Biomass Technology in Ghana

8/2/2019 Biomass Technology in Ghana

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B I O M A S S T E C H N O L O G I E S IN G H A N AS e f a - B o n s u A t a k o r a

K u m a s i I n s ti tu t e o f T e c h n o l o g y a n d E n v i r o n m e n t (K I T E )4 th F l o o r S S N I T B u i l d i n g A n n e x , H a r p e r R o a d , A d m n , K u m a s i - G h a n a .P . O . B o x 6 5 3 4 K u m a s i , G h a n a .T e l / F a x : + 2 3 3 - 5 1 - 3 3 8 2 4 E - M a i l : k i t e @ g h a n a . c o m

A B S T R A C TB i o m a s s e n e r g y a c c o u n t s f o r 3 5 % o f t h e d e v e lo p i n g w o r l d ' s t o t a l en e r g yc o n s u m p t i o n a n d 7 5 % o f a ll p e o p l e i n t h is r e g i o n d e p e n d o n it . I n S u b - S a h a r a nA f r i ca , b i o m a s s c o n s t i t u t e s 7 3 % o f t h e t o t a l e n e r g y c o n s u m p t i o n a n d i n G h a n a , 7 0 %o f t h e t o t a l n a t i o n a l e n e r g y c o n s u m p t i o n is a c c o u n t e d f o r b y b io m a s s . B i o m a s s e n d -u s e p r o d u c t s f o r e n e r g y i n G h a n a a r e m a i n l y f u e l w o o d a n d c h a r c o a l. T h i s p a p e r d o e sa n a s s e s s m e n t o f t h e b i o m a s s e n e r g y r e s o u r c e s a n d g o e s o n t o l o o k a t t h e d i f fe r e ntc o n v e r s i o n t e c h n o l o g i e s i n t h e c o u n t r y . A r e v i e w o f t h e m a n y s t u d ie s a n d p r o j e c t s o nb i o m a s s i n it i at e d t o d a t e i n G h a n a i s d o n e a n d a n a t t e m p t m a d e a t e v a l u a t in g e a c h o ft h e m t o v e r i fy t h e v i a b il i ty a n d e n v i r o n m e n t a l i m p a c t s a s w e l l a s a s s e s s t h e r e a s o n sf o r s u c c e s s o r f a il u re o f t h e p r o j e c t s a n d t e c h n o l o g i e s . S e v e n m a i n t e c h n o l o g i e scove r ing a l l p ro jec t s a r e co ns ide red and r ev iew ed . T he m a in ba r r ie r s inhib i tinge f fe c t iv e d is s e m i n a t i o n o f re n e w a b l e e n e r g y t e c h n o l o g i e s ( R E T s ) a r e f o u n d t o i n c lu d ep o o r m a n a g e m e n t o f p r o j e c t s , l a c k o f n e c e s s a r y f i na n c ia l i n ce n t iv e s , f la w s i nf e as i b il it y a s s e ss m e n t , h i g h i n it ia l c o s t s o f r e n e w a b l e e n e r g y p r o d u c t s a n d p o o rm a r k e t i n g a n d a w a r e n e s s p r o g r a m s . I t is re c o m m e n d e d a t th e e n d t o d o a m o r ed e t a il e d an a l ys i s o f s o m e o f th e t e c h n o l o g i e s t h a t a r e k n o w n t o h a v e b e e n q u i t es u c c e ss f u l in o r d e r t o g e t t h e m t h o r o u g h l y a s s e ss e d a n d l e a r n f r o m t h e i r e x p e ri e n ce s .Keywords: B i o m a s s , R e n e w a b l e , E n e r g y , T e c h n o l o g i e s , R e s o u r c e s .

I N T R O D U C T I O NB i o m a s s ( a b b r e v i a ti o n f o r b i o l o g i c a l m a s s ) i s a n y o r g a n i c m a t t e r p r o d u c e d b y p l a n t sbo th t e r r e s t r ia l and aqua t i c . I n f ac t a l l f ue l ene rgy d e r ived d i r ec t ly o r ind i r ect ly f romb i o l o g i c a l s o u r c e s i s t e r m e d ' b i o m a s s e n e r g y ' a n d i s m a i n l y c o m p o s e d o f w o o d , c r o pres idues and dung as w e l l a s the i r de r iva t ives l ike b iogas an d b r ique tt e s . B iom ass i sn o r m a l l y c o n s id e r e d a s a f o r m o f s o l a r e n e r g y a s t h e l a t te r i s u s e d i n a n i n d i re c t w a yt o g r o w p l a n t s t h r o u g h p h o t o s y n t h e s i s .I n G h a n a b i o m a s s i s t h e m o s t d o m i n a n t s o u r c e o f e n e r g y a n d i s u se d s i gn i fi c an t ly i nt h e d o m e s t i c s e c t o r f o r c o o k i n g a n d m a n y o t h e r h e a t a p p l ic a t io n s . W o o d f u e ls , i n t h ef o r m o f fo r es t w o o d , c h a r c o a l a n d w o o d p r o c e ss i n g re s id u e s a r e t h e m o s t d o m i n a n tb i o m a s s f o rm s o f e n e r g y i n u s e i n G h a n a a l t h o u g h c r o p r e s id u e a n d o t h e r n o n - w o o d ym a t e r i al s a l so f in d s o m e u s a g e . M o s t r u r a l d w e l l e rs ( a b o u t 7 0 % o f p e o p l e i n G h a n a )a n d a l m o s t a l l f a rm e r s h e a v i l y d e p e n d o n f u e l w o o d f o r a ll t h e i r d o m e s t i c a n d o t h e rc o m m e r c i a l a c t iv i ti e s t h a t r e q u i r e h e a t . U s e o f b i o m a s s i n m a n y c o m m e r c ia l a n din s t i tu t iona l e s t ab l i shmen t s a l l ov e r the cou n t ry i s a l so a case in po in t w or th y o f


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m e n t i o n . A b o u t 7 0 % o f t h e t o t a l n a t i o n a l e n e r g y c o n s u m p t i o n i s a c c o u n t e d f o r b yb i o m a s s i n e i th e r t h e d i r e c t o r p r o c e s s e d f o r m [ K I T E , 1 9 99 ].T h e a g r i cu l t u ra l a n d t h e f o r e s t p r o d u c t s e c t o r s i n G h a n a a r e m a j o r f o r e ig n ex c h a n g ee a r n e rs f o r t h e c o u n t r y . T h e c o n t r i b u t i o n o f a g r i c u lt u r e t o G h a n a ' s G D P i s c u r r e n t l yr a ted a t ab ou t 40% (1998 f igu re ) and th i s i s a dec l ine f rom 42 .6% in 1992 . The c rop sg r o w n i n c lu d e s u c h c a s h c r o p s a s c o c o a , c a s h e w n u t s , p a l m n u t s a n d s e a s o n a l c r o p sl ike r i ce, ma ize an d o the r s , w h ich y ie ld a lo t o f r e s idue . I n r ecen t yea r s abou t onem i l l i o n c u b i c m e t e r s ( 1 , 0 0 0 , 0 0 0 m 3) o f l o g s h a v e b e e n h a r v e s t e d i n t h e c o u n t r yannua l ly fo r the w oo d p roces s ing indu s t ry a lone . The logg ing ac tiv i ti e s y ie ld a lo t o fr e s id u e s w h i c h a r e u s e d a t v a r y i n g e ff ic i e n ci e s f o r e n e r g y p u r p o s e s [ A t a k o r a , B r e w -H a m m o n d , 1 9 9 9 ] .A l s o a v a i la b l e i n t h e c o u n t r y a re c o n s i d e r a b le a m o u n t s o f n o n - w o o d y b io m a s s i n th ef o r m o f a n i m a l a n d h u m a n w a s t e . L i v e s t o c k r e a r i n g i s a m a j o r a c ti v i ty i n s o m e p a r t so f t h e c o u n t r y e s p e c i a ll y t h e n o r t h a n d t h e n u m b e r o f h e a d o f ca t tl e , s h e ep , g o a t s , p i g sa n d o t h e r a n i m a l s is q u i te s u b s t a n ti a l. T h e w a s t e p r o d u c e d i s e n o r m o u s a n d t h e r e h a v eb e e n a n u m b e r o f p r o je c t s a n d s t u d ie s a i m e d a t i m p r o v e d b i o g a s t e c h n o l o g i e s i n t h ec o u n t r y .

R E S O U R C E A S S E S S M E N TF o r e st R e s o u r ce s A n d L o g g i n g R e s i d u e s

T h e f o r e s t r e s o u r c e s i n G h a n a a r e c a t e g o r i s e d i n t o t h e o p e n ( s a v a n n a ) a n d t h e c l o s e d( h i g h f o r e s t) z o n e s . T h e f o r m e r m a d e u p o f t h e w h o l e o f th e t w o u p p e r r e g io n s , t h en o r t h e r n r e g i o n , m o s t o f t h e B r o n g A h a f o a n d t h e V o l t a r e g io n s c o v e r s a n e s ti m a t e dt o t a l a r e a o f 9 .6 m i l l io n h e c t a r e s ( h a ) o f w h i c h 2 . 9 m i l li o n h a i s b u s h f a ll o w [ N k e t i a ,1992 ] . The r ema ind e r i s deg rad ed savanna .T h e c l o s e d f o r e s t z o n e c o v e r s a l it tl e m o r e t h a n a t h i r d o f t h e c o u n t r y ' s t o t a l la n d a r e aa n d h a s a s iz e o f a b o u t 8 .2 m i l l i o n h a . , 2 0 % o f w h i c h i s re s e r v e d e i t h e r a s f o r e s tr e se rves o r fu e lw ood p lan ta t io ns [Nke t i a , 1992 ] . A l to ge the r fo r es t r e se rves in thec o u n t r y c o v e r a b o u t 2 . 4 7 m i l l i o n h a . w h i c h is a b o u t 1 0 . 5 % o f t h e t o t a l l a n d ar e a. T h er e s e rv e s a r e c a t e g o r i s e d i n to p r o d u c t i o n r e s e r v e s ( c o v e r i n g 1 2 , 1 05 k m 2) an dp ro tec t ive r e se rves ( cove r ing 12 ,604 km2). Th e fo rm er a r e m anage d fo r su s ta inab lep r o d u c t i o n o f t i m b e r a n d n o n - t i m b e r f o r es t p r o d u c t s a n d t h e l a t t e r a r e m a n a g e d s o l e l yf o r e n v i r o n m e n t a l p r o t e c t i o n a n d a r e t h u s c l o s e d t o t i m b e r e x p l o it a ti o n .T h e m e r c h a n t a b l e w o o d m a t e r i a l e x tr a c t e d f r o m l o g g i n g a c ti v it ie s f r o m t h e f o r e s t i sp r inc ipa l ly the f a i r ly s t r a igh t , sou nd bo le vo lum e pa r t o f the t r ee w h ich is abou t 49 .6 %o f t h e t o t a l t r e e v o l u m e . A l l o t h e r p a r t s o f t h e p l a n t s u c h a s t h e s t u m p , b u t t- e n d o f f -c u t , c r o w n - e n d o f f - c u ts a n d b r a n c h w o o d a r e c o n s i d e r e d a s l o g g in g w a s t e s a n d t r e a t e da s s u c h . I n 1 9 9 0 a n e s t im a t e d 6 8 8 , 2 6 2 t o n s o f r e s i d u e w a s g e n e r a t e d f r o m lo g g i n gac t iv i ti e s a lone . These r e s idues a r e u sed on r a r e occa s ions fo r fue l w oo d ( logg inga r e a s a l w a y s h a v e a b u n d a n t f u e l w o o d r e s o u r c e s ) , a n d c h a r c o a l p r o d u c t i o n ( s p ec i e s f o rmi l l ing a r e no t p r e f e r r ed by cha rcoa le r s ) . The logg ing r e s idues a r e som et imes u sed fo rp a r t ic l e b o a r d a n d f i b re b o a r d p r o d u c t i o n a n d s o m e t i m e s a s r a w m a t e r i a l f o r th es e c o n d a r y m a n u f a c t u r e o f s m a l l d i m e n s i o n p r o d u c t s l ik e f l oo r in g , t o o l h a n d l es , c r a t e s


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and pa l le t s . A l l in a ll on l y a ve ry sm a l l pe r c en tag e o f logg ing re s idues f ind any m a jo ruse a t a l l.C o n v e r s i o n o f w o o d y b i o m a s s t o c h a r c o a l is g o o d b u s in e s s f or m a n y p e o p l e ( a b o u t5 5 , 0 0 0 ) i n G h a n a [ N k e t ia , 1 9 9 2] . C h a r c o a l p la y s a n i m p o r t a n t r o l e i n t h e n a t i o n a le c o n o m y an d a c c o u n t s fo r a b o u t 3 % o f t h e G r o s s N a t i o n a l P r o d u c t [ N k e t ia , 1 9 9 2 ].S t a t is t ic s i n d i c a te t h a t a b o u t 4 . 8 m i l li o n m 3 o f r o u n d w o o d i s c o n v e r t e d to c h a r c o a lw i t h a c o r r e s p o n d i n g l o g g i n g r e s id u e g e n e r a t i o n fr o m c h a r c o a l p r o d u c t i o n o f a b o u t1 .36 mi l l ion m 3 each yea r .W ood Processing , Res idu esT h e t i m b e r i n d u s t ry i n G h a n a h a s s e e n a d r a s t i c c h a n g e f r o m a n a l l e x p o r t t r a d e o ff e w p r e f e r r e d r o u n d l o g s ( w h i c h d e p l e t e d o u r f o r e s t o f m o s t o f t h e p r i m e s p e c i es ) i nt h e e a r li e r y e a r s t o a n i n t en s i v e w o o d p r o c e s s i n g a c t i v i ty r e s u lt in g i n e x p o r t o f l u m b e ra n d v e n e e r i n r e c e n t y e a r s . L o g p r o d u c t i o n i n G h a n a i n 1 9 90 w a s 1 .3 6 m i l l io n m 3 a n dt h o u g h p l a nt m a n a g e r s c o m p l a in o f s c a rc i ty o f w o o d / t i m b e r r e s o u rc e s o v e r t h ed e c a d e , a n o v e r v i e w o f t h e w o o d p r o c e s s i n g i n d u s t ry re v e a l s t h a t t h e s p r in g i ng u p o fn e w e r f ir m s i n t h e c o u n t r y m i g h t b e p a r t l y re s p o n s i b le f o r t h e d w i n d li n g p r o d u c t i o n i ni n d iv i d u a l f ir m s . T h e r e m o v a l o f 1 .4 m i l l i o n m ~ o f t im b e r e v e r y y e a r a c c o r d i n g t o as t u d y b y t h e F o r e s t r y R e s e a r c h I n s t i tu t e i n 1 9 92 c a n b e e x p e c t e d f o r a n i n d e f in i tep e r i o d b a s e d o n a f e l li n g c y c l e i n e x c e s s o f 6 0 y e a r s . T h e u s e a n d p r o l if ic g r o w t h o fo t h e r s e c o n d a r y a n d l es s p r e fe r r e d s p e c i e s i n t h e t i m b e r i n d u s t r y t o m a i n t a inp r o d u c t i o n l e v e ls is a l so w o r t h m e n t i o n i n g .T h e r e i s a r e c o m m e n d e d a n n u a l a l l o w a b l e c u t (A A C ) o f ti m b e r f r o m G h a n a i a n f o r e s tsfo r bo th exp o r t a nd d om es t i c co nsum pt ion , w h ich i s abou t 1 .0 x 106 m 3. Th i s f igu red o e s n o t i n c l u d e t h e v a s t a m o u n t o f w o o d l e ft in t h e f o r e s t a s b ra n c h e s , st u m p ,d e f e c t iv e l o g a n d f a ll e n p a r t s o f s t a n d i n g tr e e s . F o r e s t P r o d u c t s I n s p e c t i o n B u r e a u ,( F P I B ) r e p o r t e d i n 1 99 3 t h a t o u t o f 8 0 5 , 6 6 5 m 3 o f l o g e q u i v a le n t p r o c e s se d ,5 1 7 , 8 4 5 m 3 w e n t t o w a s t e r e p r e s e n t i n g s o m e 5 1 . 8 % o f t h e a n n u a l a ll o w a b l e c u t.A c c o r d in g to a U N D P / W O R L D B A N K E n e r g y S e c to r M a n a g e m e n t A s s is ta n ceP r o j e c t o n S a w m i ll R e s i d u e U t i l i s a ti o n i n 1 9 8 8 , s o l i d s a c c o u n t f o r 7 9 % w h i l sts a w d u s t a c c o u n t s f o r 2 1 % o f r e s i d u e s p ro d u c e d . M o r e t h a n h a l f o f th e i n d u s tr ia l w o o dres idue i s u sed o f f -s i te . O f the r e s idue u s ed o f f - s it e , abo u t 28 % i s u sed d i r ec t ly a sf i re w o o d f o r f o o d p r e p a r a t i o n a n d a b o u t 7 0 % c o n v e r t e d t o c h a rc o a l in e a rt h m o u n dk i ln s. Th e ba rk , w oo d o f f - cu t s , s labs and ed g ings a r e c ons ide red a s a f r ee fue l and inm o s t e a s e s h a v e a n o p p o r t u n i t y c o s t a n d a r e s o l d a s d o m e s t i c o r i n d u s tr ia l f u el o r a sc o n s t r u c t i o n m a t e r ia l . I n c o n t r a s t , s a w d u s t a n d s h a v in g s g e n e r a te d a s a b y - p r o d u c t i nc o n s i d e r a b l e a m o u n t s a r e u s u a l l y c o n s i d e r e d a w a s t e m a t e r i a l a n d p o s e a d i s p o s a lp r o b l e m a n d c a n c o n s t i t u t e f ir e h a za r d s . T h e y o f t e n h a v e a n e g a t i v e v a lu e a s r e s o u rc e sa r e e m p l o y e d t o b u r n t h e m a t e r ia l o n s i t e o r t r a n s p o r t f o r d i sp o s a l e l se w h e r e . T h ec o m m o n m e t h o d o f d is p o s a l b y b u r n i n g c a u s e s a g r e a t d e a l o f p o l l u t i o n a n d i s am e n a c e t o t h e g e n e r a l p u b li c .A g r i c u lt u r a l R e s id u e A n d O t h e r W a s t esA g r i c u l t u r e is th e b a c k b o n e o f e c o n o m i c a n d s o c i a l d e v e l o p m e n t in G h a n a a n d t h i ss e c t o r p r o v i d e s e m p l o y m e n t f o r a l a r g e p e r c e n t a g e o f th e p o p u l a t i o n . A l l k i n d s o f


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t rop ica l c rops are in cu l tiva t ion an d res idues such as m aize cobs , r ice husks , pa lmbranches , shell s and nut a re m ajor po ten t ia l fue l used in many par t s o f the count ry .Th ey are n ormal ly pop ular fue ls tha t burn rap id ly and w el l and are usual ly used inre la tive ly smal l quant it ies to supplement or augm ent ign it ion w hen the main fue l i sfores t w oo d o r charcoal. T here are ma ny ins tances where the y are used exclus ive ly forheat ing purposes such as in t radi t ional palm oi l processing, f ish smoking, small scalesmel t ing and palm kernel o il p rocess ing . Table 1 be low show s the product ion o f somem ajor crop s and the i r res idue in G han a in 1990.

Table 1 : Prod uct ion o f Som e Ma jor A gricu l tura l Residues in Ghana.C r o p

M a i z e

Res idue

C ob

ResidueProduc t ion( t / t c rop)1.00

Tota l CropProduc t ion'000 tonnes553

ResidueProduct ion'000 tonnes553O il Pa lm Shells 0 .45 429 193

Pad dy Rice Hu sk 0 .23 81 19So rghu m Sta lk 1 .00 136 136M illet Stalk 2.00 75 150G roundn ut Shel l 0 .5 113 56T o t a l

Source : Le tus Pow er P lan t, Hagan , 1997.1,387 1,107

An o the r fo rm o f ene rgy tha t can be de r ived f rom ag r icu l tu ra l was t e i n t he fo rm o fanimal (and human) w aste i s b iogas . Biog as i s the produ ct (main ly methane) o f thebio logica l ac t ion o f cer ta in bacter ia on organic m at ter such as dung . T he resu l tingcombu st ib le g aseous prod uct c ould be used l ike L PG in s toves for cooking , gas lampsfor l igh ting and be used to p rovide m ot ive po w er fo r wate r pumping and gra in mi llingapplicat ions.

I M P L E M E N T E D P R O J E C T S A N D S T U D IE S

The ove r -dependence o f ma jo r it y o f the popu la t ion on cha rcoa l and fuelwood asenerg y sources h as brough t in it s w ak e the threa t o f defores ta t ion and deser t i fica tionin many pa r t s o f t he coun t ry . W i th w oodfue l s re spons ibl e fo r ove r 70% o f theco un t ry 's en ergy deman d [M O M E, 1998 A nnual Rep ort ] , the sus ta inabili ty o f th isb iomass re sou rce i s h igh on the agen da o f a ll and sundry . The number o f p ro j ec t s andstudies in the co unt ry tha t a re a imed a t de termining effec t ive technologies and cos teffec t ive so lu tions to ensure be t te r u t i l isa t ion o f th is resourc e are many.M any o f the p ro j ec t s imp lemen ted gave go od re su lt s bu t su f fered f rom a lo t o fse tbacks an d had to be su spended or ha l ted a long the pro jec t li fe . Som e of thesese tbacks h ave been addres sed an d there are curren t ly a lo t o f pro jec ts a t leas t in thepi lo t phase tha t a re be ing wel l m anag ed and have som e promis ing fu ture . TheRenew ab le E nergy D eve lopmen t Un i t unde r t he M in is t ry o f M ines and Energy aloneunder took t en (10 ) p ro j ec ts under B iom ass and So la r /W ind Energy p rog ramm es in1998.


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U nfortunate ly m any of the pro jec ts ( those a l ready implem ented as wel l as thoseunderw ay) a re no t rea lly docum en ted and in fo rma t ion had to be sough t f rom someinformants o f the indiv idual pro jec ts for the prepara t ion o f th is report . W heredocum enta t ion ex is t s, a qu ick rev iew is done and evaluat ion of the pro jec t done b yin te rv iew w i th some re sou rce pe rsons f rom the p ro j ec t . T he m a in b iomasstechnologies and s tud ies are d iscussed below.Pyrolysis TechnologyTo dem onst ra te pyro lys is ( the therm al convers ion o f organic mater ia ls in the absenceo f a ir to produc e charcoa l and gases) as a feasible m eans o f provid ing a l te rna tive fue lsin G hana and o ther developing count r ies , a pyro ly t ic p lan t w as se t up in Ku ma si in1980. The feasib il ity s tudy fo r the p lan t w as jo in t ly cond ucted by personnel f rom theBu i ld ing and R oad Resea rch In s t i tu t e (BR RI) , G hana , The Techno logy andConsu l t ancy Cen t re (TC C) o f t he Un ive rs i ty o f Sc i ence and Techno logy, Ghana andG eorg ia In s t it u te o f Techno logy (GIT ) in the U SA . G IT had a l ready done som e initia lw ork o n Py ro lys is and the BR RI m ade a reques t t o t he US A ID fo r a s si st ance to se t upth is p lan t as par t o f the re search and developm ent effor t to f ind a l te rna tive fue l o i l fo rbric k kilns.The bas ic des ign w as provided by G IT and a pro to type py ro ly t ic reac tor tha t i s fed onsaw dust an d wo od shavings w as fabr ica ted by the v is iting and o ther personnel f romBR RI and TC C. Al l i tems w i th the excep t ion o f gas b lowers , measu r ing in s trumen tsand an e lec t r ic t ransform er w ere fabr ica ted local ly . Som e m odif ica t ion wa s done tothe or ig ina l des ign and fo ur pyro ly t ic reac tors and anci l la ry equipment w as produced ,ins ta l led and com miss ioned by the team in 1980.The demon s t ra tion p l an t was s it ed nea r t he B RR I w i th the p r imary a im o f p rov id ingal ternat ive fuel oi l for a brick ki ln . The pro du cts o f the pyrolyt ic plant - oil ,combus t ib l e gases and powd ered c ha rc oa l - a re good subs t it u te s fo r w ood as domes t i cand indust ria l fue l and w ere in tended to hav e been used as such .The des ign capaci ty o f the p lan t was s ix- tonne sa wd ust per 3 - sh if t day wi thpow der ed charcoal and o il y ie lds of 25% and 18% respect ive ly . The p lan t in prac t icey ie lded 6% to 13% depending o n the m ois ture conten t o f the feed and how eff ic ien tlythe reac tor tempera ture was cont ro l led [Hagan , 1985] . The demonst ra t ion p lan t wasnot v ery successfu l and the p lan t w as f ina lly been shut down .Problem s en countered inc luded po or supply cycle o f ra w m ater ia l s , ineff ic ien t d ry ingof saw dus t and manua l p rocess con t ro l l ead ing to l ow y ie ld s. Lac k o f funds fo r ma jo rrepai rs and mo dif ica t ion w as a l so a major problem. A wel l p lanned manag ement teaminvolv ing the organised p ar t ic ipa t ion o f po ten t ia l comm ercia l users wi th a goodtechnica l sup port w as see n as the so lu t ion to ach iev ing a s e l f sus ta in ing p lan t wh ichcou ld g ive a payback o f abou t t h ree yea rs .Improved Cook stoves TechnologyThere have been m any a t tempts to in fi lt rate the G hanaian mark et w i th var ious des ignso f improved cooks toves and d i ssemina te t he t echno logy in Ghana . Des ign o fcooks toves depends on the fo rm o f b iomass p rov id ing the ene rgy . Fue ls wi th


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i m p r o v e d d e s i g n s o f c o o k s t o v e s o f a r in c l u d e f i re w o o d , c h a r c o a l a n d s a w d u s t. T h e r ea re d i f f e r ences be tw een s toves u se d in the ru r a l , u rban and in s t i tu t ions o r com me rc ia lv e n t u re s . U s e o f f i re w o o d i s p r e d o m i n a n t i n t h e r u r a l a r e a s a n d a s o n e t ra v e l s in t o t h eu rban a r eas the re i s a sh i f t t o cha rcoa l .S t o v e s i n u s e i n ru r a l ar e a s a r e n o r m a l l y a d a p t a b l e t o u s i n g m o r e t h a n o n e f o r m o fb i o m a s s s u c h a s w o o d a n d a g r i c u lt u r a l w a s t e s. F i r e w o o d i s u s e d w i d e ly in t h e r u ra la r ea s . T h e t r a d i t i o n a l f i r e w o o d s t o v e i s n o r m a l l y a t n o c o s t t o t h e u s e r a n d t h e r e a r e alo t o f ine f f ic i enc ie s . On e s tove f it s any s i ze o f po t a nd the in tens i ty o f the f i r ec o n t r o l l e d b y a d d in g o r r e m o v i n g f u e l f r o m t h e s t o v e. T h e f u e l i s n o r m a l l y n o t b o u g h tb u t c o l l e c t e d fr e e o f c h a r g e f r o m t h e f o r e s t o r f a rm s . U r b a n s t o v e s a r e n o r m a l lys ing le -fue l dev ices . Ch arco a l is a ve r y imp or tan t f ue l f o r u rban a r eas and i s no rm a l lyp u r c h a s e d r a t h e r t h a n c o l l e c t e d . C h a r c o a l i s t h e p r e d o m i n a n t d o m e s t i c f u el fo r 6 9 % o fu r b a n h o u s e h o l d s i n G h a n a [ N k e t i a e t . a l. , 1 9 8 8 ].C o o k s t o v e d e s i g n s i n G h a n a t o d a t e a r e n o r m a l l y t a r g e t e d a t u r b a n d w e l le r s. T h i s h a sp r o b a b l y b e e n d u e t o t h e h i g h e r i n c o m e l e v e ls o f th i s g r o u p o f p e o p l e a n d t h e f a ct t h a tt h e y a r e a l r e a d y b u y i n g i n e ff i ci e n t c o o k s t o v e s . I m p r o v e d c h a r c o a l s t o v e s a re t h e m o s tw i d e l y d i s s e m i n a te d c o o k s t o v e t e c h n o l o g y . S a w d u s t s t o v e d e s i g n s a re a l s o f in d i ngt h e i r w a y i n t o t h e G h a n a i a n m a r k e t a l t h o u g h t h e r e a r e s o m e f e w p r o b l e m s t h a t w o u l dn e e d t o b e a d d r e s s e d . V e r y l i t tl e h a s b e e n d o n e o n i m p r o v e d c o o k s t o v e s f u e ll e d o nf i r e w o o d .I m p r o v e d C h a r c o a l S t o ve sI m p r o v e d c h a r c o a l s t o v e s a r e h i g h e f f ic i e n c y s t o v e s t h a t s a v e s f u e l a n d m o n e y a s h e a tt o b e l o s t i s m i n im i s e d b y s o m e f o r m o f in s u la t io n . T h e M i n i s tr y o f M i n e s a n d E n e r g yi n t h e i r q u e s t t o p r o m o t e t h e u s e o f a m o r e e f fi c ie n t c o o k s t o v e d e v e l o p e d t h e" A h i b e n s o " i m p r o v e d c h a r c o a l s t o v e i n 1 9 8 9 . I t h a s s a v in g s o f a b o u t 3 5 % - 4 0 % o fc h a r c o a l o v e r t h e t r a d i ti o n a l c o a l p o t , h a s a n e f f i c ie n c y o f 3 9 % a n d a p a y b a c k p e r i o do f 6 m o n t h s . D i s s e m i n a t i o n o f t h e s t o v e s t a r t e d i n 1 9 9 2 a n d m o r e t h a n 3 0 , 0 0 0 p i e c e so f s t o v e a r e k n o w n t o h a v e b e e n d e v e l o p e d a n d s o l d b y l o c a l a r ti s a n s t o r e s id e n t s o fA c c r a a n d t h e o t h e r r e g i o n a l c a p i t a ls [ M O M E , A n n u a l r e p o r t , 1 9 98 ].T h e U n i v e r s i t y o f S c i e n c e a n d T e c h n o l o g y i s a l so k n o w n t o h a v e a f e w d e s i g n s o fi m p r o v e d c o o k s t o v e s f u e l le d o n c h a r c o a l , f ir e w o o d o r s a w d u s t . M a n y o f t h e s e d e si g n sa r e f r o m s t u d e n t p r o j e c t s a n d w e r e n o t c o m m e r c ia l is e d . T h e M e c h a n i c a l E n g i n e e r in gD e p a r t m e n t h a s p e r f o rm e d m a n y te s t s o n M O M E ' s c o o k s t o v e s t o v e r if y t h ee f f i c ienc ie s am ong o the r th ings .S a w d u s t C o o k s t o v e sT h e A g r i c u lt u ra l E n g i n e e ri n g D e p a r t m e n t i s k n o w n t o h a v e d e v e l o p e d o n c o m m e r c i a lb a s is t w o d e s i g n s o f s a w d u s t s t o v es . O n e d e s i g n is fu e l le d o n o n l y s a w d u s t a n d u s e df o r d o m e s t i c c o o k i n g a n d w a t e r h e a t i n g . T h e r e i s a m o d i f i e d d e s i g n o n t h is th a t h a s aw a t e r h e a t i n g t a n k c o m p o n e n t s u c h t h a t a g o o d p e r c e n t a g e o f t h e e x c e s s h ea t t h a t i s t ob e l o s t i s r e c a p t u r e d a n d u s e d t o h e a t w a t e r i n t h e t a n k . T h e o t h e r d e s i g n c a n b ef u e ll e d o n b o t h s a w d u s t a n d c h a r c o a l d e p e n d i n g o n t h e h e a t r e q u i re m e n t .S a w d u s t s t o v e d e s i g n b y t h e A g r i c u l t u r a l E n g i n e e r i n g D e p a r t m e n t s t a r t ed i n 1 98 3 a n dt h e t e c h n o l o g y w a s i n t r o d u c e d a t a f a i r o r g a n i s e d a t th e G e r m a n G o e t h e I n s ti t ut e i nA c c r a i n t h e s a m e y e a r. T h e t w o p r i n ci p a l d e s i g n s w e r e a ls o p r e s e n t e d a t IN D U T E C H


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1984 and a l l s toves sen t for the fa i r were so ld out . A ccord ing to a technic ian a t theAgricu l tura l Engineer ing workshop, over 5 ,000 sawdust s toves have been so ld out bythe depa r tment s ince.

O t h e r S t o v e sDes igns o f cooks toves have been cons ide red fo r t he py ro ly t ic p lan t a t BRR I inKum asi . The en ergy s i tua t ion in the coun t ry m ade i t wo rthwhi le in assess ing theut il isa t ion o f the by-pro ducts as en ergy sources an d the cookstove technology wasadapted to bu m pulver i sed char , par t icu lar ly for domest ic cooking .The techno logy i s on ly effec tive in the urban are as w here income levels a re no t solow and w here s toves are a l ready being bou ght ( regard less of i ts effic iency). A bout30 ,000 A hibenso and 5 ,000 saw dust s toves are know n to have been d isseminated .Benef it s o f improved s toves range f rom sav ings in amo un t o f fue l t o reduced cook ingt ime, reduced acc identa l burns and c leaner and m ore hygien ic cooking condit ions.Problem s wi th saw dust and o ther im proved co okstov es are princ ipa lly lack of fundsfor promot ing agencies , soc ia l acceptanc e o f these s toves and po orly organiseds t ra tegy fo r t he marke t ing o f t hese .B i o m a s s - F i r e d D ~ . e r s T e c h n o l o g y

Som e des igns o f fue lw ood (f ro m the fores t and sawm ill s ) d ry ing unit s for agr icu l tura lp roduc t s such a s ma ize , beans and "kon kon te" have been d i s semina ted in Ghana . Thedesign , man ufacture and ins ta l la t ion i s by a loca l a r t i san w ho a lso provides a f ter sa lesserv ice . The loca l a r t i san is a technic ian a t the Ag ricu l tura l Engineer ing Departm enta t KN U ST and does these a s a p r iva t e ven tu re . H e has deve loped two d ry ing un it s sofa r . One o f the p ro duc t s is u sed by a po u l t ry fa rmer fo r d ry ing ma ize and feed fo rch ickens. T he o the r un i t is owned by the m anufac tu re r wh o does d ry ing o fagr icu l tura l p rodu cts o n com m ercia l bas is.B r i q u e t t i n g T e c h n o l o g y /Biom ass su i tab le for br iquett ing in Gh ana inc ludes res idues f rom the w ood industr ies,rubbish , charco al res idues and o th er com bust ib le w aste products . The pr incipa l a im o fbriquet t ing pulverised sol id fuel is to beneficiate the fuel by providing a resul tant sizetha t can be m ore readi ly handled and u t i l ised in convent ional an d o ther s toves .A t temp ts a t b riquet te prod uct ion a re as o ld as a ttem pts a t cookstove technology . TheBR RI has been involved in briquet ting inves t iga t ion of the i r pyro ly tic by-product o fcha r for qu i te somet ime. The ch ar br iquet tes tha t go t developed w ere sa t i s fac tory fue lfor gril ling and dry ing purpose s.The mos t advanced p ro j ec t i n Gh ana on b r ique t ti ng i s p robab ly the sawdus tbr iquet ting p lan t o f 2 ,200 tonnes /year capa ci ty tha t w as es tab li shed by a Taiwaneseent repreneu r and a Ghanaian par tne r in A kim - O da in 1984. The Plan t , Chao wu sLimi ted was producing uncarbonised sawdust br iquet tes f rom sawdust ob ta ined a t nocos t f rom sawmi ll s i n t he Ak im - O da a rea . The p l an t had a l abour fo rce o f abou t 24m en 6 o f w hich w ere skil led o r semi-skil led.


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A ne w saw dust br iquet ting p lan t i s kn ow n to be in opera t ion in Kum asi . Thebriquet tes ha ve not as ye t en tered the m arket , and specimen produ cts a re s ti ll be ingtes ted a t the Agricu l tura l Engineer ing Department , KNUST. There are a l so p lans bythe man agem ent of the new p lan t to d es ign a specia l cookstov e tha t w ould be fue lledon the br iquet tes to be produ ced .The use o f t he b r ique t te s deve loped a t the B RR I fo r gene ra l domes t ic cook ing wasinhib ited by the fac t tha t they were not s t rong e noug h to supp ort la rge cooking po tsw i thout d is in tegra t ing . The crush ing s t rength thus needed to be improved . T hegenera l ly h igh price o f the prod uced br iquet tes w ere ano ther problem tha t h inderedw idespread use o f the br iquet tes in the dom est ic sec tor [Hagan , 1994].Dem and fo r the saw dus t b r iquet te s f rom C haow us L imi t ed wa s ve ry h igh and fa routstripp ed the supply. As a resul t o f ope rat ion al inefficiencies, ho w eve r the actualproduct ion was only 1 ,100 tonnes/year . The sawdust dry ing capaci ty was woefu l lyinadequa te and the p resses were o f t en id le 30% o f t he work ing day due tounavailab il ity o f dry saw dust . There w as no prop er s to rage fac i li ty for the saw dustwh ich was kep t in the o pen an d ex pose d to ra in . The f lash tube dryer used in thefac tory wa s a l so not insu la ted and in genera l the p lan t suffered f rom poorm anagem ent as far as produ ct ion and m arket ing wa s concerned . T he p lan t fina llyc losed do w n in 1989, 5 years a f te r be ing se t up .The br iquet tes w ere m ore m arketab le as a fue l for industr ial purp oses (br ick m akersand bake rs were the m ajor cus tom ers) th an as a household fuel. Fo r one th ing , thebr iquet tes pro duce d w ere no t carbonised a nd as such requi red specia l s toves , wh ichw ere no t avai lab le and too expensive anyw ay. They a lso d id not ca tch up too wel lwi th the househo ld sec to r a s a re su l t o f compe t i ti on f rom cha rcoa l and fue lwoodwhich cost less.The br iquett ing p lan t a t A kim -O da has provided importan t po in ters re lat ing to thefeasibil ity , des ign and opera t ion o f such p lan ts and the subsequ ent m arket ing and useo f the produc ts in the count ry . E valuat ion o f the p lan t could led to severa limprove men ts tha t could be effec ted in the opera t ions to y ie ld overa l l p roduct iv itywhi le s imul taneously reducing p lan t -opera t ing cos t .C h a r c o a l P r o d u c t io n T e c h n o l o g yA UN D P/N at iona l Energy Bo ard P ro jec t on "The Charcoa l Cyc le in Ghan a - ABasel ine S tudy " comple ted in 1988 se t ou t to provide base l ine da ta on var ious aspectso f the ch arcoal cycle in Ghana. The s tudy successfu lly provided a da ta necessary for acom prehensive na t ional w oodfu els po l icy to chec k the r is ing cos t o f energy and thepace o f envi ronmenta l deg radat ion to the fores t resource . A b road er s tudy a lso by theU N D P/W or ld B ank in 1988 es t ima ted tha t an 80% increase in cha rcoa l p roduc tion isachievable in the Ku ma si a rea a lone w i th the use o f imp roved technology such asbeehive brick ki lns.Sev era l recom m endat ions inc luding prope r o rganisa t ion of a l l charcoalers , t ree-p lan t ing p rogram m es, es tab li shment o f w oo d p lan ta t ions specif ica lly for charcoalp roduc t ion e t c . were m ade a t t he end o f t he UN D P/N EB s tudy . Ef fo r t s t o da t e onimpro ved k i ln technolog y in Gha na ind icate tha t the bes t appr oach to achiev ing any


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s ignif ican t improvem ent in charcoal prod uct ion i s no t to in t roduce new er technologiesbut to he lp charcoalers ge t a be t te r unders tanding o f the i r p resent m ethod o fcarbonising . Th e d i f ference in eff ic iencies be tween the new er and the o ld ear thmound technologies are seen to be qui te marg inal . There are however o thercont rad ic tory resu l ts f rom o ther s tud ies .Bio2as TechnologyA num ber o f in teres ting pro jec ts tha t a re on-going inc lude:

M O M E 's b io to ile t a t O for i -Panin Seco ndary school : In i tia ted in 1996, th i sfaci li ty pro du ces ga s for l ight ing the toi let and i ts surrounds.M O M E and I IR ' s dem ons t ra t ion a t Appo lon ia : Ga s p roduced i s u sed fo r d i rec tcooking in 27 hom es as w el l be ing u sed to gether wi th d iesel in a min i-gr idproducing 12.5 kWel.A 100m 3 d iges ter cap aci ty p lan t u ti lizing hum an w aste to be com miss ioned byGuiness Gha na L imi ted and W ate r fo r L i fe (UK) . Ga s gene ra t ed is t o be u sedfor comm uni ty l igh t ing , cook ing in a loca l school and used to ru n acommunity cornmil l .

Biogas could faci l i tate decentral ised electrici ty generat ion as well as serving as a lowcost w aste recycling process . Studies in 1994 ind icated tha t p roduct ion of b io ga s fore lec tr ic ity genera t ion w as 14 t imes as m uch as product ion f rom hydro sources andwi th the present ta r if fs th is s tud ies need to b e rev is i ted . T he u se of b io ga s as fue l forcook ing is no t favoured by many .Cogeneration TechnoloevTw o sawmi ll s -A T & P in Sam rebo i and STP in Kum as i - have been repo r ted to beproducing e lec tr ici ty and po w er us ing the i r p rocess ing w aste . O ther progress in th isarea i s main ly in the form o f s tud ies to go in to com mercia l pow er produc t ion main lyfrom sawmil l w aste and agr icu l tura l res idues . Studies to da te inc lude"Po ten t ia l Fo r C ogenera t ion f rom W ood re s idues : case S tudy o f Three C i tie s InGh a n a " b y Dr . E . C . Q u a y e ,"Pre feas ib il it y S tudy on L e tus P ow er P lan t " by Esse l Ben H agarg anda n d " P re fe a si bi li ty S t u d y o n a W o o d W a s t e P o we r P l a nt f o r M O W " b y KI T E .The cheap nature o f e lec t r ic i ty ta r i f fs p revai ling in the co unt ry unt il recently has beenresponsib le f or the v i r tua l absence o f th i s technology in the coun t ry . A l l s tud ies todate ind ica te tha t the econom ics o f the technology are very encouraging and need tobe explored . KITE's s tudy in 1999 es tab l i shed tha t Maxwel l Owusu Timbers couldgene ra te 1 MWe~ from a l l the i r genera ted res idues . The in ternal ra te o f re turnsach ievab le i s 21 -2 7% wi th a d i scoun ted pa yback o f 5 - 7 yea rs under two cons ide redscenar io .

C O N C L U S IO N S A N D R E C O M M E N D A T I O N SIt has been es tab li shed tha t b iomas s i s the m ost usable and perh aps the mo st importan trenew able energy source in the coun t ry a t p resent . The go vernm ent , dec is ion makers


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and o ther s takeholders in the coun t ry have rea l i sed the im portance o f the b iomassresour ce and have been responsib le for a t tempts to have the resource sus tainedth rough a num ber o f e ffo r t s and p ro j ect s . M any o f t he b iomass t echno log ies t ha t a reavai lab le have been t r ied w i th m ixed resu l t s and exper iences .The rev iews o f pas t and on -go ing RE Ts in t he b iomass sec to r cons idered under t h iss tudy as w el l as the c hanging eco nom ic s i tua t ion and nat ional i ssues have ind ica tedtha t th ree b road RE Ts - Im prov ed Ch arcoa l Kiln s, Saw dus t Br ique tt e s and B iogasTechnologies - would need to be fo cused on and deta iled analys is done i f the l imi tedresou rces availab le are to f ind opt imum use . The se lec ted RE Ts w ere cho sen on thebasis of their com m ercial viabi li ty , job crea t ion opportuni t ies, environm ental benefi tsand avai lable technologies.De ta i led ana lys is o f the chosen R ET s w ou ld need to be done to ge t t hem m orethoroug hly assessed and to learn f rom the i r exper iences . Su rveys of produce rs andusers a nd in terv iews w i th key inform ants d i rec tly involved wi th the R ET s (eg . Pro jec tM anag ers) w ould ha ve to be m ade an d in som e cases pro jec t s i tes v is ited to ge t thef i rs t hand inform at ion ins tead o f re ly ing on secondary l i te ra ture on the pro jec t.

R E F E R E N C E S

1. A tako ra S . B . , Brew -H am m ond A . , 1999 , Ava il ab il it y o f W ood R es idues fo rCogenera t ion in Gh ana2 . H aga n E . B . , 1985 , Py rolys is o f W ood Shav ings and Saw dus t - A rev iew o fthe dem ons t ra tion p ro j ec t i n Ghana3 . H aga n E . B . , 1994, Produc t ion o f Saw dus t Br ique tt e s in Kum as i

4 . H aga n E. B. , 1997 , Pre-feas ib i li ty s tudy on prop osed L etus Po w er Plan t5 . KIT E, 1999, Ene rgy U se in some pe r i-u rban a reas i n Kum as i6 . M inist ry of M ines and Ene rgy , 1998, Annual Re port7. N ke tiah K . S. et . a l . , 1988, Th e charco al Cycle in G ha na - A baseline stu dy8 . Nk e t i ah K. S . , 1992 , The Prospec t s fo r Com merc ia l Charcoa l Produc t ion f rom

logging Residues in Gh ana.9 . U N DP /W or ld Bank , E SM A P Pro jec t, 1988, S awmi l l Res idue Ut i li sat ionS t u d y

Biomass Technology in Ghana

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