Method for processing biomass materials

Abstract

1. A method for processing biomass material, the biomass material being provided in the form of a mixture comprising the biomass material and a medium comprising a nitrogen compound, the method comprising the steps of: - feeding the mixture into a container of an apparatus, the apparatus comprising a means for heating an inner surface of the container and a plurality of blades arranged to rotate within the container; - treating the mixture with the plurality of blades such that the mixture is subjected to shear and causes the mixture to form a continuously regenerated evaporation surface between the mixture and a gas phase; - causing the nitrogen compound to form a gaseous form and pass the gaseous form through the evaporation surface into the gas phase; - removing the gas phase comprising the nitrogen compound in gaseous form from the container; and - collecting the remaining biomass material.

Description

[Technical field]

[0001] The present invention relates to a method for processing biomass material, wherein the biomass material is provided in a mixture comprising the biomass material and a medium comprising a nitrogenous compound. [Background technology]

[0002] Biomass processing is an important aspect in the production of, for example, biofuels, bioplatform chemicals, biopolymers, biopharmaceuticals, biomaterials, and any other type of bioproduct from sustainable feedstocks.

[0003] Biomass is macroscopically and chemically heterogeneous, i.e., it typically contains various components that differ in their chemical nature and their physical properties. For example, the highly abundant lignocellulosic biomass contains the biopolymers cellulose, hemicellulose, and lignin. The process of separating the components of biomass and obtaining various valuable compounds includes steps such as thermochemical (pre)treatment (pulping using temperature and non-neutral pH conditions) and biochemical conversion (i.e., enzymatic treatment and fermentation for hydrolysis of the components).

[0004] These steps can be carried out either in aqueous or non-aqueous solvent systems. Besides water, other liquid (pre)treatment media with acidic or preferably alkaline properties have been found to be particularly suitable for deconstructing and decomposing the structure of biomass mixtures.

[0005] Nitrogen compounds have been described as suitable (pre)treatment agents. For example, in the context of the pretreatment of lignocellulosic biomass for the solubilization of cellulosic materials, especially delignification, butylamine has been disclosed for pretreatment (Tanaka, M., Robinson, CW & Moo-Young, M. Biotechnol Lett 5, 597-600 (1983). https: / / doi.org / 10.1007 / BF00130839). More recently, a class of alkanolamines has been disclosed as effective pretreatment solvents for biomass deconstruction and bioenergy production (Achinivu, EC, Frank, S., Baral, NR et al. Green Chem 3, 8611 (2021). DOI: 10.1039 / d1gc02667d).

[0006] Organic nitrogen compounds also include a subclass of ionic liquids with cations bearing nitrogen atoms. In these compounds, the nitrogen formally carries the positive charge of the cation. Ionic liquids (ILs) are described as a series of compounds that are particularly efficient for the depolymerization and deconstruction of various feedstocks for biofuel production (Keasling, J., Garcia Martin, H., Lee, TS et al. Nat Rev Microbiol 19, 701-715 (2021). DOI: 10.1038 / s41579-021-00577-w). More specifically, protic ILs, i.e. compounds with protonated cations, are described as beneficial pretreatment agents for lignocellulosic materials in WO 2013 / 192572 A1 and WO 2021 / 168154 A1.

[0007] In general, ILs are a class of compounds that include organic salts or salt mixtures consisting of organic cations and organic or inorganic anions with melting points below 100° C. - recognized literature (e.g. Wasserscheid, Peter; Welton, Tom (Eds.); “Ionic Liquids in Synthesis, 2 ndEdition,” Wiley-VCH 2008; ISBN 978-3-527-31239-9; Rogers, Robin D.; Seddon, Kenneth R. (Eds.); “Ionic Liquids - Industrial Applications to Green Chemistry,” ACS Symposium Series 818, 2002; ISBN 0841237891). The melting point limit of 100°C is arbitrary and in a broader sense this definition may also include salt melts with melting points above 100°C but below 200°C. Additional inorganic salts may be dissolved in these salts as well as molecular adjuvants. Ionic liquids generally have very interesting properties such as very low vapor pressure, very wide liquidus range, good electrical conductivity and rare solvation properties. When using ionic liquids, optimizing the properties for the respective application within wide limits can be achieved by varying the anion and cation structures or their combination, which provides two more degrees of freedom compared to classical molecular structures, for this reason ionic liquids are also called "designer solvents" (see, for example, Freemantle, M.; Chem. Eng. News, 78, 37 (2000)).

[0008] Due to their low vapor pressure, recovery of ILs can be difficult. Recovery and purification from solution has been reviewed (Jingjing Zhou, Hong Sui, Zhidan Jia, Ziqi Yang, Lin He and Xingang Li, RSC Adv., 8, 32832-32864 (2018)). It has been proposed to remove ILs from pretreated biomass or fermentation products by washing (Neupane, B., Konda, NVSNM, Singh, S., Simmons, BA, Scown, CD ACS Sustainable Chem. Eng. 5 (11), 10176-10185 (2017) DOI: 10.1021 / acssuschemeng.7b02116; WO 2013 / 192572 A1). This obviously has the drawback of using large amounts of wash water, which then requires an energy-intensive separation of the wash water from the ionic liquid in solution to obtain economically feasible recoveries, e.g., greater than 99% and approaching 100%.

[0009] Thus, distillable ionic liquids have recently attracted attention to achieve at least partial separation of ionic solvents from biomass. The use of volatile salts for biomass pretreatment was disclosed in WO 2021 / 168154 A1. Therein, it was confirmed that hydroxyethylammonium acetate, an example of a protic ionic liquid or acid-base conjugate salt, is suitable for biomass pretreatment and is recovered at a rate of about 85-95% after biomass pretreatment with 15% biomass loading using vacuum distillation. Exemplarily, the distillation setup disclosed in WO 2021 / 168154 A1 includes a Kugelrohr apparatus (Figure 1 therein) and vacuum distillation from a double-walled mixed reactor (Figures 2 and 3 therein).

[0010] However, higher recovery rates are needed to obtain economic viability from the recovery of expensive nitrogen compounds such as ionic liquids as well as the remaining biomass in a pure form. Summary of the Invention [Problem to be solved by the invention]

[0011] It is therefore an object of the present invention to provide a method for processing a mixture containing a biomass material and a (pre)treatment medium comprising nitrogen compounds, such that ionic liquid is removed from the biomass material. [Means for solving the problem]

[0012] The present invention relates to a method for processing a biomass material, the biomass material being provided in the form of a mixture comprising the biomass material and a medium comprising a nitrogen compound, the method comprising: - feeding the mixture into a vessel of an apparatus, the apparatus including a means for heating an inner surface of the vessel and a plurality of blades arranged to rotate within the vessel; - treating the mixture with a plurality of blades such that the mixture is subjected to shear and causes the mixture to form a continuously regenerating evaporation surface between the mixture and a gas phase; - forming the nitrogen compound in gaseous form and transferring the gaseous form to the gas phase by passing the evaporation surface; - removing the gas phase comprising the nitrogen compounds in gaseous form from the vessel; and - collecting the remaining biomass material; The present invention solves the problem by providing a method, comprising: [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a graph showing the recovery of the ionic liquid ethanolammonium acetate over time from a pretreated mixture further comprising biomass material derived from Sorghum bicolor from a static film of biomass having a thickness of about 1 mm (squares) compared to the recovery using a conventional rotary evaporator at a temperature of 140° C. and a pressure of 1 mbar (triangles). [Diagram 2]FIG. 2 is a graph showing the recovery of the neutral nitrogen compound butylamine over time from a pretreated mixture further comprising the biomass material spelt husk by using a conventional rotary evaporator (triangles) and a laboratory model of a large capacity processor (squares) at a temperature of 80° C. and a pressure of 40 mbar. [Figure 3A] FIG. 3A is a graph showing the recovery of the ionic liquid triethylammonium formate over time from a pretreated mixture further comprising the biomass material spelt husk by using a conventional rotary evaporator (triangles) and a laboratory model of a large capacity processor (squares) at a temperature of 120° C. and a pressure of 40 mbar. [Figure 3B] FIG. 3B is a graph showing the recovery of the ionic liquid pyridinium formate over time from a pretreated mixture further comprising the biomass material spruce sawdust by using a conventional rotary evaporator (triangles) and a laboratory model of a large capacity processor (squares) at a temperature of 100° C. and a pressure of 100 mbar. [Figure 4] FIG. 4 is a schematic diagram of a thin film processor. [Diagram 5] FIG. 5 is a schematic diagram of a high capacity processor. [Figure 6] FIG. 6 is a graph showing the relationship of the overboiling point (ΔTb) to the difference in aqueous pKa values ​​(ΔpKa) for base B and acid HA forming their respective acid-base conjugated ionic liquids, where ΔTb is determined as the difference between the pseudo-boiling point and the arithmetic mean of the boiling points of the pure acid and the pure base. [Figure 7] FIG. 7 is a schematic diagram of the setup for the study used to investigate the static evaporative surface from the top (left) and side (right). [Figure 8] FIG. 8 is a diagram of a process for producing biofuel (ethanol) from a mixture containing biomass material and nitrogenous compounds, such as ionic liquids, according to the state of the art. [Figure 9]FIG. 9 is a process chart for producing biofuel (ethanol) from a mixture containing biomass material and a nitrogenous compound, such as an ionic liquid, using a method according to the present invention for separating and recovering the nitrogenous compounds. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The method allows the efficient removal of nitrogen compounds, preferably the total medium, from a mixture containing biomass material. More specifically, said medium can be called a treatment and / or pretreatment medium, i.e. a (pre)treatment medium. The mechanical treatment in the device is essential to repeatedly regenerate the surface of the mixture, thus allowing the efficient and rapid removal of the nitrogen compounds in gaseous form. The gaseous form of the nitrogen compounds arises from the interface between the mixture and the gas phase and passes through this interface / surface, called the evaporation surface. The method thus allows the separation of the biomass material in the form of the remaining biomass material, typically in solid state, from the nitrogen compounds, preferably the total liquid medium.

[0015] Separation of the biomass and the nitrogen compounds occurs in that the nitrogen compounds are removed in gaseous form while the biomass remains in a solid or liquid state. Thus, the method does not include or rely on a washing step, and the nitrogen compounds are not separated in the liquid phase by a washing or coagulating solvent such as water.

[0016] The gaseous form of the nitrogen compound can be obtained by evaporation or decomposition of the nitrogen compound. If the nitrogen compound is distillable, it can be recovered after evaporation to the gas phase and removal from the container, but if not, the nitrogen compound may be destroyed when converted to gaseous form.

[0017] In one embodiment, the nitrogen compounds are distillable and evaporated, and the method further comprises the step of condensing the nitrogen compounds from the gas phase removed from the vessel. Thus, in this embodiment, at least a portion of the medium is recovered, and the method of the present invention is directed to recovery into the medium. Preferably, the entire medium is distillable and recovered.

[0018] During the removal of the nitrogen compounds, the composition of the mixture changes and the biomass content increases. The biomass content in the mixture affects the rheological properties. The resulting changes in rheological properties, as well as potential phase transitions from a liquid, slurry, pulp or pasty state to a solid state, complicate the processing of the mixture. In the method according to the invention, the mixture is treated to spread, for example in a film (or thin layer), forming an evaporation surface. The important role of the evaporation surface was first investigated using a static set-up (Example 1 and Figure 1). Furthermore, the inventors found that a (mechanical) treatment with multiple blades makes it possible to efficiently remove the medium from larger volumes of the mixture, overcoming the challenges described before. The treatment step involving shearing (mechanical processing) allows the mixture to form a continuously regenerated evaporation surface to separate the nitrogen compounds from the biomass. A comparison with a classical rotary evaporator showed the importance of the mechanical treatment with multiple blades to form a continuously regenerated evaporation surface between the mixture and the gas phase (Example 2, and Figures 2 and 3). Furthermore, the examples have shown that recoveries of more than 98% by weight, preferably more than 99% by weight, of the nitrogen compounds initially used can be reached within reasonable processing times.

[0019] The biomass mixture typically has a high initial viscosity and thickens further as the medium is continuously removed, thus becoming increasingly resistant to deformation before finally undergoing a phase transition from a liquid starting material to a paste and solid state. Furthermore, the biomass mixture may develop a crust at the surface by sticking, gumming and sticking, which may prevent or even make it impossible for the nitrogen compounds to form gaseous form and migrate through the evaporation surface into the gas phase. The preferred configuration of the device, in particular the multiple blades and the vessel, ensures forced circulation of the load in the vessel and the formation of a continuously renewed evaporation surface between the load, in particular the mixture, and the gas phase, and also continuously removes, crushes or breaks such crusts.

[0020] Suitable types of equipment for carrying out the method according to the invention may differ from each other, for example, in terms of the volume of the vessel, its orientation (horizontal or vertical), the shape of the blades and their (rotational / circumferential) speed, in terms of the setup (and the time during which the mixture is treated) configured for batchwise or continuous processing. On the other hand, suitable equipment share common components required for operating the method according to the invention. These are in particular a vessel having a plurality of blades configured to subject the load of the vessel to shear and to repeatedly form on the load a continuously regenerated evaporation surface between the mixture and the gas phase, and an inner surface, which may be heated.

[0021] In the following, exemplary and preferred configurations of the device, in particular the plurality of blades and the vessel, are described.

[0022] The term blades is understood to refer to a collection of mechanical attachments in the device that are configured to rotate in the vessel. The term blades should not be limited with respect to the geometric form of these attachments, and includes various shapes such as, for example, agitator paddles, kneading elements, screw segments, cutting blades, disks, or rotating knives.

[0023] As the blades subject the mixture to shear, the crust breaks up and a new evaporation surface is created. Depending on the blade and container geometry, the evaporation surface forms a film on the interior surface of the container, but also along any other interface between the mixture and the gas phase within the container. The term evaporation surface is used in a broad sense to include any interface between the mixture and the gas phase, for example, formed by a film, droplet, or string of the mixture that is spread in the container and that falls freely or shoots through the gas phase of the container.

[0024] In one embodiment, the step of treating the mixture with a plurality of blades comprises repeatedly spreading the mixture into a film, in particular a film on the inner surface of the container. The term film should be understood to refer to a (thin) layer of the mixture, which thus provides a large evaporation surface.

[0025] Preferably, the plurality of blades are attached to one or more rotor elements. Thus, in a preferred embodiment, the rotating plurality of blades defines at least one axis of rotation.

[0026] A suitable device preferably has a specific arrangement of the blades with respect to the vessel to force a continuous regeneration of the evaporation surface during the treatment of the load. The blades rotating in the vessel define a three-dimensional outer geometric form that can be referred to as a corresponding body of revolution. Preferably, the inner surface of the vessel corresponds to a plane of revolution, which plane of revolution relates to the body of revolution defined by the rotating blades.

[0027] In an apparatus with this configuration of blades and containers, the movement of the blades ensures that the entire load is mixed and spread continuously, i.e., participates in the complete circulation of the load. This limits the formation of dead rooms and pools where material may escape the evaporation surface. When using two or more rotating shafts, the blades of one rotating shaft can be arranged to pass close to the blades and rotor elements of another rotating shaft. Such an arrangement is called self-cleaning and further contributes to the complete circulation of the load, especially the mixture.

[0028] Furthermore, the blades can spread the load, in particular the mixture, in the form of a thin film on the inner surface of the vessel. For this purpose, the rotating blades preferably have a small radial clearance (distance) to the inner surface of the vessel. This distance can vary along the height of the vessel.

[0029] In a preferred embodiment, the rotating blades have a radial clearance to the inner surface of the vessel in the range of 0.1-50 mm, preferably 0.5-20 mm, for example 0.5-5 mm or 1-10 mm.

[0030] In a preferred embodiment, the vessel essentially has the geometric form of a right cylinder. Preferably, the blades of each axis of rotation extend to a uniform maximum radial extension (coaxial length), and the rotating rotor of the blades also has the geometric form of a right cylinder. When the blades define one axis of rotation, the vessel is preferably a cylinder with a circular bottom area. When the blades define more axes of rotation, the bottom area of ​​the cylinder preferably has the shape of overlapping circles.

[0031] Thus, in a preferred embodiment, the container essentially has the geometry of a right cylinder with a bottom region having the shape of either a circle or overlapping circles.

[0032] The cylindrical vessel further has a height, which may be defined relative to its bottom region. Preferably, the height of the cylindrical vessel corresponds to the length of at least one axis of rotation of the blades. The vessel, essentially having the form of a cylinder, may be oriented horizontally or vertically, depending on the orientation of the at least one axis of rotation.

[0033] In a preferred embodiment, the height of the cylindrical vessel (and the length of at least one of the rotation axes of the blades) is greater than the diameter of the bottom region, which is the diameter of one of the circular bottoms or the maximum diameter of the overlapping circles of the bottom region. In this embodiment, the vessel provides a large internal surface, which advantageously allows efficient transfer of heat to the load in the vessel, in particular the mixture. The transfer of heat, and thus the conversion of the nitrogen compounds to gaseous form, can be further enhanced by additional heated elements. For example, besides the means for heating the internal surface of the vessel, the device may further comprise means for heating the blades or part of the rotor elements.

[0034] Furthermore, it is preferred that a large evaporation surface is formed when processing a load, especially a mixture. In a preferred embodiment, the blades and the vessel are configured to allow the formation of a continuous gas phase, i.e. they produce a single gas space of a certain volume. The configuration of the blades affects the expansion and volume of the gas phase. In particular, a staggered arrangement of the blades, i.e. an arrangement shifted along the rotation axis, and open blades, for example open, for example Z-shaped kneader blades, are preferred over large screw segments that would separate the gas phase when the load, especially the mixture, is filled into the vessel.

[0035] In a preferred embodiment, the blades are configured to transport the load, in particular the mixture, along at least one axis of rotation. Thus, the load, in particular the mixture, not only circulates around the axis of rotation, but also moves in a further direction, for example along the height of the cylindrical vessel or along at least one axis of rotation. The material transport along the axis of rotation further contributes to ensure complete circulation and efficient mixing of the load, in particular the mixture.

[0036] Furthermore, the mass transport can contribute to the continuous or semi-continuous operation of the device. The mass transport, preferably coaxial with the rotating shaft, can contribute to the feeding or discharging of the vessel, i.e. also affecting the feeding of the mixture to the vessel and the collection of the remaining biomass material. When using more rotating shafts, the shafts rotating in the opposite direction can nullify the net mass transport. Therefore, these embodiments are typically operated in batch mode.

[0037] Apparatus suitable for the method according to the invention has been used previously in other technical fields: suitable apparatus are used, for example, in polymer processing technology, for example for the devolatilization of plastic polymers, i.e. for the separation of fluids (gases or solvents) from highly viscous polymers (melts).

[0038] In a preferred embodiment, the apparatus comprises: - a thin film processor, in which the rotating blades define an axis of rotation and the vessel is essentially a cylinder having a vertical orientation; and - A processor, in particular a large capacity processor, in which the rotating blades define one or two axes of rotation and the vessel is essentially a cylinder having a horizontal orientation. is selected from the group consisting of:

[0039] Suitable thin film processors, in which the rotating blades define one axis of rotation and the vessel is essentially a cylinder with a vertical orientation, are for example the Filmtruder® or Viscon® processors manufactured and offered by Buss-SMS-Canzler GmbH (Butzbach, Germany) or the Viscofilm® processor offered by GIG Karasek GmbH (Gloggnitz-Stuppach, Austria). A scheme of a thin film process with a vertically oriented cylindrical vessel and rotating blades is exemplarily shown in FIG. 4 and discussed in Example 3. These types of thin film processors are also used in the context of fiber technology, in particular for producing solutions of cellulose in aqueous tertiary amine oxides from a suspension of cellulose in an aqueous solution of the tertiary amine oxide (EP 0 356 419).

[0040] Suitable large-volume processors, in which a plurality of rotating blades defines one or two rotation axes and the vessel is essentially a cylinder with a horizontal orientation, are typically called reactors or kneaders, such as, for example, two-rotor degassing kneaders with open screw segments forming the rotating elements. Suitable large-volume processors are the ReaCom® and ReaSil® processors manufactured and provided by Buss-SMS-Canzler GmbH (Butzbach, Germany), or the "Large Volume Devolatilization Kneaders" with one or two rotation axes provided by LIST Technology AG (Arisdorf Switzerland). Exemplarily, a schematic of a large-volume processor, i.e. a cross-section through a horizontal vessel with a plurality of blades defining two rotation axes, is shown in FIG. 5 and discussed in Example 3.

[0041] Other commercially available processors with rotating blades and a vessel with (appreciable) means of heating the internal surface also include extruders, such as twin-screw extruders. Extruders are typically designed to work with high viscous loads, and although certain set-ups are equipped with means to remove the gas phase for devolatilization and degassing, they typically result in a smaller effective evaporation surface and are therefore less preferred for the process according to the invention. Furthermore, their screw-type blades may impede a large continuous gas phase.

[0042] In a suitable industrial device, multiple blades are configured to rotate and operate at high power to ensure mechanical processing. Industrial processors can typically be characterized by parameters selected from the group consisting of peripheral speed (i.e., the speed at maximum peripheral extension of the blades), inner surface (i.e., the surface of heat transfer) area, mean residence time (i.e., the time the mixture is processed in the vessel), evaporation surface regeneration rate, specific evaporation performance, specific product throughput, and specific driving force (i.e., the mechanical energy input to rotate the blades).

[0043] Industrial thin film processors typically: - peripheral speed in the range of 0.5-5 m / s, e.g. 1-2 m / s, - 12~40m 2 The area of ​​the inner surface of the - average residence time in the range of 2 to 15 minutes, e.g. 4 to 8 minutes, - 0.25~25s -1 , for example 2 to 10 s -1 Evaporation surface renewal speed in the range of - 10~250kg / h m 2 , e.g. 20-150kg / h m 2 Specific evaporation performance in the range of - 20~300kg / h m 2 , for example 40-150kg / h m 2 and / or - Specific driving power in the range of 0.01 to 0.20 kWh / kg, e.g. 0.05 to 0.12 kWh / kg It is characterized by:

[0044] Industrial processors with horizontal orientation of cylindrical vessels typically: - peripheral speed in the range of 0.2-2m / s, e.g. 0.5-1.2m / s, - Average residence time ranging from 8 to 200 minutes, - a specific driving power in the range of 0.01 to 0.20 kWh / kg, and / or - An internal space with a minimum volume of approximately 3 to 50,000 liters and a normal volume of approximately 1,000 to 20,000 liters (especially for large-capacity processors) It is characterized by:

[0045] In a preferred embodiment, during the step of treating the mixture, the plurality of blades rotate at a maximum peripheral speed in the range of 0.2-5 m / s, preferably 0.5-2 m / s, for example about 1 m / s.

[0046] In the step of removing the gas phase, the nitrogen compound in gas form is removed together with the gas phase. The movement of the gas phase defines a gas flow in the container, more particularly in the gas space of the container. In the embodiment called thin film processor, the gas flow is preferably coaxial with the mass transport along at least one rotation axis, and may be co-current or countercurrent.

[0047] The active extraction of the gas phase can be efficiently achieved by means of a vacuum, which also supports the conversion of the nitrogen compounds into gaseous form. Therefore, the vessel is preferably evacuable and the apparatus has an evacuation means.

[0048] Instead of or in addition to the gas flow applied by vacuum, the removal of the gas phase may also be achieved by an induced strip gas flow, i.e. by pumping a strip gas (carrier gas) externally through the vessel. Furthermore, volatile components of the medium may contribute to the gas flow and carry nitrogen compounds with them. However, these embodiments are less preferred, since further measures or components are required.

[0049] Thus, in one embodiment, the gas phase is removed using an exhaust and / or a induced strip gas stream, preferably a gas stream drawn off by an exhaust.

[0050] Preferably, the method according to the invention is carried out under evacuation, i.e. under reduced pressure in the vessel, below atmospheric pressure (i.e. below about 1,000 mbar or 1 atm). -2 The apparatus can operate at pressures down to 1000 psi (0.5 to 10 mbar). Pressures in the range of 0.5 to 10 mbar, for example 1 mbar, can be economically maintained in the vessel by convenient evacuation means such as liquid ring vacuum pumps, membrane vacuum pumps, screw vacuum pumps, roots vacuum pumps, and scroll vacuum pumps. Preferably, reduced pressure is applied during the steps of treating the mixture and removing the gas phase, which steps are typically performed essentially simultaneously.

[0051] Thus, in a preferred embodiment, the method comprises the steps of: -2 mbar~10 3 mbar range, preferably 10 -1 The pressure is preferably in the range of 0.5 to 10 mbar, for example 1 mbar.

[0052] In addition to the low pressure, the internal heating affects the conversion of the nitrogen compounds into gaseous form.

[0053] In a preferred embodiment, the inner surface is heated to a temperature in the range of 20°C to 200°C, preferably 50°C to 170°C, more preferably 80°C to 160°C, for example 100°C to 140°C.

[0054] The skilled artisan will select the temperature of the inner surface depending on the desired target temperature of the mixture, taking into consideration that the desired target temperature depends on the pressure applied and the properties of the compounds to be removed, which are discussed below. Additionally, the temperature sensitivity of the biomass material should be considered, and thus temperatures below 160° C. are more preferred for certain applications. For example, if the remaining biomass is to contain saccharides / sugars, they may decompose at higher temperatures.

[0055] In one embodiment of the invention, the mixture has an initial shear viscosity in the range of 10 to 50,000 Pa*s, typically 100 to 20,000 Pa*s, for example about 500 to 15,000 Pa*s, and the initial mixture shear viscosity is preferably less than 1 s -1 The viscosity is determined using an oscillatory rheometer having a two-plate geometry at a shear rate of about 100 MPa and a measurement temperature of about 25° C.

[0056] This advantage of the invention is particularly beneficial where the mixture is a heterogeneous mixture having difficult rheological properties such as high viscosity. Thin film processors described above are known to process loads having viscosities of up to 10,000 Pa*s or 15,000 Pa*s at processing conditions, and large volume processors are known to process loads having viscosities of up to 50,000 Pa*s at processing conditions.

[0057] The mixture of biomass material and medium, as it typically results from a biomass pretreatment step, is typically heterogeneous and may also be described as a slurry or suspension. In one embodiment, the biomass material is a heterogeneous shaped or fibrous material present as a dispersed phase in the mixture. The mixture may exhibit elements of a fluid and / or solid-like rheological behavior.

[0058] Illustratively, mixtures having 3% to 60% by weight of switchgrass biomass material pretreated with the ionic liquid 1-ethyl-3-methylimidazolium acetate have been described as having apparent dynamic, or shear, viscosities in the range of about 10 to 1,000 Pa*s at a shear rate of 1 / s and 25°C using a two-plate rheometer in which the sample was sandwiched between 25 mm sawtooth plates (Cruz, AG, Scullin, C., Mu, C. et al. Biotechnol Biofuels 6, 52 (2013) https: / / doi.org / 10.1186 / 1754-6834-6-52). The mixtures exhibited strong shear thinning, and this effect was greater for higher biomass contents. Illustratively, for a biomass loading of 50% by weight, the complex viscosity of these pretreated slurries showed a significant decrease of about 130 times when the frequency was increased by 100 times. Although the apparent viscosity decreases with increasing shear rate for shear-thinning mixtures, the viscosity of the mixture typically increases as liquid medium is continuously removed during the process. In addition, factors such as measurement temperature affect the rheological properties. Therefore, due to their non-Newtonian behavior and the multifactorial dependence of shear viscosity, individual shear viscosity values ​​cannot comprehensively characterize the rheology of the mixture. Therefore, the initial shear viscosity defined above may not be adequate to fully describe the rheological behavior within the process according to the present invention.

[0059] As mentioned above, the initial shear viscosity of the mixture depends mainly on the nature of the biomass and the medium, and their quantitative relationship, i.e. their content / biomass load. Typically, the amount of medium and nitrogen compounds used in biomass processing represents a relevant cost factor and is therefore as low as possible. The efficient recovery provided by the method according to the invention allows these costs to be limited, and the excessive use of medium, especially (pre)treatment medium, can be considered in order to explore beneficial effects during (pre)treatment.

[0060] In a preferred embodiment, the mixture has an initial content of biomass in the range of 10-80% by weight, preferably 5-70% by weight, more preferably 10-50% by weight, for example 15-40% by weight or 15-25% by weight.

[0061] Thus, the mixture of biomass and medium has an initial content of medium in the range of 20-90% by weight, preferably 30-95% by weight, more preferably 50-90% by weight, for example 60-85% by weight or 75-85% by weight.

[0062] In this specification, the term medium refers to a composition that comprises or consists of a nitrogen compound and is in a liquid state. The term (pre)treatment medium was chosen to include the aspect in which a medium containing a nitrogen compound is preferably used for pretreatment and / or treatment of biomass. It may be used for pre-processing, such as for example deconstructing the (cellular) structure of the biomass before applying a subsequent step of enzymatic / microbial hydrolysis or fermentation (pre-treatment medium). However, the term (pre)treatment medium should not exclude the case in which no subsequent steps are carried out and no further treatment medium is ultimately used, so that the (pre)treatment medium may be called the treatment medium of the process.

[0063] The skilled person bases the choice of medium and the nitrogen compounds contained mainly on the properties required for the desired (pre)treatment effect on the biomass. However, the following specifications for the medium are particularly preferred in the context of the method according to the invention:

[0064] The medium comprises a nitrogen compound, preferably a protonatable or protonated nitrogen compound. The term protonable is synonymous with protonatable or protonizable. A protonatable nitrogen compound is a compound that can catalyze the transfer of hydrogen ions / protons (H + A protonated nitrogen compound is a compound that contains a nitrogen atom with a free electron pair that can accept / bond a hydrogen ion / proton (H+ ), i.e., Bronsted acids. Protonatable nitrogen compounds can react to protonated nitrogen compounds by protonation and vice versa by deprotonation. Considering that these reactions may be competitive, the term nitrogen compounds includes both compounds containing protonatable nitrogen compounds, compounds containing protonated nitrogen compounds, as well as hybrid forms thereof.

[0065] In a preferred embodiment, the nitrogen compound is the main component of the medium. Preferably, the nitrogen compound is in the liquid state at room temperature or at the temperature of the (pre)treatment step preceding the method according to the invention, and therefore the nitrogen compound itself may constitute the medium, in particular the (pre)treatment medium.

[0066] In a preferred embodiment, the nitrogen compound is - neutral nitrogen compounds, - nitrogen-based protic ionic liquids, preferably selected from acid-base conjugate salts and alkyl carbamate ionic liquids; - and their hybrid forms is selected from the group consisting of:

[0067] The term neutral nitrogen compounds should be understood to refer to compounds that are neutral in terms of charge and have a free valence at nitrogen, such as protonatable nitrogen compounds. Suitable liquid nitrogen compounds are also described as nitrogen-containing bases and are used, for example, as polar and basic solvents in organic chemistry. Due to their alkaline properties and their liquid nature, some of these neutral nitrogen compounds should be useful (pre)treatment media for biomass. Indeed, neutral nitrogen compounds such as, by way of example, butylamines and alkanolamines have been discussed for this purpose (Tanaka, M., Robinson, CW & Moo-Young, M. Biotechnol Lett 5, 597-600 (1983). https: / / doi.org / 10.1007 / BF00130839; Achinivu, EC, Frank, S., Baral, NR et al. Green Chem 3, 8611 (2021). DOI: 10.1039 / d1gc02667d). However, some neutral nitrogen compounds may be undesirable for safety reasons due to flammability or environmental and health hazards.

[0068] In a preferred embodiment of the present invention, the neutral nitrogen compound is represented by the formula B

[0069] [ka]

[0070] [wherein R1, R2 and R3 are each independently selected from hydrogen and an alkyl group having 1 to 6 carbon atoms; or R1 and R2 together with the nitrogen atom form an aliphatic or aromatic 5-6 membered heterocyclic group, and R3 is selected from hydrogen and an alkyl group having 1 to 6 carbon atoms, or R3 is absent when R1 and R2 form an aromatic heterocyclic group; any alkyl groups are, independently of one another, unsubstituted or substituted with a hydroxyl group or one or two further NR4R5 groups, where R4 and R5 are, independently of one another, selected from hydrogen and unsubstituted alkyl groups having 1 to 3 carbon atoms; Any heterocyclic group may be aliphatic or aromatic and may further contain 1-2 additional heteroatoms selected from O, S, N, and NR6, where R6 is selected from hydrogen and unsubstituted alkyl groups having 1-4 carbon atoms, preferably O, N, and R6. It is a compound according to the present invention.

[0071] Any alkyl group having 1 to x carbon atoms is C1 to C x -Alkyl, also known as straight chain C1-C x -Alkyl (e.g. methyl, ethyl, etc.), branched C3-C x -Alkyl (e.g. isopropyl, but-2-yl, tert-butyl, etc.) and cyclic C5-C x -alkyl (eg, cyclopentyl and cyclohexyl).

[0072] In a preferred embodiment, the neutral nitrogen compound has a boiling point of up to about 250° C. at atmospheric pressure.

[0073] Based on the considerations of the present inventors, the boiling point (T b ) should be distillable under the preferred conditions (temperature, pressure) of the process according to the invention.

[0074] In a preferred embodiment, the neutral nitrogen compound is a compound according to formula B, which contains an ammoniacal (NH3) group as well as various organic groups, such as Primary, secondary and tertiary alkylamines, Alkanolamines (amines substituted with hydroxyalkyl groups), such as ethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, 2-(dimethylamino)ethanol, 2-(methylamino)ethanol, 2-amino-1-propanol, 3-amino-1-propanol, 3-amino-2-propanol, 2-amino-1-butanol, 3-amino-1-butanol, and 4-amino-1-butanol; Diamines (alkylamines further substituted with -NR3R4 groups), for example of the formula H2N-(CH2) x -NH2 [wherein x ranges from 2 to 6], 1,3-diamino-2-propanol, N-methylethylenediamine, and N,N,N',N'-tetramethylethylenediamine (TMEDA); Guanidines (methylamines further substituted with two -NR3R4 groups), such as 1,1,3,3-tetramethylguanidine and Heterocycles, such as pyridine, pyrrole, morpholine, N-alkylmorpholines (alkyl is C1-C4-alkyl), piperidine, N-alkylpiperidines (alkyl is C1-C4-alkyl), pyrimidine, pyrazine, pyridazine, piperazine, N-methylpiperazine, N-ethylpiperazine, N,N'-dimethylpiperazine, N,N'-diethylpiperazine, imidazole, N-methylimidazole, N-ethylimidazole, pyrrolidine, N-methylpyrrolidine, N-ethylpyrrolidine and N-butylpyrrolidine. is selected from the group consisting of:

[0075] More preferably, the neutral nitrogen compound is NH3, methylamine, ethylamine, propylamine, isopropylamine, butylamine, hexylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, cyclohexylamine, ethanolamine, N-methylethanolamine, N,N-dimethylethanolamine, 3-amino-1-propanol, 3-amino-2-propanol, 4-amino-1-propanol, 5-amino-1-propanol, 6-amino-1-propanol, 7-amino-1-propanol, 8-amino-1-propanol, 9-amino-1-propanol, 10-amino-1-propanol, 11-amino-1-propanol, 12-amino-1-propanol, 13-amino-1-propanol, 14-amino-1-propanol, 15-amino-1-propanol, 16-amino-1-propanol, 17-amino-1-propanol, 18-amino-1-propanol, 19-amino-1-propanol, 20-amino-1-propanol, 21-amino-1-propanol, 22-amino-1-propanol, 23-amino-1-propanol, 24-amino-1-propanol, 25-amino-1-propanol, 26-amino-1-propanol, 27-amino-1-propanol, 28-amino-1-propanol, 29-amino-1-propanol, 30-amino-1-propanol, 31-amino-1-propanol, 32-amino-1-propanol, 33-amino-1-propanol, 34-amino-1-propanol, 35-amino-1- N-butanol, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,3-diamino-2-propanol, 1,1,3,3-tetramethylguanidine, pyridine, pyrrole, morpholine, N-methylmorpholine, N-ethylmorpholine, piperidine, N-methylpiperidine, N-ethylpiperidine, imidazole, N-methylimidazole, N-ethylimidazole, pyrrolidine, N-methylpyrrolidine, N-ethylpyrrolidine, N-butylpyrrolidine, N-methylethylenediamine, and N,N,N',N'-tetramethylethylenediamine.

[0076] These preferred neutral nitrogen compounds are advantageous not only because of their commercial availability, but also because of their boiling points (T b ) is selected.

[0077] Within each of the different organic groups mentioned above, the boiling point of the neutral nitrogen compound tends to increase with molecular weight. Preferably, the neutral nitrogen compound has a molecular weight of about 200 Da or less.

[0078] In another embodiment, the nitrogen compound is selected from the group of ionic liquids, in particular nitrogen-based protic ionic liquids. The class of nitrogen-based protic ionic liquids meets the criteria of nitrogen compounds defined above, since the cations of these ionic liquids represent protonated (organic) nitrogen compounds.

[0079] In a preferred embodiment of the present invention, the nitrogen-based protic ionic liquid has the formula (C): [BH y y+ ] x [A x- ] y (C) [In the formula, BH y y+ is a cation and is derived from a compound according to formula B as defined above by protonation, A x- is an inorganic or organic anion, x and y are integers, preferably x is in the range of 1 to 3 and y is in the range of 1 to 2, more preferably x and y are 1. It is defined according to

[0080] Preferably, the ionic liquid is an acid-base conjugate salt ionic liquid, i.e., a compound according to formula (C), - is the anion derived from the acid by deprotonation. The formation of the acid-base conjugate salt ionic liquid can be described according to simplified Equation I:

[0081] [ka]

[0082] wherein B is a neutral nitrogen compound of formula B (i.e., base B) and HA is an acid.

[0083] The stoichiometry of Equation I depends on the number of protons the nitrogen compound can bind and the number of protons the acid can donate. In Equation II below, acids and bases that donate / accept more than one proton can be considered:

[0084] [ka]

[0085]

[0023] where B is a nitrogen compound of formula B that can be protonated with up to m protons, H nA is an acid that donates up to n protons, and x and y are integers, where x is in the range of 1 to n and y is in the range of 1 to m.

[0086] As shown in Equations I-II, acid-base conjugate salt ionic liquids are in equilibrium with neutral compounds. Thus, they offer the advantage of ionic compounds over their precursors (i.e., free base B and acid H). n This can be combined with the volatility of A, e.g. B and HA). Upon cooling, they can be recovered in ionic form. Some of these ionic liquids are therefore called distillable acid-base conjugate salts (DABCS), a term also used in WO 2021 / 168154.

[0087] In a preferred embodiment, the ionic liquid has a pseudo-boiling point (T) of about 210° C. or less, preferably about 200° C. or less, at atmospheric pressure (i.e., about 1,000 mbar or about 1 atm). b ).

[0088] Based on the considerations of the present inventors, the pseudo-boiling point (T b ) should be distillable under the preferred conditions (temperature, pressure) of the process according to the invention.

[0089] The pseudo-boiling point of an ionic liquid defines the temperature at a given pressure, e.g., atmospheric pressure, at which the ionic liquid changes from liquid to gas form or at which the ionic liquid can be recovered in liquid form from gas form.

[0090] The pseudo boiling point T of the compound b can be detected as the onset temperature of mass loss by thermogravimetric analysis (TGA) at a typical heating rate of e.g. 5 K / min, as well as a strong endothermic signal in differential scanning calorimetry (DSC) experiments under similar conditions, as known to those skilled in the art.

[0091] For acid-base conjugate salt ionic liquids, the gas form is preferably a vaporizable neutral base and a vaporizable neutral acid (B and H nA, e.g., B and HA). Thus, distillable ionic liquids are at least partially converted to their neutral precursors to form gaseous forms. Thus, the pseudo-boiling point of an acid-base conjugated ionic liquid is greater than or equal to i) the boiling point (T b B), ii) The acid H from which the anion of the acid-base conjugate salt ionic liquid is derived n Boiling point of A (T b HA) but also iii) the equilibrium reaction between the neutral and ionized compounds. This equilibrium reaction is strongly influenced by the Brönsted basicity of the base and the Brönsted acidity of the acid. These two factors, and especially the delta between basicity and acidity, are driving the position of the equilibrium for the above mentioned equations (I) and (II), i.e., between the side with the ionic component and the side with the neutral precursor. The formation of the ionic liquid is driven by the enthalpy of the neutralization reaction and is governed by Coulombic forces and additional hydrogen bonds. This reaction enthalpy becomes more exothermic as the basicity of the base increases and the acidity of the acid increases. The more the equilibrium is on the side of the ionic liquid, the less volatile the ionic liquid is and the higher the pseudo-boiling point of the ionic liquid is.

[0092] The relationship between these factors has been previously described for protic ionic liquids (Yoshizawa, M., Xu, W., Angell, CA; J. Am. Chem. Soc. 125, 15411-15419 (2003). DOI: 10.1021 / ja035783d). Yoshizawa et al. defined the "excess boiling point" ΔT b i) the experimentally measured boiling, i.e., (pseudo) boiling point T b and ii) the arithmetic mean (T b B and T b They defined ΔT as the difference between the ΔT and the ΔH for some distillable acid-base conjugate ionic liquids. b We found a strong linear correlation between ΔpK and Brønsted activity. a which is expressed as the two aqueous pKs of the precursora The difference between the pK values, i.e., the pK of the corresponding acid conjugated with base B a from the pK of acid HA a For seven diverse distillable acid-base conjugate ionic liquids, they found that ΔT b We found a strong linear correlation between ΔT and ΔpKa. We extended this analysis to 30 ionic liquids (see Table 1 and Figure 6). b and ΔpK a The high linear correlation between 2 This was confirmed by a Pearson correlation coefficient of 0.9696.

[0093] [Table 1] JPEG2025506857000006.jpg170161

[0094] Sources: a CAS SciFinder™ (SciFinder; Chemical Abstracts Service: Columbus, OH; https: / / scifinder.cas.org; values ​​accessed January 2022); b Schroth, W., Schadler, H.-D., Andersch, JZ Chem. 29 (4) (1989) 129-135; c Wikipedia DE (Wikipedia; https: / / de.wikipedia.org; German or English article for the respective compound accessed January 2022); d Rashid, T., Kait, CF, Murugesan, T. Chinese Journal of Chemical Engineering 25 (2017) 1266-1272; e Brigouleix, C., Anouti, M., Jacquemin, J. et al. J Phys Chem B 114 (2010) 1757-1766; f Yoshizawa, M., Xu, W., Angell, CA; J. Am. Chem. Soc. 125, 15411-15419 (2003). DOI: 10.1021 / ja035783d); g Greaves, TL, Drummond, CJ, Chem Rev 108 (2008) 206-237; h Proionic GmbH (in-house data by TGA); i Pinto, RR, Mattedi, S., Aznar, M. Chemical Engineering Transactions 43 (2015) 1165-1170; j Avantor® delivered by VWR® (https: / / at.vwr.com / store / product / 2358460 / methansulfonsaure-sigma-aldrich, accessed February 2022); k predicted pK by CAS SciFinder™ a(SciFinder; Chemical Abstracts Service: Columbus, OH; https: / / scifinder.cas.org; values ​​accessed January 2022); l thermal decomposition point of the analogue carbamic acid is −23 °C (RK Khanna and MH Moore, Spectrochimica Acta Part A 55 (1999) 961-967, DOI: 10.1016 / S1386-1425(98)00228-5); m sublimation point at 1 atm, Wikipedia DE (Wikipedia; https: / / de.wikipedia.org, accessed February 2022).

[0095] ΔT b and ΔpK a Based on the correlation between the distillable acid-base conjugate salt ionic liquid BH + A - The following priorities were identified for the selection of neutral nitrogen compounds (bases B) and acids (HA) that form:

[0096] Lower ΔpK a The lower superboiling point ΔT for ionic liquids b (see FIG. 6 ), and therefore a higher boiling point (i.e., T b HA and T b Consider precursor compounds with higher pK a is about 10, ΔT b is about 145° C., therefore, to meet the preferred maximum pseudo-boiling point of about 210° C., the precursor should have a low boiling point T of 55° C. b HA+B(T b HA and T b However, ΔpK a is about 5, ΔT b is about 70° C., therefore, to meet the preferred maximum pseudo-boiling point of about 210° C., the precursor should have a boiling point T of up to 130° C. b HA+B(T b HA and T bB).

[0097] Thus, in a preferred embodiment, the acid-base conjugate salt ionic liquid has a ΔpK of ≦10, preferably ≦7.5, for example ≦6.0 or ≦5.0. a and ΔpKa is the aqueous pK of the corresponding acid conjugated with base B. a value and the aqueous pK of the acid HA a and the ionic liquid comes from its base B and acid HA.

[0098] In a further embodiment, the ionic liquid is derived from its base B and acid HA by the boiling point of base B (T b B) and the boiling point of acid HA (T b HA) is similar at a given pressure, especially T b B≧T b Preferably it is HA.

[0099] Next to the pseudo-boiling point of the ionic liquid, the relationship of the boiling points of the precursor compounds to each other is the second criterion for the selection of a preferred ionic liquid. If the boiling points of the base B, at which the ionic liquid is formed, and the acid HA differ significantly from each other, this may lead to enrichment of the higher boiling compounds during the pseudo-boiling of the ionic liquid. In the case of such asymmetric evaporation, two stages of mass loss can be detected in the TGA and two peaks can appear in the DSC experiment. An ideal ionic liquid would not enrich either B or HA during the conversion to gaseous form, which would be due to the fact that the two boiling points T b HA and T b This is true not only when B is close to each other, but also when the two enthalpies of vaporization are close to each other.

[0100] However, enrichment of base B (which is a neutral nitrogen compound and is also potentially suitable as a medium) may be a negligible disadvantage compared to enrichment of acid HA (which is potentially corrosive or reacts aggressively with biomass in undesirable ways). Thus, the boiling point of acid HA is preferably approximately equal to or less than the boiling point of base B at a given pressure, i.e., T b B≧T b It's HA.

[0101] In a preferred embodiment, the acid from which the anion of the acid-base conjugate salt ionic liquid is derived is - carboxylic acids R-COOH, where R is selected from alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 6 carbon atoms, and aryl groups having 6 carbon atoms, any alkyl, alkenyl or aryl group being unsubstituted or substituted with a hydroxyl group, Phenols (hydroxybenzenes) (the phenyl of the phenol is unsubstituted or substituted with a methoxy or methyl group), such as phenol, 2-methoxyphenol, o-, m- and p-cresol, and - Carbonic acid or carbon dioxide (CO2) is an acid selected from the group consisting of:

[0102] Any alkenyl group having 2 to x carbon atoms is C2 to C x -Alkenyl, also called alkenyl, contains at least one double bond, for example one or two, preferably one double bond, and is a linear C x -Alkenyl (e.g. vinyl, propenyl, allyl, etc.), branched C3-C x -Alkenyl (e.g. isoprenyl) and cyclic C3-C x -It should be understood to include alkenyl (eg, cyclopentenyl).

[0103] Preferred acids are carboxylic acids which do not contain halogen atoms, especially fluorine atoms.

[0104] More preferably, the acid is selected from the group consisting of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, acrylic acid, glycolic acid, lactic acid, phenol, and salicylic acid.

[0105] These preferred acids are selected based on their boiling points, which are below about 210° C. at atmospheric pressure, as well as their commercial availability.

[0106] In a preferred embodiment, the boiling point (T b HA) is about 200°C or less, more preferably 175°C or less, for example less than 150°C.

[0107] Moreover, the neutral nitrogen compounds which form cations are preferably compounds according to formula B, in which none of R1, R2 and R3 is hydrogen, i.e. the compounds are tertiary amines in the broadest sense. Such neutral nitrogen compounds have the advantage that they do not form acid amides when contacted with acids, whereas primary or secondary amines, under the conditions of the process according to the invention (i.e. reduced pressure, high temperature), may undergo undesirable side reactions with acids to form acid amides, e.g. carboxamides, by condensation.

[0108] Thus, the cation-forming neutral nitrogen compounds are preferably selected from the group consisting of trimethylamine, triethylamine, tripropylamine, tributylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, N,N-dimethylethanolamine, pyridine, N-methylmorpholine, N-ethylmorpholine, N-methylpiperidine, N-ethylpiperidine, N-methylimidazole, N-ethylimidazole, N-methylpyrrolidine, N-ethylpyrrolidine, N-butylpyrrolidine, and N,N,N',N'-tetramethylethylenediamine.

[0109] In a preferred embodiment, the acid-base conjugated ionic liquid is selected from the group consisting of butylammonium formate, dibutylammonium formate, diethylammonium formate, dimethylammonium formate, dipropylammonium formate, ethanolammonium formate, ethylammonium formate, methylammonium formate, morpholinium formate, N-ethylimidazolium formate, N-ethylmorpholinium formate, N-methylimidazolium formate, N-methylmorpholinium formate, N-methylpyrrolidinium formate, propylammonium formate, pyridinium formate, pyrrolidinium formate, tributylammonium formate, triethylammonium formate, trimethylammonium formate, tripropylammonium formate, α-picolinium formate, butylammonium acetate, dibutylammonium acetate, diethylammonium acetate, dimethylammonium acetate, dipropylammonium acetate, ethanolammonium acetate, ethylammonium acetate, methylammonium acetate, ammonium acetate, morpholinium acetate, N-ethylimidazolium acetate, N-ethylmorpholinium acetate, N-methylimidazolium acetate, N-methylmorpholinium acetate, N-methylpyrrolidinium acetate, propylammonium acetate, pyridinium acetate, pyrrolidinium acetate, tributylammonium acetate, triethylammonium acetate, trimethylammonium acetate, tripropylammonium acetate, α-picolinium acetate, butylammonium propionate ammonium propionate, dibutylammonium propionate, diethylammonium propionate, dimethylammonium propionate, dipropylammonium propionate, ethanolammonium propionate, ethylammonium propionate, methylammonium propionate, morpholinium propionate, N-ethylimidazolium propionate, N-ethylmorpholinium propionate, N-methylimidazolium propionate, N-methylmorpholinium propionate, N-methylpyrrolidinium propionate,Propylammonium propionate, pyridinium propionate, pyrrolidinium propionate, tributylammonium propionate, triethylammonium propionate, trimethylammonium propionate, tripropylammonium propionate, α-picolinium propionate, butylammonium butyrate, dibutylammonium butyrate, diethylammonium butyrate, dimethylammonium butyrate, dipropylammonium butyrate, ethanolammonium butyrate, ethylammonium butyrate, methylammonium butyrate, morpholinium butyrate, N-ethylimidazolium butyrate, N-ethylmorpholinium butyrate, N-methylimidazolium butyrate, N-methylmorpholinium butyrate, N-methylpyrrolidinium butyrate, propylammonium butyrate, pyridinium butyrate, pyrrolidinium butyrate, tributylammonium butyrate, The ammonium lactate is selected from the group consisting of triethylammonium butyrate, trimethylammonium butyrate, tripropylammonium butyrate, α-picolinium butyrate, butylammonium lactate, dibutylammonium lactate, diethylammonium lactate, dimethylammonium lactate, dipropylammonium lactate, ethanolammonium lactate, ethylammonium lactate, methylammonium lactate, morpholinium lactate, N-ethylimidazolium lactate, N-ethylmorpholinium lactate, N-methylimidazolium lactate, N-methylmorpholinium lactate, N-methylpyrrolidinium lactate, propylammonium lactate, pyridinium lactate, pyrrolidinium lactate, tributylammonium lactate, triethylammonium lactate, trimethylammonium lactate, tripropylammonium lactate, and α-picolinium lactate.

[0110] Additionally, the definition of nitrogen compounds also includes the class of alkyl carbamate ionic liquids (a subclass of nitrogen-based protic ionic liquids), which are formally derived from secondary amines, or less preferably primary amines, and CO2. They are also called (distillable) CO2-based alkyl carbamate ionic liquids. The formation of alkyl carbamate ionic liquids is represented by Equation III:

[0111] [ka]

[0112] [wherein R1 and R2 are independently selected from hydrogen and an alkyl group having 1 to 6 carbon atoms, preferably R1 and R2 are both selected from an alkyl group having 1 to 6 carbon atoms, or R1 and R2 together with the nitrogen atom form a 5- to 6-membered heterocyclic group; any alkyl group may, independently of one another, be unsubstituted or substituted with a hydroxyl group or a further NR3R4 group, where R3 and R4 are, independently of one another, selected from hydrogen and unsubstituted alkyl groups having 1 to 3 carbon atoms, preferably R3 and R4 are both selected from unsubstituted alkyl groups having 1 to 3 carbon atoms; Any heterocyclic group may be aliphatic or aromatic and may further contain 1-2 additional heteroatoms selected from O, S, N, and NR5, where R5 is selected from hydrogen or an unsubstituted alkyl group having 1-4 carbon atoms, preferably R5 is selected from an unsubstituted alkyl group having 1-4 carbon atoms. It can be described according to:

[0113] Thus, the secondary amine (R1R2NH) involved in the formation of the alkyl carbamate ionic liquid may be defined as a compound according to formula B, where at least R3 is hydrogen.

[0114] As acid-base conjugated ionic liquids, alkyl carbamate ionic liquids may be referred to as distillable. The alkyl carbamate ionic liquid is in equilibrium with the neutral compound from which it is derived. The considerations and preferences discussed for pseudo-boiling point and the selection of a preferred base for distillable acid-base conjugated ionic liquids apply to alkyl carbamate ionic liquids as well.

[0115] In a preferred embodiment, the alkyl carbamate ionic liquid is selected from the group of carbamate ionic liquids (R1 and R2 are independently selected from ethyl, methyl, propyl, pyrrolidinium pyrrolidine carbamate (CAS 1349851-87-1), piperidinium piperidine carbamate (CAS 2455-83-6) and morpholinium morpholine carbamate (CAS 62038-13-5)).

[0116] In a further aspect, the nitrogen compound may be in hybrid form between a neutral nitrogen compound and an ionic liquid. The term hybrid form is understood to include mixtures of neutral nitrogen compounds and ionic liquids in any quantitative relationship to each other. In one embodiment, the hybrid form comprises a neutral nitrogen compound and an ionic liquid, the cation of the ionic liquid being derived from said neutral nitrogen compound. The term hybrid form also encompasses nitrogen compounds representing mixtures of ionic liquids having a protonated nitrogen compound as cation with different (i.e. unrelated) neutral nitrogen compounds. Preferably, the hybrid form comprises a neutral nitrogen compound according to formula B and an ionic liquid according to formula C, the cation BH y y+ , preferably BH + is the protonated form of the neutral nitrogen compound according to formula B. Such hybrid forms can be obtained by mixing the compound of formula B with a less than stoichiometric amount of an acid.

[0117] As discussed above, neutral nitrogen compounds and nitrogen-based protic ionic liquids, preferably ionic liquids selected from acid-base conjugate salts and alkyl carbamate ionic liquids, and hybrid forms thereof, can all be reacted with nitrogen compounds under the pressure and temperature conditions preferred for the process according to the invention, for example, at temperatures up to 10 -1 These include compounds which are readily vaporized at pressures of up to 100 mbar, for example 1 mbar or 10 mbar, and at temperatures of 80° C. to 140° C., for example 100° C. They are therefore particularly suitable for the method according to the invention.

[0118] In a preferred embodiment, the medium has a nitrogen compound content in the range of 10-100% by weight, preferably 50-100% by weight, more preferably 90-100% by weight, for example essentially 100% by weight.

[0119] While it may be preferred that the medium consists essentially of the nitrogen compounds defined above, in further embodiments the medium comprises one or more additional components, hi certain embodiments the additional components of the medium are selected from the group consisting of co-solvents, buffers, detergents, dispersants, corrosion inhibitors, and antioxidants.

[0120] Suitable co-solvents include, for example, water, alcohols (e.g., methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and ethylene glycol), ethers (e.g., ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, dipropyl ether, di-n-butyl ether, di-iso-butyl ether, di-sec-butyl ether, di-tert-butyl ether, 2-methoxy-2-methylpropane), dihydrolevoglucosenone (Cyrene™), isosorbide-dimethyl ether, levoglucosenone, γ-valerolactone, carbonic acids (e.g., formic acid, acetic acid, propionic acid, and lactic acid), DMSO, 2,5-dimethylfuran, triethyl phosphate, acetone, and dissolved CO2.

[0121] In one embodiment, the biomass material that remains collectable after removal of the nitrogen compounds is obtained in combination with a co-solvent, in particular a co-solvent from the medium. In this embodiment, the biomass is not recovered as a dry solid, but is kept moist or wet by a co-solvent such as water or alcohol. This is desirable in situations where the remaining biomass material, for example a biomass material containing intact cell structures, should not be allowed to dry out. Preferably, the remaining biomass material may be collected in combination with a co-solvent, in particular water, which is present in a concentration of 5-30% by weight, preferably 10-25% by weight, for example 20% by weight, with respect to said combination. Typically, the co-solvent, such as water or alcohol, forms a gaseous form in the method according to the invention, evaporates and is removed together with the gas phase. However, the replenishment of the co-solvent during processing makes it possible to maintain a certain concentration of the co-solvent while the nitrogen compounds are removed. Thus, in this embodiment, the method may further comprise a step of adding a co-solvent, in particular a step of continuously adding a co-solvent, preferably water, while removing the gas phase.

[0122] The neutral nitrogen compounds defined above can act as co-solvents. In fact, they may be advantageously added to ionic liquids, resulting in hybrid forms of the neutral nitrogen compounds and ionic liquids described above.

[0123] Suitable buffers include, for example, ammonium carbonate, ammonium bicarbonate, ammonium carbamate. Of note, neutral nitrogen compounds or ionic liquids themselves can act as a buffer system.

[0124] In a preferred embodiment, any one of the additional components is distillable or heat-sensitive. Thus, each of the additional components can be converted into gaseous form and removed from the mixture during the process according to the invention. More preferably, any one of the additional components is distillable under the conditions (temperature, pressure) of the process according to the invention, and is preferably recovered together with the nitrogen compound.

[0125] In one embodiment, the relationship between the biomass material contained in the initial mixture provided first and the remaining biomass is that the first is the feedstock for the latter, and the remaining biomass material is substantially free of nitrogen compounds (or media) because the nitrogen compounds (or media) can be efficiently removed.

[0126] In a preferred embodiment, the biomass material is a lignocellulosic biomass and / or a cellulosic biomass material. For example, the biomass material may be: - any kind of agricultural residues, such as husks, straw, stover, spelt, seeds, leaves, empty fruit bunches, for example oil palm empty fruit bunches (i.e. residual biomass left from the collection of the oil-rich seeds of Elaeis guineensis), - forestry and orchard waste, or - Energy crops, such as switchgrass, sorghum bicolor, poplar, hemp, and giant miscanthus It comes from.

[0127] In general, the biomass material can be any woody biomass, grass biomass, herbaceous biomass, etc. that contains polysaccharides such as glucans or xylans.

[0128] In another preferred embodiment, the biomass material is or contains proteins, such as wool, feathers, in particular the proteins silk, keratin, collagen, gorgonin (or protein hydrolysates derived from proteins), or polyaminosaccharides, such as chitin, chitosan, heparin, chondroitin, dermatan, keratan and hyaluronic acid.

[0129] Furthermore, the nitrogen compounds (or medium) can be recovered with high purity. Preferably, the nitrogen compounds are recovered with a recovery rate of 98% by weight or more, preferably 99% by weight or more, most preferably 99.5% by weight or more, based on the amount of nitrogen compounds in the initial mixture. If necessary, the recovered medium can be subjected to further cleaning steps. For example, volatile compounds of the gas stream or biomass material removed with undesirable components of the medium can be removed from the nitrogen compounds, which are ionic liquids, by mild distillation conditions.

[0130] The methods of the invention may be usefully incorporated into processes for producing sugars or biofuels (e.g., ethanol, butanol or hydrocarbons) from biomass, as discussed in Example 4. Thus, in a further aspect, the invention relates to methods for producing sugars or biofuels from biomass.

[0131] Illustratively, a method for producing sugar or biofuel from biomass includes: (a) generating a mixture comprising a biomass material and a pretreatment medium comprising a nitrogen compound and pretreating the mixture under conditions allowing at least partial solubilization of the biomass material and / or disruption and / or transformation of the (cellular) structure of the biomass material; (b) separating the pretreatment medium containing the nitrogen compounds by applying the method according to the invention to obtain the remaining biomass and preferably recovering the pretreatment medium containing the nitrogen compounds; (c) transferring the remaining biomass material to an essentially aqueous medium; (d) hydrolyzing the biomass, comprising introducing enzymes and / or microorganisms such that the enzymes and / or microorganisms produce sugars from the biomass, resulting in a hydrolysate; (e) optionally fermenting sugars in the hydrolysate into biofuels, such as ethanol, butanol or hydrocarbons, to result in a fermentation mixture; (f) optionally separating the biofuel from the fermentation mixture by distillation; (g) optionally separating the unprocessed (non-hydrolyzable) biomass material from the fermentation mixture by solid-liquid separation; and (h) optionally carrying out the method in a recycle setup and reusing the recovered pretreatment medium comprising the nitrogen compounds in step (a). Includes.

[0132] In one embodiment, step (a) of pretreating the biomass can be conveniently carried out in the same equipment as the method according to the invention. Indeed, both thin film and large volume processors as discussed above can be used for the pretreatment step, as high shear forces and intensive mixing may be preferred even during pretreatment.

[0133] Non-limiting figures and examples are discussed below to visualize and demonstrate certain aspects of the present invention. EXAMPLES

[0134] Example 1: Evaluation of the recovery of pretreatment media containing ionic liquids from biomass mixtures with static evaporation surfaces This preliminary experiment aimed to study the evaporation of ionic liquids (ILs) from a biomass mixture through a static evaporation surface.

[0135] A mixture containing biomass material was prepared by the following pretreatment process: the grass Sorghum bicolor was dried at 40 °C for 24 h and subsequently knife-milled to a particle size of 2 mm. 1.5 kg of completely dried material was dissolved in 8.5 kg of distillable 1L ethanol ammonium acetate (CAS 54300-24-2, T b The mixture containing the biomass and IL was transferred to a 20 L pressure-resistant stainless steel autoclave (Kiloclave, Büchi AG) equipped with an impeller stirrer together with a 100 rpm stirring tank (T = 210 °C) and heated at 140 °C for 3 h under stirring at 100 rpm. After this pretreatment, the mixture containing the biomass and IL showed a pasty consistency and a dark brown color.

[0136] In the first experiment, 4 g of this pretreated biomass mixture was weighed into a 50 mL round-bottom flask with an accuracy of 1 mg. The sample was then adjusted to a standard rotary evaporator and rotated at 50 rpm; the ionic liquid was then distilled at a constant vacuum of 1 mbar and 140° C. The initially formed film had a thickness of approximately 5 mm; in the process of removing the ionic liquid, the biomass turned into a very sticky, dark brown, hard mass. The recovery of the distillate was measured as mass loss and plotted as a function of time (FIG. 1, triangles) until no further changes in mass were observed. A blank experiment of untreated biomass without ionic liquid resulted in negligible mass loss.

[0137] In the second experiment, we studied the evaporation of ionic liquids through a static but thin evaporation surface. This setup mimics a single evaporation surface in a thin-film processor with the central shaft stopped from rotating. For this purpose, a 4dm 2 A wiped-film short path distillation device (manufacturer VTA Verfahrenstechnische Anlagen GmbH & Co. KG, Niederwinkling, Germany) with an inner surface of 100 mm and a central coaxial condenser was modified as depicted in FIG.

[0138] FIG. 7 shows two schematic cross-sections of the evacuable vessel 1 of the device, the left hand side cross-section and the right hand side cross-section.

[0139] The dispenser unit including the wiper was removed from the device. A thin curved magnetic steel plate 5 (approximately 0.75 dm 2 , and having a radius that precisely fits the inner surface of the device, and a fixed weight determined with an accuracy of 1 mg, was attached (i.e., removably fixed) into the container 1 using a strong magnet 6. To prevent loss of biomass particles that would eventually fall off the steel plate during the process and not be subsequently weighed, the steel plate 5 had a U-shaped lower end (see side view).

[0140] Subsequently, 4 g of the biomass-IL mixture 4 was dispensed onto a metal plate 5 to form a static film with a thickness of about 1 mm. The mass of the biomass film was weighed to an accuracy of 1 mg.

[0141] Thus, the film of mixture 4 was subjected to a temperature of 140° C. and a pressure of 1 mbar, and the condenser 7 was cooled with tap water. Colorless, transparent droplets of the distilled ionic liquid formed on the condenser, which were collected after the experiment and 1 H-NMR showed identical signals compared to fresh ionic liquid.

[0142] The weight loss on the metal plate was determined every 5 min to evaluate the evaporation from the static layer and thus the recovery of IL (Figure 1, squares).

[0143] Thus, preliminary results suggested that a method that could ensure the provision of a large evaporation surface would be useful for evaporating distillable ionic liquid into gas form, removing it from the vessel, and further recovering it by condensation. The recovery rate was determined to be 99.9% by weight. In contrast, when the biomass mixture formed a crust and a thicker film, evaporation of the ionic liquid was slowed down and generally limited to a recovery rate below 70%.

[0144] Example 2A: Evaluation of mechanical processing for recovery of pretreatment media containing neutral nitrogen compounds or ionic liquids Biomass material containing spelt husk was provided in the form of a mixture with two different (pre)treatment media comprising either the neutral nitrogen compound n-butylamine or the ionic liquid triethylammonium formate, both processed in various devices to study the effect of mechanical processing during the method according to the invention.

[0145] A first biomass mixture was prepared by the following pretreatment process: spelt wheat husk was dried at 40° C. for 24 hours and subsequently knife-milled to a particle size of 2 mm. 1.5 kg of completely dried material was mixed with 8.5 kg of the nitrogen compound n-butylamine (CAS 109-73-9, T at 1 atm). bThe mixture was transferred to a 20 L pressure-resistant stainless steel autoclave (Kiloclave, Büchi AG) equipped with an impeller stirrer together with the ethanol (=78° C.) and heated at 120° C. for 2 h under stirring at 100 rpm. After this treatment, the mixture exhibited a pasty consistency and a dark brown color.

[0146] A second biomass mixture was prepared by the following pretreatment process: Spelt wheat husk was dried at 40° C. for 24 hours and subsequently knife-milled to a particle size of 2 mm. 750 g of completely dried material was dissolved in 4250 g of triethylammonium formate (CAS 585-29-5, T at 1 atm). b = 153 °C, ID 11 in Table 1) was transferred to a 20 L pressure-resistant stainless steel autoclave (Kiloclave, Büchi AG) equipped with an impeller stirrer and heated at 100 °C for 3 h under stirring at 100 rpm. After this treatment, the mixture showed a pasty consistency and a dark brown color.

[0147] The mixtures were fed separately to a) a conventional rotary evaporator (Heidolph Instruments GmbH & CO. KG, Schwabach, Germany) and b) a laboratory model of a large capacity processor (Werner & Pfleiderer Lebensmitteltechnik GesmbH, formerly Werner & Pfleiderer AG, Vienna, Austria). The large capacity processor model is equipped with two rotating Z-shaped kneading elements that are arranged to rotate within a vessel so as to circulate the entire load of the vessel. The two elements are in near contact throughout one revolution, with a gap of approximately 0.5 mm or less, and are therefore "self-cleaning".

[0148] Both devices provide an evacuable vessel, the inner surface of which can be heated, and have an internal volume of 2 liters. Both devices were operated at a rotational speed of 50 rpm, which results in a peripheral velocity of about 0.22 m / s for a lab-scale large-volume processor. A pressure of 40 mbar was applied in all experiments, and the vessel was heated to temperatures of 80° C. and 120° C. for the nitrogen compounds and ionic liquids, respectively.

[0149] In conventional rotary evaporators, the recovery of the pretreatment medium was determined by the mass loss of the mixture as a function of time. In laboratory-scale large-volume processors, a cold trap operated with liquid nitrogen was used to determine the actual recovery of the pretreatment medium as it was condensed downstream.

[0150] Results for pretreatment media containing the neutral nitrogen compound n-butylamine and the ionic liquid triethylammonium formate, for both a conventional rotary evaporator (triangles) and a laboratory model of a large-volume processor (squares), are shown in Figures 2 and 3A, respectively, and the final recoveries are summarized in Table 2 below.

[0151] [Table 2]

[0152] The methods using this mechanical treatment step reach higher maximum recovery rates in a shorter time. These results impressively show the effect of multiple blades (kneaders) arranged to rotate in a vessel, which ensure that the mixture is treated in such a way that it is subjected to shear and causes it to form an evaporation surface that is continuously regenerated between the mixture and the gas phase.

[0153] Example 2B: Evaluation of mechanical processing for recovery of pretreatment media containing ionic liquid and co-solvent Similar to the process in Example 2A, additional biomass material was provided in a mixture with a medium including the ionic liquid pyridinium formate and water as a co-solvent.

[0154] A biomass mixture containing spruce-derived sawdust was prepared by the following pretreatment process: spruce sawdust was dried at 40 °C for 24 h and sieved to a particle size of 2 mm or less. 1 kg of dried material was transferred to a 20 L pressure-resistant stainless steel autoclave (Kiloclave, Büchi AG) and diluted with 70 wt. % of the ionic liquid pyridinium formate (CAS 15066-28-1, T at 1 atm). b = 113°C, ID 5 in Table 1) and 30 wt% water. The autoclave was equipped with an impeller stirrer and heated at 80°C for 2 hours under stirring at 100 rpm. After this treatment, the mixture had a pasty consistency and a dark brown color.

[0155] As described in Example 2A, the mixture was fed independently to a) a conventional rotary evaporator (Heidolph Instruments GmbH & CO. KG, Schwabach, Germany) and b) a laboratory model of a large-volume processor (Werner & Pfleiderer Lebensmitteltechnik GesmbH, formerly Werner & Pfleiderer AG, Vienna, Austria).

[0156] Both devices were operated at a rotation speed of 50 rpm, a pressure of 100 mbar (vacuum) was applied in both setups and the vessel was heated to a temperature of 100°C.

[0157] In conventional rotary evaporators, the recovery of the pretreatment medium was determined by the mass loss of the mixture as a function of time. In laboratory-scale large-volume processors, a cold trap operated with liquid nitrogen was used to determine the actual recovery of the pretreatment medium as it was condensed downstream.

[0158] The results for the recovery of the pretreatment medium containing the ionic liquid pyrimidinium formate and water are shown in Figure 3B for both a conventional rotary evaporator (triangles) and a laboratory model of a large-volume processor (squares). The recovery percentages at certain time points are also shown in Table 3 below.

[0159] [Table 3]

[0160] The data clearly support the role of the mechanical processing step, as higher maximum recoveries are reached in a shorter time in a laboratory-scale large-volume processor compared to a conventional rotary evaporator applying similar conditions but without multiple blades that manipulate the mixture to expose it to shear and force it to form a continuously regenerating evaporation surface between the mixture and the gas phase.

[0161] Example 3: Description of a Preferred Processor An exemplary embodiment of the apparatus is a thin film processor, in which the rotating blades define an axis of rotation and the vessel is essentially a cylinder with a vertical orientation, is shown diagrammatically in FIG.

[0162] Figure 4 is a scheme of the thin film processor, showing the vessel 1 without the front face to reveal the interior of the vessel 1. The apparatus has an essentially cylindrical vessel 1 with a circular bottom. The vessel 1 can be filled with a load at the top of the vessel, i.e. biomass feedstock mixed with a pretreatment medium (not shown in Figure 4).

[0163] Within the vessel 1, a linear set of several blades 2 are arranged on a central rotor element 3. As the central rotor element 3 rotates, the blades 2 rotate within the vessel along a single axis of rotation, as indicated by the arrows in Figure 4.

[0164] Each of the blades extends radially to the inner surface of the vessel 1, leaving only a small radial gap between the plurality of blades 2 and the inner surface of the vessel 1. Due to the staggered arrangement of the rows of blades 2, the plurality of blades defines a body of revolution that essentially corresponds to the cylindrical portion of the vessel 1. Upon rotation, the plurality of blades 2 shear the load 4, e.g. a mixture comprising biomass material and (pre)treatment medium, to spread it as a film. The figure depicts a state in which the mixture 4 is evenly distributed as a film on the inner surface of the vessel 1.

[0165] The blades 2 are twisted with respect to the axis of rotation so as to transport the load continuously. This allows a mass transport along the axis of rotation 3, i.e. towards the bottom of the cylindrical vessel 1, where a step of collecting the remaining biomass can be carried out. Furthermore, the movement along the axis of rotation 3 also ensures the regeneration of the evaporation surface, since the membrane 4 is continuously rebuilt.

[0166] The nitrogen compounds evaporate from the mixture and move into the gas phase, which can then pass further through the vessel. A plurality of blades 2 are arranged to allow gas flow. The gas flow may be removed from the vessel by exhaust means (not shown), preferably arranged to collect the gas flow, for example at the top of the vessel.

[0167] Another exemplary embodiment of the apparatus, namely the high capacity processor, is illustratively shown in FIG.

[0168] FIG. 5 shows a cross-section through the vessel 1 of the device, revealing how the blades 2 are arranged to rotate around two axes of rotation 3.

[0169] The vessel 1 has the form of a cylinder with an essentially bicircular bottom area and is operated in a horizontal orientation. The load 4, i.e. the mixture comprising the biomass material and the (pre)treatment medium, therefore accumulates at the bottom of the vessel 1. However, as the blades 2 rotate about the axis of rotation 3, as indicated by the arrows in Figure 5, they subject the mixture 4 to shear, causing it to form an evaporation surface that is continuously regenerated between the mixture 4 and the gas phase in the vessel.

[0170] Since the blades 2 are configured as a kneader, the cross-sectional view does not show how each of the blades is connected to one of the rotor elements 3. The open arrangement of the blades allows a continuous large gas phase in the vessel. Furthermore, the blades 2 arranged on one rotor shaft 3 interact with the other rotor shaft 3 in a way that ensures a complete circulation of the biomass mixture in the radial and axial directions and a self-cleaning of the device, preventing the formation of any pools of biomass.

[0171] The vessel shown in Figure 5 does not have a means for transporting the mixture / biomass to or from vessel 1. Thus, the mixture is loaded / fed into vessel 1 in batches.

[0172] Example 4: Implementation of the method according to the invention in a biofuel production process and comparison with a standard process In order to visualize how the method according to the invention can be implemented in a process for the production of ethanol as a biofuel, Figures 8 and 9 show a comparison between a process according to the art (Figure 8) and a process based on the method according to the invention (Figure 9).

[0173] FIG. 8 shows a state-of-the-art process using microbial production of advanced biofuels, recently summarized, for example, by Keasling et al. (Keasling, J., Garcia Martin, H., Lee, TS et al. Nat Rev Microbiol 19, 701-715 (2021). DOI: 10.1038 / s41579-021-00577-w). Biomass and pretreatment medium (e.g., nitrogenous compounds) are mixed in a first reactor for pretreatment (a). Subsequently, a washing step (c) involves washing with water for several runs (x-runs) to remove not only nitrogenous compounds and soluble lignin, but also washing water and impurities. The remaining biomass is further subjected to (enzymatic) hydrolysis (d) to liberate sugars from the biomass material, this step being typically carried out in an aqueous medium. Prior to hydrolysis, typically the pH must be adjusted to a neutral or slightly acidic pH value using an acid. This is the case when the pretreatment medium is washed away, as the alkaline pH remains and would prevent effective hydrolysis. The fermentation of sugars to ethanol and CO2 (e) is then also carried out in aqueous medium. The final step of ethanol production is distillation (f). To recover water and ionic liquid, a complex system including solid-liquid separation (g) and ultrafiltration (i) is required to first remove the solid fraction, and then the nitrogen compounds can be recovered from the water by distillative removal of the water (j). Even if the water is subjected to wastewater treatment and / or reclaimed for further use in the process, the whole process obviously requires a cumbersome and energy-intensive step for the recovery of the (pre)treatment agent.

[0174] In comparison, FIG. 9 impressively shows the simplification of the process achieved by the present invention when relying on the method according to the invention, i.e. when separating / recovering the pretreatment medium containing nitrogenous compounds. The distillable pretreatment medium is completely separated in this processing step (b), visualized here by a thin-film device that can be operated continuously. No washing step (c) is required. The remaining biomass is obtained essentially pure and dry, so that it can be directly transferred to an aqueous medium, which makes it possible to carry out both hydrolysis (d) and fermentation (e) in a one-pot setup. Remarkably, the lignin and impurities remaining in the biomass do not adversely affect the hydrolysis and fermentation of the sugars of the biomass. The subsequent separation of the formed product ethanol by distillation (f) from the lignin, residues and impurities, and solid-liquid separation (g) can be carried out according to the state of the art, but with a significantly lower water content.

[0175] The nitrogen compounds are recovered in a condensation step (h) in a condenser external to the apparatus for separation (b) and are directly recovered for reuse as a pretreatment medium.

Claims

1. A method for processing a biomass material, the biomass material being provided in the form of a mixture comprising the biomass material and a medium, in particular a treatment and / or pretreatment medium, comprising a nitrogen compound, the method comprising the steps of: - feeding the mixture into a vessel of an apparatus, the apparatus including a means for heating an inner surface of the vessel and a plurality of blades arranged to rotate within the vessel; - treating the mixture with a plurality of blades such that the mixture is subjected to shear and causes the mixture to form an evaporation surface between the mixture and a gas phase that is continuously regenerated; - forming the nitrogen compound in gaseous form and transferring the gaseous form to the gas phase by passing the evaporation surface; - removing the gas phase comprising the nitrogen compounds in gaseous form from the vessel; and - collecting the remaining biomass material; A method comprising:

2. 10. The method of claim 1 further comprising recovering the medium, wherein the nitrogen compound is distillable and the nitrogen compound is evaporated to a gaseous form, the method comprising: - condensing the nitrogen compound from the gas phase removed from the vessel such that at least a portion of the medium is recovered. The method of claim 1 further comprising:

3. The method of claim 1 or 2, wherein the rotating blades define at least one axis of rotation.

4. 4. The method according to any one of claims 1 to 3, wherein the rotating blades have a radial clearance to the inner surface of the vessel in the range of 0.1 to 50mm, preferably 0.1 to 20mm, such as 0.5 to 5mm or 1 to 10mm.

5. A method according to any one of claims 1 to 4, wherein the container essentially has the geometric form of a right circular cylinder with a bottom region having the form of either a circle or overlapping circles.

6. The device, - a thin film processor, in which the rotating blades define an axis of rotation and the vessel is essentially a cylinder having a vertical orientation; and - A processor, in particular a large capacity processor, in which the rotating blades define one or two axes of rotation and the vessel is essentially a cylinder having a horizontal orientation. The method according to any one of claims 1 to 5, wherein the compound is selected from the group consisting of:

7. A method according to any one of the preceding claims, wherein the plurality of blades rotate at a maximum peripheral speed in the range 0.2 to 5 m / s, preferably 0.5 to 2 m / s, for example about 1 m / s.

8. A method according to any one of the preceding claims, wherein the gas phase is removed using a gas stream, which is withdrawn from the vessel by evacuation and / or a induced strip gas stream, preferably evacuation.

9. The method is 10 -2 mbar to 10 3 mbar range, preferably 10 -1 9. The process according to any one of claims 1 to 8, carried out at a pressure in the range of mbar to 100 mbar, more preferably in the range of 0.5 to 10 mbar, for example 1 mbar.

10. A method according to any one of the preceding claims, wherein the inner surface is heated to a temperature in the range of from 20°C to 200°C, preferably from 50°C to 170°C, more preferably from 80°C to 160°C, for example from 100 to 140°C.

11. The mixture has an initial shear viscosity in the range of 10 to 50,000 Pa*s, preferably 100 to 20,000 Pa*s, more preferably about 500 to 15,000 Pa*s, and the initial mixture shear viscosity is preferably less than 1 s -1 The method according to any one of claims 1 to 10, wherein the shear rate is determined using an oscillatory rheometer having two plate geometry at a shear rate of about 0.05 to about 0.5 and a measurement temperature of about 25°C.

12. 12. The method according to any one of the preceding claims, wherein the mixture has an initial content of medium in the range of 20 to 90% by weight, preferably 30 to 95% by weight, more preferably 50 to 90% by weight, for example 60 to 85% by weight.

13. The method according to any one of claims 1 to 12, wherein the nitrogen compound is a protonatable or protonated nitrogen compound.

14. Nitrogen compounds are - neutral nitrogen compounds, - a nitrogen-based protic ionic liquid, preferably an ionic liquid selected from the group of acid-base conjugate salt ionic liquids and alkyl carbamate ionic liquids, - and their hybrid forms The method according to any one of claims 1 to 13, wherein the compound is selected from the group consisting of:

15. 15. The method according to any one of the preceding claims, wherein the medium has a nitrogen compound content in the range of 10 to 100% by weight, preferably in the range of 50 to 100% by weight, for example essentially 100% by weight.

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