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Molecular sieve compositions having three-dimensional microporous
framework structures of LiO.sub.2 AlO.sub.2 PO.sub.2 and SiO.sub.2
tetrahedral oxide units are disclosed. These molecular sieves have
an empirical chemical composition on an anhydrous basis expressed
by the formula: wherein "R" represents at least one organic
templating agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Li.sub.w Al.sub.x P.sub.y Si.sub.z)O.sub.2 ; and "w",
"x", "y" and "z" represent the mole
fractions of lithium, aluminum, phosphorus and silicon, respectively,
present as tetrahedral oxides. Their use as adsorbents, catalysts,
etc. is also disclosed.
In the purification of light hydrocarbons to remove carbonyl sulfide
impurity by selective adsorption thereof on molecular sieve adsorbents,
significant losses of the hydrocarbon are incurred by its coadsorption
on the adsorbent with the COS impurity. Conventional desorption
procedures produce a desorbate which is a non-commercial mixture
of COS and hydrocarbon. The purge desorption method of the present
invention utilizing a mixture of CO.sub.2 and a non-sorbable purge
gas permits recovery of the coadsorbed hydrocarbon in a pure and
commercially useful form.
This invention relates to a method and apparatus for providing
an in-line molecular sieve conversion kit for generating oxygen
from the atmosphere which includes an elongated tube filled with
separating material, pressurized air from the atmosphere introduced
into the tube and conduits exiting from the tube carrying the oxygen
to the point of use. An auxiliary spirally wound reservoir tube
for storing pressurized atmospheric air to aid in the removal of
nitrogen from the separating tube through a solenoid operated valve.
Ferrisilicate molecular sieves of the ZSM-5 type, having SiO.sub.2
/Fe.sub.2 O.sub.3 mole ratios ranging from 20 to 400 are prepared
by adding a silica source and a quaternary ammonium salt in that
order to an acedified solution of an iron (III) compound, crystallizing
the resulting gel to form a ferrisilicate molecular sieve, and thermally
treating the molecular sieve with nitrogen, air and/or steam at
300.degree. to 700.degree. C. Preferred thermal treatment comprises
treating with nitrogen first, then with air or steam. Thermally
treated molecular sieves contain iron both in and outside the crystal
framework; most of the non-framework iron is dispersed as very finely
divided iron oxides on internal surfaces. Molecular sieves are useful
as catalysts in Fischer-Tropsch and other iron oxide-catalyzied
reactions.
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