EP4626621A1

EP4626621A1 - Alternative method for moving organic plant material to an underground location with an anaerobic environment and injection lance head for use in the method

Info

Publication number: EP4626621A1
Application number: EP23832848.8A
Authority: EP
Inventors: Renze Anne SCHRAM; Jurriaan Pieter Jan REIJS
Original assignee: Restore Carbon BV
Current assignee: Restore Carbon BV
Priority date: 2022-12-01
Filing date: 2023-11-29
Publication date: 2025-10-08
Also published as: WO2024117903A1

Abstract

The invention relates to an alternative method for moving organic plant material to an underground location with an anaerobic environment, comprising the following steps: step a). selecting the underground location; step b). selecting organic material; step c). moving the slurry to the underground location.

Description

ALTERNATIVE METHOD FOR MOVING ORGANIC PLANT MATERIAL TO AN UNDERGROUND LOCATION WITH AN ANAEROBIC ENVIRONMENT AND INJECTION LANCE HEAD FOR USE IN THE METHOD

The invention relates to a method for moving organic plant material to a location in which sustainable anaerobic conditions prevail, comprising the following steps: step a), selecting the location; step b). selecting organic material; step c). moving the organic material to the site.

The method according to the preamble is known in the field and is described in the Dutch patent application 2030634.

The known method has to object to provide a method for sustainable storage of carbon dioxide captured in biomass in an anaerobic environment, so that the captured carbon dioxide is no longer released into the atmosphere and contributes to global warming.

The known method has the disadvantage that the locations for carrying out the known method are limited, and the locations are deep.

It is the object of the method according to the invention to provide an alternative method according to the preamble and to store carbon dioxide stored in biomass in a simpler manner, whereby the method can be used in many more places and underground locations are much less deep and therefore easier to reach.

To this end, the method according to the invention is characterized in that step a), the underground location meets the following criteria:

- the location is located underground in a soft soil type with an anaerobic environment, such as peat or clay soil;

- the location is located below the local groundwater level and in the groundwater.

There are many peat or clay soil areas in the Netherlands, where the local groundwater level is situated shallow below the ground surface. The chosen underground location is located just below this groundwater level, making the location accessible in a technically and economically feasible manner. This allows biomass to be transported to the underground location below the groundwater level, so that the injected biomass is stored anaerobically and the carbon dioxide stored in the biomass cannot be released.

Preferably, the organic material is reduced in size, making it easier to move to the underground location.

To easily move the reduced organic material to the underground location, the reduced material can first be mixed with a liquid, preferably water, to form a slurry, after which the slurry can be pumped to the underground location. In a first embodiment of the method according to the invention, step c) comprises the following sub-steps: c3) creating a shaft to the underground location by mechanical means and moving the organic material to the underground location by means of the shaft.

In a first preferred embodiment of the method according to the invention, step c3) comprises the following sub-steps: step c3-1). pressing one or more hollow injection lances into the ground from an aboveground location by mechanical means to the underground location, in which a first end of the first injection lance is arranged for connecting a hose; step c3-2). coupling the first end of each first injection lance pressed into the ground to the hose, which hose is connected to a pumping device for pumping the slurry; step c3-3). pumping the slurry under pressure using the pumping device via a second end of the one or more injection lances to the underground location; step c3-4). removing the one or more injection lances from the ground by mechanical means.

Using the previous steps, it becomes possible to install a transport tube, namely the first injection lance, in unstable, soft soil without drilling. For example, when drilling in unstable peat or clay soil, there is a very good chance that the borehole will collapse after removing the drill before the transport tube can be placed.

In a second preferred embodiment of the method according to the invention, an injection lance head is coupled on the second end before pressing the first injection lance into the ground, which is arranged for penetration of the weak soil type. The injection lance head makes it easier to press the first injection lance into the ground.

The injection lance head preferably comprises one or more outflow openings for allowing the slurry to flow out under pressure.

Preferably water is pumped under pressure via the first injection lance to the second end of the first injection lance while pressing the first injection lance into the ground, whereby the water flows out of the one or more outflow openings. This prevents one or more outflow openings from becoming clogged with soft soil.

In a first elaboration of the preferred embodiment of the method according to the invention, water flows from the outflow openings in a direction of the underground location of the first injection lance while pressing the first injection lance in the ground. This has the effect that at the location of the injection lance head the soft soil under the first injection lance is pushed away by the water or becomes saturated, which makes it easier to press the first injection lance into the ground.

In said first embodiment, water under pressure preferably also flows out of the one or more outflow openings in a direction from the above-ground location. This has the effect that the soft soil around the injection lance head is pushed away by the water or becomes saturated, which makes it easier to press the first injection lance into the ground.

In a second elaboration of the preferred embodiment of the method according to the invention, after pressing the injection lance head into the ground, the injection lance head is disconnected from the first injection lance by slightly retracting the first injection lance. The injection lance head is mainly used to facilitate pressing the first injection lance into the ground. After disconnecting the first injection lance from the injection lance head, there is space under the first injection lance to move slurry to the underground location via the open second end of the first injection lance.

In a third elaboration of the preferred embodiment of the method according to the invention, the pumped slurry flows in a direction different from the longitudinal direction of the first injection lance, preferably transverse direction, from one or more outflow openings. This injects the slurry in a more horizontal direction.

In a more effective elaboration of the preferred embodiment of the method according to the invention, the one or more injection lances are raised in step c3-3) during pumping of the slurry, with the second end remaining below the groundwater level. This allows more slurry and therefore more biomass to be pumped into the ground during injection at one above-ground location.

The method according to the invention can also be used to raise compacted, soft soil in which step c3-1) the height of the ground level is determined; and step c3) comprises the following sub-step: c3-5) allowing the injected soft soil to settle; and wherein steps c3-1) to c3-5) are repeated until a predetermined desired height of the ground level is reached.

The method according to the invention can also be used to increase the bearing capacity of soft soil, in which: step c3-1) the bearing capacity of the soft soil type is measured using one or more cone penetration measurements (CPT); and step c3-3) comprises allowing the injected soft soil to drain out, in which the slurry has been allowed to settle and the excess water from the slurry has spread or been drained; and wherein steps c3-1) to c3-5) are repeated until a predetermined desired bearing capacity is reached.

In a first alternative embodiment of the method according to the invention, step c3) comprises the following sub-steps: step c3-6). pressing one or more hollow second injection lances into the ground from an above-ground location by mechanical means to the underground location; step c3-7). filling the one or more second injection lances with the reduced material via a first end of the second injection lance; step c3-8). pressing the reduced material into the second injection lance to the underground location; step c3-9). removing the one or more second injection lances from the ground by mechanical means.

The above-mentioned method makes it possible to move organic material directly to the underground location without having to first create a slurry.

Preferably, in the first alternative embodiment in step c3-7). the second injection lance is tubular; and in step c3-8).the pressing is carried out by

- placing a closed inner tube in the second injection lance via the first end of the second injection lance, the outer diameter of the inner tube of which is smaller than the inner diameter of the second injection lance;

- moving the inner tube to a second end of the second injection lance by mechanical means.

This has the effect that the organic material can be economically moved to the underground location.

In a second alternative embodiment of the method according to the invention, step c) comprises the following sub-steps: step c4). removing the soil above the underside of the underground location; step c5). filling the underground location with the organic material; step c6). restoring the soil;

This method is particularly applicable when the underground location is not too deep, preferably 0,1-3 meters. The underground location can then be reached more easily by temporarily removing the soil above it than by installing first or second injection lances. After the soil has been removed, the organic material can easily be placed. After installation, the removed soil can be placed back, so that the organic material is stored sustainably and no longer contributes to greenhouse gas emissions.

The soil is preferably removed by pulling trenches with, for example, a tractor.

The invention also relates to an injection lance head for use in the method according to the invention, in which:

- the injection lance head comprises a first side, which is arranged for penetration of the soft soil type, and is preferably conical or spherical, and a second side facing away from the first side is arranged for coupling to the second end of the first injection lance. This has the effect of facilitating the pressing of the first injection lance into the ground.

In a first preferred embodiment of the injection lance head according to the invention, the injection lance head comprises one or more outflow openings, which are arranged for passing liquid from the second end of the first injection lance to one or more outflow openings.

In a first elaboration of the first preferred embodiment of the injection lance head according to the invention, at least one first outflow opening is provided in the first side of the injection lance head and runs parallel to the longitudinal direction of the injection lance head. This has the effect that liquid, for example slurry or water, can be injected into the ground under pressure via the underside of the injection lance head.

In a second elaboration of the first preferred embodiment of the injection lance head according to the invention, the second side of the injection lance head has a substantially similar circumference as the circumference of the second end of the first injection lance, and one or more second outflow openings are provided in the circumference of the second side of the injection lance head, which second outflow openings are at an angle to the longitudinal direction of the injection lance head. This has the effect that liquid, for example water, can be sprayed in an upward direction via the second outflow opening, as a result of which the first injection lance will sink further in response when the first injection lance is pressed into the ground.

In a second preferred embodiment of the injection lance head according to the invention, the injection lance head is made of an environmentally friendly material, preferably wood, and the second side of the injection lance head is arranged for releasable coupling to the first injection lance, and in which the largest circumference of the first side of the injection lance head is larger than the largest circumference of the second side of the injection lance head, such that when the first injection lance is withdrawn, the injection lance head remains behind in the ground.

By using these means the injection lance head can be used to easily press the first injection lance into the ground, whereby after reaching the underground location the injection lance head is disconnected by raising the first injection lance slightly. This causes the second end of the first injection lance to open again and the slurry can be brought to the underground location via the second end of the first injection lance. This allows the slurry to be pumped into the underground location at a high feed rate. The injection lance head will therefore remain in the ground, but since it is made of environmentally friendly material, this does not cause any problems for the environment.

In a third preferred embodiment of the injection lance head according to the invention, the second side of the injection lance head is connected to the second end of the first injection lance by means of spacers, wherein the spacers extend from the second end of the first injection lance to near the first side of the injection lance head and in which the space between the spacers forms third outflow openings. In a further elaboration of the third preferred embodiment of the injection lance head according to the invention, the second side of the injection lance head is arranged to deflect the flow of slurry to a direction other than the longitudinal direction of the injection lance head. This allows the slurry to be injected more towards the sides of the injection lance head in the underground location, allowing more slurry and therefore more biomass to be injected. This increases the effectiveness of the method according to the invention.

Preferably, the second side of the injection lance head is conical or spherical, effectively deflecting the direction of the slurry flow.

In a third preferred embodiment of the method according to the invention, step c3) comprises the following sub-steps: c3-10). creating a shaft in the ground from an above-ground location by mechanical means to the underground location, after which the shaft wall is formed by the ground; c3-11). filling the shaft with the organic material; c3-12). exerting downward pressure on the organic material placed in the shaft from an upper side, such that the organic material mainly moves to the underground space.

The third preferred embodiment is an alternative to the first and second embodiment, wherein a shaft or a hole is made in the ground that extends to the underground space, the shaft wall being formed by the ground. This hole is then filled with the organic material, after which this material is pushed into the underground space.

Preferably in step c3-10). the shaft is constructed by placing a first tube in the ground by mechanical means up to the underground location, after which the first tube is (at least partially) removed from the ground by mechanical means. Placing the first tube can, for example, take place by pushing the first tube into the ground.

Preferably in step c3-12). the exertion of downward pressure takes place by placing a second tube on the organic material placed in the shaft by mechanical means and moving the second tube in the direction of the underground space. Moving the second tube can, for example, take place by pushing the second tube into the ground.

For deeper underground locations, deeper than 3 meters, the first and second tubes are preferably assembled from several tube sections that can be connected to each other and the tube sections are linked together or taken apart during installing the tube in the ground and removing it from the ground. This makes the first and second tubes easier to transport and the first and second tubes can achieve a greater combined length.

In a first elaboration of the third embodiment of the method according to the invention, the first tube has a first head that is arranged to displace soil, such as, for example, a point-shaped or spherical or flat closed head, and in step c3- 10) the first tube is pressed or pushed into the ground. As a result, the soil is pressed to the side by the first head while the first tube is being pushed into the ground, which makes it easier to push the first tube into the ground and after removing (at least in part) the first tube from the ground, the shaft wall is formed by the ground that is pushed to the side.

In a second elaboration of the third embodiment of the method according to the invention, the second tube has a second head that is arranged to push the organic material substantially downwards, such as, for example, a flat or hollow head. This second head ensures that the organic material moves as little as possible to the sides of the shaft while pressing the organic material into the ground, so that the organic material can be largely pushed into the underground space and the shaft wall remains intact for as long as possible.

Preferably, the first tube and second tube are similar tubes or the same tube.

The tube has an interchangeable head and the first head is attached to the tube before placing the tube in the ground and the second head is attached to the tube before pushing of pressing the organic material to the underground location.

In a third elaboration of the third embodiment of the method according to the invention, the first head of the first tube comprises a remotely controllable first sealing valve, and wherein step c3-10) comprises the following sub-steps: step C3-10-1) closing of the first sealing valve; step C3-10-2) pressing the first tube into the ground beyond the groundwater level; step C3-10-3) removing the first tube (at least partially) from the ground, after which the shaft is formed in the ground; and step c3-11) comprises the following sub-steps: step c3-11-1) opening the first sealing valve; step c3-11-2) filling the shaft with organic material via an upper side of the first tube and via the open first sealing valve; and step c3-12) comprises the following sub-step: step C3-12-1) performing steps C3-10-1), C3-10-2) and C3-10-3).

In a fourth elaboration of the third embodiment of the method according to the invention, the first tube comprises a feed connection for connecting a third tube for feeding organic material via the third tube under the first tube, in which step c3-10) comprises the following sub-steps: step C3-10-4) placing the first tube in the ground; step C3-10-5) placing the second tube in the first tube, in which the second head of the second tube is closed off; step c3-10- 6) moving the second tube downwards beyond the groundwater level and moving the second tube upwards again relative to the first tube, in which the second tube forms a shaft in the ground under the first tube ; and wherein step c3-11) comprises the following sub-step: step c3-11-3) filling the shaft with organic material via the third tube and the feed connection; and wherein step c3-12) comprises the following sub-step: step C3-12-2) performing step C3-10-10.

In step C3-10-4 it is important that when placing the first tube in the ground, there is no soil in the tube before step C3-10-6 is carried out. There are various options to achieve this.

A first method is a first punching method in which the first tube is pushed into the ground to the desired position, after which the first tube is removed from the ground again. After the soil has been removed from the first tube, the first tube can then be placed back into the resulting hole in the ground.

A second way is a second punching method, in which step C3-10-4 and step C3-10-5 are combined. Before the first tube is pressed into the ground, the second tube is placed in the first tube and locked, with the bottom of the second tube lying near the bottom of the first tube. Subsequently the first tube is pressed into the ground, after which the second tube is unlocked and step C3-10-6 is continued.

A third method is a third punching method, in which a closing element is attached to the underside of the first tube, after which the first tube is pressed into the ground. The first tube is then removed from the ground, after which the closing element is removed. The first tube is then placed in the ground again in the same position.

The third and fourth elaboration of the third embodiment of the method according to the invention are best suited for moving organic material to the underground location in a continuous and rapid process.

In all mentioned methods it is preferable to finalize the method with an additional step d) in which the access to the shaft is filled and sealed with a similar soil type as above the shaft and above the groundwater level. Preferably, soil is used that was removed during the construction of the shaft. Practical tests have shown that the methane resulting from bacterial breakdown of the organic material introduced into the soil and below the groundwater level is converted into CO2 by oxidation caused by bacteria in the soil above the groundwater level. After the organic material has been brought into anaerobic conditions in the shaft, methane formation starts depending on temperature and time. It is possible that a peak of methane formation is reached in a short period of time, after which a gradual decline starts to an almost negligible level within a longer period of time. This means that no more CO2 is released and the vast majority of carbon remains in the organic material without causing greenhouse gases. Sealing the shaft with a similar type of soil as above the shaft and above the groundwater level guarantees that there are bacteria in the soil that can convert methane into CO2 and thus prevents a methane leak into the ambient air from the shaft.

The invention will be further elucidated with reference to the following figures, in which:

Figure 1 schematically shows the first basic principle of the method according to the invention;

Figure 2 schematically shows an application of the method, in which a series of injection lances are arranged;

Figure 3 shows the first embodiment of the injection lance head according to the invention;

Figure 4 shows the second embodiment of the injection lance head according to the invention;

Figure 5 shows the third embodiment of the injection lance head according to the invention;

Figures 6A-6D schematically show the second basic principle of the method according to the invention;

Figures 7A and 7B show the first head of the first tube, in which the first head comprises a remotely controllable first sealing valve for application of the fourth embodiment of the third embodiment of the method;

Figure 7C shows an alternative sealing valve;

Figures 8A and 8B show a bottom view of the first head of the first tube for use in the fourth embodiment of the third embodiment of the method according to the invention.

Like reference numerals in different figures indicate like parts.

Figure 1 schematically shows the first basic principle of the first embodiment of the method according to the invention. The first basic principle of the method for moving organic plant material to an underground location 101 with an anaerobic environment comprises the following steps: step a), selecting the underground location 101 in a soft soil type G, wherein the underground location 101 is below the local groundwater level W; step b). selecting organic material; step c3). moving the organic material to the underground location including: step c1). reducing the size of the material; step c2). mixing the reduced material with a liquid, preferably water, into a slurry 100 in a mixer 5; step c3-1). pressing one or more hollow injection lances 1 into the ground from an aboveground location by mechanical means to the underground location 101, wherein a hose 8 is connected to a first end 9 of the first injection lance 1 ; step c3-2). connecting the hose 8 to a pump device 6; step c3-3). pumping the slurry 100 under pressure using the pump device from the mixer 5 via hose 7 and hose 8 to the second end 4 of the one or more injection lances 1 to the underground location 101 ; step c3-4). removing one or more injection lances 1 from the ground by mechanical means.

Figure 2 schematically shows an application of the method, in which a series of injection lances 1 are arranged. The figure shows a system where multiple injection lances 1 can be arranged on multiple interconnected platforms 2 that can be mounted on the back of a tractor, truck or tracked vehicle. The number of platforms 2 is variable. In said figure four platforms 2 are shown. These injection lances 1 can be simultaneously pressed into the soft soil, for example with the aid of hydraulically driven wheels or other mechanism. This system can also be further expanded by placing several rows of injection lances one behind the other, for example on a trailer. The rows of injection lances 1 are then positioned between the front and rear wheels of the trailer. With current regulations in the Netherlands, the trailer has a maximum width of 2.55 m wide and a length of 12.12m. Such a trailer provides a usable platform between the wheels of about 9m by 2.55m. With a mutual lance distance of 50 cm, such a trailer can carry up to 19 rows of 6 first injection lance arrangements and therefore 19x6=114 injection lances 1 can be inserted into the ground at the same time. Multiple trailers can also be used to inject faster at underground locations. The number of injection lances 1 that can inject simultaneously is unlimited.

A variation on this system is a setup where the injection lances 1 are not positioned vertically on a trailer or platform behind a vehicle, but at an angle. In this way, the injection lances 1 can be placed under roads or other buildings and inject underground locations there with biomass to prevent subsidence.

The application according to Figure 2 can achieve three goals:

1) Sustainable storage of carbon fixed in biomass in the reducing anaerobic environment of soft soil below the groundwater level. Due to the lack of oxygen below the groundwater level, this biomass does not compost and therefore does not cause additional greenhouse gas emissions. This way, this captured carbon remains sustainably removed from the carbon cycle.

2) Lifting of weak soil type. By injecting organic material underground, the ground level can be raised and the natural process of subsidence is compensated.

3) Improve the bearing capacity of soft soil. By composing the biomass slurry to be injected in such a way that a high density of woody fibers is achieved underground in the injection layer, the bearing capacity of soft soils is improved and can thus become more useful for agriculture without having to lower the groundwater level.

Peat or clay soil is often too unstable to drill, to remove the drill and to insert an injection tube, because the borehole can become closed before the injection tube can be inserted. Needle-shaped injection lances 1 , on the other hand, can be hydraulically pressed into soft soil due to their point-shaped front and small diameter (25-150 mm). These injection lances 1 comprise segments of 2-6 m that can be connected to each other using a screw connector to a length of 10-15 m. These injection lances 1 are placed in a serie of 1-10 injection lances 1 with a spacing of 0. 25 - 2m behind a tractor or a tracked vehicle, each suitable for the bearing capacity of soft soil. By working with multiple injection lances 1 at the same time and not inserting them into the ground one by one, injection can even be done much cheaper. The injection lances 1 have an opening at the second end 4 or the lower side making them suitable for injection while pushing or raising the first injection lance in and out the ground. This can help to work both faster and to better distribute the biomass slurry underground. The injection lances 1 are connected via a first side or upper side with hoses to a pump system at the rear of the vehicle that can suck biomass slurry from a moving tank wagon or trailer with a feed hose and pump it to the injection lances 1.

The injection lance installation and injection unit are built according to existing grout injection techniques. Each injection lance installation consists of a small injection rack with injection tubes and an injection unit. The first injection lance can be installed in the ground by hydraulically pressing into the ground, flushing drilling, percussion drilling or vibration. The diameter of the first injection lance is usually about 50 mm in diameter, with exceptions of up to 300 mm.

The injection unit comprises a biomass mixer and a pump. Due to the high internal friction in the biomass-water mixture, a special mixer and (concrete) pump must be used. A pressure of up to 15 MPa and a flow rate of 0.1 m3/min are typical, but this can vary greatly depending on soil composition and local injection targets. Before the first injection lance goes into the ground, it must be determined whether a loose tip or a fixed tip is used. The first injection lance is hydraulically inserted into the ground or by using one of the other techniques mentioned above. If a segment has been completely inserted into the ground and the desired depth has not yet been reached, a next segment can be screwed on with a connector and the insertion can be repeated. This can be repeated until a maximum depth of 15m is reached.

Preferably, several injection lances 1 are pressed into the ground simultaneously until the desired maximum depth (0.5-15m) is reached. At greater depths, the pressing into the ground of lances can occur in phases to connect extensions to the injection lances 1 before inserting the injection lances 1 deeper. The slurry injection is started at the maximum depth. The pump speed is adjusted in advance to the composition of the subsurface, the length of the first injection lance and the distance between the injection lances 1. The distribution of the biomass slurry underground can be further controlled by allowing the injection to take place simultaneously with the slow upward movement of the injection lances 1.

Prior to the application of the method according to the invention, the bearing capacity and the height relative to NAP (Amsterdam Ordnance Datum) are measured with existing measuring technologies. This comprises soil investigation tests for bearing capacity. Height measurements can for example be point measurements with a laser or GPS system, but also Digital Elevation Models (DEM) for the entire treated plot. These types of DEMs can be obtained using a drone with a LiDAR (Light Detection And Ranging) system, or a simpler drone system that only takes photos and where a DEM can be calculated using postprocessing with photogrammetry. These measuring procedures can be repeated periodically after application of the method to measure the increase in the height of the ground level. If necessary, the method can be repeated at a specific underground location to achieve the desired ground level and bearing capacity. Moreover, based on the measured settlement rates of a treated piece of soil, it can be determined when the method according to the invention needs to be repeated to maintain the desired ground level.

The bearing capacity of the plot can be measured by means of soil investigation tests. Immediately after applying the method according to the invention, it is (expected) difficult to determine the improved bearing capacity due to the temporarily increased water content as a result of the aqueous component of the bioslurry that has been injected into the soil. After some time, this watery part will stabilize with the groundwater level and the slurry will have settled, with the excess water from the slurry being dispersed or drained. Once this drainage process has been stabilized, the resulting improvement in bearing capacity can be determined.

Figures 2 to 4 show injection lance heads that are suitable for the soil-displacing injection of slurry.

A first injection lance 1 is a hollow tube that is open at both the first (upper side) and second ends (bottom side). When pressing into the ground, soft soil could enter the tube and possibly clog the tube without additional countermeasures. The invention provides several injection lance heads, which can be used to prevent clogging.

Figure 3 shows the first preferred embodiment of the injection lance head 10 according to the invention. In this injection lance head 10, the first side 11 is cone-shaped and the second side 12 is similar to the first injection lance 1 . The injection lance head 10 is coupled to the first injection lance 1 by means of the second side 12 with known connecting means, such as a screw connection. A first outflow opening 13 is arranged in the tip of the cone-shaped first side 11. Second outflow openings 14 are provided in the circumference of the second side 12, which point obliquely in a direction facing away from the first side 11. This injection lance head 10 is suitable for driving a first injection lance 1 into the ground using water that loosens the soil through the first outflow opening 13 and where the upward jets of water from outflow openings 14 help to drive the first injection lance 1 into the ground.

Figure 4 shows the second preferred embodiment of the injection lance head 20 according to the invention, which can be advantageously used if it is undesirable to make the soft soil type unnecessarily extra soggy, such as when using the injection lance head 10 according to Figure 3. The injection lance head 20 is made of wood. The second side 22 of the injection lance head 20 has a similar circumference to the circumference of the second end 4 of the first injection lance 1 , such that the second side 22 partly fits into the first injection lance 1. The first side of the injection lance head 20 is cone-shaped, which makes it easier to press the first injection lance 1 into the ground. Moreover, this also keeps the first injection lance 1 itself free of soil. The largest circumference of the cone-shaped first side of the injection lance head 20 is larger than the largest circumference of the second side 22 of the injection lance head 20. As a result, when the first injection lance 1 is retracted, the injection lance head 20 will experience resistance from the surrounding soil and disconnect itself from the first injection lance 1 and remain in the ground. After disconnection of the injection lance head 20, the opening at the second end 4 of the first injection lance 1 is free, so that slurry can be transported from the first side via the second end 4 of the first injection lance 1 to the underground location. Since the injection lance head 20 is made of wood, leaving the head remaining in the subsurface will not cause environmental pollution. In addition, the carbon dioxide stored in the wooden injection lance head 20 is also captured for a long time.

Figure 5 shows the third preferred embodiment of the injection lance head 30 according to the invention, which is suitable for injecting the slurry in a horizontal soildisplacing manner. To this end, the second side 32 of the injection lance head 30 is coupled to the second end 4 of the first injection lance 1 by means of spacers 34, for example with a weld or screw connection. The spacers 34 extend from the second end 4 of the first injection lance 1 to near the first conical side 31 of the injection lance head 30. The space between successive spacers 34 form third outflow openings 33, from which slurry originating from the second open side 4 of the first injection lance 1 can flow to the underground location. Furthermore, the second side 32 of the injection lance head 30 is conical or spherical, effectively deflecting the direction of the slurry flow to a horizontal direction.

Figures 6A-6D schematically show the second basic principle of the method according to the invention. The second basic principle is based on the following method: A first tube 50 (or piston) with a closed bottom side, which is preferably point-shaped, convex or blunt, wherein the first tube 50 may have a diameter of 0.05-1 meter (50-1000mm) and a length of 1- 15 meters, is pressed into the soft soil to the intended depth (between 1 and 15 meters). This is shown in Figure 6A. The depth is preferably near or beyond the groundwater level W. Moreover, the first tube 50 may be hollow.

Subsequently, the first tube 50 is pulled out of the ground and a shaft 51 is formed in the ground. This is shown in Figure 6B.

The shaft 51 is then filled with either dry biomass or a wet biomass-water mixture (slurry). This is shown in Figure 6C.

After filling with biomass 100, a second tube 52 is inserted into the ground from the upper side of the shaft 51 to press the biomass present there below the groundwater level W. This is shown in Figure 6D. The second tube 52 preferably has a blunt or concave bottom side.

Subsequently, the second tube 52 is pulled out of the ground again and the shaft is again filled with biomass 100.

Figures 7A and 7B show the first head 54 of the first tube 50, in which the first head 54 comprises a remotely controllable first sealing valve 55 for application of the fourth embodiment of the third embodiment of the method, wherein in the method step c3-10) comprises the following sub-steps: step C3-10-1) closing the first sealing valve 55; step C3-10-2) pressing the first tube 50 into the ground beyond the groundwater level; step C3-10-3) at least partially removing the first tube 50 from the ground, after which the shaft is formed in the ground; and step c3-11) comprises the following sub-steps: step c3-11-1) opening the first sealing valve 55; step c3-11-2) filling the shaft with organic material via an upper side of the first tube 50 and via the open first sealing valve 55; and step c3-12) comprises the following sub-step: step C3-12-1) performing step C3-10-1), C3-10-2) and C3-10-3).

The sealing valve 55 is, for example, a butterfly valve, which can be opened or closed by means of a rod or a hydraulic cylinder, both not shown. This rod and/or hydraulic cylinder is attached to the inside of the first tube 50 or hollow tube so that no external forces are placed on it. The sealing valve 55 is preferably eccentric so that the portion opposite the hydraulic cylinder and/or rod rests on the bottom of the first tube. This allows the forces for driving the biomass into the ground to be absorbed on the jacket of the hollow first tube. The first tube can be driven into the ground by means of a pile driver, as well as a hydraulic or pneumatic mechanism. The sealing valve 55 is closed when the first tube enters the ground to prevent soil from entering the hollow first tube. The sealing valve 55 is opened at the moment that the first tube 50 rises. At the same time, biomass is supplied via the upper end of the first tube 50, which falls through the open sealing valve 55 into the hole already formed under the lower end of the first tube 50 in the subsoil. During the next downward movement, the sealing valve 55 is closed again, so that the first tube 50 can press the biomass into the subsoil. These upward and downward movements are repeated until the hole in the subsoil is filled with biomass to the desired level below ground level.

In Figures 7A and 7B, the sealing valve 55 hinges on two opposite hinge points 56 on the peripheral edge of the end of the tube.

Figure 7C shows an alternative sealing valve 55, wherein the sealing valve 55 is hinged on one hinge point 58 on the peripheral edge of the end of the first tube 50. As an example, a remotely controllable rod 57 is shown for operating the alternative sealing valve 55.

Figures 8A and 8B show a bottom side view of the first tube 60 for use in the fourth embodiment of the third embodiment of the method according to the invention. The first tube 60 comprises a feed connection 61 for connecting a third tube for feeding organic material via the third tube. Step c3-10) comprises the following sub-steps: step C3-10-4) placing the first tube 60 in the ground; step C3-10-5) placing the second tube 63 in the first tube 60, in which the second head of the second tube 63 is closed off; step c3-10- 6) moving the second tube 63 downwards beyond the groundwater level and moving it upwards again relative to the first tube 60, in which the second tube 63 forms a shaft in the ground under the tube 60.

Step c3-11) comprises the following sub-step: step c3-11-3) filling the shaft with organic material via the third tube and the feed connection 61.

Step c3-12) comprises the following sub-step; step C3-12-2) performing step C3-10-10.

In step c3-10) the first tube 60 is pressed into the ground together with the third tube connected to the feed connection 61 . This can be done using the aforementioned punching methods. In step c3-11) the formed shaft is filled with biomass via the third tube and the feed connection 61. The biomass in the shaft is then pressed further into the shaft by moving the second tube 63 towards the bottom, after which the cycle is repeated.

This cycle is repeated until the biomass 100 can no longer be pushed away and the second tube 53;63 is therefore pressed less and less deeply. When the second tube 53;63 can only press so shallowly that the upper limit of the biomass 100 placed underground almost reaches the intended upper limit (for example the groundwater level W), the process is stopped, and the remaining shaft is closed.

This process is then repeated in adjacent biomass-filled spaces until the intended amount of biomass has been stored within the intended area of land.

The bioslurry for use in the method according to the invention consists of chopped and ground wood and/or plant material. Suitable sources for biomass injection are, for example, poorly fermentable woody biomass waste streams. This material has little other value and offers relatively high strength for stabilizing soft soils.

To achieve the maximum density of the underground layer of biomass to be applied, a mixture of biomass materials is preferably used that have been chopped and ground into different particle sizes (from sawdust of ± 0.1 mm particle size to wood pieces up to 50 mm). By optimizing the distribution of biomass with different particle sizes for maximum stackability, an underground layer of high-density biomass is created if the slurry has been allowed to dewater after injection. A higher density of the biomass layer contributes to a higher bearing capacity of this layer.

This biomass mixture is mixed with water in a hopper, where mixing arms stir the biomass slurry into a homogeneous mass. Depending on the depth of the injection, the composition of the soil and the working pressure of the slurry, a more viscous biomass slurry can be chosen that contains relatively little water and relatively much woody biomass or a less viscous slurry that contains a large amount of water compared to of biomass.

By introducing biomass into a reducing anaerobic environment, it can be demonstrated that carbon dioxide is sustainably kept out of the atmosphere, just like with deeper peat below the groundwater level. Per ton of injected dry biomass material, up to approximately 1.8 tons of carbon dioxide can be sustainably stored, which carbon dioxide would otherwise have entered the atmosphere over time through rotting or burning of the biomass. The avoided carbon dioxide emissions can be certified and traded.

Claims

1. Method for moving organic plant material to a location in which sustainable anaerobic conditions prevail, comprising the following steps: step a), selecting the location; step b). selecting the organic material; step c). moving the organic material to the location; characterized in that, in step a), the location meets the following criteria:

2. Method according to claim 1, wherein step c). comprises the following sub-step: step c1) reducing the size of the organic material;

3. Method according to claim 2, wherein step c). comprises the following sub-step: step c2). mixing the reduced material with a liquid to form a slurry.

4. Method according to any of the claims 1-3, in which step c) comprises the following sub-steps: c3) creating a shaft to the underground location by mechanical means and moving the organic material to the underground location by means of the shaft.

5. Method according to claim 4, wherein step c3) comprises the following sub-steps: step c3-1). pressing one or more hollow injection lances into the ground from an aboveground location by mechanical means to the underground location to form a shaft, in which a first end of the first injection lance (1) is arranged for connecting a hose; step c3-2). coupling the first end of each first injection lance (1) pressed into the ground to the hose, which hose is connected to a pumping device for pumping the slurry; step c3-3). pumping the slurry under pressure using the pumping device via a second end (4) of the one or more injection lances (1) to the underground location; step c3-4). removing the one or more injection lances (1) from the ground by mechanical means.

6. Method according to claim 5, wherein, before pressing the first injection lance (1) into the ground, an injection lance head (10, 20, 30) is coupled to the second end (4), which is arranged for penetration of the soft soil.

7. Method according to claim 5, wherein slurry is pumped under pressure from the second end (4) of the first injection lance (1) to the underground location via one or more outflow openings (13, 14, 33) on the injection lance head (10, 30).

8. Method according to claim 7, wherein, while pressing the first injection lance (1) into the ground, water under pressure flows out of the one or more outflow/openings (13, 14, 33) via the first injection lance (1).

9. Method according to claim 8, wherein when the first injection lance (1) is pressed into the ground, the water flows out of the one or more outflow openings (13) in a direction of the underground location.

10. Method according to claim 8 or 9, wherein the water flows out of the one or more outflow openings (14) under pressure in a direction towards the above-ground location.

11. Method according to any one of claims 6-10, wherein the injection lance head (20) is disconnected from the first injection lance (1) after pressing the injection lance head (20) into the ground by slightly retracting the first injection lance (1).

12. Method according to one of claims 6-11 , wherein the pumped slurry flows from one or more outflow openings (33) in a direction other than the longitudinal direction of the first injection lance (1).

13. Method according to one of claims 5-12, wherein in step c3-3) the one or more injection lances (1) are raised during pumping of the slurry, with the second end (4) remaining below the groundwater level.

14. Method according to one of claims 5-13, wherein the method is used to raise compacted soft soil, wherein in step c3-1) the height of the ground level is determined; and step c3) comprises the following sub-step: c3-5) allowing the injected soft soil to settle; and wherein steps c3-1) to c3-5) are repeated until a predetermined desired height of the ground level is reached.

15. Method according to one of claims 5-13, wherein the method is used to increase the bearing capacity of soft soil, wherein in: step c3-1) the bearing capacity of the soft soil is measured with the aid of one or more soil investigation tests; c3-5) allowing the injected soft soil to drain out, wherein the slurry has been able to settle and the excess water from the slurry has spread or been drained; and wherein steps c3-1) to c3-5) are repeated until a predetermined desired bearing capacity is reached.

16. Method according to claim 2, wherein step c3) comprises the following sub-steps: step c3-6). pressing one or more hollow second injection lances into the ground from an above-ground location by mechanical means to the underground location to form a shaft; step c3-7). filling the one or more second injection lances with the reduced material via a first end of the second injection lance; step c3-8). pressing the reduced material into the second injection lance to the underground location; step c3-9). removing the one or more second injection lances from the ground by mechanical means.

17. Method according to claim 16, wherein in step c3-7). the second injection lance is tubular; and in step c3-8). the pressing takes place by

18. Method according to claim 1, 2 or 3, wherein step c) comprises the following substeps: step c4). removing the soil above the bottom of the underground location; step c5). filling the underground location with the organic material; step c6). restoring the soil;

19. Method according to claim 18, wherein in: step c4). the soil above the underground location is removed by pulling trenches using mechanical means, such as a tractor.

20. Injection lance head (10,20,30) for use in the method according to any one of claims 7-15, wherein

- the injection lance head (10,20,30) comprises a first side (11 ,21,31) which is arranged for penetration of the weak soil type, and is preferably conical or spherical, and a second side (12,22,32) facing away from the first side is arranged for coupling to the second end (4) of the first injection lance (1);

21. Injection lance head (10,30) according to claim 20, wherein the injection lance head (10,30) comprises one or more outflow openings (13, 14, 33), wherein the injection lance head (10,30) is arranged for passing liquid from the second end (4) from the first injection lance (1) to one or more outflow openings (13, 14, 33).

22. Injection lance head (10) according to claim 21, wherein at least one first outflow opening (13) is arranged in the first side (11) of the injection lance head (10) and runs parallel to the longitudinal direction of the injection lance head (10).

23. Injection lance head (10) according to claim 21 or 22, wherein the second side of the injection lance head (10) has a substantially similar circumference as the circumference of the second (4) end of the first injection lance (1), and in the circumference of the second side (12) of the injection lance head (10), one or more second outflow openings (14) are arranged, which second outflow openings (14) are at an angle to the longitudinal direction of the injection lance head (10).

24. Injection lance head (20) according to claim 20, wherein the injection lance head (20) is made of an environmentally friendly material, preferably wood, and the second side (22) of the injection lance head (20) is arranged for releasable coupling to the first injection lance (1) , and wherein the largest circumference of the first side (21) of the injection lance head (20) is larger than the largest circumference of the second side (22) of the injection lance head (20), such that when using the method according to the invention when the first injection lance (1) is retracted, the injection lance head (20) remains in the ground.

25. Injection lance head (30) according to claim 21, wherein

- the second side (32) of the injection lance head (30) is coupled to the second end (4) of the first injection lance (1) by means of spacers (34), wherein the spacers (34) extend from the second end (4) of the first injection lance (1) to near the first side (31) of the injection lance head (30) and wherein the space between successive spacers (34) form third outflow openings (33).

26. Injection lance head (30) according to claim 25, wherein the second side (32) of the injection lance head (30) is arranged for deflecting the flow of slurry to a direction other than the longitudinal direction of the injection lance head (30) when applying the method according to the invention.

27. Injection lance head (30) according to claim 26, wherein the second side (32) of the injection lance head (30) is conical or spherical.

28. Method according to claim 4, wherein step c3) comprises the following sub-steps: c3-10). creating a shaft (51) in the ground from an above-ground location by mechanical means to the underground location, after which the shaft wall is formed by the ground; c3-11). filling the shaft (51) with the organic material; c3-12). exerting a downward pressure on the organic material placed in the shaft (51) from an upper side, such that the organic material mainly moves to the underground space.

29. Method according to claim 28, wherein in step c3-10) the construction of the shaft (51) takes place by placing a first tube (50) in the ground by mechanical means up to the underground location, after which the first tube (50) is removed from the ground again by mechanical means.

30. Method according to claims 28 and 29, wherein in step c3-12). the downward pressure is exerted by placing a second tube (53) on the organic material placed in shaft (51) by mechanical means and moving the second tube (53) in the direction of the underground space.

31. Method according to claims 29 and 30, wherein the first and second tube (53) are assembled of several tube sections to be connected to each other and during placing the tube in the ground and removing the tube from the ground, the tube sections are connected and disconnected.

32. Method according to one of claims 29 or 31 , wherein the first tube (50) has a first head that is arranged to displace soil, such as, for example, a point-shaped or spherical head.

33. Method according to one of claims 30 or 31 , wherein the second tube (53) has a second head that is arranged to push the organic material in a downward direction, such as, for example, a flat or hollow head.

34. Method according to any one of claims 29-33, wherein the first tube (50) and second tube (53) are similar or the same tubes.

35. Method according to claim 34, wherein the tube (50;53) has an interchangeable head and before placing the tube in the ground the first head is arranged to the tube (50;53) and before pushing the tube to the underground location organic material the second head is attached to the tube (50;53).

36. Method according to claim 32, 33 and 34, wherein the first head (54) of the first tube (50) comprises a remotely controllable first sealing valve (55) and wherein step c3-10) comprises the following sub-steps: step c3-10- 1) closing the first sealing valve (55); step C3-10-2) pushing the first tube (50) into the ground beyond the groundwater level; step C3-10-3) at least partially removing the first tube (50) from the ground, after which the shaft is formed in the ground; and step c3-11) comprises the following sub-steps: step c3-11-1) opening the first sealing valve (55); step c3-11-2) filling the shaft with organic material via an upper side of the first tube (50) and via the open first sealing valve (55); and step c3-12) comprises the following sub-step: step c3-12 -1) performing steps C3-10-1), C3-10-2) and C3-10-3).

37. Method according to claim 33, wherein the first tube (60) comprises a feed connection (61) for connecting a third tube for feeding organic material via the third tube to the first tube (60), wherein step c3-10) comprises the following sub-steps: step C3-10-4) placing the first tube (60) in the ground step C3-10-5) placing the second tube (63) in the first tube (60), wherein the second head of the second tube (63) is closed off; step C3-10-6) moving the second tube (63) downwards beyond the groundwater level and moving it upwards again relative to the first tube (60), wherein the second tube (63) forms a shaft in the ground under the first tube (60); and wherein step c3-11) comprises the following sub-step: step c3-11 -3) filling the shaft with organic material via the third tube and the feed connection (61); and wherein step c3-12) comprises the following sub-step; step C3-12-2) performing step C3-10-10.

38. Method according to any one of claims 5-19, wherein each injection lance comprises a remotely controlled second sealing valve at its second end, and before inserting the injection lance into the ground the second sealing valve is closed and after inserting the injection lance into the ground the first sealing valve is opened.

39. Method according to one of claims 4-19, 28-37, comprising the additional step d) filling and sealing the access to the shaft with the same type of soil as above the shaft and above the groundwater level.