Many materials originated
by agriculture could be used for production of densified biomass
fuels agripellet: Some of them are straw, grain hull waste, sugar
beet waste, pruning, fruit stone, dry fruit waste, cork, grain,
cotton, malt and tobacco waste, with obviously, woody residues.
Agricultural residues refer to the portion of plant material that
remains after a crop has been harvested and separated.
Primary residues are those that are the result of farm-level activities;
they include items such as straw, stalks and leaves that are left
over after harvest.
Secondary residues are those that result from processing , such
as sugar beet pulps, cotton mill wastes, peanut shells, etc. For
most crops, and said roughly, primary residues are produced in quantities
approximately equal in weight to the crop production, and are already
used for different purposes (soil conservation, animal feeding and
litter, heating). The amount of secondary residues varies widely
depending on the crop and processing methods used.
EN 14961-6 Non-woody pellets for non-industrial
use This European standard determines the fuel quality classes and
specifications of non-woody pellets for non-industrial use. This
standard covers only non-woody pellets produced from the following
Herbaceous biomass, Fruit biomass, Biomass blends and mixtures.
Standard include for specification of straw, miscanthus and reed
canary grass pellets and for blends and mixtures.
The standard EN 14961 - Part 6: Non woody
pellets for non-industrial use is too wide and contain lot of materials,
what was not tested by CARBOROBOT, bellow we list materials, what
was tested and the boiler can work with him.
whole wheat plant
whole corn plant
wheat husks or shells
All other materials, what is listed in
the standard EN 14961-6 was not tested and the Producer can not
give any warranty for using.
Known pellets what problematic for
Rape seed if it is too small and dusty - heavy
smoke due to small sizes particles, and emit too much gases in short
Rape-straw - heavy smoke, due to this have slow burning gases,
due to in clean form not burn normal, must be mixed with wood min.50%
for better burning in CARBOROBOT
Soya straw - heavy smoke, must be used similar to the rape-straw
seeds - wheat, corn, barley - they burn irregular, slow,
they must be mixed with other good burning pellets, or wood chips,
sunflower shell - very corrodative, the boiler must be prepared
with stainless steel parts in the fuel hopper.
Straw bale and straw chaff not available
to burn in CARBOROBOT.
How many groups
of agripellet exist?
Containing potassium and chlorine: straw, maize, energy grass, hay,
No potassium and chlorine content: rape, sunflower,soya, olives
What do we have to watch when using fuels with
high potassium or chlorine content?
During the combustion of straw, maize,energy grass and rape straw,
the potassium and the chlorine content combines and turns into a
salt that appears to be a white-brownish dust. This dust deposits
in the pipes of the heat exchanger and in the dust-extractor, therefore
the boiler has to be cleaned frequently. If the salt gets damp,
it becomes extremely corrosive. In order to avoid the condensation,
the return water temperature must be kept above 60-70C using an
automatic mixing valve. The boiler must not be operated with cold
(below 60C) water for prolonged periods. These pellets generally
have glassy cinder stucked together in lumps.
What do we have to watch when using agripellets
that do not contain potassium and chlorine?
These pellets burn without salt formation and do not pollute the
heat exchanger so much. The smoke has a pleasent smell and optimal
combustion can easily be achieved. The airflow plate for this fuel
is generally agripellet/coal (No1)
Sometimes these pellets burn and gassify similarly
to the wood pellets and therefore the wood pellet airflow plate
performs better. In this case, the operator has to decide whether
the boiler is well controllable and burns without smoke with the
wood pellet plate. (wood pellets with lots of bark and large ash
content, or reed pellets burn better generally with wood pellet
setting) These fuels produce a light and loose ash.
What do we have to watch when using oily agripellets?
These fuels have high calorie content and require a lot of air.
Sometimes these pellets burn and gassify similarly to the wood pellets.
The oily agipellets may produce a dark-grey smoke that smells unpleseant.
The boiler should be optimized to eliminate the dark smoke, but
the unpleseant smell sometimes can’t be avoided. These fuels produce
a light and loose ash.
The sunflower seed and refuse grain pellets strongly
corrode the boiler tank. Consult the manufacturer before using them
as necessary to incorporate stainless steel components.
How do we store the pellets?
In any case, the pellets must be kept dry, otherwise they disintegrate.
Do not store the pellets for years ahead without stirring it, because
pests may proliferate in the pile. Protection required against rodents
(poison or cat)
Can bricket, straw-bricket or wood bricket be used?
Brickets can not be used except in the wood chamber of Farmer
type, burnt manually just like logs.