1. Multi-criteria Analysis of
Alternative Biogas Technologies
Bakul Rao1,*, Archana Mane2, Anand B. Rao1, and Vishal Sardeshpande1,3
1 Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology,
Bombay, Mumbai, India 400076
2 Mechanical Department, MIT Academy of Engineering, Alandi, Pune 412105, India.
3 ATE Entreprises Pvt. Ltd., Pune
* Corresponding Author. Tel: +91-22-25767830, E-mail: bakulrao@iitb.ac.in

2. Motivation
With issues of climate change taking a forefront
there is a need to promote technologies like
biogas which effectively addresses the problem of
greenhouse gas emissions and solid waste
management.
This will lead to self-reliant development of a
country by meeting the energy needs through
renewable sources, and decentralised energy
supply in domestic, industrial and commercial
segments in rural and urban areas.

3. Problem Statement
• The current study carries out a multi criteria
analysis using Analytical Hierarchical Process
(AHP) tool for selection of biogas technology
(2m3 capacity) among the widely promoted
models by GOI with a perspective of overall
self-reliant development.

4. Tool Used for Analysis - AHP
• Developed by Prof. Thomas Saaty in 1970s
• Aids in understanding and analysing diverse
information about various technologies and arriving at
a right technology option.
• Uses a pair-wise comparison method for assigning
weights to the attributes and also measures
consistency of pair-wise comparisons.
• AHP also helps in quantifying the qualitative attributes
• Structures a decision problem into a number of
hierarchical levels
• Hence AHP is chosen for analyzing the technology
alternatives in this paper.

5. RESEARCH METHODOLOGY
• Biogas Technologies Identification and Data Collection
• Information regarding the technical, social, economic and
environmental attributes were obtained through primary
surveys and interviews.

6. Characteristics of various biogas plants
Attributes
Units
KVIC digester KVIC digester with KVIC digester KVIC digester with FRP
Deenbandhu
Nisargaruna
(T1)
(T5)
technology
ferrocement
digester and gas holder
digester (T2)
6000
200
3
6
holder (T3)
8000
150
3
6
(T4)
Capital cost
Maintenance cost
Skilled labor
Unskilled labor
for construction
Time to set up
Rs
Rs/year
Nos.
Nos.
Days
5
5
Life of the plant
Years
10
Payback period
Years
Energy Required/ kWh/day
Consumed
Feed to water ratio 1
Raw material
*
Location
Transport
*
*
CH4 content in the %
biogas
Sturdiness
*
Skills
*
Accessories
required
*
Degree of
mechanization
*
*- qualitative attribute
11000
299
3
6
with FRP gas
(T6)
360000
24000
3
4
25000
100
5
7
7000
150
3
6
3
3
4
45
12
15-20
25-30
12
10
4
2
4
6
4
NR
NR
NR
NR
NR
3
1
FRP
1
Bricks, Cement,
Sand
1 to 3
Mild Steel
Sheets
Village
Tempo
Village
Not Transportable
City
Truck
55-60
50-55
70-75
Less Sturdy
Sturdy
1
1
1
Bricks,
Bricks, Concrete, Bricks, Concrete,
Concrete,
Cement, Sand, M.S. Cement, Sand,
Cement, Sand, Sheet, M.S. Wire
FRP
M.S. Sheet
Village
Village
Village
Not
Not transportable
Not
transportable
Transportable
55-60
55-60
55-60
Sturdy
Sturdy
Sturdy
Sturdy
Initial training is
required
none
Initial training is
required
none
Initial training is
required
none
Initial training is required
Manually
operated
Manually operated
Manually
operated
Manually operated
none
In depth training Intense training
required
required
none
Large no of
accessories
required
Manually
Partially
operated
mechanized

7. AHP Methodology
• AHP involves three stages namely, decomposition,
comparative judgment and synthesis of priorities
Stage 1: Decomposition

8. Quantitative and qualitative attributes of
various technology alternatives
Level 2
Attributes
A1
Capital cost
A2
A3
Maintenance cost
Skilled labor
A4
Unskilled labor for construction
A5
A6
A7
A8
A9
A10
Time to set up
Life of the plant
Payback period
Energy Required/ Consumed
Feed to water ratio
Raw material
A11
Transport
A13
A14
CH4 content in the biogas
Sturdiness
A15
A16
Skills
Accessories required
A17
Degree of mechanization
Rs
Cost/
Benefit
Location
A12
Units
Cost
Rs/year Cost
Nos. Cost
Nos.
Benefit
Days
Years
Years
kWh/day
1
Cost
Benefit
Cost
Cost
Cost
%
Benefit

9. AHP Methodology
• Stage 2: Comparative judgment an attribute to attribute comparison is
carried out.
• Attribute weights are obtained by doing pairwise comparison of the
attributes
• The quantitative attributes are defined as cost attribute or benefit
attribute and accordingly its normalized values are calculated
• Stage 3: Ranking the alternatives following formula is used
Here,
Rj = Ranking of the alternatives
pij = Normalised attribute values of the alternatives
wi = Attribute weight

10. RESULT OF AHP STUDY
• The summary of rankings is shown below:
Alternative T1
Rj
Rank
T2
T3
T4
T5
T6
3.83 3.81 3.83 4.05 3.97 0.60
4
5
3
1
2
6
• KVIC with FRP gas holder and digester ranks 1st because of its:
 Corrosion resistance and hence less maintenance cost,
 High strength to weight ratio which makes it easy to transport and
improved life, and
 Unskilled person with meager amount of training can also be
employed in its construction and repaire hence meeting the goal of
regional self reliant development.