Nghiên cứu công nghệ cacbon hóa để xử lý chất thải đô thị ở Việt Nam

Tieu ban: Moi tru&ng vd Ndng luang ISBN: 978-604-913-013-7<br /> <br /> <br /> NGHIEN ClTU CONG NGHE CACBON HOA DE XtT LY CHAT THAI<br /> DO THI O VIET NA]VI<br /> <br /> Trinh Van Tuyen', To Thi Hai Yen', Shuji Yosizawa^<br /> 'Vien Cong nghe moi tru6ng; "Dai hgc ting hgp Meisei, Tokyo, Nhat Ban<br /> trvtuven^hotmail.com<br /> Tom tat:<br /> Xu ly rdc thdi do thi theo cdng nghe nhiet phdn cd kiem soat khi thdi vd tgo ra<br /> sdn phdm la than cacbon cd hdm luang tdng cacbon huu ca (TOC) cao Idm nhien<br /> lieu trong cdng nghiep vd vdt lieu xie ly mdi tricdng la xu the phdt trien ben vieng<br /> cua ddt nude.<br /> Trong thdi gian qua, Vien Cdng nghe Mdi truang dd tien hdnh nghien cieu<br /> cdng nghe cacbon hod de xic ly chdt thdi rdn dd thi Hd Ndi vd da cd mdt sd ket<br /> qud khd quan cho viec dp dung vdo thicc te. Bdi bdo ndy trinh bdy cdc ket qud thu<br /> hdi sdn phdm, chdt luang sdn phdm thu duac ciing nhu dnh hudng cita cdc thdng<br /> sd cdng nghe nhu nhiet dd (T), thdi gian luu (t) den hieu sudt xic ly (rj), tdng<br /> cacbon hieu ca (TOC), dien tich be mat rieng (S). Nghien cieu duac tien hdnh tren<br /> 3 quy md khdc nhau: 10-20 g/me, 3-5 kg/me vd 50 kg/me. Cdc thuc nghiem duac<br /> tien hdnh vdi cdc logi hinh chdt thdi phd bien nhu gidy, gd, nhua, cao su, vdi...<br /> Abstract:<br /> The treatment of municipal solid waste (MSW) using pyrolysis technology<br /> integrated with air emission control and product M'ith high TOC concentration<br /> which can be used as fuel for industrial production as well as material for<br /> environmental treatment system. This method can be seen as a solution toward<br /> sustainable development of our country.<br /> In recent years. Institute of Environmental Technology has been studying the<br /> carbonization technology to treat the municipal solid waste of Hanoi city. Some<br /> satisfactory results have been achieved. This paper presents the results about<br /> recovery ratio of product, product quality, and impacts of related parameters<br /> such as temperature (T), retention time (t), treatment efficiency (rj), total organic<br /> carbon (TOC), and the specific surface area (S). The research was carried out<br /> with 3 system scales: 10 - 20g/batch, 3 - 5kg/batch and 50 kg/batch. The<br /> experiments used common types of solid waste such as paper, wood, plastic,<br /> rubbers and textile.<br /> <br /> <br /> 1. M O DAU<br /> Co nhieu phuong phap xir ly rac thai do thi da dugc nghien ciiu va ap dung trong do co<br /> phuong phap thieu dit. Phuong phap thieu dit xir ly dugc nhilu loai chdt thai (dac biet la cac<br /> chat thai ran kho phan buy nhu plastic, da, cao su...) tilt kiem dugc dien tich cho cac bai chon<br /> lap. Tuy nhien, phuong phap thieu dot gay tac dgng xdu din moi truang khong khi, ngoai ra<br /> chi phi cho viec xir ly khi thai ciia qua trinh thieu dit rdt tin kem. Mot phuang phap xir ly<br /> moi ap dung doi vai chat thai ran giau cacbon bdng nhiet phan da bdt ddu dugc cac nha khoa<br /> <br /> <br /> 72<br />  Hoi nghi Khoa hoc ky niem 35 ndm Vien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10/2010<br /> <br /> hoc a Viet Nam va tren the gioi nghien cim. Cong nghe nay vira co the xir ly dugc 6 nhiem<br /> cua chat thai voi chi phi xir ly thap hon, vira tao ra dugc loai san pham tai che phuc vu kinh te<br /> xa hgi nhu than sach lam nhien lieu hoac vat lieu hap phu diing trong cong nghe xu ly 6<br /> nhiem moi truang. Ban chat ciia phuong phap la dot cac chat thai ran chay dugc trong dieu<br /> kien thieu oxy hoac khong c6 oxy hoan toan [1-5].<br /> Trong thai gian qua, Vien Cong nghe Moi tru6ng da tien hanh nghien cim cong nghe<br /> cacbon hoa de xir ly chat thai ran do thi Ha Noi va da co mot so ket qua kha quan cho viec ap<br /> dung vao thuc te. Bai bao nay trinh bay cac ket qua thu hoi san pham, chat lugng san pham<br /> thu dugc ciing nhu anh huong ciia cac thong so cong nghe nhu nhiet do (T). thoi gian lim (t)<br /> den hieu suat xir ly {r\), tong cacbon htiii co (TOC), dien tich be mat rieng (S). Nghien cim<br /> dugc tien hanh tren 3 quy mo khac nhau: 10-20 g/me, 3-5 kg/me va 50 kg/me. Cac thuc<br /> nghiem dugc tien hanh voi cac loai hinh chat thai pho bien nhu giay, go, nhua, cao su, vai...<br /> <br /> <br /> 2. DOI TU^gfNG VA PHLTONG PHAP NGHIEN CtTU<br /> 2.1 Doi tuong nghien ciru: Chat thai do thi, cu the lay cac thanh phan chay dugc nhu: go.<br /> nhua, da, giay, cao su, vai...<br /> 2.2 Phuong phap nghien ciru:<br /> - Phuang phdp thuc nghiem: dugc diing trong qua trinh nghien cim cong nghe cacbon<br /> hoa cac loai chat thai ran kho phan hiiy nham xac dinh cac thong so thuc nghiem toi im nliu<br /> thai gian, nhiet do, bieu suat thu hoi san pham... de viec tien hanh ap dung cong nghe cho<br /> hieu qua cao ban.<br /> Qua trinh cacbon boa dugc tien hanh tren 3 quy mo thi nghiem khac nhau: quy mo trong tii<br /> dot voi khoi lugng 20-30 g/mau; quy mo 16 pilot 3-5 kg/me va quy mo 16 50 kg/me. Chat thai<br /> dugc xir ly theo mo hinh thuc nghiem nhu tren hinh 1.<br /> <br /> t<br /> Khoi 16 Khong khi<br /> ^<br /> ' Buong gia nhiet Dau dot, Nhien<br /> 'V lieu dau DO<br /> Cira gio<br /> <br /> <br /> Ong khoi I<br /> Buong cacbon hoa<br /> Quat ejector<br /> <br /> <br /> Thiing chira chat thai<br /> <br /> < --<br /> ^•n • Chat thai ran<br /> <br /> <br /> Hinh 1: Sa dd cdu tgo cita thiet bi thi nghiem pilot<br /> Mo ta thuc nghiem: Chdt thai dugc cho vao Thiing chira CTR, sau d6 dong kin nap thiing.<br /> Nli ong thoat khi tir ndp thiing voi quat ejector. Quat ejector c6 chirc nang lam thoal hoi am<br /> va cac khi bay ra tir buing cacbon boa. Ong khi thoat tir thiing chira chat thai den buong gia<br /> nhiet tilp xiic true tilp vai nggn lira tir dau dot nham xir ly khi sinh ra tir thiing carbon boa.<br /> <br /> <br /> 73<br /> Tieu ban: Moi tru&ng vd Ndng luang ISBN: 978-604-913-013-7<br /> <br /> <br /> Khi sinh ra chay se lam tang nhiet do buIng gia nhiet, nhu vay se giam chi phi nhien lieu cho<br /> qua trinh xii' ly.<br /> Tieu ban: Moi tru&ng vd Ndng luang 978-604-913-013-7<br /> Cira gio lam viec theo chi do tu dgng va dilu khien bdng tay: khi nhiet do buong cacbon<br /> h6a c6n thdp chua dat din nhiet do cdn thiit thi cira gio lam nhiem vu huong nguIn nhiet di<br /> tir buIng gia nhiet xuIng buIng carbon boa. Khi nhiet do dat den gia tri can thiet da dat truoc,<br /> canh gio buong nguIn nhiet thoat tnre tilp ra Ing khoi va dau dot tu ngat va 16 dot lam viec<br /> theo che do ii nhiet.<br /> Ddu dit dugc dilu chinh tu dgng dl chay nhien lieu va cdp nhiet do cho qua trinh cacbon<br /> boa. Nhiet do c6 thi khing cbl tu dgng bdng rale dieu khien va van gio.<br /> Nhiet do thuc nghiem tir 300-500 °C, thai gian cacbon boa tir 10-60 phiit.<br /> - Phuang phdp phan tich: Phuong phap phan tich nhdm xac dinh cac tinh chat dac trmig<br /> cho chdt lugng san phdm than nhu dien tich bl mat rieng, chup kich thuac mao quan, xac dinh<br /> nhiet tri ciia san phdm, TOC. Cu thi, cac thiit bi dugc sir dung trong nghien cim nhu sau:<br /> + Trgng lugng: can co do chinh xac din hang gam AND HV-15 KgL - Nhat Ban; can<br /> OHAUSd-0.01g,ThuySi<br /> + Ham lugng cacbon hiru ca c6 trong than san pham: TOC Analyzer TOC-VCPH TNMl-<br /> Shimadzu 4100, Nhat Ban<br /> + Dien tich bl mat rieng, m2/g: Thiet bi Automatic Water Vapor Adsorption Apparatus<br /> Belsorp-18, Nhat Ban ; thiet bi Micromeritics M<br /> + cdu tnic, mat do 16: Thiit bi Scanning electron micrograph SEM (S-4700 Hitachi, Nhat Ban)<br /> + Nhiet tri: Thiit bi DTA-50 Shimadzu, Nhat Ban<br /> <br /> <br /> 3. KET QUA VA THAO LUAN<br /> 3.1 Thu'c nghiem carbon hoa cac thanh phan rac thai do thi<br /> Thuc nghiem dugc tien hanh trong 16 cacbon boa doi voi cac thanh phan chay dugc ciia<br /> chdt thai do thi nhu: giay, vai, cao su, go, nhua ... va hon hgp trgn theo ty le ciia chat thai.<br /> Lugng mau lay tir 2-20 g tiiy timg loai hinh chat thai. Nhiet do cacbon boa dugc tien hanh o<br /> cac giai nhiet do khac nhau: 300 C, 400 C va 500 C. Thai gian carbon h6a (thai gian luu)<br /> dugc tien hanh lay mau do dac: 10, 20, 30, 40, 50 va 60 phut.<br /> Ket qua thi nghiem doi vol giay dugc trinh bay a bang 1 sau day:<br /> Bdng 1: Cacbon hod gidy<br /> <br /> Nhiet do T= 300"C Nhiet dd T= 400"C Nhiet dd T= 400"C<br /> Ky<br /> hieu C D A B<br /> A B C D A B C D<br /> <br /> Ml 10 1,843 1,509 81,88 10 1,589 0,666 41,91 10 1,916 0,650 33,94<br /> <br /> M2 20 2,042 0,725 35,50 20 1,663 0,417 25,12 20 2,187 0,596 27,25<br /> <br /> <br /> <br /> 74<br />  Hoi nghi Khoa hoc ky niem 35 ndm I'ien Khoa hoc vd Cong nghe Viet Nam - Hd .Vd/ 10/2010<br /> <br /> <br /> <br /> <br /> Ghi chii: A - Thdi gian cacbon hod (phitt); B - Khdi luang mdu (g); C - Khdi luang scm phdm<br /> (g); D - Hieu sudt thu hdi (%o).<br /> Thao luan:<br /> Trong khoang 10 phiit dau khoi lugng mau giam rat nhanh. Luc nay chii yeu xay ra<br /> hien tugng thoat hai nuac trong chat thai. Tiep theo den khoang 20 phut, qua trinh boc<br /> hoi ket thuc hoan toan va xay ra qua trinh hinh thanh cac thanh phan khi thoat ra. Tir<br /> 30 phut den 60 phut qua trinh khi hoa giam dan va on dinh. San pham c6n lai la than<br /> sach, hieu suat thu h6i on djnh doi voi giay a nhiet do 300 °C vao khoang 32-33%.<br /> () nhiet do 400^0, trong 10 phut dau qua trinh boc hoi xay ra rat nhanh va da bat dau<br /> binh thanh khi. Khoang 30 den 40 phut qua trinh cacbon hoa da bat dau on dinh. Hieu<br /> suat thu hoi 6n dinh doi voi giay 6 nhiet do 400 °C vao khoang 19-22%.<br /> Hieu suat thu hoi on dinh doi voi giay 6 nhiet do 500 °C vao khoang 18-21 %.<br /> Ket qua thi nghiem doi vol nhira dugc trinh bay o bang 2 sau day:<br /> Bdng 2: Cacbon hda ddi vdi nhua<br /> <br /> Nhid dd T= 30(fC Nhiet dd T= 400"C Nhiet do T= 400"C<br /> TT<br /> A B C D A B C D A B C D<br /> <br /> 1 10 16,823 11,459 68.12 10 16,240 9,520 58,62 10 17,143 7,906 46,12<br /> <br /> 2 20 15.100 7.161 47.42 20 17,006 6,851 40,29 20 13,245 4,484 33,85<br /> <br /> 3 30 12,745 4,718 37,02 30 14,622 5,747 39,31 30 14,402 4,235 29,41<br /> <br /> 4 40 11.870 4.342 36.58 40 14,458 4,372 30,24 40 15,145 4,101 27,08<br /> <br /> 5 50 13,230 4.793 36,23 50 15,231 4,595 30,17 50 16,352 4,129 26,25<br /> <br /> 6 60 16,353 5,802 35.48 60 16,856 4,993 29,62 60 14,346 3,747 26,12<br /> <br /> Ghi chit: A - Thdi gian cacbon hod (phut); B - Khdi luong mdu (g); C - Khdi luang sdn phdm<br /> (g); D - Hieu sudt thu hdi (%).<br /> Thao luan: Hieu sudt thu hoi on dinh doi voi nhua a nhiet do 300°C vao khoang 35-37%; o<br /> nhiet do 400''C la 29-30% va a nhiet do 500°C vao khoang 26-27%.<br /> Nhu vay doi voi nhua ta co the tien hanh a nhiet do 400-500 °C, ty le thu hoi san pham 26-30%.<br /> <br /> <br /> <br /> <br /> 75<br /> Tieu ban: Moi tru&ng vd Ndng luang ISBN: 978-604-913-013-7<br /> <br /> <br /> Lam thi nghiem tuong tu a cac giai nhiet do va thai gian khac nhau doi vol cac loai chat<br /> thai khac nhu g6, da, tre ta co kit qua sau day: Hieu suat thu hoi doi vai giay tir 22-30%;<br /> Hieu sudt thu hIi dli vol nhua la 26-30%; Hieu sudt thu hIi doi vai vai tuong doi cao tir 60-<br /> 75% a nhiet do 300 - 400°C, nhung giam hdn xuIng c6n 14-59% a nhiet do 500°C; Hieu sudt<br /> thu hoi doi vai go: dat tir 15,5-25,2%; Hieu suat doi vai cao su la 20-35%).<br /> Kit qua van hdnh thiet bi pilot 3-5 kg/mi VA 50 kg/me.<br /> Sau hon 2 thang van hanh 16 carbon boa vol cac thanh phan chat thai khac nhau chiing toi<br /> thu dugc cac ket qua sau: Thofi gian de 16 dat den nhiet do on dinh: 10-15 phiit; Nhiet do<br /> buIng gia nhiet: 600-800°C; Nhiet do buIng carbon hoa: 300-500^^0; Thai gian carbon hoa<br /> 30-60 phiit, thai gian ii nhiet tir 240-300 phiit; Hieu sudt thu hIi dli vai giay la 30- 40%; voi<br /> go la 30-32,5%o; vai tre: 25-35,5%; voi trdu: 35-37%; voi loi ngo la 30%; va vai da va cao su<br /> la san pham ket chay dinh.<br /> 3.2 Xac djnh chat lugng san pham cua qua trinh carbon hoa<br /> - Xdc dinh TOC<br /> San pham dugc dinh huong de sir dung nhu nhien lieu dot cho cong nghiep va nhu vat lieu<br /> de xir ly 6 nhiem moi truang. De lam nhien lieu dot thi vat lieu khi dot phai sinh ra nhiet lugng<br /> cao, dac tnmg b6d thanh phan TOC c6 trong san pham. Tien hanh do TOC cho tat ca cac mau<br /> san pham da cacbon hoa o 300°C - 500°C trong cac khoang th6ri gian tir 10 phiit den 50 phut<br /> va thu dugc ket qua nhu sau (bang 3,4):<br /> Bdng 3: Ket qud TOC ciia gd<br /> <br /> Nhiet dd T= 300"C Nhiet do T= 400"C Nhiet dd T= 400"C<br /> Thdi<br /> gian<br /> TC IC TOC % TC IC TOC % TC IC TOC %<br /> (phiit)<br /> (mg) (mg) (mg) TOC (mg) (mg) (mg) TOC (mg) (mg) (mg) TOC<br /> <br /> Ml-10 5,908 0,035 5,873 58,73 6,315 0,005 6,312 63,12 6,882 0,027 6,857 68,57<br /> <br /> M2-20 6,731 0,030 6,701 67,01 7,475 0,011 7,464 74,64 7,497 0,034 7,463 74,63<br /> <br /> M3-30 7,520 0,008 7,512 75,12 7,278 0,022 7,256 72,56 7,630 0,008 7,622 76,22<br /> <br /> M4-40 8,536 0,002 8,534 85,34 8,607 0,015 8,592 85,92 8,775 0,014 8,761 87,61<br /> <br /> M5-50 8,651 0,006 8,645 86,45 8,891 0,009 8,883 88,83 8,920 0,007 8,913 89,13<br /> <br /> Thao luan: Thanh phan TOC tang theo thai gian carbon hoa va nam trong khoang tir 60-<br /> 90%. So lieu nay c6 the cao hon neu nhu san pham dugc bao quan tot hon dl khong hut hoi<br /> am vao san pham; Gia tri TOC cao nhat khoang 88-89. Tuy nhien, nlu tinh din hieu qua thu<br /> hoi thi nen tien hanh qua trinh cacbon hoa a thai gian khoang 30-50 la phii hgp.<br /> Bdng 4: TOC ciia than cacbon hda<br /> <br /> Vdt lieu Tre Gd Gidy Da Ldi ngd Trdu<br /> <br /> TOC(%) 86,77 88,82 52,81 57,58 79,35 68,15<br /> <br /> <br /> <br /> 76<br />  Hoi nghi Khoa hoc ky- niem 35 ndm Vien Khoa hoc vd Cong nghe Viet Nam - Hd Not 10/2010<br /> <br /> <br /> Tir ket qua nay chiing ta thay thanh phan TOC ciia tre, gl va loi ngo tuong dli cao tir 80-<br /> 90%. Dieu nay noi len trien vgng ling dung cong nghe carbon hoa chdt thai thanh san pham<br /> than diing nhu nhien lieu sach.<br /> - Xdc djnh dien tich be mat rieng ciia san phSm<br /> Myc dich cua viec xac dinh dien tich be mat la de danh gia kha nang diing vat lieu nay lam<br /> gia the sinh hgc trong xir ly 6 nhiem moi truang.<br /> Cac hinh anh SEM cho thay cac san pham tir nguyen lieu go, tre rdt phii hgp dl lam vat lieu xu-<br /> ly 6 nhiem moi truang vi kich thuoc mao quan va dien tich bl mat rdt phii hgp 10-150|am.<br /> <br /> <br /> <br /> <br /> Hinh 3: Hinh dnh SEM ciia than carbon hod cdc thdnh phdn chdt thdi: a) gd; b) tre; c) vdi; d) gidy<br /> Cac ket qua do kich thuoc 16 va dien tich be mat dugc trinh bay 6 bang 5.<br /> Bdng 5: Kich thudc vd dien tich be mat rieng cita cdc thdnh phdn chdt thdi (do tren thiet bi<br /> Micromeritics M)<br /> Logi than Kich thudc mao qudn Dien tich be mat (m^/g)<br /> Vai Kich thuoc rat nh6, phan Ion khoang l-2nm 60-70<br /> Giay Kich thuoc nho, 1 -2nm 50-70<br /> Tre 10-20)im (chilm 89.6%) 300 - 400<br /> Go 50-150|im 100-300<br /> <br /> <br /> <br /> 77<br /> Ti^u ban: Moi tru&ng vd Ndng luong ISBN: 978-604-913-013-7<br /> <br /> <br /> KET LUAN<br /> 1) Carbon boa la phuang phap xir ly chdt thai co triln vgng do co mot so uu diem so voi<br /> cac phuang phap thong thu6ng khac nhu giam chi phi cho qua trinh dot. lugng khi thai<br /> sinh ra dugc kiem soat va c6 the dot true tiep de sinh nhiet.<br /> 2) Da tiln hanh thuc nghiem tren 3 quy mo thiit bi trong ph6ng thi nghiem va pilot<br /> tuong ling 2-20g/me; 3-5kg/me .<br /> 3) Da xac dinh hieu sudt thu hIi vai cac loai hinh chdt thai khac nhau a thai gian \uu<br /> nhiet tir 10-60 phiit a cac giai nhiet do 300, 400 va 500°C. Cu thi: hieu sudt thu hIi dli<br /> vol gidy tir 22-30% va tuong dli In dinh; dli voi nhua la 25-39%; doi vol vai tuong<br /> dli cao tir 60-75% o nhiet do 300, 400°C, nhung giam hdn xuong con 14-59% or nhiet<br /> do 500°C; dli vol go dat tir 15,5-25,2%; dli vol cao su la 20-35% .<br /> 4) Da tiln hanh phan tich cac chi tieu danh gia chat lugng san pham theo tieu chi nhi?t<br /> nang thong qua chi tieu TOC va nhiet tri cho thdy TOC cua cac san pham tuong doi<br /> cao tir 80-90%). Chi tieu vl vat lieu lgc dl xir ly 6 nhiem moi truong dugc danh gia<br /> thong qua chi tieu kich thuac mao quan va dien tich be mat rieng cho thay co the su<br /> dung lam vat lieu lgc.<br /> <br /> <br /> TAI LIEU THAM KHAO<br /> 1. Frank M. Gentry, "The Technology of low temperature", 1928.<br /> 2. FAO, "Simple technologies of charcoal making", 1983.<br /> 3. W.M. Qiao, Y. Song, S.H. Yoon, Y. Korai, I. Mochida Shiga, H. Fukuda, A.<br /> Yamazaki, "Carbonization of waste PVC to develop porous carbon material Without<br /> further activation ", 2005.<br /> 4. Kazuhiro Mochidzuki, Lloyd S. Peredes, and Michael J. Antal, Jr. Flash,<br /> "Carbonization of Biomass", 2002.<br /> 5. To Thi Hai Yen, Pham Thi Thu Ha, Kawai, Nguyen The Dong, Trinh Van Tuyen,<br /> Saburo Matsui, "Domestic solid waste - Remarkable resource of waste recycling in<br /> Vietnam", Vietnam - Korea Workshop on Resource Recycling, Hanoi October 2,<br /> 2007.<br /> 6. M.J. Antal, "Renewable Resources Research Laboratory", 2QQ1.<br /> 7. To Thi Hai Yen, Pham Thi Thu Ha, Nguyen The Dong, Trinh Van Tuyen, "Household<br /> solid waste in city - some results of study on present situation in Hanoi, Vietnam ", Tap<br /> chi Khoa hgc va Cong nghe, tap 46, so 3 (DB), 2008<br /> 8. Hoang Kim Co va nnk, "Tinh todn ky thuat nhiet Id cdng nghiep - tap 1 vd 2 ", NXB<br /> Khoa hgc va ky thuat. Ha Noi, 1985<br /> <br /> <br /> <br /> <br /> 78<br />