CN101623636B - Catalyst for synthesizing pyridine and alkyl pyridine and preparation method thereof - Google Patents

Abstract

The present invention relates to a catalyst and a preparation method thereof, in particular to a catalyst for synthesizing pyridine and alkyl pyridine used for gas-phase synthesis of aldehyde and ammonia and a preparation method thereof. SiO2, SiO2-Al2O3, Al2O3 or bergmeal is taken as the carrier, soaking corrosion is performed to the carrier through chemical corrosive, and then metal or metal oxide is loaded on the carrier, and finally the catalyst is obtained through drying and sintering. The catalyst has excellent catalytic performance and lower preparation cost. The yield coefficients of the pyridine and the alkyl pyridine prepared through the catalyst are obviously improved.

Description

A kind of pyridine and alkyl pyridine synthetic catalyst and preparation method thereof

Technical field

The present invention relates to a kind of Catalysts and its preparation method, specifically a kind of synthetic pyridine of aldehyde ammonia gas phase and synthetic Catalysts and its preparation method of alkyl pyridine of being used for.

Background technology

Pyridine and alkyl pyridine are the important industrial chemicals of a class, be used widely in fields such as medicine, agricultural chemicals and dyestuffs, and still be important solvent and other catalysts simultaneously.Industrial pyridine (C 5 Hs N) is mainly used in produces sulfanilamide (SN), penicillin, vitamin A, cortisone and anthelmintic, also is used for stabilizing agent, softening agent, paint solvent, synthetic resin etc.; 3, the 5-trimethylpyridine is the important source material of producing the anti-ulcer agent Omeprazole; The 3-picoline is used to produce nicotinic acid and derivative thereof; The 4-picoline can be produced the isoniazid with the vanadic anhydride catalytic oxidation; 3-ethylpyridine is used for tobacco and essence as spices; The 2-picoline can be used for producing chlorpheniramine etc.

Pyridine and alkyl pyridine are fractionation and getting from coal tar at first, and chemical synthesis prepares alkyl pyridine abroad in the industrialization of the sixties in last century.The alkalization of pyridine and alkyl pyridine learns that synthetic raw material is different to mainly contain: aldehyde ammonia method, unsaturated hydrocarbons method according to adopting.The aldehyde ammonia method is the synthetic main method of industry, according to the reaction bed difference vapor phase method and liquid phase method is arranged, and wherein vapor phase method divides fixed bed and fluid bed again, and what industrialization was at present adopted substantially is fluidized-bed process.

Aldehyde ammonia method pyridine base synthesis technique is to adopt carbonyls (aldehyde/ketone), perhaps the original position alcohol that can generate carbonyls and ammonia generate the method for different pyridine bases under the acid catalyst effect, this technology obtains 2-picoline and 4-picoline by Chichibabin acetaldehyde and ammonia phase reaction on aluminium oxide catalyst, so claim the Chichibabin method again.This technology almost can be synthesized all simple alkyl pyridines from the monomethyl pyridine to many alkyl pyridines, and raw material is easy to get, and is fit to large-scale continuous production, is the key industry synthetic method.

Reaction condition is generally in the aldehyde ammonia method gas phase synthesis of alkyl pyridine: temperature is at 300-600 ℃, and the key reaction temperature is at 400-450 ℃, when temperature is higher than 450 ℃, in the reaction coking serious, might stop up reacting pipe; The gas phase air speed is at 300-3000H ^-1Between; Ammonia and total aldehyde ratio are 0.5: 1-1: 5; Reaction pressure is a normal pressure or near normal pressure.Generally between 40-70%, the highest yield of report can reach 87% to aldehyde ammonia synthetic method pyridine base total recovery.

The aldehyde ammonia synthetic method generally is High Temperature Gas phase reaction under the solid acid catalyst effect.Because aldehyde is self-polymerization easily on solid acid surface, thereby causes catalyst to need constantly regeneration because of coking and deactivation, target product yield is low, and high boiling substance makes product separation difficulty etc.Except that aspects such as technological parameter, feed composition are improved, catalyst-directly be the research emphasis of this technology.This class catalyst must have dehydration and dehydrogenation dual-use function.Employed catalyst mainly contains three classes: the one, and Al ₂O ₃, Al ₂O ₃-SiO ₂Deng solid acid; The 2nd, the phosphoric acid salt catalyst; The 3rd, have the molecular sieve catalysts that shape is elected to be usefulness.

First generation industrial catalyst is Al ₂O ₃, soon basically by Al ₂O ₃-SiO ₂Replace.Generally require alumina content between 7-15% for Si-Al-O.The catalyst pore volume is at 0.4-0.8cm ³/ g, surface area is at 400-600m ²/ g.Simple oxide solid acid activity is not high, require to add the 4-10% coagent, its amount preferably is no more than 25%, otherwise easily reunite at catalyst surface, roasting has more aggravated to reunite and further sintering, reduced catalyst activity, the auxiliary agent of literature research has almost comprised all transition metal oxides or halide.The Industrial Catalysis agent aid mainly is the oxide or the halide of four kinds of metals: Pb, Zn, Cd, Cu etc.As PbF ₂, ZnF ₂, CdF ₂, CuCl ₂Deng, PbO, ZnO, CdO, CuO etc.Rare earth oxide is used for improving catalyst stability, anti-coking performance, catalyst activity; W, Mo oxide are also more commonly used as catalyst promoter.

Phosphate is to be used for one of pyridine base synthetic catalyst in early days.The phosphate of being studied has: Co, Al, Cd, Pb, Cr, B etc. and their double salt thereof.For the picoline compounds, the phosphate catalyst poor-performing.

Molecular sieve with shape selective catalysis effect is that maximum sieve and silica-sesquioxide catalyst that also successfully replaced are explored in the synthetic field of pyridine base.Studies show that in a large number the molecular sieve catalyst that has good catalytic action in aldehyde ammonia gas phase synthesis technique all has common feature: at first be the molecular sieve restricted index between 1-12, restricted index is the parameter that molecular sieve pore passage is described; Next is that requirement molecular sieve space index is between 5-25; Silica alumina ratio is generally between 30-200; The molecular sieve that meets these requirements has: ZSM-5, ZSM-11, ZSM-12, ZSM-35, ZSM-38, ZSM-22, ZSM-23, ZSM-48, ZSM-57, ZSM-58, MCM-22, MCM-36, MCM-49, MCM-56.Wherein, ZSM-5 uses maximum effective catalysts at present.The same with the sieve and silica-sesquioxide catalyst, molecular sieve catalyst also needs to add certain coagent, mainly contains Pb, Zn, and Cd, Cu, Th, Co, Tl, noble metals etc. adopt ion-exchange and infusion process to add.

U.S. Pat 4861894 discloses a kind of ZSM-5 molecular sieve pyridine base catalyst, and its Si/Al ratio is 225, and pyridine and 3-picoline yield are 61%; Open (CN101161343A) a kind of method for preparing catalyst of University Of Tianjin, its dealuminzation desiliconization is handled too complicated, and initial yield is not high.CN101347744 adopts amine to have the synthetic ZSM-5 molecular sieve of hydro-thermal down, and element modified through Pb, Sn, Zn etc., its pyridine and alkyl pyridine yield reach 90%.Though molecular sieve pyridine base catalyst has been obtained effect preferably, the total preparation cost of catalyst is very high, especially adopts the molecular sieve catalyst that has amine synthetic.

Summary of the invention

The objective of the invention is to overcome the existing too high problem of Preparation of Catalyst cost, a kind of pyridine and alkyl pyridine synthetic catalyst are provided, catalyst of the present invention had both had good catalytic performance, and lower preparation cost is arranged again.

Another object of the present invention is to provide a kind of above-mentioned Preparation of catalysts method.

In order to realize above-mentioned target, the technical solution used in the present invention is as follows: it is with SiO ₂, SiO ₂-Al ₂O ₃, Al ₂O ₃Or diatomite is as carrier, adopts chemical mordant that carrier is carried out immersion corrosion, and carried metal or metal oxide then get through oven dry, roasting preparation.

Such scheme adopts SiO ₂-Al ₂The O carrier, the mol ratio of its Si atom/Al atom is for being 50-300, the best is 80-150.

The chemical mordant that such scheme adopts is the organic or inorganic bases, as KOH, NaOH, TMAH etc.

The chemical mordant that such scheme adopts also can be hydrofluoric acid and its esters, as HF, NaF, KF, NH ₄F and other organic or inorganic fluoride.

The chemical mordant that such scheme adopts also can be phosphoric acid, phosphorous acid and derivative thereof, as trimethyl phosphate, POCl3, phosphorus trichloride, and solutions of dimethyl phosphoryl chlorine etc.

Described immersion corrosion is that the toluene solution at the KOH aqueous solution or POCl3 carries out.Also can add under the gas phase condition that phosphorus trichloride or HF add POCl3 and carry out at HF.

Described metal or metal oxide are Al, Pb, Zn, Cd, Cu, one or more in Tl, Co, Cr, La, Y or Ce metal and the oxide thereof, load capacity is 0～15% of a carrier quality, the optimised quantity that every kind of metal and oxide thereof add is 0～5%, but total load capacity is no more than 15%.Load can be adopted incipient impregnation and ion-exchange process to divide and once or several times be written into.

Drying course adopts tube furnace to carry out at 90-180 ℃ air or the atmosphere that contains organic amine, and its organic amine can reclaim in condensation, and the organic amine in the scheme is cyclo-hexylamine, hexamethylene diamine, cycloheximide, triethylamine etc.Sintering temperature is 450-600 ℃ in the technique scheme, and optimum temperature is 480～570 ℃.

Adopt the catalyst of the present invention's preparation both to have good catalytic performance, lower preparation cost is arranged again.The pyridine of Preparation of Catalyst of the present invention and alkyl pyridine yield are significantly improved, and be the highest near 90%.

The specific embodiment

Embodiment one:

With commercial SiO ₂Bead (S _BET=270M ²) in the NaOH of isopyknic 0.1M solution 50 ℃ soaked 1 hour down, drain NaOH solution then, water is given a baby a bath on the third day after its birth time, oven dry, and then with Al (NO ₃), Y (NO ₃) ₃, Cr (NO ₃) ₃With the mixed solution incipient impregnation of palladium nitrate, 120 ℃ of oven dry, then 550 ℃ of roastings 4 hours.Gained catalyst cupport metal contains Al=2%, Y=1%, Cr=1%, Pd=0.01% in oxide.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 69%, pyridine base total recovery 85%.

Embodiment two:

Adopt commercial SiO ₂-Al ₂O ₃Bead, wherein the mol ratio of Si atom/Al atom is 128,150 ℃ of drying nitrogen bakings 5 hours, adds 10% (v5) phosphorus trichloride gas then in nitrogen earlier, handles 3 hours, stops to feed phosphorus trichloride gas, keeps 3 hours again.And then with Y (NO ₃) ₃, Cu (NO ₃) ₂The mixed solution incipient impregnation, 120 ℃ of oven dry are then 550 ℃ of roastings 4 hours.Gained catalyst cupport metal in oxide contain, Y=2%, Cu=1%.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 68%, pyridine base total recovery 86%.

Embodiment three:

With commercial SiO ₂Bead (S _BET=300M ²) in isopyknic 10% NaF solution, soaked 1 hour under 50 ℃, drain NaF solution then, water is given a baby a bath on the third day after its birth inferior, and oven dry is being used Al (NO then ₃), Y (NO ₃) ₃, Cu (NO ₃) ₃With the mixed solution incipient impregnation of palladium nitrate, 120 ℃ of oven dry, then 550 ℃ of roastings 4 hours.Gained catalyst cupport metal contains Al=2%, Y=1%, Cu=2%, Pd=0.01% in oxide.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 70%, pyridine base total recovery 84%.

Embodiment four:

Adopt commercial SiO ₂-Al ₂O ₃Bead, the mol ratio ratio of its Si/Al atom is 150, passes through 50 ℃ of hydrofluoric acid solutions with drying nitrogen, and then by 50 ℃ of catalyst carriers, handles 3 hours, stops to feed HF gas, keeps under the nitrogen 3 hours again.Using Pb (NO then ₃) ₂, Y (NO ₃) ₃, Cu (NO ₃) ₂The mixed solution incipient impregnation, 120 ℃ of oven dry are then 550 ℃ of roastings 4 hours.Gained catalyst cupport metal in oxide contain, Pb=1%, Y=1%, Cu=1%.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 70%, pyridine base total recovery 88%.

Embodiment five:

With commercial SiO ₂Bead (S _BET=270M ²) in the NaOH of isopyknic 0.1M and 0.5M TMAH mixed solution 50 ℃ soaked 1 hour down, drain solution then, water is given a baby a bath on the third day after its birth time, oven dry, and then with Al (NO ₃), Y (NO ₃) ₃, Cr (NO ₃) ₃With the mixed solution incipient impregnation of palladium nitrate, flooded the back and adopted tube furnace 120 ℃ of oven dry, feed hexamethylene diamine during oven dry.Dried the back 550 ℃ of roastings 4 hours.Gained catalyst cupport metal contains Al=2%, Y=1%, Cr=1%, Pd=0.01% in oxide.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 69%, pyridine base total recovery 85%.

Embodiment six:

Adopt commercial SiO ₂-Al ₂O ₃Bead, the mol ratio ratio of its Si/Al atom is 150, passes through 50 ℃ of hydrofluoric acid solutions with drying nitrogen, and then by 50 ℃ of catalyst carriers, handles 3 hours, stops to feed HF gas, keeps under the nitrogen 3 hours again.Using Pb (NO then ₃) ₂, Y (NO ₃) ₃, Cu (NO ₃) ₂The mixed solution incipient impregnation has flooded the back and has adopted tube furnace 120 ℃ of oven dry, feeds triethylamine during oven dry.Dried the back 550 ℃ of roastings 4 hours.Gained catalyst cupport metal in oxide contain, Pb=1%, Y=1%, Cu=1%.Under 450 ℃, normal pressure, acetaldehyde/formaldehyde/ammonia=2/1/4 condition, the pyridine yield is 70%, pyridine base total recovery 88%.

Claims (3)

1. pyridine and alkyl pyridine synthetic catalyst, it is with SiO ₂-Al ₂O ₃As carrier, carrier is carried out immersion corrosion at the toluene solution of POCl3, carried metal or metal oxide prepare and get described SiO through oven dry, roasting then ₂-Al ₂O ₃The mol ratio of the Si atom/Al atom of carrier is 80-150, and described metal or metal oxide supported amount are 15% of carrier quality.

2. a kind of pyridine according to claim 1 and alkyl pyridine synthetic catalyst, wherein said drying course adopt tube furnace to carry out 90-180 ℃ of atmosphere that contains organic amine.

3. a kind of pyridine according to claim 2 and alkyl pyridine synthetic catalyst, wherein said organic amine are cyclo-hexylamine, hexamethylene diamine, cycloheximide or triethylamine.