che bien dau

8/2/2019 Che Bien Dau

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1

MC LC

mc Trang

MC LC ................................................................................................................................... 1

GII THIU V MUN ............................................................................................................ 3CC HNH THC HC TP CHNH TRONG MUN .............................................................. 4YU CU NH GI HON THNH MUN ........................................................................... 5BI 1. VAI TR CA QU TRNH CRACKING XC TC.......................................................... 6M bi: HD E1 ............................................................................................................................ 61.1. Nhu cu v s lng v cht lng ca xng nhin liu ..................................................... 61.1.1. Nhu cu tng s lng ..................................................................................................... 61.1.2. Yu cu tng cht lng v cc cng ngh sn xut xng ............................................... 81.2.Cc phn on nng t du th, S cn thit phi c qu trnh Cracking ............................ 91.2.1. Cc phn on nng t du th........................................................................................ 9

1.2.2.S cn thit phi c qu trnh Cracking ........................................................................... 101.2.3. Sn xut xng t v xng my bay ............................................................................... 111.3. Cu hi .............................................................................................................................. 12BI 2. BN CHT HA HC CA CRACKING XC TC ....................................................... 13M bi:HD E2 ........................................................................................................................... 132.1. C s ha hc ca Cracking ............................................................................................. 132.2. C ch phn ng cracking ................................................................................................. 132.3. Cracking hydrocacbon parafin, naphten, aromat ................................................................ 152.4. Cc phn ng ph km theo phn ng cracking xc tc ................................................... 172.5. Vai tr ca phn ng cracking xc tc ............................................................................... 182.6. Cu hi .............................................................................................................................. 18

BI 3. LCH S PHT TRIN CA XC TC ZEOLIT ............................................................ 19M bi: HD E3 .......................................................................................................................... 193.1. Lch s pht trin xc tc ................................................................................................... 193.2. Xc tc zeolit v xc tc cha zeolit .................................................................................. 203.3. Phng php iu ch xc tc zeolit ................................................................................. 223.4. Xc nh cc c trng ca xc tc zeolit .......................................................................... 223.5. Phn thc hnh ................................................................................................................. 233.6. Cu hi .............................................................................................................................. 23BI 4. NGUYN LIU V SN PHM THU ............................................................................. 25M bi: HD E4 .......................................................................................................................... 25

4.1. Cc ngun nguyn liu v tnh cht ca mi loi ............................................................... 254.2. Cc loi sn phm thu c t qu trnh cracking xc tc ................................................ 264.3. c im cc sn phm kh v lng thu c t qu trnh cracking xc tc ...................... 274.3.1. Kh hydroccbon ............................................................................................................. 274.3.2. Phn on xng.............................................................................................................. 284.3.3. Cc phn on 200350oC ............................................................................................. 284.4. Phn thc hnh ................................................................................................................. 284.5. Cu hi .............................................................................................................................. 29


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BI 5. CC LOI CNG NGH CRACKING XC TC ........................................................... 30M bi: HD E5 .......................................................................................................................... 305.1. Cracking vi lp xc tc c nh ........................................................................................ 305.2. Cracking vi lp xc tc tng si ....................................................................................... 305.3. Cng ngh FCC ngy nay.................................................................................................. 32

5.3.1. Qu trnh ca hng UOP................................................................................................. 335.3.2. Qu trnh ca Kellog ....................................................................................................... 345.3.3. Qu trnh ca hng SHELL ............................................................................................. 355.3.4. Qu trnh IFP Total v Stone & Webster ...................................................................... 365.3.5. Qu trnh Exxon .............................................................................................................. 375.4. So snh cc loi cng ngh ............................................................................................... 385.5. Cu hi .............................................................................................................................. 40BI 6. VN HNH CNG NGH CRACKING .......................................................................... 41M bi: HD E6 .......................................................................................................................... 416.1. c im ca s cng ngh FCC ................................................................................. 416.1.1. chuyn ha................................................................................................................ 416.1.2. Tc np liu ............................................................................................................... 426.1.3. T l xc tc/Nguyn liu ................................................................................................ 426.1.4. Nhit .......................................................................................................................... 426.1.5. p sut ........................................................................................................................... 426.2. Ti sinh xc tc cracking .................................................................................................... 426.3. Vn hnh s cng ngh cracking .................................................................................. 436.3.1. L phn ng ................................................................................................................... 436.3.2. L ti sinh ....................................................................................................................... 446.3.3. B phn phn on sn phm ........................................................................................ 446.4. Phn thc hnh ................................................................................................................. 44

6.5. Cu hi .............................................................................................................................. 44BI 7. C IM CA XNG CRACKING XC TC .............................................................. 46M bi: HD E7 .......................................................................................................................... 467.1. c im v thnh phn ha hc....................................................................................... 467.2. c im v tr s c tan.................................................................................................... 467.3. ng dng ca xng cracking xc tc ................................................................................. 477.4. Phn thc hnh ................................................................................................................. 477.5. Cu hi .............................................................................................................................. 48TM TT NI DUNG MODUN ................................................................................................. 49Mc ch ca qu trnh cracking xc tc ................................................................................... 49Cc phn ng ha hc sy ra trong qu trnh cracking xc tc ................................................. 49Cc sn phm ca qu trnh cracking xc tc........................................................................... 49C ch ca qu trnh cracking xc tc ...................................................................................... 49Cht xc tc ca qu trnh cracking .......................................................................................... 49

c trng quan trng ca cht xc tc ..................................................................................... 50Quy trnh vn hnh ca thit b cracking xc tc cng nghip ................................................... 50KIM TRA, NH GI HON THNH MN HC ................................................................... 50CC THUT NG CHUYN MN ........................................................................................... 52


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3

GII THIU V MUN

V tr, ngha, vai tr mun

Cracking xc tc l mt qu trnh cng ngh c bit quan trng trong cng

nghip ch bin du m. Thc hin cng ngh cracking nhm tng t l khilng cc sn phmnh nh, xng t, du ha, nhin liu Diezen...c bit l

cho xng t t cht lngthng phm. Cng qua qu trnh crc kinh xc tc

cn cho ta nhng lfin nh lm nguyn liu c bn cho ha du nh Etylen,

Propylen.

Mc tiu ca mun

Hc mn ny hc sinh cn phi:

1. Hiu bit v nm vng bn cht ha hc v vai tr xc tc trong qu trnh

cracking

2. iu ch c xc tc zeolit v xc tc cha zeolit.

3. Thc hin phn ng cracking xc tc trong PTN

4. Xc nh cc ch tiu ca xng cracking xc tc thu c.

Mc tiu thc hin ca mun

Hc xong mun ny hc vin c kh nng:

1. M t c bn cht ha hc v xc tc ca cracking xc tc.

2. iu ch c xc tc cracking: Xc tc zeolit.

3. Xc nh cc c trng ca xc tc iu ch

4. Thc hin phn ng cracking xc tc trn s PTN

5. Xc nh c ch tiu ca sn phm xng cracking xc tc

6. Thc hin cc th nghimlm trong PTN chuyn ha du.

Ni dung chnh/cc bi ca mun

1. Vai tr ca qu trnh cracking xc tc trong lc ha du.

2. Bn cht ha hc ca cracking xc tc.

3. Lch s pht trin xc tc.4. Xc tc zeolit

5. Nguyn liu v sn phm thu

6. Cc loicng ngh cracking xc tc

7. Vn hnh s cng ngh cracking

8. c im ca xng cracking xc tc.


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CC HNH THC HC TP CHNH TRONG MUN

1. Hc trn lp vcc ni dung chnh ca mun

2. Thm quan phng cng ngh lc ha du v phng nghin cu xc tc ti

Trung tm Nghin cu & Pht trin Ch bin du kh(tm hiu s cracking hi nc, xem thit b nh gi xc tc cracking MAT)

3. Thm quan h thng chng ct du m, xem mu du m, cc phn on

chng ct c tdum vtm hiu nguyn liu cho qu trnh cracking

xc tc, cc thit b phn tch cht lng cc sn phm (Xng t)

4. Thc hnh cng ngh cracking (s trong phng th nghim)

5. Thc hnh phn tch cc ch tiu cht lng ca xng (ch tiu ha l) .

Thc hnh phn tch thnh phn hydrocacbon trong sn phm cracking

bng phng php xc k.6. Nghe chuyn gia nghnh du kh ni v cng ngh cracking xc tc cn

du (RFCC) ca nh my lc du Dung qutQung ngi.


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YU CU NH GI HON THNH MUN

V kin thc

- Hiu bit v nm vng bn cht ha hc v vai tr xc tc trong qu

trnh cracking trong cng nghip ch bin du m.

- Vai tr, v tr ca cracking xc tc trong cng nghip ch bin du m

- Sn phm ca qu trnh cracking xc tc.

V k nng

- Bit phn tch mt s ch tiu cht lng sn phm xng trong phng

th nghim

- Nm c cch thc hin quy trnh cracking xc tc quy m thit b

phng th nghim.- Bit xc nh mt s c trnng ca xc tc zeolit

V thi

- Hc trn lp nghim tc

- Chun b chu o cho cc hat ng tham quan, nghe ngai kha

- Lin h, chun b chu o chocc bui thc hnh th nghim (vt t,

ha phm, cc iu kin hat ng ca thitb phn tch)

- Nhc nh thc an ton lao ng trong phng th nghim, vn

phng nga v chng chy,n trong PTN.Phng php nh gi mdun

TT Phng php nh gi S ln nh gi Trng s(%)

1 Kim tra gia k 2 20

2 Thc hnh th nghim 2 30

3 Thi cui k 1 50


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BI 1. VAI TR CA QU TRNH CRACKING XC TC

M bi: HD E1

Giithiu

Yu cu v s lng v cht lng cc sn phm nh, nguyn liu cho

cc ngnh cng nghip ho hc l rt ln, nu ch chng ct trc tip t du

th th khng th p ng nhu cu. Do cracking xc tc ng vai tr quan

trng chuyn ho cc phn nng ca du thnh cc sn phm nh v to

nguyn liu cho ho du.

Mc tiu thc hin

Hc song bi ny hc sinh c kh nng:

- M t nhu cu v s lng v cht lng ca xng nhin liu- M t qu trnh sn xut xng.

Ni dung

1.1. Nhu cu v s lng vcht lng ca xng nhin liu

1.1.1. Nhu cu tng s lng

Nhin liu sn xut t du m gm c:

- Nhin liu kh (FG)

- Xng t, xng my bay

- Nhin liu phn lc vdu ha dn dng (Jet/Kero)- Nhin liu Diezen (DO)

- Nhin liu cho cc l t cg nghip (FO)

Nhin liu cho giao thng vn ti c 2 loi chnh l xng t v nhin liu

iezen. S pht trin khng ngng ca nn kinh t th gii, nhin liu s

dng cho giao thng vn ti cng tng lin tc do yu cu v s lng

xng nhin liu cng tng ln dn n tng nhu cu du m. Trong bng.1.1.

cho thy nhu cu du m th gii t 19702020.

Bng 1.1. Tiu th du th gii 19902020 (International Energy Outlook)

Khu

vc

Nm D boTng TB

nm,%

1990 1995 1996 2000 2005 2010 215 2020

Cc nc cng nghip pht trin

Bc M 1050,6 1094,3 1128,3 1216,2 1305,9 1419,5 1491,5 1551,7 1,4

Ty u 664,4 724,4 733,4 733,8 744,8 766,3 781,8 739,7 0,3

Chu 319,3 359,7 364,1 395,1 413,2 442,3 473,2 505,2 1,4

Tng 2034,2 2178,2 2225,8 2340,0 2489,3 2628,1 2741,3 2850,8 1,1ng u v Lin x (c)


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Khu

vc

Nm D boTng TB

nm,%

1990 1995 1996 2000 2005 2010 215 2020

515,0 303,1 292,3 302,8 341,8 401,2 462,9 520,7 2,2

Cc ncang phttrinChu 391,4 580,5 610,3 682,5 851,9 1023,5 1224,1 1474,4 3,8

Tr.

ng175,1 210,6 215,4 225,8 255,1 288,0 324,0 366,0 2,2

Chu

Phi108,2 118,2 123,1 159,1 188,7 210,9 236,6 262,9 3,2

Trung

NamM175,1 200,4 205,1 266,8 316,3 175,4 437,2 505,2 3,8

Tng 849,8 1109,7 1153,9 1334,2 1611,9 1897,8 2221,8 2806,5 3,5

Tngth gii

3399 3591 3672 3977 4443 4927 4526 5980 2,1

C cu nhin liu c sn xut t du mc th hin ttrong bng 1.2.

Bng 1.2. C cu sn phm nhin liu t du mc s dng Vit Nam

(19901998)

STT Loisn phmt l

% khi lng

Nhin liu

1 Nhin liu kh (F.G),LPG 8102 Xng t, xng my bay 2225

3Nhin liu phn lc vdu ha dn dng

(Jet/Kero)1115

4 Nhin liu Diezen (D.O) 4045

5 Nhin liu cho cc l t cg nghip(F.O) 1520

Phi nhin liu

6 Du nhn 23Bng 1.3. Tnh hnh tiu thsn phm du Vit Nam (19901998)

Tiu th sn

phm du,tn1990 1995 1996 1997 1998

LPG 1.000 55.000 76.000 249.000 177.000

Xng 700.800 1.378.100 1.310.000 1.376.000 1.564.000

Du ha 229.000 260.000 324.000 269.000 300.000

Nhin liu Phn

lc 120.000 229.000 237.000 391.000 300.000


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Nhin liu iezen 1.353.000 2.724.000 3.103.000 3.347.000 3.642.000

Nhin liu t l 568.000 891.000 1.072.000 961.000 1.321.000

Du nhn 65.210 122.000 142.000 155.000 167.000

Nha ng 36.000 104.000 163.000 142.000 155.000

Tng cc sn

phm du3.072.000 5.763.000 6.427.000 6.890.000 7.626..000

Ngun: Statistic General Department, B Thng Mi,Tng cc Hi quan,

Kinh t Vit nam v Th gii(9899)

Vi nhng s liu c th nu trong bng 1.2, v 1.3.cho thy s gia tng

nhu cu v s lng cc sn phm du ni chung v xng t ni ring .

Vit nam nm 1990 mi ch s dng c 700.000 tn xng nhng n nm

1998 tiu th ti 1.564.000 tn.1.1.2.Yu cu tng cht lng v cc cng nghsn xut xng

Do s tin b ca cng nghip ch to t, tng cng sut ng c

ngi ta ch to cc ng c c t s nn ngy cng cao, cc loi xe i

c trc (1980) xe thng c t s nn t 78.Nhng ngy nay cc xe i

mi c sn xut c t s nn 910.Do s tng cht lng cc loi xe t

nn cng i hi cht lng xng nhin liu phi thay i cho ph hp.Nhng

loixe i c c t s nn thp ch cn s dng loixng c trs ctan RON

8385. Cc loixe i mi yu cu xng c trs ctan RON 90, RON 92,RON 95 v RON 98.

Xng chng ct trc tip t du m t v khi lng li cn km v

cht lng. Nhiu gii php cng ngh ra i nhm lm tng tr s cctan

RON nh cng ngh crackking, reforming, isome ha, alkyl ha.Ngoi ra cn

tm cc loiph gia cho thm vo xng tng tr s ctan nh Tetra Etyl Ch,

MtylTerbutylEter(MTBE), vv..

Mt s qu trnh cng ngh nng cao c tr s c tan nhng cc

cht lm tng trs ctan nh cc hp cht thmc bit l Benzen rt c hi

cho sc khe con ngi.

Tiu chun cho php hm lng Benzen trong xng trc cho php ti

5% th tch, nhng nay yu cu phi < 1% th tch. Cc loi ph gia cho

vo xng tng trs ctan nh Tetra Etyl Ch, MBTE th hin nay cng

cm s dng nh xng ch, v MBTE cng ch s dng mt cch gii hn.

Cc cht gy nhim khng kh nh lu hynh cng yu cu phi gim

nhiu ch cho php lu hynh trong xng < 10 phn triu.


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9

Nh vy cng ngh ch bin du m phi khng ngng pht trin gia

tng tha mn yu cu c vs lng v cht lng i vi xng nhin liu

p ng yu cu ca k thut i vi ng c v yu cu kht khe bo v

mi trng.

1.2.Cc phn on nng t du th, S cn thit phi c qu trnh

Cracking

1.2.1. Cc phn onnng t du th

Cc phn onnngc nhit si trn 360oC c trong phn cn cn li

ca chng ct kh quyn thng chim t l cao, trung bnh t 3070% ty

theo tng loidu nh, du nng khc nhau. Xem bng 1.4.

- Trong bng 1.4.cho thy 02 loidu:

- Du nh c t trng 35o

API, du nng 25o

API v thnh phn t nhinca du cho sn phm tng ng l kh, xng, cc phn on trung

bnh (diezen) v cc phn onnng. Tng ng c cu nhu cu sn

phm thc t yu cu th trng

Ta thy loi du nh c ti 68% cho xng v cc phn ct trung bnh

(diezen), ch c ~30% thuc phn onnng.Trong khi loidu nng th ch c

29% cho xng v cc phn ct trung bnh (diezen) v ti 70% thuc cc phn

ondu nng.

Bng 1.4.Thnh phn t nhin chng ct trc tip t du m

Phn onsn phmDu nh

(35o API)

Du nng

(25oAPI)

Yu cu sn

phm ca th

trng

Nhin liu kh,% 02 01 510

Xng nhin liu,% 30 19 2530

Phn onchng ct trung

bnh(diezen),%38 10 40

Phn ondu nng,% 30 70 1520

Ngun: The fuels Quality Training Seminar on 2527 October 2003 Sydney,

Australia.

Bng1.5..Cc phn ont du th Bch Hv i hngca Vit nam

Phn onsn phm Du th Bch h Du thi

hng

Cc phn on Napta sn xut

xng nhin liu;


10/53

10

3570oC,%Khi lng

70140oC,%Khi lng

35190oC,%Khi lng

2,81

8,21

18,57

1,05

6,54

13,08

Cc phnon sn xut du ha v

nhin liu phn lc:

190230oC,%Khi lng

140260oC,%Khi lng

7,55

19,78

5,60

17,30

Cc phn on trung bnh sn xut

nhin liu diezen:

230360oC,%Khi lng 26,98 22,42

Cc phn onnng:

360540o

C,%Khi lng>540oC,%Khi lng

32,1516,35

31,7820,76

Ngun:International Symposium on Technology Transfer and Project

Implementation for Refining and Petrochemical Industries in Vitnam

1.2.2.S cn thit phi c qu trnh Cracking

- Nhu cu cc phn onnh v trung bnh sn xut xng, du ha,

nhin liu phn lc v iezen nhiu hn s lng hin c nu ch

chng ct trctip t du th.

- Do nhu cu v nguyn liu cho ha du nh etylen, propylen, benzen,toluen, xylen...

- Do yu cu cht lng xng phi c ch s c tan cao.

Nhng yu cu trn i hi phi c qu trnh cracking. Qu trnh cracking

bin i cc phn onnng thnh cc phn onnhgip ta tng hiu sut

v s lng cc sn phm nh, tng tr s ctan ca xng v to ngun

nguyn liu cho ha du.

T ban u, khi m ngi ta bit chng ct du m vi mc tiu l ly

du ha thp sng. Phn nh trong dum cha bit dng vo vic g.

Nhng khi c ng c t trong ra i, phn nh t du m c s dng

lm nhin liu v t loixng nhin liu c ra i. S lng, chng loi

cc ng c t trong lin tc tng khng ngng cho ti ngy nay. Cc loi

ng c t trong s dng xnglm nhin liu chim t lch yu l cc loi

xe t trong vn chuyn, c bit l cc loixe hi c nhn.T l xng cho

ng c my bay th lin tc gim v khi ng c phn lc ra i, do c nhiu

u im nn ngnh hng khng chuyn sang s dng mybay phn lcv dng phn ondu ha sn xut nhin liu phnlc.


11/53

11

Phn nh chng ct trc tip t du th thng ch c khong t

1520% khi lng. Nhng nhu cu v xng t chim t 2530%. Vi s

tng lin tc cc loixe s dng xng, mc d sn lng khai thc du th

cng tng ln nhanh chng nhng nu ch c cng ngh chng ct trc tip

du th th khng th p ng nhu cu v xng.

Cc phn onnh t du th c s dng sn xut xng, du ha,

nhin liu phn lc v nhin liu diezen. Cc phn on ny c nhit si

ti 350360oC. Trong cng nghip c thc hin chng ct iukin p

sut khquyn gi l(chng kh quyn).

Qu trnh cracking c thc hin i vi cc phn onnng cnhit

si trong khong 350540oC. Qu trnh cracking quyen thuc l crking xc

tac gisi FCC. Trng hp du th c t tp cht, loidu parafinc ch scc Conradson thp c th tin hnh cracking xc tc trc tip cn chng ct

kh quyn m khng cn qua chng ct chn khng c cc phn on

nng lm nguyn liu cho qu trnh cracking.

1.2.3. Sn xut xng t v xng my bay

Xng t v xng my bay u l nhin liu cho ng c t trong (c

bugi nh la). Ngoi t du lch, xng cn c dng cho cc xe ti, tu

thuyn. Xng my bay l loikhc vi xng t.Thnh phn v c tnh ca

hai loi ny c khc nhau. Loixng my bay tiu th ngy cng t v chuynsang dng loing c phn lc dng loinhin liu l du ha phn lc.

c trng th hin cht lng quan trng i vi xng cc loi l: bc hi,

ng cong chng ct tiuchun, tr s ctan v n nh ha hc.

bc hi c o p sut bo ha (phng php Reid), v ng

cong chng ct tiu chun(ASTM D86).Trs ctan th hin tnh chng kch

nca nhin liu i vi ng cc o bng loing c tiu chun l

my o tr s ctan. Thnh phn ca xng l hn hp cc loihydrocacbon t

C4n C10, C11 v c khongnhit t 40180oC.Xngc sn xut qua

pha trn t nhiucu t ca cc qu trnh cng ngh khc nhau nh:

- Phn on chng ct trc tip t du

- Qu trnh cracking nhit, cracking xc tc

- Qu trnh reforming xc tc,

- Qu trnh alkyl ha, Izome ha,

- Qu trnh hydrocracking

- Butan.


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Xng t c cc loi khc nhau ty theo loing c, cc quy nh theo

tiu chun ca tng quc gia, tng khu vc lin quan n cc vn an ton

cho sc khe, mi trng v iu kin a l catng khu vc.ng c my

bay hat ng trong iu kinkhc nghit hn so vi t do cht lng

xng my bay cn c s m bo nghim ngt.ng c my bay khi lm vic

c 2 qu trnh: Qu trnhh ct cnh s dng cng sut ti a, lng xng

trong hn hp ha kh cng tng ti a (hn hp giu). Trong khi bay ng c

c khi gim cng sut lng xng trong hn hp ha kh cng gim theo(hn

hp ngho).

Ch s ctan ca xng my bay bng hoc ln hn 100. Trng hp tr

s c tan trong hn hp giu cn gi l trs ctan phm . Ngi ta biu th

tr s ctan ca xng my bay bng phn s, trong t s l tr s ctan cnmu s l trs phm .

Xng my bay c khong nhit chng ct 30170oC, khng cha

butan nhtrong xng t v butan c bc hi cao, d to cc nt hi trong

ng dn nhin liu gy tc xng. Trong xng my bay thnh phn

hydrocacbon nParafin v lfin v Benzen (Benzen c nhit ng c l

6oC),cn c gii hn thp trong thnh phn. Nparafin c kh nng kt tinh,

lfin d to keo, benzen d ng c lm tc ng dn, v phin lc xng

khi my bay bay cao nhit xung rt thp.Tiu chun i vi xng mybay quy nh im kt tinh, ng c phi thp hn 60oC.

Nh vy xng t v xng my bay hin nay thc cht c sn xut

qua qu trnh pha trn cc cu t ca cc qu trnh cng ngh khc nhau theo

yu cu tiu chun c quy nh c th.

1.3. Cu hi

1. Nhng phn onchng ct c bn t du m sn xut cc loi nhin

liu l phn on no?, khongnnhit si ca cc phn on?

2. Cho bit t l cc loinhin liu c s dng trong thc t?, Xng cho

ng c t trong?, nhin liu cho ng c diezen?.

3. Tnh hnh tiu th nhin liu Vitnam hin nay th no?.

4. Ti sao trong cng ngh lc du phi tin hnh qu trnh cracking?

5. Xng t v xng my bay c g khc nhau?.


13/53

13

BI 2. BN CHT HA HC CA CRACKING XC TC

M bi:HD E2

Giithiu

Bit c vai tr ca qu trnh cracking xc tc, hc sinh phi bit r bn

cht ho hc ca qu trnh cracking.

Mc tiu thc hin

Hc bi ny hc sinh bit:

- M tc s ho hc ca qu trnh cracking

- M t c ch cracking i vi cc loi hydrocacbon.

Ni dung

2.1. C s ha hc ca CrackingQu trnh cracking xc tc c tin hnh iu kin:

- Nhit : 470550oC,

- p sut: 23MPa

- Tc khng gian th tch: t 1120m3/m3.h (ty theo dy chuyn

cng ngh.

Nhiu phn ng ha hcs sy ra trong qu trnh v cc phn ng ny

s quyt nh cht lng v hiu sut ca qu trnh, l:

- Phn ng phn hyct mch (b gy), phn ng cracking- Phn ngng phn ha,

- Phn ng chuyn v tr ca hydro, phn ng ngng t, polyme ha v

phn ng to cc.

Cc phn ng phn hy l phn ng thu nhit mnh, phn ng ng

phn ha, chuyn v hydro, polyme ha v phn ng ngng t l cc phn

ng ta nhit yu.

2.2. C ch phn ng cracking

C ch phn ng cracking xc tc l c ch ion cacboni.Cc tm hat

tnh l ion ccboni c to ra khi cc phn t hydrocacbon ca nguyn liu

tc dng vi tm axt ca xc tc.

- Tm axt xc tc c 2 loi: Loi Bronsted (H+) v Lewis (L).

- Tm Bronsted l khi tham gia phn ng c kh nng cho proton hat

ng (H+) cn tm Lewis th thiu electron nn c xu hng nhn

thm in t.

Phn ng cracking xc tc sy ra theo cc giai on sau:Giai on 1: to ion cacboni


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14

V d:trong trng hp i vi cc hydrocacbon mch thng (alkan):

CnH2n+2 + L(H+) +CnH 2n+1 + LH

Trng hpphn hy izopropylbenzen:

- Trn tm axt kiu xc tc Lewis:

C3H7C6H5 + L H:L + C3H6 + [C6H+

5]

[C6H5] + H:L C6H6 + L

- Trn tm axt kiu xc tc Bronsted:

C3H7C6H5 + HB [C3H+7] + C6H6 + B[C3H

+7] + B

C3H6 + HB

Giai on 2:.Cc phn ng ca ion cacboni to cc sn phm

Khi cc ion cacboni c tao ra s lp tc tham gia vo cc phn ng

bin i khc nh

- Phn ng ng phn ha

[RCH2CH2CH2+] [RCH2CH

+CH3]

Phn ng ct mch theo quy tc (ct mch v tr so vi ccbon

mang in tch)

CH3C+H2

2H CH3CH3 + H+

Cc ion tip tc tham gia cc phn ng ng phn ha, ct mch

tip,alkyl ha hay ngng t. Bin i cc ion cacboni tip din cho n khi c

cu trc bn vng nht.

bn ca cc ion cacboni c th xp xp theoth t:

ion ccboni bc 3 > ion ccboni bc 2 > ion ccboni bc 1


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15

bn ca cacboni s quyt nh mc tham gia cc phn ng tip

theo ca chng.Cht lng sn phm c quyt nh bi cc phn ng ca

cc ion cacboni, c bit l phn ng phn hy, ng phn ha v chuyn v

hydro.

Giai on 3: giai ondng 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 xc tc.

2.3. Cracking hydrocacbon parafin, naphten, aromat

Cracking hydrocacbon parafin

Parafin l thnh phn quan trong ca cc phn ongasoil. Nng lng

hat ha ca phn ng cracking parafin gim dn theo chiudi ca mchparafin tng. V vy khi cracking mch hydrocacbon parafin cng di th cng

d b gy.

S phn nhnh v s lng nhnh ca parafin l rt quan trng trong

qu trnh cracking, chng lin quan n s to thnh ion cacboni v do

quyt nh n tc to thnh sn phm.

V d trng hp chuyn ha parafin nC6 (nhecxan) khi cracking trn

xc tc aluminosilicat:

CCCCCC Chuyn ha 14%

Chuyn ha 25%

Chuyn ha 25%

Chuyn ha 32%

Chuyn ha 10%

Phn ng chnh to sn phm ph thuc vo s tng quan gia phn

ng cracking theo quy tc v phn ng chuyn hydro ca ion cacboni.


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Cracking hydrocacbon Naphten

Trong qu trnh cracking xc tc naphten chuyn ha thnh olefin C3 v

C4.Cc naphten c mch bn di hn thng b ct nhnh to thnh

cyclohexan v olefin. Vng naphten tip tc c th b kh hydro to thnh

hydrocacbon thm.R

R

+L

+H

R - C + - R

ion cacboni b ng phn v cracking to thnh izoparafin.(L l tm

axit Lewis v H l tm axit Bronsted).

Cracking cyclohexan:

Nh vy qua cracking c th thu c sn phm l vng nh hn hoc

vng i v cho nhiu sn phm lng hn.Do vy ngi ta cho rng naphten

l thnh phn u im nht i vi nguyn liu cracking xc tc.

Cracking hydrocacbon thm (aromat)

Do cc hp cht alkyl thm c vng thm rt bn nn khi cracking, qu

trnh s ct nhnh alkyl trc. Toluen c bn rt ln v khng th tch

nhm metyl hay etyl trong iu kin cracking.Mch alkyl cng di th cng d

b b gy v nu mch alkyl li c nhnh th tc ct nhnh cng ln.

V d khi cracking xc tc propylbenzen, phn ng nh sau:

C6H5CH2CH2CH3 C6H6 + CH3CH=CH2

- Phn ng ng phn ha i vi hydroccbon thm:

ParaXylen MetaXylen OrtoXylen

- Phn ng khp vng to ra hydrocacbon thm a vng v v cui

cng hydrocacbon thm a vng tham gia phn ng ngng t to cc.

Tm tt qu trnh cracking xc tc i vi hydrocacbon ring l nh sau:


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Hydrocacbon Sn phm qu trnh cracking xc tc

Parafin

- Olefin v parafin

- Olefin v hydro

- izoparafin

- Cc hp cht olefin c trng lng phn t

thp

Olefin

- Parafin v ien

- Parafin, naphten v hydrocacbon thm

- Polyme, cc

Naphten

- Olefin

- Xyclohexan 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

2.4. Cc phn ngph km theo phn ng cracking xc tc

- Vi nguyn liu l parafin ngoi phn ng chnh l ct mch cn kmtheo phn ng dehydho ha

V d:

C4H10tcxcCt

o, CH4 + C3H6

C4H10tcxcCt

o,

C2H6 + C2H4

C4H10tcxcCt

o,

C4H8 + H2

- Vi nguyn liu l olefin th ngoi phn ng cracking cn c phn ngtrng hp

2CH3CH2CH=CH2 CH3(CH2)5CH=CH2

- Phn ng ng phn ha

- Phn ng kt hp hydro to parafinRCH=CH2 2

H

RCH2CH3


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- Phn ng khp vng sau c th b kh H2 thnh cc Aren

CH2=CH-CH2-CH2-CH2-CH3 -3H2

CH2-CH2-CH2-CH3

CH2- CH2 -CH2 -CH3

toC, xuc tac

+ 5H2

- Ngoi ra cn sy ra phn ng ngng t v to cc

Trong qu trnh cracking xc tc, phn ng to cc cn tm gii php hn

ch v chng lm gim hat tnh ca cht xc tc.

Phn ng to kh (C1, C2) cng cn gii hn, v mc tiu chnh ca cracking

xc tc l sn xut xng t c ch s ctan cao.

2.5. Vai tr ca phn ng cracking xc tc

Phn ng cracking xc tc nhm tng khi lng xng c sn xut

nhm p ng nhu cu tiu th xng cho t du lch v vn ti ngy cng cao,

trong khi xng c th thu c trc tip t chng ct du ch chim t l thp,

khng p ng yu cu v khi lng v cht lng . Phn ng ccracking xc

tc cn to ra cc olefin (etylen, propylen) l nguyn liu c bn rt quan

trng cho cng nghip ha du.

2.6. Cu hi1. Cho bit c ch phn ng cracking?

2. Cc phn ng ha hc no sy ra trong qu trnh cracking? Vai tr ca

mi phn ng i vi qu trnh?

3. Cracking i vi mi nhm hydrocacbon? (parafin, naphten, aromat?)


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BI 3. LCH S PHT TRIN CA XC TC ZEOLIT

M bi: HD E3

Giithiu

Qu trnh xc tc cracking c p dng t lu v hin nay t

c nhng tin b rt quan trng c bit l cht xc tc. Chng ta c ng

cn phi bit nhng mc quan trng ca s pht trin khoa hc trong lnh vc

cracking xc tc.

Mc tiu

Truyn t hc sinh bit v lch s pht trin ca xc tc, nhng mc

quan trng ca s pht trin.

Bit xc nh c trng ca xc tc geolit.Ni dung

3.1. Lch s pht trin xc tc

Trong qu trnh cracking, tc dng xc tc ca cc halogen cua hp cht

vi kim loi nh nhm clorua, km clorua., cc khong st hc cc cht tng

hp tng t trong thnh phn c cha silic, nhm, oxy(alumino silicat).

Tc dng xc tc cu nhm clorua khi cracking phn onca du m, c

N.D.Zelinski pht hin nm 1918 trong khi nghin cu sn xut xng my bay

cho lc lng hng qun trong chin tranh v quc.Rt nhiu nghin cunhm gim bt lng nhm clorua nhng khng t kt qu tt.

Nm 1911, Ubbelhode v Voronin pht hin tc dngxc tc ca

khong st. Nhiu nghin cu tip theo c thc hin do Gurvici v

S.V.Lebedev theo hng lm gim s to cc trn b mt xc tc nhng

khng t kt qu mong mun.

Qu trnh cng ngh cracking c thc hin quy m cng nghip nm

1936 do k s ngi Php l Houdry v gii php loib lp cc trn xc tc

bng qu trnh ti sinh xc tc trong khongthi gian ngn(1015 pht). Qu

trnh Houdry c thc hin trn lp xc tc c nh. Nguyn tc ca qu

trnh cracking xc tc l loi xc tc aluminosilicat v ti sinh xc tc trong

khongthi gian ngnqua s t chy cc bao ph trn xc tc.

Nhiu cng trnh nghin cu trong nhng nm tip theo, tp trung vo

cu trc ca khong st, cu trc ca aluminosilicat tng hp v l bn cht

t nhin ca cc tm axit. S nghin cu ny khng nhng ch quan trng v

l thuyt m cn lin quan cht tr n c ch tc dng ca cht xc tc vvn hat ha cht xc tc.


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c trng axt ca khong st t nhin c V.I.Vernadski pht hin

t 1891. Tc dng xc tc tng t nh axt sunfuric, axit phosphoric v

nhm clorua c A.V.Frost v B.A.Cazanski chng minh. Ngy nay hu

ht nghin cu u tp trung gii thch v tc dng xc tc ca khong st,

aluminosilicat tng hp v c trng axit ca chng.

Thomas thy phn chtxc tc vi t l Al/Si thay i trong dung dch

nc, cn etylic hn hp etyl ortosilicat vi etyl hoc nhm izopropylat v

thy rng: hat tnh xc tc ti a khi t s A l/Si =1.Khi tng ngvi s

lin kt ti a Al O Si.Thomas a ra s gii thch mt cch tha mn

s tn ti cc tm axit trn mng tinh th nhng li khng ph hp vi nhiu

nghin cu sau , nht l i vi khong st t nhin nh st montmorilonit.

Chng c th biu th di dng: Al2.4SiO2. H2O+nH2O.Nh vy xc tc cracking c dng rn, xp, ban u l cc khong st t

nhin hay tng hp.

Xc tc cracking ban u l khong st thin nhin c tnh axit

(montmorillonit) sau c thay bng aluminosilicat c hat tnh v chn

lc cao hn. Cui thp nin ca th k 20 chuyn sang dng xc tc cha

zeolit. Zeolit l hp cht aluminosilic, l tinh th c cu trc c bit. Xc tc

cha zeolit c hat tnh cao, chn lc tt.

3.2. Xc tc zeolit v xc tc cha zeolitCc cht zeolit c cng ch to cng vi xc tc aluminosilicat hay vi

khong st thin nhin ri sau s l bng cc phng php c bit

thnh xc tc zeolit.

V thnh phn ha hc ca zeolt c biu din bng cng thc:

M2/nO.AL2O3xSiO2yH2O

y: x> 2 v nl ha tr ca cation kim loi M

Zeolit c to thnh t cc n v cu trc(hnh 1.1)

Hnh 1.1.n v cu trcc bn ca zeolit


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Hnh 1.2.Cu trc c bn ca Aluminosilicat

Khi cc n v cu trc c bn ni vi nhau theo cc mt 4 cnh ta cloizeolit A, nu ni vi nhau theo cc mt 6 cnh ta c loizeolit X hoc Y

c cu trc tng t.(Hnh 1.3)

Zeolit A Zeolit X, Y

Hnh 1.3. Cu trc ca zeolit A v X, Y

Ngy nay ngi ta ch c nhiu loizeolit c kch thcca s

khc nhau.

Khi ch to xc tc cracking lng Na cn gim ti mc cc tiu v khi nhit cao, c mt ca hi nc Na s lm gim hat tnh v chn lc

ca xc tc. Tnh cht hp ph ca zeolt xut hin sau khi chng c tch

m (bng cch sy kh 300350oC) v trong qu trnh tng hp cc l rng

ca tinh th b cht y cc phn t nc. Mng tinh th sau khi sy vn

c bo ton v c dung lng hp ph rt ln.

Qu trnh cracking xc tc thng dng loi zeolit X, Y c ch cc

nguyn ttrong t himhay dng trao i ionv c s l bng cc

phng php c bit kt hp vi cc hp phn lm tng bn c, bn


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nhit,hay iu chnh kch thc l xp. Zeolit c hat tnhcao nn ngi ta

thng dng n dng hn hp vi xc tc v nh hnh hay aluminosilicat

tinh th v c gi lxc tc cha zeolit.

3.3. Phng php iu ch xc tc zeolit

Trong cng nghip xc tc zeolit c ch to di hai dng chnh l

dng cu v dng bt.

Ngoi yu cu v hat tnh cao, xc tc cracking cn phi p ng cc

yu cu khc nh bn nht, bn c, khng gy n mn hay mi mn thit

b v m bo d khuch tn nguyn liu ti cc tm hat tnh v sn phm t

bmt ra bn ngoi. m bo s khuch tn ca xy ti b mt xc tc d

t chy cc khi ti sinh, v m bo gi thnh sn xut xc tc c th chp

nhn c.Xut pht t cc yucu trn m ngi ta phi chn cc hp phn thch

hp chto xc tc.

Trong zeolit c 2 loikch thc l xp: kch thc ca s v kch thc

l ln.Khi a chng trn vi aluminosilicat ta s iu chnh c cu trc l

ca chng trong gii hn thch hp. V d nh xc tc cha zeolit A c kch

thc l trong khong 45Ao

Xc tc zeolit loiX v Y c kch thc l 810Aoc dng cracking

nguyn liu c thnh phn phn on rng. Khi cc phn t ln canguyn liu c th d dng tib mt ca xc tc v cc phn t nh hn th

c th tip xc vi cc tm hat tnh b mt trong ca xc tc. Cn cc l

loicao phn t nn chng bm mt ngoi ca xc tc s thun li trong

qu trnh t chy khi ti sinh xc tc.

3.4. Xc nh cc c trng ca xc tc zeolit

3.4.1. hat tnh ca xc tc cracking

Cc phng php u da vo thit b tiu chun v nguyn liu mu

cng cc iu kin cng ngh ca phng th nghim, xc nh hiu sut

sn phm.(xng, phn ct, kh v cc).V mc ch chnh ca qu trnh

cracking l sn xut xng nn phng php dng hiu sut xng thu c

nh gi hat ng ca xc tcl n gin hn.Nh vy hat tnh ca

xc tc thng biu din qua ch s hat tnh, l hiu sut xng(%kl) khi

cracking nguyn liu mu trong iu kin phng th nghim.Hat tnh ca xc

tc ph thuc vo cc tnh cht l, ha ca xc tc, vo thnh phn ha hc

ca xc tc v cng ngh ca qu trnh.3.4.2. chn lc ca xc tc


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Kh nng lm tng tc cc phn ng c li v ng thi lm gim tc

cc phn ng khng mong i chnh l chn lc ca xc tc. Trong

qu trnh cracking xc tc, chn lc ca xc tc quyt nh n s to

thnh xngvi cc cu t c tr s octan cao. chn lc ca xc tc c

nh gi qua t l gia hiu sut xng v cc (hay kh) cng mc bin

i.

3.4.3. S thay i tnh cht ca xc tc khi s dng

Khi lm vic hat tnh v chn lc ca xc tc cracking b gim i

n khi ht tc dng (tr ha) do cc nguyn nhn:

- Nhit qu cao,

- Thi gian tip xc qu di,

- Nguyn liu xu.S tr ha ca xc tc qua 2 qu trnh l tr ha do cc cht lm ng c

xc tc v tc dng lm thay i tnh cht l, ha ca xc tc.

S tr ha do cc nguyn nhn trc tip l:

- Tc dng ca cc c t nh NH3, CO2, cc hp cht lu hynh c

bit l H2S khi nhit cao.

- S tch t cc kim loi nng di dng cc oxyt lm thay i chc

nng ca xc tc.

- S tc ng ca nhit cao v hi nc.Cc hp cht c kim, cc hp cht cha nit trong nguyn liu l cc

cht lm gi nhanh xc tc. Sc mt ca nit trong nguyn liu lm gim

hiu xut xng v cc sn phm trng.

Cc kim loinng lm ng c xc tc nhanh, lm gim hat tnh, gim

su cracking, gim hiu sut xng v tng nhanh qu trnh to cc. Trong

cc phn nng ca du m c nhiu lu hynh thng c nhiu nha,

asphalten th cng c nhiu kim loinng nh vanadi, niken.

3.5. Phn thc hnh

Hc sinh thc hin xc nh mt s c trng ca xc tc geolit ti phng

th nghim xc tc ca Trung tm nghin cu v pht trin ch bin du kh

(RDCPP), Thi gian thc hnh 08 gi, do cn b ca phng th nghim cung

cp quy trnh v hng dn th hnh.

3.6. Cu hi

1. im qua cc mc quan trng trong lch s pht trin ca xc tc

crackinng?2. Ngi ta iu ch xc tc nh th no?


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3. chn lc caxc tc l g?, lm th no nh gi c chn lc?

4. Cch xc nh hat tnh ca xc tc?

5. Xc tc b mt hat tnh do nguyn nhn no?.


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BI 4. NGUYN LIU V SN PHM THU

M bi: HD E4

Giithiu

Bi ny gii thiu v cc ngun nguyn liu cho qu trnh cracking xc

tc v nhng sn phm thu c t qu trnh.

Mc tiu

Phn l thuyt hc sinh phi bit c cc ngun nguyn liu v tnh cht

ca nguyn liu ca qu trnh cracking xc tc.

Phn thc hnh: Phn tch mt s ch tiu ca xng cracking nh: Thnh

phn ct phn on, psut hi bo ho, t trng...

Ni dungGing bi trn lp:

4.1. Cc ngun nguyn liu v tnh cht ca mi loi

Nguyn liu cho qu trnh cracking xc tc truyn thng c khongnhit

si t 300550oC v nhit si trung bnh l 400oC.

Cc phn onthng c t cc ngun:

- Cc phn ct chn khng (380550oC)

- Mt s phn ct t chng ct kh quyn.

- Cn chng ct kh quyn (>360oC) trong trng hp t kim loi, c chs ccConradson thp

- Cc phn ct t qu trnh cc ha

- Cc phn ct t qu trnh Visbrackinh

- Nhng phn cn chn khng kh asphalten(>550oC)

Qua cc cng trnh nghin cu ch ra:

- Nguyn liu l nhng phn ct nhs cho sn phmc hiu sut C3,

C4 tng cn H

2 v cc gim. Nhng phn on nh (200 360oC)

nhn c t chng ct trc tip l nguyn liu tt nht sn xut

xng t v xng my bay.

- Nguyn liu t cc phn on nng (cc gasoil) chn khng l ph

bin nht trong qu trnh cracking xc tc. Nhm ny cho sn phm l

xng v cc phn onsn phm trng, qua chng ct chn khng

lm gim nhng cu t v hp cht c hi cho qu trnh cracking.

Thc t l thnh phn nhng kim loi nng lm nhim c xc tc

nh vanadi, niken thng c trong cc hp cht c kim, trong thnhphn ca nha, asphalten l nhng phn t ln, c nhit si cao,


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khi chng ct chn khng nhng cht ny s li phn cn ca

chng ct chn khng, chnh v vy m cc phn ct c lm

sch, c loiv c gim cc cht gy nhim c xc tc. Cng

chnh cc hp cht nha, asphalten khng nhngcha cc kim loi

nng mchng cn l ngun chuyn thnh cc nhiu nht, lm gim

hat tnh ca xc tc.

Thnh phn ha hc ca nguyn liu nh hng rt ln n hiu sut

ca qu trnh. Vi nhm hydrocacbon parafin s cho hiu qu chuyn ha cao

nht.Nhm hydrocacbon thm cho hiu sut xng km hn v li tng mc

chuyn ha to cc. Nhng cht phi hydrocacbon l c hi cho qu trnh

cracking xc tc, chng gy ng c cho xc tc v cn chuyn vo sn phm

lm gim cht lng sn phm nh cc hp cht lu hynh.Trong thc t vi s tin b ca cng ngh, qu trnh cracking xc tc c

th sdng cn chng ct kh quyn lm nguyn liu trc tip cho qu trnh

m khng phi qua chng ct chn khng. Qu trnh ny gi l qu trnh

cracking xc tc cn (RFCC).Nhng loidu th parafin, t lu hynh thng

c t cc cht gy nhim c xc tc v ch s cc Conradson thp rt thun

li cho vic dng thng cn chng ct kh quyn lm nguyn liu cho qu

trnh RFCC.

tng ngun nguyn liu, ngay c cn chng ct chn khng cngc lm nguyn liu cho qu trnh cracking xc tc sau khi kh nha v

asphalten.

4.2. Cc loisn phm thu c t qu trnh cracking xc tc

Cht lng ca sn phm cracking xc tc thay i trong phm vi rt

rng phthuc vo rt nhiu yu t nh nguyn liu, loi xc tc v cc thng

s cng ngh ca qu trnh.Hn hp sn phm ca qu trnh cracking c

chuyn tip n thitb chng ct phn ra cc phn onsn phm:

- Sn phm kh,

- Cc phn onxng, du ha,

- Cc phn ongasoil nh vnng.

- Phn oncn dng lm nhin liu t l... Trong bng 4.1. th hin

hiu sut v cht lng ca sn phm cracking ph thuc vo tnh

cht ca nguyn liu:

Bng 4.1.nh hng ca nguyn liu i vi cht lng v s phn b sn

phm


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c trng

loinguyn liu

Parafin Naphten Aromat

C

nhiu

lu

hynh

C nhiu

Nit

Nguyn liu:

- Hng s c trng KUOP

- Giihn chng ct, oC

12,2

280540

11,9

250466

11,3

220462

12,0

245570

11,5

218471

Thnh phn nhm hydrocacbon:

- Parafin,% th tch

-Aromat+olefin,% th tch

- Naphten,% th tch

- S,% trng lng- N,% trng lng

60

14

26

0,17-

49

28

23

--

24

40

36

--

-

-

-

2,140,07

-

-

-

0,70,25

Hiu sut:

- H2S, % trng lng

- H2 , % trng lng

- CH4 , % trng lng

- C2H4 , % trng lng

- C2H6 , % trng lng

- C3H6 , % trng lng- C3H8, % trng lng

- i-C4H10 , % th tch

- n-C4H10 , % th tch

- C4H8 , % th tch

-

0,05

0,7

0,6

0,6

3,81,6

7,2

1,7

6,9

-

0,02

0,7

0,6

0,6

3,61,9

8,5

1,9

5,7

-

0,03

0,6

0,6

0,5

3,01,3

7,7

1,1

5,0

0,9

0,05

0,8

0,4

0,8

2,62,4

7,1

1,8

3,6

0,3

0,1

1,2

0,5

1,0

1,91,8

5,3

1,7

3,6

- Xng(C5+), %th tch

- Gasoil nh, %th tch

- Cc, %trng lng

- Tr s octan ca xng(RON)

39,3

45,0

3,1

93

36,7

45,0

4,3

94,5

41,4

45,0

3,8

97,2

39,3

45,0

6,5

89,8

38,7

45,0

8,0

97,0

4.3.c im cc sn phm kh v lng thu c t qu trnh cracking

xc tc

4.3.1. Kh hydroccbon

Hiu sut kh c th t 1025% nguyn liu ph thuc vo nguyn liu v

iu kin cracking.

Trong iu kin nhit cao, tc nguyn liu nh, bi s tun hon

xc tc ln th hiu sut sn phm kh s ln v ngc li th hiu sut kh

nh.Nguyn liu c hm lng lu hynh cao th sn phm kh c nhiu khH2S v khi nguyn liu c nhiu nit th sn phm kh cracking c nhiu NH3.


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28

Thnh phn kh cracking cn ph thuc bi loixc tc c s dng.(v d

nh trong bng 4.2).

Bng 4.2. Thnh phn kh cracking ph thuc bi loixc tc c s dng.

Cu t hydrocacbon Xc tc cha zeolit Xc tc cha aluminosilicat

H2S

H2

CH4

C2H4

C2H6

C3H6

C3H8

nC4H8iC4H8

nC4H10

iC4H10

4,9

0,1

1,6

2,7

1,8

23,1

7,9

16,65,7

6,4

28,1

3,6

3,1

8,0

6,9

2,8

25,6

5,7

16,010,1

3,0

15,2

Sn phm kh, kh kh c dng lm nhin liu kh, etylen v propylen

l nguyn liu cho sn xut nha polyetylen (PE) v polypropylen (PP),

Propanpropen lm nguyn liu cho qu trnh polyme ha v sn sut cc

cht hat ng b mt v lm nhin liu t (LPG).

Propanpropen, butanbuten cn lm nguyn liu cho qu trnh alkyl ha nhn cu t ctrs octan cao pha vo xng, vlm nguyn liu cho cc

qu trnh tng hp ha du.

4.3.2. Phn onxng

Phn onxng thng c nhit 40200oC, phn onny l cu t

c bn pha trn vi nhng cu t khc t cc qu trnh Reforming,

alkylha, v cc phn on naphta t qu trnh chng ct trc tip sn

xut cc loixng t, xng my bay.

Phn onxng t qu trnh cracking xc tc khc vi cc phn on c

cng khongnhit si t qu trnh chng ct trc tip l c tr s ctan cao

hn v cc bit l c thm thnh phn hydrocacbon olefin.

4.3.3. Cc phn on 200350oC

Phn on 200280oC dng lm du ha v phn on 200350oC c

dng pha trn v sn xut nhin liu diezen

Cc phn on > 350oC c dng lm nhin liu t l FO hay c

dng lm nguyn liu cho qu trnh cc ha.4.4. Phn thc hnh


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Phn thc hnh trong phng th nghim ca Trung tm nghin cu v

pht trin ch bin du kh (RDCPP), Thi gian thc hnh 08 gi, do cn b

ca phng th nghim cung cp quy trnh v hng dn thc hnh. S thc

hnh xc nh thnh phn chng ct theo tiu chun ASTM D86, xc nh t

trng v o p sut hi bo ho.

4.5. Cu hi

1. Cho bit cc ngun nguyn liu cho qu trnh cracking xc tc?.

2. Cc loisn phm chnh thu c t qu trnh cracking xc tc?

3. Tnh cht ca nguyn liu nh hng nh th no n hiu sut v cht

lng cc sn phm thu c t qu trnh cracking?


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30

BI 5. CC LOICNG NGH CRACKING XC TC

M bi: HD E5

Giithiu

Trong cng nghip lc du v angp dng nhiu cng ngh cracking

khc nhau theo bn quyn ca cc hng. Chng ta cn bit nhng nt c bn

khc nhau ca mi loai cng ngh ny.

Mc tiu

Khi hc song hc sinh phi:

- M t c bn cht ca cc loi cngg ngh cracking

- So snh u, nhc im ca cc loi cng ngh.

Ni dung5.1. Cracking vi lp xc tc c nh

Dy truyn cracking xc tc u tin do Houdry,mt k s ngi Php

thit k c a vo cng nghip ch bin dut nm 1936.Cng ngh ny

hat ng theo kiu gin onvi lp xc tc c nh. Nhc im ca cng

ngh ny l hat ng gin onv vy rt phc tp trong vn hnh. Hai chu

k l phn ng xc tc cho sn phm v chu k ti sinh xc tc trong cng

mt thit b. Dy truyn ny nhanh chng c ci tin v ch nm nm sau,

nm 1941 xut hin qu trnh cracking vi lp xc tc chuyn ng.5.2. Cracking vi lp xc tc tng si

Qu trnh cracking c lp xc tc chuyn ng thay th qu trnh

Houdry. Qu trnh phn ng xc tc v ti sinh xc tc c thc hin cc

thit b ring bit: thit b phn ng(l phn ng) v thit b ti sinh xc tc.(l

ti sinh). Xc tc lm vic c cha cc chy t l phn ng vo l ti sinh

v sau khi ti sinh li ngc v l phn ng (hoc bng t chy hoc bng

cng bc) to thnhmt chu trnh lin tc. Nm 1942 quy trnh cracking xc

tc gi si(FCC) u tin c a vo hat ng c tn l Up Flow (model

I) hnh 5.1

Nm 1944 ngi ta tng ng knh ca l phn ng v l ti sinh, tch

hi sn phm c thc hin ngay trong l phn ng v ti sinh xc tc

dng tng si v qu trnh thi cho xc tc chuyn ng t pha di v ly ra

ngoi y l. Dy truyn hat ng nh vy c tn l Dow Flow (Model II)

hnh 5.2. Ngi ta lin tc ci tin thit b v c hng dng ca xc tc.

Hnh dng xc tc ph bin l dng vin hnh cu nhm lm gim s mt mtxc tc v gim s mi mn thit b v nng cao hiu qu tch ca xyclon.


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Hnh 5.1. S FCC Model I

Model I, t l xc tc/nguyn liu ch t ti a l 3 nhng model II c th

tng ti a l 10. Hng M.B.Kellog thit k loicn bng p sut Model III

nm 1946, hnh 5.3.

Hnh 5.2. S FCC Model II

Hng StandardOil (New Jersey) thit k loi FCC mi (Model IV)

hnh 5.4. t ci tin ca Model II v a vo hat ng t 1952.


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32

Cng ngh FCC ngy cng c ci tin nhm t hiu sut v cht

lng xng cao hn, vi cht lng nguyn liu ngy cng xu hn.

Hnh 5.3. S FCC Model III

1.Kh, 2. Hi nc, 3. L ti sinh, 4.Kh, khi, 5.Nguyn liu, 6. L phn ng,

7. Ct chng ct phn on, 8.Xng v kh, 9.Hi lu nh, 10.Hi lu,

11. ct bay hi ph, 12.Gasoil nh, 13. Gasoil nng, 14.Cn

Hnh 5.4. S cng ngh FCC Model IV

5.3. Cng ngh FCC ngy nay

Qu trnh FCC ca mt shng cng nghip ni ting gm c:


33/53

33

5.3.1. Qu trnh ca hng UOP

Qua cc bc ci tin lin tc, hin nay cng ngh FCC ca UOP cng

p dngg cracking nhm chuyn ha cn du nng. Qu trnh ca UPOP

c cng ty Ashland OilCo pht trin. Chnh hng UOP thit k 2 loi

FCC:

- Loil ti sinh t chy hon ton 1 cp (hnh 5.5)

- Loiti sinh hai cp.(hnh 5.6)

Hnh 5.5. S RCC ti sinh 1 cp ca hng UOP


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34

Hnh 5.6. S RCC loi ti sinh 2 cp ca hng UOP

5.3.2. Qu trnh ca Kellog

S vn chuyn xc tc c thc hin theo phng thng ng rt

thun liv c th dng van chn iu khin qu trnh tun hon ca xc

tc. Qu trnh cracking c thc hin hon ton trong l phn ng dng ng

ng.(l ng ng). H thng xyclon c t ngay ca ra ca ng ng.

Trong l ti sinh xc tc v khng kh tip xc ngc chiu nhau. Kiu RFCC

c trnh by trong hnh 5.7.c im chnh ca model ny l vi phun

nguyn liu c ci tin nhm tng cng s tip xc gia xc tc v

nguyn liu, b phn lm ngui c thay i bng cch t t pha cthay cho pha lang trong l ti sinh trnh n mn, mi mn trang thit b do


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xc tc v nhm lm tng tc truyn nhit. Hnh dng b phn lm ngui

xc tc do Kellog thit k cng tng t ca UOP ch khc l cch b tr cc

ng trao i nhit t ngc chiu.

Hnh 5.7. S RFCC ca hng Kellog

5.3.3. Qu trnh ca hng SHELL

Shell c nhiu ng gp trong vic pht trin cracking xc tc phn cn

nng (RFCC). Qu trnh Shell LRFCC(Long Residue FCC) cracking xc tc

cn nng v rng, c b phn lm ngui xc tc trnh s t chy qu

nhit. Thit b trnh by trong hnh 5.8.


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36

Hnh 5.8. S RFCC ca hng Sheell5.3.4. Qu trnh IFP Total v Stone & Webster

Hai hng cng nghip ny hp tc tht k qu trnh RFCC vi ti sinh

xc tc 2 cp. Qu trnh nhm cracking xc tc cn nng v c tn lR.2.R

Process. Qu trnh cng c trang b b phn lm ngui xc tc, h thng kim

tra v iu khin nhit ca khi l phn ng.

c im ca cng ngh R.2.R l l ng, ti sinh 2 cp, c s ci tin

thit b phun nguyn liu trc tip vo dng xc tc mng. (hnh 5.9).


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37

Hnh 5.9. Qu trnh R.2.R ca IFP

5.3.5. Qu trnh Exxon

Hnh 5.10. Qu trnh RFCC ca hng Exxon


38/53

38

Exxon lin tc nghin cu ci tin cng ngh FCC,t khi a ra model IV

v n nay a ra loi model IIIR, cracking c c tnh linh hat.C th s

dng nguyn liu khc nhau t cc phn ct chn khng n cc loi cn

nng (hnh 5.10).

5.4. So snh cc loicng ngh

Trong nphn m t cng ngh chung nu c im chnh ca tng

loi. Qua m t ny ta c th so snh s ging nhau v cc c trng khc

nhau gia cc cng ngh. Mi loicng ngh c nhng u im v s hn

ch. Ty theo mc tiu ca nh u t, mc ch s dng nguyn liu g

c th quyt nh chn cng ngh no?

Thc t tnh ti nm 1994, nhng bn quyn cng ngh c cc

nh u t chn v c xy dng.(bng 5.1)*Bng 5.1.Bn quyn cng ngh c nh u t chn

Ngun: Idemisu Kosan.Co.LTD. 1994

Nh bn quynScng ngh c chn, trin

khai trong cc nh my trn th gii

UOP 7

KELLOG 6

STONE&WEBSTER 16

IFP/TOTAL 6SHELL 5

Sau y l c thnhng ni mua bn quyn cng ngh ca cc hng,

ni xy dngv thi gian a vo vn hnh.

Bng 5.2.Cc n v mua bn quyn cng ngh v a im xy d

Khch hng mua bn

quyn

Ni xy dngNm a vo

hotngICng ngh RFCC ca UOP

1.Ashland Oil

2.Statoil

3.Kyushu Oil

4.Pertamina

5.Undesclosed

6.Yukong

7.Kuyng In Energy

Catlettsburg,Kentuka, USA

Mongstat, Nauy

Ohita, Nht bn

Bologan, Indonesia

Chu u

Hn quc

Hn quc

1983

1989

1991

1994

thit k(1994)

1996

1996


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39

Khch hng mua bn

quynNi xy dng

Nm a vo

hotng

IICng ngh RFCC ca KELLOG

1.Phillip Petroleum

2.Phillip Petroleum

3.Valero Refining Co.

4.Chinese Petroleum Corp.

5.Misubishi Oil

6.Kyokuto Petroleum Ind.

Borger, Texas, USA

Sweeny, Texas, USA

Corpus Chiristi,Texas, USA

Ta lin Pu,i loan

Sen dai, Nht bn

Chiba, Nht bn

1961

1981

1983

1991

1992

1995

IIICng ngh RFCC ca S&W

1.Total Petroleum

2.Total Petroleum3.Petro Canada

4.Shel Canada

5.BPAustralia

6.SINOPEC

7.SINOPEC

8.SINOPEC

9.SINOPEC

10.SINOPEC11.Chevron USA.Inc.

12.Nipon Petrpoleum

13.Honam Oil

14.Pacific Refining

15.Singapore.Refining

16.Star Petroeum Refinery

Arkansas,Kansas,USA

Ardmore,Oklahoma, USAMontreal, Canada

Montreal, Canada

Kwinana,Australia

Wuhan. Trung Quc

Changling,Trung Quc

Guangzhou,Trung Quc

Zhenhai,Trung Quc

Nanjing,Trung QucPortAthur,Texas,USA

Negishi,Nht bn

Yeochum, Hn quc

Sanfrancisco,USA

Singapore

Thi lan

1881(nng cp)

19821985

1987

1987

1987(nng cp)

1989

1990

1990(nng cp)

19911991(nng cp)

1992

1994

1994

1996

1996

IVCng ngh R.2.R.ca IFP/TOTAL

1.Idemisu Kosan

2.Pertamina

3.Sang Yong Oil

4.Idemisu Cosan

5.Ancap

6.Ecopetrol

Aichi,Nht bn

Musi,Indonesia

Ulsan, Hn quc

Hokkaido, Nht bn

Montenvideo, Urugoay

Barrancebermeyja, Columbia

1987

1993

1993

1994

1994(nng cp)

1995(nng cp)

VCng ngh LRFCC ca Shell

1.Shell UK Stanlow, Anh quc 1989


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40

Khch hng mua bn

quynNi xy dng

Nm a vo

hotng

2.Shell Singapore

3.Shell Australia

4.Shell Oil

5.Showa Yokkaichi Sekiyu

Pulau Bukom, Singapore

Geelong, Australia

Norco, Lousiana

Yokkaichi, Nht bn

1990

1992

1992

1995

Bng 5.3.So snh cng ngh

Nh bn

quynIFP SW UOP KELLOG SHELL

Tn cng

ngh

R.2.R S&W

FCC

RCC Kellog&MobilFCC ShellLR

FCCPhun

nguyn liu

Vi p

sut

cao

Vi p

sut cao

Vi p

sut thp

Vi p sut thp Vi p sut

thp

Xyclon Bn

ngoi

Bn

ngoi

Bn trong Bn trong Bn trong

H thng

ti sinh

Hai cp Hai cp 1

cp/2cp

1 cp 1 cp

Lm ngui

xc tcKhng c c c c

Hat ng

ca h

thng

Xyclon

H

thng

m

H thng

m

H thng

ng

H thng ng h thng

m

5.5. Cu hi

1. M t, trnh by v nguyn l hat ng ca 1 loicng ngh cracking xctc gi si?

2. Cng ngh FCC ngy nay, nu nhng c im khc nhau ca cng ngh

FCC gia cc hng?


41/53

41

BI 6. VN HNH CNG NGH CRACKING

M bi: HD E6

Giithiu

Nm c nguyn lvn hnh s cng ngh cracking l vic phi bit

i vi hc sinh. Mi cng ngh khc nhau c nhng im ging v khc

nhau, hc sinh cng cn phi bit.

Mc tiu

- Hc sinh cn phi nm c c im ca s cngg ngh FCC.

- Bit c nhng vn quan trng trong ti sinh xc tc

- c thchnh thit b nh gi hot tnh xc tc trn thit b MAT.

Ni dung6.1.c im ca s cng ngh FCC

c im cng ngh FCC l qu trnh cracking xc tc lp si (gi si),

qu trnh thc hin trn dng xc tc chuyn ng lin tc trong l phn ng

cng nguyn liu v sang l ti sinh thc hin vic t cc cng vi oxy

khng kh trn xc tc tham gia phn ngri li sang l phn ng, c th

xc tc lin tc chuyn ng.

Cng ngh FCC hat ng vi nhng thng s quan trng sau::

- chuyn ha.- Tc np liu,

- T l xc tc/Nguyn liu

- Nhit

- p sut

6.1.1. chuyn ha

chuyn haC c tnh bng:

C = Tng hiu sut (kh +Xng +Cc)

C = 100 y(100z)

y: l% th tch ca sn phm cnhit si cui cao hn im si

cui ca xng

z: l% th tch xng c trong nguyn liu


42/53

42

6.1.2. Tc np liu

L t s gia lng nguyn liu c np trong mt n v thi gian trn

lng xc tc trong l phn ng.v c k hiu bng M/H/M

Khi tng tc np liu s lm gim chuyn ho v ngc li v tc np liu l i lng ngc vi thi gian phn ng. Khi s dng xc tc c

hat tnh cao ta c th tng tc np liu khi y s tng nng sut ca

thit b.

6.1.3. T l xc tc/Nguyn liu

T l xc tc zeolit/nguyn liu,cn gi l bi s tun hon xc tc

(X/RH). Vi loi xc tc zeolt th X/RH=10/1 cn xc tc v nh hnh

X/RH=20/1. Khi thay i t l X/RH s lm thay i thi gian lu ca xc tc

trong l phn ng v l ti sinh v thay i c lng cc bm trn xc tc.

ch n nh t l X/RH tng s lm tng chuyn ha v gim hm lng

cc bm trn xc tc,khi thi gian tip xc gia xc tc v nguyn liu

gim nhng hat tnh trung bnh ca xctc li tng ln.

6.1.4. Nhit

Nhit trong l phn ng khi vn hnh trong khong 470540oC. Khi

nhit tng ln th tc phn ng phn hy nhanh hn nhng cng thc

y cc phn bc 2 nh kh hydro tng ln dn n tng hiu suthydrocacbon thm v olefin. Khi C1C3trong kh tng, C4gim, t trng v

tr s octan ca xng tng ln.

Khi nhit cao hiu sut xng gim, hiu sut kh tng v cc khng

tng.

6.1.5. p sut

Khi p sut tng th hiu sut xng tng ln, hiu sut C1C3gim, hm

lng olefin v hydrocacbon thm gim dn ti tr s octan ca xng gim.

6.2. Ti sinh xc tc cracking


43/53

43

s dng xc tc c lu, trong cng ngh phi thc hin vic ti

sinh xc tc. Nguyn nhn chnh lm mt hat tnh ca xc tc l do cc

to thnh bm kn b mt hat tnh ca xc tc.

ti sinh xc tc ngi ta tin hnh t cc bng khng kh nng

trong l ti sinh.

Khi t cc s to thnh CO, CO2, cc phn ng kh cc hp cht lu

hynh.

C + O2 CO2

C + O2 CO

CO + O2 CO2

H2 + O2 H2O

S + O2

SO2SO2 + O2 SO3

MeO + SO3 MeSO4

MeSO4 + 4H2 MeO + H2S + 3H2O

Nhit lng ta ra c dng cp nhit cho xc tc mang vo l phn

ng.

6.3. Vn hnh s cng ngh cracking

Sau y trnh by s vn hnh ca mt dy truyn cng ngh FCC thng

dng (hnh 6.1)t cc b phn chnh:6.3.1. L phn ng

Nguyn liu mi t b cha (1), i qua cc thit b trao i nhit ng

chm, nguyn liu mi c th c trn vi phn tun hon (HCO)(2) v cn

y (3), sau cho qua l t nng nguyn liu cracking.Nguyn liu cracking

(5)c tip xc vi xc tc nng ti sinh (6 ) y ca l ng, lc ny

nguyn liu c bay hi, v hn hp vi hi nng cng xc tc i ln pha

trn ti nh ca ng ng, trong qu trnh i ln trong ng th hu ht cc

phn ng cracking xc tc sy ra, cn phn l pha trn lm nhim v tch

xc tc v hi hydroccbon.Mt b phn c thit k b tr gn van chn,

dng hi nc thi xc tc v du nhm hn ch ti a hin tng quay

tr li ca xc tc v hi kh lm vic. Hi sn phm nng (7) c chuyn

ti ct phn on. Xc tc lm vic (8) cho qua vng tch hi bng cch

thi hi nc.B phn lm sch khng nhng ch lm nhim v ui ht

hydrocacbon hp ph trn xc tc m cn lm ticc ht xc tc trc khi

sang l ti sinh.Vic thi hi nc c b iu chnh tc hi mt cch thchhp, kim tra cht ch thi gian lu ca xc tc trong b phn ra nhm trnh


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44

phi dng qu nhiu khng kh trong l ti sinh.p sut trong l phn n g

c bng b phn iu chnh p sut ca ct phn on.

6.3.2. L ti sinh

Xc tc lm vic b bm cc(8) c chuyn qua van iu khin v b

khng ch bi b kim tra mc xc tc trong l phn ng sau i vo l ti

sinh. Theo hung tip tuyn vi thnh l. Vic t cc trn xc tc trong l

ti sinh bng oxy khng kh to thnh CO v CO2 v xc tc c ti sinh.

Khng kh t sau khi nn uc cho vo l ti sinh qua li phn phi

trn khng kh v xc tc.S chy ca cc c thc hintrong lp si, mun

t iu ny tc cca khng kh phi ln hn 1m/s.Xc tc ti sinh

c chuyn vo ng ng sau khi i sch kh nh mt van t

ng ca l ti sinh ri sau xc tc c trn vi nguyn liu cracking vhon thnh mt chu trnh. Ngi ta tho xc tc bn gi ha ra, b sung

xc tc mi m bo hat tnh ca xc tc n nh trong thi gian

lm vic.Kh to thnh qua s chy cc cng cc ht xc tc b cun theo ln

nh l ti sinhsqua hai cp xyclon gi li cc ht x tc, Kh v khi

c qua bung lng tch tip bi xc tcri qua b phn tn dng nhit

(12), tip tc c lm sch bng lc in ri i ra ngoi theo ng khi.

6.3.3. B phn phn onsn phm

Hi sn phm (7) c np vo ct phn on chia thnh cc snphm khc nhaunh: xng v phn nh hn c di qua b phn ngng t

ri vo b phn tch kh.Sau khi tch kh nhn c phn on C1, C2 s

(16). Phn onny c dng lmkh nhin liu.

Phn on C3, C4 cha nhiu propylen v buten (17) c dng lm

nguyn liu cho qu trnh alkyl ha v tip l phn onxng kh butan

(18). T ct phn on chnh cn nhn c cc phn on Naphta nng

(19), LCO (20), HCO(21). Phn HCO c th cho tun hon li ng ng ca l

phn ng qua ng (22) v cui cng l du cn c lm sch (24).

6.4. Phn thc hnh

Phn thc hnh trong phng th nghim ca Trung tm nghin cu v

pht trin ch bin du kh (RDCPP), Thi gian thc hnh 08 gi, do cn b

ca phng th nghim cung cp quy trnh v hng dn thc hnh. S thc

hnh trn thit b nh gi hot tnh ca xc tc trn thit b MAT

6.5. Cu hi

1. Nhng thng s k thut quan trng ca qu trnh cng ngh cracking xctc khi vn hnh?nh hng ca tng thng s i vi qu trnh?


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2. Mc chuyn ha c tnh nh th no?

3. Ti sinh xc tc trong cng nghip nh th no? sn phm to thnh trong

qu trnh ti sinh?

4. M t, trnh by qutrnh vn hnh 1 s cng ngh FCC thng (hnh

6.1).


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BI 7.C IM CA XNG CRACKING XC TC

M bi: HD E7

Giithiu

Qu trnh cracking xc tc cho sn phm xng c cht lng khc nhau

tu theo loi nguyn liu v c im ca tng loi cng ngh vi cc bn

quyn khc nhau.

Mc tiu

Sau khi hc bi ny hcsinh phi:

- Giithiuc c im ca xng cracking

- Xc nh cthnh phn ca xng cracking.

Ni dung7.1. c im v thnh phn ha hc

Xng cracking xc tc l sn phm chnh ca qu trnh cracking xc tc.

Ty theo loinguyn liu s dng v cc ch khi thc hin cng ngh (xc

tc, nhit , p xut...) dn n thnh phn ha hc ca xng thu c cng

thay i.Hiu sut xng t qu trnh cracking xc tc thng khong 3035%

lng nguyn liu.

Thnh phn ha hc ca xng cracking:

- Hydrocacbon thm: 2540%- Olefin: 1530%

- Naphten: 210%

- Parafin: 3560%

- Hm lng lu hynh: 0,010,02%khi lng

Hiu sut v cht lng ca xng ph thuc vo cht lng nguyn

liu,xc tc v ch cng ngh.

Nguyn liu c nhiu naphten th xng c cht lng cao, nguyn liu c

nhiu parafin th xng thu c c tr s ctan thp hn.

Xng cracking c t trng trong khong 0,720,77.

Xng cracking c dng pha ch sn xut xng t v xng my bay.

Xng cracking xc tc c lng olefin cao, dn ti tnh n nh ca xng km,

trong tncha v s dng d b to nha, gy tc kim phun nhin liu,nh

hng ti cht lng xng.

7.2. c im v tr s c tan


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ca phng th nghim cung cp quy trnh v hng dn thc hnh xc nh

thnh phn nhm hydrocacbon

7.5. Cu hi

1. c im, thnh phnha hc ca xng cracking xc tc

2. ng dng caxng cracking xc tc, Xng cracking xc tc c nhng u

im, nhc im g khi pha trn v sn sut xng thng phm.


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TM TT NI DUNG MODUN

Ni dung trng tm ca modun ny

Mc chca qu trnh cracking xc tc

- S ra i cng ngh cracking xc tc nhm p ng yu cu sn

phm nh t du ngy cng cao nht l xng cho t m nu ch

chng ct du th th khng tha mn nhu cu.

- Qu trnh cracking xc tc cn cho cc olefin nh lm nguyn liu cho

ha du.

- Cracking thng thc hin i vi phn cn chng ct kh quyn (si

trn 350oC), thng c gi tr thp hn duth, nn cn cracking (ch

bin su) thu cc sn phm nh c gi tr cao v qua lm tnghiu qu kinh t ca nh my lc du.

Cc phn ng ha hc sy ra trong qu trnh cracking xc tc

- Phn ng phn hy ct mh CC (phn ng cracking)

- Phn ng ng phn ha

- Phn ng chuyn v hydro

- Phn ng ngng t

- Phn ng polyme ha

- Phn ng to cc.Cc sn phm ca qu trnh cracking xc tc

- Snphm kh: Sn phm kh quan trng l cc olefin nh nh etylen,

propylen, butadien...l nguyn liu c bn cho cng nghip ha du,

- Sn phm lng: c xng cracking, du ha, gasoil, trong quan

trng nht l xng cracking.

C chca qu trnh cracking xc tc

C ch ca qu trnh cracking xc tc l c ch ion cacboni. C s l

thuyt ny da vo cc tm hat tnh l cc ion cacboni, chng c to ra

khi cc phn t hydrocacbon ca nguyn liu tc dng vi cc tm axt ca

cht xc tc loi Bronsted(H+) hay Lewis (L).

Cht xc tc ca qu trnh cracking

- Zeolit v xc tc cha zeolit.Zeolit l hp cht ca aluminosilic dng

tinh th c cu trc c bit, c cc l rng, rnh nh thng vi nhau

- Cc cht zeolit c ch to cng vi cc xc tc aluminosilicat hay

vi t st thin nhinri sau c s l bng cc phng phpc bit to thnh xc tc cha zeolit.


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c trng quan trng ca cht xc tc

- hat tnh ca xc tc: thng c biu din thng qua ch s

hat tnh, l gi tr ca hiu sut xng (% khi lng ) khi cracking

nguyn liu mu trong iu kin phng th nghim

- chn lcca xc tc: l kh nng lm tng tc cc phn ng c

li v ng thi lm gim tc cc phn ng khng c li, qua

lm tng hiu sut v cht lng ca sn phm thu c.

- bnca xc tc: Trong qu trnh tham gia phn ng,hat tnh ca

cht xc tc b gim i v sht tc dng do bcc bm kn b mt, b

nhim c bi cc c t nh NH3, CO2, H2S,v s tcht cc kim loi

nng di dng oxit lm thay i chc nng ca xc tc. Ngi ta

nghin cu nhiu phng php tng bn tng thi gian s dngca xc tc. Bin php quan trng nht v ch yu trong cng nghip

l phi ti sinh xc tc.

- Qu trnh cng nghip cracking xc tc l qu trnh tham gia phn ng

v ti sinh lin tc theo chu trnh khp kn.

Quy trnh vn hnh ca thit b cracking xc tc cng nghip

Ty theo cng ngh ca cc hng khc nhau c cch vn hnh kh c

nhau nhng u qua chu trnh.

a nguyn liu v cht xc tc ti sinh vo l phn ng vi c mth thng iukhin phc tp. Xc tc v nguyn liu qua l phn ng s cho

sn phm dng hi c tch v thatkhi l ti h thng phn tch sn

phm v xc tc tham gia phn ng i sang l ti sinh ri li i tr li l

phn ng cng vi dng nguyn liu mi. Qu trnh nh vy din ra lin tc

di s iu khin t ng ca h thng m bo cc iu kin phn ng

nh p sut,nhit ,cc ch ti sinh, phn tch sn phm....

KIM TRA, NH GI HON THNH MN HC

Kim tra gia k 02 ln mi ln 30 pht, gio vin chn bt k bi no

trong s cc bi ging. Chm theo thang im 10. (trng s im l 20%)

bi kim tracui k 01 ln, bt buc i vi hc vin. bi gio vin s

t la chn, mc ch l kim tra s tip thu caa hc sinh i vi nhng vn

rt c bn ca modun ny. Bi kim tra cui k rt quan trng, cng chm

theo thang im 10, v trng s trong ton modun l 50%.

im thc hnh trong phng th nghim s do ngi hng dn trong

phng th nghim, kt hp vi gio vin cho im khi thc hin th nghim(ch


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v k nng v tinh thn, thi ca hc sinh). Mi ln c thc hnh, gio

vin cho im theo thang im 10, trong s ca thc hnh l 30%.

Sau y l mt s th d thi kim tra cui k:

Cu hi 1

1. Ti sao trong cng ngh lc du phi tin hnh qu trnh cracking?

2. Cc phn ng sy ra trong qu trnh cracking phn ng c ch cn tng

cng? Phn ng khng c li cn hn ch?

3. Cc thng s quan trng ca cng ngh cracking xc tc, ngha ca

cc thng s ny?

Cu hi 2

1. C ch phn ng ca qu trnh cracking xc tc?

2. Gii thiu mt s cng ngh ca cchng ln v nhng khc bit giacc cng ngh :

nh gi kt qu kim tra theo sch hng dn gio vin


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CC THUT NG CHUYN MN

Cracking: S phn hy ct mch cu to CC trong phn t hydrocacon

F.G: nhin liu kh

Jet/kero: nhin liu phn lc v du ha

D.O: nhin liu cho ng ciezen

F.O: Nhin liu cho l t cng nghip

Gasoil: phn onchng ct t du th c nhit si (280 540oC)

PE: Polyetylen (nha PE)

PP: Polypropylen(Nha PP)

MTBE: Metylter butyleter


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TI LIU THAM KHO

[1]. PGS.TS. inh Th Ng, Ha hc du m & kh. Nh xut bn khoa hc

v k thut,H ni,2001

[2]. PGS.TS. L Vn Hiu, Cng ngh ch bin du m, Nh xut bn khoa

hc v k thut,H ni,2000

[3]. Ch.Marchilly, Catalytic cracking, ENSPMFormation Industrie 1991

[4]. Dr.Docent. ing.Rdulescu.G.A. Fabricarea Produselor Petroliere, Editura

Tehnical.

[5]. Prof.ing.S.D.Raseev. Procese Distructive de Prelucrare a Titeiului.Editura

Tehnic

[6]. 6.Statistic General Department, B Thng Mi,Tng cc Hi quan, Kinht Vit nam vTh gii (9899)

che bien dau

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