Nghien cQu tong hap vgt lieu hdp phu oxit kem dgng hgt de xCr ly cdc nguon khi chCra H2S cho.
cdc nhd mdy dgm a Viet Nam
ThS. L I Th| Phuvng T$p dodn D^u khi VidI Nam
ThS. Tr&n Mai Khdi, ThS. Cao Thj Thu Hlng KS. Dodn Thdnh D^t, KS. Ph^m Hdng Tnrd^g ThS. Dd Thj Thanh Nga, ThS. Nguyin Vln Nhan Vi$n DSU khi Vidt Nam
Tdm t i t
Bdi bdo trinh bdy kit qud nghiin cUu tdng hup vdtll^u hdp phu oxit kem (ZnO) dgng hgt tUmudlkim sunfat thdng qua giai dogn kit tda tgo sdn phdm trung gian Zn(OH)y Cdc yiu t6 dnh hUdng din tinh chdt cua ZnlOH)^ dd dUdc nghiin cdu, ddnh gid vd tdi Uu hda. Kit qud tot nhdt thu duac khi tdng hap b d^iiu klin: nhiit dd phdn Ung 64'C mm trudng pH=11, thdi gian gid hda kit tinh 2 gid, hdm luang phu gia tret keo tu 2ppm. Sdn phdm trung gian Zn(OH)j sau khi say, tgo hgt vd nung dchidd 60"C trong 3 gid, 12(yC trong 4 gid, 2S0'C trang 1 gid, ASVC trong 1 gid, BOff'C trang 3 gicfcd dung lUOng hdp phu khodng 37g H^S/IOOg ZnO, dd bin ca dgt yiu cdu d6l vdi vdt Iliu xuc tdc hip phu cdng nghiip. Sdn phdm ZnO dgng hgt Mnh tru cd dUdng kinh 4mm, chiiu ddi 4 - 8mm, thude logi mao qudn tnmg binh, dudng kinh Id xdp tap trung trong khodng 20 - 40A. Kit qud nghiin cUu ndy md ra triin vong trong nghien diu vdt Iliu hdp phu xCf ly tong thi tap chdt lUu huynh trong khi (nhu COS, RSH, H^...) dp dung cho nganh edng nghiep ddu khi Viit Nam.
Phuong phdp h i p phu thudng dupc dp dyng 64 xd ly, lam sach hodn todn tap c h i t luu huynh trong khi nguyen lieu trUde khi dUa vao cdc cdng doan tdng hpp hda hpc cd sir dung xye tac nhay cdm vdi tap c h i t lUu huynh (tranh ngd ddc xuc tdc) [5]. Trin t h i gidi, vdt lieu h i p phu oxit k i m dupc sCf dung phd b i l n de xd ly loai bd HjS trong khi thien nhien vd khi ddng hanh tai cle nhd mdy sdn xuat amoniac, s i n x u l t dam [8, 9]. d Viet Nam, Nhd may Dam Phu My dang sy dyng vat lieu h i p phu oxit kem nhap khau t y nha eung e l p HaldorTopsoe vdi nhu elu khodng 20 t l n / n d m . Hien tai, chua cd don vj ndo trong n u d c e u n g e l p vat lieu h i p phu tren.Trong cdng trinh n g h i i n cyu nay, chyng tdi trinh bay cde k i t qua nghien cyu tdng hpp v l t lieu h i p phu oxit k i m (ZnO) dang hat t y ngudn n g u y i n lieu trong nude n h I m thay the hang nhdp khIu.
I. Ndi dung nghiin ciJTu
1. Nghiin eUu tdng hap vdt liiu hdp phu oxit kem dgng hgt
Mudi kem sunfat {ZnS0^.7HjO) sau khi xCf ly loai bft tap chat eho t i l n hanh phdn dng vdi dung dich NaOH 30%. SCfdung dung djeh dn djnh pH d l duy tri mdi trUdng p h l n yng d gid trj pH mong mudn t y 7 - 1 1 . Gia nhiet len n h i l t dp cIn khdo sdt vd d i m b l o khuly trdn hdn hpp lien tuc trong sudt thdi gian p h l n yng. Bd sung phy gia trfl keo tu vdi hdm lupng thich hpp. Ket thuc p h l n iJng, tien hdnh gid hda k i t tinh d n h i l t dd p h l n Ung trong khoang 1 - 4 gid. Loc rya k i t tCia Zn(OH)j l l l n tuc bdng nydc cat cho den khi loai bd hodn todn Na^SO^ {thd bIng BaCy.
Sin p h l m trung gian k i m hydroxit {Zn(OH)j) sau khi tinh che dupc sly so bd d eO^C trong 3 gid, 120°C trong 4 gift thanh dang bdt khd tUOng ddi; dupe trdn vdi c h i t kit dinh vdi ty I I p h l n t r i m thich hpp thdnh dang bdt nhaodep
i 40 DlllKHl-SOr/2012
PETROVIETNAM
(paste). Sau do dua vdo may ep dun kieu true vit vd t h i l t bj elt hat l i i n tuc sii dung dao e l t djnh thdi gian. Hat hinh tru cd kich thudc: dudng kinh 4mm, ehilu ddi 4 - 8mm duoe nung chuyin pha d c h l dd 250*^ trong 1 gid, 450°C trong 1 gid, 800°C trong 3 gid tao s i n pham cudi eung oxit kem {ZnO).
2. Ddnh gid chdt lUOng sdn phdm vdt lieu hdp phu oxit kem dgng hgt
Sii dung phuong phap n h i l u xa Ronghen (XRD) d l nghien eyu, d i n h gid c l u true tinh t h i cua v l t lilu. Phd nhilu xa XRD eOa m l u nghiin cyu dUOc ghi t r i n mdy Brueker D8 Advance (Dufe), dng phdt tia Ronghen bdng Cu {ed bude sdng X = 1,5405 A); gdc qu^t thay ddi t y 5 - 70°;
bude quet 0,05° vd tdc dd quet 0,5 gidy [1 ].
Diln tich b l mat rilng {BET) vd kich thude id xdp cua vat lieu hap phu ZnO dupe xac djnh theo phuong phdp ding nhiet h i p phu vd gidi h i p phu v l t ly tren mdy ASAP 2010 Micromericties. TrUde khi do, m l u dupc Idm sach trong ddng khi heli d nhiet dp 350°C trong 90 phut vdi tdc dp gia nhiet 5''C/phut. Qud trinh h i p phu d nhiet do -196*^, dp suat 770mmHg, luu lUpng khi mang 25ml/phut.
Tap c h i t kim loai (sit, chi, cadimi) trong mau nghiin cyu dupe xac djnh b I n g phuong phap quang phd hap thu nguyin t y (/VAS), thuc hien tren hap thu nguyin t d Perkin Elmer A300. Dp b i n nen, dp b i n m l i mdn cua m l u v l t lieu duac xac djnh theo ASTM D 4179 vd ASTM D 4058.
Dung lupng h i p phu cua v l t lieu hat oxit kem dUpc xlc dinh dua tren ehinh lech khdi lupng mau ZnO nghien cUy trudc va sau khi bdo hda hap phu H^S. Qud trinh hap phu dupc tien hanh d dieu kien n h i l t dd 350''C, dp suit t y 1 - 4 bar, sy dung khi H^S 5% pha trong N^.
11. Ket qud va thdo luan
1. Khdo sdt ede yiu to dnh hudng din qud trinh tong hap sdn phdm trung gian Zn(0H)J6,7]
Phan ung giya mudi kem sunfat vd dung djeh k i l m tao ra k i t t y a hydroxit kem {san pham trung gian trudc khi tao hat vat lieu h i p phu oxit kem)
ZnSO, + 2NaOH ^ Zn(OH)j 4- + Na^SO^
Phdn yng siJdung khuay trdn vdi tdc do 600 vdng/phut.
Cdc chit tham gia p h l n yng ZnSO^ vd NaOH dupc elp vao binh phan yng t y 2 ngudn song song vd lien tuc.
Da t i l n hanh khdo sat ddnh gia cde yeu t d dnh hUdng:
nhiet do phan dng, pH, ndng dp phu gia trp keo tu, thdi
gian gid hda k i t tinh d i n c l u true tinh t h i eua Zn(OH)j, dac trung b I n g cudng dd pic tai gdc nhilu xa 2e = 36,2 cya phd XRD {dly Id pic eye dai nhilu xa cd cUdng dp Idn nhat tren phd XRD cua mdu Zn{OH)j). Cudng dp pie edng Idn the h i i n hdm lupng pha tinh the cya Zn{OH)j edng cao. Cudng do pic ndy Id gid tri hdm muc t i l u d l tinh todn quy ho?eh thUc nghi|m vd tdi Uu hda.
1.1. Anh hudng cua nhiit dd phdn Ong
Nhdm tdc gid da t i l n hdnh khdo sat I n h hudng ciia nhilt dd phdn dng trong khodng t y 25 - 80''C d i n sU tao thdnh k i t tua Zn(OH)j. Cdc thdng sd khde dUpc giy cd djnh nhu sau: pH = 9, ndng dp phy gia trp keo tu 4ppm, thdi gian gid hda k i t tinh 2 gid.
(3 n h i l t dp t y 25 d i n dUdi SO^C, k i t tua Zn(OH)^ thu dupe ed dang gel trong sudt, sau khi say sdn pha'm bj vdn cue dang rdn. Cd t h i khi t i l n hdnh p h l n yng d nhiet do dudi s e c se khdng thudn Ipi cho vile k i t tinh iai eCia gel Zn{OH)^ vd dinh hinh thanh Zn{OH)j tinh the.
d nhiet dp tren SCC, gid tri eudng do pie XRD ddc trung (tai goc nhieu xa 2e = 36,2) cd xu hUdng tang dan khi tang nhiet dp (kit qud the hien t r i n Bdng 1). Tuy nhien, khi tien hanh phdn yng d nhiet dp 80°C thi eudng dp pic gidm rd ret, hay ndi cdch khac ham lUpng pha tinh t h i Zn{OH)j gidm. NhU vdy, nhiet dp phdn yng qud cao cung khdng thuan Ipi cho viec tao thdnh Zn{OH)j tinh the.
Bdng I.Anh hudng ciia nhiet do den cudng do pic XRD cua ZnfOH)^
Nhiet do k ^ t^a Zn(OH), rc)
so 60 70 80
cudng do pic tai 26 = 36,2 ; (Cps) __i 1.020 i 1.305 1 1.170 1 1.118 ; 1.2. Anh hudng cOa pH
Theo quy lult hoa ly, thi pH cdng eao thi cdng thuan lOi eho qud trinh phan Ung tao k i t tua Zn(OH)j trong moi trudng k i l m . Cd djnh cdc d i l u kien phdn ufng k i t tua Zn(OH)j nhu sau: n h i l t dd 52"C, ndng do phu gia trp keo tu 4ppm, thdi gian gia hda k i t tinh 2 gid. Thay ddi gid trj pH t y 7 - 1 1 . Khi thyc nghiem tien hanh d gia trj pH thap (pH = 7, pH = 8), phan tich bdng phuong phap XRD cho thay cudng dp pic nhd (dudi BOOCps) chung td ham lupng pha tinh t h i thap. D i l u ndy la do d pH t h i p , mde dp thuy p h l n tao ra Zn(OH)j t h i p .
Tsii ele gid tri pH = 9 - 11, cdc mau Zn(OH)j thu dupc cd cudng dp pic Idn (tren dudi 1.300Cps), n i n pic phIng, dinh pie nhon chUng td hdm lypng pha tmh t h i vd
mye dd t i p trung cao. \ Khi tang pH l l n > 11, } sU thyy phdn tao ra Zn(OH)j tdng. Do tinh c h i t lUdng tinh cua Zn{OH)j n i n khi pH t i n g q u i cao ed t h i Idm mdt p h l n Zn(OH)j bi tan ra t^o thdnh phye hydroxozincat, d i n d i n Idm gidm lupng Zn(OH)j k i t tua. Tinh t h i dupc tao ra phdn tdn mjn n^n r l t khd Ipc rda, chyng td mdt p h l n k i t
tua cd h i i n tuong bi tan ra d d i l u k i l n pH qud eao.
1.3. Anh hudng cua phu gia trakeo tu
Trong qud trinh tdng hpp Zn{OH)j, phu gia trp keo tu dupc t h i m vao nhdm tdng tde ddqud trinh keo tu Zn(OH)j, gidm thdi gian ling, loe. Cde thi nghiem trong nghiin cyu ndy sir dung phu gia polyaerylamit (ed ten thuong mai Id N208) la loai phu gia sin ed t r i n thj trUdng. Phu gia trp keo tu phdi duoc them vdo vdi ndng dp hpp ly sao eho tdc dp keo tu vya phai, tao mixel keo hop ly.
Vdi ndng dp qua nhd {< 2ppm), thi ehua 6ii de Idm thay ddi sd lupng cung nhU kich thude tinh t h i . ThUe t l nghien cdu cho thay, vdi ndng dp phu gia nhd hon 2ppm, kich thudc tinh the van cdn nhd, g l y t i c Ipc. Khi sCf dung phu gia tro keo tu vdi ndng dp t y 2 - 6ppm trong dieu k i l n giy cd djnh cdc thdng sd nhiet dp 52''C, pH = 9, thdi gian gid hda k i t tinh 2 gid, eudng dd pie ddc trUng eua phd XRD cd xu hudng tdng d i n khi t i n g ndng dp phy gia.
Xu hudng nay cd the dupc g i l i thich nhu sau: phu gia trp keo tu ed vai trd tao cau ndi vd h i p phu cdc tinh t h i nhd Zn(OH)j tao ra elc k i t tua cd kich thudc Idn hon vd g i l m thdi gian ling. Vdi ndng dp nhd, sU keo tu xdy ra vdi tde dp vd mde do vya phdi {hay ndi cdch khde, mdt phdn tLf phu gia se h i p phu va tao cau ndi vdi hai hay mdt sd lupng hat keo Zn{OH)^ visa p h l i .
Khi sir dung phu gia vdi ndng dp Idn hon 6ppm xdy ra h i i n tupng bien ddi tinh chat vat ly eCia dung mdi, tdng sye cdng be mat, gay khd Ipc. Vdi ndng dd phy gia Idn thi
Hinh I. Phd XRD cua Zn(OH)^ tSng hgp d diiu ki^n pH=11
Bdng 2. Anh hudng cua phi^ gia tra keo tu din cudng dd picXHD cuaZn(OH)^
t
Ndng dd phu (ppm)
2 3 4
gia Cirdng dd pic
(Cps) __
1.068 1.110 1.160 1.199 cdc phdn t y phu gia s i l l l n k i t vdi nhau {polyme hda}t^
thdnh mdng bdng xdp, Idm tdng dp nhdt va bit Id khi loc 1.4. Anh hudng cda thdi gian gid hda kit tinh
Thdi gian gid hda r l t quan trpng ddt v<S vile tang do tinh t h i eua Zn(OH)j. CIc k i t qud nghien eyu cho thSy thdi gian gia hda Idm cho dd tinh t h i tang nhung lam g i l m dien tieh b l m I t r i l n g do kich thUdc tinh t h i tang vd eung ldm tang kich thudc mao ijudn. Kit qud khdosSt dnh hudng cya thdi gian gid hda den qud trinh tdng h ^ Zn(OH), trong d i l u k i l n n h i l t dd phdn dng 52-0 pH = 9, ndng dd phu gia trp keo tu 4ppm dupe trinh bdy trong Bdng 3.
K i t q u i XRD eho t h i y khi tang thdi gian gid hoa, cudng dp pie tang chdng td dd tinh the tang l l n . CacmSu yng vdi thdi gian gid hda n h d h o n 1 gidthiddtinhthSIS t h i p n h l t . CIc m l u yng vdi thdi gian gia hdaty3-4gift thi cudng dp pie khdng cd sy khac b i l t Idn. M l u c6 thdi gian gia hda 2 gid cd cUdng dp pie Id Idn n h l t nen d6tinh the Id eao nhlt.
I 42 Di[UKHi-Sd7/2012
PETROVIETNAM
Thdi gian gia hda ldm cho tinh the dn dmh v l cau trOe, cle tinh t h i be tan ra vd tdi nhap lai vdo elc tinh t h i Idn hon vd Idm tang ham lUpng pha tinh the. NhUng tdi mpt lue ndo dd, qud trinh ndy se dat eIn bang vi v|y hdm lupng tinh t h i Zn(OH)^
khong t i n g l l n nya.
Tren cO sd k i t qud khdo s i t cdc y i u td dnh hudng den cau true tinh t h i cua Zn{OH)j neu tren, nhdm tac gid da thyc hiin quy hoach thye nghiem vd xde djnh dupc cdc thdng sd tdi Uu cho qud trinh tdng hpp sdn p h l m trung gian Zn(OH)j nhusau:
+ Nhilt dp phdn yng: 64°C + pH: 11
+ Ndng dp phu gia trp keo tu: 2ppm -I-Thdi gian gia hda k i t tinh: 2 gid.
Sin pham Zn(OH}j thu duac sau khi say khd dat h i l u suit 96%.
2. Anh hudng cda chedd say nung ehuyin hda Zn(0H) thdnh ZnO
Bdng 3. Anh hudng cua thdi gian gid hda den cudng do pic XRD cua Zn(OH)^
Thdi gian gi^ hoa (giif}
0 1 2 3 4
cudng dd pic tai 2e = 36,2 (Cps) 1.020 1.318 1.325 1.305 1.308
Hinh 2. Gidn ddphdn tich nhiit TG - DSCcOa mduZn(OH)
Vdi muc dich x l y dUng mpt qui trinh cdng nghe sly, nung tdi Uu cho s i n pham nhan daac. nhdm chuyen hda hoan toan hydroxit k i m thdnh oxit kem, nhdm t i e gia da t i l n hanh nghiin edu qua trinh say nung m I t nude v l t 1^, mIt nudc l l l n k i t hda hpc, chuyen pha eua sdn pham thu duoc theo chuong trinh nhiet do. Mau sdn pham dupc nung den SOCC trong mdi trudng khdng khi vdi tdc dd ndng nhiet la 10°C/phut, qua trinh ehuyin pha ed t h i quan sat t r i n gidn dd phan tich n h i l t TG - DSC (Hinh 2).
Quan sat t r i n giari dd p h l n tieh nhiet Hinh 2, cd the thay rd cac pic d i e trUng d cac gid trj n h i l t dd 105,4''C;
244,5''C; 435,6°C; 831,6°C, tUOng OTig vdi cac pie nay deu cd sy mat khdi lUpng cya mau dde trung eho sy mat nudc vdt ly vd mat nude lien ket hda hpc trong qua trinh chuyen pha cua hydroxit kem. Pic d 105,4''C Idn nhat va rd net nhat tUOng yng vdi sU mat khdi lUpng mau do qua trinh m I t nude vdt ly. Cac pic tuong dng vdi n h i l t dd eao hon chinh la q u i trinh mat nUde elu true v l ehuyen pha.
Cd the chia q u i trinh say nung thdnh cac giai doan chinh nhusau:
+ Giai doan 1:Ty n h i l t dp phdng tdi 160'C, khdi lupng miu gidm manh 46,21 %. Day la qud trinh tach nUde vdt ly
va mdt p h l n nudc l i i n k i t hoa hpc. Pic tin hieu nhiet DSC t h i h i i n qua trinh thu nhi^t trong giai doan nay.
+ Giai doan 2:Ty 160''C d i n khoing 250"^, lupng mau g i l m it 4,84%. Day la qud trinh tdch nUde li^n k i t hda hpe.
Pie tin hieu nhiet DSC the hien qud trinh thu nhiet de bay hoi nudc.
+ Giai doan 3: TU 250''C den 450''C, lUpng mau giam nhe 1,01%. £)ay la qua trinh t i l p tue tdch nUde lien k i t hda hpc.Tuy nhien, da xuat hien pie DSC tda nhiet d v| tri nhi&t dp 435,6°C, chyng t d bdt dau cd sUgidi phdng nang lupng chuyin pha vd djnh hinh thanh pha tinh the, tao thanh cau trye b i n vdng hPn.
+ Giai doan 4: Sau 450''C, lUpng mau gidm hau nhU khdng dang ke, nghia Id nude l i i n k i t da tach h i t . Vile nung mau d 800°C cd t h i chuyin hda hodn toan Zn(0H)3 thanh ZnO. Neu t i l p tue nung d n h i l t dp Ic^ hon 800°C thi lupng mau cd gidm r l t it do m I t mdt lupng nhd oxy trong c l u true. Tinh t h i ZnO thay ddi mau t y trang sang vdng nhat. Pic tin hieu n h i l t DSC the hien qua trinh tda n h i l t chyng td da xay ra qua trinh thay ddi cau true (mIt oxy trong cau trye).
K i t qud nghiin ciJfu sy chuyin pha bSng phyong phdp phan tich n h i l t vi sai d t r i n Id co sd d l xde djnh c h l dp sly nung hpp ly cho qud trinh nung Zn(OH)j nhdm thu dupc s i n pham ZnO c6 hdm lUpng pha tinh t h i eao. Thdi gian sly nung tdi Uu dupe xle dinh nhu sau: dCC (3 gid) - 1ZO-C (4 gid) - 250"^ (1 gid) • 450''C (1 gid) - BOCC (3 gid).
3. Khdo sdt cdc yiu td dnh hUdng din qud trinh tgo hgt vdt liiu hdp phu ZnO [4]
3.1. Anh hudng ctia chung logi vd hdm lupng chdt kit dinh din do bin ca, bi mdt rling, cdu true xdp cua v^tli^u hdp phu ZnO
Cdng trinh t i p trung nghiin edu dnh hUdng cua 3 loai c h i t k i t dinh dd Id axit axetic {ky h i | u m l u A), axit nitric (ky hieu mau N) vd gel Zn(OH)j (ky h i l u m l u G). Cdc m l u hat thu dupc sau dd duoc t i l n hdnh do vd ddnh gid dd b i n CO theo yeu c l u tdi t h i l u cua v l t l i l u xuc tde h i p phy cdng nghiip: do b i n n i n y i u c l u a 50kg/em^ dd b i n mdi mdn y i u elu hut khdi do mdi mdn s 2% khdi luong. Cdc mau dat y i u elu v l do b i n eo s l dUpc t i l n hanh do vd danh gid be mat rilng.
Cde mau sd dung c h i t k i t dinh A ed dp ben co k4m, khdng dat y i u elu toi thieu v l do b i n nen vd dd b i n mai mdn cua vat lieu hap phu edng nghiep. Cde mau sd dung chat k i t dinh A khi nung d i n nhiet dp 400''C d l u bi ndt vd.
Kit qud n g h l i n cyu ddi vdi c h i t k i t dinh N cho thiy quy lu^t dd b i n cocOa hgt v l t ll|u g i l m d i n khi t i n g nhi|t d ^ nung m l u . M l u N2.0 n l u ehi nung d khoing 400°Cthl dd b i n CP ed t h i d^t >1 OOkg/cm', tuy n h i i n khi nlng len 800"C thi d$ b i n eP g i l m xudng chi edn mdt nya.
Theo k i t q u i trong BIng 4, quy l u l t khi tdng hdm lupng c h i t k i t dinh thi d$ b i n co t i n g vd be mat rilng gidm. Khi sijf dyng hdm lUpng nhd, sd lupng cdc tdm lien k i t t^o ra gida ede t i l u phdn oxit kem chua nhilu n^n do b i n CO cua hat khdng cao. Tuy n h i i n , hdm lupng chat kft dinh chi t i n g dUpc trong mdt gidi han n h l t djnh vi n^u t i n g cao qud thi tinh lUu b l l n eCia bdt nhao gidm vd se rlt khd I p dun d l tgo hat.
Thyc n g h i l m cung cho thiy, khi tdng hdm lupng tac n h i n N l l n t r i n 2% thi khi nung 800°C xult h i i n hiin tUong nyt vd hat. Bdi khi hdm luong t i e n h i n pepti hda dua vdo q u i Idn se d i n d i n tao ra qud n h i l u tdm lien k i t Cdc hat l i i n k i t vdi nhau nhilu hon s l xdy ra h i i n tumig nijit vddo dng suit co ngdt eua khdi hat trong qud trinh dehydrattao thdnh ZnO vd sU p h l n huy cua tdc n h i n pepti hda (chat k i t dinh). Hon nya, dp xdp tang cung Id mdt trong nhiiiig nguyin nhan Idm g i l m dp ben cO cua hat.
Khlo s i t qua trinh tao hat ZnO sir dyng chat ket dinh dang pha l i i n k i t Gel Zn(OH)j vdi hdm lugmg gel tir 3 - 100% eho dp t l l n eo dat yeu elu ddi vdi h l u h i t cac man.
Bang 4. Anh hudng cua hdm luang chdt kit dinh N din dd ben ca vd bi mdt rling cua hgt ZnO (nhiit dd nung SOO'C)
Mau o{b6tZnO)
No 5
^1.0 Nl.5 N2.0
Him li/tfng chit k i t dfnh l%l
0,0 0,5 1,0 1,5 2,0
D6 b i n m i l mdn (% k h i i luong)
7,8 4,6 3.1 2,4
Dd b i n n i n (kg/cml
Khdng d^t Khdng d^t 47 50
B i m i t rieng BET (m'/g)
9,01 8,70
Bdng 5. Anh iiudng cOa tfdm Itigng chatkit dinh G dSn d^ din ca, d i m^t riing vd cdu tnjc x6p cua hgtZnO Him lucfng gel Dd b i n m i i mdn,
1%) % k h i l i u a n g
G,
G, 5
10 100
Dd b i n nin, ikg/cm')
93 102 114 125 218
Be m^t rieng, BET ImVg)
9,04 8,48 6,54 6,26 4,16 4,10
The tfch lo xdp V^
(cmVg) __.
o,o^M___2 0,0164 0,0117 ^ 0A1T7___J 0,0112
44 DlUHli-Sd7/2012
PETROVIETNAM
IMlu
G4-2.S00 G4-3.500
Bdng 6. Anh hudng cua phdn bocd hgt din dd bin nin, bi mat rling, cdu true xdp cua vdt tiiu hdp phu ZnO Phln bd cd hat
Tdc dd nghien (vdng/phut)
2.500 3.500
>70%(10-20|im) 65% (5,0 - 20Mm) 25%{0,l-0,2Mm) 60% (2,0-1 Sum) 35%(0,l-0,2ym)
D6 ben n^n (kg/cm^)
BimltridngBET , T h i tich Id xdp (mVg) (cmVg)
6,5 0,011
7,4 0,016
Kit qua d BIng 5 phdn dnh quy lult: khi tang hdm lupng gel Zn{OH)j sd dung Idm c h i t ket dinh, dd b i n eo tdng, tuy nhiin b l mat r i l n g gidm vd the tich Id xdp (clu true xdp) g i l m . ThUe n g h i l m eung ehi ra ring, viec tang hdm lupng gel se dnh hudng r l t nhilu d i n q u i trinh sin xuat, khd kiem sodt qud trinh tao hat. Vi khi dua vao nhilu gel se lam paste qud nhdo d i n d i n phdi sly tdch bdt I m , qua trinh sly lai d l g l y ra h l l n tupng ddng r l n gel.
Vdi gel Zn{OH)j 4%, dp b i n mdi mdn dat 1,6% khdi lupng, dp ben nen dat 102kG/cm', be mat rieng bang 6,54mVg (giam 27% so vdi bdt ZnO khdng cd chat k i t dinh), t h i tich Id xdp b I n g 0,0117emVg (gidm khdng nhieu so vdi bdt ZnO khdng cd chat k i t dinh). Do dd, ham lupng gel thich hpp dupc lya chpn la 4%, thuan Ipi cho qua trinh san xuat (kiem sodt qud trinh tao hat), trong khi b l mat r i l n g va c l u true xdp cua v l t lieu iai khdng bi giam qua nhieu.
3.2. Anh hudng cua kich thudc hgt den do ben ca, be mat rieng, cdu true xop cOa vdt liiu hdp phu ZnO
Sii dung phuong phap nghien cd hat micron (thdi gian nghiin 30 phiJt, thay ddi tdc dp nghien) de tao ra cac kich thude hat khac nhau phuc vy nghiin cyu. Phln bd cd hat dupc xde dinh b I n g phUOng phap tdn xa laser. Kit qua khdo sat cae mau G4, G4 - 2500 (mau G4 dupe nghien vdi tdc dp 2.500 vdng/phut), G4 - 3.500 { m l u G4 dupc nghien v&i tde dp 3.500 vdng/phut) dupe trinh bay trong BIng 6.
K i t qud cho t h i y khi tang tdc do nghiin, kich thudc hat g i l m xudng, do silt chat eua vdt lilu tdng l&n, Idm cho dd b i n nen tang, b l mdt rilng tang vd c l u true xdp tang.
4. Xde dinh ddc tinh eda sdn phdm vdt liiu hdp phu ZnO dgng hgt
M l u vdt lieu hap phu ZnO duac chup phd nhieu xa Ronghen (XRD) (Hinh 3) va dUpc so sanh ddi chyng
ft 3. Phd XRD mau ZnO tong hap ddieu kiin tdi du
1
JL- f
r
.
MuMSSf^iiH
1 h
Bi U i
Hinh 4. PhdXRD cua mdu HTZ-3 (HaldorTopsoe)
DJhlWll-Sd 7/2012 4 5 ^
1 1 I'^iTTTi 1 1 1 1 1 1 1 1 1 1 1 in
____J It
^y i_
^ • " ' ^ ° '
^
{ J
1
'"
}^\
I V1 t ' " ^
•
• ->
...
^
\ \
\ ,
* • .
— ^ \ - .—•
""
,1 }
,_
Hinh 5. Gidn dd ddng nhiit hdp ph^i Hinh 6. Phdn bd dudng kinh Id x6p Bdng 7. Chat iuang sdn phdm vdt liiu hdp phu ZnO dgng hat hinh tru Chi tidu PhUtfng phdp phdn tfch
06 tinh khiet s^n pham (% khdi luang ZnO) 06 ben n^n (kg/cm^) Hut khoi lupng do mai mon (%}
Be mat rieng (m^/g) Ty trong (kg/I) Dung lupng hap phu (%)
Oudng kinh (mm) Chieu ddi {mm^
AAS ASTM D 4179 ASTM D 4058
BET
Haldor Topso«]
99 9S 2 6,50 1,1 - 1,3
39 4 4 - 8
1 Sin phlm ZnO iiat
99 102 1,6 6,54 1,1-1,3
37 4 4-8
vdi mau vdt lieu h i p phu thuong mai HTZ-3 eua Haldor Topsoe {Hinh 4). Op trung lap eao giUa cde pie chdng t d mau nghiin cdu dupe tdng hpp cd k i t qud dang tin edy.
Gian dd d i n g n h i l t h i p phu t r i n Hinh 5 eho t h i y dudng cong h i p phu va nhd h i p phu khdng trung nhau tao nen mpt vdng tre, d i e trUng eho vat lieu cd mao qudn trung binh (20A < d < 500A).
Tren gidn dd phan bd dUdng kinh Id xdp tren Hinh 6, cd t h i t h i y dudng kinh Id xdp phan bd trong mdt ddi rdng t y 20 - lOOA, tuy n h i i n tap trung chy yeu d k h o i n g 20 - 40A.
Cdc chl t i l u ky thu^t cua sdn pham v l t li|u hap phu oxit kem d^ng hat (hinh try) dupe n l u t^i Bdng 7.
Ty k i t q u i t r i n cd the t h i y , p h l n Idn cdc chi tilu;ky thuat cya sdn p h l m hat ZnO tao ra nhu dd tinh khilt <10 b i n CO, b l mat rilng, ty trpng, dUdng kinh, chilu d^deu dat y i u c l u {so vdi m l u v l t l i l u h i p phu HTZ-3 cOa Haldor Topsoe). Chi t i l u dung lupng h i p phu cOa sin p h l A o ra t h i p hcfn so vdi s i n phSm nhdp ngoai {37% so wS399|.
Cd t h i n l n g cao chl t i l u dung lupng h i p phu ndy thfiffl qua vile n g h i i n ciJu tdng hop ZnO cd b l mat rilng lOT hon, b I n g cdch gidm kfeh thudc h^t ho^c dUa Z n O M t r i n c h i t mang cd b l mdt rilng Idn (vi du oxit nhdmjJ'lp
PETROVIETNAiVl
III. Ket luan
- Da tdng hpp dupe vdt lieu hap phu oxit kem dang hat t y nguyin l i l u mudi kem sunfat thdng qua giai doan kit tCia tao sdn pham trung gian hydroxit kem d d i l u kien nhilt dp p h l n yng 64''C, pH = 11, ndng do phu gia trp keo tu polyaerylamit 2 ppm, thdi gian gid hda k i t tmh 2 gid.
Cac thdng sd nay da duac tinh toan tdi Uu hda b I n g quy hoach thyc nghilm, k i l m chyng bIng thyc nghilm, cd do lap lai ddng tin edy. C h l dp nhiet dd sly, nung chuyin hda hydroxit kem thdnh oxit kem dupc xde dmh: 60'<; {3 gid) -»120''C (4 gid) -* 250°C (1 gid) -» 450°C {1 gid) -> BOO^C (3 gid). Chit k i t dinh phu hpp nhat cho qud trinh tao hat Id Gel Zn{OH)j hdm luong 4%.
- Hat ZnO dupe tao ra cd dudng kinh 4mm, ehilu ddi khodng 4 - 8mm, thude loai vdt lieu mao qudn trung binh, dudng kinh Id xdp tdp trung trong khodng 20 - 40A. Cac chi t i l u ky thudt ( b l mdt rieng, dung lupng h i p phu, dd bin eo) dap yng yeu cau ciia vat li^u xuc tdc h i p phu edng nghiep.
IV. Hudng nghien cihj tiep theo
Cle k i t qua nghien cdu eho t h i y da e h l tao dUpc ehat hap phu oxit kem (ZnO) dang hat cd dung lupng h i p phy khodng 37%, dp b i n co dat yeu c l u cua v l t l i l u xue tac hap phu edng nghiep. De cd the yng dung s i n pham vao thyc te, can nghien cyu hoan thien t h i m mdt sd v l n de sau:
+ Thy nghiem k h i n l n g hap phy, xde dmh dung lupng hap phy cua san pham trong d i l u k i l n thyc t l sdn xuat {luu lupng khi, ap s u i t thyc te).
+ Ddnh gid mdt each ehi tiet hon dnh hudng cOa cac khi khde trong thanh p h l n khi t h i i n n h i i n nhu H^, CO, COJ... den kha nang hap phu H^S cua san pham.
+ Nghiin cyu dnh hudng cua nhiet dp, dp suit trong d l i bien t h i i n rdng hon den k h i ndng h i p phu cua san pham.
Ben canh dd, k i t qud nghien cdu eung md ra mdt sd hudng phdt t r i i n nhU;
+ Nghiin cyu hoan thien vdt lilu h i p phu oxit kem de xy ly khi gidu HjS ngodi gidn khai thIe.
+ Bd sung oxit nhdm trong thdnh phln oxit k i m d l cd t h i x d l y c l tap chat COS.
+ Nghiin cyu tdng hpp v l t li^u xue tde h i p phu trong q u i trinh xii ly luu huynh bSng hydro (HDS) de xii ly mereaptan RSH trong khi thien nhien va LPG. TUdd tien tdi t h i l t k l h i thdng xy ly tdng t h i tap chat lUu huynh (COS, RSH, HjS...) ap dung cho cac hd tieu thu thUOng mai va cdng nghiip.
Tai lieu tham khdo
1. G. ErtI, H. Knozinger, J. Weitkamp. Preparation of Solid Catalyst.WAey-\/CH
2. Diane Stirling. The sulfur problem: Cleaning up industrial feedstocks. Thomas Graham House, Cambridge, UK. 2000.
3. AthurLKohland Richard B.Nielsen.Gaspurlficaf/on -f;fl'/i£d/f;on. Gulf Publishing Company, USA. 1997.
4. A comprehensive review of ZnO materials and deWces. Journal of Applied Physics 98.
5. Bu, X. et al. Research improvement In zinc-based sorbent for hot gas desulphurisation. Fuel Processing Technology. 2008; 180: p. 253 - 258.
6. Schuiz, D. et al. Inductively heated Brldgman method for the growth of zinc oxide single crystals, ioutrxai of Crysta\