With the polyhydroxy ruthenium complex is that the ruthenium of presoma is an ammonia synthesis catalyst
Technical field
The invention belongs to the ammonia synthesis catalyst preparing technical field, more specifically relating to a kind of is that the ruthenium of presoma is ammonia synthesis catalyst and preparation method thereof with the polyhydroxy ruthenium complex.
Background technology
Ammonia synthesis catalyst is a most important catalyst in the ammonia synthesizing industry.The 80s and 90s in last century, people just after deliberation the application of various oxides in ruthenium-based ammonia synthetic catalyst, some early stage documents have been introduced the achievement in research of this part: the main presoma of ruthenium catalyst is Ru
3(CO)
12,RuCl
3, Ru (acac)
3(acac=acetylacetone,2,4-pentanedione), RuNO (NO
3)
3, RuCl
3Deng, but in ruthenium catalyst the input of noble metal too high be the biggest obstacle that hinders its extensive use.Generally speaking, adopt Ru in the ruthenium catalyst
3(CO)
12Or other commercial no chlorine presoma, influenced promoting the use of of ruthenium catalyst because of its cost performance is low.Though and that relatively cheap ruthenic chloride is made the catalyst cost performance of presoma preparation is higher; But residual chlorion possibly influence the safety of activity of such catalysts and ammonia synthesis production equipment in the catalyst; And the Preparation of Catalyst efficient that with the ruthenic chloride is the presoma preparation is lower, in the complex process, preparation process the loss of ruthenium bigger, be that ammonia synthesis catalyst is unfavorable to the ruthenium of preparation high performance-price ratio.Find in the research,, possibly form and have the nanocrystalline of high index crystal face that it all has active influence to the raising of catalyst activity and stability thereof through the catalyst that different ruthenium complex presomas make.
With the ruthenic chloride is United States Patent (USP) (the U. S. Patent 4 600 571 of presoma; U. S. Patent 4 142 993) preparation technology is more loaded down with trivial details, and preparation facilities is complicated, and the industrialization difficulty is bigger; Chinese patent (CN161148A, CN1270081A, CN101053834A; 200810071876.X) be presoma with the ruthenic chloride, adopt hydrogen or hydrazine hydrate reduction, or to adopt the precipitation method to prepare ruthenium be ammonia synthesis catalyst; The residual quantity of chlorion is bigger; Preparation efficiency is lower, has influenced the production efficiency of catalyst, and the cost performance of catalyst is lower.
Summary of the invention
The object of the present invention is to provide a kind of is that the ruthenium of presoma is ammonia synthesis catalyst and preparation method thereof with the polyhydroxy ruthenium complex, and its production equipment, flow process are simple, and manufacturing cycle is short, and efficient is high, and energy-conserving and environment-protective are easy to accomplish scale production; The catalyst cost performance of preparation is high.
For realizing above-mentioned purpose, the present invention adopts following technical scheme:
With the polyhydroxy ruthenium complex is that the ruthenium of presoma is that the presoma of ammonia synthesis catalyst is RuL; Described RuL is the water miscible ruthenium complex that ruthenium and polyhydroxy-acid, polyhydroxy phenol, polyhydroxy ethers, polyhydroxy aldehyde, polyhydroxyketone, polyhydroxy benzenes, polyhydroxy quinone, multi-hydroxy ester reaction generate.Described polyhydroxy ethers is a kind of in methylcellulose, carboxymethyl cellulose, the ethyl cellulose.Described polyhydroxy aldehyde is glucose, wood sugar, mannose, arabinose, galactolipin, a kind of in glyceraldehyde, galactolipin, lactose, maltose, the gossypose.Described polyhydroxyketone is a kind of in fructose, sorbose, the ribulose.
Described RuL adds potassium ruthenate solution and makes in polyol solution.
Said catalyst consist of RuL+ M1+ M2/AC, M1-(RuL+ M1+ M2)/AC, a kind of among (RuL+ M1+M2-M1)/AC or (RuL+ M1+ the M2)-M2-M1/AC; Be one or more the composition in barium nitrate, barium acetate, magnesium nitrate, the ammonium nitrate wherein for M1; M2 is one or more the composition in alkali metallic sodium, potassium, rubidium, caesium and rare earth nitrades, acetate or the hydroxide; AC is a carrier, i.e. the graphitization active carbon.Catalyst is to be carrier with the graphitization active carbon, makes described ammonia synthesis catalyst through potassium ruthenate preparation, presoma preparation, mixed solution preparation, Preparation of Catalyst, these steps of drying.
The concrete preparation process of said catalyst is:
(1) potassium ruthenate preparation: weighing ruthenium powder, sylvite, place nickel crucible to mix, 400-650 ℃ of processing 1-4h promptly gets potassium ruthenate in Muffle furnace; Described sylvite is one or both the composition in potassium nitrate, potassium hydroxide or the potassium acetate; The mol ratio of said sylvite and ruthenium is 1:1~10:1;
(2) presoma preparation: in polyol solution, add potassium ruthenate solution while stirring and make ruthenium complex;
(3) mixed solution preparation: with pH value to 0~8 of the ruthenium complex solution of a kind of regulating step (2) in nitric acid, acetate, oxalic acid, citric acid, tartaric acid or the ammoniacal liquor, the nitrate or the acetate that add alkaline-earth metal or rare earth metal again are made into mixed solution; The mass fraction of the acid solution that said adjusting is used is 10~65%, and the mass fraction of ammoniacal liquor is 10~25%;
(4) Preparation of Catalyst: be immersed in the graphitization active carbon in 0~60 ℃ of mixed solution, each dip time is 3~60 minutes;
(5) drying: the product behind the dipping is dried down at 50-120 ℃ and was processed described ammonia synthesis catalyst in 20~60 minutes.
Wherein the described ruthenium powder of step (1) is pure ruthenium powder, reclaims a kind of in ruthenium powder, hydroxide ruthenium or the ruthenic oxide; The described potassium ruthenate aqueous solution of step (2) is that the potassium ruthenate that step (1) makes is dissolved in 0~80 ℃ the distilled water; The reaction temperature of potassium ruthenate and polyol is at 0~100 ℃, and the mol ratio of polyol and ruthenium is 0.5:1-8:1; The pH value of the said ruthenium complex solution of step (3) is 0~8.
Catalyst bulk density 0.55~0.65 g/ml of the present invention.
Remarkable advantage of the present invention is:
(1) to adopt the ruthenium powder or reclaim metal Ru be that starting material prepares the potassium ruthenate intermediate in the present invention; Again at ambient temperature with polyhydroxy ethers or polyhydroxy aldehyde or polyhydroxyketone and the water miscible ruthenium complex of the direct prepared in reaction of potassium ruthenate; The preparation of ruthenium complex presoma is simply efficient, is suitable for mass preparation.
(2) to be used for ruthenium be that the preparation process of ammonia synthesis catalyst does not need hydrogen reduction or washing dechlorination step in the present invention, and Preparation of catalysts efficient increases substantially, and the utilization rate of ruthenium is higher, and catalyst has higher cost performance.
(3) the ruthenium presoma is the complex compound of ruthenium and polyhydroxy ethers/aldehyde/ketone in the catalyst of the present invention preparation, in reactor, just need be reduced to ruthenium nano particle during reduction reaction, and therefore, the stability of preparation, use and transportation catalyst better.
(4) in the catalyst preparation process, said presoma RuL can with auxiliary agent mixed load such as barium potassium, make ruthenium barium potassium in the activated carbon surface high degree of dispersion, isolate each other, the anti-caking power of catalyst is strong, the methanation resisting ability of catalyst is strong.
(5) energy-saving and environmental protection in presoma preparation and the use are a kind of Green Chemistry chemical processes.
The specific embodiment
Said catalyst consist of RuL+ M1+ M2/AC, M1-(RuL+ M1+ M2)/AC, a kind of among (RuL+ M1+ M2)-M1/AC or (RuL+ M1+ the M2)-M2-M1/AC; Be one or more the composition in barium nitrate, barium acetate, magnesium nitrate, the ammonium nitrate wherein for M1; M2 is one or more the composition in alkali metallic sodium, potassium, rubidium, caesium and rare earth nitrades, acetate or the hydroxide; AC is a carrier, i.e. the graphitization active carbon.Catalyst is to be carrier with the graphitization active carbon, makes described ammonia synthesis catalyst through potassium ruthenate preparation, presoma preparation, mixed solution preparation, Preparation of Catalyst, these steps of drying.
The presoma that contains polyhydric ruthenium and be ammonia synthesis catalyst is RuL; Described RuL is the water miscible ruthenium complex that ruthenium and carboxylic acid, polyhydroxy phenol, polyhydroxy ethers, polyhydroxy aldehyde, polyhydroxyketone, polyhydroxy benzenes, polyhydroxy quinone, multi-hydroxy ester reaction generate.Said polyhydroxy ethers is methylcellulose, carboxymethyl cellulose, ethyl cellulose; Described polyhydroxy aldehyde is glucose, wood sugar, mannose, arabinose, galactolipin, glyceraldehyde, galactolipin, lactose, maltose, gossypose etc.; Described polyhydroxyketone is sorbose, ribulose.
Described RuL adds potassium ruthenate solution and makes in polyol solution.
The concrete preparation process of said catalyst is:
(1) potassium ruthenate preparation: weighing ruthenium powder, sylvite, place nickel crucible to mix, 400-650 ℃ of processing 1-4 h promptly gets potassium ruthenate in Muffle furnace; Described sylvite is one or both the composition in potassium nitrate, potassium hydroxide or the potassium acetate; The mol ratio of said sylvite and ruthenium is 1:1~10:1;
(2) presoma preparation: in polyol solution, add potassium ruthenate solution while stirring and make ruthenium complex;
(3) mixed solution preparation: with pH value to 0~8 of the ruthenium complex solution of a kind of regulating step (2) in nitric acid, acetate, oxalic acid, citric acid, tartaric acid or the ammoniacal liquor, the nitrate or the acetate that add alkaline-earth metal or rare earth metal again are made into mixed solution; The mass fraction of the acid solution that said adjusting is used is 10~65%, and the mass fraction of ammoniacal liquor is 10~25%;
(4) Preparation of Catalyst: be immersed in the graphitization active carbon in 0~60 ℃ of mixed solution, each dip time is 3~60 minutes;
(5) drying: the product behind the dipping is dried down at 50-120 ℃ and was processed described ammonia synthesis catalyst in 20~60 minutes.
Wherein the described ruthenium powder of step (1) is pure ruthenium powder, reclaims a kind of in ruthenium powder, hydroxide ruthenium or the ruthenic oxide; The described potassium ruthenate aqueous solution of step (2) is that the potassium ruthenate that step (1) makes is dissolved in 0~80 ℃ the distilled water; The reaction temperature of potassium ruthenate and polyol is at 0~100 ℃, and the mol ratio of polyol and ruthenium is 0.5:1-8:1; The pH value of the said ruthenium complex solution of step (3) is 0~8.
Through embodiment the present invention is detailed below:
Embodiment 1:
Get the ruthenium powder of 0.40 gram, after adding 1.15 gram potassium nitrate and 0.64 gram potassium hydroxide mix in nickel crucible, place Muffle furnace to handle 1 hour for 600 ℃; Be cooled to after the room temperature with 10 ml deionized water dissolving potassium ruthenate, under the room temperature condition, the potassium ruthenate aqueous solution joined (glucose is 2:1 with the ratio of the amount of substance of ruthenium in the glucose solution; 2 milliliters of D/Ws); Dropwise the back and transfer pH value of solution=2, add 10% barium (with the quality of activated carbon is benchmark, and barium nitrate is a presoma) with nitric acid; Dissolving back incipient impregnation, oven dry.Change the addition of ruthenium complex and auxiliary agent, can make the serial ammonia synthesis catalyst of different barium ruthenium ratios.Than being 3:1, air speed is 10000 h at hydrogen mixed gas nitrogen
-1, reaction pressure is 10 MPa, and reaction temperature is under 400 ℃ of conditions, and the ammonia synthesis activity is 18.50%.
Embodiment 2:
Repeat embodiment 1, just glucose changes sucrose into.Change the addition of ruthenium complex and auxiliary agent, can make the serial ammonia synthesis catalyst of different barium ruthenium ratios.Than being 3:1, air speed is 10000 h at hydrogen mixed gas nitrogen
-1, reaction pressure is 10 MPa, and reaction temperature is under 400 ℃ of conditions, and the ammonia synthesis activity is 14.23%.
Embodiment 3:
Repeat embodiment 1, just glucose changes fructose into.Change the addition of ruthenium complex and auxiliary agent, can make the serial ammonia synthesis catalyst of different barium ruthenium ratios.Than being 3:1, air speed is 10000 h at hydrogen mixed gas nitrogen
-1, reaction pressure is 10 MPa, and reaction temperature is under 400 ℃ of conditions, and the ammonia synthesis activity is 18.01%.
Embodiment 4:
Repeat embodiment 1, just glucose changes methylcellulose into.Change the addition of ruthenium complex and auxiliary agent, can make the serial ammonia synthesis catalyst of different barium ruthenium ratios.Than being 3:1, air speed is 10000 h at hydrogen mixed gas nitrogen
-1, reaction pressure is 10 MPa, and reaction temperature is under 400 ℃ of conditions, and the ammonia synthesis activity is 15.15%.
The above is merely preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.