Agriculture Reference
In-Depth Information
module of hemp to the first mill process stage
and feeds the module into the first-stage mill
processing equipment at a rate of 10 t/h,
but cannot process up to 20 t/hr if the main
processing line is made larger.
Chanvriers de l'Est and started in 2005 with a
few hectares of land.
At the end of their first year of production,
the lessons learned were of two types:
1. An efficient hemp harvesting system is eco-
nomically essential.
2. The pressing of high-density parallelipi-
pedic bales, or 'square bales' as they are more
commonly known, is a technical imperative.
The technique commonly used in France con-
sisted of a first pass by the combine harvester
in order to collect the seed, followed by the
reaping of the hurds. This was very labour-
intensive and had few supporters.
The farmers therefore approached an
agricultural worker and together they visited
the offices of Goetz, the company responsible
for the modified combine harvester equipped
with the Kemper maize beak.
The first machine purchased in 2008
demonstrated clear limitations and was mod-
ified dramatically for the 2009 season. It
then gave very satisfactory results, allowing
250 ha to be harvested in excellent
condition.
Another problem then arose. Impurity in
the hemp seed was often found to be too high
and this caused problems at the drying silo.
A mobile cleaning system was therefore
designed that allowed the impurity level to be
reduced to under 5%.
A further line of improvement was also
explored. The swaths of retting hemp needed
turning in order to improve retting and encour-
age the hemp to dry uniformly. None of the
machines trialled performed satisfactorily and
so a prototype was constructed and used with
great success during the harvest of 2009.
In order to ensure a good 2010 harvest of
a crop covering some 500 ha, a new John
Deere combine harvester was equipped and a
number of 'swath turners' are in production.
In this way, it will be possible to harvest
hemp seed while cutting the hurds at the same
time. This will allow hurd pressing to be pre-
pared efficiently, spending less than 20 min/
ha, after which the hurds can be pressed into
square bales.
The initial specifications are now filled.
Figures 6.18-6.21 illustrate the equip-
ment used.
The classification mill. The first step in the
mill is to remove the free shives, which reduces
the flow-on material by 50%. This is done
by feeding the material through a rotating
screen. As the free hurds, dust and fines fall,
the second step is to separate the remaining
fibre and shives. The third step is to classify the
remaining materials.
The end result of measures such as these
will reduce labour and energy costs, capital
costs on machinery and also reduce the unit
processing cost by increasing throughput. This
will mean a reduction of up to 25% of the tradi-
tional Stage 1 processing 'classification' cost.
At this moment in time, Stage 2 process-
ing, or 'fibre refining', remains the same as the
existing technology. This process needs further
analysis. Techniques such as steam explosion,
enzyme separation and even ultrasonic process-
ing are being considered.
6.3.5 Summary
Regardless of the end processing technique,
the area of production that presents the need
for the greatest increase of efficiency is in the
four points outlined. The methods illustrated
are only one view as to how efficiency can be
achieved and there may well be many other
ways to achieve a similar outcome. Nevertheless,
the fact remains that the present methods are
not as efficient as they could or should be if
bast fibre is to become one of the fibre sources
to supply a world looking for more and more
renewable resources.
6.4 The Harvesting Process
Developed by the Chanvriers de l'Est
As part of the development of hemp cultivation
and processing/transformation, a new organi-
zation was set up in the Lorraine region in the
west of France. This project was named the
 
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