Tir CO xua nguod ta da biet den cac qua trinh khac nhau nhu: Igc. sdv tu\ nhien thiet bi su dung rat so dang. \'6d sir phat trien cua cong nghiep hoa chdt culi thi kv XVTII - dau the k[r]
(1)Hgi nghi Khoa hoc ky' niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010
NGHIEN CLTU iTNG DUNG CONG NGHE HOA HOC
• • •
TRONG XLT LY NHIEM VA BAO VE MOI TRUTOTVG
Pham Hong Hai
Vien Hoa hgc cac hgp chat thien nhien; 18 - Hoang Quoc Viet, Ha Noi E- mail: hai.inpcfSjyahoo.com
Tom tat:
Cdng nghe mdi truorng lien quan chat che vdi cdc nganh khoa hoc cdng nghe khdc, trudc het Id hod hoc vd cdng nghe hod hoe Cdc qud trinh vd thiet bi cdng nghe hod hoc Id ca sa khoa hoc quan trong viedinh todn cdc cdng trinh xic ly d nhiem vd bdo ve mdi truang
Md hinh hod todn hoc- phuang phdp nghien cicu hien dgi ciia cdng nghe hod hoc cd the duac sic dung cd hieu qud cdng nghe mdi tricdng
Han 15 ndm qua, Lien hiep KHSX Cdng nghe hod hoc (UCE) dd nghien cicu trien khai nhieu cdng trinh xic ly d nhiem bdo ve mdi truang cd ket qua nha nghien cicu, tinh todn cdc qud trinh thiet bi cdng nghe mdi truang theo cdc bdi ban cita cdng nghe hod hoc
Abstract:
Environmental technology is closely associated with other branches, firstly with chemistry and chemical technology And processes and apparatuses of chemical technology are considered as important background in pollution control and environmental protection
Mathematical modelling - the modern research method of chemical technology can be used effectively in environmental technology
Over last 15 years the Union of scientific research and production on Chemical Engineering (UCE) has carried out successfully many waste treatment systems to environmental protection due to good application of chemical engineering knowledges in reseaching and calculating of proecesses and apparatuses of environmental technology
L MO DAU
Viet Nam dang a thai ky day manh CNH, HDH dat nuoc De phat trien ben viing phai tien hanh cac boat dong bao ve moi truang Nha nuoc ta tir nam 1994 da ban hanh Luat Bao ve moi truang ddu tien, nam 2005 Quoc hgi khoa XI lai thong qua Luat Bao ve moi truong moi thay thi luat va hien dang c6 hieu luc Dang ta cung da Nghi quyet so 41-NQ/TW khoa IX vl bao ve moi tru6ng khang dinh "Bdo ve mdi truang Id mdt nhirng vdn de
sdng cdn ciia nhdn logi, vica la muc tieu viea Id mdt nhirng ndi dung ca bdn cua phdt Iriin bin virng, Id quyen lai vd nghia vu cua moi to chirc, moi gia dinh vd ciia mdi ngudi"
(2)Tieu ban: Moi truang va Nang lucmg ISBN: 978-604-913-013-7
\'6i to cong nghe \ a >"eu cau giai quyet hang loat van de co yeu cau tiet kiem nang lugng tai nguyen \"a bao \ e moi truong can bang sinh thai
Truoc >eu cau bao \ e moi truong mot ngaah cong nghe mod da hinh thanh: cong nghe moi truong Theo dinh nghTa ciia H.Pea^"\" (1985) "Cdng nghe mdi truang Id nganh cdng nghe
lien quan den bao ve mdi trucnig khoi nhirng huy hogi tiem tdng hogt ddng cua ngudi bao ve lodi ngircri khoi tdc ddng cua nhirng yeu to mdi truorng bdt lai vd cai thien chdt luang mdi truang vi sire khoe vd sir tdn tgi tdt ciia ngudri" [1]
Cong nghe m6i truong quan he chat che den cac nganh khoa hgc \"a cong nghe khac: hoa hgc vat ly sinh hgc xay dung Dac biet co the noi cong nghe moi truong truoc het la sir van dung cac qua trinh va thiet bi cong nghe hoa hgc de xu ly chat thai (ran long, khi) \ a kiem soat nhiem phuc xu cho muc dich bao \ e moi truong
Bai \ iet na}' de cap den \an de nghien ciiu ling dung cong nghe hoa hgc xu ly nhiem \k bao \ e moi truang neu len co so khoa hgc cua bg mon qua trinh thiet bi cong nghe hoa hoc phuang phap nghien cim hien dai cua no \ a sir \'an dung cong nghe moi truang
2 KHOA HOC \1 CAC QU.\ TRINH VA THIET BI CONG NGHE HOA HOC Cong nghe hoa hgc la mot nganh cong nghe gan vod san xuat cac loai hoa chat, rat da dang \a phiirc tap "Cdc qua trinh vd thiet bi' Id khoa hoc dua tren ca sa nhimg dinh luat
chung cua vdt ly vd Iiod hoc ve ban chdt la ca sa ly luan cua nganh cdng nghe hod hoc cho phep phdn tich vd tinh todn qud trinh tim cdc thdng sd cd lai nhdt vd tinh todn thiit bi de
thuc hien qud trinh
2.1 So liroc ve Ijch su phat trien
Tir CO xua nguod ta da biet den cac qua trinh khac nhu: Igc co chung cdt sdv tu\ nhien thiet bi su dung rat so dang \'6d sir phat trien cua cong nghiep hoa chdt culi thi kv XVTII - dau the k\- XIX da xa>- \dec hoan thien thiet bi cho cac qua uinh da bilt \a xudt hien nhiing qua trinh rnod \ a i thiet bi moi Dieu na>- lien quan den hai nganh san xudt duang \a rugu \ana Xhimg thiet bi mod la thiet bi co dac chan khong cot chung luyen may ep Igc khuna ban Cu6i the k}- XIX la cac thiet bi lam lanh gan \ 6d san xuat axit sulftiaric xa cac chdt
Tu>- nhien thieu ly luan \ e cac qua trinh xa phuong phap tinh thiit bi ma mot thai gian dai luon kh6 khan de dua nhung thiet bi tien bg hieu qua hon vao san xudt Do ^•ay sana the kv XX (1909 - Krupxky A.K; 1912 - Chisento I.A) nha kit qua cua viec ting kit kinh ngh"iem san xuat da hinh nen ly thuyet cac qua trinh xa thiit bi Bg mon khoa hgc moi niy lap nic dugc phat trien rat nhanh \-a dat dugc nhimg urn dang ke gop phdn quan trgna \ a o sir phat trien ciia nganh cong nghiep boa chat nen kinh t l thi gioi thi ky XX \ a hien
2.2 Phan loai cac qua trinh co ban cua cong nghe hoa hoc
Cac qua trinh xa thiet bi chung cho nhiing nganh khac ciia cong nghe hoa hgc dugc ggi la cdc qud trinh vd thiet bi ca ban [2.3]
Cac qua trinh co ban cua cong nghe hoa hgc co thi dugc phan loai theo nhima ddu hieu khac
a) Theo cdc dinh luat ca bdn qiiyit dinh toe ciia qud trinh chia t h a n h :
(3)Hoi nghi Khoa hoc ky' niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Not 10 2010
nguyen lieu co dang khoi, tang Cu the cac qua trinh co hgc co the la: nghien, phan loai (sang) va trgn cac chat ran
+ Cac qua trinh thuy co co toe qua trinh dugc xac dinh bang cac dinli luat cua thuy dong hgc - bg mon khoa hgc ve chuyen dong ciia cac chat long va Thuoc ve cac qua trinh la van chuyen chat long, van chuyen va nen khi, phan rieng cac he chat long va khong dong nhat bang trgng lire (qua trinh lang) va bang ly tam, ciing nhu duoi tac dong ciia ap suat qua lop xop (qua trinh Igc) va trgn chat long
+ Cac qua trinh nhiet xay vol toe dugc xac dinh boi cac dinh luat truyen nhiet - bg mon khoa hgc ve cac phuong phap lan truyen nhiet Do la cac qua trinh dun nong lam lanh, boc hoi va ngung tu ciia hoi Thuoc ve cac qua trinh nhiet c6n la cac qua trinh lam lanh den nhiet thap ban nhiet moi tru6ng (cac qua trinh lam lanh vira va sau)
Toe ciia cac qua trinh nhiet a mire dang ke phu thuoc vao cac dieu kien thuy dong (toe do, che chay) de thuc hien chuyen nhiet giiia cac moi truang trao doi voi bang nhiet
+ Cac qua trinh trao doi khoi (Ithuyech tan) dac trung bod sir chuyen mot hoac mot vai cau tir ciia hon hgp ban dau tir pha sang pha khac qua be mat phan each pha Khuyech tan phan tu chat phan bo la giai doan cbam nhat vi the thuong la giai doan quyet dinh cua cac qua trinh trao doi khoi Thuoc ve nhom cac qua trinh mo ta boi nhirng dinh luat truyen khoi la: hap thu, chung cat (chung luyen), trich ly tir dung dich, boa tan va trich ly tir vat ran xop, ket tinh, hap phu va say
Qua trinh trao doi khoi xay lien quan chat che voi cac dieu kien thuy dong cac pha va tren ranh gioi pha Thu6ng thi ciing voi trao doi khoi c6 ca trao doi nhiet
+ Cac qua trinh hoa hoc (phan ung) xay voi toe quyet dinh boi cac dinh luat ciia dong hgc boa hgc Nhung cimg voi cac phan ling hoa hgc thu6ng la c6 sir chuyen khoi va nang lugng, tiep niia la toe cac qua trinh hoa hgc (dac biet o quy mo cong nghiep) phu thuoc vao cac dieu kien thuy dong Chinh vi the toe cac phan irng tuan thii cac quy luat dong hgc vT mo va dugc quyet dinh boi giai doan cham nhat so cac tac dong hoa hgc lien tiep xay va khuyech tan
Tuong img vol cac qua trinh co ban tren co cac thiet bi co ban de thuc hien qua trinh ciia nganh cong nghe hoa hgc
b) Theo phuang phdp td chuc cac qua trinh cong nghe hoa hgc co ban chia gian doan
va lien tuc
+ Cac qua trinh gian doan dugc tiln hanh cac thiet bi ma sau nhiing khoang thai gian nhat djnh nap nguyen lieu ban dau vao thiet bi de xir ly chung roi lai thao san pham khoi thiit bi Nhu vay qua trinh gian doan co dac trung la tat ca cac giai doan deu xay mot cho (trong mot thiet bi) nhung a thai gian khac
+ Cac qua trinh lien tuc thuc hien thiit bi ma viec nap lieu va thao san pham dugc thuc hien ding thai va lien tuc Nhu vay qua trinh lien tuc c6 dac trung la tat ca cac giai doan cua no dIu xay dong thai nhung nhung ch6 khac khong gian tiic la thuc hien o nhung phdn khac ciia thiit bi hay o nhung thiet bi khac
So voi qua trinh gian doan, qua trinh lien tuc co uu diem:
- Co kha nang tu dong hoa va co gioi hoa qua trinh, qua giam lao dong thii cong den mire toi thieu
(4)Tieu ban: Moi truang va Nang luang ISBN: 978-604-913-013-7
- Co the trang bj dong bg, qua d6 giam gia dau tu va gia
c) Theo su thay doi ciia cdc thong so thai gian
Cac thong so ciia qua trinh (toe do, nhiet do, nong ) thay doi theo th6fi gian va cac qua trinh dugc chia
+ Cac qua trinh on dinh + Cac qua trinh khong on dinh
2.3 Quy luat dong hoc cua cac qua trinh co ban
Khong hieu dong hgc ciia cac qua trinh thi khong thi tinh dugc cac thong s i co ban ciia thiit bi
Quy luat dong hgc ciia cac qua trinh thuy co, nhiet, trao d l i khoi va boa hgc co thi phat trien dang dinh luat tong quat sau: Tdc dd qud trinh ty le thuan vai ddng lire vd ty le nghich
vai trd luc Ggi dai lugng ty le nghich voi tra luc la he sd tdc ta co thi vilt cac phuang
trinh dong hgc co ban sau:
a) Ddi vdi chuyen ddng ciia ddng vdt lieu (Idng hay khi) qua thiit bi dV Ap ,
rdT i?|
Trong V- the tich chat 16ng chuyin qua, F- tilt dien thiit bi; T- thai gian; K|-he s i tic qua trinh (dai lugng nghich dao ciia tro lire thuy lire Ri)
b) Ddi vdi trao ddi nhiet:
do ^t /-.^ Fa T /?,
c) Ddi vdi trao ddi chdt tic pha ndy sang pha khdc dM Ac
Fd T i?3 - K,hc (3)
Trong M-lugng chdt chuyin tir pha sang pha khac; F-bl mat tilp xiic pha- K3 - he so truyen khoi (dai lugng nghich dao tra lire khuylch tan R3); Ac- hieu s i giira ning can bang va nong boat dong ciia chat cac pha
d) Ddi vdi bien ddi hod hoc: dM
Vdz K/ic) (4)
Trong M- lugng chdt da phan ung qua trinh hoa hoe; V-thI tich thiit bi" K4 - he so van toe qua trinh boa hgc; f (c) - dong lire cua qua trinh la ham s i nIng cac chdt tham
gia phan ung ' 2.4 Nguyen tdc chung tinh thiet bj hoa chdt
^ Muc dich cua tinh toan cac qua trinh va thiit bi hoa hgc la xac dinh cac dong khii luona vat heu dugc che bien, xac dinh tieu bao nang lugng dl thirc hien qua trinh va tinh nhirng kich
(5)Hoi nghi Khoa hoc ky niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010
Nhung viec can lam:
- Tir dieu kien thuy dong xac dinh dieu kien can bang va huong di ciia qua trinh cac gia trj dau va cuoi ciia cac thong so
- Lap can bang vat chat:
X G = Z G, (5)
Trong do: Yfii' lu^png vat lieu ban dau; XGc - lugng san pham cuoi ciing - Lap can bang nhiet:
Trong Qj - lugng nhiet vao thiet bi cimg vat lieu ban dau; Qqi - hieu img nhiet ciia qua trinh; Qc - lugng nhiet rai thiet bi ciing san pham cuoi; Qmt - lugng nhiet mat mat vao moi truang
- Theo cac dai lugng dac trung cho thong so lam viec va can bang xac dinh ddng luc cua
qud trinh tren co so cac dinh luat ciia dong hgc (thuy dong, nhiet, khuyech tan, hoa hgc) tim he sd tdc dd ciia qud trinh
- Xac dinh kich thudc ca ban cua thiet bj: dung tich, tiet dien, be mat dot nong, be mat tiep
xuc pha bang each sir dung he thirc
A = ^ (7) ' DK
Trong A- kich thuoc co ban ciia thiet bi; M - lugng vat lieu che bien don vi thai gian; D - dong luc ciia qua trinh; K- he so toe ciia qua trinh
Qua phan trinh bay o tren ta thay viec hieu ro cac qua trinh cong nghe hoa hgc co ban va thiet bi de thuc hien chung cho phep ta:
1) Trong nghien cim khoa hgc co phuong phap nghien cim hgp ly, co kha nang thirc hien va danh gia ket qua chinh xac de chinh ly va khai quat hoa cac ket qua irng dung vao thuc te san xuat
2) Trong thiet ke biet danh gia va lira chgn so cong nghe va loai thiet bi thich hgp cho timg qua trinh; biet tinh toan, thiet ke thiet bi
3) Trong dieu hanh san xuat de dang tiep can dugc che lam viec thich hgp de nang cao nang suat thiet bi va chat lugng san pham; biet tim khau yeu day chuyen san xuat de cai tien
3 MO HINH HOA CAC QUA TRINH CONG NGHE HOA HOC VA MOI TRUONG
Mo hinh hoa toan hgc la phuong phap nghien cim hien dai ciia cong nghe hoa hgc va cong nghe moi truang Phirong phap dugc ap dung rong rai viec nghien cim tinh toan, thiit kl va xay dung cac qua trinh cong nghe hoa hgc va moi truang [4-7]
(6)Tieu ban: Moi truang va Ndng luong ISBN: 978-604-913-013-7
Trong cac giai doan tren thi xay dung mo hinh toan la kho khan va quan trgng nhat O day doi h6i sir hilu bilt sau sdc ban chdt ciia qua trinh cdn mo ta bat dau tir nghien cim thuy dong hgc sau rli moi din dong hgc nhiet, dong hgc chuyen khoi, dong hoa hgc, dong hgc phat trien ciia vi sinh vat
Mo hinh toan ting thi se cdu tao tir cac mo hinh cdp thap theo cau tnic phan cap Vi du mo hinh ciia thiit bi phan ling hoa sinh co thi dugc ap dung cho mot thiet bi nhu aeroten hay biophin CO cau tnic nhu tren hinh
Ta thay rang co mire phan cap (1 - V) tir thap den cao
Co so mo ta muc I la cac he thirc xet tod cac hien tugng hoa sinh xay te bao Nliiem vu nghien ciiu ciia mire la giai ma co che cac qua trinh cue ky phirc tap te tao va chung a dang khai quat co the mo ta bieu dien sir phat trien ciia mot te bao rieng biet Thuc te hien viec c6n chua lam dugc va ngu6d ta phai bat dau tir miic II
0 mire II la mo hinh dong hgc phat trien cua quan the vi sinh vat dugc hinh tir nhiing mo hinh cap thap miic I Hien nguai ta da chap nhan va dang sir dung rgng rai mo hinh dong hgc Monod, Andrews, Monod-Ierusalimsky
O miic III la nhirng he tbiic xac dinh dieu kien khuay trgn thiet bi Trgn vi mo la dilu kien ly tuong, thuc te la trgn vT mo van ton tai nhimg hgp thi nao Danh gia mire khudy trgn dugc thuc hien theo cong thiic Dankwerts
V
IV
III
II
Mo hinh thiet bi phan img hoa sinh
Mo hinh trao doi khoi Mo hinh thuy dong
Mo hirih tron vi sinh
Mo hinh trao doi nhiet
Mo hinh tron vT mo
Mo hinh dong hgc tang truong ciia quan the vi sinh vat
Mo hinh tang truong cua
mot te bao rieng biet Mo hinh van tai va biin doi CO chat te bao Mo hinh sinh hoa sinh ly tuoi ciia te bao
LTinh 1: Sa dd cdu true md hinh todn ciia thiit bi phdn icng hod sinh
Cac mo hinh o miic IV mo ta cac qua trinh thuy dong, trao dli nhiet, trao dli chdt thiet bi Mo hinh thuy dong hgc can nghien ciiu xac lap tren co so van dung cac mo hinh cdu triic dong tieu bieu thiet bi Do la: Mo hinh ddy ly tu6ng; Mo hinh trgn ly tuong; Mo hinh khuyech tan (mot tham so va hai tham so); Mo hinh phii hgp
(7)Hoi nghi Khoa hoc ky niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010
Nhu vay tong hgp lai ta se co mo hinh toan ciia thiet bi phan img hoa sinh a mire V hinh tir cac mo hinh cac mire thap Mo hinh bao gom he phuong trinh (dai so, vi phan ) kha phirc tap thuoc vao qua trinh cu the
Hien ky thuat va phuang tien tinh toan da phat trien den trinh cao cho nen viec giai mo hinh toan c6 the noi co thuan Igi rat nhieu Va nhu vay phuong phap mo hinli hoa toan rat nen va rat can dugc cac nha nghien ciiu cong nghe moi truang sir dung de dua dugc nhung giai phap cong nghe chinh xac va hieu qua
4 iTNG DUNG QUA TRINH THIET BI CONG NGHE HOA HOC TRONG Xlf LY NHIEM VA BAO VE MOI TRLTCJNG
Moi quan tam chii yeu thiet ke cac cong trinh xir ly nhiem va cac thiet bi ciia chung la phai van dung dugc nhiing tuu moi nhat ciia cac nganh khoa hgc cong nghe, dua dugc nhiing giai phap tien bg va kinh te nhat de cong trinh hoat dong hieu qua va lau dai
Nhu da noi a tren nghien cim tinh toan thiet ke che tao cac cong trinh xir ly nhiem ngoai nhung kien thiic co ban ve hoa, ly, sinh c6n phai hieu sau sac cac qua trinh thiet bi co' ban ciia cong nghe hoa hgc tien hanh cong viec theo bai ban neu tren ket hgp ca phuong phap mo hinh hoa toan hgc de tiet kiem thai gian, cong sue va ca vat chat trien khai img dung
4.1 Lira chon phuong phap xu' ly nhiem
Ton tai nhirng phuong phap khac nhau, nhieu qua trinh khac de xir ly nhiem (nuoc thai, thai, chat thai ran) Vi du xem xet van de xir ly nuoc thai ta thay cac phuang phap xir ly dugc chia ba nhom Ion:
A Cac phuang phap tren co so tach tap chat B Cac phuong phap tren co so bien doi tap chat C Cac phuong phap boa sinh
Sir dung cac phuong phap nhom dan den viec tach tap chat kh6i nude ma khong lam thay doi nhirng tinh chat boa hgc ciia no Dieu c6 dugc tru6ng hgp ma nuac va tap chat nam a nhirng trang thai pha khac cung nhu ca truong hgp chung tao pha Neu nuac va tap chat nam a pha (vi du tao nen dung dich thuc sir) va theo suy luan thay khong the true tiep sir dung cac phuang phap ciia nhom mot thi nuoc can xu ly can phai CO xir ly so bg dua tap chat ve mot pha khac Do vay cac phuang phap nh6m mot lai dugc chia hai nhom nh6
A l Tach true tiep tap chat khoi nuoc A2 Thay doi trang thai pha cua nuoc Doi vol nhom nho Al la cac phuong phap:
A L L Tach co hgc cac tap chat Ion (sang, luoi) A1.2 Lang