The content of the invention
An object of the present invention is:A kind of coated catalyst carrier is provided, the carrier has suitable hole simultaneously
Structure and excellent heat conductivility, are highly suitable for strong exothermal reaction.
Another object of the present invention is to:The preparation method of above-mentioned carrier is provided, the preparation method has raw material sources wide
General, process is simple, the characteristics of reproducible.
It is yet a further object of the present invention to provide a kind of coated catalyst, the catalyst has preferably mechanical strong
Degree, during for unsaturated olefin selective oxidation reaction, will not occur temperature runaway phenomenon, while showing excellent conversion ratio and choosing
Selecting property.
To reach object above, the present invention is adopted the following technical scheme that:
A kind of coated catalyst carrier, is a kind of porous inert porcelain ball, and carrier surface is coarse, and its chemical composition includes
SiO2And Al2O3, the mass ratio of the two is 0.1~0.6;There is the groove of a large amount of irregular alignments and a diameter of in the carrier
50~500 μm of duct, internal gutter communicates with each other, and each duct connects with carrier surface, the duct that 50~500 μm of diameter
Shared pore volume accounts for the 20~70% of total pore volume, and preferably 40~70%;The porosity of carrier is 1~30%, preferably 10~25%, is carried
The heat conductivity of body is 2~20W/ (mK), preferably 4~10W/ (mK).
In order to ensure during coated catalysts are prepared.Carrier is in high speed scroll, and the binding agent of absorption is not fast
Speed throws away in a large number, and the duct of carrier should long and narrow as far as possible, bending, complexity.Additionally, the hole of carrier ball surface can cause surface recessed
Convex injustice, with certain roughness, is conducive to powder body catalyst attaching in carrier surface, while enhancing therebetween
Active force.Therefore exist in the carrier of the present invention a large amount of irregular alignments groove and a diameter of 50~500 μm of duct, it is interior
Portion duct communicates with each other, and each duct connects with carrier surface.The carrier of the coated catalyst of the present invention is a kind of porous
Inert ceramic balls, inside needs the reticulated channel structure with the insertion of a large amount of three-dimensionals.However, the porosity of porous porcelain ball and its heat conduction
Performance is the relation of contradiction, and the heat conductivity of solid is higher than gas, and excessive hole will necessarily affect its heat-transfer capability, therefore,
Carrier ball is needed with suitable pore-size distribution, to reach mass-and heat-transfer to greatest extent, improves the overall heat conduction energy of catalyst
Power.Therefore pore volume shared by the hole of 50~500 μm of diameter accounts for the 20~70% of total pore volume, preferably 40~70% in the carrier.
Too high or too low porosity may be such that every layer of coating is too thick or too thin during cladding, coat inside or painting
The interphase interaction of layer is poor, and catalyst overall mechanical strength is poor.Therefore the catalyst carrier of the present invention requires that porosity is 1
~30%, preferably 10~25%.
The main component of the coated catalyst carrier of the present invention is generally aluminium oxide and silicon dioxide, and pure alumina is led
Preferably, heat conductivity is up to 29W/ (mK), and silicon dioxide heat conductivity is generally less than 2W/ (mK) for hot property.But it is pure
The sintering temperature of alumina ball is higher, is more than 1600 DEG C, and raw material is also relatively harsh, and production cost is higher.In aluminium oxide
Adding silicon dioxide in porcelain ball can reduce sintering temperature, the source relative moderate of raw material.Therefore the titanium dioxide of porous porcelain ball
Silicon directly affects the heat conductivility and production cost of material with the mass ratio of aluminium oxide, and in the present invention SiO is required2And Al2O3, two
The mass ratio of person is 0.1~0.6.
The present invention coated catalyst support chemistry composition also include account for carrier gross weight 1~10% alkali metal and/
Or the oxide of alkaline-earth metal, preferred Na2O、K2At least one in O, CaO, MgO.
The carrier of the present invention needs to be provided simultaneously with excellent heat conductivility and suitable pore structure.Too high or too low hole
Rate may be such that every layer of coating is too thick or too thin during cladding, and the interphase interaction of coat inside or coating is poor, catalysis
Agent overall mechanical strength is poor.Excessive aperture is unfavorable for the diffusion of reactant and hot-fluid, the probability of side reaction occurs and increases,
It is unfavorable to catalyst choice;And aperture is excessive, the mechanical strength of carrier can be deteriorated, and the capacity of heat transmission accordingly dies down.Additionally, in order to
Increase powder body and the friction of carrier surface, strengthen adhesive ability of the coating in carrier surface, and carrier surface is needed with certain
Roughness.Therefore, prepared by carrier of the invention needs strict control technological parameter to have good heat conductivility and machine
Tool intensity.
The preparation method of the coated catalyst carrier of the present invention, comprises the following steps:1) certain draw ratio will be met
Wood fibre mass concentration is 0.3%~1% aqueous sulfuric acid, and 4~8h, Ran Houshui are processed at a temperature of 150~250 DEG C
Wash filtering drying;
2) polyethylene particle for meeting certain particle size range is placed in the container of rotation at a high speed, is heated to 100~150
DEG C, step 1 is added into container) in the wood fibre that processed carry out mechanical mixture, room temperature is cooled to after 0.5~1h and is taken out
To polyethylene particle and the mixture of wood fibre;
3) by step 2) mixture and silicon source, silicon source, extrusion aid, flux of the polyethylene particle that obtains and wood fibre
Mechanical mixture is uniform, adds peptizer, kneading to obtain pug A;
4) pug A is made into a diameter of 1~10mm, the spherical semi-finished product B of preferably 3~6mm;
5) semi-finished product B is put in the seed-coating machine of rotation at a high speed, adds into seed-coating machine and account for the 0.5~3% of carrier gross weight
The wood flour for being ground into 20~60 mesh, while spray binding agent, attach wood flour or be embedded in B surface, obtain semi-finished product C;
6) semi-finished product C is dried and roasting.
The carrier of the present invention needs for raw material to make plasticity pug in preparation process, and carries out extrusion and pelletizing behaviour
Make, this requires that pug has preferable toughness and moisture-keeping functions, to ensure smooth shaping and avoid in extrusion, the interval of pelletizing
Dry and chap of the skin.For this purpose, this patent adds wood fibre in raw material so as to form three-D space structure with other raw materials, improve
The adhesion strength of material, while moisture content is locked in therebetween, efficiently reduces moisture evaporation, it is to avoid cracking.The present invention is to business wood
Matter fiber has carried out diluted acid heat treatment, makes fibre structure partial hydrolysiss, further improves the toughness and flexibility of fiber.The present invention
Also the fiber after process is sticked on the polyethylene particle of close molten state, form long and narrow duct, bending, intricate, end
End is approximately the structure of cyst, and using capillary effect the storage liquid energy power of carrier is strengthened, and finally improves the machine of coated catalyst
Tool intensity.
In the preparation method of the catalyst carrier of the present invention, in order that pore creating material (wood fibre and polyethylene particle) roasting
The hole of 50~500 μm of a large amount of diameters, the wood fibre are formed afterwards, and fibre length is 1~5000 μm, preferably 200~1000 μ
M, draw ratio is 3~10.Described polyethylene particle particle size range is 1~1000 μm, preferably 50~500 μm.Both use
Amount accounts for the 2~5% of silicon source and silicon source quality sum.
In the preparation method of the catalyst carrier of the present invention, described silicon source can be bauxite, Kaolin, intend thin water aluminum
At least one in one or more in stone, alumina powder, preferably bauxite, Kaolin.Silicon source can be Kaolin, two
At least one in one or more in silica powder, Ludox, carborundum, silicon nitride, preferably Kaolin, carborundum.
The extrusion aid for adopting is one or more in sesbania powder, paraffin, stearic acid, preferably sesbania powder, and addition accounts for silicon source and silicon
The 1~3% of source quality sum.
In the preparation method of the catalyst carrier of the present invention, described peptizer is water or nitre aqueous acid, preferably
Aqueous solution of nitric acid, mass concentration is 1~3%, and consumption is the 20~60% of silicon source and silicon source quality sum.
In order to reduce sintering temperature, support strength is improved, present invention adds a certain amount of alkali metal or alkaline-earth metal
Oxide makees flux, corresponds to one or more of raw material in feldspar in powder, albite in powder, magnesium oxide, and addition accounts for aluminum
Source and the 5~15% of silicon source quality sum.In the preparation method of the catalyst of the present invention, pellet processing machine is by mud used in step (4)
Material A makes the spherical semi-finished product B, preferably 3~6mm of a diameter of 1~10mm;Pellet processing machine used has extrusion and pelletizing two
Function, extrudes first pug and makes bar by the hollow cylinder orifice plate of certain diameter, reuses a pair interlaced roller systems
Bar is cut globulate and files circle by ball knife.
In the preparation method of the catalyst carrier of the present invention, the binding agent used by step (5) is sodium lignin sulfonate, poly- second
The aqueous solution of alkene pyrrolidone, polyvinyl alcohol, preferably mass concentration are the lignin sulfonic acid sodium water solution of 1~3wt%.Utilize
Wood flour is attached or is embedded in spherome surface by its cementation and ball with the extruding force of ball, ball and wall.Consumption of binder is aluminum
Source and the 5~15% of silicon source quality sum.
In order to improve the roughness of carrier ball surface, improve cladding ability of the carrier ball to powder body coating, strengthen cladding and urge
The mechanical strength of agent, the wood flour of 20~60 mesh that the present invention crushes height attaches or is embedded in spherome surface, technique behaviour
Work is completed in the seed-coating machine of high speed rotation.
The present invention catalyst carrier preparation method in, in step (6) drying mode dry for self-heating, microwave drying,
Two or more combination in oven drying, infrared drying, vacuum drying.Baking temperature be 50~200 DEG C, preferably 60
~120 DEG C, semi-finished product C is preferably carried out 4~6h of microwave drying by drying time for 8~12h at 60~70 DEG C, is then shifted
4~6h is dried to 110 DEG C of baking ovens.
In the preparation method of the catalyst carrier of the present invention, sintering temperature is 800~1500 DEG C in step (6), preferably
1000~1300 DEG C, 2~10h of roasting time, preferably 3~6h.
A kind of coated catalyst, including metal composite oxide and the coated catalyst being prepared by the method for the present invention
Carrier, it has below formula:
(Mo12BiaFebCocCudCseVfNbiWjPbkOy):N carriers
Wherein, a, b, c, d, e, f, i, j, k represent respectively the atomic ratio of corresponding element, a=0.5~5, b=0.5~5,
C=0.5~5, d=0.02~1, e=0.2~1, f=0~3, i=0~3, j=0~3, k=0~3, y is to meet each element
The atomic ratio of oxygen required for quantivalence;N is carrier and the mass ratio of metal-oxide, n=0.5~20.
Coated catalyst powder body (i.e. metal composite oxide) preparation process and Chinese patent of the present invention
Consistent described in CN102211027B, described coated catalyst raw powder's production technology:By the atomic ratio that each element is constituted,
With water or water solublity of the diluted acid dissolving containing Mo, Bi, Fe, Co, Cu, Cs, V, Nb, W, Pb element or acid-soluble compound, mixing is
PH=0.5~7 are adjusted with ammonia after even, ripening 1~12 hour is stirred, 80 in preferred pH=2~5 at a temperature of 20~100 DEG C
It is evaporated at a temperature of~150 DEG C, then obtains catalyst powder within 1~10 hour in 250~550 DEG C of roasting temperatures, in mass ratio
Catalyst powder is coated on carrier ball in the way of spraying, and in air atmosphere, in 400~600 DEG C roasting 3~
10h。
The molding of the coated catalyst of the present invention is completed in seed-coating machine, and concrete operation step is:By spherical load
Body is placed in the cylinder of seed-coating machine, and is rolled;Then automatic charging equipment is passed through by catalyst powder, shaping assistant and bonding
Agent is sprayed onto respectively carrier surface, the powder compaction moulding that will be attached using the upset repeatedly and reciprocating motion of carrier.Cladding
The binding agent for adding is needed to be any one in glycerol, polyvinyl alcohol, Ludox, Alumina gel, the matter of addition in forming process
Measure as the 10%~20% of catalyst powder weight;The shaping assistant of addition be starch, curdlan, polyvinylpyrrolidone,
At least one in methylcellulose, the quality of addition is the 1~5% of catalyst powder weight.
The coated catalyst of the present invention, for being catalyzed unsaturated olefin selective oxidation for unsaturated aldehyde or unsaturation
Acid, under relatively low hot(test)-spot temperature, that is, (oxidation reaction for being applied to isobutene. can be with to show excellent conversion ratio and selectivity
Reach isobutene conversion>99%, target product effective selectivity>84%), and mechanical strength preferably, beneficial to industrialized production
And long-term operation.
Embodiment 1
1) preparation of carrier
Weigh 400~800 μm of 20g fibre lengths, the wood fibre of draw ratio 4~7, using dilute sulfur of 100ml 0.8%
Acid, carries out process 6h at 200 DEG C, and washing and drying exists at 130 DEG C with 20g polyethylene (particle size is 150~300 μm)
At a high speed mechanical mixture in the container of rotation, is cooled to room temperature after 0.5h.By wood fibre, the mixture of polyethylene and 500g aluminum
Alumina (alumina content 85%), 300g Kaolin (alumina content 40%, dioxide-containing silica 45%), 20g sesbania powders,
60g potassium carbonate, 50g magnesium oxide mechanical mixture is uniform.400g aqueous solution of nitric acid (nitric acid mass fraction is 3%) is added to into mixing
In material, transfer to abundant kneading in kneader and obtain pug.Pug is made using pellet processing machine for the bead of diameter 4mm, by
Seed-coating machine 10g is highly crushed after the wood flour of 20 mesh in 80g lignin sulfonic acid sodium water solutions, (sodium lignin sulfonate mass fraction is
2%) do and be embedded under the conditions of binding agent bead surface, and the microwave drying 1h at 70 DEG C, be dried 4h in 110 DEG C of baking ovens, 1300
DEG C roasting 4h, obtains about 800g ball type carriers.The parameters such as pore-size distribution, porosity, the heat conductivity of carrier ball are as shown in table 1.
2) preparation of catalyst
Under the conditions of 50 DEG C, by 400g ammonium heptamolybdates (molecular weight 1235.86), 20g ammonium metavanadates (molecular weight 116.98)
In input 500m1 deionized waters, solution A is obtained after being completely dissolved.By 300g bismuth nitrate (molecular weight 485.1), 100g cobalt nitrates
(molecular weight 291.05), 280g ferric nitrates (molecular weight 404.02), 20g cesium carbonates (molecular weight 325.82), 20g copper nitrates (point
241.60) son amount is put in 425g dust technologies (15wt%) aqueous solution, and solution B is obtained after being completely dissolved.Keep solution temperature
For 65 DEG C, B is added into A in stirring, then adjust pH=3 with ammonia.After having adjusted, 5~6h of ripening is stirred, at a temperature of 110 DEG C
It is evaporated, 450 DEG C of roasting temperature 4h, obtain catalyst powder after grinding.
Catalyst powder 200g and 10g curdlans are mixed to get into powder, by the Ludox that 45g mass concentrations are 25%
Aqueous solution progressive spraying is to 300g steps 1) on the ball type carrier for preparing, while described powder is added in cylinder, with
Catalyst powder coats the concrete form of spherical carried catalyst and is write as:
(Mo12Bi3.3Fe3.7Co1.8Cu0.4Cs0.6V0.9Oy):1.5 carrier.
3) oxidation reaction of isobutene.
By Catalyst packing obtained above in the middle of fused salt device reaction pipe, reaction tube remainder is filled out by inert filler
Fill.Isobutylene oxidation condition is:Salt temperature is set as 350 DEG C, pressure 0.08MPa, the total air speed of reaction raw materials gaseous mixture
900h-1, isobutene. is 3 with water molar ratio:1;Oxygen is 2 with isobutene. mol ratio:1.Products therefrom is carried out into gas chromatogram
Analyze, isobutene conversion and product selectivity are as shown in table 2.
Embodiment 3
Weigh 200~400 μm of 30g fibre lengths, the wood fibre of draw ratio 3~5, using dilute sulfur of 80ml 0.8%
Acid, carries out process 5h at 220 DEG C, and washing and drying exists at 110 DEG C with 30g polyethylene (particle size is 50~150 μm)
At a high speed room temperature is cooled to after 0.5h after mechanical mixture in the container of rotation.By wood fibre, the mixture of polyethylene and 300g
Bauxite (alumina content 85%), 500g Kaolin (alumina content 40%, dioxide-containing silica 45%), 20g sesbania powders,
60g potassium carbonate, 50g magnesium oxide mechanical mixture are uniform.Remaining step be prepared as described in Example 1 carrier ball (800g) and
Catalyst, the property for obtaining carrier ball is as shown in table 1.Formula and technique according to embodiment 1 prepares carrier ball and catalyst, obtains
Property to carrier ball is as shown in table 1.
Isobutylene oxidation condition is:Salt temperature is set as 350 DEG C, and pressure 0.05MPa, reaction raw materials gaseous mixture is total
Air speed 1000h-1, isobutene. is 3 to 1 with water molar ratio;Oxygen is 2 to 1 with isobutene. mol ratio, the hot(test)-spot temperature of reaction,
Isobutene conversion, methylacrolein (acid) selectivity are as shown in table 2.
Comparative example 1
Weigh 1000~1200 μm of 50g fibre lengths, the wood fibre of draw ratio 12~14, using 100ml's 0.8%
Dilute sulfuric acid, carries out process 6h at 200 DEG C, and (particle size is 500~800 μ to washing and drying with 50g polyethylene at 130 DEG C
M) mechanical mixture in the container of high speed rotation, is cooled to room temperature after 0.5h.By wood fibre, the mixture of polyethylene with
500g bauxites (alumina content 85%), 300g Kaolin (alumina content 40%, dioxide-containing silica 45%), 20g fields
Cyanines powder, 60g potassium carbonate, 50g magnesium oxide mechanical mixture is uniform.Remaining step be prepared as described in Example 1 carrier ball and
Catalyst, the property for obtaining carrier ball is as shown in table 1.
Catalyst activity evaluation, hot(test)-spot temperature, isobutene conversion, methylacrolein are carried out with the method for embodiment 1
(acid) selectivity is as shown in table 2.
Comparative example 2
Weigh 400~800 μm of 20g fibre lengths, the wood fibre of draw ratio 4~7, using dilute sulfur of 100ml 0.8%
Acid, carries out process 6h at 200 DEG C, and washing and drying exists at 130 DEG C with 20g polyethylene (particle size is 150~300 μm)
At a high speed mechanical mixture in the container of rotation, is cooled to room temperature after 0.5h.By wood fibre, the mixture of polyethylene and 100g aluminum
Alumina (alumina content 85%), 700g Kaolin (alumina content 40%, dioxide-containing silica 45%), 20g sesbania powders,
60g potassium carbonate, 50g magnesium oxide mechanical mixture is uniform.Remaining step is prepared as described in Example 1 carrier ball and catalysis
Agent, the property for obtaining carrier ball is as shown in table 1.
Catalyst activity evaluation, hot(test)-spot temperature, isobutene conversion, methylacrolein are carried out with the method for embodiment 1
(acid) selectivity is as shown in table 2.
Comparative example 3
Formula and technique according to embodiment 1 prepares carrier ball and catalyst, except for the difference that without wooden fibre in raw material
Peacekeeping polyethylene, the property for obtaining carrier ball is as shown in table 1.
Catalyst activity evaluation, hot(test)-spot temperature, isobutene conversion, methylacrolein are carried out with the method for embodiment 1
(acid) selectivity is as shown in table 2.
It is attached:
The embodiment 1~3 of table 1, the characterization result of the carrier ball of comparative example 1~3
The embodiment 1~3 of table 2, the attrition of catalyst rate of comparative example 1~3 and Activity evaluation