Catalyst used in the production of ethylene and propylene from methanol and/or dimethyl ether, method for preparing the same and method for using the same

Abstract

The application provides a catalyst for producing ethylene and propylene from methanol and/or dimethyl ether, and a preparation and application thereof. In the present application, a molecular sieve catalyst co-modified by rare earth metals and silanization is utilized. First, the material containing methanol and/or dimethyl ether reacts on the catalyst to generate hydrocarbons. The hydrocarbons are separated into a C.sub.1-C.sub.5 component and a C.sub.6.sup.+ component. Then the C.sub.6.sup.+ component is recycled to the feeding port and fed into the reactor after mixing with methanol and/or dimethyl ether. The above steps are repeated, to finally generate C.sub.1-C.sub.5 products, in which the selectivity for ethylene and propylene can reach more than 90 wt % in the C.sub.1-C.sub.5 component, so that the maximal yield can be achieved in the production of ethylene and propylene from methanol and/or dimethyl ether.

Claims

1. A process for producing ethylene and propylene from methanol and/or dimethyl ether, comprising the steps of; (a) contacting methanol and/or dimethyl ether with a catalyst to generate a first stream containing hydrocarbons, the catalyst produced by the steps consisting of: (i) impregnating a HZSM-5 and/or a HZSM-11 zeolite molecular sieve in a lanthanum nitrate solution for 1-12 hours, followed by filtering, drying and calcining to obtain a lanthanum-modified molecular sieve; (ii) impregnating said obtained lanthanum-modified molecular sieve in one or more silicon sources selected from the group consisting of tetramethyl silicate, tetraethyl silicate, and silicon tetraethyl for 1-12 hours, followed by filtering, drying and calcining to obtain a molecular sieve catalyst co-modified by lanthanum and silanization; (b) separating said first stream obtained from step (a) into a first C.sub.1-C.sub.5 component and a first C.sub.6+ component; (c) mixing said first C.sub.6+ component obtained from step (b) with methanol and/or dimethyl ether to generate a mixture material, and contacting the mixture material with said catalyst to generate a second stream containing hydrocarbons; (d) separating said second stream obtained from step (c) into a second C.sub.1-C.sub.5 component and a second C.sub.6+ component, wherein said second C.sub.1-C.sub.5 component contains ethylene and propylene and is collected as a target product and said second C.sub.6+ component is recycled to step (c); and (e) repeating step (c) and step (d), wherein the mixture material formed by mixing said second C.sub.6+ component obtained in step (d) with methanol and/or dimethyl ether is used in step (c), so that said second C.sub.1-C.sub.5 component containing ethylene and propylene is obtained continuously; wherein said catalyst co-modified by lanthanum and silanization is the only catalyst used in the process, said catalyst is loaded by lanthanum, and a surface acidity of said catalyst is modified by silicon compounds; and wherein a loading amount of said lanthanum is 0.5-5 wt % of a total weight of said catalyst, and a loading amount of said silicon compounds, which is based on silicon oxide, is 0.1-10 wt % of the total weight of said catalyst.

2. The process according to claim 1, wherein process is carried out at a temperature of 400-600° C. and a pressure of 0-2.0 MPa, and methanol and/or dimethyl ether are fed at a weight hourly space velocity of 0.2-10 h.sup.−1.

3. The process according to claim 1, wherein the process is conducted in a fixed bed, a moving bed or a fluidized bed reactor.

4. The process according to claim 1, wherein the loading amount of said lanthanum is 1-5 wt % of the total weight of said catalyst; and the loading amount of said silicon compounds, which is based on silicon oxide, is 1-10 wt % of the total weight of said catalyst.

5. The process according to claim 1, wherein said silicon source is tetraethyl silicate.

6. A process for producing ethylene and propylene from methanol and/or dimethyl ether, comprising the steps of; (a) contacting methanol and/or dimethyl ether with a catalyst to generate a first stream containing hydrocarbons, the catalyst produced by the steps consisting of: (i) impregnating a HZSM-5 and/or a HZSM-11 zeolite molecular sieve in a lanthanum nitrate solution for 1-12 hours, followed by filtering, drying and calcining to obtain a lanthanum-modified molecular sieve; (ii) impregnating said obtained lanthanum-modified molecular sieve in one or more silicon sources selected from the group consisting of tetramethyl silicate, tetraethyl silicate, and silicon tetraethyl for 1-12 hours, followed by filtering, drying and calcining to obtain a molecular sieve catalyst co-modified by lanthanum and silanization; (b) separating said first stream obtained from step (a) into a first C.sub.1-C.sub.5 component and a first C.sub.6+ component; (c) mixing said first C.sub.6+ component obtained from step (b) with methanol and/or dimethyl ether to generate a mixture material, and contacting the mixture material with said catalyst to generate a second stream containing hydrocarbons; (d) separating said second stream obtained from step (c) into a second C.sub.1-C.sub.5 component and a second C.sub.6+ component, wherein said second C.sub.1-C.sub.5 component contains ethylene and propylene and is collected as a target product and said second C.sub.6+ component is recycled to step (c); and (e) repeating step (c) and step (d), wherein the mixture material formed by mixing said second C.sub.6+ component obtained in step (d) with methanol and/or dimethyl ether is used in step (c), so that said second C.sub.1-C.sub.5 component containing ethylene and propylene is obtained continuously; wherein said catalyst co-modified by lanthanum and silanization is loaded by lanthanum, and a surface acidity of said catalyst is modified by silicon compounds; and wherein a loading amount of said lanthanum is 0.5-5 wt % of a total weight of said catalyst, and a loading amount of said silicon compounds, which is based on silicon oxide, is 0.1-10 wt % of the total weight of said catalyst.

Description

DETAILED EMBODIMENTS

(1) In order to achieve the above objects, a catalyst used for producing ethylene and propylene from methanol and/or dimethyl ether is investigated and developed, i.e. a molecular sieve catalyst co-modified by lanthanum and silanization. In said molecular sieve catalyst, the molecular sieve is HZSM-5 and/or HZSM-11 zeolite molecular sieve. Said catalyst co-modified by lanthanum and silanization is loaded by lanthanum and its surface acidity is modified by silicon compounds. The loading amount of the lanthanum is 0.5-5 wt % of the total weight of said catalyst; the loading amount of the silicon compounds, which is based on silicon oxide, is 0.1-10 wt % of the total weight of said catalyst; and the rest of said catalyst is HZSM-5 and/or HZSM-11 zeolite molecular sieve.

(2) A method for producing said catalyst is investigated and developed, wherein said zeolite molecular sieve is HZSM-5 and HZSM-11 zeolite molecular sieve. The method comprises the steps as follows: HZSM-5 and/or HZSM-11 zeolite molecular sieve is impregnated in a lanthanum nitrate solution for 1-12 hours, then filtered, dried at 100-120° C. and calcined in air at 450-650° C. to obtain lanthanum-modified molecular sieve; and said obtained lanthanum-modified molecular sieve is impregnated in one or more silicon sources selected from a group consisting of tetramethyl silicate, tetraethyl silicate and silicon tetraethyl, preferably tetraethyl silicate, for 1-12 hours, then filtered, dried at 100-120° C. and calcined in air at 450-650° C. to obtain a molecular sieve catalyst co-modified by lanthanum and silanization.

(3) A new process for producing ethylene and propylene from methanol and/or dimethyl is investigated and developed. The process comprises the steps of: contacting methanol and/or dimethyl ether alone with said catalyst, to generate a first hydrocarbons; separating said first hydrocarbons into a first C.sub.1-C.sub.5 component and a first C.sub.6.sup.+ component; recycling said first C.sub.6.sup.+ component and allowing it to be fed in a mixture with methanol and/or dimethyl ether; contacting the mixture with said catalyst to generate a second hydrocarbons having a new composition; separating said second hydrocarbons having the new composition into a second C.sub.1-C.sub.5 component and a second C.sub.6.sup.+ component; recycling said second C.sub.6.sup.+ component and collecting said second C.sub.1-C.sub.5 component as the product; wherein by recycling said second C.sub.6.sup.+ component and feeding it in a mixture with methanol and/or dimethyl ether, the conversion from methanol and/or dimethyl ether to ethylene and propylene is improved, so that said second C.sub.1-C.sub.5 product containing ethylene and propylene in a high selectivity is obtained continuously.

(4) In said catalyst, the loading amount of the lanthanum is 0.5-5 wt %, preferably 1-5% of the total weight of said catalyst; and the loading amount of the silicon oxide modified by silanization is 0.1-10 wt %, preferably 1-10% of the total weight of said catalyst.

(5) In the process of the present application, the raw material is methanol or dimethyl ether or a mixture of methanol and dimethyl ether. Wherein said methanol is pure methanol or an aqueous solution of methanol, and the concentration of methanol in aqueous solution is between 50 wt % and 100 wt %. After vaporized, the raw material is pumped into a reactor, then contacting with said catalyst and converting to target products.

(6) In a preferable embodiment, said process of converting methanol/dimethyl ether into ethylene and propylene is conducted in a fixed bed, a moving bed, or a fluidized bed.

(7) In a preferable embodiment, said process of converting methanol/dimethyl ether into ethylene and propylene is carried out at temperature of 350-650° C., more preferably 400-600° C.; and a pressure of 0-5.0 MPa, more preferably 0-2.0 MPa; and the raw material is fed in a weight space hourly velocity of 0.2-10 h.sup.−1, more preferably 0.2-10 h.sup.−1.

(8) In present application, said pressure is a gage pressure.

(9) For the catalyst used in the conversion from methanol/dimethyl ether to ethylene and propylene and the application thereof according to the present application, a C.sub.1-C.sub.5 product containing ethylene and propylene in a high selectivity is obtained finally, wherein the selectivity for ethylene and propylene is more than 90 wt % in the C.sub.1-C.sub.5 product.

EXAMPLES

(10) The application is described in detail by the following Examples, but not limited to the Examples.

(11) In this application, the parts, percentages and amounts are all based on weight, unless indicated otherwise.

Example 1: Preparation of Catalyst

(12) 1) The raw powder containing a template agent inside of HZSM-5 zeolite molecular sieve (100 g, The Catalyst Plant of Nankai University, molar ratio of SiO.sub.2/Al.sub.2O.sub.3=50) was weighted, and then impregnated overnight in a lanthanum nitrate solution which was prepared according to the requirement of 3 wt % La loading amount. After the upper layer liquid was decanted, the impregnated HZSM-5 zeolite molecular sieve solid was dried out at 120° C., and calcined in air at 550° C. for 3 hours. Then La-modified HZSM-5 zeolite molecular sieve was obtained.

(13) 2) The La-modified HZSM-5 zeolite molecular sieve (50 g) obtained in step (a) was impregnated in tetraethoxysilane (TEOS) at room temperature for 12 hours. After the upper layer liquid was decanted, the impregnated HZSM-5 zeolite molecular sieve solid was dried out at 120° C., and calcined in air at 550° C. for 6 hours. Then a HZSM-5 catalyst co-modified by lanthanum and silanization was obtained, and named as MATO-1.

(14) 3) The HZSM-5 catalyst co-modified by lanthanum and silanization was subjected to an elemental analysis, wherein the loading amount of lanthanum was 2.8 wt % of the total weight of said catalyst and the loading amount of silanization, which was based on silicon oxide, was 4.8% of the total weight of said catalyst.

Example 2: Preparation of Catalyst

(15) 1) The raw powder containing a template agent inside of HZSM-5 zeolite molecular sieve (100 g, The Catalyst Plant of Nankai University, molar ratio of SiO.sub.2/Al.sub.2O.sub.3=50) was weighted, and then impregnated overnight in a lanthanum nitrate solution which was prepared according to the requirement of 5 wt % La loading amount. After the upper layer liquid was decanted, the impregnated HZSM-5 zeolite molecular sieve solid was dried out at 120° C., and baked in air at 550° C. for 3 hours. Then La-modified HZSM-5 zeolite molecular sieve was obtained.

(16) 2) The La-modified HZSM-5 zeolite molecular sieve (50 g) obtained in step (a) was impregnated in tetraethoxysilane (TEOS) at room temperature for 24 hours. After the upper layer liquid was decanted, the impregnated HZSM-5 zeolite molecular sieve solid was dried out at 120° C., and calcined in air at 550° C. for 6 hours. Then a HZSM-5 catalyst co-modified by lanthanum and silanization was obtained, and named as MATO-2.

(17) 3) The HZSM-5 catalyst co-modified by lanthanum and silanization was subjected to an elemental analysis, wherein the loading amount of lanthanum was 4.6 wt % of the total weight of said catalyst and the loading amount of silanization, which was based on silicon oxide, was 6.9% of the total weight of said catalyst.

Example 3: Preparation of Catalyst

(18) 1) The raw powder containing a template agent inside of HZSM-11 zeolite molecular sieve (100 g, The Catalyst Plant of Nankai University, molar ratio of SiO.sub.2/Al.sub.2O.sub.3=61) was weighted, and then impregnated overnight in a lanthanum nitrate solution which was prepared according to the requirement of 5 wt % La loading amount. After the upper layer liquid was poured off, the impregnated HZSM-11 zeolite molecular sieve solid was dried out at 120° C., and calcined in air at 550° C. for 3 hours. Then La-modified HZSM-11 zeolite molecular sieve was obtained.

(19) 2) The La-modified HZSM-11 zeolite molecular sieve (50 g) obtained in step (a) was impregnated in tetraethoxysilane (TEOS) at room temperature for 24 hour. After the upper layer liquid was poured off, the impregnated HZSM-11 zeolite molecular sieve solid was dried out at 120° C., and calcined in air at 550° C. for 6 hours. Then a HZSM-11 catalyst co-modified by lanthanum and silanization was obtained, and named as MATO-3.

(20) 3) The HZSM-11 catalyst co-modified by lanthanum and silanization was subjected to an elemental analysis, wherein the loading amount of lanthanum was 4.8 wt % of the total weight of said catalyst and the loading amount of silanization, which was based on silicon oxide, was 7.3% of the total weight of said catalyst.

Reference Example: Evaluation for Reactions

(21) The MATO-1, MATO-2 and MATO-3 catalysts were used as the catalysts in the reactions. The catalysts were tabletted, crushed and then sieved to 40-60 meshes. Ten grams of each catalyst was loaded into a reactor, and treated in air at 550° C. for 1 hour followed by being blown and purged in nitrogen for 0.5 hour. Methanol was pumped into the reactor using a feeding pump, then it was contacted and reacted with the catalyst at a temperature of 550° C. and a pressure of 0 MPa. The raw material methanol was fed in a weight space hourly velocity of 2 h.sup.−1. The reaction products were analyzed online by gas chromatography. The compositions of the total products, the C.sub.1-C.sub.5 component and the C.sub.6.sup.+ component were shown in Tables 1, 2 and 3. In the total products, the C.sub.1-C.sub.5 component accounted for 84.26 wt %, 85.63 wt % and 85.89 wt %, respectively; whereas the C.sub.6.sup.+ component accounted for 15.74 wt %, 14.37 wt % and 14.11 wt %, respectively. In the C.sub.1-C.sub.5 components, the selectivity for ethylene and propylene was 56.19 wt %, 53.52 wt % and 55.23 wt %, respectively.

(22) TABLE-US-00001 TABLE 1 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 550 550 550 Conversion rate of 100 100 100 methanol (%) Distribution of total products (wt %) C.sub.1-C.sub.5 84.26 85.63 85.89 C.sub.6.sup.+ 15.74 14.37 14.11 Total 100.00 100.00 100.00 * C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

(23) TABLE-US-00002 TABLE 2 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 550 550 550 Conversion rate of 100 100 100 methanol (%) Distribution of C.sub.1-C.sub.5 products (wt %) CH.sub.4 5.32 5.58 5.64 C.sub.2H.sub.4 13.88 12.25 12.90 C.sub.2H.sub.6 3.52 3.35 4.23 C.sub.3H.sub.6 42.31 41.27 42.33 C.sub.3H.sub.8 7.34 7.85 8.37 C.sub.4 17.35 18.16 17.21 C.sub.5 10.28 11.54 9.32 Total 100.00 100.00 100.00 C.sub.2H.sub.4 + C.sub.3H.sub.6 56.19 53.52 55.23

(24) TABLE-US-00003 TABLE 3 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 550 550 550 Conversion rate of 100 100 100 methanol (%) Distribution of *C.sub.6.sup.+ products (wt %) Benzene 10.23 9.52 8.96 Toluene 36.14 35.28 36.25 Ethyl benzene 1.28 1.05 1.56 Xylene 32.54 34.26 33.21 Trimethyl benzene 11.26 10.89 11.08 Tetramethylbenzene 5.34 5.68 6.01 Others 3.21 3.32 2.93 Total 100.00 100.00 100.00 *C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

Example 4: Evaluation for Reactions

(25) The MATO-1, MATO-2 and MATO-3 catalysts were used as the catalysts in the reactions. The catalysts were tabletted, crushed and then sieved to 40-60 meshes. Ten grams of each catalyst was loaded into a reactor, and treated in air at 550° C. for 1 hour followed by a cooling process in nitrogen to reach the reaction temperature of 450° C. Arene solutions were prepared according to requirement for the proportions of benzene, toluene, xylene, trimethyl benzene and tetramethylbenzene in the C.sub.6.sup.+ products obtained from the methanol conversion performed on MATO-2 catalyst, as shown in Table 3 of Example 3. The prepared arene solutions and methanol (calculated by CH.sub.2), in a ratio of 1:1 by weight, were pumped into the reactors by a metering pump, then they were contacted and reacted with the catalysts. The reactions were carried out at a pressure of 0 MPa. Methanol was fed in a weight space hourly velocity of 1 h.sup.−1. The reaction products were analyzed online by gas chromatography. The compositions of the total products, the C.sub.1-C.sub.5 component and the C.sub.6.sup.+ component are shown in Tables 4, 5 and 6. In the total products, the C.sub.1-C.sub.5 component accounted for 52.15 wt %, 53.24 wt % and 53.76 wt %, respectively; whereas the C.sub.6.sup.+ component accounted for 47.85 wt %, 46.76 wt % and 46.24 wt %, respectively. In the C.sub.1-C.sub.5 components, the selectivity for ethylene and propylene was 90.43 wt %, 90.45 wt % and 90.11 wt %, respectively.

(26) TABLE-US-00004 TABLE 4 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 450 450 450 Conversion rate of 100 100 100 methanol (%) Distribution of total products (wt %) C.sub.1-C.sub.5 52.15 53.24 53.76 C.sub.6.sup.+ 47.85 46.76 46.24 Total 100.00 100.00 100.00 * C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

(27) TABLE-US-00005 TABLE 5 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 450 450 450 Conversion rate of 100 100 100 methanol (%) Distribution of C.sub.1-C.sub.5 products (wt %) CH.sub.4 1.56 1.58 1.52 C.sub.2H.sub.4 52.88 52.70 51.65 C.sub.2H.sub.6 0.04 0.05 0.04 C.sub.3H.sub.6 37.55 37.75 38.46 C.sub.3H.sub.8 0.55 0.51 0.46 C.sub.4 6.21 6.13 6.44 C.sub.5 1.21 1.27 1.42 Total 100.00 100.00 100.00 C.sub.2H.sub.4 + C.sub.3H.sub.6 90.43 90.45 90.11

(28) TABLE-US-00006 TABLE 6 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 450 450 450 Conversion rate of 100 100 100 methanol (%) Distribution of *C.sub.6.sup.+ products (wt %) Benzene 5.11 5.35 5.16 Toluene 15.53 16.36 15.23 Ethyl benzene 1.04 1.13 1.32 Xylene 55.29 54.57 56.11 Trimethyl benzene 14.26 13.35 12.81 Tetramethylbenzene 5.34 5.68 6.01 Others 3.43 3.56 3.36 Total 100 100 100 *C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

Example 5: Evaluation for Reactions

(29) The MATO-1, MATO-2 and MATO-3 catalysts were used as the catalysts in the reactions. The catalysts were tabletted, crushed and then sieved to 40-60 meshes. Ten grams of each catalyst was loaded into a reactor, and treated in air at 550° C. for 1 hour followed by a cooling process in nitrogen to reach the reaction temperature of 500° C. Arene solutions were prepared according to the requirement for the proportions of benzene, toluene, xylene, trimethyl benzene and tetramethylbenzene in the C.sub.6.sup.+ products obtained from the methanol conversion performed on MATO-2 catalyst, as shown in Table 6 of Example 4. The prepared arene solutions and methanol (calculated by CH.sub.2), in a ratio of 1:1 by weight, were pumped into the reactors by a metering pump, then they were contacted and reacted with the catalysts. The pressure in the reaction system was adjusted to 0.5 MPa using a back pressure valve. Methanol was fed in a weight space hourly velocity of 4 h.sup.−1. The reaction products were analyzed online by gas chromatography. The compositions of the total products, the C.sub.1-C.sub.5 component and the C.sub.6.sup.+ component are shown in Tables 7, 8 and 9. In the total products, the C.sub.1-C.sub.5 component accounted for 50.32 wt %, 51.86 wt % and 51.21 wt %, respectively; whereas the C.sub.6.sup.+ component accounted for 49.68 wt %, 48.14 wt % and 48.79 wt %, respectively. In the C.sub.1-C.sub.5 components, the selectivity for ethylene and propylene was 90.95 wt %, 91.22 wt % and 91.45 wt %, respectively.

(30) TABLE-US-00007 TABLE 7 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Conversion rate of 100 100 100 methanol (%) Distribution of total products (wt %) C.sub.1-C.sub.5 50.32 51.86 51.21 C.sub.6.sup.+ 49.68 48.14 48.79 Total 100.00 100.00 100.00 * C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

(31) TABLE-US-00008 TABLE 8 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Conversion rate of 100 100 100 methanol (%) Distribution of C.sub.1-C.sub.5 products (wt %) CH.sub.4 1.22 1.23 1.21 C.sub.2H.sub.4 52.42 52.23 52.11 C.sub.2H.sub.6 0.06 0.06 0.06 C.sub.3H.sub.6 38.53 38.99 39.34 C.sub.3H.sub.8 0.39 0.26 0.26 C.sub.4 5.88 5.86 5.78 C.sub.5 1.50 1.38 1.25 Total 100.00 100.00 100.00 C.sub.2H.sub.4 + C.sub.3H.sub.6 90.95 91.22 91.45

(32) TABLE-US-00009 TABLE 9 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Conversion rate of 100 100 100 methanol (%) Distribution of *C.sub.6.sup.+ products (wt %) Benzene 4.89 5.05 4.96 Toluene 14.32 14.54 14.37 Ethyl benzene 1.13 1.15 1.12 Xylene 56.20 56.76 56.23 Trimethyl benzene 14.19 13.17 13.92 Tetramethylbenzene 5.76 5.61 5.89 Others 3.51 3.72 3.51 Total 100 100 100 *C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

Example 6: Evaluation for Reactions

(33) The MATO-1, MATO-2 and MATO-3 catalysts were used as the catalysts in the reactions. The catalysts were tabletted, crushed and then sieved to 40-60 meshes. Ten grams of each catalyst was loaded into a reactor, and treated in air at 550° C. for 1 hour followed by a cooling process in nitrogen to reach the reaction temperature of 500° C. Arene solutions were prepared according to the requirement for the proportions of benzene, toluene, xylene, trimethyl benzene and tetramethylbenzene in the C.sub.6.sup.+ products obtained from the methanol conversion performed on MATO-2 catalyst, as shown in Table 6 of Example 4. The prepared arene solutions and methanol (calculated by CH.sub.2), in a ratio of 0.5:1 by weight, were pumped into the reactors by a metering pump, then they were contacted and reacted with the catalysts. Dimethyl ether was fed in a weight space hourly velocity of 3 h.sup.−1. The pressure in the reaction system was adjusted to 1.0 MPa using a back pressure valve. The reaction products were analyzed online by gas chromatography. The compositions of the total products, the C.sub.1-C.sub.5 component and the C.sub.6.sup.+ component are shown in Tables 10, 11 and 12. In the total products, the C.sub.1-C.sub.5 component accounted for 67.46 wt %, 68.57 wt % and 68.83 wt %, respectively; whereas the C.sub.6.sup.+ component accounted for 32.54 wt %, 31.43 wt % and 31.17 wt %, respectively. In the C.sub.1-C.sub.5 components, the selectivity for ethylene and propylene was 90.76 wt %, 91.03 wt % and 90.90 wt %, respectively.

(34) TABLE-US-00010 TABLE 10 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Conversion rate of 100 100 100 methanol (%) Distribution of total products (wt %) C.sub.1-C.sub.5 67.46 68.57 68.83 C.sub.6.sup.+ 32.54 31.43 31.17 Total 100.00 100.00 100.00 * C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.

(35) TABLE-US-00011 TABLE 11 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Reaction pressure (MPa) 1.0 1.0 1.0 Conversion rate of dimethyl 100 100 100 ether (%) Distribution of C.sub.1-C.sub.5 products (wt %) CH.sub.4 1.42 1.48 1.59 C.sub.2H.sub.4 54.35 55.21 54.98 C.sub.2H.sub.6 0.13 0.09 0.21 C.sub.3H.sub.6 36.41 35.82 35.92 C.sub.3H.sub.8 0.83 0.65 0.83 C.sub.4 5.55 5.51 5.33 C.sub.5 1.31 1.25 1.14 Total 100.00 100.00 100.00 C.sub.2H.sub.4 + C.sub.3H.sub.6 90.76 91.03 90.90

(36) TABLE-US-00012 TABLE 12 Catalyst MATO-1 MATO-2 MATO-3 Reaction temperature (° C.) 500 500 500 Reaction pressure (MPa) 1.0 1.0 1.0 Conversion rate of 100 100 100 dimethyl ether (%) Distribution of *C.sub.6.sup.+ products (wt %) Benzene 4.45 4.76 4.87 Toluene 13.96 14.21 13.58 Ethyl benzene 1.17 1.28 1.22 Xylene 56.43 56.41 56.73 Trimethyl benzene 13.97 13.61 13.93 Tetramethylbenzene 5.76 6.32 5.81 Others 3.43 3.41 3.86 Total 100 100 100 *C.sub.6.sup.+ represents the hydrocarbon products with carbon number no less than six.