Method for preparing magnesia-zirconia composite carrier for catalyzing oxidative dehydration of normal-butane, method for preparing magnesium orthovanadate catalyst supported by magnesia-zirconia composite carrier prepared thereby, and method for preparing normal-butene and 1,3-butadiene using magnesium orthovanadate catalyst
The present invention discloses a method of producing a magnesia-zirconia complex carrier for a catalyst for oxidative dehydrogenation of n-butane by sol-gel method; a method of producing a magnesium orthovanadate catalyst containing vanadium supported by said magnesia-zirconia complex carrier; and a method of producing n-butene and 1,3-butadiene using said catalyst.
1. A method for preparing n-butene and 1,3-butadiene, comprising:
(a) preparing a mixed precursor solution of magnesium and zirconium by dissolving a magnesium precursor and a zirconium precursor in a first solvent;
(b) preparing a solid acid solution by dissolving at least one solid acid selected from the group consisting of citric acid, succinic acid, malic acid, and tartaric acid in a second solvent;
(c) preparing a carrier forming solution by mixing the mixed precursor solution prepared in the step (a) and the solid acid solution prepared in the step (b);
(d) producing a magnesia-zirconia complex carrier by heat-drying the carrier forming solution prepared in the step (c) and heating a resultant solid product;
(e) impregnating the magnesia-zirconia complex carrier prepared in the step (d) with an aqueous vanadate solution;
(f) preparing a magnesia-zirconia complex carrier-supported magnesium orthovanadate catalyst by heating the product obtained from the step (e); and
(g) carrying out an oxidative dehydrogenation of n-butane on the magnesia-zirconia complex carrier-supported magnesium orthovanadate catalyst prepared in the step (f) with a mixed gas comprising n-butane, oxygen and nitrogen as a reactant.
2. The method according to claim 1 , wherein the oxidative dehydrogenation of n-butane in the step (g) carried out at the temperature of 300-800° C.
3. The method according to claim 1 , wherein the mixed gas used in the step (g) comprises n-butane, oxygen and nitrogen, at the ratio by volume of n-butane:oxygen:nitrogen=2-10:0.5-40:50-97.5.
4. The method according to claim 1 , wherein the magnesium precursor used in the step (a) includes at least one selected from a chloride or a nitrate of magnesium, and the zirconium precursor used in the step (a) includes at least one selected from a chloride, an oxynitrate, or oxychloride of zirconium.
5. The method according to claim 1 , wherein the first solvent used in the step (a) and the second solvent used in the step (b) are independently selected from water and alcohol.
6. The method according to claim 1 , wherein the drying in the step (d) is carried out at 40-200° C., and heating is carried out at 400-1000° C.
7. The method according to claim 1 , wherein the heating in the step (f) is carried out at 350-800° C. for 1-6 hours.