Tổng hợp Diesel sinh học từ bã cà phê (Đồ án tốt nghiệp)

L IC
Qua th

T t Nghi p tuy th i gian ng

u ki n th c m

ng ki n th
il ic

ih

n:
c

ng h c t

KS. Nguy

t tin trong h c t p.

a

ThS.Di

Ngh Th c Ph m

u t t.
ng d n t

i

om

th c hi
u ki

t th i gian th c hi

c hi n
n l

i cho

u
i nh

y,

uc g
r t mong nh

cs

u c a th

ng

d ng t
M tl nn a

nh c

1

7

6

c hi n

Hu

o Th nh

i


M CL C
DANH M C B NG...................................................................................................... v
DANH M C
T

...................................................................................................... vi

VI T T T ............................................................................................................. vii

L IM

U ................................................................................................................ 1
T............................................................... 3

1.1

Diesel sinh h c. .................................................................................................... 3

1.1.1

m. ........................................................................................................ 3

1.1.2

.............................................................................................................. 3

1.2

s n xu t diesel sinh h c............................................. 3

1.2.1 D u th c v t...................................................................................................... 4
1.2.2 M
1.3

ng v t...................................................................................................... 7
d

ng h p biodiesel............................................... 8

1.3.1

...................................................................................................... 8

1.3.2

.................................................................................................... 8

1.3.3

th . ................................................................................................... 8

1.4

ng d ng c a biodiesel t

1.5

................................................................ 10
ng c

..................... 11

1.5.1

............................................................................ 11

1.5.2

ng. ........................................................................ 13

1.5.3 M t s ch

u. .................................................. 15

1.5.4 M t s ch

t cho s n ph m biodiesel ............................................ 16

1.6
1.6.1 Khu y gia nhi

ng h p biodiesel................................................................. 17
ng th . ................................................................. 17

1.6.2 Nhi t d th . .................................................................................................... 18

ii


1.6.3

.................................................................................................. 18

1.6.4

........................................................................................................... 19

1.6.5 S d

i h n........................................................... 19

1.6.6 M t s
1.7

s n xu

ng........................................... 19

cho ph n ng cho ph n

i. .................................................... 23

1.7.1 V

.............................................................................................. 23

1.7.2 V

............................................................................................ 25
2. TH C NGHI M. .................................................................................. 27

2.1

u. .................................................................................... 27

2.1.1 D ng c , thi t b . ............................................................................................ 27
2.1.2

u..................................................................................................... 28

2.1.3

t. ......................................................................................................... 30

2.2

u. .................................................................................. 30

2.2.1

u......................................... 30

2.2.2

ng h p biodiesel. ................................................................... 37

2.2.3 Kh

ut

n hi u su t ph n

KOH. ........................................................................................................................ 39
2.2.4

li u. .............................................................................. 39
T QU

3.1

O LU N ............................................................... 42

K t qu

-hexan. ......................... 42

3.1.1

................................................ 43

3.1.2 Chu
3.1.3
3.1.4
3.1.5 Chu

........................................................................ 44
nh

ng h c c a d

tr ng c a d
nh ch s

.......................................................... 44
.......................................................................... 44
........................................................ 45

iii


3.1.6

nh h

............................................. 45

3.2

................................................................ 48

3.2.1 Chu
3.2.2

n ph m biodiesel. .......................................................... 49
nh

3.2.3 Chu
3.3

ng h c c a biodiesel.............................................................. 49

peroxit cho s n ph m biodiesel. ..................................................... 50

K t qu kh

ut

n hi u su t ph n ng. ...................... 51

3.3.1

ng c a t l mol methanol/d u. ......................................................... 51

3.3.2

ng c

K T LU

...................................................... 52

N NGH ...................................................................................... 55

U THAM KH O............................................................................................ 57

iv


DANH M C B NG
B ng 1.1.

c

t ng h p biodiesel. ................................... 9

B ng 1.2.
B ng 1.3.

u ki

ng ngh c

nc

..... 10

........................................................................... 11

B ng 1.4.

u

................................................... 12

B ng 2.1. D ng c , thi t b c n s d

u.......................................... 27

B ng 2.2.
B ng 2.3.

u. .......................................................... 30
u ki n t

n ng chuy

B ng 3.1.

do.................... 33
................................................... 43

B ng 3.2. K t qu chu
B ng 3.3. K t qu

ad
nh t

........................................................ 44

ng h c c a d

B ng 3.4. K t qu chu

ad

B ng 3.5.

ng c a d

............................................. 44
................................................ 45
. ........................................................... 46

B ng 3.6. K t qu chu

2SO4. ................... 47

B ng 3.7. K t qu chu

a biodiesel. ........................................................... 49

B ng 3.8. K t qu

nh

B ng 3.9. K t qu chu
B ng 3.10.

B ng 3.12. K t qu kh

B ng 4.1.

peroxit c a biodiesel....................................................... 50
a biodiesel t

B ng 3.11. K t qu kh

B

ng h c c a biodiesel................................................. 49

l methanol/d

......................................... 50
n hi u su t ph n ng. .................... 51
n hi u su t ph n ng. ...................... 52

n biodiesel.................................................................................. 53
n ng x y ra. ........................................................ 55

v

DANH M C
u cho s n xu t biodiesel.............................................. 4
Ph

HPLC c a d

..................................................................... 12

Thi t b

............................................ 13
n d ng ngu

u. ....................................... 20

t ng h p biodiesel t d u th c v t..................................... 21
s n xu

n. ................................... 22

s n xu

c........................................ 22

H th

l yd

H th

................................................. 28

-hexan................................................................. 28
u.................................................................................................. 29
c. ..................................................................................... 29
kh

Thi t b ph n

............................................... 31
a ph n

............ 37

kh i ph n

........................................ 38

D

................................................. 42

.

............................................................................ 42
D

2SO4......................................... 47

tc

i d u....................................... 48
u chi t.................................................. 48

ng c a t l mol methanol/d u
ng c

n hi u su t ph n ng. ................ 51

n hi u su t ph n ng............................................. 52

Ph GC-MS c a biodiesel. .......................................................................... 53

vi


T

VI T T T

p Nh t B n

ISO: T ch

ct
n theo hi p h

FAME:

aM

n

CBDF: Coffe Bio Diesel Fatty
GC-MS: S

vii


t nghi

i h c-

-2016

iH

L IM

a

U

tv
N

i

v

m tv
n ph

ng,
cv

th

v n

u

Kh th i l nguy n nh n tr c ti p g y ra nh ng bi n

ng nh k nh v h ng lo t c c v n
Nhi u n l c
ng thay th . Trong

v

v m i tr

ang

ng.

, m t trong nh ng ngu n n ng l

i nhi u l

i kh h u, hi u

c th c hi n nh m t m ki m nh ng ngu n n ng

t m hi n nay l nhi n li u sinh h c (NLSH).

c uv

i,

t nhi

ng, bi

l

m s m t nh c c

ng m i ang

y l ngu n n ng l

c quan

ng kh ng c n ki t,

mb

ng.
Vi

u v ngu

ng t ngu
m

us

nv

i ta hay b

u

d ng, d u t h t cao su, t h

xu t kh

c

u th gi

u nhi

nt

u ki
n

c kinh doanh c a

nh

ng, th ph

nhi

mb

t n d ng ngu

y

ng h p diesel sinh h c t
ng d

c

u t c n thi

n xu t diesel sinh h c.

B. M
+T nd

us

nv

c nh m l

ad
c hi

ng h

c

1

ng.


t nghi

i h c-

-2016

iH

+ Ki

m.

+X
s

mb
i ph (GC-MS).

c

2

a


t nghi

i h c-

-2016

CH
1.1

iH

NG 1. T NG QUAN

a

T

Diesel sinh h c

1.1.1 Kh

ni m

Biodiesel hay diesel sinh h c l thu t ng d
ng c diesel

ch lo i nhi n li u d

c s n xu t t d u th c v t v m

ng v t.

u ch b ng ph n ng transester chuy
triglyxerit,

t do v

t carbon. Th ng d ng hay d

u b c nh

d um

l methanol.

ng, th c v

ng nh

b

is

ester

u, m
ac

th

i hay ester

c ch a t 1

ester
t

cho

s x

am

ch

ch n d u th c v t, m

ng v t

u s n xu t biodiesel. [1,2]
1.1.2 Vai tr
a. Thay th ngu n nhi n li u h

b. Gi i quy t c

1.2

v n

v bi n

c. T ng c

ng an ninh n ng l

d. T ng tr

ng kinh t cho

C

th ch ng

ngu n nguy n li u

c

c n d n.

i kh h u.

ng qu c gia.
tn

c

s n xu t diesel sinh h c

K t

cs d

u th c v

u d u th c v

u

c l a ch
ad um

h n ch v s

li u d u th c v

thay th

n.
D u th c v t s d

KOH/g d
tinh ch

n ng ph

i v i d u th c v
lo i b t p ch t,

u th i

[2]

c

3

s
u t p ch

th

mg
c n ph i


t nghi

i h c-

-2016

u

iH

th

a

c.

c: M

o, m

u d u, l c, v ng

c: D u th

a. D u th i

ng, h

ng d

b. H t jotropha
1.

u cho s n xu t biodiesel.

1.2.1 D u th c v t
u d u th c v
u c , d u d a,

sinh h

s n xu t diesel sinh h
c d u

u ki n t

c s n xu t t nhi u ngu
D u th c v t khi s d

ng h

s

iv
lo i b

t ch
i d u th

i

p ch t nh m h n ch ch s
d

m.
a d u th c v t

Lipit: L ch
c.

Triglyxerit: L

u 3 ch c c

u th c v t
2 ho c 3 n
t 6-

i:

c ut o

ng

cacbon. Triglyxerit

cacboxylic m ch th
n chi m 90 -98% trong qu

d u.

c

a 1,

4

ut o
t

t nghi

i h c-

-2016

iH

a

R1COOCH2
R2COOCH
R3COOCH2
1,

gi

R2, R3

c alkyl c

glyxerol

ut o

ng nh t, n

ut o

glyxerol h n t p.
Photpholipit: L

n xu t c a triglyxerit, photpholipit k t h

t kh

u t o k t t a l ng xu ng.
a

u 1 ho c 2 ch c. S

m tc

tr
n c a d u th c v

h pv

c v i

ng.

glyxerol, n m

d ng k t

glyxerol.

b. M t s

tv

a d u th c v t

Nhi

c: C

id

nhi

t

s c

t kho ng.
D

c,
c(

ph thu c nhi

tan c a d u

.
a d u: Ph thu

p ch

khi

u. D u tinh
n xu t, d

a clorophin...
nh t: D u th c v t

nhi

cl

nh

nh t c a d u th c v t gi m nhanh.
Tr s

nh t c a d u th c v t cao

s xetan cho d u th c v
Kh

nh t c a diesel . Mu n

ester d u th c v t.

h

a d u th c v

c

5

ng nh

c


t nghi

i h c-

-2016

iH

a

g/cm3, d

tr

cao.
c. M t s ph n ng

c c a d u th c v t

Ph n ng th

triglixerit b th

1.1 sau:

R1COOCH2

CH2 OH

R2COOCH

CH OH

+ 3H2O

R3COOCH2

( 1.1)

+

CH2 OH

Ph n

N

t ki m (KOH,

s t o ph n ng v i ki m t

1.2.
(1.2)

Ph n

n ng th

mu

n

ng h

su t t

ng triglyxerit, gi m hi u

k t kh
c ph n

m kh

ti

t, th

n h n ch

Ph n ng c ng h p: T

u ki

c ng h p v i ch
Khi c ng hydro

u ki n nhi

n ng nh

p

ms n

ng gi cho d
CH

CH

ch carbon.
tr

o qu n.

+ H2

CH2

n

(1.3)

CH2

Ph n ng ester
glyxerol

u ki

tc

bazo m nh (NaOH, KOH) s x y ra ph n
(e

t

i ester

ester c

c

m nh (H2SO4, HCl) ho c

6

ub cm t
glyxerol.

t nghi

i h c-

-2016

CH2-O-CO-R1

xúc tác

CH-O-CO-R2 + 3 CH3OH
CH2-O-CO-R3

iH

CH OH

R3COOCH3

n y g m m t lo t

r i t diglyxerit chuy n

+ ROH

Diglyxerit

+ R1COOR

(1.5)

Diglyxerit

+ ROH

monoglyxerit + R2COOR

(1.6)

glyxerol

a ph n

(alkyl ester

(1.7)

+ R3COOR

n h p c a nhi u h p ch

-

alkyl ester,

n ph

ph n ng t ng h

c.

ct r tl
cs d

n ph m c

us

glyxerol

ng.

kinh t cao.

Ph n

u th c v t ch a nhi u lo i
n l n x y ra t
x

b

cn
n ch t d u.

i chua d u m : Trong d

c, vi sinh v

N

y

ng bi

n

nh

c a d u.
ng v t
ng v

t trong nh

u r ti n cho s n xu t biodiesel. M t

s lo

n ch y

triglyxerit, diglyxerit, monoglyxerit
ng ester

glyxerol:

Triglyxerit

glyxerol, ancol, tri-

M

c th nh diglyxerit,

a ti p th nh monoglyxerit v cu i c ng

H n h p cu

1.2.2 M

c ph n ng thu n

triglyxerit chuy n h a t ng

Monoglyxerit +ROH

S

(1.4)

R2COOCH3

+

CH2 OH

ngh ch n i ti p nhau. T c

M

R1COOCH3

CH2 OH

Th c ch

a

ub cm

ot
t o biodiesel.[2,3]

c

7

tham gia ph n


t nghi

i h c-

1.3

-2016

d

iH

a

ng h p biodiesel

1.3.1
y

2SO4

th trong pha l ng.

ng th

s n ph m.
ph n ng ch

ng
i nhi

ng cho

chuy

ester
o

chuy

gi m

i gian ph n ng

chuy

1.3.2
ester d u th c v
ng th trong pha l
CH3

2CO3,

chuy

CH3

T

t, th i gian ph n ng ng n nh

u

tc
1.3.3

p.

th
ng th

u su

p ph i m t s

c r a s n ph
d

c m t nhi

h n h p ph i th i b

x

i l n ph n ng,

kh c ph

th . Trong

th
a.

MgO
y ra

th

d ng r n. Hi u su t s n ph m (

p 10 l n so v

u su

ng NaOH. D th
ti t ki
b.

2

H

t

i

ng.

3

u su

n-hexan

ho t

n d l c r a s n ph m, m

c kinh t , gi

Na/NaOH/

c

cho hi u su

us d
n 94%.

ch

n

c

8

i

Al2O3

i


t nghi

i h c-

3200

-2016

h nh p

iH

C

tc ah

a

c th hi n

b ng

1.1.
B ng 1.1.

Lo

c

t ng h p biodiesel.

Di

m t
,

Th

x p,
3

cm /g

x p

m2/g
Al2O3
NaOH /
Na /

Al2O3
Al2O3

Na / NaOH /

Al2O3

c. X

143,1

0,481

134,3

120,7

0,416

137,8

97,7

0,362

148,2

83,2

0,322

155,0

-5
mc

l Si/Al=18, b m
c s d ng trong ph n

u ch

hydrocracking.
d.

Rh-Al 2O3

c s d ng trong ph n ng hydrocraking d
S n ph

n ph

e. X

enzyme
enzyme

ch

l p th

n

enzyme s

ng i v

c ph c t

methanol, glyxerol
chuy

i ester s d ng
n ph m
c

ester m

mc

enzyme

chuy

i gian ph n ng ng n,

n.
m: C

c ng d ng r

t

.[1,2,3]

c

9


t nghi

i h c-

B ng 1.2. So s nh c

-2016

i u ki n c ng ngh c a x

th ng s c ng
ngh
Nhi t

X

t

N

Tham gia v

t

enzyme.

s d ng

ki m

S n ph m x ph

a

ki m v x

X

t

60 700C

ph n ng

c trong nguy n li u

t

X ct

C
b t do trong
nguy n li u

30
h

ph n ng

Enzyme
400C

Metyl Ester
Kh ng tham gia

Hi u su t

Cao

R t cao

Thu h i glyxerol

Kh

D

R a nhi u l n

Kh ng c n r a

L

s ch s n ph m

Gi th
1.4

iH

R

t

ng d ng c a biodiesel t
C i thi n

ng k ch t l

ng nhi n li u v hi u su t

ng c

-t , c i thi n t nh

n ng c a d u diesel truy n th ng v t nh b i tr n v tr s xetane.
Ethanol c th d ng
l

n ng tr s octane c a x ng. Trong th c t ,

m ch m

ng th p (<5%) trong h n h p v i x ng ho c d u diesel, ethanol v biodiesel c vai

tr nh l nh ng ph gia c i thi n ch t l

c

ng nhi n li u.

10


t nghi

1.5

i h c-

-2016

C

ph

ng ph

nh t

1.5.1 C

ph

ng ph

nh t

v

iH

nh l

a

ng c

nc
c th hi n

b ng 1.3.
B ng 1.3.

nc

.

n
m, (%)

12,20

ng C, (%)

52,20
2,10

Protein, (gprotein/100g)

13,30

Tro, (%)

1,43

Xenlulo,(%)

13,80

Nhi t tr , (MJ/kg)

4619,20
t nd

ng tro, nhi t tr cho ta th

ct nd

t cung c p nhi

c ngu
ng.[9]

h p ch t glyxerol
diglyxerit, triglyxerit

monoglyxerit,

do.

n glyxerol
ph

h nh pc
. Ta th

ph n c a d

nhi u triglyxerit

u t quy

t
y

n m

d ng k t h p.[12]

c

11

nh


t nghi

i h c-

-2016

iH

a

do

MG: Monoglyxerit

TG: Triglyxerit.

Th
2. Ph

HPLC c a d u

n quan tr
b

trong d

kh i ph (GC-MS)

c th hi n

b ng 1.4.

B ng 1.4. T

n

.

a

ng,%kh

capric (C10:0)

0,49

lauric (C12:0)

3,62

myristic (C14:0)

3,29

plamitic (C16:0)

28,44

margaric (C17:0)

0,33

arachidic (C20:0)

0,08

oleic (C18:1)

58,21

linoleic (C18:2)

1,06

eicosedienoic (C20:2)

0,15

eicosatrienoic (C20:3)

1,12

Th nh ph n FAME c a CBDF ch y u l C10
chi m nhi u nh t (58,21%) ti p
chi m

ax t

ng

n C20. Th nh ph n C18:1

n l C16:0 (28,44%). T ng hai th nh ph n n y

n 86% v nh ng th nh ph n c n l i ch t n t i

c

12

d ng l

ng v t. H m l

ng


t nghi

c a an i

i h c-

-2016

iH

a

i ch chi m m t ph n r t nh 2,36%.[4]
Chu Th B ch Ph

ng th c hi
t lu n Trong d u b c ph c ch a nhi u

b o c chi u d i m ch C kh c nhau (t C6
palmitic (C16:0),
Th nh ph n

oleic (C18:1) v

c c

b o

linoleic (C18:2) chi m h m l

ng cao.

b o trong h t c ph g m hai

stearic. Hai

n C24), trong

b o no ch y u l

palmitic v

b o kh ng no ch y u l oleic v linoleic.[1].

M ts

u

c

gi A.Deligiannis th c hi n

-hexan cho th y

n

arachidic C20:0 (4,04%)

.[10]
1.5.2 C

ph

a. H th

ng ph

nh l

ng

ly Soxhlet [4]
ng d

ng h th

c

Siphon

3. Thi t b tr

Dung d

ly Soxlet b ng dung m i hexan.

u, ch t c

l y tinh d

ch s

i
ch a ch t c

a tan tinh d

ng siphon, khi

c

13

c ch y


t nghi

i h c-

xu ng l

-2016

iH

a

u mang theo tinh d u. C

n
ng.

b.

Dung
u ph

u sau:

-

.
-D

i

u ki
n-h

ng m t s

diethylether, petroleum ether , isopropanol, ethanol, n-octan hay
i cao su...
diethylether

ng s

i n m i

4,2720) v v y c th h a tan th m m t s th nh ph n ph n c c trung b nh trong
nguy n li u nh c c

b o t do, c c s c t

h p, d

mc

t

b t l a nguy hi

Petroleum ether,

c

nhi

cao.

, hexan l h n h p c a nhi u hydrocacbon

kh c nhau, trong

th nh ph n ch y

t hydrocacbon kh ng

ph n c c (h ng s

i n m i 1,8420) ch h a tan c c ph n t kh ng ph n c c trong

nguy n li u (glyxerol, diglyxerit, triglyxerit

o

, th nh ph n d u th thu

b c ph khi t ch chi t b ng c c lo i dung m i c

ct

ph n c c kh c nhau c th

kh ng gi ng nhau.[5]
c. Ph i tr n

l
ph i tr

cv

kh

c nh

c

14

t hi u su

h n ch


t nghi

i h c-

-2016

iH

a

ly cao.
c nhi u h p ch

c, d

-hexan/isopropanol ph i tr n v i t l
50:50, 60:40, 70:30 ,80:20 s t

h nh p

i hi u su t cao.

mc

t n d ng cho

n

i tr

l n

cc
1.5.3

M t s ch
Ch s

u
: Ch s

miligam KOH c n thi

tt tc

do ch a trong 1 gam m u.

Ch s AV c a d u th c v
s r t quan tr

nh, d

iv id us d

u s n xu t biodiesel.

Ch s

u, n

t ng h p biodiesel s

n

Ch s

m hi u su t ph n ng

ng d u th c v

260. Ch s
d

c ti p

s mg KOH c n thi

u.

s

ng t 170-

ng t d u s d b

ng h p diesel s

m m nh ph i h t s

ph n ng l

l y s n ph m.

Ch s iot: Ch s i
th m

mg i

ng v i 100 gam d u, m . Ch s i t bi u

a d u m . Ch s
cl

k
qu

n ch

ad u

y, n

s i

n ph m biodiesel d b bi n ch
p.[2,3]

c

15

u ch a nhi u l
n ph

o


t nghi

i h c-

-2016

iH

a

t ICl.

H H H H

H HH H

C C C C

C C C C

H

H I Cl H

H
I

1.5.4 M t s ch

(1.8)

Cl

t cho s n ph m biodiesel

Ch s xetan: D

b

u

c a h n h p chu

H nh p

m hai lo

b t ch

n-

Biodiesel c

s

- metyl naphthalen.

mb

ts

n

cacbon t do (mu

nhi

cao trong xilang s

u ch s

ps d

(do

ng

i ph i phun r t nhi

li

ix

ub

u, nhi

b

rung gi t).
Ch s peroxit: L

ng ch

u th

ng c a oxy ho

u.

Ch s
li

c ch

s

u cho ch

ng c a d u. N
o qu n d b oxi

ut
c: C

a ch

ng

n ng v i KI gi

R1 CH CH R2 CH3COOH KI
O

n ng:

R1 CH CH R2 2CH3COOK H2O I2

(1.9)

O

O

2Na2S2O3

c: L

2NaI

I2

h nh pb

c

16

(1.10)

Na2S4O6

uv

t s ch t b

u


t nghi

i h c-

-2016

k

iH

t quan tr

i v i d u diesel. Khi nhi

nh t s

u. N u nhi
t om mk

th

sang th l

m ch
nhi

c ngh

ng ng

a h n h p chuy n pha t th r n
nh m d

d ng c a

th p.

m ch

:L

h nh pb

ub tl

u theo kh
0

ester

s

c

m ch

cx

u ch

th p nhi

a

t o

ng.

m ch y: L

u nguy hi

th

h th

k th pl

tb l

biodiesel

a

ng th

ch

t

t ch

cs d

n ch

m ch p

ng v

ki

ng methanol

a.[7]
1.6

ng h p biodiesel

1.6.1 Khu y gia nhi t v nhi t

ng th
n, r

cs d

n s d ng thi t b khu y (khu
nhi t tr c ti p b ng b

n tr

c ho c khu y t ) k t h p v i gia
P

th c hi n, n u

chuy

i th i gian ph n
ng th

c th c hi n gi a s n ph
ng th

c th c hi n b

n ng 2 c , khu y m
th
n

tk
y, gia nhi

khu

C
n ph

ki

ph n

khu y h n h p ph n ng. Ph

nh trong su t th i gian ph n ng. Sau khi k
c ngu

u chi

i ch y

ester

a s ch nhi u l

c

17

mb
h nh p

glyxerol
c


t nghi

i h c-

-2016

iH

a

c thu h i b ng thi t b

[1,2]

1.6.2 Nhi t d th
a.
Ph n ng gi a me

c th c hi

ng th

th ng ph

n

dung d ch sau khi l c b

lo i h
t, t

d

ester
c thu h

nh SEM, ph

cr as

p ch t, s

ki m tra ho

d ng cho nh ng l
b.

b ng dung

m sau.

KOH
chuy

t cao, th i gian ph n ng ng n (t 1

t trong ph n

n

t o kh i, gi m hi u su t t o ra s n ph

s n ph

kh c ph
th

1,5 gi ).

p ch t c a kim lo i ki m hay ki m

n ch t mang r n.
+

c.

/ Al2O3

c th c hi

n

n khi l

u chi

a, tinh

ch metyl ester .
c r a s ch b ng methanol, s
kh

c ho

ngu

nh

t n s th p 20 Hz v

ng

d ng.[1,2]

1.6.3
t b ph n ng d

i gian ph n
i ph c t

i.

ng d

ho m t thi t b

p, do
tl

n b gi i h

m.

c

18

m vi c a

n