초록 ▼

Promoted skeletal iron catalysts are provided which contain 70-90 wt % iron together with promoters 0-5.0 wt. % copper, 0.1-10.0 wt. % manganese, and 0.1-3.0 wt. % potassium, with the balance being aluminum. The catalysts are prepared by mixing the metal chips or powders uniformly together, then mel

Promoted skeletal iron catalysts are provided which contain 70-90 wt % iron together with promoters 0-5.0 wt. % copper, 0.1-10.0 wt. % manganese, and 0.1-3.0 wt. % potassium, with the balance being aluminum. The catalysts are prepared by mixing the metal chips or powders uniformly together, then melting and rapidly quenching the molten metals to form a solid metal alloy precursor including the promotor metals except potassium, removing most of the aluminum by caustic extraction/leaching to provide a base skeletal iron form, then loading the potassium promoter from a suitable potassium alcohol solution promoter. After evaporation of the solvent, the promoted skeletal iron catalyst is activated by contact with hydrogen. The promoted skeletal iron catalysts are utilized for F-T synthesis processes at 10-30 wt % catalyst concentration, 200-350° C. temperature, 1.0-3.0 Mpa pressure and gas hourly space velocity of 0.5-5.0 L/gcat-h to produce desired hydrocarbon liquid products. The promoted skeletal iron catalysts provide good catalytic activity and selectivity for hydrogen and CO conversions, for distillate fuel products are attrition resistant synthesis, and are readily separable from waxy liquid product by gravity sedimentation.

대표청구항 ▼

1. A particulate promoted skeletal iron catalyst having high catalytic activity and product selectivity, good attrition-resistance under hydrodynamic reaction conditions, and enhanced separation of used catalyst particles from reaction product slurry in Fischer-Tropsch (F-T) synthesis processes, the

1. A particulate promoted skeletal iron catalyst having high catalytic activity and product selectivity, good attrition-resistance under hydrodynamic reaction conditions, and enhanced separation of used catalyst particles from reaction product slurry in Fischer-Tropsch (F-T) synthesis processes, the catalyst comprising 70-90 wt. % iron, 0.-50. wt. % copper, 0.1-5.0 wt. % manganese, and 0.1-3.0 wt % potassium, with the balance being aluminum; said iron, copper, manganese and aluminum comprising a metal alloy having a skeletal structure; said skeletal iron catalyst having a 20-80 m 2 /gm surface area and 10-10,000 micron particle size. 2. The promoted skeletal iron catalyst of claim 1, wherein the catalyst comprises 84-88 wt. % iron, 8-10 wt % aluminum, 1-3 wt % maganese and 0.5-2 wt % potassium. 3. The promoted skeletal iron catalyst of claim 1, wherein the catalyst surface area is 25-65 m 2 /g and the particle size range is 60-2000 microns. 4. A method for preparing a promoted skeletal iron catalyst for use in Fischer-Tropsch synthesis processes, comprising the steps of:(a) mixing iron and aluminum chips or powders and copper chips or copper compound and a manganese compound together uniformly to provide a metal chips and/or powder mixture, then heating and melting said mixture under inert gas protection and forming a molten metal alloy;(b) cooling said molten metal alloy to provide a precursor solid metal alloy;(c) pulverizing said precursor solid metal alloy to provide catalyst precursor particles having particle size range of 0.1-10 mm (100-10,000 microns), said precursor particles containing 35-55 wt % iron, 40-60 wt % aluminum, 0-10 wt % copper and 1-15 wt % manganese;(d) contacting said catalyst precursor particles with a caustic solution of 10-50% concentration, at 50-90° C. for 50-150 minutes so as to extract and/or leach out a major portion of the aluminum to provide base catalyst particles having a skeletal structure, and(e) impregnating said base catalyst particles with a potassium promotor solution, followed by removing solvent by evaporation to provide the promoted skeletal iron catalyst containing 0.1-3.0 wt. % potassium. 5. The skeletal iron catalyst preparation method of claim 4, wherein said precursor metal alloy contains 39 wt % iron, 59 wt % aluminum and 2 wt. % maganese. 6. The skeletal iron catalyst preparation method of claim 4, wherein said molten metal alloy is cooled in less than 10 seconds to room temperature (15-20° C.) by quenching in water. 7. The skeletal iron catalyst preparation method of claim 4, wherein said base catalyst particles are screened to a desired particle size range in an alcohol medium so as to prevent exposure of the catalyst particles to air. 8. The skeletal iron catalyst preparation method of claim 4, wherein the potassium promotor is impregnated onto said base skeletal iron catalyst particles by mixing the base skeletal iron catalyst particles with an organic potassium-containing alcohol solution selected from methanolic potassium hydroxide, ethanolic potassium hydroxide, or ethanolic potassium carbonate, and then removing the alcohol solvent by vaporizing the solvent and drying the catalyst particles, whereby the potassium promotor is impregnated onto said base skeletal iron catalyst. 9. The skeletal iron catalyst preparation method of claim 8, wherein evaporating the potassium promotor alcohol solvent occurs at 40-80° C. temperature and 100-500 mm Hg vacuum, and provides a potassium to catalyst mass ratio of 0.5-3:0:100. 10. The skeletal iron catalyst preparation method of claim 8, wherein said potassium promotor is conducted by using an organic alcohol solution of a potassium compound with a concentration of 0.1-0.5 N potassium for impregnating the potassium promoter on the base skeletal iron. 11. The skeletal iron catalyst preparation method of claim 4, including activating said promoted skeletal iron catalyst by fixed-bed activation in a fixed-bed reactor at hydrogen flow rate of 0.05-1.00 NL/g-cat/h and temperature of 300-350° C. for 2-12 hours, then mixing said catalyst with a liquid reaction medium to form a slurry which is transferred into a slurry-phase Fischer-Tropsch reactor. 12. The skeletal iron catalyst preparation method of claim 4, including activating said promoted skeletal iron catalyst by in-situ activation by mixing the catalyst with a suitable liquid reaction medium and forming a catalyst liquid slurry, then introducing said slurry into a Fischer-Tropsch reactor, and activating said catalyst in-situ at 300-350° C. with a hydrogen gas flow rate of 0.3-3.0 NL/g-cat/h for 3 to 48 hours. 13. The skeletal iron catalyst preparation method of claim 12, wherein said promoted skeletal iron catalyst is mixed with liquid paraffinic hydrocarbon and placed in a slurry Fischer-Tropsch reactor for in-situ activation. 14. A catalytic Fischer-Tropsch (F-T) synthesis process utilizing a promoted skeletal iron catalyst in a reactor for producing hydrocarbon liquid products, the process comprising:(a) feeding H 2 and CO-containing synthesis gas having H 2 /CO molar ratio of 0.5-5:1 into a reactor containing a suitable reaction medium and the promoted skeletal iron catalyst as defined by claim 1;(b) maintaining said reactor at conditions of 200-350° C. temperature, 1.0-3.0 MPa pressure, and gas hourly space velocity of 0.5-5.0 NL/g-Fe/h; and(c) withdrawing from said reactor a hydrocarbon gas/vapor and hydrocarbon liquid product containing fine sized used catalyst particles. 15. The catalytic F-T synthesis process of claim 14, said promoted skeletal iron catalyst having a particle size of 1-10 mm (1,000-10,000 micron) and being utilized in a fixed-bed reactor. 16. The catalytic F-T synthesis process of claim 14, said skeletal iron catalyst having a particle size of 0.02-0.2 mm (20-200 micron) and being utilized in a slurry-phase reactor. 17. The catalytic F-T synthesis process of claim 14, wherein said skeletal iron catalyst has a concentration of 5-40 wt. % relative to said reaction medium. 18. The catalytic F-T slurry-phase synthesis process of claim 14, including withdrawing a hydrocarbon gas/vapor and a hydrocarbon liquid/slurry product containing spent skeletal iron catalyst particles, and separating the spent skeletal iron catalyst from the hydrocarbon liquid product by a sedimentation step. 19. A catalytic Fischer-Tropsch (F-T) synthesis process utilizing a promoted skeletal iron catalyst in a reactor for producing hydrocarbon liquid products, the process comprising:(a) feeding H 2 and CO-containing synthesis gas having H 2 /CO molar ratio of 0.5-5:1 into a slurry-phase reactor containing the promoted skeletal iron catalyst as defined by claim 2 and a liquid medium at catalyst loading of 5-40 wt. % relative to the liquid medium;(b) maintaining said reactor at conditions of 200-350° C., 1.0-3.0 MPa pressure, and gas hourly space velocity of 0.5-5.0 NL/g-Fe/h; and(c) withdrawing from said reactor a hydrocarbon gas/vapor and hydrocarbon liquid product containing particles of said promoted skeletal iron catalyst, and separating the used skeletal iron catalyst from the hydrocarbon liquid product by a sedimentation step.