ALKYL HOA BENZEN B A N G P R O P E N TREN ZEOLIT H-ZSM-5 T r a n T h i N h i i Mai, N g u y e n T h i H a , Le Thai Stfn, N g u y i n Thi IVIinh Thif, N g u y i n Thi Viet N g a Khoa hod hoc, DHKHTN, DHQGHN ALKYLATION OF BENZENE BY PROPENE OVER H-ZSM-5 ZEOLITE SUMMARY The reaction of synthesis ofiso-propyl benzene has been an important signification in chemical industry It had been carried on different catalysts but the obtained results hadn't been satisfactory until the zeolite ZSM-5 was invented Experiments has shown that it can be good catalyst for the alkylation of benzene by propen MODAU Phan ling ankyl boa benzen iso-propyl benzen (IPB) - mot san pham trung gian qua trinh san xuat phenol va axeton - c6 vai tro quan trong c6ng nghiep Miic tieu thu cumen (hay IPB) nam 1990 la 6,3 trieu tan va khdng ngifng tang len [1] TrUdc day, phan iing tong hdp cumen dUa tren he xiic tac Friden-Kraft hoac axit photphoric r^n (SPA) [1] Tuy nhien, cac xiic tac deu ton tai nhieu ban che nen viec tim kiem mot he xiic tac t6't hdn cho phan utng la can thie't Su ddi cua zeolit ZSM-5, mot loai zeolit c6 tinh chon loc hinh hoc cao va rat ben nhiet da md hudng ting dung mdi nhieu trien vong cho phan ling ankyl boa c6 qua trinh tong hdp cumen Nhieu loai xuc tac da dUdc nghien ciiu ling dung cho phan ling [1,2,3] va da dUdc thudng mai boa nhu zeolit Mordenit, zeolit Y nhUng cac to hdp loc hoa dau da dan dUdc thay the hoan 190 toan, sxi dung xiic tac zeolit ZSM-5, nhd dac tinh chon loc hinh hoc cua xiic tac Mat khac, tinh ch^'t phUc tap cua phan ling nen cong nghe san xuat cumen vkn lu6n dUdc cai tien, chang ban nam 1999, qua trinh tong hdp cumen tii benzen va propen svL dung zeolit ZSM-5, vdi ky thuat chUng cat xiic tac, da dUdc hang Mobil dUa vao san xuat d Thai Lan Viec sii dung zeolit ZSM-5 d^ kh^c phuc dUdc nhieu nhudc diem cua cac xiic tac trUdc nhU: thdi gian lam viec cua xiic tac dai hdn, qua trinh phu va tbii cap it hdn, khong gay an mon thie't hi va nhilm moi trUdng Cling vdi sU hinh va phat trien cua nganh c6ng nghiep loc boa dau d Viet Nam thi viec nghien ciiu kha nang iing dung ciia olephin C3= (san pham ciia qua trinh loc dau) dong thdi nghien ciiu kha nang dng dung ciia xiic tac zeolit ZSM-5 la can thie't Tren cd sd chung t6i da khao sat phan ting propyl hoa benzen hkng propen tren zeolit H-ZSM-5 THUC NGHlfiM Miu xuc tac sii dung la Na-ZSM-5 cd ty sd Si/Al = 43 Chuyen dang Na-ZSM-5 ve dang H-ZSM-5 b^ng each trao ddi vdi dung dich NH4C1 va nung d 550OC de loai NH3 Miic trao ddi dUdc danh gia theo phUdng phap phd hap thu nguyen tii, xac dinh ham lUdng Na trUdc va sau trao ddi Xiic tac sii dung la cac hat cd kich thudc tii 0,5 den 1,0 mm San pham phan ling dUdc ngUng tu va phan tich tren may s^c ki Shimadzu-14B va may s^c ki khd'i phd GCMSHP6890 K £ T QUA v A THAO LUAN Trong thUc te, phan ling tong hdp cumen tiif benzen va propen da dUdc nghien ciiu va di vao san xu^'t d quy mo c6ng nghiep, sii dung xiic tac SPA tii nam 1945 [1] Ciing vdi sU phat trien cua khoa hoc vat lieu, nhieu xiic tac khac da dUdc thxi nghiem cho phan ling Tuy nhien, viec thUc hien phan iing cho chon loc cao theo cumen gap nhieu khd khan 191 Khi thUc hien phan iing tong hdp cumen tut benzen va propen tren Mordenit bien tinh, Meima va cong sU [1] cho thay san pham phan ling luon sinh di iso-propyl benzen (DIPB) va mot s6 san pham nang khac Becker va cong sU [2] cung cho ket qua tUdng tU Ching ban, tren xiic tac Mordenit, d ty le mol C3 : Ce = : 5,6; td'c dong 30 ml/phiit va nhiet 150°C, ham lUdng DIPB san pham phan Ung la 45,1 % va naphtalen thu dUdc d dang vet, nang nhiet len 400°C thi lUdng DIPB giam xud'ng 0,6% nhUng cac san pham nang khac lai len den 37,3% [1] (cac san pham vdi cac thie't hi phan tich trUdc day khdng xac dinh dUdc cau tao) Dieu c6 the giai thich tii dac diem cua phan ting ankyl boa Phan tii mono ankyl benzen sinh (d day la IPB) c6 mat electron d nhan thdm Idn hdn benzen nen dl tham gia phan iing ankyl hoa hdn benzen de tao cac san ph^m the nhieu l^n Ngoai sU phiic tap cua san pham sU ankyl boa benzen b^ng cac anken sinh cac phan iing tbii cap Do do, nhiing xiic tac c6 dUdng kinh 16 mao quan Idn nhU zeolit Y, Mordenit thi deu thuan Idi cho sU hinh cua cac san ph^m cong kenh NgUdc lai, doi vdi zeolit ZSM-5, he mao quan c6 kich thudc trung binh (5,3x5,6 A va 5,1x5,7 A) va kha dong deu [3,4] nen san pham phu cong kenh bi ban che Bang trinh bay ket qua phan tich san ph^m phan ting d dieu kien nhiet 300*^C, toe dong (tinh theo benzen) gid'^ va ty le mol nguyen lieu C3 : Cg = : Bang Phan tich san pham tren GCMS-HP6890 STT *> 10 11 192 Hop chat Benzen loluen htyl benzen p-xylen Cumen n-propyl benzen -metyl propyl benzen n-buiyl benzen 1-metyl butyl benzen n-pentyl benzen San pham nhe Ham luong % theo khoi lircmg 34,3 U 1,6 hi 17,5 5,8 7,0 3,^ 2,1 ^,3 b,« Nhu vay, ben canh san pham chlnh la cumen, phan iing sinh mot so'san pham khac nhU n-pentyl benzen, toluen, etyl benzen, p-xylen sU xuat hien cua cac san pham cho thay qua trinh oligome hoa cac phan tii propen va qua trinh crackinh cac san pham oligome boa da xay Bang ciing cho thay cac san pham cong kenh nhU naphtalen, antraxen, cac poli ankyl benzen hau nhU khdng xuat hien Dieu the hien Uu diem chon loc hinh hoc ciia ZSM-5 so vdi cac xiic tac khac [3,5,6,7] Mot khd khan ma cac xiic tac ciia qua trinh tong hdp cumen trUdc thUdng gap phai la sU giam nhanh chong boat tinh xiic tac theo thdi gian Xiic tac SPA mat boat tinh nhanh chong d nhiet cao, xiic tac Mordenit va Y giam boat tinh sU tao c6'c lam che phu tam boat dong tren be mat mao quan [1] Ddi vdi ZSM-5, cau triic he mao quan dong deu vdi kich thudc 16 trung binh nen da ban che dUdc r a t nhieu qua trinh tao co'c Khao sat phan Ung d cac thdi diem khac cho thay san pham phan iing kha dn dinh (bang 2) •> Bang 2: Anh hUofng cua thdi gian tien hanh phan iing den san pham phan iing Thoi gian (phut) 15 60 120 Do chuyen hoa theo benzen (%) 41,1 41,9 40,5 Cumen (%) 16,9 17,5 17,2 Do chon loc theo cumen (%) 41,1 41,7 42,4 Dieu kien phan iing: Nhiet do: 300^C Tdc the tich: gid "^ Ty le mol nguyen lieu: C3 : C6 = : Trong nghien ciiu va cong nghe, ben canh viec lUa chon loai xiic tac thi dieu kien tien hanh phan iing ciing anh hUdng rat manh den xu hUdng hinh t h a n h san pham cuo'i ciing Khao sat anh hudng cua nhiet va ty le mol nguyen lieu den ke't qua phan iing cho thay phan ling tdng hdp cumen kh6ng n^m ngoai quy luat chung: chuyen 193 hoa nguyen lieu cang cao thi chon loc theo san pham chinh cumen cang tha'p Bang Anh hudng cua ty le mol nguyen lieu ^^6 : ^3 Do chuyen hoa theo benzen (%) Do chon loc theo cumen (%) San ph^m phu (%) 2,5 3,0 4,0 6,0 42,0 39,0 28,0 30,0 43,3 22,3 31,6 13,5 56,5 70,1 13,8 4,1 Do H-ZSM-5 c6 tinh axit cao nen qua trinh oligome boa cac phan tii propen rat de xay ra.Viec nang cao ty le mol Ce : C3 c6 vai tro ban che qua trinh oligome hoa nen mac dii chuyen hoa nguyen lieu giam nhUng chon loc theo cumen lai tang nhanh, tiic la ham lUdng san pham phu giam di nhieu (bang 3) Day la bai toan dat cho cac nha cong nghe san xu^'t c6ng nghiep vi viec tach cumen khdi h6n hdp phan ting d chuyen hoa tha'p (tiic la d chon loc cao) de hdn nhieu so vdi viec tach cumen khdi hdn hdp san pham phiic tap d chuyen boa cao Day ciing la cC sd cua sU ddi mdi c6ng nghe san xuat cumen cua hang Mobil Trong cong nghe ma hang Mobil l^p dat tai Thai Lan nam 1999, propen sau tiep xiic vdi benzen Id phan ling chiia xiic tac dUdc tach khdi he phan iing de tranh sU oligome hoa [8] > Bang Anh hUdng cua nhiet den san pham phan iing Nhiet («C) 250 300 350 Do chuyen hoa theo benzen (%) 32,2 39,6 38,9 Ham luong cumen(%) 10,8 17,2 9,9 Do chon loc theo cumen(%) 33,6 43,4 25,4 Phan nhe(%) 12,5 11,0 8.1 Phan ndng(%) 8,9 11,4 20,9 194 Dieu kien phan iing: Ty le mol nguyen lieu: Cg : C3 = : T6'c dong: gid'-"- Bang trinh bay ket qua phan iing d cac nhiet tieu bieu khac Mac du chuyen boa nguyen lieu thay ddi khdng nhieu nhUng cac san pham cuo'i cung lai khac kha Idn Do chon loc theo cumen dat cao nhat d khoang 300°C, tha'p hdn so vdi nhiet cua qua trinh alkyl hoa benzen bang etylen tren Mordenit (khoang 350^C) [2] Dieu la hdp ly vi so vdi etylen thi propen la tac nhan alkyl hoa boat dong hdn Nhiing nghien ciiu ban dau cho thay H-ZSM-5 la mot xiic tac tot cho phan ling tdng hdp cumen, dong thdi cho thay mo'i lien he chat che giiia cau tnic va boat tinh xiic tac cua ZSM-5 .Ben canh nhiing thuan Idi da dat dUdc, tinh axit cao la mot ban che' cua ZSM-5 phan iing Viec nghien ciiu tim nhiing he xiic tac mdi dd'i vdi qua trinh cumen hien van luon la hudng nghien ciiu ciia cac nha khoa hoc va cac nha c6ng nghe tren the' gidi ciing nhU nhiing nam dSu the ky XXI xiic tac MCM-22 dang htia hen sU thUdng mai hoa doi vdi qua trinh [9] Ktr LUAN Zeolit ZSM-5 c6 kha nang kh^c phuc nhieu nhUdc diem cua cac xiic tac trUdc phan iing tdng hdp cumen tii benzen va propen Dac trUng cau triic la thu^in Idi ciia ZSM-5 phan iing nghien ciiu San pham cumen cd chon loc cao, sU tao cac san pham nang bi ban che TAI LifiU THAM KHAO [1] G.R Meima, M.J.M Van Der Aalst, M.S.U Samson, J.M Garces, J.L Lee, Cumen Production Based on Modified Mordenit Catalysts, Proceedings of the 9^1^ International Zeolits Confernce, Montreal, p.327-334 (1992) [2] K.A Becker, H.G Karge, W.D Streubel, Benzen Alkylation 195 with Ethylene and Propylene over H-Mordenite Catal, Vol.28, p.403-413 (1973) as Catalysts, J [3] Nguyen Hiiu Phii, Nguyin Hong Lien, Tap chi hod hoc, T.37, s6'4, Tr.3-6(1999) [4] Sankarasubier Narayaman Calorymetric measuments of acidity oftemplated and non-templated H-ZSM-5 zeolites and their correlation with catalytic activity, J.App.Cat, Vol 143,p.337-342 (1996) [5] S Siffert, L Gaillard and B.-L Su, In situ FIR studies of the alkylation of benzene by propene on a series of H-Beta zeolites, 12^*^ International zeolite conference, Materiels Rechearch Society, p.121-123 (1999) [6] S Siffert, L Gaillard and B.-L Su Alkylation of benzene by propene on a series of Beta zeolites, J Mol Catal.,153 (1-2), p.267279 (2000) [7] A.V Smirnov Benzene alkylation with propene over Ga, B and Al pentasils, 10*^^ International zeolit conference, Berlin, p.1797-1804 (1994) [8] Ngo Thi Thuan, Tran NhU Mai, Nguyen Tien Thao, Nguyen Thanh Bao, Vu Ngoc Toan Xuc tdc H-ZSM-5 mot so'phan i2ng hod dau, Hoi nghi xiic tac - hap phu toan quo'c lan thii 2, Ha Noi (2001) [9] A Corma and H Garcia Lewis Acids: From Conventional Homogeneous to Green Homogeneous and Heterogeneous Catalysis, Chem Rev 2003, 103, 4307-4365 196 ... t6i da khao sat phan ting propyl hoa benzen hkng propen tren zeolit H- ZSM- 5 THUC NGHlfiM Miu xuc tac sii dung la Na -ZSM- 5 cd ty sd Si/Al = 43 Chuyen dang Na -ZSM- 5 ve dang H- ZSM- 5 b^ng each trao... khac da dUdc thxi nghiem cho phan ling Tuy nhien, viec thUc hien phan iing cho chon loc cao theo cumen gap nhieu khd khan 191 Khi thUc hien phan iing tong hdp cumen tut benzen va propen tren Mordenit... ciing cho thay cac san pham cong kenh nhU naphtalen, antraxen, cac poli ankyl benzen hau nhU khdng xuat hien Dieu the hien Uu diem chon loc hinh hoc ciia ZSM- 5 so vdi cac xiic tac khac [3 ,5, 6,7]