Biowaste to Biogas

Significance of waste digestion in developing countries
10 Significance of waste digestion
in developing countries
In developing countries and emerging economies, biogas technology can
play an important role in integrated waste and recourse management. Anaerobic
digestion of organic waste provides a unique opportunity to tackle
waste management problems, reduce environmental pollution, provide
green energy, and to close the nutrient cycles.
Biowaste collection for
biological treatment
Inadequate solid waste management in urban centres
of low- and middle-income countries is a serious environmental
and health problem. Rapid urban population
growth and the continual increase in waste generation
intensifies the challenge. Often, more than 50 %,
sometimes up to 70–80 %, of waste produced is organic
and biodegradable. Suitable treatment options
for the large organic fraction could help alleviate the
waste problem. At the same time, the worldwide drive
to find clean, renewable energy sources remains a main
priority. Countries are keen to cut their reliance on fossil
fuels due to concerns over the security of supplies and
to provide alternatives to wood fuel, the main energy
source for cooking and heating which is causing severe
deforestation. Banning the dumping or landfilling of organic
waste is therefore of great benefit: it reduces the
generation of landfill gas, relieves pressure on scarce
landfill capacities and mitigates all of the conflicts,
costs and social burdens involved.
Anaerobic digestion of organic waste, resulting in the
generation of biogas and digestate, which is a high caloric
organic fertilizer, provides a unique opportunity
to fulfil a number of objectives: tackling waste management
problems, reducing environmental pollution,
supporting energy recovery and closing the nutrient cycle.
There is no need for purpose-grown crops (“energy
crops”) for fuel as organic waste supply is abundant.
This approach contributes to improved waste management
practices and, at the same time, fulfils the goals
of sustainable energy generation. Furthermore, using
waste biomass to produce biogas creates a carbon-neutral
cycle, in which the carbon emitted from burning
the gas is absorbed by new crops from which the waste
residues can again be used as feedstock: Anaerobic
biowaste digestion and the energetic use of biogas is
helping to reduce GHG emissions directly, by reducing
uncontrolled CH 4
emissions from e.g. landfills and
informal dump sites, and indirectly by replacing the use
of fossil fuels. Let’s keep this in mind: CH 4
emissions
caused by human activities are the second largest drivers
of climate change after CO 2
.
Biogas waste treatment facilities reduce the amount of
waste disposed in uncontrolled dumping sites, which, if
unmanaged, release pollutants into air, water and soil,
endangering the environment and contributing to GHG
emissions. Digestate from biogas facilities is a valuable
fertilizer for farmers and is particularly useful in countries
where soil quality is naturally poor (thin humus layer
and organic content) or has become degraded through
over-intensive farming and the use of artificial fertilizers.
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