mtbe tt

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LI GII THIU

Trc vn bo v v chng nhim mi trng ang ngy cng c

cp nhiu hin nay, vic thay th xng pha ch, gy nhim mi trng,

bng xng khng pha ch l xu hng chung ca nhiu quc gia trn th

gii.

tng tr s octan ca xng, ngi ta thay th s dng ph gia ch bi

cc hp cht cha oxi c ch s octan cao v khng gy nhim mi trng.

Nhng hp cht cha oxi thng c s dng l ru v ete nh Metanol,

Etanol, v Metyl tert Butyl Ete (MTBE), Etyl tert Butyl Ete (ETBE),Tert-

amyl Metyl Ete (TAME),..

y l nhng hp cht c tr s octan rt cao v rt thch hp pha vi

xng nhm lm tng tr s octan ca xng, ci thin cht lng xng.Hp cht oxi c s dng ch yu pha vo xng hin nay l Metyl

tert Butyl Ete (MTBE). y l hp cht oxi c nhng tnh cht ni bt nh:

c tr s octan cao, bay hi thp, bn oxi ho, c nhng tnh cht tng

thch tt vi xng,.. v c bit l khng gy nhim mi trng. Cc quc

gia pht trin hin nay u s dng xng c pha MTBE nh l: M, Anh,

c, Nht, Canada,..

Nhu cu v MTBE trn ton th gii ang tng rt nhanh. Cc qu trnhcng ngh sn xut MTBE c thit k v lp t nhiu ni nhm p

ng nhu cu MTBE ang tng ln ny.

Hin nay, Vit Nam ang xy dng nh my lc du u tin ti Dung

Qut, Qung Ngi, hn na trc sc p mi trng, chnh ph Vit Nam d

tnh s loi b xng pha ch vo nm 2006. V vy vic tnh ton thit k quy

trnh cng ngh sn xut MTBE cho xng l iu ht sc cn thit v quan

trng. cng l l do chng ti thc hin bn n ny.

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CHNG I: TNG QUAN L THUYT

I.GII THIU CHUNG V MTBE

I.1 Tnh hnh sn xut v s dng

Metyl tert Butyl Ete (MTBE) l hp cht cha oxi c cha khi lngphn t l 88,15 v c cng thc cu to nh sau:

CH3

CH3 - O - C - CH3

CH3

MTBE l mt trong nhng ete c vai tr quan trng i vi cng nghip

sn xut xng. N ng dng lm cht ph gia cho xng nng cao tr s

octan, nhm p ng c yu cu lm vic ca ng c xng cng nhm bo v yu cu v sinh mi trng v sc kho con ngi.

Trc y vic nng cao tr s octan cho xng ngi ta dng cht ph

gia l nc ch (CH3)4Pb, (C2H5)Pb. Tuy nhin loi ph gia ny bn cnh

vic nng cao tr s octan, gim gi thnh sn phm nhng vn cn nhc

im: nh hng n sc kho ca con ngi. nhim mi trng nh

hng trc tip n ng c, khi ng c lm vic nhiu. Chnh v cc

nhc im ny ca nc ch m mt s nc trn th gii ban lut cmv hn ch dng nc ch.

Hin nay loi ph gia c dng thay th. Vic thay th ny ng

ngha vi vic s c mt s thay i trong thnh phn xng khng ch,

nhng ch yu l s khc nhau i vi ph gia nhm tng cng tr s

octan.

C mt s gii php hu hiu t ti tr s octan cao hn khi khng

s dng ch:- Pha trn xng c tr s octan cao (nh xng alkyl ho, izome ho,..)

vo nhin liu c tr s octan thp.

- Nng cp v a thm cc thit b lc du sn xut hn hp xng c

tr s octan cao.

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- S dng cc cht ph gia khng cha ch, nh cc hp cht cha oxi:

etanol, MTBE, MTBA, TAME,..

Trong s cc ph gia cha oxi ni trn th MTBE v etanol c s dng

vi s lng nhiu nht. Chng hn nh M, MTBE c pha trn vi15% th tch, etanol ti 10% th tch. Braxin pha trn ti 22% etanol

vo xng trong nhiu nm.

Bn cnh vic tng tr s octan, hn hp ca xng vi ph gia cha oxi

gip thi hyrocacbon v CO t xe c s dng nhin liu.

C th thy r tr s octan ca mt s cht cha oxi in hnh trong bng:

Bng 1: tr s octan ca mt s cht cha oxi

Ph gia cha oxi RON MONMetanol

Etanol

Tert-butanol (TBA)

Metanol/TBA (50/50)

Metyl tert-butyl ete(MTBE)

Tert-amyl metyl ete(TAME)

Etyl tert-butyl ete (ETBE)

127136

120135

104110

115123

115123

111116110119

99104

100106

9098

96104

98105

9810395104

T ta thy, tr s RON ca MTBE vo khong 115123, do hn

hp 15% MTBE trong xng c tr s octan gc l 87 s to nn mt hn hp

c tr s RON nm trong khong 91 n 92, lm tng t 4 n 5 n v

octan, tng ng vi hm lng ch t 0,1 n0,15g/l. Tng t, tr s

octan ca etanol l 120135, do hn hp 10% ca etanol vi xng c tr

s octan l 87 s to ra hn hp c tr s RON vo khong 9092.Nn nhim mi trng trn th gii trong nhng nm gn y gy

nh hng nghim trng. Mt trong nhng nguyn nhn gy nn nn

nhim mi trng l kh thi ca ng c c cha mt lng kh c hi nh:

CO, NO, NO2,.. Lng kh ny gy nh hng trc tip n mi trng.

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Do vy vn t ra u tin l phi gim lng kh thi lm cho nhin liu

ca ng c v lm c iu ny ta phi lm cho nhin liu ca ng c

sch hn, tc l phi sn xut xng sch, hm lng thm trong xng thp,

hm lng benzen thp hn 1%.

Mt khc c hiu sut ca ng c cao hn v tnh nng thot kh thi

hon thin hn th ng c phi t s nn ln hn, tc l yu cu nhin liu

phi c tr s octan cao, m xng chng ct trc tip th tr s octan cn thp,

cha yu cu ca ng c. Do vy ngi ta s dng cc hp cht nng

cao tr s octan pha vo xng, v ph gia u tin c s dng lm

nhin liu cho xng l TEL (tetra etyl ch) v TML (tetra metyl ch) loi ph

gia ny cho php nng cao ng tr s octan v lm cho gi thnh h. Loi

ph gia ny do MDOLE ngi M tm ra vo thng 11-1921 Vo nm 1929,

loi ph gia ny c mt trong xng thng phm ca M v c trong xng

thng phm ca c trc chin tranh th gii th II khng xa.

Tuy nc ch khi s dng pha vo xng b p c lng octan

thiu ht v gi thnh xng kh r, song bn cnh vic to nn c cc u

im th n cng li nhng tc hi nghim trng cho sc kho con ngi

(v ch l cht c trch lu), cho mi trng v nh hng trc tip n tnh

nng ca ng c nh:

+Trong qu trnh chy to nn hp cht ch rn trong ng c.

+Kch thch s nhim bn bugi, lm tng s mi mn xylanh v cc van.

+Lm mt hot tnh ca xc tc trng hp x l kh thi, chnh v cn

nhiu nhc im nn hu ht cc nc ban lut cm hay s dng nc

ch lm cht mang tr s octan cho xng.

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Gii hn TEL cc i trong xng (g/l) nm 1998 mt s nc:

Bng 2: Gii hn TEL cc i trong xng

Nc Lng TEL trong xng (g/l)

MCanada

, Php, B o Nha,TyBan

Nha

Cc nc khc

Australia

o, Thu in, Phn Lan

Triu Tin

Venezuela

Nht Bn

0,260,291

0,399

0,151

0,3040,840

0,151

0,301

0,840

0,000

Xu hng hin nay l s dng hp cht cha oxi lm tng octan. Trong

cc hp cht oxi c ng dng thc tin nht l cc ete: Metyl tert-Butyl ete

(MTBE), Tert amyl-metyl ete (TAME), etyl tert butyl ete (ETBE).

Khi thm hp cht cha oxi vo xng, ngoi vic lm tng octan, n cn

lm gim lng kh thi CO.

Khi cho MTBE vo trong xng th:

+Khng cn bt c thay i no i vi ng c hin hnh.

+p sut hi ca nhin liu gim do vy tn tht bay hi khi cp nhin

liu v vn hnh gim.

+Gim khi thi c bt l CO v cc hyro cacbon cha chy.

+Thm 20% th tch MTBE vn khng c hi ti cng sut ng c

cng nh tng s tiu tn nhin liu, trong iu kin lnh kh nng khi

ng ng c cng d dng, ngn cn s ng bng trong b ch ho kh.

+MTBE tan ln tt vi H2O nn im ng c ca nhin liu gim ng

k.

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+Nhin liu trn MTBE tng thch vi tt c cc vt liu s dng

sn xut t nh: m cao su, sn cc kim loi trong b ch ho kh, bm

phun,..

+MTBE khng nh hng n h bi tit l thuc m yu.Metyl Tert Butyl Ete l hp cht cha oxi thuc loi hp cht alkyl tert

butyl ete c cng thc cu to:

CH3

|

CH3 O C CH3

|

CH3MTBE c tng hp t metanol v isobuten vi xc tc l acid rn.

Ngoi ra, MTBE cng c nhng ng dng khc trong cng nghip lc

ho du nh: dng sn xut metaacrolein, metacylic acid, v isopren, sn

xut isobuten (bng cch phn hu MTBE, tuy nhin y l bin php khng

kinh t).

Nhu cu tiu th MTBE ang tng nhanh, MTBE l mt trong nhng

ho cht tng trng mnh nht trn th gii vi tc tng trng trungbnh 20% mi nm (1989-1994). D bo ti nm 2010 nhu cu MTBE s

ln ti 29.000 nghn tn/nm.

C nhiu qu trnh cng ngh sn xut MTBE cc hng trn th gii

c pht minh v lp t sn xut MTBE. Qu trnh cng ngh sn xut

MTBE ca Snamprogetti (M) s dng nguyn liu l hn hp kh C4 cha

isobuten. Qu trnh Hiils (CHLB c) qu trnh ca CD Tech dng nguyn

liu C4 v C5 (hn hp kh). Qu trnh ARCO vi nguyn liu t qu trnh

hyrat ho Tert-Butyl Acolhol,.. Tng cng sut ca cc xng sn sut

MTBE ang hot ng vo khong 25.275 nghn tn/nm.

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I.2 Tnh cht ca MTBE :

I.2.1 Tnh cht l hc :

Metyl tert butyl ete trng thi bnh thng l cht lng, khng mu,

linh ng, nht thp, d chy, tan v hn trong cc dung mi hu c vcc hydro cacbon.

Mt s tnh cht vt l c trng ca MTBE c a di bng 3 [1]

Bng 3: Tnh cht vt l ca MTBE

Khi lng phn t, M

Nhit si, ts

Nhit nng chy

Hng s in mi (20oC)

nht (20oC)

Sc cn b mt

Nhit dung ring (20oC)

Nhit ho hi

Nhit chy

Nhit chp chyGii hn n vi khng kh

p sut ti hn, Pc

Nhit ti hn, tc

88,15

55,3oC

-108,6oC

4,5

0,36 mPa.s

20 nN/m

2,18 KJ/kg.

337 KJ/kg

-34,88 MJ/kg

-280C1,6584% th

tch

3,43 MPa

224,0oC

T trng, p sut hi v ho tan trong nc ca MTBE theo nhit

c cho bng 4 [1]

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Bng 4: T trng, p sut hi bo ho v ho tan ca MTBE

Nhit oC

p sut

KPa

ho tan T trng

G/cm2Nc trong

MTBE, %KL

MTBE trong

nc, % KL0

10

12

15

20

30

40

10,8

17,4

26,8

40,6

60,5

1,19

1,22

1,28

1,36

1,47

7,3

5,0

3,3

2,2

1,5

0,7613

0,7510

0,7489

0,7458

0,7407

0,7304

MTBE c th to hn hp ng ph vi nc, hoc vi Metanol.

Bng 5: Hn hp ng ph ca MTBE [1]

Hn hp ng ph Ts,o C Hm lng MTBE,

%KL

MTBE - ncMTBE - Metanol

MTBE - Metanol (1,0MPa)

MTBE - Metanol (2,5MPa)

52,651,6

130

175

9686

68

54

.MTBE khng c gii hn v tan ln vi cc dung mi thng thng.

.MTBE rt n nh trong mi trng kim trung tnh v axit yu.

.Trong mi trng axit mnh MTBE tch metanol v izo buten.

I.2.2 Tnh cht ho hc:

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MTBE l cht kh n nh di iu kin acid yu, mi trng kim

hoc trung tnh. Trong mi trng c cn bng:

CH3 CH3H+

CH3- O - C - CH3 CH3OH + CH2 = C

CH3 CH3

(MTBE) (Metanol) (Iso butylen)

Trong iu kin phn ng mi trng acid, MTBE gn nh tr vi cc

tc nhn khc nh buten-1, buten-2, n-buten, isobutan,.. iu ny lm gimcc sn phm ph v tng chn lc. Tuy vy do cn bng c th chuyn

dch sang c th to thnh iso butylen v metanol nn c th gim chuyn

ha. Do vy cn phi ly MTBE ra khi mi trng phn ng lin tc

lm cn bng dch chuyn sang tri.

I.2.3 Tnh cht ca MTBE nh hng n cng ngh:

Vi cc tnh cht vt l nh trnh by, MTBE c th thu hi bng

chng tch v nhit si ca MTBE l 55,3

o

C tc l ln hn hn hp ngph ca metanol - hn hp cc hyrocacbon C4 (tos

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II.1C s ha hc ca qu trnh ete ha: [1]

CH3 CH3

| |

CH2 = C + CH3OH CH3 - C - O - CH3

| |CH3 CH3

Qu trnh phn ng xy ra d dng iu kin nh nhng v trong pha

lng (hoc pha lng - kh hn hp). Nhit phn ng trong khong 40-

90oC v p sut t 7-20at(p sut duy tr phn ng trng thi lng).

y l phn ng to nhit nh, ( )mol/KJ37H = thun nghch, c

chn lc cao mc d c mt cc cu t C 4 khc (buten, n-butan, iso butan...)

trong mi trng phn ng. Xc tc cho phn ng thch hp l xc tc acid

rn. C th s dng xc tc acid rn nh bentonit nhng hay s dng nht l

nha trao i ion cationit, gn y ngi ta nghin cu s dng xc tc

zeolit.

Phn ng tng hp l phn ng thun nghch, cn bng dch chuyn

sang phi th ngi ta phi ly d lng metanol hn so vi h s t lng.

Qu trnh tng hp MTBE l qu trnh d th E R

II.1.2 ng hc v c ch phn ng: [4]

Phn ng tng hp MTBE l phn ng thun nghch, xc tc acid, ng

hc v c ch phn ng ph thuc vo mi trng phn ng, iu ny c

ngha l ph thuc vo t l:

C th xem l phn ng xy ra theo c ch ion vi s proton ho iso

buten trc:

CH3 CH3

mol)l(t

Metanol

IsobutenR=

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Trong :

r: tc phn ngKf: hng s tc phn ngthunKMe: hng s cn bng hp ph ca MetanolK: hng s cn bng nhit ngCi: nng ca cu t i, mol/li = Isobuten, Metanol, MTBE

KMT: hng s cn bng hp ph

Khi b hp ph Metanol c ni hyro theo 3 kchthc mng li ca

3 nhm SO3H v phn ng vi isobuten t dung dch trong cc mao qun v

pha to gel. S hot ng ng tc dng ca c 3 nhm SO3H s to ranhm tert-butyl c cu trc ging cation, v s trao i phi hp proton xy

ra.

Cng theo c ch ny c th xy ra s to thnh Metyl-sec butyl Ete

ging nh to ra MTBE, song s to thnh ny mc nh bi v kh

nng phn ng thp ca alken thng, Buten-1 hu nh khng hp ph

R

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ng hc theo c ch ny s theo phng trnh:

Trn quan im phn t, c th suy ra rng s trao i phi hp protonm c lin quan n s hp ph isobuten l c tc dng. S hp ph isobuten

dn n s gi c nh cu trc ging cation ca tert-Butyl vo nhm SO3H,

nhm m phn ng vi ni hyro ca Metanol vi SO3H bn cnh. S ng

tc dng ca 3 nhm SO3H l cn thit n nh cu trc ca tert-Butyl v

s trao i proton xy ra. MTBE c to ra v ni hyro vi nhm SO3H

v lm gim tc phn ng, nu qu trnh phn ng khng lm cho cc ht

nha co li c ch L-H c th xy ra nhanh hn c ch E-R v tc phnng tng dn. Chm t R=0,7 v mn m khi R=1,7. Khi C IB cao, iso

butylen trong dung dch, trong cc mao qun v trong cc th gel phn ng

vi cc phn t iso butylen c n nh trn nha theo c ch E-R

to ra di isobutylen (DIB), Metyl Sec-butyl Ete (MSBE) l cc sn phm

ph.

Khi R=1,7 th c s tng t ngt tc phn ng khi mo ca phn

ng isome ho buten-1, iu ny c th l do gi tr ny hm lng mol

butanol trong pha lng ln (khong 25%). Do s hp ph thun nghch

buten-1 ln nha kh ln.

Khi R=3,5, hm lng CH3OH trong pha lng cn t hn 15% mol trong

khi hm lng iso buten l 50% (nu nguyn liu l phn on C 4 t qu

trnh Craking hi nc). CMe thp ny ht nha polime b co li v mng

li SO3H dy c, c ch L-H bt u chim u th. Do lc ny phn

ng tng hp MTBE xy ra ch yu theo c ch L-H. S to thnh DIB theo

c ch L-H cng c tc dng.

Khi R=10, lc ny phn ng ch xy ra theo c ch L-H cui cng khi

tng hp MTBE t cn bng ho hc, mt c ch chuyn tip c th xy ra.

R

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Trong qu trnh phn ng xy ra phn ng tng hp MTBE chuyn sang c

ch L-H v tc phn ng tng dn v t cn bng ho hc.

II.1.3 Xc tc cho phn ng: [5]

Trong cng ngh sn xut cht oxy thng s dng xc tc l nha traoi ion dng cationt c mao qun ln. Nha cationt l 1 acid rn, l hp

cht cao phn t gm matrix l hp cht trng hp ca styron v c thm

divynyl benzen butadien hay cc hp cht khc ni i lin hp to thnh

cu trc mng khng gian mc no khng tan trong nc v cc

dung mi hu c nhng c cu trc xp h c kh nng trao i cc

nhm chc nh l -SO3H c nh vo matrix polime ni trn (nh vo

cc nhn thm)

Matrix ca cation to thnh gia Styren v divinyl benzen c th biu din nh sau:

acid cng mnh th hot tnh xc tc cng cao. acid ph thuc

vo kiu loi v s nhm acid trn nha v b nh hng bi ni ngang

(lin kt ngang). hot ng ca xc tc nha ph thuc ch yu vo hnhthi ban u ca nha v vo tng tc ca n vi pha phn ng gm c

dung mi v nhng cht khc trong h thng phn ng.

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Hnh thi ca nha trao i ion lin quan n cch tip cn ca cc phn

t vo nhm Sulfonic. N c th b nh hng bi tng tc ca dung mi

v nhng phn t hp ph vi nhm nh chc.

Mt s loi xc tc nha trao i ion v tnh cht ca chng c a bng 7.

Bng 6: Tnh cht ca mt s loi nha trao i ion [5]

Tn thng

mi

acid

C

B mt

ring

theo

BET,

m2

/g

B mt

ring

theo

ISEC,

m2

/g

Th

tch

mao

qun,

mL/g

n

g knh

mao

qun,

Ao

Kch

thc

ht tb,

nm

Bayer K2631

Bayer OC-1501

Ambalyst 15

Ambalyst 35

Dowex M32

PuroliteCT 151

PuroliteCT 165

PuroliteCT 169

PuroliteCT 171

PuroliteCT 175

PuroliteCT 179

4,83

5,47

4,75

5,32

4,78

5,40

5,00

4,90

4,94

4,98

5,25

41,5

25,0

42,0

34,0

29,0

25,0

6,2

48,1

31,0

29,0

35,0

163,8

156,9

165,7

151,2

220,1

0,67

0,52

0,36

0,28

0,33

0,30

0,16

0,38

0,47

0,48

0,33

650

832

343

329

455

252

1148

342

597

662

386

0,63

0,66

0,74

0,51

0,63

0,43

0,43

0,43

0,40

0,40

0,43

II.1.4 Cc yu t nh hng n qu trnh cng ngh:

II.1.4.1 nh hng ca t s Iso butene/Metanol n tc phn ngtng hp:

Khi tng t s IB/MeOH tc l hm lng Iso butylen [6] trong hn hp

phn ng tng s dn n vic gim hng s tc phn ng tng hp. iu

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ny l do s n nh ca isobuten v phc hot ho, v do s tng ln nhiu

cc proton hot ng.

V vy trong cng ngh cn iu chnh t l ny ph hp trnh lm

gim tc phn ng tng hp.II.1.4.2 nh hng ca nng MTBE to thnh n phn ng tng

hp

Khi nng MTBE tng dn n s tng hng s tc , hng s m

khng ph thuc v nha trao i ion. C th thy rng s tng hm lng

MTBE trong hn hp phn ng dn n nhng thay i, khng ph thuc

vo nha, ca nhng thng s hot ho ( H v S), nhng thng s m dn

n s thay i phc hot ho. V iu ny lm tng tc phn ng. [6]II.1.4.3 nh hng ca s c mt ca nc [7]

S c mt ca nc vi mt lng nh, bng hoc t hn so vi trong

hn hp ng ph vi metanol khng nh hng nhiu n hng s cn bng

ca MTBE, thm ch c th lm tng chuyn ho iso buten.

Nc vi mt lng nh cng c nh hng c ch v lm gim tc

to ra MTBE, c bit l phn u (phn trn) ca thit b gin on hoc

thit b ng chm. nh hng c ch s mt i khi nc b tiu th to raTBA. TBA c to thnh rt nhanh. Cn bng TBA t c nhanh chng

hn so vi ete. V vy s c mt ca nc s dn n s to ra phn ng

ph.

II.2 Cc phng php sn xut:

T cc ngun iso-butan khc nhau m ta c hng sn xut MTBE khcnhau.

Hng 1:i t phn on C4 ca qu trnh cracking hi nc sau khi tch

butadien( Raffinat-1)

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Hng 2: t hn hp C4 ca qu trnh FCC

Hn hp C4 t pah Raffinat-1 ca qu trnh cracking hi nc v tqu trnh FCC l cc ngun nguyn liu truyn thng, c s dng kh

ph bin trong cc phn xng sn xut MTBE trn th gii do githnh sn xut r, nguyn liu l sn phm th yu ca qu trnh lc duv c th s dng lm nguyn liu trc tip sn xut MTBE. Tuy vy,do s hn ch v k thut v d lng nguyn liu m phng php nyang dn b thay th.Mt s cng ngh dng ngun nguyn liu ny l:+ Cng ngh ca hng CD-Tech+ Cng ngh ca hng Phillips+ Cng ngh ca hng Snamprogetti+ Cng ngh ca hng IPF, hng Hills Hng 3: T n-butan tch ra t kh t nhin

Trong thnh phn kh thu c t cc m kh thin nhin c cha mtlng kh butan kh ln. V th, ngi ta a ra phng php sn xutmi s dng nguyn liu l n-butan tch ra t kh t nhin vi tr lng

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ln. Qu trnh ny gm 3 bc c bn vi nhiu cng ngh ca cc hngkhc nhau :+ Isome ha n-butan thnh iso-butan: Cng ngh ABB ca Lummus v

cng ngh Butamer ca UOP+

Dehydro ha iso-butan thnh iso-buten: Cng ngh Catofin caLummus, Cng ngh Oleflex ca UOP, cng ngh STAR ca Phillips,qu trnh FBD-4 ca Snamprogetti

+ Ete ha: Cng ngh CD-Tech ca Lummus, Ethermax ca UOP,Phillips Etherfication process ca Phillips.

Hng 4: T tert butyl alcol (TBA)

II.3 Nguyn liu tng hp MTBE

Nguyn liu tng hp MTBE l Metanol v Iso buten

II.3.1 Metanol: [1]

II.3.1.1 Tnh cht vt l:

Metanol l cht lng khng mu, linh ng, d chy v tan nhiu trongnc, tan hu ht trong cc dung mi hu c, tan t trong cht bo v du,

Metanol l cht phn cc v vy n tan nhiu trong cc cht v c phn cc

v c bit l cc mui. Metanol to hn hp ng ph vi nhiu cht nh

MTBE, Acrylonitrile, hyrocacbon (n-pentan, benzen, toluen...), Metyl

acetat, Metyl metacrylat...

Mt s tnh cht vt l quan trng ca Metanol c da vo bng 7.

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Bng 7: Mt s tnh cht vt l ca Metanol

II.3.1.2 Tnh cht ha hc:

Metanol l ru n gin nht, hot ng ca n c xc nh vi

nhm chc OH. Phn ng ca Metanol xy ra qua s phn hu ca ni C-O

hoc H-O v c trng vi s thay th H hoc nhm OH.

Mt s phn ng c trng:

Tc dng vi kim loi kim to mui ancolat

Phn ng este ha

Metanol tc dng axit v c, hu c to thnh este, phn ng thunnghch v xy ra trong mi trng axit H2SO4 c:

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Tc dng vi HX

Tc dng vi NH3

Metanol c th b oxy ha bi CuO hoc dung dch KMnO4 to thnhfomaldehyt:

Trong khng kh, metanol chy to thnh CO2 v H2O ng thi tanhit:

Khi cho hi metanol i qua ng nung 200 300 oC c mt xc tc Cuth xy ra phn ng dehydro ga to thnh formaldehyt:

II.3.2 Isobuten [8].

II.3.2.1 Tnh cht vt l:

Isobuten l cht kh khng mu, c th chy nhit v p sut

thng. N c th ho tan vi ru, ete v hyro cacbon, ch tan t trong

nc.

Mt s tnh cht vt l ca isobuten c da bng 8:

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Bng 8: Mt s tnh cht vt l ca isobuten [8]

II.3.2.1 Tnh cht ha hc:

Iso buten c cc tnh cht ca mt defin c trng vi nhng phn ng

chnh nh phn ng cng, xc tc acid (phn ng cng ru to ete, phn

ng cng cc halogen to cc dn xut halogenna, phn ng cng H2O toTBA, phn ng isome ho, phn ng polime ho to DIB, phn ng vi CO

v H2O to ra axit cacbo xlic)(CH3)3C COOH, phn ng vi fomaldehyde

to hp cht dng sn xut isopren.

Phn ng cng:+ Cng ru to ete

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+ Cng nc to TBA

+ Cng hydro halogenua (HX)

Phn ng oxy ha

Phn ng polyme ha

III. CC QU TRNH CNG NGH

Cc qu trnh sn xut MTBE khc nhau da trn cc ngun nguyn liu

khc nhau.

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III.1 Sn xut MTBE t hn hp kh C4 Raffinat-1 t phn xng

etylen v t hn hp FCC-BB t qu trnh cracking xc tc.

S khi ca qu trnh sn xut MTBE t kh C4 t xng etylen.

Nu ngun nguyn liu l isobuten t qu trnh cracking xc tc:

y l ngun nguyn liu truyn thng thng c s dng trong cc

xng sn xut MTBE trn th gii. V vy qu trnh sn xut i t hn hp

kh Raffinat-1 hoc FCC-BB l qu trnh sn xut MTBE ph bin trc

y. u im ca n l gi thnh sn xut r, do nguyn liu l c sn gi

thnh sn phm r v nguyn liu l cc sn phm th yu ca cc qu trnh

lc du v c th s dng trc tip sn xut MTBE. Tuy vy do s hn

ch v s lng nguyn liu m phng php ny ang dn b thay th.

Mt s cng ngh dng ngun nguyn liu l hn hp Raffinal-1 hoc

FCC-BB gm c:

Cng ngh ca snamprogetti

Cng ngh MTBE ca hiils

Cng ngh CD-Tech

Cng ngh ca phillip

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III.1.1 S cng ngh ca snamprogetti

Hnh 1: S cng ngh sn xut MTBE ca hng snamprogetti1. Thit b phn ng ng chm 2. Thit b phn ng on nhit

3. Thp tch MTBE 4. Thp hp th Metanol

5. Thp tch Metanol

S cng ngh ny s dng nguyn liu l hn hp C4 t qu trnh

cracking hi nc hoc hn hp kh FCC-BB. Thit b phn ng th nht l

thit b ng chm thc hin phn ng ng nhit, thit b th 2 thc hin

on nhit. Xc tc c sp xp sao cho vic iu khin nhit l tt nhtv chuyn ho t xp x 100%.

Nguyn liu u gm metanol v hn hp kh C4 giu iso-buten c

a vo thit b phn ng ng chm (1). Thit b ny cho php tin hnh

phn ng ch ng nhit. Sau , hn hp phn ng c a sang

thit b (2) tip tc phn ng theo ch on nhit. Sn phm t y (2)

c dn vo thp tch (3). MTBE ly ra y cn li l metanol v hn

hp C4 cha phn ng c a qua thp hp th bng nc (4) tch hnhp C4 trn nh. Dung dch hp th metanol c a qua thp (5) thu

hi metanol cho tun hon tr li cng dng nguyn liu u i vo thit b

phn ng (1).

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III.1.2 S cng ngh Hiils

Qu trnh tng hp MTBE theo cng ngh ny chuyn ha iso-buten

99,9% mol.

Hnh 2: Cng ngh sn xut Hiils ( hai giai on)

Giai on 1:

1. L phn ng dng ng (ng chm) 2. L phn ng on nhit

3. Thp chng ct C4 th nht 4. Thp chng ct hn hp ng ph

Giai on 2:

5. L phn ng th cp 6. Thp chng ct C4 th 2

7. Thp hp th Metanol 8. Thp tch Metanol

III.1.3 S cng ngh CD-Tech

S ny c th s dng nguyn liu l hn hp l hyro cacbon C4

hoc isobuten t qu trnh hyro ho isobutan. Cng ngh CD Tech s

dng 2 thit b phn ng. Thit b th nht l thit b phn ng on nhit,

cn thit b 2 l thit b phn ng chng tch, va thc hin phn ng va

chng tch. Trong thp phn ng chng tch 2 ngi ta b tr nhng

khong chng tch v nhng khong cha xc tc thc hin phn

ng tng chuyn ho sn phm. y l cng ngh mi s dng k

thut phn ng chng tch (3) l ct tch MTBE kkhi Metanol, (4) l ct

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tch Metanol - nc, Cng ngh cho ta chuyn ha iso-buten ti 99,9%

mol. Nhit mang vo ct chng tch c tit kim nh nhit t thit b

phn ng th nht.

Hnh 3: S cng ngh ca hng CD-tech

1. Thit b phn ng c lp xc tc c nh

2. Thit b phn ng chng tch xc tc

3. Thp hp th Metanol

4. Thp chng ct Metanol

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III.1.4 S cng ngh ca hng Phillip

Hnh 4: S cng ngh ca hng Phillip

1,2 Thit b phn ng 3. Thp tch MTBE

4. Thp hp th Metanol 5. Thp ti sinh Metanol

Qu trnh ny c tin hnh nh sau:

Iso-buten cng vi metanol nguyn liu v metanol tun hon c lm

giu ti b phn l phn ng (1,2) cha ng nha trao i ion axit. thitb (1) di xc tc c nh (gian on 1) c lm lnh bn ngoi. Cng

ngh ny cho php cht xc tc d thay i m khng ngng hot ng v

ng thi cho sn phm MTBE cht lng cao.

MTBE t y thp RWD c lm lnh trc khi vo b cha. Phn lng ra

khi nh c cha C4S. Metanol d v hydrocacbon nh khc c bay hi

qua van tit lu sao i vo thp ra bng nc, ti y Metanol c tch

ra theo nc vo thp chng ct thu Metanol hi lu li qu trnh ete hacn nc quay tr li ra kh. Phn kh ra khi thp ra c x l hi

lu li iso-buten ti nh my dehydro ha.

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III.2 Sn xut MTBE t kh butan t m kh [9], [10], [2].

y l xu hng sn xut mi s dng nguyn liu l phn butan tch t

kh t nhin vi tr lng ln.

S qu trnh sn xut MTBE t kh n-butan nh sau:Metanol

Qu trnh bao gm 3 giai on:+ Isome ho kh m n-butan to thnh isobutan, qu trnh isome ho xy

ra nhit thp (150-200oC) v p sut l 200-400psig trong pha hi. Xc

tc cho qu trnh l Pt hoc Al 2O3 hoc Pt/Al2O3 c tm mt lng hp cht

hu c dn xut clo. Kh n-butan a vo s chuyn ho thnh isobutan

gn im cn bng. Mt s qu trnh isome ho thc hin isome n-butan

to thnh isobutan l: qu trnh isome ho ca Lummus (hnh 6), qu trnh

Butamer (UOP) (hnh 7)

Hnh 6: Qu trnh isome ha ca Lummus

1.Thp tch iso-butan 2.Thp sy 3,4.L phn ng 5.Thit b chng tch

6. Thp n nh 7.Thp ra kh 8.My nn

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Hnh 7: Qu trnh isome ha butamer ca UOP

1. Thp tch 2,7,9. Thit b lng 3,4. L phn ng

5,6. Thit b sy 8. Thit b chng tch 10. Thp ra

I. Nguyn liu butan II. Iso-butan

III. Nhin liu kh IV. Na2CO3

+Qu trnh hyro ho isobutan thnh isobuten:

Qu trnh hyro ho ny c thc hin t=540760oC v p sut

thp. Xc tc phn ng c th l Cr/Al2O3 hoc Pt. Sn phm thu c cha

7585% iso buten v isobutan. Cc qu trnh hyro ho hin nay snxut iso buten l: qu trnh Catofin (Lummus) hnh 8, qu trnh oleflex ca

UOP (hnh9), qu trnh STAR ca Phillip, qu trnh FBD-4 ca

Snamprogetti (hnh10 v 11).

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Hnh 8: Qu trnh Catofin ca Lummus

1. Trao i nhit 2. L thi 3. L hi 4. L gia nhit

5. My nn sn phm 6. Ni chng 7. Thp sy kh

8. Thit b lm lnh 9. PSA 10. un nng s bI. Parafin C3-C5 II. Sn phm III. Kh nhin liu IV. Kh thi

Qu trnh ny s dng xc tc Crom oxit, nhit cp cho phn ng bng

cch t chy ci to thnh xc tc nh dng khng kh nng.

Hnh 9: Qu trnh Oleflex

1. Thit b phn ng 2. Thit b gia nhit 3. L ti sinh xc tc

4. Thp sy 5. Tuabin gin n kh 6. Thp tch hydro7. Thp ct phn sn phm nh

I. Nguyn liu iso-butan k thut v tun hon

II. Kh thi III. Sn phm iso-buten

IV. Phn ct sn phm nh V. Hydro tun hon

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Hnh 10: Qu trnh STAR ca Phillip

1. L phn ng 2. ng khi 3,4,5. Thp chng6. Thp sy kh 7. Thit b lm lnh

8. Thp tch sn phm 9. My nn

I. Kh nhin liu II. Nguyn liu iso-butan III. BFW

Hnh 11: Cng ngh dehydro ha ca hng snamprogetti (FBD-4)

1.Dng trao i nguyn liu 2.L phn ng ti sinh 3.Thit b phn tch

4.Thp tch sn phm 5.ng khi 6.Lc kh nhin liu

7.Thit b lm lnh 8.Thp sy kh 9.My nn

10. B phn lc

I. Iso-butan II. Kh thi III. Khng kh

IV. Kh nh V. Sn phm

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+ Qu trnh ete ho isobuten thnh MTBE: qu trnh ny c tin hnh

to=40-90oC v p sut t 7-29 at, xc tc l nha trao i ion. Phn ng

thc hin trong qua lng. Cng ngh qu trnh ete ho ca mt s hng nh

qu trnh CD Tech (Lummus), Ether max (UOP), Phillip, Etherfication

Process (Phillip)...

Hnh 12: Cng ngh Ethermax ca UOP

1.Thit b phn ng 2.Thp chng ct

3.Thp ra kh bng nc 4.Thp chng ct ru nc

I. Iso-buten II. Metanol

III. MTBE IV. Raffinat C4

III.3 Sn xut MTBE t Tert Butyl Alcohol:

y l qu trnh sn xut MTBE i t nguyn liu iso buten ca qu

trnh hyrat ho TBA. TBA thu c l ng sn phm trong qu trnh

sn xut propylen oxit.

S qu trnh:

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Qu trnh sn xut MTBE t TBA do hng Texaco thc hin c s

nh sau:

Hnh 13: Cng ngh sn xut MTBE t TBA ca Texaco1. L t 2. Thit b phn ng

3. Thit b phn ng on nhit 4. Thit b phn ng chng ct

5. Thp hp th Metanol 6. Thp ti sinh Metanol

I. Nguyn liu Metanol II. Nhin liu

III. Hn hp Raffinat C4 IV. Metanol ti sinh

V. Nguyn liu Metanol VI. Iso-buten

VII. Sn phm MTBE

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CHNG 3 : TNH TON THIT B

I.TNH TON CN BNG VT CHT:

Dy truyn sn xut MTBE t nguyn liu kh isobutan vi cng sut

50.000 tn/nm.Dy chuyn sn xut 24h/ngy v mt nm lm vic 330 ngy cn 35

ngy ngh sa cha, bo dng nh k.

*Cc ch tiu sn xut:

Nng sut MTBE: 50.000 tn/nm Nh vy nng sut dy chuyn tnh

theo gi l:

Tnh theo Kmol/h:

(khi lng phn t ca MTBE l 88)

Nng sn phm:

MTBE chim 99% (khi lng)Metanol chim 0,5%Cn li l Dime ca i-Butylen, ru, TBA, nc...

Nguyn liu l kh iso-butan tiu chun c cho bng 12 (theo

TY38.101492-79) Loi B

h6313,13kg/330.24

50.000.000=

h71,74Kmol/88

6313,13=

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Bng 12: Thnh phn kh iso-butan nguyn liu

Thnh phn % th tch

Iso butan

Propan

Tng Buten

n-butan

C +5

Cc cht khc

H2S v Mercaptan

H2O v kim

90

4,5

0,5

6

0,5

0,005

0

Metanol nguyn liu l metanol thng phm vi thnh phn:

Metanol 99,9% (khi lng)

Nc 0,1%

Tng aceton v aldehyd < 30 mg/kg

Tng acid < 30 mg/kg

Phn cn < 10 mg/kg.

I.1 Tnh cn bng vt cht chung

Qu trnh sn xut MTBE qua 2 giai on: giai on hyro ha

isobutan v giai on tng hp MTBE. Ta tnh cn bng vt cht tng giai

on:

Giai on tng hp MTBE:

Cn bng: khi lng vo = khi lng ra- Cc dng khi lng i vo phn tng hp MTBE gm c:

+ Hn hp C4 lng i ra t phn hyro ha: G1, kg/h

+ Dng nguyn liu Metanol : GMeOH , kg/h

- Cc dng sn phm i ra khi phn tng hp MTBE gm c:

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+ Hn hp kh C4 cha phn ng : GC 4 chaphnng , kg/h

+ Sn phm MTBE : GMTBE , kg/h

H2 O do trong nguyn liu Metanol cha 0,1% (W).

y on gin ta coi rng trong qa trnh hp th Metanol v qatrnh chng tch thu hi Metanol v nc, lng H2O s dng khng b mt

mt v c tun hon li cho qa trnh hp th Metanol v lng H 2O ly

ra bng lng nc a vo dy chuyn do c trong nguyn liu Metanol

v bng GH 2 O, kg/h

Tnh ton cc khi lngG1, GMEOH , GC 4 cha phn ng , GMTBE , nh sau:

+ Khi lng sn phm MTBE i ra phi l nng sut quy nh ca ton

dy chuyn sn xut v bng 6313,13 kg/h.

Vy GMTBE = 6313,13 kg/h

+ giai on tng hp, phn ng tng hp nh sau:

Iso-buten + MeOH MTBE

y l phn ng thun nghch, tuy vy khi qua thp phn ng chng ct

(thp CD) theo cng ngh CD Tech th chuyn ha chung t 99%,

chn lc t 100% (tnh theo iso buten).Vy to ra MTBE t nng sut yu cu l 71,74 kmol/h th lng iso

buten cn to ra t phn hyro ha tiu th cho phn ng tng hp l:

72,40,99

71,74= kmol/h

(0,99 l chuyn ha ca phn ng tng hp theo iso buten)

y n gin trong tnh ton ta coi chn lc MTBE t 100% v

iso buten khng tiu th cho phn ng ph to ra TBA v DIB.Vy GIB =72,46 . 56 = 4057,76 kg/h

(MIB = 56)

+ Khi lng Metanol a vo thit b phn ng MTBE theo t l:

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=

buteniso

Metanol1,1 (t l mol).

Vy lng Metanol a vo l:

72,46 . 1,1 = 79,706 kmol/hHay 79,706 . 32 = 255,60 kg/h

Lng Metanol a vo thit b = lng metanol (99,9% W) mi a

vo

+ lng metanol tun hon.

Trong :

Lng Metanol tun hon = lng Metanol cn li sau phn ng- lng

Metanol trong sn phm MTBE.Lng Metanol cn li sau phn ng = Lng Metanol a vo -

Metanol tiu th cho phn ng.

Lng Metanol tiu hao cho phn ng cng bng s kmol MTBE to ra

(theo phn ng tng hp) v bng 71,74 kmol/h.

Vy lng Metanol cn li sau phn ng l:

79,76 -71,74 = 7,966 kmol/h Hay 7,17. 32 = 254,91 kg/h.

Ta coi cc sn phm ph khc trong MTBE sn phm ch gm c

Metanol v khng cha DIB, TBA... Lng Me cn li trong sn phm

MTBE chim 1% khi lng tc l bng:

0,01. 6313.13 = 63,13 kg/h.

Coi rng Metanol c thu hi theo dng sn phm chnh ra khi thp

phn ng 2 l 100%.

Nh vy lng Metanol tun hon l:254,91. 63.13 = 191.78 kg/h.

Lng Metanol (100% W) mi cn a vo l:

2550,60 - 191,78 = 2358,82 kg/h.

Lng Metanol (99,9%) mi cn a vo dy chuyn l:

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kg/2361,180,999

2358,82=

Vy lng nc a vo dy chuyn l:

GH2 O = 2361,18 - 2358,82 = 2,36 kg/h.

Cn bng ta c:

G1 + GMeOH (99,9%) = GC 4 cha phn ng + GMTBE + GMeOH trong MTBE + GH 2 O

Hay G1 + 2361,18 = GC 4 cha phn ng + 6313,13 + 63,13 + 2,36

tnh G1 v G +4c ta tnh cn bng vt cht cho giai on hyro ha.

* Cn bng vt cht giai on hyro ha:

Khi cn bng: khi lng vo = khi lng ra.- Cc dng vt cht i vo phn hyro ha gm:

+ Hn hp C4 lng iso butan nguyn liu: Giso- 104HC , kg/h

- Cc dng vt cht i ra gm:

+ Hn hp lng C4 sn phm c cha iso buten: Giso- 104HC , kg/h

+ Hn hp kh thi giu H2: Gkh thi , kg/h

Vy cn bng ta c:

Giso- 104HC nguyn liu = Giso- 84HC sn phm + Gkh thi

Tnh ton cc khi lng nh sau:

+ Giso- 84HC nguyn liu:

Ta c phn ng:

iso-C4H10 iso-C4H8 + H2 (*)Lng iso-C4H8 cn to ra giai on hyro ha tng hp c

6313,13 kg hMTBE nh ta tnh: 72,46 kmol/h.

Phn ng hyro ha (*) thc hin trong dy chuyn t chuyn

ha 40%, v chuyn ha t 92% mol [2]

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Nh vy lng iso-C4H10 cn hyro ha cn l:

78,40,92

72,46= kmol/h.

V chuyn ha ca (*) t 40%, vy lng iso-C4H10 nguyn cht cna vo dy chuyn l:

90,1964,0

46,78= kmol/h.

Trong 72,46 kmol/h iso-C4H10 s tiu hao cho phn ng chnh (*)

to ra 72,46 kmol/h iso-C4H8 v 78,76 - 72,46 = 6,3 kmol/h s tham gia phn

ng ph iso-C4H10.

Gi s iso-C4H10 ch tham gia cc phn ng ph cracking:iso-C4H10 C2H6 + C2H4 (1)

x (kmol/h) x x

iso-C4H10 CH4 + C3H6 (2)

x (kmol/h) x x

n gin ta gi s cc phn ng (1) v (2) xy ra vi tc nh nhau,

tiu th lng iso-C4H10 nh nhau, cc phn ng c hiu sut nh nhau v

bng 100%.

Vy lng iso-C4H10 tiu th cho mi phn ng l:

3,12

6,3x == kmol/h.

Lng iso-C4H10 cn li khng chuyn ha l:

196,90 - 78,76 = 118,14 kmol/h.

V khi lng nguyn liu iso-C4H10 cn cha cc thnh phn kh khc

nh propan, n-butan, buten... v iso-C4H10 ch chim 90% th tch.

Vy lng kh iso-C4H10 nguyn liu cn a vo l:

Giso- 104HC nguyn liu 78,2189,090,196

== kmol/h

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Vy thnh phn v khi lng kh iso-C4H10 nguyn liu a vo nh

sau:

Bng 13: Thnh phn v khi lng kh iso-C4H10

nguyn liu a vo:STT Tn cu t % kmol/h kg/h

1

2

3

4

5

6

iso-C4H10

Propan

n- C4H10

Tng n- C4H8

C+

5

H2Sv Meroaptan

90

3

6

0,5

0,495

0,005

196,90

0,03. 218.78 = 6,56

0,06. 218,78 = 13,127

0,005. 218 78 = 1,09

0,495. 10-2.218,78 = 1,08

0,005 . 10-2.218,78 = 0,01

196,90. 58 = 11420,2

6,56. 44 = 288,79

13,127. 58 = 761,35

1,09. 56 = 61,26

1,08. 72 = 77,97

0,01. MTB = 0,45

Tng 100 = 218,78 Vi MTB

142

4 83 4

2

32 =+

=+

=S HC HSH

MM

Vy Giso- 104HC nguyn liu = 11420,2 + 288,79 + 761,35

+31,26 +77,97 +0,45 = 12610,02 kg/h.

Gi s ch c cc phn ng hyro ha v cc phnng no cng chuyn ha 40%.

C3H8 C3H6 + H2 (3)

6,56 2,62 2,62

n-C4H10 n-C4H8 + H2 (4)

13,127 5,25 5,25

Lng C3H8 tham gia phn ng (3) l:0,4. 6,56 = 2,62 kmol/h.

Lng n-C4H8 tham gia phn ng (4) l:

13,127. 0,4 = 5,25 kmol/h.

+ Giso-sn phm :

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Dng vt cht i ra khi thit b hyro ha s c

ngng t cc cu t t C3 tr ln s ngng khi b nn p sut.

Cc cu t C2 tr xung s khng ngng v i ra khi dy

chuyn th kh (kh thi).

Vy hn hp lng Iso- C4H8 sn phm i ra khi phn

hyro ha c khi lng v thnh phn nh sau:

Iso- C4H8: l lng Iso- C4H8 to ra: 72,46 kmol/h = 405,76

kg/h

Iso- C4H10: bng lng Iso- C4H10 cn li cha chuyn ha v

bng:

196,90 - 78,76 = 118,14 kmol/h = 6852,12 kg/hn-C4H10 : bng lng c ban u - lng tham gia phn ng

v bng:

13,127 - 5 25 = 7 88 kmol/h = 456,87 kg/h.

n-C4H8 : bng lng c ban u trong nguyn liu + lng to

ra phn ng (4):

1,09 + 5 25 = 6 34 kmol/h = 355,04 kg/h.

C3H8 : bng lng c ban u trong nguyn liu - lng phn

ng theo (3):

6,56 - 2,62 = 3,94 kmol/h = 177,36 kg/h.

C3H6 : bng tng lng to ra do phn ng (2) v (3):

3,16 + 2,62 = 5,77 kmol/h = 242,34 kg/h.

C +5 : bng lng c ban u:

1,08 kmol/h = 77,97 kg/h.

Vy Giso- 84HC sn phm = 12215,46 kg/h.

+Gkh thi : kh thi gm c H2, CH4, C2H4, C2H6, H2S v

Mercaptan khi lng v thnh phn hn hp kh thi nh sau:

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H2 l tng lng kh thi to ra do cc phn ng

(*), (3) v (4) bng: 72,46 + 2,62 + 5,25 = 80,33 kmol/h =

160,66 kg/h.

CH4: l lng to ra do phn ng (2) l:3,15 kmol/h =50,4 kg/h.

C2H4: l lng C2H4 to ra do phn ng (1):

3,15 kmol/h = 88,2 kg/h.

C2H6: l lng C2H6 to ra do phn ng (1):

3,15 kmol/h = 94,5 kg/h

H2S: l lng H2S c ban u:

0,01 kmol/h = 0,45 kg/h.

Vy Gkh thi = 394,21 kg/h.

Vy cn bng :

Giso- nguyn liu = Giso- sn phm + Gkh thi

12610,02 = 12215,46 + 394,21

2610,02

Hn hp C (iso-C4H8) sn phm i ra khi phn hyro

ha c khi lng Giso- 84HC

sn phm v cng l G1:

G1 = 12215,46 kg/h

Trong thnh phn v khi lng nh trong bng 14.

Bng 14: Thnh phn v khi lng kh ra khi phn

hyro ha:

Thnh phn % Kmol/h Kg/h

iso-C4H8

iso-C4H10

n-C4H10

33,6

54,8

3,7

72,46

118,14

7,88

4057,76

6582,12

456,87

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n-C4H8

C3H8

C3H6

C+

5

2,9

1,8

2,7

0,5

6,34

3,94

5,77

1,08

355,04

173,36

242,34

77,97

Tng 100 215,61 12215,46

Hn hp ny l dng nguyn liu i vo phn tng hp

MTBE. By gii ta thay G1 = 12215,46 kg/h vo phng

trnh cn bng vt cht cho giai on tng hp MTBE ta

c:

G1 + GMeOH (99,9%) = G+

4Ccha phn ng + GMTBE + GMeOH trong MTBE + GH 2

O

G1 = 12215,46 kg/h

GMeOH (99,9%) = 2361,18 kg/h

GMTBE = 6313,13 kg/h

GMeOH trong MTBE = 63,16 kg/h

GH 2 O =2,36 kg/h

Ta c G+

4Ccha phn ng = 8198,02 kg/h

Xc nh thnh phn v khi lng dng C4 cha phn ng:

Phn ng:

Iso- C4H8 + MeOH MTBE

71,74 71,74 71,74 (kmol/h).

Nu coi rng phn ng t chuyn ha 90% mol

(theo iso-C4H8) v chn lc t 100% th lng MTBE to

ra 71,74 kmol/h.

Lng iso-C4H8 cn to ra lng 71,74 kmol/h MTBE l:

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72,40,99

71,74= kmol/h

Lng iso-C4H8 cha chuyn ha l:

72,74 - 71,74 = 0,72 kmol/h.Ngoi ra cc cu t khc trong hn hp l tr khng phn

ng. Vy thnh phn v khi lng ca kh C +4 cha phn ng

theo bng 15 sau:

Bng 15: Thnh phn v khi lng ca kh C +4 cha

phn ng.

Thnh phn % Kmol/h Kg/hiso-C4H8

iso-C4H10

n-C4H10

n-C4H8

C3H8

C3H6

C+

5

0,5

82,1

5,5

4,4

2,7

4,0

0,8

0,72

118,14

7,88

6,34

3,94

5,77

1,08

40,32

6852,12

456,87

355,04

173,36

242,34

77,97

Tng 100 143,87 8198,02

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Tm li ta c bng cn bng vt cht chung cho ton b

phn xng bng sau:

Bng 16: Cc dng vt cht cho ton phn xng.

Cc dng vt cht i vo (kg/h) Cc dng vt cht i ra (kg/h)Giso- 104HC nguyn liu = 12610,02

GMeOH (99,9%) = 2361,18

GMTBE = 6313,13

G+

4Ccha phn ng = 8198,02

GMeOH trong MTBE = 63,13

GH 2 O =2,36

Gkh thi = 394,21

Tng = 14971,20 Tng = 14970,85*Tnh lng nguyn liu mi cn thit a vo dy chuyn:

Kh Raffinat-2 sau khi thu hi c em x l loi cc cu t cha oxi

nh: Metanol, MTBE, H2O (vi lng nh), loi Propan v Propylen...

t tiu chun nh kh iso-butan nguyn liu ri c tun hon trn vi

nguyn liu mi.

Ta c:

Dng iso-C4H10 + lng iso-C4H10 tun hon = lng iso-C4H10 i vo dy

chuyn.

Tnh theo cu t iso-butan ta c:

196,90- 118,14 = 78,76 (kmol/h).

V trong Iso-butan nguyn liu th isobutan ch chim 90% th tch. Vy

trong isobutan nguyn liu mi cn a vo dy chuyn l:

87,50,978,76= kmol/h

Bng 17: Lng iso-butan nguyn liu mi cn a vo dy chuyn.


iso-C4H10 90 78,76 4568,08

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Propan

n-C4H10

Tng n-C4H8

C+

5

H2S v Mercaptan

3

6

0,5

0,4950,005

0,03. 87,51= 2,63

0,06. 87,51= 5,25

0,005. 87,51= 0,44

0,495. 10-2. 87,51= 0,430,005. 10-2. 87,51= 4,4.10-3

2,63. 44= 115,51

5,25. 58= 304,54

0,44. 56= 24,50

0,43. 72= 31,194,4.10-3. 41= 0,18

Tng 100 87,51 5044

Giso- 104HC nguyn liu mi = 5044 kg/h.

Isobutan tun hon c thnh phn ging nh nguyn liu mi v khi

lng nh sau:

Bng 18: Thnh phn v khi lng ca dng tun hon.


iso-C4H10 90 118,14 6852,12

Propan 3 0,03. 9,014,118 = 3,94 3,94. 44 = 137,27

n-C4H10 6 0,06. 9,014,118 = 7,88 7,88. 58 = 456.81

Tng n-C4H8 0,5 0,005. 9,014,118 = 0,66

0,66. 46 = 36,75

C+

5 0,495

0,495. 10-2. 9,0 14,118 = 0,65 0,65. 72 = 46,78

H2S v Mercaptan 0,00

50,005. 10-2. 9,0

14,118 = 0,0066 0,0066. 41= 0,27

Tng 100 131,28 7566

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Cn bng ta c:

Lng iso-C4H10 mi vo+ lng iso-C4H10 tun hon = lng iso-C4H10 vo

dy chuyn.5044 + 7566 = 12610,02

12160,00 = 12160,02

mtbe tt

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