CN104588033B

CN104588033B - Slurry bed Fischer-Tropsch synthesis catalyst, and preparation method and application thereof

Info

Publication number: CN104588033B
Application number: CN201310529717.0A
Authority: CN
Inventors: 倪向前; 张舒冬; 尹泽群; 李�杰; 陈楠
Original assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Current assignee: China Petroleum and Chemical Corp; Sinopec Fushun Research Institute of Petroleum and Petrochemicals
Priority date: 2013-11-01
Filing date: 2013-11-01
Publication date: 2017-02-22
Anticipated expiration: 2033-11-01
Also published as: CN104588033A

Abstract

The invention discloses a slurry bed cobalt-based Fischer-Tropsch synthesis catalyst, and a preparation method and an application thereof. The catalyst adopts a composite metal oxide with a perovskite structure ABO3 as a carrier, wherein A is rare earth metal lanthanum, B is transition metal nickel; and the catalyst adopts cobalt as an active component and Pt as an assistant, and comprises 5-30wt% of cobalt and 0.1-2wt% of Pt. The preparation method of the Fischer-Tropsch synthesis catalyst comprises a preparation process of the composite metal oxide with the perovskite structure ABO3, and an active component and assistant supporting process. The catalyst has the advantages of high catalytic activity, low methane selectivity, good stability and long life cycle in slurry bed cobalt-based Fischer-Tropsch synthesis reactions.

Description

A kind of syrup state bed Fischer Tropsch synthetic catalyst and its preparation method and application

Technical field

The present invention relates to a kind of fischer-tropsch synthetic catalyst and its preparation method and application, belong to urging in F- T synthesis field Change technology.

Background technology

F- T synthesis refer to synthesis gas（Carbon monoxide and hydrogen）Catalyze and synthesize the anti-of liquid hydrocarbon fuel on a catalyst Should.F- T synthesis have the advantages that to be independent of oil, product cleans.With world energy sources structure from single oil dependent form to Coal, oil and natural gas alliance type change and environmental requirement increasingly improves, and F- T synthesis technology will be developed rapidly.

Efficient co-based fischer-tropsch catalyst is one of key technology in F- T synthesis technology, and each major oil companies priority is opened Send out with amorphous Si O₂、TiO₂And Al₂O₃Co based Fischer-Tropsch synthesis catalyst for main carriers.

US6765026B2 discloses the Fischer-Tropsch synthesis method that a kind of application special catalyst is catalyzed.The method adopts Catalyst precursor be a kind of iron group（Especially cobalt）The soluble compounds of the soluble compounds of metal or salt and platinum or salt.Will Presoma is contacted with the solution of hydroxyhy-drocarbyl amines or ammonium hydroxide, obtains a kind of special catalyst, makes C₅ ⁺Hydrocarbon selective reaches To 58% ~ 80%.But it is worth low gaseous products CH using the method₄Selectivity be up to 10%.So that proposing a kind of new Fischer-Tropsch synthesis method is to reduce CH further₄Selectively.

CN1417292A reports a kind of preparation method with activated carbon for carrier Co based Fischer-Tropsch synthesis catalyst, for Synthesis gas prepares linear paraffin within 20 for the carbon number for raw material and carbon number is concentrated mainly on the hydro carbons of diesel oil distillate section.In reaction Temperature is 240 DEG C, reaction pressure 2.5MPa, air speed 500h^-1Under the conditions of, the conversion ratio of fixed bed reaction system CO is 64.1%, CH₄Selectivity be 8.5%, C₅ ⁺It is selectively 80.7%.

CN101224430A reports a kind of hydrophobic organic modification of Co group Fischer-Tropsch synthesized catalyst, and noble metal and cobalt are negative It is downloaded on silica supports, then carry out organically-modified.Wherein when noble metal adopts Pt, catalyst system 15%Co0.8% Pt/SiO₂, organically-modified reagent adopts dimethyldiethoxysilane modified, and on pressurization static bed, reaction condition is 230 DEG C, 1.0MPa, 1000h^-1（V/V）, H₂The conversion ratio of/CO=3/1, CO is 72.7%, and the selectivity of methane is 8.4%.Above-mentioned technology CH₄Selectively need to reduce further, C₅ ⁺Selectively need to improve further.

Content of the invention

For the deficiencies in the prior art, the present invention provides a kind of slurry bed system Co based Fischer-Tropsch synthesis catalyst and preparation method thereof And application.This catalyst is applied to syrup state bed Fischer Tropsch synthetic reaction and has catalysis activity height, and methane selectively is low, catalyst stabilization The advantages of property is good, usage cycles are long.

A kind of fischer-tropsch synthetic catalyst, to have perovskite structure ABO₃Metal composite oxide be carrier, wherein A is Rare earth lanthanum, B is transiting metal nickel, and with cobalt as active component, Pt is auxiliary agent, the weight of active component cobalt in final catalyst Content is 5% ~ 30%, weight content 0.1% ~ 2% of auxiliary agent Pt.

A kind of preparation method of fischer-tropsch synthetic catalyst, including having perovskite structure ABO₃Metal composite oxide carry The preparation process of body and the loading process of active component and auxiliary agent.

In the preparation method of above-mentioned fischer-tropsch synthetic catalyst, described has perovskite structure ABO₃Composition metal oxidation The preparation process of thing carrier is as follows：With nickel nitrate and lanthanum nitrate as presoma, with citric acid or ethylene glycol as complexing agent, it is made into molten Liquid mixing and stirring, then carry out moisture evaporation, and the colloidal sol of solution went from clear is transformed into sticky gel, be finally dried, Roasting, the sample after roasting is the composite oxides F- T synthesis carrier with perovskite structure.Wherein, complexing agent and metal from Sub- mol ratio is 1：1～8：1, preferably 1：1～4：1.Prepare and agitating solution is at 20～90 DEG C, enter at preferably 50～70 DEG C OK.Stir speed (S.S.) is 200～500rpm, preferably 300～400rpm.Mixing time is 3～8 hours, preferably 4～6 hours. Baking temperature is 60～200 DEG C, preferably 80～150 DEG C.Drying time is 1～36 hour, preferably 8～24 hours.Roasting Temperature is 400～1000 DEG C, and roasting time is roasting 2 ~ 15 hours, roasting 3～8 hours preferably at 700～900 DEG C.Can With prepare using basic ammonium salts solution impregnation, there is perovskite structure ABO₃Metal composite oxide carrier it is carried out Further process.Basic ammonium salts solution includes ammoniacal liquor, ammonium carbonate and ammonium hydrogen carbonate, preferably ammonium hydrogen carbonate.Basic ammonium salts solution Mass concentration is 5-15%, and dipping temperature is 60 ~ 90 DEG C, and dip time is 2 ~ 6h.The impregnation process of basic ammonium salts solution can be bright The aobvious performance improving catalyst.

In the preparation method of above-mentioned fischer-tropsch synthetic catalyst, the loading process of described active component and auxiliary agent is using dipping Method, crosses volume impregnation or incipient impregnation, co-impregnation or step impregnation, preferably first impregnates active component cobalt and then dipping helps Agent Pt, the pH more preferably controlling cobalt salt dipping solution during dipping active component Co is 3 ~ 5, preferably 3.5 ~ 4.5；? The pH containing Pt solution is controlled to be less than 3, preferably 0.1 ~ 3 during impregnation aids Pt.Cobalt salt dipping solution is generally nitric acid Cobalt liquor, solution containing Pt is generally platinum acid chloride solution.The pH value of dipping solution adopts various appropriate substances to adjust, and such as can adopt Nitric acid, ammonium nitrate, ammoniacal liquor etc. are adjusted.Dipping includes being dried after terminating and roasting is it is also possible to only be dried, and is dried and roasts Burn the method conventional using this area and condition.

The application of fischer-tropsch synthetic catalyst of the present invention, reaction temperature is 180 ~ 250 DEG C, F- T synthesis unstripped gas（By hydrogen With carbon monoxide composition）Volume space velocity be 200 ~ 1000h^-1, reaction pressure is 1.0 ~ 4.0MPa, H in unstripped gas₂/ CO=1～3 （Mol ratio）.

The present invention using there is the perovskite of suitable composition as carrier, its synergy with active component and auxiliary agent, Significantly improve the performance of catalyst.Especially in the dipping process of active component and auxiliary agent, regulate and control certain pH value, so that The decentralization of active component cobalt reduction degree and auxiliary agent Pt improves, and is more difficult in the reaction generate the carbonyl cobalt leading to catalyst inactivation Compound, and then be conducive to improving the activity of catalyst, and greatly reduce the selectivity of its methane production.

Application in syrup state bed Fischer Tropsch synthetic reaction for the fischer-tropsch synthetic catalyst of the present invention.Experiment shows, in suitable process Under the conditions of, CO conversion ratio reaches C while more than 85%₅ ⁺Selectivity can reach more than 85%（Selectively press certain product with All product（Except water）Weight ratio meter calculate）, and product methane, selectively less than 5%, greatly reduces subsequent products and divides From investment and the operating cost of equipment, and can stable operation, be conducive to improve F- T synthesis technology application when economy.

Specific embodiment

Further illustrate process and the effect of the inventive method with reference to embodiment.

The preparation method of fischer-tropsch synthetic catalyst carrier of the present invention：Take 23gNi (NO₃)₂6H₂O puts into the beaker of 500mL In, add the distilled water of 100mL, then beaker is placed in 80 DEG C of water-bath, mixing speed is 400rpm, stir to all molten Solution.Take 34.3g La (NO₃)₃6H₂O, is placed with the beaker of 100mL distilled water, stirs and dissolves to whole.Then lanthanum nitrate Solution is added drop-wise in cobalt nitrate and nickel nitrate solution, stirs in dropping, takes 40g citric acid, citric acid and metal ion total amount Mol ratio is 1：1, it is placed with the beaker of 100mL to stir and dissolve to whole, now after above-mentioned mixed solution stirs 30 minutes, Slow addition citric acid solution, stirs in dropping.Now continue after 5 hours of stirring after above-mentioned mixed solution, brown is molten Liquid has been dehydrated the gel becoming thick, gel is taken out in the drying box putting into 110 DEG C, is dried overnight.Then take out Dried perovskite predecessor, is placed in Muffle furnace, rises to 400 DEG C with the heating rate of 3 DEG C/min from room temperature, constant temperature calcining 3 hours, then rise to 800 DEG C with the heating rate of 10 DEG C/min, 4 hours of constant temperature calcining, obtain composite metal catalyst and carry Body.

Embodiment 1

（1）Take above-mentioned carrier 30 as one kind g dipping active component and auxiliary agent, based on catalyst cobalt content 10wt%, weigh cobalt nitrate 10.49g is dissolved in 34ml, and adjusts pH value equal to 4 with ammonium nitrate, adds in above-mentioned carrier, aging 3 hours, 80 DEG C of dryings 8 were little When, roasting 4 hours in 350 DEG C.

（2）Based on catalyst platinum content 1wt%, weigh after chloroplatinic acid 1.04g is dissolved in 34ml water, and use nitre acid for adjusting pH Value is equal to 0.5, adds in above-mentioned carrier and impregnates, aging 2 hours, 80 DEG C of dryings 6 hours, roasting 4 hours in 350 DEG C.It is obtained Catalyst is designated as C-1, and evaluation result is shown in Table 1.

Embodiment 2

With the pH value not adjusting dipping solution in the embodiment 1 simply dipping process of cobalt and Pt, prepared catalyst is designated as C- 2, evaluation result is shown in Table 1.

Embodiment 3

With embodiment 1 simply carrier dipping active component preposition in mass concentration be 10% ammonium bicarbonate soln in, leaching Stain temperature is 80 DEG C, and dip time is 4h.Prepared catalyst is designated as C-3, and evaluation result is shown in Table 1.

Embodiment 4

（1）Take above-mentioned carrier 30 as one kind g dipping active component and auxiliary agent, based on catalyst cobalt content 15wt%, weigh cobalt nitrate 15.74g is dissolved in 34ml, and adjusts pH value equal to 3.5 with ammonium nitrate, adds in above-mentioned carrier, aging 3 hours, 80 DEG C of dryings 8 Hour, roasting 4 hours in 350 DEG C.

（2）Based on catalyst platinum content 1.5wt%, weigh after chloroplatinic acid 1.56g is dissolved in 34ml water, and adjusted with nitric acid PH value is equal to 0.2, adds in above-mentioned carrier and impregnates, aging 2 hours, 80 DEG C of dryings 6 hours, roasting 4 hours in 350 DEG C.System Obtain catalyst and be designated as C-4, evaluation result is shown in Table 1.

Embodiment 5

（1）Take above-mentioned carrier 30 as one kind g dipping active component and auxiliary agent, based on catalyst cobalt content 20wt%, weigh cobalt nitrate 20.99g is dissolved in 34ml, and adjusts pH value equal to 4 with ammonium nitrate, adds in above-mentioned carrier, aging 3 hours, 80 DEG C of dryings 8 were little When, roasting 4 hours in 350 DEG C.

（2）Based on catalyst platinum content 0.2wt%, weigh after chloroplatinic acid 0.21g is dissolved in 34ml water, and adjusted with nitric acid PH value is equal to 1.5, adds in above-mentioned carrier and impregnates, aging 2 hours, 80 DEG C of dryings 6 hours, roasting 4 hours in 350 DEG C.System Obtain catalyst and be designated as C-5, evaluation result is shown in Table 1.

Embodiment 6

（1）Take above-mentioned carrier 30 as one kind g dipping active component and auxiliary agent, based on catalyst cobalt content 10wt%, weigh cobalt nitrate 10.49g is dissolved in 34ml, and adjusts pH value equal to 4.5 with ammonium nitrate, adds in above-mentioned carrier, aging 3 hours, 80 DEG C of dryings 8 Hour, roasting 4 hours in 350 DEG C.

（2）Based on catalyst platinum content 1wt%, weigh after chloroplatinic acid 1.04g is dissolved in 34ml water, and use nitre acid for adjusting pH Value is equal to 0.3, adds in above-mentioned carrier and impregnates, aging 3 hours, 80 DEG C of dryings 6 hours, roasting 6 hours in 350 DEG C.It is obtained Catalyst is designated as C-6, and evaluation result is shown in Table 1.

Comparative example 1

Contain the metal composite oxide of lanthanum, nickel, cobalt using coprecipitation preparation（No perovskite structure）, then dip loading Pt, the content of each metal component is with embodiment 1.Prepared catalyst is designated as B-1, and evaluation result is shown in Table 1.

Comparative example 2

Infusion process Supported Co, lanthanum, nickel, platinum are adopted for carrier with silica, cobalt, lanthanum, nickel, the addition of platinum are with embodiment 1. Prepared catalyst is designated as B-2, and evaluation result is shown in Table 1.

Activity rating is carried out to the catalyst prepared by above-described embodiment and comparative example, evaluation test continuously stirs in high pressure In tank reactor, using paraffin as solvent, reduce 12 hours with 350 DEG C of pure hydrogen, pressure is 1.0MPa.After cooling, switching is closed Gas is become to be reacted.Reaction effluent is collected by hot trap, cold-trap respectively.Reaction condition is 200 DEG C, 500h^-1, 2.0MPa, H₂/CO =2（Mol ratio）.300h evaluation result is shown in Table 1.

The reactivity worth of table 1 catalyst

Catalyst	CO conversion ratio（%）	C₅ ⁺Selectively（wt%）	CH₄Selectively（wt%）
				C-1	88.3	87.2	4.74
B-1	37.9	62.4	23.1
				B-2	74.7	75.7	10.7
C-2	81.2	82.2	6.54
				C-3	89.0	88.1	3.17
C-4	85.7	87.2	4.54
				C-5	86.0	85.1	4.97
C-6	87.1	86.3	4.43

Claims

1. a kind of fischer-tropsch synthetic catalyst it is characterised in that：This catalyst is to have perovskite structure ABO₃Composition metal oxidation Thing is carrier, and wherein A is rare earth lanthanum, and B is transiting metal nickel, and with cobalt as active component, Pt is auxiliary agent, in final catalyst The weight content of active component cobalt is 5% ~ 30%, weight content 0.1% ~ 2% of auxiliary agent Pt.

2. catalyst described in claim 1 preparation method it is characterised in that：Including having perovskite structure ABO₃Compound gold Belong to the preparation process of oxide carrier and the loading process of active component and auxiliary agent.

3. in accordance with the method for claim 2 it is characterised in that：With nickel nitrate and lanthanum nitrate as presoma, with citric acid or Ethylene glycol is complexing agent, wiring solution-forming mixing and stirring, then carries out moisture evaporation, the colloidal sol of solution went from clear is transformed into Sticky gel, finally dry, roasting, the sample after roasting is the composite oxide carrier with perovskite structure.

4. in accordance with the method for claim 3 it is characterised in that：Complexing agent and metal ion mol ratio are 1：1～8：1.

5. in accordance with the method for claim 4 it is characterised in that：Complexing agent and metal ion mol ratio are 1：1～4：1.

6. in accordance with the method for claim 3 it is characterised in that：Prepare and agitating solution is carried out at 20～90 DEG C, stirring Time is 3～8 hours, and mixing speed is 200～500rpm.

7. in accordance with the method for claim 6 it is characterised in that：Prepare and agitating solution is carried out at 50～70 DEG C, stirring Time is 4～6 hours, and stir speed (S.S.) is 300～400rpm.

8. in accordance with the method for claim 3 it is characterised in that：Baking temperature is 60～200 DEG C, and drying time is 1～36 Hour, roasting roasting 2-15 hour at 400～1000 DEG C.

9. in accordance with the method for claim 8 it is characterised in that：Baking temperature is 80～150 DEG C, and drying time is 8～24 Hour, roasting roasting 3～8 hours at 700～900 DEG C.

10. in accordance with the method for claim 2 it is characterised in that：Using what basic ammonium salts solution impregnation was prepared, there is calcium Perovskite like structure ABO₃Metal composite oxide carrier it is further processed.

11. in accordance with the method for claim 10 it is characterised in that：Basic ammonium salts solution is selected from ammonium carbonate and ammonium hydrogen carbonate, Basic ammonium salts concentration of polymer solution is 5-15%, and dipping temperature is 60 ~ 90 DEG C, and dip time is 2 ~ 6h.

12. in accordance with the method for claim 11 it is characterised in that：Basic ammonium salts solution includes ammonium hydrogen carbonate.

13. according to the method described in claim 2 or 10 it is characterised in that：The loading process of active component and auxiliary agent is using leaching Stain method.

14. in accordance with the method for claim 13 it is characterised in that：The loading process of active component and auxiliary agent adopted volume Dipping or incipient impregnation.

15. in accordance with the method for claim 13 it is characterised in that：The loading process of active component and auxiliary agent adopts co-impregnation Or step impregnation.

16. in accordance with the method for claim 13 it is characterised in that：First dipping active component cobalt and then impregnation aids Pt.

17. in accordance with the method for claim 16 it is characterised in that：Control cobalt salt dipping during dipping active component Co The pH of solution is 3 ~ 5；The pH containing Pt solution is controlled to be less than 3 during impregnation aids Pt.

18. in accordance with the method for claim 17 it is characterised in that：Control cobalt salt dipping during dipping active component Co The pH 3.5 ~ 4.5 of solution.

19. in accordance with the method for claim 17 it is characterised in that：Control the pH containing Pt solution during impregnation aids Pt For 0.1 ~ 3.

20. in accordance with the method for claim 17 it is characterised in that：Cobalt salt dipping solution is cobalt nitrate solution, solution containing Pt For platinum acid chloride solution, the pH value of dipping solution is adjusted using nitric acid, ammonium nitrate, ammoniacal liquor.

21. in accordance with the method for claim 2 it is characterised in that：Loading process terminate after include be dried and roasting, be dried and Roasting adopts the conventional method in this area and condition.

The application of catalyst described in 22. claims 1 it is characterised in that：Reaction temperature is 180 ~ 250 DEG C, F- T synthesis raw material The volume space velocity of gas is 200 ~ 1000h^-1, reaction pressure is 1.0 ~ 4.0MPa, H in unstripped gas₂The mol ratio of/CO is 1～3；Its Middle F- T synthesis unstripped gas is made up of hydrogen and carbon monoxide.