CN104837558A

CN104837558A - Method for oxidative dehydrogenation of N-butenes to butadiene

Info

Publication number: CN104837558A
Application number: CN201380063881.5A
Authority: CN
Inventors: P·格鲁尼; W·鲁廷格尔; C·瓦尔斯多夫
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2012-12-06
Filing date: 2013-12-03
Publication date: 2015-08-12
Also published as: EP2950928A1; KR20150094620A; WO2014086768A8; EA201591040A1; JP2016502549A; WO2014086768A1

Abstract

The invention relates to a method for the oxidative dehydrogenation of n-butenes to butadiene, comprising two or more production steps (i) and at least one regeneration step (ii), in which (i) in a production step an n-butene-containing starting gas mixture is mixed with an oxygen-containing gas and is contacted in a fixed-bed reactor at a temperature of 220 to 490 DEG C with a multimetal oxide catalyst arranged in a catalyst fixed bed, which multimetal oxide catalyst contains at least molybdenum, and one further metal, and, before the loss in conversion rate at constant temperature is > 25%, (ii), in a regeneration step the multimetal oxide catalyst is regenerated by passing an oxygen-containing regeneration gas mixture at a temperature of 200 to 450 DEG C over the catalyst fixed bed and burning off the carbon deposited on the catalyst, wherein, between two production steps (i), one regeneration step (ii) is carried out, characterized in that, per regeneration step (ii), 2 to 50% by weight of the carbon deposited on the catalyst is burnt off.

Description

For n-butene oxidative dehydrogenation being become the method for butadiene

Describe

The present invention relates to a kind of method n-butene oxidative dehydrogenation being become butadiene.

Butadiene is a kind of important basic chemical, it is for such as preparing synthetic rubber (dienite, SBR styrene butadiene rubbers or nitrile rubber) or for the preparation of thermoplasticity terpolymer (acrylonitrile-butadiene-styrene copolymer).Butadiene is also converted to sulfolane, chlorobutadiene and Isosorbide-5-Nitrae-hexamethylene diamine (via Isosorbide-5-Nitrae-dichloro-butenes and adiponitrile).In addition, butadiene can dimerization to prepare VCH, the latter can dehydrogenation formed styrene.

Butadiene can be prepared by the thermal cracking of saturated hydrocarbons (steam pyrolysis), and wherein naphtha is typically used as raw material.The steam pyrolysis of naphtha obtains methane, ethane, ethene, acetylene, propane, propylene, propine, allene, butane, butylene, butadiene, butine, methyl-prop diene, C ₅the hydrocarbon mixture of-hydrocarbon and higher hydrocarbon.

The oxidative dehydrogenation that butadiene also can pass through n-butene (1-butylene and/or 2-butylene) obtains.Any mixture containing n-butene can be used for the oxidative dehydrogenation of n-butene to butadiene as starting gas mixture.Such as, also can use containing the fraction of n-butene (1-butylene and/or 2-butylene) as main component, and this fraction is from the C from naphtha pyrolysis device ₄fraction is obtained by removing butadiene and isobutene.In addition, the admixture of gas containing 1-butylene, cis-2-butene, Trans-2-butene or its mixture obtained by ethylene dimerization also can be used as starting gas.In addition, the additional gas mixture containing n-butene obtained by sulfide catalyst cracking (FCC) can be used as starting gas.

The admixture of gas containing n-butene being used as starting gas in the oxidative dehydrogenation of n-butene to butadiene also can carry out Non-oxidative dehydrogenation preparation by the admixture of gas containing normal butane.

WO2009/124945 discloses a kind of for 1-butylene and/or 2-butylene oxidation-dehydrogenation being become the coated catalyst of butadiene, and it can obtain from the catalyst precarsor containing following material:

(a) carrier,

(b) shell, its contain (i) containing molybdenum and other metal of at least one and there is the catalytic activity poly-metal deoxide of following general formula:

Mo ₁₂Bi _aCr _bX ¹ _cFe _dX ² _eX ³ _fO _y

Wherein

X ¹=Co and/or Ni,

X ²=Si and/or Al,

X ³=Li, Na, K, Cs and/or Rb,

0.2≤a≤1,

0≤b≤2,

2≤c≤10,

0.5≤d≤10,

0≤e≤10,

0≤f≤0.5, and

The numerical value that y=is determined by the valence link of the element different from oxygen and abundance to reach neutral charge,

(ii) at least one pore former.

WO 2010/137595 discloses the multi-metal-oxide catalyst for alkene oxidative dehydrogenation being become diene, and it contains at least molybdenum, bismuth and cobalt have following general formula:

Mo _aBi _bCo _cNi _dFe _eX _fY _gZ _hSi _iO _j

In this formula, X is the element that at least one is selected from magnesium (Mg), calcium (Ca), zinc (Zn), cerium (Ce) and samarium (Sm).Y is the element that at least one is selected from sodium (Na), potassium (K), rubidium (Rb), caesium (Cs) and thallium (Tl).Z is the element that at least one is selected from boron (B), phosphorus (P), arsenic (As) and tungsten (W).A-j is the atomic ratio of respective element, wherein a=12, b=0.5 – 7, c=0 – 10, d=0 – 10, (wherein c+d=1 – 10), e=0.05 – 3, f=0 – 2, g=0.04 – 2, h=0 – 3 and I=5-48.In an embodiment, in the oxidative dehydrogenation of n-butene to butadiene, use consists of Mo ₁₂bi ₅co _2.5ni _2.5fe _0.4na _0.35b _0.2k _0.08si ₂₄catalyst, its to be diameter be 5mm and be highly the pellet form of 4mm.

In the oxidative dehydrogenation of n-butene to butadiene, the precursor of carbonaceous material can such as be formed from styrene, anthraquinone and Fluorenone, and they finally can cause carbonization and the inerting of multi-metal-oxide catalyst.Pressure drop in catalyst bed can increase owing to forming carbon-containing sediment.Regeneration can be undertaken by the carbon that oxygen-containing gas burn off in interval is deposited on multi-metal-oxide catalyst according to the rules, thus recovers the activity of catalyst.

JP 60-058928 describes the regeneration containing at least multi-metal-oxide catalyst of molybdenum, bismuth, iron, cobalt and antimony for n-butene oxidative dehydrogenation being become butadiene, wherein carry out at the temperature of 300-700 DEG C, preferably 350-650 DEG C with oxygen-containing gas mixture, oxygen concentration is 0.1-5 volume %.Added as oxygen-containing gas mixture by the air of suitable inert gas such as nitrogen, steam or carbon dioxide dilution.

WO 2005/047226 describes for propenal moiety being oxidized to acrylic acid regeneration containing at least multi-metal-oxide catalyst of molybdenum and vanadium, wherein at the temperature of 200-450 DEG C, passes into oxygen-containing gas mixture.As oxygen-containing gas mixture, preferably use the poor air containing 3-10 volume % oxygen.Admixture of gas can also containing steam except oxygen and nitrogen.

The object of this invention is to provide the oxidative dehydrogenation processes of a kind of n-butene to butadiene, wherein very effectively and carry out the regeneration of multi-metal-oxide catalyst simply.

This object becomes the method for butadiene to realize n-butene oxidative dehydrogenation by a kind of, and the method comprises two or more preparation processes (i) and at least one regeneration step (ii), wherein

I () is in preparation process, starting gas mixture containing n-butene mixes with oxygen-containing gas, and be arranged in catalyst fixed bed in multi-metal-oxide catalyst contact at the temperature of 220-490 DEG C in fixed bed reactors, described multi-metal-oxide catalyst contains at least molybdenum and other metal

With, before conversion ratio at a constant temperature reduces degree >25%,

(ii) in regeneration step, multi-metal-oxide catalyst is regenerated by making the carbon that deposited on a catalyst by catalyst fixed bed and burn off at the temperature of 200-450 DEG C containing oxygen regeneration gas mixture,

Wherein regeneration step (ii) is carried out between two preparation processes (i),

The carbon deposited on a catalyst of burn off 5-50 % by weight is wherein counted according to each regeneration step (ii).

Be surprisingly found out that, when burn off only at the most 50 % by weight the carbon deposited on a catalyst time, the activity of multi-metal-oxide catalyst catalyst is recovered substantially.Even according to each regeneration step (ii) count burn off only 5 % by weight deposit carbon just major part can recover the activity of catalyst.

According to each regeneration step meter burn off only at the most the deposit carbon of 50 % by weight recovery time can be made significantly to shorten, which improve the economy of technique.

Preferably, according to the carbon deposited on multi-metal-oxide catalyst of each regeneration step meter burn off 5-50 % by weight, particularly preferably 10-35 % by weight, especially 10-30 % by weight.

Thus, what the activity of multi-metal-oxide catalyst generally returned to the multi-metal-oxide catalyst activity when previous preparation process (i) starts is greater than 95%, is preferably greater than 98%, is especially greater than 99%.

Generally relatively ought reduce when degree (that is, based on the conversion ratio meter when corresponding preparation process (i) starts) is not more than 25% and carry out regeneration step (ii) by conversion ratio at a constant temperature.The preferred conversion ratio at a constant temperature of regeneration step (ii) relatively reduces before degree is greater than 15% and carries out, and conversion ratio especially at a constant temperature relatively reduces before degree is greater than 10% and carries out.Generally, regeneration step (ii) is only carried out when relatively to reduce degree be at least 2% to conversion ratio at a constant temperature.

Generally, preparation process (i) relatively reduces degree at conversion ratio to reach and carry out 5-5000 hour, based on the conversion ratio meter when preparation process (i) starts before 25% degree at the most.Catalyst can experience 5000 or more preparations and regeneration step circulates.

That deposit on a catalyst and can be measured by quantitatively detecting the oxycarbide formed in corresponding regeneration step (ii) period by the amount of the carbon of burn off, such as detect the oxycarbide in the waste gas from regeneration by online IR.The total amount of the carbon deposited on a catalyst is by using the whole burn off carbon of the mixture of 10 volume % oxygen, 80 volume % nitrogen and 10 volume % steam to measure at least 400 DEG C.Selective temperature is to make additionally not form oxycarbide when further raised temperature.Alternatively, the amount of the carbon deposited on a catalyst can measure by detecting the carbon content of the sample extracted from catalyst.

The catalyst being applicable to oxidative dehydrogenation is generally based on the poly-metal deoxide system containing Mo-Bi-O, and it is generally other containing iron.Generally speaking, catalyst system also containing other catalyst component of 1-15 race being selected from the periodic table of elements, such as potassium, caesium, magnesium, zirconium, chromium, nickel, cobalt, cadmium, tin, lead, germanium, lanthanum, manganese, tungsten, phosphorus, cerium, aluminium or silicon.Also advise that the ferrite of iron content is used as catalyst.

In a preferred embodiment, poly-metal deoxide contains cobalt and/or nickel.In a further preferred embodiment, poly-metal deoxide contains chromium.In a further preferred embodiment, poly-metal deoxide contains manganese.

Generally speaking, the catalytic activity poly-metal deoxide containing molybdenum and other metal of at least one has general formula (I):

Mo ₁₂Bi _aFe _bCo _cNi _dCr _eX ¹ _fX ² _gO _x(I),

Wherein each symbol has following implication:

X ¹=W, Sn, Mn, La, Ce, Ge, Ti, Zr, Hf, Nb, P, Si, Sb, Al, Cd and/or Mg;

X ²=Li, Na, K, Cs and/or Rb,

A=0.1-7, preferred 0.3-1.5;

B=0-5, preferred 2-4;

C=0-10, preferred 3-10;

d＝0-10；

E=0-5, preferred 0.1-2;

F=0-24, preferred 0.1-2;

G=0-2, preferred 0.01-1; With

The numerical value that x=is determined by valence link and the abundance of elements different from oxygen in (I).

Catalyst can be full active catalyst or coated catalyst.If catalyst is coated catalyst, then it has carrier (a) and the shell (b) containing catalytic activity poly-metal deoxide, and wherein catalytic activity poly-metal deoxide contains molybdenum and other metal of at least one.

The carrier material being suitable for coated catalyst is the aluminium oxide of such as porous or preferred atresia, silica, zirconium dioxide, carborundum or silicate, such as magnesium silicate or alumina silicate (such as from the talcum of the rank C 220 of CeramTec).Carrier material is chemically inert.

Carrier material can be porous or atresia.Carrier material be preferably atresia (based on the stereometer of carrier, the cumulative volume in hole preferably≤1 volume %).

Particularly preferably use spherical talcum (such as from the talcum of the CeramTec Type C 220) carrier of substantially non-porous, it has rough surface, and diameter is 1-8mm, preferred 2-6mm, particularly preferably 2-3 or 4-5mm.But the cylinder be made up of carrier material also can be used as carrier, and length is 2-10mm, external diameter is 4-10mm.When ring is used as carrier, wall thickness is 1-4mm normally.Preferred annular carrier has the length of 2-6mm, and external diameter is 4-8mm, and wall thickness is 1-2mm.Particularly, physical dimension is that the ring of 7mm x 3mm x 4mm (external diameter x length x internal diameter) is also suitable as carrier.The layer thickness normally 5-1000 μm of the shell (b) of the multimetal oxide compositions containing molybdenum and other metal of at least one.Preferred 10-800 μm, particularly preferably 50-600 μm, very particularly preferably 80-500 μm.The layer thickness normally 5-1000 μm of the shell (b) be made up of the multimetal oxide compositions containing molybdenum and other metal of at least one.Preferred 10-800 μm, particularly preferably 50-600 μm, very particularly preferably 80-500 μm.

The example of the poly-metal deoxide containing Mo-Bi-Fe-O is the poly-metal deoxide containing Mo-Bi-Fe-Cr-O or Mo-Bi-Fe-Zr-O.Preferred system is for example, see US 4,547,615 (Mo ₁₂biFe _0.1ni ₈zrCr ₃k _0.2o _xand Mo ₁₂biFe _0.1ni ₈alCr ₃k _0.2o _x), US 4,424,141 (Mo ₁₂biFe ₃co _4.5ni _2.5p _0.5k _0.1o _x+ SiO ₂), DE-A 25 30 959 (Mo ₁₂biFe ₃co _4.5ni _2.5cr _0.5k _0.1o _x, Mo _13.75biFe ₃co _4.5ni _2.5ge _0.5k _0.8o _x, Mo ₁₂biFe ₃co _4.5ni _2.5mn _0.5k _0.1o _xand Mo ₁₂biFe ₃co _4.5ni _2.5la _0.5k _0.1o _x), US 3,911,039 (Mo ₁₂biFe ₃co _4.5ni _2.5sn _0.5k _0.1o _x), DE-A 25 30 959 and DE-A 24 47 825 (Mo ₁₂biFe ₃co _4.5ni _2.5w _0.5k _0.1o _x).

Suitable poly-metal deoxide and preparation method thereof also can see US 4,423,281 (Mo ₁₂biNi ₈pb _0.5cr ₃k _0.2o _xand Mo ₁₂bi _bni ₇al ₃cr _0.5k _0.5o _x), US 4,336,409 (Mo ₁₂biNi ₆cd ₂cr ₃p _0.5o _x), DE-A 26 00 128 (Mo ₁₂biNi _0.5cr ₃p _0.5mg _7.5k _0.1o _x+ SiO ₂) and DE-A 24 40 329 (Mo ₁₂biCo _4.5ni _2.5cr ₃p _0.5k _0.1o _x).

The particularly preferred catalytic activity poly-metal deoxide containing molybdenum and other metal of at least one has general formula (Ia):

Mo ₁₂Bi _aFe _bCo _cNi _dCr _eX ¹ _fX ² _gO _y(Ia),

Wherein

X ¹=Si, Mn and/or Al,

X ²=Li, Na, K, Cs and/or Rb,

0.2≤a≤1,

0.5≤b≤10,

0≤c≤10,

0≤d≤10,

2≤c+d≤10

0≤e≤2,

0≤f≤10，

0≤g≤0.5，

The numerical value that y=is determined by valence link and the abundance of elements different from oxygen in formula (1a) is to reach neutral charge.

Preferably such catalyst, its catalytic activity oxide composition is only containing the Co being selected from two kinds of metal Co and Ni (d=0).X ¹preferably Si and/or Mn, X ²preferably K, Na and/or Cs, X ²particularly preferably K.

Chemical Calculation coefficient of discharge a in formula (Ia) preferably makes 0.4≤a≤1, particularly preferably 0.4≤a≤0.95.The value of symbol b preferably in the scope of 1≤b≤5, particularly preferably in the scope of 2≤b≤4.The summation of Chemical Calculation coefficient of discharge c+d preferably in the scope of 4≤c+d≤8, particularly preferably in the scope of 6≤c+d≤8.Chemical Calculation coefficient of discharge e preferably in the scope of 0.1≤e≤2, particularly preferably in the scope of 0.2≤e≤1.Chemical Calculation coefficient of discharge g advantageously >=0.Preferably 0.01≤g≤0.5, is particularly preferably 0.05≤g≤0.2.

The value of the Chemical Calculation coefficient of discharge y of oxygen is derived from cationic valence link and abundance, thus keeps neutral charge.Advantageously coated catalyst, it has catalytic activity oxide composition, and wherein the molar ratio of Co/Ni is at least 2:1, preferably at least 3:1, particularly preferably at least 4:1.Most preferably only there is Co.

Coated catalyst is that also prepared by drying and the coated carrier of calcining by being administered to by the layer adhesive containing the poly-metal deoxide containing molybdenum and other metal of at least one on carrier.

The poly-metal deoxide containing molybdenum and other metal of at least one of segmentation used according to the invention can in principle by the tight drying composite of the initial compounds of each elemental constituent of preparation catalytic activity oxide composition, by the heat treatment preparation at the temperature of 150-650 DEG C of this tight drying composite.

Prepare multi-metal-oxide catalyst

In order to prepare the multimetal oxide compositions of this suitable segmentation, the known initial compounds of elemental compositions different from oxygen in required poly-metal deoxide catalyst composition is used as raw material according to corresponding chemical calculating ratio, from the drying composite that their preparations closely, are preferably segmented, and then this drying composite is heat-treated.These sources can be oxide or the compound being converted to oxide by heating at least in the presence of oxygen.Except oxide, thus also can use particularly halide, nitrate, formates, oxalates, acetate, carbonate or hydroxide as initial compounds.

The initial compounds of other suitable molybdenum be they carbonyls (molybdate) or from they derivative acid.

The initial compounds of suitable Bi, Cr, Fe and Co particularly their nitrate.

The tight mixing of initial compounds can be carried out in principle in a dry form or with the form of the aqueous solution or aqueous suspension.

Aqueous suspension can such as by containing the solution of at least molybdenum and contain the aqueous solution merging of all the other metals and prepare.Alkali metal or alkaline-earth metal may reside in these two kinds of solution.Precipitation is by being undertaken these solution combination, and this causes forming suspension.Temperature in precipitation can higher than room temperature, preferred 30-95 DEG C, particularly preferably 35-80 DEG C.Suspension then can at high temperature aging specific time.Be generally 0-24 hour for the aging time, preferred 0-12 hour is particularly preferably 0-8 hour.Temperature between aging period is generally 20-99 DEG C, preferred 30-90 DEG C, particularly preferably 35-80 DEG C.Suspension generally mixes by stirring between precipitation and aging period.The solution of mixing or the pH of suspension are generally pH1 to pH12, preferred pH2 to pH11, particularly preferably pH3 to pH10.

Except the operation of anhydrating has obtained solid, it represents the immixture of each metal component added.Drying steps can generally be undertaken by evaporation, spraying dry or freeze drying etc.Drying is carried out preferably by spraying dry.For this purpose, suspension is at high temperature with shower nozzle atomization, and this generally carries out at the temperature of 120-300 DEG C, and the product of drying is collected at the temperature of >60 DEG C.Residual moisture content detects by spray-dried powder is dry at 120 DEG C, is generally be less than 20 % by weight, is preferably less than 15 % by weight, be particularly preferably less than 12 % by weight.

In order to prepare full active catalyst, in another step, spray-dried powder is converted to formed body.Possible shaping assistant (lubricant) is such as water, boron trifluoride or graphite.Based on wanting the shaping composition meter obtaining catalyst precarsor formed body, add the shaping assistant of general≤10 % by weight, usually≤6 % by weight, often≤4 % by weight.Above-mentioned addition is >0.5 % by weight normally.Preferred lubricant is graphite.

Carry out at the heat treatment of the catalyst precarsor formed body temperature generally more than 350 DEG C.But, be during heating treatment usually no more than the temperature of 650 DEG C.According to the present invention, the temperature in heat treatment, advantageously not more than 600 DEG C, preferably more than 550 DEG C, is particularly preferably no more than 500 DEG C.In addition, in the methods of the invention, in the temperature of the Heat Treatment of catalyst precarsor formed body preferably more than 380 DEG C, advantageously more than 400 DEG C, particularly advantageously more than 420 DEG C, very particularly preferably more than 440 DEG C.Heat treatment also can be divided into multiple stage along with the time.Such as, first can heat-treat at the temperature of 150-350 DEG C, preferably 220-280 DEG C, and heat-treat at the temperature of 400-600 DEG C, preferably 430-550 DEG C subsequently.The heat treatment of catalyst precarsor formed body needs a few hours (being usually greater than 5 hours) usually.Usually extend to heat treated total time and be greater than 10 hours.Usually the processing time of 45 hours or 35 hours is no more than in the heat treatment of catalyst precarsor formed body.Total processing time is less than 30 hours usually.Preferably more than the temperature of 500 DEG C in the heat treatment of catalyst precarsor formed body, and the processing time in >=400 DEG C of temperature ranges preferably extend to 5-30 hour.

The heat treatment (calcining) of catalyst precarsor formed body can under an inert gas or under oxidizing atmosphere such as air or at reducing atmosphere (such as inert gas, NH ₃, CO and/or H ₂or the mixture of methane) under carry out.There is no doubt that, heat treatment also can under reduced pressure be carried out.The heat treatment of catalyst precarsor formed body can be carried out in principle in various stove type, such as heatable convection cell, column plate stove, rotation pipe furnace, belt calcinatory or shaft (tower) furnace.The heat treatment of catalyst precarsor formed body is preferably carried out in the such as belt calciner described in DE-A 10046957 and WO 02/24620.The heat treatment of the catalyst precarsor formed body below 350 DEG C is general comprise with in catalyst precarsor formed body needed for the thermal decomposition in source of catalyst elements composition relevant.This catabolic phase occurs during being usually heated to the temperature of <350 DEG C in the methods of the invention.

In order to prepare coated catalyst, the catalytic activity multimetal oxide compositions obtained after firing can subsequently by grinding to form fine powder, being then administered on formed body outer surface under the help of liquid adhesive and transforming.The fineness being administered to the catalytic activity multimetal oxide compositions on carrier surface is mated with required thickness of the shell.

The carrier material being suitable for preparing coated catalyst is the aluminium oxide of porous or preferred atresia, silica, zirconium dioxide, carborundum or silicate, such as magnesium silicate or alumina silicate (such as from the talcum of C 220 rank of CeramTec).The material of carrier is chemically inert.

Carrier material can be porous or atresia.Carrier material be preferably atresia (based on carrier bulk meter, the cumulative volume in hole preferably≤1 volume %).

Hollow circular cylinder preferably as carrier has the length of 2-10mm and the external diameter of 4-10mm.In addition, wall thickness is preferably 1-4mm.Particularly preferred annular carrier has the length of 2-6mm, and external diameter is 4-8mm, and wall thickness is 1-2mm.Example be there is physical dimension 7mm × 3mm × 4mm (external diameter × length × internal diameter) ring as carrier.

The layer thickness D of the multimetal oxide compositions containing molybdenum and other metal of at least one is generally 5-1000 μm.Preferred 10-800 μm, particularly preferably 50-600 μm, very particularly preferably 80-500 μm.

Poly-metal deoxide containing molybdenum and other metal of at least one to carrier surface use operation can conventionally described in mode carry out, for example, see US-A 2006/0205978 and EP-A 0 714 700.

Generally, the metal oxide composition of segmentation under the help of liquid adhesive, be applied to carrier surface on or be administered on the surface of ground floor.Possible liquid adhesive is such as water, organic solvent, or organic substance (such as organic solvent) solution in water or organic solvent.

Solution containing 20-95 % by weight water and 5-80 % by weight organic compound is particularly advantageously used as liquid adhesive.The organic content of aforesaid liquid adhesive is preferably 10-50 % by weight, particularly preferably 10-30 % by weight.

General preferred organic bond or adhesive component, its boiling point under atmospheric pressure (1atm) or sublimation temperature be >=100 DEG C, preferably >=150 DEG C.These organic bonds or adhesive component boiling point under atmospheric pressure or sublimation temperature are very particularly preferably in the temperature lower than maximum calcination temperature used during the segmentation poly-metal deoxide of preparation containing molybdenum simultaneously.This maximum calcination temperature normally≤600 DEG C, often≤500 DEG C.

The example of the organic bond that can mention is unitary or polynary Organic Alcohol, such as ethylene glycol, 1,4-butanediol, 1,6-hexylene glycol or glycerine, unitary or polybasic organic carboxylic acid, such as propionic acid, oxalic acid, malonic acid, glutaric acid or maleic acid, amino alcohol such as monoethanolamine or diethanol amine, and the organic amide of unit price or multivalence, such as formamide.Suitable energy is water-soluble, organic bond promoter in the mixture of organic liquid or water and organic liquid is such as monose and compound sugar, such as glucose, fructose, sucrose and/or lactose.

Particularly preferred liquid adhesive is the solution containing 20-95 % by weight water and 5-80 % by weight glycerine.The ratio of the glycerine in these aqueous solution is preferably 5-50 % by weight, particularly preferably 8-35 % by weight.

Containing the using operation and can be undertaken, see DE-A 1642921, DE-A 2106796 and DE-A 2626887 by the segmentation composition of poly-metal deoxide containing molybdenum being dispersed on the carrier that to be sprayed onto in liquid adhesive and by gained suspension and to stir and optionally heat of segmentation poly-metal deoxide of molybdenum.After spraying completes, the moisture of the coated catalyst of gained as described in DE-A2909670 by passing into hot-air on a catalyst to reduce.

Pore former such as malonic acid, melamine, nonyl phenol ethoxylate, stearic acid, glucose, starch, fumaric acid and butanedioic acid can be added in the segmentation poly-metal deoxide be applied on carrier in addition, thus obtained suitable catalyst pore structure and improvement material transportation performance.Catalyst is not preferably containing any pore former.

But carrier preferably first soaks with liquid adhesive, and by wetting carrier is rolled across in segmentation composition, the multimetal oxide compositions of segmentation is administered to subsequently on the carrier surface that soaked by adhesive.In order to reach required layer thickness, said method preferably repeatedly carries out, and the carrier namely with the first coating is soaked again, then applies by contacting with the segmentation composition of drying.

In order to carry out described method at industrial scale, suggestion uses the method described in DE-A2909671, but is preferably used in the adhesive described in EP-A 714700.That is, the carrier that will apply introduces the rotary container (such as swivel plate or coating drum) of preferred angled (angle of inclination is 30-90 DEG C normally).

Temperature for removing adhesion promotor necessity is lower than the maximum calcination temperature for catalyst, is generally 200-600 DEG C.Catalyst is generally heated to 240-500 DEG C, particularly preferably 260-400 DEG C.Until the time that adhesion promotor is removed can be a few hours.Catalyst is generally heated to said temperature and reaches 0.5-24 hour to remove adhesion promotor.This time is preferably 1.5-8 hour, particularly preferably 2-6 hour.Air-flow around catalyst can accelerate to remove adhesion promotor.Gas is preferably air or nitrogen, particularly preferably air.The removing operation of adhesion promotor such as can be flow through wherein in the baking oven of air-flow or in suitable drying equipment and carry out, such as belt dryer.

Oxidative dehydrogenation (oxidative dehydrogenation, ODH)

In multiple preparation circulation (i), n-butene to the oxidative dehydrogenation of butadiene be by the starting gas mixture containing n-butene and oxygen-containing gas are mixed with optional extra inert gas or steam and at the temperature of 220-490 DEG C be arranged in catalyst fixed bed in catalyst contact in fixed bed reactors and carry out.

The reaction temperature of oxidative dehydrogenation is generally controlled by the heat transfer medium be positioned at around reaction tube.As this liquid heat-transfer medium, the melt of such as salt can be used, such as potassium nitrate, potassium nitrite, natrium nitrosum and/or sodium nitrate, and the melt of metal, such as the alloy of sodium, tribute and various metal.But, also can use ionic liquid or heat-transfer oil.The temperature of heat transfer medium is 220-490 DEG C, preferred 300-450 DEG C, particularly preferably 350-420 DEG C.

Due to the exothermal nature of reaction, temperature during reaction may form focus higher than the temperature of heat transfer medium in the moment of inside reactor.Position and the size of focus are determined by reaction condition, but also can by the dilution ratio of catalyst layer or by passing into mist to regulate.

Oxidative dehydrogenation can be carried out in the known fixed bed reactors of prior art, such as in column plate baking oven, in fixed-bed tube reactor or in fixed-bed shell-and-tube reactor or in plate type heat exchanger reactor.Shell-and-tube reactor is preferred.

In addition, the catalyst bed of installing in the reactor can be made up of single region or 2 or more region.These regions can be made up of pure catalyst or with diluting with starting gas or by the material of the component reaction of reacting the product gas formed.In addition, catalyst area can be made up of the coated catalyst of full active catalyst or load.

As starting gas, pure n-butene (1-butylene and/or cis-/Trans-2-butene) can be used, and the admixture of gas containing butylene.These mixtures can such as be obtained by the Non-oxidative dehydrogenation of normal butane.Also can use containing the fraction of n-butene (1-butylene and/or 2-butylene) as main component, it is from the C from naphtha pyrolysis ₄cut is obtained by removing butadiene and isobutene.In addition, admixture of gas containing pure 1-butylene, cis-2-butene, Trans-2-butene or its mixture also can be used as starting gas, and it is obtained by the dimerization reaction of ethene.Also admixture of gas containing n-butene can be used as starting gas, and it is obtained by sulfide catalyst cracking (FCC).

In an embodiment of the inventive method, the starting gas mixture containing n-butene is obtained by the Non-oxidative dehydrogenation of normal butane.Based on normal butane meter used, high butadiene productive rate by combination nonoxidation catalytic dehydrogenation and can obtain from the oxidative dehydrogenation of formed n-butene.The nonoxidation catalytic dehydrogenation of normal butane obtains the admixture of gas containing butadiene, 1-butylene, 2-butylene and unreacted normal butane and submember.Common submember is hydrogen, steam, nitrogen, CO and CO ₂, methane, ethane, ethene, propane and propylene.The composition leaving the admixture of gas of first dehydrogenation zone can depend on the operator scheme of dehydrogenation to a great extent.Therefore, when carrying out dehydrogenation when introducing oxygen and added hydrogen, product gas mixture has steam and the oxycarbide of high level.Do not introducing in the operator scheme of oxygen, the product gas mixture from Non-oxidative dehydrogenation has the hydrogen of high level.

From butadiene, the 1-butylene of 1-15 volume %, the 2-butylene (cis/trans-2-butylene) of 1-25 volume %, the normal butane of 20-70 volume %, the steam of 1-70 volume %, the low boiling hydrocarbon (methane of 0-10 volume % of product gas stream usually containing 0.1-15 volume % of the Non-oxidative dehydrogenation of normal butane, ethane, ethene, propane and propylene), the oxycarbide of the hydrogen of 0.1-40 volume %, the nitrogen of 0-70 volume % and 0-5 volume %.Product gas stream from Non-oxidative dehydrogenation can when adding in oxidative dehydrogenation without when further process.

In addition, any impurity may reside in the starting gas for oxidative dehydrogenation, and its amount can not suppress effect of the present invention.Preparing in the process of butadiene from n-butene (1-butylene and cis-/Trans-2-butene), the impurity that can mention is saturated and undersaturated, branching and nonbranched hydrocarbon, such as methane, ethane, ethene, acetylene, propane, propylene, propine, normal butane, iso-butane, isobutene, pentane, and diene such as 1,2-butadiene.The amount of impurity normally 70% or less, preferably 30% or less, more preferably 10% or less, particularly preferably 1% or less.In starting gas, the concentration with the straight chain mono-olefins (n-butene and higher homologue) of 4 or more carbon atoms does not limit in any specific mode; It is 35.00-99.99 volume % normally, preferred 71.00-99.0 volume %, more more preferably 75.00-95.0 volume %.

Under transforming completely at butylene, carry out oxidative dehydrogenation, there is oxygen: n-butene mol ratio be at least 0.5 admixture of gas be necessary.Preferably at oxygen: n-butene mol ratio is 0.55 to 10 time operation.In order to set this value, starting gas can mix with oxygen or oxygen-containing gas such as air and optionally extra inert gas or steam.Then the oxygen-containing gas mixture obtained adds in oxidative dehydrogenation.

Gas containing molecular oxygen is such gas, and it is usually containing being greater than 10 volume %, being preferably greater than 15 volume %, again more preferably greater than the molecular oxygen of 20 volume %, being especially preferably air.The upper limit of molecular oxygen content is generally 50 volume % or less, preferably 30 volume % or less, more more preferably 25 volume % or less.In addition, any inert gas can be present in the gas of molecule-containing keto according to suppressing the amount of effect of the present invention.As possible inert gas, nitrogen, argon gas, xenon, helium, CO, CO can be mentioned ₂and water.When nitrogen, the amount of inert gas is generally 90 volume % or less, preferably 85 volume % or less, more more preferably 80 volume % or less.When the composition different from nitrogen, their amount is generally 10 volume % or less, preferably 1 volume % or less.If this content is excessive, then becomes and be more difficult to provide required oxygen to reaction.

In addition, inert gas such as nitrogen and water (as steam) can with comprised together with the mist of the gas composition of molecule-containing keto by starting gas.The existence of nitrogen is for setting oxygen concentration and forming explosive gas mixture for preventing, and this is equally applicable to steam.The existence of steam is also for controlling carbonization and the removing reaction heat of catalyst.Water (as steam) and nitrogen are preferably mixed in mist, and are introduced in reactor.When steam is introduced into reactor, based on the introducing gauge of above-mentioned starting gas, preferably introduce the ratio of 0.2 – 5.0 (parts by volume), preferably 0.5 – 4 (parts by volume), more more preferably 0.8 – 2.5 (parts by volume).When nitrogen is introduced into reactor, based on the introducing gauge of above-mentioned starting gas, preferably introduce the ratio of 0.1 – 8.0 (parts by volume), preferably 0.5 – 5.0 (parts by volume), more more preferably 0.8 – 3.0 (parts by volume).

The ratio of starting gas containing hydrocarbon in mist is generally 4.0 volume % or larger, preferably 6.0 volume % or larger, more more preferably 8.0 volume % or larger.On the other hand, the upper limit is 20 volume % or less, preferably 16.0 volume % or less, more more preferably 13.0 volume % or less.In order to avoid the formation of explosive gas mixture safely, before obtaining mist, nitrogen is first introduced into starting gas or introduces in the gas of molecule-containing keto, by the gas and vapor permeation of starting gas and molecule-containing keto to obtain mist, then preferably introduces this mist.

During stable operation, the time of staying is in the reactor subject to specific restriction in the present invention never in any form, but lower limit is generally 0.3 second or more, preferably 0.7 second or more, more more preferably 1.0 seconds or more.The upper limit is 5.0 seconds or less, preferably 3.5 seconds or less, more more preferably 2.5 seconds or less.In inside reactor, the ratio between the amount of mist and the amount of catalyst is 500 – 8000h ^-1, preferably 800 – 4000h ^-1, more more preferably 1200 – 3500h ^-1.In stable operation, butylene air speed on a catalyst (is expressed as g _butylene/ (g _catalyst* hour) normally 0.1-5.0h ^-1, preferred 0.2-3.0h ^-1, more more preferably 0.25-1.0h ^-1.The volume of catalyst and quality are the whole catalyst gauge based on being made up of carrier and active compound.

The regeneration of multi-metal-oxide catalyst

According to the present invention, regeneration step (ii) is carried out between every two preparation processes (i).The usual conversion ratio at a constant temperature of regeneration step (ii) reduces before degree is greater than 25% and carries out.Regeneration cycle (ii) is by making to be undertaken by catalyst fixed bed at the temperature of 200-450 DEG C containing oxygen regeneration gas mixture, thus the carbon that burn off deposits on multi-metal-oxide catalyst.According to the present invention, by the carbon deposited on a catalyst of each regeneration cycle (ii) burn off 5-50 % by weight.

What use in regeneration step (ii) contains oxygen-containing gas and extra inert gas, steam and/or hydrocarbon usually containing oxygen regeneration gas mixture.Generally, it contains the oxygen of 0.5-22 volume %, preferably 1-20 volume %, particularly 2-18 volume %.

The preferred oxygen-containing gas existed in regeneration gas mixture is air.In order to prepare containing oxygen regeneration gas mixture, can optionally inert gas, steam and/or hydrocarbon be additionally mixed in oxygen-containing gas.As possible inert gas, nitrogen, argon gas, xenon, helium, CO and CO can be mentioned ₂.The amount of inert gas is generally 90 volume % or less when nitrogen, preferably 85 volume % or less, even more preferably 80 volume % or less.When other composition different from nitrogen, its amount is 10 volume % or less normally, preferably 1 volume % or less.Select the amount of oxygen-containing gas to make the volume ratio of molecular oxygen existed in regeneration gas mixture when regenerating and starting be 0-50%, preferred 0.5-22%, more more preferably 1-10%.The ratio of molecular oxygen can increase at regeneration period.

In addition, steam also can be included in containing in oxygen regeneration gas mixture.The existence of nitrogen is that this is also suitable for steam for setting oxygen concentration.Steam can also exist to remove reaction heat and as mild oxidizer for removing carbon-containing sediment.Preferably water (as steam) and nitrogen are mixed in regeneration gas mixture, and the latter is introduced in reactor.When introducing steam when regenerating and starting to reactor, the volume ratio preferably introduced is 0-50%, preferred 0.5-22%, more more preferably 1-10%.The ratio of steam can increase at regeneration period.Select nitrogen amount to make the volume ratio of dinitrogen existed in regeneration gas mixture when regenerating and starting be 20-99%, preferred 50-98%, more more preferably 70-96%.The ratio of nitrogen can reduce at regeneration period.

In addition, regeneration gas mixture can contain hydrocarbon.They can in addition with inert gas or replace inert gas to mix.Be generally be less than 50% at the volume ratio containing the hydrocarbon in oxygen regeneration gas mixture, be preferably less than 10%, then be more preferably less than 2%.Hydrocarbon can containing saturated and undersaturated, branching and nonbranched hydrocarbon, such as methane, ethane, ethene, acetylene, propane, propylene, propine, normal butane, iso-butane, n-butene, isobutene, pentane, and diene such as 1,3-butadiene and 1,2-butadiene.Especially, they contain the hydrocarbon that can not react in the presence of a catalyst at regeneration conditions in the presence of oxygen.

During stable operation, regeneration gas mixture in regenerative process time of staying in the reactor not by any specific restriction, but lower limit is generally 0.3 second or more, preferably 0.7 second or more, more more preferably 1.0 seconds or more.The upper limit is 7.0 seconds or less, preferably 5.0 seconds or less, more more preferably 3.5 seconds or less.Mixed gas flow in inside reactor and the ratio between catalyst volume are 500 – 8000h ^-1, preferably 600 – 4000h ^-1.The temperature of heat transfer medium is 220-490 DEG C, preferred 300-450 DEG C, particularly preferably 350-420 DEG C.Above all and hereafter relate to about the temperature described in preparation process (i) and regeneration step (ii) temperature be in for the heat transfer medium of the porch of heat transfer medium on reactor.

Temperature in regeneration cycle (ii) preferably exceeds 20 DEG C at the most than the temperature in preparation circulation (i), particularly preferably exceeds 10 DEG C at the most.Temperature in preparation circulation (i), preferably higher than 350 DEG C, particularly preferably higher than 360 DEG C, particularly higher than 365 DEG C, and is not more than 420 DEG C.Described temperature relates to the temperature be in for the heat transfer medium of the porch of heat transfer medium on reactor.

The post processing of product gas stream

The product gas stream leaving the oxidative dehydrogenation of preparation process contains butadiene and generally also contains unreacted normal butane and iso-butane, 2-butylene and steam.As submember, it is generally containing carbon monoxide, carbon dioxide, oxygen, nitrogen, methane, ethane, ethene, propane and propylene, and possible hydrogen, and oxygen containing hydrocarbon, be called oxide.Generally, it contains 1-butylene and the isobutene of only small scale.

The product gas stream leaving oxidative dehydrogenation such as can contain butadiene, the normal butane of 20-80 volume %, the iso-butane of 0-5 volume %, the 2-butylene of 0.5-40 volume %, the 1-butylene of 0-5 volume %, the steam of 0-70 volume %, the low boiling hydrocarbon (methane of 0-10 volume % of 1-40 volume %, ethane, ethene, propane and propylene), the oxide of the oxygen of the hydrogen of 0-40 volume %, 0-30 volume %, the nitrogen of 0-70 volume %, the oxycarbide of 0-10 volume % and 0-10 volume %.Oxide can be such as formaldehyde, furans, acetic acid, maleic anhydride, formic acid, MAL, methacrylic acid, crotonaldehyde, crotonic acid, propionic acid, acrylic acid, methyl vinyl ketone, styrene, benzaldehyde, benzoic acid, phthalic anhydride, Fluorenone, anthraquinone and butyraldehyde.

Some oxides can oligomeric and dehydrogenation further on catalyst surface and in post processing, thus forms the deposit of carbon containing, hydrogen and oxygen, hereinafter referred to as carbonaceous material.These deposits can cause during technological operation for interruption that is clean and regeneration, so be disadvantageous.The precursor of typical carbonaceous material comprises styrene, Fluorenone and anthraquinone.

The product gas stream being positioned at reactor outlet has the temperature similar to the temperature of catalyst bed end.Then, product gas stream is made to reach the temperature of 150-400 DEG C, preferred 160-300 DEG C, particularly preferably 170-250 DEG C.The pipeline wherein flowing through product gas stream can be separated remain in required scope to make temperature, but preferably use heat exchanger.This heat exchanger system can be any type, as long as the temperature of product gas can remain on desired level by this system.As the example of heat exchanger, spiral heat exchanger can be mentioned, plate type heat exchanger, Dual-tube heat exchanger, multi-pipe heat exchanger, ebullator spiral heat exchanger, ebullator jacketed type exchanger, liquid-liquid contact heat-exchanging device, air heat exchanger, direct-contact heat exchanger, and tubule heat exchanger.Can precipitate when the temperature of product gas is set to temperature required because a part contained in product gas is high boiling point by-products produced, heat exchanger system should preferably have two or more heat exchangers.Be arranged in parallel at two or more provided heat exchangers and in these heat exchangers when independent cooling products therefrom gas, the high boiling point by-products produced amount reduction in heat exchanger may be deposited on, and the operating time of heat exchanger can extend.As the another kind of replacement scheme of said method, two or more heat exchangers provided can be arranged in parallel.Product gas is added one or more heat exchanger, but is not whole heat exchanger, and these heat exchangers can discharge with other heat exchanger after the specific operation time.In this method, can continue cooling, a part of reaction heat can be recovered, and parallel therewith, and in one of heat exchanger, the high boiling point by-products produced of deposition can be removed.As above-mentioned organic solvent, any unrestricted solvent can be used, as long as it can dissolve high boiling point by-products produced, such as aromatic solvent such as toluene, dimethylbenzene etc., or basic aqueous solvent, the aqueous solution of such as NaOH.

If product gas stream contains the oxygen of not only a small amount of trace, then can carry out for the processing step from product gas stream removing residual oxygen.Residual oxygen can play interference effect, because it causes form Butadiene Peroxide in processing step subsequently, and can be used for polymerisation as initator.The 1,3-butadiene of non-stabilisation can form dangerous Butadiene Peroxide in the presence of oxygen.These peroxide are viscous liquids.Their density is higher than the density of butadiene.Because they are also only slightly soluble in liquid 1,3-butadiene, they settle in the bottom of reservoir vessel.Although they have lower chemical reactivity, peroxide is very unstable compound, its meeting Auto-decomposition at the temperature of 85-110 DEG C.Special danger is the high vibration sensing of peroxide, and it explodes along with the brisance of explosive.Special exist the danger forming polymer when being gone out butadiene by separated, and this can cause the polymer deposits in tower (forming " puffed rice ").The removing of oxygen is preferably carried out immediately after oxidative dehydrogenation.Generally speaking, carry out the catalytic combustion stage for this purpose, wherein oxygen in the presence of a catalyst with the hydrogen reaction added in this stage.This makes oxygen content be reduced to little trace.

Then the product gas from the oxygen removing stage is made to reach and the identical temperature levels described in the downstream area for ODH reactor.The cooling of Compressed Gas is undertaken by heat exchanger, and heat exchanger such as can have the structure of shell-and-tube heat exchanger, spiral heat exchanger or plate type heat exchanger.The heat here removed is preferred for heat integration in process.

The higher boiling accessory constituent of major part and water can be separated from product gas stream by cooling subsequently.This separation is preferably carried out in quenching.This quenching can comprise one or more stage.The method that preferred use is such, wherein product gas and cooling medium directly contact and the medium that is cooled cools.For cooling medium without any special restriction, but preferably use water or alkaline aqueous solution.This obtains gas streams, wherein remains normal butane, 1-butylene, 2-butylene, butadiene, possible oxygen, hydrogen, steam, and a small amount of methane, ethane, ethene, propane and propylene, isobutene, oxycarbide and inert gas.In addition, not yet in quenching, Quantitative Separation trace high boiling component out can be retained in this product gas stream.

Product gas stream from quenching compresses subsequently at least one compression stage, and cool subsequently, result condensation goes out the moisture condensate stream of at least one, and remains the gas streams containing normal butane, 1-butylene, 2-butylene, butadiene, possible hydrogen, steam and a small amount of methane, ethane, ethene, propane and propylene, isobutene, oxycarbide and inert gas and possible oxygen and hydrogen.Compression can be carried out in one or more stage.In a word, gas streams is compressed to the pressure in 3.5-20 bar (definitely) scope from the pressure of 1.0-4.0 bar (definitely).Be cooling stage after each compression stage, wherein gas streams is cooled to the temperature of 15-60 DEG C.Condensate stream can also contain multiple stream when multiple compression stage.Condensate stream generally contains the water of at least 80 % by weight, preferably at least 90 % by weight, and also containing a small amount of low boilers, C4 hydrocarbon, oxide and oxycarbide.

Suitable compressor reducer is such as steamer compressor reducer, rotary-piston compressor reducer and reciprocating-piston compressor reducer.These compressor reducers such as can pass through motor, expander or gas steam turbine or steam turbine drives.The compression ratio (outlet pressure: inlet pressure) of typical each compression stage is in the scope of 1.5-3.0 according to structure type.The cooling of Compressed Gas is undertaken by heat exchanger, and its structure example is shell-and-tube heat exchanger, spiral heat exchanger or plate type heat exchanger in this way.Cooling water or heat-transfer oil for the cooling agent in heat exchanger.In addition, the Air flow with air blast is preferably used.

Stream containing butadiene, butylene, butane, inert gas and possible oxycarbide, oxygen, hydrogen and low boiling hydrocarbon (methane, ethane, ethene, propane, propylene) and small amounts thing adds in processing further as initial stream.

The operation being separated low boiling submember from product gas stream can be undertaken by conventional separation methods, such as distillation, rectifying, membrane process, absorption or absorption.

In order to isolate any hydrogen comprised in product gas stream, optionally after cooling, such as, in heat exchanger, product gas mixture can be made to pass through can the film of only permeable molecule hydrogen, and this film is typically designed to pipe.The molecular hydrogen separated in this way can where necessary at least in part in hydrogenation or pass into other application in, such as, for producing electric energy in a fuel cell.

Carbon dioxide contained in product gas stream can be separated by carbon dioxide scrubbing.Can be independent combustion phases before carbon dioxide scrubbing, wherein carbon monoxide be optionally oxidized to carbon dioxide.

In a preferred embodiment of the method, incondensible or the lower boiling gas componant nitrogen that such as hydrogen, oxygen, oxycarbide, low boiling hydrocarbon (methane, ethane, ethene, propane, propylene) and inert gas are such as possible is separated in absorption/desorption circulation by higher boiling absorbing medium, obtains C ₄product gas stream, it is substantially by C ₄hydrocarbon forms.Generally speaking, C ₄product gas stream contains the C of at least 80 volume %, preferably at least 90 volume %, particularly preferably at least 95 volume % ₄hydrocarbon is normal butane, 2-butylene and butadiene substantially.

For this purpose, product gas stream was contacting in the absorption stage with inertia absorbing medium in advance before anhydrating, and C ₄hydrocarbon is absorbed in inertia absorbing medium, obtains load C ₄the absorbing medium of hydrocarbon and the tail gas containing residual gas composition.In desorption phase, C ₄hydrocarbon discharges from absorbing medium again.

Absorption stage can carry out well known to a person skilled in the art in any suitable absorption tower.Absorption can be carried out simply by absorbing medium by making product gas stream.But, also can carry out in tower or helical rotating absorber.Absorption can be carried out in following current, adverse current or cross-current.Absorb and preferably carry out in adverse current.Suitable absorption tower is such as the plate column with bubble cap plate, centrifugal column plate and/or sieve plate, has the tower of structured packing, such as, has 100-1000m ²/ m ³the sheet metal filler of specific area, such as 250Y, and the tower with random packing.But, also can use trickling tower and spray tower, graphite block absorber, surface absorber such as thick film absorber and film absorption device, and rotary column, board-like scrubber, cross spray scrubber, and rotary scrubber.

In one embodiment, the stream containing butadiene, butylene, butane and/or nitrogen and possible oxygen, hydrogen and/or carbon dioxide is added the lower area on absorption tower.In the upper area on absorption tower, add the stream containing solvent and optional water.

For the normally high boiling non-polar solven of the inertia absorbing medium in the absorption stage, wherein want isolated C ₄hydrocarbon has the dissolubility significantly larger than isolated remaining gas composition in this solvent.Suitable absorbing medium is the organic solvent of relative non-polarity, such as aliphatic C ₈-C ₁₈alkane, or aromatic hydrocarbons, such as, from the middle oil fraction of paraffin distillation, toluene or there is the ether of bulky group, or the mixture of these solvents; Polar solvent can be added wherein, such as 1,2-dimethyl phthalate.Other suitable absorbing medium is benzoic ether and phthalic acid and straight chain C ₁-C ₈the ester of alkanol, and heat-transfer oil such as biphenyl and diphenyl ether, its chlorinated derivatives and triaryl alkene.Suitable absorbing medium is a mixture for biphenyl and diphenyl ether, preferably has azeotropic composition, such as commercially available the dimethyl ester of this solvent mixture usually containing 0.1-25 % by weight.

Suitable absorbing medium is octane, nonane, decane, hendecane, dodecane, tridecane, the tetradecane, pentadecane, hexadecane, heptadecane and octadecane, or obtains from refining stream and contain the fraction of above-mentioned straight chain as key component.

In a preferred embodiment, the alkane mixture such as tetradecane (industrial C14-C17 fraction) is used as the solvent of absorption.

At the top on absorption tower, take out the waste gas stream containing inert gas, oxycarbide, possible butane, butylene such as 2-butylene and butadiene substantially, possible oxygen, hydrogen and low boiling hydrocarbon (such as methane, ethane, ethene, propane, propylene) and steam.This stream partly can be added ODH reactor or O ₂remove in reactor.This such as can make the charging adding ODH reactor be adjusted to required C ₄hydrocarbon content.

Load C ₄the solvent stream of hydrocarbon is added in desorber.According to the present invention, well known to a person skilled in the art that all tower internals are suitable for this object.In a process program, desorption procedure is undertaken by the solvent of decompress(ion) and/or heating load.A preferred process program is bottom water stripping steam and/or fresh water steam being added desorption device.Dilution C ₄during the solvent of hydrocarbon adds be separated as the mixture together with condensed steam (water), thus from separated from solvent water outlet.Well known to a person skilled in the art that all devices is suitable for this object.In addition, the water gone out from the separated from solvent for generation of water stripping steam can be used.

The preferred use solvent of 70-100 % by weight and the water of 0-30 % by weight, the particularly preferably solvent of 80-100 % by weight and the water of 0-20 % by weight, the especially solvent of 85-95 % by weight and the water of 5-15 % by weight.The absorbing medium regenerated in desorption phase is recycled to the absorption stage.

Especially high boiling hydrocarbon is separated and usually do not complete completely, so according to the type of separation, on a small quantity or only other gas componant of trace, may reside in C ₄in product gas stream.Burden to processing step is subsequently decreased by being separated the reduction of volume flow caused.

Substantially the C be made up of normal butane, butylene such as 2-butylene and butadiene ₄the butadiene of product gas stream usually containing 20-80 volume %, the normal butane of 20-80 volume %, the 1-butylene of 0-10 volume % and the 2-butylene of 0-50 volume %, wherein total amount is 100 volume %.In addition, can containing a small amount of iso-butane.

C ₄product gas stream can be separated into substantially by the stream of normal butane and 2-butylene and the stream containing butadiene by extractive distillation subsequently.Substantially the C adding ODH reactor can be completely or partially recycled to by the stream of normal butane and 2-butylene ₄in charging.Because the butylene isomer in this recycle stream is made up of 2-butylene substantially, and these 2-butylene generally than 1-butylene more slowly oxidative dehydrogenation become butadiene, so this recycle stream can carry out catalytic isomerization metallization processes before entering ODH reactor.In this Catalytic processes, the isomeric distribution corresponding with the isomeric distribution existed in thermodynamical equilibrium can be set.

Extractive distillation can such as " und Kohle-Erdgas – Petrochemie ", the 34th (8) rolls up 343-346 page or " Ullmanns der Technischen Chemie ", the 9th volume the 4th edition, 1975, carry out described in 1-18 page.For this purpose, C is made ₄product gas stream contacts in extraction section with extractant, preferred 1-METHYLPYRROLIDONE (NMP)/aqueous mixtures.The form of extraction section normally scrubbing tower, its contain column plate, random packing element or in order filler as internals.It has 30-70 theoretical tray usually, thus reaches enough good centrifugation.Scrubbing tower preferably has backwash region at tower top.This backwash region is used for reclaiming by liquid hydrocarbon backflow the extractant comprised in the gas phase, top stage is divided in advance for this purpose and carries out condensation.In the charging adding extraction section, extractant and C ₄the quality ratio of product gas stream is generally 10:1 to 20:1.Extractive distillation is preferably 100-250 DEG C at bottom temp, especially carries out at 110-210 DEG C, and head temperature is 10-100 DEG C, especially 20-70 DEG C, and pressure is 1-15 bar, especially 3-8 bar.Extraction distillation column preferably has 5-70 theoretical tray.

Suitable extractant is butyrolactone; nitrile is acetonitrile, propionitrile, methoxypropionitrile such as; ketone is acetone, furfural such as; lower aliphatic acid acid amides such as dimethyl formamide, DEF, dimethylacetylamide, diethyl acetamide that N-alkyl replaces; N-formoxyl-morpholine; ring-type acid acid amides (lactams) such as N-alkyl pyrrolidone, especially 1-METHYLPYRROLIDONE (NMP) that N-alkyl replaces.The ring-type acid acid amides that the lower aliphatic acid acid amides that usual use alkyl replaces or N-alkyl replace.Particularly advantageously dimethyl formamide, acetonitrile, furfural and especially NMP.

But, also the mixture of these extractants can be used, such as NMP and acetonitrile, the mixture of these extractants and cosolvent and/or tertbutyl ether, such as methyl tertiary butyl ether(MTBE), ethyl tert-butyl ether (ETBE), propyl group tertbutyl ether, normal-butyl tertbutyl ether or isobutyl group tertbutyl ether.Specially suitable extractant is NMP, preferably in aqueous, preferably has the water of 0-20 % by weight, particularly preferably has the water of 7-10 % by weight, particularly have the water of 8.3 % by weight.

From the overhead product stream of extraction distillation column substantially containing butane and butylene and a small amount of butadiene, and take out with gas or liquid form.Usually, the stream be substantially made up of normal butane and 2-butylene contains the normal butane of 50-100 volume %, the 2-butylene of 0-50 volume %, and other composition of 0-3 volume % such as iso-butane, isobutene, propane, propylene and C ₅ ⁺-hydrocarbon.

In the bottom of extraction distillation column, obtain the stream of butylene containing extractant, water, butadiene and small scale and butane, and added in destilling tower.In a distillation column, butadiene is obtained at top or as side feeding.Obtain the stream containing extractant and water in the bottom of destilling tower, wherein contain the composition of the stream of extractant and water corresponding to the composition being introduced into extracting operation.Stream containing extractant and water is preferably recycled to extractive distillation.

Extractant solution is transported to desorption zone, here from extraction solution desorb butadiene.Desorption zone can be such as the form of scrubbing tower, and it has 2-30, preferably 5-20 theoretical tray, and optionally backwash district, and it has such as 4 theoretical trays.This backwash district is used for reclaiming extractant contained in the gas phase by liquid hydrocarbon reflux, for this purpose condensing tower tops in advance.There is provided orderly filler, column plate or random packing as internals.Distillation is preferably 100-300 DEG C at bottom temp, especially carries out at 150-200 DEG C, and head temperature is 0-70 DEG C, especially 10-50 DEG C.Pressure in destilling tower is preferably 1-10 bar.Generally, lower than extraction section pressure and/or higher temperature are occupied an leading position in desorption zone.

Product stream needed for obtaining at tower top usually containing the butadiene of 90-100 volume %, the 2-butylene of 0-10 volume %, and the normal butane of 0-10 volume % and iso-butane.In order to butadiene of purifying further, other distillation as described in the prior art can be carried out.

Below by embodiment, the present invention is described.

The parameter conversion ratio (X) calculated in an embodiment and selective (S) as follows:

Wherein mole (XXX _enter) be the mole of component XXX at reactor inlet place, mole (XXX _{go out}) be the mole of component XXX at reactor exit, butylene is the summation of 1-butylene, cis-2-butene, Trans-2-butene and isobutene.

Embodiment

Kaolinite Preparation of Catalyst

Embodiment 1

Prepare two kinds of solution A and B.

Solution A:

3200g water is placed in the stainless cylinder of steel of 10L.While stirring with anchor agitator, in the initial water loaded, add the KOH solution (KOH of 32 % by weight) of 5.2g.This solution is heated to 60 DEG C.Then by 1066g Ammoniun Heptamolybdate Solution ((NH ₄) ₆mo ₇o ₂₄* 4H ₂o, the Mo of 54 % by weight) add gradually in 10 minutes.The suspension of gained stirs 10 minutes again.

Solution B:

Cobalt nitrate (II) solution (Co of 12.3 % by weight) of 1771g is added in the stainless cylinder of steel of 5L, and (anchor agitator) is heated to 60 DEG C while stirring.Then ferric nitrate (III) solution (Fe of 13.7 % by weight) of 645g is added gradually while maintenance temperature in 10 minutes.The solution stirred for additional formed 10 minutes.Then while keeping temperature, add the bismuth nitrate solution (Bi of 10.7 % by weight) of 619g.After stirring again 10 minutes, along with the time adds the chromic nitrate (III) of the 109g as solid gradually, and formed dark red liquid is stirred 10 minutes again.

While maintenance 60 DEG C of temperature, with peristaltic pump, solution B was pumped in solution A in 15 minutes.During adding and afterwards, this mixture super mixer (Ultra-Turrax) stirs.After the addition was complete, mixture is stirred 5 minutes again.Then the SiO of 93.8g is added ₂suspended substance (Ludox; SiO ₂, and mixture is stirred 5 minutes more about 49%, Grace).

The suspension of gained spraying dry 1.5 hours in from the spray dryer (shower nozzle No.FOA1, rotary speed: 25000rpm) of NIRO.The temperature of initial charging remains on 60 DEG C during this period.The gas inlet temperature of spray dryer is 300 DEG C, and gas outlet temperature is 110 DEG C.The powder of gained has the particle diameter (d being less than 40 μm ₅₀).

The powder of gained mixes with 1 % by weight graphite, compacting 2 times under the pressing pressure of 9 bar, and broken with the sieve with 0.8mm sieve aperture.Broken material mixes with 2 % by weight graphite again, and mixture Kilian S100 tablet press machine is pressed into the ring of 5 × 3 × 2mm (external diameter × length × internal diameter).

The catalyst precarsor of gained calcines (500g) with intermittent mode in from the convection oven (type K, 750/2S, internal volume 55L) of Heraeus, DE.Following program is used for this object:

-in 72 minutes, be heated to 130 DEG C, keep 72 minutes

-in 36 minutes, be heated to 190 DEG C, keep 72 minutes

-in 36 minutes, be heated to 220 DEG C, keep 72 minutes

-in 36 minutes, be heated to 265 DEG C, keep 72 minutes

-in 93 minutes, be heated to 380 DEG C, keep 187 minutes

-in 93 minutes, be heated to 430 DEG C, keep 187 minutes

-in 93 minutes, be heated to 490 DEG C, keep 467 minutes

After firing, the stoichiometric relationships that the catalyst obtained has calculating is Mo ₁₂co ₇fe ₃bi _0.6k _0.08cr _0.5si _1.6o _x.

Embodiment 2

By the calcining ring grind into powder from embodiment 1.

With this precursor composition coated carrier (being of a size of the talcum ring of 5 × 3 × 2mm (external diameter × length × internal diameter)).For this purpose, the carrier of 1054g is placed in coating drum (2L internal volume, inclination angle=30 ° between central dram axle and level).Drum is arranged to rotate (25rpm).The liquid adhesive (glycerine: the 1:3 mixture of water) of about 60ml is sprayed onto on carrier in about 30 minutes with the nozzle that compressed air (spray air: 500 standard l/h) operates.Nozzle is installed and makes sprinkling cone cylinder soak the carrier rousing and carry in the first half of lower curtate in rotation.Add in drum with powder screw rod by the fine powder precursor composition of the abrasive catalyst of 191g, wherein the feed point of powder is arranged in rotate downward section but be positioned at and sprays under cone cylinder.Be metered into powder to be uniformly distributed from the teeth outwards to make powder.After completing coating, the coated catalyst be made up of precursor composition and carrier of gained at 300 DEG C in drying oven dry 4 hours.

Dehydrogenation is tested

Dehydrogenation experiment is carried out in screen cloth reactor.The salt bath reactor of screen cloth reactor is length to be 120cm and internal diameter be 14.9mm, and there is the temperature sensor shell that external diameter is 3.17mm.Multiple sensor element with 7 test points is arranged in temperature sensor shell.4 test points of bottom have the interval of 10cm, and uppermost 4 test points have the interval of 5cm.

Butane and raffinate II or 1-butylene are metered into via coriolis force flowmeter in liquid form under about 10 bar, mix in static mixer, and to unzip to subsequently in the evaporator stage of heating and to evaporate.Then this gas mix with nitrogen, and add in the preheater with talcum bed.Water is metered in liquid form and evaporates in the air stream in evaporimeter endless tube.Air/water steam mixture and N ₂/ raffinate II/ butane mixture merges in the lower area of preheater.Then the feed gas mixed completely adds in reactor, wherein can take out the stream analyzed for online GC.Stream for analyzing also takes out from the product gas leaving reactor, and can be analyzed by online GC or be analyzed to measure CO and CO by IR analyzer ₂volume ratio.For analyze pipeline arm after be pressure-regulating valve door, it is for setting stress level in the reactor.

Embodiment 3

The talcum ball of 3.5-4.5mm diameter will be had containing 16g and the rear bed with 6cm length be placed on be in screen cloth reactor lower end catalyst carrier grid on.Then the catalyst from embodiment 1 of 44g is mixed with the 88g talcum ring with identical physical dimension well, and add reactor (146ml bed volume, 88cm bed height).Be the elementary bed of 7cm length after this catalyst bed, it contains the talcum ball with 3.5-4.5mm diameter of 16g.

This reactor uses the reacting gas of 200 standard l/h to operate 50 hours under the salt temperature of 330 DEG C, described reacting gas has the 1-butylene consisting of 8 volume %, the butane of 2 volume %, the oxygen of 7.5 volume %, the water of 15 volume %, the nitrogen of 67.5 volume %.Product gas GC analyzes.Conversion ratio and selective data row are in Table 1.

Then the mixture of 10 volume % oxygen, 80 volume % nitrogen and 10 volume % steam is passed through 20 hours on a catalyst, and be heated to 400 DEG C in the process.The oxycarbide formed is by IR detecting instrument record.Also arranged in Table 1 by the amount of the carbon of burn off.

Embodiment 4

The talcum ball of 3.5-4.5mm diameter will be had containing 16g and the rear bed with 6cm length be placed on be in screen cloth reactor lower end catalyst carrier grid on.Then the catalyst from embodiment 2 of 120g is added reactor (active compound of 18g, 113ml bed volume, 68cm bed height).Be the elementary bed of 7cm length after this catalyst bed, it contains the talcum ball with 3.5-4.5mm diameter of 16g.

This reactor uses the reacting gas of 200 standard l/h to operate 50 hours under the salt temperature of 357 DEG C, described reacting gas has the 1-butylene consisting of 8 volume %, the butane of 2 volume %, the oxygen of 7.5 volume %, the steam of 15 volume %, the nitrogen of 67.5 volume %.Product gas GC analyzes.Conversion ratio and selective data row are in Table 1.

Table 1

	Embodiment 3	Embodiment 4
			Initial conversion	89.3％	94.8％
Conversion ratio after 50 hours	84.0％	72.9％
			By the carbon of burn off	165mg	18mg
Conversion ratio after regeneration	88.1％	90.0％

Initial conversion is restored basically by burn off carbonaceous sediment.

Embodiment 5

This reactor uses the reacting gas of 200 standard l/h to operate 20 hours (each preparation process) under the salt temperature of 384 DEG C, described reacting gas has the butylene consisting of 8 volume %, the butane of 2 volume %, the oxygen of 7.5 volume %, the steam of 15 volume %, the nitrogen of 67.5 volume %.Product gas GC analyzes.Conversion ratio and selective data row are in table 2.

After each preparation process, by the mixture of 10 volume % oxygen, 80 volume % nitrogen and 10 volume % steam at the same temperature on a catalyst by (regeneration step).The oxycarbide formed is by IR detecting instrument record.The amount of carrying out the preparation of 2.5 circulations and the carbon of regeneration step (burn off operation) institute's burn off also arranges in table 2.

After these circulations, catalyst uses above-mentioned gas to operate 20 hours again.Then reactor purges while temperature is elevated to 400 DEG C with having the gas consisting of 10 volume % oxygen, 10 volume % steam and 90 volume % nitrogen, thus measures by the total amount of the carbon of burn off.By the amount of the carbon of burn off row in table 2.

Table 2

Embodiment 6

This reactor uses the reacting gas of 200 standard l/h to operate 20 hours (each preparation process) under the salt temperature of 348 DEG C, reacting gas has the butylene consisting of 8 volume %, the butane of 2 volume %, the oxygen of 7.5 volume %, the steam of 15 volume %, the nitrogen of 67.5 volume %.Product gas GC analyzes.Conversion ratio and selective data row are in table 3.

After each preparation process, by the mixture of 10 volume % oxygen, 80 volume % nitrogen and 10 volume % water at the same temperature on a catalyst by 30 minutes (regeneration step).The oxycarbide formed is by IR detecting instrument record.The amount of carrying out the preparation of 3.5 circulations and the carbon of regeneration step (burn off operation) institute's burn off also arranges in table 3.

After these circulations, catalyst uses above-mentioned gas to operate 20 hours again.Then reactor purges while temperature is elevated to 400 DEG C with having the gas consisting of 10 volume % oxygen, 10 volume % steam and 90 volume % nitrogen, thus measures by the total amount of the carbon of burn off.By the amount of the carbon of burn off row in table 3.

Table 3

When burn off is less than the deposit carbon total amount of 5%, activity no longer can return to satisfaction.

Claims

1. n-butene oxidative dehydrogenation is become a method for butadiene, the method comprises two or more preparation processes (i) and at least one regeneration step (ii), wherein

With, before conversion ratio at a constant temperature reduces degree >25%,

The carbon deposited on a catalyst of burn off 2-50 % by weight is wherein counted according to each regeneration step (ii).

2. method according to claim 1, wherein contains the oxygen of 0.5-22 volume % containing oxygen regeneration gas mixture.

3., according to the method for claim 1 or 2, wherein contain the steam of 0-30 volume % containing oxygen regeneration gas mixture.

4. method as claimed in one of claims 1-3, the temperature wherein in preparation process (i) is 350-410 DEG C.

5. method as claimed in one of claims 1-4, the temperature wherein in regeneration step (ii) exceeds 0-20 DEG C than the temperature in preparation process (i).

6. method as claimed in one of claims 1-5, wherein counts the carbon deposited on a catalyst of burn off 10-35 % by weight according to each regeneration step (ii).

7. method as claimed in one of claims 1-5, wherein counts the carbon deposited on a catalyst of burn off 10-25 % by weight according to each regeneration step (ii).

8. method as claimed in one of claims 1-7, the poly-metal deoxide wherein containing molybdenum and other metal of at least one has general formula (I):

Mo ₁₂Bi _aFe _bCo _cNi _dCr _eX ¹ _fX ² _gO _x(I),

Wherein each symbol has following implication:

X ¹=W, Sn, Mn, La, Ce, Ge, Ti, Zr, Hf, Nb, P, Si, Sb, Al, Cd and/or Mg;

X ²=Li, Na, K, Cs and/or Rb,

A=0.1-7, preferred 0.3-1.5;

B=0-5, preferred 2-4;

C=0-10, preferred 3-10;

d＝0-10；

E=0-5, preferred 0.1-2;

F=0-24, preferred 0.1-2;

G=0-2, preferred 0.01-1; With