CN1240757A - Process for preparing synthetic gas by two-stage catalytic oxidization of natural gas - Google Patents

Abstract

The present invention is a combination of low-temperature catalytic combustion and partial oxidation of natural gas to produce synthesis gas, including the required catalyst and its preparation. Catalytic oxidation is carried out in two-stage reactors, and 10-60% of the total oxygen intake is added to the first-stage reaction. In the second stage, the remaining oxygen is added, and the catalyst contains _nickel oxide, _{alkaline earth} or rare earth oxide _. 20%. M1 ~ 15%. The invention has high conversion rate and good selectivity, eliminates the possibility of explosion, can realize the industrialized production of synthesis gas, and has a simple reactor structure, low cost, and is safe and reliable. The catalyst has good stability, anti-sintering, good regeneration and anti-coking ability, and the price is cheap. At 800°C and 1 atm, feed gas space velocity GHSV=5000/h, methane conversion >94%, _H2 and CO selectivities are over 98% and 96% respectively.

Description

A method for producing synthesis gas by two-stage catalytic oxidation of natural gas

The invention relates to a technology for combining synthesis gas with low-temperature catalytic combustion and partial oxidation of natural gas, including a catalyst required for the reaction process and its preparation, in particular to a method for producing synthesis gas through two-stage catalytic oxidation of natural gas.

Catalytic partial oxidation of natural gas to synthesis gas is a natural gas utilization method with great industrial application prospects, but there is a risk of explosion due to the mixture of natural gas and air or pure oxygen, and the explosion limit range widens with the increase of temperature and pressure , such as when the original pressure is 101.3kPa, the lower explosion limit of methane is 5.6%, and the upper limit is 14.3; when the original pressure is 1013.0kPa, the lower explosion limit of methane is 5.9%, and the upper limit is 17.2; The lower limit is 5.7%, and the upper limit is 45.7. Since the downstream utilization of synthesis gas needs to be carried out under a certain pressure, the production of synthesis gas under a certain pressure is more practical. However, if the reaction pressure is 5×10 ⁶ Pa, the composition of the theoretical feed gas of methane and oxygen is close to the upper limit of the explosion limit, and the production is dangerous. At the same time, the oxidation reaction of natural gas is an exothermic reaction, and the reaction heat needs to be removed in time. Otherwise, it will cause catalyst sintering and damage to the material of the reactor, and also bring many difficulties to the operation. Patent No. 91108515 proposes a reaction method for producing synthesis gas from natural gas that is combusted and converted separately, but the reaction process adopts the method of feeding methane in stages, which cannot effectively avoid the risk of explosion during the reaction. At the same time, the process uses platinum group metals as catalysts , especially rhodium, ruthenium, palladium and platinum as the active components in the reaction, and these metal elements are expensive, the production cost is high, and it is difficult to be widely used in industry.

The purpose of the present invention is to provide a safe, reliable and low-cost synthesis gas production technology, including the required catalyst and its preparation, which is a method for producing synthesis gas by two-stage catalytic oxidation of natural gas.

The present invention realizes through following technical scheme:

A method for producing synthesis gas by two-stage catalytic oxidation of natural gas is characterized in that the catalytic oxidation of natural gas is carried out in stages in two connected atmospheric pressure fixed-bed reactors, and 10- 60%, carry out the following reaction: , the reactor is burned at 200-500°C, the pressure is 0.1-5.0MPa, and the metal oxide catalyst or oxide catalyst is added; the remaining oxygen is added to the second-stage reactor, and the following reaction is carried out: , burning at 700-1000°C, pressure 0.1-5.0MPa, the catalyst used in the reactor contains nickel oxide, alkaline earth or rare earth oxide, the composition formula is: Ln _x O _y -Ni base/M Al ₂ O ₄ ; The loading (weight) of the components relative to the carrier is: Ni1.0-20%, Ln1-20%, M1-15%; the reaction product of the first stage and the oxygen or water added in the second stage Mixing between reactors.

The present invention is also realized through the following technical solutions:

The side reaction of oxygenation in the first stage reactor is , the side reaction of adding oxygen in the second stage reactor is and . The first-stage reactor burns at 200-500°C and the pressure is 0.1-5.0MPa, and the second-stage reactor burns at 700-1000°C and the pressure is 0.1-5.0MPa.

In the first stage of reaction, metal oxide catalyst or oxide catalyst is added.

The catalyst used in the second-stage reactor contains nickel oxide, alkaline earth or rare earth oxide, and the composition formula is: Ln _x O _y -Ni base/M Al ₂ O ₄ ; ) is: Ni1.0-20%, Ln1-20%, M1-15%.

In each component, Ln can be elements La, Ce, Mg, Ca, Ba, Co, Pd, and M can be elements Ni, Co, Mg, Ca, Ba. The support or support surface is a spinel structure.

The catalyst preparation method used in the second stage reactor comprises the steps:

a. Take an appropriate amount of Al(NO ₃ ) ₃ and the second component (M)Ni, Co, Mg, Ca, Ba solution, with NH ₃ ·H ₂ O, NH ₄ HCO ₃ or (NH ₄ ) ₂ CO ₃ The solution is a precipitating agent, which is completely precipitated, aged, washed and dried to prepare a carrier precursor;

b. The precursor prepared in step a is calcined for 5-24 hours at a temperature of 700-1200° C., and a spinel structure is formed on the carrier or the surface of the carrier;

c. immerse the carrier containing the spinel structure prepared in the above step b into the mixed solution of the active component (Ni) and the auxiliary agent (Ln) of suitable composition, so as to immerse into the incipient wetness;

d. Place the catalyst precursor prepared in the above step c, dry it, and activate it at 550-650° C. for 5-15 hours.

In step a, γ-Al ₂ O ₃ may be soaked in incipient wetness, soaked in an appropriate amount of second component Ni, Co, Mg, Ca, Ba solution, and dried.

The present invention is described in detail below in conjunction with embodiment:

In the present invention, the catalytic oxidation of natural gas is carried out in stages in two connected reactors. In the first stage reactor, 10-60% of the total oxygen intake is added earlier, and the following reactions are carried out: , the side reaction is , so that the proportion of methane in the feed gas composition at the reactor inlet deviates from the explosion limit. In this section of the reactor, low-temperature catalytic conversion of methane is used instead of non-catalytic combustion, which reduces the requirements on the material of the reactor. The use of air or oxygen-enriched air as an oxygen source avoids the possibility of the reaction of N ₂ and O ₂ to generate NOx under high temperature conditions in non-catalytic combustion, and reduces environmental pollution. The adiabatic temperature rise of the combustion reaction in the first-stage reactor is 300-600°C, which can effectively heat the raw material gas to the reaction temperature of 700-1000°C required by the second-stage reactor. The remaining oxygen, oxygen-enriched air or air is supplemented at the inlet of the second stage reactor, and the reaction product of the first stage is mixed with the oxygen or water added in the second stage between the first stage and the second stage reactor, and the following reaction is carried out in the second stage : . The side reaction is and . Since part of the oxygen has been consumed in the first stage, and inert components such as H ₂ O and CO ₂ exist in the product of the first stage reactor, the composition of the raw material gas at the inlet of the second stage reactor deviates further from the explosion limit. The first-stage reactor adopts low-temperature feed and generates H ₂ O and CO ₂ to carry out reforming reaction in the second-stage reactor, and the partial oxidation reaction, steam reforming and CO ₂ reforming in the second-stage reactor are carried out simultaneously, The adiabatic temperature rise of the second-stage reactor can be reduced, so the fixed-bed adiabatic reactor can be used to realize the industrial production of synthetic gas by catalytic oxidation of natural gas.

The catalyst used in the first-stage reactor of the present invention can be a combustion catalyst commonly used at present. The combustion catalyst is divided into a metal catalyst and an oxide catalyst. The metal catalyst can include Pt, Pd, Cu, etc., and the oxide includes TiO ₂ , CeO ₂ , V ₂ O ₃ etc. The catalyst carrier is Al ₂ O ₃ .

The catalyst used in the second stage reactor of the present invention contains nickel oxide, alkaline earth or rare earth oxide, and the component formula is: Ln _x O _y -Ni base/M Al ₂ O ₄ ; Wherein the loading of each component relative to the carrier ( Weight) is: Ni1.0～20%, Ln1～20%, M1～15%, Ln can be elements La, Ce, Mg, Ca, Ba, Co, Pd, M can be elements Ni, Co, Mg, Ca , Ba, the catalyst support or the surface of the support is a spinel structure.

The following are the catalyst preparation examples used in the second stage reactor:

Catalyst preparation example one:

Take 0.5 g of commercially available γ-Al ₂ O ₃ , soak it in 0.09 ml of 2M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 900°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 0.10ml 1M Ni(NO ₃ ) ₂ and 0.76ml 0.1M La(NO ₃ ) ₃ solution, impregnated for 24 hours, dried at 80°C, and baked at 630°C for 6 hours. The loading amount of each component relative to the carrier is: Ni1%, Ln=La2%, M=Mg1%. Catalyst preparation example two:

Take 0.5 g of commercially available γ-Al ₂ O ₃ , soak it in 0.59 ml of 1M Co(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 1100°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 0.60ml 1M Ni(NO ₃ ) ₂ and 0.63ml 1M Mg(NO ₃ ) ₂ solution, soaked for 24 hours, dried at 80°C, and baked at 630°C for 6 hours. The loading amount of each component relative to the carrier is: Ni8%, Ln=Mg3%, M=Co5%. Catalyst preparation example three:

Take 1 gram of commercially available γ-Al ₂ O ₃ , soak it in 0.72ml 2M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 1100°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 0.60ml 1M Ni(NO ₃ ) ₂ and 3.16ml 0.1M Ba(NO ₃ ) ₂ solution, soak for 24 hours, dry at 80°C, and bake at 550°C for 6 hours. The loading amount of each component relative to the carrier is: Ni3.5%, Ln=Ba12%, M=Mg3.5%. Catalyst preparation example four:

Take 200ml of 1M Al(NO ₃ ) ₃ and 14.69ml of 2M Mg(NO ₃ ) ₂ solution, slowly drop the concentrated NH ₄ OH solution into the solution until the pH of the solution is 14, and maintain the solution temperature at 40°C during the precipitation process. The stirring speed is slowly increased to 1800 rev/min from the initial 1200 rev/min as the viscosity of the solution increases. After the reaction, maintain the same temperature and stirring speed for two hours, stop stirring and heating, precipitate for 100 hours, filter with suction, and wash overnight. Dry at 80°C for 12h and 120°C for 12h, bake at 900°C for 10h, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier was immersed in 12.16ml of 1M Ni(NO ₃ ) ₂ and 2.68ml of 1M Ca(NO ₃ ) ₂ solution for 24 hours, dried at 80°C, and calcined at 500°C for 6 hours. The loading amount of each component relative to the carrier is: Ni 71%, Ln=Ca9%, M=Mg7%. Catalyst preparation example five:

Take 2 grams of commercially available γ-Al ₂ O ₃ , soak it in 5 ml of 1M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 900°C for 10 hours, cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier, and immerse the prepared carrier in 5ml 1M Ni(NO ₃ ) ₂ and 30ml 1M Ba(NO ₃ ) ₂ solution, soaked for 24h, dried at 80°C, and baked at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni15%, Ln=Co20%, M=Mg15%. Catalyst preparation example six:

Take 100ml 2M Al(NO ₃ ) ₃ and 7.5ml 2M Mg(NO ₃ ) ₂ solution, slowly drop 320ml 1M(NH ₄ ) ₂ CO ₃ solution into the solution, keep the solution temperature at 40°C during the precipitation process, stir The speed starts at 1200 rev/min, and slowly increases to 2000 rev/min as the viscosity of the solution increases. After the reaction, maintain the same temperature and stirring speed for two hours, stop stirring and heating, precipitate for 100 hours, filter with suction, and wash overnight. Dry at 80°C for 12h and 120°C for 12h, bake at 1100°C for 10h, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier was immersed in 12.16ml of 1M Ni(NO ₃ ) ₂ and 14.65ml of 1M La(NO ₃ ) ₃ solution for 24 hours, dried at 80°C, and calcined at 500°C for 6 hours. The loading amount of each component relative to the carrier is: Ni7%, Ln=La20%, M=Mg3%. Catalyst preparation example seven:

Take 2 grams of commercially available γ-Al ₂ O ₃ , soak it in 0.5 ml of 1M Ca(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 900°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 5ml 1M Ni(NO ₃ ) ₂ and 2ml 0.5M Ce(NO ₃ ) ₂ solution, impregnated for 24 hours, dried at 80°C, and baked at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni15%, Ln=Ce2%, M=Ca1%. Catalyst preparation example eight:

Take 1 gram of commercially available γ-Al ₂ O ₃ , soak it in 1.44ml 2M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12h, bake at 1100°C for 10h, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier, and immerse the prepared carrier in 2ml of 1M Ni(NO ₃ ) ₂ and 0.15g of 0.88wt% PdCl ₂ solution , impregnated for 24h, dried at 80°C, and fired at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni12%, Ln=Pd1%, M=Mg7%. Catalyst preparation example nine:

Take 1 gram of commercially available γ-Al ₂ O ₃ and soak it in 0.165 ml of 0.5M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 1100°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 0.5ml 1M Ni(NO ₃ ) ₂ and 0.72ml 0.1M La(NO ₃ ) ₃ solution, soak for 24 hours, dry at 80°C, and bake at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni3%, Ln=La1%, M=Mg1%. Catalyst preparation example ten:

Take 1 g of commercially available γ-Al ₂ O ₃ , soak it in 3.09 ml of 2M Mg(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 1100°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 2.9ml 1M Ni(NO ₃ ) ₂ and 10.8ml 0.1M La(NO ₃ ) ₃ solution, soak for 24 hours, dry at 80°C, and bake at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni17%, Ln=La15%, M=Mg15%. Catalyst preparation example eleven:

Take 2 grams of commercially available γ-Al ₂ O ₃ , soak it in 0.5 ml of 1M Ba(NO ₃ ) ₂ solution overnight. Dry at 80°C for 12 hours, bake at 900°C for 10 hours, and cool naturally to room temperature to form a spinel structure on the carrier or the surface of the carrier. The prepared carrier is immersed in 5ml 1M Ni(NO ₃ ) ₂ and 2ml 0.5M Ce(NO ₃ ) ₂ solution, impregnated for 24 hours, dried at 80°C, and baked at 600°C for 6 hours. The loading amount of each component relative to the carrier is: Ni15%, Ln=Ce2%, M=Ba1%.

The following examples further illustrate the synthesis gas reaction of the present invention.

Reaction Example 1: Adopt two sections of interconnected normal pressure fixed-bed reactors, add natural gas (the total ratio of methane and oxygen is 2:1) and oxygen accounting for 10% of the total oxygen amount to the first section of the reactor inlet, and the inlet temperature is 350 ℃. The oxide catalyst used in the first stage is TiO ₂ , and the amount added depends on the capacity of the reactor. Add the remaining 90% of oxygen between the second-stage reactor and the first-stage reactor to mix it with the first-stage reaction product. The catalyst in the above-mentioned second-stage catalyst preparation example is selected, and the amount of addition varies with the capacity of the reactor. Set, the reaction temperature is 700°C, and the raw material gas space velocity GHSV=5000/h. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 90.3 82.8 7.5 91.7 89.3 98.8

Reaction Example 2: 12% of the total oxygen is added to the inlet of the first-stage reactor, and the inlet temperature is 300°C. The oxide catalyst used in the first stage is CeO ₂ . The remaining 88% of oxygen is added between the second-stage reactor and the first-stage reactor, and the catalyst in the above-mentioned second-stage catalyst preparation example is selected, the reaction temperature is 750° C., and the space velocity of raw material gas GHSV=5000/h. All the other reaction conditions are the same as example one. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 90.8 86.5 4.3 95.2 88.4 97.3

Reaction Example 3: Oxygen accounting for 15% of the total oxygen is added to the inlet of the first-stage reactor, and the inlet temperature is 300°C. The oxide catalyst used in the first stage is Pd-Ni/Al ₂ O ₃ . The remaining 85% of oxygen is added between the second-stage reactor and the first-stage reactor, the catalyst in the above-mentioned second-stage catalyst preparation example is selected, the reaction temperature is 800° C., and the raw material gas space velocity GHSV=5000/h. All the other reaction conditions are the same as example one. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 96.6 94.8 1.8 98.2 95.8 99.2

Reaction Example 4: 25% of the total oxygen is added to the inlet of the first-stage reactor, and the inlet temperature is 350°C. The oxide catalyst used in the first stage is Pd-Pt/Al ₂ O ₃ . Add the remaining 75% of oxygen between the second-stage reactor and the first-stage reactor, select the catalyst in the above-mentioned second-stage catalyst preparation example, the reaction temperature is 850°C, the reaction pressure is 0.4Mpa, and the raw material gas space velocity GHSV=50000/ h. All the other reaction conditions are the same as example one. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 88.0 80.0 8.0 90.9 86.0 97.7

Reaction Example 5: Oxygen accounting for 60% of the total oxygen is added to the inlet of the first-stage reactor, and the inlet temperature is 450°C. The oxide catalyst used in the first stage is CeO ₂ . Add the remaining 40% of oxygen between the second-stage reactor and the first-stage reactor, select the catalyst in the above-mentioned second-stage catalyst preparation example, the reaction temperature is 950 °C, the reaction pressure is 2.5Mpa, and the raw material gas space velocity GHSV=150000/ h. All the other reaction conditions are the same as example one. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 80.2 73.2 7.0 91.2 71.1 88.6

Reaction Example 6: Oxygen accounting for 45% of the total oxygen is added to the inlet of the first-stage reactor, and the inlet temperature is 400°C. The oxide catalyst used in the first stage is NiO. Add the remaining 55% oxygen between the second-stage reactor and the first-stage reactor, select the catalyst in the above-mentioned second-stage catalyst preparation example, the reaction temperature is 900 ° C, the reaction pressure is 1.5Mpa, and the raw material gas space velocity GHSV=100000/ h. All the other reaction conditions are the same as example one. The reaction results are shown in the table below: CH ₄ Conversion (%) CO yield (%) _CO2 yield (%) CO selectivity (%) _H2 yield (%) _H2 selectivity (%) 88.0 80.0 8.0 90.9 86.0 97.7

The invention can use natural gas field gas, oil field associated gas or refinery gas, has the characteristics of high methane conversion rate and good product selectivity, eliminates the possibility of explosion under pressure operation, uses reaction heat to heat raw material gas, adopts conventional The fixed-bed adiabatic reactor realizes the industrial production of synthesis gas, and the reactor has simple structure, low cost, easy operation, safety and reliability. The catalyst used has high stability, high selectivity, high activity, anti-sintering, anti-loss, good regeneration and anti-coking capabilities, and the components are cheap.

Claims (10)

1. A method for producing synthesis gas by two-stage catalytic oxidation of natural gas, characterized in that the catalytic oxidation of natural gas is carried out in stages in two connected reactors, adding 10-60% of the total oxygen intake in the first stage reactor , the following reaction takes place: , add the remaining amount of oxygen in the second stage reactor, and carry out the following reaction: . 2. a kind of method for producing synthesis gas by two-stage catalytic oxidation of natural gas according to claim 1, is characterized in that the side reaction of adding oxygen in the first stage reactor is , the side reaction of adding oxygen in the second stage reactor is and . 3. A method for preparing synthesis gas by two-stage catalytic oxidation of natural gas according to claim 1, characterized in that the first stage reactor burns at 200-500°C and the pressure is 0.1-5.0MPa, and the second stage reactor burns at 700-1000℃, pressure 0.1-5.0MPa. 4. A method for preparing synthesis gas by two-stage catalytic oxidation of natural gas according to claim 1, characterized in that the reaction product of the first stage is mixed with the oxygen or water added in the second stage between the first-stage reactor and the second-stage reactor. 5. A method for preparing synthesis gas by two-stage catalytic oxidation of natural gas according to claim 1, characterized in that the first stage of reaction adds metal oxide catalyst or oxide catalyst. 6. The catalyst used in the second-stage reactor of a method for producing synthesis gas by two-stage catalytic oxidation of natural gas is characterized in that it contains nickel oxide, alkaline earth or rare earth oxide, and the composition formula is: Ln _x O _y -Ni base/M Al ₂ O ₄ ; wherein the loading amount (weight) of each component relative to the carrier is: Ni 1.0-20%, Ln 1-20%, M 1-15%. 7. the catalyst used in the method second stage reactor of a kind of natural gas two-stage catalytic oxidation synthesis gas according to claim 6, is characterized in that in each component, Ln can be element La, Ce, Mg, Ca, Ba , Co, Pd, M can be elements Ni, Co, Mg, Ca, Ba. 8. The catalyst used in the second-stage reactor of a method for producing synthesis gas through two-stage catalytic oxidation of natural gas according to claims 6 and 7, characterized in that the carrier or the surface of the carrier is a spinel structure. 9. The catalyst used in the second stage reactor of a method for producing synthesis gas by two-stage catalytic oxidation of natural gas according to claim 6, wherein the preparation method comprises the steps of: a. Take an appropriate amount of Al(NO ₃ ) ₃ and the second component (M) Ni, Co, Mg, Ca, Ba solution, and use NH ₃ ·H ₂ O, NH ₄ HCO ₃ or (NH ₄ ) 2CO ₃ solution Preparation of carrier precursors for precipitant, complete precipitation, aging, washing and drying; b. The precursor prepared in step a is calcined for 5-24 hours at a temperature of 700-1200° C., and a spinel structure is formed on the carrier or the surface of the carrier; c. immerse the carrier containing the spinel structure prepared in the above step b into the mixed solution of the active component (Ni) and the auxiliary agent (Ln) of suitable composition, so as to immerse into the incipient wetness; d. Place the catalyst precursor prepared in the above step c, dry it, and activate it at 550-650° C. for 5-15 hours. 10. According to claim 6 and 9, the catalyst used in the second-stage reactor of a method for preparing synthesis gas by two-stage catalytic oxidation of natural gas is characterized in that step a of the preparation method of the catalyst can use r-Al ₂ O ₃ Soak to incipient wetness, soak in an appropriate amount of the second component Ni, Co, Mg, Ca, Ba solution, and dry.