Feasibility of Bio-Gasification Technology for Rural Off...

Feasibility of Bio-Gasification Technology for Rural Off-Grid Electrification in Namibia

Palyomwene Mutilifa (NUST)

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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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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


(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


N$

10

00

Net Present Value

Wood Charcoal

0.0

10.0

20.0

30.0

40.0

50.0

60.0


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


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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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



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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!

Feasibility of Bio-Gasification Technology for Rural Off...

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