CN1958155A - Selective hydrogenation catalyst of alkine and diolefin, preparation method and application - Google Patents

Abstract

A selective hydrocatalyst for the alkine and diolefin in C2-10 fraction is composed of a inertial carrier chosen from silicon carbide, talc powder and fire-proof earth and a coated alumina layer containing Pd, Ag, Bi and at least one of Cu, Zn, alkali metal, AE metal and RE element. Its preparing process is also disclosed.

Description

A kind of alkynes and diolefin hydrogenate catalyst and preparation and application

Technical field

The present invention relates to a kind of for C2～C10 cut alkynes and diolefin hydrogenate Catalysts and its preparation method. Be particularly related to a kind of scribbling on the inert carrier surface with the palladium of the aluminium oxide coating of active component and select hydrogenation catalyst and preparation method thereof.

Technical background

At the petrochemical industry industrial circle, contain 0.3～3% acetylene in the cracking centrifugal station in the ethene cut, this acetylene impurity is the poisonous substance of polyethylene catalyst, affects normally carrying out of vinyl polymerization reaction. For fear of the generation that above-mentioned vinyl polymerization catalyst poisoning phenomenon occurs, usually adopt catalyst to select the method for hydrogenation to make the acetylene in the ethene cut be converted into ethene. But selecting hydrogenation except in the reaction of acetylene, being adsorbed on acetylene on the catalyst surface is easy to the degree of depth and is hydrogenated to ethane, or by hydrogenation dimerization reaction generation 1, the unsaturated C4 hydrocarbon such as 3-butadiene, and they continue reaction again, generate C6～C24 high polymer, be commonly called as green oil, green oil sticks to alkynes and selects can cause catalysqt deactivation on the hydrogenation catalyst.

Usually, the major catalyst of alkynes and diolefin hydrogenate catalyst is take the noble metal palladium as main, add different co-catalysts, such as silver (US6465391), gold (US6509292), alkali metal and alkaline-earth metal (US6576586) and copper (US66275798), platinum (US6462244), bismuth (US6459008) etc., these co-catalysts are arranged to the crystal structure of adjusting major catalyst and outer-shell electron and are played certain facilitation, can also suppress the carrying out of alkynes hydrogenation side reaction simultaneously.

As everyone knows, the carrier material for alkynes and diolefin hydrogenate catalyst comprises aluminium oxide (CN12798126A), reticular fiber structure aluminium oxide (US6388150), silica (US5856262), titanium dioxide, ceria (US4906602), zirconia, CaCO₃, diatomite and honeycomb cordierite (CN1176291), wherein general with alumina support, compare with other carrier, it is simple and direct that alumina support has the preparation method, the characteristics that production cost is low, and the variation of the crystal phase structure of aluminium oxide is more, and the controllability of duct size, pore structure and the specific area of formation carrier is stronger, and the skeleton structure of simultaneous oxidation aluminium is combined closely with the active component of catalyst.

Be coated with the active oxidation aluminized coating that contains catalytic active component at ceramic honey comb or metallic carrier and in the catalytic purification of automobile and internal combustion engine tail gas, obtained certain application. The Main Function of this catalyst is that carbon monoxide, hydro carbons and hydro carbons containing oxygen derivative are oxidized to carbon dioxide and water by catalytic combustion. The ceramic honey comb of this combustion catalyst or the passage of metallic carrier are as the mobile pipe of locomotive waste, and they are to have the regulation shape of vertical in the circle in carrier cross section, square or foam-like passage. Because aluminium oxide itself the high specific area, fire-resistant, the resistant to elevated temperatures performance that have are coated in it on ceramic honey comb or the metallic carrier as coating, can disperse well, the supported catalyst active component. This catalyst adopts double-deck carrier load form (US6294140) take platinum, rhodium as major catalyst, the high-performance catalyst (US6524992) of individual layer load and employing base metal chromium, copper, nickel have substituted platinum, rhodium noble metal as major catalyst combustion catalyst (US5534475) also occurred recently.

Infusion process is adopted in the preparation of traditional alkynes and diolefin hydrogenate catalyst more, it mainly is the salting liquid dipping solid carrier by major catalyst Pd and co-catalyst silver etc., metal ion enters along the duct of carrier, and the metal ion that has can be moved to the carrier center.

The research of alkynes selective hydrogenation reaction process is found that the selective hydrogenation reaction major part concentrates on the Pd in catalyst coating duct, and then utilization rate is very low to be in the hydrogenation reaction of Pd of depths, duct. Because even acetylene molecule can enter the depths, duct, also cause easily the reactions such as acetylene secondary hydrogenation, oligomerisation, block the duct, reduce reactivity and selective.

Alkynes selects hydrogenation catalyst mostly to contain precious metals pd, Ag and Au etc., because the part noble metal is distributed in carrier inside, reduced the due activity of catalyst coating and selective, therefore need the extra precious metal ion that adds, thereby the activity that guarantees catalyst coating has formed.

Summary of the invention

An object of the present invention is to provide a kind of catalyst that is used for C2～C10 cut alkynes and diolefin hydrogenate with the aluminium oxide coating, wherein major catalyst Pd and co-catalyst only are distributed in the aluminium oxide coating of catalyst coating, and the thickness of aluminium oxide coating only has 10～300 microns.

Another object of the present invention has provided the method for preparing catalyst of the present invention, has reduced the consumption of major catalyst Pd and co-catalyst Ag etc.

In order to achieve the above object, the inventor has carried out intensive research. In conjunction with the research of combustion catalyst is found that inert carrier generally only plays the effect of matrix, its specific area is almost nil, intensity is high, and chemistry, physical property are stable. Activated alumina is coated in the surface as coating, can not slacken because of the change of external condition the combination of coating and inert carrier, and the catalytic active component that is present in the aluminium oxide coating can not migrate in the inert carrier yet, guaranteed the total amount of the active component on carrier surface. Because the thickness of aluminium oxide coating only has 10～300 microns, major catalyst Pd and co-catalyst can both be participated in the selective hydrogenation reaction of alkynes and alkadienes completely, improved the hydrogenation efficiency of catalyst activity component, than the traditional catalyst major catalyst or the consumption of co-catalyst all decreases, thereby reduce production costs.

The invention provides a kind of for C2～C10 cut alkynes and diolefin hydrogenate catalyst, described catalyst comprises inert carrier, aluminium oxide coating, catalyst activity component, the catalyst activity component is present in the aluminium oxide coating, the catalyst activity component comprises the major catalyst palladium and co-catalyst is silver-colored, bismuth, and at least a copper, zinc, alkali metal, alkaline-earth metal, rare earth element, wherein:

Inert carrier is selected from carborundum, talcum powder, seat clay, and that its shape is selected from is granular, spherical, profile of tooth, annular, tooth are spherical, sheet or strip, and its specific surface is less than 10m²/g；

The aluminium oxide coating is in the inert carrier outer surface, and thickness is 10～500 microns, and its specific area is at 1～200m²/g；

In the catalyst activity component, the percentage by weight of major catalyst palladium and inert carrier (following percentage is all the percentage by weight with inert carrier) counts 0.001～1.0%.

Particularly, the preferred carborundum of inert carrier or talcum powder, its shape preferably granular, spherical, annular, tooth is spherical, strip, its specific surface is preferably less than 5m²/ g. The aluminium oxide coating is in the inert carrier outer surface, and thickness is preferably 10～300 microns, and its specific area is preferably 5～120m²/g。

The major catalyst palladium content that is present in the aluminium oxide coating is preferably 0.01～0.05%.

Being present in co-catalyst in the aluminium oxide coating and the percentage by weight of inert carrier is 0.002～14%. The co-catalyst silver content that is present in the aluminium oxide coating is preferably 0.001～8%, and the co-catalyst bi content that is present in the aluminium oxide coating is preferably 0.001～5%.

Described alkali metal can be potassium, sodium, rubidium, caesium, and alkaline-earth metal can be calcium, magnesium, strontium, barium, and rare earth element can be lanthanum, neodymium, cerium.

Of the present invention for C2～C10 cut alkynes and diolefin hydrogenate catalyst, can be applied in the C2 cut of cracking separative element in the petrochemical industry except in acetylene reaction (comprising front-end hydrogenation flow process, back end hydrogenation flow process), the C3 cut except propine and allene reaction, and the high-carbon chain hydrocarbon is (among the C4～C10) except alkynes and alkadienes reaction.

The preparation method of catalyst of the present invention: by with containing 1～30 % by weight aluminium oxide colloidal solution, add acid-conditioning solution and under pH=2～6 conditions, flood inert carrier, at 60～300 ℃ after 3-30 hour drying, be cooled to room temperature 300～1200 ℃ of calcinings after 4～20 hours, obtain the inert carrier with the aluminium oxide coating, then with contain palladium solution and contain the solution total immersion of co-catalyst composition or step impregnation in the aluminium oxide coating on inert carrier surface, 100～300 ℃ after 5～24 hours dryings, made in 4～20 hours 350～650 ℃ of calcinings.

Catalyst of the present invention can also adopt another kind of preparation method: by with the solution that contains palladium solution, contains the co-catalyst composition with contain that 1～30 % by weight aluminium oxide colloidal solution is even and mix after, add acid-conditioning solution and under pH=2～6 conditions, flood inert carrier, 60～300 ℃ after 5-30 hour drying, made in 4～20 hours 300～1200 ℃ of calcinings.

Particularly, the colloid of described aluminium oxide is that the aqueous solution with high pure alumina makes; The acid that adds is selected from nitric acid, acetic acid, citric acid, hydrochloric acid; Contain palladium solution and be selected from palladium bichloride, palladium nitrate, palladium solution; The solution of argentiferous is selected from silver nitrate, silver perchlorate solution in the co-catalyst; Bismuth-containing solution is selected from bismuth nitrate, bismuth chloride solution.

Of the present invention for C2～C10 cut alkynes and diolefin hydrogenate catalyst, because the thickness of aluminium oxide coating only has 10～300 microns, major catalyst Pd and co-catalyst can both be participated in the selective hydrogenation reaction of alkynes and alkadienes completely, improved the hydrogenation efficiency of catalyst activity component, than conventional catalyst catalyst major catalyst or the consumption of co-catalyst all decreases, thereby reduce production costs.

The specific embodiment

The invention is further illustrated by the following examples, to deepen the understanding of the present invention. Invention itself is not subjected to the restriction of these embodiment. Content among each embodiment is the percentage by weight with inert carrier.

Embodiment 1

To contain 5g Al₂O ₃20% Al₂O ₃Colloidal solution is used HNO₃Adjust pH=3.5, take by weighing 100g SiC annular carrier and impregnated in the colloidal solution for preparing, at 120 ℃ of dry 24h, it is stand-by then to be cooled to room temperature behind 300 ℃ of calcining 8h. The PdCl that will contain 0.02g Pd₂Solution contains the AgNO of 0.1g Ag₃Solution contains the Bi (NO of 0.1g Bi₃) ₂Solution contains the Ca (NO of 0.01g Ca₃) ₂The carrier that step impregnation is stand-by, behind a kind of element of every dipping all should 150 ℃ dry through 24h, obtain catalyst A at 600 ℃ of calcining 8h at last, wherein Pd content is that 0.03%, Ag content is that 0.1%, Bi content is that 0.1%, Ca content is 0.01%.

Embodiment 2

Containing 10g Al₂O ₃5% Al₂O ₃In the colloidal solution, add HNO₃Adjust pH=2.5, take by weighing 100g SiC annular carrier dipping, at 200 ℃ of dry 8h, it is stand-by to be cooled to room temperature behind 300 ℃ of calcining 15h. Stand-by carrier be impregnated in first in the nitrate solution that contains 0.01g Ag, 0.05g Bi, 0.02g La, at 200 ℃ of dry 8h, and then this carrier be impregnated in the chloride salting liquid that contains 0.05g Pd, 0.005g Ca, 0.005g Sr and 0.02g K, at 200 ℃ of dry 8h, 300 ℃ of calcining 15h obtain catalyst B, wherein Pd content is 0.05%, Ag content is 0.01%, Bi content is 0.05%, Ca content is 0.005%, K content is that 0.02%, Sr content is that 0.005%, La content is 0.02%.

Embodiment 3

Containing 6g Al₂O ₃30% Al₂O ₃In the colloidal solution, use HNO₃Adjust pH=4.2, take by weighing 100g talcum powder annular carrier and impregnated in the solution for preparing, at 100 ℃ of dry 13.5h, it is stand-by then to be cooled to room temperature behind 780 ℃ of calcining 20h. Pd (the NO that will contain again 0.01g Pd₃) ₂, contain the AgNO of 0.5g Ag₃, contain the Bi (NO of 0.5g Bi₃) ₂, contain the Cu (NO of 0.05g Cu₃) ₂, contain the NaNO of 0.05g Na₃Be made into mixed solution, stand-by carrier be impregnated in the mixed solution, at 135 ℃ of dry 30h, then behind 550 ℃ of calcining 20h, obtain catalyst C. Wherein Pd content is that 0.01%, Ag content is that 0.5%, Bi content is that 0.5%, Cu content is that 0.05%, Na content is 0.05%.

Embodiment 4

Containing 3g Al₂O ₃25%Al₂O ₃In the colloidal solution, add the CsCl that contains 0.05g Cs₂, mixed solution is made in dissolving, behind HCl adjustment pH=5.5, and dipping 100g granular refractory soil, at 240 ℃ of dry 18h, it is stand-by then to be cooled to room temperature behind 1000 ℃ of calcining 20h. Pd (the NO that will contain again 0.02g Pd₃) ₂, contain the AgNO of 0.02g Ag₃, contain the Bi (NO of 0.01g Bi₃) ₂Be made into mixed solution, stand-by carrier be impregnated in the mixed solution, at 140 ℃ of dry 20h, then behind 600 ℃ of calcining 20h, obtain catalyst D. Wherein Pd content is that 0.02%, Ag content is that 0.02%, Bi content is that 0.01%, Cs content is 0.05%.

Embodiment 5

Containing 5.5g Al₂O ₃31% Al₂O ₃In the colloidal solution, adjust pH=3.7 with acetic acid, take by weighing 100g SiC bead-type substrate and impregnated in the solution for preparing, at 210 ℃ of dry 5.5h, it is stand-by then to be cooled to room temperature behind 430 ℃ of calcining 18h. Stand-by carrier be impregnated in first the nitrate solution that contains 0.005g Ag and contain 0.03g Bi, behind 120 ℃ of dry 20h, containing the CuCl of 0.01gCu again₂Middle dipping behind 120 ℃ of dry 20h, impregnated in the PdCl that contains 0.06g Pd₂Solution again at 120 ℃ of dry 20h, obtains catalyst E behind 650 ℃ of calcining 10h. Wherein Pd content is that 0.06%, Ag content is that 0.005%, Bi content is that 0.03%, Cu content is 0.01%.

Embodiment 6

Containing 8g Al₂O ₃15% Al₂O ₃In the colloidal solution, adjust pH=2.1 with citric acid, take by weighing 100g talcum powder bead-type substrate and impregnated in the solution for preparing, at 220 ℃ of dry 14h, it is stand-by then to be cooled to room temperature behind 900 ℃ of calcining 15h. Stand-by carrier be impregnated in first the PdCl that contains 0.005g Pd₂Solution behind 120 ℃ of dry 20h, impregnated in the nitrate solution that contains 0.01gAg and contain 0.04g Bi again, behind 120 ℃ of dry 20h, obtains catalyst F behind 430 ℃ of calcining 13h. Wherein Pd content is that 0.005%, Ag content is that 0.01%, Bi content is 0.04%.

Embodiment 7

Containing 6g Al₂O ₃10%Al₂O ₃In the colloidal solution, add the KCl that contains 0.01g K, mixed solution is made in dissolving, behind HCl adjustment pH=2.3, and the spherical carrier of dipping 100g SiC, at 340 ℃ of dry 18h, it is stand-by then to be cooled to room temperature behind 780 ℃ of calcining 13h. Stand-by carrier be impregnated in first the Pd (NO that contains 0.04g Pd₃) ₂Solution behind 120 ℃ of dry 20h, impregnated in the nitrate solution that contains 0.1gAg and contain 0.01g Bi again, behind 120 ℃ of dry 20h, obtains catalyst G behind 430 ℃ of calcining 13h. Wherein Pd content is that 0.04%, Ag content is that 0.1%, Bi content is that 0.01%, K content is 0.01%.

Embodiment 8

Al ₂O ₃The coating preparation process impregnated in stand-by carrier first Pd (the NO that contains 0.025g Pd with embodiment 7₃) ₂Solution behind 120 ℃ of dry 20h, impregnated in the nitrate solution that contains 0.15g Ag and contain 0.009g Bi again, behind the identical drying condition, obtains catalyst H behind 430 ℃ of calcining 13h. Wherein Pd content is that 0.025%, Ag content is that 0.5%, Bi content is that 0.009%, K content is 0.01%.

The catalyst of selecting above-described embodiment to prepare carries out the acetylene hydrogenation reaction experiment, and reaction condition is as follows:

The 1ml catalyst is packed in the tubular reactor, and beds is filled up and down the porcelain ring. Use nitrogen replacement, again after reduction, from top to bottom pass through reactor after simulation prepared from the unstripped gas of deethanization cat head and a certain amount of hydrogen. Hydrogen alkynes ratio is 1.5, entrance acetylene concentration 0.11mol%, air speed 15000hr^-1。

Catalyst A～H is carried out catalyst selection hydrogenation examination under the different temperatures, the highest conversion of alkyne and corresponding selection such as the table 1 of each catalyst.

The performance assessment criteria of each catalyst of table 1

Catalyst	Aluminium oxide coating content (with the percentage by weight of inert carrier)	The inert carrier type	Form content (with the percentage by weight of inert carrier)	Maximum conversion and corresponding selection
						Conversion ratio (%)	Selectively (%)
				A	5％			The SiC annular	Pd 0.03％；Ag 0.1％     Bi 0.1％；Ca 0.01％	85	87
B	10％	The SiC annular	Pd 0.05％；Ag 0.01％   Bi 0.05％；Ca 0.005％，     K 0.02％；Sr 0.005％，   La 0.02％。			90	83
				C	7％			The talcum powder annular	Pd 0.01％；Ag 0.5％   Bi 0.5％；Cu 0.05％   Na 0.05％	74	91
D	3％	Seat clay is granular	Pd 0.02％；Ag 0.02％     Bi 0.01％；Cs 0.05％			73	82
				E	4％			SiC is granular	Pd 0.06％；Ag 0.005％     Bi 0.03％；Cu 0.01％	87	80
F	8％	Talcum powder is granular	Pd 0.005％；Ag 0.01％     Bi 0.04％			69	77
				G	6％			SiC is spherical	Pd 0.04％；Ag 0.1％     Bi 0.01％；K 0.01％	85	79
H	6％	SiC is spherical	Pd 0.025；Ag 0.15％     Bi 0.009％；K 0.01％			71	81

Claims (14)

1. one kind is used for C2～C10 cut alkynes and diolefin hydrogenate catalyst, comprise inert carrier, aluminium oxide coating, catalyst activity component, the catalyst activity component is present in the aluminium oxide coating, the catalyst activity component comprises at least a in major catalyst palladium and co-catalyst silver, bismuth and copper, zinc, alkali metal, alkaline-earth metal, the rare earth element, wherein:

Inert carrier is selected from carborundum, talcum powder, seat clay, and that its shape is selected from is granular, spherical, profile of tooth, annular, tooth are spherical, sheet or strip, and its specific surface is less than 10m²/g；

The aluminium oxide coating is in the inert carrier outer surface, and thickness is 10～500 microns, and its specific area is 1～200m²/g；

The percentage by weight of major catalyst palladium and inert carrier is 0.001～1.0%.

2. hydrogenation catalyst according to claim 1 is characterized in that inert carrier is carborundum or talcum powder, that its shape is selected from is granular, spherical, annular, tooth is spherical and strip in a kind of, its specific surface is less than 5m²/g。

3. hydrogenation catalyst according to claim 1 is characterized in that the aluminium oxide coating layer thickness is 10～300 microns, and its specific area is 5～120m²/g。

4. hydrogenation catalyst according to claim 1, it is characterized in that being present in major catalyst palladium in the aluminium oxide coating and the percentage by weight of inert carrier is 0.01～0.05%.

5. hydrogenation catalyst according to claim 1, it is characterized in that being present in co-catalyst in the aluminium oxide coating and the percentage by weight of inert carrier is 0.002～14%.

6. hydrogenation catalyst according to claim 5, the percentage by weight that it is characterized in that being present in co-catalyst silver and inert carrier in the aluminium oxide coating is 0.001～8%.

7. according to claim 5 or 6 described hydrogenation catalysts, it is characterized in that being present in co-catalyst bismuth in the aluminium oxide coating and the percentage by weight of inert carrier is 0.001～5%.

8. described hydrogenation catalyst preparation method one of according to claim 1～7, step is as follows:

(1) with containing 1～30 % by weight aluminium oxide colloidal solution, adds under acid-conditioning solution pH=2～6 conditions and flood inert carrier;

(2) with step 1) carrier that obtains after 60～300 ℃ of dry 3-30 hours, 300～1200 ℃ of calcinings 4～20 hours, be cooled to room temperature again, obtain the inert carrier with the aluminium oxide coating;

(3) with containing palladium solution, containing the solution total immersion of co-catalyst composition or step impregnation in the aluminium oxide coating on inert carrier surface;

(4) behind the dipping, after 100～300 ℃ of dry 5-24 hours, made in 4～20 hours 350～650 ℃ of calcinings.

9. described hydrogenation catalyst preparation method one of according to claim 1～7, step is as follows:

(1) with the solution that contains at least a element in palladium and the co-catalyst composition with contain 1～30 % by weight aluminium oxide colloidal solution and evenly mix after, flood inert carrier under adding acid-conditioning solution pH=2～6 conditions;

(2) carrier 300～1200 ℃ of calcinings 4～20 hours, then was cooled to room temperature again after 60～300 ℃ of dry 5-30 hours;

(3) more remaining co-catalyst component is made into salting liquid and continues impregnated carrier,, made in 4～20 hours 350～650 ℃ of calcinings again after 5～24 hours 100～300 ℃ of dryings.

10. according to claim 8 or 9 described method for preparing catalyst, it is characterized in that in described step 1) in, the colloidal solution that contains 1～30 % by weight aluminium oxide is that the aqueous solution by high pure alumina makes, and the acid of adding is selected from nitric acid, acetic acid, citric acid, hydrochloric acid.

11. according to claim 8 or 9 described method for preparing catalyst, it is characterized in that the described palladium solution that contains is selected from palladium bichloride, palladium nitrate, palladium; The solution of argentiferous is selected from silver nitrate, silver perchlorate in the co-catalyst; Bismuth-containing solution is selected from bismuth nitrate, bismuth chloride.

12. the described catalyst of one of claim 1～7 is applied to remove acetylene in the C2 cut of cracking separative element.

13. the described catalyst of one of claim 1～7 is applied to remove in the C3 cut of cracking separative element propine and allene.

14. remove alkynes and alkadienes among that the described catalyst of one of claim 1～7 is applied to the cracking separative element and the high-carbon chain hydrocarbon C4～C10.