CN103084170A - C3 fraction selective hydrogenation catalyst, preparation method and applications thereof - Google Patents

Abstract

The present invention provides a C3 fraction selective hydrogenation catalyst, a preparation method and applications thereof. According to the present invention, active components of the catalyst are prepared through a microemulsion method, and are loaded on a carrier, and the prepared main active component Pd of the catalyst has characteristics of small particle size, controllable particle size, and good dispersion, wherein the particle size is less than 10 nm; the catalyst preparation method has characteristics of simpleness, easy operation, and mile preparation conditions; and with application of the catalyst in selective hydrogenation reactions of propyne and allene in cracking product C3 fractions, high activity and high selectivity are provided.

Description

A kind of C 3 fraction selective hydrogenation catalyst and its preparation method and application

Technical field

The invention belongs to a kind of C 3 fraction selective hydrogenation catalyst and its preparation method and application, relate in particular to a kind of microemulsion method that utilizes and select hydrogenation to generate supported selective hydrogenation catalyst of propylene and its preparation method and application for the preparation of propine and allene in the pyrolysis product C3 fraction.

Background technology

Petroleum hydrocarbon contains propylene after separating through cracking, propane, and a small amount of propine and allene (being called for short MAPD), and propine and allene are about 1%～5% (volume content) in C3 fraction.Can reduce the activity of polypropylene catalyst due to impurity MAPD, affect the quality of polymerization product, therefore the content of MAPD need to be removed to certain level.Industrial widely used acetylene removal method is the catalysis selective hydrogenation method at present.

Patent CN 100512955C has announced a kind of alkynes and diolefin hydrogenate Catalysts and its preparation method, be coated on the inert carrier outer surface by aluminum oxide coating layer, catalyst master active component and help active component only to be distributed on the aluminum oxide coating layer of catalyst surface has improved the hydrogenation efficiency of catalyst activity component.But the activity and selectivity of catalyst is still unsatisfactory.

Patent CN 101875009A has announced a kind of Catalysts and its preparation method for C3 fraction propylene and the standby propylene of allene selection Hydrogenation, the catalyst activity component precursor loads on carrier by the impregnating method, process by ionising radiation, metal active constituent is by direct-reduction, can directly put into production, not need to use hydrogen reducing.But the activity and selectivity of catalyst is still unsatisfactory.

Show the characteristics such as quantum size effect, bulk effect, surface and interface effect, quantum size tunnel-effect due to nano particle, make nano-particle catalyst show good characteristic.The method for preparing nano particle mainly comprises steam condensing method, mechanochemical reaction, sol-gel process, the precipitation method, hydro-thermal method, irradiation method, microemulsion method etc.Wherein microemulsion method as a kind of effective ways that prepare nano particle, is wrapped to form the drop of microemulsion by the interfacial film of surfactant and cosurfactant composition, by adjusting the consumption of water and surfactant, can control the particle diameter of nano particle.The advantages such as microemulsion method has the experiment condition gentleness, and equipment is simple, and particle diameter is controlled.

Summary of the invention

For the problems of the prior art, the purpose of this invention is to provide and a kind ofly select hydrogenation to generate supported selective hydrogenation catalyst of propylene and its preparation method and application for pyrolysis product C3 fraction propine and allene, the catalyst that the method makes has higher activity and selective preferably.

One of the object of the invention is to provide a kind of C 3 fraction selective hydrogenation catalyst, this catalyst is used for pyrolysis product C3 fraction propine and allene selects hydrogenation to generate the reaction of propylene, comprise carrier and the active component that is carried on carrier, the active component of described catalyst is utilize the microemulsion method preparation and get.

Described carrier is Al ₂O ₃, SiO ₂, ZnO, TiO ₂, V ₂O ₅, SnO ₂In one or both and two or more mixtures.The bar shapeds such as that preferred vector is shaped as is granular, spherical, profile of tooth, annular, tooth are spherical, sheet shape, bar shaped or clover.

Described active component comprises main active component and/or helps active component;

Described main active component is the simple substance palladium, and palladium content is the 0.01wt%～2.0wt% of described carrier gross weight, is preferably the 0.05wt%～0.5wt% of total weight of carrier;

The described active component that helps is one or more in La, Ag, Au, Bi, Cu, Sn, Cs, Ge, alkali metal, and content is the 0.0wt%～10.0wt% of described carrier gross weight, is preferably the 0.0wt%～5.0wt% of total weight of carrier.

The grain diameter of described main active component is less than 10nm;

In described catalyst of the present invention, active component is adopt microemulsion method to prepare and get, and is carried on carrier, comprises the following steps:

(1) preparation microemulsion: in water bath with thermostatic control, the water, cosurfactant, the oil phase that are comprised of the salting liquid of non-ionic surface active agent, catalyst activity component mix in proportion, stir the stable w/o type microemulsion system of preparation, the mass ratio of each component is non-ionic surface active agent: cosurfactant: oil phase: salting liquid=1: x: y: z, wherein x is 0.1～5, y is that 0.1～10, z is 0.1～4;

(2) reduction: reducing agent is joined in the microemulsion that step (1) makes, and the mol ratio of reducing agent and salt is (1～10): 1;

(3) load: the catalyst activity component that step (2) reduction is fully obtained loads on carrier;

(4) microemulsion that step (3) is made is dry, roasting obtains C 3 fraction selective hydrogenation catalyst of the present invention.

Wherein said non-ionic surface active agent is at least a in TX-100, Tween85, Tween80, Tween60, Tween20, Span80, Span40, NP-10, NP-4, OP-10; Described cosurfactant is C ₃～C ₈Alcohols, more preferably from normal propyl alcohol, isobutanol, n-amyl alcohol, a kind of in isooctanol; Described oil phase is selected from C ₆～C ₁₂Linear paraffin, cyclic alkane, branched paraffin at least a, more preferably from cyclohexane, n-hexane, isooctane; Described salting liquid is selected from a kind of in described nitrate, sulfate, chloride, acetate.

Reduction reaction temperature in step (2) is 0～60 ℃, and described reducing agent is at least a in hydrazine hydrate, metal hydroboron, hydrogen, sodium hypophosphite, aromatic aldehyde, fatty aldehyde.

The catalyst activity component that above-mentioned reduction is fully obtained loads on carrier by conventional methods such as dipping, sprayings, and more preferably the catalyst activity component of described microemulsion preparation loads on carrier by a step dipping or step impregnation.

The present invention has adopted the microemulsion method preparation loaded catalyst that combines with catalyst preparation process, mix by the surfactant in microemulsion and cosurfactant the size that the interfacial film that forms is controlled water core, namely control the particle diameter of metal active constituent in microemulsion system, then by the method for flooding or spray, metal active constituent is loaded to and be prepared into loaded catalyst on carrier, can obtain the different metal nanoparticle of particle diameter by the ratio of adjusting water and surfactant.By the method for microemulsion Kaolinite Preparation of Catalyst of the present invention, form the particle diameter of nano particle in microemulsion by the demonstration of high resolution transmission electron microscopy (TEM) test result, the particle diameter＜10nm of the nano particle of formation can be with reference to accompanying drawing 1.

Another object of the present invention is to provide a kind of method for preparing C 3 fraction selective hydrogenation catalyst.In the method, the aqueous solution of activity component metal salt is dispersed in oil phase through non-ionic surface active agent and cosurfactant parcel, mode by dipping, spraying after the reducing agent reduction loads on carrier, and the metal nanoparticle average diameter that forms in microemulsion is less than 10nm.Specifically comprise the following steps:

(1) preparation microemulsion: in water bath with thermostatic control, the water, cosurfactant, the oil phase that are comprised of the salting liquid of non-ionic surface active agent, catalyst activity component mix in proportion, stir the stable w/o type microemulsion system of preparation, the mass ratio of each component is non-ionic surface active agent: cosurfactant: oil phase: salting liquid=1: x: y: z, wherein x is 0.1～5, y is that 0.1～10, z is 0.1～4;

(2) reduction: reducing agent is joined in the microemulsion that step (1) makes, and the mol ratio of reducing agent and salt is (1～10): 1;

(3) load: the catalyst activity component that step (2) reduction is fully obtained loads on carrier;

(4) microemulsion that step (3) is made is dry, roasting obtains C 3 fraction selective hydrogenation catalyst of the present invention.

The 3rd purpose of the present invention is to provide this catalyst propine and allene in the pyrolysis product C3 fraction and selects hydrogenation to generate application in the reaction of propylene.

The present invention compared with prior art has the following advantages:

(1) preparation method of the present invention is simple, and is easy to operate, and experiment condition is gentle.

(2) C 3 fraction selective hydrogenation catalyst of the present invention's preparation is prepared from because adopting microemulsion method, and its particle diameter is controlled, evenly, good dispersion, good stability has improved the activity and selectivity of catalyst in reaction significantly.

Description of drawings

Fig. 1 is the distribution of catalyst nanoparticles in microemulsion system

The specific embodiment

The present invention will be further described below in conjunction with specific embodiment, but the present invention is not limited in following embodiment.

Embodiment 1

Take the Pd (NO of 100mg/ml ₃) ₂Solution 2.17ml uses deionized water to be diluted to 5ml, and 25 ℃ are mixed 13.8mlTween80 and 17.73ml isopropyl alcohol under magnetic agitation in water bath with thermostatic control, and then add the Pd (NO of dilute with water with the 20ml cyclohexane ₃) ₂Solution, the magnetic agitation certain hour is until obtain transparent microemulsion; Add in the above-mentioned microemulsion a certain amount of hydrazine hydrate to make Pd (NO in microemulsion ₃) ₂Be reduced into simple substance Pd; Take 100g Al ₂O ₃Carrier is impregnated into the microemulsion after reduction on carrier.Then dry, roasting is prepared into described catalyst A, and wherein Pd content is 0.1wt%.

Embodiment 2

Take the PdCl of 200mg/ml ₂Solution 1.23ml, use deionized water to be diluted to 5ml, 25 ℃ are mixed 14.2ml TX-100 and 18.23ml n-butanol under magnetic agitation in water bath with thermostatic control with the 25ml normal octane, and then add the metal salt solution of dilute with water, and the magnetic agitation certain hour is until obtain transparent microemulsion; Add in the above-mentioned microemulsion a certain amount of hydrazine hydrate to make PdCl in microemulsion ₂Be reduced into simple substance Pd; Take 100gTiO ₂Carrier is impregnated into the microemulsion after reduction on carrier.Then dry, roasting is prepared into described catalyst B, and wherein Pd content is 0.15wt%.

Embodiment 3

Take the Pd (NO of 200mg/ml ₃) ₂Solution 1.62ml, the AgNO of 300mg/ml ₃Solution 1.57ml uses deionized water to be diluted to 5ml.20 ℃ are mixed 10mlNP-10 and 5ml n-amyl alcohol under magnetic agitation in water bath with thermostatic control with the 30ml cyclohexane, and then add the metal salt solution of dilute with water, the magnetic agitation certain hour is until obtain transparent microemulsion, adds in the above-mentioned microemulsion a certain amount of potassium borohydride to make the metal ion in metal salt solution in microemulsion be reduced into the simple substance state.Take 100gAl ₂O ₃Carrier sprays to the microemulsion after reduction on carrier, and then dry, roasting is prepared into described catalyst C.Wherein Pd content is 0.15wt%.Wherein Ag content is 0.3wt%.

Embodiment 4

Take the Pd (NO of 100mg/ml ₃) ₂Solution 2.17ml adds the Cu (NO of 100mg/ml ₃) ₂Solution 3.77ml adds the La (NO of 200mg/ml ₃) ₃Solution 1.56ml, use deionized water to be diluted to 10ml, 25 ℃ are mixed 10ml OP-10 and 5ml normal propyl alcohol under magnetic agitation in water bath with thermostatic control with the 25ml normal heptane, and then add the metal salt solution of dilute with water, and the magnetic agitation certain hour is until obtain transparent microemulsion; Add in the above-mentioned microemulsion a certain amount of hydrazine hydrate to make the metal ion in metal salt solution in microemulsion be reduced into the simple substance state; Take 100g Al ₂O ₃Carrier sprays to the microemulsion after reduction on carrier.Then dry, roasting is prepared into described catalyst D, and wherein Pd content is 0.1wt%, and wherein Cu content is 0.1wt%, and wherein La content is 0.1wt%.

Embodiment 5

Take the Pd (NO of 200mg/ml ₃) ₂Solution 1.62ml adds the HAuCl of 200mg/ml ₄Solution 2.09ml, use deionized water to be diluted to 5ml, 25 ℃ are mixed 10mlTween60 and 10ml n-hexyl alcohol under magnetic agitation in water bath with thermostatic control with the 25ml normal octane, and then add the metal salt solution of dilute with water, and the magnetic agitation certain hour is until obtain transparent microemulsion; Add in the above-mentioned microemulsion a certain amount of hydrazine hydrate to make the metal ion in metal salt solution in microemulsion be reduced into the simple substance state.Take 100g Al ₂O ₃Carrier sprays to the microemulsion after reduction on carrier, and then dry, roasting is prepared into described catalyst E, and wherein Pd content is 0.1wt%, and wherein Au content is 0.1wt%.

Embodiment 6

Take the Pd (NO of 200mg/ml ₃) ₂Solution 2.17ml, the AgNO of 100mg/ml ₃Solution 1.57ml adds the Bi (NO that contains 100mg/ml ₃) ₃5H ₂O solution 2.32ml uses deionized water to be diluted to 10ml; 25 ℃ are mixed 10mlTween80 and 5ml n-hexyl alcohol under magnetic agitation in water bath with thermostatic control with the 25ml cyclohexane, and then add the metal salt solution of dilute with water, and the magnetic agitation certain hour is until obtain transparent microemulsion; Add in the above-mentioned microemulsion a certain amount of hydrazine hydrate to make the metal ion in metal salt solution in microemulsion be reduced into the simple substance state.Take 100g Al ₂O ₃Carrier sprays to the microemulsion after reduction on carrier, and then dry, roasting is prepared into described catalyst F, and wherein Pd content is 0.2wt%, and wherein Ag content is 0.1wt%, and wherein Bi content is 0.1wt%.

Comparative Examples

Take the Pd (NO of 100mg/ml ₃) ₂Solution 6.5ml, the AgNO of 100mg/ml ₃Solution 1.57ml uses deionized water dilution 50ml, takes 100gAl ₂O ₃Carrier adds the standing 30min of the metal salt solution of dilution, drying, and roasting obtains catalyst G.Wherein Pd content is 0.3wt%, and wherein Ag content is 0.3wt%.

Evaluation test

Above-mentioned catalyst A, B, C, D, E, F, G are carried out C3 fraction propine and allene selective hydrogenation reaction, and reaction condition is as follows:

The 1ml catalyst is packed in the stainless steel tube reactor, after using nitrogen replacement, individual hour of 180 ℃ of reductase 12s of hydrogen, then unstripped gas is passed in reactor, the composition of reaction raw materials (molar fraction) is: the mol ratio of propane 4.99%, propylene 92.3%, allene 1.19%, propine 1.39%, hydrogen and propine and allene (MAPD) is 1.4～1.6.The experiment air speed is 10000h ^-1With each catalyst reaction to the computational methods of the conversion ratio (Conversion) of (MAPD) and selective (Selectivity) be:

$\mathrm{MAPD\; Conversion}=\frac{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}-{\left(\mathrm{MAPD}\right)}_{\mathrm{out}}}{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}}\×100\%$

$\mathrm{MAPD\; Selectivity}=\frac{{\left(C_2{H}_6\right)}_{\mathrm{out}}-{\left(C_2{H}_6\right)}_{\mathrm{in}}}{{\left(\mathrm{MAPD}\right)}_{\mathrm{in}}-{\left(\mathrm{MAPD}\right)}_{\mathrm{out}}}\×100\%$

The reactivity worth of table 1 catalyst

Experimental result shows, the load capacity of catalyst metals active component Pd of the present invention is low, but is hydrogenated into the reaction of propylene for MAPD, compares with Comparative Examples, and catalyst of the present invention has higher active and selective.

Claims (10)

1. one kind prepares C 3 fraction selective hydrogenation catalyst, comprises carrier and the active component that is carried on carrier, it is characterized in that:

Described carrier is Al ₂O ₃, SiO ₂, ZnO, TiO ₂, V ₂O ₅, SnO ₂, at least a in SiC, kaolin;

Described active component comprises main active component and/or helps active component;

Described main active component is the simple substance palladium, and palladium content is the 0.01wt%～2.0wt% of described carrier gross weight;

The described active component that helps is at least a in La, Ag, Au, Bi, Cu, Sn, Cs, Ge, alkali metal, and the content that helps active component is the 0.0wt%～10.0wt% of total weight of carrier.

The grain diameter of described main active component is less than 10nm;

Active component in described catalyst is adopt microemulsion method to prepare and get, and is carried on carrier.

2. C 3 fraction selective hydrogenation catalyst according to claim 1, is characterized in that described palladium content is the 0.05wt%～0.5wt% of described carrier gross weight.

3. C 3 fraction selective hydrogenation catalyst according to claim 1, is characterized in that the described active component content that helps is the 0.0wt%～5.0wt% of described carrier gross weight.

4. C 3 fraction selective hydrogenation catalyst according to claim 1, the specific area that it is characterized in that described carrier is 1～200m ²/ g, its face shaping are that spherical, profile of tooth, annular, tooth are spherical, granular, sheet, strip, clover or bunge bedstraw herb.

5. C 3 fraction selective hydrogenation catalyst according to claim 1 is characterized in that described catalyst adopts the microemulsion preparation method in preparation process, comprise the following steps:

(1) preparation microemulsion: in water bath with thermostatic control, the water, cosurfactant, the oil phase that are comprised of the salting liquid of non-ionic surface active agent, catalyst activity component mix in proportion, stir the stable w/o type microemulsion system of preparation, the mass ratio of each component is non-ionic surface active agent: cosurfactant: oil phase: salting liquid=1: x: y: z, wherein x is 0.1～5, y is that 0.1～10, z is 0.1～4;

(2) reduction: reducing agent is joined in the microemulsion that step (1) makes, and the mol ratio of reducing agent and salt is (1～10): 1;

(3) load: the catalyst activity component that step (2) reduction is fully obtained loads on carrier;

(4) microemulsion that step (3) is made is dry, roasting obtains C 3 fraction selective hydrogenation catalyst of the present invention.

6. C 3 fraction selective hydrogenation catalyst according to claim 5, it is characterized in that described non-ionic surface active agent is at least a in TX-100, Tween85, Tween80, Tween60, Tween20, Span80, Span40, NP-10, NP-4, OP-10, described cosurfactant is C ₃～C ₈Alcohols, described oil phase is C ₆～C ₁₂Linear paraffin, cyclic alkane, branched paraffin at least a, described salting liquid is at least a in the nitrate, sulfate, chloride, acetate of noble metal.

7. C 3 fraction selective hydrogenation catalyst according to claim 5, is characterized in that described cosurfactant is normal propyl alcohol, isobutanol, and n-amyl alcohol, isooctanol, described oil phase are cyclohexane, n-hexane, isooctane.

8. C 3 fraction selective hydrogenation catalyst according to claim 5, the reduction reaction temperature that it is characterized in that described step (2) is 0～60 ℃, and described reducing agent is at least a in hydrazine hydrate, metal hydroboron, hydrogen, sodium hypophosphite, aromatic aldehyde, fatty aldehyde.

9. the preparation method of the described C 3 fraction selective hydrogenation catalyst of one of claim 1-8 comprises the following steps:

(1) preparation microemulsion: in water bath with thermostatic control, the water, cosurfactant, the oil phase that are comprised of the salting liquid of non-ionic surface active agent, catalyst activity component mix in proportion, stir the stable w/o type microemulsion system of preparation, the mass ratio of each component is non-ionic surface active agent: cosurfactant: oil phase: salting liquid=1: x: y: z, wherein x is 0.1～5, y is that 0.1～10, z is 0.1～4;

(2) reduction: reducing agent is joined in the microemulsion that step (1) makes, and the mol ratio of reducing agent and salt is (1～10): 1;

(3) load: the catalyst activity component that step (2) reduction is fully obtained loads on carrier;

(4) microemulsion that step (3) is made is dry, roasting obtains selective hydrogenation catalyst.

10. C 3 fraction selective hydrogenation catalyst claimed in claim 1 is applied in C3 fraction propine and allene and selects hydrogenation to generate the reaction of propylene.

Images