best available technologies for manure treatment - Baltic Green Belt

Best Available Technologies for manure treatment baltic sea 2020
4: RESULT OF DATA ANALYSIS
4: RESULT OF DATA ANALYSIS
4.1: Reduced list of livestock manure
handling technologies
The complete list of identified livestock manure
treatment technologies has been reduced in different
ways in relation to the specific needs and purposes of
this project. Technologies that are without leaching
reduction effect, that are not commercially implemented,
that are not in focus in this project, that
have apparent other negative impacts on the environment,
that have no proven or unacceptable economic
performance, or have ethical considerations have
been removed.
4.1.1: Non–project relevant technologies
It is for this project given on beforehand, that focus is
not on technologies in relation to evaporation (emissions),
storage or spreading of livestock manures.
4.1.2: Technologies that are not
commercially implemented
A number of the technologies we have identified are
still being researched or piloted, and we can of this
reason not recommend them to be put into operation
on a broad scale in the BSR.
4.1.3: Technologies without leaching
reduction effect
Some of the technologies have neither directly or
indirectly any leaching reduction effect.
4.1.4: Technologies with apparent negative
environment or climate impacts
Especially the aeration technologies are reported to
lead to smaller or larger evaporation of laughter gases
and ammonia. Seepage is also seen in connection to
composting, when material for composting with less
than 30% dry matter is placed on the bare soil.
Therefore, of the aeration technologies we do
alone recommend that the fibre fraction from separation
is composted in order to make it
• stable in the storage, i.e. it will not start fermenting,
moulding, leaching, evaporating or other
during storage and transport; and
• with a high dry matter percentage, as we acknowledge
that composting is an effective and cheap
way to remove water from a substrate without
consumption of external energy, because the
temperatures normally raises to above 70°C
during the composting process – a high dry
matter percent is especially important if the fibre
fraction shall be used in a later thermal gasification
or combustion process.
If composting of the fibre fraction is done, then we
recommend it happens in a way so that neither emissions
of harmful gases nor seepage is possible, i.e. it
should be in closed containers.
4.1.5: No proven or unacceptable economic
performance for general use
Despite having been implemented in practice, meaning
that we could not consider the technologies as
being research or piloted, we are in doubt about their
viability in commercial use without subsidisation.
These technologies counts for instance those that are
related with total purification of the liquid fraction,
as well as the temperature and pressure treatment,
which seems mainly to be relevant in case of a need
to treat animal by-products.
4.1.6: Technologies with ethical
considerations
We do not see any ethical considerations for any of
the listed technologies in Table 6.
However, we remind that N is an expensive and
limiting resource in the agricultural production,
wherefore it seems uneconomic to convert it to free
N (N2), rather than using it for fertilising of crops
instead of buying N fertilisers, that have been produced
with high consumption of fossil fuels.
We also remind that P is a scarce resource, and
that there is a risk that the P in the ash after combustion
of livestock manure is converted to forms with
low plant availability.
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