bao cao semina sfe dlieu 3

8/3/2019 Bao Cao Semina Sfe Dlieu 3

1/19

Ni dung :

S lc v cht lng siu ti hn v SFE

Qu trnh xy ra trong SFE

CHT LNG SIU TI HN

1. Gii thiu:

Khi nhit v p sut ca cht lng trn im ti hn ca n, cht lng

c xem l trong vng ti hn v c g l cht lng siu ti hn, ni

m khng c s khc bit giu pha lng v kh.


2/19


3/19

Nhit ti hn ca cht lng c xc nh nh l nhit cao nht m

cht kh c th ha lng khi tng p sut ca h thng. Tng t th, p sut

ti hn l p sut cao nht ca cht m cht lng c th chuyn thnh cht

kh khi tng nhit ca h thng.

Cht lng siu ti hn c th to ra t cht kh hoc lng, khng th t

cht rn c. Khi cht lng trong trng thi siu ti hn n s mang nhiu

c tnh ca c cht kh v cht lng.

Trong sut 10 nm va qua, ng dng ca k thut siu ti hn c

c nhng bc tin nhy vt v kh nng c th s dng cho nhiu

nguyn liu ha hc khc nhau v thay th dung mi hu c trong nhng

qu trnh ha hc khng nhng trong lnh vc cng nghip dc phm m

cn trong nhng ngnh cng nghip ha hc khc.

2. Nhng u im ca vic s dng cht lng siu ti hn so vi nhng

phng php khc:

- Cht chit xut c tinh khit cao hn.

- Khng tn ng dung mi chit trong sn phm.

- Gim gi thnh ca qu trnh sn xut.

- Chn lc.

- Phn tch tt hn.

- Thn thin vi mi trng.

- Gim s bin cht hay phn hy ca sn phm nhy cm vi nhit(v

s dng nhit khng cao).

3. S lt v lch s:


4/19

L phng php khng c hi, thn thin vi mi trng, chi ph hp

l v vn hnh vi iu kin nhit v p sut khng cao lm cho

phng php ny tr nn cun ht trong vic nghin cu dc phm.

S tn ti ca cht lng trng thi siu ti hn ln u tin c ch

ra bi Cagniard de la Tour vo nm 1822. T vic quan st mt chai cha

kn bng thy tinh khi tng nhit , ng quan st c s mt i s phn

pha ca cht kh v cht lng.

Tip theo sau vo nm 1879, Hannay v Hogarth bo co v

vic tng kh nng ha tan ca cloride kim loi trong cht lng siu ti

hn(Ethanol siu ti hn) p sut thp. Sau Villard chng minh rng

nhng cht kh nh Methan, Ethylen, CO2 v Nito oxid c th ha tan rt

nhiu nhng hp cht rn v lng nh comphor, acid stearic v parafin sp

ong. K t , mt s tc gi khc cng m t kh nng ha tan nguyn

liu ca cht lng siu ti hn.

Nm 1948 Diepen v Scherffer nghic cu kh nng ha tan

Napthalene trong Ethylen siu ti hn, mt s nghin cu theo sau xem xt tan ca napthalen khi s dng cht lng siu ti hn khc nhau.

Sut t nhng nm u n gia th k 20 phng php ny c

ch n nhiu. Nm 1936, Welson et al thc hin trn propan bng qu

trnh kh asphalt khi h s dng propan c tng kh nng ha tan

trng thi siu ti hn v phn tch c nhng phn khc nhau nh

parrafin sp ong, asphalt, tinh khit ha du nh t du nhn nguyn liu.Qu trnh ny cng to ra s pht trin ca qu trnh Solexol(loi kh c tnh

acid) cho vic tinh khit ha v chit xut vitamin A t du c v nhng

triglicerid khng bo ha t rau qu s dng propan siu ti hn.


5/19

Sau vo nm 1971 qua trnh ny c s dng tch cafein t ht

caf m n tr thnh mt ng dng quan trng ca cht lng siu ti hn

trong mc nh thng mi trong giai on ny. Trong cng nghip dc

phm s dng cht lng siu ti hn ln u tin c s dng trong qutrnh lm gim v ng nht kch thc tiu phn v v th lm tng sinh kh

dng. V vic s dng n rng ri trong cng nghip dc phm bt u

sut nhng nm 1980-1990.

4. c tnh ca cht lng siu ti hn.

Ni chung, cht lng siu ti hn nhng tnh cht trung gian ca cht

kh v cht lng. Bng vic thay i nhit v p sut ca cht lng, nhng

c tnh ca cht lng siu ti hn c th tr nn ging cht kh hoc ging

cht lng. Cht lng trng thi siu ti hn c th khuych tn xuyn qua

cht rn ging nh kh v ha tan nguyn liu ging nh cht lng. Thm

vo , khi gn ti im ti hn mt s thay i nh v p sut hay nhit

cng to nn mt s thay i ln v mt , lm bin i nhiu c tnh ca

cht lng siu ti hn trong c kh nng ha tan cc cht. S thay i khnng ha tan ny xy ra ch vi mt s thay i nh nhit v p sut cho

chng ta t do chn la cht lng siu ti hn thch hp cho mt mc ch

c th no . V th cht lng siu ti hn rt thch hp cho vic thay th

cc dung mi hu c trong lnh vc cng nghip v trong phng th nghim.

V k thut ng dng cht lng siu ti hn c gi l cng ngh siu ti

hn.

Trong Bng 1 l nhng iu kin ti hn ca mt s phn t c s

dng ph bin nh nhng cht lng siu ti hn.

Bng 1. Critical properties of various solvents (Reid et al., 1987)


6/19

Dung mi

Khi lng

phn t

Nhit

ti hn

p sut ti

hn

Khi lng

ring ti hn

g/mol K MPa (atm) g/cm3

Carbon dioxide (CO2) 44.01 304.1 7.38 (72.8) 0.469

Water(H2O)

(acc. IAPWS)18.015 647.096

22.064

(217.755)0.322

Methane (CH4) 16.04 190.4 4.60 (45.4) 0.162

Ethane (C2H6) 30.07 305.3 4.87 (48.1) 0.203

Propane (C3H8) 44.09 369.8 4.25 (41.9) 0.217

Ethylene (C2H4) 28.05 282.4 5.04 (49.7) 0.215

Propylene (C3H6) 42.08 364.9 4.60 (45.4) 0.232

Methanol (CH3OH) 32.04 512.6 8.09 (79.8) 0.272

Ethanol (C2H5OH) 46.07 513.9 6.14 (60.6) 0.276

Acetone (C3H6O) 58.08 508.1 4.70 (46.4) 0.278

Bng 2 Ch ra s khc nhau v mt , khuych tn v nht ca cht

lng , kh, cht lng siu ti hn in hnh.

S so snh gia Kh, Lng v Cht lng siu ti hn

T trng nht khuych tn
http://en.wikipedia.org/wiki/Kelvinhttp://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Atmosphere_(unit)http://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_(molecule)http://en.wikipedia.org/wiki/IAPWShttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Ethanehttp://en.wikipedia.org/wiki/Propanehttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Propylenehttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Acetonehttp://en.wikipedia.org/wiki/Pascal_(unit)http://en.wikipedia.org/wiki/Atmosphere_(unit)http://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Water_(molecule)http://en.wikipedia.org/wiki/IAPWShttp://en.wikipedia.org/wiki/Methanehttp://en.wikipedia.org/wiki/Ethanehttp://en.wikipedia.org/wiki/Propanehttp://en.wikipedia.org/wiki/Ethylenehttp://en.wikipedia.org/wiki/Propylenehttp://en.wikipedia.org/wiki/Methanolhttp://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Acetonehttp://en.wikipedia.org/wiki/Kelvin


7/19

(kg/m3) (Pas) (mm/s)

Kh 1 10 110

Cht lng siu ti

hn1001000 50100 0.010.1

Cht lng 1000 5001000 0.001

Thm vo , khng c sc cng b mt cht lng siu ti hn cng

nh khng c mt phn cch lng-kh nn lm tng c tnh di ng cadung mi siu ti hn n c th thm nhp vo trong cht rn c l xp nh

hiu qu hn cht lng dn n s chuyn khi v chit xut s nhanh hn.

S chuyn sang pha siu ti hn ca CO2

hnh ny chng ta c th thy c s

phn cch 2 pha d dng ca CO2

Khi tng nhit b ng phn

m dn.
http://en.wikipedia.org/wiki/Viscosity#Dynamic_viscosityhttp://en.wikipedia.org/wiki/Viscosity#Dynamic_viscosity


8/19

Tng nhit cao hn na s lm cho t

trng ca cht kh v cht lng gn nhau hn,

ng phn cch pha vn tn ti nhng kh

quan st.

Khi t n nhit v p sut ti hn

th khng cn phn bit c 2 pha na,

ng phn cch cng khng cn to thnh

mt pha ng nht gi l pha siu ti hn.

Mt trong nhng c tnh quan trng ca cht lng siu ti hn l ha

tan c nguyn liu trong cht lng. Kh nng ha tan ca cht lng siu

ti hn c xu hng tng theo s tng ca t trng ca cht lng( nhit

hng nh). V t trng tng theo p sut nn kh nng ha tan cng c xu

hng tng theo p sut. Trong khi mi quan h vi nhit t phc tp

hn. Vi mt mt hng nh, kh nng ha tan tng theo nhit . Tuy

nhin, khi gn vi im ti hn, mt c th gim mnh khi nhit tng.


9/19

Chnh v th, khi gn vi nhit ti hn, kh nng ha tan thng gim khi

tng nhit , sau tng tr li.

Tt c nhng cht lng siu ti hn u hn ha vi nhau to thnh

hn hp mt pha iu ny c m bo nu im ti hn ca hn hp c

vt qu. im ti hn ca hn hp 2 thnh phn c th c tnh ton bng

phng php s hc ca nhit ti hn v p sut ti hn ca 2 cht lng.

Tc(hh) = (t l mol ca A) x TcA + (t l mol ca B) x TcB.

chnh xc hn, im ti hn c th c tnh ton da vo phng

trnh trng thi nh ca Peng Robinson, hoc bng phng php cng cc

thnh phn tham gia( group contribution methods).

Biu cc pha ca vt cht
http://en.wikipedia.org/w/index.php?title=Group_contribution&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Group_contribution&action=edit&redlink=1


10/19

Figure 1. Biu m t CO2 theo nhit v p sut

Figure 2.

Biu ca CO2 theo t trng v p sut

Hnh 1 v 2 m t cc pha ca vt cht. Trong s ca p sut-

nhit (hnh 1) im si l ni tch bit ra pha kh v pha lng v kt thc

im ti hn, ni m pha kh v pha lng bin mt v tr thnh mt phasiu ti hn. iu ny c th c quan st trong biu m t theo t

trng-p sut ca CO2, nh c m t trong hnh 2. di nhit ti

hn v d nh 280k, khi p sut tng, kh nn li v cui cng( khong trn

40bar) c c li thnh cht lng c hn, to nn s ngt qung ca

ng thng(ng chm dc). H thng gm 2 pha trng thi cn bng,

1 cht lng c c v 1 cht kh c khi lng ring thp, Khi n gn nhit

ti hn(300K), mt ca kh trng thi cn bng tr nn c hn, v

mt ca cht lng th thp hn. Ti im ti hn(304.1K v

7.38Mpa(73.8 bar)) khng c s khc bit no v t trng v 2 pha tr thnh

1 pha lng. V vy, trn nhit ti hn 1 cht kh khng th c ha


11/19

lng bi p sut. nhit trn nhit ti hn 1 cht(310K), khi ln cn

vi p sut ti hn, ng thng gn nh thng ng. Mt s thay i nh

v p sut cng gy ra mt s thay i ln v t trng ca pha lng siu ti

hn. Nhng tnh cht vt l khc cng thay i ln khi p sut gn vi imti hn v d nh nht, tnh thm tng i v mnh ca dung mi,

m tt c u lin quan n t trng. nhit cao hn, cht lng tr nn

ging kh nh theo hnh 2 khi CO2 400K, t trng tng gn nh tuyn tnh

vi p sut.

Cht lng siu ti hn khng nhng c nht trung bnh n cao m

cn c kh nng nn cao khi vng ti hn. iu ny c ngha, thm ch chmt thay i nh v p sut cng gy ra s thay i v t trng v v vy lm

thay i kh nng ha tan. C th so snh hiu lc ha tan ca cht lng siu

ti hn vi cht kh v lng trn cn bn v t trng v nht.

Khi la chn cht lng siu ti hn cho nhng sn phm khng bn

vi nhit nh nhng protein v peptides, nhit ti hn c xem l rt

quan trng. CO2 l cht lng siu ti hn c s dng ph bin nht v nc nhit ti hn(310C) v p sut ti hn(73.8 bar) thp lm cho n tr

thnh dung mi rt hu dng cho nhng thuc v nguyn liu nhy cm vi

nhit.

5. CO2 siu ti hn:

C nhiu cht c th c s dng nh dung mi siu ti hn nhng

CO2 c s dng nhiu trong cng ngh siu ti hn trong lnh vc thcphm v thuc v tnh tr, tng i khng c, r, d kim, khng mi,

khng v, khng gy chy n v c th t trng thi ti hn d

dng(T=31.10C, P=73.8 bar), c bit l d dng thu hi li v ch cn thay

i nhit v p sut l CO2 s chuyn thnh kh v c ht ra ngoi nn


12/19


13/19

dung mi c s dng l cht lng trng thi siu ti hn. SFE ny c th

c s dng chun b mu cho mt phn tch no , hay quy m ln

hn l loi b nhng cht tp khng mong mun cho sn phm(loi

cafein trong ht caf) hoc thu c mt sn phm mong mun. CO2 trng thi siu ti hn c s dng nhiu nht. i khi ngi ta thm

nhng cht iu chnh nh Ethanol hay Methanol. iu kin c c

CO2 trng thi sieu ti hn l trn nhit ti hn(310C) v trn p sut

ti hn(73.8 bar), v s thm nhng cht iu chnh ny vo vn khng lm

thay i iu kin to trng thi siu ti hn ca CO2.

2. Quan im v kha cnh mi trng v cht lng sn phmc iu ch bng SFE: chtlng siu ti hn l mt dung mi thay th

cho vic chit cht cn tch ra khi hn hp lng bng nhng dung mi nh

hexan, diclomethan v dung mi c th tn d li trong sn phm lm nh

hng n sc khe ngi dng. Trong khi c CO2 d dng c loi ra

khi sn phm sau qu trnh ch bin n gin bng vic gim p sut, CO2

s bay hi hon ton.

3. Tnh chn lc ca SCF: Nhng tnh cht ca SCF c th thay i

khi nhit v p sut thay i to nn chn lc ca SCF. V d nh

nhng tinh du d bay hi c th c chit xut t thc vt p sut

thp(100bar).


14/19

4. Tc : Qu trnh chit xut da trn s khuych tn v vy dung

mi i hi phi khuych tn vo trong hn hp nn(lng hay rn) v

cht(nguyn liu) c chit xut phi khuych tn ra khi cht nn vo cht

lng. Kh nng khuych tn ca SCF nhanh hn so vi cht lng bnhthng v th qu trnh chit xut din ra nhanh hn. V v khng c sc

cng b mt v nht thp hn nhiu so vi cht lng thng thng nn

dung mi c th thm nhp vo trong tng l nh trong cht nn m qu

trnh khng th xy ra c nu l cht lng bnh thng. C hai yu t

khuych tn cao v nht thp lm tng ng k tc ca qu trnh

chit xut(mt s chit xut bng dung mi hu c c th mt vi gi trong

khi SFE ch mt khong 10-60 pht).

5. Hn ch SFE: Vic i hi p sut cao lm tng gi thnh so vi

chit xut bng phng php thng thng v th SFE ch c s dng khi

c nhng li ch ng k. CO2 c bn cht l khng phn cc v v th gii

hn kh nng ha tang mt phn no v khng th s dng chit tch

nhng cht phn cc. V th ngi ta s dng thm nhng cht ph tr

lm tng thm kh nng chit nhng c bn cht phn cc.

QU TRNH CHIT SIU TI HN


15/19

Chit lng siu ti hn thng dng chit mt cht no trong

mt hn hp cht. Nhng thng s chnh trong qu trnh l nhit , p sut

v tc dng. Figure 2 m t s ca nhng qu trnh trong chit siu ti

hn. Bn bc chnh ca qu trnh l: chit xut, trin khai, phn tch v thu

hi dung mi.


16/19

Mu np liu thng l cht nn rn c cho vo b phn chit xutcng vi CO2(c np vo b phn chit xut bi mt bm p sut cao).

Dng CO2 cha cht c chit xut s a n b phn phn tch thng

qua mt van gim p. Khi nhit v p sut c gim c cht chit

xut s ngng t li trong b phn phn tch trong khi CO2 s c thu hi

ti s dng li cho gian on chit xut.

Gn y ngi ta ch vo vic phn tch tng giai on ni mnguyn liu u s c chit xut vi nhng b phn chit xut ring bit

c iu kin nhit v p sut khc nhau to nn tnh chon lc khc

nhau nhm tch c hon ton nhng phn t mong mun. V dng

cht CO2 siu ti hn mang cht chit xut s c a ti nhng b phn

phn tch c iu kin nhit v p sut khc nhau ngng kt mt cch

chn lc thnh phn ring bit m h quan tm.


17/19

S liu chit xut tiu biu t nguyn liu rn(h thng gm mt b

phn chit xut v mt b phn phn tch) c thy Figure 8, trong

lng cht chit xut c so vi lng trong mu np vo ban u cxem xt vi thi gian chit xut. Theo s liu th nhit cng cao th

ng thng s cng dc v c 2 phn: phn ng thng l lng chit xut

c trong CO2 siu ti hn v ng cong t khong l lng chit xut

gn kt vi nn rn. Trong giai on u vic chit xut b gii hn bi kh


18/19

nng ha tan, trong giai on sau s chit xut b nh hng bi s khuych

tn v c tnh khuych tn c vai tr quan trng trong s thnh cng ca

chit siu ti hn.

Figure 8 cng cho thy nh hng ca nhit trong qu trnh chit

xut. Mt s yu t khc cng c vai tr kh quan rng trong qu trnh chit

xut l p sut, tc dng CO2 v m ca nguyn liu em chit xut.


19/19

TI LIU THAM KHO

1. Jounal A OVERVIEW OF SUPERCRITICAL FLUIDEXTRACTION FOR HERBAL DRUGSby Karale Chandrakant K.*1,

Dere Pravin J.1, Honde Bharat S. 1,Kothule Sachin1,Kote Amol P (in

Department of Pharmacognosy, S.V._.H.TS College of B.Pharmacy,

Shrishivajinagar

(Rahuri factory), Tal-Rahuri, Dist-Ahmednagar, MS, India-413706.)

2. Jounal A review on methodology and application of supercriticalfluid technology in pharmaceutical industry by Lovenish Bhardwaj*,

Pramod Kumar Sharma, Sharad Visht, Vipin Kumar Garg, Nitin

Kumar(Department of Pharmaceutical Technology, Meerut institute of

Engineering and Technology Meerut, Uttar Pradesh, India)

3. Jounal Supercritical fluid extraction: An upcoming green

technology

4. http://en.wikipedia.org

5. Jounal Supercritical fluid extraction of organic compounds fromsolids and aqueous solutions by technical research centre of finlandespoo 1999

6. JounalIntroduction to supercriticalfluidsby Muslim Dvoyashkin
http://en.wikipedia.org/http://en.wikipedia.org/

bao cao semina sfe dlieu 3

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