Feasibility of Bio-Gasification Technology for Rural Off-Grid Electrification in Namibia
Palyomwene Mutilifa (NUST)
2
Background
• Bush Encroachment! • Biomass Gasification is a thermochemical conversion process through which
combustible material such as biomass, is subjected to partial combustion in the presence of limited supply of air
• The combustible gas is composed primarily of carbon monoxide (CO), Hydrogen (H2) and methane (CH4) as fuels.
• Ancient Technology:• Street lights in the 1800s• 900 000 Cars ran on 1900s BOTH FROM WOOD GAS
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Background
Gasifier Unit
Conversion UnitCleaning and Cooling unit
Wood
Charcoal
Biomass Gasification CAN provides clean alternative source of base load electricity
3
76%
4
Existing Gasification Plant In Namibia
Name Location ManufacturerType of
GasifierBiomass
Rated
OutputStatus
CBEND Farm Pierre,
Outjo
Ankur Scientific Energy
Technologies Pty. Ltd
Downdraft fixed
bed
Woodchip /
woodblock 250 kW
Shut
down
Makarra
BriquetteOtjiwarongo Local Updraft fixed bed Charcoal 42.4 kW
Shut
down
Makarra
CharcoalOtjiwarongo Local
Downdraft fixed
bedCharcoal 44 kW Running
NUST
TrailerNUST,
Windhoek
Carbo Consult &
Engineering (Pty) LtdUpdraft fixed bed
Wood /
Charcoal15 kW Running
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Existing Gasification Plant In Namibia: CBEND• Project costed N$14 000 000.00 • 1.0-1.1 N$/kW Levellised cost• Created 30 Jobs
Challenges Recommendations
Wood Preparation Equipment Reliable and efficient wood preparation methods
Heat loss not stored as source of Thermal Energy
Heat loss should be captured for energy application
Usage of Refrigeration system(15 kw) The electricity generated should be in directly fed to off-grid communities rather than the national grid.Only 50kW/250kW was registered
• Gasification system on such a large scale are simply not feasible forrural Namibia (Andrew, Richard, Robert, & Wang, 2011).
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Existing Gasification Plant In Namibia: Makarra BriquetteNo. Parameter Unity Value
1 Operational Hours h 23
2 Operational days day 6
3 Capital cost (Technology & Installation) N$ 25 000.00
4 Biomass Cost N$/t 1500.00
5 Required Biomass t/yr. 45
8 Diesel cost saved N$/yr. 811 200.00
9 Total fuel cost N$/yr. 448 350.00
10 Producer Gas: Diesel Ratio - 77:23
11 Approx. Biomass Collection Radius Km 0.5
12 Peak Load Kw 20
• Problems: Lack of technical knowledge, maintenance, Instrumentations, Mismanagement of tar, ash • The plant was expanded in April 2019 & is now powered by CENORED and planning to switch to
solar power by 2020.
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Existing Gasification Plant In Namibia: Makarra Charcoal
No. Parameter Unity Value
1 Operational Hours h 8
2 Operational days day 5
3 Capital cost (Technology & Installation) N$ 45 000.00
4 Biomass Cost N$/t 1500.00
5 Required Biomass t/yr. 4
10 Producer Gas: Diesel Ratio - 25:85
11 Approx. Biomass Collection Radius Km 0.05
• Lack of constant monitoring at the grate, Frequent shaking
• Poor gas filtering system :Mattress Foam
• Lack of Instrumentation
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Existing Gasification Plant In Namibia: NUST TRAILER
• ¼ systems to run on Petrol• On average, petrol engine running on
combustible gas produces 0.55-0.75 kWh of energy from 1kg of biomass (Rajvanshi, 1986).
• Excellent gas clean-up systems (Cyclone, wet charcoal & wood shaving).
• Still being renovated for experimental purposes
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Feasibility for Rural Off-grid Electrification
Barriers
Feedstock quality and availability Constraint
Technology Limitation
Lack of Viable Business Model
Limited Operator technical capacity
Poor access to manufacturer support and spare parts
"The barriers facing gasification are meanwhile toosignificant and wide-ranging for research to make asignificant difference to uptake. Gasification-relatedresearch is therefore not deemed worth supporting“(LTS, 2017)
Disagree!Abundant Biomass
Training
Local Manufacturers
• Feedstock ash Content• Different Feedstocks
Kernel shell exudes acidic oil
• Lack of instrumentations• International manufacturer• Installing Capacity>100 kW
• Fulfils HPP-to increase the provision of rural electrification by 50%.
• Gasification Awareness
Feasible In Namibia
Fuel Wood works well with gasifiers (Dimpl,2011)
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Feasibility for Rural Off-grid Electrification
Plant Maintenance Once a week 312 days/yr.Instrumentation
Downdraft gasifier70% Syngas
Engine deration 30%
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Feasibility for Rural Off-grid Electrification: Woodfeedstock
0 1000 2000 3000 4000 5000
5kw
30kw
100kw
N$1000
Net Present Value
-1000000
-500000
0
500000
1000000
1500000
2000000
2500000
3000000
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00
N$
Years
Cash Flow
5 kw 10 kw 30 kw 50 kw 100 kw
0.00 5.00 10.00 15.00 20.00
1
IRR (%)
Internal Rate of Return (%)
100kw 50kw 30kw 10kw 5kw
12
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
5kw
30kw
100kw
N$/kWh
Production Cost
Diesel Generator Production Cost0
200
400
600
800
1000
5 K W 1 0 K W 3 0 K W 5 0 K W 1 0 0 K W
CO
ST (
N$
10
00
)
INVESTMENT COSTS
35
1626
52
0 10 20 30 40 50 60
1
Total Number of Household Supplied
100 kw 50 kw 40 kw 10 kw 5 kw
Feasibility for Rural Off-grid Electrification: Woodfeedstock
0
500
1000
0
500000
1000000
1500000
5kw 10kw 30kw 50kw 100kw
(t/y
)
(t)
Feedstock Consumption per Plant
Biomass consumption (t/year) <10% of Biomass Available
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0
2000
4000
6000
8000
10000
12000
14000
5kw 10kw 30kw 50kw 100kw
N$
10
00
Net Present Value
Wood Charcoal
0.0
10.0
20.0
30.0
40.0
50.0
60.0
5kw 10kw 30kw 50kw 100kw
Internal Rate of Return
Wood Charcoal
0100200300400500600700800900
1000
N$
10
00
Investment Cost
Wood Charcoal
Feasibility for Rural Off-grid Electrification: Charcoal Vs. Wood
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Feasibility for Rural Off-grid Electrification: Charcoal Vs. Wood
0
5
10
15
20
25
30
35
40
45
50
5kw 10kw 30kw 50kw 100kw
N$
/kW
h
Production Cost
Wood Charcoal
0 10 20 30 40 50 60
5kw
10kw
30kw
50kw
100kw
No. of Households
Total Number of Household Supplied
Charcoal Wood
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Feasibility for Rural Off-grid Electrification
Marula Kernel
• Drought-resistant tree that is widelydistributed in sub-Saharan tropicalAfrica.
• Mostly found in the northern part ofNamibia.
• Dry kernels are used as source of fire aswell as fertilizer.
• 80 000 households, 5 estimated Trees.
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1km Distance
5kw 10kw 30kw 50kw 100kwProduction Cost (N$/kwh) 15.82 8.27 4.53 3.77 3.02
Investment Costs (N$1000) 45.98 84.28 262.17 433.29 862.08
Net Present Value (N$1000) 1309.4 1341.64 2007.22 2678.23 4076.81Internal rate of Return(%) 17.16 9.72 4.79 3.91 3.05Biomass consumption (t/year) 39.04 78.07 234.22 390.36 780.72
Biomass Available (t) 15.00 45.00 195.00 300.00 600.00No Of Households 1 3 13 20 40
• Distribution Cost• Transportation Cost
?
Feasible for Small scale <10kW
Feasibility for Rural Off-grid Electrification
Feasibility for Rural Off-grid Electrification
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• For as long us the plant is maintained, monitored &understood locally, small scale plant will always befeasible.
• ELECTRICITY IS THE PASSWORD!• Establishment of Policies to effortlessly influence the
integration of biomass gasification with other existingrenewable technology.
Feasibility of Bio-Gasification Technology for Rural Off-Grid Electrification in Namibia
Thank You!