CN103657669A - Fluidized bed catalyst for preparing unsaturation nitrile through ammoxidation and method thereof - Google Patents

Abstract

The invention discloses a fluidized bed catalyst for preparing unsaturation nitrile through ammoxidation and a method thereof, and mainly solves the problems that the lattice oxygen content of an acrylonitrile catalyst is low, the bulk phase lattice oxygen/surface lattice oxygen proportion is low, the propylene is easily subjected to deep oxidation, and the acrylonitrile selectivity is low, so that the acrylonitrile yield is low in the prior art. According to the technical scheme, the fluidized bed catalyst provided by the invention comprises the active components expressed by the following general forma: Mo[12]Bi[a]Fe[b]Ni[c]X[d]Y[e]Z[f]K[g]O[x], wherein b/(a+e)=1.0-3.5, and b/e=2.0-5.0 by adopting a silica solution as a carrier. The fluidized bed catalyst and the method provided by the invention have the advantages that the problem is well solved, and the fluidized bed catalyst is used for industrial production of acrylonitrile by propylene ammoxidation.

Description

The fluid catalyst of prepared by ammoxidation unsaturated nitrile and method thereof

Technical field

The present invention relates to a kind of fluid catalyst and method thereof of prepared by ammoxidation unsaturated nitrile.

Background technology

The prepared by ammoxidation of alkene is for α, beta unsaturated nitrile technique YouBP company in exploitation sixties last century in last century, and the core technology of this technique is the catalyst that uses a kind of active component to contain Mo, Bi.Through constantly improving, Mo-Bi series catalysts is very ripe at present, industrial, by preparing acrylonitrile by allylamine oxidation technique, is widely used.The improvement of catalyst is in the past mainly to carry out from activity and the stability aspect of catalyst by the design of catalyst formulation, as added transition metal to improve activity in active constituent, increases the single of product and receives; Add rare earth element to improve redox ability; Add the elements such as Na, P to improve the wearability of catalyst; Add the elements such as Fe, Co, Ni to suppress the distillation of Mo, improve stability of catalyst etc.

Patent CN 99119905.7, CN 99119906.5, CN 97106771.6 and CN 96101529.2 have all introduced the improved Mo-Bi catalyst for propylene, isobutene ammonia oxidizing unsaturated nitrile catalyst processed, the advantage of these catalyst has good oxidation-reduction stability and good reaction yield, and reacting ammonia is lower than empty ratio and reaction temperature.

Patent CN 01113194.2, CN 01113193.4 and CN 01113192.6 introduced in catalyst preparation process, get part metals and organic ligand, chelating agent or surfactant separately the method for preparation improve catalyst at low ammonia than the performance under reaction condition.

Patent CN 03151170.8 and CN 03151169.4 have introduced in catalyst preparation process, and in carrier starting material Ludox, adding 2～25% grain diameter is that the solid silica of 5～100 nanometers improves catalyst performance.

The conversion ratio of above patented technology to raising catalyst, the discharge of ammonia ratio and then minimizing amine wastewater of sulphuric acid in reduction course of reaction, there has been certain effect the aspects such as the life-span of extending catalyst; Yet patent report up to now, all exist acrylonitrile catalyst Lattice Oxygen content low, and body phase Lattice Oxygen/lattice surface oxygen ratio is low, and deep oxidation easily occurs propylene, and acrylonitrile is selectively low, causes the problem that acrylonitrile yield is low.

Summary of the invention

One of technical problem to be solved by this invention is in prior art, to exist acrylonitrile catalyst Lattice Oxygen content low, easily there is deep oxidation in propylene, acrylonitrile is selectively low, causes the problem that acrylonitrile yield is low, and a kind of new unsaturated nitrile fluid catalyst prepared by ammoxidation is provided.It is high that this catalyst has Lattice Oxygen content, and body phase Lattice Oxygen/lattice surface oxygen ratio is high, there is selective high oxidation reaction in the Lattice Oxygen in propylene and catalyst, and suppress it, react with gas phase oxygen generation deep oxidation, acrylonitrile is selectively high, for the reaction of prepared by ammoxidation unsaturated nitrile, the advantage that acrylonitrile yield is high.Two of technical problem to be solved by this invention is to provide a kind of purposes of described catalyst.

For one of solving the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of fluid catalyst of prepared by ammoxidation unsaturated nitrile, take Ludox as carrier, and contain the active component that following general formula represents:

Mo ₁₂Bi _a?Fe _b?Ni _c?X _d?Y _e?Z _f?K _gO _x

Wherein:

X is at least one being selected from Mg, Co, Ca, Be, Cu, Zn, Pb, Mn or Te;

Y is at least one being selected from La, Ce or Sm;

Z is at least one being selected from Rb, Li or Cs;

The span of a is 0.1～6.0;

The span of b is 0.1～10.0;

The span of c is 0.1～10.0;

The span of d is 0.1～10.0;

The span of e is 0.1～9.5;

The span of b/ (a+e) is 1.0～3.5;

The span of b/e is 2.0～5.0;

The span of f is >0～0.5;

The span of g is >0～0.2;

X meets the required oxygen atom of other element valence sum, and the consumption of carrier is catalyst weight 30～70%; The span that wherein span of b/ (a+e) is 1.0～3.5, b/e is 2.0～5.0.

The preferred span of b/ in technique scheme (a+e) is 1.5～2.5.The preferred span of b/e is 3.0～4.0.The value preferable range of g is 0.01～0.1; The consumption preferable range of carrier is catalyst weight 40～60%.The calcination activation temperature preferable range of catalyst is 550～640 ℃; Calcination activation time preferable range is 0.5～2 hour.The value preferable range of a is 0.5～4.5; The value preferable range of b is 1.0～8.0; The value preferable range of c is 1.0～7.5; The value preferable range of d is 1.0～7.0; The value preferable range of e is 1.0～6.5; The value preferable range of f is 0.01～0.4; The value preferable range of g is 0.001～0.2.X preferred version is at least one being selected from Mg, Co, Ca or Cu.

Catalyst can be prepared by the familiar coprecipitation of those skilled in the art.The starting material of required metallic element is corresponding water soluble salt, by coprecipitation, make slurry with Ludox carrier, the aging rear spray drying granulation of slurry, then high-temperature roasting obtains catalyst finished product, calcination activation temperature preferable range is 550～640 ℃, and calcination activation time preferable range is 0.5～2 hour.

For solve the problems of the technologies described above two, the technical solution used in the present invention is as follows: a kind of method for prepared by ammoxidation unsaturated nitrile, wherein catalyst used is one of technical solution problem catalyst used.

In technique scheme, take propylene, ammonia and air as raw material, material molar ratio propylene/ammonia/air=1/ (1.05～1.30)/(9.2～9.8), reaction condition is: 420～440 ℃ of reaction temperatures, reaction pressure 0.06～0.14MPa, propylene load WWH=0.06～0.10 hour of catalyst ^-1.

In the embodiment providing below, to the investigation appreciation condition of catalyst, be:

Reactor: fluidized-bed reactor, 38 millimeters of internal diameters

Catalyst filling amount: 550 grams

Reactor top pressure: 0.084 MPa (gauge pressure)

Reaction temperature: 430 ℃

Reaction time: 4 hours

Raw material ratio: propylene/ammonia/air=1/1.1/9.5

WWH: 0.06 hour ^-1

Product absorbs with 0 ℃ of diluted acid, with gas-chromatography and chemical analysis binding analysis product.And calculate Carbon balance, when Carbon balance is valid data during at (95～105) %.

Propylene conversion, acrylonitrile yield and be optionally defined as:

unreacting propylene C molal quantity

Propylene conversion (%)=1- * 100 %

All product C molal quantitys (comprising unreacting propylene)

Generate acrylonitrile C molal quantity

Single-pass yield of acrylonitrile (%)=

* 100 %

All product C molal quantitys (comprising unreacting propylene)

Single-pass yield of acrylonitrile

Acrylonitrile selective (%)=

* 100 %

Propylene conversion

The present invention is by optimizing the ratio of Fe/ (Bi+Y) in acrylonitrile catalyst formula, effectively improved Lattice Oxygen content in catalyst, the ratio of Fe/Y in while optimization of catalysts formula, body phase Lattice Oxygen/lattice surface oxygen ratio obviously improves, thereby the non-selective oxidation reaction that had both suppressed gas phase oxygen in propylene and unstripped gas, it is deep oxidation reaction, effectively guaranteed that again catalyst has sufficient body phase Lattice Oxygen to the migration of lattice surface oxygen, and then it is selective to have significantly improved acrylonitrile, acrylonitrile yield obviously improves.As shown in table 2 result: the Lattice Oxygen of catalyst is increased to the approximately 200 μ mol/g of embodiment by 65 μ mol/g of comparative example 1,1～3 times of rising ratio, body phase Lattice Oxygen/lattice surface oxygen ratio has 58.2%, significantly rises to approximately 80%, and effect is remarkable; Acrylonitrile is selectively increased to 86% left and right of embodiment by 80.3% of comparative example 1, single-pass yield of acrylonitrile is increased to and is up to 85.7% by 78.5%, has obtained good technique effect.

Below by embodiment, the present invention is further elaborated.

The specific embodiment

[comparative example 1]

By the Ludox of 1400 gram 40% (weight), stir 0.5 hour, obtain material A.

By 441.4 grams of (NH ₄) ₆mo ₇o ₂₄4H ₂o joins in the warm water of 330 grams 70 ℃, stirs and makes it all dissolve and obtain material B, A is added fast in the B of strong stirring, obtains material C.

By 213.1 grams of Fe (NO ₃) ₃9H ₂o adds in 70 ℃ of hot water of 150 grams, adds 201.8 grams of Bi (NO after stirring and dissolving again ₃) ₃5H ₂o, 274.8 grams of Ni (NO ₃) ₃6H ₂o, 96.3 grams of Mg (NO ₃) ₃6H ₂o, 72.5 grams of La (NO ₃) ₃3H ₂o, 18.6 grams of Sm (NO ₃) ₃3H ₂after O stirring and dissolving, make material D.

In 20 grams of water, add 1.1 grams of KNO ₃, 0.9 gram of NaNO ₃with 2.0 grams of CsNO ₃after dissolving, added and in material D, formed material E.

Material E is dripped under rapid stirring in material C, form catalyst pulp.Dry in 70 ℃ of sprayings after aging 3 hours, by the roasting 3 hours at 580 ℃ in rotary calciner of the particle of gained, obtain finished catalyst.

 

[embodiment 1～15]

According to [comparative example 1] 1 identical preparation process, according to table 1 catalyst, form Kaolinite Preparation of Catalyst, by above-mentioned investigation appreciation condition, to investigate, activity rating result and Lattice Oxygen content analysis the results are shown in Table 2.

Table 1

?	Catalyst forms
		Comparative example 1	Mo 12Bi 2.0Fe 2.5Ni 4.5Mg 1.8La 0.8Sm 0.2K 0.05Cs 0.05Na 0.05+50%SiO 2
Embodiment 1	Mo 12Bi 0.4Fe 2.5Ni 4.6Co 2.0Ce 0.9K 0.07+46%SiO 2
		Embodiment 2	Mo 12Bi 0.3Fe 1.8Ni 5.8Mg 2.3La 0.6K 0.1Rb 0.08+46%SiO 2
Embodiment 3	Mo 12Bi 0.2Fe 2.0Ni 6.8Mg 0.9 Sm 0.6K 0.1Cs 0.05+50%SiO 2
		Embodiment 4	Mo 12Bi 0.4Fe 1.5Ni 4.5Co 4.0La 0.4K 0.02Cs 0.09+52%SiO 2
Embodiment 5	Mo 12Bi 0.5Fe 3.2Ni 3.0Mg 1.8La 0.8K 0.05Cs 0.05+50%SiO 2
		Embodiment 6	Mo 12Bi 0.4Fe 2.8Ni 5.3Mn 0.7Ce 0.8Ca 0.2K 0.11Cs 0.05+50%SiO 2
Embodiment 7	Mo 12Bi 0.8Fe 4.9Ni 3.5Mg 1.8Pb 0.2Ce 1.5 K 0.12Cs 0.13+52% SiO 2
		Embodiment 8	Mo 12Bi 0.5Fe 2.5Ni 5.5Ce 0.7K 0.15Cs 0.1Li 0.05 +47%SiO 2
Embodiment 9	Mo 12Bi 1.0Fe 3.0Ni 4.5Mg 2.3La 1.2K 0.05Cs 0.1Zr 0.03+48%SiO 2
		Embodiment 10	Mo 12Bi 0.5Fe 2.5Ni 6.5Mg 1.8Ce 0.7K 0.08 Rb 0.05Cs 0.05 +50%SiO 2
Embodiment 11	Mo 12Bi 0.3Fe 1.8Ni 4.3 Mg 2.2Ce 0.6K 0.12Cs 0.07Li 0.03 +51%SiO 2
		Embodiment 12	Mo 12Bi 0.4Fe 1.6Ni 4.8Mg 1.8La 0.2Sm 0.4K 0.15Cs 0.05+50%SiO 2
Embodiment 13	Mo 12Bi 0.7Fe 3.8Ni 3.3Mn 0.5Ce 1.2Ca 0.2K 0.11Cs 0.09 +50%SiO 2
		Embodiment 14	Mo 12Bi 0.2Fe 1.6Ni 3.8Mg 1.8Ce 0.5K 0.06Rb 0.07Cs 0.08 +50%SiO 2
Embodiment 15	Mo 12Bi 0.5Fe 2..7Ni 2.0Mg 2.4Ce 0.8K 0.14Cs 0.12+51%SiO 2

Table 2

Claims (8)

1. a fluid catalyst for prepared by ammoxidation unsaturated nitrile, take Ludox as carrier, contains the active component that following general formula represents:

Mo ₁₂Bi _a?Fe _b?Ni _c?X _d?Y _e?Z _f?K _gO _x

Wherein:

X is at least one being selected from Mg, Co, Ca, Be, Cu, Zn, Pb, Mn or Te;

Y is at least one being selected from La, Ce or Sm;

Z is at least one being selected from Rb, Li or Cs;

The span of a is 0.1～6.0;

The span of b is 0.1～10.0;

The span of c is 0.1～10.0;

The span of d is 0.1～10.0;

The span of e is 0.1～9.5;

The span of b/ (a+e) is 1.0～3.5;

The span of b/e is 2.0～5.0;

The span of f is >0～0.5;

The span of g is >0～0.2;

X meets the required oxygen atom of other element valence sum, and the consumption of carrier is catalyst weight 30～70%; The span that wherein span of b/ (a+e) is 1.0～3.5, b/e is 2.0～5.0.

2. the fluid catalyst of prepared by ammoxidation unsaturated nitrile according to claim 1, the span that it is characterized in that b/ (a+e) is 1.5～2.5.

3. the fluid catalyst of prepared by ammoxidation unsaturated nitrile according to claim 1, the span that it is characterized in that b/e is 3.0～4.0.

4. the fluid catalyst of prepared by ammoxidation unsaturated nitrile according to claim 1, the consumption that it is characterized in that carrier is catalyst weight 40～60%.

5. the fluid catalyst of prepared by ammoxidation unsaturated nitrile according to claim 1, the span that it is characterized in that a is 0.5～4.5; The span of b is 1.0～8.0; The span of c is 1.0～7.5; The span of d is 1.0～7.0; The span of e is 1.0～6.5; The span of f is 0.01～0.4; The span of g is 0.001～0.2.

6. the fluid catalyst of prepared by ammoxidation unsaturated nitrile according to claim 1, is characterized in that X is selected from least one in Mg, Co, Ca or Cu.

7. for a method for prepared by ammoxidation unsaturated nitrile, it is characterized in that catalyst wherein used is the fluid catalyst of prepared by ammoxidation unsaturated nitrile claimed in claim 1.

8. the method for prepared by ammoxidation unsaturated nitrile according to claim 7, it is characterized in that take that propylene, ammonia and air are as raw material, material molar ratio propylene/ammonia/air=1/ (1.05～1.30)/(9.2～9.8), reaction condition is: 420～440 ℃ of reaction temperatures, reaction pressure 0.06～0.14MPa, propylene load WWH=0.06～0.10 hour of catalyst ^-1.