|
|
| Line 18: |
Line 18: |
| | and can be fixed by farmers.</span> | | and can be fixed by farmers.</span> |
| | | | |
| − |
| |
| | | | |
| − | <span>Below are some extracts of information collected from the Internet from | + | |
| | + | <span>Below are some extracts of information collected from the project and from the Internet from |
| | experiences with plastic tube digesters in other countries</span> | | experiences with plastic tube digesters in other countries</span> |
| − |
| |
| − |
| |
| | | | |
| | ''' ''' | | ''' ''' |
| | + | Bolivia - EnDev project: == |
| | | | |
| − | == ''Vietnam''''':''' ==
| + | |
| | + | ''Vietnam''''':''' == |
| | | | |
| | <span>Over 30,000 Units have been installed over the past ten years in Vietnam and was | | <span>Over 30,000 Units have been installed over the past ten years in Vietnam and was |
| | widely accepted by the farmers</span> | | widely accepted by the farmers</span> |
| | | | |
| − | ''<span>(Presentation by Vo Lam, Takeshi Watanabe, College of Agriculture,</span>'' Cantho University. Vietnam) | + | ''<span>(Presentation by Vo Lam, Takeshi Watanabe, College of Agriculture,</span>'' Cantho University. Vietnam)<span /> |
| | | | |
| − | <span> </span>
| |
| | | | |
| − |
| |
| | | | |
| − | == ''Tanzania''' == | + | == ''Tanzania:'' == |
| | | | |
| | <span>It is concluded that the main reasons for failure was insufficient | | <span>It is concluded that the main reasons for failure was insufficient |
| Line 45: |
Line 43: |
| | ''<span>(Evaluation of small scale biogas digesters in</span>'' Turiani, Nronga and Amani, Tanzania | | ''<span>(Evaluation of small scale biogas digesters in</span>'' Turiani, Nronga and Amani, Tanzania |
| | | | |
| − | by University of Aarhus, Denmark) | + | by University of Aarhus, Denmark) |
| | | | |
| − |
| |
| − |
| |
| − |
| |
| | | | |
| | == ''Honduras''''':''' == | | == ''Honduras''''':''' == |
| Line 60: |
Line 55: |
| | ''<span>(Emerging Biodigester Technology in Honduras:</span>'' Biophysical Process and Operation | | ''<span>(Emerging Biodigester Technology in Honduras:</span>'' Biophysical Process and Operation |
| | | | |
| − | ''<span>By N. Stuart Green; Montana</span>'' Tech of the Universityof Montana, 1999)<br> | + | ''<span>By N. Stuart Green; Montana</span>'' Tech of the Universityof Montana, 1999)<br> |
| | | | |
| − |
| |
| | | | |
| − |
| |
| | | | |
| | == ''Kenya''''':''' == | | == ''Kenya''''':''' == |
| Line 77: |
Line 70: |
| | | | |
| | | | |
| − | ''Based ''<span>on'' Promoting Biogas Systems in Kenya, a''</span | + | ''Based ''<span>on'' Promoting Biogas Systems in Kenya, '' |
| | + | </span> |
| | | | |
| | <span>“Pioneer Technologies” (a Kenyan plastic company) has built 200 plants | | <span>“Pioneer Technologies” (a Kenyan plastic company) has built 200 plants |
Revision as of 08:27, 25 February 2010
Experience Polyethylene Biogas Digester (PBD) from some countries.
Overview
Polyethylene Biogas Digesters have been used repeatedly over the last 15
years. In some areas they have been abandoned after unsuccessful introduction
but usage has never stopped completely. Although data about the lifespan and
reliability of plastic digesters are rare, reports show that the lifespan of
the plastic tubes is always a main issue.
They can just be operated properly if the farmers take care about the
digesters. This needs intensive training and raised responsibility amongst the
farmers.
If they do, experiences showed that most problems are easily to handle
and can be fixed by farmers.
Below are some extracts of information collected from the project and from the Internet from
experiences with plastic tube digesters in other countries
Bolivia - EnDev project: ==
Vietnam: ==
Over 30,000 Units have been installed over the past ten years in Vietnam and was
widely accepted by the farmers
(Presentation by Vo Lam, Takeshi Watanabe, College of Agriculture, Cantho University. Vietnam)<span />
Tanzania:
It is concluded that the main reasons for failure was insufficient
training of farmers and insufficient follow up by Surude.
(Evaluation of small scale biogas digesters in Turiani, Nronga and Amani, Tanzania
by University of Aarhus, Denmark)
Honduras:
Polyethylene Plastic tubes must be purchased in large quantities. Need
of a third party to act as a distributor to farmers.
Flooding for digesters laid in trench
(Emerging Biodigester Technology in Honduras: Biophysical Process and Operation
By N. Stuart Green; Montana Tech of the Universityof Montana, 1999)
Kenya:
After a false start in promoting this energy source in Kenya in the
mid 1990s, it was successfully reintroduced by KARI-Embu in 2005. According to
Erastus Kiruiro from KARI-Embu there are around 300 tubular digesters in use,
mostly in Central Kenya but also around Nairobi
(The Organic Farmer, The Magazine for sustainable agriculture in Kenya, Nr. 45 February 2009)
Based on Promoting Biogas Systems in Kenya,
“Pioneer Technologies” (a Kenyan plastic company) has built 200 plants
since 2006.
They improved the plastic tubes to be better sun and pressure resistant.
It has not been a successful story yet due to:
- there is no reliable back-up support
- “The digester seems to suffer from effects of variable
temperature, and there is a possibility that the heat catalyses some reactions
that produce other volatile gases as well as methane”
It is still a promising approach which is strongly driven by KARI. Currently
there are many problems and referring to the feasibility study mentioned above
4 of 5 visited plants had some technical problems but most of them could have
been solved easily.
“Development of the plastic tubular technology was initiated in August
2006.
The Plastic Tubular bio-digesters are designed for households with two
to three animals although bigger ones have been installed. Capacity of the
former is about 8-9 m3, with a gas holding chamber of 1-3 m3. A larger one that
doubles this size has already been installed. The smaller Plastic Tubular
Bio-digesters can give gas for six hours using one burner. Methane production
is initially dependent on temperatures.
Currently, Pioneer Technologies Ltd receives support from Land O’lakes
and has entered into research collaboration with Jomo Kenyatta University of
Agriculture and Technology (JKUAT). Land O’Lakes gives financial support to the
company in the production of biogas digesters. JKUAT is supposed to carry out
investigations into issues arising from the use of the technology, with focus
on how the technology can be improved, made more efficient etc. However,
Pioneer Technologies Ltd gave the JKUAT one digester only, and so the
university should acquire more digesters for any meaningful research to be
done.
Pioneer Technologies Ltd has installed its
bio-digester in various parts of the country including Nakuru, Meru, Kisumu,
Kiambu, the coastal regions and the environs of Nairobi. The company has capacity to install
up to 3,000 units a year, but there are several challenges including:
-
Most
households need some financial support to acquire the technology. At cost, a
Plastic Tubular Bio-digester goes for €322 only. However, this excludes the
cost of transport – and so areas further away from Nairobi pay more money. In Meru, users paid
up to €399. The cost of the technology, though coming down is prohibitive to
most farmers, although when financial and economic analyses are made,
especially taking into account opportunity costs vis a vis other energy
technologies, it is very likely that bio-digesters will be economical and
profitable.
-
Training
of technicians to support the technology is costly. Not all technicians trained
will work on the digesters forever, some move on. There is need for the technology
to be supported by some form of extension. Regular visits to households that
have installed it are critical for longevity, good use and success of the
technology.
-
Many
people are not aware of the existence of the technology, or if aware, do not
have adequate information on how the technology actually works. This is a
hindrance to large-scale adoption.
-
At
times, the technology fails because of unmet expectations. Even the Plastic
Tubular Bio-digester has some technical problems – and these need to be sorted
out. Without a reliable back-up support, small problems can lead potential
users to shun away from it. But companies like Pioneer Technology Ltd cannot
afford to have an extension/back-up support team because it already charges
very low figures to install a unit.
-
Users
need to be trained, and this is quite costly. This is where organisations like
Land O’Lakes come in.
-
There are many research needs on the technology
Pioneer Technologies
Ltd has trained 7 technicians to support the technology and at least 300 or so
units have been installed country wide and despite small problems, all are now
working.”
