JPWO2021095782A5 - - Google Patents

Description

The concentration of the carbon source (preferably hydrocarbon) contained in the carbon-containing gas (volume ratio of the carbon source to the carbon-containing gas) is preferably 1% by volume or more and 30% by volume or less, particularly 5% by volume . The above is particularly preferable, while 20% by volume or less is particularly preferable. When the concentration of the carbon source is 1% by volume or more, a sufficient amount of carbon can be supported better, and the selectivity of unsaturated hydrocarbons can be further increased. Further, when the concentration of the carbon source is 30% by volume or less, the carrier of excess carbon can be more easily controlled, and the decrease in the alkane conversion rate and the selectivity of unsaturated hydrocarbon can be more sufficiently suppressed. ..

Claims (28)

A catalyst in which a transition metal and carbon are supported on a carrier, and the carbon contains fibrous carbon. The ratio of the crystallite diameter of the transition metal when the carbon carried on the carrier to the crystallite diameter of the transition metal supported on the carrier is the ratio of the crystallite diameter of the transition metal when the carbon supported on the carrier does not contain fibrous carbon. , 0.80 or less, according to claim 1. The catalyst according to claim 1 or 2, wherein the amount of carbon with respect to the transition metal is 510% by mass or more and 2500% by mass or less. The catalyst according to any one of claims 1 to 3, wherein the catalyst is an alkane dehydrogenation catalyst. The catalyst according to any one of claims 1 to 4, wherein the transition metal is Ni. The catalyst according to any one of claims 1 to 5, wherein the carrier is at least one selected from the group consisting of silica, alumina, zirconia, and titania. The catalyst according to any one of claims 1 to 5, wherein the carrier is γ-alumina. A step of mixing a solution containing a transition metal compound and a carrier and heating to remove the solvent to obtain a catalyst precursor.
A step of contacting the catalyst precursor with a carbon-containing gas to form a catalyst carrying a transition metal and carbon.
A method for manufacturing a catalyst, including
A method for producing a catalyst, which forms and supports fibrous carbon by contacting a carbon-containing gas with the catalyst precursor in the step of forming the catalyst. The step of obtaining the catalyst precursor is a step of mixing a solution in which a transition metal compound is dissolved and a carrier and heating to evaporate the solvent to obtain a solid, and a step of crushing the solid to obtain a powdery catalyst precursor. The method for producing a catalyst according to claim 8, which comprises a step of obtaining the catalyst. The method for producing a catalyst according to claim 8 or 9, wherein the carbon-containing gas contains a hydrocarbon. The method for producing a catalyst according to claim 10, wherein the hydrocarbon is an alkane having 2 to 5 carbon atoms. The method for producing a catalyst according to claim 10, wherein the hydrocarbon is isobutane. The method for producing a catalyst according to any one of claims 10 to 12, wherein the volume ratio of the hydrocarbon to the carbon-containing gas is 1% by volume or more and 30% by volume or less. The method for producing a catalyst according to any one of claims 8 to 13, wherein the temperature at which the carbon-containing gas is brought into contact with the catalyst precursor is 300 ° C. or higher and 1000 ° C. or lower. When the ratio (W / F) of the amount of the catalyst precursor to the supply rate of the carbon-containing gas when the carbon-containing gas is brought into contact with the catalyst precursor is 0.03 g · min / ml or more and 0.5 g · min / ml or less. The method for producing a catalyst according to any one of claims 8 to 14. The method for producing a catalyst according to any one of claims 8 to 15, wherein the transition metal is Ni. The method for producing a catalyst according to any one of claims 8 to 16, wherein the carrier is at least one selected from the group consisting of silica, alumina, zirconia, and titania. The method for producing a catalyst according to any one of claims 8 to 16, wherein the carrier is γ-alumina. Claims 8 to 18 wherein the ratio of the crystallite diameter of the transition metal carried on the catalyst to the crystallite diameter of the transition metal on the catalyst precursor when the carbon-containing gas is not brought into contact is 0.80 or less. The method for producing a catalyst according to any one of the above. A method for producing an unsaturated hydrocarbon, wherein the catalyst according to any one of claims 1 to 7 is brought into contact with a mixed gas containing an alkane and carbon dioxide to produce an unsaturated hydrocarbon from the alkane. The method for producing an unsaturated hydrocarbon according to claim 20, wherein the molar ratio of carbon dioxide to the alkane in the mixed gas is 0.1 or more and 1.9 or less. The method for producing an unsaturated hydrocarbon according to claim 20 or 21, wherein the alkane is an alkane having 2 to 5 carbon atoms. The method for producing an unsaturated hydrocarbon according to claim 20 or 21, wherein the alkane is isobutane. The method for producing an unsaturated hydrocarbon according to any one of claims 20 to 23, wherein the temperature at which the mixed gas is brought into contact with the catalyst is 300 ° C. or higher and 1000 ° C. or lower. 20 to 24, wherein the ratio (W / F) of the amount of the catalyst to the supply rate of the mixed gas when the mixed gas is brought into contact with the catalyst is 0.001 g · min / ml or more and 1000 g · min / ml or less. The method for producing an unsaturated hydrocarbon according to any one of the above. A catalyst is produced by the production method according to any one of claims 8 to 19, and subsequently, the obtained catalyst is brought into contact with a mixed gas containing alkane and carbon dioxide to obtain unsaturated hydrocarbons from the alkane. A method for producing unsaturated hydrocarbons. A carbon-containing gas was brought into contact with the catalyst precursor on which the transition metal compound was supported on the carrier, carbon containing fibrous carbon was supported on the catalyst precursor, and the transition metal and carbon containing fibrous carbon were supported. The process of forming the catalyst and
A method for producing an unsaturated hydrocarbon, wherein an unsaturated hydrocarbon is produced from the alkane by contacting the obtained catalyst with a mixed gas containing an alkane and carbon dioxide. The method for producing an unsaturated hydrocarbon according to claim 26 or 27, wherein the molar ratio of carbon dioxide to the alkane in the mixed gas is 0.1 or more and 1.9 or less.