BR102014028798A2 - zsm-22 zeolite synthesis with reduced crystallization time and no use of organic structure - Google Patents

Abstract

Summary for Patent Application: Synthesis of SM-22 Zeolite with Short Crystallization Time and No Use of Organic Structure Guidance The present invention relates to a process for obtaining pure, high silicon zeolite zeolite free from organic directors, and in short crystallization times (times less than 6 hours) in static and dynamic systems. The process comprises the preparation of a reaction mixture composed of an aluminum source, sodium silicate as silicon and alkaline cation source, a small amount of seeds and crystallization (zsm-22 crystals), water and methanol as solvents. zeolit zsm-22 is a mineral inorganic compound formed from silicon and luminium, with chemical and physical properties of great interest in influential sets in the world macroeconomics, such as petroleum processing and its derivatives, and may be employed as a catalyst for acid sites, as well as peculiar structural characteristics that make them extremely interesting in the renal and / or secondary cracking reactions. The process described in this document results in the composting of the compound in much less time than previously described and considerably reduced production costs, making this mechanism economically attractive for the industrial sector of interest.

Description

Descriptive report for patent: SUMMARY J) ZEOLITE ZSM-22 WITH REDUCED CRYSTALIZATION TIME AND WITHOUT USE OF ORGANIC DRIVERS

STRUCTURES

Field of the Invention The present invention relates to a process for obtaining pure, high silicon zeolite zeolite free of organic directors and in short crystallization times (times less than 6 hours) in static and dynamic systems. . The process comprises preparing a reaction mixture composed of an aluminum source, sodium silicate as the source of silicon and alkaline cation, a small amount of crystallization seeds (ZSM-22 crystals), water and methanol as solvents. The processes for preparing zeolites are described in various documents, each having its particularity. In the case of ZSM-22, the high crystallization time reported in the existing patent examples (longer than 20 hours), the use of costly organic (usually diamine) drivers, and the need for systems with strong agitation (in 400 rpm), are the main difficulties encountered in the synthesis processes described in the state of the art. Therefore, the present invention relates the synthesis process of a porous crystalline aluminosilicate called ZSM-22, which can be used as molecular sieve, support and catalyst in reactions for conversion of organic compounds, locating the technical sector of this document within the mineralogy and crystal growth as well as the synthesis of inorganic compounds.

Background of the Invention and Prior Art ZSM-22 was first synthesized in 1982, being a silicon-rich zeolite with TON topological structure, featuring a smaller one-dimensional channel system than those found in ZSM-5 zeolites, ZSM-11 and ZSM-35. The channel opening (free diameter) is 0.45 x 0.55 nm with no intersections between the channels. (KOKOIAILO, GT; SCHLENKER, JL, DWYER, FG; VALYOCSIK, EW The topology framework of ZSM-22: The high silica zeolite. Zeolites, Amsterdam, v. 5, no. 6, p. 349, nov. 1985; BORADE , RB, ADNOT, A. KALIAGUE, S. Acid sites in AI-ZSM-22 and Fe-ZSM-22. Zeolites, Amsterdam, v. 11, No. 710, pp. 1-10, Sep./out. 1991). The TON frame type includes materials ZSM-22, Theta-1, Nu-10, KZ-2 and ISI-1 (ERNST, S.; WEITKAMP, J .; MARTENS, JA; JACOBS, PA. Zeolites: catalysts for the Applied Catalysis, Amsterdam, vol. 48, η. 1, pp. 137-148, ma ". 1989.) and has acidic properties and selectivity that are particularly desirable in the petroleum industry. Applications studied include: a xylene isomerization (MOBIL. Mobil Oil Corporation (New York). David Harold Olson; Robert Bruce Calvert; Emest William Valyocsik. A process for isomerizing xylenes. EP No. 0102716, 13 July 1983, 14 March 1984.), a toluene methylphonate with p-xylene methanol, alkylation of aromatic hydrocarbons (HOGAN, PJ; WPDTTAM, TV; BIRTILL, JJ STEWART, A. Synthesis properties and catalytic behavior of zeolite Nu-10. Zeolites, Amsterdam, v. 4, n 3, pp. 275, Jul. 1984.) and 1-butene isomerization (MARK, W .; SIMON, SL; CHI, L. Synthesis and Characterization of ZSM-22 Zeolites a. Their Catalytic Behavior in 1-Butene Isomerization Reactions. Journal of Catalysis, Amsterdam, v. 147, no. 2, p. 484, jun. 1994.).

Although the ZSM-22 performs efficiently in these specific reactions, the challenge lies in the production of the material due to the use of structural directing agents (SDAs), commonly referred to as organic directives, the need for vigorous agitation (400 rpm) and long crystallization times (over 20 hours). Numerous documents report its synthesis process, in general, the composition of the reaction mixture consists of a source of silicon, an aluminum source, a source of alkaline or alkaline earth cations, an organic director and water, however, the Dres Organic chemicals are very expensive and toxic, and they also generate liquid and gaseous effluents, also toxic, during the solids separation steps (CASCI, JL Zeolite molecular sieves: preparatory and scale-up. Microporous and Mesoporous Materials, Amsterdam, v. 82, No. 3, pp. 217-226, August 2005; VORTMANN, S.; MARLER, B.; GIES, H.; DANIELS, P. The Synthesis and Crystal Structure of the New Borosilicate Zeolite RUB-13. Microporous and Mesoporous Materials Amsterdam, Vol. 4, No. 2-3, pp. 11-121, June 1995). And in relation to the crystallization time, the shorter, the greater the daily production, the greater the number of batches per day.

US 4,902,406 and US 4,481,177 disclose synthesis methods using organic directors, vigorous stirring, temperatures ranging from 80 ° C to 210 ° C and minimum crystallization times of 24 hours, as shown in the examples shown. In EP 065,400 zeolite called Nu-10 was crystallized in the presence of the tetramethylene pentamine director. It also indicates that agitated reactions are preferable since an improper stirring process increases the possibility of contamination with ZSM-5 zeolite or cristobalite. US 5,783,168 describes the production of ZSM-22 in a system that can be free or with low agitation, but still in the presence of the 1,6-diaminohexane director. Crystals of zeolite (seeds) were added to the reaction mixture in small amounts, about 1000 ppm.

The examples set forth in US Patent 4,533,649 were made using aqueous ammonia solutions in place of the organic director, expensive reagents (such as ammonia solution, colloidal silica and gel), vigorous stirring and minimum crystallization times. 48 hours EP 087,017 describes the production of material called ISI-1 using methanol in place of the organic director. According to Sugimoto et al. (1986) the action of methanol on crystallization is solvent along with water (SUGIMOTO, M .; TAKATSU, K.; KAWATA, N.; KONISHI, T. Studies in Surface Science and Catalysis, v. 28, p. 193-230, 1986.). In the example of this latter patent document they were necessary for the formation of the material; stirring, crystallization time of 20 hours and temperature of 170 ° C. In US Patent 5,063,038, alcohols or diol were used as co-directers for the synthesis of ZSM-22 and ZSM-23 to inhibit the formation of ZSM-5. Not only the elimination of the use of organic directors, but also the use of cheap reagents (sources of s: lithium, aluminum and cations), along with reduced crystallization times, are paramount to lowering the cost of producing ZSM-22. The non-agitated systems make it possible to save electricity, as well as the use of simpler equipment and lower acquisition and operating costs. This document has identified a process for improving the preparation of ZSM-22 zeolite with crystallization times of less than 6 hours without the use of organic directives and the use of low cost reagents.

Description of the Figures [006] Figure 1 shows the X-ray Diffraction (XRD) graph of the Example 1 product, showing that after 6 hours of crystallization ZSM-22 was produced without ZSM-5 or cristobalite contamination.

Figure 2 shows the ZSM-22 XRD graph obtained from example 2. After 5 hours of crystallization, without stirring, pure and better crystallinity ZSM-22 was obtained than that of Figure 1.

[008] Figure 3 shows the ZSM-22 cris: 3-hour XRD graph for example 3. It was also free of contamination and good crystallinity.

[009] Figure 4 shows the 4 hour time crystallized ZSM-22 XRD graph for example 4.

[010] Figure 5 shows the 3 hour time-lapse crystallized ZSM-22 XRD graph for example 5.

[011] Figure 6 shows the XRD graph of zeolite ZSM-22 used as crystallization seed.

Figure 7 shows the SEM image of the sample synthesized according to example 4.

[013] Figure 8 shows the SEM image of the sample synthesized according to example 5.

Summary of the Invention Zeolites have a very wide structural diversity and such characteristics have been studied since the early twentieth century, with discussion and detailing of properties such as adsorption and porosity characteristics. Based primarily on such knowledge, the first applications in the fuel industry have emerged. The present invention, which is the subject of this patent application, relates to the process of obtaining zeolite ZSM-22, a silicon-formed mineral inorganic compound and aluminum, with chemical and physical properties of great interest in industrial sectors influential in the world macroeconomics, such as petroleum and its derivatives, which can be used as a catalyst due to its acid sites, as well as peculiar structural characteristics that make it extremely interesting in the reactions of primary and / or secondary cracking>. The process described in this document results in obtaining the compost in a much shorter time than previously described and considerably reduced production costs, making this mechanism economically attractive for the industrial sector of interest.

Detailed Description of the Invention The proposed invention is presented as developed in two steps: i) Synthesis of zeolite ZSM-22; and ii) Growth of the crystals of said zeolite. i) Synthesis of zeolite The present invention reports an improvement in the synthesis process of ZSM-22 zeolite without contamination, free of organic directors and with short crystallization time. The following reagents (Table 01) were used for synthesis of ZSM-22 samples: Table 01 - Sample precursor reagents.

Sources Reagents Silicon and cation Sodium silicate (11.2% Na2G, 31.5% alkaline S1O2, Pernambuco Chemical P Q1 -40).,,. Hydrated aluminum sulphate (> 99%, Aluminum λ., X v Merck) r Solvent Distilled water and methanol (99.8%, Synth) 0, Zeolite ZSM-22 synthesized accordingly Seeds of 11 11 * + τ tc. With US Patent Example 11 crystallization 44) 02.406 Alkalinity adjustment Sulfuric acid (98%, JT Baker) [017] High silica ZSM-22 can be prepared in agitated static systems with temperatures between 150 ° C and 200 ° C, preferably 170 ° C, with the following reaction mixture molar compositions (Table 02) in terms of oxides: Table 02 - Synthesis gel parameters.

Parameters Range Preference CH3OH / Si2 0.5-5.0 1.0-40 Si02 / Al203 20-00 50- 100 0H7Si02 0.1 -0.3 0.2 H20 / Si02 10-100 15-40 Seeds / Gel of 0.003 -0.03 Λ „„, „. 0.40 * 0.006 - C, 01 Synthesis * * Mass ratio.

[018] The procedure for producing the reaction mixture follows the following methodology: Five solutions are prepared, each containing 20% of the water required for synthesis; 1 Solution A: sulfuric acid and water; 2 Solution B: aluminum source and water; 3 Solution C: sodium silicate and water; 4 Solution D: alcohol and water; 5 Solution E: seeds and water.

With the solutions prepared: (i) Add to solution A solution B; ii) Add to solution C mixture AB; iii) Add to solution D the above mixture; iv) Finally add the seed solution.

After each addition step, the solutions were stirred (mechanical stirring) until homogeneous, about 20 minutes at 400: pm. ii) Growth of zeolite crystals The procedure for the growth of ZSM-22 zeolite crystals occurred from the process under agitation (dynamic) and without agitation (static) as described below.

For the cases where crystallization occurred without agitation, the resulting mixture was transferred to 70 ml Teflon vessels, which were inserted into stainless steel autoclaves and brought to the oven for crystallization. When the desired temperature is reached, the predetermined crystallization time starts. After the crystallization time had elapsed, the autoclave was removed from the oven and cooled to room temperature. Its contents were transferred to a beaker containing 100 mL of distilled water and the solid resulting from the crystallization process was separated from the supernatant liquid by vacuum filtration, washed several times with distilled water (until the pH of the filtrate reached ~ 7%). 0) and oven dried at L20 ° C for 12 hours.

In the case of stirring crystallizations, the resulting mixture was transferred to a 700 mL Teflon vessel. This container is placed into the Parr reactor model 4520 stainless steel vessel (1L volume) under constant agitation at 400 rpm. After crystallization, the solid phase obtained was recovered by a procedure similar to the case of the static conditions syntheses described above.

The only dry acid was characterized by X-ray diffraction (E> RX), 77 K N2 adsorption (BET) and scanning electron microscopy (SEM). These techniques allowed to identify the crystalline phases present in the samples, as well as their textural properties. EXAMPLE 1 - 3 The distillation of the ZSM-22 reaction mixture was performed at temperatures between 150-200 ° C without stirring. The synthesis parameters are shown in Table 3.

Table 03 - Synthesis parameters of material produced in static system. Parameters Example 1 Example 2 Example 3 <3 OH / Si02 β 4.0 1.0 Si02 / Al203 50 100 100 0H7S02 0.2 0.2 0.1 H20 / Si02 18 18 18 Seeds / Gel,) 01 Synthesis '* · CH; OH / S ments * 21.37 21.37 5.34 temperature 17 (+) 170 170 preferred (° C) Crystallization time (h) * Mass ratio 20.

The X-ray diffractogram (XRD) of the product of example 1 (Figure 1) shows that after 6 hours of crystallization ZSM-22 was produced without contamination of ZSM-5 or cristobalite. The result indicates that ZSM-22 is formed in static medium with good crystallinity.

[026] Figure 2 shows the ZSM-22 XRD obtained according to example 2. After 5 hours of crystallization, without stirring, pure and better crystallinity ZSM-22 was obtained than that of Figure 1.

[027] For example 3, Figure 3 shows the XS crystallized ZSM-22 XRD of 3 hours. It was also free of contamination and good crystallinity. EXAMPLE 4-5 The crystallization of the ZSM-22 reaction mixture was performed at temperatures between 150-200 ° C, with constant stirring of 400 rpm. The synthesis parameters are shown in Table 4.

Table 04 - Synthesis parameters of material produced in agitated system. Parameters Example 4 Example 5 OT3ÕH / Si02 4.0 1.0 Si02 / Al203 100 100 Ol I7Si02 0.2 0.2 H20 / Si02 18 18 Seeds / Gel of 'mn ni Synthesis *' Ui U, U1 CT13 OP1 / S ements * 21.37 5.34 Temperature Preferred temperature (° C) 1 / U 1 ° Crystallization time (h) * Mass ratio.

The respective figures 4 and 5 show the XRD graph of examples 4 and 5. In both examples the ZSM-22 zeolite was formed with excellent crystallinity.

[030] Table 05 presents results concerning the calculation of the relative crystallinity of each sample when compared to the sample synthesized with organic director (ZSM-22 used as seeds - figure 6) and surface area of the solid obtained by BET. All samples were submitted to calcination and ion exchange with 1M HCl solution before characterization.

[031] The calculation of the relative crystallinity of the material was obtained using the peaks relative to 2Θ values of the regions of 19.7-20.9 and 23.6-25 degrees, according to equation 01.

Equation 01 [032] Equation 01 expresses the relationship between surface and microporous areas obtained by adsorption / desorption of nitrogen at 77K to obtain surface area (P / Po points = 0.06 to 0.20) and pore volume .

Table 05 - Calculation of relative crystallinity and BET and microporous surface areas of the samples. . .. .., Surface area Volume Crystallinity. ZSM-22 microporous BET (m2 / g) (cm 3 / g) Org. Δ00 216 ± 3.5 ....... 0.214 Example 1 69 97 ± 1.6 0.086 Example 2 89 170 ± 2.8 0.171 Example 3 83 210 ± 2.9 0.207 Example 4 90 189 ± 3.1 0.160 Example 5 88 220 ± 3.0 0.218 [033] The material has good surface area and through microscopy images (Figures 7 and 8) It is possible to observe a cluster of crystals, with cylindrical shape and average size of 2 pm, typical of the height.

[034] As a result of this approach, which is the subject of patent application, the present document provides the development of a high crystallinity pure and synthetic ZSM-22 synthesis methodology without using organic directives, in static and agitated systems, and in short times. crystallization time (less than 6 hours).

I

Claims (7)

1. ZEOLITE TYPE ZSM-22 PREPARATION PROCESS WITHOUT USE OF ORGANIC STRUCTURE DIRECTORS characterized by including in the synthesis a mixture containing: (i) a source of silicon oxide, (ii) a source of aluminum oxide, (iii ) an alkali metal source, (iv) a solution of methanol and water, and (v) a suspension of water crystallization seeds (ZSM-22 synthesized crystals suspended in water) to yield the material called zeolite ZSM-22 in static or agitated systems and crystallization times of less than 6 hours. ZSM-22 TYPE ZEOLITE PREPARATION PROCESS WITHOUT THE USE OF ORGANIC STRUCTURE DIRECTORS according to claim 1, characterized by a reaction mixture composed of the molar ratio of CH30H / Si02 between 1.0 and 4.0; molar ratio of S1O2 / Al2O3 between 50 and 100; 0H7 SiO2 molar ratio between 1.0 and 2.0; molar ratio of H2 O / Si2 between 15 and 40; Seeds / Synthesis Gel mass ratio between 0.006 and 0.01; and crystallization times not exceeding 4 hours for static or agitated systems. ZSM-22 TYPE ZEOLITE PREPARATION PROCESS WITHOUT THE USE OF ORGANIC STRUCTURE DIRECTORS according to claim 1, characterized in that a reaction mixture composed of the molar ratio of CH3OH / S1O2 equal to 1.0; molar ratio of S1O2 / Al2O3 between 50 and 100; 0H7 SiO2 molar ratio between 1.0 and 2.0; molar ratio of H2 O / Si2 between 15 and 40; Seeds / Synthesis Gel mass ratio between 0.006 and 0.01; and crystallization times not exceeding 3 hours for static or agitated systems. 4. ZSM-22 ZEOLITE PREPARATION PROCESS WITHOUT THE USE OF STRUCTURE ORGANIC DIRECTORS according to claim 1, 2 and 3, characterized in that any source of silicon and alkaline cations is used together and / or separately, in part or in place. total sodium silicate employed in the examples shown in this document. ZEOLITE TYPE ZSM-22 PREPARATION PROCESS WITHOUT THE USE OF STRUCTURE ORGANIC GUIDELINES according to claim 1,2,3 and 4, characterized by the use of any aluminum source in partial or total replacement of aluminum sulphate employed in the examples shown in this document. ZEOLITE TYPE ZSM-22 PREPARATION PROCESS WITHOUT THE USE OF STRUCTURE ORGANIC GUIDELINES according to claim 1, 2, 3,4 and 5 characterized by crystallization temperatures between 150 and 200 ° C, preferably 170 ° C, and times less than 6 hours. TYPE ZSM-22 ZEOLITE PREPARATION PROCESS WITHOUT THE USE OF ORGANIC STRUCTURE DIRECTORS according to claims 2 and 3 wherein the mass ratio of methanol to seed (CH3OH / Seeds) added to the medium is in the range of 5 to 215.