CN105732270A - Front-hydrogenation method of trace amount of acetylene in methanol to olefin (MTO) apparatus - Google Patents

Abstract

The invention relates to a front-hydrogenation method of trace amount of acetylene in a methanol to olefin (MTO) apparatus. An adiabatic bed reactor for hydrogenation is located before a demethanizing column or a deethanizing column. A Pd-Au-series catalyst is arranged in a fixed bed reactor. During preparation of the catalyst, a carrier is combined with a bipyridine derivative having a hydroxyl group, wherein a metal complex is formed from the hydroxyl bipyridine derivative combined with the carrier and active components. Activity and selectivity of the hydrogenation method are greatly better than those in a conventional hydrogenation method, ethylene loss is reduced and purity of ethylene is increased so that performance of a polymerization-grade ethylene product is improved well. Through reduction on green oil, active center of the catalyst is not covered by side product, so that the activity and the selectivity of the catalyst are maintained well, thereby prolonging the service life of the catalyst.

Description

A kind of front-end hydrogenation method of trace acetylene in methanol-to-olefins device

Technical field

The present invention relates to the selection method of hydrotreating of trace acetylene in a kind of selection method of hydrotreating, particularly a kind of methanol-to-olefins device.

Background technology

The low-carbon alkene such as ethylene, propylene is important basic chemical raw materials, and along with the demand of low-carbon alkene is day by day risen by the development of the development of Chinese national economy, particularly modern chemical industry, imbalance between supply and demand also will become increasingly conspicuous.Up to now, the important channel of the low-carbon alkene such as preparing ethylene, propylene, remain by Petroleum, the catalytic cracking of light diesel fuel (being all from oil), cracking, as raw material resources such as the Petroleum of ethylene production raw material, light diesel fuels, be faced with increasingly severe short situation.It addition, crude oil in China import volume has accounted for about the half of processing total amount in recent years, the at a relatively high percentage of import will be maintained with the polyolefin products that ethylene, propylene are raw material.Therefore, development non-oil resource carrys out the technology of preparing low-carbon olefins and day by day causes the attention of people.

Methanol ethylene, the MTO technique of propylene and the MTP technique of preparing propylene from methanol are Chemical Engineering Technologies important at present.The methanol that this technology synthesizes with coal or natural gas, for raw material, produces low-carbon alkene, is the development non-oil resource core technology that produces the product such as ethylene, propylene.

MTO technology is the committed step in coal-based alkene industrial chain, its technological process is mainly under suitable operating condition, with methanol for raw material, choose suitable catalyst (ZSM-5 zeolite catalyst, SAPO-34 molecular sieve etc.), in fixing bed and vulcanization bed reactor, pass through preparing low-carbon olefin through methanol dehydration.Difference according to purpose product, MTO technology is divided into methanol ethylene, propylene (methanol-to-olefin, MTO), preparing propylene from methanol (methanol-to-propylene, MTP).The representative technology of MTO technique has AP Oil company (UOP) and the UOP/HydroMTO technology of Hydro company (NorskHydro) joint development, the DMTO technology of Dalian Inst of Chemicophysics, Chinese Academy of Sciences's autonomous innovation research and development；The representative technology of MTP technique has the FMTP technology of LurgiMTP technology that LURGI (Lurgi) develops and the independent research of Tsing-Hua University of China.

The whole reaction of methanol-to-olefins can be divided into two stages: water smoking, cracking reaction stage

1. the water smoking

2CH₃OH→CH₃OCH₃+H₂O+Q

2. the cracking reaction stage

The catalytic cracking reaction that this course of reaction is mainly dehydration reaction product dimethyl ether and a small amount of unconverted material benzenemethanol carries out, including:

Primary response (generation alkene):

nCH₃OH→C_nH_2n+nH₂O+Q

nCH₃OH→2C_nH_2n+nH₂O+Q

N=2 and 3 (mainly), 4,5 and 6 (secondary)

Any of the above olefin product is gaseous state.

Side reaction (generates alkane, aromatic hydrocarbons, oxycarbide coking):

(n+1)CH₃OH→C_nH_2n+2+C+(n+1)H₂O+Q

(2n+1)CH₃OH→2C_nH_2n+2+CO+2nH₂O+Q

(3n+1)CH₃OH→3C_nH_2n+2+CO₂+(3n-1)H₂O+Q

N=1,2,3,4,5 ... ...

nCH₃OCH₃→C_nH_2n-6+3H₂+nH₂O+Q

N=6,7,8 ... ...

Above product has gaseous state (CO, H₂、H₂O、CO₂、CH₄In alkane, aromatic hydrocarbons etc.) and solid-state (macromolecule hydrocarbon and coke) point.

Methanol, after dehydration, cracking, separation, still contains the acetylene of 5～100ppm in the ethylene feed of deethanizer overhead, it affects the polymerization process of ethylene, and causes product quality to decline, it is necessary to by selecting method of hydrotreating to be removed.In ethylene feed, the polymerization process of ethylene is had extremely important impact by the hydrogenation that selects of trace acetylene, except ensureing that hydrogenation has enough activity, have good in alkynes performance when low acetylene content, ensure that the acetylene content of reactor outlet is up to standard, outside the hydrogen content of reactor outlet is up to standard, also require that selectivity of catalyst is excellent, it is possible to make the generation ethane that ethylene is the least possible, it is ensured that hydrogenation process does not bring the loss of device ethylene.

The separative element of methanol-to-olefins device, the order separation process of current commonly used Lummus company.The refining adoptable front-end hydrogenation of ethylene, two kinds of techniques of back end hydrogenation.Hydrogenation reactor is front-end hydrogenation before being positioned at separative element, and hydrogenation reactor is back end hydrogenation after being positioned at separative element.The commonly used back end hydrogenation technique of current methanol-to-olefins device, carries out hydrofinishing elimination acetylene by the isolated ethylene of pyrolysis product, and propylene does not set hydrofining reactor, and isolated carbon four blending ingredients carries out selective hydrogenation and removing butadiene.But this technique exists drawback, adopting first to separate and ethylene, propylene are refined respectively again, plant energy consumption is of a relatively high.Therefore, it is proposed to before separative element, arrange refining reaction device, the front-end hydrogenation process route separated again after elimination acetylene, contribute to reducing plant energy consumption, improve device economic benefit.

For front-end hydrogenation technique, in methanol-to-olefins device ethylene feed, the selection hydrogenation of trace acetylene is main adopts single hop reactor process.The volume content of each material is as follows: acetylene 5～100ppm, CO1～10ppm, and hydrogen adopts the hydrogen itself contained in material, H₂Content is generally 1.2%～2.5%.Reaction pressure 1.5～2.5MPa, air speed 2000～15000h^-1, inlet temperature 30 DEG C～50 DEG C.Reactor content composition is complex, and particular make-up is by table 1.

Table 1 methanol-to-olefins device front-end hydrogenation technique acetylene hydrogenation reactor entrance material forms

Component	Compositing range (v%)	Composition citing (v%)
			H2	1.2～2.5	1.72
N2	0.5～1.0	0.72
			O2	0.005～0.015	0.01
CO	0.60～1.0	0.85
			CO2	0.20～0.60	0.38
H2S	0～0.0008	0.0001

CH4	6～10	8.09
			C2H2	0～0.01	0.0005
C2H6	1～2	1.64
			C2H4	40～60	51.10
C3H8	1.5～3	2.06
			C3H6	15～40	20.91
C3H4	0～0.01	0.001
			C4	3～6	4.49
C5+	6～10	8.03

Alkynes and diolefin hydrogenate catalyst are (US4762956) by noble metal such as palladium load being obtained in the Inorganic material carrier of porous.In order to increase selectivity of catalyst, reduce the catalysqt deactivation that the green oil produced by oligomerization when being hydrogenated with causes, prior art have employed that to add such as group ib element in the catalyst be the method for co-catalysis component: Pd-Au (US4490481), Pd-Ag (US4404124), Pd-Cu (US3912789), or adding alkali metal or alkaline-earth metal (US5488024) etc., carrier used has aluminium oxide, silicon dioxide (US5856262), the loyal cordierite of honeycomb (CN1176291) etc..

US5856262 reports with the modified silicon oxide of potassium hydroxide (or hydroxide of barium, strontium, rubidium etc.) for carrier, and the method for preparation low in acidity palladium catalyst, at air speed 3000h^-1, inlet temperature 35 DEG C, entrance acetylene molar fraction 0.71%, when hydrogen alkynes mol ratio 1.43, outlet acetylene molar fraction is less than 0.1 μ L/L, and ethylene selectivity reaches 56%.Patent US4404124, with aluminium oxide for carrier, adds promoter silver and palladium effect, is prepared for the C2 hydrogenation catalyst of function admirable.This catalyst has minimizing ethane growing amount, it is suppressed that is adsorbed on the acetylene on catalyst surface and carries out partial hydrogenation dimerization reaction, it is suppressed that 1,3-butadiene generates, and reduces green oil and generates, improves ethylene selectivity, reduce the feature of oxygenatedchemicals growing amount, be applied widely in ethylene industry.But, above-mentioned catalyst all adopts infusion process to prepare, and by the restriction of preparation method, metal dispersity is only about 30%, and catalyst performance there is also many deficiencies, still has necessity of improvement further.

CN101745389A discloses a kind of egg-shell catalyst for preparation of ethylene through selective hydrogenation of acetylene, belong to the synthesis of oil (natural gas) chemical products and new catalytic material technical field, relate to a kind of egg-shell catalyst that preparation of ethylene through selective hydrogenation of acetylene is had superior catalytic performance.It is characterized in that with aluminium oxide (Al₂O₃) bead is carrier, adopt infusion process to prepare the loaded catalyst that active component palladium be eggshell type and is distributed, and adopt Ag to eggshell type Pd/Al₂O₃Catalyst is modified.Pd load capacity is 0.01～0.1wt%, Ag and Pd atomic ratio is 1～5.The invention have the advantages that, a kind of egg-shell catalyst for preparation of ethylene through selective hydrogenation of acetylene provided, can when high conversion of alkyne, especially close to 100% conversion of alkyne time, it is achieved high ethylene selectivity.

Traditional Pd-Ag bimetallic selective hydrogenation catalyst is all adopt aqueous impregnation method to prepare.When adopting sub-dip method, what a kind of component can be more is enriched in carrier surface, and another kind of component is enriched in outer surface, and only part metals atom interpenetrates, and defines alloy structure.When adopting total immersion method, owing to the presoma of two metal ion species and the interaction of carrier are different, and surface tension and solvation, it is hardly formed the uniform load of two kinds of components, also can only partly form alloy structure.When this catalyst is applied to C 2 fraction selective hydrogenation, often better at initial reaction stage selectivity, with the prolongation of the time of operation, selectivity constantly declines, and generally runs 3～6 months and is accomplished by regeneration, and economic loss is bigger.

CN201110086174.0 by adsorbing specific macromolecular compound on carrier, macromolecule wrapped layer is formed at carrier surface certain thickness, with with the compound of function base and high molecular weight reactive, can with the function base of active component complexation so as to have, on carrier surface function base, complex reaction is there is, it is ensured that active component is in order and high degree of dispersion by active component.Adopt this patented method, the specific macromolecular compound of carrier adsorption, carry out chemisorbed by the hydroxyl of aluminium oxide and macromolecule, the amount of carrier adsorption macromolecular compound is subjected to the hydroxyl value quantitative limitation of aluminium oxide；Not strong with the complexing of Pd through the macromolecule of functionalization, activity component load quantity does not reach requirement sometimes, goes back residual fraction active component in impregnation liquid, causes catalyst cost to improve；Adopt the method to prepare C2 hydrogenation catalyst and there is also the shortcoming that technological process is complicated.

Along with the requirement of catalyst is improved by methanol-to-olefins trace acetylene hydrogenation plant day by day, require catalyst at a lower reaction temperature, there is activity and the selectivity of excellence, to reach to save energy and reduce the cost, improve device ethylene increment, thus reaching to improve the purpose of device economic benefit.

Summary of the invention

It is an object of the invention to provide the selection method of hydrotreating of trace acetylene in a kind of methanol-to-olefins device.By selecting active component high degree of dispersion, there is the Pd-Au catalyst of height alloy structure, improve hydrogenation selectivity, improve ethylene increment, improve plant running stability and economic benefit.

The inventors discovered that, when the catalyst adopting the preparation method of the present invention to prepare, the Pd in catalyst is separated by Au, the spacing making active center widens, and catalyst selectivity improves, and therefore the surface coking rate of catalyst is greatly reduced, catalyst on-stream cycle time extends, and economic benefits are obvious.

The invention provides the selection method of hydrotreating of trace acetylene in a kind of methanol-to-olefins device.Before adiabatic reactor reactor for being hydrogenated with is positioned at domethanizing column or dethanizer, from the carbon one at the bottom of drying tower tower, carbon two and carbon 3 material in methanol-to-olefins device, enter adiabatic reactor reactor to carry out selecting hydrogenation, it is characterised in that: equipped with Pd-Au series catalysts in adiabatic reactor reactor, with Al₂O₃Or Al₂O₃Being carrier with other hopcalite, with the quality of catalyst for 100%, wherein Pd content 0.015～0.060%, Au content is 0.02～0.30%, and the specific surface area of catalyst is 20～60m²/ g, pore volume is 0.15～0.70mL/g；This catalyst, in preparation process, is combined with hydroxyl-bipyridyl by carrier, and the hydroxyl bipyridyl on carrier forms metal complex with active component；Reaction condition is: adiabatic reactor reactor inlet temperature 30 DEG C～50 DEG C, reaction pressure 1.5～3.0MPa, air speed 2000～15000h^-1。

The feature of the Pd-Au series catalysts used in the present invention is: this catalyst is by the employing PdAu-hydroxyl-bipyridyl/Al of the present invention₂O₃Prepared by the method for precursor.

The catalyst preparation process recommended, at least includes: load on carrier by hydroxyl dipyridyl derivatives, and the cation of the hydroxyl unnecessary again through hydroxyl dipyridyl derivatives and/or nitrilo and Pd, Au forms complex ion.

The hydroxyl dipyridyl derivatives of the present invention, preferably hydroxyl 2,2,-dipyridyl derivatives, hydroxyl 3,3 ,-dipyridyl derivatives, preferably hydroxyl 2,2 ,-dipyridyl derivatives, can there is good complex reaction with Pd, Au in two nitrilo at hydroxyl unnecessary after being combined with aluminium oxide and ortho position because of it.

The present invention is the selection method of hydrotreating of trace acetylene in methanol-to-olefins device, and in entrance raw material, composition is mainly ethylene, propylene, and reactor inlet material forms in Table 1.Reactor inlet temperature 30 DEG C～50 DEG C, reaction pressure 1.5～3.0MPa, air speed 2000～15000h^-1。

Defining the catalyst type of use in the present invention, such catalyst selectivity and traditional catalyst have bigger difference.

Principles of the invention is: in selective hydrogenation reaction, along with the catalyst activity component Pd, the Au that use form alloy, the quantity of the hydrogen that caltalyst phase is adsorbed is greatly reduced, and the trend of acetylene generation deep hydrogenation is substantially reduced, and catalyst selectivity significantly improves.

The acquisition of this catalyst preferably includes following steps: by the organic solution of hydroxyl dipyridyl derivatives, impregnates carrier, obtains hydroxyl-bipyridyl/Al after drying₂O₃Precursor, the mixed solution dipping hydroxyl-bipyridyl/Al of preparation Pd, Au₂O₃Precursor, dry at 60 DEG C～150 DEG C, obtain PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor.At 300～600 DEG C of roasting temperature 2～12h, obtain required catalyst.

Carrier of the present invention is preferably aluminium oxide, or mainly contains Al₂O₃, wherein also doped with other hopcalite, other oxide is silicon oxide, titanium oxide, magnesium oxide and/or calcium oxide.Described aluminium oxide is γ, δ, θ, alpha-crystal form or wherein several mixing crystal formations, it is desirable to for θ, α or its mixing crystal formation.

In the present invention, carrier can be spherical, cylindrical, annular, bar shaped, cloverleaf pattern, Herba Galii Bungei shape etc..

Catalyst preparing of the present invention can adopt procedure below to implement, and this process can be divided into 3 steps to carry out.

A. hydroxyl-bipyridyl/Al₂O₃The preparation of precursor

The organic solution of hydroxyl dipyridyl derivatives is mixed with carrier, makes solution be absorbed, at 20 DEG C～60 DEG C temperature, react 2～24h, take out solid particle, dry at 60 DEG C～150 DEG C, obtain hydroxyl-bipyridyl/Al₂O₃Precursor；The volume of organic solution is preferably greater than 80% equal to carrier cumulative volume.

B.PdAu-hydroxyl-bipyridyl/Al₂O₃The preparation of precursor

The mixed solution of preparation Pd, Au, with step A gained hydroxyl-bipyridyl/Al at 30 DEG C～100 DEG C temperature₂O₃Precursor reaction 2～24h, takes out solid particle, dry at 60 DEG C～150 DEG C, obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor.

The ratio of the molal quantity of best Au and the molal quantity of Pd is 0.5～7, it is desirable to regulating pH value is 1.5～4.0；The volume of the mixed solution of Pd, Au is hydroxyl-bipyridyl/Al preferably₂O₃The 60%～200% of precursor cumulative volume.

C. the preparation of catalyst

PdAu-hydroxyl-bipyridyl/Al prepared by step B₂O₃Precursor is at 300～600 DEG C of roasting temperature 2～12h so that PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor is changed into corresponding metal composite oxide, obtains catalyst.

When catalyst uses, the catalyst that above method can be prepared, use H in the reactor₂Carry out reduction treatment, obtain reduction-state catalyst.

In step, hydroxyl dipyridyl derivatives, it is preferred to hydroxyl 2,2 ,-dipyridyl derivatives, hydroxyl 3,3 ,-dipyridyl derivatives, it is preferred to hydroxyl 2,2 ,-dipyridyl derivatives.May insure that Al₂O₃While it is produced extensive chemical absorption, two nitrilo that unnecessary hydroxyl is adjacent with bipyridyl combine with active component Pd, Au.With molar basis, the molal quantity of hydroxyl-bipyridyl/(Pd+Au) is preferably 3～100.

Adding solvent in step to make hydroxyl-bipyridyl be completely dissolved, to be conducive to macromolecule absorption on carrier, solvent can be ethanol and ether.The addition of solvent is how many, mainly to control institute's solubilizer and macromolecule can be made to be completely dissolved.

In stepb, the solution of palladium-Jin can be the soluble salt solutions of palladium, gold, as being the mixed solution of Palladous chloride. and gold chloride.In described mixed solution, palladium, gold salt consumption are can make Pd, Au content of final catalyst.

In step C, roasting preferably carries out in having oxygen atmosphere, sintering temperature of the present invention preferably 300 DEG C～600 DEG C.

When catalyst uses, the catalyst that above method can be prepared, use H in the reactor₂Carry out reduction treatment, obtain reduction-state catalyst.

The present inventors have additionally discovered that, when adopting the method to carry out selective hydrogenation reaction, the activity of catalyst reaction, selectivity are all significantly improved, and catalyst stability strengthens.

Simultaneously, the palladium-gold catalyst that the inventive method uses, owing to its alloy structure is obvious, alloy effect is stronger, it is more suitably applied to the hydrogenation plant of the methanol-to-olefins trace acetylene that catalyst activity, selectivity requirement is all higher, this alloy catalyst is applied to the hydrogenation plant of trace acetylene, at a lower reaction temperature, has activity and the selectivity of excellence.

Accompanying drawing illustrates:

Accompanying drawing 1 is just C2 hydrogenation process chart with a kind of methanol-to-olefins adopting predepropanization technique of the present invention.1 DME reactor；2 MTP reactors；3 pre-chillings separate；4 chillings separate；5 level Four compressions；6 level Four separate；7 drying towers；8-acetylene hydrogenation reactor；9 domethanizing columns；10 dethanizers.

Detailed description of the invention

Embodiment 1

Weighing Φ 4.0, specific surface area is 20.0m²Spherical α-the Al of/g, pore volume 0.35mL/g, bulk density 0.85g/ml₂O₃Carrier 500g.

By 36.09g4,4-dihydroxy-2,2-bipyridyl is dissolved in 650mL alcoholic solution, by above-mentioned carrier impregnation in above-mentioned solution, after standing 2h, dihydroxy-2,2-bipyridyl is loaded to after on alumina support completely, and 60 DEG C of dry 10h obtain hydroxyl-bipyridyl/Al₂O₃Precursor.

Weighing appropriate Palladous chloride., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 2.0, is configured to mixed solution.By above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 10min, stands 2h, pours out residual liquid, obtain PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Au)=20).After 120 DEG C of dry 4h at 550 DEG C of temperature roasting 2h in air atmosphere, obtain (Pd-Au)/Al₂O₃Catalyst.

Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst S-1.Recording this catalyst Pd content is 0.017%, and Au content is 0.25%.

Comparative example 1

Weighing Φ 4.0, specific surface area is 20.0m²Spherical α-the Al of/g, pore volume 0.35mL/g, bulk density 0.85g/ml₂O₃Carrier 500g.

A, functionalized poly vinyl chloride (PVC)/Al₂O₃Preparation

PVC8.9g is dissolved completely in 800mlTHF (oxolane), in above-mentioned carrier impregnation to above-mentioned solution, after standing 2h, PVC will be made to be adsorbed in Al₂O₃Surface, drying for standby.Obtain PVC/Al₂O₃。

Add 119.28g dicyandiamide and 4.0gNa₂CO₃, add above-mentioned preparation PVC/Al₂O₃Backflow 1h, is cooled to room temperature, with deionized water wash to neutral, and 60 DEG C of dry 10h, obtain functionalized PVC/Al₂O₃。

B, Pd-Au-high-molecular complex/Al₂O₃The preparation of presoma

Weighing appropriate Palladous nitrate., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 2.0, is configured to mixed solution, takes the functionalized-PVC/Al prepared₂O₃Presoma, adds it to Pd (NO₃)₂, AuCl4H mixed solution in, stir 30min, pour out residual liquid, by above-mentioned product deionized water wash to neutral, 120 DEG C of dry 4h obtain (Pd-Au)-PVC/Al₂O₃Presoma.

C, catalyst preparation

By the presoma of above-mentioned preparation, 550 DEG C of roasting 2h in air atmosphere, obtain oxidation state (Pd-Au)/Al₂O₃Catalyst.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst D-1.Recording this catalyst Pd content is 0.017%, and Au content is 0.25%.

Adopting the C2 hydrogenation technique of methanol-to-olefins, its process chart as shown in Figure 1, adopts 500mL evaluating apparatus, and working condition is in Table 1, and raw material forms in Table 2.

Table 1 micro anti-evaluation parameter

Table 2 raw material forms

Component	Compositing range (%)	Component	Compositing range (%)
				H2	1.2～2.5	C2H2	0～0.01
N2	0.5～1.0	C2H6	1～2
				O2	0.005～0.015	C2H4	40～60
CO	0.60～1.0	C3H8	1.5～3
				CO2	0.20～0.60	C3H6	15～40
H2S	0～0.0008	C3H4	0～0.01
				CH4	6～10	C4	3～6
C2H2	0～0.01	C5+	6～10

Table 3 catalyst 1000h performance meansigma methods

Embodiment 2

Weighing Φ 4.5mm, high 4.5mm, specific surface area is 60.0m²/ g, pore volume is 0.42ml/g, and bulk density is cylindrical vector 500g, the Al of 0.73g/ml₂O₃Mixing crystal formation for δ and θ.

By 4.86g4,4-dihydroxy-2,2-bipyridyl is dissolved in 600mL alcoholic solution, by above-mentioned carrier impregnation in above-mentioned solution, after standing 8h, dihydroxy-2,2-bipyridyl is loaded to after on alumina support completely, and 90 DEG C of dry 8h obtain hydroxyl-bipyridyl/Al₂O₃Precursor.

Weighing appropriate Palladous chloride., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 2.5, is configured to mixed solution, by above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 60min, stands 8h, pours out residual liquid, and remaining solid dry 8h at 110 DEG C obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Au)=4.28).

By the presoma of above-mentioned preparation, 500 DEG C of roasting 4h in air atmosphere.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst S-2.Recording this catalyst Pd content is 0.038%, and Au content is 0.025%.

Comparative example 2

Catalyst preparing

Weighing Φ 4.5mm, high 4.5mm, specific surface area is 60.0m²/ g, pore volume is 0.42ml/g, and bulk density is cylindrical vector 500g, the Al of 0.73g/ml₂O₃Mixing crystal formation for δ and θ.

A, functionalized polystyrene acrylonitrile (SAN)/Al₂O₃Preparation

Weighing SAN resin 2.2g, be dissolved in 600mLDMF (dimethylformamide) solvent, under room temperature, stirring makes SAN resin be completely dissolved, add in this solution and above-mentioned weighed carrier, stand 1 hour after being sufficiently stirred for, dry after separating solvent, obtain SAN/Al₂O₃。

By SAN/Al obtained above₂O₃, joining in 1000ml deionized water, add 57.6g ethylenediamine, backflow 4h, after cooling, take out product, washing, to neutral, dry and obtains functionalized-SAN/Al₂O₃。

B、(Pd-Au)-SAN/Al₂O₃The preparation of presoma

Weighing appropriate Palladous nitrate., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 2.5, is configured to mixed solution, takes the functionalized-SAN/Al prepared₂O₃Presoma, by functionalized-SAN/Al₂O₃Join in the mixed solution prepared, stir 5min, pour out residual liquid, by above-mentioned product deionized water wash to neutral, obtain (Pd-Au)-SAN/Al after drying₂O₃Presoma.

C, catalyst preparation

By the presoma of above-mentioned preparation, at 500 DEG C of roasting 4h of air atmosphere, obtain Pd-Au/Al₂O₃Catalyst.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst D-2.Recording this catalyst Pd content is 0.038%, and Au content is 0.025%.

Adopting the C2 hydrogenation technique of methanol-to-olefins, its process chart as shown in Figure 1, adopts 500mL evaluating apparatus, and working condition is in Table 4, and raw material forms in Table 2.

Table 4 micro anti-evaluation parameter

Table 5 catalyst 1000h performance meansigma methods

Embodiment 3

Weighing Φ 3.0mm, specific surface area is 40.0m²/ g, pore volume is 0.18ml/g, and heap is than the tooth ball type carrier 500g, wherein θ-Al for 0.78g/ml₂O₃460g, titanium oxide 40g.

By 47.65g6,6'-dihydroxy-3,3'-bipyridyl is dissolved in 650mL alcoholic solution, by above-mentioned carrier impregnation in above-mentioned solution, after standing 12h, make 6,6'-dihydroxy-3,3'-bipyridyl loads to after on alumina support completely, 120 DEG C of dry 4h, obtains hydroxyl-bipyridyl/Al₂O₃Precursor.

Weighing appropriate Palladous chloride., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 3.2, is configured to mixed solution, by above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 60min, stands 8h, pours out residual liquid, and remaining solid is dry 4h at 120 DEG C, obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Au)=80).

By the presoma of above-mentioned preparation, 450 DEG C of roasting 6h in air atmosphere.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst S-3.Recording this catalyst Pd content is 0.042%, and Au content is 0.25%.

Comparative example 3

Catalyst preparing

Weighing Φ 3.0mm, specific surface area is 40.0m²/ g, pore volume is 0.18ml/g, and heap is than the tooth ball type carrier 500g, wherein θ-Al for 0.78g/ml₂O₃460g, titanium oxide 40g.

Weighing appropriate Palladous nitrate., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 3.2, it is configured to mixed solution, by concussion after this solution spraying to above-mentioned carrier 0.5 hour, after drying, in air atmosphere, 450 DEG C of roasting 6h obtain (Pd-Au)/Al₂O₃Catalyst.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst D-3.Recording this catalyst Pd content is 0.042%, and Au content is 0.25%.

Adopting the C2 hydrogenation technique of methanol-to-olefins, its process chart as shown in Figure 1, adopts 500mL evaluating apparatus, and working condition is in Table 4, and raw material forms in Table 2.

Table 6 micro anti-evaluation parameter

Table 7 catalyst 500h performance meansigma methods

Embodiment 4

Weighing Φ 4.0mm, high 4.0mm, specific surface area is 55.0m²/ g, pore volume is 0.45ml/g, and bulk density is cylindrical vector 500g, the Al of 0.76g/ml₂O₃Mixing crystal formation for δ and θ.

By 20.56g4,4-dihydroxy-2,2-bipyridyl is dissolved in 600mL alcoholic solution, by above-mentioned carrier impregnation in above-mentioned solution, after standing 10h, dihydroxy-2,2-bipyridyl is loaded to after on alumina support completely, and 100 DEG C of dry 6h obtain hydroxyl-bipyridyl/Al₂O₃Precursor.

Weighing appropriate Palladous chloride., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 3.7, is configured to mixed solution, by above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 60min, stands 10h, pours out residual liquid, and remaining solid dry 10h at 90 DEG C obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Au)=14).

By the presoma of above-mentioned preparation, 600 DEG C of roasting 2h in air atmosphere.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst S-4.Recording this catalyst Pd content is 0.018%, and Au content is 0.038%.

Comparative example 4

Weighing Φ 4.0mm, high 4.0mm, specific surface area is 55.0m²/ g, pore volume is 0.45ml/g, and bulk density is cylindrical vector 500g, the Al of 0.76g/ml₂O₃Mixing crystal formation for δ and θ.

A, functionalized polystyrene acrylonitrile (SAN)/Al₂O₃Preparation

Weighing SAN resin 2.2g, be dissolved in 600mLDMF (dimethylformamide) solvent, under room temperature, stirring makes SAN resin be completely dissolved, add in this solution and above-mentioned weighed carrier, stand 1 hour after being sufficiently stirred for, dry after separating solvent, obtain SAN/Al₂O₃。

By SAN/Al obtained above₂O₃, joining in 1000ml deionized water, add 57.6g ethylenediamine, backflow 4h, after cooling, take out product, washing, to neutral, dry and obtains functionalized-SAN/Al₂O₃。

B、(Pd-Au)-SAN/Al₂O₃The preparation of presoma

Weighing appropriate Palladous nitrate., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 3.7, is configured to mixed solution, takes the functionalized-SAN/Al prepared₂O₃Presoma, by functionalized-SAN/Al₂O₃Join Pd (NO₃)₂, AuCl4H mixed solution in, stir 5min, pour out residual liquid, by above-mentioned product deionized water wash to neutral, obtain (Pd-Au)-SAN/Al after drying₂O₃Presoma.

C, catalyst preparation

By the presoma of above-mentioned preparation, at 600 DEG C of roasting 2h of air atmosphere, obtain Pd-Au/Al₂O₃Catalyst.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst D-4.Recording this catalyst Pd content is 0.018%, and Au content is 0.038%.

Adopting the C2 hydrogenation technique of methanol-to-olefins, its process chart as shown in Figure 1, adopts 500mL evaluating apparatus, and working condition is in Table 8, and raw material forms in Table 2.

Table 8 micro anti-evaluation parameter

Table 9 catalyst 500h performance meansigma methods

Embodiment 5

Weighing Φ 3.0mm, specific surface area is 40.0m²/ g, pore volume is 0.18ml/g, and heap is than the tooth ball type carrier 500g, wherein θ-Al for 0.78g/ml₂O₃460g, titanium oxide 40g.

By 68.08g6,6'-dihydroxy-3,3'-bipyridyl is dissolved in 650mL alcoholic solution, by above-mentioned carrier impregnation in above-mentioned solution, after standing 12h, make 6,6'-dihydroxy-3,3'-bipyridyl loads to after on alumina support completely, 120 DEG C of dry 4h, obtains hydroxyl-bipyridyl/Al₂O₃Precursor.

Weighing appropriate Palladous chloride., gold chloride is dissolved in the 600mL deionized water containing appropriate hydrochloric acid, and adjusting pH is 3.2, is configured to mixed solution, by above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 60min, stands 8h, pours out residual liquid, and remaining solid is dry 4h at 120 DEG C, obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Au)=80).

By the presoma of above-mentioned preparation, 450 DEG C of roasting 6h in air atmosphere.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain support type palladium-gold catalyst S-3.Recording this catalyst Pd content is 0.042%, and Au content is 0.25%.

Comparative example 5

Weighing Φ 3.0mm, specific surface area is 40.0m²/ g, pore volume is 0.18ml/g, and heap is than the tooth ball type carrier 500g, wherein θ-Al for 0.78g/ml₂O₃460g, titanium oxide 40g.

Weighing appropriate Palladous nitrate., silver nitrate is dissolved in 10ml salpeter solution, adds 600mL deionized water, and adjusting pH is 3.2, is configured to mixed solution, by above-mentioned hydroxyl-bipyridyl/Al₂O₃Precursor joins the solution prepared, and stirs 60min, stands 8h, pours out residual liquid, and remaining solid is dry 4h at 120 DEG C, obtains PdAg-hydroxyl-bipyridyl/Al₂O₃Precursor (hydroxyl-bipyridyl molal quantity: (Pd+Ag)=80).

By the presoma of above-mentioned preparation, 450 DEG C of roasting 6h in air atmosphere.Being positioned over before using in fixed-bed reactor, be 99.9% by hydrogen purity, air speed is 200h^-1Gas, at 120 DEG C of temperature reduce, obtain load type palladium-silver catalyst D-5.Recording this catalyst Pd content is 0.060%, and Ag content is 0.14%.

Adopting the C2 hydrogenation technique of methanol-to-olefins, its process chart as shown in Figure 1, adopts 500mL evaluating apparatus, and working condition is in Table 4, and raw material forms in Table 10.

Table 10 micro anti-evaluation parameter

Table 11 catalyst 500h performance meansigma methods

Can be seen that, compared with adopting tradition preparation catalyst, with when active component content is identical, with organic polymer grafted functional group load on a catalyst support, the solution of this carrier impregnation activity Pd, Au obtaining the method for organic polymer metal complex again prepare catalyst and compare, have employed the method for hydrotreating of the present invention, the activity of hydrogenation reaction and selectivity are significantly better than traditional method of hydrotreating, Ethylene purity improves, such that it is able to improve the performance of polymer grade ethylene product very well.The reduction of green oil simultaneously so that the active center of catalyst is not covered by by-product, catalyst activity and selectivity are able to good maintenance, and catalyst extends service life.

Claims (13)

1. the front-end hydrogenation method of trace acetylene in a methanol-to-olefins device, before adiabatic reactor reactor for being hydrogenated with is positioned at domethanizing column or dethanizer, from the carbon one at the bottom of drying tower tower, carbon two and carbon 3 material in methanol-to-olefins device, enter adiabatic reactor reactor to carry out selecting hydrogenation, it is characterized in that: equipped with Pd-Au series catalysts in adiabatic reactor reactor, with Al₂O₃Or Al₂O₃Being carrier with other hopcalite, with the quality of catalyst for 100%, wherein Pd content 0.015～0.060%, Au content is 0.02～0.30%, and the specific surface area of catalyst is 20～60m²/ g, pore volume is 0.15～0.70mL/g；This catalyst, in preparation process, is combined with hydroxyl dipyridyl derivatives by carrier, and hydroxyl dipyridyl derivatives forms metal complex with active component；Reaction condition is: adiabatic reactor reactor inlet temperature 30 DEG C～50 DEG C, reaction pressure 1.5～3.0MPa, air speed 2000～15000h^-1。

2. front-end hydrogenation method according to claim 1, it is characterized in that catalyst preparation process, at least including: load on carrier by hydroxyl dipyridyl derivatives, the cation of the hydroxyl unnecessary again through hydroxyl dipyridyl derivatives and/or nitrilo and Pd, Au forms complex ion.

3. front-end hydrogenation method according to claim 2, it is characterised in that hydroxyl dipyridyl derivatives, it is preferred to hydroxyl 2,2 ,-dipyridyl derivatives or hydroxyl 3,3 ,-dipyridyl derivatives, it is preferred to hydroxyl 2,2 ,-dipyridyl derivatives.

4. front-end hydrogenation method according to claim 1, it is characterised in that the acquisition of catalyst comprises the steps: the organic solution with hydroxyl dipyridyl derivatives, impregnates carrier, obtains hydroxyl-bipyridyl/Al after drying₂O₃Precursor, the mixed solution dipping hydroxyl-bipyridyl/Al of preparation Pd, Au₂O₃Precursor, dry at 60 DEG C～150 DEG C, obtain PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor；At 300～600 DEG C of roasting temperature 2～12h, obtain required catalyst.

5. front-end hydrogenation method according to claim 1, it is characterised in that carrier mainly contains Al₂O₃, wherein also doped with other hopcalite, other oxide is silicon oxide, titanium oxide, magnesium oxide and/or calcium oxide；Described Al₂O₃For γ, δ, θ, α or wherein several mixing crystal formations, it is desirable to for θ, α or its mixing crystal formation.

6. front-end hydrogenation method according to claim 1, it is characterised in that carrier is spherical, cylinder, annular, bar shaped, cloverleaf pattern or Herba Galii Bungei shape.

7. according to the arbitrary described front-end hydrogenation method of claim 1-6, it is characterised in that the preparation method of catalyst comprises the steps:

A. hydroxyl-bipyridyl/Al₂O₃The preparation of precursor

The organic solution of hydroxyl dipyridyl derivatives mixes with carrier, reacts 2～24h, take out solid particle at 20 DEG C～60 DEG C temperature, dry at 60 DEG C～150 DEG C, obtains hydroxyl-bipyridyl/Al₂O₃Precursor；

B.PdAu-hydroxyl-bipyridyl/Al₂O₃The preparation of precursor

The mixed solution of preparation Pd, Au, with step A gained hydroxyl-bipyridyl/Al at 30 DEG C～100 DEG C temperature₂O₃Precursor reaction 2～24h, takes out solid particle, dry at 60 DEG C～150 DEG C, obtains PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor；

C. the preparation of catalyst

PdAu-hydroxyl-bipyridyl/Al prepared by step B₂O₃Precursor is at 300～600 DEG C of roasting temperature 2～12h so that PdAu-hydroxyl-bipyridyl/Al₂O₃Precursor is changed into corresponding metal composite oxide, obtains catalyst.

8. front-end hydrogenation method according to claim 7, it is characterised in that in step A, the molal quantity of hydroxyl-bipyridyl/(Pd+Au) is 1～100:1.

9. front-end hydrogenation method according to claim 7, it is characterised in that in stepb, the mixed solution of Pd, Au is the mixed solution of Palladous chloride. and gold chloride.

10. front-end hydrogenation method according to claim 7, it is characterised in that in stepb, the ratio of the molal quantity of Au and the molal quantity of Pd is 0.5～7:1.

11. front-end hydrogenation method according to claim 7, it is characterised in that in stepb, the mixed solution pH value regulating Pd, Au is 1.5～4.0.

12. front-end hydrogenation method according to claim 1, it is characterised in that adiabatic reactor reactor reaction bed number is single hop bed.

13. front-end hydrogenation method according to claim 1, it is characterised in that hydrogen and acetylene volume ratio are 2～6:1.