FR3161219A1 - Process for transforming Jussie into combustible biomass - Google Patents

Abstract

The invention relates to a method (500) for transforming water primrose into a combustible biomass product, such as combustion pellets, comprising: a step (510) of storing the previously harvested water primrose; a step (520) of drying the stored water primrose to a moisture content that promotes combustion; a step (531) of removing the dried water primrose; a step (532) of grinding the water primrose in a grinder (320) that finely chops the water primrose; a step (533) of granulating the water primrose using a press (360) to form combustion pellets; and a step (540) of packaging and storing the pellets produced. The invention also relates to a mobile system (400) for implementing this method. Abstract: Figure 2

Description

Process for transforming Water Primrose into combustible biomass

The present invention belongs to the field of ecological treatment of invasive plants, in particular Water Primrose, and relates more particularly to a process of transforming previously uprooted Water Primrose into combustible biomass product such as combustion pellets.

The invention finds a direct, but not exclusive, application as an alternative heating source in industrial boiler rooms, for example.

State of the art

Water primrose (or creeping water primrose), scientifically known as Ludwigia peploides , is a fast-growing aquatic plant often considered invasive in some ecosystems. Several methods can be used to manage its impact or find uses for it.

Composting transforms water primrose into an organic soil amendment, reducing its volume and utilizing its nutrients. Its biomass can also be used to produce biogas in anaerobic digesters, providing a renewable energy source while controlling its spread. In horticulture, prepared water primrose is used as a growing medium, taking advantage of its beneficial physical properties. The fiber extracted from this plant can also be used in papermaking, thus contributing to its sustainable management.

In addition, under certain conditions, it can be used as feed for livestock or poultry, although this use requires careful evaluation to avoid risks to animal health.

Finally, water primrose contains bioactive compounds that could be useful in the pharmaceutical and cosmetic sectors, encouraging research into the extraction of these phytochemicals. These different approaches not only help to limit the negative ecological impact of water primrose but also open avenues for its economic and environmental valorization.

Controlling water primrose requires a multifaceted approach. It is now widely recognized that the use and sale of water primrose for ornamental purposes should be avoided due to the high risk of uncontrolled spread, even in seemingly confined environments. In Europe, certain environmental conditions, such as the presence of dense riparian forests or vigorous native species, can limit its spread.

Although it seems difficult to completely eradicate the species in regions like France, management efforts aim to limit its spread and its impacts on biodiversity. Measures such as reducing nitrogen and phosphorus levels in water, collecting and destroying the plant, and using biological control methods are being explored.

Regarding biological control, although animals such as certain beetles appear to feed on water primrose in its native habitat, their introduction into Europe carries risks of adverse effects on local ecosystems. Attempts at biological control through grazing with livestock or the introduction of fish have shown mixed or even counterproductive results.

On the other hand, the use of herbicides presents challenges due to their harmful effects on other species and the risk of water eutrophication. Currently, light and regular manual maintenance appears to be the preferred method, combined with close monitoring to allow for early intervention. This is sometimes followed by more intensive work to remove a large portion of the seagrass bed, with precautions taken to avoid the dispersal of propagules.

The document US2002119891 describes methods for controlling aquatic weed populations such as Water Primrose using fluridone, which is an aquatic herbicide.

Document WO2023126621 describes a control method consisting of applying an effective amount of a defoliant comprising a metallic chlorate.

Document US2015218099 relates to methods for controlling aquatic weeds, which involve the use of 4-amino-3-chloro-6-(4-chloro-2-fluoro-3-methoxyphenyl)pyridine-2-carboxylic acids and agriculturally acceptable esters or salts thereof.

However, these chemical control solutions present significant risks to the environment.

Document FR2987719 describes a system for eradicating proliferating terrestrial plants, employing a means for creating a layer of plants to be treated and a means for generating electromagnetic waves to sterilize the plants within said layer. The electromagnetic wave generation means emits microwaves and/or is adapted to heat the plant seeds to a temperature exceeding 60°C. This system further comprises a plant receiving hopper, a means for extracting metals and/or stones, and a means for crushing the plants upstream of the electromagnetic wave generation means.

This solution, however, remains complex to implement and requires a significant energy input. Furthermore, this solution does not allow for the use of the destroyed plants in a virtuous ecological cycle.

To the applicants’ knowledge, there is currently no solution that allows for the efficient transformation of Water Primrose into a usable biomass product, without chemical inputs and in an environmentally responsible manner.

The present invention aims to overcome all or part of the disadvantages of the prior art described above by proposing an innovative solution to transform Water Primrose into usable biomass without negative impact on the environment.

One objective of the invention is therefore both to destroy the Water Primrose to limit its proliferation and to make it a producer of exploitable biomass, which constitutes a virtuous circle.

To this end, the present invention relates to a process for transforming Water primrose into a combustible biomass product, such as combustion pellets, comprising: a step of storing the previously uprooted Water primrose; a step of drying the stored Water primrose to a moisture level that promotes the combustion of said Water primrose; a step of grinding the Water primrose in a grinder that finely cuts the Water primrose; and a step of granulating the Water primrose using a press to form combustion pellets.

According to an advantageous embodiment, the water primrose storage stage consists of storing the water primrose in a pile on sloping ground, placing it on a sealed silage tarp ensuring the flow of water primrose juice towards a pit.

According to one aspect of the invention, the stored water primrose is covered with a tarpaulin surmounted by a net against birds.

Advantageously, the drying stage includes dynamic ventilation by means of perforated tubes, lower and upper, passing through the stored Water Primrose and connected to controlled mechanical ventilation (CMV) type ventilation devices.

According to one embodiment, the process further includes a step of collecting the dried Water Primrose using a grapple mounted on the end of a crane, to deposit it in the crusher.

According to one aspect of the invention, the water primrose is stored in the open air in the direction of the winds.

According to one embodiment, the process further includes a step of conditioning and storing the combustion pellets.

The invention also relates to a combustible biomass product, obtained by the process of transforming Water primrose as presented.

This product, for example, has a form of combustion pellets.

The invention also relates to a system for transforming Water Primrose, for the implementation of the presented process, said system being mobile and comprising a vehicle, a trailer, a crane equipped with a grapple, a crusher and a press, the crusher and the press being installed on the trailer.

The fundamental concepts of the invention having been set out above in their most elementary form, other details and characteristics will become clearer from the reading of the description which follows and with regard to the attached drawings, giving by way of non-limiting example an embodiment of a process and a system for the transformation of Water Primrose, in accordance with the principles of the invention.

Presentation of the drawings

The figures are provided for illustrative purposes only to aid understanding of the invention without limiting its scope. The various elements may be represented schematically and are not necessarily to scale. Throughout the figures, identical or equivalent elements are identified by the same numerical reference.

This is illustrated as follows:

FIG. 1 : a botanical drawing of the Water Primrose;

FIG. 2 : an flowchart of the main steps of a process for transforming Water Primrose according to an embodiment of the invention;

FIG. 3 : a schematic perspective view of the Water Primrose stored in a pile on a sloping ground;

FIG. 4 : a schematic cross-sectional view of the Water Primrose stored in a pile with the elements of covering, ventilation, drainage and filtration;

FIG. 5 : a functional diagram of a stationary transformation chain of Water Primrose implementing the process;

FIG. 6 : a mobile system for implementing the process according to the invention.
Detailed description of implementation methods

It should be noted that certain technical elements well known to those skilled in the art are recalled here to avoid any insufficiency or ambiguity in the understanding of the present invention.

The embodiment described below refers to a process for transforming water primrose or similar plants, primarily intended for manufacturing fuel pellets. This non-limiting example is given for a better understanding of the invention and does not preclude the use of the process to produce other types of consumables.

In the rest of the description, the term Jussie refers by extension to creeping water primrose, whose scientific name is Ludwigia peploides .

There FIG. 1 is a botanical illustration of the Water Primrose.

• une étape initiale 510 de stockage de la Jussie arrachée ;
• une étape 520 de séchage de la Jussie lors de son stockage ;
• une phase 530 de transformation de la Jussie séchée comprenant :
  • une étape 531 de prélèvement d’une quantité déterminée de Jussie ;
  • une étape 532 de broyage fin de la Jussie prélevée ;
  • une étape 533 de granulation de la Jussie broyée dans une presse pour former le produit ;
• une étape final 540 de stockage et de conditionnement du produit obtenu en sortie du processus de transformation.

There FIG. 2 represents a process 500 for transforming previously uprooted Water primrose into a combustible biomass product, said process comprising:

• an initial step 510 of storage of the uprooted Water primrose;
• a step 520 of drying the Water Primrose during its storage;
• a phase 530 of the transformation of dried Water Primrose comprising:
  • a step 531 of collecting a determined quantity of Water Primrose;
  • a step 532 of fine grinding of the collected Water Primrose;
  • a step 533 of granulation of the crushed Water Primrose in a press to form the product;
• a final step 540 of storage and packaging of the product obtained at the end of the transformation process.

Prior to implementing the Water Primrose 500 transformation process, the plants are uprooted in the areas where they proliferate. Uprooting is carried out sustainably, avoiding damage to local ecosystems.

For example, the removal of the Water Primrose can be carried out using an amphibious vehicle equipped with a pulling grapple as described in document FR2306570 on behalf of the applicants.

Step 510 of the Water Primrose storage process, once the primrose has been transported to its storage location, consists of gathering the primrose in a suitable storage area prepared to receive it. Ideally, the storage area is dry and well-ventilated to prevent the primrose from deteriorating.

According to one embodiment, the uprooted water primrose is stored in piles on a plot of land. This storage method requires no energy input and allows the water primrose to dry in piles, as in silage piles known as molehills, which are mounds or piles of plant biomass, generally composed of forage plants such as grass, corn, clover, etc.

There FIG. 3 schematically represents a pile of Water primrose 10 stored on a plot of land 20, preferably in the direction of the winds.

For example, the Jussie 10 pile has an overall parallelepiped shape with a width of about 10m, a length between 25 and 30m and a maximum height of about 1m.

The limited height of the Water Primrose pile compared to other dimensions allows for good air circulation inside the pile and thus improves drying.

Plot 20 has undergone slight terracing, notably with a downward slope on the south side allowing the Water Primrose pile 10 to be positioned facing the wind. The sales direction is represented by the three parallel arrows on the FIG. 3 .

The excess soil removed for the earthworks on plot 20 is stored in the immediate vicinity of said plot so that it can be returned at the end of the water primrose drying cycle. This allows the land to be restored to its initial state before the water primrose was stored.

The pile of water primrose 10 is placed on a silage sheet 30 which separates the water primrose from the soil 20 and thus prevents germination in the soil. In addition, the sheet 30 follows the slope of the soil 20 and thus allows the water primrose's sap and seeds to drain away.

In addition, 40 ditches are dug around and around the periphery of the Water Primrose pile 10 to drain rainwater.

There FIG. 4 highlights the other elements involved in the storage and drying of the Water Primrose, in particular the elements placed above the Water Primrose pile 10.

The 520 drying stage of the Water Primrose lasts approximately between 2 and 4 months and allows the Water Primrose to reach a moisture level compatible with its future transformation.

Ideally, the moisture content of the water primrose after drying should be between 35 and 60%. These levels can vary slightly depending on the requirements.

The drying of the water primrose is carried out using the installation shown in FIG. 4 and described below.

The pile of water primrose 10 is placed on the silage tarp 30, which is itself placed directly on the ground 20. The ground 20 has an earthwork defining a downward slope down to a septic tank 50.

Tarpaulin 30 extends to pit 50 and therefore allows the juices to be poured into the latter.

Indeed, the silage tarp 30 acts as an impermeable barrier between the Water Primrose 10 and the soil 20. This tarp prevents the Water Primrose from germinating in the soil and also allows the collection of juices produced during the drying process.

The juices of the Water Primrose, mixed with seeds and other plant debris, flow naturally through the silage tarp 30. This tarp is inclined following the slope of the earthwork to facilitate the flow of liquids towards the all-water pit 50 located below.

The all-water pit 50 is a tank designed to collect the liquids flowing from the Water Primrose pile 10. It is placed under the silage tarp 30 and is equipped with a filtration system 51 to separate the juices from the seeds and other solid debris.

The 51 filtration system includes filters that can be made of porous materials or special sieves designed to retain solid particles while allowing liquids to pass through.

For example, the 51 filtration system is a settling tank type filter for wastewater generally used in homes.

Once the water primrose juices have been collected in the all-water pit 50 and filtered through the filtration system 51, they can be directed via a drainage means 52 to ditches in the natural environment or to a further treatment system, while the seeds and other solid debris are retained by the filter.

Furthermore, the septic tank 50 includes a partition 53 located downstream of the effluent, approximately halfway up. This partition 53 divides the tank 50 into two compartments, physically separating the liquid and solid phases of the hydrangea effluent and thus facilitating the filtration of the liquid phase, which is located behind the partition 53 in direct contact with the filtration system 51.

In other words, partition 53 improves juice settling by retaining seeds and other solid debris in the upstream compartment, which promotes the flow of the settled liquid into the downstream compartment to be filtered.

The juices are collected and conveyed to pit 50 by means of lower tubes 61.

According to one embodiment, three smooth lower tubes 61 are arranged on the silage tarp 30. These tubes are pierced with a plurality of holes of about 10mm in diameter and covered with a geotextile sock to filter the juices of the Water Primrose.

Preferably, the lower tubes 61 are regularly spaced, transversely to the pile of Jussie 10.

The lower tubes 61 include a mushroom-shaped roof vent 611 for mechanical ventilation, creating dynamic ventilation. This vent 611 allows moisture-laden air to be expelled from the pile of water primrose 10 while simultaneously preventing the penetration of external elements such as rainwater or debris.

The broken line inside the lower tube 61 represents the airflow.

Similarly, upper tubes 62 are placed at the top of the Jussie pile 10 to provide ventilation through ventilation devices 621 identical to the lower ventilation devices 611.

Thus, dynamic ventilation within the entire water primrose storage and drying system is ensured by the interaction between the lower tubes 61 and upper tubes 62. Each perforated lower tube 61, positioned at the base of the water primrose pile 10, allows for efficient aeration thanks to its openings distributed along its axis. Air can therefore circulate freely, penetrating and passing through the plant mass to remove moisture. This tube is connected to the VMC funnel 611, which acts as an air extractor, promoting air renewal and moisture removal from below.

Simultaneously, each upper tube 62 located above the Jussie pile 10 works in concert with the lower tube to maintain a constant airflow. If air is blown in from below, the upper tube acts as an escape for the rising humid air, and conversely, if air is introduced from above, the lower tube ensures its evacuation.

This orchestrated air circulation ensures homogeneous drying of the Water Primrose, preventing the formation of mold areas and promoting rapid and uniform drying, while being protected from the weather by a cover tarpaulin 35, which is also a silage tarpaulin, placed over the pile of Water Primrose 10 and the bird nets 70 which cover the installation.

During the excavation of soil 20 to create the slope, the excess soil 25 is stored in the immediate vicinity of the water primrose pile to be returned to its place at the end of the operation. Part 251 of this excess can be used to create a sealing strip on the sides, with the silage tarp 30.

Alternatively, the storage (510) and drying (520) steps can be carried out in covered industrial facilities to provide greater storage volume and drying capacity. However, since this alternative is more energy-intensive, it is preferable to carry out storage and drying in piles as described.

Preferably, tarpaulins 30 and 35 are special silage films, reusable and recyclable, so that they can be reused, if they are not soiled by Water Primrose, or recycled.

After the water primrose has dried, the processing phase can begin. This processing phase begins with step 531 of sampling, continues with step 532 of grinding and ends with step 533 of granulation.

After step 531 of water primrose removal, the septic tank 50 can be cleaned for reuse, in which case the filtered debris is removed for recycling. The septic tank 50 can also be completely removed and recycled, leaving the soil in its original natural state.

Figures 5 and 6 represent the means and system enabling the implementation of this phase of transformation of the Water Primrose.

There FIG. 5 represents a processing line designed to convert dried Water Primrose 10 into pellets, following a sequential and automated process. The dried Water Primrose 10 is first conveyed to a defibrator 310, a device that breaks down the material into finer fibers, facilitating further processing.

However, passing through the 310 defiber machine remains optional.

The defibrated Jussie fibers are then transported by a conveyor belt 315, which carries them continuously and uniformly to a grinder 320.

The 320 grinder reduces the size of the fibers to obtain a particle size suitable for pelletizing.

After the grinding stage 532, the fibers are carried by a pneumatic conveying system 325, which propels them with an airflow towards a cyclonic separator 330, also known as a cyclone. In this cyclone, the fibers are separated from the air by centrifugal force. A fan 331 is integrated into the cyclone to maintain a constant airflow and to expel the particle-free air.

The materials separated by the cyclone 330 are then directed to an Archimedes screw conveyor 340, which transports the material in a controlled manner to a hopper 350 located on a press 360. This press 360, equipped with dies and rollers, compacts the fibers into pellets. Once formed, the pellets are mechanically conveyed 370 to a cooler 380, where they are cooled to a temperature that stabilizes their shape before the final storage and packaging stage 540.

There FIG. 6 It describes a mobile system 400 for implementing phase 530 of the transformation of dried water primrose into pellets, designed to be used in addition to or as a replacement for the previous stationary processing line. This system comprises processing equipment mounted on an agricultural forage platform 410 which can be towed by an agricultural tractor 405, thus allowing the equipment to be moved to pellet production sites or water primrose uprooting areas.

In other embodiments, the 410 agricultural tractor can be replaced by any other suitable vehicle, such as a truck or a self-propelled vehicle.

The implementation of the transformation phase 530 by the system 400 begins with the collection of the dried Water Primrose using a specific grapple 425 connected to a forestry type crane 420. This crane is mounted via a three-point hitch on the tractor 405 and operated via a mobile electric/hydraulic auxiliary power unit 430. The grapple 425 grabs the dried Water Primrose and deposits it in a receiving cone 305, where it begins its processing.

From the receiving cone 305, the dried water primrose is directed to a grinder 320, which reduces the material into small particles, thus facilitating pelletizing. Once ground, the material is temporarily stored in a mulch storage tank 321, which can be replaced by a large bag, known as a big bag, for easy storage and transport.

When it's time to pelletize, the shredded material is transferred from the shredded material storage tank 321 to the press 360 where it is compressed into pellets. The pellets are then moved to a pellet storage tank, or big bag 361, ready for transport or further use.

The System 400, as described, offers an on-site processing solution, reducing the need to transport raw materials over long distances. Thanks to its mobility and autonomy, it allows for the direct integration of processing operations into agricultural or forestry workflows, thus optimizing the pellet production stages from dried water primrose.

The fine grinding of the dried water primrose, carried out by the 320 grinder, plays a crucial role in the mobile processing chain by significantly reducing the initial volume of the water primrose. Through the grinding action, the structure of the water primrose is fragmented into small particles, which increases the density of the material. A denser material means that a greater weight of water primrose can occupy the same space, or that for a given weight, the space required for its storage is reduced.

By reducing the volume through increased density, the storage and transport of tanks 321 and 361 are optimized. This densification allows for more efficient use of space on the agricultural forage plateau 410 and minimizes the costs associated with logistics, such as the number of trips required for the movement of the processed Water Primrose.

It is apparent from the present description that certain non-essential elements of the transformation process can be modified, replaced, or omitted without departing from the scope of the invention as defined by the claims. For example, the dried water primrose granulation in the press can produce various solid fuels other than pellets. The press can be adjusted to manufacture briquettes, which offer a slower-burning fuel solution, ideal for long-term heating systems. Larger cylindrical shapes, such as sausages, can also be produced, particularly suitable for larger boilers. These different fuel formats derived from water primrose allow for a high degree of adaptability to the technical specifications of combustion installations.

Claims (10)

A process (500) for transforming Water primrose into a combustible biomass product, such as combustion pellets, said process being characterized in that it comprises: a step (510) of storing the previously uprooted Water primrose; a step (520) of drying the stored Water primrose to a moisture level that promotes combustion of said Water primrose; a step (532) of grinding the Water primrose in a grinder (320) that finely cuts the Water primrose; and a step (533) of granulating the Water primrose using a press (360) to form combustion pellets (15). Method according to claim 1, wherein the step (510) of storing the Water Primrose consists of storing the Water Primrose in a pile (10) on a sloping ground (20), placing it on a sealed silage tarp (30) ensuring the flow of Water Primrose juice towards a pit (50). Method according to claim 1 or 2, wherein the stored Water primrose is covered with a cover tarpaulin (35) surmounted by a net (70) against birds. A method according to any one of the preceding claims, wherein the drying step (520) comprises dynamic ventilation by means of lower (61) and upper (62) perforated tubes, passing through the stored Water Primrose and connected to ventilation devices (611, 612) of the controlled mechanical ventilation (CMV) type. A method according to any one of the preceding claims, further comprising a step (531) of collecting the dried Water Primrose by means of a grapple (425) mounted at the end of a crane (420), to deposit it in the crusher (320). A method according to any one of the preceding claims, wherein the water primrose is stored in the open air in the direction of the winds. A method according to any one of the preceding claims, further comprising a step (540) of conditioning and storing the combustion pellets (15). Combustible biomass product, obtained by a process (500) of transforming Water primrose according to one of the preceding claims. Product according to claim 8, having a combustion pellet form (15). Water primrose processing system (400) for implementing a process (500) according to any one of claims 1 to 7, characterized in that it is mobile, in that it comprises a vehicle (405), a trailer (410), a crane (420) equipped with a grapple (425), a crusher (320) and a press (360), and in that the crusher and the press are installed on the trailer.