Process for a continuous synthesis of zeolitic materials using seed crystals loaded with organotemplate
Disclosed herein is a continuous process for preparing zeolitic material with a CHA-type framework structure comprising SiO 2 and X 2 O 3 and the zeolitic material so-obtained. The processes comprises (i) preparing a mixture comprising one or more sources of SiO 2 , one or more sources of X 2 O 3 , seed crystals, one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds as structure directing agent, and a liquid solvent system; (ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity; and (iii) crystallizing the zeolitic material with a CHA-type framework structure from the mixture in the continuous flow reactor.
1. A continuous process for preparing a zeolite material with a CHA-type framework structure comprising SiO 2 and X 2 O 3 , the process comprising:
(i) preparing a mixture comprising one or more sources of SiO 2 , one or more sources of X 2 O 3 , seed crystals, one or more tetraalkylammonium cation R 5 R 6 R 7 R 8 N + -containing compounds as a structure directing agent, and a liquid solvent;
(ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity ranging from 0.3 h −1 to 20 h −1 for a duration of at least 1 h; and
(iii) crystallizing the zeolite material with the CHA-type framework structure from the mixture in the continuous flow reactor, wherein the mixture is heated to a temperature ranging from 100° C. to 300° C. and wherein the volume of the continuous flow reactor ranges from 50 cm 3 to 75 m 3 ;
wherein the seed crystals comprise one or more zeolite materials with one or more cationic organotemplates as counter-ions at the ion exchange sites of the framework structure;
wherein X is a trivalent element;
wherein each of R 5 , R 6 , and R 7 is independently chosen from one another and is an alkyl; and
wherein R 8 is a cycloalkyl;
wherein (a) a surface of the inner wall of the continuous flow reactor is lined with an organic polymer material, and/or
(b) wherein the mixture constituting the feed crystallized in (iii) consists of a first liquid phase, a second liquid phase, and a solid phase comprising the seed crystals, wherein the first liquid phase comprises the liquid solvent and the second liquid phase comprises a lubricating agent, wherein the lubricating agent comprises one or more fluorinated compounds.
2. The process of claim 1 , wherein the continuous flow reactor is chosen from a tubular reactor, a ring reactor, and a continuously oscillating reactor.
3. The process of claim 1 , wherein in (iii) the mixture is heated under autogenous pressure.
4. The process of claim 1 , wherein the process further comprises one or more of the following:
(iv) quenching a reaction product effluent continuously upon exiting the reactor in step (iii) with a liquid comprising one or more solvents, via expansion of the reaction product effluent, or combinations thereof;
(v) isolating the zeolite material obtained in step (iii) or step (iv);
(vi) washing the zeolite material obtained in step (iii), step (iv) or step (v);
(vii) drying the zeolite material obtained in step (iii), step (iv), step (v), or step (vi); and
(viii) calcining the zeolite material obtained in step (iii), step (iv), step (v), step (vi), or step (vii).
5. The process of claim 1 , wherein the one or more cationic organotemplates are chosen from tetraalkylammonium cations and mixtures thereof.
6. The process of claim 1 , wherein X is chosen from Al, B, In, Ga, and combinations of two or more thereof.
7. The process of claim 1 , wherein the mixture prepared in (i) and crystallized in (iii) further comprises one or more tetraalkylammonium cation R 1 R 2 R 3 R 4 N + -containing compounds, wherein each of R 1 , R 2 , R 3 , and R 4 is independently chosen from one another and is an alkyl.
8. The process of claim 4 , wherein the process further comprises:
(ix) subjecting the zeolite material obtained in (v), (vi), (vii), or (viii) to an ion-exchange procedure, wherein at least one ionic non-framework element or compound contained in the zeolite material is ion-exchanged against one or more metal ions.
9. The process of claim 8 , wherein in (ix) the step of subjecting the zeolite material to an ion-exchange procedure comprises:
(ix.a) subjecting the zeolite material obtained in (v), (vi), (vii), or (viii) to an ion-exchange procedure, wherein the at least one ionic non-framework element or compound contained in the zeolite material is ion-exchanged against NH 4 + ;
(ix.b) calcining the ion-exchanged zeolite material obtained in (ix.a) for obtaining the H-form of the zeolite material; and
(ix.c) subjecting the zeolite material obtained in (ix.b) to the ion-exchange procedure, wherein H + contained in the zeolite material as ionic non-framework element is ion-exchanged against one or more metal ions.
10. The process of claim 9 , wherein the one or more metal ions are chosen from ions of alkaline earth metal elements, transition metal elements, and combinations thereof.
11. A zeolite material obtained according to the process of claim 1 .
12. The zeolite material according to claim 11 , wherein the zeolite material is as a molecular sieve, an adsorbent for ion-exchange, a catalyst, a catalyst precursor, a catalyst support, and a catalyst support precursor.