Distr*
LIMITS)
December 10, I980 Original: ENGLISH
^ECONOMIC OMISSION FOR AFRICA
Regional Preparatory Meeting on New
and Renewable Sources of Energy
Addic Ababa, 12-15 January 1931
GELATION FROM ANIMAL ANE) ACSICULTURAL
WAST35 IN AFRICA
: Mohamed Molchtar El- Halwagi
Abdel Daiem
National Receartrfi Centre Egypt, October 1930
iiconomic Commission for Africa
ECA/NRD/E/So/lHF
TABLE OF CONTENTS
SUMMARY
Biocas froa AGrioaltural Biora
fflLE alternative enercy source ad a solution to many rural problems
32-Enerey sources and Needs in Rural Egypt
B3-Biogas
3. Biogas prospects in rural areas of Africa fc
Sr^^ UrfUzation °f BioGaS Technology
ica-, Ways, Means and Problems
-IValning' ExohanSe of ^o^ation and
ion aspects of Biogas development us! in Africa U
# Case Histories A—Tanzania
AX-Cfeneral ' l6
A2-EnerGy Needs in Rural Tanzania
A3-Biogas Developments
A4^valuation of the Biogas Implementation Programme ^
3-Egypt
Bl-General . 2l
21
Bibliography . 4
Annex I Commonwealth Science Council '
African Energy ProgrammeAnnex 2 Report on working group on energy'policy' ■
Annex 3 Tanzanian Case (Supplementary Tables)
ECA/NRD/E/8O/INF.13
SULKdARY
nio-PG derived fro:n rgriculturr-1 biorasc t1 ro-.r; anaerobic fermentation, is
- nronisin^l^e^rtivs ener^ source fp.'1 ? solution to m-ny i-:r*l problems
relating to-land"productivity, conserving resources, i;nProvinrr environmental
v-rrdene and decentralised development.
Aoprooriete villas-type biogas" teCnolory' is 'mown rnd reliable. Generrtion
met' ods devslooed in Asir, particularly f-e Indian pjxr- Chinese schema, en oe adapted rnr*' modified to suit local African conditions and skills.
I- rural ar<=as of Africa, agricultural residues, Needs and ' ydrop1 v Wet'-r wit' Hunan and animal excreta represent gooc^ feedstocks for biogas eevelopaients. A orolimxnrry T ypot'^tical -estinu-te or? t'-e bioCar. t'.t coulr oe nroeucee, assuming'5Of5 cattle 6unn collection *n<». 5^. of rural ^utnrn excrement,,, to w'-ic1' ^i (Qf weip*-.t of cattle rung) agricultural wrstes j?e arde- in-icatec
Ebo.it ^ m3 BTuMEi g^s production ec-Uv.-lent to 13?- x 101; k crl. In r^xtxon,
f e cUpested msterirl pro^icer1 would : ?ve a nitrogen content ecuiv^lant to abovM
?..4 million tons of ures.; ^it- of er intangible benefits stt<* as environmentrl effects, prospects of biopss rre eneourrgingo
re application of villape-tTrpe biogaa tecbnolocy (&X) in some
countries ex' ibite<* various decrees of success. Previous experience vSs s-oim t'^t sttcc-ss entails t\e development of viable conditions to ensure acceptance, ^ adoption ,nd Brooapption of tec' -nolo^. T^e tec^noloPy s" oul^ be rpproone ts anr com^tible vrif tVe existing socio-economic conditions. Furthermore, are^^e
scientific ,nd. technical infrastructure should b2 ^velope^ ^ z. atrxnc nr.xxoa, 1
policy End plans on technology promotion riust be drr.wn upo
Siccecs-Ful implementation of bioras programs in Africe would necessitate f-o develooment of" strong scientific ?.nd technical support. Hese?rc snc _ develo^r-t (^fiD) wit'- tVe hi^ est pryoff in Africa apperrs to be xn t-e rr.pcive r'om.-1-i'. Some specific rrers for needed R £ D in Africc are outline^ ?nd join, 3 AD proEramme. ,mounP t-e Africen countries rre recommended. Tr.mn^overxn, different "skill levels - s'oulr' be a basic and inte^rrl co^nponent m *ny oio^rs
- "ere
Two case 'istories of biopP.s progrr.mmes - t'--e Tanzamrn an^ En'pti s-l-cted for presentation. T'e spplic^bility and restraints of viewpoints expressed i.i t'-e P^per are illustrated to some extent wit-in f e presentation.
Finally, concrete suggestions were outlined for development and utilisation of
blopas at nation*1 -iibrepionrl, and regional levels in Africa. T e possible role
of UN agencies, particularly UNEP, was also touched upon.
eca/nrd/e/3o/inf;i3
1. INTRODUCTION; /Biotas from Agricultural Piomasa ?s & Promising Altaic? :iv^
Enerpy'Source and, a solution to Bfc:vy Ivargl Problems.
Among t'-e most important problems of oar age, ?.nc more so of future
generations, are t' ose pertaining to energy sources, foo^' supnly ?n-* pollution abatements In feet, the application of biogEs technology ir mrrl c.rs?s fits perfectly in t'is context. On t* e top of its contribution to improving f e rurel community conditions, it c?n help in solving the t^-res mentioned priority
problems in "a'balanced wsy am:1 in a uanner that is "arraonious wit' n-ture r.'v1
envi ronment. :
First, recycling of animal, human and agricultural nsstes t* rourv rnrerobic disgestion provides a clean and renewable source of energy, i.e. t'a biogps.
Second, it furnishes a stabilized effluent that can be user1 ss an excellent organic fertilizer to sustain or even increase lane1 productivity, or err, ?r well be \isef- as animal feec" supplement, zvA ?lternatively ;nay be uiriliseri ir t" s so cslle^ integrated biogas system to grow rlgaej rr-aatic plrntc anc1. fic'~ rnr so provide more feed for the eniraels, more food for t'ie '■■uaiens z.nrJ also :nore biom? as for digestion. T'-ird, through Hastes digestion, t<:-e biogas technology would contribute to combating Dollution, wzste disposal rnd s?-iitrry repects.
3y the same token, Ve problems relrtec7, to tve introduction of biogrs to r rural area are more complex fan t1 ose of ?ny of er small-scale source of energy*
Ap?rt from providing energy, it is rlso a technology forVrste treatment, nutrient recycling and soil conservation.
In recent yesrs, particularly in t-e afterma.t'i of t':e 1973 oil crisic, biog-s systems have attracted considerable attention. It is now becoming pc^.oiottlegged as a promising component of decentralised rurel development.
Excellent reviews on t'-e current stste of 'aiovled.gs m? tec'-.nology priperred in t';e published literature. A selscted list is given in t'-e bibliogr?p'y (l - 5).
Since these reviews provide e. fairly complete cover?.go of t?-e essential features o.
BiS Technology/ (DGT) , only ? very brief description is given ' ere»
Biotas, bssicf-lly ? mixture* of net'i^ne <^^ csrbon dioxide plus .so'ne minor constituents, is produced byt.anaerobic fermentation of organic matter. 3y
containing tT-e matter in a digester (or biogss; plant) , t1 e combustible g?s can be
trapped end used as fuel. T? ey^igested slurry that. remains err. be usurlly use^ on land as soil conditipner and jKertilizer.
biochemistry and microbiology of anaerobic fsrnent?,tion is-extremely complex. It is established that in general teryis t%£. orocess proceeds seriall through t'.ree steps. In the first step? the poly^neric compounds of carbo proteins and fats are broken down into soluble monomers by e group of fpc bacteria t'Troujglj enzymatic ' ydrolysis.
* The' general composition of biogas produced from f?rm wr.ctes is usup11-»- (7).
0% 54-7P?S, OOo Z?-h.K?*9 No 0.5-3?^ H2 1-10^ nv\ V. trace of TI^S. Its ener.-y content (8) is about 5500 K csl/m^.
