By Clive Mutame Siachiyako
http://holdren.com/methane/images/digester.gif |
Before the year ends, I have to drop these thoughts to the Lusaka Water and Sewerage and other sewer companies in Zambia. I am doing this against the misery of power outages business of all sizes and everybody within the vicinity of the country is facing due to high shortage of hydro power supply. ZESCO has been cursed enough; we can do something beyond this company before we are swum over with power blackouts.
I am bringing LWSC into the picture of energy
generation because it is sitting on an important energy resource. I am not talking
about forms of energy like solar or wind, but bio-energy. The human waste is a
great resource for bio-energy, yet we are talking about "urinating in the Kariba dam." With resources
becoming so dice, utilising anything promising value is paramount. Human waste turned into bio-energy is importantly
a sustainable way of protecting the environment. It relieves so much waste from the environment. What falls in this waste’ bracket can be either
solid, human or animal.
We may need a policy and other things to kicking
in such a direction. But with the will and commitment, that is a small baby to
take care of considering the dire need for power in the country and region. Few
countries are already doing it at different scales. Kenya and Uganda for
instance. Beyond the African borders, many countries are benefiting massively
in generating energy from human and other forms of waste, thanks to their
innovative and pragmatic approaches in energy generation. You can talk of
Nepal, USA and Sweden, etc.
We have so many engineers to put into good use in putting
this into practice. Away from noise making and chasing political favours, we
can do something valuable for the country and the environment. Copper will
finish, but waste we will always produce it as long as we are eating. It is a
worthwhile investing in the short and long term. Lusaka City Council will in
the process be relieved of the solid waste management headaches as recyclers
will scramble for waste for varied uses. Different business opportunities and
jobs will emerge from waste related activities to support the system.
Statisticians put human waste [bio-energy] energy financial
benefits at US$9.5 billion globally. To bring it closer, biogas from human waste alone
is capable of generating electricity for up to 138 million households!! This is
equal South African, Kenyan, Zambian and Angolan population combined. Can
engineers help me quantify waste generated in Zambia in relation to how much bio-energy
we can generate to keep home on constant energy supply 24/7 even on leap year?
LWSC is already dealing with sewer waste, we can
get started with it and look at other players later on. We have to begin
somewhere. Policy makers have to get their heads aching for the good reasons to
get us somewhere. Time to lazing around and draining ourselves into endless
complaints in over, we got to get working and get things straight.
Rains are not likely to get normal again. With climate
change effects getting more lethal, we have to dream differently. We have to
face reality and dare new ways of getting around our problems. What we need in
place to get things moving in that direction? It is not me to tell you about
it, I am throwing the idea for those in positions to put in place right
apparatus to get things heading the biogas direction has to do their part. We
do not live silver-platter life-world anymore. Let those who went to school to
thinking engineering-way do their
part.
What goes on with it?
Waste-to-wealth principles go for utilisation of
modern anaerobic digestion technologies linked to sanitation systems to
generate energy. I am talking about connecting pipes somewhere to your toilet
to the biogas digester. These can be made at household, small-commercial and
large-national scale. Whatever we can manage, we have to get moving, too much
on sitting akimbo waiting for miracles. Time for manna from heaven happened
during the time of Moses according to biblical recordings.
Technical and vocational training here becomes more
practicable. Training centres dotted anywhere in the country can teach people
to generate their own biogas and government can do its part to make facilities
and utilities that use biogas accessible and cut off some tax on them if it
means so to get people using them. The same way we gave up old pots to accommodate
electrical appliances, we can do it again. I agree it is a process, but we can
start something, and LWSC could be the starting point to me. Others will join
the music later.
With a focus on rural growth centres and small
towns, as well as high population density institutions such as schools and
prisons, the biogas and residual material left from energy conversion is a
valuable economic resource to provide a return on investment in bio-energy
technologies. The ultimate goal of Waste to Wealth is decentralised (on site)
faecal waste management and to help bridge the finance gap for sanitation in
Uganda. By identifying value in waste (energy and /or fertilizer), Waste to Wealth
provides an incentive to use toilets and a mechanism to finance both upfront
capital costs as well as facility operation, maintenance, and expansion. In
addition to the economic opportunities, sanitation interventions have known
benefits to individual, household and community health and wellbeing.
Few projects to share in Africa include those in
Kenya and Uganda. What is happening in Kenya? The following are some of their
projects:
i. Collecting and converting human waste into solid fuel for use by cement
plants and other industries
ii. Franchising toilets; profitably, safely collecting and removing the
waste daily, converting it into fuel and fertilizer, and
iii. Collecting human waste and converting it into high quality, emission
free bio-charcoal cooking fuel
On the part of Uganda, among other things, the
country produces biogas and organic fertilizer from street waste. Zambia too
can make good news on this one. We have enough waste to take us for somewhere
for now. By the time we exhaust it we would have matured to buy from our neighbours
if it means to do so.
Biogas Basics
Biogas is the result of gases released during the
decomposition of organic matter by methanogenic bacteria. Biogas is comprised
of multiple gases, the most dominant of which is methane (CH4) followed by a
smaller concentration of carbon dioxide (CO2). It may also contain
traces of hydrogen (H2), nitrogen (N2), water vapour (H2O),
and hydrogen sulfide (H2S). Biogas turns what would be waste -- such
as sewage, manure, or food scraps -- into a clean renewable energy. The gas
burns cleanly, is smokeless, and is non-toxic. The premise behind biogas is a simple one –
organic matter decomposes. The decomposition resulting from anaerobic digestion
releases methane. Biogas units turn organic wastes into a mixture of methane
and carbon dioxide gases that can be used for lighting and cooking. For
example; each household builds its own plant to channel waste from the domestic
toilet and nearby shelters for animals, usually pigs, cows into a sealed tank.
The waste ferments and is naturally converted into gas and compost, resulting
in improved sanitary conditions at home.
Biogas technology is best suited to convert the
organic waste from agriculture, livestock, industries, municipalities and other
human activities into energy and manure. Technology systems, ranging from the
very simple and affordable to the very complex and expensive, can capture
methane from decomposing material and convert it into a usable energy. The
technology to harness the energy potential released by anaerobic digestion
varies in scale, complexity, and feeder materials. Regardless of design, a
biogas plant has three primary components: an inlet to get organic matter into
the digestion chamber where anaerobic digestion and gas capture occurs and an
outlet to remove the digested organic matter. The gas use devices and equipment
vary based on the intended end-use of the generated biogas. A biogas plant can
be constructed at home with some ingenuity at minimal cost and can use methane
from human sewage, animal excrement, food waste, or a combination thereof to
provide cooking fuel or lighting.
From the climatology viewpoint, biogas is a plus
towards the environment. I can write a lot on this point, but in a synopsis; by
using biogas, the living conditions and the environment can be improved via
cheaper and more available energy, forests protected, and the labour force
would have more time for e.g. agricultural production. A large amount of straw,
which was previously burned, is now put into biogas tanks to ferment. This
reduces air pollution from smoke and helps produce high-quality organic
fertilizer. Such straw can burned in an internal combustion engine to generate
electricity. Biogas is also successfully compressed for use as an alternative
transportation fuel in light- and heavy-duty vehicles.
Rather than treating our waste as a major
liability, with proper controls in place we can use it in several circumstances
to build innovative and sustained financing for development while protecting
health and improving our environment in the process. Valuing Human Waste as an
Energy Resource!!
References
Barnhart S.(2012). Teaching Sustainability across
Scale and Culture: Biogas in Context. Journal of Sustainability Education, Vol.
3, March 2012
Karki et al A. B., J. N.(2009). Biogas as
Renewable Source of Energy in Nepal: Theory and Development. Kathmandu:
BSP-Nepal.
Sharma et al R., T. (2010). “Design of Farm
Waste-Driven Supply Side Infrastructure for Data Centers,” presented at ASME
2010 4th International Conference on Energy Sustainability. May 17-22. Phoenix,
Arizona.
Themelis, N J. and P. A. Ulloa. (2007). “Methane
Generation in Landfills,” in Renewable Energy. 32(7): 1243-1257.
http://oneworld.org/2015/10/29/biogas-from-human-waste-worldwide-worth-up-to-95bn/[Accessed:
December 28, 2015]
http://www.sgem.org/sgemlib/spip.php?article1019
[Accessed: December 28, 2015]
Production of biogas and organic fertilizer from
street wastehttp://www.sciencedaily.com/releases/2015/11/151103064551.htm