Metal sulfide catalysts and methods of making same
View Patent ↗Methods and apparatus relate to catalysts and preparation of the catalysts, which are defined by sulfides of a transition metal, such as one of molybdenum, tungsten, and vanadium. Precursors for the catalysts include a metal ion source compound, such as molybdenum trioxide, and a sulfide ion source compound, such as thioacetamide. Once the precursors are dissolved if solid and combined in a mixture, homogenous precipitation from the mixture forms the catalysts. Exemplary uses of the catalysts include packing for a methanation reactor that converts carbon monoxide and hydrogen into methane.
1. A method comprising the steps of:
preparing a mixture comprising metal ions from a salt of one of molybdenum, tungsten and vanadium and a source of sulfur ions; and
forming metal sulfide by subjecting the mixture to conditions that permit homogenous precipitation of metal sulfide particles;
wherein the source of sulfur ions is thioacetamide.
2. The method according to claim 1 , wherein the salt is a molybdenum salt.
3. The method according to claim 1 , wherein the salt is molybdenum trioxide.
4. The method according to claim 1 , wherein the mixture further includes zirconium ions from a zirconium salt.
5. The method according to claim 1 , further comprising shaping the metal sulfide particles into catalyst material.
6. The method according to claim 1 , further comprising loading the metal sulfide particles into a methanation reactor that converts carbon monoxide and hydrogen into methane.
7. The method according to claim 1 , wherein the source of sulfur ions is different from the salt.
8. A method comprising the steps of:
preparing a mixture comprising metal ions from a salt of one of molybdenum, tungsten and vanadium and a source of sulfur ions; and
forming metal sulfide by subjecting the mixture to conditions that permit homogenous precipitation of metal sulfide particles;
wherein the mixture further includes zirconium ions from zirconyl nitrate hydrate.
9. A method comprising the steps of:
preparing a mixture comprising metal ions from a salt of one of molybdenum, tungsten and vanadium and a source of sulfur ions; and
forming metal sulfide by subjecting the mixture to conditions that permit homogenous precipitation of metal sulfide particles;
wherein the metal sulfide particles have an activity defined by at least 80% carbon monoxide conversion being achievable in a methanation reaction under conditions defined by a 455° C. reactor temperature and 3171 kilopascal reactor pressure with a gas hourly space velocity of 2400 hr −1 and feed gas flow of 37% hydrogen, 34% carbon monoxide, 1% hydrogen sulfide and 28% nitrogen.
10. A method comprising the steps of:
dissolving molybdenum trioxide and thioacetamide to provide a mixture;
generating a precipitate within the mixture by heating the mixture to cause homogenous precipitation; and
collecting the precipitate, wherein the precipitate that is collected provides molybdenum disulfide catalyst.
11. The method according to claim 10 , further comprising dissolving zirconyl nitrate hydrate added to the mixture.
12. The method according to claim 10 , further comprising sulfiding and then reducing the precipitate, wherein the sulfiding and the reducing occur at above 300° C.
13. The method according to claim 10 , further comprising loading the molybdenum disulfide catalyst into a methanation reactor that converts carbon monoxide and hydrogen into methane.
14. The method according to claim 10 , wherein the molybdenum disulfide catalyst that is collected has an activity defined by at least 80% carbon monoxide conversion being achievable in a methanation reaction under conditions defined by a 455° C. reactor temperature and 3171 kilopascal reactor pressure with a gas hourly space velocity of 2400 hr −1 and hydrogen to carbon monoxide ratio of 1.08.
15. The method according to claim 10 , further comprising:
adding an acid to a first solution into which the molybdenum trioxide is dissolved to reduce pH of the first solution from basic to acidic;
dissolving zirconyl nitrate hydrate in the first solution that is made acidic; and
mixing the first solution with a second solution in which the thioacetamide is dissolved in order to form the mixture.
16. The method according to claim 10 , wherein generating the precipitate occurs by heating the mixture to above 90° C.
17. A molybdenum disulfide catalyst, comprising:
a solid composition containing molybdenum disulfide and prepared to achieve at least 80% carbon monoxide conversion in a methanation reaction, wherein conditions of the methanation reaction are defined by a 455° C. reactor temperature and 3171 kilopascal reactor pressure with a gas hourly space velocity of 2400 hr −1 and feed gas flow of 37% hydrogen, 34% carbon monoxide, 1% hydrogen sulfide and 28% nitrogen.
18. The catalyst according to claim 17 , wherein the solid composition further contains zirconium.