Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD FOR PROCESSING WHOLE HEMP STALKS TO FORM DRY
HEMP PRODUCT COMPRISING CANNABINOID OIL
FIELD OF THE INVENTION
The present invention relates generally to processing hemp, and more
particularly to an economical and efficient manner of processing hemp so as to
derive
a dry hemp product including cannabinoid oil.
BACKGROUND
Use of hemp in consumer products and the like has increased in recent
years. Hemp is grown in Canada, where hemp stalks covered 75,000 acres of
agricultural land in 2014. Fibers and hurd from hemp plants may be used to a
variety
of items such as building materials, insulation and livestock bedding. Oils
from hemp
plants are increasingly sought after for their health benefits and for
therapeutic
purposes.
SUMMARY OF THE INVENTION
According to an aspect of the invention there is provided a method for
processing hemp to form a dry hemp product including cannabinoid oil,
comprising:
cutting hemp plants, which are growing in a field, between about 85 days
and about 120 days after seeding of the hemp plants, such that the hemp plants
include
at least one of leaves and flower buds but are free of seed;
drying the hemp plants to a prescribed moisture content of about 5% to
about 15%, by leaving the hemp plants in the field to air dry;
and, in a processing facility, to which the hemp plants are transported
after drying:
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shaking the hemp plants to shear said at least one of the leaves
and the flower buds from stalks of the hemp plants so as to form separated
stalks and
said at least one of the leaves and the flower buds which are not deformed;
and screening the separated stalks and said at least one of the
.. leaves and the flower buds so as to be separated from one another.
Preferably, shaking the hemp plants comprises passing the hemp plants
between a pair of counter-rotating rollers carrying a plurality of generally
axially
extending cleats in spaced angular relation to one another, which are spaced
apart to
shake the hemp plants without crushing said at least one of the leaves and the
flower
buds.
Preferably, the cleats of each of the pair of counter-rotating rollers follow
a linear path which extends axially and angularly of a respective one of the
pair of
counter-rotating rollers across substantially a whole length of the respective
one of the
pair of counter-rotating rollers.
The. cutting may be performed between about 95 days and about 110
days after the seeding of the hemp plants.
The method may further include pelletizing the at least one of the leaves
and the flower buds after screening the separated stalks and said at least one
of the
leaves and the flower buds.
According to another aspect of the invention there is provided a method
of processing whole hemp stalks at a single location, each whole hemp stalk
including=
bast fiber and shive, the method comprising:
providing the whole hemp stalks at said location;
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at said location, reducing the whole hemp stalks into particulate hemp
which is smaller in size than the whole hemp stalks and still includes bast
fiber and
shive;
at said location, processing the particulate hemp without separating bast
.. fiber and shive including:
reducing the particulate hemp in size so as to lie in a first size range
so as to be usable for further processing of the particulate hemp into one of
a plurality
of different products each with different size;
wherein the particulate hemp includes unseparated bast fiber and shive
.. throughout the step of processing the particulate hemp.
According to a further aspect of the invention there is provided a system
of processing whole hemp stalks into particulate hemp at a single location,
wherein the
whole hemp stalks have been harvested and each of the whole hemp stalks
includes
bast fiber and shive, the system comprising:
a preliminary size reduction station arranged at said location for reducing
the previously harvested whole hemp stalks into particulate hemp, which is
smaller in
size than the whole hemp stalks and still includes bast fiber and shive;
a processing stage arranged at said location for processing the particulate
hemp without separating bast fiber and shive, the processing stage including:
a first size reduction station arranged for reducing the particulate
hemp in size so as to lie in a first size range so as to be usable for further
processing
of the particulate hemp into one of a plurality of different products each
with different
size;
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at least one further size alteration station receiving the particulate
hemp sized in the first size range as input thereto for said further
processing so as to
derive a selected one of said plurality of different products;
wherein the particulate hemp includes unseparated bast fiber and shive
throughout the processing stage.
According to a further aspect of the invention there is provided a method
of processing whole hemp stalks, each whole hemp stalk including bast fiber
and shive,
the method comprising:
providing the whole hemp stalks;
reducing the whole hemp stalks into particulate hemp, which is smaller in
size than the whole hemp stalks and still includes bast fiber and shive;
processing the particulate hemp, which includes:
reducing the particulate hemp in size so as to lie in a first range
between 25 microns and 500 microns;
wherein the particulate hemp includes bast fiber and shive throughout the
step of processing the particulate hemp.
In the embodiment as described in more detail hereinafter, the particulate
hemp is sized into one of several forms including hemp fines or flour, hemp
pellets, and
hemp crumbs (which are also termed hemp crumbles). Each hemp product, which is
differentiated from one product to another by particle size, is advantageous
for certain
applications based on physical form, as will become apparent later. The
present
embodiment is suited for using an entirety of the hemp stalks for producing
the
particulate hemp therefrom. As such, processing the hemp stalks to form the
particulate
hemp may be less expensive than prior art processes in which the constituent
components of the hemp stalks such as the bast fiber and the shive are
separated from
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one another before processing into the particulate hemp.
As the particulate hemp includes bast fiber and shive, close to 100% of
the whole hemp stalks, if not all thereof, is processed into the particulate
hemp. As
such, separation of bast fiber and shive is not required.
'Pulverize' as used in this specification means `to reduce to fine particles.'
'Hemp crumbs' may also be called 'hemp crumbles'; irrespective of the
particular term used, 'crumb' or 'crumble' as used in this specification refer
to a small
particle or portion of something ¨ in this case of hemp.
The step of reducing the particulate hemp in size so as to lie in the first
range between 25 microns and 500 microns may be performed using a hammer mill.
In one instance, the particulate hemp comprises an average dimension
between 1.10 centimetres and 7.70 centimetres after the step of reducing the
whole
hemp stalks into particulate hemp but prior to the step of processing the
particulate
hemp. In another instance, the particulate hemp comprises an average dimension
between 1.30 centimetres and 6.40 centimetres after the step of reducing the
whole
hemp stalks into particulate hemp but prior to the step of processing the
particulate
hemp. In a further instance, the particulate hemp comprises an average
dimension
between 1.50 centimetres and 5.30 centimetres after the step of reducing the
whole
hemp stalks into particulate hemp but prior to the step of processing the
particulate
hemp.
The step of reducing the whole hemp stalks into particulate hemp may be
performed using a shredder.
"Average dimension" refers generally to an average of respective
maximum dimensions of a unit of the particulate hemp measured on the
respective unit
in any direction since the unit may be of a variety of shapes. That is, the
maximum
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dimension of each hemp unit is averaged for all of the hemp units belonging to
the
particular category comprising the units. Moreover, any reference to sizing of
hemp
particles, hemp fines, hemp pellets, hemp crumbs, hemp cubes, or hemp
briquettes
hereinafter may be understood similarly to the aforementioned understanding of
average dimension. The understanding of "average piece dimension" or "average
particle dimension" hereinafter is similar to that of 'average dimension'.
In one instance, the step of processing the particulate hemp, after the step
of reducing the particulate hemp in size so as to lie in the first range,
additionally
includes further altering the particulate hemp in size such that the
particulate hemp
comprises an average dimension between 0.5 microns and 3.20 centimetres. In
another
instance, the step of processing the particulate hemp, after the step of
reducing the
particulate hemp in size so as to lie in the first range, additionally
includes further
altering the particulate hemp in size such that the particulate hemp comprises
an
average dimension between 0.8 microns and 3.00 centimetres. In a further
instance,
the step of processing the particulate hemp, after the step of reducing the
particulate
hemp in size so as to lie in the first range, additionally includes further
altering the
particulate hemp in size such that the particulate hemp comprises an average
dimension between 0.9 microns and 2.80 centimetres.
In one arrangement, the step of processing the particulate hemp, after the
step of reducing the particulate hemp in size so as to lie in the first range,
may
additionally include further reducing the particulate hemp in size so as to
lie in a second
range between 0.5 microns and 300 microns. Alternatively, the second range of
the
step of further reducing the particulate hemp in size, which comes after the
step of
reducing the particulate hemp in size so as to lie in the first range, may be
between 0.8
microns and 250 microns. The second range of the step of further reducing the
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particulate hemp in size, which comes after the step of reducing the
particulate hemp
in size so as to lie in the first range, may also alternatively be between 0.9
microns and
200 microns.
The step of reducing the particular hemp in size so as to lie in the second
range such as that between 0.5 microns and 300 microns may be performed using
a
hammer mill.
In one arrangement, the step of processing the particulate hemp, after the
step of reducing the particulate hemp in size so as to lie in the first range,
further
includes binding together the particulate hemp into a prescribed size range
between
0.60 centimetres and 3.20 centimetres. Alternatively, the prescribed size
range of the
step of binding together the particulate hemp may be between 0.80 centimetres
and
3.00 centimetres. The prescribed size range of the step of binding together
the
particulate hemp may also alternatively be between 1.00 centimetres and 2.80
centimetres. The prescribed size range of the step of binding together the
particulate
hemp may also alternatively be between 1.20 centimetres and 2.60 centimetres.
The step of binding together the particulate hemp into the prescribed size
range such as that between 0.60 centimetres and 3.20 centimetres may be
performed
using a pellet mill.
In one arrangement, the step of processing the particulate hemp, after the
step of binding together the particulate hemp into the prescribed size range
such as
that between 0.60 centimetres and 3.20 centimetres, additionally includes
reducing the
particulate hemp in size so as to lie in a prescribed range between 0.30
centimetres
and 2.80 centimetres. The prescribed range of the step of reducing the
particulate hemp
in size, which comes after the step of binding together the particulate hemp,
may
alternatively be between 0.50 centimetres and 2.60 centimetres. Alternatively,
the
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prescribed range of the step of reducing the particulate hemp in size, which
comes after
the step of binding together the particulate hemp, may be between 0.50
centimetres
and 2.60 centimetres. The prescribed range of the step of reducing the
particulate hemp
in size, which comes after the step of binding together the particulate hemp,
may also
alternatively be between 0.75 centimetres and 2.30 centimetres. The prescribed
range
of the step of reducing the particulate hemp in size, which comes after the
step of
binding together the particulate hemp, may also alternatively be between 1.00
centimetres and 2.00 centimetres.
The step of reducing the particulate hemp in size so as to lie in the
prescribed range such as that between 0.30 centimetres and 2.80 centimetres is
performed using a roller mill.
Optionally, the step of binding together the particulate hemp includes
adding moisture to the particulate hemp at a beginning or throughout said step
of
binding together the particulate hemp so as to aid in binding the particulate
hemp.
Preferably, the step of processing the particulate hemp, after the step of
binding together the particulate hemp, further includes a step of cooling the
particulate
hemp.
In one arrangement, the step of processing the particulate hemp, after the
step of binding together the particulate hemp, further includes a step of
separating
inadequate hemp units from the particulate hemp, the inadequate hemp units
having
an average dimension sized outside the prescribed size range such as that
between
0.60 centimetres and 3.20 centimetres. In one instance, the step of removing
the
inadequate hemp units comprises applying suction to the particulate hemp to
separate
therefrom the inadequate hemp units that are sized smaller than said
prescribed size
range such as that between 0.60 centimetres and 3.20 centimetres.
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In one arrangement, the step of processing the particulate hemp, after the
step of reducing the particulate hemp in size so as to lie in the prescribed
range such
as that between 0.30 centimetres and 2.80 centimetres, additionally includes a
step of
separating inadequate hemp units from the particulate hemp, the inadequate
hemp
.. units having an average dimension sized outside said prescribed range such
as that
between 0.30 centimetres and 2.80 centimetres. In one instance, the step of
removing
the inadequate hemp units comprises applying suction to the particulate hemp
to
separate therefrom the inadequate hemp units that are sized smaller than said
prescribed range such as that between 0.30 centimetres and 2.80 centimetres.
In certain consumer products for which hemp is suitable such as animal
litter and bedding, it is desirable that the litter or bedding is free of dust
which may be
defined by the inadequate hemp units removed by suction.
Additionally or alternatively to applying suction, the step of removing the
inadequate hemp units may comprise screening the particulate hemp. Preferably,
the
step of screening comprises a first separating step segregating or removing
the
inadequate hemp units which are larger than the respective range and a second
separating step segregating or removing the inadequate hemp units which are
smaller
than the respective range.
Typically, the inadequate hemp units removed by suction are defined by
the particulate hemp which was not properly pelletized. Also, these inadequate
hemp
units, which are removed by suction, may be defined by fines generated during
the step
of reducing the particulate hemp in size so as to lie in the prescribed range
such as that
between 0.30 centimetres and 2.80 centimetres. The suction may be applied to
the
particulate hemp in addition to the screening, and the suction may be applied
during or
after the screening of the particulate hemp.
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It is preferred that the step of processing the particulate hemp, after the
step of separating inadequate hemp units, includes reforming the inadequate
hemp
units back into the particulate hemp that is sized in the prescribed size
range such as
that between 0.60 centimetres and 3.20 centimetres by reiterating each one of
(i) the
step of reducing the particulate hemp in size into the first range, and (ii)
the step of
binding together the particulate hemp on said inadequate hemp units. The step
of
reforming the inadequate hemp units back into the particulate hemp augments
efficiency of the method and affords very near 100% of the whole hemp stalks
to be
used, with little to no portion of the stalks wasted.
Preferably, the method, after the step of reducing the whole hemp stalks
into particulate hemp, further comprises a step of mixing the particulate hemp
so as to
produce a blend of the particulate hemp which has a substantially uniform
distribution
of moisture. The step of mixing allows for the particulate hemp to be
substantially
uniformly moist prior to later size alteration steps of the step of
processing.
In one instance, the step of providing the whole hemp stalks comprises
providing bales thereof and the step of reducing the whole hemp stalks into
particulate
hemp comprises reducing the bales of the whole hemp stalks into the
particulate hemp.
Preferably, the whole hemp stalks have a moisture content less than 15%
by weight.
If moisture content of the whole hemp stalks is unsuitably high, in one
instance the method, prior to the step of reducing the whole hemp stalks into
particulate
hemp, further comprises a step of drying the whole hemp stalks so that the
whole hemp
stalks have a moisture content less than 15% by weight.
In one arrangement, the method, after the step of processing the
particulate hemp, further comprises a step of storing the particulate hemp in
a manner
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suitable for selling the particulate hemp as or in a final product.
According to a further aspect of the invention there is provided a system
of processing whole hemp stalks into particulate hemp, wherein the whole hemp
stalks
have been harvested and each of the whole hemp stalks includes bast fiber and
shive,
the system comprising:
a preliminary size reduction stage arranged for reducing the previously
harvested whole hemp stalks into particulate hemp, which is smaller in size
than the
whole hemp stalks and still includes bast fiber and shive;
a processing stage arranged for processing the particulate hemp and
which includes:
a first size reduction station arranged for reducing the particulate
hemp in size so as to lie in a first range between 25 microns and 500 microns;
wherein the particulate hemp includes bast fiber and shive throughout the
processing stage.
The whole hemp stalks comprise bast fiber and shive. In the embodiment
as described hereinafter, the system is able to form the particulate hemp from
the whole
hemp stalks without separating the bast fiber and shive. Thus, the system may
be more
efficient in processing whole hemp stalks as compared to prior art systems for
doing
same.
The first size reduction station may comprise a hammer mill.
In one instance, the preliminary size reduction stage is arranged for
reducing the whole hemp stalks to the particulate hemp such that the
particulate hemp
has an average dimension between 1.10 centimetres and 7.70 centimetres. In
another
instance, the preliminary size reduction stage is arranged for reducing the
whole hemp
stalks into the particulate hemp such that the particulate hemp has an average
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dimension between 1.30 centimetres and 6.40 centimetres. In a further
instance, the
preliminary size reduction stage is arranged for reducing the whole hemp
stalks into the
particulate hemp such that the particulate hemp has an average dimension
between
1.50 centimetres and 5.30 centimetres.
The preliminary size reduction stage may comprise a shredder, such as
an agricultural shredder.
In one instance, the processing stage, after the first size reduction station,
additionally includes a further size alteration stage which is arranged for
altering the
particulate hemp in size such that the particulate hemp has an average
dimension
between 0.5 microns and 3.20 centimetres. In another instance, the processing
stage,
after the first size reduction station, additionally includes a further size
alteration stage
which is arranged for altering the particulate hemp in size such that the
particulate hemp
has an average dimension between 0.8 microns and 3.00 centimetres. In a
further
instance, the processing stage, after the first size reduction station,
additionally includes
a further size alteration stage which is arranged for altering the particulate
hemp in size
such that the particulate hemp has an average dimension between 0.9 microns
and
2.80 centimetres.
In one arrangement, the processing stage, after the first size reduction
station, additionally includes a second size reduction station which is
arranged for
further reducing the particulate hemp in size so as to lie in a second range
between 0.5
microns and 300 microns. Alternatively, the second range of the second size
reduction
station may be between 0.8 microns and 250 microns. The second range of the
second
size reduction station may also alternatively be between 0.9 microns and 200
microns.
The second size reduction station may comprise a hammer mill.
In one arrangement, the processing stage, after the first size reduction
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station, additionally includes a pelletizing station arranged for binding
together the
particulate hemp into in a prescribed size range between 0.60 centimetres and
3.20
centimetres. Alternatively, the prescribed size range of the pelletizing
station may be
between 0.80 centimetres and 3.00 centimetres. The prescribed size range of
the
pelletizing station may also alternatively be between 1.00 centimetres and
2.80
centimetres. The prescribed size range of the pelletizing station may also
alternatively
be between 1.20 centimetres and 2.60 centimetres.
In one arrangement, the processing stage, after the pelletizing station,
additionally includes another size reduction station arranged for reducing the
particulate
hemp in size so as to lie in a prescribed range between 0.30 centimetres and
2.80
centimetres. Alternatively, the prescribed range of said another size
reduction station
may be between 0.50 centimetres and 2.60 centimetres. The prescribed range of
said
another size reduction station may also alternatively be between 0.75
centimetres and
2.30 centimetres. The prescribed range of said another size reduction station
may also
alternatively be between 1.00 centimetres and 2.00 centimetres.
Said another size reduction station, which is arranged for reducing the
particulate hemp in size so as to lie in the prescribed range such as between
0.30
centimetres and 2.80 centimetres, may comprise a roller mill. For example, the
roller
mill may have counter-rotating rollers arranged for crushing the particulate
hemp from
the prescribed size range such as that between 0.60 centimetres and 3.20
centimetres
into the prescribed range such as that between 0.30 centimetres and 2.80
centimetres.
Optionally, the pelletizing station is also arranged for adding moisture to
the particulate hemp so as to aid in binding of the particulate hemp at the
pelletizing
station.
Preferably, the pelletizing station is also arranged for cooling the
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particulate hemp at a conclusion of the pelletizing station.
In one arrangement, the processing stage, after the pelletizing station,
further includes a separation station arranged for segregating inadequate hemp
units
from the particulate hemp where the inadequate hemp units have an average
dimension sized outside the prescribed size range between 0.60 centimetres and
3.20
centimetres.
In one instance, the separation station comprises a suction station
arranged for applying suction to the particulate hemp to separate therefrom
the
inadequate hemp units that are sized smaller than said prescribed size range
such as
that between 0.60 centimetres and 3.20 centimetres.
In one arrangement, the processing stage, after said another size
reduction station for reducing the particulate hemp in size so as to lie in
the prescribed
range such as that between 0.30 centimetres and 2.80 centimetres, additionally
includes a separation station arranged for segregating inadequate hemp units
from the
particulate hemp where the inadequate hemp units have an average dimension
sized
outside the prescribed range such as that between 0.30 centimetres and 2.80
centimetres.
In one instance, the separation station comprises a suction station
arranged for applying suction to the particulate hemp to separate therefrom
the
inadequate hemp units that are sized smaller than said prescribed range such
as that
between 0.30 centimetres and 2.80 centimetres.
Additionally or alternatively to the suction station, in one arrangement the
separation station comprises a screening station arranged for screening the
particulate
hemp.
The suction station may be integrated with the screening station such that
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the suction is applied during the screening. Alternatively, the suction
station may be
independent of the screening station and come thereafter in the processing
stage such
that the suction is applied after the screening has been performed.
It is preferred that the system includes a conveyor arranged to transfer
the inadequate hemp units from the separation station to a start of the
processing stage
for reforming the inadequate hemp units back into the particulate hemp sized
in the
prescribed size range such as that between 0.60 centimetres and 3.20
centimetres.
Preferably, the system includes an initial mixing station at a start of the
processing stage that is arranged for mixing the particulate hemp so as to
produce a
blend of the particulate hemp which has a substantially uniform distribution
of moisture.
In one instance, the preliminary size reduction stage is arranged to accept
bales of the whole hemp stalks.
When the preliminary size reduction stage is arranged to accept the bales
of the whole hemp stalks, the preliminary size reduction stage is preferably
arranged
for reducing the bales of the whole hemp stalks into the particulate hemp.
In one instance, the system also comprises a preliminary drying stage
before the preliminary size reduction stage that is arranged for drying the
whole hemp
stalks so as to have a moisture content less than 15% by weight.
In one instance, the system includes a holding stage after the processing
stage that is arranged for storing the particulate hemp in a manner suitable
for sale as
or in a final product.
In one instance, the system includes a conveyor operatively coupled
between the preliminary size reduction stage and the processing stage.
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According to another aspect of the invention there is provided a method
of processing whole hemp stalks at a single location, each whole hemp stalk
including
bast fiber and shive, the method comprising:
providing the whole hemp stalks at said location;
using a shredder at said location, reducing the whole hemp stalks into
particulate hemp which is smaller in size than the whole hemp stalks and still
includes
bast fiber and shive;
at said location, processing the particulate hemp without separating bast
fiber and shive including:
reducing the particulate hemp in size so as to lie in a first range
between 25 microns and 500 microns so as to be usable for further processing
of the
particulate hemp into one of a plurality of different products each with
different size;
and using the particulate hemp sized in the first range as input to
said further processing so as to derive a selected one of said plurality of
different
products;
wherein the particulate hemp includes unseparated bast fiber and shive
throughout the step of processing the particulate hemp.
According to another aspect of the invention there is provided a system
of processing whole hemp stalks into particulate hemp at a single location,
wherein the
whole hemp stalks have been harvested and each of the whole hemp stalks
includes
bast fiber and shive, the system comprising:
a shredder arranged at said location for reducing the previously harvested
whole hemp stalks into particulate hemp, which is smaller in size than the
whole hemp
stalks and still includes bast fiber and shive;
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a processing stage arranged at said location for processing the particulate
hemp without separating bast fiber and shive that includes:
a first size reduction station arranged for reducing the particulate
hemp in size so as to lie in a first range between 25 microns and 500 microns
so as to
be usable for further processing of the particulate hemp into one of a
plurality of different
products each with different size;
at least one further size alteration station receiving the particulate
hemp sized in the first range as input thereto for said further processing so
as to derive
a selected one of said plurality of different products;
wherein the particulate hemp includes unseparated bast fiber and shive
throughout the processing stage.
According to a further aspect of the invention there is provided a method
of obtaining cannabinoid oil from processed hemp comprising:
receiving the processed hemp, which has been processed from a whole
hemp stalk to a particulate form having reduced size;
extracting the cannabinoid oil from the processed hemp using a fluid
extraction process in which an extracting solvent is applied to the processed
hemp;
wherein the received processed hemp is characterized in that it has been
previously pelletized as part of its processing from the whole hemp stalk to
the
= 20 particulate form.
In the embodiment as described in more detail hereinafter, very low
strains of tetrahydrocannabinol (THC) and higher strains of cannabidiol are
preferably
sought and these are obtained by starting with a raw material which has these
characteristics, that is the raw material is preferably low in THC and high in
cannabidiol.
Therefore, appropriate strains of hemp plant are chosen to meet such
requirements.
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Preferably, when the processed hemp is received from another external
facility, the processed hemp is bagged at the other external facility so as to
prevent the
processed hemp from drying out before the method for obtaining the cannabinoid
oil is
carried out.
Preferably, the whole hemp stalk, from which the processed hemp is
formed, was harvested when the hemp plant was in flower before seed had
formed. As
such, the processed hemp does not contain any hemp seed.
Preferably, the processed hemp includes leaves and flower buds of the
harvested whole hemp stalk.
Preferably, the processed hemp includes bast fiber and shive of the
harvested whole hemp stalk.
Preferably, the harvested whole hemp stalk, from which the processed
hemp is formed, was left to dry outdoors (typically in the field) after being
cut but prior
to being processed into the processed hemp.
Suitable fluid extraction processes include carrier oil extraction, super- or
sub-critical carbon dioxide (CO2) extraction, or solvent extraction (an
example of a
solvent conventionally associated therewith is grain alcohol, butane, and
hexane).
These examples form part of the category of processes including liquid-liquid
extraction
which can also be referred to as solvent extraction.
Preferably, the harvested whole hemp stalk is of the variety having higher
levels of cannabidiol than tetrahydrocannabinol.
In one arrangement, the step of extracting the cannabinoid oil includes
generating used processed hemp deprived of the cannabinoid oil initially
contained
therein. The aforementioned extraction arrangement comprising the pressurized
fluid
may be better suited for generating the used processed hemp that is still
usable in or
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as a vendible product as compared to an extraction arrangement using pressing
which
crushes the subject material.
Preferably, a step of drying the used processed hemp so as to be suited
for use as or in a salable product.
Preferably, the processed hemp comprises an average dimension
between 0.5 microns and 50 centimetres. Such sizing may make the processed
hemp
better suited for transportation between facilities.
All or any of the above features may be combined with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in conjunction with the accompanying
drawings in which:
Figure 1 is a flow diagram of an arrangement of system for processing
whole hemp stalks;
Figure 2 is a flow diagram of an arrangement of system of processing
particulate hemp for extracting cannabinoid oil therefrom;
Figure 3 is a flow diagram of an arrangement of method for processing
hemp plants to form a dry hemp product which comprises cannabinoid oil;
Figure 4 is a schematic illustration of a system in a processing facility for
performing some of the steps of the arrangement of method of Figure 3;
Figure 5 schematically illustrates an end view of a pair of cleated counter-
rotating rollers forming one station in the system of Figure 4; and
Figure 6 is a cross-sectional view of the pair of cleated counter-rotating
rollers of Figure 5 with other components omitted for clarity of illustration.
In the drawings like characters of reference indicate corresponding parts
in the different figures.
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DETAILED DESCRIPTION
Referring to the accompanying figures, there is illustrated a system for
processing whole hemp stalks that is generally indicated by reference numeral
10. The
system 10 is configurable to produce one of hemp fines or flour, hemp pellets,
and
hemp crumbs. Each of the hemp fines, pellets, and crumbs define particulate
forms of
hemp stalk. Each of the particulate forms are produced from whole hemp stalks
such
that the fines, pellets, and crumbs maintain characteristics of the hemp stalk
and differ
in terms of physical size.
The system 10 commences with a receiving stage 12 for receiving the
whole hemp stalks. Typically, the whole hemp stalks are delivered in the form
of round
or square bales. At the receiving stage, weight and moisture content of the
bales is
determined. Preferably, the whole hemp stalks have a moisture content in a
range
between 12% and 15% by weight; however, the moisture content may be below this
range and the hemp stalks may still be suited for processing into the
particulate hemp.
Any one of the bales which have moisture content exceeding 15% by weight may
be
rejected; alternatively, these bales that define excessively moist whole hemp
stalks may
be passed through a preliminary drying station 14 arranged for drying the
bales. When
the bales are passed to the preliminary drying station, the bales are dried
until the
moisture content thereof is less than 15% by weight which defines an upper
range limit
for acceptable moisture content.
After the receiving stage 12, the bales are transferred to a cutting stage
16 which performs a step of cutting the whole hemp stalks into hemp pieces
smaller
than the whole hemp stalks. The cutting stage comprises a shredding station 16
which
produces the hemp pieces sized to have an average piece dimension in a
prescribed
piece range which is preferably between 1.50 centimetres and 5.30 centimetres.
CA 3009554 2018-06-26
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Alternatively, the prescribed piece range may be between 1.30 centimetres and
6.40
centimetres and provide comparable results to the preferred prescribed piece
range.
The prescribe piece range may also be between 1.10 centimetres and 7.70
centimetres
and provide comparable results to the preferred prescribed piece range. The
preferred
prescribed piece range of the average piece dimension is analogous to a
typical,
average dimension of mulch for use in landscaping or gardening. In the
illustrated
embodiment, the shredding station comprises an agricultural shredder which has
a
body and a rotor rotatably carried within the body. The body includes at least
one
stationary counter knife supported in the body. The rotor, which is made of
steel,
supports counter shredding blocks. Each shredding block is sized to be 40
millimetres
by 40 millimetres by 20 millimetres. The hemp stalks are shredded between the
rotor
and the at least one stationary counter knife. Further to the rotor and the
counter knife,
the shredder comprises a screen locating openings for passing the hemp pieces
therethrough once the hemp stalks are cut into sufficiently small portions.
The openings
are selectively sized to transfer out of the shredder the portions of the hemp
stalks
which are sized in the prescribed piece range mentioned hereinbefore. Size of
the
openings may be adjusted depending on the average piece dimension within the
prescribed piece range that is desired. The shredder may be capable of
performing the
step of cutting the hemp stalks at a processing or cutting rate of 4,000
pounds per hour;
however, in other embodiment the shredder may have a cutting rate less than
that of
the illustrated embodiment and still yield comparable results to that of the
illustrated
embodiment. Such agricultural shredders are known in the art and thus are not
illustrated in detail herein. Note that the hemp pieces include bast fiber and
hurds
collectively defining shive of the whole hemp stalks. As such, the shredding
station 16
is arranged to cut through the bast fibers in order to form the hemp pieces.
Further to
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the bast fiber and the hurds, the hemp pieces may also include leaves or
flower buds
of the hemp stalk.
Once the whole hemp stalks have been reduced to the hemp pieces, the
hemp pieces are transferred to a size reduction stage 18 which performs a step
of
granulating the hemp pieces into the particulate hemp. The size reduction
stage is
configured so as to produce one of the hemp fines, the hemp pellets, and the
hemp
crumbs. The size reduction stage may produce the particulate hemp defined by
one of
the hemp fines, pellets, or crumbs having an average particle dimension
between 0.5
microns and 3.20 centimetres. First, the stations which are common to each one
of the
hemp products produced by the system 10 are discussed.
At a start of the size reduction stage, the hemp pieces are transferred
from the shredding station 16 to a mixing station 20 which performs a step of
mixing
the hemp pieces so as to produce a blend of the hemp pieces which has a
substantially
uniform distribution of moisture. Typically, the moisture content of the bales
is contained
closer to outer faces of the respective bale. Thus, the step of mixing the
hemp pieces
ensures that the blend of hemp pieces has uniform moisture content, and this
blend is
then converted to one of the hemp products. In the system of the illustrated
embodiment, the mixing station comprises a metering bin 20. It will be
appreciated that
the mixing station can be considered to be part of either one of the cutting
stage 16 or
size reduction stage 18; alternatively, the mixing station 20 can be
considered as
independent of either one of the cutting or size reduction stages so long as
the mixing
station is intermediate the shredding station 16 and a coarse granulating
station 22 of
the size reduction stage.
The size reduction stage comprises the coarse granulating station 22
which is common to each configuration of the illustrated embodiment. The
coarse
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granulating station 22 performs a coarse pulverizing step which reduces the
hemp
pieces to hemp particles sized in a first granule range which is preferably
between 75
microns and 400 microns. Alternatively, the first granule range may be between
25
microns and 500 microns and provide comparable results to that of the
preferred first
granule range. Size of the hemp fines is analogous to that of sawdust. In the
system 10
of the illustrated embodiment, the coarse granulating station comprises a
coarse
hammer mill.
To produce the hemp fines, the hemp particles are transferred from the
coarse granulating station 22 to a fine granulating station 24 which performs
a fine
pulverizing step for further reducing the hemp particles into hemp fines. The
hemp fines
are sized in a second granule range which is preferably between 0.9 microns
and 200
microns. Alternatively the second granule range may be between 0.8 microns and
250
microns and provide comparable results to that of the preferred second granule
range.
The second granule range may also be between 0.5 microns and 300 microns and
provide comparable results to that of the preferred second granule range. In
the
illustrated embodiment, the fine granulating station 24 comprises a fine
hammer mill
which is arranged to grind the hemp particles more finely than the coarse
hammer mill
of the coarse granulating station. As such, the hemp fines contain the bast
fiber and the
hurds of the hemp stalks. If the hemp stalks also included the leaves and
flower buds,
the hemp fines also include the leaves and flower buds thereof albeit in
portions. The
hemp fines define one form of the particulate hemp which is produced by the
system of
the illustrated embodiment. The hemp fines or flour can then be bagged in a
manner
suitable for storage or in a manner suitable for sale in or as a consumer
product.
Alternatively, the hemp fines may be transferred to a storage station 25 which
will be
.. described later in more detail.
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To produce either one of the hemp pellets or the hemp crumbs, the hemp
particles are transferred from the coarse granulating station 22 to a
pelletizing station
26 which performs a pelletizing step. In the pelletizing step, the hemp
particles are
formed into hemp pellets sized in a pellet range which is preferably between
1.20
centimetres and 2.60 centimetres. Alternatively the pellet range may be
between 1.00
centimetres and 2.80 centimetres and provide comparable results to that of the
preferred pellet range. The pellet range may also be between 0.60 centimetres
and
3.20 centimetres and provide comparable results to that of the preferred
pellet range.
In the system of the illustrated embodiment, the pelletizing station 26
comprises a pellet
mill or pelletizer 28. One example of the pellet mill that is appropriate for
producing the
hemp pellets sized in the desired pellet range has the following parameters,
as
understood by a person with normal skill in the art: (i) die diameter of 26";
(ii) hole
diameter of 1/4"; (iii) effective thickness of 21/8; (iv) relief of 13/16; and
(v) operating
temperature of 190 degrees Fahrenheit to 205 degrees Fahrenheit (operating at
200
degrees Fahrenheit is preferred). In some instance where the moisture content
of the
hemp particles is too low such that the hemp particles do not bind together in
the
pelletizing step, moisture typically comprising steam or water is added to the
hemp
particles in the pelletizing station so as to aid in forming the hemp pellets.
The hemp
pellets still contain the bast fiber and the hurds of the hemp stalks. If the
hemp stalks
also included the leaves and flower buds, the hemp pellets also include the
leaves and
flower buds thereof albeit in portions.
Since formation of the hemp pellets involves high temperatures, the hemp
pellets are transferred to a cooling station 30 belonging to the pelletizing
station. The
cooling station performs a step of cooling the hemp pellets such that the hemp
pellets
.. harden. The cooling station comprises a cooler bin 30 in the system of the
illustrated
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embodiment.
To produce the hemp crumbs or crumbles, the hemp pellets are
transferred from the cooling station 30 to a crushing station 32 which
performs a
crushing step. In the crushing step, the hemp pellets are reduced to hemp
crumbs sized
in a crumb range which is preferably between 1.00 centimetres and 2.00
centimetres.
Alternatively, the crumb range may be between 0.75 centimetres and 2.30
centimetres
and provide comparable results to that of the preferred crumb range. The crumb
range
may also be between 0.30 centimetres and 2.80 centimetres and provide
comparable
results to that of the preferred crumb range. In other embodiments, the crumb
range
may lie between 0.03 centimetres and 0.65 centimetres depending on intended
applications of the crumbs. In the system of the illustrated embodiment, the
crushing
station comprises a roller mill 32; however, in alternative embodiments the
crushing
station comprises a hammer mill separate from the hammer mill 22 of the coarse
granulating station. The crushing station may also be referred to as a
crumbler which
.. forms the hemp crumbs or crumbles. The hemp crumbs still contain the bast
fiber and
the hurds of the whole hemp stalks. As such, some of the bast fiber which is
difficult to
break may remain such that some hemp crumbs are similar in size to the
respective
hemp pellets because the respective crumbs are held together by strands of the
fiber
even after grinding or crushing the hemp pellets. Additionally, if the hemp
stalks also
included the leaves and flower buds, the hemp crumbs also include the leaves
and
flower buds thereof albeit in portions.
Regardless of whether the system is configured to produce the hemp
pellets or the hemp crumbs, in both instances the particulate hemp defined
thereby is
transferred to a screening station 34 of the size reduction stage for removing
hemp
pellets or bad hemp crumbs that have an average unit dimension lying outside
the
CA 3009554 2018-06-26
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respective one of the pellet range or the crumb range depending on which hemp
product is being produced; these hemp pellets or crumbs define inadequate or
bad
hemp units. The bad hemp pellets or crumbs are transferred to a start of the
size
reduction stage 18 so as to pass through the coarse granulating station 22 and
pelletizing station 26 a subsequent time. In the illustrated embodiment, the
bad hemp
units are transferred back to the mixing station 20 instead of being
transferred directly
back to one of the coarse granulating station 22 or the pelletizing station
26. The mixing
station typically has sufficient capacity to accept additional material for
processing,
while the coarse granulating station and pelletizing station are typically
near full
capacity. In alternative embodiments comprising granulating and pelletizing
stations of
greater capacity, the bad hemp units can be transferred to either one of these
stations
in lieu of the mixing station.
The bad hemp units which exceed the allowed range are first separated
from acceptable hemp units having the average unit dimension which lies within
the
respective range. In the illustrated embodiment, the first separation step is
performed
by a first screen which allows the acceptable hemp units to pass through
openings
located in the first screen. For example, the first screen has openings sized
at the upper
range limit of the pellet or crumb range. A second separation step performed
by a
second screen separates the bad hemp units that have the average unit
dimension
below the respective range. The bad hemp units segregated by the second screen
include dust defined by the hemp particles that were not properly pelletized
in the
pelletizing station. In the case of the hemp crumbs, the dust may also be
defined by
fines generated during crushing of the hemp pellets to form the hemp crumbs.
For
example, the second screen locates openings sized at the lower range limit of
the pellet
or crumb range so that the bad hemp units that are below the lower range limit
of the
CA 3009554 2018-06-26
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respective range pass through the openings. In another example, the openings
of the
second screen are 4 mm in diameter. In addition to the screens, a suction
station
separates the dust from the particulate hemp by applying suction to the
particulate
hemp. The suction station comprises a vacuuming apparatus. The suction can be
applied during the second separation step; alternatively the suction can be
applied after
the second separation step has been performed. Once the dust has been removed
from
the particulate hemp, the bad hemp units are transferred to the start of the
size
reduction stage. The screening station and suction station collectively define
a
separating station for segregating the bad hemp units from the particulate
hemp.
Overall, the system 10 is capable of processing 2 tonnes to 2.5 tonnes of
whole hemp stalk per hour.
After the separation or segregation station, the hemp pellets and crumbs
that are acceptably sized are transferred to the storage station 25. At the
storage
station, a portion of the particulate hemp is stored in a manner suitable for
selling as a
consumer product or for use in a consumer product. Another portion of the
particulate
hemp is stored so as to be prepared for loading for transportation to a
separate oil
extraction facility 38 which performs a step of extracting cannabinoid (CBD)
oil from the
particulate hemp. In other embodiments, the particulate hemp may be loaded
directly
onto a vehicle such as a tanker for transportation (i.e., by road) to the oil
extraction
facility. The transportation arrangement may also include train (i.e., by
rail) and ship
(i.e., by water). In further embodiments, a facility comprising the system 10
may also
include subsequent stages and/or stations 40 for performing the step of
extracting the
CBD oil; as such, the particulate hemp may be transferred directly to the
appropriate oil
extraction stages and/or stations after the screening station.
Similarly to the hemp crumbs and pellets, the hemp fines may also be
CA 3009554 2018-06-26
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stored in preparation for transfer to the oil extraction facility for
extracting oil from the
hemp fines.
Furthermore, it will be appreciated that the term 'particulate hemp',
especially as the term pertains to the concept of oil extraction, is broadened
to be
.. understood as processed hemp. 'Processed hemp' refers to a smaller forms
(i.e.,
relating to physical size) reduced in size from the hemp stalks such that the
smaller
forms are easier to transport. Thus, the processed hemp may include the hemp
fines,
hemp pellets, and hemp crumbs that are sized as described hereinbefore. The
processed hemp may also include hemp cubes and hemp briquettes. The hemp cubes
are sized typically in a cube range between 1.20 centimetres and 7.70
centimetres so
as to be larger than or similarly sized as the hemp pellets. The hemp cubes
may be
produced from the hemp stalks in a similar fashion to the hemp pellets
produced by the
system 10. That is, in other embodiments the pelletizing station 26 or the
pelletizer 28
may be replaced with similar equipment so as to produce the cubes which are
cubic in
.. form instead of the hemp pellets which may be of varying shapes. The
processed hemp
may also include hemp briquettes which are sized larger than the hemp cubes so
as to
be in a briquette range typically between 5 centimetres and 50 centimetres. In
other
embodiments, the system 10 may be configured to produce the hemp briquettes
such
that the pelletizing station 28 or pelletizer is replaced with a briquetting
station or
briquetting machine, respectively. Additionally, the processed hemp may
include all or
any combination of the constituent components of the hemp stalks including the
bast
fiber, the hurds, the leaves, and the flower buds. Typically, inclusion of the
leaves or
the flower buds of the hemp stalks may augment an amount of CBD oil contained
in the
processed hemp. Also, using different strains of hemp may yield different
amounts of
CBD oil in the processed hemp.
CA 3009554 2018-06-26
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Returning to the extraction of the CBD oil, the step of extracting the CBD
oil typically generates used particulate hemp which is deprived of the CBD oil
initially
contained therein. Typically, the used particulate hemp has moisture content
which is
greater than that suited for consumer products such as animal litter, animal
bedding,
.. and absorbency products. Thus, the used particulate hemp is dried in a
drying station
42 so as to be suited for use in the consumer products like those mentioned
hereinbefore. Typically, the step of drying the used particulate hemp is
performed with
heat and air. The used particulate hemp may then be stored in a storage
station 44
similar to the storage station 25.
Tests commissioned by the applicant show that for at least one particular
strain of hemp, the hemp pellets contain about 0.02% of CBD. Thus, the tests
indicate
that the processed hemp is not devoid of the CBD oil initially contained in
the hemp
stalks. As mentioned before, the content or amount of CBD oil in the processed
hemp
may be increased by using different strains of hemp and if the hemp stalks
that are
processed include the leaves or the flower buds.
It will be appreciated that the system of the illustrated embodiment may
also be suited for other types of organic matter and crops.
It will also be appreciated that a particular shape of each one of the hemp
products may vary so long as each individual particle of each hemp product
fits within
the corresponding size range.
It will also be appreciated that binding materials are not necessary to
produce any one of the hemp fines, crumbs, or pellets in the system 10 of the
illustrated
embodiment.
The hemp products produced by the system 10 and corresponding
method have many applications. The following are attributes of hemp may lend
to its
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advantages in the applications which are mentioned later: (i) bast fiber
length is 5
millimetres to 40 millimetres in length; (ii) primary bast fibers, which may
be most
favourable for certain applications, are long and low in lignin content; (iii)
secondary
bast fibers, which are secondary to the primary fibers for the certain
applications, are
shorter than the primary bast fibers and high in lignin content; and (iv)
tertiary bast
fibers, which are third to the primary fibers for the certain applications,
are shorter than
the secondary bast fibers and high in lignin content. Also, hemp comprises
cellulose
typically in a range between 32% and 38%.
Hemp is suited for a number of consumer products such as animal litter
(e.g., cat litter); animal bedding for animals like horses, birds, snakes, and
rabbits;
absorbing or absorption products suited for use in spills comprising oil, gas,
chemicals
considered hazardous and/or having adverse effects on humans and the
environment,
sewage, and water; absorption products for absorbing gases generated by sewer
tanks
or ponds; and 3D printing filament or molding when the hemp is combined with
plastic
material.
In particular, the hemp pellets and hemp crumbs are suitable for use in
animal litter for domestic pets such as cats, birds, and horses because these
hemp
products provide desirable characteristics suited for the animal litter
including (i) rapidly
and efficiently absorbing animal excretions; (ii) ability to rapidly minimize
unpleasant
odors; (iii) non-adherence to animal paws and fur; (iv) biodegradability; and
(v) low cost.
The hemp pellets and hemp crumbs, when made from hemp having low
tetrahydrocannabinol (THC) content, also provide the following characteristics
desirable in the animal litter such as (i) ability to inhibit the growth of
microorganisms;
(ii) ability to repel insects and pests such as fleas and moths; (iii) little
to no dust content;
and (iv) sufficiently low levels of psychoactive chemicals so as to not
produce physical
CA 3009554 2018-06-26
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or psychological effects. Moreover, since animal litter is widely used, it is
important that
the material from which the litter is made is environmentally friendly. Hemp
may be
grown without application of insecticides or pesticides so that hemp is 100%
organic
the hemp, thereby meeting one of the preferred requirements of animal litter.
Additionally, the hemp products produced by the system 10 have
characteristics including (i) high absorbency; and (ii) ability to rapidly
minimize
unpleasant odors. Thus, the hemp fines and crumbs are suited for absorbing or
absorption products. Generally speaking, hemp is able to absorb liquids up to
490% of
its weight; however, the hemp fines are likely to absorb liquids more quickly
than the
hemp crumbs or the hemp pellets because the hemp fines are smaller in size
than the
crumbles or pellets, and the hemp crumbles are likely to absorb liquids more
quickly
than the hemp pellets because the crumbles are smaller in size compared to the
pellets.
Additionally, hemp is able to neutralize chemicals to a pH near 7. In chemical
or oil
spills, acid neutralization may afford the chemicals or the oil to be rendered
less harmful
to an external environment surrounding the spill. In animal litter as
mentioned earlier,
acid neutralization may afford neutralization of ammonia contained in animal
excretions
(especially in animal urine) so as to minimize an unpleasant smell of the
ammonia.
The hemp crumbs or the hemp pellets may be blended with binders like
corn or wheat starch to form an animal litter which is able to form clumps.
In another example, the hemp crumbs and pellets may also be suited for
use as mulch. In a further example example, the hemp fines are suited for
absorbing
liquid such as in scenarios of water, oil, or chemical spills. In a yet
further example, the
hemp fines are suited for mixing with at least one of polypropylene,
polyethylene,
polyurethane, polylactic acid, PHA-green resin, and magnesium oxide for making
.. plastic filament or for use in molding.
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The hemp products produced by the system 10 may also be suited for
use as or in loose fill insulation.
It will be appreciated that the hemp retains its desirable characteristics
regardless of the physical form in the present embodiment, i.e., regardless of
whether
the hemp is in the form of the hemp fines, the hemp pellets, and the hemp
crumbs. As
such, the aforementioned qualities of one of the hemp product are likely
maintained in
another one of the hemp products produced by the system 10.
Hemp may also be suited for use as or in biomass.
Furthermore, hemp contains the CBD oil and the CBD oil contained in the
hemp may be extracted without considerably affecting performance of the hemp
for the
consumer products mentioned hereinbefore.
The CBD oil is found in an upper portion of the plant such as in leaves
and flower buds of the stalks. Typically, the CBD oil content in the hemp
stalk ranges
between 2% and 7%. It may be desirable to extract the CBD oil from the hemp
stalks
because the oil is suited for therapeutic use for a variety of diseases such
as anxiety
disorders, post-traumatic stress disorder, psychosis, epilepsy, dystonia,
diabetes,
cancer, inflammatory diseases, and skin diseases.
The hemp stalks from which the particulate hemp may be harvested
differently depending on whether the hemp products derived from the hemp
stalks are
.. to be used primarily for such consumer products as those mentioned
hereinbefore or
primarily for oil extraction. In case of the latter, the hemp stalks may be
harvested once
the hemp stalks have flowered such that the CBD oil content in the stalks is
higher than
prior to or during flowering. In other cases, the hemp stalks may be harvested
during
flowering. Furthermore, depending on a state in which the hemp stalks are
harvested a
swather or combine harvester may be better suited for cutting the hemp stalks.
After
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the hemp stalks are cut, the hemp stalks may be left outside in a field to dry
until the
hemp stalks have the proper moisture content. Once dried, the hemp stalks may
be
baled. Once baled, the hemp stalks may be covered under tarps or stored in a
shed
before sending the hemp stalks to a facility comprising the system 10 for
processing.
In another arrangement of the present invention, the whole hemp stalks
are harvested when the stalks are in full flower (full bloom/blossom) but
before any
seeds have formed in order to obtain economically suitable yields of CBD oil.
This is
because the hemp seeds do not contain the desired strain of cannabinoid used
and
therefore need not be present in the raw material, which is the processed
hemp, from
which the oil is later extracted. However, at the time of harvest, the whole
hemp stalks
do have flower buds (also known as blooms) and leaves, and these are not
removed
from the stalks so as to remain in the particulate processed hemp that is
formed
therefrom. Typically, when the stalks are destined for oil extraction, the
whole hemp
stalks are left in the field after cutting so as to dry to a moisture content
between 10%
and 18% by weight. Alternatively, drying to a moisture content between 10% and
14%
or to that between 15% and 18% may be equally suitable. The hemp stalks are
then
baled once they have dried in the field, and subsequently the dried and baled
hemp
stalks are passed through the size alteration stages to form the particulate
hemp that
is later used in the oil extraction.
In some instances, separate facilities carry out each of the processing of
the whole hemp stalks into particulate hemp and the oil extraction. The
particulate
processed hemp is bagged at a conclusion of its processing in the first
facility so that
the particulate hemp retains its moisture/oil content before the oil
extraction is carried
out. That is, the processed hemp is stored in a way suitable for shipping but
in a closed
arrangement (for example, closed bags or other sealed containers) such that
the
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particulate hemp is prevented from drying out before the oil extraction. As
such, the
particulate form of the hemp, which is a consequence of its processing from a
whole
stalk state, by its significantly reduced size makes the hemp better suited
for transport
and better suited for holding in a moisture sealing/retaining arrangement.
At the oil extraction facility, a fluid extraction process is used to remove
the oil from the processed hemp. That is, a suitable fluid (typically in
liquid state) is
applied as an extracting solvent to the processed hemp using suitable
apparatus for
carrying out the extraction. Typically, the processed hemp is carried in a
first immiscible
liquid such as water and is transferred to the extracting solvent by mixing
together in
the suitable apparatus. Vice versa, the extracting solvent may be first
applied to the
processed hemp and then mixed with another immiscible liquid so that the other
immiscible liquid carries the desired CBD oil at the end of the process. The
carrier liquid
which contains the desired component at the end of the process is then removed
from,
and in this way the CBD oil is extracted.
A number of suitable such processes forming a category of processes
known as liquid-liquid extraction or otherwise as solvent extraction are
effective for
extracting the desired strains of cannabinoids, and examples include
supercritical fluid
extraction (for example, using supercritical carbon dioxide), conventional
solvent
extraction (conventional extraction solvents associated therewith include, for
example,
grain alcohol or ethanol high grade alcohol), or carrier oil extraction (for
example, using
olive oil). Subcritical carbon dioxide (CO2) extraction may also be suitable.
These
processes are known in the art in how they are applied to hemp and thus are
not
described in detail herein. Where possible, subcritical or supercritical CO2
extraction is
desirably used because this extraction process uses a chemical (i.e., CO2)
that is non-
toxic and non-flammable as compared to the chemicals employed in solvent
extraction
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(e.g., butane, grain alcohol, isopropyl alcohol, hexane, or ethanol). CO2
extraction also
retains beneficial plant waxes which are present and removes the chlorophyll
from the
end product. On the other hand, conventional solvent extraction is typically
less
expensive and may be easier to perform over supercritical CO2 extraction. Note
that
the specifically chosen process for extracting the oil may vary depending on
the end-
use of the oil that is derived.
Based on presently known applications for oil derived from hemp, the
strain of cannabinoid having gained in popularity is cannabidiol. Therefore,
cannabidiol
is the strain which is typically desired and therefore isolated from the hemp,
although
.. other cannabinoid strains may be extracted alternatively or additionally to
cannabidiol.
As a result of the oil extraction process, used processed hemp is
produced and it is deprived of the CBD oil initially contained therein. As
such, in addition
to other benefits provided by the respective extraction process, the fluid
extraction
processes mentioned above may be better suited for providing such used
processed
hemp that can still be used in or as a vendible product because these fluid
extraction
processes leave the physical form of the hemp substantially unaltered as
compared to
an extraction arrangement using pressing which crushes the subject material.
That is,
the fluid extraction processes remove the CBD oil without compromising other
physical
properties of the processed hemp which make it suitable for use in/as a
salable product
but which do not depend on presence of CBD oil in the hemp. The used processed
hemp which will be used in/as the salable product is dried, for example by
placing the
used processed hemp in a heated storage chamber to let the hemp air-dry, so as
to be
suited for its subsequent use.
As described in detail hereinbefore, the harvested whole hemp stalks are
processed into one of pellets, flour, and crumbles. Each of these products
include both
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bast fiber and shive, which remain substantially intact throughout the
processing
stages, as well as the leaves and flower buds which augment the content of the
desired
CBD strains in the processed hemp. Although it is possible to extract CBD oil
from the
flour, the physical form of the pellets and crumbles may make them more
manageable
.. for extraction when compared to a powdery flour form as apparent above, and
thus the
pellets and crumbles are preferred for the oil extraction over the flour. As
such, the
processed hemp from which the oil is extracted has typically gone through a
pelletizing
step as part of its processing.
Furthermore, the processed hemp is generally preferred as the raw
.. material for oil extraction over the original whole hemp stalks as the
processed hemp
is more suitably sized and each unit thereof contains a plurality of
components of the
original whole hemp stalk like the shive, bast fiber, leaves, and flowers
(through the
processing as described hereinbefore) such that uniform yields of the CBD oil
may be
produced in terms of quality and relative proportions of desired CBD strains
in the oil.
The same is not necessarily true if the whole hemp stalks, as harvested, were
used as
the raw material for oil extraction or even if the whole hemp stalks were
separated into
constituent parts of the plant and then used as the raw material.
Figure 3 illustrates a method 50 for processing hemp to form a dry hemp
product including cannabinoid oil. In particular, a majority of the respective
hemp
plant's cannabinoid oil is carried in its leaves and flower buds. Thus, the
method 50
comprises at 52 a first step of cutting the hemp plants, which are growing in
a field,
between about 85 days and about 120 days after seeding thereof, such that the
hemp
plants include at least either one of leaves and flower buds but are free of
seed. That
is, the respective hemp plant comprises a stalk including shive and bast
fiber, and may
include leaves and flower buds attached to an upper portion of the stalk after
sufficient
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growth of the plant. After a time period of about 85 to 120 days has elapsed
following
seeding of the plants, depending on rate or speed of growth of the hemp plants
which
is affected by human-uncontrollable factors such as weather conditions, the
hemp
plants are producing an optimal amount of cannabinoid oil which is excreted by
the
plants at their leaves so as to form a sticky residue upon surfaces of the
leaves. This
optimal amount of cannabinoid oil is produced before the plant has formed
seed. It is
therefore at this prescribed time that the hemp plants are cut, whereby the
hemp plants
cease to grow. For example, the hemp plants are cut with a haybine conditioner
or a
swather. Furthermore, after such prescribed time has passed since seeding,
typically
the hemp plants carry both leaves and flower buds.
Within the broad range of about 85 to 120 days, cutting may be performed
between about 95 days and about 110 days after the seeding of the hemp plants.
After the step of cutting at 52 in the method 50, the cut hemp plants are
left to air dry in the field to a prescribed moisture content of about 5% to
about 15% as
indicated at 55. During this step of drying, the excreted cannabinoid oil
disposed on
the surfaces of the leaves and/or flower buds is absorbed into the drying
leaves and/or
flower buds, such that these parts of the hemp plants act as the carriers of
the
cannabinoid oil. The hemp plants are dried before baling.
Once the hemp plants reach the prescribed moisture content, the dried
plants are baled to form bales of the dried hemp plants which are readily
transportable
from the field to a processing facility where subsequent steps of the method
50 are
performed. Figure 4 illustrates a system 58 in a processing facility for
processing the
dried hemp plants transported thereto from the field.
At the processing facility, where the hemp plants are transported after
drying, the dried hemp plants are unbaled so as to release the respective
dried hemp
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plants. In the illustrated arrangement, the unbaling is carried out by
unwinding the bales
using a bale unroller 60 to gradually release the respective dried hemp
plants. The
unbaled hemp plants form a swath which is deposited from the unbaler 60 upon a
conveyor 62.
Next, the dried hemp plants are shaken in the next step 64 of the method
50 (Figure 3) to shear the leaves and/or the flower buds from the stalks of
the hemp
plants so as to form separated stalks and leaves and/or flower buds which are
not
deformed. The step of shaking or vibrating the hemp plants to remove the
leaves and/or
flower buds from attached condition to the stalks at 64 is performed by
passing the
hemp plants between a pair of counter-rotating rollers, which station in the
system 58
is schematically indicated at 67 in Figure 4. As shown in Figures 5 and 6, the
counter-
rotating rollers 69, 70 of system station 67 carry a plurality of generally
axially extending
cleats 72 in spaced angular relation to one another. The cleated rollers 69,
70 are
spaced apart to shake the hemp plants without crushing the at least one of the
leaves
and the flower buds. The cleated rollers 69, 70 are arranged in spaced
relation to form
a gap 74 upon passing through which the hemp plants are not pinched and
deformed,
but rather are shaken or vibrated with sufficient force that the leaves and
buds tear from
attachment to the stalks. Typically, the cleated rollers 69, 70 are spaced
apart by about
2 inches to about 5 inches, and preferably by about 3 inches to achieve the
non-
deforming shaking action.
Still referring to Figures 5 and 6, the cleated rollers 69, 70 are arranged
in vertically upright stacked condition such that an axis of rotation R of
each of the rollers
is generally horizontally oriented and one roller is located above the other
with their
roller axes R lying in a common vertically upright oriented plane P. Each of
the rollers
69, 70 is driven in opposite rotational direction to the other as indicated by
arrows 76,
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77 by a drive arrangement such as a hydraulic power pack 78. The rollers 69,
70 are
mounted on a frame comprising a pair of vertically upstanding posts 79A, 79B
on which
each roller 69, 70 is respectively rotatably supported.
The rollers 69, 70 which are cleated thus each comprise a plurality of
raised protrusions defining the cleats 72 which are arranged on a circular
cylindrical
body 80 of the respective roller 69, 70 in spaced parallel condition to one
another. Thus
is defined a groove or recess 81 between each one of an adjacent pair of the
protrusions. The cleats 72 of each counter-rotating roller are linear and
extend axially
and angularly of thereof across substantially a whole length of the respective
roller.
Thus, each cleat 72 follows a path along the roller body 80 which is
substantially linear
from a position at or adjacent one roller end 83 to a position at or adjacent
the other
roller end 84, however, as an outer surface 85 of the roller body 80 is curved
than a tip
88 of the respective cleat 72 which is raised above the outer body surface 85
so as to
be radially spaced therefrom follows a twisting path in a generally axial
direction of the
respective roller along its body 80. In yet other words, opposite ends 72A,
72B of the
respective cleat are angularly spaced from one another relative to the roller
axis R, and
a body of the cleat spanning therebetween follows the substantially linear
path from
one cleat end 72A to the other 72B.
The cleats 72 of the counter-rotating rollers 69, 70 are angularly offset
from one another along their respective roller axes R such that during
rotation a raised
portion of one roller is located directly opposite a recessed portion of the
other roller.
Furthermore, the cleats 72 of each roller 69, 70 extend in an opposite angular
direction
to the other so that the cleats 72 of the counter-rotating rollers would
effectively mesh
with one another if the rollers 69, 70 were located more closely to one
another.
Referring again to Figure 4, on an output side of the counter-rotating
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cleated rollers station 67 is another conveyor 90 which transfers the
separated stalks
and leaves and/or flower buds to a screener 92 where the separated stalks and
the
leaves and/or the flower buds are screened so as to be separated from one
another,
as indicated at 94 in Figure 3. The screener 92 operates in the conventional
sense as
a sieve where the smaller sized leaves and flower buds, with respect to the
stalks which
are still intact and not deformed, pass through a mesh or a grid to pass
through a distinct
first output 93A of the screener 92 from a second output 93B of the screener
which
discharges the hemp stalks. Each of the hemp stalks and the leaves and/or
flower buds
which are saturated with cannabinoid oil in comparison to the stalks are
transferred by
respective conveyors 95, 96 to a designated separate holding bin 97, 98 for
temporary
storage.
As such, hemp plants with an optimal amount of cannabinoid oil are
processed to separate the oil-rich part of the plant carrying a majority of
the cannabinoid
oil from the hemp stalks which comprise bast fiber and shive and carry a
substantially
smaller proportion of a total amount of the cannabinoid oil of the respective
plant. Thus,
oil-rich leaves and/or flower buds may be used for one type of vendible
product for
which cannabinoid oil is suited, and the hemp stalks can be further processed
for
another type of vendible product for which bast fiber and shive are
particularly suited.
Also, neither the hemp stalks nor the removed leaves and/or flower buds are
substantially deformed by the processing stages so that further processing of
either
parts of the plant may commence with a substantially intact starting material.
Furthermore, the leaves and/or flower buds provide one example of dry form of
hemp
comprising cannabinoid oil which may be usable alone or in combination with
another
substance to form a dry hemp product.
After the flower buds and/or leaves are separated from one another,
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cannabinoid oil may be extracted from them at the same site, or the flower
buds and/or
leaves may be shipped to an extraction plant. Alternatively, the flower buds
and/or
leaves may be made into a pellet form and then have an oil extraction process
performed on the same to extract the cannabinoid oil, the latter being
performed at the
same site or at another site. In a further alternative, the pelletized flower
buds and/or
leaves form a vendible product, for example, which is sold as a supplement
feed for
livestock or pets.
Since various modifications can be made in my invention as herein above
described, and many apparently widely different embodiments of same made, it
is
intended that all matter contained in the accompanying specification shall be
interpreted
as illustrative only and not in a limiting sense.
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