383<br />
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Tuyen tftp cdng trinh Hdi nghi Cff hoc toiin qudc<br />
Ky niem 30 ndm Vien Cffhgc vd 30 ndm Tgp chi Cff hoc<br />
Hd Ndi, ngdy 8-9/4/2009<br />
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Han che phat thai chat khi gay hieu iing nha kinh voi cong nghe ung<br />
dung khi sinh hoc tren dong co" dot trong<br />
Biii Van Ga, Le Minh Tien, Truong Le Bich Tram, Nguyen Van Dong<br />
D(:n hge Dd Ndng<br />
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Ton tat: Viec nghien cieu icng dung cdc ngudn ndng liegng tdi sinh la rdt bice bdch nhdm dam bdo an<br />
ninh ndng lugng vd bdo vi mdi trudng trong bdi cdnh ngudn nhien lieu hda thgch dang ngdy cdng cgn<br />
kiet vd SIC dm ddn len ciia bdu khi quyin dang trd thdnh mdi hiem hoa ddi vpi nhdn logi<br />
Viet Nam vdi 80% ddn sd sdng a ndng thdn, chdt thdi him ca trong qud trinh sdn xudt ndng nghiep vd<br />
chdn nudi Id ngudn rdt tot de sdn xudt khi sinh hoc. Ngudi ddn Viet Nam da rdt quen thude vdi ngudn<br />
ndng lugng ndy vd sdn lugng biogas dang gia tdng nhanh chdng. Tuy nhien khi biogas a nude ta hien nay<br />
chii yen chi mdi diing Igi a viic sic dung cho dun ndii. Khi methane cd tdc dung gdy hieu ieng nhd kinh lan<br />
han CO:, vi vay niu thai biogas thica vdo khi cpiyin thi vdn di d nhiim mdi trudng cdng trd nen trdm<br />
trong han.<br />
Trong nhirng cdng trinh trudc ddy chimg tdi dd die tgo ra cdc bd phu kien di chuyin ddi ddng ca xang<br />
vd diesel sang thdnh ddng ca hcang nhiin lieu biogas-ddu md de sdn xudt dien ndng a ndng thdn. Vdi dd<br />
phdt triin ndng lugng biogas nhu hiin nay ciing vdi viec sdn xudt biogas a cdc trgm xie ly nude, cdc bai<br />
chdn lap rac, trong tuang lai gdn, sdn lugng biogas a medc ta se tdng ddng ke, vi vay viec nghien cim<br />
hodn thiin cdng nghi sic dung biogas tren ddng ca tTnh tgi vd heu trie biogas di ldm nhien lieu cung cdp<br />
cho phuang tiin giao thdng ca gidi Id rdt cdn thiit<br />
Bdi bdo ndy gidi thiiu cdng nghi sie dung biogas tren ddng ca ludng nhien lieu vd khd ndng img dung<br />
cdng nghe dd tren phicang tiin ca gidi a ndng thdn.<br />
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Viec nghien ciru irng dung cae ngudn nang lugng tai sinh la rat biic bach nham dam bao an<br />
ninh nang lugng va bao ve moi trudng trong bdi canh nguon nhien lieu hda thach dang ngay<br />
cang can kiet va sir am dan len eiia bau khi quyen dang trd thanh mdi hiem hoa doi vdi nhan<br />
loai.<br />
Viet Nam vdi 80% dan sd sdng d ndng thdn, chat thai hii'u ca trong qua trinh san xuit nong<br />
nghiep va chan nudi la ngudn rat tdt de san xuat biogas. Tuy nhien viec sir dung rpng rai biogas<br />
can cdng nghe de bien chimg thanh cac dang nang lugng khac. Bai bao nay gidi thieu cong nghe<br />
chuyen ddi ddng co sir dung nhien lieu Idng sang chay bang biogas. Neu sir dung cong nghe<br />
nay, mdi nam nude ta cd the san xuat 10%) dien nang bang nhien lieu tai tao va giam 6,5%) phat<br />
thai Carbon vao bau khi quyen.<br />
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L S u gia tang nong do CO2 trong khi quyen va tac hai doi voi moi truong<br />
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Trong vdng 4,5 ti nam tdn tai, qua dat da eo nhirng ehu ky nong len roi lanh di. Tir thdi<br />
diim euli eiia thdi ky bang ha cuoi ciing, each day khoang 13000 nam, qua dit da ndng len<br />
trung binh 4°C. Ngay nay qua dat nong len nhanh chong. Trong 1 the ky nhiet dp eiia qua dit da<br />
384 Bill Vdn Ga, Le Minh Tiin, Truong Li Bich Trdm, Nguyin Vdn Ddng<br />
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tang len 0,5°C. Phan tich mau lay ra tir bang ha cho thay ky nguyen ciia chiing ta ndng nhat tii<br />
hon 600 nam va 20 nam culi cimg cua thi ky XX, su gia tang nhiet do da vugt qua mpi ky luc<br />
vdi dinh cao la nam 1998.<br />
Nhiet dp gia tang nhanh chong nhu vay khien cho thien nhien khdng cd thai gian de thich<br />
nghi. Neu sir gia tang nhiet dp trong qua khii' gay ra do qua trinh tir nhien thi sir gia tang nhiet<br />
dp ngay nay chii yeu la do boat ddng cua eon ngudi.<br />
Can bang nhiet ciia qua dat dugc dam bao khi he thdng khdng tfch Ifjy nang lupng thang du<br />
tir m^t trdi. Ban ngay biic xa mat trdi dugc hap thu bdi khf quyen, dai duong va dai luc va ban<br />
dem cac thanh phan nay truyen ngugc biie xa ra khdng gian trong viing hdng ngoai. Cac tia biic<br />
xa hdng ngoai nay den lupt nd bj hap thu bdi may va mpt sd chat khf ed mat trong khf quyen.<br />
Cac chat khi gay hieu ung nha kinh phan xa lai mpt phan biie xa nay ve mat dat va lam nong Idp<br />
khi quyen dudi ciing: Dd la hieu ung nha kfnh. Klidng cd hieu irng nay, nhiet dp trung binh ciia<br />
mat dat la -18°C thay vi +15°C nhu hien nay. Hieu ung nha kfnh la mpt hien tugng tu nhien<br />
khdng the thieu tren hanh tinh xanh cua chung ta. Tuy nhien khi tac dpng cua nd vugt qua miic<br />
cho phep thi nd gay ra nhung hau qua nghiem trgng ddi vdi mdi trudng.<br />
Trong so nhQng chat khf gay hieu irng nha kfnh thi CO2 chiem den 50%) tae dung. Tir khi<br />
bat dau thdi ky cong nghiep den nay (khoang 200 nam), sir phat thai CO2 vao bau khf quyen da<br />
khdng ngirng gia tang. Ndng do CO2 hien nay da tang 35%) so vdi thdi ky tien cdng nghiep, vupt<br />
xa ndng do cua ehiing 600 000 nam trudc. Ndng do CO2 da tang tii' 280ppin d thdi ky tien cong<br />
nghiep den 379ppm vao nam 2005. Mue tang trung binh cua CO2 la +l,5ppm/nam trong<br />
khoang 1970 den 2000 va +2,1 ppm/nam trong khoang 2000 den 2007. Cae hoat dpng eua con<br />
ngudi nhu su dung nhien lieu hda thach, pha rirng... san sinh ra mdi nam 6 ty tan carbon. Tinh<br />
toan dien bien nong dp CO2 trong khf quyen theo cac kieh ban khac nhau cho thay ndng dp nay<br />
dat can bang on djnh khoang 500ppmV trong trudng hgp ngay tir bay gid chiing ta khdng lam<br />
gia tang them CO2 va dat gia trj can bang cue doan khoang 1 lOOppm neu tiep tuc phat thai nhu<br />
hien nay (hinh 1). Cac nghien ciiu ve dien bien khi hau cho thay mdi quan he true tiep giua<br />
nong dp CO2 trong khf quyen va su dao dpng ehu ky cua nhiet do trong vdng 150000 gan day.<br />
Neu ndng dp CO2 tang len gap doi se lam gia tang nhiet dp trung binh eua mat dat len 2,8°C.<br />
Dieu nay se lam dao Ion khf hau tren hanh tinh.<br />
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1900 2000 2100 2200,,. 2300 1900 20 2100 2200,,- 2300<br />
i4ata<br />
Hinh 1. Tinh toan du bao ndng dp CO2 trong khi quyin vdi cac kjch barilJhac nhau<br />
ve sii dung nang lupng [9]<br />
Hcin chi phdt thdi chdt khi gdy hiiu img nhd kinh vdi cdng nghi iing dung 385<br />
khi sinh hge trin dgng ca dot trong<br />
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Sir gia tang nhiet dp khi quyin gin mat dit gay ra nhung hau qua nang ne ddi vdi mdi<br />
trudng. d cac vimg Chau Phi nhiet ddi, Trung My, Nam My, Dong Nam A va Uc cay cdi Idn<br />
nhanh ban va chet sdm hon. Cd chii'ng 20 giong ddng thuc vat bien mat mdi ngay do bien doi<br />
khi hau. Neu mdi trudng tiep tuc bj tae ddng bdi sir khd ban, bao kit thi sir can bang he thdng<br />
sinh thai ciia hanh tinh se bj anh hudng nang ne.<br />
Khi nhiet do hanh tinh tang len, cac vi khuan, vi triing va cac yeu td truyen benh se phat<br />
trien nhanh chdng. Tren thuc te, nguy co benh tat do bien ddi khi hau da dien ra nhting nam<br />
1993-1995 d Trung My sau mgt giai doan nong bat thudng va do am tang. Nam 1993 benh dich<br />
ta phat trien manh d An Dp sau giai doan mua keo dai. Nam 1996 benh viem mang nao da giet<br />
che hang nghin ngudi d Ddng Phi sau thdi ky khd ban kbimg khiep.<br />
Cae nghien ciru cdng bd nam 2005 eho thay cudng dp nhfrng con bao trong 30 nam qua<br />
tang manh nhung sd lugng cac eon bao ed giam di so vdi trirde day. Cac nghien cii'u tren eiing<br />
cho thay sir gia tang cudng do ciia cac tran bao la do nhiet do khi quyen gia tang.<br />
Ngudi ta udc tinh dai duong hap thu tren 80%) nang lugng cap them vao he thdng khf ban.<br />
Su gia tang nhiet dp dai duong khien nude gian nd va lam tang eao mirc nude bien. Cac sd lieu<br />
nghien ciru do ve tinh cung cap cho thay trong the ky 20, muc nude bien da dang cao khoang<br />
vai chuc cm (0,l-0,2m). Rieng trong giai doan 1961 den 2003, mire nude bien da tang<br />
l,8min/nain. Sir gia tang muc nude bien chii yeu la do gian nd nhiet. Anh hudng eiia sir tan<br />
bang d cac cue the hien trong quang thdi gian dai nhieu the ky. Muc nude bien se dang cao tii'<br />
18 den 59cm vao nam 2100 (hinh 2). Nd cd<br />
the dang cao 2m vao nam 2300 [3]. Sir 80<br />
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dang cao mire nude bien vai cm khong gay 7 0 .-.<br />
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c<br />
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anh hudng dang ke ddi vdi bd bien da — CGCM1 HO —'<br />
— CSIRO Mk2 c;<br />
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