Infiltration evaporation is a kind of isolation technics that recent two decades develops rapidly, because the infiltration evaporation separation process is not subjected to the restriction of VLE, thereby in the reluctant azeotrope separation of traditional separation means, minor amount of water remove and the aspects such as removing and concentrate of underwater micro-organic matter demonstrates unique advantages, infiltrating and vaporizing membrane is divided into water penetrated preferably film and penetrated preferably by organic substances film two big classes, for water penetrated preferably film, carried out extensive studies in the past twenty years, its isolation technics has realized industrialization in the dehydration of organic solvent field, for the penetrated preferably by organic substances film, it is started late, compare with water permeable membrane, the ubiquity separation selectivity is low, shortcomings such as the saturating amount of infiltration is low, and there is the membrane material of fine selectivity also less to organic matter component, yet osmotic vaporizing membrane penetrated preferably by organic substances has very big business development potentiality and tempting application prospect, atomic as organic content in organic sewage, the organic sewage of the adsorption method processing of adopting usually, the processing of adsorbent and recovery be difficulty relatively, utilize osmotic vaporizing membrane penetrated preferably by organic substances can make the micro-content organism penetrated preferably in the sewage and obtain separating, in addition, osmotic vaporizing membrane penetrated preferably by organic substances also can be used for extracting alcohol from low concentration alcohol water by fermentation liquid, from dilute aqueous solution, reclaim organic matter and food, concentrating etc. of thermosensitive products in the pharmaceuticals industry, yet existing osmotic vaporizing membrane penetrated preferably by organic substances is the permeability and separation poor performance not only, and mostly be organic film, in heat endurance, mechanical stability and chemical stability aspect exist unsurmountable defective.
Zeolite molecular sieve, owing to having ion characteristic, its crystal inner surface has the Coulombian field effect, variation along with the molecular screen material silica alumina ratio, the Coulombian field effect also changes thereupon, thereby the difference that causes the hydrophilic and hydrophobic matter of molecular screen material, the molecular sieve of high silica alumina ratio or total silicon molecular sieve (as Silicalite-1) are very little or do not have an electrostatic field because of the electrostatic field of its crystals, so have strong hydrophobicity, constitute film by it and can extract the organic matter of high concentration by infiltration evaporation from the organic matter/aqueous solution of low concentration, the molecule that varies in size in addition also can obtain selecting shape by infiltration evaporation on molecular screen membrane separates.
The object of the present invention is to provide a kind of osmotic vaporizing membrane penetrated preferably by organic substances--the synthetic method of Silicalite-1 molecular screen membrane, composite membrane separation and the saturating amount synthetic with this method are high, and synthetic method is simple.
The invention provides a kind of osmotic vaporizing membrane penetrated preferably by organic substances--the preparation method of Silicalite-1 molecular screen membrane, it is characterized in that utilizing the synthetic method of hydro-thermal original position synthesizing molecular sieve film once on the porous basement membrane, the aperture of basement membrane is 0.05~100 μ m, and the sol formulation of synthesizing molecular sieve film is: aNa
2O: bTPABr: 100SiO
2: cH
2O, a=3.0~20.0 wherein, b=3.0~50.0, c=5000~40000; The hydro-thermal synthesis temperature is 150~200 ℃, 10~100 hours time.
Among the preparation method provided by the present invention, sol formulation is with a=4.0~10.0, and b=3.0~15.0, c=8000~20000 are good.
The basement membrane of synthesis of molecular sieve provided by the invention both can be porous α-Al
2O
3Basement membrane also can be other porous basement membrane (as porous stainless steel basement membrane etc.), and the aperture of basement membrane is 0.05-100 μ m, is good with 0.1-10 μ m wherein; The shape of basement membrane can be sheet or tubulose.
The preparation method of molecular screen membrane provided by the invention, by the synthetic method of original position hydro-thermal at porous α-Al
2O
3Synthesized molecular screen membrane on the basement membrane, rather than by indirect means dip-coatings such as sol-gels, the molecular screen membrane that provides utilizes X-ray diffraction (XRD) and SEM characterization methods such as (SEM) to be indicated as the Silicalite-1 molecular screen membrane.
The Silicalite-1 molecular screen membrane that the present invention synthesizes is applied to infiltration evaporation to be separated, in temperature is 30-60 ℃, the vacuum of per-meate side is under the condition of 200-400Pa, and the reason of the ethanol/water solution of the synthetic Silicalite-1 molecular screen membrane coefficient that is separated is 40-60, and saturating amount is 0.1-0.4kg/m
2.h.
The present invention has developed the novel infiltrating and vaporizing membrane-molecular screen membrane of high score from performance, separates with the infiltration evaporation of organic film and compares, and molecular screen membrane not only stability is better, and separating property also improves, and explains detailedly below by embodiment.
The preparation of embodiment 1 tubulose Silicalite-1 molecular screen membrane
The synthetic used basement membrane of Silicalite-1 molecular screen membrane is α-Al
2O
3Basement membrane, its aperture is 0.1-0.3 μ m, porosity is 50%, basement membrane be shaped as tubulose, external diameter of pipe is 11mm, thickness is 1mm, length is 260mm, and basement membrane is before use with the balance of polishing through fine sandpaper, ultrasonic washing in the distilled water, dry for standby then, the membrane surface after the oven dry can not done any processing and be directly used in synthetic.
The synthetic liquid of synthetic Silcalite-1 molecular screen membrane is prepared as follows:
Solution (1): 1 gram NaOH is dissolved in 260 ml deionized water, adds 4.18 gram TPABr then, and dissolving promptly gets solution (1);
Solution (2): with the deionization of 60 milliliters of Ludox and 250 milliliters mix solution (2), wherein contain SiO in the Ludox
227wt%.
Wait to join solution (1) and solution (2) afterwards, solution (2) is added in the solution (1) in stirring, mix until obtaining transparent colloidal sol, the prescription of the colloidal sol that finally obtains is 4Na
2O: 5TPABr: 100SiO
2: 10000H
2O.
The effective support of film is fixed, vertically be positioned over (as Fig. 1) in the stainless steel synthesis reactor, to synthesize liquid then changes among the synthesis reactor, place the baking oven that is warming up to 180 ℃ in advance, heating crystallization took out after 24 hours, was cooled to room temperature, the distilled water washing, oven dry, the molecular sieve after the oven dry proves the Silicalite-1 molecular screen membrane through X-ray diffraction (as Fig. 2), and SEM shows that the thickness of molecular screen membrane is 50 μ m.
The Pervaporation Separation of embodiment 2 tubulose Silicalte-1 molecular screen membranes
The film pipe of embodiment 1 gained is carried out the infiltration evaporation Separation Research, the infiltration evaporation schematic representation of apparatus as shown in Figure 4,1 is water bath with thermostatic control, 2 is raw material tank, 3 is the magnetic force circulating pump, 4 is membrane separator, and 5 is cold-trap, and 6 is triple valve, 7 is separator tube, 8 is vavuum pump, is the vacuums of 60 ℃ and per-meate side when being 200-400Pa in the infiltration temperature, and the bent type result that organic matter/aqueous solution separates as shown in Table 1 and Table 2, by table 1 and table 2 as can be seen, the Silicalite-1 molecular screen membrane can extract organic matter from organic matter/water, be 40-60 as the separation of ethanol/water solution, and saturating amount is 0.1-0.4kg/m
2.hr.
The organic segregative line of the infiltration evaporation performance separation system organic penetrating fluid of temperature material liquid of table one Silicalite-1 molecular screen membrane is measured thoroughly
[℃] substrate concentration [wt%] substrate concentration [wt%] number α [kg/m
2.hr] methanol 60 4.63 35.06 11.4 0.84 ethanol/waters 60 2.78 57.03 46.4 0.37 n-propanol/water 60 3.89 59.14 35.8 0.013 isopropanol 60 3.17 38.67 19.3 0.021
The ethanol/water infiltration evaporation performance of table two Silicalite-1 molecular screen membrane
The organic segregative line of the organic penetrating fluid of temperature material liquid is measured thoroughly
[℃] substrate concentration [wt%] substrate concentration [wt%] number α [kg/m
2.hr] 30 2.92 64.32 59.9 0.1040 2.74 57.16 47.4 0.1550 2.78 55.94 44.4 0.2560 2.78 57.03 46.4 0.37
The stability of embodiment 3 tubulose Silicalite-1 molecular screen membranes
The Silicalite-1 molecular screen membrane that this patent uses after using in 5000 hours, its to the separating property of ethanol/water mixture with separate just as the time more as shown in Table 3, as shown in Table 3, the separating property of Silicalite-1 molecular sieve does not significantly descend, and saturating amount has decline slightly.
The stable separation system temperature material liquid service time organic matter segregative line of table Three S's ilicalite-1 molecular screen membrane is measured thoroughly
[℃] (hr) concentration [wt%] number α [kg/m
2.hr] ethanol/water 60 1 2.78 46.4 0.37 ethanol/waters 60 5,000 2.89 45.1 0.33
Comparative example 1
Holland Twente professor Smolder of university has studied silicone rubber membrane and has filled the Pervaporation Separation of the silicone rubber membrane of Silicalite-1 molecular sieve to different alcohol/aqueous mixtures, the result (plucks the Science to Journal of Membrane as shown in Table 4, Vol.35,1987, p39-55) the infiltration evaporation performance of the Silicalite-1 molecular screen membrane that synthesizes with the present invention relatively, the saturating amount of Silicalite-1 molecular screen membrane and selectivity all obviously are better than silicone rubber membrane and fill the silicone rubber membrane of Silicalite-1 molecular sieve, as under the separation condition that is close, the Silicalite-1 molecular screen membrane is when 30 ℃ and material liquid concentration of alcohol are 2.92wt%, separation is 59.9, and saturating amount is 0.10kg/m
2.hr, obviously greater than when 22.5 ℃ and the material liquid concentration of alcohol 5~5.5wt%, the separation 7.6 of silicone rubber membrane, saturating amount is 0.0223kg/m
2.hr with the separation 16.5 and the saturating amount 0.0442kg/m of Silicalite-1 molecular sieve filled silicon rubber film (loading 60 wt%)
2.hr.
The Pervaporation Separation separation system temperature molecular sieve of table four silicone rubber membrane and filling Silicalite-1 molecular sieve silicone rubber membrane is filled out the organic segregative line of material liquid and is measured thoroughly
[℃] charge (wt%) substrate concentration [wt%] number α [kg/m
2.hr] methanol 22.5 0 5~5.5 7.6 0.0188
30 5~5.5 9.5 0.0322
60 5~5.5 13.0 0.0707 ethanol/waters 22.5 0 5~5.5 7.6 0.0223
40 5~5.5 14.9 0.0324
60 5~5.5 16.5 0.0442 n-propanol/water 22.5 0 5~5.5 19.1 0.0244
30 5~5.5 21.2 0.0255
60 5~5.5 38.3 0.0337 isopropanol 22.5 0 5~5.5 9.5 0.0243
30 5~5.5 11.9 0.0263
60 5~5.5 23.0 0.0337
Comparative example 2
Professor Noble of U.S. Corolado university waits and has synthesized the Silicalite molecular screen membrane from gel at the Woelm Alumina basement membrane, and when 32 ℃ and material liquid concentration of alcohol were 9.7wt%, separation was 11.5, and saturating amount is 0.1kg/m
2.hr (pluck Science to Journal of Membrane, vol.1.117,1995, p163-174) the infiltration evaporation performance of the Silicalite-1 molecular screen membrane that synthesizes with the present invention is compared, saturating amount is suitable with the present invention, but separation is then low than of the present invention, this is because the synthesis condition that the present invention adopts is a sol system, gel rubber system than the U.S. is more even, easier film forming, from synthetic process, synthetic only need synthesizing once of the present invention just can synthesize molecular screen membrane in addition, and the U.S. then needs repeatedly to synthesize and just can synthesize complete molecular screen membrane.