Bg Hoacnva Mt Cobich

7/31/2019 Bg Hoacnva Mt Cobich

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I HC NNGTRNG I HC S PHM

KHOA HO******

BI GING MN:

HA K THUT

TRN TH NGC BCH


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Chng I: NGUYN TC CA NN SN XUT HA HC

M u: i tng ca ho hc cng nghipSn phm ca cng ngh ho hc ng vai tr rt quan trng trong s pht trin

ca mt quc gia. T nhng sn phm s dng trong sinh hot n cc sn phm cngngh cao u c sn xut t nhng nh my ho hc.

Qu trnh sn xut ho hc qui m cng nghip ph thuc rt nhiu yu t.Ngoi vic nghin cu ng hc cc chuyn ho ho hc c bn chn la cu to thi tb, xc nh cc tnh cht nh bn ho, bn nhit, bn c hc ca thit b, n cn gipla chn nguyn liu v t chc lc lng lao ng ph hp.

T chc mt qu trnh sn xut phi tnh n yu t kinh t, tnh kinh t ph thuc - Cht lng v gi thnh ca nguyn liu,- Nng lng tiu tn cho mt n v sn phm- Trnh c kh ho, t ng ho qu trnh sn xut.Mt cch tng qut nhim v ch yu ca cng nghip ho hc l:- T nguyn liu u iu ch, tng hp thnh cc cht c gi tr khc nhau- Nghin cu qu trnh sn xut hon chnh t hiu qu tt nht m khng gy

nhim mi trng. Khng ngng ci tin thit b p ng yu cu ngy cng cao casn phm.- Xc nh cc ch k thut tng nng sut, cht lng sn phm n nh.- Xc nh hiu qu kinh t v gii quyt hng lot cc vn kinh t, k thut.Nhng ch tiu quan trng c trng cho hiu qu kinh t ca mt qu trnh CN hohc:- Tiu hao nguyn liu, nhin liu cho mt n v sn phm thp nht.- Hiu sut v cht lng sn phm cao nht.- Gi thnh h.Phng hng hin nay ca ngnh ho hc th gii: gii quyt, p/ trin cc mi linquan:

- t ti a nng sut vi mt thit b sn xut.- C kh ho cc qu trnh lao ng.- T ng ho v iu khin t xa, thay cc qu trnh gin on thnh qu trnh lin tc- S dng tng hp nguyn liu.- Lin hip cc x nghip sn xut ho hc lin quan

p ng cc nhu cu t ra trn, thc t sn xut ho hc phi tun theo mts cc nguyn tc c bn sau

1.1. TNG TC PHN NG HA HC

Sn xut ha hc l lm bin i thnh phn ha hc ca nguyn liu to ra ccsn phm nh cc phn ng ha hc. V vy, tc ca qu trnh sn xut ph thuc votc ca cc phn ng ha hc. Tngtc ca cc phn ng ha hc tc ngn gi thnh sn phm.Gi s trong mt h xy ra phn ng ha hc gia hai cht A v B ta c phng trnh:

mA + nB = qDPhng trnh tng qut biu th tc phn ng: v =

l s bin thin nng ca cc cht tham gia phn ng/n v thi gian.- Vi phn ng mt chiu din ra trong h ng th:

dCdt


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V = k. maC .nbC Ca - Nng cht A

Cb - Nng cht Bk - Hng s tc phn ngm, n - H s t lng ca cc cht tng ng

- Vi phn ng thun nghch v din ra trong h ng th:V = V1 - V2 = k1

maC .

nbC - k2

qdC

- Nu phn ng ha hc xy ra trong h d th (gia kh - lng, kh - rn, lng - rn) thngoi yu t nng , tc phn ng cn ph thuc vo din tip xc ca cc pha.V = k.C.F C - Cc yu t nng

F - Din tch tip xcNgoi cc yu t trn trong phng trnh tc cn c cc yu t khc nh chiu

chuyn ng ca cc cht tham gia phn ng trong thit b (ngc chiu, cng chiu...). tng tc ca phn ng ta phi tng h s tc k. H s n y ph thuc vo

nhit v cht xc tc ca phn ng.k = k0.e

-RT

E E - Nng lng hot ng ha hc ca phn ng

T - Nhit tuyt i

R - Hng s khKhi dng xc tc th nng lng hot ng ha hc ca phn ng (E) s gim do lmtng h s tc ca phn ng (k). Nhit tng cng lm tng h s tc phn ng. 1.1.1. Tng nng cc cht tham gia phn ng * Cc nguyn liu ban u cn phi lm giu, tc l loi b bt tp cht.* Khuch tn sn phm ra khi vng phn ng

Lm gim tc phn ng nghch, hoc h thp nng cn bng tng ch nhlch gia nng thc v nng cn bng.Cc phng php thng c dng nh sau:- Sn phm th kh: Dng phng php ngng t hp th s/phm ra khi vng p/ng.- Sn phm th lng: Tu theo tnh cht ca sn phm m c th thc hin tch sn

phm bng phng php kt tinh, cho bay hi hoc hp th vo cht rn.- Sn phm th rn: Tho sn phm ra lin tc tng nng cc cu t ban u1.1.2. S dng xc tc thch hp

Dng xc tc lm gim nng lng hot ha E nn tng hng s tc k v vylm tng vn tc phn ng. Trong thc t, hu ht cc qu trnh sn xut ha hc u sdng cc cht xc tc lm tng tc . Rt nhiu qu trnh nu thiu cht xc tc,trong iu kin bnh thng phn ng ha hc xy ra rt chm, thm ch hu nh khngxy ra, nhng khi c mt xc tc thch hp, nhit thch hp th phn ng xy ranhanh gp hng triu ln

Cng nghip sn xut cc hp cht hu c cng cn c xc tc. Ngoi cc xc tcha hc cn c cc xc tc vi sinh.

1.1.3. Tng nhit phn ngNh trn gii thch khi tng nhit s tng hng s tc ca phn ng.

Trong sn xut ha hc hu ht cc phn ng u din ra nhit cao hn n hit thng, c khi rt cao.V mt l thuyt nhit tng, tc phn ng tng, nhng nhit cao nhiu cht b phn hy, s n mn thit b rt nhanh, tiu hao nhiu nng lngcho qu trnh sn xut nn s tng nhit cn ph hp vi tnh hnh thc t sn xut.1.1.4. Tng din tch tip xc


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Nhiu qu trnh ha hc din ra trong h d th, trong trng hp phn ngdin ra trn ranh gii tip xc gia hai pha,v vy tng din tch tip xc gia chng slm tng mnh tc ca qu trnh.- Cht rn thng c p, nghin.- Cht lng a vo thit b di dng dng chy hoc ti chy trn trn cc vt m- Khuy trn.

1.2. THC HIN CC QU TRNH LIN TC TUN HON KN

Trong sn xut c nhng qu trnh gin on, lin tc, tun honQu trnh lin tc l qu trnh c thc hin khng mang tnh chu k: nguyn liu

c a vo ng thi sn phm c ly ra khi thit b mt cch lin tc, cc iukin phn ng trong thit b lun lun n nh.Qu trnh lin tc c cc u im sau:- Nng sut lm vic ca thit b cao, gim c gi thnh sn phm.- Do gi n nh iu kin lm vic ca thit b nn d dng t ng v c kh ha.- Gim c chi ph xy dng trn mt n v sn phm.

i vi nhng qu trnh hiu sut chuyn ha thp, cn a cc cht ban u chaphn ng quay tr li iu kin phn ng ban u tn dng trit nguyn liu, hiu

sut chuyn ha. Qu trnh nh vy gi l qu trnh lin tc tun hon kn,

1.3. LIN HIP GIA CC X NGHIP V NH MY

Trong sn xut ha hc, c th sn phm ca nh my ny l nguyn liu ca nhmy khc hoc nguyn liu ca nh my ny l ph phm ca nh my kia, v vy, slin hip s lm gim bt chi ph vn chuyn, bo m an ton sn xut, gp phn chng nhim mi trng, t lm gim gi thnh sn phm. Do vy cc nh my ha chtthng xy dng cnh nhau to ra mt khu cng nghip ha hc rng ln gm nhiungnh sn xut.V d: lin hip ha cht Vit Tr, lin hip ha cht phn m Bc Giang, lin hip ccnh my Bin Ha, cm cng nghip kh in m Ph M...

1.4. C KH HA V T NG HA QU TRNH SN XUT

Thc hin c kh ha, t ng ha qu trnh sn xut ngoi mc ch tng nngsut lao ng, tng hiu qu s dng cc ngun nguyn liu cn bi nguyn nhn sau:- Cc phn ng ha hc xy ra trong thit b thng iu kin t0 cao, P cao n nh vnghim ngt, con ngi rt kh hoc khng iu khin trc tip th cng c.- Cc nguyn liu cng nh cc sn phm u l nhng cht c th nh hng trc tiphoc gin tip n sc khe c khi cn gy chy, n lm thit hi n ca ci v tnhmng.

C kh ha, t ng ha qu trnh sn xut l mt yu cu tt yu khch quan khng

phi ch v mc ch kinh t m cn v an ton i vi con ngi.

1.5. TN DNG CC PH THI CN CHNG NHIM MI TRNG

Bn cnh vic x l cc cht c hi c hi cho sc khe, ngi ta phi tm cchbin cc cht ph thi thnh sn phm c ch cho con ngi.

V d : Trong sn xut axit sunfuric giai on t pirit st to kh SO2 sinhra mt khi lng rt ln Fe2O3, qu trnh lm sch kh SO2 cng thu c bi x, oxitkim loi asen v selen.- S dng ph thi lm gim gi thnh ca sn phm chnh, chng nhim mi tr ng


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-Trong sn xut ha hc hin i dng rt nhiu cht xc tc qu, sau mt thi gian lmvic cc cht ny mt hot tnh, ngi ta tm cch ti sinh li phc hi hot tnh cachng v tip tc dng.- Chng nhim mi trng khng ch s dng cc ph thi ch bin thnh cc snphm c ch m cn phi chuyn ha cc cht thi ca nh my thnh nhng cht khnghoc t lm hi mi trng.

Cng nghip ha hc hng ngy, hng gi ang cung cp cho con ngi nhngcht mi, nhng sn phm tiu dng phc v nhu cu cuc sng ngy cng cao, nhngcng tng ngy, tng gi ang a vo mi trng khi lng ln cc cht c, u cchnh s sng ca con ngi. Chng nhim mi trng tr thnh mt nguyn tc cacng nghip ha hc v phi l mt tiu ch u tin c xt duyt trc khi xy dngmt nh my, x nghip


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Chng II: SN XUT AXIT SUNFURIC

2.1. VAI TR CA AXIT SUNFURIC

Axit sunfuric l mt ha cht c s dng rng ri nht trong nn kinh t qucdn v cng l mt sn phm c khi lng ln ca cng nghip ha hc.

- L mt cht lng khng mu. N chuyn sang mu vng en khi c ln tp cht+ Tan trong nc theo mt t l bt k v to nhit mnh to ra cc hyrat+ T trng 1,84g/cm3+ Cht hot ng mnh, ho tan phn ln cc kl v oxyt kl. Ht nc mnh to cchyrat.- Ngi ta thng oxi ha SO2 trn xc tc rn thnh SO3, nn c gi l phng phptip xc. Sn xut c H2SO4 nng trn 98%.- c s dng nhiu sn xut phn bn, ch bin nhin liu lng, tng hp hu c,sn xut thuc nhum, dng trong ngnh luyn kim, m in v.v.

2.2. NGUYN LIU SN XUT AXIT SUNFURIC

Lu hunh v cc hp cht cha lu hunh u c th lm nguyn liu sn xutH2SO42.2.1. Lu hunh

S l nguyn liu tt nht sn xut ra kh SO2. Dy chuyn sn xut axit sunfurici t lu hunh n gin hn i t cc ngun nguyn liu khc v nhit t chy luhunh thp v qu trnh tinh ch kh SO2 n gin hn. S thng c khai thc t ccm2.2.2. Qung pirit- Thnh phn ch yu ca qung pirit l pirit st FeS2, ngoi ra cn c pirit ca kim loimu, cc hp cht ca niken, ng, silic, cacbonat, canxi, cc oxit nhm, bc v vng.

- Hm lng lu hunh trong qung dao ng t 40 - 50%.2.2.3. Thch cao: CaSO4 ngm nc hoc CaSO4 khan. Ngy nay t s dng2.2.4. Cc hp cht cha lu hunh khc

Sn phm ph thi v kh thi m trong thnh phn c cha SO2 u c s dng sn xut axit sunfuric va kinh t va gip gii quyt cc vn v mi trng

2.3. QUI TRNH SN XUT2.3.1. Sn xut SO2

Axt sulfuric c sn xut t lu hunh, xy v nc theocng ngh tip xc.

Trong giai on u lu hunh b t to ra ixt lu hunh.

(1) S(rn) + O2(kh) SO2(kh)

Sau n b xi ha thnh trixt lu hunh bi xy vi s c mt ca cht xctcxt vanadi (V).

(2) 2SO2 + O2(kh) 2SO3(kh) (vi s c mt ca V2O5

Cui cng trixt lu hunh c x l bng nc (trong dng 97-98%

H2SO4 cha 2-3% nc) sn xut axt sulfuric 98-99%.


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(3) SO3(kh) + H2O(lng) H2SO4(lng)

Bn cnh , SO3 cng b hp th bi H2SO4 to raleum (H2S2O7),

cht ny sau b lm long to thnh axt sulfuric.

(4) H2SO4(lng) + SO3 H2S2O7(lng)

leum sau phn ng vi nc to H2SO

4m c.

(5) H2S2O7(lng) + H2O(lng) 2 H2SO4(lng)

2.3.2. Tinh ch hn hp kh SO2Lm sch v lm kh hn hp kh SO2

2.3.3. Oxi ho SO2 bng xc tc V2O52.3.3.1. C s l thuyt- Phn ng gia SO2 v O2 iu kin thng v nhit cao hu nh khng xy ra- Mt khc SO3 li khng bn nhit cao, d b phn hy thnh SO2 v O2. Nh vyphn ng oxi ha SO2 bng O2 l mt qu trnh thun nghch v ta nhit.

2SO2 + O2

2SO3

H < 0Trong thc t sn xut ngi ta duy tr nhit khong 4500C khi dng xc tc loxit vanadi (V2O5).- Xc tc:

Thi k u ngi ta dng Pt lm cht xc tc, Pt c hot tnh cao, nhng khngkinh t. Nhng nm gn y ngi ta dng vanadi oxit V2O5 v c hot tnh cao hn, trnthm Al2O3, SiO2, K2O, CaO v V2O5 .- Nng ca cc cht tham gia phn ng:

Nng ca O2 trong hn hp kh tng tc ca phn ng tng cn bngchuyn dch v pha to thnh SO3, ng thi hiu sut chuyn ha SO2 thnh SO3 cngtng.

Trong sn xut, oxy ha SO2 trn xc tc vanaioxit t0

4500

C, hm lng caoxy trong hn hp kh 11% cn SO2 l 7% th chuyn ha ca SO2 c th t c98%.2.3.3.2. Thit b oxi ha

Ti cng ty supephotphat Lm Thao c thit b kiu ny.


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1

2

3

1

2

3

SO3

SO2

1

2

3

Hnh II.4. Thp oxi ho

1 - Cht xc tc; 2- Sn xc tc; 3 - ng trao i nhit

2.3.4. Hp th SO3: SO3 + H2O = H2SO4 H < 0- khc phc hin tng SO3 hp th nc to thnh m axit sunfuric, ngi ta dngoleum hp th (dung dch SO3 trong H2SO4 m c). Oleum ha tan SO3 t do tothnh dung dch axit sunfuric.- Thng dng hai thp hp th t lin nhau hp th hon ton SO3 trong hn hp kh(99%). Lm ngui kh SO3 n 30

0C, gi nhit trong thp khng qu 600C, bng cchlm ngui dung dch ti.

Qui trnh sn xut xt sunfuric lu hunh

Bi

Tc M H2SO4

Hi nc

Oleum

Lu hunh

Oxi ha

H th SO

Oxi ha SO2 thnhSO3

Tinh ch hn hp kh SO2

SO2

N hin

Dung dch H2SO4 98%


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Chng III: TNG HP AMONIAC V SN XUT AXITNITRIC

3.1. GII THIU CHUNG

Nit c trong thnh phn ca cc cht protit- C th ni nit l nguyn t ca s sng.- Hp cht ch yu tng hp protit trong thc vt l NH3 v cc mui ca HNO3- ng dng quan trng nht ca hp cht cha nit: phn bn v thc n gia sc.- NH3 v HNO3 cn c s dng trong cng nghip sn xut cc sn phm trunggian, thuc nhum, thuc tr su, cht do, dc phm, si ha hc...

Trong t nhin khng c nhiu m cha hp cht ca nit phi tm nhngphng php tng hp .Phng php h quang nhit cao ca ngn la h quang, N2 kt hp trc tip vi O2 to thnh NO

N2 + O2 = 2NO H > 0 L phn ng thu nhit.

Tip theo: 2NO + O2 = 2NO2

H < 0Hp th NO2 bng nc ta c HNO33NO2 + H2O = 2HNO3 + NO

Khi tri c sm st, di tc dng ca hin tng phng in trong khng gian xy ra qu trnh tc dng trc tip gia N2 v O2 v sao, sau nhng trn ma ln cnhiu sm st th la li mau pht trin hn. (bn cnh vic ph v ni ba)Phng php xianamitPhng php amoniacL phng php ph bin nht chuyn N2 n cht trong khng kh cc hp cht caN2.

N2 + 3H22NH3 H < 0 (Xc tc thch hp, t0 4500C)

Trong chng ny s trnh by chi tit hn qu trnh chuyn N2 n cht trongkhng kh cc hp cht ca N2 qua con ng NH3.

3.2. SN XUT AMONIAC

Nguyn liu u tng hp amoniac l H2 v N2, khng c sn trong t nhin - iu ch t nc v khng kh, sau hn hp vi nhau theo t l thch hp - To ng thi hn hp kh cha c H2 v N2 theo t l thch hp.

3.2.1. iu ch hiro v Nit ring3.2.1.1. iu ch nit

Khng kh l ngun nguyn liu v tn cung cp N2 , kk cha 78% N2, 21% O2

, cn li l mt t cc kh tr v C.Thc hin bng cch: ha lng khng kh t0 thp v P cao, sau cho khng kh

lng bay hi. V N2 c nhit si thp hn nn bay hi trc, cn O2 bay hi sau. Bngcch bc hi phn on, c th ly ring c N2 dng nguyn cht cn O2 dng chocng ngh hn ct v trong cc bnh vin.3.2.1.2. Sn xut kh hiro: trong cng nghip- in phn nc : 2H2O = 2H2 + O2 (Phng php ny rt tn in nn t dng)- Chuyn ha kh metan hoc ng ng ca n: chuyn ha metan thnh hyr bng cctc nhn v xc tc thch hp nhit t 8000C - 9000C.


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CH4 + 2H2O = CO2 + 4H2CH4 + CO2 = 2CO + 2H22CH4 + O2 = CO + 4H2

CO sinh ra li b chuyn ha tip thnh CO2 bng hi nc nh xc tc Fe2O3, nhit 470 - 5200C: H2O + CO = CO2 + H2- Tch H2 t kh sinh ra trong qu trnh ch to than cc

Ha lng cc sn phm nha v cht hu c c trong kh than cc, hp th NH3 ctrong kh, phn kh cn li cha ch yu l H2.* Sau khi c H2 v N2 ngi ta hn hp chng vi nhau theo t l phn ng v avo thp tng hp NH3.

3.2.2. iu ch ng thi H2 v N2 - Phng php kh than tTo ng thi hn hp H2 v N2 i t cc cht u l khng kh, nc v than bng

cch cho hn hp khng kh - hi nc i qua than nng s thu c mt hn hp:H2 : 40%; O2 : 0,2%N2 : 18 - 20% CH4 : 0,5%CO : 31,7% H2S : 0,1%CO2 : 8 %

Loi b cc kh CO, CO2, H2S, bi c hn hp kh H2 v N2 l ch yu3.2.2.1. Tch bi

Hn hp kh ra khi cc l kh ha cha nhiu bi, tro v c du my. Dng thitb lng bi li tm, ra qua nc, qua lc in gi tp cht c hc trn li.3.2.2.2. Tch H2S

H2S c trong hn hp kh s lm ng c cht xc tc ca giai on chuyn haCO v tng hp amoniac phi loi b tht trit .3.2.2.3. Chuyn ha CO thnh CO2

Trong kh cha rt nhiu CO, ngi ta dng hi nc chuyn ha CO CO2ng thi thm H2 cho hn hp kh.

CO + H2O = CO2 + H2 H < 0 (Xc tc l Fe2O3 nhit 4500C - 5000C)

3.2.2.4. Tch CO2Dng nc hp th CO2. Mun hp th hon ton cn dng cc dung dch

kim.2.2.2.5. Tch CO

Qu trnh chuyn ha CO thnh CO2 l qu trnh thun nghch nn trong hn hpkh vn cn mt lng nh CO. Dng dung dch mui axetat ng trong dung dchamoniac hp th trit hn CO.

Sau khi qua cc giai on tinh ch, hn hp kh cn li cha ch yu l H2 v N2.3.2.3. Tng hp amoniac3.2.3.1. C s l thuyt:

Qu trnh tng hp NH3 din ra theo phng trnh :3H2 + N2 = 2 NH3 H < 0

L phn ng thun nghch, ta nhit, gim th tch v cn xc tc. Do vy cc iukin ca phn ng nh t0, P, C s c nh hng n s chuyn dch cn bng- Nhit : thng duy tr nhit ca phn ng ny khong 4500C do

Khi tng dn nhit , tc phn ng giai on u tng dn, h nhanh t ntrng thi cn bng.+ Nu tng nhit qu, hiu sut chuyn N2 NH3 gim do nhit cao NH3 bphn hy tr li H2 v N2. Cn bng chuyn dch v pha tri.


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+ nhit thp di 4000C tc phn ng nh, nn khng c li cho sn xut.- p sut: Trong sn xut, thc hin phn ng ny p sut thp 100 - 150at, hoc trungbnh 250 - 600at hoc p sut cao 600 - 1000at

Phn ng theo chiu thun l qu trnh lm gim P ca h, nn khi tng P phnng s chuyn dch cn bng v pha to thnh NH3, H chuyn ho cng cao hn.

Sau khi to thnh NH3 cn c tch ra cn bng lun chuyn theo chiu thun.

VH

chuyn ha nit thnh NH3 thp, H2 v N2 cha tham gia phn ng phiquay tr li thp tng hp nhiu ln nn t l gia H2 v N2 c gi ng t l 3:1.- Cht xc tc

Phn ng ny nu khng c xc tc thch hp th d t0 cao v P cao phn ngcng hu nh khng xy ra.

Xc tc c th l Fe, Pt, Mn v.v... Trong cng nghip thng dng cht xc tc lst. Dng ban u ca xc tc l hn hp oxit FeO v Fe2O3 c thm cc cht ph khcnh Al2O3, CaO, SiO2, K2O ... Trc khi cho hn hp kh H2 v N2 i qua xc tc, xctc phi tri qua mt qu trnh gi l "hon nguyn" bng cch cho mt dng kh H2 iqua xc tc nhit cao, cc oxit st s b kh oxi to thnh cc nguyn t kim loiphn b trn b mt cc oxit khc. Chnh nhng tp hp nguyn t nh vy ng vai tr

xc tc cho phn ng.Fe3O4 + 4H2 = 3Fe + 4H2O3.2.3.2. Thp tng hp amoniac

Hn hp nit- hiro a vo thp tng hp t trn xung di qua khng giangia hp ng xc tc v v thp ri vo b phn trao i nhit i ngoi cc ng dnNH3 ra khi thp, tip tc i theo ng trung tm ln pha trn hp ng xc tc ivo cc ng t trong khi xc tc, ti y hn hp kh N2 v H2 c t nng ti4500C nh nhit ta ra trong phn ng. Tc ng ny cn c tc dng iu chnh nhit

N H 3

H 2+ N 2

1

2

3

4

56

7

Hnh III.1. Thp tng hp NH3


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ca khi xc tc khng b t nng qu cao. Sau khi t c nhit nh trnhn hp kh H2 v N2 i qua cc lp xc tc to thnh NH3. Sn phm thu c quacc h thng ng dn xung y thp v ra ngoi ha lng NH3

3.3. SN XUT AXIT NITRIC (HNO3)

HNO3 c dng rt nhiu sn xut phn m, thuc n. HNO3 m c

dng iu ch cc hp cht nitro dng trong cng nghip sn xut cc cht mu vnhiu hp cht khc. L mt axit v c cc k quan trng trong i sngKhi dng phng php h quang in cho nit tc dng trc tip vi oxi to

thnh NO tn nhiu in nng phng php ny khng pht trin rng ri. T khitng hp c NH3 t N2 v H2 th ngi ta u sn xut HNO3 t amoniac. Qu trnhny bao gm cc giai on: oxi ha NH3 thnh NO, oxi ha NO thnh NO2, hp thNO2 thu c dung dch HNO3 nng khong 50%. Mun c HNO3 c ta phic c.3.3.1. Oxi ho amoniac

Qu trnh oxi NH3 bng oxi c th din ra theo cc phn ng sau:

4NH3 + 5O2 = 4NO + 6H2O (*)4NH3 + 4O2 = 2N2O + 6H2O4NH3 + 3O2 = 2N2 + 6H2O

sn xut axit nitric, ngi ta tm cch tc ca phn ng (*) xy ranhanh chng v hn ch cc phn ng khc n mc thp nht. t c iu ta dng cht xc tc thch hp nht l platin. Trong thc tin sn xut ngi ta sdng hp kim platin vi roi v palai, (Pt - 95%, Rh - 3%, Pd - 2%)

Xc tc c ko thnh si, ri dt thnh li tng b mt tip xc. Cngcc li xc tc theo tit din ca thp oxi ha. Ty theo qu trnh oxi ha p sutcao hay p sut thng th c 3 - 4 li, p sut 10at dng 16 - 19 li platin.

Hn hp kh NH3 phi sch khng lm bn xc tc Pt. Phn ng oxiha NH3 trn xc tc cng ch xy ra nhit cao. Ngi ta duy tr nhit t 800 -9000C, vt qu nhit ny s gy mt mt khi lng ca platin.

hiu sut chuyn ha ca NH3 thnh NO cao ngi ta thng dng d oxiso vi phng trnh, c th l oxi ln hn 1,7 ln so vi NH3.

3.3.2. Oxi ho NO2NO + O2 = 2NO2 H < 0, nhit thng, khng cn xc

tcDi 1500C phn ng xy ra hon ton theo chiu thun to thnh NO2. Trn

1500C hu ht NO2 b phn hy, cn bng chuyn sang tri. Nhit cao hn (8000C)

s oxi ha NO thnh NO2 khng xy ra. (l phn ng thin nghch)Tng p sut, phn ng oxi ha NO thnh NO2 s chuyn dch theo chiu thuniu kin thch hp cho qu trnh oxi ha ny l n xy ra khp khng gian ca

dy chuyn sn xut: trong cc thp hp th, trn ng ng dn ...


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3.3.3. Hp th NO2NO2 v N2O4 tc dng vi nc

2NO2 + H2O = HNO3 + HNO2N2O4 + H2O = HNO3 + HNO2

Axit nitr HNO2 khng bn v b phn hy:3HNO2 = HNO3 + 2NO + H2O

Phn ng tng qut ca qu trnh hp th s l:3NO2 + H2O = 2HNO3 + NO

- tng tc ca qu trnh hp th NO2 ta phi tng din tip xc ca kh vi chtlng do y l qu trnh d th L-K. Bng cch to ra cc thp c cc a nm ngang,kh s chui qua cc a t y thp i ln cn cht lng s chy t nh thp xung cca.- Lm lnh cht lng trong thp hp th n t0 khong 750C hp th tt

Hp thu NO2 iu kin thng ch thu c axit nitric long khong 50%.Khi tng P ca thp hp th n 6 - 8at th c th thu c HNO3 nng khong62%.

3.4. SN XUT HNO3 C

3.4.1. C c HNO3 long3.4.2. Ch to HNO3 c t N2O4 lng

Tin hnh qu trnh hp th N2O4 lng trong thit b c P= 50at 750C.


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Chng IV: CNG NGH IN HO

4.1. I CNG V CNG NGH IN HA

NHNG KHI NIM C BN

- Qu trnh in ho: nhng qu trnh ho hc xy ra di tc dng ca dng in mtchiu.- Dng in mt chiu i qua dung dch in ly to nn hin tng in phn; lqu trnh phn hu cc cht in ly v to nn cc in cc nhng cht mi.- Thit b thc hin qu trnh in phn c gi l thng in phn.Qui c: -Antl cc dn dng in t mch ngoi vo thng in phn.

- Cattl cc m dng in t thng in phn i ra.Khi dng in mt chiu i qua dung dch in ly, cc anion chy n ant, cn cccation chy n catt, v phng in trn cc in cc ny.

Qu trnh in phn ch xy ra khi in p cung cp cho thng in phn lnhn mt tr s gi l in p phn hu. Mi cht in ly c mt tr s in p phn

hu nht nh.in p phn hu bng hiu i s cc th ant v catt. Th ant vth catt gi chung l th in cc, chnh l hiu in th gia in cc tng ng vdung dch.

Th in cc cn ion phng in tnh theo l thuyt, thng thp hn thc t

4.2. NHNG NG DNG CA QU TRNH IN HA

- Dng iu ch hyr v xi, xt clo, cc hp cht cha xi ca clo; tng hp cchp cht v c nh axit peroxidisunfuaric v mui ca n l cc pesunfat dng iu ch nc oxigi, cc hp cht peroxit, pemanganat; i oxit mangan...- Thy luyn cc kim loi nh ng, niken, km, coban, caimi.... v c cc kim loi

bt; n cng c dng in phn mi trng nng chy nhm iu ch cc kimloi kim v kim th, cc kim loi him v t him...- Sn xut cc ngun in ho (pin, acquy) v m in.* u im: - Cng ngh n gin;

- S dng nguyn liu v nng lng ton din hn;- To c nhiu sn phm c gi tr, c sch cao;

* Nhc im: tiu hao nhiu nng lng do chi ph nng lng chim mt t ltng i cao trong gi thnh sn phm. Chnh v vy m mc s dng cc phngphp in ho ph thuc nhiu vo trnh in kh ho v gi in nng tngnc.

4.2.1. Cng ngh in phn iu ch xut - clo: dng ph bin hai phng php

- Phng php catt rn hay mng ngn- Phng php catt thu ngn (catot lng)

4.2.1.1. Phng php catt rn.a/ Mui v iu ch nc mui.

Mui l nguyn liu chnh iu ch xt - clo bng phng php in phnv phi m bo mt s cc tiu chun.NaCl 97,5% Mg+2 0,05%Cht khng tan 0,5% K+2 0,02%Ca+2 0,4% 24SO

0,84%


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Nc mui c iu ch vi nng 310 - 315 g/l NaCl.- Ion 24SO

lm tng qu trnh n mn anot- Ion Ca+2, Mg+2 l nhng ion c hi cho qu trnh in phn do Ca+2, Mg+2 tc dngvi kim, to thnh cc hyroxit kh tan, kt ta trn mng ngn, bt kn cc l mng,cn tr qu trnh in phn, v vy cn phi loi b chng (theo 3 phng php phbin)

* Phng php xa xtDng Na2CO3, NaOH v BaCl2 kt ta cc tp chtCaCl2 + Na2CO3 = CaCO3 + 2NaCl (loi Ca

2+)Thc hin t0 cao CaCO3 kt ta tinh th ln, ho tan gim d dng cho qutrnh lc.

MgCl2 + 2NaOH = Mg(OH)2 + 2NaClMgSO4 + 2NaOH = Mg(OH)2 + Na2SO4

Kt ta cc ion Mg+2 bng cch trn nc mui mi iu ch vi nc mui hi lut cng on in phn sang, lng xt trong nc mui hi lu tha kt ta cc ionny.* Phng php sa vi xt

* Phng php sa vi sunfat kt ta hon ton cc ion Mg+2 v Ca+2, xt v xa cn phi cho d v nhit ca nc mui c tng n 40-50oC. Sau , trung ho xt d bng HCl. Hmlng xt sau khi trung ho phi khong 0,05 - 0,1g/l; cn xa l 0,2 -0,3g/l.b/ in phn.* C s l thuyt ca qu trnh in phn.

Ant graphit v catt st c dng li chia thng in phn lm hai phn:Khng gian ant v khng gian catt. Mng ngn aming ph trn catt pha i dinvi ant.- Anot cn c bn c hc, bn ho hc trong mi trng axit v dn in ln.

iu quan trng l c qu th Clo nh, qu th oxy ln. Thng dng graphit

bi qu th clo khng ln v kh bn. Tuy nhin anot graphit b ph hu do s oxyho ca oxy thot ra trn ant khi ant b chy tng phn cn mt s b ri rngthnh nhng mu nh v vy thay th bng anot m platin cho php gim in th,gim tiu tn nng lng.- Catt: Vt liu lm catt phi c qu th hyro thp c dn in cao , bn cho cao, d gia cng. Thp c s dng tho mn cc yu cu trn.- Mng ngn: Dng vi aming hoc si aming.

Khi dng in mt chiu i qua thng in phn cc anion ch yu l OH-, Cl-,chy v ant, cn cc cation, ch yu l H+ v Na+ chy v catt phng in.Nhng ion no c th phng in thp hn th phng in trc.

Trn catt in th phng in ca Na+ ln hn ca H+ nhiu; do , ch c ion

H+ phng in theo phn ng in cc.H+ + e = H

Catolit d Na+ v OH- tr thnh dung dch xt.Trn ant graphit, mc d OH- c th thun nghch thp hn Cl-, nhng qu th caoxi cao lm cho th phng in ca Cl- tr nn thp hn ca OH-cht t, do , Cl-phng in

2Cl- - 2e = Cl2Ngoi ra, trong qu trnh in phn cn xy ra cc qu trnh ph:* Trn Cattch c H2 thot ra, khng c phn ng ph


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* Trn antc phn ng ph in cc v oxy thot ra2OH- - 2e = H2O + 1/2O2

- Cl2 to ra trn ant s ho tan trong anolit v b thu phn theo phn ng:Cl2 + H2O HOCl + HCl (a)

Axit hypoclorit (HOCl) to thnh, chu hai qu trnh phn ly c chung mt sn phml OCl-

HOCl

H

+

+ OCl

-

HOCl + OH OCl- + H2O (b)- in th phng in ca OCl- trn ant thp hn ca Cl- rt nhiu, nn d dngphng in to thnh 3COl theo phn ng: 6OCl

- + 6OH- - 6e = 32ClO + 4Cl- + 3O +

3H2O (c)Oxi to thnh n mn ant graphit: C + O = CO

2CO + O2 = 2CO2- Axt hypoclorit c trong dung dch cn tc dng vi xt trong catolit to thnh nhiusphm

HOCl + NaOH = NaOCl + H2O (d)

NaCl + 2HOCl = NaClO3 + 2HCl2NaOCl = NaClO2 + NaClNaClO2 + NaCl = NaOClO3 + NaCl

Trong trng hp khng c mng ngn, xt catotit s t/dng vi axit ca anolit theop/:

HClO3 + 2HCl + 3NaOH = NaClO3 + 2NaCl + 3H2O (e)Qua cc phn ng (b), (c), (d) v (e) trn ta thy ngun gc ca cc phn ng

ph xy ra trong khng gian ant l do ion OH- t khng gian catt sang. Do , hn ch cc phn ng ph, cn phi dng mng ngn khng cho cc sn phm catolit,ch yu l OH-, trn ln vi anolit. V vy dung dch mui n phi lin tc chy tkhng gian ant sang khng gian catt. Ngoi ra, mng ngn cn c tc dng gi cho

H2 v Cl2 khng hn hp c vi nhau to thnh mt hn hp n.* iu kin in phn:- Mc d dng mng ngn, vn khng ngn c cc phn ng ph, c bit, khimc phn hu mui n to thnh xt vt qu 50%th hiu sut dng in gimxung nhanh. Do trong thc t, ngi ta ch duy tr phn hu mui n khong45-55%. Mui khng b phn hu s theo dung dch xt ra ngoi thng in phn.- Nng mui n trong dung dch phi gn bo ho (khong 310-315g/l).- Nhit in phn tng i cao, khong 85-97oC tc dng hn ch cc qu trnhph ging nh dung dch mui m c. Ngoi ra, nhit v nng dung dchmui cng cao th qu th phng in ca cc ion v in tr ca dung dch cnggim.

c/ Thng in phn.


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Hn hng c phn hy trong thit b c bit to ra NaOH v H2 theophn ng:

Na(Hg)n + H2O = NaOH + 1/2 H2 + nHgTrn ant graphit, ngoi clo l sn phm chnh, cn c qu trnh phng in

ca OH- to thnh cc sn phm ph l O2, CO2 nh thng in phn vi catt rn.Trong cng nghip, in p thc ca qu trnh in phn giao ng trong khong 4,4~ 4,8 von

Hnh IV.5. S h thng in phn mui n s dng catt thu ngn. A- Thit b in phn: B - Thit b phn hy hn hng C- TB b sung mui1. Ca dung dch mui vo 6. Ca dn hn hng vo 12. Ca b sungmui2. Ca dung dch mui ra 7. Ca tho dung dch xt ra 13. B ha tan.3. Ca thu clo 8. Ca thu hydr 14. B iu ha4. Ant rn 9. Ca dn nc vo 15. Bm dung dchmui5. Catt thy ngn 10. B cha thy ngn 1b. QT phn hy hn

hng 11. Bm hon lu HgThu ngn, theo y nghing ca thang in phn, lin tc chy vo thng

phn hu hn hng. Nc nng c lin tc a vo y phn hu hn hng, tothnh xt v H2

NaHgn + H2O = NaOH + 1/2H2 + nHgThc t, qu trnh ny gm cc phn ng sau:

NaHgn e Na+ + nHg

H2O + e 1/2H2 + OH-

Na+ + OH- NaOHP/php ny c th iu ch c dd xt sch, c nng cao, khong 650 -760g/l

NaOH.4.2.1.3. So snh hai phng php in phn.* u im: Phng php in phn vi catt thu ngn c u im ln l iu chc xt sch c nng rt cao, gp 5 -6 ln nng xt khi iu ch bng phngphp in phn mng ngn. V vy tit kim c nhiu hi nc v nng lng cc xt.*Nhc im:- Tiu hao nhiu in nng. E cn sn xut 1 tn NaOH 1,3 ln so vi pp Cattrn.


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- Vn u t rt cao, cao hn phng php mng ngn ti 40%. - Phi dng Hg l kim loi qu, him, ng thi li c hi.

Do c nhiu nhc im nh vy, nn nu khng cn xt sch (nh trong cngnghip sn xut si nhn to) th in phn mng ngn s dng thch hp hn, kinh thn.4.2.2. C c v iu ch xt rn4.2.2.1. C c xt.

Xt iu ch bng in phn theo phng php mng ngn, c ba thnh phnch yu:

NaOH: 100-140g/l; NaCl: 160-200g/l; Nc: ~900g/l tan ca mui s gim nhiu khi tng nng xt trong dung dch. Do cn phic c nng cao nng ca xt v loi c mui n trong dung dch. Vi dungdch xt khong 40-50%, nhit h t 100oC xung 20o, tan ca mui trong dungdch gim 2/3. tan ca mui trong dung dch xt c c

tan ca mui nhngnhit khc nhau (g/l)

Hm lng xttrong dung dch (%)

100

o

C 20

o

C

T trng hm lng mui 20oC so vi 100oC (%)

42 48,3 18,4 3850 46,6 13,9 29,9

Hnh IV.7. tan ca mui n trong dung dch xt nhng nhit khc nhau

- Giai on I: c c qua ba ni lin tip cho ti nng 25-26% NaOH (khong340g/l)

- Giai on II: dng hi th cp ca ni u giai on th nht c c tip dung dchxt n nng 42-50%.4.2.2.2. Sn xut xt tinh th:

Xt tinh th thun li khi cn bo qun v vn chuyn i xa.Dung dch xt c nng khong 50% c bm vo thit b truyn nhit.

Nhit c tn dng nhit tha bng hi th ca cc thit b c c, dung dch xtc c c qua ba giai on:- Giai on I: a dung dch xt ti nng 65%. Gia nhit bng hi th ca thit bc c.


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- Giai on II: a nng xt ln 70-72%. Thc hin p sut 8 atm, v nhit 3800C.- Giai on cui: p sut thp. Ti y, dung dch hon ton ht nc, hm lngcht rn t c 99%.

Xt nng c a vo thit b kt tinh lin tc kiu trng quay. Trong lngtrng chia thnh cc khu vc ring c nhit khc nhau. Xt kt tinh trn ngoi catrng, c dao gt gt ri xung my nghin, ri t a i ng thng.


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Chng V: SN XUT PHN BN HA HC

Trong sn xut nng nghip hin nay thng s dng hai loi phn bn chyu l phn ln v phn m.A/ Phn ln: l nhng hp cht cha nguyn t photpho. Cht lng hay hiu qu caphn ln c nh gi bng hm lng P2O5 cha trong n m cy c th hp th

c. Hm lng ny thng nh hn hm lng tng s P2O5 c trong n theo lthuyt.Cc loi phn ln hin nay thng dng:- Supephophat kp thnh phn chnh l Ca(H2PO4)2.- Phn ln nung chy, hay cn gi l phn ln thu tinh thnh phn chnh l Ca3(PO4)2.

Nguyn liu chnh sn xut cc loi phn ln l apatit. Nc ta c m apatitln v cht lng cao Lo Cai.B/Phn m: l nhng hp cht cha nguyn t nit.Phn m gm cc loi sau: ure - CO(NH2), (NH4)2SO4, NH4NO3, NH4Cl,(NH4)2CO3.

Ngoi nhng hp cht ch cha nit hoc photpho nh trn cn c hp cht

cha c hai nguyn t, loi phn bn thng gi l phn hn hp, v d nhamophot, l cc mui amoni phophat.

5.1. SN XUT PHN LN

Supephtphat l loi phn ln c dng ph bin. Ty theo mc ha tanm ngi ta chia phn phtphat thnh 2 loi: loi ha tan trong nc v loi khngha tan- Loi ha tan trong nc gm supephotphat n v kp.- Loi ha tan trong axit gm prexipiat amopht nng chy.

Phtpht l lp khong cha phtpho ch yu dng fluorapatit v cc tp chtkhc. Hm lng P2O5 trong qung phtphat khong 20-30%.

Mun iu ch phn phtpho d dng ngm thu c th s dng bt kloi t no phi tin hnh chuyn mui phtphat khng ha tan thnh mui ha tanhoc d dng ngm thu. l mc ch ch yu ca k thut phn ln- Supephtphat n Ca(H2PO4)2.CaSO4.2H2O: cn cha CaSO4, iu ch qua 1 giaion.- Supephtphat kp Ca(H2PO4)2.2H2O: khng cha CaSO4,iu ch qua 2 giai on.

5.1.1. Sn xut Superphotphat n theo phng php axitSuperphotphat n c hm lng P2O5 hu hiu khong 14-20%. nc ta hin nay c nh my Lm Thao (Ph Th) do Lin X c gip

xy dng sn xut Supephophat n theo phng php ny.

5.1.1.1. C s l thuytCho H2SO4 tc dng vi fluorcanxi apatit Ca5F(PO4)3. y l qu trnh d thnhiu pha xy ra ch yu vng khuch tn. C th chia thnh 2 giai on:* Giai on 1:

u tin phn ng tin hnh trn b mt cc ht qung, d H2SO4 do tothnh H3PO4 t do, sunfat canxi kt tinh tch ra di dng khan v nm li trong phnln

Ca5F(PO4)3 + 5H2SO4 = 3H3PO4 + 5CaSO4 + HF


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Phn ng ny din ra vi tc rt nhanh so vi tc ca phn ng sau.Thng kt thc sau 20 n 40 pht k t khi trn qung apatit vi dung dch H 2SO4.Nhng yu t nh hng:- Nng H2SO4 nh hng r rt n qu trnh phn hu qung trong iu kinkhuy trn lin tc. Nng H2SO4 thch hp l 62 - 68%, thp hoc cao hn ukhng thun li.

- Nhit phn ng duy tr khong 110-120

0

C

t

0

ban u ca dung dch H2SO4 daong t 60 - 70oC tu thuc thi tit tng ma v nng H2SO4.- Thi gian lu ca hn hp phn ng: vi nng axit nh trn th thi gian lu 2-4pht.- nh ht qung: tng din tch tip xc, nghin qung d= 0,15mm. Nu phn ng thc hin hon ton th chng 70% apatit b phn hy giai on uny.* Giai on 2:

H3PO4 sinh ra tip tc tc dng vi qung apatit to thnh mui canxi photphat,l giai on quyt nh cht lng ca phn ln superphotphat.

7H3PO4 + Ca5F(PO4)3 + 5H2O = 5Ca(H2PO4)2. H2O + HF

giai on 2, lc u phn ng xy ra rt nhanh, khi nng Ca(H 2PO4)2 tngln th tc chm dn v kt thc sau khi supe trong kho 6-25 ngy m tu thucvo nguyn liu, t0 35-450C. Bi v mng mono canxi phtphat to thnh bao quanhht apatit lm gim s khuch tn ca H3PO4 v s kt tinh pha rn mi (Ca(H2PO4)2.H2O) xy ra chm.+ Sau khi mt lng H3PO4 t do cn tha phi qua gia on trung ho.Dng bt xng, bt vi hoc NH3 kh:

CaCO3 + 2H3PO4 = Ca(H2PO4)3+ CO2 + H2ONH3 + H3PO4 = NH4H2PO4

* Supephtphat n phi m bo cc yu cu cht lng sau:P2O5 khng di 14-19%

m khng qu 13-15%H3PO4 t do (tnh theo P2O5) 5-5,5%

5.1.1.2. Qu trnh sn xut superphotphat

5.1.2. Sn xut superphotphat kpTrong thnh phn ca superphotphat

kp khng c CaSO4. Hm lng P2O5 hiuqu cao, tn ti ch yu di dng Ca(H2PO4)v mt t H3PO4 t do.Cc phn ng c bn xy ra khi sn xut

superphotphat kp:7H3PO4 + Ca5F(PO4)3 + H2O =5Ca(H2PO4).H2O + HF + Mg(H3PO4)2 +2CO2Fe3O3 + 3H3PO4 + H2O = 3FePO4.2H2OAl2O3 + 2H3PO4 + H2O = 2AlPO4.H2O* iu kin: Nng H3PO4 m c, t

0 80-900C. Hiu sut phn hu 70%Qua qu trnh 25 ngy, apatit cn li tip tc

1 2

4

A atitH2O 75%H2SO4

68% H2SO4

Vo kho

Hnh V.I. S d sn xut superphotphattheo phng php lin tc


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b phn hu, hiu sut chuyn ho tng ln 77-83%. Sau sn phm c emnghin v to ht.

5.1.3. Sn xut phn ln thu tinhThnh phn chnh ca phn ln ny l hn hp ca canxi photphat v magie

photphat, ngoi ra cn c mui canxi silicat. y l loi phn c tnh kim, t ha tantrong nc nhng ha tan nhiu trong axit citric 2% do d c axit trong r cy

hp th. Hm lng P2O5 khong 20-25%.5.1.3.1 .C s l thuyt:Nguyn liu chnh sn xut phn ln nung chy l apatit v cc loi

(olivin, secpangtin v lmit) c nung chy bng than cc nhit 1450 -15000C trong cc l cao tng t l luyn gang

2Ca5F(PO4)3 + SiO2 + H2O = 3Ca3(PO4)2 + CaSiO3 + 2HFNguyn t F trong tinh th qung apatit tch ra khi nguyn liu, ton b

sn phm chy lng. Dng mt tia nc lnh c p sut cao lm lnh t ngt s tora Ca3(PO4)2 c cu to tinh th ging thy tinh, c bit d ha tan trong mi trngca ng t chua.

nc ta c nhiu c s sn xut loi phn ny nh cng ty phn ln Vn

in, phn ln Ninh Bnh, X nghip phn ln Bc Giang5.1.3.2. Qu trnh sn xut- Giai on 1: em trn cc nguyn liu theo t l tnh ton sn. T l thng l:

MgO : P2O5 = 2 : 3 ; MgO + CaO : SiO2 = 1,8 : 2,7Cho phi liu vo l nung t0 = 1450-15000C, phi liu s chy lng v xy ra phnng

2Ca5F(PO4)3 + SiO2 + H2O = 3Ca3(PO4)2 + CaSiO3 + 2HFNu trong phi liu c cha than, s xy ra phn ng ph:

2Ca5F(PO4)3 + 10C + 6SiO2 = 6CaSiO2 + P4 + 10COLm lnh t ngt sn phm nng chy bng dng nc c p lc 3-4atm to httinh th

- Giai on 2: Sy v nghin ht tinh th thnh sn phm dng bt.- Giai on3: Thu hi kh fluor bng cch dng sa vi hp th.

5.2. SN XUT PHN M

- Phn ln phn m c s dng dng rn, trong khong 80% dng phn nv 20% dng phn phc hp. Loi phn n ch yu l NH4(NO)3, (NH2)2CO.Nguyn t dinh dng tn ti trong chng l ion amn (NH4+), nitrat (NO3

-), v nhmamin (NH2).- Tt c cc loi phn m u ha tan trong nc, thc vt hp th tt, d ngm suvo t.

Thc t mi loi phn m u sn xut t amoniac, m gi amoniac chimkhong 60-75% tng gi thnh. Do chi ph sn xut mt tn phn m cc loi ugn bng nhau.

5.2.1. Sn sut amoni nitratAmoni nitrat cha 35% nit, l mt trong nhng loi phn m thng dng.

N c th dng cho bt k loi t no v bt k loi cy ci no. Nhc im c bnca loi phn ny l:- C kh nng gy n rt mnh kh bo m an ton trong qu trnh sn xut, tng

tr v vn chuyn.


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- D ht nc v khi thay i nhit , d chuyn mt phn thnh dng tinh th, dvn cc.Thng sn xut theo hai phng php: phng php bc hi v khng bc hi.Nguyn tc sn xut da vo phn ng

NH3 + HNO3 = NH4NO3 + Q H < 0L phn ng d th, ta nhit nn tn dng nhit to ra c c NH4NO3.

Qu trnh sn xut gm 4 giai on5.2.1.1. Giai on trung ho: tng b mt tip xc ngi ta xp

trong thng trung ho nhng tm m. Dngvi phun NH3 qua lp HNO3 tm trn cc tmm- Nhit phn ng: 110 - 1350CKhi ra khi thit b nng NH4NO3 t 63-64%5.2.1.2. Giai on c c

Sau khi ra khi thit b trung ho phi

tin hnh c c nhit 150

0

C, P= 9atm nng cao nng chun b cho giai on kttinh.Cui gia on ny nng NH4NO3 t 82-84%5.2.1.3. Giai on kt tinh to ht

Trc khi qua thit b kt tinh dung dchNH4NO3 c chy qua thit b c c th 2 nng cao nng ln 98%.Phun dung dch NH4NO3 nhit t= 160

0C t thit b c c qua thp to ht. Cctia dung dch NH4NO3 lng phun xung gp lung khng kh lnh c ht t di

ln bng qut gi, nhit h xung trong khong 60-900

C. Ra khi thit b gpkhng kh cc ht m kt tinh.5.2.1.4. Sy

Lm gim m ca ht NH4NO3 xung cn 0,9-1%. Phng php thngdng l thi lung khng kh lnh -100C ngc chiu vi NH4NO3* Yu cu cng ngh:- Nng HNO3 45-50%; amoniac 60-80%, p sut 2,5- 3,8 atm.5.2.2. Sn xut Amoni sunphat

(NH4)2SO4 cha 21% N2, t ht m v kt khi, nhng bn nhiu nm s lm chot b chua. (NH4)2SO4 c sn xut theo phn ng:

2NH3 + H2SO4 = (NH4)2SO4

5.2.3. Sn xut UreUre [(NH2)2CO] c dng tinh th hoc dng ht. N l loi phn m c gi trnht v c s dng rng ri nht, cha 46% nit. Ure ha tan nhiu trong nc, mtphn to thnh amn cacbamat. Trong iu kin nhit v m thng thng urkhng ho nc, cn khi m khng kh cao (95%) th ur ho nc mnh. N tvn cc, khng chy n.

Ure sch l nhng tinh th khng mu. Ure k thut c mu trng hi vngUre cn dng iu ch nha formandehyt, sn xut cht do, keo dn, si

tng hp.

Hnh V.2. Thit b trung ha HNO3bng NH31. V ; 2. Vng trung ha ; 3. Dd NH4NO3

32

1

HNO3NH3

Hi nc

ddHNO3


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Nguyn tc sn xut c da theo phn ngCO2 + 2NH3 = CO(NH2)2 + H2O

Trn thc t qu trnh ny gm 2 giai on- Giai on 1: iu ch cacbamatamon

2NH3 + CO2 = NH2COONH4 (Cacbamat)- Giai on 2: Kh nc nhit cao

NH2COONH

4= CO(NH

2)

2+ H

2O

Nc to thnh, lc u lm tng mc chuyn ho v n to thnh pha lng.Nhng khi lng nc sinh ra nhiu phn ng s chm li v vy trong qu trnh phnng ngi ta cho tho nc ra lin tc tng nng ure to thnh. Cng ty phnm Bc Giang p dng qu trnh sn xut ny.


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Chng VI: CNG NGHIP SILICAT

Phn ln cc tnh cht qu gi ca vt liu silicat c c l nh phn t cachng c cu trc c bit bi nhm t din SiO4. c trng i vi cu to ny l slin kt rt bn vng gia ion Si4+ v ion O2

- lm cho silicat c tnh cng rn v khnng kh nng chy. Ngoi ra vt liu silicat cn c bn ha, bn nhit, r tin li

d kim.

6.1. SN XUT THU TINH6.1.1. Nguyn liu* Nguyn liu chnh:- Ct (SiO2): l thnh phn ch yu ca cc loi thy tinh, chim 60 - 70%. Trong ctcn cha cc oxit khc nh CaO, MgO, Al2O3, Fe2O3. Nu hm lng ca Fe2O3 caos lm cho thy tinh c mu lm gim truyn nh sng. Thy tinh thng i hict cha Fe2O3 0,2%, thy tinh cao cp 0,1%.- Hn the (Na2B4O7.10H2O): nhit cao hn the b phn hy cung cp cho thytinh B2O3. Oxit ny lm gim h s gin n ca thy tinh, tng bn ha, bn

nhit. N thng c dng cho thy tinh trong phng th nghim, bng n.- Al2O3 lm tng bn ca thy tinh, nhng cng lm cho qu trnh nu chy khkhn v gim s gin n ca thy tinh.- Na2CO3: cung cp Na2Ocho thy tinh. C tc dng h thp nhit nu v kh bt.Nu Na2Onhiu s lm gim bn c hc.- BaO v PbO: lm cho thy tinh c trng lng ring ln, chit sut cao, nh p do c dng trong vic sn xut thy tinh quang hc. Hm lng PbO cao c th tora ngc thch nhn to lm trang sc.* Nguyn liu ph:

L cc nguyn liu a vo thu tinh gip qu trnh nu nhanh v c tc dngnh l cht kh bt, kh mu, nhum mu hoc tng cng mt tnh cht ring bit

no .- Cht kh bt: L cht c th gii phng khi thu tinh cc bt kh. Cc cht kh btthng dng l mui nitrat, oxyt asen, sunfua, cc mui fluor v amoniV d: NaNO3 = Na2O + N2 + O2- Cht nhum mu: Gm 2 loi+ Cht nhum mu phn t: l cc oxyt v c mang mu

Mn2O3 : Cho mu tm Selen : Mu hngCoban : Mu en n xanh m Oxyt st : Mu vng, xanh

lcOxyt Cu, Cr : Mu vng

+ Cht nhum mu phn tn keo

Gm cc hp cht ca Au, Cu, Sb (Antimon) nm trong thu tinh dng phntn keo thu tinh, sau khi to hnh th em gia cng ln th hai vi cc cht nhummu trn v s cho cc mu sc khc nhau

Cu2S, Sb2O3: Cho mu Au : Cho mu ta

- Cht gy c: Ch yu l cc hp cht cha Fluor nh CaF2, Na2SiF6AlF3 to cho thu tinh c mu trng nh sa, nh mu ca s.


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- Cht kh mu: Trong ct cha nhiu ion Fe2+ s cho mu t nhin ca thu tinh lmu xanh lc v ion ny gy mu rt mnh. nhum mu trc ht phi kh muFe2+ bng cch chuyn FeO Fe2O3 dng cht oxy ho NaNO3.6.1.2. Qu trnh nu thu tinh

u tin phi trn cc nguyn liu theo ng t l v o trn nguyn liuphn tn ng u vo nhau.

6.1.2.1. Giai on to silicat: 600-1000

0

CKhi nhit tng dn, nc trong nguyn liu b tch ra, to ra cc mui kp.CaCO3 + Na2CO3 = Na2Ca(CO3)2

* 600 8000C mui kp to silicat v thot CO2Na2Ca(CO3)2 + 2SiO2 = Na2SiO3 + CaSiO3 + 2CO2

* 720 - 9000CNa2CO3 + SiO2 = Na2SiO3 + CO2Na2Ca(CO3)2 + Na2CO3 + 3SiO2 = 2Na2SiO3 + CaSiO3 + 3CO2

* 9120C: CaCO3 b phn hyCaCO3 = CaO + CO2

* 10100C: CaO + SiO2 = CaSiO3

* Cc yu t nh hng n qu trnh nu:- Nhit : Nhit tng qu trnh nu c rt ngn. 13000C nu thu tinh thngthng ht 15 gi, nu 14000C th ch cn li 5 gi.

Nhng nhit qu cao s nh hng n vt liu chu la lt ni v ni nuthu tinh. Thng thng sn xut thu tinh gia dng nhit nu 1400-15000C- Kch thc ht nguyn liu: phi m bo, ht to qu qu trnh nu s kh khn.- Thnh phn ho hc: Cc oxyt kim loi kim v kim th c nhit nng chythp, nu hm lng cc oxyt ny thp th qu trnh nu s c d dng nhng linh hng n tnh cht ho l ca thu tinh. Cc oxyt Fe2O3, Al2O3, SiO2 lm tngc cc tnh cht ca thu tinh nhng li lm tng nhit nu. Do qu trnh hnhp phi liu theo mt t l sao cho m bo c cht lng sn phm ng thi

khng ch nhit nu va phi.6.1.2.2. Giai on to thy tinh:Bt u t 9000C n 12000C: Trong khong nhit ny cc mui silicat chy

lng thnh mt khi trong sut, nhng cn nhiu bt kh v thnh phn thy tinh chang nht.6.1.2.3. Giai on kh bt:

Nhit khong 1400 - 15000C giai on ny cc bt s c thot ra ht do nhit tng lm nht ca

cht lng gim v cc cht kh bt pht huy tc dng (cc kh nh O2, CO2 thot ra).Cui giai on kh bt, bng mt thng ta khng th nhn thy cc bt trong thytinh.

6.1.2.4. Giai on ng nhtSau khi giai on kh bt kt thc, ngi ta vn phi gi thy tinh trong mtthi gian nht nh nhit cao. Do nhit nh vy nht ca thy tinh rtthp to iu kin khuych tn cc thnh phn ca nguyn liu ng u cc hng6.1.2.5. Giai on lm lnh

trng thi qu lng khng th gia cng thu tinh thnh sn phm c phih thp nhit ca xung 1100 - 13000C c nht m bo cho qu trnh tohnh.


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6.1.3. L nu thu tinh6.1.3.1. L lm vic gin on6.1.3.2. L lm vic lin tc

6.2. SN XUT XIMNG POOCLNG6.2.1.Mt s khi nim

Nhng loi ximng ngy nay ang s dng c nhng thnh phn ha hc rtkhc nhau v c s dng vo nhiu mc ch khc nhau nh xi mng chu nhit,ximng chu axit, kim, nc mui, ximng x v.v

Ximng Pooclng l loi chu nc, sn xut t hai nguyn liu chnh l viv t st nung n 14500C, sau lm lnh v nghin mn dng ch yu trong xydng.

Thnh phn ha hc ximng Pooclng: gm bn loi oxit ch yu:CaO : 63% - 67% Al2O3 : 4 - 7%SiO2 : 21% - 24% Fe2O3 : 2,5 - 4%

Nu xt v thnh phn khong th trong ximng Pooclng bao gm canxi silicat,canxi aluminat v canxi ferit

Nu k hiu: CaO = C; SiO2 = S; Al2O3 = A; Fe2O3 = Fth thnh phn khong c trong ximng l:Canxi silicat : C3S, C2S, C3S2Canxi aluminat : C3A, C5A, CA, CA2Canxi ferit : C4AF, C2F, C3A3F, v.vNgoi ra cn c khong cha oxit kim loi kim.

* C3S: Quyt nh cht lng ximng. C3S ng rn nhanh cho cng chu nncao. C3S ch hnh thnh trong qu trnh nung luyn trn c s cc khong khc tothnh pha lng.6.2.2. Nguyn liu sn xut ximng- vi: vi chim khong 75 - 80% khi lng nguyn liu.

- t st: chim khong 20 - 35% phi liu- Ph gia: tng cng hoc hn ch mt s tnh no ca ximng + Ph gia khong ho: C tc dng nh xc tc nhng sau nm li trong ximng.+ Ph gia iu chnh: iu chnh tc kt dnh v thi gian ng rn ca snphm+ Ph gia thu: Tng tnh bn nc trong mi trng kho ca ximng: x l cao+ Ph gia y: C tc dng lm cht n, gim gi thnh ca sn phm: gch, , vi,tro.

Cc nguyn liu c trn ln v nghin mn n kch thc 0,06 - 0,07mm ria vo l nung theo phng php t hoc phng php kh theo mt t l tnhton

6.2.3. Nung luyn Clinke6.2.3.1. Cc phn ng ho l:-Phng php kh: nguyn liu c nghin ring tng loi hoc nghin chung thnhdng bt ri trn ln vi nhau, cho thm mt t nc c th ng bnh hoc vvin.- Phng php t: nghin nguyn liu cng vi nc to thnh hn hp dng bn(pat) sau rt vo l nung.

Di tc dng ca nhit cao cc oxyt trong nguyn liu ban u phn hy vtc dng vi nhau to thnh nhng hp cht mi gi l cc khong silicat. Cc khong


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t0 cao (14500C) nm trong pha lng. Khi lm lnh kt li thnh nhng ht gi lclinker nghin mn xi mng tc dng vi nc sau mt thi gian s ngrn.- Trong khong nhit t 500 - 6000C cc khong st mt nc.

Al2O3.2SiO2.2H2O Al2O3.2SiO2 + 2H2O- nhit khong 9000C cc khong khan phn hy thnh cc oxt:

Al2O3.2SiO2

Al2O3 + 2SiO2- t0C 10000C to ra Al2O3.SiO2 v 12000C 13000C to ra 3Al2O3.2SiO2 do tng

tc gia cc axit tng ng.- Ti nhit trn 9000C vi cng b phn hy.

CaCO3 CaO + CO2 H > 0Trong khong t 800 12500C hu ht cc khong quan trng trong thnh phn

ca clinke ximng c to thnh. Ring khong C3S(3CaO.SiO2) c to thnhrt chm do kt qu phn ng ca C2Svi CaO. Qu trnh ny ch din ra vi tc nhanh khi c mt ca pha lng. Pha lng l do C5A3 v C4AF nhit 1450

0C bchy lng to thnh. Khong C3S l thnh phn quan trng quyt nh tnh cht caximng. Nhng khong ny ch c to thnh nhit cao. Do vy nhit nung

luyn clinke c nh hng n cht lng6.2.3.2. L nung clinkera. L ng:

L mt hnh tr ng, rng, chiu cao c kch thc gp 3 4 ln ng knh.L c chia lm 3 vng: vng sy, nung, lm sch. Nguyn liu a vo l ng dng kh.b. L quay:

Loi l quay l mt ng kim loi hnh tr rng, t nghing mt gc t 30 50.Chiu di ln hn ng knh t 30 40 ln.

Ton b chiu di l c t trn mt h thng b c con ln, t trn tr lbng b tng. L lm vic theo nguyn tc ngc chiu: nguyn liu vo u cao (u

lnh) clinke ra u thp (u nng ca l), nhin liu v kh i vo u thp. L chialm 6 vng:

Vng sy v t nng chim 50 60% chiu diVng phn hy chim 20 23% chiu diVng ta nhit chim 5 4% chiu diVng kt khi chim 10 15% chiu diVng lm lnh chim 2 4% chiu diPhi liu c np vo l, chuyn ng theo chiu di ca l, ch yu l trt

trn b mt trong ca l. Thi gian vt liu lu trong l vo khong 3 6 gi.

Nguyn liu

1 2

3

Khngkh

Clenke

Nhinliu


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Hnh VI.3. L quay nung xi mng1. B phn np nguyn liu ; 2. L quay ; 3. Phn lm ngui sn phm

Vt liu ra khi l nung nhit 100 2000C. y mi l bn thnh phm,ngi ta tip tc , thm ph gia, nghin v ng bao chng m d vn chuyn nni tiu th.6.2.4. X l Clinke v to ximng

- : Clinker ra khi l c a vo kho , c tc dng cc CaO t do cn litrong clinker ht hi m to ra Ca(OH)2 lm n th tch . Khi clinker b nt n ddng cho qu trnh nghin- Nghin: Trong qu trnh nghin ngi ta cho vo cc ph gia nh CaSO4.2H2O, xl cao. mn cng cao th cng nn cng ln kt dnh v ng rn cao


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Qui trnh cng ngh sn xut xi mng theo phng php l quay

vi

My p hm

Kt cha

My nghin bi

My ng bao

Xyl cha xi mng

My nghin bi

Kho Clinker

B phn lm lnh Clinker

L quay

B cha bn (pat)

Bm

B ba bn

My cn

t st

Kho cha sn phm

My ba

Ph gia iu chnh(Thch cao)

Cha

p

Than

Kt cha

My sy nghinlin hp

My p

Thi bng p lckh nn

Cha

p

Ph gia thyPh ia


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Chng VII: CNG NGH SN XUT GANG THP

7.1. MT S KHI NIM V GANG V THP

Gang thp hay cn gi l kim loi en rt thng gp trong i sng. Kim loien chim 95% tng s lng kim loi dng trong ch to dng c, my mc v xy

dng.Thnh phn chnh ca gang v thp l st v cc nguyn t khc nh C, Si, Mn,

P, S. Gang v thp ch khc nhau v t l gia Fe v thnh phn C cha trong nThp cha < 2% C; Gang cha 2-6%Ci vi thp hm lng P,S rt nh v nu hm lng 2 nguyn t ny cao th

thp d b ph hu trong mi trng n mn.7.1.1. Cc loi gang7.1.1.1. Gang xm

Nu b ra ta thy vy en lng lnh trn mt nn trng, vy en l garaphit.Nhit nng chy l 12000C 13000C. Gang xm d c.7.1.1.2. Gang trng

Nu b ra th ch thy mt nn trng, c th coi nh thp rt gi. Hm lngcacbon chim t 3 4%. Gang trng kh c, thng luyn thp.7.1.1.3. Gang hp kim

Ngoi C cn cha cc kim loi khc gia tng mt s tnh cht ring bit

7.1.2. Cc loi thp7.1.2.1. Thp cacbon

Thp cacbonch cha 1% C, rt t cc kim loi khc. y l loi thp rt cngthng dng lm mi khoan, ch to cng c. Tnh cht ca loi thp ny do hmlng C quyt nh7.1.2.2. Thp hp kim:

Cha cc nguyn t Mn, Cr, Ni, Mo... chu c nhit, t b n mn

7.2. LUYN GANG7.2.1.Nguyn liu7.2.1.1. Qung st- Qung: Bao gm cc qung st Fe2O3 v cc qung Fe3O4 qua giai on ch bin sb nh nghin, p, sn, luyn vin.P, S thng ln trong qung, sau khi luyn cn litrong gang lm gim cht lng ca gang v thp. Ngoi ra cn s dng st vn, stht, x l cao.7.2.1.2. Nhin liu- Gm than cc, antraxit, than g, kh thin nhin, kh l cc, du diezel.

- C hai nhim v: cung cp oxit C lm cht kh cc oxit kim loi v chy cung cpnhit.7.2.1.3. Cht tr dung

Cc cht a vo nguyn liu lm h nhit nng chy ca phi liu, tc dngvi bn qung to thnh x v kh c cc hp cht ca S. Cht tr dung thngdng l vi.7.2.2. Cc qu trnh ho hc xy ra trong l cao7.2.2.1. S phn hy ca cc mui cabonat- Phn hy CaCO3: CaCO3 = CaO + CO2


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- Phn hy FeCO3: FeCO3 = FeO + CO23FeO + CO2 = Fe3O4 + CO

7.2.2.2. S kh cc oxit st thnh Fe di tc dng ca CO.- Kh gin tip: 3Fe2O3 + CO = 2Fe3O4 + CO2

Fe3O4 + CO = 3FeO + CO2FeO + CO = Fe + CO2

Fe nng chy ho tan C, P, S v cc kim loi khc to thnh gang- Kh trc tip FeO bng C rn:

Fe2O3 + Cr = FeO + COkFeO + Cr = Fe + COk

* Qu trnh kh gin tip hiu sut cao hn, v kh nng tip xc tt hn7.2.2.3. S oxi ha ca than cc

C + O2 (kk) = CO2 H < 07.2.2.4. S to x

nhit t0 cao cht tr dung tc dng vi cc oxit trong bn qung hoc bnc to ra trong qu trnh to gangthnh nhng hp cht d chy lng c t trngthp hn t trng ca st, do ni ln trn mt ca lp gang

7.2.2.5. S kh lu hunh trong l caoMt s hp cht ca S d bay hi nh SiS, SO2, H2S bc ra khi gang cng khl.

Nhng hp cht nh FeS b loi b ni l theo phn ng:FeS + CaO = CaS (x) + FeO

7.2.3. L cao luyn gang

Hnh VII.1. L luyn gang

7.3. LUYN THP7.3.1.C s l thuyt

- Trong thp, Fe chim hm lng cao nht ngoi ra cn c C, Si, Mn, P,S.Hm lng ca C nh hn 2%. Nhim v ca qu trnh luyn thp l h thp hmlng ca cc nguyn t ny n mc cn thit bng cch ox i ha chng thnh nhnghp cht v chuyn vo x.


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u tin cung cp cho thp lng mt lng oxi cn thit oxi ha Fe thnhFeO

2Fe + O2 = 2FeOTip theo, FeO khuch tn vo khi gang lng thc hin qu trnh oxi ha cc

nguyn t khc thnh x h thp hm lng ca chng v khi gang chuyn thnhthp.

FeO + Mn = Fe + MnO2FeO + Si = Fe + SiO2FeO + C = Fe + CO5FeO + 2P = 5Fe + P2O5

Cc oxit c to thnh s bin thnh x.* FeO d, mt phn ln tan trong thp v c nh hng xu n cht lng

thp. kh FeO ta li a vo thp mt lng va Mn hon nguyn ht FeOd.

* c c thp dn dng ch cn iu ha cc thnh phn sn c trong gangtrn c s cc phn ng ha hc trn.7.3.2. Cc phng php luyn thp

7.3.2.1. Phng php l chuyn- Nguyn liu l gang lng va mi ra khi l.- Khng dng nhin liu t m da vo nhit ca cc phn ng ha hc cng vinhit ca gang lng ban u.- Thi gian luyn: 30 pht- Tng l: gch chu axit (SiO2, Al2O3)- Cht to x: t st, ct.Thi gian luyn ngn nn khng iu chnh c qu trnh nu, thp c cht lngkhng caoa. L Betxmeb. L Tomat

* u im: vn u t xy dng nh, thi gian nu thp nhanh. * Nhc im: nhit luyn khng cao, khng kp iu chnh t l cc cht c trongthp nn cht lng thp khng cao.7.3.2.2. Phng php luyn thp Mactanh

Khng kh v kh t c dn vo l t chy trn mt nguyn liu, ta nhitlm ton b vt liu chy lng, khi xy ra cc phn ng nh nu phn trn. Mtlp x c to thnh trn mt thp. Thnh phn v tnh cht ca lp x c nh hngln n cht lng thp. Oxi thng qua lp x c tc dng oxi ha cc tp cht ctrong gang.

Thi gian nu mt m thp ko di nhiu ginn c thi gian phn tch, iu chnh thnh

phn ca thp theo mun. L Mactanh c cng sutln v nhit luyn thp cao nn to ra thp c chtlng cao hn so vi cc l chuyn.7.3.2.3. Phng php h quang* Phng php ny da trn c s nhit ta ra ca

ngn la h quang nu chy nguyn liu- Nguyn liu: thp c, gang rn.

Hnh VII.5. L h quang

loThep

in ccN p lo

Cun thcp bi n thlo


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- H in cc xung gn kim loi v ng mch in h quang. Di tc dng canhit h quang pht ra, nguyn liu b nu chy.

FeO c trong kim loi oxi ha cc tp cht C, Si, Mn, P, v.v nh trong lMactanh. kh S c trit , gn cui thi gian nu cho vi, hunh thch (CaF2)v bt than cc vo l. nhit cao nh c CaO m C,S b kh trit hn theophng trnh:

FeS + CaO +C = Fe + CaS + COCng t0 cao C trong than cc tc dng vi CaO:

Cao + 3C = CaC2 + CONh c nhit cao, giai on cui ngi ta c th cho th m cc kim loi khc

vo to ra thp hp kim.- L in h quang rt thun tin trong vic ch to cc loi thp c cht lng cao vnu li cc thp c ch to cc cng c mi.- Nhc im: nng sut khng cao v gi thnh thp cao, nu in nng t.

nc ta, cc nh my c kh u c cc l in h quang nh t 0,5 -1 tn thp/mt m.


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Chng VIII: TNG HP MT S HP CHT HU C C BN

8.1. SN XUT RU ETYLIC (C2H5OH)

Ru etylic c s dng rng ri trong cng nghip v i sng nh dnglm dung mi, dng trong ngnh y hc v cng nghip thc phm. CC PHNG

PHP SN XUT8.1.1. Phng php ln men

(C6H10O5)x + xH2OEnzim xC6H12O6 (1)

C6H12O6Nm men

2 C2H5OH + 2CO2 (2)8.1.1.1. Qu trnh dch haMc ch: Amilaza l loi enzim chuyn ho tinh bt. Bnh thng tinh bt khng trng thi ho tan nn tc dng ca men amilaza ln n rt kh khn, qu trnh dchho lm ph v cu trc ca ht tinh bt v chuyn v trng thi ho tan, gip cho stc dng ca amilaza ln n hiu qu hn- Thng nu t0~ 1450C (ng/ liu cha nghin k) hoc t0~1300C (ng/ liu nghink)

- Nhng bin i xy ra trong qu trnh dch ha:Khi un tinh bt vi nc ln ti 400C, ht tinh bt bt u trng n, khi nhit

cao hn th tch ca ht tinh bt tip tc tng, mi lin kt gia cc phn t ca httinh bt yu dn v ti mt lc no th cc phn t tinh bt tan ra, hin tng nygi l h ha.Photpho trong mi lin kt tinh bt b t ra dng t do v to thnh axit photphoric.8.1.1.2. Qu trnh ng ha- Do nm men khng c kh nng chuyn ha tinh bt thnh ru. Chng ch c khnng s dng ng v chuyn ng thnh ru. V vy sau khi dch ha v trckhi ln men, tinh bt cn c chuyn thnh ng. S chuyn ho tinh bt thnhng c th xy ra nh xc tc ha hc (axit, baz) hoc men amilaza (ca thc

mm hoc nm mc).+ Chun b dch amilaza t thc mm:Thc phn loi lm sch ngm ny mm sy nghin phi chdch men+ Hin nay ngnh vi sinh vt hc pht trin mnh v c ng dng trong nhiungnh cng nghip, ngnh sn xut ru p dng qu trnh ng ha nh dchamilaza t nm mc.* ng ha khi cho ngi ta tin hnh nh sau:- Lm lnh khi cho n nhit thch hp cho s hot ng ca men amilaza. - Trn dch men vi khi cho lm long v ng ha- Lm ngui dch ng ha n nhit ln men v bm sang b phn ln men.8.1.1.3. Qu trnh ln men ru- L qu trnh bin ng thnh ru etylic di tc dng ca nm men.

- Nhit ln men 25 - 300C. Hai phn ng (1) v (2) xy ra trong khong 50gi. T 1 tn ng cc cho khong 280 kg etanol v 260 kg CO2 (sn xut nc khv nn vo chai, dng trong i sng v sn xut). Hn hp phn ng cha 8-12%etanol.Ln men l giai on cui cng v ch yu nht ca qu trnh sn xut ru. Trongqu trnh ny, cc cht men ca nm men thc hin qu trnh thy phn ng phc


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tp thnh ng n gin, cn cc ng n gin nh glucoza, fructoza c th lnmen trc tip v nhanh.

Ngoi ru etylic cn to thnh mt s sn phm ph nh glixerin, axit succinic,axetaldehyt, metylic v mt hn hp amilic, butilicgi chung l du fulzen. Thng95% ng chuyn thnh ru v CO2, cn 5% ng bin thnh cc sn phm phkhc.- Ln men chnh: Tc ln men nhanh, 90-95% tng lng ru to thnh giaion ny - - Ln men ph: Tc ln men chm, ng tip tc c chuyn hathnh ru v cc sn phm to hng thm cho ru thnh phm.Cc ch tiu k thut ca dm chn c nh gi bng cc ch s sau:+ ln men: L ng sau khi ln men. c tnh theo % saccaromet.+ axit: L ch tiu nh gi tinh khit ca qu trnh ln men. Trong qu trnh lnmen axit tng ln 0,2% do s hot ng sng ca nm men. Nu axit tng lnqu mc cho php chng t c s hot ng ca vi khun v gy c ch s hot ngca nm men.+ ru ca dm chn l % ru thu c trong qu trnh ln men.8.1.1.4. Chng ct v tinh ch ru etylic

- Chng ct: Mc ch chnh l tch ru etylic cng cc tp cht d bay hi ra khidm chn, sau khi chng ct ta thu c cn th.- Tinh ch: tch ru etylic trong cn th ra khi cc tp cht d bay hi khcRu vang (do ln men t nc qu), ru cn l loi ru khng chng ct.8.1.2. Phng php thu phn g

G c thy phn bng dung dch H2SO4 long (0,3-1%) nhit 160-1800C v p sut 12 atm. Trong qu trnh thy phn cc polisaccarit chuyn thnhmonosaccarit

(C6H10O5)n + nH2O nC6H12O6xenluloz glucozTrong g c khong 50% xenluloz, sau khi thu phn to thnh glucz theo

phn ng trn, tin hnh ln men to thnh ru.8.1.3. Phng php tng hp- Sn xut ru bng phng php tng hp cho hiu sut thu hi cao v nng ru cao

Thng tng hp ru etylic theo phng php hydrat ho olefin. Ru tnghp c s dng lm cao su tng hp, axit acetic, hng liu, dc phm v nhiucht khc.* Nguyn liu: l etilen

Etilen l sn phm ca qu trnh cracking v nhit phn du m. Ngi tadng cc phn ct du m (xng, du ho), hoc kh thin nhin, kh ch bin du mc cha etan, propan, butan... nhit phn trn 7000C, sau chng phn on p

sut thp tch ring cc olefin8.1.3.1. Hidrat ho gin tip c axit sunfuric tham giaNguyn liu: hn hp c 47-50% th tch etilen, 50 - 52% etan v 1% cht khc.+ Giai on 1: Etilen tc dng vi axit sunfuric to thnh etyl sunfat axit v este ietylsunfat.

C2H4 + H2SO4 C2H5OSO2OH2C2H4 + H2SO4 (C2H5O)2SO2

iu kin ti u ca phn ng: p sut ring phn ca etilen l 15at, t0= 70-850C v nng axit sunfuric 97 -98%.


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+ Giai on 2: Thy phn este bng nc.C2H5 - O - SO2 -OH + H2O C2H5OH + H2SO4(C2H5O)2SO2 + 2 H2O 2C2H5OH + H2SO4

Trong qu trnh cn c sn phm ph l ietyl ete. gim sn phm ph, tatch nhanh ru ra khi vng phn ng, hay cho d nc tin hnh phn ng thuphn ete.

C2H5OC2H5 + H2O

2C2H5OH (t

0

thch hp l 90-100

0

C)Cn tnh ton t l H2O/H2SO4 sao cho sau khi thy phn nng H2SO4 50-60%.8.1.3.2. Phng php hirat ha trc tip etileniu kin: t0 = 280-3000C; P = 70at; xc tc H3PO4/silicagen hoc alumino silicat.Trong xc tc cha 35% H3PO4 t do v c kh nng lm vic trong 400-500 gi, sau gim hot tnh phi thay mi. y l phng php n gin v c pht t rinnhanh.

CH2= CH2 + H2O C2H5OH H = - 46,2 Kj/mol.Phn ng tin hnh trong pha hi. Do H3PO4 d bay hi v n mn mnh thit

b, gn y ngi ta s dng xc tc vonfram oxit WO3.

T l hi nc/olefin l 0,6/1 n 0,7/1. Mc chuyn ha sau mi qu trnh 4,5% theo etilen hoc 7% theo nc. Hiu sut xc tc theo ru 200 kg/m3h. Snphm thu c l dung dch ru 15%. Tuy mc chuyn ha sau mi ln nhnhng do tun hon etilen nn hiu sut chung ca ru t 95%.

8.2. SN XUT ACETYLEN

- Acetylen l mt sn phm quan trng trong ngnh cng nghip tng hp hu c- dng nguyn cht acetylen c mi ete nh, khi chy to nhit mnh nn thngdng ct, hn kim loi.- L nguyn liu sn xut cc hp cht hu c CH3CHO, CH3COOH, C2H5OH, nha

8.2.1. Phng php Cacbua canxi: thng sn xut acetylen hn ct kim loiCaC2 + 2H2O = C2H2 + Ca(OH)2 + 130Kj8.2.2. Phng php i t RH loi paraphin: C 2 phng php, nhit phn oxi hov cracking8.2.2.1. Nhit phn oxy hoNguyn liu ban u l kh thin nhin qua cc qu trnh nhit phn thu c C2H2

2C2H4nhit CH=CH + 3H2

hoc C2H6nhit CH=CH + H2

iu kin: l tng t0 v gim p sut nhit cng cao, hiu sut chuyn ho C2H2cng lnTuy nhin nhit 1400-15000C C2H2 s b phn hu

C2H2 nhit cao 2C + H2 khc phc nhc im ny thng tin hnh phn ng vi vn tc ln.

Nguyn liu ch trong khu vc phn ng 1/1000 giy, sau lm lnh nhanh acetylen to thnh khi b phn hu.8.2.2.2. Phng php cracking:

2CH4 C2H2 + 3H2C2H6 C2H2 + H2

C 2 loi cracking: cracking nhit v cracking in


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8.3. SN XUT VINYL CLRUA (CH2 =CHCl)

VC l bn sn phm quan trng ca cng nghip sn xut cht do,polymevinylclorua v cc polime ng trng hp. VC dng ch yu trng hpthnh polivinyl clorua (PVC), dng sn xut si ha hc clorin, sn chu n mnv.v

CC PHNG PHP SN XUT

8.3.1. Phng php i t axetilenThc hin phn ng cng vi HCl, t0C = 140 -2100C, p sut 1,5at trong pha kh

CH CH + HCl CH2 = CHCl (Xc tc 5-10% HgCl2/than hot tnh)8.3.2. Phng php i t etilen8.3.2.1. Sn xut trong pha kh:

CH2 = CH2 + Cl2 CH2Cl - CH2ClT0 phn ng 1000C, 1,2 -iclo etan (Kp: 83,50C) c lm lnh tun hon li

thit b, mt phn c ct tch ra dng sch.- Tip theo: ehiro ha 1,2-iclo etan trong thit b ng 400 -5000C, p sut 1-4MPa

CH2Cl - CH2Cl

CH2 = CHCl + HClto thnh VC (Kp : - 13,40C), tch ra cng vi nc tun hon. Sau chuyn hahiro clorua bng etilen v oxi hoc khng kh, 3000C c mt CuCl2/cht mangAl2O3.

CH2=CH2 + 2HCl + 0,5O2 CH2Cl - CH2Cl + H2OPhn ng s dng lng ln HCl sinh ra oxi ha etilen. 1,2-iclo etan

quay tr li thit b nhit phn.8.3.2.2. Sn xut trong pha lng

CH2Cl -CH2Cl + NaOHdd CH2 = CHCl + NaCl + H2ONu d kim: CH2Cl -CH2Cl + 2NaOH CH CH + 2NaCl + H2ONu d nc, iclo etan b phn hy: CH2Cl -CH2Cl + 2H2O CH2OH - CH2OH +

2HCliu kin: phn ng tin hnh vi t l icloetan : NaOH 42%: metanol = 1 : 1,1: 0,26. Mi trng ng th v metanol ha tan iclo etan. t0= 60 -700C, T phn ng 4-5 gi, P= 3-4at. Qu trnh tin hnh trong thit b lm vic gin on. Phng phpny c nhc im l qu trnh lm vic gin on, thit b phc tp, kh t ng ha,hao tn nhiu nguyn liu


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Chng IX: K THUT NHIN LIU

Nhin liu l tn gi chung ca cc cht chy hu c dng rn, lng, kh, ctrong thin nhin hay nhn to, dng lm ngun cung cp nhit hoc lm nguyn liutrong cng nghip ha cht. Nhin liu thin nhin gm c than cc loi, g, du mv kh thin nhin.

9.1. K THUT SN XUT KH THAN9.1.1. nghaKh ho than l qu trnh oxi ho than khng hon ton thnh kh gi l kh than- u im: So vi nguyn liu rn th kh than c nhiu u im: t chy hon ton,c nhit chy cao, d iu chnh ngn la, kh chy khng tro bi, d vn chuyn bngng ng.

Nhin liu kh c dng ph bin trong l luyn thp, nu thu tinh, l luyncc v lm nguyn liu trong tng hp ho hc v.v...9.1.2. C s ho l sn xut kh than9.1.2.1. Nguyn l chung

y thc cht l qu trnh oxi ha khng hon ton than thnh kh, nh cc tcnhn cha oxi nh khng kh, hi nc, kh cacbonic hoc oxi nguyn cht. Qu trnhny bin phn hu c ca than thnh cc sn phm kh, ch yu gm CO, CO2, H2,CH4, N2, H2S, v.v... nhit n 1200

0C.9.1.2.2. Phn ng ha hc xy ra trong qu trnh ha kh thanPhn ng vi oxi:

C + O2 CO2 (1)2C + O2 2CO (2)

Phn ng vi nc (kh ho than t):C + H2O (hi) CO + H2 (3)C + 2H2O CO2 + 2H2 (4)

Phn ng vi cc sn phm kh va mi sinh ra do cc phn ng trn:C + CO2 2CO (5)C + 2H2 CH4 (6)

Ngoi ra cn c cc phn ng ph:Phn ng ca nguyn liu kh vi CO v H2Phn ng ca hai sn phm CO v H2 to CH4

Phng php kh ha than t theo chiu thun (kh c thi t di ln, thanlun t trn xung) l phng php c s dng rng ri nht.9.1.3. Thit b kh ho than9.2. K THUT LUYN CC

Luyn cc l qu trnh chuyn ho than thnh cc sn phm than cc- Than cc: Lm nhin liu dng trong cng nghip luyn kim, sn xut phn ln nungchy- Nha than cc: Lm nguyn liu v l nhin liu sn xut nhiu hp cht c gitr nh toluen, benzen, ru etylic, NH3...

Trong than cc hm lng C rt cao nn khi t to nhit lng rt ln, cn thitcho cc nh my luyn gang thp.9.2.1. C s ho l ca qu trnh luyn cc9.2.1.1. Khi nim chung:


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Thc cht qu trnh cc ho l chng kh than khng c khng kh, t 0 >1000oC.

Than Than ccCc phn ng din ra rt phc tp bao gm cc hin tng vt l v ho hc

nh hp th, kh hp th ca hi v kh, hp th pha lng ca trng thi do, cc qutrnh bin i trng thi lin hp, cc chuyn ho ha hc nh ng vng, ct tmch...9.2.1.2. Cc giai on ca qu trnh luyn cca/Sy: Khi t0 ln n 100-200oC, hi m v kh hp ph (N2, O2, CO2, CH4 ) thotra.b/Nhit phn than: Nhit 200 - 400oC l qu trnh bn cc ho. Than bt u phnhu, to thnh cc hp cht hu c bay hi. Phn rn cn li l bn cc, cn nhiucht bay hi.

Khi nhit n 4000C cc kh tch ra gn ht v cc ng ng ca metan,oleifin, du bt u thot ra.c/Giai on to trng thi do: Khi nhit t 4000C kh than chuyn thnh trng

thi do, giai on ny c s chuyn ho ct mch C ln to thnh cc phn tthp hn. Nhit ho do ph thuc vo cht lng ca than cc hod/ Giai on kt dnh: Khi khi cht lng t c n nht nht nh, t>=5000C khi do bt u kt dnh chun b cho giai on bn cce/To bn cc: Cc sn phm thp phn t tng trng lng phn t nh cc phnng trng hp v ngng t.f/To cc: Nhit t n 1000-11000C sn phm bn cc chuyn thnh cc s ktkhi cht kht hn v to nn hin tng co li, khi cc to cc vt nt v cc tr nnxp.

Tu theo loi than v ch cc ho sn phm thu c thng bin ng.Than m khi t nng s to khi do c kch thc phn t ca cht hu c v

nht tng ng vi kh nng dnh bm cao nht. Than kh to khi do t nht vkt dnh km. Than gy to ta khi do rt nht, s khuch tn pha lng ca khi dort kh, lm gim kh nng kt dnh gia cc ht v khi do. Thng hn hp ccloi than trn luyn cc.9.2.2. Cc phn ng ho hc xy ra khi to cc * Giai on 1 (to


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Ngng t cc hydrocacbon thm thp thnh cc hydrocacbon thmcao

+

Thc ra qu trnh cn phc tp v xy ra nhiu loi phn ng hn. Sn phmto ra hng trm loi v ph thuc vo than ban u.9.2.2. Gii thiu l luyn cc* Nguyn liu: Nguyn liu dng iu ch than cc cn bo m tiu chun:

W : 6 - 8%; Hm lng P: 0,01%; Hm lng kh ~ 25%Thnh phn c ht 1 - 3mm hoc 6 - 8mm

* L luyn cc:

Hnh IX.2. L luyn cc1. Bung cc; 2. Bung t; 3. Rnh nhm ; 4. Rnh vt ; 5. Dn kh v;, 6. Bungthu hi nhit ; 7. Kh l ra ; 8. Kht vo ; 9. Ca dn u than; 10. Kh ra khi l

t ; 11. Kh vo l t9.3. K THUT CH BIN DU M9.3.1.Ngun gc thnh phn v ngha ca qu trnh ch bin du m9.3.1.1. Ngun gc

C nhiu kin gii thch khc nhau v ngun gc ca du m. Tuy nhin phnln kin u cho rng du m c ngun gc t ng, thc vt, nhng sinh vt bin v c nhng xc ng, thc vt trn t lin theo cc d ng sng ra bin, quabin i to nn du m. Nhng vt liu hu c ny tch ng v bin i xy ra

trong khong thi gian t nht l hng triu nm, di nhiu iu kin thay i khcnhau ca mi trng, nhit , p sut, vi khun hoc ca cc bc x do phng xtrong lng t v.v9.3.1.2. Thnh phn ho hc

Thnh phn ho hc ca du m v du kh ni chung rt phc tp. Tuy vy uc mt nt chung l thnh phn cc hp cht loi hirocacbon chim ch yu t 50n 98%, t C1 n C60, trong C1 n C4 nm trong kh, cn C5 n C60 nm trongdu. Chng gm n-paraphin, iso - paraphin, xicloparaphin hay naphten, hirocacbonthm v hirocacbon hn hp. Phn cn li dao ng t 2 n 50% l cc hp cht d


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nguyn t cha O, N, S, hp cht c kim v nha. Du m trn th gii khc nhau rtnhiu v thnh phn ho hc, song v thnh phn nguyn t ch yu l C v H li rtgn nhau, thay i trong phm vi rt hp (C = 83 - 87% v H = 11 - 14%).9.3.1.3. ngha:

Du m cung cp mt lng ln xng cho cc loi ng c, cung cp nguynliu cho cng nghip, to ra nhng sn phm phc v cng nghip, nng nghip v tiu dng nh cc loi si tng hp, cht do, cao su nhn to, cht ty ra tng hp,thuc tr su, thuc cha bnh, hng liu, dung mi, sn, thuc n v.v.. Vit Namdu m ang c thm d vng thm lc a v c trn t lin v bt u khaithc cc m Bch H, Rng, i Hng, Thanh Long .9.3.2. Ch bin du m9.3.2.1. Chun v du th trc khi a vo ch bin. - Tch kh v n nh du: Du di mt t chu mt p sut ln nn c mt phnkhv xng nh ho tan. trnh mt mt cc cht ny trong qu trnh bo qun vvn chuyn du th cn tch kh bng cch un nng nh hoc gim p sut, mt phnkh ho tan v xng nh s tch ra, qu trnh nh vy gi l n nh du.- Tch nc ln trong du bng cch un nng du th, cho cht chng nh tng vo,

kh nh tng bng in trng.- Tch cc mui khong v t ct... bng cch lng lc nhiu ln v chit tch.9.3.2.2. Ch bin gi nguyn cu to (chng ct)

Qu trnh chng ct p sut thng, hoc chn khng ngi ta thu c:- Xng, ly ra nh thp, dng lm nhin liu cho ng c t trong.- Du xng l loi du dng lm nhin liu cho ng c phn lc.- Du ho c ly trong khong nhit 180 - 2800C, dng lm nhin liu cho ngc, cho cc nhu cu tiu dng, nhng nhiu nht l lm nguyn liu cho cng nghipho cht.- Du nng (du xla) c ly trong khong nhit 250 - 3500C, lm nhin liu chong c iezen v dng cracking.

- Mazut c ly ra y thp chng vi nhit trn 2750

C, chim ti 40 - 50%lng du m em chng. Mazut s c ch bin tip trong thp chng chn khng ly thm mt s sn phm.

Qu trnh chng chn khng nhm h nhit si ca mazut, trnh c s phnhu, p sut chng khong 60 mmHg. Sn phm ca qu trnh l cc loi du bi trnv nha ng. Du bi trn c nhit si trong khong 250 - 3500C, l loi snphm c tm quan trng th hai sau xng- Hc n l phn cn li sau khi chng, c ly ra y thp vi nhit khong3800C, c th s dng trc tip hoc qua ch bin lm nha ng, cht lp.

Ch bin du m theo phng php ny ch thu c 20% khi lng xng dut du th, do s dng du m cha kinh t.

9.3.2.3. Ch bin kh cu toQu trnh chuyn ho ho hc du m t cc cht c phn t lng cao, cu tophc tp thnh cc sn phm c phn t lng thp, cu to n gin hn nh vonhit (Cracking nhit), v xc tc (Cracking xc tc) gi chung l qu trnhcracking. Gn y cn tin hnh rifoming xc tc v hirocracking sn xut ranhiu xng hn v cht lng xng cao hn, ng thi to ra lng ln hn cc snphm ho hc.a) Cracking nhit


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Phn ng phn hu l phn ng c bn nht ca qu trnh cracking nhit, ngoira cn c cc phn ng ngng t th cp, phn ng ng phn ho, phn ng ngvng v.v

Trc y trn 60% xng c sn xut bng phng php ny. ng thi,ngi ta cn thu c nhng hirocacbon th kh (t C1 - C4), chim t l lnhirocacbon khng no, l nguyn liu qu trong cng nghip ho cht. N khc viqu trnh nhit phn l y qu trnh c thc hin nhit trn 700 - 8000Choc cao hn v p sut thng cao hn cht t to ra hp cht thm v cchirocacbon khng no th kh, bn cnh c sn phm lng cha nhiu hp chtthm nh benzen, toluen.

Cc phng php cracking nhit:- p sut cao (12 - 70 at) v nhit tng i thp (di 5400C);- p sut thp (2 - 5 at) v nhit di 6000C;- p sut thng v nhit cao(670 - 7200C);

Cracking nhit cho sn phm theo t l: Xng 13%, kh 5%, cn 80%, mt mt2%.b) Cracking xc tc

Nhng bin i ho hc xy ra trong qu trnh cracking xc tc rt phc tp, cth nu mt s phn ng chnh xy ra nh sau:- Phn ng phn hu mch nhng phn t c kch thc ln thnh nhng phn t ckch thc nh hn. y l phn ng chnh ca qu trnh.

Cn+mH2n+2m+2 -> CnH2n+2 + CmH2m- Phn ng ng phn ho l phn ng to ra hirocacbon c cu trc mch nhnh.y l cu t lm tng tr s octan ca xng.

CH3 - (CH2)3 - CH3 -> (CH3)2CH - CH2 - CH3- Phn ng chuyn di hiro: l qu trnh kt hp hiro vo phn t hoc th mt hayvi nguyn t trong phn t bng hiro di tc dng ca xc tc, v vy lm no cmt s hydrocacbon khng no, nh lm tng kch thc n nh ho hc cc sn

phm thu cCH CH + H2 CH2 = CH2CH2 = CH2+ H2 CH3 - CH3

- Phn ng ankyl ho v kh ankyl: phn ng ankyl ho xy ra mnh nhit thp,s lm giu hiu sut kh; cn phn ng kh ankyl ho xy ra mnh nhit cao,phn ng ny to nhiu kh.CH2 = CH - CH2 - CH3 + (CH3)2CH - CH3 (CH3)3C - CH (CH3) - CH2 - CH3- Phn ng kh hiro - vng ho cc hirocacbon no

CH3 - (CH2)4 - CH3 C6H6 + 4H2- Kh hiro cc naphten: C6 H12 C6H6 + 3H2- Phn ng trng hp xy ra t0 thp, p sut cao, ch yu i vi hirocacbon khng

no.- Phn ng ngng t xy ra i vi hirocacbon a vng. Phn ng ny l phn ngto ra cc bm ln b mt xc tc, lm gim hot tnh xc tc.

Ngoi nhng phn ng chnh trn cn c th xy ra mt s phn ng ph khc.V tc phn ng, so vi cracking nhit, cracking xc tc c tc ln hn

nhiu (n hng trm, hng nghn ln). Nh chn lc ca xc tc cho php qutrnh xy ra theo xu hng to sn phm mong mun.Xc tc cracking:c) Riforminh xc tc


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T cc loi nguyn liu chng ct trc tip, xng ca qu trnh cc ho, xngcracking nhit, tin hnh rifominh vi xc tc l MoO2/Al2O3 hoc Pt/Al2O3. Qu trnhdng xc tc platin cn c tn platfominh, nu thc hin nhit 480 - 510oC v psut 15 - 30at, th to thnh benzen, toluen, xilen, nu 50at th to thnh xng c chs octan cao. Trong qu trnh platfominh, ngoi cc sn phm lng, ngi ta cng thuc cc sn phm th kh (hiro, metan, etan, propan,)

Qu trnh rifominh to ra sn phm xng c cht lng cao, cha nhiuhirocacbon thm v paraphin, hirocacbon olephin < 3%, hirocacbon naphten

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