Engineering Service-Learning in Ghana
Biogas Project Team Pre-Trip Report
Kave Anderson
Meng Cheng
Victor Haynes
Kan Liu
In collaboration with Dr. Roger Dzwonczyk, Mariantonieta Gutierrez Soto
and the Engineering Education Department, Columbus, Ohio,
The Ohio State University
December 3, 2015
Table of Contents
1. Introduction ............................................................................................................................................... 1
1.1 Definition of Terms ........................................................................................................................... 1
1.2 Executive Summary .......................................................................................................................... 1
1.3 Team Members and Other Participants ............................................................................................. 2
1.4 Project Location ................................................................................................................................ 3
2. Background ............................................................................................................................................... 3
3. Scope of Work .......................................................................................................................................... 3
3.1 Problem Statement ............................................................................................................................ 3
3.2 Customer Identification ..................................................................................................................... 4
3.3 Needs Assessment ............................................................................................................................. 4
3.4 Specific Objectives ........................................................................................................................... 6
3.5 Deliverables ...................................................................................................................................... 6
3.6 Sustainability Assessment ................................................................................................................. 7
4. Background Research ................................................................................................................................ 9
5. Representation ......................................................................................................................................... 10
6. Prototyping .............................................................................................................................................. 15
6.1 Prototyping Details .......................................................................................................................... 15
6.2 Testing and Results ......................................................................................................................... 16
6.3 Evaluation ....................................................................................................................................... 17
7. List of Materials ...................................................................................................................................... 18
8. In Country Schedule ................................................................................................................................ 20
Table 4. In-country Pre-Trip Schedule .................................................................................................... 20
Table 5. In-country Post-Trip Schedule .................................................................................................. 21
9. Post-Trip Results..................................................................................................................................... 22
9.1 Objectives Achieved ....................................................................................................................... 22
9.2 Project Diagram .............................................................................................................................. 22
9.3 Issues Encountered ......................................................................................................................... 23
9.4 Sustainability Statement ................................................................................................................. 23
10. In-Country Project Evaluation ............................................................................................................ 24
10.1 Success ............................................................................................................................................ 24
10.2 Weakness ........................................................................................................................................ 24
10.3 Improvements in the Future ............................................................................................................ 24
10.4 Cost Analysis for Research & Development .................................................................................. 25
10.5 Cost Analysis in Ghana ................................................................................................................... 26
11. Conclusion .......................................................................................................................................... 27
12. Recommendation ................................................................................................................................ 27
13. References ........................................................................................................................................... 29
14. Acknowledgements ............................................................................................................................. 30
15. Appendices .......................................................................................................................................... 31
15.1 Extra Figures ................................................................................................................................... 31
15.2 Biogas Technology Team Agreement ............................................................................................ 33
15.3 Meeting Notes ................................................................................................................................. 36
15.4 Maintenance & Use ......................................................................................................................... 41
15.5 Overall Gantt Chart ......................................................................................................................... 43
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1. Introduction
1.1 Definition of Terms CCO Chief Communication Officer
CFO Chief Financial Officer
GO ENGR Global Option in Engineering
GSC Ghana Sustainable Change
LPG Liquefied Petroleum Gas
ONDA Offinso North District Assembly
1.2 Executive Summary
The human race’s increased use of fossil fuels has led to much speculation regarding the
well-being of the planet. These speculations have led to a new paradigm in thinking. Over the
past decade, increased focus has been placed on sustainability throughout many avenues. Solar
energy, wind energy, and geothermal heating are a few of the many developments that have
arisen. While these new “clean” energies are better for the environment, they are still rather
expensive and inefficient. One such energy that is more feasible to use is Biogas Technology.
Biogas Technology is a fairly recent development in the worlds of engineering and
academics. The main product of biogas is methane gas, which is a cleaner, more efficient fuel for
cooking than commonly used firewood. Because of its low cost, ease of construction and
environment friendly, this option is the most popular in underdeveloped countries. One such
country, Ghana, is the focus of the International Engineering Service-Learning Program. The
team will travel to Akomadan, Offinso North District Assembly, Ghana in order to construct a
Biogas Digester for the community residents to use. Residents will be able to use the bio-digester
to generate biogas to use primarily for cooking when wood had previously been used.
For the pre-trip biogas project testing, the group has built a 5 gallon digestion tank
prototype to test the possibility of producing, filtering and collecting the biogas. With the
experience from the prototype, the group decided to build a 1000L digestion tank with steel wool
filter and larger floating water trap for the in country project. The team hopes this can bring
Ghanaian partners lower cost energy and better life.
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1.3 Team Members and Other Participants
Table 1. Team members and participants
Members Roles Major (Minor) Phone Email
Kave
Anderson
Team
Leader, CCO
Biological
Engineering (GO
ENGR)
(404) 468 - 2806 [email protected]
du
Kan Liu Co-Leader,
Director of
Testing,
Logistics
Manager
Aerospace
Engineering
(GO ENGR)
(917) 250 - 9768 liu.1891 @osu.edu
Meng Cheng Primary
Documenter
Mechanical
Engineering
(Math, Russian)
(614) 254 - 9351 cheng.643 @osu.edu
Victor
Haynes
CFO, Lead
Design,
Multimedia
Civil
Engineering
(Design, GO
ENGR)
(815) 302 - 3242 haynes.249 @osu.edu
Other
Participants
Title Phone Email
Roger
Dzwonczyk
Resident Director (614) 570 - 2073 [email protected]
u
Mariantonieta
Gutierrez Soto
Resident Director (614) 315 - 4988 gutierrez-
Honorable
Kojo
Appiah-Kubi
District Chief Executive (020) 922 - 2222 [email protected]
m
Augustine
Yeboah
Electrical Technician (024) 816 - 5422 Augustineyeboah22@
gmail.com
3
1.4 Project Location
During the fall semester, the initial research, design, and prototyping was one at The Ohio
State University located in Columbus, Ohio, United States of America. Prototype building is
conducted in Smith Laboratory and testing is carried out in the Agricultural Engineering
Building. The in-country portion of the project is conducted in the Offinso North District
Assembly (ONDA), which is located in Akomadan, Ghana.
2. Background
Ghana implemented a Liquefied Petroleum Gas (LPG) promotion program in 1989. Since
then, LPG has grown in popularity as a source of clean cooking fuel among Ghanaian
communities and households. The National Energy Policy of 2010 indicates that, “the
Government intend to increase the access of households to LPG as main cooking fuels to 50%
by 2015.” (Ghana Energy Action Plan, 2012). The growing demand of LPG brought not only
fast development but also challenges. The Ghana Energy Action Plan overestimated the speed
of LPG use in households; only 18% of the households were actually using LPG.
There is a huge demand among the Ghanaian population for a clean cooking fuel that is
not being met. Without the LPG, the current economically cooking fuel left for Ghanaian
people is wood. However, the side products of burning wood like CO and ashes are harmful
for the environment and human.
In order to protect Ghanaian people’s health, save the environment, and satisfied the
huge demand of cooking fuel, the group need to find an economical, clean and easy to use
fuel. One of the most suitable energy sources available is naturally occurring methane gas
harnessed by biogas digester technology.
3. Scope of Work
The following section clearly documents the project requirements, milestones,
deliverables, end products, documents and reports that are expected to be provided by the bio-gas
technology group.
3.1 Problem Statement
Methane gas is a cleaner, more efficient fuel for cooking than commonly used firewood.
In 2013, Ghana Sustainable Change (GSC) introduced biogas technology as a means to
produce methane gas. However, the bio-digester that was created is currently inoperable. The
current situation calls for renovation of the existing bio-digester and/or the implementation of
more updated technology--possibly in the form of completely new bio-digesters.
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3.2 Customer Identification
This project is a collaboration of The Ohio State University students and Ghana partners,
ONDA to deliver sustainable biogas technology to Ghanaian people.
3.3 Needs Assessment
The prototype completed before departure was operable; it created methane gas in its
closed system as intended. Because it was built from the ground up, the prototype served its
secondary purpose of identifying unanticipated complications in the engineering design process.
The current issues with the entire scope of the biogas project are divided into two categories:
binary (simple) problems, and open-ended problems.
Binary Problems:
● Addition of valve(s):
○ An open and shut valve (i.e. a ball valve) is needed somewhere in the piping
between the septic tank and the water trap. The addition of this valve would help
coax the trapped gas to flow in the proper direction. This would be especially
helpful in the early stages of gas production due to the minimal internal pressure.
● Slurry and excess waste liquid pipe:
○ A slurry and or excess liquid runoff pipe with an open and shut valve needs to be
added. Emptying the contents of the septic tank or over filling it were controlled
variables that were removed from our focused design and the scope of our testing.
In country, there will need to be a way to remove excess liquid from the system
without exposing the contents of the tank to too much oxygen. A simple runoff
pipe solves this.
Open-ended Problems:
● Necessity of water trap:
○ The efficacy and salience of the water trap needs to be assessed. The water trap
makes the design process markedly more complicated. There is reason to believe
that a digester without a water trap would be serviceable, comparably efficacious,
and much easier to design.
● Weak internal flow:
○ While the prototype did produce methane gas, the gas did not flow into the
designed capture bag as intended. The gas either stayed in the septic tank, in the
steel wool filter, or in the water trap. This is a point of contention because it is not
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clear as to why this system had very poor flow. It is probably due to the fact that
this very small scale digester is not generating substantial amounts of internal
pressure. The lack of flow is a major motivating factor for the possible removal of
the water trap--the gas would collect directly above the waste in this design.
● Minimizing the introduction of oxygen introduced through routine use:
○ The feedline design for the septic tank needs to be slightly more robust and
sophisticated. Quasar Energy Group recommended that the feedline be kept full
so oxygen cannot reach the fermenting bacteria, only the top of the waste that is
being added.
● Carbon dioxide filtering (with calcium hydroxide as the primary agent):
○ The efficacy and design-feasibility of using soda lime, calcium hydroxide, or
limewater (calcium hydroxide and water) to filter the gas and absorb harmful and
useless carbon dioxide gas (which is an occurring byproduct) needs to be
determined.
● Bonding with glue and materials in country:
○ Because the materials in country are not precisely known, there is a question of
which types of plastics will be available (for the septic tank, various fixings,
piping etc.). Not all types of plastic easily bond together. Working with PVC
would be ideal but it is unknown if all the necessary components will be made out
of PVC.
● Safety of the gas capture bag(s):
○ The materials for the in country capture bag(s) or equivalent storage unit(s) are
not precisely known. In the prototype, a thick standard material trash bag was
used along with PVC fixings. There were no clear issues with the design. The
capture bag needs to be robust and airtight if they are going to be used. For safety
reasons, at the cost of convenience, they can easily be removed from the
deliverables if necessary.
● Wide possible array of fuel sources in country:
○ Having a more precise idea of methane potential would be ideal. Unfortunately,
knowing precisely largely depends on the fuel sources. However, there are known
general figures, current design features in place and known techniques that
generally increase the amount of gas generated whilst filtering out unwanted
gases (i.e. carbon dioxide, hydrogen sulfide).
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3.4 Specific Objectives
● The team will build a biodigester with all parts entirely from Ghana at an affordable cost
to ensure the sustainability of the program.
● The team will make the biodigester serviceable, fitting for use, and fit to produce enough
methane for daily cooking.
● The team will teach the Ghanaian people operation and maintenance procedures of the
biodigester.
● The team will simplify the usage and maintenance procedure of the biodigester and leave
operation manual to Ghanaian households.
● The team will focus on the sustainability aspect of the bio-digester, the delivered product
should be easy to maintain and replacement parts should be accessible in Ghana.
● The team will ensure the biodigester be durable and usable for an extended period of
time.
● The team will investigate the local community and find the possibility of installing biogas
electricity generators in the future.
3.5 Deliverables
At the end of a two week implementation and evaluation period in Ghana, the following
will be delivered to the Offinso North District
● A Biogas Digester will be deployed to one residence following the recommendations of
our in country hosts (primarily: Isaac Tenkorang, Augustine Yeboah, Honorable Kojo
Appiah-Kubi, and Andrews Bediako).
● Training will be given to the community residents who will receive and/or use the
Biogas Digester for cooking.
● Training will take the form of an educational presentation, a brochure detailing
procedures, and a “One-Point Lesson” to be attached to the Biogas Digester.
● Pending the approval of our in-country hosts, one or several community residents will
help with the implementation gaining expanded knowledge which will aid in
maintenance and upkeep.
The following points detail aspects of the project that are “Out of Scope” or that will not be
included in our implementation of the Biogas Digester:
● A Biogas Digester will be implemented that supplies biogas used for cooking. This
does not include a cooking stove or any related paraphernalia.
● There will be no evaluation of the Biogas Digesters that may have been constructed
during previous trips unless requested by residents.
● There was a request to investigate the possibility of generating electricity from
biogas. After research it was decided that this venture would be too expensive.
Almost all Biogas systems that create electricity have a generator available.
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3.6 Sustainability Assessment
There are several factors that keep effective programs sustained over time. The ultimate
goal of the Ghana International Engineering Service-Learning curriculum is to implement
projects that take into account the needs of the community. An important aspect of this is that the
residents must find the deliverables to be something that they can use and will make life a little
easier. There are several elements that we believe will aid in the ability to maintain the benefits
of the Biogas Digester over time. Those elements include: Environmental Support, Funding
Stability, and Communication/Partnership,
Environmental Support:
● Waste Management
○ As long as maintenance is kept up, a biogas digester can last as long as 10 years.
○ End of life disposability could be tricky however. Because the contents of the
digester are flammable and chemical hazards, the contents must be disposed of
properly and the materials used must be sanitized.
○ A Biogas Digester is extremely useful for waste management because the fuel for
the biogas product is literally waste. Manure, food wastes, and cooking greases
are all viable fuels for the digester. A Biogas Digester runs off of organic material
which makes it highly efficient.
● Energy Efficient
○ A Biogas Digester is highly sustainable. There is no gasoline, electricity, or any
materials other than organic waste needed to run it.
● Safety
○ The purpose of the Biogas Digester being implemented in Ghana is to generate
gas to be used for cooking. Currently, most Ghanaians use biomass like wood for
cooking. Cooking with wood is dangerous because chemicals like carbon
monoxide, formaldehyde, and sulfur dioxide are abundant. The smoke from wood
interferes with lung development in children and can cause cancer (The Health
Effects of Wood Smoke). Because of this a Biogas Digester is a cleaner, healthier
way to cook.
Funding Stability:
● Cost to build, operate, and maintain;
○ The cost of a Biogas Digester is relatively inexpensive.
○ For details regarding costs and materials, refer to Section 8.
8
● Scalability
○ For prototyping, the group experimented with a smaller version of the plug flow
biodigester that was built in Ghana in 2011. The prototype used a five gallon
bucket as the holding tank. In Ghana the biodigester was constructed with a 250L
tank.
○ A Biogas Digester is extremely scalable and the simple construction can be
duplicated to build multiple units for each home.
Partnership:
● Entrepreneurial potential
○ One point that was emphasized at the very beginning of the curriculum was the
aspect of entrepreneurial potential. Dr. Dwonczyk stressed that the class keep
entrepreneurship in mind during research and implementation of the projects.
○ Biogas Digesters have moderately low entrepreneurial potential. The most
obvious venture would be for restaurants, diners, and other food services. Biogas
can be used to cook and sell meals in the community.
○ On a more technical level, the biogas can be harnessed and sold to families to heat
their homes. But because Ghana is closer to the equator and therefore hotter than
countries like the United States there is little use for the excess heat.
● Ownership
○ As previously mentioned, one of the most important aspects of sustainability is
ownership. If there is no one available to learn to construct and maintain the
Biogas Digester then the project will be useless.
○ In order to prevent this from happening, education has to be a point of emphasis.
○ Please see Section 3.5 for further information about training and ownership
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4. Background Research
In order to build a biogas digester that fills all the previous requirements, the team began
background research in the 5th week. The information was collected mainly through three
resources: construction videos online, research papers, and an interview with the professor.
Videos:
The team focused on three videos found on Youtube. The team confirmed the first
prototype construction process based on the video “How to make a Bio-gas Digester”5. From the
video, the group decided to use large poly tank with one inlet and two outlets as digestion tank.
And the PVC glue should be used to fix and seal the connection between parts.
Based on the video “Biodigester - Methane as fuel”1, the team learnt that the side product
of digestion process, H2S can be removed by a steel wool filter. The reaction between iron and
H2S will form FeS. So, the team added a steel wool filter in order to remove the H2S, which is
harmful to user.
Based on the video “Storing biogas in a plastic trash bag”10, the team learnt that the
biogas can be easily collected in a seal trash bag. And the pressure caused by the weight of
blanket on the bag is proper for burning usage. The team the installed a gas storage bag on the
prototype.
Research Papers:
The team learned that the biogas digestion process is actually the anaerobic digestion of
the organic by certain stereotypes of microbes.8 During the process, methane as the gas fuel as
well as side products like CO2 , H2S will be produced.4 In order to keep the microbes active, the
temperature, pH and C/N ratio of the rough materials should be kept in a proper range.4
Interviews:
The team scheduled an interview with Dr. Yebo Li, a specialist on biogas digester aspect.
Dr. Li shared a lot of his own experience like accelerating the process by using “seeds” and oil;
adjusting the pH by adding buffer or stop feeding. He also shared some maintenance skills with
the team
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5. Representation
For more information see: Prototyping 7.1. The pictures listed below represent various preliminary design
ideas and concepts.
Preliminary Photos and Sketches
Figure 1. Concept of a water trap
The first drawing made. It depicts the concept of a water trap. Biogas containing methane enters from the
left and exits from the bottom of the pipe immersed in water. The gas bubbles up through the surface and
escapes through its only route on the right.
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Figure 2. A birdseye view of the lid of the septic tank
The black marks indicate the size and location of the necessary cuts for tubing and the feedline.
Figure 3. The underside of a plastic bucket
It is the top face of the water trap. The black marks indicate holes for tubing. Gas enters on the right and
exit on the left.
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Figure 4. Drilling the tubing hole (Kave) The water trap being assembled. The holes depicted in Figure 3 are being drilled through. On the table,
the lid of the septic tank can be seen.
Figure 5. Assembling the prototype. Left: the septic tank with the feedline, a rubber plug/lid for the feedline, a threaded adapter.
Right: the top of the water trap, a threaded adapter, tubing through the adapter (this is on both sides. See:
Figure 3 and Figure 4)
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Figure 6. The underside of the septic tank lid with adaptor installed. This piece along with tubing that will be attached to it will allow the gas to escape from the septic tank.
These pieces greatly simplify the building process.
Figure 7. A drawing of the idealized prototype design
From left to right: a capture gas bag, tubing, a valve, more tubing, the water trap, tubing, a valve, steel
wool filter and tubing, septic tank, waste feedline. Circled components are possible improvements.
14
Figure 8. The steel wool filter being stuffed (white pipe with lid
removed).
15
6. Prototyping 6.1 Prototyping Details
Figure 9. Prototype Design Diagrammatic Sketch
Details:
● The aforementioned depicts a closed-system anaerobic biogas digester.
● Aside from instructions, the final prototype consists of:
A. Biogas digester
The container where the digestion process happened inside. The biogas production part.
B. Water trap (optional)
Used to store the gas when gas bag not available, and control the pressure inside.
Stop the possibly gas reverse flow.
C. Steel wool filter (optional)
Fix toxic H2S gas.
D. Gas capture bag (optional)
For convenience and short to medium term storage.
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6.2 Testing and Results
After two weeks of digestion process, the prototype was tested on three aspects: the gas
production, the toxic filtering and the gas storage.
Of the gas production:
Method: Flame test. The team held a burning object at the end of the tube and checked whether
the emission gas will accelerate the burning process.
Observation: The bubbles came out from the mixture and released gas. The area on the object
contacted with gas was ignited suddenly and formed larger flame.
Result: The burning phenomenon above shows that the flammable biogas was produced and
stored in the tank at a proper concentrate.
Of the toxic filtering:
Method: Steel observation. The team took the steel wool out from the filter and checked the
color. The iron atom will react with H2S and form dark brown FeS compound.
Observation: Compared with original steel wool, the steel wool in the filter did not appear to
have color change.
Result: There is not enough evidence show that the hydrogen sulfide was fixed on the steel
wool. The immeasurable color change may due to the short usage period and the small
amount of H2S. A further acid test will give clear answer.
Of the gas storage:
Expected Result: Based on the calculation. Around 1.5lb of the cow manure, dry grass and palm
oil mixture should produce around 20L of biogas within two weeks. The storage
bag should be around ⅛ full.
Observation: The gas storage bag was completely flat.
Result: The flat bag means there was no gas in the bag. After detailed examination,
the team found a leak between the flexible tube and the PVC adaptor. The leak reduced
the maximum pressure in the tank. The gas cannot pass through water trap but is emitted
into air.
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6.3 Evaluation
Successes
The prototype verified the assumption that the seeds and oil can accelerate the digestion
process. For the in-country project, the group is going to keep on using seed to accelerate the
process.
The design of the inlets/outlets positions can be applied in the in-country project.
The team used PE pipes when transferring the biogas increased the flexibility and mobility
of the gas tank.
Failures and Experiences
The sealing problem is the most serious failure in the prototype design. The team used
two kinds of plastic which are PE & PVC, and the sealing between two different materials is a
big difficulty. The contact area between tank and leaked even after sealing two times. Based on
the previous lesson and the larger tank used in the in-country project, the team decided to use
pure hard PVC tube connection in the in-country project and seal every connection tightly with
PVC glue.
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7. List of Materials
Table 2: Prototype 1 Material List
Part Description Quantity Cost (USD) Consumed
5 gallon blue lid 2 2.54 2/2
5 gallon blue bucket 2 5.96 2/2
2 gallon blue bucket 1 3.58 1/1
3" PVC tube 1 x 2 ft 4.98 2/2ft
3" plug 1 4.99 1/1
1/2" PVC adaptor 2 0.77 2/2
#5 o-ring 10 2.49 1/104/10
super fine steel wool 1 x 4 3.97 2/4
5.5 oz fast dry 1 2.78 2.5/5 oz
3"/4" PVC closet flange 2 7.36 2/2
3/8" ball valve 1 7.77 0/1
3/4" to 1/2" adaptor 4 3.88 0/4
1/2" out (3/8" in) flexible tube 13 ft 3.77 13/13 ft
3/4" 90° PVC elbow 4 1.88 0/4
3/4" PVC ball valve 2 14.66 0/2
3/4" insert combination 1 1.21 0/1
8 oz PVC cement 1 4.98 2/8 oz
1/4" PVC tubing 1 x 3 ft 0.48 0/3 ft
1/2" PVC pipe 1 x 5 ft 2.79 1/5
3/4" to 1/2" adaptor 1 0.97 0/1
duct tape 1 x 75 ft 8.98 12/75 ft
3/4" to 1/2" PVC coupler 1 0.24 0/1
1/2" PVC ball valve 1 6.2 1/1
42-gal trash bag 24 12 1/24
palm oil 10oz Provided by Victor 9.5/10 oz
lime juice 2.5oz Provided by Victor 2.5/2.5 oz
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Table 3: In-Country(Ghana) Project Material/Tool List
Part Description Quantity Purchase Location
3' PVC tube 1 x 2 ft Ghana
3" test plug 1 Ghana
1/2" PVC adaptor 1 Ghana
#5 o-ring 10 Ghana
super fine steel wool 1 Ghana
5.5 oz fast dry 1 Ghana
3"/4" PVC closet flange 2 Ghana
3/8" ball valve 1 Ghana
3/4" to 1/2" adaptor 4 Ghana
1/2" out (3/8" in) flexible tube 13 ft Ghana
3/4" 90° PVC elbow 4 Ghana
3/4" PVC ball valve 2 Ghana
3/4" insert combination 1 Ghana
8 oz PVC cement 1 Ghana
1/4" PVC tubing 3 x 1 ft Ghana
1/2" PVC pipe 1 x 5 ft Ghana
3/4" to 1/2" adaptor 1 Ghana
1/2" PVC adaptor 1 Ghana
duct tape 1 x 75 ft Ghana
3/4" to 1/2" PVC coupler 1 Ghana
1/2" PVC ball valve 1 Ghana
42-gal trash bag 24 Ghana
palm oil 10oz Ghana
lime juice 2.5oz Ghana
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8. In Country Schedule
The overall project timeline is presented in the Overall Gantt Chart section of the
Appendix. The in-country pre-trip schedule is presented in table 4. The in-country post-
trip schedule is presented in table 5.
Table 4. In-country Pre-Trip Schedule
Date Goals
Saturday, December 26th 0700: Depart from Columbus
Sunday, December 27th 0750: Arrive in Accra
Monday, December 28th
Morning:
Site visit
Implement project plan Afternoon: Supplies shopping
Tuesday, December 29th
Morning:
Start bio-digester building Measure
and drill connection holes Measure and
cut PVC pipes
Afternoon:
Supplies shopping Searching
for cow manure Wednesday, December 30th
Morning: Supplies shopping( if needed) Install and connect PVC pipes
Afternoon: Sealing gaps Obtain cow manure
Thursday, December 31th
Morning: Extra time for bio-digester building
Afternoon: Extra time for obtaining cow manure and supplies shopping
Friday, January 1st
Morning: Extra time for biodigester building
Afternoon: Extra time for obtaining cow manure and supplies shopping
Saturday, January 2nd Rest day (other activities)
Sunday, January 3rd Rest day (other activities)
Monday, January 4th
Morning: Finish up bio-digester building
Afternoon: Start collecting data (if possible)
Tuesday, January 5th
Morning: Test bio-digester (if possible)
Afternoon: Troubleshooting
Wednesday, January 6th
Morning: Make bio-digester instructions/manual
Afternoon: Extra time for troubleshooting
Thursday, January 7th
Morning: Extra time for troubleshooting
Afternoon: Education/teaching time
Friday, January 8th
Morning: Time reserved for extra event
Afternoon: Time reserved for extra event
Saturday, January 9th 2200: Depart from Accra
Sunday, January 10th 2238: Return to Columbus
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Table 5. In-country Post-Trip Schedule
Date Goals
Saturday, December 26th Departed from Columbus
Sunday, December 27th Arrived in Accra
Monday, December 28th Morning: Project supplies purchasing (PVC parts)
Afternoon: Meet and greet with ONDA staff
Tuesday, December 29th Morning: Met with Augustine and project discussion
Afternoon: Purchased poly tank
Wednesday, December 30th Morning: Obtained cow manure Biodigester building (80% completion)
Afternoon: Purchased project supplies (PVC parts and connectors)
Thursday, December 31th Morning: Purchased project supplies (PVC sealing parts and steel wood)
Afternoon: Visited Techiman Processing Complex Biodigester building (95% completion)
Friday, January 1st Morning: Waterfall visit
Afternoon: Monkey sanctuary visit
Saturday, January 2nd Visited the hospital and Nana’s village
Sunday, January 3rd Rest day and football
Monday, January 4th Morning: Finished biodigester building (100%)
Afternoon: Filled up the water tank Took pictures
Tuesday, January 5th Morning: Searched for gas bags
Afternoon: Obtained more cow manure
Wednesday, January 6th Morning: Put in the last batch of cow manure
Afternoon: Augustine showed us his work and company
Thursday, January 7th Morning: Interviewed by the radio station Presented the biodigester to Kojo and other OSU teammates
Afternoon: Presented the biodigester to ONDA staff
Friday, January 8th Morning: Traveled to Cape Coast
Afternoon: Ghana national forest visit
Saturday, January 9th Cape Coast Elmina Castle visit Departed from Accra
Sunday, January 10th Returned to Columbus
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9. Post-Trip Results 9.1 Objectives Achieved
Upon reaching the worksite, the team found that the biogas tank would only be used by
Augustine’s family. So, the scale of the design had been changed. After investigating the wasted
biogas tank built by the previous 2012 team, the group concluded that their failure was caused by a
defective design. However, the wasted tanks were still good to use. In order to save the cost and
protect the environment, the group decided to recycle the wasted tanks from previous design.
While In Country, the team competed the following tasks:
The team built a 1000L biogas digester with all parts entirely from Techiman and
Akomadan, Ghana.
Biogas digester was built at a relatively affordable cost ($226 US dollars) to ensure the
sustainability of the program.
The team made the biogas digester serviceable, fitting for use, and fit to produce enough
methane for daily cooking.
The team collaborated closely with Augustine Yeboah and Isaac Tenkorang to ensure
someone was knowledgeable about the operation and maintenance procedures of the biogas
digester.
The team left a simple operation manual with ONDA.
The team focused on sustainability of the bio-digester to ensure the delivered product was
easy to maintain and replacement parts were accessible in Ghana.
The team investigated the local community and found examples of biogas electricity
generators. A partnership between ONDA and Techiman Processing Company (TEPCO)
was established to explore future projects in this field.
9.2 Project Diagram
Figure 10. Overall Diagram for the In-Country Project
23
9.3 Issues Encountered 1. Budget
The budget for the whole project was $400 ($100 for each team member). After the prototype
testing, the team brought around $250 budget for the In-Country Project. And the final total budget
is $394.31 (hardly anything left). The polytank was really expensive and worth 540 Ghana cedi
(about $142). So the team used two wasted tanks from previous group project to save cost. Even
though, the team was out of budget for the short term gas storage bag design.
2. Material
Most of the materials were bought from Techiman which is about 30 min from the
construction site. When the team forgot to buy some parts, it took over 1 hour to buy and bring it
back. It wasted a lot of time.
The team cannot find heavy duty plastic bags in Ghana. Plastic bags on market were too thin
and leaking. This is another reason why the team gives up short term gas storage bag design.
3. Vehicle Arrangement
Ghana is not a developed country and the vehicles resources are limited. Usually, the team
need to wait until the vehicles sent two other teams to the site and came back. The room of the
vehicle is also limited. Most of the time, team members need to sit in the trunk of the pickup. When
the pickup was full loaded with materials/water/manure, the team members also need to keep the
loadings fixed.
4. Sealing
The sealing was still a problem in the In-Country Project. As the size of the project increased,
the water level inside the tank increased. In this case, the high pressure in the water tank can cause
leaking easily. In order to solve the problem, the team used epoxy to seal between plastic; Teflon
tape to seal between threads; silicon to fill the leakages.
9.4 Sustainability Statement The ultimate goal of the Ghana International Engineering Service-Learning curriculum was
to implement projects that take into account the needs of the community. An important aspect of
this is that the residents must find the deliverables to be something that they can use and will make
life a little easier. There are several elements that we believe aided in the ability to maintain the
benefits of the biodigester over time.
Waste Management
The biodigester is extremely useful for waste management because the fuel for the biogas
product is literally waste. Manure, food wastes, and cooking greases are all viable fuels for the
digester. A biodigester runs off of organic material which makes it highly efficient.
Safety
The purpose of the biodigester being implemented in Ghana is to generate gas to be used
for cooking. Currently, most Ghanaians use biomass like wood for cooking. Cooking with wood is
dangerous because chemicals like carbon monoxide, formaldehyde, and sulfur dioxide are
abundant. The smoke from wood interferes with lung development in children and can cause
24
cancer (The Health Effects of Wood Smoke). Because of this a Biogas Digester is a cleaner,
healthier way to cook.
Entrepreneurial potential
Biogas Digesters have entrepreneurial potential, but this is primarily on a large scale.
Restaurants, diners, and other food services could use Techiman Processing Company as an
example. In their production of tomatoes, Techiman Processing Company is using wastes to go into
a biodigester that would provide natural gas and electricity for the company to use at its leisure. In
addition, Biogas can be used to cook and sell meals in the community.
10. In-Country Project Evaluation 10.1 Success
Compare with the prototype, the in-country project is a more successful project. In the project
construction, the team improve design; saved cost; simplified usage and maintenance; achieved
requirements.
In the previous design, digestion tank was open to the air. Oxygen in the air will dissolve in
the water and kills anaerobic bacteria which producing methane. Of the new project, the digestion
tank was separated from the water trap and seal tightly.
In order to save the cost, the team recycled the wasted tanks from previous group and
transformed them into a storage water trap. The new water trap can store around 400L of biogas
and adjust pressure in a small range. It saved the team at least 1000 Ghana cedi (around $263) by
recycling the two tanks.
All of the parts were bought in Techiman and Akomadan. This means it’s convenient for user
to replace any broken parts.
The biogas digester tank is 1000L and will start producing enough biogas for a family
cooking usage after 3 months.
10.2 Weakness
Similar to the prototype, sealing problem still appears. When recycling the wasted tank,
most of the sealing parts are too old to be used. Although the team replaced them with new parts,
the leaking still happens because of the uneven surface between connections. The team should
clean the surface of the sealing parts before replacing.
10.3 Improvements in the Future
There are still some aspects can be improved on this project and similar projects in the
future. Three important parts are: production rate measurement; gas tank pressure adjustment
measurement and CO2 filter.
For the production rate measurement:
Since the production of the biogas depends on ingredient type, outdoor temperature,
humidity and many other factors. It’s really hard to calculate how much biogas will be produced
daily instead of testing. If the production rate can be measured, it will be easier to choose the size
of the digestion tank and the ingredients amount based on the demand. To measure the production
rate, label volume marks on the gas tank based on the height and the inside diameter of the tank.
Then let the digestion tank run out of ingredients and use up all biogas in the tank. Finally, measure
25
the amount of the ingredients injected and the volume of the biogas produced daily.
For the gas tank pressure adjustment:
To use the biogas at stove, the pressure need to be controlled at a proper range. For the project,
the user can adjust the pressure with stones. However, a quantified standard will be better for
operation. The relationship between the weight of stone and the pressure can be calculated from the
inside diameter of the gas tank. Based on the calculation, the user could know the proper weight of
the stone should be put on the gas tank.
For the CO2 filter:
The raw biogas usually contains up to 40% of inflammable CO2, which reduced the
combustibility of the biogas. In order to improve the performance, a CO2 filter can be added if the
budget available.
10.4 Cost Analysis for Research & Development
Table 6. Cost Analysis for Research & Development
Vender Description Cost
Agent of Duraplast Plumbing parts $34.74
Lowe's 3/4'' X10FT CPVC pipe $5.89
Lowe's 3"* 2' PVC tube $4.98
3" test plug $4.99
5 gallon blue lid $1.27
5 gallon bucket (2) $5.96
1/2" PVC adaptor $0.77
3/4" to 1/2" adaptor (3) $2.91
3/4" 90°PVC elbow (4) $1.88
3/4" PVC ball valve (2) $14.66
3/4" insert combination $1.21
8 oz PVC cement $4.98
1/4" *1 ft PVC tubing (3) $0.48
2 gallon blue bucket $3.58
Others $3.58
Lowe's Plumbing parts $30.38
Lowe's Plumbing parts $34.35
OSU Bookstore Educational materials $11.24
In U.S. Research & Development Cost $167.85
26
10.5 Cost Analysis in Ghana
Table 7. Cost Analysis in Ghana
Vender Description Cost
God's Power Paint & Hardware Valve and PVC glue $15.79
God's Power Paint & Hardware PVC plumbing items $20.79
Kwao Electrical Tubing $8.42
ASPET Rambo 100 Tank $136.84
Awurade Okoye Woko 2'' Plugs (2) $1.31
1/2'' Valve socket (7) $1.84
1/2'' Air valve $5.27
Angle valve $5.27
1/2'' F28 (2) $2.63
1/2'' K2 $1.32
1/2'' Bends (7) $1.84
1'' Valve socket (2) $1.58
1/2'' Pipe $2.63
Others $8.02
Winnax Age Company 1'' Tank connector $2.63
1'' Valve socket (2) $1.05
1'' Bend (2) $1.05
Nasa Frimpong Provisions Palm oil $5.53
Winnax Age Company 1'' Tank connector $1.58
1'' Thread plug $0.53
Akomadan roadside store Soap $0.53
Tools(Provided by Augustine)
Shovels $0.00
Saw $0.00
Tools(Provided by Roger, brought from
Columbus)
Power drill $0.00
Plumbers putty $0.00
Wrench $0.00
Teflon tape $0.00
USD to Cedi Conversion (January 2016) 1 : 3.79746
In Ghana Cost $226.46
27
11. Conclusion As previously mentioned, methane gas is a cleaner, more efficient fuel for cooking as
commonly used firewood. In 2013, Ghana Sustainable Change (GSC) introduced biogas
technology as a means to produce methane gas. However, the bio-digester that was created was
inoperable. After in country assessment it was determined that the underlying cause of failure for
the previous design was lack of education about the biodigester. The Ghanaian owners of the
biodigester (primarily Augustine Yeboah) started to use the biogas after a 7-day wait period. This
allowed the biogas to be exposed to oxygen for long periods of time which decimated the anaerobic
bacteria culture needed for fermentation. From research, we understand that it takes about 1-3
months to obtain a sustainable amount of biogas. All in all, in 2 weeks the team renovated the
existing bio-digester and implemented updated technology.
This project was a collaboration of The Ohio State University students and Ghana partners,
ONDA to deliver sustainable biogas technology to Ghanaian people. More specifically, the team
collaborated with Augustine Yeboah and Isaac Tenkorang to deliver the final product.
Some of the issues encountered in-country were centered on Budget, Material, and sealing.
After using 98.5% of our budget for prototyping and in-country materials, the team was unable to
construct a short term gas storage bag. In addition to the budget, the team struggled to find heavy
duty plastic bags in Ghana that were thick and nonporous enough to prevent leaking. Sealing the
biodigester system was also a major problem. In order to solve the problem, the team used epoxy to
seal between plastic; teflon tape to seal between threads; and silicon to fill the leakages.
12. Recommendation Overall, the design and implementation was a success. However, there are delicate details that
need to be communicated to future teams. Many improvements can also be made. The
recommendations below are listed in terms of priority.
Remain consistent with construction materials. PVC, for example, is a desirable
construction material in low-tech biodigesters because of its availability, affordability,
durability, and ability to be cut. While PVC is very compatible with other PVC parts such
elbows, valves, PVC glue, and various fixings, it is not easily compatible with most other
materials. Bonding PVC with other types of plastics or materials is challenging and must
be done with skill and care. The success of a biodigester is largely dependent on the quality
of its seals and bonds. Also, low pressure pipes can certainly be used and are widely
available. They are flexible, but they further complicate bonding issue.
Carbon dioxide gas can be eliminated from the final product. Calcium Hydroxide
[Ca(OH)2] reacts with carbon dioxide [CO2], creating a harmless precipitate calcium
carbonate [CaCO3] and water. All of these reactions and byproducts occur in equal
amounts. Carbon dioxide is a harmful gas and byproduct of biogas digestion--up to 25 to
40%. The [CO2] can be removed by running the gas through a liquid filter (most
commonly a “U tube”) comprised of water and dissolved calcium hydroxide or calcium
oxide13. Calcium oxide [CaO] can also be used to achieve a similar effect with a similar
absorption rate. Calcium oxide and carbon dioxide yields the same precipitate and oxygen
instead of water.
28
These findings come from the literature on biogas and carbon dioxide scrubbing.
Experimental, and therefore practical, results were not obtained. Because of this, the design
of the carbon dioxide scrubber must be robust enough to be effective while also being able
to be removed from the system for occasional desludging.
Be certain to design a feedline or feeding system that can be utilized whilst simultaneously
minimizing the introduction of oxygen from the outside air. Preferably, the level of the
sludge inside the main tank should rise above the opening of the feedline. The feedline
should be backed up with newly fed waste or some sludge from the main tank. This
prevents oxygen from interacting with the primary sludge whenever the tank is fed. The
design implemented could be appropriate. An angled or more complicated feeding system
is likely better but this complicates the building process and durability.
Create a steel wool or iron or iron shavings filter. The filter (iron [Fe] is the agent) removes
hydrogen sulfide [H2S] from the product which is a harmful gas that occurs in small
amounts. A steel wool filter can easily and cheaply be created.
Create a short term gas storage mechanism. The design featured previously can be made
affordably and relatively easily. Because of prototyping errors and the inability to obtain a
strong enough bag in country, the design was not fully tested (it did past a leakage test
when filled with water).
Create the water trap inexpensively. In general, the water trap is a very helpful design
feature because it gives a clear visual representation of how much gas is ready for use.
While respecting the first priority, the water trap can be built very inexpensively. In
country, two polytanks were utilized and recycled from the previously implemented
digester. Something so expensive and robust is not at all necessary for a water trap.
Requirements for the water trap construction in the future:
o Be penetrated by a pipe and sealed water tight.
o Generally not have any leaks; be solid (it is a container of water).
o Have a slightly smaller upside container for the gas to be stored. This upside down
container will also need an air tight seal for a gas line; the gas is forced out of this
container.
o Be durable enough to hold large amounts of water for long periods of time.
Thoroughly research feedstock options and ways to optimize methane creation. For about
as free as the primary feedstock (animal or human waste), various substances such as
cooking oil waste and rice straw can be added to the primary sludge to increase the gas
output. In general, high lipid food wastes and various natural grown products and farm
waste increase gas output11. Too much of either can be added, however. Reference No.11
provides an excellent breakdown of these details.
29
13. References 1Biodigester - Methane as Fuel. Accessed December 3, 2015.
https://www.youtube.com/watch?v=xAkIKxA3Jm0.
2“Biogas Production and Applications,” n.d. Accessed December 3, 2015.
3Foodwaste Biogas Generator. University of Malaya, n.d.
https://www.youtube.com/watch?v=KpYdHXvQ50g.
4“Fundamentals of Anaerobic Digestion,” n.d. Accessed December 3, 2015.
5How to Make a Bio-Gas Digester, n.d. https://www.youtube.com/watch?v=mWefbc1spd0.
6Lansing S, Botero RB, and Martin JF. Wastewater Treatment and Biogas Production in
Small-Scale Agricultural Digesters. Bioresour Technol, 2008.
7Lansing S, Vı´quez J, Martı´nez H, Botero R, and Martin J. Optimizing Electricity
Generation and Waste Transformations in a Low-Cost, Plug-Flow Anaerobic
Digestion System. Ecol Eng, 2008.
8Mamun, Muhammed Rashed et. al. Methane Enrichment of Biogas by Carbon Dioxide
Fixation with Calcium Hydroxide and Activated Carbon. Journal of the Taiwan
Institute of Chemical Engineers 58 (2016): 476-81. Accessed December 30,
2015.http://www.sciencedirect.com/science/article/pii/S1876107015003132 9Peter Weiland. “Biogas Production: Current State and Perspectives.” Appl Microbiol
Biotechnol, 2010.
10Rajabapaiah P, Jayakumar S, and Reddy AKN. Biogas Electricity. 1993rd ed. Renewable
Energy: Sources for Fuels and Electricity. Washington DC: Island Press, n.d.
11Storing Biogas in a Plastic Trash Bag. Accessed December 3, 2015.
https://www.youtube.com/watch?v=fZJ6mu7O3c8.
12The Health Effects of Wood Smoke. Accessed December 3, 2015
http://www.ehhi.org/woodsmoke/health_effects.shtml 13Xiaohua W, Li J. Influence of Using Household Biogas Digesters on Household Energy
Consumption in Rural Areas. 2005th ed. A Case Study in Lianshui County in
China. Renewable Sustainable Energy, n.d.
30
14. Acknowledgements
The authors would like to thank resident directors Dr. Roger Dzwonczyk and
Mariantonieta Gutierrez Soto for their the advice and planning. Thanks to Nana Odeneho,
Andrew Bediako, and other Ghana in-country partners for their help and patience. Thanks to Dr.
Yebo Li for technical advice, Dr. Scott Shearer for providing prototyping facility in Agricultural
Building, Aleksandr Yakhnitskiy from Quasar Energy Group, and the Waterman farm for
providing project related materials. Thanks to Anne Christy, Michael Lichensteiger for proving
the laboratory to test the prototype.
For the Ghana trip, the authors would also like to thank to Kojo Appiah-Kubi for
providing the service learning program. Thanks to Augustine Yeboah for his great help during
whole construction. Thanks to Wil Aparloo Ofori for showing the huge biogas digestion in
Techiman Processing Complex. Thanks to Andrew Bediako, Evans Kwame for their help during
the trip. Thanks to Mahadi Annor for proving pick up service. Thanks to all ONDA partners for
their patience and help.
31
15. Appendices
15.1 Extra Figures
Figure 11. Flame test. Figure 12. Steel wool condition.
Figure 13. The team replaced the sealing part on old tank
32
Figure 14. Team member (Kave) was injecting manure into the digestion tank
Figure 15. The completed final project
Figure 16. Business Card of Wil
33
15.2 Biogas Technology Team Agreement
Biogas Technology Team Agreement
Identifying the project:
● Term of contract: 09/13/2015 05/01/2016
● Team members and contact information:
Victor Haynes: (815) 3023242 [email protected]
Major: Civil Engineering
Minor: Design
Kan Liu: (917) 250 9768 [email protected] Major:
Aerospace Engineering
Minor: Global Option in Engineering
Meng Cheng: (614) 2549351 [email protected]
Major: Mechanical Engineering
Minor: Russian & Math
Kave Anderson: (404) 4682806 [email protected]
Major: Biological Engineering
Minor: Global Option in Engineering
Teamwork Criteria:
1. Team Leadership Roles:
● Kave Anderson: Team Leader, CCO (Chief Communications Officer)
● Kan Liu: Coleader, Director of Testing, Logistics Manager.
● Meng Cheng: Primary Documenter/Scribe/Recording Secretary.
Victor Haynes: CFO (Chief Financial Officer) Accountant, Photographer,
Videographer.
2. Preferred Methods of Communication:
● Email, phone communication, and Whatsapp.
● Information will be stored on a Google Drive.
● Project timeline will be created and edited with Excel on Google Doc.
3. Meeting Guidelines:
34
● There will be a regularly scheduled meeting on Wednesday at 8 P.M. at SEL
weekly.
● Before every meeting, an agenda will be written and followed.
● Every meeting will be documented by recording secretary.
● Attendance is required for every team member unless communicated 24 hours in
advance.
● All members should arrive no later than five minutes after meeting time.
● All members should stay on task during the meeting.
● Meetings will be arranged at times when all members are available.
● At the end of each class session/meeting, members will define tasks required for
next class session/meeting.
4. Participation:
● Project partners will put forth effort to complete all tasks and participate as much as
possible.
● All are free and encouraged to equally participate in meetings.
● All members should perform the tasks described in the team agreement.
5. Responsibilities:
The project is a partnership. All members are equally responsible for completing the
project.
● Team members will hold each other accountable during all aspects of the project.
● The Chief Communications Officer will be in charge of communicating with
Ghana partners and anyone else involved in developing the project.
● The Chief Financial Officer is responsible for maintaining financial records of
project expenses and budgeting.
● The Logistics Manager is responsible for creating a project timeline and maintaining
the schedule throughout the duration of the project.
● The Primary Documenter is responsible for submitting documents on time and
assembling any written reports required for the project. Any documents should be
checked by all members before submitting. The receipt should be forwarded to all
members after submitting.
6. Approaches to conflict resolution:
● Conflicts will be resolved internally on a flexible, casetocase basis.
● For conflicts that cannot be resolved internally, group members will seek help from
one of the instructors to serve as a mediator.
35
7. Approaches to problem solving:
● All team members will have equal opportunity to solve a problem. All ideas will be
considered.
● After all possible solutions have been proposed, team members will discuss further
options for solving the problem.
8. Approaches to decision making:
● Decisions will be made as a team as often as possible.
● Decisions will be made by majority vote by team members.
● In the case that team members cannot agree on a decision, efforts will be made to try
all ideas given that the circumstances permit trying more than one.
9. Signatures (dated) of all team members, thereby agreeing to abide by this contract
36
15.3 Meeting Notes
Bio-gas team meeting notes.
1st Meeting
Location: SEL underground
Date: Sept. 13th 2015
Time: 8 P.M.
Main purpose: Writing the Team Agreement.
Based on the Team Agreement template provided on Carmen, a detailed and strict Agreement
had been approved and signed. Major improvements includes task assignment, regularly meeting
weekly, strict on time rule and majority vote rule.
P.S.
(An Email will be sent on Tuesday before every regularly meeting with discussing topics as
reminders.)
(Remind: Add Augistine and other technicians on Whatsapp)
(Updated on Sept. 14th)
2nd Meeting
Location: SEL underground
Date: Sept. 16th 2015
Time: 8 P.M.
Main purpose: Writing the Project Proposal
The team was confused on the goal of the project. Should the biogas electricity generator be
considered during the program? The team decided to discuss with Roger on next lecture.
The Proposal version 1.0 was finished during the meeting. The team decided to bring a hard copy
and ask for Roger’s opinion on the following lecture. More detailed information or correction
may be applied based the advices from instructor.
(Updated on Sept. 16th 9:54 P.M.)
The proposal was fixed according to comments from Roger and Mariant, and the latest version
was uploaded to carmen on 8:10PM. Sept. 23rd.
3rd Quick Meeting
Location: Smith lab
Date: Sept. 22nd 2015
Time: 5:20 P.M.
Due to the career fair and the complement of proposal, the team decided to call off the next
regularly meeting on Wednesday (Sept. 23rd).
The team will start the research work and try to build the first prototype in the following classes.
Each team member needs to collect information and learn about bio-digester before next class.
37
On Thursday, the team member will brainstorm the bio-digester design and draw out the
timeline. Kave (CCO) will reach Augustine within the week in order to discuss prototype design.
(Updated on Sept. 23rd 8:27 P.M.)
4th Meeting
Location: Smith lab
Date: Sept. 24th 2015
Time: 4:20 P.M.
Main purpose: Draw out the Gantt Chart
Pre-Trip Technical Report Contains:
SOW- stated needs
deliverable list- include sustainability and ownership (Owner: Kave)
description of research, design, prototyping, testing (Owner: Meng)
cost analysis of project (Owner: Vic)
lists of tools, equipment and supplies (Owner: Vic & Kave)
timeline of design, development, prototyping, implementation (Owner: Kan)
The SOW has already roughly down during the previous proposal. The 4 terms need to be
considered about are researching, designing, prototyping & testing. From this meeting to the
final report due, there are ten weeks. The team decided to spend 2 weeks on researching, 2 weeks
on designing, 3 weeks on prototyping and 2 weeks on testing. The rest week is going to be used
as analyzing and documenting week. The team also going to list the tools and supplies will be
used in Ghana during the last week. The time can be flexible based on the project process.
Team will start the research process since next week.
The research progress includes reading articles, connecting with professors at OSU experienced
with bio-digester, investigating the experimental bio-digester at Waterman Farm and collecting
local informations(ingredients source, local soil, etc.) at Ghana from Adam and Agustine.
The team will also research different methods of generating electricity with biogas.
5th Meeting
Location: Smith lab
Date: Sept. 29th 2015
Time: 4:20 P.M.
Main purpose: Research Report
38
Kave:
● Emailed 7 professors and received 3 responses. Get contact information.
Yibo Li: Can be contact with video/audio chat. Oct. 2nd ,6th- 9th.
Will schedule a remote meeting on Oct. 9th at 10:10 A.M.
Rest of the professors suggested Dr. Li on the issue.
● One video instruction and one website on how to build bio-digester.
● Need more research on the usage of “steel wool”.
Kan:
● Video: how to build bio digester.
● Listed the materials to build a prototype.
● Need to stir the tank after a period of using. (Need a string rod inside?)
● Trolley to move the biodigester.
Victor:
● The amount of the solid “bad waste” will leave in tank. How long do we need to clean it?
Meng:
● Ingredients to use in the digester.
● Ph, Temp in the digester and the pressure to keep for the natural gas.
More Q:
● What kind of ingredients or catalysts can speed up the progress?
● What are the mainly maintenance procedure? Can we make it easier? Charging time?
● Should have one man in the community shadowing with the group to learn most of the
procedure and principle.
● How long does it take for the gas work?
● Source of ingredients for the prototype testing.
● What is the container made out of?(What type of plastic, PVC or PET?)
● What is the gas output?(The percentage of the methane for the 1st time and normally
works.)
● What issues/complications generally arise? (In your experience, if any)
● Do we need to have a mechanism for stirring the contents?
Actions to do Next:
● Schedule meeting with Dr. Li. and Dr. Martin. Contact with Dr. Micheal. (Kave)
● Finish the Gantt Chart. (Kan)
● Complete the work updated.(Meng)
● Schedule a meeting room.(Victor)
● Finish the Capstone quizzes. (Meng, Kave, Victor)
39
10 OCTOBER 15
(Class Workday)
● Kave’s idea: look into different types of oil for testing (palm oil?)
○ Ask Augustine about the kinds of cooking oil that are available
■ Frytol, palm oil?
● Look at articles 38-42 in Kave’s link (figure out which oils work best/lipids?)
● Continue research
Meeting with Dr. Li
Of usage:
o At least 500 kWh or electricity it’s not econ.
o The usage amount for cooking is actually not much.
Of maintenance:
o Too much dirt or ashes my precipitated at the bottom.
Of food waste:
o It doesn’t matter. Any organic things can be used.
Of mixing:
o Small size of the digester don’t need to be stirred but can add a slope.
Of materials:
o The materials are mainly choose by cheaper materials
Of time:
o It’s all depends on the seeds (bacteria). Better get from another bio-digester local.
Of Steel Wool:
o It’s really useful from avoiding loss of heat.
Of gas amount:
o Need to be calculated from the ingredients’ potential specific heat.
Of pH
o The ph mainly caused by fatty acid added.
o If the ph is lower than 6, stop feeding. If the pH is even low at 5, add things to
bring pH up.
6th Meeting
Location: Smith lab
Date: Oct. 13th 2015
Time: 4:20 P.M.
Main purpose: prototype progress.
Based on the discussion result, the team canceled the second prototype test with a 200 L plastic
drum due to time reason. The team also canceled the tour to the Quasar Company because of
lacking storage place. The team will go contact Quasar first to find out can we get the seed from
40
them. According to Adam’s experience, the team will go contact with waterman farm later for
digestion ingredients.
P.S.
A email from Quasar was received on 19th which confirmed that they can offer seeds.
The tour is scheduled on Friday.
Oct 27th update
1. The team get the place but need permission.
2. Farm tour canceled and will be re-scheduled
3. Received reply from Andy.
4. Prototype Connection issue. The flexible tube will be replaced by PVC tube in the real project.
Nov 3rd update
1. Contacting Techiman Processing Complex
2. Confirmed lab place at AG 150
3. Scheduled visit to Quasar & Waterman Farm
4. Pre-trip Report
5. Put limes in water to reduce the concentrate of CO2
41
15.4 Maintenance & Use
Operation: When to inject?
The bio-digestion process is a long term process. Feeding too frequently may cause failure.
The right time to inject the ingredients is when the pressure in the floating gas tank begin to
decrease. This means the production amount of biogas is less than the usage amount, and the
digestion tank need more materials.
What to Inject?
Many kinds of organic waste can be used as ingredients for the digester, including animal and
human manure, kitchen waste and straw. However, the user should control the humidity and the
C/N ratio of the ingredients injected. The best C/N ratio is from 20 to 30, the water and dry
ingredients ratio is 1:3.
The following is a C/N ratio table.
For example, using the common ingredients cow manure and straw, the ratio of manure to
straw should be 2:1 in order to give 25 C/N ratio.
How to inject?
Open both injection tubes, put the ingredients in the vertical tube and push it in through
horizontal tube. Other time, keep the injection tubes closed.
When to collect fertilizer?
At the same time of injecting new ingredients. The materials inside has already undergone
digestion process and turned into fertilizer. It’s a good time to take these fertilizer out.
How to collect fertilizer?
Just open the fertilizer valve and collect with a bucket.
When to replace steel wool?
Since the concentrate of H2S in the biogas is really small, the steel wool does not need to be
replaced frequently. Check the condition of the steel wool every 3 months. If most part the steel
wool turned into dark brown, then we need to replace the steel wool.
How to replace steel wool?
Close the two valves on each side of the steel wool filter. Open the top lid of the filter and take
the old one out. Tear the new steel wool to make it fluffy, then full fill the filter. Close the top lid
and open two valves.
How much water should be added?
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Due to the leakage and evaporation, the water in the water tank is losing all the time. User
need to add more water in order to keep the water trap working. The water level should never
higher than the alert mark on the PVC pipe. (Or the water may flow back through the gas tube.)
How to control a proper pressure?
The pressure inside the equipment is controlled by the weight on the gas tank. Increase the
weight to increase the pressure or vice versa.
Maintenance: What if there’s no biogas?
Check all the connections and make sure there’s no leakage. Take some fertilizer out and
exam the pH level. The proper pH level inside the digestion tank is around neutral. If the pH is
lower than 6, stop feeding and wait it until it turns back.
How to deal with leaking?
The leaking may happened as time goes by. Clean the leaking part and keep it dry, then seal
the leakage with PVC glue or silicon for the PVC tube or poly tank.
Caution: The biogas is a highly flammable gas fuel. Do not smoke or burn around the
equipment.
The equipment need to be kept in tightly sealed condition. Do not use sharp object
scratch the equipment.
The oxygen burning ratio of biogas and LPG are different. Do not use biogas to cook
with the stove for LPG.
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15.5 Overall Gantt Chart
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