Catalyst composite comprising an alkaline earth metal containing CHA zeolite and use thereof in a process for the conversion of oxygenates to olefins

#This application is a national stage application (under 35 U.S.C. § 371) of PCT/EP2017/080654, filed Nov. 28, 2017, which claims benefit of European Application No. 16200871.8, filed Nov. 28, 2016, both of which are incorporated herein by reference in their entirety.

#The present invention relates to a catalyst comprising one or more metal oxides and/or metalloid oxides and a zeolitic material having the CHA framework structure comprising YO2 and X2O3, wherein Y is a tetravalent element and X is a trivalent element, wherein the zeolitic material comprises one or more alkaline earth metals selected from the group consisting of Mg, Ca, Sr, Ba, and combinations of two or more thereof, and wherein the framework of the zeolitic material comprised in the catalyst contains substantially no phosphorous. Furthermore, the present invention relates to a process for the production of the inventive catalyst and to a process for the conversion of oxygenates to olefins employing the inventive catalyst. Finally, the present invention relates to the use of the inventive catalyst, in particular in the conversion of oxygenates to olefins.

#The conversion of oxygenates (methanol, ethanol and dimethyl ether) to olefins has a high technical potential as an alternative, non-petroleum based route for obtaining petrochemical raw materials like for instance the olefins ethylene, propylene and butylenes. Suitable catalysts are zeolite based e.g. ZSM-5 (MFI), ZSM-11 (MEL), and SAPO-34 (CHA), as well as isomorphous zeolites from the pentasil family. The conversion of oxygenates can either proceed in a fluidized or fixed bed reactor—depending on which type of zeolite is used. SAPO-based catalysts have higher selectivities to lower olefins but coke/deactivate rapidly, thus, they are usually used in fludized mode. In contrast, ZSM-5 based catalysts have lower olefin selectivities than SAPO-based catalysts, but deactivation (loss of conversion) in a single-pass reaction cycle is much slower. In both catalysts binders are used to shape the zeolite materials to particles/granulates or extrudates for use in the appropriate reactor type (extrudates: fixed bed; fluidizable particles).

#FIG. 1 shows the isobutene isotherms as obtained for the extrudates from Reference Example 2, Example 1, and Comparative Examples 1 and 2, respectively. In the figure, the pressure in mbar is shown along the abscissa and the absorption in mg/g are plotted along the ordinate.

#FIG. 2 shows the yields of methanol, dimethylether and C2-C4 olefins as obtained from the conversion of dimethylether to olefins using the extrudates from Example 1. In the figure, the time on stream in hours is shown along the abscissa and the yield of methanol “▴” and dimethylether “♦” in grey lines and the yield of C2H4 “▪”, C3H6 “▴” and C4H8 “●” in black lines are respectively plotted along the ordinate in %.

#FIG. 3 shows the yields of methanol, dimethylether and C2-C4 olefins as obtained from the conversion of dimethylether to olefins using the extrudates from Reference Example 1. In the figure, the time on stream in hours is shown along the abscissa and the yield of methanol “▴” and dimethylether “♦” in grey lines and the yield of C2H4 “▪”, C3H6 “▴”, and C4H8 “●” in black lines are respectively plotted along the ordinate in %.

#2,040 kg of water were placed in a stirring vessel and 3,924 kg of a solution of 1-adamantyltrimethylammoniumhydroxide (20% aqueous solution) are added thereto under stirring. 415.6 kg of a solution of sodium hydroxide (20% aqueous solution) were then added, followed by 679 kg of aluminum triisopropylate (Dorox D 10, Ineos), after which the resulting mixture was stirred for 5 min. 7800.5 kg of a solution of colloidal silica (40% aqueous solution; Ludox AS 40, Sigma Aldrich) were then added and the resulting mixture stirred for 15 min before being transferred to an autoclave. 1,000 kg of distilled water used for washing out the stirring vessel were added to the mixture in the autoclave, and the final mixture was then heated under stirring for 19 h at 170° C. The solid product was then filtered off and the filter cake washed with distilled water. The resulting filter cake was then dispersed in distilled water in a spray dryer mix tank to obtain a slurry with a solids concentration of approximately 24% and the spray dried, wherein the inlet temperature was set to 477-482° C. and the outlet temperature was measured to be 127-129° C., thus affording a spray dried powder of SSZ-13 zeolite having the CHA framework structure.

#The resulting material displayed a particle size distribution affording a D10 value of 1.4 μm, a D50 value of 5.0 μm, and a D90 value of 16.2 μm. The material displayed a surface area of 558 m2/g, a silica to alumina ratio of 34, a crystallinity of 105% as determined by powder X-ray diffraction. The sodium content of the product was determined to be 0.75 wt.-% calculated as Na2O.

#100 g of chabazite from reference example 1 was placed in a kneader, together with 5 g of hydroxyethyl methyl cellulose (Walocel), after which the components were kneaded for 5 min. 107.1 g of an aqueous solution of colloidal silica (40 wt.-%; Ludox AS 40) were then added and the mixture kneaded for 5 min. 45 g of distilled water were then continually added over a period of 40 min while kneading. The kneaded mass was then extruded to extrudates with a diameter of 2.5 mm. The extrudates thus obtained were dried for 4 h at 120° C. and subsequently heated under air at a rate of 2° C./min to 500° C. and calcined at that temperature for 5 h for obtaining 139.5 g of extrudates.