorific value were higher than those of other loading methods. Surprisingly, the nickel-based catalyst layer for the downstream methanation reaction has a side reaction (for example, a water gas conversion reaction) and a by-product (C5 +) of an upstream FT synthesis iron-based catalyst layer for FT synthesis using hydrogen and carbon monoxide as a common reaction gas Hydrocarbons) can be reduced.

(iii) the case where only the Fe-based catalyst layer for the FT synthesis reaction (Comparative Example 1) and the Ni-based catalyst layer for the methanation reaction were used alone (Comparative Example 2) and the sequential laminating ratios thereof were different (CO) to HC conversion (HC is abbreviated as hydrocarbon) increased with increasing use of Ni catalyst, CO to CO ₂ conversion rate decreased to the contrary Respectively. It showed a higher CO to HC conversion rate as the Fe-based screen is the unreacted CO in a catalytic methane from the Ni-containing catalyst of the bottom, instead of a part of the CO that the CO ₂ by the water gas shift reaction occurs in the Fe-based catalyst Ni-based Methanized by the catalyst and exhibited low CO to CO ₂ conversion.

(iv) because of Fe-based high is selected in my C2-C4 hydrocarbon by the FT synthesis reaction product through a catalyst even if the hydrocarbon selectivity due to the increase of the Ni-containing catalyst stacking ratio, CH ₄ selectivity is greatly increased and vice versa The C2-C4 and C5 + hydrocarbon selectivities decreased, the calorific value of SNG decreased, and the SNG yield increased.

(v) the CO conversion was about 97% when the Fe-based catalyst and the Ni-based catalyst were physically mixed (Comparative Example 3) and only the Fe catalyst was used (Comparative Example 1). In the case where the lamination method is applied (Example 2), FT reaction and methanation reaction occur step by step, and unreacted CO and generated CO ₂ in the Fe-based catalyst are methanated in the downstream Ni catalyst, Was highest in the case of using the catalyst loading method and lowest in CO ₂ .

(vi) the case where only the Fe-based catalyst is used (Comparative Example 1), the FT reaction only occurs, and thus the C2-C4 selectivity and the C5 + selectivity are high and the SNG heating value is high due to the high C2- Exhibit a low SNG yield due to high CO ₂ production due to activity and high C5 + selectivity.

In the case of Fe and Ni, the active metal is co-precipitation of Fe and Ni-containing catalyst, if used only (Comparative Example 4) and Ni-containing catalyst (Comparative Example 2) The hydrocarbon selectivity, increase the methanation reaction activity CH ₄ selectivity is very high The SNG yield is high, but the methanation reaction is very dominant and the SNG heating value is low.

The FT reaction and the methanation reaction occurred in a stepwise manner when the Fe-based catalyst and the Ni-based catalyst were laminated (Example 2), as compared with the Fe- and Ni-containing catalysts in which the Fe and Ni active metals were coprecipitated (Comparative Example 4) The CH ₄ selectivity can be lowered by lowering the methanation reaction activity, and it has been found that the heat generation amount of SNG can be increased.

The process for producing methane and C2-C4 paraffin-containing synthetic natural gas (SNG) having a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ according to the present invention

The Fischer-Tropsh (FT) synthesis reaction and the methanation reaction are sequentially carried out in a single reactor. In a reactor in which an FT-synthesizing iron-based catalyst layer is upstream and a nickel-based catalyst layer is downstream, To produce methane and C2-C4 paraffin-containing synthetic natural gas,

The FT synthetic iron-based catalyst and the methanation reaction of nickel-total based on 100 parts by weight of a catalyst for, controlling the amount of the deposited nickel-based catalyst portion 10 to 50 parts by weight to lower the CO ₂ generation amount while increasing the SNG yield 10,000 Kcal / Nm ^And a step of forming a synthetic natural gas of a composition exhibiting a high heating value of ³ to 13,000 Kcal / Nm ³ .

a phase and the FT synthesis reaction and the methanation reaction is the methanation reaction the nickel-based catalyst for laminating the iron-based catalyst and the downstream for the FT synthesis at the upstream according to the reaction sequence to take place in sequence in a single reactor, the lower the CO ₂ generation amount 100 parts by weight of the sum of the iron-based catalyst for FT synthesis and the nickel-based catalyst for methanation reaction was added so as to form a synthetic natural gas having a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ while increasing SNG yield , And the amount of the deposited nickel-based catalyst is controlled to 10 to 50 parts by weight.

Therefore, in the reactor in which the iron-based catalyst layer for FT synthesis and the nickel-based catalyst layer for methanation reaction are laminated upstream in accordance with the present invention, the synthetic natural gas produced from hydrogen and carbon monoxide is 11,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ And can have a composition that exhibits a high calorific value. In one embodiment, the synthetic natural gas may be methane: C2-C4 paraffin (molar ratio) = 1: 0.05 to 1.5.

When the amount of the nickel-based catalyst is more than 50 parts by weight based on 100 parts by weight of the sum of the iron-based catalyst for FT synthesis and the nickel-based catalyst for the methanation reaction, the amount of heat generated by the CH ₄ selectivity is low, When the amount is less than 10 parts by weight, the amount of produced CO ₂ is high and the SNG yield is low.

Further, according to Experimental Example 3, when the SNG synthesis reaction is carried out by laminating the iron-based catalyst layer for FT synthesis and the nickel-based catalyst layer for methanation reaction in the upstream direction in accordance with the present invention, the lamination ratio of the Fe- , High yield SNG can be produced at a high yield even though synthesis gas having a low H ₂ / CO ratio is used as a feed gas.

On the other hand, the FT-synthesizing iron-based catalyst used for the FT-synthesizing iron-based catalyst layer may be one produced by the precipitation method, and the Fe-based precursor solution is mixed with the precipitating agent aqueous solution, Drying and firing at 450 to 650 ° C.

Non-limiting examples of Fe-based precursors include iron nitrate, iron chloride, iron sulfate, iron acetate, and mixtures thereof.

The iron-based catalyst for FT synthesis may further contain a cocatalyst capable of easily controlling the catalyst performance. Non-limiting examples of the cocatalyst component include Mn, Cu, Co, Zn, K, Mg and combinations thereof. The Cu and Co promoters can increase methane and paraffin selectivity, and Mn is effective in improving the stability of Fe and the hydrocarbon selectivity for the synthesis of high calorie SNG. The co-catalyst component preferably maintains 0.5 to 5 parts by weight based on 100 parts by weight of the Fe metal used. When the weight of the cocatalyst is less than the lower limit, the effect of promoting the cocatalyst is insufficient, which is undesirable. If the weight of the cocatalyst is more than the upper limit, undesired side reactions may occur due to the cocatalyst.

The iron-based catalyst for FT synthesis may further contain a structural promoter component that is not active, and may be a metal oxide such as, but not limited to, alumina or silica. Structural enhancers can be used for the active metal dispersion in the Fe oxide structure. Thus, a structure enhancing agent can be added to the catalyst by co-precipitation using an aluminum precursor (e.g., aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O) without using an alumina support with other iron precursors. Further, when an aluminum precursor is used, since the ratio of the active metal in the overall composition of the catalyst can be maximized, it is possible to produce a catalyst having a high reaction activity.

The precursor of the cocatalyst and / or the precursor of the structure enhancer may further be included in the Fe-based precursor solution.

Non-limiting examples of precursors of the cocatalyst and / or of the structure enhancer include nitrates, chlorides, sulfur oxides, super oxides, and mixtures thereof.

The precipitant-containing aqueous solution for precipitating or coprecipitating Fe precursor and / or cocatalyst precursor and / or structure enhancer precursor is preferably an aqueous basic compound solution. Non-limiting examples of precipitating agents include aqueous ammonia, sodium hydroxide, potassium hydroxide, magnesium hydroxide, ammonium carbonate, sodium carbonate, potassium carbonate, and mixtures thereof.

The precipitant is preferably used in an amount of 0.9 to 1.1 equivalents based on 1 equivalent of Fe and the co-catalyst and the structure-enhancing component. If the amount of the basic compound used is less than 0.9 equivalent, the precipitation of the catalyst component is not complete. If the amount of the basic compound exceeds 1.1 equivalent, the precipitated catalyst component may be re-dissolved or the pH of the solution may be excessively increased. In addition, the pH of the basic compound aqueous solution is preferably maintained in a range of 6 to 9.

When the catalyst precursor solution and the precipitant solution are mixed, the slurry state can be obtained. The catalyst precursor solution and the precipitant solution may be stirred while heating. The slurry is heated and stirred for a predetermined time, and the heating temperature and heating time are preferably 60 to 100 ° C and 1 to 5 hours. When the heating temperature and the heating time are less than the lower limit, it is difficult to uniformly disperse the Fe active component and the cocatalyst. If the heating temperature and the heating time are more than the upper limit, the catalyst particle size increases and the active point decreases. It is not preferable.

In the precipitation filtration, the slurry is washed with deionized water, and the amount of deionized water used is preferably washed three to five times using 30 to 50 ml per 1 g of the slurry mass. If the amount of the deionized water and the number of times of washing are less than the lower limit, the removal of the impurities due to the precursor and the precipitant is insufficient, which is undesirable and when the upper limit is exceeded, there is no significant difference from the upper limit.

On the other hand, the water content of the filtrate is preferably 50 to 80%. When the moisture content is less than the lower limit, it takes a considerable time to perform slurry filtration, which is not preferable because it takes a considerable time. When the upper limit is exceeded, pores are formed due to rapid evaporation of moisture in the slurry during drying, can do.

 The filtrate is preferably dried at a temperature of 90 to 110 ° C. for 3 to 5 hours per 1 g of the slurry, and the dried product is preferably calcined at 450 to 650 ° C. for 4 to 6 hours.

If the drying temperature is lower than the lower limit, it takes a considerable time to dry the slurry, which is not efficient. When the drying temperature exceeds the upper limit, voids are formed due to rapid evaporation of moisture in the slurry, . When the drying time is lower than the above-mentioned range, the drying condition of the slurry is insufficient, which is undesirable. When the drying time is over the upper limit, the drying time is not significantly different from the upper limit and is inefficient.

If the firing temperature is less than the lower limit, the solvent and the organic impurities used in the production process are difficult to be completely removed by firing, the uniform dispersion of the active ingredient and the promoter is lowered, the catalyst strength is weak, The specific surface area and the active site of the catalyst component due to sintering of the catalytically active component may be reduced to lower the catalytic activity, so that the above range is preferably maintained.

In iron-based catalysts for FT synthesis, the iron oxide as the active metal may be Fe ₂ O ₃ , Fe ₃ O ₄ , or both. The iron-based catalyst for FT synthesis may have a specific surface area of 75 to 150 m &lt; ² &gt; / g and an average particle size of pores of 4 to 8 nm while containing magnetite of spinel structure. Here, the pore structure and the specificity of the phase can be controlled according to the composition ratio of the active metal and the calcination temperature. If the specific surface area is less than the lower limit, dispersion of the Fe active metal and the promoter is insufficient, and if it exceeds the upper limit, the dispersibility of the Fe active metal and the enhancer becomes high, but the catalyst strength is lowered.

The nickel-based catalyst for the methanation reaction used in the nickel-based catalyst layer for the methanation reaction may be one in which nickel and optionally a co-catalyst component (s) selected from Fe, Co, Zr, Ce and Ga are supported on a metal support. In the case of Ce, it is effective to improve the stability of Ni active metal, catalyst stability and hydrocarbon selectivity for synthesis of high calorie SNG. The cocatalyst component is preferably maintained at 0.5 to 50 parts by weight based on 100 parts by weight of the Ni metal used. When the weight of the cocatalyst is less than the lower limit, the effect of promoting the cocatalyst is insufficient, which is undesirable. If the weight of the cocatalyst is more than the upper limit, undesired side reactions may occur due to the cocatalyst.

The nickel based catalyst may be prepared by impregnating a support with a promoter metal precursor (s) selected from a nickel precursor and optionally Fe, Co, Zr, Ce and Ga, followed by firing.

Non-limiting examples of Ni precursors include nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, and mixtures thereof. A non-limiting example of a support is alumina. Preferably, the support may support calcium, magnesium or the like to prevent inactivation due to sintering, coking, dirt, or the like.

A reactor in which an iron-based catalyst layer for FT synthesis is upstream in the order of the reaction and a nickel-based catalyst layer for methanation reaction is laminated downstream may be a tube type reactor. As shown in FIG. 1, when the hydrogen and carbon monoxide-containing feed gas is supplied from the top of the tube type reactor and flows downward, a nickel-based catalyst layer for methanation reaction may be laminated on the FT synthesis iron- . Conversely, when the hydrogen and carbon monoxide-containing feed gas is supplied from the lower portion of the tube type reactor and flows upward, the nickel-based catalyst layer for the methanation reaction may be laminated on the FT synthesis iron-based catalyst layer below.

Meanwhile, the method for producing SNG having a high heating amount according to the present invention may further include a step of reducing the catalyst in a hydrogen atmosphere at a temperature ranging from 300 to 600 ° C before or after the step a. According to the present invention, two kinds of catalytic beds laminated in one reactor can be used in a reaction after being reduced in the same environment.

The hydrogen and carbon monoxide containing feed gas in step a may be a syngas produced from gasification of coal, biomass, heavy residues, or carbon containing waste or purified gas therefrom.

The H ₂ / CO ratio of the feed gas in step a is preferably 1.5 to 3.5. When the H ₂ / CO ratio is lower than the lower limit, the SNG yield is lowered due to the water gas conversion reaction and the carbon deposition is increased. When the upper limit is exceeded, the selectivity of the C 2 -C 4 hydrocarbon is low, It is not preferable.

The synthetic natural gas synthesis reaction conditions are not particularly limited as they are generally used.

In the step a, the reaction temperature is preferably 300 to 400 ° C., the reaction pressure is 20 to 40 bar, and the space velocity is 1000 ml / g _cat · h to 20000 ml / g _cat · h.

According to the present invention, the conversion rates on the two catalytic beds laminated in one reactor are in the range of 90-100 carbon mole% at 350 ° C, 30 atm and 6000 ml / g _cat.h space velocity .

The composition of the synthetic natural gas to be produced is 30 to 75 carbon mole% of methane and 15 to 40 carbon mole% of C2-C4 hydrocarbon. The ratio of paraffins in the C2-C4 hydrocarbon ranges from 90 to 100 carbon%, and the by-product C5 or higher hydrocarbons, specifically the C5-C12 gasoline fraction, ranges from 5 to 20 carbon%.

According to the present invention, a single reactor in which an iron-based catalyst layer for FT synthesis and a nickel-based catalyst layer for methaneization is laminated upstream in the order of reaction according to the present invention is a FT synthesis using hydrogen (H ₂ ) and carbon monoxide (CO) Reaction and methanation reaction are sequentially carried out to produce a high calorific value synthetic natural gas mainly composed of hydrogen (H ₂ ) and carbon monoxide (CO) to methane and having a high content of C2-C4 paraffin, The high conversion to C4 hydrocarbons makes it possible to produce high yield calorific synthetic natural gas in a single process.

Further, since the iron-based catalyst for FT synthesis and the nickel-based catalyst for methane-based catalyst are separately prepared and used, it is possible to simplify the manufacturing process of the catalyst than the Ni- and Fe-containing catalysts.

1 is a schematic diagram of a method of loading a catalyst according to the present invention into a reactor.
FIG. 2 is a graph of conversion and hydrocarbon selectivity according to the deposition ratio of the iron-based catalyst layer for FT synthesis and the nickel-based catalyst layer for methanation reaction.
FIG. 3 is a graph showing the heating value and yield of SNG according to the deposition rate of the iron-based catalyst layer for FT synthesis and the nickel-based catalyst layer for methanation reaction.
4 is a graph of conversion and hydrocarbon selectivity according to the method of using two kinds of active metals Fe and Ni.
FIG. 5 is a graph showing the calorific value and yield of SNG according to the method of using two kinds of active metals Fe and Ni.
FIG. 6 is a graph showing conversion and hydrocarbon selectivity according to the H ₂ / CO ratio of a catalyst obtained by laminating an Fe-based catalyst: Ni-based catalyst at 8: 2.
7 is a graph showing the amount of heat generated and the yield of SNG according to the H ₂ / CO ratio of a catalyst obtained by laminating an Fe-based catalyst: Ni-based catalyst at 8: 2.
8 is a graph of conversion and hydrocarbon selectivity according to the H ₂ / CO ratio of a catalyst obtained by laminating Fe-based catalysts: Ni-based catalysts at a ratio of 6: 4.
FIG. 9 is a graph showing a heat emission amount and yield of SNG according to the H ₂ / CO ratio of a catalyst obtained by laminating a Fe-based catalyst: Ni-based catalyst at 6: 4.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to clearly illustrate the technical features of the present invention and do not limit the scope of protection of the present invention.

EXPERIMENTAL EXAMPLE 1 Synthesis of SNG According to the Laminating Ratio of a Fe-Based Catalyst and a Ni-Based Catalyst ₂ / CO = 3) (Examples 1 to 4, Comparative Examples 1 and 2)

The composition was prepared in each of 100Fe-6Cu-16Al and _{15Ni-6Ce / MgO-Al 2} O ₃ was such that, to Fe-based, using the respective common coprecipitation method and the impregnation method in accordance with Table 1, the catalyst and Ni catalyst. Fe-based catalyst is iron nitrate _{(Fe (NO 3) 3 ·} 9H 2 O), copper nitrate _{(Cu (NO 3) 2 ·} 3H 2 O) and aluminum nitrate _{(Al (NO 3) 3 ·} 9H 2 O) a precursor (Ni (NO ₃ ) ₂ · 6H ₂ O) and cerium nitrate (Ce (NO ₃ ) ₃ · 6H ₂ O) were used as the precursors, and magnesium nitrate Mg (NO ₃ ) ₂ .6H ₂ O) supported on Al ₂ O ₃ as a support.

division Catalyst composition Catalyst preparation method Used precursor Support Fe catalyst 100Fe-6Cu-16Al Coprecipitation method Fe (NO ₃ ) ₃ .9H ₂ O,
Cu (NO ₃ ) ₂ .3H ₂ O,
Al (NO ₃ ) ₃ .9H ₂ O - Ni catalyst _{15Ni-6Ce / MgO-Al 2} O 3 Impregnation method Ni (NO ₃ ) ₂ .6H ₂ O,
Ce (NO ₃ ) ₃ .6H ₂ O MgO-Al ₂ O ₃

0.5 g of the Fe-based catalyst and the Ni-based catalyst were placed in a 1/2 inch stainless steel fixed bed reactor as shown in Fig. 1, and the Ni-based catalyst was placed in the lower part of the reactor in the ratio shown in Table 2 below. To allow the Fe-based catalyst to contact the syngas prior to the Ni-based catalyst. That is, the FT synthesis reaction first occurred in the upper Fe-based catalyst, followed by the methanation reaction in the lower Ni-based catalyst. The catalytic reduction was carried out under H ₂ atmosphere for 4 h at 400 ° C. The SNG synthesis reaction was carried out at 350 ° C. and 30 bar under the condition of SV = 6000 ml / g _cat · h and H ₂ / CO = Respectively.

division Fe-based catalyst: Ni-based catalyst Fe-based catalyst composition Ni-based catalyst composition Example 1 (0.45 g) in 9: 1 (0.05 g)
100Fe-6Cu-16Al


_{15Ni-6Ce / MgO-Al 2} O 3

Example 2 (0.40 g) in 8: 2 (0.10 g) Example 3 (0.35 g) in 7: 3 (0.15 g) Example 4 (0.30 g) was dissolved in 6: 4 (0.20 g) Comparative Example 1 (0.50 g) in 10: 0 (0.00 g) 100Fe-6Cu-16Al - Comparative Example 2 (0.00 g) was dissolved in a 0: 10 (0.50 g) - _{15Ni-6Ce / MgO-Al 2} O 3

2 shows the conversion and hydrocarbon selectivity according to Examples 1 to 4 and Comparative Examples 1 and 2.

CO conversion was close to 100% in all of Examples 1 to 4 and Comparative Examples 1 and 2 in which the laminating ratios were different. The CO to HC conversion rate increased with increasing use of Ni catalyst and the CO to CO ₂ conversion rate decreased inversely. Showed a higher CO to HC conversion rate as unreacted in the Fe-based catalyst of CO Chemistry methane in the Ni-containing catalyst of the lower part, instead of the unreacted CO is CO ₂ by the water gas shift reaction occurs in the Fe-based catalyst Ni Based catalysts and showed low CO to CO ₂ conversion.

In the case of hydrocarbon selectivity, the selectivity of CH ₄ was greatly increased with increasing the Ni-based catalyst deposition rate, while the selectivity of C2-C4 and C5 + hydrocarbons was decreased. Paraffin selectivity was very high (97%) for all catalysts.

FIG. 3 shows the SNG heating value and the yield according to Examples 1 to 4 and Comparative Examples 1 and 2.

The calorific value of the synthesized SNG was greatly decreased by increasing CH ₄ selectivity as the Ni - based catalyst layer ratio increased. Fe-based catalysts and Ni-based catalysts were 9: 1 and 12,122 Kcal / Nm ³ , respectively, and decreased as the Ni-based catalyst layer ratio increased. When the deposition rate was 6: 4, the calorific value was 10,041 Kcal / Nm up to ³ However, it was much higher than the heating value of 8,450 ~ 8,675 Kcal / Nm ³ of SNG produced in the general process. This is because the selectivity of C2-C4 hydrocarbons in the product is high due to the FT synthesis reaction through the Fe-based catalyst. The SNG yields were increased by decreasing CO ₂ generation and C 5 + hydrocarbon selectivity with increasing Ni-based catalyst laminating ratio, and increasing SNG yields by increasing the Ni-based catalyst laminating ratio. Was the highest at 6: 4 (about 85%).

Therefore, Fe-containing catalyst with Ni-based if the Ni ratio of the layered parts by weight of 100 of the catalyst exceeds 50 parts by weight of high-CH ₄ is not suitable because the selectivity of low calorific value by, is less than 10 parts by weight increases the CO ₂ generation amount SNG Not suitable because of low yield.

Experimental Example 2: Synthesis reaction characteristics of SNG according to the method of using two kinds of active metals of Fe and Ni (Example 2, Comparative Examples 1 to 4)

As shown in Table 3, Comparative Example 3 was used by physically mixing the same Fe-based catalyst and Ni-based catalyst used in Comparative Examples 1 and 2, respectively.

In order to compare the SNG synthesis reaction characteristics of Example 2 with the SNG synthesis reaction characteristics of catalysts in which Fe and Ni active metals coexist, Comparative Example 4 uses the same metal precursors as Comparative Examples 1 and 2, To prepare an 80Fe-20Ni-20Al catalyst.

division Fe catalyst: Ni catalyst Manufacturing method ratio Loading method Comparative Example 1 100Fe-6u-16Al Coprecipitation method 10 - Comparative Example 2 _{15Ni-6Ce / MgO-Al 2} O 3 Impregnation method 10 - Comparative Example 3
100Fe-6u-16Al Coprecipitation method 8 Physical mixing
_{15Ni-6Ce / MgO-Al 2} O 3 Impregnation method 2 Comparative Example 4 80Fe-20Ni-20Al Coprecipitation method 10 -

In order to confirm SNG synthesis reaction characteristics when Fe-based catalyst and Ni-based catalyst were stacked, SNG synthesis reaction characteristics according to Example 2 and Comparative Examples 1 to 4 were compared.

FIG. 4 shows CO conversion and hydrocarbon selectivity for Example 2 and Comparative Examples 1 to 4.

The CO conversion rate was close to 100% in most of the catalyst loading methods, but about 97% in the case of Fe catalyst alone and Fe catalyst and Ni catalyst (Comparative Example 3). The CO to HC conversion ratio was the highest when the catalyst loading method was applied and the CO ₂ emission was the lowest. This is because the FT reaction and the methanation reaction occur in a stepwise manner when the above lamination method is applied, and the unreacted CO and the generated CO ₂ in the Fe-based catalyst are methanized in the lower Ni catalyst.

The hydrocarbon selectivity showed the highest C2-C4 selectivity and C5 + selectivity because only the FT reaction occurred when only Fe-based catalysts were used (Comparative Example 1), and only 80 Fe-20Ni-20Al catalysts were used (Comparative Example 4 ) And Ni-based catalysts (Comparative Example 2), CH ₄ selectivity was very high because of the high methanation reaction activity. When the Fe-based catalyst and the Ni-based catalyst were laminated (Example 2), the FT reaction and the methanation reaction occurred step by step, showing relatively low CH ₄ selectivity and C2-C4 selectivity. Paraffin selectivity was about 100% in all results, except when only Fe catalyst was used.

FIG. 5 shows the amounts of SNG generated and the yields of the catalysts prepared in Example 2 and Comparative Examples 1 to 4.

If the heating value of the synthesis SNG is used only the Fe-containing catalyst (Comparative Example 1), due to high C2-C4 selectivity, heat value of about 13,800 was highest in Kcal / Nm ^3, the high CO ₂ production and C5 + selectivity due to a very low Yield. If only with Ni-containing catalyst (Comparative Example 2) in the case of using only 80Fe-20Ni-20Al catalyst (Comparative Example 4), but a high yield, amount of heat generated by the methanation reaction is very predominantly is, from about 9,500 Kcal / Nm ^3, and 10,000 Kcal / Nm ³ . On the other hand, when the Fe-based catalyst and the Ni-based catalyst were laminated (Example 2), the amount of generated CO ₂ and the selectivity of C ₂ -C 4 were higher than those of other catalyst loading methods.

Therefore, when only Fe-based catalyst is used for the SNG synthesis reaction, SNG yield is low due to high water gas conversion reaction activity and C5 + selection. When using only Ni catalyst, SNG heating value is low due to low C2-C4 selection Inappropriate. The method of laminating an Fe-based catalyst and a Ni-based catalyst inducing the FT reaction and the methanation reaction stepwise showed a low water gas conversion reaction activity and a high C2-C4 hydrocarbon selectivity, and thus the SNG calorific value and yield Was higher than the other loading methods.

Experimental Example 3: Synthesis of H ₂ Synthesis of SNG Syntheses of Fe-Ni Binary Metal Hybrid Catalysts by CO Ratio

The Fe-based catalyst and the Ni-based catalyst were produced and the reaction conditions were the same as in Experimental Example 1 above. However, SNG synthesis reaction characteristics of the Fe-Ni hybrid catalyst were confirmed by varying the H ₂ / CO ratio in the feed gas from 1 to 3. Table 4 below summarizes the H ₂ / CO ratio and the catalyst deposition rate in the feed gas according to each of the examples and the comparative examples.

division H ₂ / CO ratio Fe-based catalyst: Ni-based catalyst Example 2 3 (0.40 g) in 8: 2 (0.10 g) Example 4 3 (0.30 g) was dissolved in 6: 4 (0.20 g) Example 5 2.7 (0.40 g) in 8: 2 (0.10 g) Example 6 2.7 (0.30 g) was dissolved in 6: 4 (0.20 g) Example 7 2.5 (0.40 g) in 8: 2 (0.10 g) Example 8 2.5 (0.30 g) was dissolved in 6: 4 (0.20 g) Example 9 2 (0.40 g) in 8: 2 (0.10 g) Example 10 2 (0.30 g) was dissolved in 6: 4 (0.20 g) Comparative Example 5 One (0.40 g) in 8: 2 (0.10 g) Example 11 One (0.30 g) was dissolved in 6: 4 (0.20 g)

FIG. 6 shows the conversion and hydrocarbon selectivity depending on the H ₂ / CO ratio of the catalyst obtained by laminating the Fe-based catalyst: Ni-based catalyst at 8: 2.

CO conversion in the H ₂ / CO ratio in all feed gases was close to 100%. As the H ₂ / CO ratio increased, CO to HC conversion decreased and CO ₂ production increased.

In the case of hydrocarbon selectivity, as the H ₂ / CO ratio in the feed gas decreased to 2.5 and 2, the CH ₄ selectivity decreased and the C2-C4 selectivity increased. Under the condition of H ₂ / CO ratio of 2, the carbon chain growth rate was increased due to the lack of H ₂ in the relative feed, and the C 5 + selectivity was greatly increased. Paraffin selectivity was close to 100% under all conditions.

FIG. 7 shows the SNG calorific value and yield according to the H ₂ / CO ratio of the catalyst obtained by laminating the Fe-based catalyst: Ni-based catalyst at 8: 2.

The calorific value of the synthesized SNG was higher than 11,100 Kcal / Nm ³ and increased with decreasing H ₂ / CO ratio. In the condition of H ₂ / CO ratio 2, the heating value was relatively low due to the low C2-C4 selection, and the yield of SNG was about 50% because of the high CO ₂ production amount and C 5 + selection.

FIG. 8 shows CO conversion and hydrocarbon selectivity depending on the H ₂ / CO ratio of the catalyst obtained by laminating the Fe-based catalyst: Ni-based catalyst at 6: 4.

The CO conversion was close to 100% in all H ₂ / CO ratios. The CO to HC conversion was decreased and the CO ₂ production was increased by the increase of water gas conversion reaction activity with decreasing H ₂ / CO ratio.

In the case of hydrocarbon selectivity, the selectivity of CH _{4 was} about 70% or higher at the H ₂ / CO ratio of 2.7 or higher in the feed gas, and decreased greatly with decreasing H ₂ / CO ratio. The C2-C4 selectivity increased with decreasing H ₂ / CO ratio from 3 to 2.5. In the case of H2 / CO ratio of 2, the carbon chain growth rate was increased due to the lack of H ₂ in the relative feed, Respectively. Paraffin selectivity was close to 100% under all conditions.

FIG. 9 shows the SNG calorific value and yield according to the H ₂ / CO ratio of the catalyst obtained by laminating the Fe-based catalyst: Ni-based catalyst at 6: 4.

The calorific value of the synthesized SNG was higher than 10,000 Kcal / Nm ³ and increased with decreasing H ₂ / CO ratio. In the condition of H ₂ / CO ratio 2, the heating value was relatively low due to the low C2-C4 selection, and the yield of SNG was about 50% because of the high CO ₂ production amount and C 5 + selection.

From the experimental results described above, the Fe-based catalyst and Ni-based when stacking the catalyst to proceed with the SNG synthesis reaction, Fe-based catalyst, and by controlling the lamination ratio of the Ni-based catalyst, a low H ₂ / CO ratio is low synthesis gas to feed gas It is possible to produce high yield SNG with a high yield.

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, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the scope of protection of the present invention is not limited to the specific embodiments but should be construed as including all embodiments belonging to the claims attached to the present invention.

Claims (14)

A method for producing methane and C2-C4 paraffin-containing synthetic natural gas (SNG) having a composition capable of exhibiting a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ ,
The Fischer-Tropsh (FT) synthesis reaction and the methanation reaction are sequentially carried out in a single reactor. In a reactor in which an FT-synthesizing iron-based catalyst layer is upstream and a nickel-based catalyst layer is downstream, To produce methane and C2-C4 paraffin-containing synthetic natural gas,
The FT synthetic iron-based catalyst and the methanation reaction of nickel-total based on 100 parts by weight of a catalyst for, controlling the amount of the deposited nickel-based catalyst portion 10 to 50 parts by weight to lower the CO ₂ generation amount while increasing the SNG yield 10,000 Kcal / Nm Step a to form a synthetic natural gas having a high heating value of ³ to 13,000 Kcal / Nm ³
&Lt; / RTI &gt; wherein the method further comprises the steps of: The method according to claim 1, wherein step (a) exhibits a higher CO conversion and a higher SNG calorific value than when an iron-based catalyst and a nickel-based catalyst are physically mixed in the same amount. The method according to claim 1, wherein step (a) comprises laminating an iron-based catalyst layer and a nickel-based catalyst layer in such a manner that the FT reaction and the methanation reaction proceed step by step, thereby increasing SNG yield by lowering the water- SNG production method. The method according to claim 1, wherein in step (a), the FT reaction and the methanation reaction are progressed stepwise so that unreacted CO and generated CO ₂ in the upstream iron-based catalyst layer are methanized in the downstream nickel-based catalyst layer, Which is characterized in that the CO to HC conversion ratio is increased and the CO ₂ generation amount is reduced compared with the case where only the SNG is used. The method according to claim 1, wherein step (a) increases the CO to HC conversion ratio as the unreacted CO in the upstream iron-based catalyst layer is methanized in the downstream nickel-based catalyst layer, and part of the CO is oxidized in the iron- ₂ is generated instead of methane in the nickel-based catalyst layer to lower CO to CO ₂ conversion. 2. The method of claim 1, wherein the step (a) increases the CO to HC conversion ratio and decreases the CO to CO ₂ conversion rate with an increase in the use ratio of the nickel-based catalyst. The method according to claim 1, wherein in step (a), an iron-based catalyst layer and a nickel-based catalyst layer are laminated upstream and downstream so that the FT reaction and the methanation reaction proceed stepwise, compared to, SNG production method of the charged amount of heat is characterized by lowering the methanation reaction activity in the nickel-based catalyst lowers the selecting CH ₄ also increase the heating value of the SNG. The process according to any one of claims 1 to 7, further comprising a step of reducing the catalyst in a hydrogen atmosphere at a temperature ranging from 300 to 600 ° C before or after the step a. . 8. The process according to any one of claims 1 to 7, wherein the synthetic natural gas is methane: C2-C4 paraffin (molar ratio) = 1: 0.05 to 1.5. The process according to any one of claims 1 to 7, wherein the H ₂ / CO ratio in the feed gas in step a is 1.5 to 3.5. The process according to any one of claims 1 to 7, wherein the reaction pressure in step a is 20 to 40 bar, the reaction temperature is 300 to 400 ° C, the space velocity is 1000 ml / g _cat · h to 20000 ml / g _{cat &lt; RTI ID = 0.0} &gt; h. &lt; / RTI &gt; The process according to any one of claims 1 to 7, wherein the hydrogen and carbon monoxide containing feed gas in step a is a syngas produced by gasifying coal, biomass, or carbonaceous waste or purified gas therefrom A method for producing SNG of high calorific value. 1. A reactor for producing methane and C2-C4 paraffin-containing synthetic natural gas (SNG) in a composition which exhibits a high heating value of from 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ from hydrogen and carbon monoxide,
A Fischer-Tropsh (FT) synthesis reaction and a methanation reaction are successively carried out in a single reactor, and an iron-based catalyst layer for FT synthesis and a nickel-based catalyst layer for methanation reaction are laminated upstream in the order of reaction,
Based catalyst for FT synthesis and a nickel-based catalyst for methanation reaction so as to form a synthetic natural gas having a high heating value of 10,000 Kcal / Nm ³ to 13,000 Kcal / Nm ³ while increasing the SNG yield by lowering the CO ₂ generation amount Wherein the amount of the nickel-based catalysts is controlled to 10 to 50 parts by weight based on 100 parts by weight of the total. 14. The reactor for producing SNG according to claim 13, which is characterized in that it is for use in the high heat amount SNG production method according to any one of claims 1 to 7.

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