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Patented Dec. 24, 1946
2,413,134
UNITED STATES PATENT OFFICE ,
PROCESS FOR THE MANUFACTURE OF
CRYSTALLINE ABSORBENTS
Richard Maling Barrer, Bingley, England
No Drawing. Application August 22, 1944, Serial
No. 550,680.
1943
In Great Britain September 22,
3 Claims.
( Cl. 23-110)
1
2
This invention relates to the manufacture of
crystalline absorbents useful, among other pur
poses, for effecting the separation of various liq
uid hydrocarbons that are characterized by pro
aqueous solutions of sodium salts such as the car
bonate, at about 200° C. Leucite is indicated as a
nounced differences in their stereometric struc
ture and the size and shape of the molecule, such
as for example the straight chain and the
valuable source of potassium salts (Chem. Zen
tralblatt, 1941, 2, 2240-1; also Green and Mc
Carthy, Ind. Eng. Chem., 1944, 36, 412), but in
cases where base-exchange is used to obtain po
tassium the analcite is not a useful by-product.
branched chain aliphatic hydrocarbons. Because
I have discovered according to the present in
of the capability of such crystalline absorbents to
vention that a hydrothermal method using con
effect separations of various hydrocarbons based 10 centrated aqueous barium'salt solutions may be
on their differences in molecular size and shape,
employed to make crystalline molecular sieve ab
the effect of the crystalline absorbents may be
sorbents. For example, a new mineral differing
likened to the separating effect displayed by
from any hitherto synthetically prepared zeo
sieves and they have come to be spoken of as “mo
lecular sieve absorbents.”
lite and having sorptive properties similar to
15 those of chabasite can be prepared from analcite
In my United States Patent No. 2,306,610 I have
or leucite, or from various aluminosilicate gels,
described ‘the separation of straight chain hydro
by treatment at high temperatures with concen
carbons from mixtures containing straight chain
trated solutions of barium chloride or bromide.
hydrocarbons and branched chain and/or cyclic
The analcite or leucite may be synthetically pre
hydrocarbons using certain dehydrated zeolites as 20 pared, for example, as hereinbefore described in
molecular sieve absorbents. The said patent also
the case of analcite, or the naturally occurring
describes the separation in a similar manner of
methane, ethylene and ethane from hydrocarbons
containing three or more carbon atoms in the
mineral may be used.
Accordingly, the present invention provides a
process for the manufacture of crystalline sieve
molecule. The zeolite which it is preferred to use 25 absorbents by the hydrothermal alteration of the
in the process of Patent No. 2,306,610 is chabasite.
aluminosilicates analcite and leucite ' and of
aluminosilicate gels containing mainly alkali
Of suitable zeolites, however, large natural de
posits are scarce or lacking, and it is an object of
metal or alkaline earth metal cations but being
the present invention to provide processes for the
otherwise substantially of analcite composition,
manufacture of synthetic molecular sieve absorb 30. which comprises heating the said aluminosilicates
ents capable of effecting the separations described
to an elevated temperature with an excess of a
in Patent No. 2,306,610.
concentrated aqueous solution of barium chloride
Of naturally occurring zeolites only very few,
or barium bromide, extracting the products with
such as mordenite, occur as large deposits. Anal
water to remove entrained or occluded salts and
cite may be made synthetically, as is already
dehydrating the extracted, product by heating.
known, in a number of ways. A quick and con
The aluminosilicate gels may be conveniently
prepared from waterglass and sodium aluminate
venient method capable of yielding any desired
quantity of the mineral consists in crystallising
gel mixtures having the composition
NaAlSizOanJ-IzO
or from NaOH.Al(0I-I)3.Si(OH)4 mixtures as
hereinbefore indicated. They may also be syn
40 thetic gel zeolites such for example as that sold
under the trade name "Burgess Freeze-Formed
Zeolite.” The cations in the gel are mainly group
IA or IIA cations such ‘as Na+, Kf, Bah‘, Ca++,
but I prefer to use a gel in which the cation'is
sodius aluminate solutions. The reaction mixture 45 Ba++. The cations are readily replaced by base
is crystallised in suspension in water at about 200°
exchange in these gels or gel zeolites. .I prefer to
C. for a period of approximately 24 hours, when
use gels having the composition M+AlSi2OexH2O,
analcite crystals separate. It is no disadvantage
or M++Al2Si4O12wH2O or mixtures of the two,
to crystallise from an alkaline medium. The syn
where M+ and M++ denote respectively alkali
thesis of analcite, however, is not part of the pres 50 metal cations and alkaline earthmetal cations,
ent invention.
e. g. Nat, Ki“, Ca++ and Ba++. I have also found,
Another source of analcite is leucite, of which
however, that good yields of the new mineral can
or approximately that composition. These gels
are easily made by mixing NaOH.Al(OH)a and
Si'(OH)4; or by stirring together waterglass and
there are some large natural deposits. This min
be obtained from gels not of this composition, for
eral is readily converted to analcite by base-ex
example when the initial gel was “Burgess Freeze
change of potassium ion with sodium ion with 55 Formed Zeolite,” or a Ca - base - exchanged
2,413,134
3
4
atoms inthe molecule rapidly, higher normal
hydrocarbons slowly, and excludes iso-para?ins.
The actual consumption of barium salt in mak
ing the mineral was slight, for the barium salt
“Doucil.” I may therefore use gels which depart
somewhat from the above composition.
As stated hereinbefore the initial gel or mineral
is converted into the new mineral by heating it
with a concentrated aqueous solution of barium
chloride or barium bromide, but preferably
barium chloride. The barium is present in excess
over any other cations, and I prefer that the solu
used in crystallising, or occluded, was readily re
covered.
.
..
The details of some typical preparations are
given below in Table I:
TaBLrrI
No.
Raw mineral
Treatment- ‘
T521231"
Product
° 0.
1.... Barium aluminosilicate gel,
Three days’ heating with‘ concentrated aqueous BaCl; ________ _.
235
Good yield of mineral,
2__._ Barium aluminosilicate gel as ..--.d0 -------------------------------------------------------- ..
270
Moderate
3.... S y n t h e t i c a 11 a1 c i t e
NaAlSiiO°.H1O.
Six progressive treatments with concentrated aqueous Bach,
each lasting‘about one day. _
210
Excellent yield of miner
al. Occluded BaCh.
4..-. Naturally occurring analcite,
NaAlSizO?.H1O.
Five progressive treatments with concentrated aqueous BaClz,
each lasting 12 hours. AnaIcite mixed with half its volume
BBC]: and with half the total. apparent solid volume of water.
Four progressive treatments w1th concentrated aqueous Each,
each lasting about 1 day.
,
200
BHAIIShOH-IHQO.
with occluded BaClg.
above.
5.... Naturally occurring anulcita
as in 4.
Six days’ heating with concentrated aqueous B3012 ___________ ..
KAISlzOgJHzO.
7
{carbasefxchapgsad
"“
Me“ Down‘
-
,
-
233
Good to moderate yield.
<1); ncllineral. Occluded
rys
8____ Gel zeolite-"Burgess Freeze-
Five days’ heating with concentrated aqueous BaCli __________ ..
180
208
a
isa
ion
no
marked‘ _
E’éfgilené??hlaoiagg?'
205 Good yield of mineral.
_
Occluded BaCli.
One day's heating with concentrated aqueous BaClg at 210° C. ________ _.
Do.
BBAIzSiqOnJHzO.
followed by two days’ further heating at 197° 0.
m___ s y n th e ti c a 11 a1 cit e ,
NaAlSi2Or.H2O.
Two days’ heating with concentrated squeous Balm __________ __
'
typical
preparations
204
Good yield of mineral.
Occluded BaBn.
Typical extraction processes are summarized in
tion of barium salt should be saturated or very
In
z.
OeraLt (?ccluded BaOlzi
(a) Six days heating with concieiitrated aqueous B3011 _______ ..
(1;) Five days’ heating with concentrated aqueous BBC]: ____ ..‘..
concentrated.
8
Excellent yield of min
I
gel zeo_
Formed Zeolite.”
9.... Barium aluminosilicate gel,
180
g
-
only
Do.
.
6____ Potassium aluminosilicate gel,
yield
céfBréllmeral.
Occluded
2.
the 35 Table II.
TABLE II
Extraction of BaClz from the mineral
mineral or gel was powdered and well mixed with
from one-half to one-and-a-half times its volume
of solid barium chloride or bromide, and water
was added amounting to from one-half to one
times the volume of total solid. The mixtures
were then heated in autoclaves at temperatures
from 180° to 270° C. and for periods ranging from
two to six days. I may, however, choose reaction
conditions outside these ranges of composition,
temperature and time. The mixture crystallised
under the conditions described to give character
,
Pmdu“
0 we er
N0.
vféggie
egg?
of
No. 1, Table 1....
No. 3, Table I__..
No. 4, Table 1..-.
1:15
1:15
1:6
10
10
10
No. 5, Table 1....
1:15
6
No.9, Table 1....
50
The mineral thus prepared contained a great
deal of occluded barium chloride or bromide.
This salt had to be removed to leave the active
mineral, and this can be effected by heating the
cal extractions were performed in the tempera
ture range of from 180 to 270° C., in an autoclave
24 hours at 210° C.
Do.
About two days at tem
peratures 200—270° C.
About
two
days
at
nearly 270° 0. -
1:15
7
of crystals were obtained in the temperature
' mineral to high temperatures with water. Typi
tion of each extraction
about
istic small crystals. Freshly prepared gels
crystallised most easily and the best formations
range of from 180° to 220° C.
Temperature and dura
55
About one-and-a-hali
days at 208° C.
In prolonged use, involving heating in organic
vapours, powdered zeolites, including those man
ufactured according to the process of this inven
tion may become coated with a layer of carbon,‘
which eventually may impair the occlusive power.
I have found that such minerals may be reac
tivated by passing a stream of air or oxygen
through the powdered mass maintained at suit
but-I may also choose temperatures outside this
able temperatures. In a typical experiment oxy
range. In these typical experiments with a
mineral to water ratio of ‘from 1:6 to 1:15, some 60 gen was passed through a sooted chabasite pow
der for two hours at 300° 0., when it was quite
ten extractions were given of 24 hours or more.
freed of carbon. A similar experiment using an
The total time required for extraction may be
air stream at 300° 0. required 16 hours to remove,
reduced by decreasing the mineral to water ratio.
the carbon. By using a, dry air or oxygen stream,
I may also carry out the extraction by a con
I have simultaneously reactivated and dehydrated
tinuous process.
,
65
these minerals. In dehydration and reactivation
During extractions of the occluded salt there
of the minerals I prefer to use the temperature
may be some secondary change of the mineral,
range’ of from 300 to 460° C. The temperature
and I prefer to make the mineral using barium
and/or duration of heating must not be sum?
chloride rather than barium bromide, since sec
ciently high to cause collapse of, or alter irrevo-v
ondary change was then less marked.
70
cably, the crystal lattice of the mineral.. '
The active crystalline product obtained after
extraction of the occluded salt was, when de
1. A process for the manufacture of crystalline
hydrated, an excellent molecular sieve absorbent,
absorbents by hydrothermal alteration of alumi
having sorptive properties similar to those of
chabasite. Thus, at room temperature, it oc 75 nosilicates which comprises heating an alumino~
silicate‘seleoted from the group consisting of an;
cludes hydrocarbons having one and two carbon‘
I claim:
.
.
.
_
-
2,413,134
5
alcite, leucite and aluminosilicate gels whose ca
6
tions are mainly at least one cation selected from
the group consisting of barium chloride and bari
um bromide, extracting the product thus formed
the group consisting of alkali metal cations and
alkaline earth metal cations and which are other
wise substantially of analcite composition with
with water in a closed reaction zone at a tem
perature of between 180° C. and 270° C. to re
move occluded salts and dehydrating the ex
an excess of a concentrated aqueous solution of
tracted product by heating.
a barium salt selected from the group consisting
of barium ‘chloride and barium bromide in a
closed reaction zone at a temperature of between
180° C. and 270° C. for a period of between two
absorbents by hydrothermal alteration of alumi
nosilicates which comprises heating an alumina
silicate selected from the group consisting of
3. A process for the manufacture of crystalline
and six days, extracting the product thus formed
analcite, leucite and aluminosilicate gels con
with water to remove occluded salts and dehy
taining mainly barium cations but being other~
wise substantially of analcite composition with a
drating the extracted product by heating.
2. A process for the manufacture of crystal
concentrated aqueous solution of a barium salt
line absorbents by hydrothermal alteration of 15 selected from the group consisting of barium
aluminosilicates which comprises heating an
chloride and barium bromide in a closed reaction
aluminosilicate selected from the group consist
zone at a temperature of between 180° C. and
ing of analcite, leucite and aluminosilicate gels
270° C. for a period of between .two and six days,
whose cations are mainly at least one cation se
extracting the product thus formed with water
lected from the group consisting of alkali metal 20 in a closed reaction zone at a temperature ofwbe~
cations and alkaline earth metal cations and
tween 180° C. and 270° C. to remove occluded
which are otherwise substantially of analcite
salts, and dehydrating the extracted product by
composition with an excess of a concentrated
aqueous solution of a barium salt selected from
heating.
RICHARD MALING BARRER.
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