CN1217233A - Mfg. for producing alumina carrier and use thereof - Google Patents

Abstract

The present invention relates to a production method of aluminium oxide carrier and its application. Said production method includes the following steps: adopting properly-proportioned alpha-alumina trihydrate, directly mixing one with pseudo-hydrated alpha-alumina, carbon-contained material, flux, fluoride and zirconium sulfate according to a certain proportion, uniformly mixing them, adding binding agent and water, uniformly kneading, extrusion moulding, drying and calcining to obtain alpha-alumina carrier, specific surface area is 0.2-2.0 sq m/g, water absorption is greater than 70%, the pores whose diameter is greater than 60 micrometers are 20%-35% of total pore volume, and crushing strength is 30-65 N/grain. The silver catalyst made up by soaking said carrier in argentamine containing alkaline earth metal barium and alkali metal cesium is used for ethylene oxidation to prepare epoxyethane.

Description

A kind of Manufacturing approach and use of alumina support

The present invention relates to a kind of manufacture method of alumina support.Also relate to this carrier and be used to make the catalyst that ethene oxidation epoxy ethane is used.

The ethene oxidation mainly generates oxirane under the effect of silver catalyst, also generates the side reaction of carbon dioxide and water.Active and selectivity is two main initiation performance indexs of silver catalyst.So-called activity is meant reaction temperature required when reaching certain response intensity in the process for ethylene oxide production.Reaction temperature is low more, and activity of such catalysts is high more.Selectivity is meant that the reaction of ethene and oxygen changes into the ratio of the ethene molal quantity of the molal quantity of oxirane and overall reaction, and the ethene molal quantity ratio that changes into oxirane is big more, and selectivity is high more.The silver catalyst of producing high activity, high selectivity is the main direction of silver catalyst research.The performance of silver catalyst has the important relationship except that composition and the preparation method with catalyst, also and the performance and the preparation method of used carrier important relationship is arranged.Be used to make the carrier of silver catalyst, enough big specific surface must be arranged, be used for carrying attached finely divided silver granuel, make catalyst that sufficiently high activity be arranged, the while because of silver granuel disperses, maintains a certain distance between silver granuel in course of reaction, be difficult for merging sintering, help improving the stability of silver catalyst.The specific surface of carrier is big, and the hole is just little.In the ethene oxidizing process that on the silver catalyst surface, takes place, require reactant ethylene and oxygen in time to be diffused on the surface of catalyst, the timely passing hole channel of product oxirane of catalyst surface desorb is diffused in the gas phase, if diffusion velocity is slow, the oxirane of desorb can be adsorbed onto catalyst surface again again, the deep oxidation reaction taking place generate carbon dioxide and water, has reduced selectivity.Ethylene oxidation reactions is strong heat radiation reaction, and the reaction heat that generates the side reaction of carbon dioxide and water is the twelvefold that generates reacting ethylene oxide reaction heat.The heat that requires ethylene oxidation reactions to produce is in time withdrawn from by solid and gas, otherwise can aggravate the oxirane deep oxidation, reduces selectivity.The pore structure of the diffusion rate of reactant and product and rate of heat transfer and carrier has very big relation.The pore volume of carrier is big, and the shared ratio of macropore is big in the pore size distribution, and inside diffusional resistance is just little, helps improving the selectivity of silver catalyst.The specific surface of carrier is big, help silver granuel and disperse, but the shared ratio of aperture is just big, is unfavorable for reducing inside diffusional resistance.So seek selectivity height, activity stabilized, the life-span, long silver catalyst was the target that each major company does all one can to compete all the time.

I.C.I. the US4168247 of house journal proposes to adopt the carrier of diplopore distribution, porosity is 30%～80% average pore diameter, 0.1～20 μ, and aperture average pore diameter 0.1～20 μ accounts for 70% of total pore volume, macropore average pore diameter 20～500 μ account for 30% of total pore volume.Carrier pore volume 0.1～0.6ml/g that the patent US4242235 of Produits Chimigues Uginl Kuhmn Paris France adopts, diplopore distributes, the hole of average pore diameter 1～5 μ accounts for 35%～65% of total pore volume, and surplus is macropore, and average pore diameter is 60～200 μ.The hole of carrier hole diameter 1～20 μ that UCC patent US4379134 uses accounts for more than 85% of total pore volume, and the hole of bore dia 20～100 μ is not more than 30%.UCC patent US5187140 carrier specific surface is 0.7m at least ²/ g, pore volume at least 0.5 μ/g, average pore diameter 1～25 μ.The hole of bore dia 0.1～1.0 μ accounts for 10%～25% of total pore volume, and the hole of bore dia 1～10 μ accounts for 10% of total pore volume, and the hole of bore dia 10～100 μ accounts for 20% of total pore volume.Carrier water absorption rate 0.2～0.6ml/g that the US5145824 of SHELL house journal uses, specific surface 0.1 5～3m ²/ g.The carrier specific surface 0.2～2.0m of the patent US5063195 of China Petrochemical Corporation (CN1009437B) preparation ²/ g, pore volume＞0.5ml/g, the hole of bore dia＞60 μ accounts for 25%～10% of total pore volume.

Be used to prepare the carrier that silver catalyst is used at present, its basic composition is all inertia α-Al ₂O ₃But other trace element composition and preparing carriers process all have important relation in the performance of carrier and the carrier.The preparation of silver catalyst carrier is many to be initiation material with a water aluminium oxide.For example UCC patent US4379134 is an initiation material with a water aluminium oxide, adds HF, and acetic acid or aqueous solution of nitric acid and other component are mediated evenly, and the flocculation certain hour is extruded ring forming, changes into γ-Al through 400 ℃～700 ℃ roastings ₂O ₃, change into α-Al through 1200 ℃～1700 ℃ roastings again ₂O ₃Carrier specific surface 0.30～0.50m ²/ g, pore volume 0.50～0.60ml/g, intensity is greater than 5 kilograms/, and 80% pore volume bore dia is in 1～20 μ scope.SHELL house journal is many with a water α-Al ₂O ₃Silver catalyst carrier uses for initiation material prepares.The patent EP207541 of SHELL company is a raw material with a water aluminium oxide, adds various oxides, add aqueous hydrochloric acid solution and mediate, and extrusion modling, through 120 ℃ of dryings, 1400 ℃ of roastings make α-Al ₂O ₃Carrier adds various oxides in the preparing carriers process, can improve activity of such catalysts.The EP207542 of SHELL house journal, EP255975, EP299569 etc. are initiation material with a water aluminium oxide, add SnSO ₄The carrier of preparation can improve the activity of silver catalyst.The US4728634 of SHELL house journal, US4731350, US4742034, US4806518, US4829044 etc. are initiation material with a water aluminium oxide, add preparation α-Al such as a small amount of SiO2, CsF, CsOH, CsCl ₂O ₃Carrier is to improve the performance of silver catalyst.Some patent is with calcining α-Al ₂O ₃The carrier that is used for silver catalyst for main initiation material preparation.The patent US4575494 of Dow chemical company is with calcining α-Al ₂O ₃Be main initiation material, the material and the CsOH in a small amount that add silicate binder and control pore volume make low pure α-Al ₂O ₃Carrier contains α-Al approximately ₂O ₃88%, carrier specific surface 0.27m ²/ g, pore volume 0.442ml/g, average pore diameter 7.5 μ.I.C.I. patent EP179584 is with high-purity α-Al ₂O ₃Be main initiation material, grinding is sieved, particle＜45 μ.And flexibilizer, pore forming agent mixes.Add water and mediate, extrusion modling, through 100 ℃ of dryings, 1450 ℃ of roastings.The US5145824 of SHELL house journal is with α-Al ₂O ₃Powder is main initiation material, adds small amounts zirconium, silicic acid tungsten, can burnout thing, boric acid and extrusion aid, mixes, and adds water and mediates, and adds a small amount of vaseline, extrusion modling, 1390 ℃ of roastings.The gained carrier contains Al ₂O ₃〉=85%, alkaline earth oxide 0.05～6%, Si0.01～5%, zirconia 0～10%, carrier water absorption rate 0.3～0.5ml/g, specific surface 0.15～3m ²/ g.Another patent of SHELL US5380697 is a basic material with the ceramic compound, adds the organic matter that can burnout, and boric acid mixes, and adds water and binding agent, mediates evenly, adds the vaseline extrusion molding, and the carrier that high-temperature roasting makes is by two kinds of α-Al ₂O ₃Form first kind of α-Al ₂O ₃In pelletized form, average crystal grain 0.4～4 μ accounts for 95～40%, second kind of α-Al of carrier ₂O ₃Produce by process.Have only indivedual patents directly with three water α-Al ₂O ₃(Gibbsite) be basic material.The BP1465523 of Norton house journal gets with Al ₂O ₃The source meter, a water α-Al of 0～90% ₂O ₃With three water α-Al of 10～100% ₂O ₃, add acid (formic acid, acetate, propionic acid, hydrochloric acid or the nitric acid) aqueous solution, kneaded and formed, through 950～1427 ℃ of roastings, the specific surface of gained carrier is 0.1～60m ²/ g, pore volume＞0.25ml/g, bore dia greater than the pore volume of 0.1 μ greater than 0.1ml/g.The patent US5063195 of China Petrochemical Corporation, the three water α-Al that close with different grain size collocation ₂O ₃Be basic material, with a certain proportion and a false water α～Al ₂O ₃Carbonaceous material, flux, fluoride mix mutually, adding additives and water, and mediating agent is nitric acid and hydrochloric acid etc., but is kneaded into the paste of agent, extrusion molding is lower than 3% 80～120 ℃ of oven dry to moisture, again 1450～1550 ℃ of roastings, gets α-Al ₂O ₃Carrier.This carrier specific surface 0.8～1.3m ²/ g, pore volume 0.5～0.7ml/g, pore radius accounts for 75～90% of total pore volume less than the hole of 30 μ, and pore radius accounts for 25～10% of total pore volume greater than the hole of 30 μ.This carrier is used for the argent-amine complex dipping, is co-catalyst with The addition of C s and Ba, and the catalyst that makes is used for ethene oxidation epoxy ethane, has high selectivity.

The carrier that the patent US5100859 of Norton company, EP496386 make contains α-Al ₂O ₃〉=85% alkaline earth oxide 0.01～6%, silica 0.01～5%, zirconia 0～10% are made the silver catalyst of rhenium-containing Re, make ethene oxidation epoxy ethane selectivity S with little anti-lab scale evaluation ₄₀% is up to 87.3%, the high T of initial reaction temperature ₄₀℃ be 252 ℃, but patent does not disclose the long-term operation stability data.

The present invention is the above-mentioned shortcoming that overcomes prior art, with three water α-Al ₂O ₃Be basic material.Getting particle diameter is 30～160 orders, 150～300 orders and three kind of three water α-Al of 250～500 purposes ₂O ₃, respectively account for 20～60% (weights) and mix, with certain proportion and mistake 200 orders one water α-Al ₂O ₃, the carbonaceous material that 20～200 orders can burnout, flux, oxygenatedchemicals, zirconium sulfate mix mutually, mix, and add aqueous acid, mediate evenly, and extrusion molding, 80～120 ℃ of oven dry then 1300～1500 ℃ of roastings, get α-Al to moisture less than 5% ₂O ₃Carrier.

The present invention is with the industry three water α-Al of cheapness ₂O ₃Be basic material, rather than a water aluminium oxide or a α-Al of aforementioned patent ₂O ₃Be basic material.Three water α-Al ₂O ₃Account for 50～85% of compound.Three water α-Al ₂O ₃Brilliant α-the Al of one-tenth is changeed in dehydration in high-temperature calcination process ₂O ₃Can be by adjusting three water α-Al ₂O ₃Granularity and sintering temperature are adjusted the porosity and the pore size distribution of carrier.Account for the mistake 200 orders one water α-Al of total amount 10～30% in the compound ₂O ₃, adding sour kneading process neutralizing acid reaction, change into colloidal sol, play adhesive, in high-temperature calcination process, a water α-Al ₂O ₃Change into stable α-Al ₂O ₃, become α-Al ₂O ₃The part of carrier.

The present invention comprises petroleum coke with the carbonaceous material that can burnout.Carbon dust, graphite, polymer etc.Addition accounts for 10～30% of total dosage.Carbonaceous material burns into gas in roasting process overflows, and stays the bigger hole of bore dia in carrier.Can be by selecting the carbonaceous material kind, granularity and addition, the macropore content of adjustment carrier.

Flux of the present invention is selected magnesium nitrate, magnesia or feldspar etc. for use, 0.5～2.0% (weight) that its addition is formed for batching.It act as the reduction sintering temperature, improves support strength.

The fluorine compounds mineralizer that the present invention selects for use comprises fluoride, ammonium fluoride, magnesium fluoride etc.Addition is 0.5～2% of the batching composition, and its effect is that the crystal formation of accelerated oxidation aluminium transforms.

The adhesive that the present invention uses, real is a kind of aluminium colloidal sol.Contain a water α-Al in the solid mixture ₂O ₃, adding aqueous acid in the kneading process, used acid comprises nitric acid, formic acid, acetate, propionic acid etc.One water α-Al ₂O ₃And acid reaction, generation aluminium colloidal sol bonds together each component, but becomes the paste of extrusion molding, also can add aluminium colloidal sol and replace a water aluminium oxide and sour as binding agent.

Add batching in the preparing carriers process of the present invention and form the zirconium sulfate of 0.05～1.0% (weight), can improve catalyst selectivity.Arrange in pairs or groups when appropriate when carrier contains zirconium and carrier water absorption rate, can significantly improve selection of catalysts.

The carrier of forming reduces to below 5% free water content through 80～120 ℃ of dryings.Be warming up to 1300～1500 ℃ of roastings then and get α-Al ₂O ₃Carrier.

This support strength is not less than the 50N/ grain, specific surface 0.8～1.2m ²/ g, water absorption rate is not less than 70%, is preferably between 75%～85%.The above hole of bore dia 0.5 μ accounts for more than 99% of total pore volume.The above hole of bore dia 60 μ accounts for 20～35% of total pore volume.

The present invention's argent-amine complex solution impregnating carrier that contains co-catalyst cesium sulfate and barium acetate.By silver nitrate aqueous solution and Ammoniom-Acetate or oxalic acid aqueous solution reaction, separate out the silver oxalate precipitation earlier, filter, be washed till no nitrate ion with deionized water.Then silver oxalate is dissolved in ethylenediamine-monoethanolamine aqueous solution, adds cesium sulfate and barium acetate, maceration extract argentiferous 20～25% (weight), sulfur acid caesium (in caesium) 200～2000ppm contains barium acetate (in barium 0～2000ppm).Impregnated carrier, drain, in air stream, carry out thermal decomposition in 500～600 ℃ of scopes, make catalyst.Catalyst argentiferous 10～25% (weight) contains Cs 200～1000ppm, contains ^Ba100～1500ppm.

The present invention is with the performance of pilot evaluation device evaluate catalysts.Pilot evaluation device reaction device internal diameter 25mm, catalyst loads high 6 meters, catalyst admission space 3.O liter.The appreciation condition that the present invention uses is as follows:

Reaction gas is formed (mole %)

Ethene 15～35

Oxygen 6.5～7.5

CO ₂ ＜10

Cause steady agent N ₂

Inhibitor dichloroethanes 0.05～10ppm

Reaction pressure 2.1MPa

Air speed 7000h-1

Reactor outlet gas EO concentration 1.35%

Productive rate 185EO/ rises catalyst/time

When stable reach above-mentioned reaction condition after the METHOD FOR CONTINUOUS DETERMINATION reactor go into, exit gas forms, measurement result is carried out contraction factor and is proofreaied and correct the back and calculate selectivity with formula down; $S=\frac{\mathrm{\ΔEO}}{\mathrm{\ΔEO}+0.5\mathrm{\ΔCO}2}\×100\%$ Write down case temperature continuously as the index of weighing catalyst activity.

Embodiment 1

Get 30～160 orders, 150～300 orders, 250～500 purposes, three water α-Al ₂O ₃Each 2.0 kilograms; Cross 200 orders, one water α-Al ₂O ₃2.0 kilogram; 30～50 orders and 40～200 purpose petroleum cokes are respectively 1.1 kilograms and 0.5 kilogram; NH ₄The F0.18 kilogram; 0.22 kilogram of magnesium nitrate; 0.02 kilogram of zirconium sulfate.Putting into mixer mixes.Change in the kneader, add rare nitric acid (nitric acid: water=1: 3) 1.8 liters, but be kneaded into the paste of extrusion molding.Be extrusion-molded into external diameter 7mm, long 7mm more than 2 hours, reduces to below 5% moisture (free amount) 80～120 ℃ of oven dry.Carry out roasting, in 30 hours, be warming up to 1430 ℃, be incubated 2 hours.Get porous white α-Al ₂O ₃Carrier.This carrier has following performance:

Side crush intensity, N/ grain 49

Water absorption rate, % 78

Bulk density, grams per milliliter 0.45

The BET specific surface, rice ²/ gram 0.9

Pore size distribution, bore dia accounts for total pore volume %

＜0.5μ 0.2

0.5～1.0μ 2.1

1.0～5.0μ 36.0

5.0～10μ 5.3

10～30μ 14.1

30～50μ 6.7

50～60μ 2.2

＞60μ 33.4

Preparation of Catalyst is implemented by following method.The silver nitrate of getting 2.8 kilograms is dissolved in 3 liters of deionized waters, and 1.1 kilograms of oxalic acid is dissolved in 11 liters 50 ℃ the deionized water.Under high degree of agitation, mix two kinds of solution, produce white silver oxalate precipitation.More than ageing half an hour.Filter, washing to filtrate with deionized water does not have nitrate ion.Silver oxalate paste argentiferous about 60%, moisture about 15%.

In the glass of being with stirring or rustless steel container, add 1.2 kilograms of ethylenediamines, 0.44 kilogram of monoethanolamine, 1.5 kilograms are no dried up.Under agitation the silver oxalate paste that makes is slowly added in the mixed liquor, temperature remains on below 40 ℃, and silver oxalate is dissolved fully.The silver oxalate addition makes final impregnating liquor argentiferous 22% (weight).Add 4.5 gram barium acetates and 7 gram cesium sulfates, add 1 kilogram of left and right sides deionized water again.Make the maceration extract argentiferous 22% that makes, Ba300ppm, Cs650ppm.

Get 3 kilograms in carrier, put into the container that can vacuumize, vacuumize more than the 10mmHg, put into above-mentioned maceration extract, flooded 30 minutes, excess solution is gone in leaching.

Soaked carrier 550 ℃ of heating one minute in air stream.The silver catalyst argentiferous 18.2% (weight) that obtains, barium 250ppm, caesium 500ppm.

Catalyst is estimated with pilot-plant.Reactor inside diameter 25mm, catalyst bed floor height 6.0m, 3.0 liters of effective volumes, reaction tube has chuck outward, in the chuck by heat-conducting oil heating or withdraw reaction heat.Appreciation condition is as follows:

Reaction gas is formed (mole %)

Ethene 30

Oxygen 7.0

CO ₂ ＜8

Cause steady agent N ₂Surplus

Inhibitor dichloroethanes 0.1～0.3ppm

Reaction pressure 2.1MPa

Air speed 7000h-1

Reactor outlet gas EO concentration 1.35%

Productive rate 185 gram EO/ rise catalyst/time

This embodiment selectivity is 86.9%, 234 ℃ of reaction case temperatures.

Embodiment 2

Adopt prescription and the preparation method of embodiment 1 to prepare carrier.Different is that the zirconium sulfate addition is 0.03 kilogram during the preparation carrier.The carrier that makes has following performance:

Side crush intensity, N/ grain 47

Water absorption rate, water 80

Bulk density, grams per milliliter 0.45

Specific surface, rice ²/ gram 0.9

Pore size distribution, bore dia accounts for total pore volume %

＜0.5μ 0.3

0.5～1.0μ 2.7

1.0～5.0μ 46.9

5.0～10μ 6.4

10～30μ 15.3

30～50μ 6.3

50～60μ 2.0

＞60μ 20.1

Method preparation and evaluate catalysts with embodiment 1.Silver catalyst argentiferous 18.4%, barium 125ppm, caesium 540ppm, selectivity is 86.8%, case temperature is 235 ℃.

Comparative example 3

Prescription and preparation method with embodiment 1 prepare carrier.Different is not add zirconium sulfate in the preparing carriers.The carrier that makes has following performance:

Side crush intensity, N/ grain 63

Water absorption rate, water 80

Bulk density, grams per milliliter 0.45

Specific surface, rice ²/ gram 1.01

Pore size distribution, bore dia accounts for total pore volume %

＜0.5μ 0.4

0.5～1.0μ 4.5

1.0～5.0μ 47.3

5.0～10μ 4.0

10～30μ 10.5

30～50μ 5.5

50～60μ 1.9

＞60μ 25.9

Method preparation and evaluate catalysts with embodiment 1.Silver catalyst argentiferous 18.0% (weight), barium 245ppm, caesium 530ppm, selectivity is 85.1%, case temperature is 224 ℃.

Comparative example 4

Prescription and preparation method with embodiment 1 prepare carrier.Different is that sintering temperature is higher in the preparing carriers process, and the carrier water absorption rate reduces.The carrier that makes has following performance:

Side crush intensity, N/ grain 39

Water absorption rate, water 64

Bulk density, grams per milliliter

Specific surface, rice ²/ gram 1.0

Pore size distribution, bore dia accounts for total pore volume %

＜0.5μ 0.8

0.5～1.0μ 6.0

1.0～5.0μ 43.1

5.0～10μ 4.9

10～30μ 13.2

30～50μ 4.3

50～60μ 2.0

＞60μ 25.7

Method preparation and evaluate catalysts with embodiment 1.Silver catalyst argentiferous 17.3% (weight), barium 236ppm, caesium 510ppm, selectivity is 84.9%, case temperature is 231 ℃

Claims (13)

1, a kind of manufacture method of carrier may further comprise the steps:

1) mixes

(1) three water α～alumina powder

(2) a false water α～alumina powder

(3) carbonaceous material that can burnout

(4) flux

(5) fluoride

(6) zirconium sulfate

2) add water and mediate extrusion modling

3) drying becomes α～alumina support 1300～1500 ℃ of roastings.

It is characterized in that α～alumina support has following comprehensive physical property:

Crushing strength (N/ grain) 30～65

Water absorption rate (%) 〉=70

Pore volume (ml/g)＞0.7

Specific surface (m ²/ g) 0.2～2

Pore-size distribution (hole of bore dia 〉=60 μ m accounts for the percentage of total pore volume) 20～35

2, a kind of by the described method of claim 1, it is characterized in that said gibbsite is that granularity respectively is:

50～160 orders 20～60%

150～300 orders 20～60%

250～500 orders 20～60%

The alumina weight of three kinds of granularities accounts for 50～85% of total dosage.

3, a kind of described method of claim 1 of pressing is characterized in that a said water aluminium oxide, and granularity is whole mistake 200 orders, and its consumption accounts for 10～30% of dosage.

4, a kind of by the described method of claim 1, it is characterized in that the consumption of said zirconium sulfate accounts for 0.05～1.0% of dosage.

5, a kind of by the described method of claim 1, it is characterized in that the said carbonaceous material that burnouts is a kind of or mixture in petroleum coke, carbon dust, graphite, polyethylene and the polypropylene.

6, a kind of described method of claim 5 of pressing is characterized in that said petroleum coke is that granularity is 20～60 orders and 30～300 purpose mixtures, and its ratio is 1: 2 to 2: 1.

7, a kind of by the described method of claim 5, it is characterized in that the weight of said petroleum coke is 10～30% of batching.

8, a kind of by the described method of claim 1, it is characterized in that said flux is a magnesium nitrate, magnesia or feldspar.

9, a kind of by the described method of claim 1, it is characterized in that said fluoride is aluminum fluoride, ammonium fluoride or hydrogen fluoride.

10, a kind of by the described method of claim 1, water=1: 2～1: 4) or aluminium colloidal sol it is characterized in that said binding agent is an aqueous solution of nitric acid (nitric acid:.

11, a kind of by the described method of claim 1, it is characterized in that 1380～1500 ℃ of roasting maximum temperatures, 2～6 hours retention times.

12, a kind of by the described method of claim 1, it is characterized in that α～alumina support of making has following rerum natura.

Crushing strength (N/ grain) 30～65

Water absorption rate (%) 〉=70

Pore volume (ml/g) 0.7～0.8

Specific surface (m ²/ g) 0.8～1.3

Pore-size distribution (hole of bore dia 〉=60 μ m accounts for the percentage of total pore volume) 20～35

13, a kind of catalyst that is used to make ethene oxidation epoxy ethane by the described alumina support of claim 1.