CN1106314A

CN1106314A - Catalyst for preparing cyanopyridine by ammoxidation of alkyl-pyridine and its application

Info

Publication number: CN1106314A
Application number: CN 94106416
Authority: CN
Inventors: 林启欣; 吴贵勤
Original assignee: Beijing Institute Of Chemical Technology Ministry Of Chemcial Industry
Current assignee: Beijing Institute Of Chemical Technology Ministry Of Chemcial Industry
Priority date: 1994-06-23
Filing date: 1994-06-23
Publication date: 1995-08-09
Anticipated expiration: 2014-06-23
Also published as: CN1044338C

Abstract

The catalyst for preparing cyanopyridine contains such components ac primary active substance (oxides of V, Ti and Sb), catalyst promoter (at least one of oxides of P, Sn, B, Ag, Zr, rare-earth elements and mixed rare-earth elements), and optional stability (at least one oxide of alkali-metal) and features high activity and selectivity and long service life.

Description

Catalyst for preparing cyanopyridine by ammoxidation of alkyl-pyridine and its application

The present invention relates to a kind of is raw material with the alkyl pyridine, prepares the catalyst of corresponding cyanopyridine through gas phase ammonoxidation.In particular, what the present invention relates to is raw material with 3-or 4-picoline, prepares the catalyst of corresponding cyanopyridine in molecular oxygen and water vapour atmosphere through gas phase ammonoxidation.

The 3-cyanopyridine is the intermediate of preparation nicotinic acid, niacinamide, and the 4-cyanopyridine is an intermediate of making isonicotinic acid, Pyrazinamide, isoniazid.Nicotinic acid, niacinamide are a kind of of Cobastab, are extensive use of in industries such as medicine, food and feed addictive.The isoniazid is an anti-tuberculosis drugs.

The preparation method of cyanopyridine is known, referring to U.S.4, and 284,781,4,447,612,4,963,687 and 5,028,713; JP74-34673(speciallys permit bulletin) and JP82-156038.

Lummus company is at U.S.4, discloses fusion vanadic anhydride carried catalyst in 284, No. 781, and cigarette nitrile selectivity is 89.7%, and conversion per pass is 51%, and this catalyst selectivity is poor, and conversion ratio is low and need circular regeneration.Degussa company is at U.S.4, and the oxide of having described with Sb and V in 447, No. 612 is the catalyst of main active material, and this catalyst activity content of material is up to 48%, and complicated process of preparation and ammonia consumption are big, and the alkyl pyridine conversion ratio is low.It is carrier that Japan catalyst chemical industrial company has proposed with carborundum in JP74-34673 number, V-Ti is main active material, with P, Nb, K, Cs, Tl, Zn, Gd is the catalyst of co-catalyst, and the sintered silicon carbon that this catalyst employing purity is 98-99% is a carrier, the cost height.The yield of cigarette nitrile and different cigarette nitrile is not high, and has a small amount of unreacted alkyl pyridine in the reacting gas, influences aftertreatment technology.Mitsubishi gas chemical company is at U.S.4, and disclosing a kind of oxide with V, Cr and B in 963, No. 687 is main active material, and the oxide of P and/or Mo is the SiO of co-catalyst ₂Carried catalyst, this catalyst activity, selectivity is all not high.Standard Oil Company is at U.S.5, and disclosing with P, V and Mo metal oxide in 028, No. 713 is main active material, and Sb, Fe, W, Cu, K, Cs, B, Sn, Zr, Mn, Nb, U, Bi and Cr are the SiO of co-catalyst ₂Carried catalyst.This activity of such catalysts is low, and the alkyl pyridine conversion ratio is not high.Up to the present, do not have a kind of catalyst of prior art to have the conversion ratio height, selectivity is good, the premium properties that the life-span is long.

Therefore, the purpose of this invention is to provide a kind of from the method for alkyl pyridine with high conversion and the corresponding cyanopyridine of highly-selective preparation.

Another object of the present invention provides a kind of catalyst of novelty, and it is in the use of the inventive method, and selectivity is good, the conversion ratio height, and the life-span is long.

A further object of the present invention is that the preparation method of preparation new catalyst used in the present invention is provided.

Other purpose of the present invention, the feature and advantage of others, the specification and the claim gathering of calligraphers are clearer reading.

The invention provides a kind of method for preparing cyanopyridine, it is to make corresponding alkyl pyridine, reacts in the presence of catalyst with the gas and the water vapour of ammonia, molecule-containing keto.This catalyst is with V ₂O ₅, TiO ₂And Sb ₂O ₃Be main active material, at least a oxide of P, Sn, B, Ag, Zr, rare earth element and lucium is a co-catalyst, selectively adds alkali-metal at least a oxide as stabilizing agent, and it is stated from the heat-resisting inert carrier.

New catalyst of the present invention, main active material are V ₂O ₅, TiO ₂And Sb ₂O ₃, its gram atom ratio is: at least a oxide of V: Ti: Sb=1: 3-56: 0.1-1.0, P, Sn, B, Ag, Zr and rare earth element and lucium is a co-catalyst, its gram atom ratio to V is 0.001-0.3:1.Preferred Ag, Sn, La and Ce, more preferably mixed rare-earth oxide.

In above-mentioned composition, selectively add alkali-metal at least a oxide, further improve selection of catalysts and heat endurance.The preferred Li of alkali metal, Na, K, Rb, Cs, more preferably K, Rb, to the gram atom of V than being 0.001-0.1.Catalyst activity content of material 1-30%(wt), preferred 5-20%(wt), catalyst of the present invention does not in use need regeneration, and the life-span reaches 3 years.

The raw material for preparing catalyst activity material of the present invention can be used oxide, chloride, inorganic salts such as nitrate, carbonate, phosphate, sulfate, ammonium salt etc.; Organic salt such as oxalates, acetate and amine salt etc. and oxide, hydroxide.Those skilled in the art can determine arbitrarily.

Employed TiO ₂Can be commercially available TiO ₂, also can be in order to TiCl ₄Be the highly active TiO of raw material with the known method preparation ₂Perhaps their composition.TiO ₂Be anatase titanium dioxide, specific surface is 3-100m ²/ g is preferably 5-50m ²/ g, particle diameter are preferably 0.01-0.3 μ less than 1 μ.

The employed carrier of catalyst of the present invention is the heat-resisting solid material of inertia, as talcum (britesorb), aloxite (AI, carborundum, quartz and pottery etc., preferably talc and carborundum.Carrier can be sphere, cylindrical, annular, preferred spherical.The carrier diameter is 3-12mm, preferred 3-8mm.Carrier can be atresia or loose structure, and its porosity is 0-80%, preferred 0-50%.

Catalyst of the present invention can prepare with known method in the present technique field.For example, with the salt and the oxide dissolution of vanadium and various co-catalysts or be suspended in water and organic solvent in, organic solvent such as ethanol, monoethanolamine, formamide, acetamide, diethylamide, urea and ammonium sulfocyanate etc. add TiO ₂, the suspension of preparation active material.Carrier is placed the coating pan that rotating and the rotating machinery of other type, suspension is dripped or sprays on the dry carrier, till active material reaches pre-metering.Catalyst was 400-500 ℃ of activation 2-10 hour.

Method of the present invention can use 2-picoline, 3-picoline, 4-picoline, 2-methyl-5-ethylpyridine and 2-ethyl-5-picoline to be raw material.

The ammoxidation of alkyl-pyridine reaction is to carry out in the fixed bed single tube reactor, and tube inner diameter is 21-40mm, long 1-4m, and the catalyst loading amount is the 0.4-1.2 liter, is thermophore with the fused salt that circulates, the bed temperature thermocouple measurement.The process conditions of reaction are:

Air speed 1000-3000hr ^-1

Alkyl pyridine concentration 20-80g/NM ³

Alkyl pyridine: ammonia=1: the 1-10(mole ratio)

Alkyl pyridine: water vapour=1: the 1-20(mole ratio)

Reaction temperature: 300 ℃-450 ℃

In material gas mixture, if air is used as oxygen-containing gas, the concentration of alkyl pyridine can be 20-100g/NM ³, preferred 40-70g/NM ³

Employed ammonia amount in material gas mixture surpasses theoretical amount.When using a large amount of ammonia, must reclaim unreacted ammonia, preferred employed ammonia amount is theoretical amount 2-8 times.

The amount of oxygen is at least theoretical 1.5 times in material gas mixture, is preferably 2-30 times of theoretical amount.Usually air is as oxygen-containing gas, and air can be used the inert gas dilution of nitrogen and so on, CO ₂Also can be used as diluent gas with water vapour.

Reaction temperature is 300-450 ℃, and when being lower than 300 ℃, the conversion ratio of alkyl pyridine is low, when being higher than 450 ℃, generates CO ₂Amount big, the yield of cyanopyridine is low.Preferable reaction temperature is 340 ℃-400 ℃.

This reaction is under atmospheric pressure carried out usually, also can carry out being higher than atmospheric pressure or being lower than under the atmospheric pressure.

From reaction mixture gas, reclaim product and can adopt suitable method, as reaction mixture gas being cooled to the temperature that product is solidified.Or water or The suitable solvent washing reaction product, to reclaim it, these all are known methods.

The present invention utilizes following limiting examples to further specify, and all percentages are percetage by weight.Except as otherwise noted.

Example 1

With 18 gram V ₂O ₅Add in the 400ml deionized water that contains 45 gram oxalic acid, heating for dissolving is made the oxalic acid vanadyl aqueous solution of avy blue.In this solution, add 17.3 gram Sb ₂O ₃, 1.34 the gram AgNO ₃, 1.4 gram Ce ₂(C ₂O ₄) ₃9H ₂O, 80 gram formamides and specific surface are 10m ²The anatase titanium dioxide TiO of/g ₂253 grams stir and make active material suspension.

With diameter is 6mm, and porosity is 5% talcum ball carrier, 1000 grams, adds diameter and is in the coating pan of rotation of 300mm, with the suspension spraying of active material or be added drop-wise on the dry carrier, reaches till 10% up to the catalyst activity content of material.Then under air atmosphere in 460 ℃ of activation 6 hours, the gram atom ratio that the catalyst activity material that makes is formed is:

V∶Ti∶Sb∶Ag∶Ce＝1∶16∶0.6∶0.04∶0.02

At internal diameter is filling 1000ml catalyst in the single tube reactor of the long 3.6m boiler steel of 25mm control, and bed height is 2.2m, is raw material with 3-or 4-picoline, prepared by ammoxidation 3-or 4-cyanopyridine, process conditions and the results are shown in Table 1.

Raw material and product gc analysis, data are to react sampling result (as follows) after 10 days in the table.

Table 1

Air speed: 1500hr ^-1

Water: 3-or 4-picoline=10: the 1(mole ratio)

Picoline conversion ratio :～100%*

Comparative example 3

18 gram V ₂O ₅, 1.34 the gram AgNO ₃, 285 gram specific surface～10m ²/ g and anatase titanium dioxide TiO ₂, 1000 gram φ 6mm talcum ball carriers, prepare catalyst and carry out the evaluating catalyst test with example 1 method, at air speed 1500hr ^-1, 3-picoline concentration 50g/NM ³, 380 ℃ of reaction temperatures, 3-cyanopyridine yield 84.8mol%.

Claims

1, the catalyst of the corresponding cyanopyridine of a kind of ammoxidation of alkyl-pyridine system is with V ₂O ₅, TiO ₂And Sb ₂O ₃Be main active material, its gram atom is than being V: Ti: Sb=1: 3-56: 0.1-1.0, and co-catalyst is to be selected from least a oxide of P.Sn, B, Ag, Zr, rare earth element and lucium or their combination.Its gram atom ratio to V is 0.001-0.3: 1, be stated from the inorganic carrier, and the content of the activity of such catalysts material that makes is 1-30% (Wt).

2, by the catalyst of claim 1, wherein the activity of such catalysts content of material is 5-20%(wt).

3, by the catalyst of claim 1, wherein rare earth oxide is CeO ₂

4, by the catalyst of claim 1, rare earth oxide wherein is La ₂O ₃, CeO ₂And Pr ₆O ₁₁

5, by the catalyst of claim 1, the consisting of of mixed rare-earth oxide wherein: La ₂O ₃24-26%, CeO ₂48-52%, Nd ₂O ₃15-17%, Pr ₆O ₁₁5-7%, Sm ₂O ₃, Gd ₂O ₃, sum＜2%.

6, by the catalyst of one of claim 1-5, wherein catalyst can select to be added to less a kind of alkali metal oxide, and this oxide is 0.001-0.1:1 to the gram atom ratio of V.

7, by the catalyst of claim 6, wherein alkali metal oxide is the oxide of potassium or rubidium or caesium.

8, by the catalyst of claim 1, wherein inorganic carrier is to be selected from a kind of in talcum, carborundum, aloxite (AI, quartz sand and the pottery.

9, by the catalyst of claim 8, wherein inorganic carrier be annular, sphere and cylindrical in a kind of.

10, by the catalyst of claim 8, wherein the particle diameter of inorganic carrier is φ 3-8mm, and porosity is 0-50%.

11, the Preparation of catalysts method of claim 1-10, wherein catalyst is to prepare with spraying process.

12, use the catalyst of claim 1-10, with the alkyl pyridine is raw material, and the corresponding cyanopyridine of gas phase ammonoxidation system is that solid catalyst is contacted with the admixture of gas that contains alkane pyridine, ammonia, water vapour and molecule-containing keto, make alkyl change into cyano group, make cyanopyridine.

13, by the purposes of claim 12, wherein alkyl pyridine is 3-or 4-picoline.

14, by the purposes of claim 12, its reaction is to carry out in fixed bed.

15, by the purposes of claim 12, wherein air speed is 1000-3000hr ^-1

16, by the purposes of claim 12, wherein reaction temperature is 300 ℃-450 ℃.

17, by the purposes of claim 12, wherein alkyl pyridine concentration is 20-100g/NM ³