CN102371154A - Iron-based catalyst for synthesizing light hydrocarbon and preparation method thereof - Google Patents

Abstract

The invention relates to an iron-based catalyst for synthesizing light hydrocarbon and a preparation method thereof, mainly solving the problems of difficult heat removing and easy temperature runaway in the reactor and easy inactivation of the catalyst when using static bed, and high reaction temperature and relatively low selectivity of gasoline and diesel fuels when using fluidized bed in the prior art because the Fischer-Tropsch synthesis is a strong exothermic reaction. The catalyst comprises at least one of oxides of Si or Al as the carrier and an active ingredient which is measured as atomic ratio and represented by Fe100AaBbCcOx, wherein, A is at least one selected from the group consisting of V and Nb, B is one selected from the group consisting of Cu and Zn, and C is at least one selected from alkali metal. The catalyst can be used in but not limited to medium and high temperature fluidized bed reactors.

Description

Ferrum-based catalyst of synthetic light hydrocarbon and preparation method thereof

Technical field

The present invention relates to ferrum-based catalyst of the synthetic light hydrocarbon of a kind of Fischer-Tropsch and preparation method thereof.

Background technology

Along with China's rapid economy development, be to grow with each passing day to the demand of low-carbon alkene and liquid fuel.The characteristics of China's energy are that the few oil of rich coal has gas, and the environmental pollution that the direct burning of coal causes also comes into one's own day by day.Exploitation is converted into the process of low-carbon alkene and liquid fuel by coal/natural gas via synthesis gas, not only can reduce on the energy external dependence, and have great importance for solving the coal-fired problem of environmental pollution that causes.

Fischer-Tropsch (Fascher-Tropsch) is synthetic to be to utilize synthesis gas (main component is CO and H ₂) process of synthetic hydrocarbon under the effect of catalyst, be an important channel of coal and natural gas indirect liquefaction.

The cryogenic high pressure paste state bed reactor that is applicable to that the fischer-tropsch catalysts of document and patent report is many is in recent years produced high-carbon long-chain olefin type, generally mostly is precipitated iron catalyst, or the immersion-type Co catalysts.In patent USP5504118 and CN1113905A, just reported a kind of preparation method who is applicable to the synthetic precipitated iron catalyst of Fischer-Tropsch of paste state bed reactor like U.S. Rentech company---earlier with active component deposition, filtration and washing; And then mix, pull an oar with carrier, last spray-drying.Deposition, filtration and washing step that this method prepares in the catalyst process are loaded down with trivial details, operation inconvenience, and energy consumption is high.

Synthetic general how in fluidized-bed reactor, the carrying out of the Fischer-Tropsch of light hydrocarbon, the characteristics of this technology are that reaction temperature is higher, conversion ratio is higher, does not have the difficulty of liquid-solid separation.But at present existing report be applied to the fluid bed Fischer-Tropsch synthetic be mostly molten iron type catalyst, idol has the precipitated iron catalyst of some types.As just having mentioned a kind of synthetic molten iron type Preparation of catalysts of Fischer-Tropsch that is used among the patent CN1704161A; Mentioned a kind of precipitated iron catalyst that is used for fluid bed among the patent CN1695804A; But be that the molten iron legal system is equipped with catalyst or the precipitation method and prepares fluid bed and all have complex process with catalyst; Energy consumption is high, the shortcoming that the Preparation of Catalyst cycle is long.

Summary of the invention

One of technical problem to be solved by this invention be exist in the prior art because Fischer-Tropsch synthesis is a strong exothermal reaction, when using fixed bed, the heat difficulty is removed in reaction, is prone to temperature runaway, makes the easy inactivation of catalyst; When using fluid bed, the problem that the petrol and diesel oil selectivity is low provides a kind of new Fischer-Tropsch to synthesize the ferrum-based catalyst of light hydrocarbon.This catalyst has fluidized-bed reactor, low-carbon alkene and the high advantage of gasoline, diesel component selectivity that is applicable to and is not limited to middle high temperature.Two of technical problem to be solved by this invention provides the preparation method of the required catalyst-compatible of one of a kind of and technical solution problem.

Following for solving the problems of the technologies described above the technical scheme that a present invention adopts: the ferrum-based catalyst of the synthetic light hydrocarbon of a kind of high temperature fischer-tropsch; This catalyst is a carrier with at least a of oxide that is selected from Si or Al; Active component contains with atomic ratio measuring, the composition that chemical formula is following: Fe ₁₀₀A _aB _bC _cO _x(A is selected from least a among V or the Nb in the formula; B is selected from least a among Cu or the Zn; C is selected from least a in the alkali metal; The span of a is 5.0～60.0; The span of b is 0～20.0; The span of c is 0.1～10.0; X satisfies the required oxygen atom sum of each element valence in the catalyst), the carrier consumption is 15～80% of catalyst weight by weight percentage.The value preferable range of a is 10.0～50.0 in the technique scheme, and the value preferable range of b is 3.0～18.0, and the value preferable range of c is 0.2～8.0, and carrier consumption preferable range is 25～70% of catalyst weight by weight percentage.

Following for solving the problems of the technologies described above the technical scheme that two the present invention adopt: the preparation method of the ferrum-based catalyst of the synthetic light hydrocarbon of Fischer-Tropsch comprises following processing step:

(1) with the aequum soluble ferric iron salt solution I of processing soluble in water;

(2) with the aequum ammonium metavanadate in the oxalic acid solution soluble in water or that the aequum niobium hydroxide is dissolved in or two solution are mixed and made into the solution II by a certain percentage;

(3) with the aequum solubility category-B salt solution III of processing soluble in water;

(4) solution I solution, II solution, III solution mixing system are become the mixed solution IV;

(5) in boiling water bath, aequum is selected from SiO ₂Or Al ₂O ₃In at least a colloidal sol and the hydroxide or the salting liquid of C class join in the solution IV, mix making beating, adding acid-base modifier simultaneously, to regulate the pH value of slurry be 1～5 to obtain the slurry V (solid content is 15～45wt%);

(6) send into the spray dryer spray shaping after the slurry V is cooled to 20～60 ℃, 400～750 ℃ of roasting temperatures 0.15～6 hour, obtain the microspheroidal fluid bed and use iron-base fischer-tropsch synthesis catalyst then.

The spray shaping condition of said catalyst is 200～360 ℃ of inlet temperatures, 100～210 ℃ of outlet temperatures.

Best 450～700 ℃ of the sintering temperature of said catalyst;

The roasting time of said catalyst is preferably 0.5～5h;

The catalyst that according to said method obtains is carried out Fischer-Tropsch synthesis under proper reaction conditions, obtained better technical effect (result sees attached list).

Following embodiment will do further explanation to the present invention, and protection scope of the present invention does not receive the restriction of these embodiment.

The specific embodiment

[embodiment 1]

Get certain amount of ferric nitrate and be dissolved in the water and be made into certain density solution I, an amount of ammonium metavanadate is dissolved in the water obtains the solution II, gets an amount of zinc nitrate wiring solution-forming III that is dissolved in the water; The mixing of solution I II III is obtained the solution IV, place boiling water bath to heat the solution IV, add an amount of Ludox and KOH solution simultaneously and mix making beating; The pH value that uses ammoniacal liquor to regulate slurry then is 5, after fully stirring, obtains required catalyst pulp (solid content 15%), with this slurry spray drying forming; The spraying machine inlet temperature is 360 ℃, and 210 ℃ of outlet temperatures are carried out roasting then; 750 ℃ of sintering temperatures; Roasting time 6h obtains the microspheroidal fluid bed and uses iron-base fischer-tropsch synthesis catalyst A, and it is processed and consists of:

85％Fe ₁₀₀V _5.0Zn ₂₀K _0.1O _x+15％SiO ₂

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[embodiment 2]

Getting certain amount of ferric nitrate is dissolved in the water and is made into certain density solution I; An amount of niobium hydroxide is dissolved in obtains the solution II in the oxalic acid solution; Get an amount of zinc nitrate, copper nitrate wiring solution-forming III soluble in water obtains the solution IV with the mixing of solution I II III; Place boiling water bath to heat the solution IV, add an amount of Ludox and Na simultaneously ₂CO ₃Solution mixes making beating, and the pH value that uses ammoniacal liquor to regulate slurry then is 1, after fully stirring, obtains required catalyst pulp (solid content 45%); With this slurry spray drying forming, the spraying machine inlet temperature is 200 ℃, 100 ℃ of outlet temperatures; Carry out roasting then, 600 ℃ of sintering temperatures, roasting time 0.15h; Obtain the microspheroidal fluid bed and use iron-base fischer-tropsch synthesis catalyst B, it is processed and consists of:

20％Fe ₁₀₀Nb _60.0Zn _5.0Cu _3.0Na _10.0O _x+80％SiO ₂

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[embodiment 3]

Get certain amount of ferric nitrate and be dissolved in the water and be made into certain density solution I, an amount of ammonium metavanadate that is dissolved in the water is mixed obtaining the solution II with an amount of niobium hydroxide in being dissolved in oxalic acid solution, solution I II is mixed obtaining the solution III; Place boiling water bath to heat the solution III, add an amount of aluminium colloidal sol and LiOH solution simultaneously and mix making beating, the pH value that uses ammoniacal liquor to regulate slurry then is 3; After fully stirring, obtain required catalyst pulp (solid content 35%), with this slurry spray drying forming, the spraying machine inlet temperature is 230 ℃; 140 ℃ of outlet temperatures; Carry out roasting then, 400 ℃ of sintering temperatures, roasting time 4h; Obtain the microspheroidal fluid bed and use iron-base fischer-tropsch synthesis catalyst C, it is processed and consists of:

50％Fe ₁₀₀V _15.0Nb _15.0Li _7.0O _x+50％Al ₂O ₃

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[embodiment 4]

Get certain amount of ferric nitrate and be dissolved in the water and be made into certain density solution I, an amount of ammonium metavanadate is dissolved in the water obtains the solution II, gets an amount of copper nitrate, the magnesium nitrate wiring solution-forming III that is dissolved in the water; The mixing of solution I II III is obtained the solution IV, place boiling water bath to heat the solution IV, add an amount of Ludox and RbOH solution simultaneously and mix making beating; The pH value that uses ammoniacal liquor to regulate slurry then is 2.5, after fully stirring, obtains required catalyst pulp (solid content 30%), with this slurry spray drying forming; The spraying machine inlet temperature is 280 ℃, and 150 ℃ of outlet temperatures are carried out roasting then; 550 ℃ of sintering temperatures; Roasting time 2h obtains the microspheroidal fluid bed and uses iron-base fischer-tropsch synthesis catalyst D, and it is processed and consists of:

40％Fe ₁₀₀V _23.0Cu _10.0Mg _3.4K _4.5O _x+60％SiO ₂

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[embodiment 5]

Get certain amount of ferric nitrate and be dissolved in the water and be made into certain density solution I, an amount of niobium hydroxide is dissolved in obtains the solution II in the oxalic acid solution, get an amount of zinc nitrate wiring solution-forming III that is dissolved in the water; The mixing of solution I II III is obtained the solution IV, place boiling water bath to heat the solution IV, add an amount of aluminium colloidal sol and CsOH solution simultaneously and mix making beating; The pH value that uses ammoniacal liquor to regulate slurry then is 3.7, after fully stirring, obtains required catalyst pulp (solid content 25%), with this slurry spray drying forming; The spraying machine inlet temperature is 320 ℃, and 160 ℃ of outlet temperatures are carried out roasting then; 450 ℃ of sintering temperatures; Roasting time 1h obtains the microspheroidal fluid bed and uses iron-base fischer-tropsch synthesis catalyst E, and it is processed and consists of:

65％Fe ₁₀₀Nb _45.0Zn _11.5Cs _8.1O _x+35％Al ₂O ₃

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[embodiment 6]

Getting certain amount of ferric nitrate is dissolved in the water and is made into certain density solution I; An amount of ammonium metavanadate is dissolved in the water obtains the solution II; Get an amount of zinc nitrate wiring solution-forming III that is dissolved in the water; The mixing of solution I II III is obtained the solution IV, place boiling water bath to heat the solution IV, add an amount of aluminium colloidal sol and K simultaneously ₂CO ₃Solution mixes making beating, and the pH value that uses ammoniacal liquor to regulate slurry then is 3.1, after fully stirring, obtains required catalyst pulp (solid content 20%); With this slurry spray drying forming, the spraying machine inlet temperature is 250 ℃, 135 ℃ of outlet temperatures; Carry out roasting then, 650 ℃ of sintering temperatures, roasting time 3.5h; Obtain the microspheroidal fluid bed and use iron-base fischer-tropsch synthesis catalyst F, it is processed and consists of:

60％Fe ₁₀₀V _25.0Zn _5.5K _4.5O _x+40％Al ₂O ₃

Prepared catalyst carries out the experimental result of Fischer-Tropsch synthesis and lists in table 1.

[comparative example 1～4]

Adopt the catalyst that has different compositions with embodiment 1 essentially identical method preparation, gained catalyst numbering and composition are respectively:

Comparative example 1 90%Fe ₁₀₀V _5.0Zn ₂₀K _0.1O _x+ 10%SiO ₂

Comparative example 2 15%Fe ₁₀₀V _25.0Zn _5.5K _4.5O _x+ 20%Al ₂O ₃

Comparative example 3 60%Fe ₁₀₀V _2.5Zn ₂₀K _4.5O _x+ 40%Al ₂O ₃

Comparative example 4 40%Fe ₁₀₀V _23.0Cu _20.0Mg _3.4K _4.5O _x+ 60%SiO ₂

Prepared catalyst carries out Fischer-Tropsch synthesis under following reaction condition, the result also lists in table 1.

The reducing condition of the foregoing description and comparative example is:

450 ℃ of temperature

Pressure 0.5MPa

Loaded catalyst 100 grams

Catalyst loading 2500 hours ^-1

Reducing gases H ₂/ CO=2/1

36 hours recovery times

Reaction condition is:

millimeter fluidized-bed reactor

300 ℃ of reaction temperatures

Reaction pressure 1.5MPa

Loaded catalyst 100 grams

Catalyst loading 3000 hours ^-1

Proportioning raw materials (mole) H ₂/ CO=2/1

The evaluation result of table 1 embodiment catalyst

Claims (3)

1. the ferrum-based catalyst of the synthetic light hydrocarbon of a Fischer-Tropsch, this catalyst is a carrier with at least a in the oxide that is selected from Si or Al, active component contains with atomic ratio measuring, the composition that chemical formula is following:

Fe ₁₀₀A _aB _bC _c0 _x

A is selected from least a among V or the Nb in the formula;

B is selected from least a among Cu or the Zn;

C is selected from least a in the alkali metal;

The span of a is 5.0～60.0;

The span of b is 0～20.0;

The span of c is 0.1～10.0;

X satisfies the required oxygen atom sum of each element valence in the catalyst;

The carrier consumption is 15～80% of catalyst weight by weight percentage.

2. the described Fischer-Tropsch of claim 1 synthesizes the preparation method of the ferrum-based catalyst of light hydrocarbon, comprises following processing step:

(1) with the aequum soluble ferric iron salt solution I of processing soluble in water;

(2) with the aequum ammonium metavanadate in the oxalic acid solution soluble in water or that the aequum niobium hydroxide is dissolved in or two solution are mixed and made into the solution II by a certain percentage;

(3) with the aequum solubility category-B salt solution III of processing soluble in water;

(4) solution I solution, II solution, III solution mixing system are become the mixed solution IV;

(5) in boiling water bath, aequum is selected from SiO ₂Or Al ₂O ₃In at least a colloidal sol and the hydroxide or the salting liquid of C class join in the solution IV, mix making beating, adding acid-base modifier simultaneously, to regulate the pH value of slurry be 1～5 to obtain the slurry V (solid content is 15～45wt%);

(6) send into the spray dryer spray shaping after the slurry V is cooled to 20～60 ℃, 400～750 ℃ of roasting temperatures 0.15～6 hour, obtain the microspheroidal fluid bed and use iron-base fischer-tropsch synthesis catalyst then.

3. according to the preparation method of the said preparation fluid bed of claim 2 with iron-base fischer-tropsch synthesis catalyst, it is characterized in that sintering temperature is preferably 450～700 ℃, roasting time is preferably 0.5～5 hour.