13X ZEOLITE, SYNTHESIS METHOD AND USE THEREOF

Abstract

The present disclosure relates to a 13X zeolite, a 13X zeolite adsorbent and a synthesis method thereof. Wherein, the synthesis method includes preparing a seed material by mixing sodium aluminate, sodium silicate, NaOH into water to get a seed mixture, stirring the seed mixture and aging. Then preparing the 13X zeolite by mixing sodium aluminate, sodium silicate, NaOH into water, followed by 0-5 wt. % addition of the seed material to obtain a gel mixture. Stirring the said gel mixture for 1 hour and crystallization of the gel mixture, then a filtration step and a washing step is performed to obtain a 13X zeolite cake. Further, the 13X zeolite cake is dried at 120? C. for 24 hours, then crushed and grinded to obtain a 13X zeolite powder. The 13X zeolite adsorbent is prepared by binding the 13X zeolite powder with a binder.

Claims

1. A method for synthesis of a 13X zeolite, wherein, the method comprising steps of: preparing a seed material, wherein, the seed material is prepared by mixing sodium aluminate, sodium silicate, and NaOH into water to get a seed mixture, having a molar composition of 10-20 SiO.sub.2: Al.sub.2O.sub.3: 10-20 Na.sub.2O: 200-300 H.sub.2O, stirring the seed mixture for 1-1.5 hour and aging at 30-45? C. for 18-26 hours; and preparing the 13X zeolite by mixing sodium aluminate, sodium silicate, NaOH into water, followed by addition of the seed material to obtain a gel mixture having a molar composition of 2-7 SiO.sub.2:Al.sub.2O.sub.3:2-7 Na.sub.2O: 200-300H.sub.2O, stirring the gel mixture for 50-70 minutes and crystallization of the gel mixture at 95-100? C. for 8-12 hours, a filtration step and a washing step with hot demineralized water is performed to obtain a 13X zeolite cake.

2. The method as claimed in claim 1, wherein the amount of seed material added in the gel mixture is 0-5 wt. % of the gel mixture.

3. The method as claimed in claim 2, wherein the amount of seed material added in the gel mixture is 0-2 wt. % of gel mixture.

4. The method as claimed in claim 1, wherein, the seed material is prepared by mixing sodium aluminate, sodium silicate, NaOH, and water to get the seed mixture having a molar composition of SiO.sub.2: Al.sub.2O.sub.3: 13-16 Na.sub.2O:250-300 H.sub.2O.

5. The method as claimed in claim 61, wherein, the 13X zeolite is prepared by mixing sodium aluminate, sodium silicate, NaOH, and water to get the gel mixture having a molar composition of 2-4 SiO.sub.2: Al.sub.2O.sub.3: 3-5 Na.sub.2O:250-300 H.sub.2O.

6. The method as claimed in claim 1, wherein, the 13X zeolite cake is dried at 120? C. for 24 hours, then crushed and grinded to obtain a 13X zeolite powder.

7. A method for preparing a 13X zeolite adsorbent by binding the 13X zeolite powder as claimed in claim 6 with a binder, preparing extrudes or beads of the 13X zeolite adsorbent, and then drying the said extrudes or beads at 120? C.

8. The method as claimed in claim 7, wherein, the binder is selected from a clay, an organic polymer.

9. The method as claimed in claim 8, wherein, the organic polymer is a polyvinyl alcohol.

10. The method as claimed in claim 7, wherein, the 13X zeolite powder is 95-98 weight % and the binder is 2-5 weight %.

11. The 13X zeolite adsorbent as claimed in claim 7, wherein, the said 13X zeolite adsorbent has crystallinity in the range of 110-120%.

12. The 13X zeolite adsorbent as claimed in claim 7, wherein, the said 13X zeolite adsorbent has surface area in the range of 750-810 m.sup.2/g.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0029] To further clarify advantages and aspects of the present disclosure, a more particular description of the present 13X zeolite as disclosed herein will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawing(s). It is appreciated that the drawing(s) of the present disclosure depicts only typical embodiments and are therefore not to be considered limiting of its scope.

[0030] FIG. 1: illustrates a Nitrogen adsorption isotherm of the commercial zeolite adsorbent, 13X zeolite adsorbent as prepared in example 3 and example 4.

DESCRIPTION OF THE INVENTION

[0031] According to the main embodiment, the present invention provides a 13X zeolite, synthesis method thereof, and use of 13X zeolite adsorbent in oxygen production from air. The synthesis method of said 13X zeolite includes firstly preparing a seed material and then preparing the 13X zeolite. The addition of seed accelerates crystallization and enhances surface area and crystallinity of 13X zeolite.

[0032] Specifically, the present invention provides a seed assisted method for synthesis of 13X zeolite. Wherein, the seed content is 0-2 wt. % based on gel amount and the crystallization time as required is approximately 10 hours.

[0033] The 13X zeolite adsorbent synthesized by seed assisted method has high crystallinity in the range of 110-120% and high surface area in the range of 750-810 m.sup.2/g.

Preparation of Seed Material

[0034] Sodium aluminate, sodium silicate, NaOH and water are added to get a seed mixture having a molar composition of 10-20SiO.sub.2:Al.sub.2O.sub.3:10-20Na.sub.2O:200-300H.sub.2O, stirring the seed mixture for 1-1.5 hour and aging at 30-45? C. for 18-26 hours.

[0035] Preferably, the seed material is prepared by mixing sodium aluminate, sodium silicate, NaOH, water to get the seed mixture having the molar composition of 12-15SiO.sub.2:Al.sub.2O.sub.3:13-16Na.sub.2O:250-300H.sub.2O. Then stirring the said seed mixture for 1 hour and aging at 35-45? C. for 18-24 hours.

Preparation of 13X Zeolite

[0036] Sodium aluminate, sodium silicate, NaOH and water are added to get a gel mixture having molar composition of 2-7SiO.sub.2:Al.sub.2O.sub.3:2-7Na.sub.2O:200-300H.sub.2O, followed by 0-5 wt. % addition of seed material as prepared in first step. Then stirring the gel mixture for 50-70 minutes and crystallization of the gel mixture at 95-100? C. for 8-12 hours.

[0037] Preferably, the 13X zeolite is prepared by mixing sodium aluminate, sodium silicate, NaOH, water to get the gel mixture having molar composition of 2-4SiO.sub.2:Al.sub.2O.sub.3:3-5Na.sub.2O:250-300H.sub.2O, followed by 0-2 wt. % addition of seed material as prepared in first step. Then stirring the gel mixture for 1 hour, followed by crystallization of gel mixture at 95-100? C. for 10 hours.

[0038] After crystallization, filtration and washing steps are carried out and obtained 13X zeolite cake is dried at 110-120? C. for 24 hours. The washing step is performed with hot demineralized water of temperature 90? C. Washing step is repeated two to three times for removal of occluded sodium.

[0039] Further, the present disclosure provides a 13X zeolite powder, wherein, the 13X zeolite cake after drying is crushed and grinded to obtain the 13X zeolite powder.

Preparation of 13X Zeolite Adsorbent

[0040] 13X zeolite adsorbent is prepared by binding the 13X zeolite powder as obtained hereinabove with a binder. Preparing the extrudes or beads of the 13X zeolite adsorbent, and then drying the said extrudes or beads at 120? C. The said 13X zeolite adsorbent has high nitrogen adsorption capacity and crushing strength.

[0041] Specifically, the 13X zeolite powder is 95-98 weight % and the binder is 2-5 weight % and wherein, the binder is selected from a clay, an organic polymer such as a polyvinyl alcohol.

[0042] Further, the present disclosure provides a 13X zeolite adsorbent and a synthesis method thereof. Wherein, the said 13X zeolite adsorbent shows high nitrogen adsorption capacity and high crushing strength compared to commercial adsorbent.

Example 1

[0043] 97 g of sodium aluminate, 194 g of sodium silicate, 62.5 g of NaOH and 1600 g of water are added to prepare an aluminosilicate gel mixture having molar composition of 3SiO.sub.2:Al.sub.2O.sub.3:4.5Na.sub.2O:298H.sub.2O, Then stirring the gel mixture for 1 hour, followed by crystallization of gel mixture at 95? C. for 10 hours.

[0044] After crystallization, filtration and washing steps are carried out and obtained 13X zeolite cake is dried at 120? C. for 24 hours. The washing step is performed with hot demineralized water of temperature 90? C. Washing step is repeated two to three times for removal of occluded sodium.

Example 2

[0045] For seed preparation, 11.5 g of sodium aluminate, 110 g of sodium silicate, 26.3 g of NaOH and 160 g of water are added to get a seed mixture having the molar composition of 14SiO.sub.2:Al.sub.2O.sub.3:15Na.sub.2O:287H.sub.2O, which is referred as seed mixture, stirring the said seed mixture for 1 hour and aging at 35? C. for 24 hours. 97 g of Sodium aluminate, 194 g of sodium silicate, 62.5 g of NaOH and 1600 g of water are added to prepare an aluminosilicate gel mixture having molar composition of 3SiO.sub.2:Al.sub.2O.sub.3:4.5Na.sub.2O:298H.sub.2O. Then stirring the gel mixture for 1 hour, followed by addition of 40 g of seed prepared as mentioned above, followed by crystallization of gel mixture at 95? C. for hours.

[0046] After crystallization, filtration and washing steps are carried out and obtained 13X zeolite cake is dried at 120? C. for 24 hours. The washing step is performed with hot demineralized water of temperature 90? C. Washing step is repeated two to three times for removal of occluded sodium.

Example 3

[0047] 13X zeolite adsorbent is prepared by binding the 13X zeolite powder prepared in example 1 with polyvinyl alcohol binder. Extrudes are prepared by mixing 9.8 g of 13X zeolite (dry basis) prepared in Example 1 and 0.2 g of polyvinyl alcohol, and then the said extrudes are dried at 120? C.

Example 4

[0048] 13X zeolite adsorbent is prepared by binding the 13X zeolite powder prepared in example 2 with polyvinyl alcohol binder. Extrudes are prepared by mixing 9.8 g of 13X zeolite (dry basis) prepared in Example 2 and 0.2 g of polyvinyl alcohol, and then the said extrudes are dried at 120? C.

Experiments & Results

[0049] Below table 1 provides the physicochemical properties of commercial adsorbent and the 13X zeolite adsorbents as prepared in example 3 and example 4. From the table 1 it is clear that the 13X zeolite as prepared in example 4 (i.e., through seed addition) has higher crystallinity percentage and has higher microporous surface area.

TABLE-US-00001 TABLE 1 Physicochemical properties of synthesized 13X zeolite adsorbents Seed Relative External Microporous content crystallinity MBET SA surface area Sample (wt. %) (%) (m.sup.2/g) (m.sup.2/g) (m.sup.2/g) Commercial 100 769.29 39.07 730.2 Example-3 0 117 766.78 25.16 741.6 Example-4 2 128 807.4 25.9 781.6

[0050] The commercial 13X zeolite based adsorbent is procured from BASF (HYDB100D Molecular sieve 13X).

[0051] Below table 2 illustrates the crushing strength and nitrogen adsorption capacity of the 13X zeolite-based adsorbents as prepared in example 3 and example 4 and the commercial used zeolite adsorbents. From the table 2 it is clear that the 13X zeolite adsorbent as prepared in example 4 (i.e., through seed addition) has improved crushing strength and has higher nitrogen adsorption capacity.

TABLE-US-00002 TABLE 2 Nitrogen adsorption capacity of 13X zeolite-based adsorbents Nitrogen adsorption Binder Crushing capacity content 13X strength (cc/gm) Sample Binder (wt. %) zeolite (N) (at 4.8 bar) Example-3 Polyvinyl 2 Example 1 19 29 alcohol Example-4 Polyvinyl 2 Example 2 18 30.6 alcohol Commercial 15 29