CN106732702A - A kind of n butane oxidation produces the grading method of catalyst of cis-butenedioic anhydride - Google Patents
A kind of n butane oxidation produces the grading method of catalyst of cis-butenedioic anhydride Download PDFInfo
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Abstract
The invention discloses a kind of method of preparing cis-anhydride by n-butane oxidation.Normal butane is mixed with air, the vanadium-phosphor oxide catalyst bed that resulting hybrid reaction gas cocurrent is connected by three two aboves, under oxidation reaction condition, is contacted with vanadium-phosphor oxide catalyst and is reacted；Wherein, according to the engagement sequence with hybrid reaction gas, in the beds of more than three series connection average valence of vanadium successively in it is first high, rear it is low, again elevated trend carry out grading loading so that the activity distribution of catalyst is balanced, and the activation plays of catalyst are abundant.The method of the present invention, can improve the concentration of n-butane in charging, reduce the reaction focus of bed, be distributed bed temperature average, effectively suppress side reaction and occur, and improve product selectivity, increase product yield of maleic anhydride.
Description
Technical field
The present invention relates to a kind of method that n butane oxidation produces cis-butenedioic anhydride, specifically a kind of n butane oxidation produces the grading method of catalyst of cis-butenedioic anhydride.
Background technology
Maleic anhydride abbreviation cis-butenedioic anhydride, also known as maleic anhydride, are a kind of important Organic Chemicals, are to be only second to the big organic acid anhydride in the third place in the world of phthalic anhydride and aceticanhydride, are widely used in the industries such as petrochemical industry, food processing, medicine, building materials.Its concrete application includes manufacture unsaturated polyester resin, alkyd resin, maleic acid（Maleic acid）, fumaric acid（Fumaric acid）, and agricultural chemicals, coating, fiberglass, lube oil additive, papermaking chemical product additive, surfactant etc..New method cis-butenedioic anhydride esterification low-voltage hydrogenation produces the appearance of BDO technique, makes the important source material of the fine-chemical intermediate BDO with high added value, tetrahydrofuran, γ-fourth lactones, and application field is expanded rapidly.
Benzene oxidatoin method, n butane oxidation method are 2 kinds of main production process of maleic anhydride production, wherein benzene oxidatoin method is the technique of earliest application, and its reactor and catalyst technology are ripe, but because benzene feedstock price is relatively expensive, the environmental pollution of generation is also relatively serious, therefore has increasingly showed its weak point.Industrialization is realized first from Monsanto companies n butane oxidation legal system maleic anhydride process in 1974, and because the technique has raw material inexpensive, environmental pollution is small, and the advantage of cis-butenedioic anhydride low cost of manufacture has become the main route of global maleic anhydride production at present.Selective oxidation of n -butane cis-butenedioic anhydride can be divided into the production technologies such as fixed bed, fluid bed and moving bed.
At present in the production of preparing cis-anhydride by n-butane oxidation, because the butane raw material availability of fixed-bed process is high, product quality stabilization, it is easy to operate, therefore turned into the main method of maleic anhydride production, but in fixed bed mode production process, due to oxidation reaction it is strongly exothermic the characteristics of, the reaction heat of main reaction generation cis-butenedioic anhydride is 1236KJ/mol, side reaction generation CO2CO reaction heat is respectively 2656KJ/mol and 1521KJ/mol, therefore it is to circulate in the melting salt in reactor jacket to remove reaction heat using the external world in industrial production, but catalyst locally still suffers from focus, it is difficult to optimal control, and the presence for reacting focus can have a negative impact to catalyst performance, therefore focus stabilizes the key as course of reaction control in course of reaction, and further the focus height of beds directly affects the stability of conversion ratio, the selectivity of cis-butenedioic anhydride, the yield of product cis-butenedioic anhydride and the catalyst of butane.On the other hand, because the aerial LEL of butane is 1.5%（v）, therefore in industrial production generally use 1.65%（v）Butane input concentration reacted, not more than 1.8%（v）Ma Shouji etc. is in 20,000 tons/year of n butane oxidation maleic anhydride device industrial flows of Lanzhou Petrochemical Company and feature [J] petrochemical technology and application, in July, 2008, pointed out in the fourth phase of volume 26, the volume fraction of normal butane is by initial 1.0% in maleic anhydride production, 1.65% is finally reached, and normal production is maintained under the concentration.
USP4,632,915 propose a kind of vanadium-phosphor oxide catalyst prepares and activation method, and in the stirred autoclave with reflux cooler, cooling is lower to add isobutanol, phosphoric acid（100%）, vanadic anhydride, lithium chloride and iron powder, hydrogen chloride gas are passed through again, then backflow is more than 2.5 hours under conditions of 102 DEG C, obtain catalyst precursor, then by drying, roasting, after shaping, activation process is first with the heating rate of 3 DEG C/min, under aqueous 1.8% air atmosphere, the activation temperature of catalyst is risen to 280 DEG C from 230 DEG C, the normal butane for adding that molar content is 0.6% in air atmosphere is stated then up, and continue that activation temperature is risen into 400 DEG C and 1h is kept with the heating rate of 1 DEG C/min, then it is changed to keep under nitrogen atmosphere 5 hours, activation terminates.Performance evaluation is carried out to the catalyst after activation, reaction result is：Butanes conversion ＞ 78.1%, cis-butenedioic anhydride molar yield is 54.5%.
USP4,855,459 propose a kind of preparation method of preparing cis-anhydride by n-butane oxidation, are that the method loaded using inert sial ball and catalyst dilution is carried out, filling is diluted by the focus generating unit in reaction tube, reaction hot(test)-spot temperature is reduced to reach, Selectivity of maleic anhydride is improved, the purpose of yield of maleic anhydride is improved, while the stationary phase of catalyst is extended, but its unfavorable factor is the addition of inertia goods and materials, the effective volume of reactor is reduced, while also reducing production efficiency.
The content of the invention
The technical problem to be solved in the present invention is to provide the grading method of catalyst that a kind of n butane oxidation produces cis-butenedioic anhydride, to improve the concentration of n-butane in reaction gas, reduces the hot issue for even eliminating beds, extends the service life of catalyst.
A kind of n butane oxidation of the invention produces the grading method of catalyst of cis-butenedioic anhydride, including herein below：
Normal butane is mixed with air, and resulting hybrid reaction gas cocurrent under oxidation reaction condition, is contacted with vanadium-phosphor oxide catalyst and reacted by more than the three vanadium-phosphor oxide catalyst beds of series connection；According to the engagement sequence with hybrid reaction gas, the average valence of vanadium in the beds of more than three series connection（Vox）Successively in first high, rear low, elevated trend again.
The method according to the invention, in the vanadium-phosphor oxide catalyst bed connected wherein more than three, the average valence highest of vanadium in the beds of most upstream, the average valence of vanadium is minimum in Intermediate Catalyst bed, and the average valence of vanadium is to be incremented by from low to high in remaining beds.In addition to the vanadium-phosphor oxide catalyst bed of most upstream, in the flat fare successively in elevated beds of vanadium, the average valence of vanadium raises 0.01~0.3 unit, preferably 0.02~0.2 unit, most preferably 0.05~0.15 unit successively in two adjacent beds.
In the method for the present invention, wherein in each optional vanadium-phosphor oxide catalyst bed, the average valence of vanadium is generally 4.0~4.5, preferably 4.01~4.35.
In the method for the present invention, normal butane preferably passes through 3~5 vanadium-phosphor oxide catalyst beds with the hybrid reaction gas of air, preferably by 5 vanadium-phosphor oxide catalyst beds.When 5 vanadium-phosphor oxide catalyst beds are selected, according to the order contacted with hybrid reaction gas, first paragraph use Vox for 4.30~4.35 catalyst, loadings are 5~15%, second segment use Vox for 4.01~4.05 catalyst, loadings are 10~30%, 3rd section use Vox for 4.05~4.10 catalyst, loadings are 20~30%, 4th section use Vox for 4.10~4.15 catalyst, loadings be 20~40%, the 5th section use Vox for 4.15~4.20 catalyst, loadings be 20~40%.
In the method for the present invention, the average valence of vanadium generally uses ferrous ammonium sulfate titration, such as Qiao Guanghui in vanadium-phosphor oxide catalyst（《Assay laboratory》, the supplementary issue of volume 17, in May, 2008, P222 ~ 223）Etc. ferrous ammonium sulfate titration is used, the average valence of vpo catalyst vanadium ion is determined.Zeng Ling（《Table mountain Journal of Teachers College》, the 2nd phase of volume 14, in May, 1999, P34 ~ 38）It is also the average valence for determining vanadium in the research of butane oxidation cis-butenedioic anhydride vpo catalyst using ferrous ammonium sulfate titration.
The average valence of the vanadium-phosphor oxide catalyst can be prepared according to the ordinary skill in the art.In the inventive method, recommend to prepare the satisfactory vanadium-phosphor oxide catalyst with different average valences using following methods.
The preparation method of the vanadium-phosphor oxide catalyst that the present invention recommends includes herein below：
（1）The presoma of vpo catalyst can be prepared using the art conventional technology, Chinese patent CN103769181A or United States Patent (USP) USP4 is such as used, method disclosed in 632,915 can obtain the catalyst precursor of brown；
（2）By step（1）The use of gained catalyst precursor is beaten piece method and is shaped to Raschig ring shape or cylindrical catalyst particles；
（3）By step（2）Gained catalyst granules is immersed in the organic solvent containing finite concentration organic peroxide, by controlling the concentration of organic peroxide, the average valence of vanadium in regulation and control catalyst；
（4）After dipping terminates, through filtering, dry, dried catalyst is activated in nitrogen or atmosphere of inert gases, obtains the vanadium-phosphor oxide catalyst for having activated.
Wherein, in step（1）In, the precursor of vanadium-phosphor oxide catalyst can be prepared using the prior art or conventional technical means in this area --- vanadium phosphorus oxygen compound.
Wherein step（2）In, described molding mode can be extrusion, beat piece or the conventional forming method in this area such as balling-up.
Wherein step（3）In, described organic peroxide is one or more in the one group of material constituted selected from TBHP, t-amyl peroxy hydrogen, di-isopropylbenzene hydroperoxide, methyl ethyl ketone peroxide, t-octyl peroxy esters, t-amyl peroxy ester and benzoyl peroxide.
Described organic solvent is polar solvent, typically refers to alcohols such as ethanol, propyl alcohol, butanol, amylalcohol etc., ketone such as acetone, MEK, pentanone, hexanone etc., ethers such as ether, propyl ether, butyl ether etc..
The concentration of described organic peroxide is calculated according to following formula：
；
Wherein Vox is the average valence of catalyst vanadium, n1It is the molal quantity of tetravalence vanadium before activation of catalyst, n2It is the molal quantity of pentavalent vanadium after activation of catalyst, obtaining one mole of pentavalent vanadium needs 0.5 mole of oxygen.
Step（3）Described dip time is 1~6 hour, preferably 2~4 hours.
Step（4）Described drying is typically carried out in airtight oven, and described airtight oven can be steam heating, vacuum drying oven or steam heat blowing drying oven.The drying condition after moist catalysis filtering after oxide impregnation treatment is as follows：Drying temperature is generally at 80~160 DEG C, preferably 90~110 DEG C；Drying time is 0.1~20 hour, preferably 8~12 hours.The organic solvent for evaporating is reclaimed in drying process.
Described activation is carried out under nitrogen or inert gas such as helium, argon gas atmosphere.Activation temperature is generally 350~450 DEG C, most preferably preferably 395~435 DEG C, 425 DEG C；The volume space velocity of nitrogen or inert gas is generally 100~2000h-1, preferably 500~1000h-1；Soak time is generally 1~20 hour, preferably 6~8 hours.
The complex catalyst precursor preparation that the present invention is provided is illustrative only process prepared by the presoma of vanadium-phosphor oxide catalyst, but is not limited to the method that vanadium-phosphor oxide catalyst presoma is prepared using other method.
In the activation process of vanadium-phosphor oxide catalyst of the present invention, need first with oxygenerating dipping solution.According to vanadium-phosphor oxide catalyst presoma (VO)2P2O7V in phase4+Molal quantity, determine the molal quantity of organic peroxide, be then configured to oxidation dipping solution of the mass concentration scope in 0.1wt%~10wt%, then impregnated catalyst, the V of now in the peroxide in maceration extract and catalyst duct and outer surface generation4+Generation oxidation reaction, is translated into appropriate V5+Phase, after filtering out dipping solution, the roasting process in the presence of the drying, the inert gas that carry out so that the crystalline phase of catalyst precursor obtains phase inversion and regular, VOHPO40.5H in presoma2O inversion of phases is mutually (VO) for activity2P2O7Crystalline phase, V5+Inversion of phases is β-VOPO4 phases.Can obtain the vanadium-phosphor oxide catalyst of the Vox values with regulation of advance requirement.
In the method for the present invention, when selecting five levels to match somebody with somebody beds, can be loaded according to following grading composition method.According to the order contacted with hybrid reaction gas, on the basis of the volume of whole catalyst, first paragraph use Vox for 4.30~4.35 catalyst, loadings are 5~15%, second segment use Vox for 4.01~4.05 catalyst, loadings are 10~30%, 3rd section use Vox for 4.05~4.10 catalyst, loadings are 10~30%, 4th section use Vox for 4.10~4.15 catalyst, loadings be 15~40%, the 5th section use Vox for 4.15~4.20 catalyst, loadings be 15~40%.
In the method for the present invention, in normal butane and air gained hybrid reaction gas, the volume fraction of normal butane is generally 1.0%~2.0%, preferably 1.5%~2.0%, most preferably 1.8%~2.0%.Described oxidation reaction condition is：Reaction pressure is normal pressure~0.5MPa, and reaction temperature is 380~450 DEG C, and mixed reaction gas product air speed is 1000~3500h-1。
Compared with prior art, the method for the present invention has the advantages that：
1st, the characteristics of reacting strongly exothermic for n butane oxidation, using V4+/V5+Phase content is different, the different catalyst of Vox values height, according to along reaction stream direction, the average valence of catalyst（Vox values）By highest, minimum, then by low order elevated step by step, carry out grading loading, the mode of catalyst activity equilibrium modulation is loaded, the catalytic reaction of the preparing cis-anhydride by n-butane oxidation carried out using such catalyst loading pattern, because the activity of catalyst at inlet is very high, promptly can be converted normal butane under reaction gas volume space velocity operating mode very high, the volume fraction of normal butane in raw material is reduced, without producing a large amount of concentration exothermic phenomenons.Therefore the inventive method can improve the volume fraction of normal butane in raw material, and highest can be to 1.8%~2.0%.The increase of normal butane volume fraction, effectively increases the efficiency of cis-anhydride production process.
2nd, in the inventive method, on the direction of fixed bed charging, rapidly the feed volume fraction of normal butane is declined with high conversion in arrival end, balanced reaction stability.Then, reaction gas again successively with activity（It is embodied in the average valence of vanadium）The vanadium-phosphor oxide catalyst for gradually rising is contacted, and the concentration for effectively reducing oxidizing process is highly exothermic, so as to reduce the hot(test)-spot temperature of beds.And in subsequent reaction process, the activity of catalyst needs equilibrium assignment by reaction, gives full play to the activity of catalyst, reaction focus is reduced, bed temperature distribution is average, it is possible to effectively suppress the generation of side reaction, product selectivity is improved, increases product yield of maleic anhydride.
3rd, what is provided in the present invention can be in the method for the average valence of vanadium in quantitative adjusting catalyst, and with the organic solvent impregnated catalyst precursor of organic peroxide, the liquid phase oxidation relaxed to tetravalence vanadium therein is translated into pentavalent vanadium.And pass through to control the concentration of organic peroxide, can quantitatively modulation with optimization catalyst in V4+/V5+Relative amount, is obtained in the vanadium-phosphor oxide catalyst of the average valence with expected vanadium, such that it is able to be used to control the reactivity of catalyst.
4th, during maleic anhydride industry metaplasia product, the life-span of vpo catalyst is about 5 years, the loss of phosphorus in being catalyst the reason for catalyst in operation process is inactivated.The oxidation of normal butane is strong exothermal reaction, there is hot(test)-spot temperature in reaction, and the too high quick loss that can promote phosphorus in catalyst of hot(test)-spot temperature, therefore, hot(test)-spot temperature height is a key factor for influenceing catalyst activity stabilization in reaction, reaction focus can effectively be reduced using method in the present invention, the service life of catalyst can be effectively improved.
Brief description of the drawings
Fig. 1 is the structural representation of synthesis reactor used by the present invention.
Fig. 2 be embodiment 1 in obtain catalyst precursor XRD spectra.
Fig. 3 be embodiment 1 in obtain the XRD spectra after the impregnated treatment of catalyst precursor.
Fig. 4 be embodiment 1 in impregnate after and fired gained catalyst XRD spectra.
Specific embodiment
The heretofore described vanadium-phosphor oxide catalyst with different average valence vanadium, can be prepared by following recommendation method.
（1）Catalyst precursor --- the synthesis of nanometer vanadium phosphorus oxide
In the reactor with agitating device and reflux condensate device, isobutanol, phenmethylol mixed liquor, isobutanol and phenmethylol volume ratio 5 are added by charge door:1~100:1, vanadic anhydride and auxiliary agent start agitating device, while heating up and keeping reaction temperature at 95~120 DEG C, carry out back flow reaction, maintain the reflux for the reaction time 2~4 hours, add SPA（Concentration 85%~100%）, phosphorus is 0.95~1.20 with vanadium mol ratio, continues to maintain the reflux for reaction 4~8 hours, and reaction terminates to be discharged by reacting material outlet.After reaction solution is cooled to room temperature, filtered.Filter cake is with after a small amount of isobutanol drip washing three times, by filter cake natural air drying 12~24 hours at room temperature, 8~12 hours are then dried in an oven, finally in the Muffle furnace at 200~285 DEG C, roasting 4~8 hours, obtains the catalyst precursor-nanometer vanadium phosphorus oxide of dark brown.
（2）The preparation of vanadium-phosphor oxide catalyst
Step（1）Gained vanadium phosphorus oxide is first molded, and the shape of obtained vanadium-phosphor oxide catalyst can be the shapes such as compressing tablet, spherical, extrusion, and the thing of gained catalyst precursor is mutually（VOHPO4·0.5H2O）.
（3）The oxidation processes of vanadium-phosphor oxide catalyst
By step（2）Gained catalyst granules is immersed in the organic solvent containing finite concentration organic peroxide, by controlling the concentration of organic peroxide, the average valence of vanadium in regulation and control catalyst.
The mass concentration general control 0.1 ~ 10% of organic peroxide.
（4）The activation of vanadium-phosphor oxide catalyst
Step（3）Dipping terminate after, through filtering, dry, dried catalyst activated in nitrogen or atmosphere of inert gases, obtains the vanadium-phosphor oxide catalyst for having activated.
Described filtering and drying uses routine operation well known to those skilled in the art.
Through the vanadium-phosphor oxide catalyst after overactivation, performance evaluation can be as follows carried out：The vanadium-phosphor oxide catalyst of above-mentioned preparation is fitted into fixed bed reactors, normal butane air gas mixture is passed through, using the composition of gas chromatographic analysis reaction product.Evaluation response condition is as follows：380~450 DEG C of reaction temperature, pressure is normal pressure~0.5MPa, and normal butane gaseous mixture air speed is 1000~3500h-1, concentration of n-butane is 1.0%~2.0%（Percent by volume）, carry out the active evaluation test of catalyst.
The vanadium-phosphor oxide catalyst of above-mentioned preparation is loaded by following grading composition method, catalyst grading distribution scheme is on the basis of the weight of whole catalyst, first paragraph use Vox for 4.30~4.35 catalyst, loadings are 5~15%, second segment use Vox for 4.01~4.05 catalyst, loadings are 10~30%, 3rd section use Vox for 4.05~4.10 catalyst, loadings are 10~30%, 4th section use Vox for 4.10~4.15 catalyst, loadings are 15~40%, 5th section use Vox for 4.15~4.20 catalyst, loadings are 15~40%, the filling technology of catalyst is the conventional practices in this area.
With reference to embodiment, the present invention is described in further detail; following examples are not limiting the scope of the invention; those skilled in the art can do appropriate extension with reference to description of the invention and in full, and these extensions all should be protection scope of the present invention.
Crystalline phase detection is carried out using the D/max-2500X x ray diffractometer xs of RIGAKU companies of Japan in embodiment, and specific surface area uses the full-automatic specific surface area of AUTOSORB3B types and pore-size distribution instrument of Quantachrome companies of the U.S..The average valence of vanadium uses ferrous ammonium sulfate titration in catalyst.
Embodiment
1
In the reactor with agitating device and reflux condensate device shown in Fig. 1, isobutanol, phenmethylol mixed liquor 649L, isobutanol/phenmethylol volume ratio 10 are added:1, vanadic anhydride 29.53kg, auxiliary agent six water ferric nitrate 0.3kg, auxiliary agent zirconium nitrate 0.5kg, open stirring, rise high reaction temperature and be maintained at 100 ± 2 DEG C, carry out back flow reaction, maintain the reflux for the time 4 hours, add the phosphoric acid 34.98kg of concentration 100%, phosphorus/vanadium mol ratio is 1.1, continues to flow back 4 hours, and reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, after filter cake is with a small amount of isobutanol drip washing three times, reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, filter cake is with after a small amount of isobutanol drip washing three times, filter cake is put into enamel tray natural air drying at room temperature, dried 8 hours in 100 DEG C of baking ovens, it is last to be calcined 5 hours at 250 DEG C in Muffle furnace, the catalyst precursor of dark brown is obtained, its XRD spectra is shown in Fig. 2.
By the graphite powder that catalyst precursor obtained above addition mass fraction is 4%, after being sufficiently mixed, using rotary tablet machine, appropriate adjustment impact dynamics is squeezed into Raschig ring shape finished catalyst.
Take above-mentioned Raschig ring shape catalyst granules 86g, it is impregnated into the TBHP t-butanol solution that 90g concentration is 0.5wt%, dip time is kept for 2 hours, dipping terminates rear filtering catalyst, moist catalysis is dried in the close drying case at 120 DEG C, the t-butanol solvent that recovery is evaporated, dried catalyst XRD spectra is shown in Fig. 3.Above-mentioned dried catalyst is inserted in tubular reactor, in nitrogen atmosphere, with nitrogen air speed 500h-1, 3 DEG C/min of heating rate, activation temperature is risen into 425 DEG C from room temperature carries out calcination process, and is kept for 6 hours at 425 DEG C, and activation process terminates, that is, obtain by the vanadium-phosphor oxide catalyst in green state of the invention, and its XRD spectra is shown in Fig. 4.
Gained catalyst detects that its crystalline phase is (VO through XRD2)2P2O7With β-VOPO4The mixture of phase, specific surface area 45m2/ g, pore volume is 0.27cm3/g.The average valence of vanadium is+4.02 in catalyst.
Embodiment
2
In the reactor with agitating device and reflux condensate device shown in Fig. 1, isobutanol, phenmethylol mixed liquor 649L, isobutanol/phenmethylol volume ratio 10 are added:1, vanadic anhydride 29.53kg, auxiliary agent six water ferric nitrate 0.3kg, auxiliary agent zirconium nitrate 0.5kg, open stirring, rise high reaction temperature and be maintained at 100 ± 2 DEG C, carry out back flow reaction, maintain the reflux for the time 4 hours, add the phosphoric acid 34.98kg of concentration 100%, phosphorus/vanadium mol ratio is 1.1, continues to flow back 4 hours, and reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, after filter cake is with a small amount of isobutanol drip washing three times, reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, filter cake is with after a small amount of isobutanol drip washing three times, filter cake is put into enamel tray natural air drying at room temperature, dried in 100 DEG C of baking ovens 8 hours, be finally calcined 5 hours at 250 DEG C in the Muffle furnace, obtain the catalyst precursor of dark brown.
By the graphite powder that catalyst precursor obtained above addition mass fraction is 4%, after being sufficiently mixed, using rotary tablet machine, appropriate adjustment impact dynamics is squeezed into Raschig ring shape finished catalyst.
Take above-mentioned Raschig ring shape catalyst granules 86g, it is impregnated into the TBHP t-butanol solution that 112.5g concentration is 1 wt%, dip time is kept for 2 hours, dipping terminates rear filtering catalyst, moist catalysis is dried in the close drying case at 120 DEG C, the t-butanol solvent that recovery is evaporated, dried catalyst is inserted in tubular reactor, in nitrogen atmosphere, with nitrogen air speed 500h-1, 1 DEG C/min of heating rate, activation temperature is risen into 425 DEG C from room temperature carries out calcination process, and is kept for 6 hours at 425 DEG C, and activation process terminates, that is, obtain by the vanadium-phosphor oxide catalyst in green state of the invention.
Gained catalyst detects that its crystalline phase is (VO through XRD2)2P2O7With β-VOPO4The mixture of phase, specific surface area 30m2/ g, pore volume is 0.33cm3/g.The average valence of vanadium is+4.05 in catalyst.
Embodiment
3
In the reactor with agitating device and reflux condensate device shown in Fig. 1, isobutanol, phenmethylol mixed liquor 649L, isobutanol/phenmethylol volume ratio 10 are added:1, vanadic anhydride 29.53kg, auxiliary agent six water ferric nitrate 0.3kg, auxiliary agent zirconium nitrate 0.5kg, open stirring, rise high reaction temperature and be maintained at 100 ± 2 DEG C, carry out back flow reaction, maintain the reflux for the time 4 hours, add the phosphoric acid 34.98kg of concentration 100%, phosphorus/vanadium mol ratio is 1.1, continues to flow back 4 hours, and reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, after filter cake is with a small amount of isobutanol drip washing three times, reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, filter cake is with after a small amount of isobutanol drip washing three times, filter cake is put into enamel tray natural air drying at room temperature, dried in 100 DEG C of baking ovens 8 hours, be finally calcined 5 hours at 250 DEG C in the Muffle furnace, obtain the catalyst precursor of dark brown.
By the graphite powder that catalyst precursor obtained above addition mass fraction is 4%, after being sufficiently mixed, using rotary tablet machine, appropriate adjustment impact dynamics is squeezed into Raschig ring shape finished catalyst.
Take above-mentioned Raschig ring shape catalyst granules 86g, it is impregnated into the TBHP t-butanol solution that 135g concentration is 2.5 wt%, dip time is kept for 1 hour, dipping terminates rear filtering catalyst, moist catalysis is dried in the close drying case at 100 DEG C, the t-butanol solvent that recovery is evaporated, dried catalyst is inserted in tubular reactor, in nitrogen atmosphere, with nitrogen air speed 500h-1, 3 DEG C/min of heating rate, activation temperature is risen into 425 DEG C from room temperature carries out calcination process, and is kept for 10 hours at 425 DEG C, and activation process terminates, that is, obtain by the vanadium-phosphor oxide catalyst in green state of the invention.
Gained catalyst detects that its crystalline phase is (VO through XRD2)2P2O7With β-VOPO4The mixture of phase, specific surface area 45m2/ g, pore volume is 0.40cm3/g.The average valence of vanadium is+4.15 in catalyst.
Embodiment
4
In the reactor with agitating device and reflux condensate device shown in Fig. 1, isobutanol, phenmethylol mixed liquor 649L, isobutanol/phenmethylol volume ratio 10 are added:1, vanadic anhydride 29.53kg, auxiliary agent six water ferric nitrate 0.3kg, auxiliary agent zirconium nitrate 0.5kg, open stirring, rise high reaction temperature and be maintained at 100 ± 2 DEG C, carry out back flow reaction, maintain the reflux for the time 4 hours, add the phosphoric acid 34.98kg of concentration 100%, phosphorus/vanadium mol ratio is 1.1, continues to flow back 4 hours, and reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, after filter cake is with a small amount of isobutanol drip washing three times, reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, filter cake is with after a small amount of isobutanol drip washing three times, filter cake is put into enamel tray natural air drying at room temperature, dried in 100 DEG C of baking ovens 8 hours, be finally calcined 5 hours at 250 DEG C in the Muffle furnace, obtain the catalyst precursor of dark brown.
By the graphite powder that catalyst precursor obtained above addition mass fraction is 4%, after being sufficiently mixed, using rotary tablet machine, appropriate adjustment impact dynamics is squeezed into Raschig ring shape finished catalyst.
Take above-mentioned Raschig ring shape catalyst granules 86g, it is impregnated into the TBHP t-butanol solution that 90g concentration is 5 wt%, dip time is kept for 1.5 hours, dipping terminates rear filtering catalyst, moist catalysis is dried in the close drying case at 100 DEG C, the t-butanol solvent that recovery is evaporated, dried catalyst is inserted in tubular reactor, in nitrogen atmosphere, with nitrogen air speed 500h-1, 3 DEG C/min of heating rate, activation temperature is risen into 425 DEG C from room temperature carries out calcination process, and is kept for 8 hours at 425 DEG C, and activation process terminates, that is, obtain by the vanadium-phosphor oxide catalyst in green state of the invention.
Gained catalyst detects that its crystalline phase is (VO through XRD2)2P2O7With β-VOPO4The mixture of phase, specific surface area 35m2/ g, pore volume is 0.28cm3/g.The average valence of vanadium is+4.20 in catalyst.
Embodiment
5
In the reactor with agitating device and reflux condensate device shown in Fig. 1, isobutanol, phenmethylol mixed liquor 649L, isobutanol/phenmethylol volume ratio 10 are added:1, vanadic anhydride 29.53kg, auxiliary agent six water ferric nitrate 0.3kg, auxiliary agent zirconium nitrate 0.5kg, open stirring, rise high reaction temperature and be maintained at 100 ± 2 DEG C, carry out back flow reaction, maintain the reflux for the time 4 hours, add the phosphoric acid 34.98kg of concentration 100%, phosphorus/vanadium mol ratio is 1.1, continues to flow back 4 hours, and reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, after filter cake is with a small amount of isobutanol drip washing three times, reaction terminates.After reaction solution is cooled to room temperature, vacuum filtration, filter cake is with after a small amount of isobutanol drip washing three times, filter cake is put into enamel tray natural air drying at room temperature, dried in 100 DEG C of baking ovens 8 hours, be finally calcined 5 hours at 250 DEG C in the Muffle furnace, obtain the catalyst precursor of dark brown.
By the graphite powder that catalyst precursor obtained above addition mass fraction is 4%, after being sufficiently mixed, using rotary tablet machine, appropriate adjustment impact dynamics is squeezed into Raschig ring shape finished catalyst.
Take above-mentioned Raschig ring shape catalyst granules 86g, it is impregnated into the TBHP t-butanol solution that 96g concentration is 7 wt %, dip time is kept for 2 hours, dipping terminates rear filtering catalyst, moist catalysis is dried in the close drying case at 100 DEG C, the t-butanol solvent that recovery is evaporated, dried catalyst is inserted in tubular reactor, in nitrogen atmosphere, with nitrogen air speed 500h-1, 3 DEG C/min of heating rate, activation temperature is risen into 425 DEG C from room temperature carries out calcination process, and is kept for 10 hours at 425 DEG C, and activation process terminates, that is, obtain by the vanadium-phosphor oxide catalyst in green state of the invention.
Gained catalyst detects that its crystalline phase is (VO through XRD2)2P2O7With β-VOPO4The mixture of phase, specific surface area 33m2/ g, pore volume is 0.30cm3/g.The average valence of vanadium is+4.30 in catalyst.
Embodiment
6
On the small-sized preparing cis-anhydride by n-butane oxidation experimental rig of 200ml fixed beds, reaction tube is that internal diameter is 18mm stainless steel reaction pipes, divide five sections of grading loadings from the bottom to top along logistics direction, catalyst grading distribution scheme is on the basis of the weight of whole catalyst, first paragraph use Vox for 4.30 catalyst, loadings are 5%, second segment use Vox for 4.05 catalyst, loadings are 10%, 3rd section use Vox for 4.10 catalyst, loadings are 30%, 4th section use Vox for 4.15 catalyst, loadings are 30%, 5th section use Vox for 4.20 catalyst, loadings are 25%, remainder loads inertia magnet ring.In 420 DEG C of reactor salt temperature, reaction pressure 0.25MPa, reaction gas is the normal butane/air Mixture of normal butane volumetric concentration 2.0%, and gas volume air speed is 1560h-1Reaction condition under carry out normal butane cis-butenedioic anhydride reaction.Result of the test is that n-butane conversion is 84.1%（Mole）, yield of maleic anhydride 62.2%（Mole）.Result of the test and beds focus are shown in Table 1 respectively.
Embodiment
7
On the small-sized preparing cis-anhydride by n-butane oxidation experimental rig of 200ml fixed beds, reaction tube is that internal diameter is 18mm stainless steel reaction pipes, divide five sections of grading loadings from the bottom to top along logistics direction, catalyst grading distribution scheme is on the basis of the weight of whole catalyst, first paragraph use Vox for 4.30 catalyst, loadings are 5%, second segment use Vox for 4.02 catalyst, loadings are 15%, 3rd section use Vox for 4.10 catalyst, loadings are 25%, 4th section use Vox for 4.15 catalyst, loadings are 30%, 5th section use Vox for 4.25 catalyst, loadings are 25%, remainder loads inertia magnet ring.In 420 DEG C of reactor salt temperature, reaction pressure 0.25MPa, reaction gas is the normal butane/air Mixture of normal butane volumetric concentration 2.0%, and gas volume air speed is 1560h-1Reaction condition under carry out normal butane cis-butenedioic anhydride reaction.Result of the test is that n-butane conversion is 82.3%（Mole）, yield of maleic anhydride 63.4%（Mole）.Result of the test and beds focus are shown in Table 1 respectively.
Comparative example
1
On the small-sized preparing cis-anhydride by n-butane oxidation experimental rig of 200ml fixed beds, reaction tube is that internal diameter is 18mm stainless steel reaction pipes, is packed into and uses USP4, catalyst 100ml prepared by 632,915 methods for providing, remainder filling inertia magnet ring.In 430 DEG C of reaction temperature, reaction pressure 0.25MPa, reaction gas is the normal butane/air Mixture of butane volumetric concentration 1.8%, and gas space velocity is 1560h-1Reaction condition under carry out normal butane cis-butenedioic anhydride reaction.Result of the test is that butanes conversion is 78.1%, and cis-butenedioic anhydride molar yield is 54.5%.Result of the test and beds focus are shown in Table 1 respectively.
Comparative example 2
On the small-sized preparing cis-anhydride by n-butane oxidation experimental rig of 200ml fixed beds, reaction tube is that internal diameter is 18mm stainless steel reaction pipes, and filling Vox is 4.35 catalyst, and loadings are 50ml, remainder filling inertia magnet ring.In 420 DEG C of reactor salt temperature, reaction pressure 0.25MPa, reaction gas is the normal butane/air Mixture of butane volumetric concentration 1.6%, and gas space velocity is 1560h-1Reaction condition under carry out normal butane cis-butenedioic anhydride reaction.Result of the test is that n-butane conversion is 98.2%（Mole）, yield of maleic anhydride 49.7%（Mole）.Result of the test and beds focus are shown in Table 1 respectively.
Comparative example 3
On the small-sized preparing cis-anhydride by n-butane oxidation experimental rig of 200ml fixed beds, reaction tube is that internal diameter is 18mm stainless steel reaction pipes, and filling Vox is 4.02 catalyst, and loadings are 50ml, remainder filling inertia magnet ring.In 420 DEG C of reactor salt temperature, reaction pressure 0.25MPa, reaction gas is the normal butane/air Mixture of butane volumetric concentration 1.6%, and gas volume air speed is 1560h-1Reaction condition under carry out normal butane cis-butenedioic anhydride reaction.Result of the test is that n-butane conversion is 70.6%（Mole）, yield of maleic anhydride 50.2%（Mole）.Result of the test and beds focus are shown in Table 1 respectively.
The experimental result of the embodiment of table 1 and comparative example
| N-butane conversion, mol% | Yield of maleic anhydride, mol% | Bed focus/DEG C | |
| Embodiment 6 | 84.1 | 62.2 | 441 |
| Embodiment 7 | 82.3 | 63.4 | 438 |
| Comparative example 1 | 78.1 | 54.5 | 457 |
| Comparative example 2 | 98.2 | 49.7 | 470 |
| Comparative example 3 | 70.6 | 50.2 | 431 |
Claims (18)
1. a kind of n butane oxidation produces the grading method of catalyst of cis-butenedioic anhydride, including herein below：
Normal butane is mixed with air, and resulting hybrid reaction gas cocurrent under oxidation reaction condition, is contacted with vanadium-phosphor oxide catalyst and reacted by more than the three vanadium-phosphor oxide catalyst beds of series connection；According to the engagement sequence with hybrid reaction gas, the average valence of vanadium is successively in first high, rear low, elevated trend again in the beds of more than three series connection.
2. in accordance with the method for claim 1, it is characterized in that, in the vanadium-phosphor oxide catalyst bed connected more than three, the average valence highest of vanadium in the beds of most upstream, the average valence of vanadium is minimum in Intermediate Catalyst bed, and the average valence of vanadium is to be incremented by from low to high in remaining beds.
3., in accordance with the method for claim 1, it is characterised in that in addition to the vanadium-phosphor oxide catalyst bed of most upstream, in the flat fare successively in elevated beds of vanadium, the average valence of vanadium raises 0.01~0.3 unit successively in two adjacent beds.
4., in accordance with the method for claim 2, in the flat fare successively in elevated beds of vanadium, the average valence of vanadium raises 0.02~0.2 unit successively in two adjacent beds.
5. in accordance with the method for claim 3, it is characterised in that in the flat fare successively in elevated beds of vanadium, the average valence of vanadium raises 0.05~0.15 unit successively in two adjacent beds.
6., according to the method described in claim 1 or 2, it is characterised in that in described vanadium-phosphor oxide catalyst bed, the average valence of vanadium is 4.0~4.5, preferably 4.01~4.35.
7. in accordance with the method for claim 1, it is characterised in that the number of described vanadium-phosphor oxide catalyst bed is 3~5.
8. in accordance with the method for claim 6, it is characterized in that, the number of described vanadium-phosphor oxide catalyst bed is 5, according to the order contacted with hybrid reaction gas, first paragraph use Vox for 4.30~4.35 catalyst, loadings are 5~15%, second segment use Vox for 4.01~4.05 catalyst, loadings are 10~30%, 3rd section use Vox for 4.05~4.10 catalyst, loadings are 20~30%, 4th section use Vox for 4.10~4.15 catalyst, loadings are 20~40%, 5th section use Vox for 4.15~4.20 catalyst, loadings are 20~40%.
9. in accordance with the method for claim 1, it is characterised in that in described hybrid reaction gas, the volume fraction of normal butane is 1.0%~2.0%.
10. in accordance with the method for claim 8, it is characterised in that in described hybrid reaction gas, the volume fraction of normal butane is 1.5%~2.0%.
11. in accordance with the method for claim 1, it is characterised in that described oxidation reaction condition is：Reaction pressure is normal pressure~0.5MPa, and reaction temperature is 380~450 DEG C, and mixed reaction gas product air speed is 1000~3500 h-1。
12. according to any described methods of claim 1-11, wherein described vanadium-phosphor oxide catalyst is prepared by the following method：
（1）Prepare the presoma of vpo catalyst --- vanadium phosphorus oxide；
（2）By step（1）The use of gained catalyst precursor is beaten piece method and is shaped to Raschig ring shape or cylindrical catalyst particles；
（3）By step（2）Gained catalyst granules is immersed in the organic solvent containing finite concentration organic peroxide, by controlling the concentration of organic peroxide, the average valence of vanadium in regulation and control catalyst；
（4）After dipping terminates, through filtering, dry, dried catalyst is activated in nitrogen or atmosphere of inert gases, obtains vanadium-phosphor oxide catalyst.
13. methods stated according to claim 12, characterized in that, described organic peroxide is one or more in the one group of material constituted selected from TBHP, t-amyl peroxy hydrogen, di-isopropylbenzene hydroperoxide, methyl ethyl ketone peroxide, t-octyl peroxy esters, t-amyl peroxy ester and benzoyl peroxide.
14. in accordance with the method for claim 12, it is characterised in that described organic solvent is selected from ethanol, propyl alcohol, butanol, amylalcohol, acetone, MEK, pentanone, one group of material that hexanone, ether, propyl ether, butyl ether are constituted.
15. in accordance with the method for claim 12, it is characterised in that the concentration of described organic peroxide is calculated according to following formula：
；Wherein Vox is the average valence of catalyst vanadium, n1It is the molal quantity of tetravalence vanadium before activation of catalyst, n2It is the molal quantity of pentavalent vanadium after activation of catalyst.
16. in accordance with the method for claim 12, it is characterised in that step（3）Described dip time is 1~6 hour.
17. in accordance with the method for claim 12, it is characterised in that step（4）Described drying condition is：Drying temperature is at 80~160 DEG C, drying time is 0.1~20 hour.
18. in accordance with the method for claim 12, it is characterised in that described activation is being carried out in nitrogen or atmosphere of inert gases, and the volume space velocity of nitrogen or inert gas is 100~2000h-1, activation temperature is 350~450 DEG C, and soak time is 1~20 hour.
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| CN109248699A (en) * | 2017-07-14 | 2019-01-22 | 中国石油化工股份有限公司 | The method of cyclohexane oxidation KA oil |
| CN112442001A (en) * | 2019-08-30 | 2021-03-05 | 中国石油化工股份有限公司 | Method for preparing maleic anhydride by oxidizing n-butane |
| CN116212752A (en) * | 2023-04-04 | 2023-06-06 | 常州新日催化剂股份有限公司 | Filling method of low-pressure butane maleic anhydride catalyst |
| CN116212752B (en) * | 2023-04-04 | 2024-05-24 | 常州新日催化剂股份有限公司 | Filling method of low-pressure butane maleic anhydride catalyst |
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| CN103108694A (en) * | 2010-09-10 | 2013-05-15 | 亨斯迈石油化学有限责任公司 | Improved VPO catalyst with low vanadium oxidation state for maleic anhydride production |
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| CN109248699A (en) * | 2017-07-14 | 2019-01-22 | 中国石油化工股份有限公司 | The method of cyclohexane oxidation KA oil |
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| CN112442001A (en) * | 2019-08-30 | 2021-03-05 | 中国石油化工股份有限公司 | Method for preparing maleic anhydride by oxidizing n-butane |
| CN112442001B (en) * | 2019-08-30 | 2023-02-24 | 中国石油化工股份有限公司 | Method for preparing maleic anhydride by oxidizing n-butane |
| CN116212752A (en) * | 2023-04-04 | 2023-06-06 | 常州新日催化剂股份有限公司 | Filling method of low-pressure butane maleic anhydride catalyst |
| CN116212752B (en) * | 2023-04-04 | 2024-05-24 | 常州新日催化剂股份有限公司 | Filling method of low-pressure butane maleic anhydride catalyst |
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