ZEOLITE PRODUCTION METHOD
Disclosed is a method for readily and inexpensively producing zeolite without using an organic structure-directing agent (organic SDA). Specifically disclosed is a method whereby a gel containing a silica source, an alumina source, an alkaline source and water is reacted with zeolite seed crystals, to produce a zeolite with the same kind of skeletal structure as the zeolite. The gel used is a gel of a composition whereby, when a zeolite is synthesized from this gel only, the synthesized zeolite comprises at least one of the kinds of composite building units of the target zeolite.
1 - 14 . (canceled)
15 . A method of producing a zeolite comprising:
reacting a gel and zeolite seed crystals to produce a zeolite having the same kind of skeletal structure as the zeolite seed crystals;
wherein:
the gel comprises a silica source, an alumina source, an alkali source and water;
the gel is capable of synthesizing a zeolite without the use of the zeolite seed crystals, wherein the zeolite synthesized without the use of the zeolite seed crystals comprises one or more building units of zeolite;
the zeolite seed crystals comprise one or more composite building units of zeolite;
the zeolite seed crystals and the zeolite synthesized without the use of zeolite seed crystals comprise at least one equivalent composite building unit of zeolite;
wherein the reacting step occurs without the use of an organic structure-directing agent;
wherein beta zeolite is used as the zeolite crystals; and
wherein the gel has a composition of:
SiO 2 /Al 2 O 3 =10 to 14,
Na 2 O/SiO 2 =0.05 to 0.25, and
H 2 O/SiO 2 =5 to 50.
16 . The method of producing a zeolite according to claim 15 ,
wherein the zeolite synthesized without the use of zeolite seed crystals has a different kind of skeletal structure as the zeolite seed crystals.
17 . The method of producing a zeolite according to claim 16 ,
wherein the zeolite produced is beta zeolite,
beta zeolite is used as the zeolite seed crystals, and
the gel has a composition which forms a mordenite zeolite, when the zeolite is synthesized from the gel without the use of the zeolite seed crystals.
18 . The method of producing a zeolite according to claim 15 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.
19 . A method of producing a zeolite comprising:
reacting a gel and zeolite seed crystals to produce a zeolite having the same kind of skeletal structure as the zeolite seed crystals;
wherein:
the gel comprises a silica source, an alumina source, an alkali source and water;
the gel is capable of synthesizing a zeolite without the use of the zeolite seed crystals, wherein the zeolite synthesized without the use of the zeolite seed crystals comprises one or more building units of zeolite;
the zeolite seed crystals comprise one or more composite building units of zeolite;
the zeolite seed crystals and the zeolite synthesized without the use of zeolite seed crystals comprise at least one equivalent composite building unit of zeolite;
wherein the reacting step occurs without the use of an organic structure-directing agent;
wherein beta zeolite is used as the zeolite crystals; and
wherein the gel has a composition of:
SiO 2 /Al 2 O 3 =6 to 40,
Na 2 O/SiO 2 =0.05 to 0.25,
Li 2 O/SiO 2 =0.005 to 0.25, and
H 2 O/SiO 2 =5 to 50.
20 . The method of producing a zeolite according to claim 19 ,
wherein the zeolite synthesized without the use of zeolite seed crystals has a different kind of skeletal structure as the zeolite seed crystals.
21 . The method of producing a zeolite according to claim 20 ,
wherein the zeolite produced is beta zeolite,
beta zeolite is used as the zeolite seed crystals, and
the gel has a composition which forms a mordenite zeolite, when the zeolite is synthesized from the gel without the use of the zeolite seed crystals.
is used as the gel.
22 . The method of producing a zeolite according to claim 19 ,
wherein, as a post treatment, dealumination of the zeolite is carried out by mixing the zeolite and an aqueous solution of citric acid or a salt thereof, and heating a mixed aqueous solution under an autogenous pressure.