Potential evaluation study and application m ethod for biom ass energy from agricultural by-products

VNƯ Joum al o f Science, Earth Sciences 25 (2009) 76-83

Potential evaluation study and application m ethod for biom ass energy from agricultural by-products

(rice, com , peanut) in N am d in h P rovince

Luu Duc H ai*, Tran Van Q uy

College o f Science, VNU

Received 24 July 2009; received in revised form 30 July 2009

A bstract. Namdinh is a big agricultural province in Red River delta o f North Vietnam, vvhere were planted three main agricultural Products: rice, com, peanut. By case-study investigation and energy anaỉysis, the report put out detail iníormation on biomass energy o f rice stravv, rice husk, com stravv, com core, peanut stravv and total biomass energy from agricultural wastes in Namdinh province. According to investigation data, yearly the total agricultural vvastes in Namdinh province is more than 11 million tons. Most o f this agriculturaỉ vvastes in Namdinh province are not collccted and used at current time, it is mean that: Namdinh peasant dissipates a lot o f biomass energy every year. In theory, 1 ton o f com by-products generates 477 kWh o f eỉectricity; 1 ton of peanut by-products generates 450 kWh o f electricity; 1 ton o f husk by-products generates 460 kWh o f electricity; 1 ton o f straw by-products generates 447 kW h o f electricity. In comparison vvith coal, using husk and stravv as fuels is more economicaỉ eíĩectively. The report aslo have proposed and chosen technologicaỉ method o f electricity production írom husk and stravv. This mcthod is fluidized sand-bed combustion technology. Ash after being burned can be used as additive for industrial production o f cement and bulding materials.

Keyvvords: Biomass energy; By-products; Straw; Husk, Agriculture.

1. I n tr o d u c tio n

T o d a y OĨ1 a global scale, b io m ass is the íò u rth so u rce en erg y in large (average c o n trib u te is abo ut 3 5 % o f th e total energy su p p ly ). T herefo re, b io m ass en erg y (B E ) hold im p o rta n t ro le in m e etin g en erg y needs o f the w o rld in th e future. U sin g B E h elp to redu ce the am o u n t o f vvaste an d w aste redu ctio n o f g reen h o u se gases, help to pro tect the

* Corrcsponding author. Teỉ.: 84-904122770 E-mail: haiqlm@yahoo.com

e n v iro n m en t. O n th e w o rld , m a n y co u n tries are ex p an d in g tren d u sin g b io m ass [3,5]. U nlike o th er fo rm s o f re n e w a b le en erg y , B E can not only c o n tro l b u t also sim u ltan e o u sly provide both h eat an d e le c tric ity p ro d u ctio n . B iom ass sou rce v ery d iv e rse an d rich , th e re íò re BE te ch n o lo g y is also v e ry d iv e rs e an d can be d iv id ed into 2 ty pes: te c h n o lo g y o f biom ass con version d irec tly into u s e íu l energy and te ch n o lo g y o f b io m ass co n v ersio n into seco n d ary fuel.

N a m d in h , a p ro v in c e o f V ietn am , in the natural co n d itio n s fav o rab le for d ev elo p m en t o f

L.D. Hai, T .v . Q uy / V N U Ịoum al o f Science, Eartk Sciences 25 (2009) 76-83

a g ric u ltu re so th e an n u al am o u n t o f b y-products in ag ricu ltu ral cu ltiv atio n are very large and v ery d iverse in co m p o n en ts. Hovvever, until novv th e re is no research p rọ ịect vvhich e v a lu a te d a sp ecific quantity, co m p o sitio n , and e s p e c ia lly the p o te n tial use o f b io m ass in the m o st a p p ro p ria te way.

T h is article g iv es so m e resu lts o f the in v estig atio n , su rveys, assesses th e potentials, an d p ro p o ses prọ ịects in clude te ch n o lo g y o f BE ap p licatio n used to g en erate electricity in order to co n trib u te to so lid w aste P r o c e s s in g and re d u c e use o f fossil fu el reso u rces in rural V ietn am today.

A n a ỉy sis sa m p les in the lab or analyses o f m o istu re, ash c o n t-.1t, tc o f carbon, a n d q u an tity o f h eat ar?

M o istu re an d ash c o n te n t o f th e sa determ in ed b y th e m eth o d o f w eigh total am o u n t o f cacbon is determ ii m ethod C h u rin ; q u an tity o f h eat is (k by calo rim etric bom b.

A n a lysis a n d syn th esis docum ení<

b asis o f c o llected m aterials an d th e re surveys and intervievvs, it is evaluate o f c o llectio n an d use o f rice bv-prcv calcu lated th e p o te n tials o f B E ? province.

2. O b ịe c ts a n d m e th o d s o f r e s e a r c h

3 . R e s u lts a n d d isc u ssio n O b je c í o f re se a rc h: T h e ag ricu ltu ral by-

p ro d u cts afte r h a rv e st (straw , h u sk o f rice, co m leav es and co re, p ean u t stra w ) in N am dinh province.

C o lìectio n d o c u m e n ts a n d d a ta : docum ents an d d a ta for research w e re receiv ed from rep o rts o f scien tists o f th e D ep artm en t o f N atu ral R eso u rces an d E n viro nm en t, D ep artm en t o f S tatistics, N am d in h province.

T he d a ta w ere collected from th e interview s and su rv ey s at the h o u seh o ld o f so m e co m m u n es o f H ai H au and V u B an d istricts o f th e province.

3.1. S ta tu s o f cu ltiva tio n o f sonu p la n ts in N a m d in h p ro v in c e

u

- S ta tu s c u ltiv a tio n o f ric e [1]

N am d in h is hom e to v arie tie s o f ric such as T a m X o an , T am T ieu , N e p Bú C ai H o a V an g . T h e s e v arie tie s o f rice h ig h in v e stm en t cu ltiv atio n an d p ro v ; very h igh prcxluctivity, b u t th e v alu e o f tim es c o m p ared to reg u la r rice as Wc.

y ield, an d ric e p ro du ctio n in N am d in h I in 5 years are shovvn in T ab le 1.

Table 1. Area, yieỉd, and rice production in the years 2004 - 2008

Year A rea(ha) Yield (centner/ha) Production (1000 ton)

Rice season 1 Rice season 2 Rice season 1 Rice season 2 Rice season 1 Rice season

2004 80913 82059 68,75 47,51 556305 389864

2005 79953 81064 69,60 53,10 556461 430473

2006 78329 79967 69,92 29,37 547671 234878

2007 77618,5 79650 70,55 52,31 547575 416684

2008 77021 79052 67,11 52,48 516875 414894

Sources: Annuaỉ statisíic ofN am dinh province, 2009.

78 L.D. Hai, T .v . Q uy / V N U Ịournal o f Science, Earth Sciences 25 (2009) 76-83

B y 2 0 1 5 th e use o f rice grovving land in the p ro v in c e eac h y ear is 8 2 8 1 3 ,9 hectares, in c lu d in g fĩeld o f 3 seaso ns o f 34765,1 hectares, field o f 2 seaso n s o f 4 8 ,0 4 8 .8 hectares w ith d iíĩe re n t varieties o f rice cap ab le o f b earin g a g a in st th e w eath e r co n d itio n s and in se c t d ise a se s such as: Q 5 , L u o n g Q uang, K h a n g D an , T a p G iao... In ad d itio n , th e re are e ig h t v arie tie s o f rice, g lu tin o u s rice sovvn in the land u n d ig ested w ater.

- S ta tu s o f co rn cu ltiva tio n

O n th e te rrito ry o f N am d in h p ro vince som e o f stic k y c o m p lan ts are grow n quite popular.

U su ally so w n in S eptem ber, harvested in D ccem b er. C u rren t statu s o f c o m cu ltiv atio n in th e p ro v in c e is reílected in th e T a b le 2. T rend to 20 15 th e to tal area o f p lanted c o m is 6000 h ectares.

Table 2. Area o f cultivation and com production in the Namdinh province

Year 2000 2005 2006 2007 2008

Area (ha) 3407 4115 4744 5104 4144

Production (ton) 10892 15627 18672 19659 17086 Sources: Artnuaì statistic o/N am dinh province, 2009

- S ta tu s o f p e a n u í cu ltiva tio n

A cc o rd in g to statistic s rep o rted b y the D e p a rtm e n t o f A g ricu ltu re and Rural

D e v e lo p m e n t o f N a m d in h proY ince in 2 0 0 7 , the area o f p e a n u t 6 0 0 0 - 70 00 h a (in clud in g th e 3 season: S p rin g , S u m m e r-A u tu m n , and W in ter), av erag e y ie ld 33 - 35 c e n tn er/h a, th e in dividual sp rin g 2 0 0 7 a v e ra g e y ie ld vvas 38,75 centner/ha.

P ean u t p la n ts w e re p lan ted a t th e d irectio n o f c u ltiv a tio n , m a in ly n ew v arie tie s o rig in ated from C h in a . C u ltiv a tio n a re a and harvest y eild in re c e n t y e a rs a re sh o w n in T a b le 3. T ren d area o f p la n te d p e a n u t in 2015 in the p ro v in ce is

10000 h a.

Tabỉe 3. Area o f cultivation and peanut production in the Namdinh province

Year 2000 2005 2006 2007 2008

Area (ha) 3739 6115 6442 6788 6808

Production (ton) 11024 21788 22722 24855 24232 Sources: A nnual statistic o f Namdinh province, 2009

3.2. S ta tu s o f c o lle c íio n a n d use o f by-products o f a g ric u ỉtu r e p la n ts (rice, corn, p ea n u í)

- S ía íu s o f c o lle c tio n a n d u se o f rice by- p ro d u c ts

T h e b y -p ro d u c ts afte r ric e h arv est are stravv, husk. T h e d a ta c o lle c te d o n th e harvest an d at th e h u s k in g ric e to d e te rm in e the averag e m ass o f b y -p ro d u c ts a re g iv e n in T a b le 4.

Table 4. Total mass o f rice by-products in Namdiĩih province in 2008

Pỉantation Arca (ha) Production (ton) Agricultural waste Mass (ton /ha) Total mass (ton/year)

D - I«£ếvn 0 1 1 - 7 ^ 0 Straw 4>8 749150,4

Rice 156073 931769 H ^ k ______ ________________ 226305:8

T h e resu lts in T ab le 4 are n o t m uch d iíĩe re n c e from th e d a ta in vestigated by farm ers in 2 ty p ical d istricts o f N am d in h p ro vince, Hai H au a n d V u B an. S p e c iíìc a lly , o n average, ev ery 100 k g o f pad dy eq u iv alen t to ab o u t 70 k g o f d ry stravv and w hen h u sk in g it creates 25 k g o f husk.

R ic e s tu b b le is used to get b u m ed ash as fe rtiliz e r o r d is p o s a l o r in crease up hum us co n te n t o f land.

Stravv is u s e d fo r co o k in g (stravv ash used as c o m p o st) o r fo o d fo r b u íĩa lo e s, co w s; o r ưsed th e m ateria l to grovv m u sh ro o m s (fu ng us fat, straw m u s h ro o m s , w o od ear fungus with

L.D. Hai, T .v . Q u y / V N U Ịournaỉ o f Science, Earth Sciences 2 5 (2009) 76-83 79

pro d u ctiv ity o f 2 8 5 k g fu n g u s /l to n stravv). In addition, straw is also u sed to m ix w ith the anim al m an u re as th e o rg a n ic c o m p o st; som e local territo ry use th e straw to c o v e r th e soil vvhen plan tin g v egetables a im to a v o id to o high tem p eratu res o r heavy ra in , k e e p th e soil m oisture, keep soil fro m e ro d e b y w ash in g drift... W hen th e straw b u m e d , it c re a te s large sm okes an d d u sts cau se h arm n o t o n ly to hum an h ealth , v egetation , b u t a lso im p a c t on safety for particip an ts in tra ffic ; w hen cu ltiv atin g it creates th e a m o u n t o f C H4 gas influencing on th e en v iro n m en ta l air. M od el o f m ushroom s p la n tin g has its o w n ad v an tag es and difficulties in particular.

T h e am o u n t o f h u sk re c e iv e d fro m the paddy h u sk in g is large. A p a rt o f h u sk w a s sold to people as a m aterial for c o o k in g , co m p o st...

th e rest are p u t to the d u m p in g place th a t cau se en v iro n m en tal p o llu tio n . C u rren tly th e p ro v in ce has no t effe c tiv e ly u tilized th is raw m aterial.

- S ta tu s o f c o llectio n a n d use o f c o m by- p ro d u c ts

T h e seco n d ary pro d u cts from c o m plants include: th e stem , leaves, h u sk and core. W hen h arv est th e co m co b is often collected sep arately, an d the stem an d c o m leav es are ex posed to d ry a t th e field (ap p ro x im ate ly 90 % ), vvhen d rie d they are taken hom e, p u t into heaps in d ry p la c e . T h e collected d a ta in the h arv est field to d eterm in e th e averag e m a ss o f th e b y -p ro d u cts are given in T ab le 5. T h e am o u n t o f b y -p ro d u cts b y actual calcu la tio n s in T ab le 5 an d d a ta th ro ug h surv eys from farm e rs are no t m u ch d ifferen t.

Table 5. Total mass o f by-products from com plants in 2008

Plantation Area (ha) Production (ton) Agricultural waste Mass (ton /ha) Total mass (ton/year)

Com 4144 17086 Stem, leaves

Core

6,4 2,3

26521,6 9531,2 Table 6. Total m ass o f by-products from peanut plants in 2008

Plantation Area (ha) Production (ton) Agricultural waste M ass (ton /ha) Total mass (ton/year)

Peanut 6808 24232 “ em, leaves

Shells

2,8 4,5

19062,4 3063,6 Dry c o m stem a n d le a v e s a re u sed as a

m aterial for co o k in g o r a v e ry g o o d food for cattle b ecau se c o m stem h a v e a h ig h c o n ten t o f íìber (3 1 ,5 % ), c ru đ e p ro te in (7 ,6 % ) and saccharin p o w d er hig h er c o m p a re d w ith straw [11]. C o m c o b s a fte r h a rv e s t are p e e le d aw ay from leaves an d husk. M o st fresh h u s k a re dried as 2 m aterial to co o k in g , o n ly a p a rt o f com husk is used as food fo r c a ttle . C o m co re obteined afte r sep arated fro m c o m seed s often are th ro w n aw a y o r d ried as a m a te ria l for cooking.

- S ta tu s o f co llectio n a n d use o f p e a n u t by- p ro d u c ts

S eco n d ary P roducts from p e a n u t plants include: th e stem , sh ells an d leaves. S tem and shell are c o lle c te d a fte r th e p eanu t harvest.

P ean u t is d ried fo r storag e. P eel and s e e d s have been sep arated b y m ach in e o r m an u ally . T h e d a ta c o llected in th e h arv est field to d eterm in e th e av erag e m a ss o f th e b y -p rod ucts a re g iven in T ab le 6. T h e a m o u n t o f seco n d ary p rod ucts b y actu al calcu la tio n s in T ab le 6 an d d ata th r o u g h s u r v e y s fr o m f a r m e r s a r e n o t m u c h

L.D. Hai, T .v. Q uy / V N U Ịournal oỊScience, Earth Sciences 25 (2009) 76-83

ì . P e a n u t stem an d leaves can be cul 5 cm Iength, and then cu ltiv ate dow n to th e green co m p o st. A p art o f peanut d ried as a m aterial for cooking. In b eca u se th e fresh peanu t stem and ave h ig h c o n tc n t o f p ro tein sh ou ld they

•e u r a p p e d up a s a reserve food for

cattle. P e a n u t s h e lls h av e m ain ly u sed as a m aterial fo r c o o k in g .

F rom th e d a ta re c e iv e d in T ab les 4, 5 , 6 and d ata on th e a re a o f c u ltiv a tio n o f rice, c o m , and pean ut b y 2 0 1 5 in N a m d in h p ro v in ce, w e can pred ict th e a m o u n t o f b y -p ro d u cts o b ta in e d in 2015 (T a b le 7).

7. Prediction o f total mass o f by-products o f some agricultural plants in Namdinh province in 2015 ntation Area (ha) Agricuỉtural aste Medium mass o f dry matter

(ton /ha)

Total mass o f dry matter (ton/year)

:e 165627,8 Stravv 48 7950134,4

Husk 14,7 2401603,1

n 6.000 Stem, leaves 63,6 382800

Core, husk 22,5 135000

inut 10.000 Stem, leaves 27,8 278000

SheUs 4,5 45000

Total 11192537,5

P ro p o se d p r ọ ịe c t o f u sin g B E te c h n o lo g y o f r o d u c ts /r o m rice, corn, p e a n u t

E nerg}’ v a lu e o f b y-p ro d u cís fr o m rice, leanut

ìcrg y /calo ry v alue vvill shovv the value o f p ro d u cin g o f b y-p ro d u cts. B ased o n the

a te p erc e n ta g e rece iv ed b y-pro du cts

■ an aly zed b y th e h eat o f th e bom b w ith 4 iles by th e co rre sp o n d in g rate:

Table 8. Energy/calory value o f by-products o f rice, com , peanut at bum ing pressure o f 3000 kPa

Analysis sample Com Peanut Husk Stravv

Dry mass before buming (gr) First time 1,0065 1,0220 1,0251 1,0243

Second time 1,0059 1,0198 1,0 212 1,0251

Third time 1,0071 1,0226 1,0236 1,0222

Energy/Calory First time 4102,5929 3875,1348 3955,8862 3851,9790

(Cal/gr) Second time 4096,7651 3863,2762 3927,6125 3866,5978

Third time 4113,3127 3891,0761 3964,7619 3832,7656

Medium 4104,2236 3876,4957 3949,4202 3850,4475

- C o rn : 2 5 % c o re a n d p eel + 75% stem and leaves;

- P ean u t: 15% Shell + 85% stem ; - H usk: 10 0 % h u sk ;

- R ic e s tra w : 3 5 % straw + 6 5 % root

T h e re su lts o f an a ly sis are p resented in T ab le 8.

Inaccu racy o f an a ly sis resu lts in table 8 is p ean u t) sh o w th a t to tal am o u n t o f carbon sig n iíĩca n t. R esu lts o f an aly sis and total o ccu p ied hig h r a te ( a b o u t 38,5% ). W hen bum ed .ìou nt o f c a rb o n o f b y -p ro d u cts (rice, co m , the m ain ly w a s te g a s w ill be C 0 2. T hus, to

L.D. H a i T .v . Q u y / V N U Ịournal o f Science, Earth Sàences 25 (2009) 76-83 81

c alcu la te the effect o f th e e n v iro n m c n t it is need to c a lcu la te and d e te rm in e th e m eth o d s o f te ch n o lo g y th at sig n ifican tly re d u c e th e am ount o f th is w aste gas.

- T h e sch em e o f íe c h ìio lo g y o f h e a t a n d eỉecíric g en era to r

T h e ag ricu ltu ral b y -p ro d u cts from rice, c o m , peanu t c an bc used as fuel in h eat-electric g en erato r acc o rd in g to th e sch em e as su gg estcd on Fig. 1, includes thc equipm ent: fum ace, boiler, tu rb in e, ele c tric g en erators, h eat ex ch a n g er, d ry ers and o th e r au x iliary p arts [2,5].

Fig. 1. The scheme o f ĩurnace system o f bed combustion o f heat and electric generator.

ỈVorking p r in c ip ỉe: W a te r is p ro v id ed to the boiler by pum p sy stem , fu el (h u s k , straw ) are loaded into b u rn in g fu m a c e . T h e bu m in g proccss in fu m a te c re a te s a h e a t sup ply for boiler an d pu ll lu rb in e to tu rn th e electric g en erato r to su p p ly th e povver to d ry e r (or husking). S ource gas (h e a t) fro m turbin e (second g as) is used fo r d ry in g agricultural products.

E stim aíed p o te n tk ứ ab ility to provicỉe electricity fr o m bioĩĩìass o f rice by-products: B ased on the d ata an aly sis o f h e a ư c a lo ry (T ab le 8), 1 ton o f h u sk b y -p ro d u cts g e n e ra te s 4 6 0 kW h o f electricity; 1 to n o f c o m b y -p ro d u c ts gen erates 4 7 7 k W h o f electricity ; 1 to n o f peanu t by- products g en era tes 4 5 0 k W h o f e le c tric ity ; 1 lon o f straw b y -p ro d u cts g e n e ra te s 4 4 7 kW h o f electricity.

Based o n th e d ata o f b y -p ro d u c ts collected in 2008 (T ab les 4 , 5 a n d 6) in N am d in h province th e re are a b o u t 1,040 m illio n to n s o f vvhich 0 ,7 5 0 m illio n to n s o f stravv; 0 ,2 3 0 to n s o f husk: 0 ,0 3 0 m illio n to n s o f stem , le a v e s o f co m ,

0,010 m illio n to n s o f core; 0,020 m illio n to n s o f stem an d leaves o f p ean u t; 0,0 0 3 m illio n to n s o f peanu t sh ells. I f th e vvhole o f th e se b y -p ro d u cts are used to be co n v erted into e lectric en erg y , it w ould g en erate: 4 4 7 X 0,75 X 106⁺ 4 6 0 X 0,23

X 106 + 4 7 7 X (0 ,0 3 + 0,0 1) X 106 + 4 5 0 X (0 ,0 2 + 0 ,0 0 3 ) X 106 » 4 66 X 10 k W h /year.

A n d acc ro d in g to calcu la tio n s o f actual perform ance o f th e eq u ip m en ts from th e start line to th e en d o f th e h eat-elec tric g e n e ra to r as p ro po sed (F ig. 1) 12%, w e can calcu late the total electrical en erg y o f u s in g th e w ho le vo lu m e o f b y -p ro d u cts c o lle c te d fro m rice, c o m , p ean u t on th e te rrito ry o f N am d in h prov in ce in 2 0 0 8 a p p ro x im ate ly is a b o u t 4 6 6 X

107 X 0 ,1 2 = 5 5 9 X 106 k W h/year.

S im ilarly , o n e c an g et th e to tal electric energy from b y -p ro d u cts o f rice, c o m , p ean u t estim ated in 2 0 1 5 i f th ey are u sed as fu el for p ro d u cin g e le c tric ity -h e a t is a b o u t 6 0 6 X 106 kW h. W h ile th e to tal p o w er co n su m p tio n o f N am d in h p ro v in c e in 2008 is 587 X 106 kW h.

- C h o o sin g th e b u r n in g /u m a c e

82 L.D. Hai,

T.v.

P ractically th ere are g en era lly 4 ty p es o f b u m in g íu m a c e o f b y -p ro d u cts such as basic íìx ed fu m ace, m oveable fu m ace, boiling fu m a c e o f bed co m b u stio n , tu m in g fum ace.

B u m in g íu m a c e is ch o sen as FBC (F ludized

bed C o m b u stio n ) have m o re ad v an tag es than th e o th er fu m ac e: high b u m in g stren g th , stabilily, lo w rem a in in g o f vo lu m e c a c b o n in ash ; it can burn th e fu els w ith m o istu re, high

level ash , an d lo w h eaư calo ry (F ig. 2).

1. Input scction 2. Ravv materia! screw 3. Fumacc fan 4. Adjustment valve 5. Combustion section 6. Dust collcctor 7. Heat cxchangcr 8. Cyclone 9. Exhaust fan

Fig. 2. The scheme o f structure o f FBC.

F u el is b u m ed in co m b u stio n section 5.

U sin g h ig h -p ressu re fan 3 and ex h au st fan 9 m a k es th e pressure ch an g e in fu m ace and e n su re s p rop er sand b o ilin g as required.

E lem en tary and seco n d ary air line to keep the b u m in g p ro cess is pro vided b y high pressure fan 3 . E lem entary line is p ro v id ed th ro u g h the sp ray pipe. S econd lin e is ab o ve th e level o f san d su ríace to p rovid e m o re o x y g en to help fuel b u m better. A sh is settled in d u st co llector 6, th e fu m a c e g ases co m e into h eat exchanger, tra n s fe r heat to the air íb rm in g th e d ry in g te m p eratu re o r su p p ly heat to boiler.

B y -p ro d u cts has been b u m e d co m p lete ly in F B C fu m a c e , m ainly gas vvaste is C 0 2, th e re is o n ly a iittle am o u n t o f S Ơ2 gas (T ab le 9).

Table 9. The amount o f waste gases vvhile buming rice by-products and coaỉ [3]

Waste gases (kg/ton) Husk Straw Coal

C 0 2 4 0 - 8 2 3 0 - 7 7 200 - 220

S 0 2 0 ,5 - 1,5 0 ,3 - 1,8 2 8 - 3 0

NO, - - 9 - 1 1

4. C o n c lu sio n s

- In th e re c e n t y ears in N am d in h p rov in ce, so u rces o f b y - p r o d u c t s from rice, c o m , and pean ut w ere a b o u t 1,040 m illio n to n s (in 2008) o f w hich 0 ,7 50 m illion to n s o f straw ; 0,230 m illion to n s o f husk; 0,030 m illion to n s o f stem , leaves o f c o m , 0,010 m illio n to n s o f core;

0,020 m illio n to n s o f stem an d leaves o f peanut;

0,003 m illio n to n s o f p ean u t sh ells bu t until n o w th ey have n o l been co llected an d used effectively . P o ten tial electricity en erg y o f N am D inh p ro v in ce from th is bio m ass source av erag e in o n e y e a r (2 0 0 8 ) generated ap p ro x im ately 55 9 X 106 kW h.

- E stim atin g in 20 1 5 , total m a ss o f by- p ro d u cts from ric e , c o m , p ean u t in th e w hole p ro vince is a b o u t 1,130 m iỉlio n to n s o f vvhich a b o u t 0,800 to n s o f stra\v; 0 ,2 4 0 m illio n husk;

0,040 m illion to n s o f stem an d leaves o f com ; 0,015 m illio n to n s o f co re c o m ; 0 ,0 3 0 m illion

L.D. Hai, T .v . Q uỵ / V N U Ịournal o f Science, Earth Sciences 25 (2009) 76-83 83

to n s o f stem and leav es o f p eanut; and 0,005 m illio n to n s o f p ean u t sh ells. Potential e lectricity en erg y from bio m ass so urce in 2015 is a p p r o x i m a t e l y 6 0 6 X 1 0 6 k W h .

- C om p arin g to co al furnace, a fte r using seco n d ary ag ricu ltu ral P ro d u cts as fuel for the FBC it can reduce the a m o u n t o f C 02 into 3-6 tim es and S 02 into 18-20 tim es. T h is is a great a b ility to ap ply th e sy stem o f C lean d ev elo p m en t m ech anism (C D M ) u n d er the

K yoto Protocol.

- A sh afte r being b u rn ed in íu m a c e w ith bed co m b u stio n o f high c o n te n t o f S i 02 can be used as ad d itiv e for in du strial p rod uction o f cem ent and b u ld in g m aterials.

- T h e use o f s e c o n d a r y rice P ro du cts as fuel for h eat and electricity g e n e ra to r m ean s a lot for en v iro n m en t and local eco n o m ic sociaty:

co n trib u te the reso lv e o f w aste fu el from the biom ass; red u ce w astes cau seđ env iron m ental pollution; resolv e em p lo y m en t problem for people; increase incom e from th e co llectio n and sale o f th e se b y-products.

A c k n o w le d g e m e n ts

T his w o rk is sup po rted by a g ra n t o f the V N U -H an o i w ith in the research program Q G .08.17. T h e au th o rs vvould like to th a n k o f th at v alu ab le funding.

R e fe re n c e s

[1] Annuaỉ staíistic 2008 o f Namdinh province, Statistics, 2009.

[2] Chu V an Thien, Investigation o f Ị lu d ìie d b ed com bustion íechnology o f agriculturaỉ \vastes p ro vid ed energy to the process o f drying agricuturaỉ production a n d receiving cementy 8/2006.

[3] Tania Urmee, David Harries, Rene\vable Energy b a sed R uraỉ E ỉectrification Program s in D eveloping Countries: L esso n s a n d Perspectivesy Sustainable Energy and Envimment, Volume 2 o f proceedings 2006, Thaiỉand, 8/2006.

[4] Tran Van Quy, Ho Thi Phuong, Potential evaluation study and application method for biomass energy from rice by-products in Namdinh province, Journal o f Science, VNU 24, No. 1S (2008) 151 - 155.