Edited Paper for Schemcon

7/21/2019 Edited Paper for Schemcon

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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)

[email protected]

[email protected]

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

S C H E M C O N - 2 0 1 4 2 | P a g e


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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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Edited Paper for Schemcon