reforming xuctac

7/29/2019 Reforming Xuctac

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MC LC

mc Trang

LI TA ........................................................... Error! Bookmark not defined.

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

GII THIU V M UN................................................................................. 2

V tr, ngha, vai tr m un:........................................................................... 2

Mc tiu ca m un: ....................................................................................... 2

Mc tiu thc hin ca m un: ....................................................................... 2

Ni dung chnh cc bi ca m un: ................................................................ 2CC HNH THC HC TP CHNH TRONG M UN .................................. 3

YU CU V NH GI HON THNH M UN ......................................... 3

BI 1. VAI TR CA QU TRNH REFORMING XC TC ........................... 5

BI 2. BN CHT CA QU TRNH REFORMING XC TC ..................... 11

BI 3. XC TC LNG CHC NNG ....................................................... 18

BI 4. NGUYN LIU V CC SN PHM THU .......................................... 37

BI 5. CC LOI CNG NGH REFORMING XC TC ............................. 49

BI 6. S TIN B CA REFORMING XC TC........................................ 66BI 7. C IM CA XNG REFORMING XC TC................................ 70

KIM TRA, NH GI HON THNH MN HC ........................................ 75

CC THUT NG CHUYN MN ................................................................ 76

TI LIU THAM KHO ................................................................................... 77


2/77

GII THIU V M UN

V tr, ngha, vai tr m un:

Reforming xc tc l mt trong nhng qu trnh quan trng nht ca cng

nghip ch bin du m. T qu trnh ny thu c mt khi lng ln

reformat-hp phn ch yu pha xng thng phm c ch s octan cao. y

cng l mt qu trnh c bn thu BTX-mt trong nhng nguyn liu ch yu

ca ha du. M unny trang b kin thc chuyn ngnh cn thit cho cc

hc vin sau ny tham gia vn hnh trong nh my lc du cng nh lm vic

trong cc lnh vc lin quan n nghin cu ch bin du kh.

Mc tiu ca m un:

Hc xong m un ny, hc sinh phi t c:1. Hiu bit v nm vng bn cht ha hc, c ch phn ng ca qu

trnh reforming xc tc.

2. Bit iu ch c xc tc reforming

3. Xc nh c mt s c trng ha l ca xc tc iu ch c.

4. Vn hnh s reforming xc tc trong PTN

5. Xc nh cc ch tiu ca xng reforming xc tc.

Mc tiu thc hin ca m un:

1. M t c bn cht ha hc, nguyn liu v sn phm thu ca qu trnhreforming xc tc.

2. iu ch c xc tc hai chc nng.

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

ha l hin i.

4. Thc hin c phn ng reforming xc tc trn s qui m phng th

nghim.

5. Phn tch xc nh c cc ch tiu ca xng reforming xc tc.

6. Cc th nghim ca m un lm trong PTN ha du.

Ni dung chnh cc bi ca m un:

Bi 1: Vai tr ca qu trnh reforming xc tc trong lc ha du

Bi 2: Bn cht ha hc ca reforming xc tc

Bi 3: Xc tc hai chc nng

Bi 4: Nguyn liu v sn phm thu

Bi 5: Cc loi cng ngh v thit b reforming xc tc

Bi 6: S tin b ca qu trnh reformingxc tc trong lc du ngy nayBi 7:c im ca xng reforming xc tc


3/77

http://www.ebook.edu.vn 3

CC HNH THC HC TP CHNH TRONG M UN

Hc trn lp v cc ni dung chnh ca m un.

Tnghin cu ti liu lin quan n bi ging do gio vin hng dn. Tham quan, thc tptrn s reforming xc tc qui m PTN v cc

phng php iu ch xc tc reforming, cc phng php c trng

xc tc ti cc PTN Trung tm Nghin cu & Pht trin Ch bin Du

kh thuc TCT DK v Vin Ha Cng ngh thuc TT KH- CN QG.

Thc hnh phn tch cc ch tiu ca xng reforming v xngthng

phm.

Thc hnh phn tch thnh phn hydrocacbon PONA v hm lng

benzen ca xng reforming bng phng php sc k kh.

Nghe bo co chuyn v cng ngh reforming xc tc ca nh my

lcdu s 1 VN.

YU CU V NH GI HON THNH M UN

V kin thc

Hiu bit c vai tr quan trng v v tr ca reforming xc tc trongnh my lc du v trong cng nghip ha du.

Nm c bn cht ha hc ca qu trnh reforming v vai tr ca cht

xc tc i vi qu trnh. nh hng nguyn liu-sn phm v cc

thng s quan trng n qu trnh.

Hiu bit v nguyn tc v cc bc c bn trong iu ch xc tc

reforming v cc phngphp xc nh c trng xc tc.

V k nng

Bit cch vn hnh s reforming xc tc trong PTN.Bit phn tch cc thnh phn, tnh cht ha l v cc ch tiu cht

lng quan trng ca nguyn liu v sn phm reforming.

Bit xc nh mt vi c trng ca xc tc a chc nng (b mt

ring, phn b l xp, thnhphn kim loi)


4/77


V thi

Tip thu nghim tc bi ging trn lp.

Chun b chu o, tch cc, ch ng trong cc bui thc hnh th

nghim, thc tp ngoi kha v nghe ging chuyn .

Tun th ni qui, an ton phng th nghim ti cc PTN ca trng v

cc ni n thc tp.

Phng php kim tra, nh gi

Kim tra gia k

Kim tra cui k

Bo co kt qu thc tp PTN

Tham d y cc tit hc, chng tch cc trong cc bui tho

lun


5/77


BI 1. VAI TR CA QU TRNH REFORMING XC TC

M bi: HD F1

Gii thiu

Bi hc nhm gip hc vin nhn thc c vai tr quan trng ca qu trnh

reforming xc tc trong nh my lc du hin i. Qu trnh nhm cung cp xng

cht lng cao (RON t 90-95) v ngun nguyn liu qu (BTX) cho ha du.

Mc tiu thc hin

- Hc vin phi nm c vai tr, v tr ca qu trnh reforming trong nh

my lc du. ngha ca qu trnh reforming i vi vic sn xut xng

cht lng cao v p ng yu cu v mi trng.

- Nm c cc khi nim v xng thng phm, thnh phn v cht

lngch s octan RON, MON.

Ni dung chnh

- Nhu cu v xng cht lng cao cho ng c

- S cn thit ca qu trnh reforing xc tc cho sn xut xng

1. Nhu cu v xng cht lng cao cho ng c

T sau nm 1900, t ra i thc y vic sn xut xng t nh my lc

du. Lc xng ch yu ch ly t chng ct trc tip. n khong 1912 th

chng ct trc tip khng cn tho mn vi nhu cu v xng ngy mt tng cao.

Mt khc xng loi ny cha mt lng ng k kh t C 1-C4lm cho bay

hi ca xng tng v kh nng chng kch n khng cao (th hin qua ch s

octan ch xp x 60). T cc nh lc du nghin cu v pht trin mt lot cc

qu trnh ch bin du nhm sn xut ra xng c cht lng cao hn. V c bn

xng thng phm ngy nay c pha trn t cc sn phm ca cc qu trnh

sau: xng chng ct trc tip t du th, xng t cracking nhit v cracking xc

tc, xng reforming xc tc, xng t ng phn ha, alkyl ha, c th c thm

cc hp phn t hyrdocracking, t polymer ho. Ngy nay vic s dng ccng c c h s nn cao i hi cht lng nhin liu, c bit l ch s octan

cao. p ng yu cu , ngi ta pha trn vo xng cc ph gia hoc tng

cng cc hp phn hydrocacbon cho ch s octan cao.

Hin ti vi cc tiu chun nghim ngt v mi trng mt loi ph gia

truyn thng l tetraetyl ch, tuy lm tng ch s octan ln 15-20 s nhng li gy


6/77


c hi i vi sc khe con ngi, nn gn nh c loi b hon ton. i vi

cc ph gia thay th hu hiu nh MTBE, TAME cng c mt s kin nghi

ng v kh nng chm phn hy ca chng trong mi trng. Hin ti Vit

nam xut hin mt s phgia mi cha Mn, Fe c th thay th tm thi cc ph

gia truyn thng. Nhng cc ph gia trn c s kim loi ny cng cn gy nhiutranh lun, cn c tip tc lm sngt v kh nng nhim mi trng.

Ngi ta c xu hng la chn phng n th hai, tng cng cc hp

phn pha ch t cc qu trnh ch bin su nh cracking, reforming, ng phn

haCc hp phn ny cho ch s octancao hn nhiu so vi xng t chng

ct trc tip, m li t gy nhim mi trng.

Xng pha trnnhm mc ch t nhng ch tiu quan trng sau:

-p sut hi bo ha (RVP- Reid Vapor Pressure):o p sut hi ca cc

hydrocacbon, cn thit cho s khi ng ca ng c.

- Ch s octan: o mc chng kch n ca xng, ch tiu quan trng v

ng ckch n thp s hot ng hiu qu hn v tit kim c nng lng.

- c hi: o cc hp phn c hi trong xng. Cc nh my lc du

thng ch n hm lng benzen, olefin, lu hunh.

Ch s octan l i lng c quan tm hn c v thng c la chn

nh gi v iu chnh cht lng xng. Ty thuc vo ch s octan m ngi

ta c th chia thnh xng thng (regular) hoc xng cht lng cao (premium).

nhiu nc, cc phng tin vn ti la chn mc cht lng xng theo ch

s octan theo s hng dn ca cc nh ch to ng c. C 2 mc cht lng

87 v 89, thng s dng mc 87 hn. Cn hiu y l gi tri trung bnh gia

ch s octan o theo phng php nghin cu v ch s octan o theo phng

php m t: (RON+MON)/2. cc cy xng VN ngi ta nim yt gi xng theo

ch s RON.

Ch s octan ca mt nhin liu em th nghim trn mt ng c trong

phng th nghim c xc nh bng cchso snh kh nng chng kch n (ghi

trn b knockmeter) ca nguyn liu vi nguyn liu chun cha hn hp

isooctan v heptan (qui c ch s octan ca isooctan = 100 , ca heptan = 0)

trong cng iu kin th nghim. Phn trm th tch ca octan trong nguyn liu

chun cho kch n tng ng vi nguyn liu em th nghim chnh l ch

s octan ca nguyn liu . V d nguyn liu em th s c ch s octan l 70


7/77


nu kh nng chng kch n ca n tng ng vi hn hp nhin liu chun

cha 70% t.t. isooctan v 30% t.t. n-heptan.

Tu thuc vo loi ng c th nghim m ngi ta c c ch s octan

RON hay MON. Do MON c xc nh trong iu kin khc nghit hn (s

vng quay ca ng c ln hn) so vi RON nn RON thng ln hn khong 8n v i vi cng mt nhin liu. Ch s octan c ghi trn cc bm xng

c tnh trung bnh gia RON v MON: (R+M)/2.

S ph thuc ca ch s octan vo nhit si ca cc hydrocacbon ring

r v nhm hydrocacbon c m t trn hnh 1.

Hnh 1. Ph thuc ch s octan vo nhit si v nhm hydrocacbon

C th thy i vi phn on xng nh (T s-80oC) tng i kh c th ci

thin ch s octan bng cc chuyn ha ho hc, ngoi tr mt qu trnh duy

nht c th p dng, l ng phn ha, trong cc n-parafin c chuyn

thnh cc isoparafin, lm tng ng k ch s octan. Vi cc phn on xng

nng (Ts >80oC) giu parafin v naphten c th lm tng ch s octan nu

chuyn ha chng thnh cc hydrocacbon thm (aromatics). y chnh l

nguyn tc ca qu trnh reforming xc tc.

Hm lng hydrocacbon thm c nh hng kh quan trng i vi ch s

octan MON ca cc hp phn xng pha trn (Hnh 2).


8/77


Hnh 2. Ph thuc ch sMON vo hm lng aromat ca cc xng hp phn

2. S cn thit ca qu trnh reforming xc tc cho sn xut xng

C th nh ngha: Reforming xc tc l qu trnh lc du nhm chuyn ha

phn on naphta nng c chng ct trc tip t du th hoc t mt s qu

trnh ch bin th cp khc nh FCC, hidrocracking, visbreaking, c ch s octan

thp (RON =30-50) thnh hp phn c s ca xng thng phm c ch s

octan cao (RON =95-104).

V mt bn cht ha hc y l qu trnh chuyn ha cc n-parafin v

naphten c mt trong phn on thnh cc hydrocacbon thm. Chnh cc

hydrocacbon thm vi ch s octan rt cao lm cho xng reforming c ch s

octan cao ng hng u trong s cc xng thnh phn (Hnh 2).

Thnh phn xng thng dng hin nay trn th gii thng cha:

- Xng cracking xc tc (m ch yu l xng FCC) : 35% t.t

- Xng reforming xc tc : 30% t.t

- Xng alkyl ha : 20% t.t

- Xng isomer ha : 15% t.t

Xng Php c thnh phn a dng hn, trong hp phn alkyl ha thng

t hn:

- Xng FCC : 40%

- Xng reforming xc tc : 33%

MON


9/77


- Xng isomer ha : 10%

- Xng nhit phn : 6%

- Xng alkyl ha : 5%

- Butan : 4%

- Hp cht cha oxy : 2%T cc s liu trn cho thy, xng reformingng th 2 trong xng thng

phm, ch sau xng cracking. Thm ch mt s khu vc nhM, Ty u, xng

reformirng c phn vttri (hnh 3,4).

United States

5% 12%

30%

1%36%

3%

10%

3% Butane

IsomerateFCC gasoline

Polymerisation gasoline

reformate

Ether

Alkylate

HYC gasoline

Hnh 3. Phn b thnh phn xngthng mi M

Europe

5%

30%

5%50%

5% 5% Isomerate

FCC gasoline

Butane

Reformate

Ether

Alkylate

Hnh 4. Phn b thnh phn xngthng mi chu u


10/77


Thnh phn sn phm ca qu trnh reforming v hiu sut thng dng nm

trong khong:

Reformat (C5+) : 80-92%

C4 : 3-11%

C3 : 2-9%Kh nhin liu C1-C2 : 2-4%

Hidro : 1,5 -3,5%

Mt s tnh cht ca reformat:

- Thnh phn ct: thng thng t 35 190oC

- T trng: 0,76 0,78

- Ch s octan RON: 94103 (tu thuc iu kin cng ngh)

Do v tr quan trng ca xng reforming trong thnh phn xng thng

phm, c bit l xng cht lng cao m hin nay trong mi nh my lc du

trn th gii thng c ti thiu l mt phn xng reforming xc tc. Cng sut

ch bin nm trong khong 40 tn/gi n 150 tn/gi. Tng cng sut ca cc

phn xng reforming xc tc trong tt c cc nh my lc du Php ln ti 18

triu tn trong mt nm.

Cu hi Bi 1:

1. Nu s cn thit phi s dng xng cht lng cao hin nay trn th gii.

Cc gii php to xng cht lng cao.

2. nh ngha ch s octan RON, MON. nh hng cc nhm hydrocacbon

n CSOCT.

3. Mc ch qu trnh reforming xc tc. Vai tr ca reforming xc tc trong

nh my lc ha du.

4. Thnh phn c bn ca xng thng phm hin nay. V tr ca xng

reforming trong xng thng phm. Nu v d.


11/77


BI 2. BN CHT CA QU TRNH REFORMING XC TC

M bi: HD F2

Gii thiu

Reforming xc tc l mt qu trnh phc tp bao gm nhiu phn ng khc

nhau xy rang thi. Hiu bit c bn cht ha hc ca qu trnh v cc yu

t nh hng c th gip la chn iu kin thun li cho cc sn phm chnh

v hn ch cc sn phm khng mong mun.

Mc tiu thc hin

- Hc vin phi nm c bn cht ha hc ca qu trnh reforming xc

tc. Phn bit c nhm cc sn phm chnh v sn phm ph.

- Hiu c nh hng ca cc yu t nhit ng hc v ng hc n

c ch ca qu trnh reforming.

Ni dung chnh

- Cc nhm phn ng chnh v phn ng ph ca qa trnh.

- Cc yu t ng hc v nhit ng hc nh hng n c ch qu

trnh.

- nh hng ca c ch phn ng i vi s gia tng ch s octan

Nguyn liu ban u cho reformingch yu l phn on naphta nng, c

nhit si nm trong khong 80-180oC, cha nhiu parafinv naphten, di

tc ng ca nhit cao (khong 480-540oC), xc tc a chc nng v mt p

sut va phi (5 30 atm), c th xy ra cc hng chuyn ha c bn sau:

Chi tit hn, chng ta chia cc phn ng xy ra lm 2 nhm nh sau:

1. Nhm cc phn ng chnh

Dehydro ha naphten thnh hydrocacbon thm:


12/77


Dehydro ng vng ha parafin thnh hydrocacbon thm:

ng phn ha n-parafin thnh iso-parafin:

Dehydro ng phn ha naphten thnh hydroccbon thm:

Dehydro ha prafin thnh olefin:

CH3-(CH2)4-CH 3 Pt CH3-CH=CH-CH2-CH2-CH3Bn phn ng u tin ng vai tr quan trng hn c trong qu trnh

reforming, lm tng ch s octan ca h nh cc sn phm thm v isoparafin.

Phn ng th 5 xy ra yu trong iu kin reforming, nhng l phn ng cn

thit v olefin c coi l hp cht trung gian trong qu trnh vng ha to cc

sn phm thm.

2.Nhm cc phn ng ph:

Hydrocracking parafin v naphten:


13/77


Hydrodealkyl ha hydrocacbon thm:

Bt cn i ha:

Qu trnh cc ha: qu trnh trng ngngcc hyrocacbon thm a vng

(sinh ra t cc qu trnh alkyl ha vng vng ha) to cc sn phmrn giu cacbon, c th che ph ln xc tc.Qu trnh ny thun li

nhit cao v p sut thp.

Cc phn ng trn dn ti lm gim hiu sut sn phm reformat v

hidrogen, lm tng im si cui ca reformat(do to cc hydrocacbon thm a

vng, cc olefin mch div bn thn cc)v lm gim hot tnh xc tc.

Phn ng hydrocracking to nhit (H = -10 kcal/mol) v iu kin reforming

thun li cho hydrocracking, mc d qu trnh xy ra chm. nhit cao phn

ng xy ra p o so vi ng phn ha v dehydro ho parafin. Sn phmcracking ch yu l cc hydrocacbon nh C1 C5, mch thng v mch nhnh.

V phng din no qu trnh ny thun li c th to thnh cc sn phm

isoparafin c ch s octan cao hn so vi cc sn phm ca qu trnh ng phn

ha trong iu kin reforming. V d, n-octan c ch s octan cc thp (


14/77


Bng 1. Nhit phn ng ca mt s qu trnh

Phn ng H (Kcal/mol)

1 Dehydro ha parafin 31,5

2 Dehydro ha naphten 52,8

3 Dehydro vng ha parafin 63,6

4 ng phn ha parafin -1 -5

5 Hydrocracking -10

Dehydro ha naphten v dehydro vng ha parafin l cc phn ng thu

nhit mnh (endothermic), dehyro ha parafin thu nhit va phi, cn ng phn

ha parafin to nhit nh (exothermic). Ba phn ng u xy ra thun nghch, c

s gia tng s phn t trong sn phm phn ng (do hnh thnh H2), nn thun

li nhit cao, p sutthp.

Bng 2. Ph thuc nhit cn bng t chuyn ha 90% vo p sut

Phn ng Nhit cn bng chuyn ha 90%,oC

1 atm 10 atm 15 atm 50 atm

1. Dehydro ha:

Cyclohexan Benzene + 3H2

MethylCyclohexan Toluene + 3H2

294

315

355

391

443

492

487

540

2. Dehydro vng ha:

n-Hexan Benzene + 4H2n-Heptan Toluene + 4H2354305

487428

562496

623550

3. Dehydro ng phn ho:

MethylCyclopentane Benzene+

3H2

315 391 492 540

T bng 2,iu kin l thuyt thun liv p sut v nhit c th

t chuyn ha 90% cho cc phn ng thm ha l 1atm v khng qu

350oC. Tuy nhin trong thc t ngi ta khng tin hnh qu trnh reforming

iu kin trn, l do ti sao chng ta s xem xt tip theo trong phn ng hc.nh hng ca nhit vp sut n cn bng nhit ng gia parafin

v aromatic t C6n C9c biu din trn hnh 5.

T hnh 5 chng ta thy, nu tng p sut H2 ln qu cao (30atm) s lm

gim hm lng cc hydrocacbon thm to thnh, c bit i vi cc

hydocacbon c s C thp hn. Chng ta cng thy, i vi hydrocacbon no c


15/77


trng lng phn t cng cao th hiu ng thun li ca nhit v p sut cng

r rt. Ngha l trong cng mt iu kin, cc hydrocacbon mch di hn (c s

nguyn t cacbon cao hn) s d chuyn ha thnh sn phm thm hn.

3.2.ng hcv cchphn ng:

Trong bng 3 l vn tc tng ica mt s phn ng chnhca cc

hydrocacbon C6-C7 trong qu trnh reforming ( iu kin khc nghit ha

cao).

Bng 3. Vn tc tng i ca cc chuyn ha hydrocacbon C6-C7

Phn ng Parafin Naphten vng 5 cnh Naphten vng 6 cnhC6 C7 C6 C7 C6 C7

ng phn ha 10 13 10 13 - -

Dehydro vng ha 1 4 - - - -

Dehydro ha - - - - 100 120

Hydrocracking 3 4 - - - -

AR

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350 450400 500T C

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350 450400 500T C350 450400 500T C

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350 450400 500T C350 450400 500T C

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C6

C7

C8

C9

PH2 = 10 Bars PH2 = 30 Bars

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Maxi

Hnh 5. Cn bng nhitng hc cc phn ngca qu trnh reforming.(nh hng nhit , psut


16/77


T bng 3 c th sp xp vn tc phn ng theo th t sau:

Dehydro ha > ng phn ha > Hydrocracking > Dehydro vng ha

Nghin cu nh hng nhit v p sut n tc cc phn ng khng

mong mun l cc ha v cracking, ngi ta nhn thy:

-Tc hnh thnh cc gim khi tng p sut H2 v gim nhit phnng.

-Tc cracking gim khi gim p sut H2v gim nhit phn ng.

Mt khc, nh phn nhit ng hc nu, vic tng p sut hoc lm

gim nhit u nh hng khng thun li n qu trnh chnh to cc sn

phm thm. V vy, trong thc t ngi ta cn c s la chn cc thng s vn

hnh ti u tha mn c 2 yu t nhit ng hc v ng hc, ngha l bo

m cho hiu sut cc phn ng thm ha cao ng thihn ch cc sn phm

cracking v cc ha(v d t 3-4% cc trn trng lng xc tc trong khong 6-

12 thng). Trong cng ngh bn ti sinh ngi ta chn p sut vn hnh khong

10-20 atm, trong cng ngh CCR chn p sut t 3,5-4 atm v nhit phn

ng l 500oC.

3.3. C ch phn ng v s gia tng ch s octan

Nh trn nu, trong iu kin reforming, thun li cho cc phn ng

chnh l dehydro ha naphten, dehydro ng vng ha parafin, dehydro ng

phn ha naphten v ng phn ha parafin. Ba phn ng uto nn cc sn

phm l hydrocacbon thm vphn ng cui cho sn phm l cc parafinmch

nhnh. Chnh cc sn phm ny ng gp vai tr chnh lm cho ch s octan ca

xng thu c sau qu trnh reforming (cn gi l reformat) tng ln rt nhiu so

vi nguyn liu naphta ban u.

RON nguyn liu = 40-60 RON sn phm = 95-105

Ty thucvo hiu sut reformat thu c m ch s octan c th cao hn

hay thp hn.V d, reforming vi cng ngh bn ti sinh cho hiu sut xng ~

80% th RON t ~90, cng ngh ti sinh lin tc cho hiu sut reformat ~ 90%

cho RON ~100.

Cu hi Bi 2:

1. Nu bn cht ha hc ca qu trnh reforming xc tc.

2. Cc nhm phn ng chnh vcc nhm phn ng ph xy ra trong qu trnh

reforming xc tc.


17/77


3. Ti sao theo l thuyt qu trnh reforming xy ra thun li p sut thp

nhng trong thc t cng nghip qu trnh li c vn hnh p sut

tng i cao?

4. C ch phn ng reforming lin quan n s gia tng CSOCT nh th no?


18/77


BI 3. XC TC LNGCHC NNG

M bi: HD F3

Gii thiu

Xc tc ng vai tr v cng quan trng trong cng ngh reforming. Hiu

bit v xc tc reforming gip hon thin kin thc v cng ngh reforming.

Mc tiu thc hin

- Hiu c vai tr ca xc tc lng chc nng i vi qu trnh

reforming.

- Nm c cc phng php iu ch xc tc reforming lng chc

nng.

- Xc nh c c trng ca xc tc iu ch bng cc phng

php ha l hin i.

Ni dung chnh

- Lch s pht trin xc tc reforming

- Vai tr ca xc tc lng chc nng i vi qu trnh reforming

- nh hng ca cc kim loi ph gia

- S mt hot tnh xc tc v s ti sinh xc tc

- Cc phng php iu ch xc tc.

- Cc phng php c trng xc tc

Mt s khi nim lin quan n tnh nng xc tc:

- Hot tnh xc tc: Kh nng ca cht xc tc nhm bo m tnh nng

nhit thp nht c th.

- la chn: Kh nng cht xc tc to ra cc sn phm mong mun

(trong trng hp qu trnh reforming l hydro v reformat).

- bn ( n nh): Kh nng ca cht xc tc c th lm vic lu theo

thi gian gia 2 ln ti sinh lin k.

- phc hi: Kh nng cht xc tc lp li cc tnh nng ban u saukhi ti sinh..

1. Lch s pht trin xc tc reforming

Th h u tin ca xc tc reforming c ch to trn c s oxyt crom v

oxyt molypen (10%) mang trn oxyt nhm. Loi xc tc ny c u im l kh


19/77


bn vi cc tp cht cha lu hunh, nhng cho hot tnh xc tc thp v

reformat thu c c cht lng thp.

Sau chin tranh th gii th hai vi s pht trin ca k ngh xe hi yu cu

xng c cht lng cao, cng ngh reforming c nhng bc tin ng k, nht

l trong lnh vc ci tin cht xc tc. T nhng nm 50, xuthin nhng th hxc tc mi l kim loi qu Pt mang trn oxyt nhm c b mt ring ln v tm

thm Cl. So vi th h xc tc c th Pt hn hn v hot tnh xc tc, la chn

phn ng thm ha nhng li d bu c (hnh 6).

Cui thp nin 60 th h xc tc th 3 ra i: cc xc tc lng kim loi.

Bn cnh Pt ng vai tr chnh, ngi ta a thm kim loi th 2 : Re, Ir, Ge, In,

Sn...Vic a thm cc kim loi ny vo gip lm tng n nh ca xc tc

v cng lm tng hot tnh xc tc theo hng tng cc sn phm thm, nh

m p sut vn hnh cng gim ng k.Vic thay th mt phn Pt bng kim loi

ph gia cn lm cho gi thnh xc tc gim v tit kim c mt phn Pt l kim

loi qu v t tin.

2. Vai tr ca xc tc lng chc nng trong qu trnh reforming

Xc tc reforming l xc tc lng chc nng do trong thnh phn ca n

cha 2 pha c th thc hin 2 chc nng chnh sau:

- Chc nng hydro-dehydro ha c thc hin bi cc kim loi dng

phn tn.


20/77


- Chc nng axit nhm sp xp li cc mch cacbon (ng phn ha, ng

vng ha...) c thc hin bi oxyt nhm c b mt ring ln v c clo ha

iu chnh lc axit thch hp.

Chc nng kim loi ng vai tr chnh, gip hnh thnh cc hp cht

hydrocacbon khng no v dehydro ho cc naphten. Cn thit lp c s cnbng gia 2 chc nng c th c hot tnh xc tc cao v la chn tt.

Nu xc tc qu axt s d xy ra cracking lm gim nhanh hot tnh xc tc.

Trong cng nghip ngi ta lun kim tra hm lng Cl -a vo m bo

cn bng trn lun n nh.

S di y m t tng qut cc phn ng chnh xy ra trong qu trnh

reforming vi s tham gia ca 2 loi tm xc tc:

3. Vai tr ca cc kim loi ph gia

Nghin cu cc phn ng dehydro ha v dehydro ng vng ha cc

hydrocacbon ring rnh cyclohexan, n-heptan... ngi ta thy vic a cc kim

loi ph gia nh Re, Sn, Ir, Ge (cn gi l cc cht xc tin) lm tng tc phn ng dehydro ha v dehydro vng ha (nht l vng p sut thp) ca h

xc tc lng kim so vi xc tc ch cha Pt (hnh 7 v hnh 8).


21/77


Hnh 7.nh hung ca kim loi th 2 n qu trnh dehydro ha Cyclohexan

vng p sut thp (5-10 bar), cc kim loi ph gia (Re, Sn) cng ng vai

tr quan trng trong vic gim hydro phn (hydrogenolysis) v cracking (hnh 9

v hnh 10) t lm gim kh nng to cc v tng hiu sut sn phm chnh.

+ 3 H2

+ 3 H2

activity (mole/h/g) x 102

pH2 (bar)

5 % coke

PtIr

PtRe

Pt

PtSn

0

10

20

30

40

0 5 10 15 20


22/77


Hnh 9.nh hng ca cc kim loi ph gia n qu trnh hydro phn

(hydrogenolysis)

Nu nh thp nin 70 ch khong 30% reformat thu c t h xc tc

lng kim th n nhng nm 80 th phn ln ti 80%.

Trong s cc h xc tc lng kim, chng ta thy hai h xc tc Pt-Sn v Pt-

Re t ra u vit hn c, chng cho php lm vic p sut thp (


23/77


vn bo m hot tnh dehydro ha v dehydro ng vng ha cao. Ring h

xc tc Pt-Sn hi c bit, ch th hin hot tnh cao vng p sut thp. Ln

hn 5 atm, h xc tc ny khng pht huy c tc dng tch cc so vi Pt v

cc h lng kim khc trong phn ng dehydro v dehydro vng ha.

Chng ta xem xt k hn v vai tr ca 2 kim loi ph gia c a vo xctc reforming cng nghip hin nay l Re (Renium) v Sn (Thic).

Ngi ta nhn thy Re c cc chcnng sau:

- thay i c ch to cc v c tc dng bo v kim loi chnh Pt

- Lm tng bn v tui th xc tc, t lm tng chu k hot ng

ca xc tc.

Cn Snth li c cc vai tr sau:

- Lin ktvi Pt lm thay i c ch phn ng theo hng c li .

- Cho hiu sut v la chn theo reformat cao iu kin p sut

thp (< 5 atm). Tuy nhin loi xc tc ny km bn hn so vi xc tc

cha Re.

Vi cc c im trn, ngi ta thng s dng Re trong cng ngh bn ti

sinh v Sn trong cng ngh ti sinh lin tc (CCR).

Hnh 11. So snh c tnh xc tc ca 2 loi xc tc ca Php CR 201(cha Pt-

Sn) v RG 482 (cha Pt-Re)


24/77


C th lit k mt s mc xc tc lng kim mi ca cc hng xc tc tn

tui trn th gii:

UOP (M): Bn ti sinh: R-56, R-62, R-72

Ti sinh lin tc (CCR): R-132, R-134IFP (Php): Bn ti sinh: RG-102, RG-104, RG- 482

CCR: CR- 201

Criterion (M): Bn ti sinh: PR- 8, PR- 28

CCR: PS- 20, PS- 40

Exxon: KX-120, KX-130, KX-190, KX-200

Amoco: PHF-5, PRHP-30, PRHP-35, PRHP-50, PRHP-58

Engelhard (M): RD- 150, E- 501, E- 601

IMP (Mexico): RNA- 1, RNA- 2, RNA- 4, RNA- 4M

Lin x (c): A- 56, A- 64, KP-108, KP-110

4. S mt hot tnh v ti sinh xc tc

4.1. nh hng u c xc tc

Cc cht xc tc reforming rt nhy vi cc tp cht c trong nguyn liu v

kh tun hon (H2, N2). nh hng u c c th l thun nghch v khng

thun nghch. nh hng thun nghch Nu sau khi cht c thi tc dng,

bng bin php x l c bit (qu trnh ti sinh xc tc), b mt v tnh cht xc

tc c phc hi tr li. nh hng khng thun nghch (vnh vin) B mt v

tnh cht xc tc khng th khi phc li c.

4.1.1. Cc cht u c thun nghch

a. Nc v cc hp cht cha oxy:

Nc tc dng vi clo c trong xc tc lm gim tnh axit ca xc tc :

T dn ti lm gim hot tnh xc tc. Cc hp cht cha oxy th li d

dng to thnh nc trong iu kin reforming. Cn bng H2O/Cl cn c quan


25/77


tm gi axit n nh cho xc tc. vic a thm Cl vo h trong qu trnh

vn hnh l cn thit. Ngoi ra nc cn gy n mn thit b. C th s b loi

b nc bng cch cho qua cc ct hp phcha ry phn t (zeolit 5A).Lng

nc cho php trong nguyn liu ti a l 4 ppm.

b. Hp cht cha lu hunh:trong iu kin reformings d dng chuyn ha thnh H2S, u c chc

nng kim loi do hnh thnh sulfua platin.

T , chc nng quan trng nht ca xc tc l dehydro, dehydro ng

vng ha b u c.

Trong s cc hp cht cha lu hunh th mecaptan (R-S-H) v H2S c nh

hng u c ln hn c, lm gim hiu sut v cht lng reformat, lm tngt trng kh cha hydro, tng mc lng ng cc. H2S c tnh axit nn cn gy

n mn thit b.

Hm lng cho php: 0,5 ppm.

c. Cc hp cht cha nit:

Cc hp cht nit hu cd dng chuyn ha thnh amoniac trong iu

kin reforming. Cht ny s tc dngvi Cl trong xc tc to NH4Cl, lm gim

chc nng axit ca cht xc tc, ko theo s gim hot tnh xc tc, lm tng s

hnh thnh hydro. NH4Cl li d bay hi trong vng phn ng lm tng nhit thit b. Mt khc, NH4Cl d kt tinh nhng phn lnh hn ca h thng, gy

h hng thit b:


26/77


4.1.2. Cc cht u c khng thun nghch

Cc kim loi kim v kim th lm trung ha tnh axit ca cht mang (Al2O3),to thnh hp cht aluminat kh bn.

Cc kim loi As, Cu, Pb, Zn, Hg, Si, Fe kt hp vi Ptto mi linkt bn,

u c vnh vin tm kim loi khng phc hi li c .T d lm mt chc

nng chnh l hydo- dehydro ho ca xc tc.Cc kim loi ny cn tch t trong

c 4 l phn ng, lm gim nhit vng phn ng, dn ti mt hot tnh xc

tc tng th.Hm lng cho php i vi mi kim loi: ti a 5 ppb.

bo v hu hiu cc cht xc tc reforming bin php bt buc v hiu

qu trong cng ngh l phi c phn xng x l s b nguyn liu bng hydro

(hydrotreating) nhm loi b cc cht c thun nghch v khng thun nghch

trn, nht l trong trng hp c s dng nguyn liu t cc ngun ch bin th

cp khc (hydrocracking, FCC, visbreaking...) c hm lng ng k cc cht

u c trnso vi nguyn liu naphta t ngun du th.

4.2. Qu trnh ti sinh xc tc

4.2.1. Cc phng php hot ha (ti sinh) xc tc:

Trong qu trnh lm vic xc tc c th b mt mt phn hot tnh xc tc do

nh hng ca s lng ng cc trn b mt xc tc, do nh hng ca cc

cht u c...Mt iu cn lu l, chng ta cng c gng la chn iu kin

vn hnh cho hiu sut xng cao nht hoc ch s octan tt nht (v d, tng

nhit hoc gim p sut) th s lng ng cc cng tr nn trm trng hn

(xem phn c trng ng hc ca qu trnh reforming). Vi mt lng cc qu


27/77


ln,s che ph v lm gim ng k s lng cc tm hot ng. Lc , tu

thuc vo cu to cht xc tc, s mt i mt phn hoc ton b cc chc nng

xc tc. Cn thit phic qu trnh ti sinh xc tc tr v trng thi hot ng

ban u.

Qu trnh ny c th c tin hnh bng mt s phng php sau:a. Phng php oxy ha (phng php t)

Cc lng ng trn b mt cht xc tc c loi b bng cch t chy trong

dng khng kh pha long vi Nit nhit 350 500oC. cn ch trnh

hin tng qu nhit cc b lm gim b mt, gim bn c hc ca cht

mang hoc lm tng qu trnh thiu kt lm gim phn tn kim loi.

Chu k ti sinh xc tc ph thuc vo iu kin vn hnh h thng, nhng

thng khong 6 thng mt ln. Sau mi ln ti sinh, hot tnh xc tc tr v

trng thi ban u, nhng sau nhiu chu k ti sinh xc tc s gi ha v gim

kh nng xc tc. Vic ti sinh xc tc s tr nn thng xuyn hn., cho n

khi cn phi thay th xc tc mi. Thi gian tn ti ca xc tc reforming thng

khong vi nm.

Qu trnh t cc c biu din bng phong trnh sau:

CnHm + O2 CO2 + H2O + Q

y l qu trnh ta nhit, nhng khi nh hng n cht lng xc tc

cn gim thiu lng nhitta ra (T 0oC).iu ny cn thit v: nhit cao

lm gim din tch b mt v c th lm thay i pha ca oxyt nhm Al2O3,nhit

cao cng lm xy ra qu trnh thiu kt lm gim phntn ca Pt.

Trong cng ngh CCR (ti sinh xc tc lin tc) qu trnh oxy ha c thc

hin trong vng t (Burn Zone).

b. Phng php kh

Thc t cho thy, cc hp cht lu hunh khng c loi b hon ton

bng qu trnh oxy ha, cn tn ti ch yu cc hp cht dng sunfat. Phng

php kh c tin hnh nhm loi b trit cc dng hp cht ny v.cc kim

loi tp c hi trong xc tc, quan trng hn c l kh Pt oxyt v dng Pt n

cht.

Trong cng ngh CCR, qu trnh kh xy ra ti vng kh (Reduction Zone).

c. Phng php clo ha


28/77


Trong qu trnh lm vic axit ca xc tc gim, mt phn do cc lng

ng che ph b mt oxit nhm, mt phn do lng clo trong xc tc gim do

nh hng ca H2O trong nguyn liu v trong kh tun hon. Clo cng c th

mt do cun theo sn phm phn ng. Do cn phi b sung axit cho h xc

tc bng cch bm thm mt lng nhCl hu c.Lng Cl trn xc tc cgi mc 1% khi lng.

4.2.2. Qui trnh ti sinh xc tc

Qui trnh ti sinh hon chnh cht xc tc gm cc bc sau:

1. Trng ra h thng: Dng dng nit thi sch cc hydrocacbon cn st

li sau phn ng.

2. t cc: t bng dng khng kh pha long vi N2 (c kim sot hm

lng oxytrong kh) v nng dn nhit t theo chng trnh:

-Nhit : t 370oC n 480oC

-Oxy: t 0,5 n 2,0 % th tch

3. Oxy-clo ha: Bm cc tc nhn cha Cl vo h nhm gi n nh lng

Cl cn thit cho xc tc (1% trng lng).

-Nhit : 510oC

-Oxy: 5% th tch

4. Qu trnh nung: Mc ch lm kh xc tc vphn tn li platin

-Nhit : 510oC

-Lng oxy: 8% th tch

-Thi gian: 4 gi

5. Qu trnh kh: chuyn Pt t dng b oxit ha v dng kh (dng hot

ng).Loi oxy bng cch trng vi nit. Sau a hydro vo h.

-Nhit : 480oC

-Hm lng H2: ti thiu 50% th tch

-Thi gian: 4 gi

5. iu ch xc tc reforming

C th hnh dung tng th thnh phn cu to xc tc reforming hin i vi

cc chc nng ca cc thnh phn qua s di y:


29/77


Nh trn nu, xc tc reforming bao gm2 hp phn chnh:

+ Oxit nhm (dng ) c chc nng axit, to thun li cho cc qu trnh ng

phn ha, ng vng ha, cracking, ng thi ng vai tr cht mang, do c b

mt ring ln n gip tng ti a din tch b mt ca pha hot tnh. Lc axit ca

cht mang c iu chnh bng ion Cl c a vo trong qu trnh iu ch

xc tc v a thm trong qu trnh vn hnh xc tc.

+ Pt (hoc a phn l Pt kt hp vi mt s cht xc tin nh Re, Ir, Sn,

Ge...) ng vai tr pha kim loi (pha hot tnh), thc y cc qu trnh dehydroha parafin, naphten, hidro phn, cc ha..

m bo vai tr cht mang, oxyt nhm cn c cc tnh cht sau:

- Hm lng tp cht cho php:

Na < 50 ppm

Fe < 200

- Cu to:

Ttrng ht 1.1 g/cm3

B mt ring 180-220 m2/g

Tng th tch l xp 0.60 cm3/g

- Tnh cht c hc:

Ttrng nhi 0.6-0.7 g/cm3

Kch thc ht 1-2 mm


30/77


Lc nghin nt > 1 MPa

ng thi phi thun tin cho vic nh v pha kim loi v khng thay i tnh

cht trong thi gian s dng.

Oxyt nhm c thc ch to bng cc phng php to ht bng thit b

to ht dng a (Pan granulation), phng php p n (Extrusion) v phngphp to git trong du (Oil drop).

Pha kim loi (Pt v cc kim loi ph gia) thng c mang ln cht mang

bngphng php tm: thng dng dung dch mui [PtCl6]2- rt y ln cht

mang, quay u, sau dung mi c tch ra khi cht mang bng phng

php bay hi. Nh vy trn b mt cht mang to cc vi tinh th mui platin, sau

khi kh trong dng H2s to c cc ht Pt ring r.

Cc phn ng xy ra trong qu trnh tm:

Trong cng nghip, ngi ta iu ch xc tc reforming theo cc bc sau

(hnh 12):

-a Cl-

vo h


31/77


Hnh 12. Cc bc iu ch xc tc reforming trong cng nghip

Hnh 13. M hnh thit b tm trong cng nghip a kim loi ln cht mang


32/77


Hnh 14. Cc phng php to ht oxyt nhm trong cng nghip

Trn hnh 13 gii thiu m hnh phng php tm kim loi hot tnh ln cht

mang. Hnh 14 m t 3 phng php thng dng to ht cho cht mang ca xc

tc reforming: to ht trn thit b dng a (a), to ht ri trong du (b), n vin

(c).

6. Nghin cu cc c trng ca xc tc reforming

6.1. Xc nh b mt xc tc bng phng php hp phvt l

Nhm so snh cc cht xc tc khc nhau hoc nh gi nh hng qu

trnh x l n tnh cht xc tc, ngi ta thng xc nh thng s b mt ca

cht xc tc rn.

Nguyn tc ca phng php o b mt tng ca cht xc tc l o hp ph

vt l cc phn t kh hoc lng ln b m t xc tc.

a

(b)

(c)


33/77


Theo Emmet v Brunauer, nu hp ph kh bi lc Van Der Waals ti nhit

si ca kh (hp ph vt l) ta s c, p sut tng i cao, hp ph a

phn t v ngng t mao qun.

Hin nay phng trnh BET, c xy dng trn c s hp ph a phn t,

tuy cn phi t ra mt s gi thit, nhng c coi nh mt phng php tiuchun nh gi b mt ring ca cht xc tc.

Phng trnh BET c ng dng thc t dng:

Vi P-p sut cn bng ca kh hp ph

Po-p sut hi bo ha ca kh b hp ph

V- th tch b hp ph p sut P

Vm-th tch b hp ph ca mt lp n phn t

C-H s c nh ph thuc vo nng lng hp ph

y l dng phng trnh tuyn tnh vi: 1 / Vm.C l tung v

C -1 / Vm.C l h s gc.T c th d dng tnh c Vm.

B mt ringxc nh theo phng trnh BET l tch sca s phn t b

hp ph nhn vi b mt ct ca mt phn t b hp ph chim ch trn b mt

cht rn. Ngi ta thng dng nit lm cht b hp ph xc nh b mt

ring. Lc ta c phng trnh n gin:

SBET = 4,3.VmPhng trnh BET c thp dng xc nh b mt ring ca tt c cc

cht rn, vi iu kin p sut tng i (P/Po) nm trong khong 0,05 n 0,3

v hng s C >1.

6.2. Xc nh phn tn kim loi bng phng php hp ph ho hc

Xc tc thng cha pha kim loi hot ngmang trn cht mang th ng

(v d, xc tc reforming thng cha Pt kim loi mang trn oxyt nhm ). Tng

hm lng kim loi hot ng a ln cht mang c xc nh trong qu trnh

iu ch xc tc.

Tuy nhin, trong qu trnh nung, x l xc tc hoc qu trnh phn ng

thng xy ra nhit cao, lm cho mt s tm kim loi hot ng tr nn

khng thun li hoc mt hot tnh i vi phn t cht phn ng, do chng di


34/77


chuyn vo trong th tch cht mang hoc thiu kt to nn cc phn t ln

hn.... T dn ti lm gim b mt ring hot ng.

Rt cn thit phi nh lng s tm hot ng hu dng thc t v chng

lin quan n tnh nng ca cht xc tc ni chung v hiu qu hot ng xc

tc. phn tn-T l cc tm kim loi hot ng, thun li cho tc nhn phn

ng trn tng s lng cc tm hot ng.

phn tn cao lm tng hot tnh ca cht xc tc. Cc cht mang c b

mt ring ln (xc nh bng phng php hp ph vt l) cho php iu ch cccht xc tc vi phn tn cao hn.

Ngi ta thng dng phng php hp ph ha hc xc nh phn

tn ca kim loi.

Hp ph ha hc c phn bit vi hp ph vt l bi nhit hp ph (hp

ph ha hc ta nhit mnh, nhit hp ph c th ln ti 500 kcal/mol) v c

thc hin vi cc kh hp ph nh H2, CO... nhit cao hn so vi hp ph

vt l (thng nhit phng), tu thuc i lc ca kh i vi kim loi v bc

phn ly tlng.T phng trnh ng nhit hp ph ha hc Langmuir ngi ta c th tnh

c s lng cc tm kim loi hot ng hu dng Ns , t xc nh c

phn tn.

Phng trnh Langmuir:

Vi N-S lng cc tm b chim bi phn t kh b hp ph Ns-Tng s lng cc tm hu dng

b-H s, ph thuc vo H v T

Va-Th tch b hp ph

Vm-Th tch hp ph lp n

Ns c th nhn c t th ph thuc P/N = f (P)


35/77


Ngoi ra ngi ta cn c th s dng phng php ph hng ngoi xc

nh phn tn ca kim loi. Ngi ta bit kh CO d to phc vi hu ht cc

kim loi chuyn tip vi cc dng linkt khc nhau. Tn dng c im ny,

ngi ta cho CO hp ph ln tm kim loi ca xc tc v tin hnh o ph hngngoi ca CO, s tnh c s lng phn t CO hp ph v tm c cc dng

lin kt khc nhau gia kim loi v CO. T c th xc nh c phn tn

ca kim loi.

V d, ngi ta c cc s liu IR trn bng sau, khi cho CO hp ph ln cc

kim loi khc nhau:

Kim loi Cht mang di bc

sng (cm-1)

Lin kt

Pt SiO2 2075

1850

Pt =C =O

Pt

C=O

Pt

Pd SiO2 2050

1900

1830

Pd =C =O

Pd

C=O

Pd

Ni SiO2 2030

1905

Ni =C =O

Ni

C=O

Ni

6.3. o phn b kch thc ht bng phng php nhiu x tia X (phng

php Rn ghen)

Phng php nhiu x tia X cho php xc nh b rng ca cc vch nhiu

x ca cc ht nh hn 50 nm (do khi chiu tia nhiu x cc vch ny b dnrng), t c th tnh ton kch thc trung bnh ca ht theo phng trnh

Sherrer:

Bc = Kc. /d. cos

(Bc- rng ca vch, Kc-hng s = 0,893, - di sng, d-kch thc

tinh th, -gc Bragg).


36/77


T ngi ta c thxc nh c s phn b kch thc ht. Tuy nhin

phng php ny khng nhy vi cc ht 5 nm v vch b dn qu ln.

6.4. Xc nh trng thi ha trca kim loi bng phng php rn ghen.

Xc tc d th thng c hnh thnh t mt hay nhiu pha kim loi trn

cht mang. V d, xc tc reforming c th dng n kim loi Ni/Al2O3, hoccha ng thi Ni v Rh mang trn oxyt nhm. Bng phng php nhiu x tia

X, ngi ta xc nh c xc tc n kim loi (Ni) cha 2 pha: Ni kim loi v

dng spinellin kt vi cht mang NiAl2O4. pha sau t c hot tnh xc tc so vi

pha u.Ngi ta cng thytrn xc tc lng kim Ni-Ru/Al2O3, ngoi cc pha

oxyt kim loiring r, cn c s to thnh hp kim dng Ni-Rh trn xc tc lng

kim, v dng ny c hotng xc tc.

Cu hi Bi 3:

1. Th no l xc tc a chc nng. Nu v d trong trng hp xc tc

reforming.

2. Vai tr ca kim loi ph gia trong xc tc lng kim. Gii thch vai tr c

th ca Re v Sn trong cng ngh bn ti sinh v cng ngh CCR.

3. Phn bit u c xc tc thun nghch v khng thun nghch. Cho v d

trong trng hp xc tc reforming.

4. Ti sinh xc tc nhm mc ch g. Cc bin php ti sinh xc tc

reforming trong cng nghip.

5. Hy nu s tng qut iu ch xc tc reforming trong cng nghip.

6. Lit k v nu nguyn tc cc phng php nghin cu c trng xc tc

reforming.


37/77


BI 4. NGUYN LIU V CC SN PHM THU

M bi: HD F4

Gii thiu

Hiu bit v nguyn liu v cc sn phm ca qu trnh reforming gip la

chn iu kin vn hnh thch hp vi cc nh hng sn phm c th ca

cng ngh reforming trong tng nh my lc du.

Mc tiu thc hin

- Nm c c im v nguyn liu ca qu trnh. nh hng ca

thnh phn, tnh cht nguyn liu n qu trnh.

- Nm c cc sn phm thu c t qu trnh reforming, hng ng

dng.

- Nm c nh hng cc thng s vn hnh (nhit , p sut, t t

H2/ HC tc np liu) n hiu sut, cht lng sn phm chnh.

Ni dung chnh

- Nguyn liu ca qu trnh

- Cc yu t nh hng n qu trnh reforming xc tc

- Sn phm ca qu trnh reforming xc tc

1. Nguyn liu ca qu trnh

- Xut x:

Xng tchng ct trc tip

Xng t qu trnh Visbreaking, Hydrocracking

Phn on gia ca sn phm FCC

- Thnh phn:

Hn hp hydrocarbon tC7 n C11 (trong trng hp nh my khng

c phn xng isomerisation c th s dng P C5 n C11)

- Tnh cht:

Khong chng ct: 60-180CTtrng: 0.7-0.8 g/cm3

Trng lng phn t trung bnh: 100-110

RON: 40-60

Thnh phn nhm:

paraffin: 40-60 wt%


38/77


olefin: 0 wt%

naphtene: 20-30 wt%

aromatic: 10-15 wt%

- Hm lng tp cht:

Xc tc rt nhy vi cc cht c c trong nguyn liu cn thit phi lmschnguyn liu (dng cc cng ngh lm sch HDS, HDN, HDM)

Gii hn tp cht cho php trong nguyn liu(sau khi lm sch):

S < 1ppm

N (hu c) 1 ppm

H2O (v cc hp chtcha oxy) 4 ppm

Kim loi (As, Cu, Pb...) 15 ppb

Olefin v cc diolefin = 0

Halogen (F) 1 ppm

1.1.Gii hn nhit chng ct ca nguyn liu:

V nguyn tc ngi ta c th s dng phn on naphta t 60 180oC

tin hnh qu trnh reforming. Nhng ngy nay ngi ta thng s dng cc

phn on c gii hn si u 80oC lm nguyn liu. Gii hn si u uc

thit lp nh vy nhm loi bt cchp phn C6d chuyn ha thnh benzen l

mt hp cht c hi, cn tin ti loi b theo tiu chun mi v mi trng.

Cc hnh 15, 16 cho thy nh hng la chn nhit si u n hiu

sut reformat, cht lng reformat (th hin qua ch s RON) v n hm lng

benzen to thnh.


39/77


Hnh 16.nh hng nhit si u n hm lng benzen v ch s Octan.

Gii hn si cui ca nguyn liu thng c chn trong khong 165 0C -

180oC. Gii hn si cui ca nguyn liu khng nn cao qu 180oC v xngreforming cha nhiu hydrocacbon thm, c nhit si ln hn nguyn liu

khong 20oC. M gii hn si cui ca xng thnh phm (cha t 40-50%

reformat) theo tiu chun th gii ch cho php n 200 205oC. Ngoi ra nu

im si cui ca nguyn liu qu cao s dn ti qu trnh cc ha cc

hydrocacbon nng, lm gim hot tnh xc tc.

nh hng chiu di mch cacbon (lin quan n im si cui ca nguyn

liu) n chuyn ha naphten t thy r v phn ng xy ra nhanh. i vi

parafin, chiu di mch cng tng (trng lng phn t cng cao) th qu trnh

dehydro vng ho cng thun li. Tuy nhin mch cacbon cng cng d gy hn

do cracking. (hnh 17).


40/77


Hnh 17.nh hng s nguyn tC n qu trnh dehydro vng ha parafin vcracking.

1.2. Thnh phn hydrocacbon ca nguyn liu

Nh trong bi 2 trnh by,phn ng dehydro ha naphten thnh hp

cht thmxy ra d dng, vi vn tc ln hn nhiu so vi phn ng dehydro

vng ha parafin thnh hp cht thm. Nh vy, nguyn liu cng giu parafin

cng kh chuyn ha thnh reformat so vi nguyn liu giu naphten. C th m

t nh tnh s chuyn ha trn 2 phn on nh trn hnh 18.

V vy, t uc cht lng sn phm mong mun (v d, vi RON nhtrc) nguyn liu giu parafin i hi nhit phn ng cao hn (tng khc

nghit ha ca qu trnh).

Hnh 18. Ph thuc thnh phn sn phm vo tnh cht nguyn liu


41/77


Trong cng nghip ngi ta thng nh gi kh nng chuyn ha ca

nguyn liu thnh sn phm thm da vo gi tr N + 2A (N, A-% trng lng

ca naphten varomat tng ng c trong nguyn liu). Gi tr ny cng cao th

kh nng thm ha cng ln, khc nghit ca qu trnh vn hnh cng gim.

Ch s N+2A bin thin trong khong 30- 80.Hng UOP (M) c a ra h s KUOP c lin quan n ch s N+2A theo

cng thc sau: KUOP = 12,6 (N+2A)/100.

Trn bng 4 gii thiu mt s nguyn liu tiu biu ca du th th gii

thng c la chn cho qu trnh reforming xc tc.

Bng 4. Thnh phn v tnh cht ca mt s nguyn liu reforming

Naphta

trung bnh t

hydrocrackin

g

Naphta

Trungng

Naphta

giu parafin

( rp)

Naphta

giu

naphten

(Nigeria)

ASDTM D86, oC

IBP

10%

30%

50%

70%

90%

FBP

98

115

127

140

157

180

201

81

105

113

119

129

143

166

92

106

115

123

132

147

155

88

107

115

123

132

145

161

Thnh phn,% V

Parafin

Naphten

Aromatic

N+2A

RONd415

33

55

12

79

620,775

45

45

10

65

550,754

66,8

21,8

11,4

44,6

500,716

29,3

61,9

8,8

79,6

660,779

Tu thuc vo tnh cht du th m cc phn on nguyn liu ny cng rt

khc nhau v thnh phn v tnh cht. V d, du th nhiu parafin cho ch s

octan ca nguyn liu v ch s N+ 2A thp hn nhiu so vi du naphten.


42/77


Vi mc ch sn xut BTX cho ha du th vic la chn ngun nguyn liu

v gii hn im ct phn on ng vai tr quan trng. thu tng BTX ngi

ta thng chn phn on 60- 145oC. Nu ch thu benzen chn P 65-85oC.

Thu toluen chn P 85-120oC. Thu xylen chn P 120-145oC.

1.3. Hm lng tp cht trong nguyn liu:Cc hp cht khng phi hydrocacbon, nht l cc hp chtcha lu hunh

v nit cn gim ti gii hn cho php.

Gii hn cho php cc tp cht:

S: 0,5 ppm , N (hu c): 1 ppm

H2O (v cc HC cha oxy): 4 ppm, As: 5 ppb

Olefin: khng c c , diolefin: khng c c

Kim loi: 5 ppb , halogen (F,Cl): 1 ppm

1.4. X l s b nguyn liu reforming:

Trong cng nghip y l khu cn thit v bt buc, nhm mc ch sau:

- Loi tr cc cht u c xc tc reforming (hp cht S, N, nc, cc

kim loi)

-iu chnh im ct nguyn liu ph hp

C th tm tt cc bc x l s b nguyn liu nh sau:

- Cho nguyn liu v hidro i qua l phn ng c cha xc tc

NiMo(hoc CoMo) nhm loi tr cc kim loi, cc hp cht cha lu

hunh v hp cht cha nit (gi chung l cc qu trnh x l dng

hidro).

- Trong trng hp nguyn liu l cc phn on xng cracking cn thm

giai on x l lm no ha olefin nhm loi tr kh nng to nha.

- Tip theo cho nguyn liu qua ct tch loi H2S v nc.

- Trong nhiu trng hp,cn tch phn on xng nh (a vo phn

xng isomer C5/C6) ra khi phn on xngnng (dng cho reforming

xc tc).

2. Cc yu t nh hng n qu trnh reforming xc tc

- Nhit thit b phn ng

-p sut thit b phn ng

- Tc np liu

- T l mol H2/ nguyn liu


43/77


- Cht lng nguyn liu

2.1. nh hng nhit

Trong cng nghip ng nht vic nh gi hot tnh xc tc vi nhit

c cung cp u vo thit b phn ng (i vi nguyn liu c th, RON cho

trc).Nhit c ththay i nhm iu chnh cht lng sn phm, v d:

- Thay i ch s octan ca reformat

- Ph thuc cht lng ca nguyn liu np

- B tr s gi ha xc tc (gim hot tnh xc tc ) qua nhiu chu k

hot ng

- B tr mt hot tnh xc tc tm thi do cc tp cht gy ra.

Nhit tng lm tng kh nng chuyn ha thnh sn phm thm dn ti

tng ch s octan nhng li lm gim hiu sut xng. Ngc li nhit gim c

li cho hiu sut xng, gim kh, gim hiu sut to cc.

Nhit thng c chn trong cng ngh: 490-540oC

2.2. Tc np liu (tc thtch hoc tc khi lng)

c xc nh bng lu lng dng nguyn liu (th tch hoc trng lng)

i quatrong 1 gi trn 1 n v xc tc (trng lng hoc th tch lp xc tc).

Khi tng lu lng nguyn liu hay gim lng xc tc u lm tng tc

np liu, ni cch khc l lm gim thi gian tip xc ca cc cht tham gia phn

ng vi lp xc tc. Hu qu dn ti lm tng hiu sut reformat (do gim kh),

nhng ng thi lm gim cht lung reformat v gim ch s octan. iu ny

cng d hiu v cc qu trnh c tc chm nh dehydro ng vng to thm,

hydrocracking, dealkyl ha s kh xy ra hn nu thi gian tip xc t. Hiu ng

ny c th c b tr nu tng nhit l phn ng. Trong thc t, hn ch

bt hyrdrocracking v cc sn phn cc ha ngi ta thng p dng nguyn

tc sau:

- gim tc th tch: gim nhit u vo cc l phn ngsau

gim lu lng liunp.

- tng tc th tch: tng lu lng liu np sau tng nhit l

phn ng.

C th gim tc th tch tng ch s octan. Tuy nhin trong vn hnh

ngi ta khng c php gim tc trn nh hn mt na so vi thit k


44/77


hoc < 0,75 h-1. V nh vy s khng kinh t, lm tng tc kh hot tnh xc

tc.

Tc c la chnph thuc vo cc iu kin cng ngh c th: p

sut vn hnh, t l mol H2/ nguyn liu, thnh phn nguyn liu a vo v cht

lng reformat mong mun. V d cng ngh CCR mi thng chn V = 1,5 -2,5h-1.

2.3. p sut vn hnh

Cc phn ng chnh c li cho reforming u xy ra thun li p sut

thp. p sut cng thp hiu sut reformat v hidro cng cao. Tuy nhin nh

hng cc s cng trm trng hn.Do cn la chn p sut thch hp

va hn ch qu trnh to cc va t nh hng n hiu sut to xng.

p sut vn hnh i vi mt phn xng cng ngh c th l gi tr c nh

m ngi ta la chn trc nhm tho mn cht lng sn phm nht nh.

Ngy nay nh ci tin cng ngh (s dng cng ngh ti sinh lintc) vci

tin xc tc (tm c cc h xc tc c th lm vic p sut thp, cho hiu

sut xng v RON cao) m ngi ta c th vn hnh qu trnh p sut thp

nht m vn p ng yu cu vcht lng sn phm, vn u t v hiu qu

kinh t.

Cng ngh CCR tin tin nht (PLATFORMING, OCTANIZING) s dng xc

tc Pt-Sn/ Al2O3cho php vn hnh p sut t 3-5 atm (trc y cnvi chc

atm)

2.4. T l H2/ nguyn liu

Xc nh bng t l gia lu lng (mol/h) hydro tun hon v lu lng

nguyn liu np (mol/h).

Thm mt lng ln kh tun hon cha H2 (80-90% tl) nhm lm gim s

lng ng ca cc trn b mt xc tc (do tng qu trnh hydro ha cc hp cht

khng no trung gian l tin cht to cc). T l H2/NL thay i trong khong rng

(1-10). Gii hn di ph thuc lng H2yu cu nh nht nhm duy tr p sut

ring phn ca H2trong h thng. Gii hn trn xc nh bi cng sut my nn,

kch thc l phn ng v tnh kinh t qu trnh. Thay i t l ny t lm thay i

cht lng sn phm.Mt khc vi cc cng ngh CCR hin nay p sut thc

hin ch>3 atm, gim t l H2/NL trong trng hp ny tng ng vi vic lm


45/77


gim p sut ring phn ca H2 nn c tc ng thun li n hiu sut sn

phm.

V d cng ngh OCTANIZING vn hnh vi t l H2/NL =1-4, ty thuc loi

nguyn liu v gi tr RON yu cu.

C th tm tt nh hng cc thng s vn hnh (p sut, nhit , tc khi, t l H2 / nguyn liu, tnh cht nguyn liu) n hiu sut v cht lng sn

phm nh bng 5.

Bng 5.nh hng cc thng s vn hnh n hiu sut v cht lng sn

phm

S gia tng RON reformat Hiu sut reformat Hm lng cc

p sut (atm)

Nhit (oC)

Tc khi (h-1)

H2 / nguyn liu

Nguyn

liu

0,85N +A

im si u

im si cui

3. Sn phm ca qu trnh reforming xc tc

C th m t mi tng quan gia nguyn liu v sn phm ca qu trnh

reforming xc tc theo gin sau:

Naphtha

40


46/77


C3: 2-9%

Kh nhin liu C1-C2: 2-4%

Hidro: 1,5 -3,5%

Trong cc sn phm quan trng hn c l reformat (xng C5+), cc

hydrocacbon thm-m ch yu l benzen, toluen, xylen (BTX) v kh hydro kthut.

3.1. Sn phm xng reforming xc tc

Mt s tnh cht ca xng (reformat):

- Thnh phn ct: thng thng t 35 190oC

- T trng: 0,76 0,78

- Ch s octan RON: 94 103

- Thnh phn hydrocacbon: ch yu l aromatic v parafin, naphten ch

chim < 10%, olefin khng ng k.

Do c cht lng cao (ch s octan cao nht trong s cc xng thnh phn,

thu c t qu trnh lc du), hm lng olefin li rt thp nn xng reforming

c th s dng lm xng my bay.

S thay i thnh phn v tnh cht ca xng reformat trong cc gii hn

nu trn ph thuc vo nguyn liu ban u, iu kin cng ngh, cht xc tc.

V d tng quan gia nguyn liu l naptha Trung ng v sn phm

reforming trnh by trong bng 6.Thnh phn parafin trong nguyn liu kh nh

hng n cht lng xng C5+.

Bng 6. So snh Nguyn liu Sn phmreforming t du th Trung ng

d415

ASTM D86 Thnh phn, %V

IBP10

%

50

%

90

%

FB

PP N A N+2A RON

Nguyn liu 0,754 81 105 119 143 166 45 45 10 65 55

Sn phmC5+ 0,701 60 93 118 152 185 40 5 55 115 95

Nu chs dng ton breformat lm xng thng phm s khng kinh t,

do hm lng hydrocacbon thm qu cao, to nhiu cn trong ng c v gy

nhim mi trng. Xngny li c p sut hi bo ha thp, lm cho ng c


47/77


kh khi ng. Chnh v vy ngi ta a vo xng thng phm cc hp phn

khc nhxng ng phn ha, xng alkylat, butan, MTBE...

3.2. Cc sn phm kh: hydro v cc kh nh

3.2.1. Kh giu hydro

y l sn phm kh quan trng ca qu trnh reforming xc tc. Hmlng hydro trong kh chim 70 90%. Thnh phn nguyn liu, cht xc tc v

iu kin cng ngh cng nh hng n hm lng hydro trong kh. Kh ny

mt phn c s dng li cho qu trnh reforming, cn phn ln c s dng

cho cc qu trnh lm schbng hydro (HDS, HDN, HDM...) hoc cc qu trnh

chuyn ha c hydro (hydrocraking, hydroisomer ha). y l ngun thu hydro

kh r, hiu sut cao (thu c khong 90 120 Nm3/ m3nguyn liu) v c th

lm sch tumc ch s dng. Vic ci tin cng ngh, xc tc cho qu trnh

reforming nhm lm tng hiu sut xng th cng ko theo s gia tng hm

lng H2trong sn phmv thc y thm s pht trin cc qu trnh s dng

hydro.

3.2.2. Kh ho lng LPG

Kh ha lng thu c sau khicho sn phm i qua thp n nh xng,

bao gm ch yu propan v butan. Hiu sut kh ph thuc vo tnh cht

ca cht xc tc m trc tin l axit.y l sn phm khng mong mun

trong iu kin reforming, v s lm gim hiu sut ca sn phm chnh l

reformat.

3.3. Sn phm hydrocacbon thm

Qu trnh reforming cn cung cp ngunnguyn liu BTX (benzen-toluen-

xylen) cho ha du. Cc sn phm thm trong qu trnh ny chim ti 65-75%

trong tng sn phm lng hoc c th cao hn na vi cc cng ngh v xc tc

hin i. Trong c bit quan trng l paraxylen-nguyn liu cho sn xut cht

do, si tng hp, cao su nhn to, nguyn liu cho cng nghip dc phm, m

phm, thuc nhum

Cu hi Bi 4:

1. Ngun nguyn liu cho qu trnh reforming xc tc. c im chung v

thnh phn v tnh cht nguyn liu. Ti sao ngy nay ngi ta thng s

dng cc phn on si c gii hn si u 80oC lm nguyn liu?

2. Thnh phn v tnh cht nguyn liu nh hng th no n hiu sut v


48/77


cht lng sn phm? Trong CN ngi ta thng da vo i lng no

nh gi kh nng chuyn ha thnh sn phm thm ca nguyn liu?

3. Cc loi sn phm chnh thu c t qu trnh reforming xc tc?

4. Cc thng s vn hnh (nhit , p sut, tc np liu, t l H2/NL) nh

hng nh th no n hiu sut v cht lng sn phm?


49/77


BI 5. CC LOI CNG NGH REFORMING XC TC

M bi: HD F5

Gii thiu

Mc ch bi ny nhm gip hc vin tip cn vi nhng cng nghreformimg thng dng v tin tin nht trn th gii hin nay.

Mc tiu thc hin

- Nm c cc c im v thit b, xc tc, iu kin vn hnh v cht

lng sn phm ca 2 loi cng ngh reforming xc tc hin nay.

- So snh u, nhc im ca cng ngh bn ti sinh v cng ngh ti

sinh lin tc xc tc.

- Bit cch vn hnh s reforming xc tc qui m phng th nghim,

nm c phng php phn tch sn phm v cch tnh ton kt qu

thc nghim.

Ni dung chnh

- Cng ngh bn ti sinh xc tc

- Cng ngh ti sinh xc tc lin tc

- c im thit b xc tc trong cng ngh ti sinh lin tc

- nh gi hiu qu kinh t ca qu trnh reforming xc tc

- Cng ngh reforming s dng cho mc ch ha du (sn xut BTX)

- Vn hnh s reforming qui m phng th nghim

Hin nay trn th gii tn ti2 loi cng ngh reforming ch yu: cng ngh

bn ti sinh v cng ngh ti sinh lin tc (CCR).

1. Cng ngh bn ti sinh

Mt s c im c bn:

- Lp xc tc c nh

- H thng dng nguyn liu c chuyn ng t thit b phn ng nysang thit b phn ng khc.

- Ngng hot ng ton b h thng ti sinh cht xc tc ti ch, ngay

trong thit b phn ng, khi lng cc trn lp xc tc chim 15-20%

trng lng.

Thng th chu k lm vicca xc tc trong khong 6 thng n 1 nm.


50/77


Thi gian ti sinh xc tc mt khong 2 tun l. Trong mt s cng ngh bn

ti sinh ngi ta s dng cc thit b phn ng (reactor) c cc van ng m c

lp, hoc lp thm mt thit b phn ng d tr, cho php ti sinh xc tc tng

thit b ring bitm khng cn dng ton b h thng. Tuy nhin vn hnh cng

ngh cng tr nn phc tp hn.Cng ngh bn ti sinh tng i lu i (cng ngh truyn thng), cc ci

tin ch yu ch tp trung vo xc tc. T nhng nm 1949-1950 cht xc tc

trn c s Pt (xc tc nkim loi) c a vo s dng cho xc tc tng

c nh. Loi xc tc ny tuy cho hot tnh xc tc cao, nhng c nhc im l

rt d b cc ha nn phi vn hnh trong iu kin p sut hidro kh cao (xp x

40 atm). Khong nhng nm 60,mt s kim loi ph gia c a thm vo h

xc tc Pt (xc tc lng kim), khc phc tnh trng gim nhanh hot tnh xc

tc. Cht xc tc tr nn bn hn vi qu trnh cc ha, gip qu trnh cng

ngh c vn hnh p sut thp hn (khong t 15 n 30 atm).

S n gin ca cng ngh bn ti sinh c trnh by trn hnh 19.

M t hot ng ca s

Nguyn liu (phn on naphta nng) c lm sch t qu trnh hydro

ha, c trn vi kh hydro t my nn, sau khiqua cc thit b trao i nhit

c dn ln lt vo cc l phn ng (c th t 3-4 l) c cha lp xc tc c

nh. Cc sn phm c to thnh sau khi ra khi h thng phn ng, qua thit

b trao i nhit, thit b t nng v thit b lm lnh. Qua thit b ngng t, sn

phm lng gi li, kh khng ngng c s a vo thit b tch kh. Phn ln

kh c nn li nh my nn kh v tun hontr li l phn ng. Phn kh cn

lic dn sang b phn tch kh. Hydro c tch ra t y c th c s

dng cho cc qu trnh lm sch dng hydro. Phn lng tch ra c a vo

thp n nh, thc cht l mt thp chng ct vi mc ch tch phnnh (LPG)

nhm tng n nh ca xng v gim p sut hi bo ha.


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52/77


LPG tch ra c avo thit b ngngt.Xng sn phm ra y thp, mt

phn c un nng v hi lu tr li thp n nh, phn ln c lm lnh v

a vo b cha.

Cng ngh bn ti sinh hin nay vn cn rt thnh hnh Php v mt s

nc khc. V d, Vin du m Php ((IFP) lp t c 600 phn xngbn ti sinh trn th gii so vi 120 phn xng CCR.

2. Cng ngh ti sinh lin tc (continuous regenerative-vit tt CCR)

c im:

- Lp xc tc c chuyn dng nh nhng, lin tc trong h thng thit

b phn ng vi vn tc va phi (trong khong 3- 10 ngy).

- Ton b h thng c vn hnh lin tc.

- Lp xc tc sau khi ra khi h thng phn ng c a ra ngoi ti

sinh trong mt h thng ti sinh ring. Sau c quay tr li h

thng phn ng.

Cu to mt l phn ng dng ng thng vi lp xc tc chuyn ng dng

trong cng ngh CCR c m t trn hnh 20.

Hnh 20. Cu to theo mt ct dc l phn ng reforming xc tc

61


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Kch thc l phn ng thay i trong khong : ng knh 1,5 3,5 m,

Chiu cao 4 12 m, Th tch lp xc tc: 6 80 m3.

Chi tit hn chng ta thy cm h thng thit b phn ng bao gm 3-4 l

phn ng c kch thc, iu kin vn hnh, lng xc tc np vo khng ging

nhau, t phn b thnh phn sn phm ra t mi l cng khng ging nhau(hnh 21).

H thng cu tot nhiu l phn ng gip cho dng hn hp nguyn liu

v kh giu hidro (kh tun hon) t c nhit phn ng v b tr nhit

nng t cc phn ng ha hc xy ra trong qu trnh reforming.Nhit gim

nhanh trong l thnhtdo s xut hin ca cc phn ng thu nhit quan trng

(ch yu l phn ng dehydro ha naphten), lng xc tc tiu th cho giai on

ny chim 10-15% trng lng. l phn ng th 2 nhit gim t hn, lng

xc tc tiu th chim 20-30%. Ti l phn ng cui cng, nhit gn nh n

nh do c s b tr nhit gia cc phn ng thu nhit nh vi cc phn ng ta

nhitkiu nh hydrocracking

Hnh 21. S thay i thng s vn hnh v phn b sn phmtheo v tr l

Phn ng


54/77


Hin nay c2 kiu lp t h thng phn ng trong s cng ngh CCR

(hnh 22 v hnh 23):

1. S cng nghPLATFORMING ca UOP (M): Thit b phn ngc

xp chng ln nhau. Xc tc i t trn xung qua h thng thit b phn ng, sau

tp trung li v c nng ln thit b ti sinh nh kh nng. Sau khi ti sinh,cht xc tc c a tr li thit b phn ng th nht. Nh c ly ra tng

phn v ti sinh lin tc m hot tnh xc tc n nh cao hn so vi trong trng

hp lp xc tc c nh (cng ngh bn ti sinh). Cng ngh ny hin nay c

s dng ph bin hn c (chim 70% th phn cng ngh CCR trn th gii). Tuy

nhin cng c nhc im l vn hnh kh khn do chiu cao h thng thit b

phn ng (hnh 22).

2. S cng ngh OCTANIZING ca IFP (Php): H thng thit b phn

ng c sp xp theo hng ngang. Tuy khc phc c nhc im v chiu

cao nhng li tn din tch xy dng v ng ng dn ln dn n tng gi

thnh xy dng v chi ph vn hnh cao (hnh 23). Ngoi ra c th k n cng

ngh ti sinh lin tc POWERFORMING (Anh) v cng ngh hn hp

DUALFORMING (Php), trong kt hp 2 h thng bn ti sinh v ti sinh lin

tc vi 2 loi xc tc khc nhau.Phn xng reforming xc tc ca nh my lc

du s 1 Dung qut Vit nam c lpt theo cng ngh Platforming ca UOP

(M). Phn xng ny c nhim v cung cp hp phn pha xng (reformat) cht

lng cao v p ng mt phn nguyn liu (BTX) cho ha du.


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3.c im ca thit b xc tc chuyn ng v ti sinh lin tc

So vi qu trnh bn ti sinh (semiregenerative) hoc ti sinh tun hon

(cyclic regenerative)-trong ln lt tng thit bphn ng c th dng ti

sinh xc tc m khng nh hng n vn hnh chung cah thng, th qu

trnh ti sinh lin tc cho hiusut reformat (xng C5+) lun n nh theo thi gian(hnh 24).

Hnh 24. S tng quan gia c th cng ngh v hiu sut sn phm

reformat.


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Skhc bit v cc c trng k thut (p sut vn hnh, t l H2 /nguyn

liu,loi xc tc, chu k ti sinh xc tc) v hiu sut, cht lng sn phm gia

2 cng ngh bn ti sinh v ti sinh lin tc c trnh by trn bng 7 v hnh

25. Cng ngh ti sinh lin tc t ra u vit hn v hiu sut v cht lng sn

phm v vn hnh p sut thp hn. Xu hng cng ngh hin nay trn th gii thin v s dng cng ngh

reforming ti sinh xc tc lin tc vi p sut thp nht.Tuy nhin cng ngh ny

cngc hn ch l chu k hot ng ngn hn do phi ti sinh xc tc lin tc,

i hi chi ph nng lng v chi ph u t cao hn.

Bng 7. So snh cc c trng cng ngh v cht lng sn phm gia 2

cng ngh bn ti sinh v ti sinh lin tuc

Bn ti sinh Ti sinh lin tc

p sut (bar)

H2/HC (mol)

Xc tc

Chu k hot ng

C5+ (wt %)

H2 (wt %)

RONMON

12-25

5-7

Pt-Re

6-15 thng

75-84

1.5-2 %

95-98

85-88

3 -10

1.5-4

Pt-Sn

3-10 ngy

85-92

2-3.6 %

100-102

90-92


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Pt - Sn

1

2

3

4

5

6

7

8

9

0 5 10 15 20 25 30 35

P (bar)

H2/HC (mol/mol)

1

2

3

Semi-Reg

CCR

Pt

Semi-Reg

Pt - Re

Hnh 25. Tng quan giacc c trng cng ngh v cht xc tc gia 2

cng ngh bn ti sinh v ti sinh lin tc.

4. nh gi hiu qu kinh t ca qu trnh reforming xc tc:

Di y phn tch cc s liu kinh t ca mt cm CCR (cng ngh Php)

vi cng sut 25.000 thng/ ngy:

Cn bng vt cht nguyn liu snphm:

Thnh

phn

(kg/gi)

Nguyn liu Kh giu H2Sau khi lm

sch h thngLPG Reformat

H2 - 4.604 26 - -

C1 - 917 54 4 -

C2 - 1.208 241 242 -

C3 - 869 161 1.285 -

IC4 - 288 35 840 55nC4 - 253 20 634 1.043

C5+ 121.850 309 27 115 108.720

Tng 121.850 8.448 564 3.020 109.818

* Tng gi tr sn phmtng ng 200 triu Franc trong 1 nm

Chi ph vn hnh:


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Tiu hao nhin liu: 6 tn /gi

Hi nc p sut cao: 18 tn/gi

Tiu th in nng: 1700 kwh/gi

Cht xc tc: 16 tn/nm

Tng chi ph hng nm: 32 triu Franc/nmu t:

Thit b: 500 triu Franc

Platin (xc tc): 20 triu Franc

Thi gian thu hi vn: Vn u t thu hi sau khong 3 nm.

5. Cng ngh reforming s dng cho mc ch ha du (sn xut BTX):

Cc sn phm thm Benzen Toluen Xylen, m c bit l p Xylen c

nhiu ng dng quan trng trong cng nghip ha du. T qu trnh reforming

xc tc c th thu c khong 80% BTX.

V nguyn tc, cc cng ngh reforming xc tc u c th s dng chosn

xut BTX. Hin nay xu hng chnh l dng cng ngh CCR sn xut BTX v

ch tomt s cht xc tc c hiu nhm lm tng la chn theo BTX (c

bit xc tin qu trnh dehydro vng ha parafin). V d IFP c cng ngh

AROMIZING vi cc xc tc h AR-401, AR- 405. Criterion c cc xc tc PS-20,

PS-40.

Vi mc ch sn xut BTX th vic la chn ngun nguyn liu v giihn

khong nhit chng ct ng vai tr quan trng. V d: sn xut tng BTX

chn P 60 145oC, nhm mc ch thu benzen chn 65 85oC, thu toluen

chn 85 120oC, thu xylen chn P 120 145oC.

6. Cng ngh reforming vi gii php kh Benzen trong xng:

Benzen hin nay c bit n nh mt tc nhn rt c hi, gy ung th

cho con ngi. Hin nay cc nc tin tin khng ch hm lng benzen

trong xng thng phm xung < 1%. Vi mc ch sn xut xng th vic loi

tr hp phn benzen ra khi thnh phn sn phm reformat l iu m cc nh

cng ngh hin nay rt quan tm n. loi tr ti a benzen ra khi nguyn

liu, ngi ta nng im si u ca nguyn liu ln 85oC. Tuy nhin

benzen vn lun l sn phm ca qu trnh dehydro ha naphten cha 6 cacbon

v dealkyl ha cc hydrocacbon thm mch di hn. Yu cu v khc nghit

ha ca cng ngh cng cao (th hin qua yu cu cao v RON) th hm lng


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benzen trong sn phm to thnh cng nhiu hn. Cc nh cng ngh ngh

mt s gii php sau y cho vic gim thiu hm lng benzen trong sn

phm:

Loi tr benzen v cc tin chtto benzen (cc naphten cha 6 C), bng

cch tch xng nhra khi nguyn liu reforming. Sau a vo s dng chocm ng phn ha. Ti y benzen c no ha trc khi vo h thng ng

phn ha. Cch ny c th lm gim bt 1 ch s RON ca xng reforming

nhng kh c th lm gim benzen xung mc 1% theo tiu chun mi trng.

Cch th 2 l lp thm mt ct ct pha sau loi tr cc reformat nh

(cha benzen sn phm) v hydro ha benzen thnh hydrocacbon no. Cch ny

c th gip gim benzen xung 1%, tuy nhin lm mt 1,5 ch s RON.

7. Vn hnh s reforming qui m phng th nghim:

tin hnh qu trnh reforming xc tc iu kin gn vi cng nghip,

ngha l trong iu kin p sut hidro, c th s dng m hnh thc nghim c

lp t ti Trung tm nghin cu v pht trin Ch bin Du kh (xem hnh 26).

7.1. Cu to s :

S gm 3 phn chnh:

a. B phn np liu:

Bnh cha nguyn liu lng v bm nh lng chu p vi chnh xc

cao.

My pht H2v b o tc dng H2 cung cp cho h thng duy tr p

sut v phc v cho mc ch kh xc tc sau khi lm vic.

H thng kh(khng kh, nit)cho mc ch ti sinh xc tc v trng ra h

thng.

b. B phn phn ng:

L gia nhit c h thng iu khin t ng nhit vi n nh nhit

cao (T = 2oC).

Bnh phn ng chu p sut (4 atm) l ni din ra cc qu trnh phn ng.

Bnh cu to hnh ch U nhm lm tng thi gian tip xc ca dng nguyn liu

vi vng nhit phn ng trc khi dn vo lp xc tc.

c. B phn ngng, tch sn phm v ly mu phn tch:

Cc h thng sinh hn, bnh ngng v cyclon tch lng kh.

Cc b phnly mu lng, kh em phn tch.


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7.2. Qui trnh vn hnh:

Nh bm vi lng c chnh xc caodng nguyn liu c a vo bnh

phn ng vi cc tc n nh. C th thay i tc (khi lng) np liu

bng cch thay i tc dng nguyn liuhoc thay i khi lng cht xc

tc. Dng kh hidro vi tc v p sut n nh c pha trn vi nguyn liutrc khi a vo h thng phn ng.Ti yxy ra qu trnh phn ng, cc

sn phm lng v kh c to thnh.

Phn ng c kho st vi cc nhit nm trong khong 450 520oC.

Sau khi ra khi bnh phn ng, sn phm lng c ngng li nh h thng sinh

hn, bnh ngng v c ly i phn tch. Sn phm kh qua h thngo lu

lng kh thot ra ngoi v ly i phn tch .

7.3. Phng php phn tch thnh phn nguyn liu v sn phm:

Thnh phn nguyn liu v sn phm c xc nh bng phng php sc

k kh. My sc k kh hiu HP 6890 Plus (M) vi phn mm chuyn dng

AC/DHA (dng cho phn tch cc sn phm du m) cho php xc nh chnh

xc thnh phn (%tl, %tt, % mol) v tnh ton mt s tnh cht khc ca h nh

ch s octan RON, trng lng phn t trung bnh, t trng...

Cc iu kin phn tchnh sau:

- Kh mang: He

- Detect: Ion ha ngn la FID

- Ct: HP-1, 100 m x 250 m x 0,5 m

- Nhit detect: 280oC, Nhit bung bm mu: 250oC

- Lng mu bm: 0,5 l, t l chia dng 1/100

M t phn mm AC DHA:

a) Phm vi ng dng:

- Chng trnh AC DHA dng xc nh thnh phn hydrocacbon ca cc

hn hp hydrocarbon nh nh: naptha, reformate, alkylate, xng cracking,

condensate vi khong si ln n 225oC

- C th c dng nhn bit v phn tch chnh xc vi cc cu t c

hm lng t 0,01-30% khi lng.

- C th ng dng cho cc hydrocarbon lng cha olefin nh hn 25% khi

lng, c bit l cc phn on nh ca sn phm cracking xc tc.

b) Nguyn tc s dng phn mm nhn danh AC-DHA:


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- Nhn danh cc cu t

- Tnh ch s index cho mi peak sc k

- So snh vi bng tham kho

Quy trnh t ng xc nh cc thnh phn:

i vi mi peak sau khi tnh ch s, phn mm s t ng tm trong filetham kho cho vng nhn danh m ch s index nm trong . Tip theo l i

chiu peak vi tn cu t. Chng trnh phn mm sau s t sp xp,

a ra bng bo co nhn danh cc cu t theo nhm ha hc. D liu tnh tan

cho mi peak bao gm: thi gian lu, ch s index, % din tch tng ng vi %

khi lng (% th tch, % mol).

C th biu din thnh s khi nh sau:

c) Tnh ton cc thng s vt l da trn kt qa sc k kh:

Xc nh trc tip tc qu trnh tnh tan cc thng s vt l nh t trng,

khi lngphn t trung bnh,p sut hi da vo thnh phn % cc cu t ctrong mu. Phng php ny cli im l nhanh, cn lng mu t, kh chnh

xc, c th so snh vi cc phng php tiu chun.

Xc nh gin tip tc vic xc nh cc thng s vt l nh RON v MON

c thc hin thng qua phng trnh tan hc.

RON = A + kiCI


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A, kI: hng s xc nh bng thc nghim

CI: % khi lng.

7.4. X l kt qu thc nghim

Cc s liu sc k kh c trnh by di dng cc bng kt qu reforming,

ph thuc vo s thay i cc thng s nh nhit phn ng, tc np liu, tl H2/nguyn liu. T c th nh giv hiu sut reformat, chn lc theo

sn phm thm v ngh cc iu kin vn hnh ti u ca qu trnh cho mt

loi nguyn liu v mt loi xc tc c th.

V d, trn bng 8 trnh by kt qu reforming phn on nguyn liu 85-

165oC ca du th Bch h, nhit phn ng 500oC, xc tc R-134 (M) trn

s PTN Trung tm NC&PTCB Du kh:

Bng 8. Hiu sut v thnh phn snphm reformingP 85-165oC t du th

BH.% khi lng

.Hiu sut sn phm kh 16,0

. Hiu su t reformat C5+ 84,0

Trong :

Tng aromat 74,9

Tng naphten 3,4

Tng parafin 18,4

T ng olefin 3,3RON (tnh ton) 102

Cu hi bi 5:

1. c im ca cng ngh reforming bn ti sinh xc tc. V s , m t

hot ng ca qu trnh.

2. Trnh by c im, m ts n gin cng ngh ti sinh lin tc xc

tc reforming CCR.

3. So snh s khc bit gia 2 cng ngh bn ti sinh v ti sinh lin tc.

4. c im ca cng ngh reforming s dng cho mc ch ha du.

5. V 1 s reforming qui m phng th nghim. M t qui trnh vn hnh

v nu phng php phn tch thnh phn v sn phm qu trnh.


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66/77


BI 6. S TIN B CA REFORMING XC TC

M bi HD F6

Gii thiu

Bi ny gip hc vin thy c ngha ca vic ci tin cng ngh, xc tc

i vi vic nng cao cht lng sn phm mong mun v p ng yu cu kht

khe hn v mi trng.

Mctiu thc hin

- Nm c cc ci tin ca cng ngh reforming trong thi gian qua.

- Cc nh hng ci tin trong tng lai v cc yu t rng buc.

Ni dung chnh

- Cc ci tin t c trong thi gian qua ca cng ngh reforming

(thay i v xc tc, thit b cng ngh, iu kin vn hnh)

- Xu hng ci tin trong tng lai v cc iu kin rng buc (th phn

sn phm, yu t mi trng, hng pht trin ha du)

Cng ngh reforming tri qua nhiu thp nin pht trin c ci tin

theo cc hng sau:

- Gim p sut vn hnh lm tng hiu sut reformat v hydrogen.

- Tm ra cc loi xc tc mi bn hn, c tui th cao hn (t b tc ngcc

ha trong iu kin gim p sut), v c la chn theo sn phm thm cao

hn.

- Thay i s cng ngh trong xc tc c tun hon v c ti

sinh lin tc.

S ci tin cng ngh v xc tc reforming nh trn dn ti s tin b ng

k v cht lng sn phm reforming (bng 9).

Bng 9. S tin b v cht lng sn phm reforming

Sn ph m,(%tl)

1960 1970 1980 1990 1998

H2 2,0 2,7 3,2 3,3 3,8

C1 + C2 4,4 3,1 1,2 1,1 -

C3 + C4 13,1 10,4 8,0 6,9 -

C5+ (reformat) 80,5 83,8 87,6 88,7 88,0


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RON RON = 100-102

Yu cu xc tc l tng: H2 = 5%, C5+ = 95%

Vi nhng tiu chun nghim ngt mi v mi trng, vic loi b hon

ton hp phn ph gia ch c trong xng m vn phi bo m cht lng xng

thng phm (ch s octan cao) cng cho thy vai tr quan trng ca reformingtrong cng nghp lc du.

Cc s liu mi nht v thnh phn xng thng phm th gii c trnh

by trn bng 10.

Bng 10. Thnh phn xng thng phm th gii

Thnh ph n, %tl Php M Ty u

- Butan

- Xng nhit phn

- Xng nh

- Xng ng phn ha

- Xng alkyl ha

- Xng FCC

- Xng reforming

- Hp cht cha oxy

(MTBE, etanol)

4,0

6,0

-

10,0

5,0

40,0

33,0

2,0

5,5

-

4,0

4,7

13,0

36,1

34,6

2,1

5,7

-

7,6

5,0

5,9

27,1

46,9

1,8

Bng 10 cho thy M, Php hp phn xng reforming trong xng thng

phm ch thua km khng ng k so vi xng cracking , cn Ty u, xng

reforming chim phn p o (phn na th phn).

Trong nhiu trng hp, thu c xng thng phm khng ch RON 95

v RON 98 ngi ta a vo hp phn xng reforming ln ti 60%-80%.


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Xng khng ch RON 98

Xng khng ch RON 95

Hnh 27. Thnh phn mt s loi xng thng phm cao cp khng ch

Trong tng lai sp ti, ngi ta s phi tip tc ci tin cng ngh

reforming hn na nhm tho mn cc yu cu cao hn v cht lng sn


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phm. Tuy nhin cc khuynh hng ci tin v pht trin cng ngh cn ph

thuc vo nhiu yu t:

- Khuynh hng th trng xng du

-Khuynh hng cht lng xng: yu cu v ch s octan, yu cu gim

thnh phn thm (c bit benzen, t 2005 nhiu nc khng ch thp hn0,5%), xu hng s dng nhin liu hn hp (xng, alcol tng hp) cho ch s

octan siu cao.

-S thay i phn b th phn cc sn phm du m theo xu hng tng

lng sn phm nh. Mt s hp phn xng t cc qu trnh cc ha,

cracking, visbreaking s c a vo reformat trc khi pha trn

-Kh nng pht trin cng ngh reforming theo hng ha du (to ngun

hydrocacbon thm).

Cu hi Bi 6:

1. Nu cc tin b v cng ngh reforming xc tc hin nay.

2. Khuynh hng ci tin v pht trin cng ngh reforming trong tng lai

ph thuc vo cc yu t no ?


70/77


BI 7.C IM CA XNG REFORMING XC TC

M bi: HD F7

Gii thiu

Xng reforming l sn phm ch yu ca qu trnh reforming v l mt trongnhng hp phn quan trng nht pha xng thng phm. V vy hiu bit k

v cc c im ca xng reforming l cn thiti vi hc vin.

Mc tiu thc hin

- Nm c cc c im v thnh phn ha hc v tnh cht ca xng

reforming.

- Nm c cc gii php nhm lm tng cht lng xng reforming

Ni dung chnh

- Thnh phn ha hc ca xng reforming xc tc

- Ch s octan ca xng reforming xc tc

- Tnh cht ca xng reforming xc tc

- nh hng ca tin b v cng ngh, thit b v xc tc n cht lng

xng reforming ngy nay.

1. Thnh phn ha hc ca xng reforming xc tc

Xng reforming xc tc c thnh phn ha hc chyu l cc hydrocacbon

thm v cc parafin, hm lng naphten chim di 10%, olefin hu nh khng

ng k (0-2%).

Nh trn nu, thnh phn v cht lng ca reformat (xng C5+) ph

thuc vo nguyn liu ban u, cht xc tc, qui trnh cng ngh. C th tham

kho bng di y (bng 11) thy nh hng thnh phn parafin ca

nguyn liu n thnh phn ha hc v tnh cht ca xng.

Bng 11. nh hng nguyn liu n cht lng xng reforming

Thnh phn v tnh cht xng Hm lng parafin trong nguyn liu (%tl)

> 65%


71/77


Thnh phn ct, oC:

Nhit si u

10% tt

50% tt

90% ttNhit si cui

49

82

135

172202

42

76

137

170214

58

97

141

171199

58

110

141

168205

Thnh phn hydrocacbon,

%tl:

aromatic 59,0 65,4 62,0 68,5

Parafin+ naphten 38,8 33,7 37 31,1

olefin 2,2 0,9 1,0 0,5

Ch s octan:

MON 80,0 85,0 80,0 85,0

RON 89,0 95,5 89,0 95,5

Bng 11 cho thy, khi xng thu c c cng ch s octan,nguyn liu t

parafin s cho xng c thnh phn ct nng hn so vi nguyn liu nhiu

parafin.

Cc kt qu kho st phn nguyn liu (trang 34, hnh 18) cng chothy

nguyn liu giu naphten (t parafin) s cho xng giu aromat hn, ngha l xng

c cht lng cao hn so vi nguyn liu giu parafin.

Cho n nay, phng php hu hiu nht xc nh thnh phn ha hc

ca xng reforming vn l sc k kh. Vi s ci tin khng ngng v k thut

sc k kh(h thng t ng ha, iu khin in t, cc loi ct mao qun c

tch cao....) kt hp s dng cc phn mm chuyn dng cho phn tch sn

phm du kh, lm cho vic xc nh thnh phn sn phm reforming tr nn

d dng v chnh xc hn nhiu so vi trc y. C th k n h thng sc k

kh HP-6890 ca hng Agilent (M) kt hp vi phn mm phn tch chuyn

dng AC DHAca hng AC (M) t ti Trung tm nghin cu v pht trin chbin Du kh( c m ttrong phn S thc nghim reforming) nh mt

v d v loi thit b phn tch cao cp, p ng yu cuphn tch thnh phn

xng reformat.

2. Tr s octan ca xng reforming xc tc


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Thnh phn hydrocacbonthm caong vai tr quyt nhn ch s octan

cao ca xng reforming. Ch s RON ca reformat thu c nm trong khong

95 -103, tu thuc nguyn liu ban u v khc nghit ha ca iu kin vn

hnh. Trong cc cng ngh reforming xc tc hin i RON thng t 100-103.

Tuy nhin, s phn b khng ng u ca ch s octan theo cc im ct phn on xng, do hydrocacbon thm tp trung ch yu cc phn on si

cao, nn ngi tathng pha thm cc hp phn si nh, c ch s octan cao

thu c t cc qu trnh ch bin khc, ci thin nhc im ny.

Tr s octan ca xng reforming xc tc ni ring, cng nh tr s octanca

xng thng phm v cc xng thnh phn khc u c xc nh theo 2

phng php tiu chun l: phng php nghin cu (Research Method ASTM

D 2699) o ch s RON v phng php m t (Motor Method ASTM D 2700).

C hai phng php ny nhm o kh nng chng kch n ca xng t. i vi

mt loi ng c nht nh, vn hnh trong iu kin n nhth kh nng chng

kch n ch ph thuc duy nht vo cht lng nhin liu (xng) m thi.

RON v MON ch khc nhau c bn svng quay ca m tthnghim

(600 vng/ pht i vi RON v 900 vng /pht i vi MON). i vi cc phn

on sn phm du m, MON thng thp hn RON vi n v.

Ngi ta cng thng quan tm nhiu s gia gi tr RON v MON

nhy cm (Gasoline Sensitivity). i lng ny lin quan n bncht ha hc

ca xng v xng c nhy cm thp s cho hiu qu s dng tt hn khi

dng cho t. Trn bng 12 so snh tng i s khc bit v t trng, ch s

RON v nhy cm gia cc nhm hydrocacbon. Xt theo nhy th xng

reforming do nhiu hydrocacbon aromatic s khng t hiu sut cao nh cc

loi xng c thnh phn parafin cao, nn ngi ta thng phi pha thm cc

xng khc giu i-parafin nh xng ng phn ha, alkyl ha...

Bng 12. Tng quan tng ich s octan vo cu trc nhm hydrocacbon

Tnh cht Hydrocacbon

n-Parafin i- Parafin Naphten Aromatic Olefin

T trng lng thp thp trung bnh cao thp

ch s octan RON rt thp cao trung bnh rt cao cao

nhy RON- MON rt thp rt thp thp cao rt cao


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xc nh ch s octan, ngoi phng php tiu chun nu trn,

phc v cho mc ch nghin cu hoc trong cc phng k thut nh my lc

du nhm mc ch s b nh hng thnh phn octan trong pha trn xng,

ngi ta cn s dng cc phng php sc k kh, ph hng ngoi. Tuy cha

c cng nhn l phng php tiu chun nh gi ch tiu k thut caxng v t nhy vi xng pha ph gia, nhng cc phng php ny c nhng li

im nh phn tch nhanh, lng mu cn rt t, chnh xc chp nhn c

nn hin naythng c s dng cho cc mc ch nu trn.

3. Cc tnh cht ca xng reforming xc tc

Ngoi ch s octan, ngi ta cn quan tm n cc c im k thut sau

yca xng reforming:

-Khong chng ct theo ASTM D 86: im si cui: gii hn cc i l

205oC (do gii hn qui nh im sicui ca xng thng phm).

im si u: nm trong khong 35-60oC, nhng thng l 50 60oC (do

mc ch reforming hin nay nhm chuyn ha cc hp phn >C6 trong nguyn

liu vi Tsd>80oC).

-T trng ring: Nm trong khong 0,760-0,780. c trng ny thng cao

do thnh phn hydroccbon trong sn phm cao (>50%)

-p sut hi bo ho RVP: Gii hn trn khng vt qu 30 kPa

-Hm lng olefin: Lin quan n tnh n nh ca xng, khng ch < 2%tt.

Hin nay trong nhiu cngngh reforming hu nhloi tr olefin trong sn phm

xng

-Hm lng benzen: Do tnh c hi ca benzen i vi mi trng m

benzen cn gim thiu trong xng reforming. Loi tr benzen bng cc gii php :

tng nhit si u ca nguyn liu ln >80oC, s b tch benzen v

cyclohexan ra khi sn phm.

Cng ngh CCR vi xc tc PtSn khng ch benzen trong xng

khong 2%tl.

4. nh hng ca tin b v cng ngh, thit b v xc tc n cht lng

ca xng reforming xc tc ngy nay

Nhtrn nu,vic a cc h xc tc lng kim loi, m i din l cc

h xc tc Pt-Re / Al2O3, Pt-Sn / Al2O3, gip tng bn v tui th ca cht

xc tc, t tng chu k hot ng ca cht xc tc (trng hp Re) hoc gip


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lm tng hiu sut reformat v la chn theo sn phm thm (trng hp Sn)

tc l lm tng cht lng ca xng reforming.Vic a cc h xc tc lng

kim mi cng lm gim p sut vn hnh ca thit b, gim t l kh H2tun hon.

Cc ci tin v cng ngh,c bit l vic a cng ngh ti sinh lin tc

CCR, trong lp xc tc chuyn ng v c ti sinh lin tc, gip hot tnhxc tc c n nh mc cao, t n nh hiu sut v tng cht lng

xng reforming.

u im ca cng ngh ti sinh lin tcso vi cng ngh bn ti sinh c

thhin rt r qua cc c im di y:

Bn ti sinh Ti sinh lin tc

p sut (bar)

H2/HC (mol)

C5+ (wt %)

H2 (wt %)

RON

MON

12-25

5-7

75-84

1.5-2 %

95-98

85-88

3 -10

1.5-4

85-92

2-3.6 %

100-102

90-92

Tuy nhin cng ngh ny cng rt ngn chu k hot ng ca xc tc, do

xc tc lm vic p sut thp s to thnh cc tr nn mnh m hn, cn cchu k ti sinh lin tc hn.

Cu hi Bi 71. Thnh phn hydrocacbon trong xng nh hng th no i vi thnh

phn v tnh cht ca xng thng phm ?

2. Cho bit phng php ch yu phn tch thnh phn xng reforming.

3. Ch s octan (CSOCT) ca xng reforming nm trong khong no ?c

im no cn lu i vi CSOCT RON, MON ca xng reforming. Cc

phng php xc nh.4. Nu mt s c im k thut ca xng reforming.

5. Cht lng xng reforming hin nay c ci tinnh cc yu t cng

ngh no ?


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KIM TRA, NH GI HON THNH MN HC

y l bi kim tra quan trng nht nh gi kt qu hon thnh m un.

Bi kim tra nn thc hin trong 60 pht. Di y l 2 kim tra mu gio

vin tham kho (c th phn hoc cho sinh vin la chn). p n c tronggio trnh v trong phn tr li cu hi mi cui bi trong gio trnh ny.

1. (10 im)

1. Mc ch qu trnh reforming xc tc. Vai tr reforming xc tc trong cng

nghip lc ha du.(2 im)

2. Nu vai tr ca cht xc tc a chc nng i vi qu trnh reforming. Nu

2 loi cht xc tc thng dng hin nay ca qu trnh bn ti sinh v ti

sinh lin tc. Vai tr ca cc ph gia chnh (Re, Sn).(3 im)

3. nh hng cc thng s vn hnh (nhit , p sut, tc np liu, t l

H2/nguyn liu) n hiu sut v cht lng sn phm.(3 im)

4. So snh s khc bit gia 2 cng ngh bn ti sinh v ti sinh lin tc. (2

im)


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CC THUT NG CHUYN MN

1. Catalytic Reforming: Qu trnh chuyn ha (reform-ci thin, ci cch) c

xc tc nhm nng cao cht lng phn on naphta c ch s octan thpthnh hp phn pha xng c ch s octan cao.

2. Reformate: Sn phm (lng) ca qu trnh reforming.

3. CCR (continuous catalyst regeneration)- Cng ngh reforming vi ch ti

sinh xc tc lin tc.

4. PONA: Php phn tch thnh phn nhm hydrocacbo

reforming xuctac

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