Đồ Án tốt nghiệp
TRANSCRIPT
-
5/21/2018 n Tt Nghi p
1/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
PHN I
TNG QUAN QU TRNH ALKYL HA
I.
C s l thuyt chung v qu trnh alkyl haQu trnh alkyl ha l mt qu trnh quan trng trong nh my lc du nhm
ch bin cc olefin nh vizo-butan thnh cu t xng c tr s octan cao nht
l izo-parafin m ch yu l izo-octan. Sn phm ca qu trnh nhn c l cc
cu t tt nht pha trn to xng cao cp cho nh my lc du v n c tr s
octan cao v nhy nh(RON 96, MON 94 ), p sut hi thp iu cho
php ch to c xng theo bt k cng thc pha trn no. Ngoi ra, khi alkyl habenzen bng olefin nh ta cng s thu c alkyl benzen c tr s octan cao dng
pha ch xng. [1-244]
I.1. Phn loi v cc phn ng alkyl ha. [6-255]
Phn ng alkyl ha c th phn loi theo dng lin kt to thnh hoc nhm
alkyl a vo phn t hp cht.
I.1.1. Phn loi theo dng lin kt to thnh gia nguyn t C vi nguyn tca cc nguyn t khc
Alkyl ha theo nguyn t C.
Cn gi l qu trnh C - alkyl ho, y l qu trnh th nguyn t H gn vi C
bng cc nhm alkyl. C parafin v hydrocacbon thm u c th tham gia phn
ng ny.
CnH2n+2 + CmH2m Cn+mH2(n+m)+ 2
ArH + RCl ArR + HCl
Alkyl ha theo nguyn t O v S.
Cn gi l qu trnh O - alkyl ho v S - alkyl ho.y l cc phn ng dn n
to thnh lin kt gia nhm alkyl v nguyn t O hoc S.
-
5/21/2018 n Tt Nghi p
2/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
ArOH + RCl + NaOH ArOR + NaCl + H2O
NaSH + RCl RSH + NaCl
Alkyl ha theo nguyn t N
Cn gi l qu trnh N - alkyl ho, y l qu trnh th cc nguyn t H trongamoniac hoc trong amin bng cc nhm alkyl.
ROH + NH3 RNH2+ H2O
Alkyl ha theo cc nguyn t khc
Cc qu trnh Si -, Pb -, Al - alkyl ho ... y l nhng con ng quan trng
tng hpcc hp cht c nguyn t hoc c kim.
2RCl + Si R2SiCl2(xc tc l Cu)4C3H7Cl + 4NaPb Pb(C3H7)4+ 4NaCl + 3Pb
3C2H4+ Al + 3/2 H2 Al(C2H5)3
I.1.2. Phn loi da trn cu to khc nhau ca nhm alkyl a vo phn t
hp cht
Alkyl ha mch thng
Nhm alkyl ha l mch thng
C6H6+ C2H5Cl C6H5C2H5+ HCl
Alkyl ha mch vng
Nhm alkyl mch vng, v d xyclohexyl ha
C6H6 + C6H11Cl C6H5C6H11+ HCl
Aryl ha
a nhm phenyl hay ni chungl aryl vo phn t hp cht, hnh thnh lin
kt trc tip vi nguyn t C ca vng thm.
C6H5Cl+ NH3 C6H5NH2+ HCl
Vinyl ha
ROH + C2H2HO-
ROCH=CH2
-
5/21/2018 n Tt Nghi p
3/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
CH3-COOH + C2H2Zn2
+
CH3-COO-CH=CH2
-oxy alkyl ha
Nhm alkyl cha nhm oxyt, v d phn ng ca etylen oxyt vi ru
CH2-CH2O +ROH
ROCH-CH2OH
CH2-CH2ONH3 HOCH2-CH2NH2
I.2. Tc nhn alkyl ha. [6-257]
Cc tc nhn s dng cho alkyl ha cng rt a dng, v quan trng nht l
nhng loi d to thnh cacbocation. Theo lin kt b t trong qu trnh alkyl ha,
ngi ta phn loi cc tc nhn alkyl ha thnh : Cc hp cht khng no (olefin, axetylen) vi lin kt b t l
Cc dn xut halogen c lin kt b t l C-X (X l halogen).
Cc hp cht cha oxy nh ru, ete, oxit olefin c lin kt b t l C-O.
Trong 3 loi tc nhn ny, cc hp cht khng no, c bit l olefin c gi thnh
thp hn c v thng c s dng cho qu trnh C-alkyl ha. Do gi thnh cao
nn tc nhn th hai (dn xut ca halogen) ch s dng khi khng c olefin. Loi
tc nhn th ba (hp cht cha oxy) rt thch hp cho qu trnh alkyl ha theo
nguyn t C,N,O v S.
I.2.1. Tc nhn l olefin
Trong cc loi tc nhn th tc nhn olefin c gi thnh kh r, v vy ngi
ta lun c gng s dng chng trong mi trng hp c th. Cc olefin(etylen,
propylen, buten v cc olefin cao phn t) ch yu c s dng C - alkyl ho
cc parafin v cc hp cht thm.
Xc tc s dng trong trng hp ny l axit proton (Bronsted) hoc axit phi
proton (Lewis)
-
5/21/2018 n Tt Nghi p
4/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
C ch ca qu trnh ch yu xy ra theo c ch ion qua giai on trung gian
hnh thnh cacbocation. Kh nng phn ng ca cc olefin c nh gi bng
mc to ra cacbocation:
RCH=CH2+ H+RC+H-CH3
Kh nng to cacbocation tng theochiu di mch v phn nhnhca
olefin:
CH2=CH2< CH3-CH=CH2< CH3-CH2-CH=CH2< (CH3)2C=CH2
Ngoi ra trong rt nhiu trng hp, qu trnh alkyl ho bng olefin c th
xy ra di tc dng ca cc cht khi mo phn ng chui gc, hoc tc dng ca
nh sng hoc tc dng ca nhit cao. Khi cc phn t trung gian l cc gct do v trong trng hp ny kh nng phn ng ca cc olefin c cu to khc
nhau cng khng khc nhau nhiu.
I.2.2. Tc nhn l alkyl halogen ha
Cc dn xut clo c xem l cc tc nhn alkyl ho tng i thng dng
nht trong cc trng hp O -, S -, N - alkyl ho v tng hp phn ln cchp
cht c kim, c nguyn t; ngoi ra n cn c s dng trong trng hp C -
alkyl ha.
C - alkyl ho xy ra theo c ch i in t di tc dng ca cht xc tc l
ccaxit phi proton (FeCl3, AlCl3) qua giai on trung gian hnh
thnhcacbocation:
RCl + AlCl3R+Cl +AlCl3R
++ AlCl4-
Kh nng phn ng ca cc alkyl clorua ph thuc vo phn cc ca lin
kt C-Cl hoc vo bn cacbocation v s tng khi chiu di v mc
Phn nhnh ca nhm alkyl tng:
CH3CH2Cl < (CH3)2CHCl < (CH3)CCl3
-, S-, N - alkyl ha: xy ra theoc ch ai nhn v khng cn xc tc.
RCl + :NH3 RN+H3+ Cl
-RNH2+ HCl
-
5/21/2018 n Tt Nghi p
5/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Kh nng phn ng ca cc dn xut clo c sp xp theo dy:
ArCH2Cl > CH2=CH-CH2Cl > AlkCl > ArCl
v AlkCl bc I > AlkCl bc II > AlkCl bc II
Trong tng hp c kimv c nguyn t, qu trnh xy ra theo c ch gc tdo di tc dng ca kim loi
4NaPb + 4C2H5Cl 4Pb + NaCl + 4C2H5 4 NaCl + Pb(C2H5)4+ 3Pb
Tuy nhin cc alkyl halogen khng c s dng rng ri trong cng nghip
do phn ln cc phn ng c mt chng u hnh thnh axit (HCl) y n mn
mnh.
I.2.3. Tc nhn l ru, eteL mt tc nhn alkyl ha, nhng ru khng c s dng nhiu nh cc
olefin, c th bi v chng km hot ng hn trong qu trnh hnh thnh
cacbocation trung gian.
Etanol cth nghim trong qu trnh alkyl ha vi benzen sn sut
alkyl benzene, metanol cng c s dng alkyl ha toluen trong qu trnh sn
sut chn lc p-xylen. Ngoi ra, ru, c bit l etanol, cn l tc nhn alkyl ha
cho cc qu trnh sn xut cc metylphenol, metylamin nh qu trnh alkyl ha
phenol hay amin tng ng.
Ru v ete c kh nng s dng cho qu trnh alkyl ha theo C -, O-, S- .
Thc t, cc ete c s dng chnh l cc dng oxit olefin. Ru c s dng
khi gi thnh ca chng thp hn v d tm hn dn xut ca clo.
Cc xc tc s dng trong qu trnh alkyl ha vi tc nhn ru thng l
axit Bronsted hoc axit Lewis lm t lien kt gia nhm alkyl v oxy.
ROH + H+ R - +OH2 R++ H2O
Gn y, cc xc tc d th cng c th nghim sn xut mt s
alkylat quan trng. nhng nghin cu mi y v qu trnh alkyl ha tokuen vi
metanol ngi ta s dng zeolit HY v ZMS-5 nhit khong 300-700
-
5/21/2018 n Tt Nghi p
6/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
cho thy chn lc p-xylen t hn 90%. Nu qu trnh ny c chng minh l
c th thc hin c trong thc t th alkyl ha loluen trn xc tc zeolit chn lc
hnh dng c th ng dng vo sn xut cng nghip trong tng lai.
I.3. Xc tc cho qu trnh alkyl ha. [6-259]
Xc tc cho qu trnh alkyl ha thng l cc axit
I.3.1. Xc tc ng th
Xc tc thng c dng axit Bronsted nh HF, H2SO4. Khi s dng tc nhn
alkyl ha l alken, axit s chuyn proton sang cho gc hydrocacbon theo phn ng:
CH2=CH2+ H+ -CH-C+-
Trong trng hp xc tc l cc axit Lewis nh AlCl3th mt lng nh H+thng c thm vo nh cht ng xc tc thc y qu trnh hnh thnh
cacbocation.
CH2=CH2 + HCl + AlCl3 -CH-C+- + AlCl4
-
Nu ru c s dng lm tc nhn alkyl ha vi s c mt ca axit
Bronsted, chng s c proton ha vto nn hp cht trung gian cacbocation.
ROH + H+ [RO+H] R++ H2O
H
Cn trong trng hp xc tc dng axit Lewis nh AlCl33, trc ht chng
s to phc vi ru v tch ra HCl. Chnh phc ny s phn hy to cacbocation.
ROH + AlCl3 ROAlCl2+ HCl
ROAlCl2 R++ -OAlCl2
Hin nay trong cc nh my alkyl ha trn th gii s dng ph bin hai loi
xc tc lng l H2SO4v HF. Ngoi ra, cht xc tc AlCl3c s dng trong qutrnh alkyl ha hp cht vng thm. Nhc im ca cc phn ng pha lng ny
bn cht gy n mn rt mnh ca xc tc i hi vt liu lm thit b phn ng
phi l loi c bit, chu n mn. Thm vo , sn phm alkyl ha cn tip tc
x l bng ra kim v nc loi b vt AlCl3hoc BF3
-
5/21/2018 n Tt Nghi p
7/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
I.3.2.Vi xc tc d th
Cc xc tc d th thng c s dng trong qu trnh alkyl ha l Al2O3,
Al2O3/SiO2v cc zeolit. u im ca loi xc tc ny l d th ha h phn ng,
d tch sn phm, d ti sinh xc tc, gim c hi v gim n mn thit b. ivi xc tc zeolitcn cho chn lc cao.Nhng xc tc rn cha c ng dng
ph bin trong cc qu trnh alkyl ha cng cng nghip cng nh trn th trng
th gii.
Khi alkyl ha izo-butan bng buten s dng xc tc H2SO4 thu c sn
phm alkylat c cht lng cao hn khi dng xc tc HF.
II. C S L THUYT CA QU TRNH ALKYL HA IZO-BUTANBNG BUTEN VI XC TC H2SO4
II.1 Ngyn liu ca qu trnh. [1-227]
Nguyn liu alkyl ha cng nghip l phn on butan, butylen nhn c t
qu trnh hp ph, phn chia khca kh crcking xc tc l ch yu. Phn on
ny cha 80 85% C4, phn cn li l C3 ,C5. Propan v n-butan cha trong
nguyn liu mc d khng tham gia vo phn ng nhng n li nh hng n qutrnh bi v chng chim th tch vng phn ng v lm gim nng izo-butan,
lm gim nng xc tc. ci thin iu kin alkyl ha cn thit phi tch su
hn cc n-parafin nh cc ct tinh ct propan v n-butan. Trong nguyn liu cng
cn cha t etylen v nht l butadien, v khi tip xc vi axit (c bit l H2SO4)
chng s to thnh cc polyme ha tan trong axit v lm gim nng axit. Ngoi
ra, cc hi ca oxi, nit, lu hunh trong nguyn liu cng d tc dng vi axit v
tng tiu hao axit. Hm lng v thnh phn ca olefin trong nguyn liu c nh
hng quyt nh cht lng sn phm. khi alkyl ha izo-butan bng olefin, s nh
hng ca cng n cc ch tiu ca qu trnh c trnh by bng I.1
-
5/21/2018 n Tt Nghi p
8/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng I.1nh hng ca nguyn liu n hiu sut sn phm
Ch tiu C3H6 C3H6(40%)C4H8(80%)
C4H8 C5H10
Hiu sut alkylat so
vi olefin %V
178 174 172 160
Tiu hao
Izo-butan,%V
127 117 111 96
RON( alkylat sch) 8992 9295 94 97 90 93RON(+ 0,8 ml TEP/l) 101,5 103 103,5 105 104,2 106,3 103103,6
MON 87 90 90 93 92 94 90 92
II.1.1 Tnh cht ha l, phng php iu ch ca nguyn liu .
a) izo-butan:
Cng thc phn t : C4H10
Cng thc cu to :
- Mt s tnh cht cht vt l ca izo-butan.
+ Nhit nng chy: 145,0 oC
+ Nhit si 11,72o
C
+ T khi20
4d : 0,6030
+ Nhit ti hn: 134,5oC
+ p sut ti hn: 3,58 MPa
+ Gii hn nng hn hp n vi khng kh (%):
Gii hn trn: 8,4%
Gii hn di: 1,8%+ Tr s octan: RON = 100 ; MON = 99
nhit thng izo-butan l cht kh, trong sut khng mu, khng mi, t
trng nh hn nc. izo-Butan khng c tnh cht hydrophyl, ngha l khng trn
ln c vi nc. Mt khc do ha tan d dng cc cht m v tan c trong o
CH3 CH CH3
CH3
-
5/21/2018 n Tt Nghi p
9/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
s cc cht lipophyl in hnh. izo-Butan d b hp th bi nhng hydrocacbon
khc v nhng cht hp ph rn (than hot tnh). Ngi ta dng tnh cht ny
tch C4bng phng php hp th v hp ph.
S c hi ca izo-butan ln hn so vi hp cht hu c khc, vic ht th kh
v hi ca chng gy hin tng m man v c tc hi lu di v sau.
- Tnh cht ha hc ca izo-butan.
Tnh cht ha hc ca izo-butan c xc nh bi cc c im cu trc di
y:
Trong izo-butan ch cha cc lin kt i
Phn t izo-butan ch cha cc lin kt C C v CH l loi lin kt khngphn cc hoc rt t phn cc. V vy izo-butan phn ng xy ra ch yu qua con
ng phn ct lin kt theo kiu ng li, ngha l qua hnh thnh cc gc t do.
Trong cc phn ng izo-butan cht phn ng c th tn cng vo lin kt
CH (phn ng th) hoc vo lin kt C C (ct mnh cacbon).
- ng dng:
Izo-butan c dng lm nguyn liu sn xut xng alkylat v cao su tng
hp...
b) Buten.
- Cng thc cu to phn t: C4H8
- Cng thc cu to:
+ Buten 1 : CH2 = CHCH2CH3
+ Buten 2 : CH3CH = CHCH3
+ izo-buten : CH2 C CH3
CH3
-
5/21/2018 n Tt Nghi p
10/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng I.2. Mt s tnh cht ha l ca olefin
Olefin Nhit nng
chy(oC)
Nhit
si(oC)
Nhit ti hn(oC)
p sut tihn(MPa)
Gii hnn vkhng
kh(%V)Buten-1 -130,0 -5,0 146,2 3,89 1,6 9,4
cis-Buten-2 -139,0 +3,5 151,0 4,02 1,6 9,4
Trans-Buten-2 -105,0 +1,0 - - 1,6 9,4
izo-Buten -140,0 -6,0 144,7 3,85 1,8 9,6
nhit thng buten l cht kh, khng tan trong nc m ch tan trong
cc dung mi hu c v cng c hi.
-
Tnh cht ha hc ca buten.
+ Bn cht c im ca lin kt i C = C .
Lin kt i C = C c to nn bi 2 nguyn t cacbon trng thi lai to
sp2tc l kiu lai to tam gic.
Trong lin kt i c mt lin kt do s xen ph trc ca 2 electron lai to
v mt lin kt do s xen ph bn ca 2 electron p.
Lin kt i c di lin kt bng 1,34 o
A ngn hn so vi lin kt n (1,54o
A ). Nng lng lin kt i C = C bng 145,8 kcal/mol, trong khi nng lng
lin kt n C C bng 82,6 kcal/mol; gi thit nng lng lin kt ln hn
nng lng lin kt bng 145,8 82,6 = 63,2 kcal/mol. Nh vy lin kt ln
hn nng lng linkt , chnh lch vo khong 20 kcal/mol, iu ny gii
thch tnh km bn ca lin kt v kh nng phn ng cao ca lin kt i. Thcvy, so vi alkan, alken c kh nng phn ng cao hn nhiu. Cc phn ng ca
alken thng tp trung vo lin kt i, do ni i c coi l trung tm phn
ng ca alken.
-
5/21/2018 n Tt Nghi p
11/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Cc phn ng quan trng nht i vi alken l phn ng cng phn ng oxy
ha v phn ng trng hp.
+ Phn ng cng.
Cc phn ng cng c trng nht i vi alken l phn ng cng vo lin kt
i. Trong cc phn ng ny, lin kt i thc cht l lin kt b b gy v kt
hp vi hai nguyn t hoc hai nhm nguyn t mi to ra hp cht no. S
chung ca phn ng cng vo lin kt nh sau:
Kh nng phn ng cao ca alken so vi alkan cn c th gii thch l do
trong lin kt i ca alken mt electron c tri rng hn trong lin kt n
ca alkan.
Cc electron trong lin kt i b gy ra xa do sc y nhau ca chng. Do ,
nhng v tr ca lin kt i c mt electron bng vi ch c mt electron
nh th ca lin kt n th xa trc lin kt n (hnh I.1)
a) b)
Hnh I.1a) Vng c mt electron cao lin kt n C Cb) Vng c mt electron cao lin kt n C = C
Cng hydro:
Kt qu phn ng cng hydro vo vng buten cho ta butan tng ng. S chung ca phn ng cng hydro vo ni i ca buten nh sau:
C C + XY C C
X Y
C C C C
C C + H2 C C
H H
-
5/21/2018 n Tt Nghi p
12/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Cng electrophyl (AE) vo butan.
Qu trnh c th c biu din bng s chung nh sau:
Phn ng trn c c ch cng electronphyl (tc c ch cng i in t, k hiu
AE), v cc tc nhn iu l electronphyl.
Khi tc nhn electronphyl tin li gn phn t benzen, trong phn t benzen
c s chuyn mt electron ca lin kt i, lm phn cc ha lin kt i :
C ch cng electronphyl tin hnh qua hai giai on. giai on mt, tc
nhn electronphyl s kt hpvi cacbon mang ni i giu electron hn, to ra
ion cacboni. Sau giai on hai, ion cacboni s kt hp vi phn cn li ca cc
tc nhn mang in tch m :
Giai on 1:
Giai on 2:
+ Phn ng oxy ha:
Cc hydrocacbon cha lin kt i nhy cm hn nhiu i vi cc cht oxy
ha. Khi iu kin tin hnh phn ng tc nhn oxy ha khc nhau th sn phm
phn ng to ra cng khc nhau.
+ H2SO4C CC C
H OSO3H
+
-
CH3CH = CHCH3 CH3CH CHCH3
++ -
XY + C C XCC + Y-Chm
- +
X C C + Y- XCCChm+
-
5/21/2018 n Tt Nghi p
13/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Nh tc dng ca KMnO4 trong dung dch trung tnh hoc dng dch kim,
lin kt i ca buten s kt hp vi hai nhm hydroxyl, nh khi cng vi hydro
peroxyt HO-OH to ra 1,2- diol :
Phn ng ny dng trong phn tch nhn ra ni i. Cho buten tc dng vi
dng dch KMnO4trong dng mi kim, dung dch s mt mu.
Axit cromic c s dng rng ri oxy ha lin kt i hoc di dng
dung dch Cr2O3trong axit axetic m c, c mt H2SO4hoc khng, hoc didng dng dch natri hoc kali bicromat. Phn ng b gy lin kt i to ra xeton
chng t s c mt nhm R2C=, cn s to thnh axit cacbonxylic chng t s c
mt ca nhm R CH=.
Nh phn ny c th xc nh v tr ca lin kt i trong buten.
+ Phn ng trng hp
Mt trong nhng phn ng quan trng bc nht trong k thut hin nay ca cc
hp cht cha no l phn ng trng hp to ra sn phm polyme. Qu trnh trng hp
ta nhit rt ln, izo- buten l 228 cal/g (trng hp trong dng dch).
S chung ca phn ng trng hp nh sau :
C th :
CH3CH = CHCH3 + 2 [OH] CH3CHCHCH3
OH OH
CH3
CH3
C = CHCH3 + 3 [O] C = O + CH3COOH
CH3
CH3
nA (A)n
CH3
n
nCH3
CH3C = CH2 CCH2
CH3
-
5/21/2018 n Tt Nghi p
14/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Ty theo bn cht, c im ca monome, ty theo iu kin tin hnh phn
ng, qu trnh trng hp s xy ra theo c ch khc nhau, cho polyme c cu to
khc nhau v h s trng hp khc nhau.
-
Phng php iu ch buten.
Phng php iu ch olefin trong cng nghip l qu trnh ct mch cacbon
ca phn on du m v kh hydrocacbon nh qu trnh cracking xc tc sn
xut xng v olefin thu c nh sn phm ph. Ngoi ra cn c olefin thu c t
qu trnh dehydro ha ca parafin tng ng v olefin thu c nh cc phn ng
chuyn ha qua li (oligome ha v qu trnh chuyn khng cn i).
-
ng dng:
Buten-1 v buten-2 c dng ch yu iu ch butadien, buten-1 c th
trng hp thnh cc polyme c cu hnh ng pha, cc sn phm ny dai v c sc
chu ko cao nn c dng lm ng v cn thnh l.
Trng hp izo-buten cho cc sn phm c th dng lm du nhn hoc lm
vt liu cch in v lm cc mng mng. ng trng hp izo-buten vi mt lng
nh izopren hocbutadien cho loi cao su butyl c th lu ha c v rt t thot
kh, v vy dng sn xut cc loi sm cho xe vn ti.
Ngoi ra cc phng php tng hp izopren t buten v iu ch anhydric
maleic t cc hn hp n-buten c dng iu ch dibutenv mt s hydro cacbon
khc dng lm nhin liu ng c.
c) Xc tc axit H2SO4.
Axit H2SO4cng vi HF l cc xc tc ch yu cho qu trnh alkyl sn xut
izo-octan l cu t tt ca xng.
-
5/21/2018 n Tt Nghi p
15/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
- Tnh cht ha l ca xc tc H2SO4:
Axit H2SO4 l mt cht lng khng mu, khng mi, nht nh du (t nc=
10,40C), khi lng ring ca H2SO498% l 1,84 g/cm3.
Dung dch H2SO4c nng 98,2% l hn hp ng ph, di p sut thng
n si 336,60C
- Tnh cht ha hc ca H2SO4:
Axit sunfuric c hai c im ln : Khi long, n l mt axit mnh, khi c v
nng n l mt cht oxy ha mnh. Axit nguyn cht 100% khng th hin tnh
axit.
H2SO4l axit hai ln, trong dung dch n phn ly thnh hai nc: nc th nht
phn ly hon ton nhng nc th hai th km hn nhiu.
H2SO4 H+ + H2S
K1=
H2S H+ + S
K2= 2.
H2SO4c th ng ha Fe, Al, Cr nn ngi ta dng bnh bng thp ng
v chuyn ch H2SO4c, ngui.
- Sn xut H2SO4.
Axit sunfuric l mt loi ha cht c bn nn hng nm n c sn xut vi
lng ln trn th gii.
Nguyn tc chung ca cc phng php iu ch H2SO4trong cng nghip l
oxy ha SO2thnh SO3 ri cho hp vi nc.
2SO2 + O2 = 2SO3
SO3 + H2O = H2SO4
Hin nay ngi ta thng iu ch H2SO4bng hai phng php: Phng
php tip xc v phng php thp.
-
5/21/2018 n Tt Nghi p
16/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Phng php tip xc l phng php hin i, c p dng nhiu nc
trn th gii.Tuy nhin thc hin phng php ny kh khn hn nhng phng
php c in v n i hi k thut cao.
Qu trnh iu ch gm 4 giai on:
+ iu ch anhydrit sunfur SO2: Lc sch hn hp kh SO2+ O2, kh tht
sch bi v cac tp cht lm hi xc tc (nh SeO2, As2O3, PH3, H2O...).
+ Oxy ha SO2: hn hp kh c lc sch, c t nng ln 450oC ri
cho qua cht xc tc(Pt hoc V2O5). Sut giai on oxy ha nhit khng
c thay i.
2SO2 + O2 2SO3 ( hiu sut thng t 98%)
+ Giai on hp th SO3: hn hp kh SO2+ SO3+ O2c lm ngui xung
khong 50oC, ri cho tan trong dung dch H2SO498,2% (gi nhit khng i
50oC). Sn phm thu c l oleum H2SO4.xSO3. Mun c axit long hn ngi ta
pha oleum bng nc.
Axit H2SO4 lm vic trong cc nh my hin i thng c ti sinh bng
phng php phn hy nhit cao. Hiu qu ca qu trnh alkyl ha tng ln khithm vo xc tc cc cht kch hot c bit, n lm thay i sc cn b mt ca
gii hn phn chia pha hoc to thnh nh tng trong axit H2SO4.
II.2. Sn phm chnh ca qu trnh.
Sn phm thu c gm:
- Alkylat nh dng lm hp phn pha ch xng c cht lng cao.
- Alkylat nng (ts= 170 300oC) dng lm nhin liu diezen.
- Hn hp kh hydrocacbon no dng lm nhin liu.
Sn phm chnh ca qu trnh l izo-octan chim 75 80% th tch sn phm cc sn
phm.
-
5/21/2018 n Tt Nghi p
17/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Thng thng ngi ta dng n-buten alkyl ha izo-butan to thnh cc
hydrocacbon C8H18v sn phm ny c nhit si thch hp nht khi s dng lm
thnh phn ca nhin liu ng c.
Cu to ca sn phm thu c trong qu trnh alkyl ha izo-butan bng n-
buten, s thu c hn hp 2,2,4; 2,3,4 v 2,3,3-trimetyl pentan, y l cht ch
tiu dng trong thang do ch s octan ca nhin liu.
II.3. C s ha l ca qu trnh.
II.3.1.c trng nhit ng hoc ca phn ng. [1-224]
Alkyl ha izo- butan bng nguyn liu olefin nh khi c mt xc tc axit
mnh, t to thnh izo-octan. Cc phn ng c bn gm:
izo-C4H10 + C4H8 izo- C8H18(izo-otan)
(kh) (kh) (kh) : G = -18350 + 39,1T
G < 0 khi T 196oC
Alkyl ha izo-butan bng buten l mt qu trnh ta nhit c km theo gim
s lng phn t. Do vy, khi gim nhit v tng p sut s thun li cho qu
trnh, ngha l qu trnh chuyn dch v pha to thnh sn phm.
Theo s liu thc nghim ta thy, nhit ca phn ng nh sau:
Vi buten: 175 kcal/kg alkylat
II.3.2. C s ca qu trnh alkyl ha izo-butan bng butylen. [1-225]
Alkyl ha izo-butan bng butylen, phn ng xy ra theo c ch ion qua giaion trung gian hnh thnh cacbocation v c xc tc bi axit proton. Kh nng
phn ng ca cc olefin trong trng hp ny c nh gi bng mc to ra
cacbocation.
-
5/21/2018 n Tt Nghi p
18/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Vi s tng chiu di mch, cng nh phn nhnh ca dy hydrocacbon
trong buten s dn ntng kh nng phn ng ca n vi qu trnh alkyl ha:
CH3CH2CHCH = CH2 < CH3CH = CHCH3 < (CH3)2C = CH2
C ch th i in t c trng ch yu cho s alkyl ha theo nguyn t
cacbon.
Thi gian tn ti ca cacbocation dao ng trong khong thi gian nht nh,
ph thuc vo cu trc, cc hiu ng ring v kh nng solvat ha ca n.
S to thnh cacbocation cng tun theo qui tc nht nh. Khi tc dng ca
H
+
vi buten thng th u tin to thnh cacbocation bc 2 hn l bc 1, v d:CH3CH2CH = CH2 + H
+ CH3CH2+CHCH3 (bc 2)
CH3CH2CH = CH2 + H+ CH3CH2CH2
+CH2 (bc 1)
Nu buten c cu trc nhnh vi lin i v tr s cho cacbocation bc 3
nhiu hn bc 1:
iu ny c chng minh bng cc s liu nhit to thnh ca cacbocation,
H(kJ/mol) bng I.3
bn ca cacbocation c th xp theo th t gim dn nh sau:
ion bc 3 > ion bc 2 > ion bc 1.
+ H
+
CH2= C
CH3
CH3CH3C
+
CH3
CH3
CH2= C
CH3
CH3
+CH2CH
CH3
CH3
+ H+
-
5/21/2018 n Tt Nghi p
19/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng I.3:Nhit to thnh ca cacbocation
Cacbocation H, kJ/mol
...+CH4...
CH3- +CH2...
CH3- CH2-+CH2...
CH3-+CH - CH2
CH3- CH2- CH2-+CH2
CH3- CH2-+CH2- CH2
(CH3)3C+
1100
941
907
798
869
760
697
p dng trong cng nghip alkyl ha izo-butan bng buten, ta c cc phnng xy ra theo c ch cacbocation nh sau:
C4H8 + H+ +C4H9
* (1)
izo-C4H8 ++C4H9
* n-C4H10 + izo-+C4H9 (2)
izo-+C4H9 + C4H8 izo-+C8H17 (3)
izo-+C8H17 + izo-C4H10 izo-C8H18 + izo-+C4H9
(4)
izo-+C4H9li tip tc tham gia phn ng (3), trong ion izo-+C4H9
*l loi c
cu trc bt k.
V c bn phn ng alkyl ha izo-butan bng buten s dng xuc tc H2SO4
bao gm ba giai on:
- Giai on hnh thnh cacbocation.
- Giai on pht trin mch.
- Giai on to sn phm alkylat.
1) Giai on hnh thnh cacbocation:
-
5/21/2018 n Tt Nghi p
20/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Trong cng nghip, sn xut izo-octan ngi ta s dng phn on butan-
butylen ca FCC cng nh phn on C4 t qu trnh cracking sau khi tch
butadien v izo-buten bng qu trnh tng hp MTBE, trong c propylen v hn
hp ba ng phn ca butylen.
Cc hc thuyt v s khi u chui cho rng cc cacbocation c to ra
bng cch cng proton H+v mt phn t buten vi s c mt ca xc tc axit.
Theo thuyt ny, ch c cacbocation tert-butyl mi c th to ra phn ng chui
trong qu trnh alkyl ha izo-butan.
T izo-buten ta c:
Cc bc to ban u cng vi xc tc H2SO4 to thnh axit ha tan(ASO)
hoc cc polyme. Tuy nhin vai tr ca ASO trong qu trnh alkyl ha khng c
xc nh r.Rt nhiu hydrocacbon axit ha tan c sinh ra nhng ch mt s qu
trnh alkyl ha xy ra trong chu k ny. Cc hydrocacbon axit ha tan ny b ion
ha cao v chng c th nhn ion hydrit t izo-butan.
R+(polyme cation) + izo-C4H10 RH (ASO) + tert-C4H9+
Khi bt u bng cc n-buten, bc th hai to ra cacbocation tert-butyl. Do
ion hydrit c ly t phn t izo-butan v n-alcan c to thnh:
CH3CH2CH = CH2 + H+ CH3CH2
+CHCH3
CH3CH = CHCH3 + H+ CH3
+CHCH2CH3
Phn ng chuyn ion hydrit:
+ H+CH3
CH3
CH2= C CH3- C+
CH3
CH3
CH3CH2CH2CH3+
CH3C+
CH3
CH3
CH3+CHCH2CH3+
CH3CH
CH3
CH3
-
5/21/2018 n Tt Nghi p
21/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
2) Giai on pht trin mch.
Trong cc bc pht trin mch, cc phn t olefin phn ng vi cacbocation
tert-butyl (phn ng A), phn ng ny sinh ra cacbocation c khi lng phn t
nng hn, sau xy ra ng phn ha hoc tch ra ion hydrit t phn t izo-butan
(phn ng B). Trong mt vi trng hp, cacbocation phn t cao hn tip tc kt
hp vi phn t olefin khc nh c ch qu trnh polyme ha. S chuyn ha ion
hydrit (phn ng B) ti to cc cacbocation bc 3, chui c tip tc v to thnh
phn t izo-parafin.
Qu trnh c biu m t bng s sau:
+ Phn ng A vi cc ng phn ca butylen c th nh sau:
Vi izo-buten:
Vi buten -2:
Vi buten - 1:
olefin
Tert-C8H17+
Tert-C4H9+
izo-C8H18
izo-C4H10
AB
CH3C+
CH3
CH3
+ CH2= CHCH2CH3 CH3CCH2+CHCH2CH3
CH3
CH3
CH3C+
CH3
CH3+ CH3CH = CHCH3 CH3C
+
CCH2CH3
CH3
CH3
CH3
+ CH2= CHCH3
CH3
CH3C+
CH3
CH3
CH3CCH2+CCH3
CH3
CH3 CH3
-
5/21/2018 n Tt Nghi p
22/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
+ ng phn ha cacbocation:
Cacbocation bc 2 mi to thnh nhn chung d b chuyn v ni phn t vi
s di chuyn v tr ca hydro v cc nhm metyl to thnh cacbocation bc 3
bn hn.
CH3
CH3
CH3
CH3+CCCH2CH3
CH3
CH3
CH3
CH3CHCH+CCH3
CH3CCH2+CCH3
CH3
CH3 CH3
CH3
CH3
CH3+CCH2CHCH2CH3
CH3
CH3
CH3+CCHCH2CH2CH3
CH3CCH2+CHCH2CH3
CH3
CH3
CH3C+CCH2CH3
CH3
CH3
CH3
-
5/21/2018 n Tt Nghi p
23/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
3) Phn ng B v s to thnh izo-octan.
Cc cacbocation trn tc dng vi izo-butan s to ra hydrocacbon C8H18 v
tert-butyl cation:
CH3
CH3
+CH3CH
CH3
CH3
CH3
CH3+CCCH2CH3
CH3
CH3 CH3
CH3CHCCH2CH3
CH3
CH3
+ CH3C+
CH3
CH3
+CH3CH
CH3
CH3
+ CH3C+CH3CCHCH2CH3
CH3
CH3
CH3
CH3C+CCH2CH3
CH3
CH3
CH3
CH3
CH3
+ CH3C+
CH3
CH3
+CH3CH
CH3
CH3
CH3
CH3CHCH+C - CH3
CH3
CH3
CH3
CH3CHCHCH - CH3
CH3
CH3
+CH3CH
CH3CCH2+CCH3
CH3
CH3 CH3 CH3
CH3
+ CH3C+
CH3CCH2CHCH3
CH3
CH3 CH3
CH3
CH3
CH3C+
CH3
CH3
CH3+CCH2CHCH2CH3
CH3
CH3
+ CH3CH
CH3
CH3
+ CH3CHCH2CHCH2CH3
CH3
CH3
+ CH3CH
CH3
CH3
CH3+CCHCH2CH2CH3
CH3
CH3
CH3C+
CH3
CH3
+ CH3CHCHCH2CH2CH3
-
5/21/2018 n Tt Nghi p
24/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
4) Cc phn ng ph xy ra trong qu trnh alkyl ha:
Mt s lng ln cc phn ng ph xy ra trong iu kin ca qu trnh alkyl
ha nh phn ng dch chuyn hydro, phn ng polyme ha, phn ng phn b li,
phn ng cracking, phn ng oxy ha, phn ng to este Cc phn ng ny
thng khng mong mun v n lm gim cht lng sn phm v lm tng tiu
hao xc tc axit.
+ Phn ng polyme ha olefin:
Mt lng nh trong phn cn li ca qu trnh alkyl ha nhit si cao,
iu kin thch hp cho phn ng alkyl ha xy ra. Mt phn t polyme bao gm
hai hoc nhiu phn t olefin cng vi mt phn t izo-butan, phn ng xy ra nh
sau:
2C4H8 + izo-C4H9+ izo-C12H25
+
izo-C12H25+ + izo-C4H10 izo-C12H26 + izo-C4H9
+
Phn ng polyme ha c th gim ti mc ti thiu bi duy tr mt t l gia
izo-butan vi olefin cao, mt t l hydrocacbon vi xc tc cao, hot ng xctc thch hp, chuyn khi u, v t trng ca alkylat trong vng phn ng l nh
nht.
+ Phn ng phn b li:
Phn ng phn b li ng vai tr b trong qu trnh alkyl ha. N c th gii
thch v s hnh thnh c izo-pentan, izo-hexan v cc izo-heptan.
Mt v d v loi phn ng ny nh sau:
gfdgdtghfgkjkjkjkljkmjuuukj i
CH3
CH3CCH2CHCH3+
CH3
CH3
CH3- CH
CH3
CH3
+ CH3CHCH2CH3
CH3
CH3CCH2CH2CH3
CH3
CH3
-
5/21/2018 n Tt Nghi p
25/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
+ Phn ng cracking :
Rt nhiu izo-butan v C5phn nhnh c to ra thng qua qu trnh cracking
to nn cacbocation c phn t thp hn cng vi phn t olefin, trong khi buten-1,
butan-2, propylen v amylen th khng c. Trong trng hp izo-buten, s phn on
li quan trng hn trong qu trnh alkyl ha H2SO4:
izo-C12H26 izo-C5 + izo-C7=
izo-C12H26 izo-C6 + izo-C6=
izo-C16H34 izo-C5 + izo-C5= + izo-C6
=
Cc olefin nhanh chng proton ha to nn alkyl cation:
izo-C5 + H+ izo-C5
+
T c s ha hc ca qu trnh alkyl ha izo-butan bng buten, ta thy r thc
cht ca qu trnh l phi to ra ion izo-C4H9+m phn ng chnh l s chuyn
ion hydrit izo-C4H10. Ch c cc axit mnh mi c hot tnh xc tc thc y tc
vn chuyn ion hydrit. Do vy xc tc alkyl ha trong cng nghip thng l
H2SO4. Tc vn chuyn H-gim khi nng axit gim. Trong cng nghip vn
ph bin cc qu trnh ng vi xc tc trn.
Cc hng phn ng c th xy ra:
+ Hng 1:
C3=, C4
=, C5= + izo-C4
+ C7+ C9
+ + izo-C4H8 C7 C9
+ Hng 2: Oligome ha C12+
C20+
C5+
C9+
+ olefin
Phn nh v phn nng cui c sn xut bi hng phn ng ny.
+ Hng 3. Nhng cation nng:
C12+C20
+ C12C20Chuyn ion hydrit
cracking
-
5/21/2018 n Tt Nghi p
26/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
II.3.3. Xc tc cho phn ng alkyl ha. [6-259]
Cht xc tc s dng cho phn ng alkyl ha nh: HF, H2SO4, AlCl3. Hin
nay trong cc nh my alkyl ha trn th gii s dng ph bin hai loi xc tc
lng l H2SO4v HF. Ngoi ra, cht xc tc AlCl3c s dng trong qu trnh
alkyl ha hp cht vng thm.
UOP pht minh ra cht xc tc HF dng rn v xc tc zeolit. u im ca
loi xc tc ny l d th ha h phn ng, d tch sn phm, d ti sinh xc tc,
gim c hi v gim n mn thit b. i vi xc tc zeolit cn cho chn lc
cao.
Nhng xc tc rn cha c ng dng ph bin trong cc qu trnh alkyl ha
cng cng nghip cng nh trn th trng th gii.
Khi alkyl ha izo-butan bng buten s dngxc tc H2SO4thu c sn phm
c cht lng cao hn khi dng xc tc HF. Kt qu thc ngim chng minh
iu ny.
Bng I.4:So snh qu trnh alkyl ha khi s dng xc tc HF v H2SO4
HF H2SO4
+ Cht xc tc c th ti sinh bng
chng phn on.
+ Vng phn ng c th hot ng
khong nhit 3045oC v thit b
phn ng c th lm lnh bng nclnh.
+ Yu cu khuy trn vng phn ng
thp hn v HF ha tan izo-butan cao
+ Qu trnh ti sinh xc tc i hi phi
c mt phn xng x l ring.
+ Vng phn ng hot ng nhit
thp khong 510oC, cn phi lm lnh
thitb phn ng nhit phn ngdi 10oC.
+ Yu cu khuy trn vng phn ng
cao hn v H2SO4ha tan izo-butan thp
-
5/21/2018 n Tt Nghi p
27/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
hn (khong 0,3% izo-butan trong axit).
+ Tiu th izo-butan cao hn.
+ nmn mnh.
+ cc iu kin phn ng HF ha hi
v c tnh c hi cao , gy nguy him
cho con ngi.
hn HF (0,1%).
+ Tiu th izo-butan thp hn.
+ n mn km hn HF.
+ H2SO4 cng rt c, nhng iu
kin thng n th lng nn vicx l
an ton v d dng hn nhiu.
III. IUKIN CNG NGH CA QU TRNH ALKYL HA.
Hiu sut v cht lng sn phm c xc nh khng ch do tnh cht ca
nguyn liu v xc tc m cn do nh hng ca cc iu kin cng ngh ca qu
trnh alkyl ha l cc thng s chnh sau:
Nhit phn ng.
Thi gian phn ng. T l izo-butan/buten.
Nng axit.
Nng izo-butan trong vng phn ng.
Vi p sut ch chn sao cho tin hnh cng nghip thun li vi ngha duy tr
trng thi no thch hp catc nhn m thi.
Ch cng ngh cc dy chuyn khc nhau s c iu chnh khc nhau.
By gi chng ta s xt k cc yu t ny.
III.1. Nhit phn ng.
Nhit l thng s rt quan trng ca qu trnh alkyl ha, c nh hng kh
phc tp n qu trnh ny. Khi nhit tng, nht ca cc tc nhn gim
xung, iu cho php tng cng khuy trn lm cho cc tc nhn phn ng
-
5/21/2018 n Tt Nghi p
28/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
tip xc vi nhau tt hn, nh vy gim c nng lng khuy trn. Song khi
tng nhit , cc phn ng ph nh polyme ho, oligome ho v oxi ha lai tng
ln v c tc mnh tng ng vi tc phn ng alkyl ha. V th chn
lc ca qu trnh gim xung, gim nng axit v tng tiu hao axit.
Nu h thp nhit n mt gii hn nht nh no , s to iu kin
thun li cho qu trnh alkyl ha, lm cho chn lc tng, gim tiu hao xc tc
v hiu sut cng nh cht lng alkylat tng ln. Yu t hn ch khi gim nhit
l lm tng nht ca cc tc nhn v axit, lm tiu tn nng lng khuy trn
v cht ti nhit.
Trong cng nghip alkyl ha, nhit thch hp i v xc tc axit H 2SO4l
nhit t 5 10oC.
Gi tr c th nhit phn ng c chn cn phn tch n nh hng ca
cc thng s khc v cc ch tiu kinh t ca qu trnh, sao cho m bo ch tiu
cht lng v hiu sut ca sn phm. V d theo thi gian phn ng, nng xc
tc gim, hot tnh xc tc gim ngi ta c th tng nhit ln 2 3oC trong
khong cho php b li hot tnh ca xc tc nhm duy tr hiu sut.
-
5/21/2018 n Tt Nghi p
29/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Hnh I.2:Qu trnh alkyl ha trc tip nh hng bi cc yu t
III.2. Thi gian phn ng.
Thi gian phn ng ca qu trnh alkyl ha xc nh bi hai yu t c bn:
+ Tc ly nhit khi vng phn ng iu chnh nhit ca phnng.
+ Thi gian cn thit izo-butan ha tan vo pha axit to nh tng.
Nh th s m bo tin hnh nh mong mun v hn ch cc phn ph.
Do thit b hot ng lin tc, khng ch thi gian phn ng ngi ta
khng ch qua t l gia axit v hydrocacbon trong vng phn ng ca reactor.
Thng thng t s ny c chn bng 1/1 n 2/1.
Trong thc t, t hiu sut cc i, thi gian tip xc trong reactor vi xc
tc H2SO4thng t 20 n 30 pht.
Qu trnh al kyl ho trc tip
S tng l nNhit phn ngThp Cao
C4+
C4=
c 8+ izo C4
_C8 ng phn ho C8
c 12+ c20
+
=C4
_ _izo C4 C12 C20_ _C5 C7
T lI/O
S gim xung
TM P100 RON
DM H60 RON
90 RON Cc sn phm crack ing 60 - 93 RON
Ngn Thi gian cht phnng tip xc
Di
-
5/21/2018 n Tt Nghi p
30/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
III.3. Nng axit.
alkyl ha phn on C4, ngi ta thng dng axit H2SO4c nng t
90 98,5%.
alkyl ha izo-butan bng buten, qu trnh dng xc tc rng ri vi H2SO4
c nng 96 98% khi lng. Nng axit ln hn khng mong mun v tnh
cht oxy ha mnh ca n, tnh cht ny lm phc tp thm qu trnh nh d to
nha, d to SO2, SO3, H2S v gim hiu sut to sn phm. Khi nng axit thp
n xc tc cho qu trnh polyme ha v d to thnh cc alkyl sunfat tng ng v
khi t nng b phn hy thnh cc hp cht n mn v lm long nhanh axit
H2SO4. V th h thng s t c kh nng phn ng cc i trong trng hp
khi nng olefin ha tan vo bng ng lng ion cacboni.
Trong qu trnh lm vic nng axit gim xung do hai nguyn nhn chnh
sau:
-Do tch ly trong axit cc hp cht cao phn t (este phc tp ca H2SO4,
hydrocacbon cao phn t...)
-Do pha long bi nc c to ra t cc phn ng ph hay c sn trong
nguyn liu tch ly li. Chng hn mt phan t olefin c th tc dng vi H 2SO4
c to ra mt lng nc theo phng trnh:
CnH2n + H2SO4 CnH2n2+ 2H2O + SO2
Do mt phn xc tc phi ly ra khi hn hp phn ng v b vo mt
lng mi c nng cao. Lng axit tiu hao l 5 7 kg / 100 lt alkyl.[120-7]
Trong thit b phn ng, t l th tch gia axit v hydrocacbon vo khong 1:
1, thm ch c th n 70% (th tch) axit. Lng xc tc d s c tch ra trong
thit b tch v a tr li thit b phn ng.
-
5/21/2018 n Tt Nghi p
31/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Hn hp phn ng l h hai pha phn tn vo nhau nh cnh khuy hay h
thng bm phn tn cng gy nh hng n nng axit, v rng nu cc b phn
ny khng kh nng cho php nhn nh tng tt s to iu kin tin hnh cc
phn ng ph khng mong mun v nh vy s lm gim nng axit cng nhhiu sut ca phn ng.
Bng I.5: ha tan ca izo-butan trong axit
Axit Nng axit ha tan(% khi lng)
H2SO4 99,5
cn bng
0,1
0,4
III.4. Nng izo-butan trong vng phn ng.
Do kh nng ha tan izo-butan trong pha axit rt nh (H2SO4 l 0,1%), nn
mun tng tc phn ng, nng izo-butan cn phi t cc i trong vng
phn ng. ha tan cng cn ph thuc vo khuy trn c bit trong reactor.
Olefin hu nh ha tan tc thi trong axit nn lng olefin a vo cn phi
chia nh hn ch phn ng ph. iu ny c khng ch qua t l gia izo-
butan/buten. Trong cng nghip, t l ny thay i t 5/1 n 15/1, ngha l s
dng mt lng d rt ln izo-butan.
Khi s dng lng d izo-butan so vi buten s hn ch ton b cc phn ng
ph v c nh hng tt n hiu sut to sn phm, tng hm lng sn phm
mong mun, gim tiu hao xc tc. Tuy vy khng nn dng lng d qu ln izo-
butan v khi chi ph ti sinh n sau phn ng s rt cao. T l mol ti u trong
trng hp ny l t 4/1 n 6/1.
-
5/21/2018 n Tt Nghi p
32/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
IV.CC CNG NGH ALKYL HA IZO-BUTAN BNG OLEFIN
IV.1. c im chung:
Cng ngh alkyl ha izo-butan bng cc olefin bt u xut hin t trc
chin chin tranh th gii ln th hai, nhng phi n nhng nm gn y mi t
c mc hon thin. Ban u xc tc c s dng l AlCl3nhng hin nay
ngi ta thay th bng xc tc lng H2SO4v HF, th h dng xc tc AlCl3hu
nh khng cn tn ti.
- Cc qu trnh thng mi:
Trong 15 nm qua s pht trin ca qu trnh alkyl ha axit sunfuric tp trungvo vic gim chi ph u t, tng cng s tip xc gia cc cht phn ng v xc
tc. Ba h thng l phn ng c s dng trong qu trnh alkyl ha xc tc H2SO4
l: l tip xc, l phn ng nhiu giai on v thng nh gi. Nhng im khc
nhau gia cc loi l l phng php, cng tip xc vi cc cht phn ng
cng nh vi cht xc tc v phng php lm lnh, tuy nhin sn phm thu c
t cc h thng li rt tng ng.
Trong phn cng ngh ny, s gii thiu ba h thng c s dng rng ri
nht l: L phn ng nhiu giai on ca M.W. Kellogg Corp vi h thng lm
lnh t ng, sau ny c Exxon nng cp v l phn ng ca Stratco do hng
Stratford Enggineering Co,s Stratco thit k vi h thng lm lnh dngchy(dng
ng ng). Mc d mt vi nh tinh ch vn s dng l phn ng kiu thng nh
gi, nhng trong 25 nm qua loi ny khng cn sn xut na.
- Cng ngh alkyl ha izo-butan bng cc olefin dng xc tc H2SO4 c
nhng u im sau:
c im ni bt ca qu trnh dng xc tc H2SO4 l tin hnh nhit
thp, do ly nhit khi vng phn ng ngi ta c hai phng php chnh:
-
5/21/2018 n Tt Nghi p
33/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
+ Lm lnh bng dng sn phm ra khi v reactor hay bng cc tc nhn
lnh khc nh: NH3, CH3OH...
+ Cho bay himt phn izo-butan bn trong teactor.
Sn phm phn ng c tch axit mt cch n gin, axit b tiu hao c
thay th bng axit mi.
Dng xc tc H2SO4 trong qu trnh alkyl ha th khng cn quan tm c
bit n an ton v mi trng.
IV.2. Cc qu trnh cng ngh alkyl ha izo-butan bng olefin.
IV.2.1 Cng ngh alkyl ha izo-butan bng olefin nh dng xc tc H2SO4.
S khi gm cc b phn chnh:
Lm lnh vkh propan
Thit b
phn ng
Thit b x
l
Bphntch
Propan
Nguyn liu olefin
Kh c cha izo-butan
n-butan
Izo-octan
H2SO4thi (90%) H2SO4mi (98%)
Hnh I.3:S khi ca qu trnh alkyl ha dng xc tc H2SO4.
Nguyn liu olefin trc tin c trn ln vi izo-butan ri a vo thit b
phn ng. Nhit phn ng c ly ra bng cch lm lnh dng sn phm ra hoc
cho bay hi trc tip mt phn izo-butan. Hn hp phn ng sau khi x l H2SO4
c tch ra thp chng thnh izo-butan v alkylat, phn nh cho quay tr li
phn ng.
-
5/21/2018 n Tt Nghi p
34/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
IV.2.2 Cng ngh alkyl ha dng xc tc H2SO4ca hng Kellogg.
S cng ngh alkyl ha dng xc tc H2SO4ca hng Kellogg c m t
trn hnh I.4. Vi cng ngh dng xc tc H2SO4ca hng Kellogg alkyl ha izo-
butan c tin hnh vi propylen, butylen, pentylen thnh xng Mogas c tr s
octan cao v p sut hi bo ha thp.
Nguyn l hot ng ca qu trnh:
Nguyn liu olefin v izo-butan tun hon i vo thit bphn ng (1). Hn
hp c khuy trn k v c s tip xc vi H2SO4c cho vo t bn tri ca
h thng v i qua ln lt tng thit b. Nhit ca phn ng c ly ra bng cch
cho bay hi mt phn hydrocacbon c trong hn hp phn ng gi cho nhit
phn ng 40oF (khong 4 5oC). Phn hydrocacbon bay hi c a n thit
b lm lnh nn p (2) v phn ngng c tr li thit b phn ng (1). Propan
c tch ra nh thp (3), y mt phn propan c chuyn ha tip tc lm
nguyn liucho nh my. Sn phm phn ng c a n thit b phn ly (4),
hydrocacbon c tch ra khi xc tc axit sunfuric v axit c a i ti sinh.
Hydrcacbon mi tch ra c a n thp tch izo-butan (5) cng vi mt phn
izo-butan mi c ct.Phn ct nh thp (5) giu izo-butan c a tr li
phn ng (1). Phn y c a n thit b tch butan (6) ly ra phn y l
sn phm alkylat. Phn nh ca thp (6) l sn phm butan.
-
5/21/2018 n Tt Nghi p
35/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Nguynliu
olefin
Snphm
propan
Snphm
butan
Snphm
alkylate
Izo-butanmic
tc
Izo-butantunhon
Chtl
m
lnh
Axittunhon
7
2
3
5
6
4
1
1T
hitbalkylho
4.
Thitbphnly
2.Thitblm
lnh
5.
Thptchizo-butan
3.Thptchpropan
6.
Thptchbutan
7.
Mynn
HnhII.9:Scngnghalkylho
dngxctcH2SO4c
ahngKellogg
-
5/21/2018 n Tt Nghi p
36/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Cu trc l phn ng:
Reactor thng c 5 bc, trong mui bc u c b phn khuy trn mnh nn
to c nh tng thch hp cho phn ng. Cc bc c cch nhau bng tm
chn hnh ch L. Cui cng l phng lng gm hai vng, vng 1 l vng cha axit
vng 2 l vng cha sn phm. Olefin c dn ng thi vo 5 bc vi t l
chn trc (hnh I.5). Vi reactor loi ny phn ng gii nhit nh s bc hi ca
izo-butan d c hiu qu hn do vic iu khin nhit d dng hn.
iu kin lm vic ca thit b alkyl ha nh sau:
- Nhit : 4 10oC
- p sut 1 3 kG/cm2.
S thay i nng ca cc cu t tham gia vo nng phn ng trong
reactor nh sau:
Bng I.6:S thay i nng ca cc cu t vo nng phn ng trong
reactor.
Bc No % izo-butan Tl izo-butan/olefin
1
2
3
4
5
Trung bnh
83
76
68,5
59,8
50,5
67,6
30,5
28,2
22,1
18,1
14,3
22,2
-
5/21/2018 n Tt Nghi p
37/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
c tnh ch yu ca qu trnh:
+ S dng cng ngh t lm lnh vi hiu qu cao. Cho php lm lnh cho
nhit thp hn cho sn phm c cht lng cao hn nhng nng sut thp
hn.
+ S dng h thng lm lnh tng bc vi nng izo-butan trung bnh.
+ S dng vn tc b mt thp trong phn ng thu c sn phm cht
lng cao, loi tr vn n mn trong thit b ct phn on v s to thnh este.
+ L phn ng hot ng p sut thp, tin cy ca thit b cao, nht l
nhng van ca thit b khuy trn.+ S dng 5 l phn ng n lin kt vi nhau bn trong mt thit b chnh
lm h gi thnh ca dy chuyn cng ngh.
Sn lng thu c ca qu trnh:
- Sn phm: 1,78 bbl C5+/ bbl nguyn liu buten.
- izo-butan lng: 1,17 bbl/ bbl nguyn liu buten.
Nhng tiu tn cho mt barrel sn phm:
-Nc lm lnh (20oF): 1,000 gal 2,1
-Nng lng in, kWh 10,5
- Hi nc; 60 psi, 1b 200
- H2SO4, 1b 19
- NaOH, 100 ; 1b 0,1
-
5/21/2018 n Tt Nghi p
38/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
2
V
IV
III
VII
1
4
4VI
II
I
HnhII.10:Cutrccalphnng
1,2.
Ccvngphnng;3.
Cnhkhu
y;4.
nghngdng;
I-Axit;II-izo-buta
n;III,V-RHlm
lnh;IV-Ole
fin;VI-Snphmchuy
n
sangbungtsau;V
II-Hnhpphnngckhu
ytrnmnh.
-
5/21/2018 n Tt Nghi p
39/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
IV.2.3. Cng ngh alkyl ha dng xc tc H2SO4ca hng Exxon:
Hin ti Exxon s dng cng ngh alkyl ha lm lnh t ng ging nh ca
M.W.Kellogg. Cng ngh Exxon c cng sut khong 80.000 thng/ ngy.
L phn ng kiu lm lnh:
Exxon cho rng h c mt s thay i ng k trong cng on phn ng
ca lm lnh t ng alkyl ha so vi thit k c ca Kellogg.
Nhng thay i c quyn ny th hin cc c im sau:
- S tip xc gia hydrocacbon v cc phn on axit
- Vic phun olefin vo vng phn ng
- Tc khng gian
L phn ng lm lnh t ng ca Exxon gm mt thng rng thng ng c
nhiu vch ngn vn hnh p sut 0,07 kG/cm2(10psi) v mt b lng axit ring
bit (hnh I.6).
Nguyn liu olefin ha ln vi izo-butan tun hon t thp tch izo-butan v
dn vo tng thit b phn ng. Vic ha ln ny lm gim cc phn ng trng
hp. Vic khuy trn trong tng thit b to ra mt nh tng trong axit l pha
lin tc.
Nhit trung bnh trong tng thit b c duytr khong 4,5oC (45oF) bng
cch bay hi mt phn hydrocacbon d bay hi ly nhit phn ng (ch yu l
izo-butan). Cc cht bay hi b loi tr khi nh l phn ng v c chuyn n
thit b lng tch trc khi vo my nn lm lnh. Do vy khng c s bng nhau
nhit khi phn ng v cht lm lnh. Nhit cao hn thit b phn ng lm
lnh t ng so vi alkyl ha lm lnh bng dng chy, cho php u ht ca my
-
5/21/2018 n Tt Nghi p
40/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
nn vn hnh p sut cao hn, lm gim nng lng cn thit cho my nn lm
lnh.
M M M M M
M
Izo - butan
Olefin nguyn liu v i Izo butan tun hon
Hi hyro cacbon n my nn lm l nh
Thit bphn ng i t ch Izo butan
Acld
Thit blng t ch
Axit tun hon
Thit blng t ch
Axit tun hon
Thit bphn ng
Hi hyro cacbon nmy nn lm l nh
Thit bphnli hi lng
i tch Izo butan
Olefin nguyn liu v iIzo butan tun hon
Izo - butan
Hnh II.11: Hthng lm lnh t ng ca Exxon
-
5/21/2018 n Tt Nghi p
41/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Hnh I.5 cng cho thy ti sao nng izo-butan gim khi phn ng ca cht
nh tng chuyn ng qua l phn ng. V tc c izo -butan c cho vo thit
b u tin v ch mt s t olefin b nmn tng ngn nn t l izo-butan so vi
olefin cao hn so vi trong thit k mt thit b phn ng. V nh tng tham giaphn ng chuyn ng t ngn ny san ngn khc nn khi olefin phun vo nhiu
hn cng c nhiu izo-butan b bay hi. T cht hiu sut cao nht thu c
trong ngn u tin v cht lng ny gim xung trong cc ngn tip theo.
Nng izo-butan trung bnh cn thit cho thit b phn ng mt hay nhiu
ngn l nh nhau ti cng mt mc tun hon izo-butan. T cht lng sn
phm cn phi nh nhau trong cng cc iu kin vn hnh. Exxon cho rng vntc khng gian v nhit thp hn ca h thng thit b phn ng lm lnh t
ng s cho cht lng sn phm cao hn.
IV.2.4. Cng ngh alkyl ha dng xc tc H2SO4ca hng Stratco:
Vi cng ngh dng xc tc H2SO4 ca hng Stratco, alkyl ha izo-butan
c tin hnh vi propylen, butylen, amylen thnh cc hydrocacbon mch nhnh
m ch yu l izo-octan.
Nguyn l hot ng ca qu trnh:
Nguyn liu olefin, izo-butan v xc tc c trn ln v khuy trn u trc khi
ti thit b phn ng (1). y cht lng c tun hon tr li vi mc cao
tng cng s tip xc gia hydrocacbon vi xc tc axit t thit b phn ly(2) n.
Ton b th tch ca dung dch trong thit b phn ng mt c duy tr nhit
u nhau. Nhit bn trong khi phn ng khong 1oF. Sn phm i ra khi thit
b phn ng c a qua ni chng (3) v thp tch izo-butan (4). Phn bay hi
ca ni chng (3) c a n thit b nn p (5), y c cc thit b lm lnh
ti ch, sau qua thit b tch propan (6).
-
5/21/2018 n Tt Nghi p
42/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
START
START
Nguy
n
li
u
olefin
Izo-
bu
tan
1.
Thi
tbp
hnng
4.T
h
ptc
hIzo-
bu
tan
2.
Thitbp
hn
ly
5.Thitbn
n
p
3.
Th
p
tc
hlng
kh
6.T
h
ptc
hpropan
HnhII
.12
:Cngng
h
alky
lho
dngx
c
tc
H2
SO4ca
hng
Stra
tco.
lnc
Snp
h
m
propan 6
5
3
12
4
Snp
h
m
n.b
utan
Snp
h
m
aky
lat
-
5/21/2018 n Tt Nghi p
43/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Phn ct t thp tch izo-butan (4), dng cht lm lnh ti sinh (6) v ton b
lng izo-butan ti sinh c a tr li thit b phn ng. Hm lng izo-butan
v hu ht cchydrocacbon khc c duy tr xuyn sut trong pha lng ca thit
b phn ng, l qu trnh hot ha cho phn ng alkyl ha. Cng ngh ti sinhxc tc ti ch cng c s dng.
Nhng tiu tn cho 1 bbl sn phm:
-Nng lng in, kWh 13,5
- Hi nc, 150 psi, 1b 180
-Nc lm lnh (20oF), 103 gal 1,85
- Axit, 1b 15- NaOH, 1b 0,1
a) Qu trnh lm lnh bng dng chy (Stratco):
H thng lm lnh bng dng chy Stratco thit k cho 75% cng sut alkyl
ha H2SO4trn ton th gii vi tng cng sut gn 55.900 tn/ ngy.
L phn ng(bn v thit b chnh)
L phn ng l mt bnh p lc cha mt h thng trao i nhit, mt ng lu
thng bn trong v mt dng c y hn hp. Cng on phn ng c thc hin
p lc t 3,5 4,9 kG/cm2(50 70 psi) trnh s bay hi. Trong nhng nm
40 l phn ng c t theo chiu thng ng, nhng n cui nhng nm 50
c t nm ngang. S thay i ny ph hp vi vic tic kim chi ph xy dng
cng nh chi ph bo dng.
Cc iu kin s dng c th v ti u:
-
5/21/2018 n Tt Nghi p
44/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng I.7:Cc iu kin s dng ca l phn ng Stratco
Cc thng s Dy c th Ti u
Nhit vng phn ng (oC)
Tc khng gian (hr-)
izo-butan trong dng phn ng
axit trong l phn ng
5,6 18,3
0,2 0,5
55 75
40 60
5,6 10
0,2 0,3
62 70
50 60
Nguyn liu hydrocacbon v s tun hon nh tng ca axit c a vo
trong l, pha u ht ca cnh khuy.
Nh tng hydrocacbon axit c hnh thnh khi chng i qua cnh khuy.
Nh tng lu thng lin tc mc cao xung quanh vch ngoi v ngc tr
li thng qua ng thay i nhit ni m s pht trin ca alkyl ha v nng
lng c cung cp bi cnh khuy b loi b. Nh s tun hon cao ny trnh
c bt k s thay i nhit ng k no gia cc im khc nhau ca l phn
ng.
Trong mt nm trc y thit k ca l phn ng c nhng s thay i
lm nng cao cht lng alkylat v gim gi thnh vn hnh:
- ng thay i nhit di hn, nhm tng b mt trao i nhit.
- Vic hon thin hn v tr ca ng thay i nhit lm tng 50% h s trao
i nhit.
- u thy ngc c di tm ca ng dn gim ti a axit b lng
di y l phn ng.
- Vic tip liu hydrocacbon v h thng phun axit c nng cp.
-
5/21/2018 n Tt Nghi p
45/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
- Vi dng hnh lch tm, khc vi l phn ng kiu c, lm cho vic trn
hydrocacbon v axit c tt hn vloi tr cc vng cht ni cc phn ng trng
hp c th xy ra.
-
5/21/2018 n Tt Nghi p
46/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
6 5
A
7
B
C
3
2
1
D
E
F
m
t
1
4
Thitbph
nngAlkylhox
ctcH2SO4dng
nmngangcahngStratc
1.Nguynliuhydrcacbon
2.axitvo
3.Caopsut
4.Cathoht
5.Tcnhnlmlnhvo
6.Tcnhnlmlnhra
A.ngtraoinhit
7.Hnhpsnphmnthitblng
B.Vthitb
C.ngtunhon
D.Myk
huytucbin
E.uchuthulc
F.Cnhkhuy
-
5/21/2018 n Tt Nghi p
47/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Mt t l nh tng trong l phn ng c ly ra t pha y ca b phn
khuy v c chuyn n b phn lng axit. Axit c chuyn v l phn ng v
hydrocacbon c chuyn v h thng lm sch. Ty thuc vo kiu vn hnh, axit
sch hoc nh tng c ti sinh tr v l phn ng. Trong kiu axit sch, s tunhon t 85 90% axit, trong khi trong kiu nh tng tun hon cha khong
65% axit. S tun hon nh tng (kiu vn hnh khuyn dng) c th t c
bng cch gim thi gian lng axit cho nn hydrocacbon khng c lng xung
hon ton. Vic rt ngn thi gian lm cho cht lng sn phm tt hn v gim s
tiu th axit do c t cc phn ng ph nh polyme ha c th xy ra. Cc phn
ng ph khng mong mun sinh nhit ph c th pht hin bi s khc bit v
nhit gia ng ng t l phn ng n b lng v ng tun hon.
Hydrocacbon t b lng axit nhit khong 10 oC (50oF) chy qua van
gim p. Trong qu trnh chy qua van, p sut b gim xung cn 0,14 0,35
kG/cm2 (2 5 psi). Kt qu l mt s hydrocacbon d bay hi (propan v izo -
butan) b bay hi v nhit ca cht lng gim xung cn 0oC (32oF). Sau hai
phn on ny chy qua h thng ng ca lphn ng s tip tc san hi v
nhit ta ra t phn ng ha hc b loi tr khi khi phn ng. V dng chy v mt khoang ht ni m cc cht bay hi b tch khi dng chy ca thit b
phn ng.
b) Dy chuyn cng ngh alkyl izo-butan bng cc olefin nh, dng xc tc
H2SO4vi 4 thit b nm ngang (bn v s cng ngh)
nng cao nng sut trong cc nh my ln, ngi ta thng b tr 4 thit
b nm ngang vi dng hydrocacbon v axit ngc chiu.Cch b tr ny khngnhng cho nng sut cao m cn cho cht lng tt, ng thi gim chi ph do tiu
hao xc tc.
Nguyn l hot ng ca dy chuyn nh sau:
-
5/21/2018 n Tt Nghi p
48/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Hn hp hydrocacbon c cha olefin t thng cha (18) c bm (20) qua
thit b trao i nhit (22) vi alkylat lm lnh xung khong 7oC v c chia
lm 4 phn bng nhau np vo 4 thit b phn ng. izo -Butan t thng cha (19)
cng c bm qua thit b trao i nhit vi alkylat lm lnh xung khong7oC v cng vi izo-butan tthng cha (11) tun hon vo thit b phn ng (1).
Xc tc axit t thit b phn ly (5) v (6) c tun hon vo thit b phn ng (1).
Trong thit b phn ng (1) xy ra qu trnh alkyl ha; hn hp t thit b phn (1)
bao gm alkylat to thnh, izo-butan d, xc tc H2SO4, propan v n-butan c
a sang thit b phn ng (2) cng vi lng hydrocacbon mi c cha olefin
tip tc phn ng. Hn hp t thit b phn ng (2) c thnh ho hc nh thit bphn ng (1) c a sang thit b phn ly(5) tch xc tc ( do nng gim
di 90%), axit tch ra mt phn tun hon tr li thit b phn ng (1) mt phn
thi ra ngoi ti sinh. Phn cn li thit b (5) c a san thit b phn ng
(3) cng vi lng axit tun hon t thit b phn ly (6), lng axit mi v lng
hydrocacbon mi c cha olefin vo tip tc phn ng. Hn t thit b phn ng
(3) c a sang thit b phn ng (4) cng vi lng hydrocacbon mi c cha
olefin vo tip tc phn ng, ti y ta thu c alkylat c cht lng cao nht.
Hn hp t thit b phn ng (4) c a sang thit b phn ly (6), ti y axit
c tch ra v tun hon tr li thit b phn ng (3).Phn cn li thit b (6)
c chia lm 4 phn bng nhau lm lnh cho 4 thit b phn ng, sau c
a vo thit b tch lng hi (10), ti thit b (10) phn hi bay ln (gm propan
v izo-butan) qua my nn (8), qua thit b lm lnh (9) ri ngng t vo thit b
cha sn phm ngng (7), phn hi cn st lai trong (7) c quay tr li (8), qua
(9) ri vo (7). Phn lng y thit b (7), mt phn c bm qua thit b trao
i nhit un nng ri np vo thp tch propan (12), mt phn a vo thng
cha (11) cng vi lng izo-butan y thp (12). Ti thit b (11) phn hi cn
st li c quay tr li (8), qua (9) , vo (7) ri tip tc nh trn, cn phn lng
-
5/21/2018 n Tt Nghi p
49/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
c np vo thit b phn ng (1). Phn lng t thit b (10) c bm qua cc
thit b trao i nhit lm lnh cho dng hydrocacbon vo thit b phn ng, sau
khi ra khi cc thit b trao i nhit ta cho xt vo trung ha lng axit cn st
li trong hn hp ri np vo thit b lng tch (13), ti y xt c tch ra v mtphn tun hon tr li cn mt phn thi ra ngoi. Hn hp cn li thit b (13)
c bm ra bng nc ri np vo thit b lng tch (14), ti y nc thi c
tch ra, hn hp cn li c bm qua trao i nhit un nng ri np vo thp
tch izo-butan (15) cng vi phn on izo-butan (c ln n-butan). Ti thit b (15)
izo-butan tch ra c np vo thng cha (19), nc tch ra c thi ra ngoi.
Sn phm y thp (15) c a sang thp (16) tch n -butan, sn phm y thp (16) c a sang thp chng ct li (17) tch thnh alkylat nng v
alkylat nh.
-
5/21/2018 n Tt Nghi p
50/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
-
5/21/2018 n Tt Nghi p
51/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
V. LA CHN CNG NGH
Hin nay trn th trng tn ti song song hai cng ngh l cng ngh ca
Stratco v cng ngh ca Exxon. im khc bit quan trng nht v cng ngh
gia hai hng ny l thit b phn ng v phng php lm lnh. Exxon s dng
thit b phn ng loi hnh tr nm ngang c chia nhiu ngn v lm lnh t ng
bng cch bay hi trc tip mt phn iso-butan ngay trong mi bung phn ng.
Stratco s dng loi thit b dng tr nm ngang thng dng nm thit b mc ni
tip nhau v lm lnh gin tip bng cch trao i nhit qua chm ng. Hai cng
ngh trn hin ang c pht trin v song song tn ti trn th trng. Mi loi
cng ngh u c u, nhc im ring.
Bng I.8. u nhc im ca hai cng ngh Exxon v Stratco
Cng ngh ca Exxon Cng ngh ca Stratco
u im:
-Nh gn, tiu tn t nng lng, ttn km trong vic u t lp t.
-Thit b khng phi chu p nn
khng cn vt liu qu t tin.
u im:
-Kh nng khuy trn rt mnh, tc tun hon cao lm tng kh nng tip
xc pha, hn ch cc im cht v lm
nhit ng u trong ton b thit
b.
-Dng axt v hydrocabon i ngc
chiu nhau do cht lng alkylat
to ra ng u trong cc thit b.
-Trao i nhit gin tip bng ngchm do vy d iu chnh nhit
trong thit b phn ng.
Nhc im:
-Do isobutan c a vo ngay t
Nhc im:
-Thit b kh phc tp, s lng thit
-
5/21/2018 n Tt Nghi p
52/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
khoang u v b bay hi mt phn
trong mi khoang tch nhit ca
phn ng nn nng isobutan s
gim theo tng bc. Mt khc lng
axt cng c a vo ngay t u
nn nng cng gim dn theo tng
bc ca v vy nng alkylat cng
gim dn theo tng bc
-Trong mi khoang do cnh khuy
cng sut nh t thng ng nn c
th c vng cht ni xy ra cc phn
ng ph nh polyme ho, oxy holm xu i cht lng alkylat. Hn
na trong cc vng ny rt d b lng
H2SO4 pha di.
b nhiu hn nn tn km trong vic
lp t cng nh tn km vt liu ch
to.
Theo s liu thng k t nm 1991 2001 khong 90% cc nh my alkyl ho
mi c xy dng s dng cng ngh ca Stratco.Qua nhng phn tch trn em
chn cng ngh ca hng Stratco dng xc tc H2SO4 gm 4 thit b phn ng ni
tip nm ngang, trao i nhit bng cch cho bay hi mt phn propan v izo-
butan trong hn hp phn ng. u im ca loi dy chuyn cng ngh ny l s
dng xc tc H2SO4 nn t c hi cho mi trng.Thit b phn ng nm ngang
nn d dng cho qu trnh khuy trn, hn ch s phn ly nh tng trong thit b
phn ng nn hiu sut phn ng cao v hn ch c cc phn ng ph.Axit
lm vic c a qua thit b lng, ti sinh v tun hon tr li thit b phn ngu tin nn tit kim c nhiu chi ph cho xc tc.
-
5/21/2018 n Tt Nghi p
53/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
PHN II
TNH TON CN BNG VT CHT V THIT B CHNH
Nng sut thit bphn ng l 320000 tn/nm.
Hiu sut chung ca qu trnh l 38%
Suy ra, nng sut ca dy chuyn l
G =
.100 = 842000 tn/nm
- Nng sut dy chuyn: 842000 tn/nm- Sngy lm vic trong mt nm: 335 ngy
-
Nhit phn ng: 5 10o
C-
Xc tc H2SO4c Co= 98%, Cc= 90%
-
Tlizo-butan/buten bng: 6/1- TlthH2SO4/RH bng: 1/1
Kh nguyn liu c thnh phn nh sau:
Bng II.1:phn on C4ca qu trnh cracking xc tc phn on nh
Hydrocacbon Khi lngphn t(M)
Hm lng(% khi lng)
Hm lng(% mol)
Propan (C3H8)
n-butan (n-C4H10)izo-butan (izo-C4H10)
1-buten (1-C4H8)
2-buten (2-C4H8)
Izo-buten (izo-C4H8)
44
5858
56
56
56
1,0
11,033,0
12,0
25,0
18,0
1,21
10,6232.41
12,15
25,37
18.24
Tng cng 100 100
I.
Tnh cn bng vt cht cho cc thit b
n gin cho qu trnh tnh ton, chng ta chp nhn cc iu kin sau:
- Lng propan v n-butan khng tham gia phn ng trong sut qu trnh
- Lng olefin ha tan vo axit (2 3%) v mt i khng ng knn c thbqua stiu hao ny
-
5/21/2018 n Tt Nghi p
54/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
-
Nhit trung bnh trong reactor ly bng 7 oC-
Ton bolefin a vo u to sn phm
Phng trnh phn ng to sn phm chnh ca qu trnh nh sau:
Izo-CnH2n+2 + CmH2m Cm+nH2(m+n)+2+ Q (1)
Khi lng trung bnh ca alkylat:
Malkylat= Molefin+ Mizo-butan
= 56 +58 = 114
Skg sn phm alkylat to thnh trong 1 gi:
Galkylat=
= 104726,36 kg/h
Smol sn phm alkylat to thnh trong 1 gi:
nalkylat=
=
= 918,65 kmol/h
a)
Tnh cn bng vt cht cho thit bphn ng thnht
Tphng trnh phn ng (1), ta thy c1 mol olefin tham gia phn ng vi 1
mol izo-butan th to thnh 1 mol sn phm alkylat.
Vy ta c:
nolefin= nizo-butan= nalkylat= 918,65 kmol/h
Do lng olefin tham gia phn ng trong 1 gil:
Golefin= nolefin. Molefin= 918,65. 56 = 51444,53 kg/h
Lng hydrocacbon c cha olefin vo hthng thit bphn ng trong 1 gi
G =
=
= 93535,51 kg/h
Vy ta c:
H+
-
5/21/2018 n Tt Nghi p
55/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.2:Khi lng cc cu tnguyn liu i vo hthng
thit bphn ng trong 1 gi.
Cu t Khi lng phn tM % khi lng Kg/h
C3H8n-C4H10
izo-C4H10NL1-C4H8
2-C4H8Izo-C4H8
4458
5856
5656
1,011,0
33,012,0
25,018,0
935,3510288,90
30860,7211224,26
23383,8816836,39
Tng cng 100 93535,51
m bo tlizo-butan/buten = 6/1, th lng th lng izo-butan a vohthng thit bphn ng trong 1 gil:
:
= 6:1
Suy ra: Gizo-butan= 6 .
. Gbuten
= 6 .
. 51444,52 = 319690,95 kg/h
Lng nguyn liu izo-butan i vo thit bphn ng trong 1 gil:
Gizo-butanMi= Gizo-butanGizo-butanNL
= 319690,95 30860,72= 288830,23 kg/h
Lng hydrocacbon c cha izo-butan vo hthng thit bphn ng trong 1 gi:
G =
=
= 294724,72 kg/h
-
5/21/2018 n Tt Nghi p
56/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.3:Thnh phn cc cu ti vo hthng thit b
Phn ng trong 1 gi
Cu t
Khi lng
ring 7 oC(kg/m3)
Lng nguyn liu vo
Kg/h Kmol/h m3/h Nng mol
C3H8
n-C4H10
izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
515
590
569
569606
634606
935,35
10288,90
30860,72
288830,2311224,26
23383,8816836,39
21,26
117,40
532,18
4979,83200,43
417,57300,65
1,82
17,44
54,25
517,9618,52
36,8827,78
0,003
0,027
0,080
0,7510,030
0,0630,046
Tng cng 377029,96 6852,43 674,65 1,000
Thtch xc tc i vo hthng thit btrong 1 gi:
=
Vacid= 1,1.VRH
Vacid= 1,1.674,65 = 742,12 m3/h
Khi lng acid i vo hthng thit bphn ng trong 1 gi:
Gacid= Vacid. acid ( 7oC acid= 1812)
Gacid= 742,12.1812 = 1344712,44 kg/h
Tt clng izo-butan mi u i vo thit bphn ng thnht
Nguyn liu hydrocacbon chia lm 4 phn bng nhau i vo 4 thit bphnng. tbng II.2 ta c:
Lng propan trong nguyn liu i vo mi thit bphn ng trong 1 gi:
Gpropan=
= 233,84 kg/h
Lng n-butan trong nguyn liu i vo mi thit bphn ng trong 1 gi:
Gn-butan=
= 2572,26 kg/h
-
5/21/2018 n Tt Nghi p
57/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Lng izo-butan trong nguyn liu i vo mi thit bphn ng trong 1 gi:
Gizo-butan=
= 7716,86 kg/h
Lng 1-buten trong nguyn liu i vo mi thit bphn ng trong 1 gi:
G1-buten=
=2806,07kg/h
Lng 2-buten trong nguyn liu i vo mi thit bphn ng trong 1 gi:
G2-buten=
= 5845,97 kg/h
Lng izo-buten trong nguyn liu i vo mi thit bphn ng trong 1 gi:
Gizo-buten= = 4209,10kg/h
Tcc sliu trn ta c:
Bng II.4:Thnh phn nguyn liu i vo thit bphn ng thnht
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H82-C4H8
izo-C4H8
44
5858
58
5656
56
515
590569
569
606634
606
233,84
2572,267716,86
288830,23
2806,075845,97
4209,10
5,31
44,35133,05
4979,83
50,11104,39
75,16
0,46
4,3613,56
507,61
4,639,22
6,95
Tng cng 312214,33 5372,2 546,78
Gislng olefin tham gia phn ng ht, khi lng izo-butan tham giaphn ng thit bthnht l:
nolefin= n1-buten+ n2-buten+ nizo-buten
= 50,11 + 104,39 + 75,16 = 229,66 kmol/h
-
5/21/2018 n Tt Nghi p
58/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
=
= 229,66 kmol/h
= Mizo-butan.
= 58.229,66 = 1332,28 kg/h
Tuy nhin hiu sut ca phn ng cht 85% nn ta sc lng olefin vizobutan tham gia phn ng thc tl:
=
.85 = 10931,97 kg/h
=
. 85 =11322,24 kg/h
Lng izo-octan to ra thit bphn ng 1:
=
+
= 10931,97 + 11322,24 = 22254,21 kg/h
Lng izo-butan trong nguyn liu vo thit bphn ng 1 phi b l:
=
=11322,24 7716,86 = 3605,38 kg/h
m bo tlthtch acid/hydrocacbon vo thit bphn ng cui cng l1,1/1 th gisbc 1 ta ly tlny l 1,4/1 (v lng hydrocacbon ngy cngnhiu, hm lng acid ngy cng gim i).
Do thtch acid dng phn ng 1 l:
= 1,4.VRH= 1,4.674,65 = 944,51 m
3/h
Lng axit vo thit bphn ng trong 1 gi:
= . acid =944,51 .1812 = 1710528,36 kg/h
Tcc sliu trn ta c:
-
5/21/2018 n Tt Nghi p
59/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.5:cn bng vt cht thit bphn ng thnht
Cu t Lng nguyn liu vo Lng nguyn liu raKg/h m3/h Kg/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
233,84
2572,267716,86
288830,232806,07
5845,974209,10
01710528,36
0,46
4,3613,56
507,614,63
9,226,95
0944,54
233,84
2572,260
285224,86420,91
876,90631,35
22254,211710528,36
0,46
4,360
501,270,70
1,381,04
31,3944,54
Tng cng 2022742,69 1491,33 2022742,69 1485,05
Kim tra tlthtch H2SO4/RH:
VRH= VVacid= 1485,05944,51 = 540,54 m3/h
=
=1,42 t yu cu ra
b)
Tnh cn bng vt cht ca thit bphn ng thhai
Dng vt cht i vo thit bphn ng th2 gm tt ccc lng i ra thitbphn ng thnht v nguyn liu hydrocacbon mi vo.
Tng tnh thit bphn ng 1 ta c:
Bng II.6:Thnh phn nguyn liu i vo thit bphn ng th2
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8n-C4H10
izo-C4H10NLizo-C4H10Mi1-C4H82-C4H8
izo-C4H8
4458
5858
5656
56
515590
569569
606634
606
467,685144,52
7716,86285224,86
3237,776745,39
4856,54
10,6388,70
133,054917,67
57,82120,45
86,72
0,918,72
13,56432,81
5,3410,64
8,01
-
5/21/2018 n Tt Nghi p
60/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
izo-octanH2SO4
11498
7121812
22254,211710528,36
195,2117454,37
31,26944,54
Tng cng 2046176,19 23064,62 1455,80
Gislng olefin tham gia phn ng ht, khi lng izo-butan tham giaphn ng thit bth2 l:
nolefin= n1-buten+ n2-buten+ nizo-buten
=57,82 + 120,45 + 86,72= 265 kmol/h
=
= 265 kmol/h
= Mizo-butan.
= 58.265 = 15370 kg/h
Tuy nhin hiu sut ca phn ng cht 87% nn ta sc lng olefin vizobutan tham gia phn ng thc tl:
=
.87 = 12910,54 kg/h
=
. 87 = 13371,9 kg/h
Lng izo-octan to ra thit bphn ng 2:
=
+
= 12910,54 +13371,9 = 26282,44 kg/h
Lng izo-butan trong nguyn liu vo thit bphn ng 2 phi b l:
=
=13371,97716,86 = 5655,04 kg/h
Tcc sliu trn ta c:
-
5/21/2018 n Tt Nghi p
61/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.7:cn bng vt cht thit bphn ng th2
Cu t Lng nguyn liu vo Lng nguyn liu raKg/h m3/h Kg/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
467,68
5144,527716,86
285224,863237,77
6745,394856,54
22254,211710528,36
0,91
8,7213,56
432,815,34
10,648,01
31,26944,54
467,68
5144,520
279569,82420,91
876,90631,35
48536,651710528,36
0,91
8,720
491,340,7
1,381,04
425,76944,54
Tng cng 2046176,19 1455,80 2046176,19 1873,69
Kim tra tlthtch H2SO4/RH:
VRH= VVacid= 1873,69944,51 = 929,18 m3/h
=
=1,02 t yu cu ra
c) Tnh cn bng vt cht cho thit bphn ly axit thnht
Dng vt cht sau khi i ra khi thit b phn ng thhai sc a vothit bphn ly axit thnht, thit bny th dng vt cht tch thnh 2 dngkhc nhau. Mt dng chyu l axit H2SO4quay tr li thit bphn ng, dngthhai gm chyu l cc hydrocacbon c a sang thit bphn ng tip theo.
Bng II.8:Thnh phn nguyn liu i vo thit bphn ly axit thnht
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3
)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8n-C4H10
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
4458
5856
5656
515590
569606
634606
467,685144,52
279569,82420,91
876,90631,35
10,6388,70
4820,177,52
15,6611,27
0,918,72
491,340,7
1,381,04
-
5/21/2018 n Tt Nghi p
62/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
izo-octanH2SO4
11498
7121812
48536,651710528,36
425,7617454,37
68,17944,54
Tng cng 2046176,19 22834,08 1550,46
V hiu sut ca thp phn ly axit l 98% nn ta c hm lng cc cu ti rakhi thp phn ly l:
Bng II.9:Cn bng vt cht thit bphn ly axit thnht
Cu tLng nguyn liu
voLng nguyn liu ra
Tun hon trli Sang TBP th3Kg/h m3/h Kg/h m3/h Kg/h m3/h
C3H8n-C4H10
izo-C4H10Mi1-C4H82-C4H8
izo-C4H8izo-octan
H2SO4
467,685144,52
279569,82420,91
876,90631,35
48536,651710528,36
0,918,72
491,340,7
1,381,04
425,76944,54
9,35102,90
5591,408,42
17,5412,63
970,731676317,80
0,020,17
9,830,01
0,030,02
8,52925,65
458,335041,62
273978,42412,49
859,36618,72
47565,9234210,56
0,898,55
481,510,69
1,351,02
66,8118,89
Tng cng 2046176,19 1873,69 1683030,77 944,25 363145,42 579,71
d)
Tnh cn bng vt cht ca thit bphn ng th3
thit bphn ng th(3), hn hp hydrocacbon tthit bphn ly axit thnht cng vi lng hydrocacbon nguyn liu mi i vo thit b. Xc tc axit tthit bphn ly axit th2 v c bsung thm lng axit mi m bo nngaxit l 98% trc khi vo thit bphn ng th3.
Dng vt cht i vo thit bphn ng th3 gm tt ccc lng i ra thitbphn ly axit thnht v nguyn liu hydrocacbon mi vo.
Tng tnh thit bphn ng 1 ta c:
-
5/21/2018 n Tt Nghi p
63/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.10:Thnh phn nguyn liu i vo thit bphn ng th3
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
izo-octan
H2SO4
44
5858
5856
5656
114
98
515
590569
569606
634606
712
1812
692,17
132,277716,86
273978,423226,98
6705,334827,82
47565,92
1710528,36
15,73
12,91133,05
4723,7757,62
119,7486,21
417,25
17545,37
1,34
0,2413,56
481,515,33
10,587,97
66,81
944,54
Tng cng 2055374,13 23111,65 1531,88
Gislng olefin tham gia phn ng ht, khi lng izo-butan tham giaphn ng thit bth3 l:
nolefin= n1-buten+ n2-buten+ nizo-buten
= 57,62 + 119,74 + 86,21 = 263,57 kmol/h
=
= 263,57 kmol/h
= Mizo-butan.
= 58.263,57 = 15287,06 kg/h
Tuy nhin hiu sut ca phn ng cht 90% nn ta sc lng olefin vizobutan tham gia phn ng thc tl:
=
.90 = 13284,12 kg/h
=
. 90 = 13758,3 kg/h
Lng izo-octan to ra thit bphn ng 3:
=
+
= 13284,12 + 13758,3 = 27042,42 kg/h
-
5/21/2018 n Tt Nghi p
64/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Lng izo-butan trong nguyn liu vo thit bphn ng 3 phi b l:
=
= 13758,37716,86 = 6041,44 kg/h
Tcc sliu trn ta c:
Bng II.11:cn bng vt cht thit bphn ng th3
Cu t Lng nguyn liu vo Lng nguyn liu raKg/h m3/h Kg/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8
izo-C4H8
izo-octanH2SO4
692,17
132,277716,86
273978,423226,98
6705,33
4827,82
47565,921710528,36
1,34
0,2413,56
481,515,33
10,58
7,97
66,81944,54
692,17
132,270
267937,21322,70
670,53
482,78
74608,341710528,36
0,13
0,0240
470,900,53
1,06
8,00
104,79944,54
Tng cng 2055374,13 1531,88 2055374,13 1531,88
Kim tra tlthtch H2SO4/RH:
VRH= VVacid= 1531,88944,51 = 587,37 m3/h
=
=1,46 t yu cu ra
e)
Tnh cn bng vt cht ca thit bphn ng th4:
Dng vt cht i vo thit bphn ng th4 gm tt ccc lng i ra thit
bphn ng th3 v nguyn liu hydrocacbon mi vo.
Tng tnh thit bphn ng 1 ta c:
-
5/21/2018 n Tt Nghi p
65/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.12:Thnh phn nguyn liu i vo thit bphn ng th4
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8izo-C4H8
izo-octan
H2SO4
44
5858
5856
5656
114
98
515
590569
569606
634606
712
1812
926,01
2704,537716,86
267937,213128,77
6516,54691,88
74608,34
1710528,36
21,05
46,63133,05
4619,6155,87
116,3783,78
654,46
17454,37
1,80
4,5813,56
470,905,16
10,287,74
104,79
944
Tng cng 2078803,46 23185,19 1562,81
Gis lng olefin tham gia phn ng ht, khi lng izo-butan tham giaphn ng thit bth4 l:
nolefin= n1-buten+ n2-buten+ nizo-buten
= 55,87+ 116,37 + 83,78 = 256,02 kmol/h
=
= 256,02 kmol/h
= Mizo-butan.
= 58.256,02 = 14849,16 kg/h
Tuy nhin hiu sut ca phn ng cht 92% nn ta sc lng olefin vizobutan tham gia phn ng thc tl:
=
.92 = 13190,18 kg/h
=
. 92 = 13661,22 kg/h
Lng izo-octan to ra thit bphn ng 4:
=
+
= 13190,18 + 13661,22 = 26851,41 kg/h
-
5/21/2018 n Tt Nghi p
66/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Lng izo-butan trong nguyn liu vo thit bphn ng 4 phi b l:
=
= 13661,227716,86 =5944,36 kg/h
Tcc sliu trn ta c:
Bng II.13:cn bng vt cht thit bphn ng th4
Cu t Lng nguyn liu vo Lng nguyn liu raKg/h m3/h Kg/h m3/h
C3H8
n-C4H10izo-C4H10NL
izo-C4H10Mi1-C4H8
2-C4H8
izo-C4H8
izo-octanH2SO4
926,01
2704,537716,86
267937,213128,77
6516,5
4691,88
74608,341710528,36
1,80
4,5813,56
470,905,16
10,28
7,74
104,79944
926,01
2704,530
262037,84250,30
521,32
375,35
101459,751710528,36
1,80
4,580
640,520,41
0,82
0,62
142,52944
Tng cng 2078803,46 1562,81 2078803,46 1563,74
Kim tra tlthtch H2SO4/RH:VRH= VVacid= 1563,74944,51 = 619,23 m
3/h
=
=1,5 t yu cu ra
f)
Tnh cn bng vt cht cho thit bphn ly axit th2
Sau khi i ra khi thit bphn ng th4 hn hp sc a vo thit bphn ly axit th2 tch axit quay trli thit bphn ng. Hn hp sau phn ng
c thnh phn nh sau:
Bng II.14:Thnh phn nguyn liu i vo thit bphn ly axit th2
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
-
5/21/2018 n Tt Nghi p
67/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
C3H8n-C4H10
izo-C4H101-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
4458
58
56
5656
11498
515590
569
606
634606
7121812
926,012704,53
262037,84
250,30
521,32375,35
101459,751710528,36
20,0546,63
4517,9
4,70
9,316,70
90017454,37
1,804,58
640,52
0,41
0,820,62
142,52944
Tng cng 2078803,46 22959,66 1563,74
V hiu sut ca thp phn ly axit l 98% nn ta c hm lng cc cu ti rakhi thp phn ly l:
Bng II.15:Cn bng vt cht thit bphn ly axit thhai
Cu t
Lng nguyn liuvo
Lng nguyn liu raTun hon trli Sang TB tch lng
hiKg/h m3/h Kg/h m3/h Kg/h m3/h
C3H8n-C4H10
izo-C4H101-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
926,012704,53
262037,84250,30
521,32375,35
101459,751710528,36
1,804,58
640,520,41
0,820,62
142,52944
18,5254,10
5240,765,01
10,437,51
2029,201676317,80
0,040,09
9,210,008
0,020,01
2,85925,65
907,492650,43
256797,08245,30
510,90367,84
99430,5534210,56
1,764,49
631,310,402
0,80,61
139,6718,89
Tngcng
2078803,46 1563,74 1683683,33 937,88 395120,13 797,93
g)
Tnh cn bng vt cht ca thit btch lng hi
Sau khi i ra khi thit bphn ly axit th2 ton bhn hp c a ti thitbphn tch lng hi. Hn hp i vo thit bphn tch lng hi c thnh phnnh sau:
-
5/21/2018 n Tt Nghi p
68/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.16:Thnh phn nguyn liu i vo thit bphn tch lng hi
Cu tKhi lngphn tM
Khi lngring 7 oC
(kg/m3)
Lng nguyn liu voKg/h Kmol/h m3/h
C3H8
n-C4H10izo-C4H101-C4H82-C4H8
izo-C4H8izo-octan
H2SO4
44
5858
5656
56114
98
515
590569
606634
606712
1812
907,49
2650,43256797,08
245,30510,90
367,8499430,55
34210,56
20,62
45,70442,75
4,389,12
6,56872,20
349,09
1,76
4,49631,31
0,4020,8
0,61139,67
18,89
Tng cng 395120,13 1750,41 797,93
V hiu sut thit btch lng hi l 90% nn ta c hm lng cc cu ti rakhi thit btch lng hi nh sau:
Gisthit bny th ton bpropan sc tch ra phn kh v ton baxit c ly ra phn lng ca thit b.
Bng II.17:Cn bng vt cht thit bphn tch lng hi
Cu t
Lng nguyn liuvo
Lng nguyn liu raPhn lng Phn kh
Kg/h m3/h Kg/h m3/h Kg/h m3/h
C3H8
n-C4H10izo-C4H101-C4H82-C4H8
izo-C4H8izo-octan
H2SO4
907,49
2650,43256797,08
245,30510,90
367,8499430,55
34210,56
1,76
4,49631,31
0,4020,8
0,61139,67
18,89
0
2385,39231117,37
220,77459,80
331,0689487,5
34210,56
0
3,99568,18
0,3620,72
0,55125,7
18,89
907,49
265,0425679,71
24,5351,10
36,789943,05
0
1,76
0,563,13
0,040,08
0,0613,97
0
Tng cng 395120,13 797,93 358212,43 718,39 36907,7 79,54
-
5/21/2018 n Tt Nghi p
69/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
h)Tnh cn bng vt cht ca thit bra xt
Ton bphn ly ra phn lng c a qua thit bra axit loi bhtphn axit cn ln trong sn phm. Hn hp i vo thit bc thnh phn nh sau:
Bng II.18:Nguyn liu i vo thit bra xt
Cu t Khi lng phntM
Lng nguyn liu voKg/h m3/h
n-C4H10
izo-C4H101-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
58
5856
5656
11498
2385,39
231117,37220,77
459,80331,06
89487,534210,56
3,99
568,180,362
0,720,55
125,718,89
Tng cng 358212,43 718,39
Thit bra xt vi hiu sut 93%, gisl lng axit trong hn hp brasch hon ton, cc hydrocacbon sln theo xt thi ra ngoi l 7%.
Bng II.19:Cn bng vt cht thit bra xt
Cu tLng nguyn liu
vo (Kg/h)
Lng nguyn liu raPhn sn phm
(Kg/h)Phn xt thi
(Kg/h)
n-C4H10
izo-C4H101-C4H8
2-C4H8izo-C4H8
izo-octanH2SO4
2385,39
231117,37220,77
459,80331,06
89487,534210,56
2218,41
214939,17205,32
427,61307,89
83223,380
116,98
16178,2015,45
32,1923,17
6264,1234210,56
Tng cng 358212,43 301371,76 56840,67
i)
Tnh cn bng vt cht ca thit bna nc
-
5/21/2018 n Tt Nghi p
70/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Phn hn hp i ra cngsn phm c dn qua thit bra nc loi bphn kim d trong qu trnh ra axit. Vi hiu sut ca thit bra nc 90% tac cn bng vt cht thit bra nc nh sau:
Bng II.20:Cn bng vt cht thit bra nc
Cu tLng nguyn liu
vo (Kg/h)Lng nguyn liu ra
Phn sn phm(Kg/h)
Phn nc thi(Kg/h)
n-C4H10izo-C4H101-C4H8
2-C4H8
izo-C4H8
izo-octan
2218,41214939,17
205,32
427,61
307,89
83223,38
1996,57193445,25
184,79
384,85
277,10
74901,04
221,8421493,97
20,53
42,76
30,79
8322,34
Tng cng 301371,76 271234,58 30137,18
j)
Tnh cn bng vt cht ca thp chng tch izo-butan
Phn hn hp i ra cng sn phm c dn vo thp chng tch izo-butan. thp chngny th nh thp chyu thu c chyu l izo-butan v cc cu tkhc ln theo cn y thp chyu l thu cc cu tnng hn v ln mt phnizo-butan. Vi hiu sut ca thp chng l 92% ta c cn bng vt cht thpchng luyn nh sau:
Bng II.21:Cn bng vt cht thp chng tch izo-butan
Cu tLng nguyn liu
vo (Kg/h)Lng nguyn liu ra
Sn phm nh(Kg/h)
Sn phm y(Kg/h)
n-C4H10
izo-C4H101-C4H82-C4H8
izo-C4H8izo-octan
1996,57
193445,25184,79384,85
277,1074901,04
159,72
15475,6214,7830,79
22,175992,08
1836,85
177969,63170,01354,06
254,9368908,96
Tng cng 271234,58 21695,16 249539,42
-
5/21/2018 n Tt Nghi p
71/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
k)Tnh cn bng vt liu ca thp chng tch phn nh
Phn hn hp i ra y thp c dn vo thp chngtch phn nh. thpchng ny th nh thp chyu thu c chyu l n-butan, izo-butan, 1-buten,
2-buten, izo-buten v ln mt phn cc cu tnng cn y thp chyu l izo-octan v cc cu tnng hn v ln mt phn cc cu tnh. Gisthp chngluyn ny n-butan v izo-butan c ly ra hon ton nh ca thp chng luyn.Vi hiu sut ca thp chng luyn l 94% ta c cn bng vt cht thp chngluyn nh sau:
Bng II.22:Cn bng vt cht thp chng tch phn nh
Cu tLng nguyn liu
vo (Kg/h)Lng nguyn liu ra
Sn phm nh(Kg/h)
Sn phm y(Kg/h)
n-C4H10izo-C4H101-C4H82-C4H8
izo-C4H8izo-octan
1836,85177969,63
170,01354,06
254,9368908,96
1836,85177969,63
159,81332,82
239,6364774,42
00
10,2021,24
15,304134,54
Tng cng 249539,42 245358,14 4181,28
l)
Tnh cn bng vt cht ca thp tch izo-octan
Phn hn hp i ra y thp c dn vo thp chng tch izo-octan. thpchngny th nh thp chyu thu c chyu l izo-octan, v ton bcccu tnhtrong hn hp v ln mt phn cc cu tnng cn y thp chyul cc cu tnng v ln mt phn izo-octan. Vi hiu sut ca thp chng l 95%
ta c cn bng vt cht thp chng luyn nh sau:
-
5/21/2018 n Tt Nghi p
72/72
N TT NGHIP CNCN GVHD: TS. O QUC TY
SVTH: LU B MNH - CN HA DU - K55
Bng II.23:Cn bng vt cht thp chng tch izo-octan
Cu tLng nguyn liu
vo (Kg/h)Lng nguyn liu ra
Sn phm nh(Kg/h)
Sn phm y(Kg/h)
1-C4H8
2-C4H8izo-C4H8
izo-octan
10,20
21,2415,30
4134,54
10,20
21,2415,30
3927,82
0
00
206,72
Tng cng 4181,28 3974,56 206,72
V tinh khit ca sn phm l 99% nn trong sn phm c cha 1% cc cutnhv cc tp cht trong , v vy ta c tng lng sn phm ra nh thp l:
G =
.100 = 4014,70 kg/h
Tlng sn phm nh ra v cc cu tnhtnh ton c chng ta sbitc lng tp cht c trong sn phm.
Gtc== 4014,70 - 3974,56 = 40,14 kg/h