s£n xu¥t para xylen

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công nghệ sản xuất para Xylen

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ti: Sn xut para-xylenMc LcPhn 1. M u Phn 2. Ni dung 2.1. Tnh cht k thut ch yu ca para-xylen 2.2. Cc ngun sn xut chnh 2.2.1. Cc ngun t du m 2.2.1.1. T qu trnh reforming xc tc 2.2.1.2. T qu trnh Cracking hi nc 2.2.1.3. T qu trnh chuyn ha Hydrocacbon 2.2.2. Ngun t than 3 4 4 5 6 6 7 8 92.3. Cng ngh sn xut p-xylen t sn phm ca qu trnh reforming xc tc 11 2.3.1. X l nguyn liu Naphta 2.3.2. Qu trnh reforming xc tc 2.3.2.1. B phn phn ng 2.3.2.2. B phn ti sinh xc tc 2.3.2.3. B phn n nh 2.3.2.4. Xc tc cho CCR Platforming 2.3.3. Tch p-xylen t sn phm reformat 2.3.3.1. Phn xng Tatoray 2.3.3.2. Phn xng Isomar 11 12 13 14 16 23 25 25 291 ti: Sn xut para-xylen 2.3.3.3. Phn xng Parex Phn 3. Kt lun Ti liu tham kho 32 39 402 ti: Sn xut para-xylenPhn 1. Li M uPara-Xylen hay 1,4-dimetyl benzen l mt trong nhng ng phn c nhiu ng dng quan trng trong s cc ng phn ca xylen C6H4(CH3)2, Para-Xylen c s dng trong cng nghip ch yu sn xut axit terephtalic v dimetyl terephtalat, y l cc nguyn liu u cho vic sn xut s si, mng polieste v nha PET c ng dng rng ri trong mi lnh vc i sng x hi. y l sn phm cn t c sn xut trong nc3 ti: Sn xut para-xylenPhn 2. Ni Dung2.1. Tnh cht k thut ch yu ca para xylenPara xylen c khi lng phn t l 106,16 vC, si 138,40C, im nng chy nhit 13,30C, tn ti dng lng khng mu hay dng tinh th. Para xylen l cht c d bt chy, tan tt trong etanol v t tan trong nc. Mt s tnh cht khc trong bng 1.Bng 1: Mt s c trng k thut ca BTX v cumen [1]Thng sn vBenzen 78,11Toluen 92,13Khi vC lng phn t T trng 200C Nhit 0C nng chy Nhit 0C si Gii hn % th n trong tch khng kh Trn Dio-xylen mxylen 106,16 106,16p-xylen etylbenzen 106,16 106,170,879 5,330,867 -94,990.876 -25,20.86 -480.857 13,30.867 -94,980,1110,6144,4139138,4136,21,4 7,11,3 6,81,1 6,41,1 6,41,1 6,60,99 6,74 ti: Sn xut para-xylenNhit 0C chp chy cc kn T trng 2,77 hi(khng kh=1) Gii hn tip xc (ppm; gi) -11,1 4,4 17,2 25 25 153,143,73,73,73,73,75;850;8100;8100;8100;8100;82.2. Cc ngun sn xut chnhCc ng phn xylen trong t nhin thc t ch c trong du m. Tuy nhin hm lng ca chng trong du m cn ph thuc nhiu vo v tr a l cng nh tui ca du th. [Bng 2] so snh hm lng ca hydrocacbon thm C8 v C6-C8 nhiu loi du m khc nhau trn th gii. Bng 2: Hm lng Hydrocacbon thm trong cc loi du m. [2]Libi Hydrocacbon 0,56 C8, % khi lng Hydrocacbon 1,0 C6-C8, % khi lng Vnh ng Louisiana Texas 0,5 1,10 Venezuela Negiria 1,10 1,47 Iran 1.051,101,791,852,501,80D vy cng c mt vi trng hp trong du m (vd: du m ng Nam ) cha hm lng ln hydrocacbon thm (ln ti 35%). Nhng phng php tc ly xylen t nhin l khng c tnh kinh t.5 ti: Sn xut para-xylen 2.2.1. Cc ngun t du m 2.2.1.1. T qu trnh Reforming xc tc Hn hp xylen ni chung, cng nh p-xylen ni ring ch yu c tch t sn phm ca qu trnh reforming xc tc, vi nguyn liu u l thng l phn on napthta. Trc khi i vo qu trnh th nguyn liu cn phi c x l tp cht c bit l lu hunh, v lu hunh rt nhy cm ti h xc tc Pt Re ca qu trnh reforming. Thnh phn cng ca sn phm reformate cng nh hm lng ca pxylen ph thuc rt nhiu vo cch tin hnh qu trnh reforming cng nh l loi nguyn liu naphta c s dng. Thnh phn ca phn on naphtha c bit l hm lng naphthen hay cc hydrocacbon thm c nh hng ln nht n n cht lng ca sn phm reformate thu c. Trn thc t naphtha thu c t qu trnh chng du naphtenic th s ph hp nht cho qu trnh reforming sn xut hp cht thm. Tuy nhin phn on naphtha c sn xut t qu trnh hydrocracking thng cng thu c giu hm lng naphthen nn rt ph hp lm nguyn liu u cho qu trnh reforming sn xut cc ng phn xylen. Bn cnh thnh phn, khong nhit si ca naptha nguyn liu cng nh hng n hiu xut thu c xylen. Bng 3: S ph thuc ca thnh phn reformate vo nhit si ca nguyn liu u vo [2]Khong nhit si ca Naphtha, 0C 60-160 107-160 90-160 Thnh phn ca nguyn liu, % khi lng Paraffin Naphten Hydrocacbon thm Thnh phn hydrocacbon thm trong Reformat, % khi lng Benzen69,6 19,5 10,962,2 21,2 16,664,2 22,2 13,69,31,65,26 ti: Sn xut para-xylenToluen Hydrocacbon thm C8 Hydrocacbon thm C9+ 21,7 20,8 8,8 19,0 34,3 15,2 25,1 26,2 11,2Nh s liu trong bng, khong nhit si thch hp nht ca Naphtha lm nguyn liu Reforming sn xut para xylen l t 106 n 160 0C. 2.2.1.2. T qu trnh Cracking hi nc ( Xng nhit phn) Xng nhit phn c thnh phn t C5 tr ln l sn phm ca qu trnh cracking hi nc cc phn on lng. Thnh phn ca xng nhit phn c cha hm lng ln cc hydrocacbon thm, c bit l benzen, v mt lng tng i cc ng phn xylen. Chnh v vy y cng l mt ngun ng gp sn phm c gi tr co cho c cng ngh sn xut xng cng nh cng ngh tng hp hu c ha du. Sn lng xng nhit phn cng nh hm lng cc ng phn xylen trong c quyt nh bi nguyn liu s dng v iu kin tin hnh sn xut. Bng 3: nh hng ca nguyn liu u vo n lng xng nhit phn v lng hydrocacbon thm C8 t cracking hi nc trong iu kin khc nhit vi dng C2, C3 tun hon [2]Nguyn liu Sn lng xng nhit phn (C52000C), % 1,7 6,6 7,1 18,7 18,4 19,3 Sn lng Hydrocacbon thm C8, % Phn hydrocacbon thm C8 trong xng nhit phn, %Etan Propan Butan Naphtha c nhit si trung bnh Du chng p sut kh quyn Du chng p sut chn khng0,4 1,8 2,2 1,95,6 9,6 12,0 9,87 ti: Sn xut para-xylen Sn phm xylen t xng nhit phn l sn phm ph ca qu trnh sn xut etylen v propen, tuy nhin trong mt s trng hp vic tch cc ng phn xylen li mang li hiu qu v mt kinh t. Vic iu chnh iu kin sn xut tuy khng ti a ha sn lng ca xylen nhng cng c nh hng ng k, c th l nu tng nhit phn ng, gim thi gian lu, gim thi gian lu bng cch tng lng hi vo th s lm gim ng k lng xng nhit phn thu c, tuy nhin hm lng ca xylene trong li tng ln.Bng 4: nh hng ca iu kin phn ng (thnh phn etylen trong sn phm) ca qu trnh cracking hi nc n nng xut v thnh phn ca xng nhit phn [2]iu kin (% Etylen) Xylen + Etylbenzen (trong tt c cc sn phm), % khi lng 0,9 1,6 1,7 Xylen + Etylbenzen trong xng nhit phn, % khi lng 3,5 7,2 10,7Thp (24,4) Trung binh (28,5) Cao (33,4)2.2.1.3. Cc qu trnh chuyn ha Hydrocacbon a. Isome ha V p-xylen l ng phn c gi tr nht xn xut s si tng hp nn bn cnh vic thu nhn n t qu trnh tch hn hp ng phn xylen bng kt tinh phn on hoc hp ph, hiu sut p-xylen cn c tng cng nh qu trnh isome ha o-, m-xylen v c etylbenzen. b. Phn b li Toluen Qu trnh ny c pht trin thnh quy m cng nghip nhm mc tiu tng sn lng benzen v hn hp xylen trn c s chuyn ha toluen t c gi tr ng dng hn. Bng cch kt hp vi qu trnh8 ti: Sn xut para-xylen phn tch p-xylen theo phng php kt tinh hoc hp ph, hoc kt hp Isome ha, cng ngh ny c th c s dng sn xut lng tng i ln o-, p-xylen m khng cn tng lng reformat x l. c. Qu trnh Cyclar Bn cht qu trnh Cyclar l chuyn ha c xc tc LPG, mt hn hp ca propan v butan, thnh sn phm giu hydrocacbon thm. Giai on u tin c gi thit l phn ng dehydro ha ca propan v butan thnh cc olefin tng ng. Tip , cc olefin ny s oligome ha thnh cc olefin C6, C7 v C8. Phn ng tip theo l dehydro vng ha to thnh cc hydrocacbon thm BTX. Mc d olefin l cc hp cht trung gian ca qu trnh ny nhng sn phm cui cng ca qu trnh c nng olefin rt thp. Ton b qu trnh phn ng l thu nhit do tnh tri ca phn ng dehydro ha v cracking. Metan v etan l cc sn phm ph hnh thnh t phn ng Cracking. Hiu sut hydrocacbon thm t 63-66% ty thuc vo thnh phn nguyn liu. Thnh phn sn phm lng cha ti 92% khi lng BTX, 7-8% hydrocacbon thm C9 v C10, v rt t lng hydrocacbon khng thm. Nu ch s dng propan lm nguyn liu th lng hydrocacbon thm C8 thu c l 17,3% khi lng, cn s dng butan th thu c 19,8% khi lng hydrocacbon thm C8. Lng xylen thu t qu trnh ny t c khong 15% khi lng nguyn liu a vo.2.2.2. Ngun t than . Du nh, c hnh thnh nh l sn phm ca qu trnh cacbon ha than (cc ha) nhit cao, c cha khong 60% benzen v 1220 % toluen. Trong iu kin cc ha 10000C, khng c khng kh, s xy ra cc qu trnh chuyn ha su (phn hy nhit v thm ha) phn hu c ca than to thnh cc, cc sn phm lng v kh. Do thanh ngho hydro hn so vi du m nn hiu sut sn phm cc9 ti: Sn xut para-xylen to thnh (70-80%) ln hn rt nhiu so vi sn phm lng (4-5%). Tuy nhin, v qu trnh cc ha din ra nhit cao nn sn phm lng c thm ha hon ton (95-97%), v vy lng hydrocacbon thm l rt ng k. Cc sn phm hydrocacbon thm hnh thnh t qu trnh phn hy nhit v thm ha phn hydrocacbon ca than l benzen, toluen, xylen, thiophen, pyridin Cc hydrocacbon thm c th c tch ra nh qu trnh hp th ngc dng bng phn on du m c nhit si cao, khong 300-4000C. Hn hp c chng tch trong thp chng ct li cun hi nc lin tc. Cc hydrocacbon nh c tch ra nh qu trnh chng ct v sn phm th c ra bng dung dch axit sunfuric c loi b hon ton cc hp cht lu hunh, cc hydrocacbon c tip tc chuyn v b cha, trung ha ht phn axit d v ra li bng nc. Qu trnh hydro ha loi b cc cht lu hunh, nit v cc hp cht khng no cn li. Benzen c tch ra t phn on hydrocacbon thm nh qu trnh chng trch ly vi dung mi sunfolan. Cc ng phn xylen c tch ra tng t so vi i t qu trnh Reforming xc tc. Cng ngh sn xut hydrocacbon thm i t sn phm lng ca qu trnh cc ha than trn thc t ch ph bin khi du m cha c bit n v khai thc. Ngy nay cng ngh ny ch cn c s dng trng mt s nh my Nam Phi v Niudiln.10 ti: Sn xut para-xylen2.3. Cng ngh sn xut p-xylen i t sn phm ca qu trnh Reforming xc tc.S tng qutX l nguyn liu NaphtaQu trnh Reforming xc tcTch p-xylen t sn phm Reformat2.3.1. X l nguyn liu NaphtaTrong nguyn liu u hydrocacbon c cha cc hp cht lu hunh c th gy ng c cho xc tc ca qu trnh chuyn ha, v vy cc hp cht cha lu hunh cn phi c lm sch khi nguyn liu u. Cc hp cht lu hunh c chuyn sang dng H2S bng qu trnh Hydrodesulfua ha (HDS) vi xc tc Co-Mo/Al2O3. Sau H2S c hp ph bng ZnO (b mt ring 25 m2/g) H2S + ZnO = ZnS + H2O Hm lng lu hunh c gim xung mc nh hn 0,01 ppm. Cc hp cht clo gy n mn cc thit b trao i nhit v gy ng c xc tc kh ha nhit cng c lm gim xung mc di 5ppb s dng cht hp ph Al2O3 c x l vi kim.11 ti: Sn xut para-xylen2.3.2 Qu trnh Reforming xc tcHnh 1: S cng ngh CCR Platforming ca UOP [3]Cng ngh CCR Platforming ca UOP vi cc thit b phn ng chng ln nhau thnh mt khi. Xc tc chuyn ng t thit b phn ng trn xung thit b phn ng di cng, sau xc tc lm vic c chuyn sang thit b ti sinh khi phc li hot tnh ri np li thit b phn ng th nht to thnh mt chu k khp kn.12 ti: Sn xut para-xylen 2.3.2.1. B phn phn ng Nguyn liu trn vi kh H2 tun hon c t nng n nhit phn ng trong thit b trao i nhit v b phn th nht ca l ri c np vo thit b phn ng th nht ( trn cng). Sau khi tip xc vi xc tc, nguyn liu b bin i ty thuc vo kht khe, cc iu kin c