Alkaline earth metal co-precipitated nickel-based catalyst for steam carbon dioxide reforming of natural gas
Disclosed is a catalyst used for steam carbon dioxide reforming of natural gas, wherein an alkaline earth metal alone or an alkaline earth metal and a group 8B metal are supported on a hydrotalcite-like catalyst containing nickel, magnesium and aluminum. The disclosed catalyst is useful as a steam carbon dioxide reforming (SCR) catalyst of natural gas at high temperature and high pressure, while minimizing deactivation of the catalyst due to sintering of the active component nickel and deactivation of the catalyst due to coke generation at the same time. A synthesis gas prepared using the catalyst has a H 2 /CO molar ratio maintained at 1-2.2. A synthesis gas having a H 2 /CO molar ratio of 1.8-2.2 may be used as a raw material for Fischer-Tropsch synthesis or methanol synthesis and a synthesis gas having a H 2 /CO molar ratio of may be used as a raw material for dimethyl ether synthesis.
1. A hydrotalcite-like catalyst represented by Chemical Formula 1, which is used for steam carbon dioxide reforming of natural gas using steam and carbon dioxide:
A a -B b -Ni x /Mg y Al [Chemical Formula 1]
wherein A is one or more group 8B metal atoms, B is one or more alkaline earth metal atoms, a and b are supporting amounts of the group 8B metal atoms and the alkaline earth metal atoms based on Ni x /Mg y Al, with a being 0-10 wt % and b being 0.1-10 wt %, x is a Ni/Al molar ratio and is 0.25-1, y is a Mg/Al molar ratio and is 0.6-5.5, and x/y is 0.15-0.45.
2. The hydrotalcite-like catalyst according to claim 1 , wherein the nickel (Ni) is supported in an amount of 5-24 wt % based on the total weight of the catalyst.
3. The hydrotalcite-like catalyst according to claim 1 , wherein the catalyst has a specific surface area of 50-300 m 2 /g.
4. The hydrotalcite-like catalyst according to claim 1 , wherein the catalyst is sintered under a nitrogen (N 2 ) or nitrogen monoxide (NO) atmosphere.
5. A method for preparing a nickel-based catalyst, comprising:
preparing a solution of a precursor with a hydrotalcite structure comprising a magnesium precursor and an aluminum precursor;
preparing a Ni x /Mg y Al hydrotalcite-like catalyst wherein nickel partially replaces magnesium by adding a nickel precursor to the solution of the precursor with a hydrotalcite structure and stirring;
supporting an alkaline earth metal alone or an alkaline earth metal and a group 8B metal on the hydrotalcite-like catalyst; and
preparing a nickel-based catalyst represented by Chemical Formula 1 by sintering said supported catalyst under a nitrogen (N 2 ) or nitrogen monoxide (NO) atmosphere:
A a -B b -Ni x /Mg y Al [Chemical Formula 1]
wherein A is one or more group 8B metal atoms, B is one or more alkaline earth metal atoms, a and b are supporting amounts of the group 8B metal atoms and the alkaline earth metal atoms based on Ni x /Mg y Al, with a being 0-10 wt % and b being 0.1-10 wt %, x is a Ni/Al molar ratio and is 0.25-1, y is a Mg/Al molar ratio and is 0.6-5.5, and x/y is 0.15-0.45.
6. The method for preparing a nickel-based catalyst according to claim 5 , wherein the alkaline earth metal supported on the hydrotalcite-like catalyst is supported through co-precipitation by solid phase crystallization (SPC).
7. The method for preparing a nickel-based catalyst according to claim 5 , wherein the group 8B metal supported on a hydrotalcite-like catalyst is supported by impregnation.
8. A method for preparing a synthesis gas having a hydrogen/carbon monoxide molar ratio of 1-2.2, comprising performing steam carbon dioxide reforming of methane using steam and carbon dioxide in the presence of a hydrotalcite-like catalyst represented by Chemical Formula 1 under the condition of a reaction temperature of 600-1,000° C., a reaction pressure of 1-35 bar, a space velocity of 1,000-100,000 h −1 and a methane:steam:carbon dioxide molar ratio of 1:1-3:0.5-1.5:
A a -B b -Ni x /Mg y Al [Chemical Formula 1]
wherein A is one or more group 8B metal atoms, B is one or more alkaline earth metal atoms, a and b are supporting amounts of the group 8B metal atoms and the alkaline earth metal atoms based on Ni x /Mg y Al, with a being 0-10 wt % and b being 0.1-10 wt %, x is a Ni/Al molar ratio and is 0.25-1, y is a Mg/Al molar ratio and is 0.6-5.5, and x/y is 0.15-0.45.
9. The method for preparing a synthesis gas according to claim 8 , wherein the nickel (Ni) of the hydrotalcite-like catalyst is supported in an amount of 5-24 wt % based on the total weight of the catalyst.
10. The method for preparing a synthesis gas according to claim 8 , wherein the hydrotalcite-like catalyst has a specific surface area of 50-300 m 2 /g.
11. The method for preparing a synthesis gas according to claim 8 , wherein the hydrotalcite-like catalyst is sintered under a nitrogen (N 2 ) or nitrogen monoxide (NO) atmosphere.
12. The method for preparing a synthesis gas according to claim 8 , wherein the H 2 /CO molar ratio of the prepared synthesis gas is controllable with the molar ratio of the reactants and the synthesis gas is used as a raw material for Fischer-Tropsch synthesis, methanol synthesis or dimethyl ether synthesis.