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10thAnnual Session ofStudents Chemical Engineering Congress (SCHEMCON 2014)
Comarison !et"een temlate assisted and OS#$%&ree
s'nthesis o& SM%12 and eolite eta
Vaidish Sumaria1, Dr. Gopalakrishnan2*
1Department of Chemical Engineering, University of Petroleum and Energy Studies, Dehradun 2!00" #ndia2Department of Chemical Engineering, University of Petroleum and Energy Studies, Dehradun 2!00" #ndia
(Corresponding Author)
Abstract:E*er since the disco*er' o& Stil!ite !' Cronstedt a
class o& minerals namel' +eolites came into e,istence- O"ingto their uni.ue characteristics li/e cation e,change roert'
resence o& channels li/e ore s'stem aroaching molecular
si+e and e,treme thermal sta!ilit' made them attracti*e &or
*ariet' o& industrial alications as adsor!ents molecular
sie*es catal'sts etc- he earl' "or/ in +eolite s'nthesis
in*ol*ed onl' inorganic reagents namel' sources o& silicon
aluminium and al/ali and al/ali earth metals resulted in the
disco*er' o& +eolite $ 3 and Mordenite- E*er since the
introduction o& organic reagents in +eolite s'nthesis eseciall'
.uaternar' ammonium cations !' 5-M-arrer etal
re*olutioni+ed the +eolite s'nthesis resulted in ne" no*el and
silicon rich +eolites such as +eolite eta SM%6 SM%12 etc-
he' are no" used in the se*eral industrial rocesses such as
in 7luidi+ed Catal'tic Crac/ing (7CC) as catal'sts and as
adsor!ents in 'lene searation etc- $n' commercial rocesscost is the ma8or determinant arameter and hence the
alication o& these no*el +eolites is restricted o"ing to the
usage o& e,ensi*e organic structure directing agents (OS#$)
in their s'nthesis- hus the cost reduction in the s'nthesis o&
these no*el +eolites !' using seed assisted OS#$ &ree
s'nthesis constitute an imortant area o& research currentl'-
his aer criticall' anal'ses the OS#$ assisted and OS#$
&ree seed assisted s'nthesis o& t"o imortant no*el and large
ore t"el*e mem!ered ring containing high silica +eolites
namel' eolite eta and SM%12- he *arious arameters
a&&ecting the cr'stalli+ation /inetics and cr'stal si+e o& eolite
eta and SM%12 in*ol*ing OS#$ assisted and OS#$ &ree
seed assisted s'nthesis "ill !e resented in detail-
KeywordsOrganic%structure directing agents (OS#$) Seed
assisted s'nthesis OS#$ assisted eolite%eta SM%12-
. !"#$D%C"$!
"he s&nthesis o' eolites, r&stalline aluminosiliate'rameork t&pe materials, has +een etensi-el&
in-estigated 'or a long time. "o date, 2/ t&pes o' eolite
and related strutures ha-e +een identi'ied 01 and this
num+er keeps inreasing. Aluminosiliate eolites are
r&stalline miroporous materials ith 34D 'rameorkstruture onsisting o' tetrahedrall& oordinated Si$5 and
Al$5 units. "he& are idel& used as atal&sts, ation4
ehangers, and adsor+ents in man& industrial proessesoing to their ell4de'ined hannels, good ion4ehange
apa+ilities and solid4aid properties o' their 64'orm. 0247
Con-entionall& eolites suh as A (8"A), 9, : (;A%), 8
(8"8) and mordenite (41/."hesestruture direting agents a''et the nuleation proess and
ultimatel& a''et the r&stal struture. $SDAs are +ulk&
organis suh as tetraeth&lammonium h&droide("?A$6). $ne ma@or ad-antage o' these $SDA is that
aluminosiliate eolite ith higher Si$2Al2$3 ratio, suh
as S
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"his paper ompares the s&nthesis o' eolites SB1)
;ig. 2B Shemati illustration o' seed4assisted, $SDA4'ree s&nthesis o' eolites 03
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;ig. 3B "he onept o' LGreen JetaMB Completel& $SDA4'ree proess 03
+& adding unalined, eolite +eta ontaining "?AN asseeds ith SiAl ratio 2/B1 and 7 nm sie to Sodium
aluminosiliate gel ith the omposition o'B
!a2$B &Al2$3B Si$2B 62$
here O.3, &O.14.3 and O17. 022
:. Kamimura et. al. ere a+le to s&nthesie eolite +eta
using re&led seeds i.e. seeds produed using seed4assisted
$SDA4'ree s&nthesis proess. "his eolite as gi-en aspeial name +& the authors as LGreen JetaM as this
pro-ides the +asis 'or ompletel& $SDA4'ree s&nthesis o'
eolite +eta hih is eonomiall& 'a-ora+le. "he gel
omposition used in +oth the 'irst generation and GreenJeta s&nthesis asB
!a2$ B &Al2$3B Si$2B 62$
here O.2274.37, &O.14.27 and O2427, hile the
SiAl ratio o' the seeds ere 15425 and 11413 respeti-el&.
. ;AC"$#SA;;?C"!G"6?C#:S"A88A"$!K!?"CS
A$ Synthesis %ith the use of &SDAs'
t is o+ser-ed that the gel Si$2Al2$3ratio a''ets to someetent the r&stalliation kinetis o' the +eta eolite. As the
onentration o' Al2$3 as inreased in the gel, the
nuleation and r&stalliation time as marginall&
inreased. t ma& +e noted that, as the aluminum
onentration in the gel inreases, the inorporation o' the
silion in the eolite 'rameork is more e''iient, resulting
in a higher &ield o' eolite +eta. 023 !o eolite +eta as
o+tained in the a+sene o' aluminum.
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r&stalliation rate inreases. "he pro+a+le reason is highl&
ati-e and ell4de'ined r&stal sur'ae o' the eolite has
+etter nuleation a+ilit& than the $SDA. Similar
o+ser-ations ere o+ser-ed ith
;ig. 7B (a) $SDA4'ree +eta s&nthesied ith 1tF seeds. (+) $SDA4'ree
+eta s&nthesied ith 1F seeds.
V. ?;;?C"S$;S"A#"!GG?8C$
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;ig. /B "ernar& phase diagram desri+ing the r&stalliation domain o' S
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"he e''et o' p6 o' the gel is -er& ell eplained +&
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"he e''et o' alkalinit& in the s&nthesis o' eolite +eta is
shon in ;ig.. At loer $64Si$2O./ as desri+ed +& the
ur-e 3, the rate o' r&stalliation is -er& lo. 6&dro&l ion
onentration is responsi+le 'or the dissolution o' siliate
and aluminate speies. A gel ith $64Si$2O./ has -er&
lo onentration o' h&dro&l ions to pro-ide
;ig. =B "he in'luene o' $64Si$2 ratio on r&stalliation kinetis o'
eolite +etaB (1) 1.7R (2) 1.R (3) ./. Si$2Al2$3 O 37, "?ANSi$2 O .27
and 62$Si$2 O 1> at 513K. 02=
solu+iliation o' siliate and aluminate speies to aelerate
the rate o' r&stalliation. At $64Si$2O 1. (Cur-e 2), the
indution period is shortened and enough solu+ilied
aluminosiliate speies a-aila+le hih 'orm nulei and
aelerate the nuleation and hene the r&stalliationproess. 6oe-er, at a higher alkalinit& ($64Si$2O 1.7,
ur-e 1), the h&dro&l onentration is muh higher than
reuired. t is theoried that eess $64 ions pro+a+l&
dissol-e the nulei 'ormed and there'ore derease the rate
o' nuleation and hene the rate o' r&stalliation at a gi-en
temperature (513K).
"hus it is lear that an optimum $6 4onentration in the
reuired 'or the depol&meriation o' silia soure and to
initiate the nuleation proess, +ut not too high to dissol-e
the nulei and retard the r&stalliation.
t is also reported the in'luene o' !aNonentration on the
rate o' r&stalliation and the produt &ield. t as stated
that gels ith !aN onentration higher than !a2$Si$2
O.12 &ielded produt rih in eolite +eta +ut also
ontaining S
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"AJ8? SA8
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r&stalliation temperature as dereased to 15HC, the
r&stalliation reuired 2 da&s to omplete.
C$!C8%S$!
ith inrease in Al2$3 onentration in the gelr&stalliation time dereases marginall& in $SDA4assisted
s&nthesis hereas it inreases in the ase o' $SDA 'reeseed assisted s&nthesis. nreasing the h&droide
omposition 'a-ors the dissolution o' silia su+seuentl&'a-ors r&stalliation and redues the r&stalliation time.
"he 62$ Si$2ratio does not ha-e an& signi'iant impat
on the r&stalliation time. n $SDA 'ree seed assisted
s&nthesis, the inrease in SiAl ratio o' seeds and theuantit& o' seeds inreases the r&stalliation rate. n
$SDA assisted s&nthesis, ith the inrease in the 62$Si$2ratio r&stal sie inreases hile inrease in the ratio o'
"?ANAl2$3 redues the r&stal sie. n $SDA 'rees&nthesis the derease in amount o' seeds produed learer
and larger r&stals. Cr&stal sie o' Green4Jeta and Green4
5.
03 Da-is, >2, 5, 7/4/=.
05 Corma, A. Chem$ +ev. 1>>, >, 2334251>.
07 Auer+ah, S. .
0 I. eitkamp, Solid State #onic131(2) 1741==.
0= J. :ilma, %. ) ===4=>7.0> #./1) >14>=2.
01 G.". Kerr, G.". Koko&ailo, I. Am. Chem$ Soc. =3 (1>/1) 5/7.
011 #.=1) 13415.
012 >2) 7/4/=.
A. Corma, >) 7>4/.
015 A.. Jurton, S.. ones, S. ?lomari, Curr$ &pin$ Colloid
#nterface Sci. 1 (27) 211421>.
017 6. 8ee. S.. one, .
01= S.. ones,-icroporous -esoporous -ater$ 155 (211) 1P=.
01> K. &oki, K. ta+ashi, A. Shimo@ima, ". $ku+o. Synthesis of
-3)type 4eolite in the a/sence of organic structure directing
agent. "he %ni-ersit& o' "ok&o, Iapan.
02 S. Gopal et. al$ -icroporous and -esoporous-aterials 5>
(21) 15>417/.021 G. ) 51=54
51>1.
022 >1) >24>.023 Da-is, ==, >2.025 Goepper, , 21 3P31.
032 :. Kamimura et al. -icroporous and -esoporous -aterials,Vol. 15, 212, 15>P17/.
033 :. Suuki, ". akihara, K. ta+ashi, P 3=7.
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