Synthesis of Nanocrystalline MFI Zeolite, Synthesis Method and use Thereof in Catalytic Applications

Abstract

The present invention relates to a new process for synthesising a crystalline material comprising the zeolite MFI structure in nanocrystalline form, and which can comprise at least the following steps: i) preparing a mixture comprising at least one source of water, at least one source of a tetravalent element Y, at least one source of a trivalent element X, at least one source of an alkali cation or alkaline earth metal cation (A), and at least one organic molecule (OSDA1), wherein OSDA1 is preferably a monocyclic quaternary ammonium with the structure R.sub.1R.sub.2CycloN.sup.+, the molar composition of the mixture being: n X.sub.2O.sub.3:YO.sub.2:a A:m OSDA1:z H.sub.2O; ii) crystallising this mixture in a reactor; and iii) recovering the crystalline material obtained.

Claims

1. A method for synthesising a zeolite material with MFI structure in nanocrystalline form, characterised in that it comprises at least the following steps: i) preparing a mixture comprising at least one source of water, at least one source of a tetravalent element Y, at least one source of a trivalent element X, at least one source of an alkali cation or alkaline earth metal cation (A), and at least one organic molecule (OSDA1) with the structure R.sub.1R.sub.2CycloN.sup.+, wherein OSDA1 is a quaternary ammonium of structure R.sub.1R.sub.2CycloN.sup.+, wherein the Cyclo group comprises 4-7 carbon atoms, group R.sub.1 is a linear alkyl chain of 1 to 4 carbon atoms, group R.sub.2 is a linear alkyl chain of 3 to 6 carbon atoms; and the molar composition of the mixture is: n X.sub.2O.sub.3:YO.sub.2:a A:m OSDA1:z H.sub.2O wherein n is comprised in the range of 0 to 0.5; a is comprised in the range of 0 to 2; m is comprised in the range of 0.01 to 2; z is comprised in the range of 1 to 200; and ii) crystallising the mixture obtained in i) in a reactor; and iii) recovering the crystalline material obtained in ii).

2. The method according to claim 1, characterised in that the tetravalent element Y is selected from silicon, tin, titanium, zirconium, germanium, and combinations thereof.

3. The method according to claim 2, characterised in that the source of the tetravalent element Y is a source of silicon which is selected from silicon oxide, silicon halide, colloidal silica, fumed silica, tetraalkyl orthosilicate, silicate, silicic acid, a previously-synthesised crystalline material, a previously-synthesised amorphous material and combinations thereof.

4. The method according to claim 3, characterised in that the source of silicon is selected from a previously-synthesised crystalline material, a previously-synthesised amorphous material and combinations thereof.

5. The method according to claim 4, characterised in that the previously-synthesised materials contain other heteroatoms in the structure thereof.

6. The method according to claim 1, characterised in that the trivalent element X is selected from aluminium, boron, iron, indium, gallium and combinations thereof.

7. The method according to claim 1, characterised in that the OSDA1 is selected from alkyl-azetidiniums, alkyl-pyrrolidiniums, alkyl-piperidiniums, and combinations thereof.

8. The method according to claim 7, characterised in that the OSDA1 is selected from N-propyl-N-methylazetidinium, N-butyl-N-methylazetidinium, N-pentyl-N-methylazetidinium, N-propyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium, N-pentyl-N-methylpyrrolidinium, N-butyl-N-ethylpyrrolidinium, N,N-dibutyl-pyrrolidinium, and combinations thereof.

9. The method according to claim 8, characterised in that said OSDA1 is N-butyl-N-methylpyrrolidinium.

10. The method according to claim 1, characterised in that the crystallisation process described in ii) is carried out in autoclaves, under static or dynamic conditions.

11. The method according to claim 1, characterised in that the crystallisation step described in ii) is carried out at a temperature of between 80 and 200 C.

12. The method according to claim 1, characterised in that the crystallisation time of step ii) is comprised between 6 hours and 50 days.

13. The method according to claim 1, characterised in that it further comprises adding MFI crystals to the synthesis mixture in an amount of up to 25% by weight with respect to the total amount of the sources of X and Y introduced in step i).

14. The method according to claim 13, characterised in that the MFI crystals are added before the crystallisation process or during the crystallisation process of step ii).

15. The method according to claim 1, characterised in that the recovery step iii) is carried out by means of a separation technique selected from decantation, filtration, ultrafiltration, centrifugation and combinations thereof.

16. The method according to claim 1, characterised in that it further comprises the removal of the organic content trapped within the material.

17. The method according to claim 16, characterised in that the process of removing the organic content isolated within the material is performed by heat treatment at temperatures between 100 and 1000 C. for a time period comprised between 2 minutes and 25 hours.

18. The method according to claim 1, characterised in that the obtained material is pelletised.

19. The method according to claim 1, characterised in that any cation present in the material is exchanged by means of ion exchange with other cations.

20. The method according to claim 19, characterised in that the exchange cation is selected from metals, protons, proton precursors, and mixtures of same.

21. The method according to claim 19, characterised in that the exchange cation is a metal selected from rare-earth metals, metals from groups IIA, IIIA, IVA, VA, IB, IIB, IIIB, IVB, VB, VIB, VIIB, VIII, and combinations thereof.

22. A zeolite material with MFI structure in nanocrystalline form defined in claim 1, characterised in that it has the following molar composition: O X.sub.2O.sub.3:YO.sub.2:p A:q OSDA1:r H.sub.2O wherein X is a trivalent element; Y is a tetravalent element; A is an alkali or alkaline earth element; o is comprised in the range of 0 to 0.5; p is comprised in the range of 0 to 2; q is comprised in the range of 0.01 to 2; and r is comprised in the range of 0 to 2.

23. The zeolite material with MFI structure according to claim 22, characterised in that it has the following molar composition after being calcined: o X.sub.2O.sub.3:YO.sub.2:p A wherein X is a trivalent element; Y is a tetravalent element; and A is an alkali or alkaline earth element; o is comprised in the range between 0 and 0.5; and p is comprised in the range of 0 to 2.

24. The zeolite material with MFI structure according to claim 22, characterised in that the tetravalent element Y is selected from silicon, tin, titanium, zirconium, germanium, and combinations thereof.

25. The zeolite material with MFI structure according to claim 22, characterised in that the trivalent element X is selected from aluminium, boron, iron, indium, gallium and combinations thereof.

26-31. (canceled)

32. A method for the conversion of feeds formed by organic compounds into products with a higher added value or for removal/separation from the reactive stream characterised in that it comprises the following step a) contacting the zeolite material with MFI structure of claim 22 with said feed formed by organic compounds selected from an oxygenated organic compound; or an alkylatable aromatic molecule and an alkylating agent; or light olefins.

33. A method for the dealkylation characterised in that it comprises the following step a) contacting the zeolite material with MFI structure of claim 22 with alkylaromatics.

34. A method for the transalkylation characterised in that it comprises the following step a) contacting the zeolite material with MFI structure of claim 22 with alkylaromatics.

35. A method for the isomerisation characterised in that it comprises the following step a) contacting the zeolite material with MFI structure obtained of claim 22 with alkylaromatics.

36. A method for the dealkylation and transalkylation in combined process characterised in that it comprises the following step a) contacting the zeolite material with MFI structure of claim 22 with alkylaromatics.

37. A method to increase the production of olefins characterised in that it comprises the following step a) contacting the zeolite material with MFI structure of claim 22 with the hydrocarbons fractions of the cracking.

38. A catalyst for the conversion of feeds formed by organic compounds into products with a higher added value comprising the zeolite material with MFI structure of claim 22.

39. A molecular sieve for the removal or separation of reactive streams comprising the zeolite material with MFI structure of claim 22.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0060] FIG. 1: Diffraction patterns of the materials obtained according to Examples 3-11 of the present invention.

[0061] FIG. 2: SEM images of the materials obtained according to Examples 3, 4 and 10 of the present invention.

[0062] FIG. 3: TEM image of the material obtained according to Example 3 of the present invention.

[0063] FIG. 4: Methanol conversion values at 450 C. and WHSV=10 h.sub.1, obtained using as catalysts the synthesised materials according to Examples 3 and 9 of the present invention.

[0064] The present invention is illustrated by means of the following examples not intended to be limiting thereof.

EXAMPLES

[0065] The invention is illustrated below by means of tests conducted by the inventors that demonstrate the effectiveness of the product of the invention.

Example 1: Synthesis of 1-butyl-1-methylpyrrolidinium (1B1M)

[0066] 15 g of 1-butylpyrrolidine (0.118 moles) and 200 ml of chloroform are added to a glass flask. The flask is placed in an ice bath (0 C.) and is left to cool, maintaining constant stirring. After that, 33.47 g of iodomethane (0.236 moles) are gradually added. Once the system reaches room temperature, it is left to react for 72 h. Once the reaction has ended the solvent is evaporated, a mixture of ethanol-ethyl acetate is added to crystallise the product. The formed crystals of 1-butyl-1-methylpyrrolidinium iodide are separated by filtration, obtaining 27.6 g (0.1025 moles) of product.

[0067] To prepare the hydroxide form of the preceding organic salt: 15 g of the organic salt are dissolved in 75 g of water. Next, 38 g of an anionic exchange resin (Dower SBR) are added, and the resulting mixture is kept under stirring for 24 hours. Lastly, the solution is filtered and 1-butyl-1-methylpyrrolidinium hydroxide is obtained (with an exchange percentage of 95%).

Example 2: Synthesis of Triethylbutylammonium (TEBA)

[0068] 20.24 g (0.20 moles) of ethylisobutylamine are dissolved in 200 ml of chloroform. The solution is transferred to a two-necked flask connected to cooling. The mixture is cooled in an ice bath. Anhydrous K.sub.2CO.sub.3 (13.82 g; 0.10 moles) is added and left to react for one hour under constant stirring. Iodoethane (93.58 g; 0.60 moles) is slowly added by means of a pressure compensated funnel. After that it is heated at 50 C. and left to react for 24 h. It is cooled at room temperature, a new iodoethane aliquot (31 g, 0.20 moles) is added and it is left to react another 48 h. After the reaction time has lapsed, the solvent is evaporated and the obtained residue is dissolved in dichloromethane. The crude product is filtered to separate the inorganic salts, setting aside the supernatant. Lastly, the solvent is evaporated and the product is crystallised by adding ethyl acetate.

[0069] To prepare the hydroxide form of the preceding organic salt: 15 g of the organic salt are dissolved in 75 g of water. Next, 38 g of an anionic exchange resin (Dower SBR) are added, and the resulting mixture is kept under stirring for 24 hours. Lastly, the solution is filtered and triethylbutylammonium hydroxide is obtained (with an exchange percentage of 95%).

Example 3: Synthesis of Nanocrystalline Silicoaluminate with MFI Structure

[0070] 23.9 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1 of the present invention) are mixed with 0.065 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 3.7 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 Al.sub.2O.sub.3/0.4 1B1M/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 90%.

[0071] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 3 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 33.2. The average crystal size is 10-15 nm (see SEM and TEM images in FIGS. 2 and 3). The textural properties of the synthesised material according to Example 3 of the present invention have been calculated by N.sub.2 adsorption/desorption, obtaining 514 m.sup.2/g, 320 m.sup.2/g, and 194 m.sup.2/g, for the total BET area, micropore area and external area, respectively.

Example 4: Synthesis of Nanocrystalline Silicoaluminate with MFI Structure

[0072] 18.4 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1 of the present invention) are mixed with 0.01 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 1.64 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.005 Al.sub.2O.sub.3/0.4 1B1M/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 90%.

[0073] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 4 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 83.3. The average crystal size is 15-20 nm (see TEM image in FIG. 2).

Example 5: Synthesis of Nanocrystalline Silicoaluminate with MFI Structure

[0074] 1.37 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1) are mixed with 0.072 g of an aqueous solution at 20% by weight of sodium hydroxide (NaOH, Sigma-Aldrich, 98%) and 0.006 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 0.35 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 Al.sub.2O.sub.3/0.15 NaOH/0.25 1B1M/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 90%.

[0075] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 5 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 35.1. The average crystal size is 15-20 nm.

Example 6: Synthesis of Nanocrystalline Silicoaluminate with MFI Structure

[0076] 1.37 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1) are mixed with 0.074 g of an aqueous solution at 20% by weight of sodium hydroxide (NaOH, Sigma-Aldrich, 98%) and 0.006 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 0.34 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 Al.sub.2O.sub.3/0.15 NaOH/0.25 1B1M/50 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 80%.

[0077] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 6 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 31. The average crystal size is 20-25 nm.

Example 7: Synthesis of Nanocrystalline Silicoaluminate with MFI Structure

[0078] 1.38 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1) are mixed with 0.095 g of an aqueous solution at 20% by weight of potassium hydroxide (KOH, Sigma-Aldrich, 98%) and 0.012 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 0.35 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.033 Al.sub.2O.sub.3/0.15 KOH/0.25 1B1M/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 80%.

[0079] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 7 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 19.2. The average crystal size is 20-25 nm.

Example 8: Synthesis of Nanocrystalline Borosilicate with MFI Structure

[0080] 9.09 g of an aqueous solution at 6.7% by weight of 1B1M hydroxide (obtained according to Example 1 of the present invention) are mixed with 0.43 g of an aqueous solution at 5% of boric acid [H.sub.3BO.sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 1.52 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 B.sub.2O.sub.3/0.4 1B1M/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is greater than 85%.

[0081] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of MFI structure. The chemical composition of the final sample has a Si/B ratio of 29.3. The average crystal size is 10-15 nm.

Example 9: Synthesis of Silicoaluminate with MFI Structure Using Tetrapropylammonium as OSDA

[0082] 13.02 g of an aqueous solution at 20% by weight of the tetrapropylammonium hydroxide are mixed with 0.084 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 4.8 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 Al.sub.2O.sub.3/0.4 TPAOH/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is 70%.

[0083] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 9 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 31.8. The average crystal size is 200 nm (see SEM image in FIG. 2). The textural properties of the synthesised material according to Example 9 of the present invention have been calculated by N.sub.2 adsorption/desorption, obtaining 360 m.sup.2/g, 349 m.sup.2/g, and 11 m.sup.2/g, for the total BET area, micropore area and external area, respectively. This example shows that the use of TPA as OSDA, results in crystallising the MFI zeolite with an average crystal size considerably larger than those obtained in Examples 3-7 of the present invention, as also demonstrated by the obtained lower values of BET and external area (compare with Example 3).

Example 10: Synthesis of Silicoaluminate with MFI Structure Using Tetrapropylammonium as OSDA

[0084] 13.02 g of an aqueous solution at 20% by weight of the tetrapropylammonium hydroxide are mixed with 0.026 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for 20 minutes. Next, 4.83 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40, Sigma-Aldrich) are added, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.005 Al.sub.2O.sub.3/0.4 TPAOH/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours. The obtained solid yield is 50%.

[0085] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of the MFI structure (see Example 10 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 91.3.

Example 11: Synthesis Using Triethylbutylammonium (TEBA) as OSDA

[0086] 2.01 g of an aqueous solution at 8.0% by weight of TEBA hydroxide (obtained according to Example 2 of the present invention) are mixed with 0.006 g of alumina [Al(OH).sub.3, Sigma-Aldrich]. The mixture is kept under stirring for complete homogenisation for 20 minutes. 0.349 g of an aqueous solution of colloidal silica at 40% by weight (Ludox HS-40 colloidal silica, Sigma-Aldrich) are added to the mixture, and the mixture is kept under stirring until the desired concentration is achieved. The final composition of the gel is SiO.sub.2/0.0167 Al.sub.2O.sub.3/0.4 TEBA/10 H.sub.2O. This gel is transferred to a Teflon-lined steel autoclave and heated at 150 C. for 14 days under static conditions. After this time has lapsed, the obtained product is recovered by filtration, washed with abundant water, and dried at 100 C. The obtained solid is calcined in air at 550 C. for 5 hours.

[0087] It is confirmed by X-ray diffraction that the obtained solid has the characteristic peaks of MFI structure (see Example 11 in FIG. 1). The chemical composition of the final sample has a Si/Al ratio of 32.4. The average crystal size is 100 nm. This example shows that the absence of a cyclic group in the OSDA, together with the combination of linear alkyl groups of different sizes (in this case, a butyl and three ethyls), results in crystallising MFI with a significantly larger average crystal size.

Example 12: Catalytic Assay for the Methanol to Olefins Reaction

[0088] The activity of the samples has been tested in the methanol-to-olefins transformation in an isothermal fixed-bed reactor under the following reaction conditions: WHSV=10 h.sup.1, atmospheric pressure, reaction temperature=450 C., catalyst=50 mg pelletised between 0.2 and 0.4 mm. The methanol is vaporised by bubbling with 20 ml min.sub.1 of nitrogen in a methanol tank at 23 C. The catalyst is diluted in 1.95 g of inert silica (0.1-0.2 mm) and placed in a glass reactor 10 mm in diameter. The reaction temperature is constantly regulated by a type K thermocouple and a PID controller associated with a heating oven. The outlet of the reactor is controlled at 150 C. and the products are analysed in two gas chromatographs, first in a PONA 50 m capillary column, with an internal diameter of 0.25 mm, to separate C.sub.1 to C.sub.12 hydrocarbons with a temperature program of 35 to 250 C., and second in a PLOT-alumina 30 m column, with an internal diameter of 0.53 mm, with a temperature program of 50 to 180 C. to separate C.sub.2-C.sub.4 hydrocarbons and determine hydrogen transfer. The detectors used flame ionisation detectors. The conversion is defined as the sum of the yields by weight of hydrocarbons.

[0089] The catalytic results obtained for the catalysts obtained according to Examples 3 and 9 of the present invention are shown in Table 1. By comparing the results of the two materials presented in Table 1, it is concluded that the catalyst based on MFI zeolite obtained according to Example 3 is much more active than the catalyst based on MFI zeolite obtained according to Example 9, presenting a much slower deactivation (see FIG. 4). The smaller crystal size of the catalyst obtained according to Example 3 Explains this considerable increase in lifetime. Furthermore, it is shown that the reduction of the crystal size causes a higher yield into olefins with a lower production of undesired paraffins, ethylene and aromatics (see Table 1).

TABLE-US-00001 TABLE 1 Yields into hydrocarbons in the methanol-to-olefins reaction at 450 C. and WHSV = 10 h.sup.1 at a reaction time of 250 minutes Yields in % weight Example 3 Example 9 PARAFFINS C1 0.68 2.07 C2 0.11 0.27 C3 2.33 5.21 C4 3.90 8.12 C5 2.29 3.53 C6 2.17 2.27 C7 1.58 1.12 C8 0.55 0.48 OLEFINS C2 8.41 13.80 C3 38.49 26.88 C4 24.27 15.99 C5 6.43 4.01 C6 0.96 0.60 C7 0.31 0.26 AROMATICS C6 0.23 0.57 C7 1.17 3.33 C8 2.45 7.99 C9 1.94 2.11 C10 0.28 0.26 C11 0.05 0.06 C12 0.01 0.09 NAPHTHENES C5 0.32 0.28 C6 0.56 0.41 C7 0.40 0.24 C8 0.08 0.06 TOTAL OLEFINS 78.88 61.53 PARAFFINS 13.61 23.07 AROMATICS 6.14 14.41 NAPHTHENES 1.38 0.99