METHOD FOR PRODUCING ZEOLITES OF THE ZSM-12 TYPE WITH THE MTW STRUCTURE Russian patent published in 2021 - IPC C01B39/42 B01J37/30 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing zeolites of the ZSM-12 type with the MTW structure. According to the method, two solutions are mixed. The first solution is an aqueous solution where a pH varies from 8.5 to 9.5. The aqueous solution contains an aluminum compound and a template. A compound of the general formula (I) functions as a template. One should add a dry alkali or an aqueous solution of an alkali to the first aqueous solution to increase a pH so that it can vary from 11.5 to 13.5. The second aqueous solution contains a silicon compound. The resulting solutions are mixed to obtain a gel-like mass. The mixture of solutions is prepared based on the following molar ratios of the components used: template/SiО₂ = 0.06-0.15, SiО₂/Al₂О₃ = 50-300, H₂O/SiО₂ = 4-16, Ме₂O/SiO₂ = 0.05-0.15, where Me₂O may be K₂O (in terms of KOH) or Na₂O (in terms of NaOH). The two solutions are being mixed until a homogeneous gel-like mass is obtained. The homogeneous gel-like mass should be left for 60-90 minutes at room temperature so that the primary structure of the gel can be formed. Crystallization of the resulting gel-like mass is carried out for 96-120 hours at a temperature of 145-155C followed by the isolation of the crystalline product, which should be washed with distilled water so that a pH can vary from 7.8 to 8.3 and which should be dried to constant weight and annealed at 500 ± 10C for 8-12 hours. After that one should carry out the ion exchange reaction with an aqueous solution of ammonium salt followed by the isolation of the product. The product should be washed with distilled water until a pH reaches 7.8-8.3, dried to constant weight and calcined at 450 ± 10 ° C for 4-7 hours. Solutions of colloidal silicon dioxide or tetraethylorthosilicate are used as the silicon compound. Octadecahydrate of aluminum sulfate or nanohydrate of aluminum nitrate, or isopropoxide of aluminum, or hexahydrate of aluminum chloride is used as the aluminum compound.

EFFECT: invention increases the proportion of mesopores in the finished product up to 12-25% of the total number of pores when obtaining aluminosilicate zeolite.

8 cl, 2 tbl, 11 ex, 1 dwg