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Welcome to my presentation

Dept. of Farm Structure & Environmental Engineering

Bangladesh Agricultural University, Mymensingh2

Presented by:

MASRUR AHMEDID. No. 15FSEEJD-

03MReg. No. 37789

Session: 2010-11Supervisor

Prof. Dr. Md. Zainul AbedinCo-Supervisor

Prof. Dr. Md. Abdur Rashid

STUDY TITLESUSTAINABILITY STUDY OF BIOGAS PLANTS UNDER OPERATION IN LOCAL MYMENSINGH.

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BackgroundObjectiveMethodologyResultConclusion

Outline of the study

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CompositionBiogas originates from the bio-degradation of organic material contains 60-70% methane and 30-40% carbon dioxide.

Background

Feeding materialBiogas is produced from livestock manure, sludge and municipal, livestock and organic waste.

Bio-slurryBio-slurry, as by-product from biogas plant, is a nutrient-rich organic fertilizer having 20-30% more nutrients than ordinary organic fertilizers.

Background of Biogas

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Raw MaterialsBangladesh is a favorable position in respect of availability of raw materials , due to rapid expansion of poultry and dairy enterprises (5.6% growth rate) .

Background

EfficiencyOnly 40%-60% of anticipated average gas production is obtained, whereas smaller plants show better results than bigger plants.

Size selectionMost cost-effective and sustainable biogas plant size selection is of utmost important to eliminate major complication in biogas plants due to under-feeding and over-sizing.

Status of Biogas Plant

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Sustainability

ENVIRONMENTAL

SUSTAINABILITY

ECONOMICAL

SOCIAL

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Research objectives

1. To identify the capacity of the plants commonly used in local Mymensingh.

2. To analysis cost effectiveness and sustainability of the plants under operation.

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MethodologyGeneral methodology followed during study

Study of secondary data & information

Sampling household biogas for study

Field testing of questionnaire

Finalization of questionnaire

Field investigation & data collection

Data analysis & Thesis report Preparation

Preparation of final report9

Methodology (cont.)I. Selection of Study Areas:These areas were selected due to location,

availability of poultry farm, amount of cow dung produced, shortage of fund and socio-economic condition of the community. These areas are

1. Mymensingh sadar, 2. Haluaghat, 3. Phulpur

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Methodology (cont.)

Map of Mymensingh Sadar11

Methodology (cont.)

Map of Haluaghat12

Methodology (cont.)

Map of Phulpur Upazilla 13

Methodology (cont.)

II. Sizes of biogas plants in the study area:Five different sizes of biogas plant were installed by Grameen Shakti (GS) in local Mymensingh. The sizes of biogas plants are as follows:

• 1.6 m3 • 2.0 m3 • 2.4 m3

• 3.2 m3

• 4.8 m3

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Methodology (cont.)

Field TestingOnce the survey objectives, associated data and analytical design were specified and questionnaire was developed for field testing.

III. Preparation of a Questionnaire

Final QuestionnaireAfter completion of field testing final questionnaire was prepared to record the information needed for analysis.

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Methodology (cont.)

Financial and economic appraisal of different domestic biogas plants are based on decision making tools including

1. Benefit cost ratio (BCR)2. Net present value (NPV)3. Internal Rate of Return (IRR)

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Methodology (cont.)Benefit cost ratio: It is the ratio of benefit obtained from biogas plants to its cost.

𝐁𝐂𝐑=𝐏𝐕𝐛𝐞𝐧𝐞𝐟𝐢𝐭𝐬

𝐏𝐕𝐜𝐨𝐬𝐭𝐬

Where:PVbenefits = Present value of benefitsPVcosts = Present value of costs

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Methodology (cont.)Net Present Value (NPV): It is the difference between the present value of cash inflows and the present value of cash outflows.

𝐍𝐏𝐕=∑𝐭=𝟎

𝐧 (𝐁𝐞𝐧𝐞𝐟𝐢𝐭𝐬−𝐂𝐨𝐬𝐭𝐬)𝐭(𝟏+𝐫)𝐭

Where:R = discount ratet = yearn = analytic horizon (in years)

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Methodology (cont.)

Internal rate of return (IRR): It is a discount rate that makes the net present value (NPV) of all cash flows from a particular project equal to zero.

𝐈𝐑𝐑=𝐫𝐚+𝐍𝐏𝐕𝐚

𝐍𝐏𝐕 𝐚−𝐍𝐏𝐕𝐛(𝐫𝐛−𝐫𝐚 )

ra = lower discount rate chosenrb = higher discount rate chosenNa = NPV at ra

Nb = NPV at rb19

The existing condition of different components of biogas plant was observed in detail during the field investigation

Methodology (cont.)

1. To assess the quality of construction

2. effectiveness of maintenance activities carried out

3. the operational status prior to categorizing them

Condition of biogas

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in qualitative manner, dependent on the physical observation of the plant made during field investigation.

Methodology (cont.)

Condition of biogas PlantThe existing physical status of different components of biogas plant have been categorized in three different headings

1.Good (functioning without defects)2. Fair (defective but functioning)3. Poor (defective and not functioning)

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The categorization has been made based upon the condition of the following Condition of Plant as a wholeCondition of InletCondition of Digester and DomeCondition of Outlet (displacement chamber):Condition of Main Gas ValveCondition of PipelineCondition of Gas StoveCondition of Slurry Pit

Methodology (cont.)

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Number of Plants surveyedThe field study was carried out in 36 randomly sampled biogas plants from three selected upazillas in local Mymensingh region.

Locations No. of biogas plants in each size category

1.6 m3 2.0 m3 2.4 m3 3.2 m3 4.8 m3 Total Nos. of plants

Mymensingh sadar 2 2  3 2 2  12

Haluaghat 3 2 2 3  2 12

Phulpur 2 3  3 2 2 12

Grand Total 7 7 8 7 6 36

RESULTS

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1.6 2 2.4 3.2 4.80

10000

20000

30000

40000

50000

60000

2600032000

3600043000

52000

Different sizes of Biogas Plant (m3)

Cos

t in

BD

TInitial investment cost

RESULTS (cont.)

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1.6 2 2.4 3.2 4.80

0.5

1

1.5

2

2.5

3

3.5

1.58 1.75

2.35 2.51

3.17

Gas Production (m3)

Plant Size in (m3)

Gas

Pro

duct

ion

in C

ubic

m

eter

RESULTS (cont.)

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RESULTS (cont.)Benefit cost ratio of biogas plants of different sizes:

1.6 2 2.4 3.2 4.80

0.20.40.60.8

11.21.41.61.8

1.511.62 1.68

1.53 1.47

B/C RatioB/C Ratio

Plant Size (m3)

Ben

efit

Cos

t Rat

io

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RESULTS (cont.)Internal rate of return of biogas plants of different sizes:

1.6 m3 2.0 m3 2.4 m3 3.2 m3 4.8 m30

10

20

30

40

50

60

42.5448.5

54.47

45.47 46.67

Internal Rate of Return

Plant Size (m3)

IRR

(%)

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RESULTS (cont.)Net present value of biogas plants of different sizes:

1.6 2 2.4 3.2 4.80

5000

10000

15000

20000

25000

30000

35000

16815

26005

32290 3072532990

Net Present Value

Plant Size in Cubic meter

Net

Pre

sent

Val

ue in

BD

T

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RESULTS (cont.)General condition of biogas plant:

Plant Component

Plant under study different categoryGood

(functioningwithout defects)

Fair (defective but

functioning)

Poor (defective and not

satisfactorily functioning)

Nos. % Nos. % Nos. %1. Biogas Plant as a whole 2 6 28 78 6 16

2. Inlet tank 3 8 27 75 6 163. Digester and dome (gas holder) 2 6 25 69 9 25

4. Outlet (displacement chamber) 1 3 26 72 9 25

5. Pipeline 2 6 25 70 9 256. Main gas valve 1 3 27 75 8 217. Gas stove 2 6 28 78 6 168. Slurry pit 1 3 2 6 33 91

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RESULTS (cont.)General condition of biogas plant:

Who

le pla

nt

Inlet

tank

Digeste

r

Outlet

Pipelin

e

Main ga

s v...

Gas st

ove

Slurry

pit05

101520253035

2 3 2 1 2 1 2 1

28 27 25 26 25 27 28

226 6

9 9 8 6

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Good (functioningwithout defects)

Fair (defective butfunctioning)

Poor (defective andnot functioning)

Component

No.

of p

lant

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RESULTSRelationship between Training Received and Functional Status of Plant

Type of Training ReceivedFunctional Status of Plant (No of Plants)

NotFunctioning

PartlyFunctioning

FunctioningSatisfactorily Total

1. No training received 1 2 2 5

2. Training not provided butleaflet/booklet/manual provided 2 0 5 7

3. One day orientation training provided byservice provider 0 1 1 2

4. Short term O & M training (7days or less) 0 0 1 1

5. Long term O & M training (more than 7 days) 0 1 1 2

6. On the spot instructions from mason/companysupervisors etc. 4 8 6 18

7. Training provided by other NGOs (not theservice provider) 0 0 1 1

Total 7 12 17 3631

RESULTS (cont.)Relationship between Quantity of Feeding and Functional Status of Biogas Plants

Quantity of Feeding Received (% of prescribed

quantity)

Functional Status of Plant (No of Plants)

NotFunctioning Satisfactorily

PartlyFunctioning

FunctioningSatisfactorily

Total

1. Less than 25% 3 2 2 7

2. <25% but >50% 2 5 1 8

3. <50% but >75% 1 2 4 7

4. <75% but >100% 1 2 6 9

5. More than 100% 0 1 5 6

Total 7 12 17 3632

RESULTS (cont.)Relationship between Quantity of Feeding and Functional Status of Biogas Plants

> 25% 25%-50% 50%-75% 75%-100% < 100%01234567

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1 10

2

5

2 21

21

4

65

Not SatisfactorilyFunctioning

PartlyFunctioning

FunctioningSatisfactorily

Quantity of feeding type in Percentage

No.

of b

ioga

s pl

ant

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RESULTS (cont.)Relationship between User’s Satisfaction and Plant Efficiency

Efficiency of PlantUsers’ Level of Satisfaction

Not Satisfied Partly satisfied Satisfied Total

Nil (No gas production) 0 0 0 0

1. Less than 20% 3 1 1 52. >20% but < 40% 2 4 6 123. >40% but < 60% 1 6 4 114. >60% but < 80% 0 1 3 45. >80% but < 100% 0 0 3 36. More than 100% 0 0 1 1Total 6 12 18 36

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RESULTS (cont.)Relationship between User’s Satisfaction and Plant Efficiency

<20% 20%-40% 40%-60% 60%-80% 80%-100% >100%0

1

2

3

4

5

6

7

3

2

1

0 0 0

1

4

6

1

0 0

1

6

4

3 3

1

Not Satisfied Partly satisfied Satisfied

Efficiency type

No.

of b

ioga

s pl

ant

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RESULTS (cont.)

17%

33%

50%

Users’ Level of Satisfaction

Not Satisfied Partly satisfied Satisfied

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CONCLUSIONS

Condition of Biogas PlantOut of 36 plants under study, 18 plants were functioning at full capacity, 12 were functioning partly and the remaining 6 plants were not functioning satisfactorily.

Financial AnalysisAll the five sizes are sustainable as well as cost effective but 2.4 m3 plant is most cost effective and sustainable with highest B/C ratio, IRR and NPV is slightly less than 4.2 m3 plant size.

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CONCLUSIONS

Cost Effectiveness & SustainabilityThe cost effectiveness of the biogas plants would suggest the farmers to adopt the biogas technology specially 2.4m3 both for cooking and use bio-slurry for crops, and ultimately relief the huge dependency on firewood and chemical fertilizer and thus the technology would be a sustainable one contributing to national economy.

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ACKNOWLEDGEMENT Ministry of Science and Technology for their special grants to

conduct this research.

Grameen shakti, Phulpur for providing necessary information.

Rural development Academy, Bogra for providing necessary information for completion of this research work.

Department of Farm Structure and Environmental Engineering for providing me with all the necessary supports for the successful completion of this research work.

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