CN101348261B

CN101348261B - Preparation of binderless ZSM-11 zeolite

Info

Publication number: CN101348261B
Application number: CN2007100439381A
Authority: CN
Inventors: 王德举; 刘仲能; 李学礼; 李则俊
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology; China Petrochemical Corp
Priority date: 2007-07-18
Filing date: 2007-07-18
Publication date: 2010-12-01
Anticipated expiration: 2027-07-18
Also published as: CN101348261A

Abstract

The invention relates to a method for preparing no-binding agent ZSM-11 zeolite, which mainly aims at overcoming the defects of difficult recovery, easy deactivation and easy aggregation existing in the practical application of the zeolite powder and the problems of small effective surface area and limited diffusion due to the addition of the binding agent in the forming process. In the invention, at least one of diatomaceous earth, carbon white, silicasol or water glass is taken as a silicon source, at least one of aluminum oxide, aluminum salt or aluminate is taken as an aluminum source, and proper quantity of necessary crystal seed guiding agents are added and subjected to pugging, extrusion and forming so as to obtain a precursor mixture with the mass ratio of XNa2O:YAl2O3:100SiO2, wherein x is between 0.5 and 14, and y is between 0 and 6, and the precursor mixture is subjected to hydrothermal crystallization treatment in the water solution containing tetrabutyl ammonium positive ions and converted to the no-binding agent ZSM-11 zeolite. The technical proposal of the invention better resolves the problems, and can be applied to the industrial preparation of the ZSM-11 zeolite molecular sieve catalyst.

Description

Binderless ZSM-5-11 prepare zeolite method

Technical field

The present invention relates to a kind of binderless ZSM-5-11 prepare zeolite method.

Background technology

Zeolite molecular sieve has uniform sequential micropore, big specific surface, high hydrothermal stability, is widely used in catalytic field.Zeolite is owing to have short intracrystalline diffusion orifice throat length and bigger outside surface, the touch opportunity that helps active sites in augmenting response thing and the micropore, thereby improve every performance of zeolite, in reaction, show special advantages, as had macromole selectivity, the advantages of high catalytic activity of uniqueness and the catalyst life of growing etc.But zeolite is undersized, and is not very convenient in actual applications, has weakness such as difficult recovery, easy inactivation and gathering, needs to add binding agent in the moulding process, and the result reduces effective surface area, and has introduced diffusional limitation.The binder free zeolite molecular sieve is meant and does not contain inert binder in the zeolite granular or only contain small amount of binder to have higher zeolite content, and therefore available effective surface area is bigger, may have better catalytic performance.

The ZSM-11 molecular sieve has with the ZSM-5 molecular sieve similar pore passage structure is arranged, and its pore passage structure also is a ten-ring, and its duct trend can have extensive use for one dimension straight hole road in the organic catalysis conversion reaction.The binding agent conversion method is one of method for preparing the binder free zeolite molecular sieve, US5665325 and US6458736 disclose the binderless MFI prepare zeolite and have been used for the hydro carbons catalyzed reaction, at first prepare a kind of MFI zeolite powder and amorphous silica moulding, the MFI zeolite that is the amorphous silica hydrothermal conversion then, the new zeolite facies that form are around original big crystal grain zeolite molecular sieve growth and be grown in together mutually.Aforesaid method need be prepared zeolite powder earlier, carries out the crystallization processing more then with behind the binding agent mixing moulding.We utilize diatomite, white carbon black or their mixture to be main raw material, add crystal seed directed agents and proper amount of silicon colloidal sol or water glass etc. and carry out kneading and compacting, utilize hydrothermal crystallizing to handle then and be converted into incorporate ZSM-11 binder free moulded zeolite.This method can simply be converted into ZSM-11 binder free moulded zeolite to the sial raw material easily.Prepared integrated binderless ZSM-5-11 moulded zeolite has more macroporous structure simultaneously, can in actual catalyzed reaction, act synergistically with the performance of zeolite intracrystalline micropore, for example with micropore as reacting environment, macropore is as the transport passage of reactant molecule, thereby eliminated diffusional limitation to a certain extent, zeolite can be used more effectively.This inventive method might develop into a kind of economic means for preparing the Zeolite molecular sieve catalysis material.

Summary of the invention

Technical problem to be solved by this invention is that the conventional art mesolite is undersized, not very convenient in actual applications, there are weakness such as difficult recovery, easy inactivation and gathering, need to add binding agent in the moulding process, the result reduces effective surface area, and introduced diffusional limitation, a kind of new binderless ZSM-5-11 prepare zeolite method is provided.It is simple that this preparation method has a preparation flow, uses raw material to be easy to get, and the zeolite particle diameter can be controlled within the submicron order scope, and the product of preparation can not contain the advantage of binding agent with the disposable ZSM-11 zeolite that changes into of raw material.

For solving the problems of the technologies described above, the technical scheme that binderless ZSM-5 of the present invention-11 prepare zeolite method adopts is as follows: with at least a in diatomite, white carbon black, silicon sol or the water glass is the silicon source, with at least a in oxide compound, aluminium salt or the aluminate of aluminium is aluminium source raw material, the crystal seed directed agents that adds aequum is mixed the moulding of pinching bar, obtains weight ratio meter X Na ₂O: YAl ₂O ₃: 100SiO ₂Wherein, X=0.5～14, the precursor mixture of Y=0～6, hydrothermal crystallizing is handled and is converted into binderless ZSM-5-11 moulded zeolite in containing the cationic aqueous solution of TBuA then, wherein crystallization temperature is 120～200 ℃, and crystallization time is 48～240 hours, and above-mentioned used crystal seed directed agents is to be (TBA) by the feed molar proportioning ₂O: 2～10SiO ₂: 60～200H ₂The mixture of O wore out under 80～120 ℃ 12～240 hours and got, and TBA is a TBuA.

In the technique scheme, crystal seed directed agents add-on preferable range is 1.0～50% of a precursor mixture weight.TBuA is selected the TBuA positively charged ion for use in the preparation process of crystal seed directed agents, and preferred version is selected from least a in TBAH or the Tetrabutyl amonium bromide.The precursor mixture preferred version obtained binderless ZSM-5-11 zeolite in 48～240 hours for hydrothermal crystallizing under 140～180 ℃ of temperature, and ZSM-11 zeolite particle diameter is less than 1 micron.Can add or not add extrusion aid in the kneaded and formed process of precursor mixture, extrusion aid is selected from least a in sesbania powder, starch, gac, polyoxyethylene glycol, polyacrylamide or the polyvinyl alcohol, and the consumption of extrusion aid is 0.1～4% of a precursor mixture weight.

The present invention is owing to added homemade crystal seed directed agents in the kneaded and formed process of reaction raw materials, prepared crystal seed directed agents contains a large amount of ZSM-11 primary structure and secondary structure unit, can be evenly distributed in the shaping raw material in kneading process.These ZSM-11 primary structures and secondary structure unit become the nucleus of ZSM-11 zeolite crystallization growth in hydrothermal crystallization process, though add-on is few, but played vital role: induce the sial raw material in its surface growth, avoided the nucleating growth phase, accelerated conversion rate, shortened crystallization time, suppress the generation of stray crystal, reduce crystallite size, and center on the zeolite crystal of nucleus growth because therefore staggered growth can take place space constraint, can improve the intensity that generates integrated binderless ZSM-5-11 zeolite, help practical application, obtain better technical effect.

Description of drawings

Fig. 1 is the XRD figure spectrum of embodiment 2 products.

Fig. 2 is the SEM figure of embodiment 2 product subsurfaces.

Shown among Fig. 1 that embodiment 2 products are the ZSM-11 zeolite.

Show ZSM-11 zeolite crystal particle diameter among Fig. 2 less than 100 nanometers, and staggered being grown in together.

The invention will be further elaborated below by embodiment.

Embodiment

[embodiment 1～3]

With TBAH (TBAOH) solution, positive tetraethyl orthosilicate (TEOS) and water according to (TBA) ₂O: 6.22TEOS: 163H ₂The mixed in molar ratio of O stirs, and obtains ZSM-11 crystal seed directed agents in three days 95 ℃ of aging down backflows.

Take by weighing the white carbon black of 200 grams, the siliceous aluminum oxide powder of 12.5 gram sesbania powder, 36 grams (contains SiO ₂Mass percent is 26%) and 51 gram ZSM-11 crystal seed directed agents, add the aqueous solution that contains 20 gram NaOH, the silicon sol (weight percent 40%) that add 475 grams again mix to pinch and carry out drying after the shaping and obtain cylindric presoma.

Be respectively that 8% TBAH (TBAOH) solution mixes and places crystallizing kettle to carry out hydrothermal treatment consists 3 days under 160 ℃ with cylindric presoma and the 80 gram mass percentage concentrations of the above-mentioned preparation of 40 grams, 5 days and 7 days.Product with distilled water wash oven dry back in air atmosphere in 550 ℃ of roastings.The product X RD collection of illustrative plates of handling 3 days shows that product is the ZSM-11 zeolite, and baseline straightening shows that not containing unformed nothing substantially controls; The XRD figure spectrum diffraction peak intensity of handling 5 days products has growth slightly, shows that degree of crystallinity raises.The product S EM photo of handling 5 days shows that ZSM-11 zeolite granular size is less than 100 nanometers; Prolong treatment time to 7 day, product X RD collection of illustrative plates does not have considerable change.

[embodiment 4～6]

Take by weighing 100 gram diatomite and the white carbon black of 140 grams, add 7.5 gram sesbania powder, 36 gram Tai-Ace S 150 [Al ₂(SO ₄) ₃18H ₂O] and 60 grams [embodiment 1～3] plant the crystal seed directed agents prepare, the silicon sol (weight percent 40%) that add 300 grams again mix to be pinched into cylindric shape and carries out drying.

Be respectively that 10% TBAH (TBAOH) solution mixes and places crystallizing kettle to carry out hydrothermal treatment consists 5 days under 140 ℃ with cylindric presoma and the 80 gram mass percentage concentrations of the above-mentioned preparation of 40 grams, 8 days and 10 days.Product with distilled water wash oven dry back in air atmosphere in 550 ℃ of roastings.The XRD figure spectrum of product shows that all crystalline phase is the ZSM-11 zeolite, and baseline straightening shows and do not contain unformed material, and product S EM photo shows that ZSM-11 zeolite granular size is less than 100 nanometers.

[embodiment 7～10]

With TBAH (TBAOH) solution, Tetrabutyl amonium bromide (TBABr), positive tetraethyl orthosilicate (TEOS) and water according to 2TBAOH: TBABr: 15TEOS: 450H ₂The mixed in molar ratio of O stirs, and obtains ZSM-11 crystal seed directed agents in four days 100 ℃ of aging down backflows.

Take by weighing the white carbon black of 250 grams, add 12 gram sesbania powder, 27.8 gram Tai-Ace S 150 [Al ₂(SO ₄) ₃18H ₂O], 10 gram NaOH and 80 gram crystal seed directed agents, the silicon sol (weight percent 40%) that add 400 grams again mix to be pinched into cylindric shape and carries out drying.

Be respectively that 8% TBAH (TBAOH) solution mixes and places crystallizing kettle to carry out hydrothermal treatment consists 2 days under 180 ℃ with cylindric presoma and the 80 gram mass percentage concentrations of the above-mentioned preparation of 40 grams, 4 days and 6 days.Product with distilled water wash oven dry back in air atmosphere in 550 ℃ of roastings.The XRD figure spectrum of product shows that all crystalline phase is the ZSM-11 zeolite, and baseline straightening shows and do not contain unformed material, and product S EM photo shows that ZSM-11 zeolite granular size is between 100～300 nanometers.

[embodiment 11～13]

Respectively the cylindric presomas and 80 of 40 gram above-mentioned [embodiment 7～10] preparations are restrained the solution contain mass percent 4% TBAH (TBAOH) and mass percent 4% Tetrabutyl amonium bromide (TBABr) and mix and place crystallizing kettle under 150 ℃, to carry out hydrothermal treatment consists 5 days, 7 days and 10 days.Product with distilled water wash oven dry back in air atmosphere in 550 ℃ of roastings.The XRD figure spectrum of product shows that all crystalline phase is the ZSM-11 zeolite, and baseline straightening shows and do not contain unformed material, and product S EM photo shows that ZSM-11 zeolite granular size is between 300～500 nanometers.

Claims

1. binderless ZSM-5-11 prepare zeolite method, with at least a in diatomite, white carbon black, silicon sol or the water glass is the silicon source, with at least a in oxide compound, aluminium salt or the aluminate of aluminium is aluminium source raw material, the crystal seed directed agents that adds aequum is mixed the moulding of pinching bar, obtains weight ratio meter XNa ₂O: YAl ₂O ₃: 100 SiO ₂Wherein, X=0.5～14, Y=0～6, Y is at locating not to be 0 precursor mixture, and hydrothermal crystallizing is handled and is converted into binderless ZSM-5-11 moulded zeolite in containing the cationic aqueous solution of TBuA then, and wherein crystallization temperature is 120～200 ℃, crystallization time is 48～240 hours, and above-mentioned used crystal seed directed agents is to be (TBA) by the feed molar proportioning ₂O: 2～10SiO ₂: 60～200 H ₂The mixture of O wore out under 80～120 ℃ 12～240 hours and got, and TBA is a TBuA; Wherein, crystal seed directed agents add-on is 1.0～50% of a precursor mixture weight; The TBuA positively charged ion is selected from least a in TBAH or the Tetrabutyl amonium bromide in the preparation process of crystal seed directed agents.

2. according to claim 1 described binderless ZSM-5-11 prepare zeolite method, it is characterized in that reaction water thermal crystallisation temperature is 140～180 ℃.

3. according to claim 1 described binderless ZSM-5-11 prepare zeolite method, it is characterized in that ZSM-11 zeolite particle diameter is less than 1 micron.