day 6. catalytic cracking (basic catalytic in fcc)

8/13/2019 Day 6. Catalytic Cracking (Basic Catalytic in FCC)

1/43

CRACKING XC TC

FCC

FLUIDIZED CATALYTIC CRACKING


2/43

Lch s qu trnh pht trin cacracking xc tc

Qu trnh cracking xc tc c nguyn cu tcui th k XIX

Nm 1936 nh my cracking xc tc u tin trnth gii c xy dng nh cng lao ca k sngi Php Eugene Houdry

Ngy nay qu trnh cracking xc tc l mt trongnhng qu trnh khng th thiu c trong bt cnh my ch bin du no trn th gii


3/43

1. Mc ch ca qu trnhChuyn ha cc phn on nng thnh snphm nhin liu (xng, DO, )

Nng cao chn lc ca qu trnh Cracking

Nng cao cht lng sn phm


4/43


5/43

2. Xc tc Xc tc: l cht c kh nng lm tng nhanh vn tc phn ng

di tc dng ca mnh. Cht xc tc to thnh hp cht trunggianvi cht phn ng. Cui cng xc tc c hon nguyn (tc

khng c s thay i v phng din ha hc).

+ Xc tc ng th: l cht xc tc cng pha vi cc cht tham

gia phn ng

+ Xc tc d th:l cht xc tc khc pha vi cc cht tham giaphn ng


6/43

2. Xc tc FCC

n gia nhng nm 60 ca th k trc, cc xc tccrackingcha ZEOLITmi c bt u c s dng trong

cng ngh FCC


7/43

2. Xc tc FCCSo vi cht xc tc aluminocilicat v nh hnh, cht xc tc FCC cha Zeolit cnhng tnh cht c trng c bn sau y:

a. Hot tnh xc tc cao:b. bn hot tnh tt:c. bn nhit v thu nhit caod. Hiu sut gasoline cao, hiu sut to cc v kh thpe. bn mi mn tt


8/43

2. Xc tc FCC


9/43

2. Xc tc FCCXc tc FCC bao gm 3 thnh phn chnh:

1. Zeolit:l thnh phn quan trng nht trong xc tc cracking

2. Cht nn:

+ Cha cc mao qun trung bnh v ln, cc tm axit yu nn cth cracking s b cc hydrocacbon phn t ln

+ Bt gi t xa cc tc nhn ng c zeolit (V,Ni, cc hpcht nit )

+ Lin kt gia cc hp phn xc tc to bn c hc cho chtxc tc

3. Cht ph tr:L nhng hp cht ph tr lm cho cht xc tcFCC t c nhng mc tiu c th no ca nh my lc

ho du (Pt, ZSM-5, ZSM-11)


10/43

2. Xc tc FCC Xc tc axt rn

Thnh phn phc tp


11/43

2. Xc tc FCC Tnh chtcbn Hot: cnhgibnghiusutxng

Chshot= hiusutxng nhnctrong kc

Chshot > 3435 xt c hotcao,

2832 trung bnh2728 thp


12/43

2. Xc tc FCC Tnh chtcbn bn(hottnh nnh): Tnh chtxt ginnhtrong thi

gian hotng

gibnttcnphithngxuyn lymtphnxt tcm

phnngra v thay thbngxt mi

Chi ph xt c bntt0,10,15% nguyn liu

Chsbn= chshotsau khi xl xtbnghinc

Xtphibnnhitnhithon nguyn600o

C Xt tnghpbnnhitrtcao (850900oC)

bnnhitcaxt cxc nhbngcch so snh chshottrcv sau khi xl trong dng khng kh 850oC trong 2

gi.


13/43

MAT (micro activity test)


14/43

2. Xc tc FCC Tnh chtcbn chnlc:Khnngcaxt lm tngtccaphnngc

li,ngthigimtccaphnngkhng mong mun.

T lgiahiusutxng v cc (hay kh) nhgi chnlc.

Ngoi tnh chtaxit bmttocho zeolit l mtxc tc axitphbin, zeolit cn c mtctnh rtqu v n l mt loivtliumao qun, n c tnh chnlchnh dngivicc chtkhc nhau:

1. Chnlchnh dng do kich thcchtphnng

2. Chnlchnh dng do kich thcsnphm

3. Chnlchnh dng do kich thccht trung gian


15/43

2. Xc tc FCC Nguyn nhnsuy gim hot tnh xc tcNguyn nhn suy gim hot tnh xc tc: c th chia lm hai

loi

1. Nguyn nhn vt l:bao gm s t hp cc tm xc tc, s bttc cc mao qun, tn tht gim b mt ring .

2. Nguyn nhn ho hc:thng sy ra phc tp hn nhiu

+ Ng c thun nghch: do s hp ph cnh tranh cc tp chttrong nguyn liu

+ Ng c khng thun nghch: bi cc tap cht kim loai trongnguyn liu

+ T ng c:s suy gim hot tnh do cc phn ng khngmong mun. y l nguyn nhn chnh ca s suy gim hot tnhca xc tc cracking => l do pht trin cc dng thit k khc nhau

v reactor v thit b hon nguyn cht xc tc cracking


16/43

2. Xc tc FCC Nguyn nhnsuy gim hot tnh xc tc Hin tng ng c xc tc crackingxy ra do s che ph mt lp

vt liu cacbon ho trn b mt v bn trong cac mao qun cht xctc.

Tnh cht ca cc lun bin i v ph thuc vo bn cht xc tc,ngun nguyn liu, iu kin phn ng. Ngi ta c th phn bit s tocc theo cc c ch sau

1. Cc do cn:c to thnh do dehydro ho cc phn cn khng bayhi ca nguyn liu

2. Cc do tp cht kim loi:do tp cht kim loi trong nguyn liu

3. Cc xc tc:c hnh thnh do cc qu trnh xc tc to ra snphm v mt l do no ma phi nm li trn b mt xc tc

4. Cc do nguyn liu:mt s nguyn liu khng kp cracking ng litrong cc mao qun cht xc tc


17/43


18/43

2. Xc tc FCC Ti sinhxc tc

C + O2 CO2

C + 1/2O2CO

CO + 1/2O2CO2

H2+ 1/2O2H2OS + O2SO2SO2+ 1/2O2SO3MeO + SO3MeSO4

MeSO4+ 4H2MeO + H2S + 3H2O

ti sinh xc tc, ngi ta tin hnh t cc bng khng kh nngtrong l ti sinh

+ Lng cc to ra trong qu trnh FCC:1,31,8% kh.l xt+ Lng cc sau khi ti sinh 0,10,05% kh.l xt

Phn ng to nhit => cung cp nhit cho

l phn ng v tn dng sn xut hi nc


19/43

2. Xc tc ZEOLIT Zeolit: l hp cht ca alumino-silic, l cht tinh th

c cu trc c bit. Cu trc ca chng c ctrng bng mng cc l rng, rnh, rt nh thng vinhau.

OHySiOxOAlOn

M2232

...2

Thnh phn ha hc

n l ho tr ca cation kim loi M


20/43

2. Xc tc ZEOLIT

Zeolit Thnh phn ha hcng knh l

trung bnh, A

A Na2O.Al2O3.2SiO2.4,5H2O 3,63,9

X Na2O.Al2O3.2,5SiO2.6H2O 7,4

Y Na2O.Al2O3.4,8SiO2.8,9H2O 7,4

Mordenit Na8.(Al2O3)8.(SiO2)40.24H2O6,77,0

(2,95,7)

ZSM 5 v 11 Nan.Aln.SiO96-n.16H2O 5,45,6


21/43

2. Xc tc ZEOLITCu trc xc tc Zeolit c bn gi l n v cutrc sodalit


22/43


23/43

2. Xc tc ZEOLIT Tnh cht Sphn loitheo quy ccaZEOLIT X va ZEOLIT Y

bnvnhitv bn thunhitcaZeolit Y cao hn so viZeolit X

Vd: NaAbnnhitn650oC,NaY - 700750oCCaY - 800oC

Chnh v th m trong ch to xc tc FCC hin nay ngi takhng s dng Zeolit X v Zeolit Y c t l Si/Al thp. CcZeolit Y c tlSi/Al cao (>2,5) ccbitquan tm khi ch

toxc tc FCC (ZSM-5, ZSM-11)


24/43

2. Xc tc

Cchhnh thnh tm hotng: Cc trung tm hotngtrnb

mtchtxc tc l cc tm axit Bronsted v Lewis

+ Tm axit Bronsted:c khnngcho proton

+ Tm axit Lewis: c khnngnhncpelectron


25/43

3. Cchphn ng3.1 Cc giai on phn ng trn b mt XT

Bc1.Hpphcc ion Hydride trn cc tm Lewis:


26/43


Bc 2. Phn ng gia cc proton t Bronsted vi cc olefin:


27/43


Bc3.Phnnggiacc ion cacboni sinh ra tbc1v 2 vicc hydrocacbon bngcch tora cc ion hydride

khng bnsbphn hythnh


28/43

3. Cchphn ng3.2 C ch phn ng: ion cacboni

- Giai an1: toion cacboni:

V d: trong trng hp i vi cc hydrocacbon mchthng(Alkan):


29/43


- Giai an 2: Cc phn ng ca ion cacboni to cc snphm:

Phnngngphn ha:


30/43


- Giai an2: Cc phnngca ion cacboni to cc sn

phm: Phnngctmchtheo quy tc (ctmchvtr so viccbon mang intch)


31/43


- Giai an 3: giai on dng phn ng

Khi cc ion cacboni kt hp vi nhau,nhng hay nhn nguyn t hydro ca xc

tc to thnh phn t trung ha v chngchnh l cu t ca sn phm cracking xctc.


32/43

4. Ha hc qu trnh crackingXT4.1 Phn ng mong mun

Phn ng ct mch (cracking ): xy ra theo c ch ion cacboni.

Hottnh cracking cacc hydrocacbon gimdntheo thtsau:Olefin Ankyl Aromatic Ankyl naphten, isoparafinn-parafin,

naphtennhn thm.


33/43


34/43

4. Ha hc qu trnh crackingXT4.2 Phn ng khng mong mun

Phn ng chuyn v hydro:


35/43


Phn ng ngng t:


36/43


- Phn ng to hydro: do phn ng dehydro ho, xy ra khi c mtca Ni lm cht xc tc.

- Phn ng to C1 C2: sinh ra do phn ng cracking nhit


37/43

Hydrocacbon Sn phm qu trnh cracking xc tcParafin -Olefin v parafin

-Olefin v hydro

-iso-parafin

-Cc hp cht olefin c trng lng phn t thp

Olefin -Parafin v dien

-Parafin, naphten v hydrocacbon thm-Polyme, cc

Naphten -Olefin

-Cyclohexan v olefin

-Hydrocacbon thm

Hydrocacbon thm(alkyl thm)

-Parafin v alkyl c mch bn ngn-ng phn ha, chuyn v nhm alkyl

-Sn phm ngng t v cc.Phn ng bc 2:Naphten+ Olefin

-Hydrocacbon thm-Parafin

Hydrocacbon thm +Olefin -Sn phm ngng t v cc


38/43

5. Nguyn liu v sn phm

5.1 Nguyn liu

Phn on chng ct kh quyn ca du th, khang si: 380-4100C

Phn an ct chng ct chn khng ca du th, khang si:

380-5500C

Phn ct t qu trnh Coking ca du th

DAO (cn chn khng deasphaltene) (5500C)

Cn chng ct kh quyn ( > 3800C) ca vi lai du th


39/43


40/43

a. Kh hydrocacbon

Hiu sut kh c th t 10-25% ngliu

Etylen v Propylen

PE v PP. Propan-propennguyn liu cho qu trnh

polyme ha v sn sut cht HBM, LPG.

Propan-propen, butan-butennguyn liucho qu trnh alkyl ha


41/43

b. Phn on xng

nhit 40-200oC

c tr s octan cao hn c thm thnh phn hydrocacbon olefin


42/43

c. Phn an 200-280oC

phn an 200-350oC

dng lm du ha sn xut nhin liu diezen


43/43

d. Cc phn an > 350oC

nhin liu t l F.O

nguyn liu cho qu trnh cc ha

day 6. catalytic cracking (basic catalytic in fcc)

Documents