ASSESSMENT OF THE POTENTIAL OF SUSTAINABLE FARMING SYSTEM THROUGH FARM LEVEL ENERGY GENERATION: A CASE STUDY OF SIJUWA VDC, MORANG DISTRICT, NEPAL By Umesh Adhikari Examination Committee Dr. H.P.W. Jayasuriya (Chairperson) Prof. V. M. Salokhe Prof. S. Kumar Dr. P. Soni Asian Institute of Technology School of Environment, Resources and Development Thailand April 21, 2009 A thesis report submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Agricultural Systems and Engineering
Transcript
ASSESSMENT OF THE POTENTIAL OF SUSTAINABLE FARMING SYSTEM THROUGH FARM LEVEL ENERGY GENERATION: A CASE
Asian Institute of TechnologySchool of Environment, Resources and Development
ThailandApril 21, 2009
A thesis report submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Agricultural Systems and Engineering
BACKGROUND
Over 2/3 of the total population in Nepal are engaged in agriculture which contributes less than 1/3 of the total GDP
Farm mechanization is gradually taking place in Nepal
Nepal relies solely on the imported petroleum products as a primary fuel source
Huge amount of agricultural residues are generated as byproducts of agricultural production system
?
Fuel price has increased rapidly in recent years, increasing the cost of farm operations
Farm mechanization process, a dire need of the country, may get retarded owing to the increased fuel price
If mechanization process is retarded, it would create a gap between energy requirement and supply in agriculture
Excessive reliance on non-renewable energy sources such as fossil fuel and fuelwood has added to the environmental pollution and is not sustainable
Local agro-processing industries are facing acute power shortage in the country
PROBLEM IDENTIFICATION
There is a need to organize the energy generation and utilization pattern so that local energy production potential is fully exploited
Certain percentage of fossil fuel can be directly replaced by Jatropha oil, which can be produced locally
Agricultural residue based briquetting technology can provide sustainable cooking fuel source
Biomass gasification based power production system can provide sustainable and reliable energy source for village mills
RATIONAL OF THE STUDY
The overall objective of this study was to assess the fuel and energy requirement of the farm production system, explore the agricultural based energy production potential, and to suggest strategies and necessary intervention so as to minimize the fuel imports, while promoting the farm mechanization, through the case study in Sijuwa VDC, Morang district, Nepal.
OBJECTIVES
Specific objectives
1. To estimate the current and future fuel and energy requirement for both mobile and immobile agricultural machinery at different farming system levels and the agricultural products processing mills located in the area.
2. To explore the agriculture based energy production and utilization patterns and potential leading to optimize the localized, farm-level energy self-sufficiency.
3. To recommend suitable residue management practices, necessary processing facility, and technology transfer to meet the future energy demand in a sustainable manner.
Energy input and output for major cereal crops √ -
Fuel requirement √ √
Residue production and utilization √ √
Agri. residue based energy production potentials √ √
Energy balance matrix √ √
RESEARCH METHODOLOGY
Recommendations for Sustainable Energy Approach
a)a) Jatropha cultivation areaJatropha cultivation area
Yl
PFA ct
A = Cultivation area (ha)Ft = total annual fuel consumption (lit)Pc = Percentage of fuel to be replaced (%)Yl = Oil yield of the Jatropha plant (lit/ha)
b)b) Briquetting plantBriquetting plant
T
QCb
Cb = Processing capacity of briquetting plant (kg/hr)Q = Quantity of residue available for briquetting (kg)T = Annual operating hours of the briquetting plant (hr)
c)c) Gasification plantGasification plant
Based on the total energy requirement of the village mills
Recommendations for Sustainable Energy Approach
a)a) Jatropha cultivation area (Jatropha cultivation area (volumetric replacementvolumetric replacement))
RESEARCH METHODOLOGY
GENERAL INFORMATION ON STUDY AREA
Study areaStudy area
Household surveyHousehold survey
Total Sampled
Area: 30.43 km2
Household: 2178 148Population: 11353 927
Mills surveyMills survey
Mills 11 11
19.6
4.1
15.0
32.4
22.0
25.8
48.0
73.9
59.3
0 20 40 60 80 100
Household (%) of Total
Land Owned (%) of Total
Land Cultivated (%) of Total
Small Medium Large
Summary of percentages of household, land owned and Summary of percentages of household, land owned and land cultivated by different farm categoriesland cultivated by different farm categories
RESULTS AND DISCUSSION
About 36% of the farmers owned bullocks, 49% owned he-buffalos and only 2.7% owned tractors.
About 70% of the farmers owned either diesel-run pump set or electric motor as irrigation power source
Rice, wheat, maize and spring rice were the major cereal crops
Cropping intensity was around 200% for each farmer group
Farm labor use was not significantly different among farmer groups; spring rice consumed the highest and wheat consumed the lowest
RESULTS AND DISCUSSION
0
2000
4000
6000
8000
10000
12000
14000
Sm
all
Me
diu
m
La
rge
Sm
all
Me
diu
m
La
rge
Sm
all
Me
diu
m
La
rge
Sm
all
Me
diu
m
La
rge
Rice Wheat Maize Spring rice
En
erg
y c
on
su
mp
tio
n (
MJ
/ha
)
Seed
Fertilizer
Herbicide/Pesticide
Animal
Human labor
Machinery
Energy input and output from different cropsEnergy input and output from different crops
RESULTS AND DISCUSSION
0
50000
100000
150000
200000
250000
300000
Rice Wheat Maize Spring rice
Crops
Ene
rgy
outp
ut (M
j/ha)
Small
Medium
Large
2.5 5.8
79.9
141.8
44.8
26.6
3.33.111.8
85.8
52.4
25.1
4.54.6
52.7
0
20
40
60
80
100
120
140
160
Rice Wheat Maize Spring rice Total
Crop
Mea
n d
iese
l con
sum
pti
on (
lit/y
ear)
Small
Medium
Large
Crop wise and total diesel used by farmers for different crop Crop wise and total diesel used by farmers for different crop cultivation at present scenariocultivation at present scenario
RESULTS AND DISCUSSION
Farmer wise diesel requirement in mechanized scenarioFarmer wise diesel requirement in mechanized scenario
RESULTS AND DISCUSSION
19.3 14.1
205.4
344.5
126.9
212.8
53.918.5 13.5
132.2
221.8
56.287.3
29.9 21.9
0
50
100
150
200
250
300
350
400
Rice Wheat Maize Spring rice Total
Crops
Mea
n fu
el r
equi
rem
ent
(lit
/yea
r)
Small
Medium
Large
?
Theoretical residue production and energy potential from major crops at present scenarioTheoretical residue production and energy potential from major crops at present scenario
CropYield (ton)
Residue type
RPRQuantity of residue (ton)
LHV (MJ/kg)
Energy (TJ)
Rice 9950.6Straw 1.8 17513.1 16.0 280.6
Husk 0.3 2686.7 19.3 51.9
Wheat 1232.6 Straw 1.1 1392.8 17.2 23.9
Maize 1084.6Stalk 2.0 2169.1 19.7 42.6
Cob 0.3 292.8 16.3 4.8
Spring rice
7071.1Straw 1.8 12445.2 16.0 199.4
Husk 0.3 1909.2 19.3 36.9
Total 38408.9 640.1
RESULTS AND DISCUSSION
Available residue and energy production potential at presentAvailable residue and energy production potential at present
Theoretical residue production and energy potential from major crops in Theoretical residue production and energy potential from major crops in mechanized scenariomechanized scenario
CropYield (ton)
Residue type
RPRQuantity of
residue (ton)LHV
(MJ/kg)Energy
(TJ)
Rice10713.6
Straw 1.8 18855.9 16.0 302.1
Husk 0.3 2892.7 19.3 55.9
Wheat 4464.0 Straw 1.1 5044.3 17.2 86.5
Maize8035.2
Stalk 2.0 16070.3 19.7 315.9
Cob 0.3 2169.5 16.3 35.3
Spring rice 17855.9
Straw 1.8 31426.4 16.0 503.5
Husk 0.3 4821.1 19.3 93.2
Total 81280.2 1392.4
RESULTS AND DISCUSSION
Available residue and energy production potential in mechanized scenarioAvailable residue and energy production potential in mechanized scenario
Monthly electricity and diesel consumption by village millsMonthly electricity and diesel consumption by village mills
Particulars Electricity Diesel
No. of mills10 1
Mean Consumption(kWh/month)/ (lit/month)
772 120
Std. Deviation 399.1
Minimum (kWh/month)/ 350
Maximum (kWh/month)/ 1700
Sum(kWh/month)/ (lit/month)
7720 120
RESULTS AND DISCUSSION
Number of plants
Area required(m2)
Present scenario
Small 14 127
Medium 26 236
Large 43 391
Mechanized scenario
Small 65 591
Medium 68 618
Large 105 954
Recommendations for Sustainable Energy Approach
a) Recommendation on Jatropha cultivation to replace 20% of diesel
RESULTS AND DISCUSSION
b) Recommendation on agricultural residue processing facility Considering the current fuelwood consumption and energy use of agricultural
residues, about 4731 tons of agricultural residues based briquetting facility would be required
Assuming that the machine can be operated 300 days annually and 16 hours daily, the processing capacity of the machine required to fulfill the briquetting need of the village was calculated as 986 kg/hr.
c) Recommendation on gasification set up for village mills A 50 kW power plant that run on the gasification of biomass would be enough
to fulfill the power requirement for all the mills in the village.
To run such a plant, about 613 tons of biomass is required annually.
RESULTS AND DISCUSSION
Annual energy demand of Sijuwa VDCAnnual energy demand of Sijuwa VDC
Biomass(ton)
Fossil fuel(lit)
Electricity (kWh)
Fuelwood(ton)
Present scenario
Small farms 184 19130 76860 776
Medium farms 264 60575 177912 1401
Large farms 406 148181 288420 2299
Processing Mills - 1440 92640 -
Total 854 229326 635832 4476
Mechanized scenario
Small farms 184 90866 76860 776
Medium farms 264 156591 177912 1401
Large farms 406 359480 288420 2299
Processing Mills - 1440 92640 -
Total 854 608377 635832 4476
RESULTS AND DISCUSSION
Plan 1
Fulfill the energy of the village mills by generating 50 kW electricity through the gasification of agricultural residues
Fulfill the household cooking energy demand of the villagers by briquetting agricultural residues
Replace 20% of the total fossil fuel by the producing biofuel locally.
Energy balance matrix 1Energy balance matrix 1
TypeAvailable
total
Distribution
Cooking (briquetting)
Mills requirement
Farm operations (biofuel)
Surplus / (deficit)
Present scenario
Bio-mass (ton) 5582 4731 613 - +238
Biofuel (lit) 0 - 288 42137 -42425
Mechanized scenario
Bio-mass (ton) 21905 4731 613 - +16561
Biofuel (lit) 0 - 288 121387 -121675
42425 lit of biofuel at the current situation and 121675 lit of biofuel for the mechanized scenario
59 ha of land at present and 169 ha of land at mechanized scenario
30 plants per household at present and 85 plants per household in mechanized scenario
Excess residues can be briquetted and supplied to urban areas
RESULTS AND DISCUSSION
Plan 2
Fulfill the energy of the village mills by generating 50 kW electricity and producing 50 kW for village lighting through the gasification of agricultural residues
Fulfill the household cooking energy demand of the villagers by briquetting agricultural residues
Replace 50% of the total fossil fuel by the producing biofuel locally.
Energy balance matrix 2Energy balance matrix 2
TypeAvailable
total
Distribution
Cooking (briquetting)
Mills requirement
Farm operations (biofuel)
Surplus / (deficit)
Present scenario
Bio-mass (ton) 5582 4731 1226 - -375
Biofuel (lit) 0 - 720 105343 -106063
Mechanized scenario
Bio-mass (ton) 21905 4731 1226 - +15948
Biofuel (lit) 0 - 720 303468 -304188
106063 lit of biofuel at the current situation and 304188 lit of biofuel for the mechanized scenario
147 ha of land at present and 423 ha of land at mechanized scenario
74 plants per household at present and 213 plants per household in mechanized scenario
Deficit residues should be imported from other village at present and supply excess briquettes to urban areas in mechanized scenario
RESULTS AND DISCUSSION
Energy balance matrix 3Energy balance matrix 3
TypeAvailable
total
Distribution
Cooking (briquetting)
Mills requirement
Farm operations (biofuel)
Surplus / (deficit)
Present scenario
Bio-mass (ton) 5582 4731 1839 - -988
Biofuel (lit) 0 - 1440 210686 -212126
Mechanized scenario
Bio-mass (ton) 21905 4731 1839 - +15335
Biofuel (lit) 0 - 1440 606937 -608377
Plan 3
Fulfill the energy of the village mills by generating 50 kW electricity and producing 100 kW for village lighting through the gasification of agricultural residues
Fulfill the household cooking energy demand of the villagers by briquetting agricultural residues
Replace 100% of the total fossil fuel by the producing biofuel locally.
212126 lit of biofuel at the current situation and 608377 lit of biofuel for the mechanized scenario
295 ha of land at present and 846 ha of land at mechanized scenario
149 plants per household at present and 426 plants per household in mechanized scenario
Deficit residues should be imported from other village at present and supply excess briquettes to urban areas in mechanized scenario
RESULTS AND DISCUSSION
1. At present scenario, based on energy matrix, 50 kW biomass gasification based electric plant and briquetting of the rest residues would be the best option.
2. In the mechanized scenario agricultural residues would be enough to run biomass gasification plant to provide electricity for village lighting, as well.
3. In all three plans considered arbitrarily in this study, surplus/deficit residue and deficit fuel was observed. This indicates need for land use management to optimize residue / biofuel balance for sustainability.
4. An extensive economic evaluation would be necessary so as to assess the economic as well as technical feasibility of adopting the briquetting and gasification techniques in the VDC.
5. A detail study should be conducted using LP technique to explore the best combination of options in terms of economic suitability, as well.
