Method and system for producing fuel from compressed biomass

Abstract

The present invention relates to a method for producing fuel from compressed biomass, wherein the method comprises the following: providing biomass; supplying the biomass; washing the biomass; comminuting, in particular finely comminuting, the biomass; mechanically dewatering the biomass; drying the biomass; and shaping the biomass, wherein, prior to the mechanical dewatering, the method further comprises increasing the moisture content of the biomass, allowing a time interval between the increase in moisture content and the mechanical dewatering. The present invention also relates to a corresponding system (100) for producing fuel from compressed biomass, to a computer-readable medium, and to a program element.

Description

[0001] Process and system for producing fuel from pressed biomass

[0002] AREA OF INVENTION

[0003] The present invention relates to a method and a system for producing fuel from pressed biomass. The present invention further relates to a computer-readable medium and a program element.

[0004] BACKGROUND AND STATE OF THE ART

[0005] The production of fuel, for example in the form of pellets or briquettes, from biomass such as green waste or leaves is a well-known process. For example, WO 2004 / 067685 Al describes a process for producing fuel from pressed biomass, in which the biomass undergoes a comminution and a drying process before being pressed into pellets. Further details on the comminution process are described, among others, in DE 10 2008 035 222 Al and DE 10 2008 064 803 B3. The use of a waterjet cutter and washing the biomass has also proven advantageous, as described in DE 10 2012 203 148 B3. For drying, a contact dryer can be used, for example, as described in DE 10 2016 213 956 Al.

[0006] When upscaling such plants and using a wide variety of biomass in different states, it has become apparent that the resulting pellet qualities and subsystem performance require optimization with regard to impurity removal and resource utilization. In particular, biomass is frequently used for weight reduction.

[0007] AD: SG: mr dried, which reduces transport and disposal costs. However, this results in lower throughput and poorer removal of contaminants with known methods.

[0008] There is therefore still a need for improvements and optimizations in a process for producing fuel from pressed biomass and in a system used or suitable for this purpose.

[0009] TASK OF INVENTION

[0010] One object of the present invention is therefore to provide an improved method and system for producing fuel from pressed biomass, which in particular has lower energy consumption and delivers an improved quality of the fuel produced, for example with regard to an increase in energy yield and a reduction in impurities.

[0011] SUMMARY OF THE INVENTION

[0012] The inventors of the present invention have carried out extensive investigations and have found that this problem can be solved by moistening the biomass in conjunction with an exposure time before mechanical dewatering.

[0013] Intentionally increasing the moisture content before subsequent dewatering is fundamentally at odds with efficient resource utilization (additional fluid consumption, additional energy expenditure for dewatering, delay and thus slowing of the process due to very long exposure times, etc.). However, the inventors of the present invention have discovered that the relationships in a process for producing fuel from biomass are far more complex, particularly since the component to be dewatered does not consist solely of water. Depending on the source of the biomass, it can contain varying proportions of salts, e.g., sodium chloride (NaCl) as a component of leaves on roads in winter. NaCl in water leads to a disproportionate increase in viscosity with increasing NaCl concentration.It is also known that chlorides bind water and change the dynamic viscosity of the water, so that drainage systems drain less effectively due to increased chloride load.

[0014] Therefore, it is important to minimize the chloride concentration not only for quality assurance purposes of the produced fuel, but also for energy-efficient processing (i.e., the actual dewatering / drying). Such a reduction in chloride concentration, as well as other ions and salts, can be achieved by moistening the biomass and allowing it to soak in before mechanical dewatering. Experience has shown that the seemingly counterproductive action of increasing the moisture content of the biomass before dewatering is actually very effective.

[0015] The present invention relates accordingly to a process for producing fuel from pressed biomass, the process comprising the following steps: providing (for example, including storage) biomass, feeding the (provided) biomass, washing the (fed) biomass, comminution, in particular fine comminution, of the (washed) biomass, mechanical dewatering of the (compressed) biomass, drying of the (mechanically dewatered) biomass, and shaping (optionally including compaction) of the (dried) biomass. The process further comprises increasing the moisture content of the biomass prior to mechanical dewatering. In addition, a period of time (action time, settling phase, waiting time) is allowed between increasing the moisture content and mechanical dewatering.Furthermore, the present invention relates to a system (arrangement, device) for producing fuel from pressed biomass, in particular for carrying out a process as described herein, wherein the system comprises a storage unit, a feeding device, a washing unit, a comminution device, in particular a fine comminution device, a mechanical dewatering device, a drying device, and a shaping device (optionally including a compaction device). The system further comprises a device for increasing the moisture content of the biomass, wherein the device is configured to increase the moisture content of the biomass before the biomass is fed to the mechanical dewatering device, and a time interval (exposure time, residence time, waiting time) is allowed between increasing the moisture content and the mechanical dewatering.

[0016] Furthermore, the present invention relates to a computer-readable medium on which a computer program is stored, wherein the computer program is configured such that, when executed on a processor, it controls and / or regulates a method and / or a system for producing fuel from compressed biomass as described herein.

[0017] Furthermore, the present invention relates to a program element which, when executed on a processor, controls and / or regulates a method and / or a system for producing fuel from pressed biomass as described herein.

[0018] Further tasks and advantages of embodiments of the present invention will become apparent from the following detailed description and the accompanying illustration.

[0019] BRIEF DESCRIPTION OF THE FIGURE Figure 1 is a schematic representation of a system for producing fuel from pressed biomass according to an exemplary embodiment.

[0020] DETAILED DESCRIPTION OF THE INVENTION

[0021] Further details of the present invention and other embodiments thereof are described below. However, the present invention is not limited to the following detailed description, which merely serves to illustrate the teachings of the invention.

[0022] It should be noted that features described in connection with one exemplary embodiment can be combined with any other exemplary embodiment. In particular, features described in connection with one exemplary embodiment of a method according to the invention can be combined with any other exemplary embodiment of a method according to the invention, as well as with any exemplary embodiment of a system according to the invention, as well as with any exemplary embodiment of a computer-readable medium according to the invention and any exemplary embodiment of a program element according to the invention, and vice versa, unless expressly stated otherwise.

[0023] When a term is used with an indefinite or definite article, such as "ein," "eine," "eines," "der," "die," and "das" in the singular, this also includes the plural form and vice versa, unless the context clearly indicates otherwise. The expressions "aufweisen" and "umfassen," as used here, do not only include the meaning of "contain" or "include," but can also mean "consist of" and "essentially consist of." Unless clearly indicated otherwise, the terms "at least partially" and "at least partially" can also mean "consist of.""at least a part" as used here means at least 1% of it, at least 2% of it, at least 5% of it, at least 10% of it, at least 15% of it, at least 20% of it, at least 25% of it, at least 30% of it, at least 35% of it, at least 40% of it, at least 45% of it, at least 50% of it, at least 55% of it, at least 60% of it, at least 65% of it, at least 70% of it, at least 75% of it, at least 80% of it, at least 85% of it, at least 90% of it, at least 95% of it, at least 98% of it, at least 99% of it, and can also mean 100% of it.

[0024] In a first aspect, the present invention relates to a method for producing fuel from pressed biomass. The fuel from pressed biomass can, in particular, be pellets and / or briquettes.

[0025] For the purposes of this application, "biomass" refers in particular to plant products that can be used to generate heating energy, electrical energy and as fuels.

[0026] For the purposes of this application, "pellets" are understood to mean, in particular, small bodies of compressed material in spherical or cylindrical shape. These can be, in particular, combustible granules used as a heating fuel. The typical diameter of pellets is between 6 and 25 mm. Pellets are mostly used in automatically fed combustion systems and pellet stoves, which offer a similar level of convenience to oil or gas heating systems; however, they are also suitable for firing large-scale systems (e.g., thermal power plants, steam boilers, etc.). For the purposes of this application, "briquettes" are understood to mean, in particular, compressed fuel material with a larger size than pellets, for example, with a diameter greater than 25 mm.

[0027] The steps of providing, feeding, washing, crushing, in particular fine crushing, mechanical dewatering, drying and shaping (including compaction) can in principle be carried out in an analogous manner as in the literature mentioned at the beginning.

[0028] In connection with the present invention, it is important that the moisture content of the biomass is increased before mechanical dewatering and that the increased moisture is allowed to act for a certain period of time before the biomass is subjected to mechanical dewatering. For example, the moisture content can be increased to at least 55%, in particular at least 63%, preferably at least 70%, and / or the exposure time can be at least 30 seconds, in particular at least 40 seconds, and / or a maximum of five days.

[0029] In the context of this application, the term "moisture" or "moisture content" of a biomass refers not only to water or aqueous components, but to the entire remaining mass that does not constitute the dry matter (DM) of the biomass. Therefore, moisture = 100% minus DM in %. In addition to water or aqueous components, moisture also includes other fluids such as volatile oil components, etc. The dry matter can be measured in a laboratory. A weighed sample of the mixture is taken and heated to over 100 °C in a drying chamber to evaporate the residual moisture (usually water). The remaining dry residue is weighed and compared to the dry matter content. This yields the dry matter content of the mixture. The liquid evaporated during this measurement is referred to as the moisture content (in %).According to an exemplary embodiment, at least a portion of the (provided) biomass is selected from the group consisting of water hyacinths, seagrass, algae, grass clippings, leaves, green waste, and combinations thereof. Particularly good results were achieved when the biomass consists of or contains seagrass, water hyacinths, algae, grass clippings, and / or leaves. Without wishing to be bound to any specific theory, the inventors currently assume that the dry matter of these materials provides a good basis for pellet production and that, at the same time, these materials are often not round but rather flat in cross-section, which results in better contact (due to a larger contact area) between the individual particles for thermal and moisture exchange. This allows shear forces and / or frictional movements to have a greater effect, which is particularly advantageous for a uniform moisture distribution.

[0030] According to an exemplary embodiment, providing biomass includes storing the biomass. Within the scope of this application, "storage" is understood to mean, in particular, that the biomass is kept as a unit, for example, as a container or in a storage unit, preferably stationary at one location, but may also include transporting the unit. The storage of the biomass, especially loose biomass, can, for example, take place at a moisture content of over 50%, particularly over 55%, preferably over 60%, for less than two months, particularly less than four weeks, preferably less than one week. Storage for too long and at excessively high moisture levels can lead to mold growth, fermentation, and decomposition processes, which in turn reduce the calorific value of the biomass. Studies have shown that this moist storage, especially when it is open (i.e., in a container), is particularly problematic.(simply material lying in a pile) is accompanied by a corresponding reduction in calorific value. It was found that the storage of biomass, especially open biomass, at a moisture content above 50%, particularly above 55%, and furthermore particularly above 60%, should be less than 2 months, particularly less than 4 weeks, preferably less than 1 week.

[0031] According to an exemplary embodiment, increasing the moisture content is achieved by one of the following measures: supplying fresh water, supplying steam, storing in humid air, supplying process fluid (e.g., press water), mixing with biomass of higher moisture content, soaking in water, or combinations thereof. These measures have proven particularly suitable for increasing moisture content, with the combination of several measures proving to be especially resource-efficient.

[0032] 1) Fresh water supply, i.e., the addition and interaction of fresh water during the manufacturing process or in a preceding phase. The type and fine distribution of the water droplets are particularly important for resource consumption. Since fresh water is usually available under considerable overpressure, this overpressure can be used for atomization (transforming it into fine droplets using nozzles).

[0033] 2) Steam injection. This is one of the most efficient ways to increase humidity, but it is associated with high energy consumption.

[0034] It can be used especially when steam is available from other processes, which can then be reused without external energy.

[0035] 3) Storage in humid air. This increase in humidity requires the least fresh water, but has a relatively long exposure time. Depending on the storage conditions (e.g., pressure storage with increased contact force between the biomass particles or in an anaerobic environment), the exposure time does not negatively affect the calorific value of the produced pellets. 4) Process fluid supply (e.g., press water). The liquid recovered during mechanical dewatering can be at least partially reused for humidification. It is particularly important to control the concentration of salts in the press water, otherwise the removal of impurities will be insufficient.

[0036] 5) Mixing with biomass of higher moisture content. When biomass with high moisture content is mixed with biomass with low moisture content, a medium moisture level is reached after some time. This has the advantage that any subsequent increase in moisture content with fresh water is faster because the dry material (e.g., dry leaves) is already moistened and can therefore absorb further moisture more quickly.

[0037] 6) Soaking in water. Basically a self-regulating process in which the amount of moisture absorbed by the biomass is controlled by the residence time in the water.

[0038] According to an exemplary embodiment, the moisture content of the biomass before mechanical dewatering, particularly in the case of multiple mechanical dewatering before the first mechanical dewatering, is more than 55%, more particularly more than 63%, and preferably more than 70%. It has proven advantageous for the process of producing fuel from pressed biomass, and for the emissions released in the process, if the biomass has sufficient and uniform moisture content. Particularly in open areas of a plant prior to the first mechanical dewatering, dust emissions are reduced if the moisture content of the biomass is above 55%, more particularly above 63%, and preferably above 70%.In addition, these moisture levels also ensure a correspondingly high removal of contaminants through the subsequent mechanical dewatering, and especially in the case of multi-stage mechanical dewatering, the high moisture content in the first mechanical dewatering brings the biomass into an ideal consistency for an energetically optimal second mechanical dewatering.

[0039] According to an exemplary embodiment, the moisture content is increased during the preparation (especially storage) of the biomass, during the feeding of the biomass, during the washing of the biomass, before, during, and / or after the comminution of the biomass, in particular where the moisture content is increased in several process steps. It has been shown that the timing (especially which process step) of the moisture increase offers particular optimization potential.

[0040] 1) During biomass storage. Here, a particularly long exposure time can be achieved without additional operational effort. At the same time, it can be prevented that a hydrophobic change occurs on the surface of the biomass, which would delay subsequent moisture increase. The pressure on the biomass is already increased slightly below the surface of the material in a storage bunker. A moisture-equalizing distribution process begins.

[0041] 2) During the feeding of the biomass. Handling of the biomass takes place at this point anyway. Therefore, mixing biomass with different moisture content or adding appropriate liquids can be done here without significant additional effort.

[0042] 3) In the washing system. Here, water absorption can be achieved, particularly through flotation separation, although flotation is actually intended for separating contaminants heavier than water. However, contact with water during flotation can also lead to an increase in moisture content if the duration is sufficient. 4) Before, during, and / or after shredding. Shredding, especially fine shredding, significantly increases the biomass's contact surface with external moisture. This allows for moisture absorption with the shortest possible exposure time.

[0043] In particular, increasing the humidity at several of these process steps can be especially advantageous because it allows both the amount of liquid supplied and the exposure time to be optimized.

[0044] According to an exemplary embodiment, the method further comprises mixing (combining) several (batches of) biomasses with different moisture content.

[0045] According to an exemplary embodiment, the biomass has a moisture content of less than 65%, particularly less than 53%, and especially less than 40%, before the moisture level is increased. In particular, it can be advantageous if the biomass supplied to the system before the moisture level is increased has a moisture content of less than 65%, particularly less than 53%, and especially less than 40%, since such partially dried biomaterial with a moisture content below its natural normal state preferentially absorbs liquid, which in turn is associated with a shorter contact time.

[0046] According to an exemplary embodiment, the time interval (exposure time, resting phase) between increasing the moisture content and mechanical dewatering is at least 30 seconds, in particular at least 40 seconds, in particular at least 1 minute, in particular at least 5 minutes, and preferably a maximum of 5 days, in particular less than 2 days, in particular less than 1 day, and in particular less than 12 hours. According to an exemplary embodiment, press water generated during mechanical dewatering is used to increase the moisture content of the biomass. In the case of multiple mechanical dewatering processes, press water generated during the first mechanical dewatering process can be used to increase the moisture content of the biomass, preferably more press water generated during the first mechanical dewatering process than press water generated during the second mechanical dewatering process. As noted above, press water (i.e.,The liquid recovered during mechanical dewatering is used to increase the moisture content of the biomass. It has been found that press water from the first mechanical dewatering stage is better suited for increasing moisture than press water from the second mechanical dewatering stage. Without wanting to be bound to a specific theory, the inventors currently assume that the press water from the first dewatering stage is less viscous and has a lower total solids content (TS) due to the reduced cell disruption compared to the press water from the second mechanical dewatering stage.

[0047] According to an exemplary embodiment, the biomass is subjected to friction and / or shear forces before mechanical dewatering. These processes can be specifically adapted to reduce the hydrophobic surface properties of the biomass, at least partially and / or in certain areas. It has been shown that when biomass dries out, a hydrophobic property develops on its surface, preventing rapid moisture absorption. However, the present fuel production process involves extensive mechanical handling prior to the initial mechanical dewatering. The resulting friction and shear forces reduce the hydrophobic properties that develop during dryness, and the rate of water absorption is increased. Additionally, the mechanical comminution exposes or creates more of the biomass's surface area for moistening.According to one exemplary embodiment, drying of the biomass is reduced (during storage). In particular, this can be achieved by encasing the biomass. Reducing drying means less subsequent rehydration is required, which in turn reduces resource consumption. The encasing creates a more anaerobic microclimate, which reduces decomposition processes and thus ensures a higher calorific value of the biomass.

[0048] According to an exemplary embodiment, the process further includes increasing the temperature of the biomass prior to mechanical dewatering. The energy for this temperature increase can be derived from one of the following sources: waste heat from thermal drying, from mechanical dewatering, local and / or external waste heat, from a high-pressure water cutter in the washing unit, from a biogas plant, and / or from a solar thermal system. Increasing the temperature reduces the viscosity of the biomass, thus requiring less energy for mechanical dewatering. Furthermore, waste heat from the process (heat recovery) or energy from renewable sources can be used for this purpose, which is additionally advantageous from both an economic and environmental perspective.

[0049] According to one exemplary embodiment, providing the biomass includes determining (estimating, in particular measuring) its moisture content. In other words, it can be advantageous to determine the moisture content of the stored biomass before further processing. Moisture determination can be carried out, in particular, while the biomass is still in a storage unit. Alternatively or additionally, the moisture content can also be determined after the biomass has already been removed from a storage unit. This can be done by an experienced operator by manual sampling; however, measuring the moisture content is more reliable, for example, using a sensor. Especially with an electronic sensor, the added liquid can then be dosed semi- or fully automatically within the framework of a control system or with a feedback loop.According to an exemplary embodiment, the increase in humidity can thus be controlled based on sensor information, in particular automatically controlled, preferably automatically regulated.

[0050] According to an exemplary embodiment, further properties of the biomass are detected by sensors, in particular processed and / or stored, with the sensor values ​​preferably contributing to process optimization. For example, other sensors can also be used to measure the salinity (e.g., indirectly via conductivity), the temperature (too much cold water makes the biomass more viscous), the turbidity (and thus certain amounts of contaminants), etc. This allows for the optimization of process resources and the improvement of the quantity and / or quality of the fuels using electronic control.

[0051] According to an exemplary embodiment, data, in particular measured values, which provide an indication of the impurity composition of a biomass, can contribute to determining the degree of moisture increase. In particular, these can at least partially control the amount of moisture and are preferably taken into account in the moisture control. The measured values ​​or data from the sensor regarding the composition of the biomass, or the proportion of foreign and / or impurities, allow the moisture increase according to the invention to be dynamically adjusted: In the case of high salt content or above-average impurity content, or in the case of excessively viscous biomass, the moisture can be further increased; otherwise, minimal additional humidification can be used.

[0052] The sensor values ​​and their possible correlations can be used for both a

[0053] The system can be used for controlling operating parameters (i.e., without a feedback loop, i.e., setting a pump speed) as well as for regulating operating parameters (e.g., humidity is regulated depending on the conductivity, whereby the conductivity is measured after water is added, so that the effect of the water addition is included in the sensor value and feedback is allowed).

[0054] According to an exemplary embodiment, the moisture determination and / or its accuracy improvement is based on one of the following measures, which can also be combined for a particularly accurate moisture determination of the biomass:

[0055] 1) Humidity measurement in close proximity to the biomass (e.g., inserting a humidity sensor into a bale). Since there is no external air exchange here, the humidity measurement is meaningful. The humidity is correlated with the moisture content of the biomass, and measuring humidity is simpler than measuring the moisture content of solids.

[0056] 2) Conductivity measurement of the biomass. Both before and after the addition of moisture. In particular, by measuring 'before' and 'after' (before / after comparison), the conductivity can be recalibrated to a reference to the moisture content by taking into account the amount of liquid added.

[0057] 3) Attenuation of an electric field. This allows the moisture present in a volume to be determined at least approximately, since water in particular causes a characteristic attenuation of an electric (especially alternating) field.

[0058] 4) Capacitance measurement. Here too, a volumetric moisture determination is indicatively possible; if the biomass is in the dielectric of two capacitor plates, the proportional water content directly affects the relative permittivity (E). r ) and thus affects the capacitor capacity.

[0059] 5) Density determination: e.g. by weighing a bale with a known volume, its moisture content can be estimated relatively well.

[0060] 6) Weight change, density change: If, for example, the weight of a known volume is weighed or the density is determined upon receipt of goods, the change and thus the change in moisture (e.g., due to evaporated water) can be determined by measuring again when leaving the warehouse (and this can then be replenished).

[0061] 7) Manual scanning: already mentioned above.

[0062] According to an exemplary embodiment, the method further includes storing data on the moisture content of the biomass. In particular, this data can be stored in an electronic data processing system. This data can then be used as a data history to determine the amount of moisture to be added. Since certain properties of the pellets can only be determined by measurement after their production, the stored data, in the sense of a data history for future biomass with similar properties, allows the determination of the optimal amount of moisture to be added.

[0063] According to one exemplary embodiment, the mechanical dewatering of the biomass is carried out in multiple stages (for example, in several stages of a dewatering system or in several process steps in different dewatering systems). In particular, the shear forces acting on the biomass in the different dewatering systems can differ. Consequently, the wastewater compositions of the different dewatering systems can also differ. In multi-stage dewatering, for example, the different dewatering systems can be designed such that they exert different shear forces on the biomass. This results in different degrees of cell disruption of the biomass, leading, for example, to the wastewater from the two dewatering systems exhibiting different protein concentrations and levels of contaminants.

[0064] According to one exemplary embodiment, a biomass is used that has been stored (at least partially) under mechanical pressure for at least one day (before being added). This can increase the homogeneity of the biomass used, particularly with regard to moisture distribution and / or the degree of microbial decomposition.

[0065] A process according to the invention for producing fuel from pressed biomass can in particular be carried out by means of a system for producing fuel from pressed biomass according to the second aspect explained in more detail below.

[0066] In a second aspect, the present invention relates to a system for producing fuel from compressed biomass. The system may be particularly suitable for carrying out a process for producing fuel from compressed biomass according to the first aspect explained in more detail above. Descriptions of features already given above in connection with the first aspect apply analogously to the same or similar features in connection with the second aspect, even if they are not explicitly repeated.

[0067] The individual components of the system, such as a storage unit, a feeding device, a washing unit, a comminution device, in particular a fine comminution device, a mechanical dewatering device, a drying device, a shaping device (possibly including a compaction device), can in principle correspond to the components as disclosed in the aforementioned literature.

[0068] In connection with the second aspect of the present invention, it is important that the system further comprises a device for increasing the moisture content of the biomass. The device is configured (and arranged) such that it increases the moisture content of the biomass before the biomass is fed to the mechanical dewatering device. Furthermore, the device or system is configured or arranged such that a period of time (exposure time, residence time) is allowed between the moisture increase and the mechanical dewatering.

[0069] According to an exemplary embodiment, at least one component of the system, in particular the storage unit, the feeding device, the washing unit, the comminution device, the mechanical dewatering device and / or an additional component (for example, a conveying system such as a screw conveyor), is arranged in such a way that a residence time and / or process time for the biomass is given or can be achieved after its moisture content has increased.

[0070] According to an exemplary embodiment, the mechanical dewatering system comprises a multi-stage (e.g., two-stage) dewatering system or several dewatering systems. Two-stage dewatering also allows for the production of two different press water compositions, which is particularly advantageous with regard to repurposing, protein extraction, biogas production, etc. Furthermore, it has been surprisingly shown that the prior increase in the moisture content of a biomass and its subsequent feeding into the first mechanical dewatering stage not only allows for particularly effective removal of contaminants, but also that the cell disruption in the first dewatering stage can be adjusted such that the biomass's pliability is within a particularly favorable range for efficient operation of a second mechanical dewatering stage.

[0071] According to an exemplary embodiment, the system is designed to produce more than 50 kg / h of fuel from pressed biomass, in particular more than 150 kg / h, and preferably more than 500 kg / h. It has been shown that the system according to the invention is particularly advantageous in industrial production with higher material throughput, because, especially with high material throughput, individual dry pockets of a larger biomass volume require longer processing times in subsystems. This is because, for pollutant removal, the focus must be on the areas with the highest levels of contaminants. Thus, it has been shown that the system according to the invention is particularly suitable for producing more than 50 kg / h, in particular more than 150 kg / h, and preferably more than 500 kg / h of fuel from pressed biomass.In addition, it has been shown that the moisture management system according to the invention achieves a particularly high level of resource optimization, especially in larger systems.

[0072] According to an exemplary embodiment, the device for increasing the moisture content of the biomass is arranged at the storage unit, the feeding device, the washing unit, and / or the shredding unit, and / or integrated into one or more of the aforementioned components. In particular, it can be advantageous to have several devices for increasing the moisture content of the biomass at different positions within the system, because this allows for optimization of both the quantity of liquid supplied and the contact time.

[0073] According to an exemplary embodiment, the system is designed such that press water from the mechanical dewatering device is routed to the device for increasing the moisture content of the biomass. In the case of multiple mechanical dewatering devices, the system is preferably designed such that press water from the first mechanical dewatering device is routed to the device for increasing the moisture content of the biomass, and in particular, more press water from the first mechanical dewatering device than from the second mechanical dewatering device is routed to the device for increasing the moisture content of the biomass. As noted above, press water (i.e., liquid recovered during mechanical dewatering) can be used for increasing the moisture content of the biomass.It has been found that press water from the first mechanical drainage device is better suited for increasing the moisture content than press water from the second mechanical drainage device. Without wishing to be bound to any specific theory, the inventors currently assume that the press water from the first mechanical drainage device is less viscous and has a lower total solids content (TS) due to the reduced cell disruption compared to the press water from the second mechanical drainage device.

[0074] According to an exemplary embodiment, the system further comprises a waterjet cutter, in particular a water cutter. By using a waterjet cutter instead of a conventional mechanical cutting system, at least a small amount of moistening and thus an increase in the moisture content of the biomass occurs. The proportion of fresh water used for the waterjet cutting system can be higher than for the other moisture supply methods according to the invention. The fresh water supply can primarily be used for the high-pressure cutting system (waterjet cutter) (because this water is very clean, there is less wear on pumps / nozzles and less clogging of filters) – in return, a higher proportion of recycled water can then be used for the general increase in the moisture content of the biomass. According to an exemplary embodiment, the system further comprises a moisture determination unit configured to determine the moisture content of the biomass.The moisture determination unit can be configured, in particular, to determine the moisture content of the biomass while it is still in a storage unit, for example, wrapped in a foil.

[0075] According to an exemplary embodiment, the system further comprises a sensor configured to control, in particular to control automatically, preferably to regulate automatically, the moisture supply based on sensor information.

[0076] According to one exemplary embodiment, the system is housed in several individual containments. These containments can be compatible with transport systems and / or offer at least one of the following additional benefits: sound insulation, energy optimization, odor reduction, simplified installation, optimized logistics, and / or simplified transport. The containments can be designed for relatively easy relocation to another site. A typical implementation involves installation in sea freight containers or using containments of compatible dimensions, allowing the individual modules to be easily transported and deployed by truck. These containments can provide additional benefits: 1) Certain areas can be additionally soundproofed. In particular, extensive containment of the functional system components inherently provides sound insulation. 2) The same applies to potential odor emissions.Targeted airflow within the enclosure (possibly with activated carbon filters) reduces potential odor emissions. 3) The enclosure also allows for the collection of waste heat and its targeted use for heat recovery or reuse. 4) Pre-assembly and adjustment of the subsystem components within the enclosure simplifies installation. The components can be pre-leveled on a support frame, so that only the entire frame needs to be leveled during installation, and the subcomponents are automatically aligned. 5) Housing the components in individual subsystems facilitates replacement in case of malfunctions, as a replacement container, for example, only needs to be delivered and connected from a central location, eliminating the need for specialists, especially in remote areas.

[0077] According to an exemplary embodiment, the mechanical dewatering device is a multi-stage dewatering device or comprises several dewatering devices. In particular, the different dewatering devices can be configured such that different shear forces act on the biomass. The different dewatering devices can also be configured such that the wastewater compositions differ from one another. In a multi-stage dewatering process with different dewatering systems designed to exert different shear forces on the biomass, different degrees of cell disruption of the biomass can be achieved, resulting, for example, in wastewater from the two dewatering systems exhibiting different protein concentrations and levels of contaminants.

[0078] According to an exemplary embodiment, the system further comprises a heat recovery device. The heat recovery device can be configured, in particular, to warm the biomass and / or process water. Preferably, the heat recovery device is configured to support the drying and / or dewatering process. For example, the heat recovery device can be configured to conserve the energy introduced by dewatering in the biomass (storage and / or transport for drying is usually thermally insulated), thus providing preheated biomass for drying that no longer needs to be heated to this preheating temperature. Numerous other heat recovery options within the system are possible.For example, the heat from the wastewater heated by the pressing energy can be recovered from the dewatering process.

[0079] According to one exemplary embodiment, the storage unit is configured to store biomass, at least partially, under mechanical pressure for at least one day. This can increase the homogeneity of the biomass used, particularly with regard to moisture distribution and / or the degree of microbial decomposition.

[0080] According to an exemplary embodiment, the system further comprises a data processing unit configured to store data on the moisture content of the biomass. This data can then be used as a data history to determine the amount of moisture to be added. Since certain properties of the pellets can only be determined by measurement after their production, the stored data, in the form of a data history, allows for the determination of the optimal amount of moisture to be added to future biomass with similar properties.

[0081] In a third aspect, the present invention relates to a computer-readable medium on which a computer program is stored, wherein the computer program is configured such that, when executed on a processor, it controls and / or regulates a method and / or a system for producing fuel from pressed biomass according to the first or second aspect.

[0082] In a fourth aspect, the present invention relates to a program element configured such that, when executed on a processor, it controls and / or regulates a method and / or a system for producing fuel from compressed biomass according to the first and / or second aspects. DETAILED DESCRIPTION OF THE FIGURE

[0083] Figure 1 is a schematic representation of a system 100 for producing fuel from pressed biomass according to an exemplary embodiment.

[0084] System 100 for producing fuel from pressed biomass comprises a storage unit 160, a feeding device 170, a washing unit 110, a comminution unit 120, which may in particular be a fine comminution unit, one or more mechanical dewatering units 130, a drying unit 140 and a shaping unit 150. These components may, in principle, be those described in the literature mentioned above.

[0085] System 100 for producing fuel from pressed biomass further comprises a device for increasing the moisture content 166 of the biomass, which is configured (and arranged) to increase the moisture content of the biomass before the biomass is fed to the mechanical dewatering device. Furthermore, the device for increasing the moisture content 166, or System 100, is configured such that a period of time (residue time, dwell time) is allowed between increasing the moisture content and mechanical dewatering.For example, in addition to the device for increasing the moisture content 166 of the biomass, another component of the system 100, in particular the storage unit 160, the feeding device 170, the washing unit 110, the shredding unit 120, the mechanical dewatering unit 130, and / or an additional component, can be configured such that a residence time and / or process time for the biomass is provided after its moisture content has been increased. The device for increasing the moisture content 166 of the biomass can, in particular, be arranged at the storage unit 160, at the feeding device 170, at the washing unit 110, and / or at the shredding unit 120 (as schematically indicated by the various lines emanating from the device for increasing the moisture content 166 in Figure 1) and / or be integrated into one or more of the aforementioned components.There may also be several devices for increasing the moisture content of the biomass at different locations within the system.

[0086] The system 100 shown in Figure 1 for producing fuel from compressed biomass further comprises an optional moisture determination unit 164, configured to determine the moisture content of the (stored) biomass. Finally, the system 100 shown in Figure 1 for producing fuel from compressed biomass further comprises an optional data processing unit 180, configured to store data on the moisture content of the biomass, which it receives in particular from the moisture determination unit 164, and an optional heat recovery device 190, configured in particular to heat the biomass and / or process water and preferably to support the drying and / or dewatering process.

[0087] The present invention has been described with reference to specific embodiments and examples. However, the invention is not limited to these, and various modifications are possible without departing from the scope of the present invention. List of reference symbols

[0088] 100 Systems for producing fuel from pressed biomass

[0089] 110 Washing unit 120 Shredding unit

[0090] 130 mechanical drainage equipment

[0091] 140 drying equipment

[0092] 150 shaping equipment

[0093] 160 Storage unit 164 Moisture determination unit

[0094] 166 Device for increasing humidity

[0095] 170 Feed device

[0096] 180 data processing systems

[0097] 190 Heat recovery device

Claims

REQUIREMENTS 1. A process for producing fuel from compressed biomass, the process comprising: Providing biomass; Supply of biomass; Washing of the biomass; Shredding, especially fine shredding, of biomass; Mechanical dewatering of the biomass; Drying of the biomass; Shaping of the biomass, characterized in that the process further comprises increasing the moisture content of the biomass prior to mechanical dewatering and a time interval is allowed between increasing the moisture content and mechanical dewatering.

2. The method of claim 1, wherein at least a part of the biomass is selected from the group consisting of water hyacinths, seagrass, algae, grass clippings, leaves, green waste and combinations thereof.

3. Method according to one of the preceding claims, wherein the provision of biomass comprises storing the biomass, wherein the storage of the biomass, in particular an open biomass, at a moisture content of over 50%, in particular over 55%, preferably over 60%, is carried out for less than 2 months, in particular less than 4 weeks, preferably less than 1 week.

4. A method according to any of the preceding claims, wherein the increase in humidity is effected by one of the following measures: supply of fresh water, supply of steam, storage in humid air, Process fluid supply, mixing with biomass of higher moisture content, soaking in water or combinations thereof.

5. Method according to one of the preceding claims, wherein the moisture content of the biomass before mechanical dewatering, in particular in the case of multiple mechanical dewatering before the first mechanical dewatering, is more than 55%, in particular more than 63%, preferably more than 70%.

6. Method according to one of the preceding claims, wherein the increase in moisture is carried out during the provision of the biomass, during the feeding of the biomass, during the washing of the biomass, before, during and / or after the comminution of the biomass, in particular wherein an increase in moisture is carried out in several process steps.

7. A method according to any of the preceding claims, wherein the method further comprises mixing several biomasses with different moisture contents and / or wherein the moisture content of the biomass is increased during storage and / or feeding.

8. Method according to one of the preceding claims, wherein, prior to increasing the moisture, the biomass has a moisture content of less than 65%, in particular less than 53%, in particular less than 40%.

9. Method according to one of the preceding claims, wherein the time interval between increasing the humidity and mechanical dewatering is at least 30 seconds, in particular at least 40 seconds.

10. Method according to one of the preceding claims, wherein for increasing the moisture content of the biomass press water obtained during the mechanical dewatering is produced, and in particular in the case of multiple mechanical dewatering, press water produced during the first mechanical dewatering is used, preferably more press water produced during the first mechanical dewatering than press water produced during the second mechanical dewatering.

11. Method according to one of the preceding claims, wherein the biomass is subjected to frictional movements and / or shear forces prior to mechanical dewatering, in particular wherein the frictional movements and / or shear forces are adapted such that hydrophobic surface properties of the biomass are reduced at least partially and / or in partial areas.

12. Method according to one of the preceding claims, wherein drying of the biomass is reduced, in particular by coating the biomass.

13. Method according to one of the preceding claims, wherein the method further comprises increasing the temperature of the biomass prior to mechanical dewatering, in particular wherein the energy for the temperature increase is derived from one of the following sources: waste heat from thermal drying, from mechanical dewatering, local and / or external waste heat, from a high-pressure water cutter, from a biogas plant and / or from a solar thermal plant.

14. Method according to any of the preceding claims, wherein the provision of the biomass comprises determining the moisture content of the biomass.

15. Method according to one of the preceding claims, wherein the increase in humidity is controlled based on sensor information, in particular automatically controlled, preferably automatically regulated.

16. Method according to claim 14 or 15, wherein further properties of the biomass are detected by sensors, in particular processed and / or stored, wherein the sensor values ​​preferably contribute to process optimization.

17. Method according to one of the preceding claims, wherein data, in particular measured values ​​which provide an indication of the contaminant composition of a biomass, contribute to determining the degree of moisture increase, in particular at least partially control the amount of moisture, preferably taken into account in the moisture control.

18. Method according to any one of claims 14 to 17, wherein the determination of moisture and / or its improvement in accuracy is based on one of the following measures: measurement of humidity in close proximity to the biomass, measurement of the conductivity of the biomass, attenuation of an electric field, measurement of capacitance, determination of density, change in weight, change in density, manual sampling and combinations thereof.

19. Method according to any one of claims 14 to 18, wherein the method further comprises storing data on the moisture content of the biomass, in particular in an electronic data processing system (180), preferably wherein this data is used as a data history for determining the moisture to be supplied.

20. A method according to any of the preceding claims, wherein the mechanical dewatering of the biomass is carried out in multiple stages, in particular wherein the shear forces acting on the biomass of the different mechanical dewatering devices (130) differ from one another, preferably wherein the wastewater compositions of the different mechanical drainage devices (130) differ from one another.

21. Method according to one of the preceding claims, wherein the biomass was stored at least partially under mechanical pressure for at least one day.

22. System (100) for producing fuel from pressed biomass, wherein the system (100) comprises: a storage unit (160); a feeding device (170); a washing unit (110); a comminution device (120), in particular a fine comminution device; a mechanical dewatering device (130); a drying device (140); a shaping device (150), characterized in that the system (100) further comprises a device for increasing the moisture (166) of the biomass, wherein the device is configured to increase the moisture of the biomass before the biomass is fed to the mechanical dewatering device (130), and a time interval is allowed between increasing the moisture and mechanical dewatering.

23. System (100) according to claim 22, wherein at least one component of the system, in particular the storage unit (160), the feeding device (170), the washing unit (110), the comminution device (120), the mechanical dewatering device (130) and / or an additional component, is arranged such that a residence time and / or process time for the biomass is provided after its moisture increase.

24. System (100) according to claim 22 or 23, wherein the mechanical drainage device (130) comprises a multi-stage drainage device (130) or several drainage devices (130).

25. System (100) according to one of claims 22 to 24, wherein the system (100) is designed to have a production quantity of fuel from pressed biomass of more than 50 kg / h, in particular more than 150 kg / h, preferably more than 500 kg / h.

26. System (100) according to one of claims 22 to 25, wherein the device for increasing the moisture (166) of the biomass is arranged at the storage unit (160), at the feeding device (170), at the washing unit (110) and / or at the comminution device (120) and / or is integrated into one or more of the aforementioned components, in particular wherein there are several devices for increasing the moisture (166) of the biomass at different positions of the system (100).

27. System (100) according to one of claims 22 to 26, wherein the system (100) is designed such that press water from the mechanical dewatering device (130) is directed to the device for increasing the moisture content (166) of the biomass, in particular in the case of several mechanical dewatering devices (130) press water from the first mechanical dewatering device (130) is directed to the device for increasing the moisture content of the biomass, preferably more press water from the first mechanical dewatering device (130) than from the second mechanical dewatering device (130) is directed to the device for increasing the moisture content (166) of the biomass.

28. System (100) according to any one of claims 22 to 27, wherein the system (100) further comprises a water cutter, in particular a water jet cutter.

29. System (100) according to any one of claims 22 to 28, wherein the system (100) further comprises a moisture determination unit (164) configured to determine the moisture content of the biomass.

30. System (100) according to any one of claims 22 to 29, wherein the system (100) further comprises a sensor configured to control, in particular to control automatically, preferably to regulate automatically, the moisture supply based on sensor information.

31. System (100) according to any one of claims 22 to 30, wherein the system (100) is housed in several individual enclosures, in particular wherein these are compatible with transport systems and / or provide at least one of the following additional benefits: sound insulation, energy optimization, odor reduction, installation simplification, logistics optimization and / or transport simplification.

32. System (100) according to one of claims 22 to 31, wherein the mechanical drainage device (130) is a multi-stage drainage device (130) or comprises several drainage devices (130), in particular wherein the shear forces acting on the biomass of the different drainage device stages or of the different drainage devices (130) differ from one another, preferably that the wastewater compositions of the different drainage device stages or of the different drainage devices (130) differ from one another.

33. System (100) according to one of claims 22 to 32, wherein the system (100) further comprises a heat recovery device (190), in particular wherein the heat recovery device (190) is configured to lead to the heating of the biomass and / or process water, wherein the heat recovery device (190) preferably designed to support the drying and / or dewatering process.

34. System (100) according to any one of claims 22 to 33, wherein the storage unit (160) is configured to store biomass at least partially under mechanical pressure for at least one day.

35. System (100) according to any one of claims 22 to 34, wherein the system (100) further comprises a data processing system (180) configured to store data on the moisture content of the biomass, in particular using this data as a data history to determine the moisture to be supplied.

36. Computer-readable medium on which a computer program is stored, wherein the computer program is configured such that, when executed on a processor, it controls and / or regulates a method according to any one of claims 1 to 21 and / or a system (100) according to any one of claims 22 to 35.

37. Program element which, when executed on a processor, controls and / or regulates a method according to any one of claims 1 to 21 and / or a system (100) according to any one of claims 22 to 35.

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