Tgp chi Khoa hgc Tniang Ggi hgc Cdn Tha Phdn A Khoa hoc Tu nhiin Cong nghe vd Mdi trudng 25 (2013} 8 12 Tap chf Khoa hpc Oai hoc Can Thd website sj ctu edu vn NGHIEN CUtJ ANH HlTdNG CUA CHAT KHANG OXY[.]
Tgp chi Khoa hgc Tniang Ggi hgc Cdn Tha Phdn A: Khoa hoc Tu nhiin Cong nghe vd Mdi trudng: 25 (201 Tap chf Khoa hpc - Oai hoc Can Thd website: sj.ctu.edu.vn NGHIEN CUtJ ANH HlTdNG CUA CHAT KHANG OXY HOA DEN SlT THAY D O I THANH PHAN DAU DIESEL SINH HOC TONG HOP TlT MOf CA TRA, CA BASA Nguyin Van Dat', Toshihiro Hirotsu' va Shinichi Goto' 'Khoa Khoa hgc TV nhiin, Truong Dgi hgc Can Tha ^Research Center for New Fuels and Vehicle Technology AIST Tsukuba, Japan Thong tin chung: Ngdy nhdn: 30/07/2012 Ngdy chdp nhdn: 25/03/2013 Title: Study of some affecting fators on the change in fam- acid profile of Catfish fat based biodiesel Tirkhda: Diesel sinh hgc, thdnh phdn acid beo Keywords: Biodiesel, fatty acid profile ABSTRACT The effects of two types of synthetic antioxidant (Ecotrve^^ and BHT) on the chemical compositions of Catfish fat based biodiesel (FAME) have been evaluated Gas Chromatography Mass Spectrometry (GCMS) analytical results showed that the compositions of fatty acid methyl esters were not significantly changed by the used antioxidants during storage for one month at room temperature TOM TAT Anh hudng ciia hai chdt khdng oxi hoa long hgp (Ecotive^ vd BHT) din phdn fatty acid methyl esters cda biodiesel tong hgp tir md cd tra cd basa (FAME) dd dugc ddnh gid trang nghien cuu Kit qud phdn tich GC-MS cho thdy thdnh phdn fatty acid methyl esters it thay doi co mat hai chdt khdng oxi hoa nghien ciru sau mgt thdng ton trii FAME tgi nhiit dg f^ong DATVANDfe Ngay na\' the gidi dang phai ddi mat su thay ddi lien tuc gia cua ngudn nhien lieu hda thach dac biet ta ddu md, nhimg ngudn nang lugng cang can kiet va Iugng tieu thu cang lang Dieu dd ddn den viec phai tim ngudn nhien Heu de thay the Phan img giira ddu thuc vat hodc ma dgng vat va mdt alcohol vdi sir cd mat ciia base manh tao mot loai hgp chat hda hgc mdi ggi la biodiesel (Ayhan Demirbas, 2009) Tuy nhien, mgt nhung bdt lgi Idn nhat cua viec dung dau diesel sinh hgc (biodiesel), la tinh bin o?d hda cua loai nhien lieu kem han nhilu so vdi ddu diesel ham lugng methyl esters chua bao hda cao Dac biet la phdn methyl esters chua bao hda vdi nhieu lien ket pi phdn hi (polyunsaturated methyl esters) chiing di dang bi oxi hda nhu methyl linoleate (Cig^) va methyl linolenate (Cigs) ddn den hinh cac acid, aldehyde, ester, ketone, peroxide va alcohol Nhimg chat khdng nhimg anh hudng den chat lugng cua biodiesel ma cdn gay nhieu tac hai cho ddng ca (Monyem A 2001) Ciing chinh vi ly nay, nen viec dung dau diesel sinh hgc tai Viet Nam cdn han che ben canh mdt nguyen nhdn khdc la gia san xuat cao cua loai nhien lieu Qud trinh oxi hda biodiesel dugc gidi thich theo ca che nhu sau: Tap chi Khoa hoc Trudng Dai hoc Cdn Tha Khoi mao Phat trien m^ch Ngat mach Phdn A: Khoa hoc Tu nhien Cdngnghi\a RH R- (a) R" - O2 ROO' (b) ROO'+RH ROOH + R' (c) R' + R R-R (d) San pham (e) b^n Stf 1: Co'che qud trinh oxi hoa biodiesel ROO' + ROO" So dd minh hga co che qua trinh oxi hda biodiesel, dd, RH la phdn tir FAME, R* ia goc tu do, ROO" la goc tu peroxide, ROOH ia hydroperoxide, R-R la san phdm ciia qua trinh oxi hda Trong qua trinh oxi hda, phan tir FAME hinh gdc tu (phan ung a) Gdc tu lap tiic phan ung vdi oxi hinh goc tu peroxide (phan ung b), gdc tu nhanh chdng tao gdc tu mdi tir phan tir FAME (phan iing c) Phdn ung se tilp tuc cho den kh! cac goc tu phan ung vdi (phan iing d) hoac cac gdc ty peroxide Moi mi&ng: 25 (2013): S-f2 (phdn ung e) phan ung vdi d giai doan ngat mach Ket tiiiic qua trinh se hinh acid, aldehyde, ketone, lam cho nhihig ddc ti'nh ly hda cua biodiesel nhu: dd nhdt dgng hgc, chi sd acid (AV) cung nhu bSn oxi hda thay ddi Chdt khang oxi hda la nhiJng chdt \XQ chl qua trinh oxi hda Cd hai kieu chat khang oxi hda dugc bilt (Pospisil, 1990): cat mach day chuyin va phan hiiy hydroperoxide Chdt khang oxi hda cd vai tro cdt mach day chuyen thudng cd hai loai ia phenolic va amine Hdu het nhihig cdng trinh nghien cuu deu tap trung vao loai hgp chdt khang oxi hda dang phenolic Ca chl dl nghi cho loai chdt khang oxi hda nhu sau: ROO* + AH ROOH+ A A* San pham ben Tir CO che tren cd the thdy rang, chat khang oxi hda chua mgt nguyen tu H kem ben dl bi lay bdi gdc tu Cudi cimg chat khang oxi hoa se hinh dang bin vung hoac tiep tuc phan U'ng de tao san pham ben Hinh 1: Minb hpa co* che khir glc tur ciia chat khing oxi h6a dang phenolic Ngudn: Sarin (2007) C^ Hinh 2: Minh hpa co* che khii- goc t\r ciia chat khang oxi hda d^ng amine Ngudn- Sarin (2007) oil Muc tieu Ciia cdn^ trinh la nghien cmi dnh hudng ciia hai chat khang oxi hda tdng hgp la Ecotive va BHT, thai gian tdn tru va nhift ton trir dSn phin hoa hgc cua dau Tgp chi Khoa hgc Trudng Dgi hge Cdn Tha Phdn 4: Khoa hoe Tu nhien Cong nghe vd Mdi ti-uong: 25 (20 diesel sinh hgc tdng hgp tir ma ca tra, ca basa, gdp phdn vao viec tim nhimg ludn chung khoa hgc ve ban chat ciia qua trinh oxi hda ddu diesel sinh hgc 809, Mefrohm) theo tieu chudn BS ISO 27107:2008 2.2.3 Nghien cuu dnh hucmg ctia chdt khdng oxihoa PHU'ONG PHAP NGHIEN C t U FAME dugc trdn vdi cdc chdt khang oxi hda BHT va Ecotive™ vdi ndng 1000 ppm Mdu dugc khao sat bin oxi hda d d nhiet dd phdng sau mdt thang tdn tru Mdu dugc bdo quan cac tu dn nhiet IWAKI incubator (ASAHl TECHNO GLASS) 2.1 Vat lieu Md ca tra, ca basa dugc mua tir Cdng ty cd phdn Ky Nguyen Xanh, khu cdng nghiep Tra ndc, q u ^ Ninh Kilu, phd Cdn Tha Hda chat diing tdng hgp va phdn tfch cd xudt xu tir Merck, Due va Fluka, Nhdt 2,6-Di-/ert-butyl-/>-cresol (Butylated Hydroxy Toluene, BHT) va Ecotive^" dugc mua tu Seiko Company, Nhat Ban 2.2 Phircmg phap nghi€n cuu 2.2.1 Phiromg phdp tong hap FAME tit ma ca tra, cd basa Biodiesel dugc tdng hgp tii ma ca tra, ca basa bang phuang phap khudy tir gia nhiet (Nguyen Van Dat, 2009) 2.2.2 Phdn tich linh chdt hoa ly cHa ddu nguyen lieu vd biodiesel Do nhdt ddng hgc (mm"/s) dugc xac dinh d 40 °C, bang each thdi gian de mgt the tich chdt long xac djnh chay qua mot mao quan thuy tinh dudi tac dung cua trgng lire Dg nhdt ddng hoc la kit qua tinh dugc tir thdi gian chay va hdng sd tuang irng cua nhdt k§ Ostwald Ham iugng nude (mg/kg) dugc xac djnh bdng each diing thiet bi 831 KF coulometer (Metrohm) theo tieu chuan BS EN ISO 12937:2001 Chi sd acid (mg KOH/g) dugc xac dinh bdng each diing thilt bi chuan dg the tu d^ng GT-lOO lien kit vdi he thdng bam mdu tu ddng GT-07 (Mitsubishi Chemical Analytech Co., Ltd., Jj^an) theo chudn JIS K 0070-1992 Chi sd iod (g h /I OOg) dugc xac dinh bdng phuong phap chudn the tich dung dich phdn ling cua ddu ho^c nhien lieu sinh hgc vdi dung dich Wijs (CI3I/I2 dung dich acid acetic) theo tieu chudn JIS K0070-1992 Chi sd peroxide (meq/kg) dugc xac dinh bdng each dung thiet bi chudn the (Titrado 2.2.4 Phan tich thdnh phdn acid beo cua FAME Phan tich phdn FAME tren may sdc ky ghep khdi phd (GC-MS 2010, Shimadzu, Co., Nhat Ban) vdi cgl (30m x 250tun x 0,25pm) Lugng mau I |.iL dugc bam tu ddng (OAL-20i, Shimadzu); nhiet bom mdu 250°C; tdc ddng khf mang (He) mL/phiit, theo chuang trinh nhiet phan tfch mdu ddu beo nhu sau: nhiet ddu fO^C, gia nhidt 5°C/phut cho din 260''C, giit 10 phiit Thanh phdn acid beo dugc xac dinh thdng qua cac dinh ciia phd dd tuong umg vdi khdi lugng phdn tu cd du lieu di kem vdi he thdng Shimadzu GC-MS KET QUA VA THAO LUAN 3.1 Nhirng tinh chat hda ly cua m& ca nguySn liSu va san pham FAME Ma ca nguyen lieu va san pham FAME dugc tien hanh danh gia chdt lugng thdng qua mdt sd chi tieu hda ly ca ban nhu ben oxi hda, chi sd acid (AV), chi so peroxide (PV), chi sd Iodine (IV), nhdt ddng hgc d 40 "C va ham lugng nude Ket qua dugc trinh bay Bang Bang 1: Tinh chat hoa ty ciia m& ca nguySn lifu va FAME Tinh chat boa ly M&ca FAME Dp ben oxi hoa theo Rancimat, 5.40 7.33 gid Dp bin oxi hoa theo PetroOXY, 1.07 gid Chi s6 acid (AV), mg KOH/g 0.98 0.10 Chi so peroxide (PV), meq/kg 1.10 10.20 Chi s6 iodine (rV),gW100g 44.42 34.00 Do nhdt dpng hpc o 46''C, mrnVs 38.86 4.62 Ham lugng nude, ppm 1283.70 380.50 Ham lugng HCOOH, ppm 1.40 Tap chi Khoa hoc Tmdng Bai hoc Can Tha Phdn A: Khoa hoc Tu nhien CongngM vo Mdi trudng 25 (20 Tu Icet qua tren cho thiy bSn oxi hoa cila FAME (5.4 gio) theo phuang phap Rancimat khong thoa tieu chuin EN (>6 gio) hay JIS (>I0 gio) D i k cOng phii hop voi phin cua FAME phan tich duoc vdi da s6 la ester ciia nhimg acid beo chua no nen chung de bi oxi hoa (Bang 2) Cac thong s6 vS AV, IV, dp nhdt dong hoc d 40 "C, ham Iugng nude cua FAME ihl thda duoc cac tieu chuan hien hanh Ngoai ra, k8t qua phan tich HPLC (Highperformance liquid chromatography) ciing cho thiy FAME cd mot ham luong nhd HCOOH, day la acid mach ngan, san phSm cua qua trinh oxi hda FAME 3.2 Thanh p h i n FAME Ket qua phan tich GC-MS cho thay phin acid beo cua FAME chu y6u la C12 dgn C20 Thanh phan Cigi chiem nhieu nhat (40.13%) tiep dSn la C.^o (32.41%) Tdng hai phan chiem den 72.54% Tdng ham lugng cua cac ester cd da ndi ddi chi chiem 7.29% BSng 2:Thanb phin acid beo chinb ciia FAME, % So carbon: Ten acid SoC=C Acid launc 12:0 0.12 Acid myristic 14:0 4.48 Acid palmitic 16:0 32.41 Acid palmitoleic 16:1 1.40 Acid stearic 18:0 11.29 Acid oleic 18:1 40.13 18:2 Acid linoleie 6.02 20:1 Acid eicosenoic 1.48 20:2 0.49 Acid eicosedienoic 20:3 0.55 Acid eicosatrienoic 20:4 0.23 Arachidonic acid Acid beo bSo boa 48.30 Acid beo chiia mot moi doi 41.61 C=C Acid b ^ chua nhi^u moi 7.29 doi C=C Thdnh phan khac 2.80 3.3 Anh hirdng cua chat khang oxi boa den phan FAME sau mgt thang liru trir t^i nhiet phong Thanh phdn acid beo chi'nh cua hon hgp gdm FAME va chdt khang oxy hda (FAME + Ecotive™ 1000 ppm) va (.FAME BHT 1000 ppm) sau mot thang t6n tru taii inhiet dp phong duoc ttinh bay torn tit a Bang Bang 3: Thanh phan acid bto chinh ciia FAME, % T£n acid So carbon: EcotiveTM BHT So C < : 1000 ppm 1000 ppm 13:0 4.65 4.46 27.44 16:0 27.40 18:0 13.20 13.43 18:1 34.80 34.09 18:2 9.00 8.73 20:1 0.02 1.69 20:2 0.41 0.40 20:3 0.16 0.17 20:4 0.17 0.16 Acid tridecanoic Acid palmitic Acid Stearic Acid oleic Acid linoleie Acid eicosenoic Acid eicosadienoic Acid eicosatrienoic Arachidonic acid TiJr kit qua d Bang cho thay, bang each sir dung hai chdt khang oxi hda Ecotive^*^ va BHT d ndng 1000 ppm, sau khoang thdi gian liru trQ mdt thdng tai nhiet phdng, ham lugng (%) methyl ester cua cac acid beo chinh ciia FAME hau nhu thay ddi khdng dang ke Ket qud cho thdy, viec sijr dung hai chat khang oxi hda Ecotive^"^ va BHT d ndng 1000 ppm cd thi giup cai thien bin oxy hda ciia biodiesel tong hgp tir md ca tra, ca basa KET LUAN Da tdng hgp dugc ddu diesel sinh hgc tu m9 ca tra, ca basa dat dugc yeu cau vl chdt lugng theo tieu chudn cua ASTM, EN va JIS Tuy nhien, dp ben oxi hda chua dat dugc cac yeu cau cua tieu chuan EN va JIS Viec su dung hai chdt khang oxi hda Ecotive^'^ va BHT d ndng 1000 ppm giup tri khd tdt thdnh phan cac methyl ester ciia cac acid beo chinh sau mflt thang tdn tru sdn phdm biodiesel tai nhi|t d? phdng Ket qua cho thdy hai chdt khang oxy hda nghien cuu cd kha nang cai thien ben oxy hda ciia biodiesel tdng hgp tiJr md ca tra, ca basa L I CAM TA Cdc tac gid chdn cdm an Trung tam nghien cuu vl ky thuat co gidi va nhien lieu mdi (NFV), Vien AIST, Tsukuba, Nhat Ban thdng qua su ho trg tai chinh tiJc du an nghien cuu nhien lieu sinh hgc td chuc NEF tai trp da cung cdp phuang tien va nhimg dilu kien Tgp chi Khoa hoc Trudng Dai hoc Cdn Tho Phdn A: Khoa hoc Tu nhien Cong nghe rd Moi trirdng: 25 (2013) • 8-J2 nghien ciru tdt nhit Dac biet, chung tdi xm chan cam on cac cgng sir cua nhdm nghien ciiu (Tanaka, Kaitsuka) tai trung tam nghien ciru NFV da giup va ho trg ky thuat phan tich de chiing tdi hoan nghien cuu TAI LIEU THAM KHAO Ayhan Demirbas, 2009 Biofuels: Securing the Planet's Future Energy Needs Springer Monyem A, Van Gerpen JH, 2001 The effect of biodiesel oxidation on engine performance and emissions Biomass Bioenergy 2001; 20:317-25 Nguyen Van Dat, 2009 A Study towards the Effect of Antioxidants on Vietnamese Catfish Fat Biodiesel, Collected Papers of Invited Research Asia Biomass Energy Researchers Program 2009, New Energy Foundation, Japan Pospisil, J.;Klemchuk, P.P (editors), 1990 Oxidation Inhibifion in Organic Materials, Volume I, CRC Press Ramos, L.P., A.K Domingos, E.B Saad, W.W D Vechiatto and H M Wilhelmc, 2007 The Influence of BHA, BHT and TBHQ on the Oxidation Stability of Soybean Oil Ethyl Esters (Biodiesel) J Braz Chem Soc 18: 416-423 Sarin, R., M Sharma, S Sinharay and R.K Malhotra, 2007 Jatropha-Palm biodiesel blends: An opdmum mix for Asia Fuel 86: 1365-1371 ... nghe vd Mdi ti-uong: 25 (20 diesel sinh hgc tdng hgp tir ma ca tra, ca basa, gdp phdn vao viec tim nhimg ludn chung khoa hgc ve ban chat ciia qua trinh oxi hda ddu diesel sinh hgc 809, Mefrohm) theo... tdn tru sdn phdm biodiesel tai nhi|t d? phdng Ket qua cho thdy hai chdt khang oxy hda nghien cuu cd kha nang cai thien ben oxy hda ciia biodiesel tdng hgp tiJr md ca tra, ca basa L I CAM TA Cdc... nhu thay ddi khdng dang ke Ket qud cho thdy, viec sijr dung hai chat khang oxi hda Ecotive^"^ va BHT d ndng 1000 ppm cd thi giup cai thien bin oxy hda ciia biodiesel tong hgp tir md ca tra, ca basa