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    • 专利摘要:
    A process is described for the production of lignin particles in the context of a continuous process in which a particle-free lignin-containing solution and a precipitant are combined in a mixing device and then passed out of the mixing device again, with a mixing quality of the lignin-containing solution with the precipitant of at least 90%. and a precipitation of lignin particles is achieved, whereby a suspension of lignin particles is formed, and which is characterized in that the residence time in the mixing device does not exceed a period of 30 seconds.
    公开号:AT521393A1
    申请号:T50527/2018
    申请日:2018-06-27
    公开日:2020-01-15
    发明作者:-Prof Dr Anton Friedl Univ；Ing Stefan Beisl Dipl；Ing Dr Angela Miltner Dipl；Ing Dr Martin Miltner Dipl；Dr Michael Harasek Prof
    申请人:Univ Wien Tech；
    IPC主号:
    专利说明:

    The present invention relates to a method for producing lignin particles by adding a precipitant to a particle-free lignin-containing solution.
    Lignins are solid biopolymers consisting of phenolic macromolecules that are embedded in the plant cell wall. In plants, lignins are primarily responsible for the strength of the plant tissue. In the production of cellulose or paper from plant material, the solid cell wall component lignin is separated from the cellulose by various processes (e.g. sulfite process, force digestion, organosolv process).
    Many petrochemicals are produced by conventional crude oil refineries, although it is expected that many products and chemicals will be produced in the future from biorefineries that are fed with lignocellulosic biomass, such as agricultural residues. This eliminates the term waste related to biomass processing terminology, since any production stream has the potential to be converted to a by-product or energy instead of waste. However, lignin, the second most common biopolymer on earth after cellulose, is underused in first generation cellulose projects and most of this lignin is currently used as an energy source. However, economic analyzes have shown that the use of biomass for energy applications in many cases is not economically viable and that the use of the entire biomass using a variety of processes is necessary to increase its economic benefit. Only around 40% of the lignin produced is required to cover the internal energy requirements of a biorefinery. Therefore, the majority of the lignin produced is available to increase the yield of a biorefinery beyond the utilization of the carbohydrate content.
    Lignin is a highly irregularly branched polyphenolic polyether, which consists of the primary monolignols, p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol, via aromatic and aliphatic ether linkages / 46
    A 50527/2018 are linked. A rough distinction can be made between three different types of lignins: softwood lignins are almost exclusively made up of coniferyl alcohol, hardwood lignins made of coniferyl and sinapyl alcohol and grass lignins from all three types. The high complexity and inhomogeneity of the lignin structure is in many cases increased even further by the currently used pretreatment technologies and leads to additional challenges for the further processing and recycling of the lignin. In comparison to other pre-treatment technologies, the lignin is extracted from the biomass in a relatively pure, low-molecular form with the Organosolv process used in the present case. This lignin shows a minimum of carbohydrate and mineral contaminants and facilitates applications of the lignin of higher value than the heat and energy generation.
    One approach to overcoming this high level of complexity and inhomogeneity is the production and use of nanostructured lignin. Nanostructured materials, especially in the range of 1-100 nm, offer unique properties due to their increased specific surface, whereby their essential chemical and physical interactions are determined by the surface properties. Consequently, a nanostructured material can have significantly different properties than a larger dimensioned material of the same composition. Therefore, the production of lignin nanoparticles and other nanostructures has aroused interest among researchers in recent years.
    Lignin nanoparticles and microparticles find diverse potential applications, ranging from improved mechanical properties of polymer nanocomposites, bactericidal and antioxidative properties and impregnations, to drug carriers for hydrophobic and hydrophilic substances. In addition, carbonization of the lignin nanostructures can lead to high-quality applications such as use in supercapacitors for energy storage. There are also initial attempts to scale up a precipitation process in tetrahydrofuran-water solvent systems. However, most manufacturing methods published to date have a very high / 46
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    Common solvent consumption. Huge amounts of solvents are required for the cleaning of the lignin before the precipitation, the precipitation itself and the subsequent processing.
    US 2014/0275501 describes the production of lignin which has a lower degree of degradation than conventionally isolated lignin. One becomes
    Biomass comprising lignin is extracted using a fluid comprising subcritical or supercritical water lignin. The
    In addition to water, the extractant can comprise, for example, methanol, ethanol or propanol, such a mixture comprising at least 80% by volume of the organic solvent. Finally, lignin can be precipitated from an extraction solution containing lignin by lowering the pH to about 2.
    WO 2016/197233 relates to an organosolv process with the aid of which high-purity lignin can be produced comprising at least 97% lignin. Here, a lignin-containing starting material is first treated with a solvent mixture comprising ethanol and water in order to remove compounds from the starting material which dissolve in the solvent mixture. The lignin-containing material is then treated with a Lewis acid, which is also in a solvent mixture comprising, for example, ethanol and water. Finally, lignin is precipitated from the lignin-containing solution by lowering the pH.
    NZ 538446 relates to processes for the treatment of lignin-containing materials, e.g. Wood, for example to incorporate active substances into it. However, a method for producing lignin particles is not disclosed.
    WO 2010/058185 describes a method for the treatment of
    Biomass is described in which the biomass is separated into lignin and other components using ultrasound and an aqueous solvent system. According to this international / 46
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    Patent application Lignin obtained by evaporation from a water-immiscible solvent.
    WO 2012/126099 also describes an organosolv process by means of which aromatic compounds, i.e. Lignin, isolated from a biomass and can be precipitated by evaporation or lowering the pH.
    WO 2013/182751 discloses methods for fractionating lignin, in which lignin is first dissolved with an organic solvent and water. The mixture is then ultrafiltered, so that lignin fractions can be produced that have a certain molecular weight. The lignin can then be precipitated.
    WO 2010/026244 relates inter alia to Various organosolv processes with which cellulose can be produced, which among other things
    is enriched with lignin.
    Lignins and especially nanolignin are used in a variety of industrial applications. The nanolignin obtained can be further processed in a variety of ways, for example by chemical (e.g. medically or enzymatically active) ligands can be fixed to the nanolignin or the nanolignin can be made UV-protective by ultrasound treatment.
    Nanolignin-based plastics are characterized by high mechanical stability and hydrophobic properties (dirt-repellent). This makes them suitable for many areas of application, including e.g. for use in the
    Automotive industry. In particular, nanolignin can be used in different types of fillings, as reinforcing fibers
    etc. Find application. The relevant literature shows, for example, that a controlled polymerization of nanolignin particles with styrene or methyl methacrylate results in a tenfold increase in material strength compared to a lignin / polymer mixture.
    Nanolignin applied to textile surfaces provides active protection against UV radiation. This can lead to use in the production of functional textiles.
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    The moisture-repellent and antibacterial properties of nanolignin open up areas of application in the packaging industry (manufacture of special packaging films), especially in the field of food packaging.
    Lignin nanoparticles can be permeated with silver ions and coated with a cationic polyelectrolyte layer, so that there is a naturally degradable and green alternative to silver nanoparticles.
    Due to the high biocompatibility and antibacterial effect, nanolignin is suitable among other things. for use in biofilms for implants. Nanolignin can also be used in the pharmaceutical industry e.g. be used in the field of drug delivery.
    Lignin particles, especially lignin nanoparticles, are currently mainly produced by dissolving already isolated and precipitated lignin (mostly using lignin sulfonates or lignosulfonate sources, for example black liquor or alkali metal lignin). The lignin precipitated for the first time has no particle or nanoparticle structure. These structures can be created by first dissolving lignin that has already been precipitated and then precipitating it again or grinding it on the other hand (see CN 103145999). Lignin particles or nanolignin can also be made from black liquor, a lignin-rich by-product or waste product from paper or Cellulose production, by means of CO 2 high pressure extraction (CN 102002165). CN 104497322 describes a method in which a lignin solution treated with ultrasound is added dropwise to deionized water and then nanolignin is separated off by means of a centrifuge.
    In Beisl et al. (Molecules 23 (2018), 633-646) describes a process for the production of lignin micro- and nanoparticles, in which various parameters for the precipitation of lignin particles from ligin solutions are described.
    Compared to this prior art, the present invention has the task of producing / 46
    A 50527/2018 of lignin particles from lignin-containing solutions which can be used to produce lignin nanoparticles that are readily reproducible and as homogeneous as possible in terms of their size distribution, the processes should be cost-effective, time-efficient and easily transferable to industrial scale. Above all, the particles obtained should be nanoparticles and their mean size should be less than 400 nm, preferably less than 300 nm, more preferably less than 200 nm or even more preferably less than 100 nm.
    Accordingly, the present invention relates to a process for the production of lignin particles in the context of a continuous process, in which a particle-free lignin-containing solution and a precipitant are combined in a mixer and then passed out of the mixer again, with a mixing quality of the lignin-containing solution with the precipitant from at least 90% and a precipitation of lignin particles is achieved, whereby a suspension of lignin particles is produced, which is characterized in that the residence time in the mixer does not exceed a period of 5 seconds.
    Furthermore, the present invention relates to a process for the production of lignin particles in the context of a continuous process, in which a particle-free lignin-containing solution and a precipitant are brought together in a mixing device and are subsequently led out again from the mixing device, the quality of the lignin-containing solution being mixed with the precipitant from at least 90% and a precipitation of lignin particles is achieved, whereby a suspension of lignin particles is produced, the mixing device comprising at least one mixer and the line leading therefrom with a diameter of 10 mm or smaller, which is characterized in that the residence time in the mixing device does not exceed a period of 30 seconds.
    With the method according to the invention, surprisingly, an extremely short mixing phase during the precipitation of the lignin particles ensured a quality of the lignin particles and a yield which correspond to those of very much more complex processes.
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    In particular, it was surprisingly found that the procedure, which Beisl et al. (Molecules 23 (2018), 633-646), even - as far as the precipitation step is concerned - can still be significantly reduced without loss of yield or quality in the resulting particle composition. In fact, with the method according to the invention, nanoparticles with average sizes of sometimes far below 400 nm, for example below 250 nm, in particular below 150 nm, can be reliably achieved, and this with remarkable homogeneity (see example part). Furthermore, according to preferred embodiments, the method according to the invention can be carried out with water alone as the precipitant, which enables extremely simple, fast, environmentally friendly and inexpensive large-scale production of such lignin particles. In addition, a comparable yield of lignin particles can be achieved if pure water as a precipitant compared to a mixture of water and sulfuric acid with a pH of 5 as a precipitant, as described in Beisl et al. (Molecules 23 (2018), 633-646) is used.
    The present invention is characterized in that in a continuous process the lignin precipitation step is carried out in a mixing step which is shortened compared to the prior art. The method can therefore be defined either by keeping the residence time in a mixer or in the entire mixing device very short (that is to say less than 5 seconds in the mixer or less than 30 seconds in the entire mixing device).
    In the context of the present invention, a “mixing device” is understood to mean a unit in the continuous process for the production of the lignin particles, in which the particle-free lignin-containing solution is contacted and mixed with the precipitant and the lignin particles are precipitated. According to the invention, this consists at least of a mixer in which the particle-free lignin-containing solution is mixed with the precipitant in such a way that the two components are mixed as completely as possible and this within a very / 46
    A 50527/2018 short time. For this reason, the precipitation process according to the invention is generally essentially completed in the short residence time in the mixer, i.e. the particle size of the lignin particles has essentially already been completely defined. In subsequent process steps, size changes are then generally made possible or achieved only by means of targeted or random procedural measures, for example by aggregation. In any case, the "precipitation process" is already completed in the mixer when a mixing quality (mixing) of the particle-free lignin-containing solution with the precipitant is more than e.g. 90 or 95% is done. In exceptional cases, however, it can also be found in the derivations from the mixer e.g. further mixing (and possibly precipitation processes) if the mixing of the particle-free lignin-containing solution with the precipitant in the mixer was insufficient. Accordingly, the mixing process of the present invention, in which the precipitation of the lignin particles is achieved, can also be carried out in a mixing device which, in addition to the actual mixer, also comprises (thin) lines in which, due to wall friction and a small diameter, any from the mixer still incompletely mixed precipitant / lignin solution can experience further mixing and precipitation. In order that such further substantial mixing can occur at all, only lines with a diameter of 10 mm or smaller, in particular 5 mm or smaller, are suitable for this. As soon as the mixture of precipitant and lignin solution emerges from the mixer or from a thermal device
    A “particle-free lignin-containing solution” is understood to mean any solution in which lignin is dissolved and which does not contain any particles which interfere with the precipitation of lignin particles and their planned use. Depending on the type of production of the particle-free lignin-containing solution and the lignin-containing starting material with which it was obtained, physical or chemical cleaning steps, with which such particles / 46
    A 50527/2018 may be removed. The “particle-free lignin-containing solution” is therefore either a solution saturated with lignin or a - in terms of the lignin concentration - diluted form of it. In the particle-free lignin-containing solution according to the present invention, the lignin concentration is therefore below the solubility limit under the given conditions.
    The particle-free lignin-containing solution is preferably specified in the context of the method according to the invention under conditions and using solvents which allow the highest possible lignin concentration.
    The "precipitant" is then used to bring about a state in which the solubility limit is exceeded in the particle-free lignin-containing solution. In principle, this can be achieved both by adding liquid, gaseous and solid precipitants to the mixer; However, the addition of liquid precipitants is preferred according to the invention. Liquid precipitants can be added to the particle-free lignin-containing solution in the continuous process stream relatively easily (for example by separate feed into the mixer, through a T-piece immediately before the mixer or by introducing the precipitant into the solution stream also immediately before the mixer). Although this also applies to the addition of solid precipitants or the introduction of gaseous precipitants, the short contact time or short mixing time of 5 seconds or less according to the invention is somewhat more complex in terms of process technology, especially when ordinary water is used
    Precipitant should be used.
    The "mixing quality" is defined by the variance of the concentrations in a control volume. The control volume in the present case is an infinitesimally small length of the flow cross section. The mixing quality is a measure of the homogeneity or uniformity of a mixture and is calculated from statistical basic parameters. The most common measure is the coefficient of variation. The closer this value is to 0, the more uniform the mixture. to
    For illustration, it is subtracted from 1 and in% / 46
    A 50527/2018. Thus, 100% mixing quality (or coefficient of variation = 0) means the best, but practically unattainable, mixing status. The ultimately relevant value is therefore (1 coefficient of variation) * 100%. Mathematically speaking, the coefficient of variation is the quotient of the standard deviation of the chemical composition of samples from the mixing room, the arithmetic mean of the samples. With static mixers, the mixing space is the cross section of the mixer tube with an infinitesimally small length. The value can thus be interpreted as a relative error of the target composition over the mixer cross section. With a mixing quality of 95% (coefficient of variation = 0.05; often referred to as technical homogeneity) - as is known from stochastics - around 68% of all samples would be in a range of +/- 5% from the target composition. Already 96% would be in the +/- 10% range. This is general for all normally distributed random experiments. A technical homogeneity is therefore spoken here from 95% (definition of mixing quality STRIKO process engineering; see also: Wikipedia "Mixing (process engineering)").
    As mentioned above, the method according to the invention is primarily characterized by the provision of a short mixing or contact time between the particle-free lignin-containing solution and the precipitant. This should enable essentially complete precipitation within this short time, as a result of which the lignin particles desired according to the invention are formed. According to the invention, the residence time in the mixer should therefore not exceed a period of 5 seconds.
    According to preferred embodiments of the method according to the invention, however, significantly reduced residence times can be provided in the mixing device or in the mixer. Thus, the residence time in the mixer is not more than 4 seconds, preferably not more than 3 seconds, even more preferably not more than 2 seconds, in particular not more than 1 second. Such short mixing times have nevertheless turned out to be sufficient to obtain the desired lignin particles in the desired quality and size.
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    If the mixing is to be achieved in the entire mixing device, the residence time in the mixing device in particularly preferred embodiments is not more than 25 seconds, preferably not more than 20 seconds, in particular not more than 15 seconds.
    The mixer according to the invention is preferably selected from a static mixer, a dynamic mixer or combinations thereof. A static mixer contains no moving parts and is therefore also referred to as a "passive mixer". Dynamic mixers according to the present invention include mixers with moving mechanical parts as well as all active mixers. In active mixers, the energy required for the relative displacement of particles of the raw materials is not obtained from the raw materials themselves (e.g. ultrasonic waves, vibrations from rising bubbles or pulsating inflow). "Passive" mixers include all mixers in which the energy required is extracted from the incoming raw materials.
    The particle-free lignin-containing solution preferably comprises at least one organic solvent and water.
    According to the invention, the particle-free lignin-containing solution can be made available in all possible ways. In principle, however, lignin-containing solutions from established industrial processes are preferably used as the starting material in the process according to the invention. Accordingly, the particle-free lignin-containing solution is preferably by a Kraft Lignin (KL) process, a SodaLignin process, a Lignosulfonate (LS) process, an Organosolv Lignin (OS) process, a steam explosion lignin process , a hydrothermal process, an ammonia explosion process, a supercritical CO 2 process, an acid process, an ionic liquid process, a biological process or an enzymatic hydrolysis lignin (EHL) process. If necessary, the lignin preparations resulting from these processes can be converted into a particle-free lignin-containing solution which are fed to the method according to the invention by means of additional suitable steps. For example, / gets 46
    A 50527/2018 man EHL lignin only after pretreatment with one of the other processes described and subsequent enzymatic hydrolysis. The lignin then remains as a solid and must first be dissolved in a solvent in order to obtain a solution containing lignin.
    According to a preferred embodiment, the precipitant is water or a dilute acid, preferably sulfuric acid, phosphoric acid, nitric acid or an organic acid, in particular formic acid, acetic acid, propionic acid or butyric acid, or CO 2 , water being particularly preferred as the precipitant.
    As already mentioned above, the precipitant is added in such a way that lignin particles form from the lignin-containing solution. The solubility limit must be exceeded by adding the precipitant. The precipitant is preferably a solution and the volume of the precipitant is at least 0.5 times, preferably at least 2 times, in particular at least 5 times, the volume of the lignin-containing solution or the volume of the precipitant is 1 to 20 times, preferably 1.5 times to 10 times, in particular 2 times to 10 times, the volume of the lignin-containing solution. A liquid precipitant is therefore preferably added such that the concentration of the solvent in the lignin-containing solution is in the range from 1 to 10,000% by weight / s, preferably 10 to 5,000% by weight / s, preferably 10 to 1,000% by weight / s, preferably 10 to 100 wt% / s, in particular 50 to 90 wt% / s, is reduced in the mixing / precipitation process.
    According to a preferred embodiment of the process according to the invention, the pH of the precipitant is in the range from 2 to 12, preferably from 3 to 11, in particular from 4 to 8, or the pH of the suspension of lignin particles in the range from 2 to 12, preferably from 3 to 11, in particular from 4 to 8.
    A substantially complete mixing is preferably achieved in the mixing device or in the mixer. Accordingly, according to preferred embodiments, the quality of the lignin-containing solution is mixed with the precipitant from / 46
    A 50527/2018 achieved at least 95%, preferably at least 98%, in particular at least 99%.
    According to a preferred embodiment, the particle-free lignin-containing solution contains an organic solvent, preferably an alcohol, a ketone or THF, ethanol being particularly preferred, in particular in a mixture with water. The water / ethanol system for dissolving lignin is well described and known in the present field, above all with regard to the optimal solution conditions and also with regard to the quantitative precipitation conditions. Surprisingly, however, it has been found according to the invention that some of these parameters are not as critical in the method according to the invention as described in the prior art. For example, the dependence of the yield on the pH value is surprisingly not so critical in the context of the present invention; in fact, according to the invention, they proved the yields, for example at pH 5 and pH 7, to be quite comparable.
    According to the invention, the particle-free lignin-containing solution preferably contains an organic solvent, preferably a C 1 to C 5 alcohol, in particular selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, ethane-1,2-diol, propane-1 , 2-diol, propane-1,2,3-triol, butane-1,2,3,4-tetraol and pentane-1,2,3,4,5-pentol; or a ketone selected from acetone and 2-butanone.
    The particle-free lignin-containing solution preferably contains an organic solvent in an amount of 10 to 90% by weight, preferably 20 to 80% by weight, even more preferably 30 to 70% by weight, even more preferably 40 to 60% by weight, even more preferably 50 to 65 wt%. As mentioned, the optimal solution conditions for the individual organic solvents are largely known in this field. It is therefore not only known which organic solvents are suitable in principle as lignin-dissolving solvents (only these are of course to be regarded according to the invention as “organic solvents according to the present invention), but also in what amount they are to be used in principle (for example also in a mixture with water) and at which quantities or at / 46
    A 50527/2018 which conditions the solubility of lignin is particularly high.
    In principle, the process according to the invention can be carried out at all temperatures at which the particle-free lignin-containing solution is in liquid form. However, process temperatures are preferably used according to the invention, which allow the process to be operated efficiently and possibly in an energy-saving manner. The precipitation according to the invention is therefore carried out at from 0 to 100 ° C., preferably from 5 to 80 ° C., more preferably from 10 to 60 ° C., even more preferably from 15 to 50 ° C., even more preferably from 20 to 30 ° C. For the sake of simplicity, the precipitation process according to the invention can be carried out at room temperature or at ambient temperature.
    As mentioned above, the particle-free lignin-containing solution is a saturated lignin solution or a dilute form thereof. Depending on the solvent and origin of the lignin, the absolute concentration of lignin in a saturated solution is of course different. Particle-free lignin-containing solutions are preferably used according to the invention, the lignin in an amount of 0.1 to 50 g lignin / L, preferably 0.5 to 40 g / L, even more preferably 1 to 30 g / L, even more preferred to 2 to 20 g / L.
    In the continuous process according to the invention, the suspension with the lignin particles obtained is passed on from the mixer or the mixing device and subjected to the further production process. This can be achieved by placing it in a collection container, from which further cleaning steps such as washing or centrifuging the lignin particles can follow. The lignin particles or the suspension of lignin particles are therefore preferably introduced into a suspension container after the mixer or after the mixing device. As already mentioned above, no fundamental changes are made to the lignin particles at this stage of the method, in particular no further significant precipitation processes or processes that determine the particle size / 46
    Move A 50527/2018 down significantly. If desired, specific aggregation processes can be initiated.
    As also mentioned above, the precipitation process according to the invention can be based on particle-free lignin-containing solutions of various origins. In principle, lignin is obtained by extracting raw materials containing lignin. The particle-free lignin-containing solution is preferably obtained by extraction of lignin-containing starting material, selected from material from perennial plants, preferably wood, wood waste or shrub cuttings, or material from annual plants, preferably straw, or biogenic waste. The lignin-containing starting material can have an average size of 0.5 to 50 mm, preferably from 0.5 to 40 mm, even more preferably from 0.5 to 30 mm, even more preferably from 1 to 25 mm, even more preferably from 1 to 20 mm, more preferably 5 to 10 mm, are subjected to the extraction process.
    For the extraction of lignin from raw materials containing lignin there are a number of extraction processes which are also established industrially and which are also used according to the invention as preferred production processes. Accordingly, the extraction of lignin-containing starting material is preferably carried out at a temperature of 100 to 230 ° C, preferably from 120 to 230 ° C, more preferably from 140 to 210 ° C, even more preferably from 150 to 200 ° C, even more preferably from 160 to 200 ° C, more preferably from 170 to 200 ° C, even more preferably from 170 to 195 ° C, even more preferably from 175 to 190 ° C. The extraction of lignin-containing starting material can be carried out, for example, at a pressure of 1 to 100 bar, preferably 1.1 to 90 bar, even more preferably 1.2 to 80 bar, even more preferably 1.3 to 70 bar, even more preferably 1. 4 to 60 bar.
    If appropriate, the particle-free lignin-containing solution is obtained by extraction of lignin-containing starting material and subsequent removal of solid particles still present in the extraction mixture.
    As also described at the beginning, the particles obtainable according to the invention are of high quality, above all with regard to their nanoparticle properties, / 46
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    Size distribution and homogeneity. Despite the short precipitation time according to the invention, the particles obtained have a comparatively very small diameter.
    According to preferred variants of the method according to the invention, the lignin particles obtainable according to the invention have an average diameter in the suspension of less than 400 nm, preferably less than 250 nm, even more preferably less than 200 nm, even more preferably less than 150 nm, in particular less than 100 nm, on.
    At least 50% or more of the lignin particles obtainable according to the invention have a size in suspension according to likewise preferred variants of the method according to the invention, measured as hydrodynamic diameter (HD), in particular measured with dynamic light scattering (DLS), of less than 400 nm, preferably less than 300 nm , even more preferably from below 250 nm, in particular from below 150 nm, even more preferably from below 100 nm.
    At least 60% or more, preferably at least 70% or more, more preferably at least 80% or more, in particular at least 90% or more, of the lignin particles obtainable according to the invention have a size in the suspension in accordance with likewise preferred variants of the method according to the invention, measured as the hydrodynamic diameter (HD), in particular measured with dynamic light scattering (DLS), from below 500 nm, preferably from below 300 nm, even more preferably from below 250 nm, even more preferably from below 200 nm, in particular from below 100 nm.
    The present invention is explained in more detail with reference to the following examples and the drawing figures, but without being restricted to these.
    Show it:
    Figure 1. (a) Turbidity against ethanol concentration in solution / suspension. The ethanol concentration was gradually lowered by adding precipitant at various pH values to the Organosolv extract in a stirred tank. (b) The recordings of the particle suspensions and supernatants after centrifugation come from precipitations in the static mixer with pH 5 precipitant and a flow rate of 112.5 ml / min.
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    Figure 2. Effect of the interaction of the independent variables on the hydrodynamic diameter of the resulting particles and SEM images of selected precipitation parameters.
    Figure 3. Distribution of the hydrodynamic diameter of and SEM images of lignin particles which were precipitated directly from Organosolv extract or from a solution of purified lignin. The parameters used were pH 7, precipitant / extract ratio of 5 and a flow rate of 112.5 ml / min in the static mixer.
    Figure 4. (a) Boxplot diagrams of the relative carbohydrate content found in the 34 individual experiments. (b) Box plot plot of total carbohydrate content in direct precipitation from Organosolv extracts and in the purified lignin.
    Figure 5. Effect of the interaction of the independent variables on the total carbohydrate content of the resulting dry precipitate.
    EXAMPLES: Direct precipitation of lignin nanoparticles
    Summary:
    Micro and nano size lignin has improved properties over standard lignin available today and has gained interest in recent years. Lignin is the largest renewable resource on earth with an aromatic skeleton, but is used for relatively low-value applications. However, the use of lignin on a micro to nano scale could lead to valuable applications. Current manufacturing processes consume large amounts of solvents for cleaning and precipitation. The method investigated in this work uses the direct precipitation of lignin nanoparticles from organosolv pretreatment extract in a static mixer and can drastically reduce the solvent consumption. pH value, ratio of precipitant to organosolv extract and flow rate in the mixer were investigated as precipitation parameters with regard to the resulting particle properties. Particles in the size range from 97.3 nm to 219.3 nm could be produced / 46
    A 50527/2018, and with certain precipitation parameters, the carbohydrate contamination reaches values just as low as in purified lignin particles. The yields were 48.2 + 4.99% regardless of the precipitation parameters. The presented
    Results can be used to optimize the precipitation parameters with regard to particle size, carbohydrate contamination or solvent consumption.
    INTRODUCTION
    This work focuses on the direct precipitation of lignin nanoparticles from Organosolv pretreatment extracts (OSE) in a wheat straw biorefinery, potentially reducing the solvent consumption of the entire process. The precipitation is carried out in a static mixer, which leads to smaller particles compared to batch precipitation (Beisl et al., Molecules 23 (2018), 633-646). It combines the most commonly used precipitation processes of "solvent shifting" and "pH shifting" and reduces the solubility of lignin by reducing the
    Solvent concentration and lowering of pH (Lewis et al., Industrial Crystallization; Cambridge University Press: Cambridge, 2015; pp. 234-260). The degree of lignin oversaturation, the hydrodynamic conditions prevailing during the process and the pH of the fluid surrounding the particles are important parameters that influence the final particle size and behavior. These mentioned process conditions are achieved by varying the
    Precipitation parameters pH value, ratio of precipitant to OSE and the flow rate in the static mixer were examined. The resulting particles were analyzed in terms of particle size, stability, carbohydrate contamination and yield of the
    Procedure examined. The best precipitation parameters were identified and a comparison was made with the precipitation of the previously cleaned and redissolved lignin.
    EXPERIMENTAL PART
    MATERIALS
    The wheat straw used was harvested in the state of Lower Austria in 2015 and under dry / 46
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    Conditions stored until use. The particle size was comminuted in a cutting mill equipped with a 5 mm sieve before the pretreatment. The dry straw composition was 16.1 wt% lignin and 63.1 wt% carbohydrates consisting of arabinose, glucose, mannose, xylose and galactose. Ultrapure water (18 Ω / cm) and ethanol (Merck, Darmstadt, Germany, 96% by volume, undenatured) was used in the organosolv treatment, and sulfuric acid (Merck, 98%) was also used in the precipitation steps.
    Organosolv TREATMENT
    The Organosolv pretreatment was carried out as previously described in Beisl et al. (Molecules 23 (2018), 633-646). Briefly, wheat straw was treated at a maximum temperature of 180 ° C for 1 h in 60% by weight aqueous ethanol. Residual particles were separated by centrifugation. The composition of the extract can be found in Table 1.
    PRECIPITATION
    The precipitation arrangement used is generally described in Beisl et al. (Molecules 23 (2018), 633-646). However, compared to Beisl et al. the time spent in the mixing device (consisting of the T-connector, a 20.4 cm long tube with an inner diameter of 3.7 mm, which contains the static mixing elements, and the 1 m long rubber hose (diameter 4 mm)) for the present invention chosen considerably shorter. While in Beisl et al. the time in the static mixer was more than 36 s (volume: about 15 ml with a flow rate of about 24 ml / min) and the time in the static mixer itself was more than 5 s (volume: about 2.2 ml with a flow rate of about 24 ml / min), shorter mixing times are used in the process according to the present invention (30 s or less). The time in the mixing device in the present examples is in the range from about 23 s to 3 s and the time in the mixer in the present examples is in the range from about 5 s to 0.6 s.
    / 46
    A 50527/2018
    The arrangement consists of two syringe pumps, a static mixer and a stirred collecting vessel. The stirrer speed in the collecting vessel was set to 375 rpm. The acidified precipitants with a pH of 3 and 5 were adjusted with sulfuric acid and the pH 7 precipitant was pure water. The particles were separated from the suspension after precipitation in a ThermoWX-80 + ultracentrifuge (Thermo Scientific, Waltham, MA, USA) at 288,000 g for 60 min. The supernatant was decanted and the precipitated substance was freeze-dried. For the purified lignin, lignin became the same
    Extraction process failed and repeated by
    Ultrasound treatment, centrifugation and replacement of the
    Supernatant cleaned. The purified lignin ("purified lignin"; PL) was freeze-dried and then dissolved in an ethanol / water mixture at the same ethanol concentrations compared to undiluted OSE. This artificial extract was used for comparison with the direct precipitation.
    DESIGN OF THE EXPERIMENTS
    The experimental design and the statistical evaluation of the results were carried out using the software Statgraphics Centurion XVII (Statpoint Technologies, Inc., USA). A face-centered (face-centered) central composite design, comprising three central points with a full repetition (34 individual experiments) was used for the precipitation parameters flow rate in the static mixer, pH value of the precipitant and volume ratio of precipitant to OSE. The flow rates in the static mixer were set at 37.5 ml / min, 112.5 ml / min and 187.5 ml / min. The precipitant to extract volume ratio was adjusted to 2, 5 and 8 while the pH of the precipitant was 3, 5 and 7. The level of significance was set at α = 0.05 in all statistical tests.
    The results from the face-centered central composite design were used to describe the effects of the independent variables using a cubic model approach. High coefficients of determination were found for the carbohydrate content / 46
    A 50527/2018 (R 2 0.89 / adj. R 2 0.87) and the particle size (0.92 / 0.88) was reached. Non-significant factors were gradually removed from the model and were not taken into account in the results.
    CHARACTERIZATION
    The ethanol concentration-dependent turbidity of the
    Particle suspension was determined using a Hach 2100Qis (Hach, CO, USA). To remain within the calibration range, the extract was diluted 1: 6 by volume with ethanol / water to maintain the undiluted ethanol concentration of the extract. Water or sulfuric acid / water mixtures were gradually added to a stirring vessel filled with the diluted extract and measured after each addition.
    The hydrodynamic diameter (HD) of the particles was measured using dynamic light scattering (DLS) (ZetaPALS, Brookhaven Instruments, Holtsville, NY, USA). The measurements were carried out in the particle suspension directly after precipitation - both undiluted and in a 1: 100 dilution with pure water. Undiluted measurements were corrected for their viscosity and the refractive index of the supernatant obtained after centrifugation. For long-term stability tests, the particles were stored at 8 ° C, but measured at 25 ° C.
    The ζ potential was examined with a ZetaPALS (Brookhaven Instruments, Holtsville, NY, USA). Dried particles were dispersed in water at a corresponding concentration of 20 mg / L and aged for 24 hours before the measurement. Each measurement consisted of five runs, each with 30 sub-runs, and was carried out at 25 ° C.
    Freeze-dried particles were dispersed in hexane, spread on a sample holder and examined in a scanning electron microscope (SEM) (Fei, Quanta 200 FEGSEM). The samples were treated with 4 nm Au / Pd (60 wt% / 40
    % By weight) sputter-coated before analysis.
    The carbohydrate content was determined using the sample preparation in accordance with the laboratory analytical procedure (LAP) of the National Renewable Energy Laboratory (NREL): “Determination of Structural Carbohydrates and Lignin in Biomass” (Sluiter et / 46
    A 50527/2018 al., Determination of Structural Carbohydrates and Lignin in Biomass; Denver, 2008), but the samples were not neutralized after hydrolysis. A Thermo Scientific ICS-5000 HPAEC-PAD system (Thermo Scientific, Waltham, MA, USA) with deionized water as eluent was used to determine arabinose, glucose, mannose, xylose and galactose.
    The yield was determined on the basis of the difference in the dry matter content of the particle suspension directly after precipitation and the supernatant of the particle suspension after centrifugation.
    RESULTS AND DISCUSSION
    RELATIONSHIP OF FELLING AGENT / ORGANOSOLV EXTRACT
    The solubility of lignin strongly depends on the ethanol concentration in ethanol / water solvent mixtures and the type of lignin (Buranov et al., Bioresour. Technol. 101 (2010), 7446-7455). To the required final
    In order to determine the ethanol concentration in the precipitation process and thus the ratio of precipitant to OSE, the turbidity was measured as a function of the ethanol concentration (see FIG. 1). Pure water and
    Water / sulfuric acid mixtures were gradually added to the OSE in a stirred flask at an initial
    Given ethanol concentration of 56.7 wt .-%. To remain within the measurement range of the turbidity meter, the initial OSE was diluted by a factor of 1: 6 by mass while maintaining the initial ethanol concentration. The undiluted lignin concentration of 7.35 g / kg was therefore reduced to 1.23 g / kg. This could result in a slight shift in the turbidity maxima towards lower ones
    Ethanol concentrations lead because the solubility limit is reached at lower ethanol concentrations. The maxima of the turbidity curves are used to determine the minimum precipitant / OSE ratios required for the precipitation. The turbidity maxima are 19.9% by weight, 18.1
    % By weight and 17.9% by weight for the addition of precipitant with a pH of 2, 5 and 7 respectively. The lowest
    Precipitant / OSE ratio for the precipitation experiments / 46
    A 50527/2018 was therefore set to 2, which resulted in a final ethanol concentration in the suspension of 17.6% by weight. Further ratios examined were set to 5 and 8, resulting in a final ethanol concentration of 8.7 wt% and 5.7 wt%, respectively, to increase the supersaturation of the lignin. The shift in the maxima of the turbidity towards higher ethanol concentrations for decreasing pH values indicates a decreasing solubility of the lignin with decreasing pH values. However, the lowest pH of the precipitant used for the precipitation experiments in the static mixer was set to 3 instead of 2 due to an isoelectric point at a pH of around 2.5, which was identified in the measurements of the ζ potential ,
    particle size
    The independent variables pH of the precipitant, flow rate in the static mixer and precipitant / OSE ratio were examined in relation to the resulting particle HD. The resulting particle suspensions were measured by dynamic light scattering (DLS) directly after precipitation in two variants: undiluted and in a 1: 100 dilution with water. After correcting the viscosity and the refractive index for the undiluted samples, the HDs for both dilution variants were compared with a paired t-test and showed significantly identical results for both conditions. The results shown in Figure 2 are based on the HDs obtained by diluted measurements.
    The resulting HDs range from 97.3 nm to 219.3 nm. The smallest HD is achieved in precipitation with a precipitant / OSE ratio of 6.29, pH 7 and a flow rate of 132.06 ml / min. The particles with the highest HD result from a precipitant / OSE ratio of 2, pH 4.93 and a flow rate of 187.5 ml / min.
    The HD of the particles shows a strong dependence on the flow rate with minima of between 107.25 ml / min and 138.0 ml / min depending on pH and ratio. This behavior / 46
    A 50527/2018 could arise from changing flow conditions that affect the balance of primary nucleation and agglomeration by changing the supersaturation of lignin and the collision rate of the resulting particles. At low flow rates, supersaturation is comparatively low and larger particles are formed. With increasing flow rates, the supersaturation of the lignin increases, which leads to smaller particles. However, further increased supersaturation leads to higher collision and agglomeration rates (Lewis et al., Industrial Crystallization; Cambridge
    University Press: Cambridge, 2015; Pp. 234-260).
    Similar behavior can be observed for the precipitant / OSE ratio. HDs decrease with increasing ratios due to higher supersaturation and coherently increasing nucleation rates. For example, at a constant pH of 5 and a flow rate of 112.5 ml / min, the HD of the particles decreases from 172.9 nm to 117.3 nm and 101.7 nm for ratios of 2, 5 and 8, respectively , The mechanical
    However, energy supply does not increase due to the constant flow rate. The particle collision rates therefore only depend on the particle concentrations. Consequently, higher precipitant / OSE ratios coherently lead to lower agglomeration (Lewis et al., Industrial Crystallization; Cambridge University Press: Cambridge, 2018; pp. 130-150).
    The pH shows the least influence of the examined variables on the HD. The HD increases from 104.0 nm to 131.2 nm by raising the pH of the precipitant from 3 to 7 at a constant precipitant / OSE ratio of 5 and a flow rate of 112.5 ml / min. The increased HD at low pH values could be explained by the ζ potential of the particles, which decreases to pH values of 3 and reaches the isoelectric point at pH values of around 2.5.
    The OSE not only contains lignin, but also components such as carbohydrates, acetic acid and various breakdown products that must be considered as contaminants during the precipitation process. To the influence of this
    To investigate impurities, lignin was purified from the OSE used and in an aqueous ethanol solution with / 46
    A 50527/2018 an ethanol concentration of 56.7 wt .-%, equal to the undiluted OSE. The solubility of the PL reached its limit at a concentration of 6.65 g / kg, which is lower than the lignin concentration of 7.35 g / kg in the OSE. Therefore, the OSE was diluted to the same lignin concentration with a constant ethanol concentration. The precipitation parameters were set to pH 7, ratio 5 and a flow rate of 112.5 ml / min, which is the closest experimental point to the calculated parameters for the smallest particles. The HD distributions and SEM images of the precipitation directly from OSE and the dissolved PL are shown in FIG. 3. The PL precipitation results in an HD of 77.62 ± 2.74 nm, whereas the precipitation directly from the OSE leads to a higher HD of 102.7 ± 7.75 nm. A comparable result was found by Richter et al. (Langmuir 2016, 32 (25), 6468-6477) with organosolv lignin, dissolved in acetone, and a precipitation which led to particles with a diameter of about 80 nm. The SEM images show only minor differences and separate particles in both cases. Based on the DLS results, however, the impurities can have a negative impact on particle size.
    YIELD
    The yields of the precipitation were found to be independent of the precipitation parameters and had an average of 48.2 ± 4.99%. The standard deviation is quite high, but the values are distributed normally. For comparison, Tian et al. (ACS Sustain. Chem. Eng. 2017, 5 (3), 2702-2710) Values between 41.0% and 90.9% using a
    Achieve dialysis using dimethyl sulfoxide as a solvent for poplar, coastal pine and thatch lignin, and water as a precipitant. Furthermore, this work represents the most comparable process to be found in the literature, since it considers an entire process chain from the raw material to the finished lignin particles including impurities. Yearla et al. (J. Exp. Nanosci. 2016, 11 (4), 289-302) showed a procedure that was 33% to 63% / 46
    A 50527/2018
    Yield was obtained by quickly adding lignin / acetone / water mixtures to water.
    KOHLEHYDRATVERUNREINIGUNGEN
    In addition to lignin, the OSE also contains carbohydrates as a major source of contaminants during precipitation. In terms of concentration, the total carbohydrate content in the extract is 10.2% of the lignin content. Therefore, the resulting precipitated substance after centrifugation and freeze-drying was analyzed for its carbohydrate content.
    The relative proportion of the carbohydrates is shown in Figure 4a. Glucose, with a relative proportion of 47.2 ± 3.36%, is the predominant carbohydrate compound in the precipitated substance. FIG. 4b compares the carbohydrate concentrations found in the precipitated substance from the direct OSE experiments with the PL precipitates. The total carbohydrate content in the PL is 2.41 ± 0.25% by weight and appears to be covalently bound to the lignin. The lowest carbohydrate content found within all direct OSE precipitates was 2.39% by weight, which is in the concentration range of the PL. This shows that certain precipitation parameters allow precipitation of almost pure lignin based on the carbohydrates dissolved in the OSE that remain on the particles. FIG. 5 shows the dependencies of the carbohydrate contents on pH, flow rate and ratio of precipitant / OSE.
    In order to further investigate the behavior of carbohydrate contaminants, their concentrations were correlated with the independent variables used in the precipitation analysis. However, a correlation between particle size or calculated surface area was not obvious. The results are in a range comparable to that of Huijgen et al. (Ind. Crops Prod. 2014, 59, 85-95), who achieved carbohydrate contents in precipitated wheat straw organosolv lignins of 0.4% to 4.9% by weight with treatment temperatures between 190 ° C and 210 ° C. The higher temperatures compared to those in this work / 46
    A 50527/2018 applied 180 ° C favor the carbohydrate cleavage and lead to lower concentrations.
    Contrary to the conclusion that a higher dilution factor would lower the carbohydrate content, the carbohydrate concentration increases with an increase in the precipitant-to-extract ratio. The carbohydrate concentrations for a ratio of 2 are between 2.35% by weight and 2.80% by weight for precipitations with pH 3 and a flow rate of 187.5 ml / min or pH 4.79 and a flow rate of 37 , 5 ml / min. For a ratio of 8, a concentration minimum of 3.47% by weight and a maximum of 6.10% by weight can both be used at a flow rate of 187.5 ml / min and a pH of the precipitant of 3 and 7, respectively being found.
    A contrary behavior is noticeable with increasing flow rates, which leads either to a decreasing or an increasing carbohydrate content in the precipitated substance, depending on the pH value and the ratio of precipitant / OSE. For a combination of pH 3, precipitant and a ratio of 2, the carbohydrate concentration decreases from 2.72% by weight to 2.35% by weight by increasing the flow rate from 37.5 to 187.5 ml / min. On the other hand, an increase in the flow rate by 150.0 ml / min at a pH of 5 and a ratio of precipitant / OSE of 8 increases the carbohydrate content from 4.18% by weight to 5.21% by weight. %.
    The pH value shows an increasing influence on increasing precipitant / OSE ratios and flow rates. The carbohydrate concentration with otherwise constant precipitation parameters can be reduced by up to 43% by changing the pH value of the precipitation agent. This maximum reduction is achieved at a precipitant / OSE ratio of 8 and a flow rate of 187.5 ml / min, and the carbohydrate content can be reduced from 6.09% by weight to 3.47% by weight by using the pH is changed from 7 to 3.
    / 46
    A 50527/2018
    CONCLUSION
    The influence of the precipitation parameters pH value, ratio of precipitant to Organosolv extract and flow rate in the mixer was examined in relation to the resulting particle properties. Direct precipitation of the lignin nanoparticles from wheat straw organosolv extracts can drastically reduce the solvent consumption in a manufacturing process for lignin nanoparticles. Particles with size ranges from 97.3 nm to 219.3 nm could be produced, and the carbohydrate impurities reached as low values with certain precipitation parameters as in cleaned lignin particles. The results found in this work can be used to optimize the precipitation parameters with regard to particle size, carbohydrate contamination or solvent consumption in an uncomplicated process design.
    Table 1. Composition of the organosolv extract used in the precipitation experiments
    Connection / property value unit ethanol 511 g / l Total carbohydrates 1 0, 677 g / l Monomeric carbohydrates 1 0.201 g / l acetic acid 1.43 g / l acid insolublelignin 5.53 g / l Acid-soluble lignin 1, 09 g / l Density 2 0, 901 g / ml Dry matter 3 1.57 Wt .-%
    1 sum of arabinose, galactose, glucose, xylose and mannose concentrations; 2 at 25 ° C; 3 determined at 105 ° C
    权利要求:
    Claims (28)
    [1]
    claims:
    1. Process for the production of lignin particles in the context of a continuous process in which a particle-free lignin-containing solution and a precipitant are combined in a mixer and then from the
    Mixers are passed out again, a mixing quality of the lignin-containing solution with the precipitant of at least 90% and a precipitation of lignin particles being achieved, whereby a
    Suspension of lignin particles occurs, characterized in that the residence time in the mixer does not exceed a period of 5 seconds.
    [2]
    2. Process for the production of lignin particles in the context of a continuous process, in which a particle-free lignin-containing solution and a precipitant are brought together in a mixing device and then passed out of the mixing device again, with a mixing quality of the lignin-containing solution with the
    Precipitant of at least 90% and a precipitation of lignin particles is achieved, whereby a suspension of lignin particles is produced, the mixing device comprising at least one mixer and the line leading therefrom with a diameter of 10 mm or smaller, characterized in that the residence time in the mixing device does not exceed a period of 30 seconds.
    [3]
    3. The method according to claim 1, characterized in that the residence time in the mixer does not exceed a period of 4 seconds, preferably 3 seconds, more preferably 2 seconds, in particular 1 second.
    [4]
    4. The method according to claim 2, characterized in that the residence time in the mixing device does not exceed a period of 25 seconds, preferably 20 seconds, in particular 15 seconds.
    30/46
    [5]
    5. The method according to any one of claims 1 to 4, characterized in that the mixer is selected from a static mixer, a dynamic mixer or combinations thereof.
    [6]
    6. The method according to any one of claims 1 to 5, characterized in that the particle-free lignin-containing solution comprises at least one organic solvent and water or at least one organic solvent.
    [7]
    7. The method according to any one of claims 1 to 6, characterized in that the particle-free lignin-containing solution by a kraft lignin (KL) process, a soda-lignin process, a lignosulfonate (LS) process, an organosolv lignin (OS -) Process, a steam explosion lignin process, a hydrothermal process, an ammonia explosion process, a supercritical CO 2 process, an acid process, an ionic liquid process, a biological process or an enzymatic hydrolysis lignin ( EHL) procedure is obtained.
    [8]
    8. The method according to any one of claims 1 to 7, characterized in that the precipitant is water or a dilute acid, preferably sulfuric acid, phosphoric acid, nitric acid or an organic acid, in particular formic acid, acetic acid, propionic acid or butyric acid, or CO 2 , or one is dilute alkali, preferably sodium hydroxide solution or potassium hydroxide, water being particularly preferred as the precipitant.
    [9]
    9. The method according to any one of claims 1 to 8, characterized in that the precipitant is a solution and the volume of the precipitant is at least 0.5 times, preferably at least 2 times, in particular at least 5 times, the volume of solution containing lignin.
    [10]
    10. The method according to any one of claims 1 to 9, characterized in that the precipitant is a solution and the volume of the precipitant is 1 to 20 times,
    31/46 is preferably 1.5 times to 10 times, in particular 2 times to 10 times, the volume of the lignin-containing solution.
    [11]
    11. The method according to any one of claims 1 to 10, characterized in that the pH of the precipitant is in the range from 2 to 12, preferably from 3 to 11, in particular from 4 to 8.
    [12]
    12. The method according to any one of claims 1 to 11, characterized in that the pH of the suspension of lignin particles in the range from 2 to 12, preferably from 3 to 11, in particular from 4 to 8.
    [13]
    13. The method according to any one of claims 1 to 12, characterized in that a mixing quality of the lignin-containing solution with the precipitant of at least 95% is achieved in the mixing device.
    [14]
    14. The method according to any one of claims 1 to 13, characterized in that the particle-free lignin-containing solution contains an organic solvent, preferably an alcohol, a ketone or THF, with ethanol being particularly preferred, in particular in a mixture with water.
    [15]
    15. The method according to any one of claims 1 to 14, characterized in that the particle-free lignin-containing solution contains an organic solvent, preferably a Cdbis C 5 alcohol, particularly selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, ethane -1,2-diol, propane-1,2-diol, propane-1,2,3-triol, butane-1,2,3,4-tetraol and pentane-1,2,3,4,5-pentol; or a ketone selected from acetone and 2-butanone.
    [16]
    16. The method according to any one of claims 1 to 15, characterized in that the precipitation at a temperature of 0 to
    100 ° C, preferably from 5 to 80 ° C, more preferably from
    10 to 60 ° C, more preferably 15 to 50 ° C, more
    32/46 is preferably carried out from 20 to 30 ° C.
    [17]
    17. The method according to any one of claims 1 to 16, characterized in that the particle-free lignin-containing solution lignin in an amount of 0.1 to 50 g lignin / L, preferably to 0.5 to 40 g / L, even more preferably to 1 to 30 g / L, more preferably 2 to 20 g / L.
    [18]
    18. The method according to any one of claims 1 to 17, characterized in that the suspension of lignin particles from the mixer or the mixing device is introduced into a suspension container.
    [19]
    19. The method according to any one of claims 1 to 18, characterized in that the particle-free lignin-containing solution is an organic solvent in an amount of 10 to 90% by weight, preferably 20 to 80% by weight, even more preferably 30 to
    70% by weight, more preferably 40 to 60% by weight, even more preferably 50 to 65% by weight.
    [20]
    20. The method according to any one of claims 1 to 19, characterized in that the particle-free lignin-containing solution by extraction of lignin-containing starting material at a temperature of 100 to 230 ° C, preferably from 120 to 230 ° C, more preferably from 140 to 210 ° C, more preferably from 150 to 200 ° C, still more preferably from 160 to 200 ° C, even more preferably from 170 to 200 ° C, even more preferably from 170 to 195 ° C, even more preferably from 175 to 190 ° C, is obtained.
    [21]
    21. The method according to any one of claims 1 to 20, characterized in that the particle-free lignin-containing solution by extraction of lignin-containing starting material at a pressure of 1 to 100 bar, preferably 1.1 to 90 bar, more preferably 1.2 to 80 bar , even more preferably 1.3 to 70 bar, even more preferably 1.4 to 60 bar.
    [22]
    22. The method according to any one of claims 1 to 21, characterized in that the particle-free lignin-containing solution
    33/46 is obtained by extraction of lignin-containing starting material, selected from material from perennial plants, preferably wood, wood waste or shrub cuttings, or material from annual plants, preferably straw, or biogenic waste.
    [23]
    23. The method according to any one of claims 1 to 22, characterized in that the particle-free lignin-containing solution by extraction of lignin-containing starting material with an average size of 0.5 to 50 mm, preferably from 0.5 to 40 mm, more preferably from 0 , 5 to 30 mm, more preferably from 1 to 25 mm, even more preferably from 1 to 20 mm, even more preferably from 5 to 10 mm.
    [24]
    24. The method according to any one of claims 1 to 23, characterized in that the particle-free lignin-containing solution is obtained by extraction of lignin-containing starting material and subsequent removal of solid particles still present in the extraction mixture.
    [25]
    25. The method according to any one of claims 1 to 24, characterized in that the lignin particles in the suspension have an average diameter of less than 400 nm, preferably less than 250 nm, more preferably less than 200 nm, even more preferably less than 150 nm, in particular less than 100 nm.
    [26]
    26. The method according to any one of claims 1 to 25, characterized in that at least 50% or more of the lignin particles in the suspension have a size, measured as hydrodynamic diameter (HD), in particular measured with dynamic light scattering (DLS), of less than 400 nm, preferably less than 300 nm, more preferably less than 250 nm, especially less than 150 nm, even more preferably less than 100 nm.
    [27]
    27. The method according to any one of claims 1 to 26, characterized in that at least 60% or more, preferably at least 70% or more, more preferably at least 80% or
    34/46 more, in particular at least 90% or more, of the lignin particles in the suspension a size, measured as hydrodynamic diameter (HD), in particular measured with dynamic light scattering (DLS), of less than 500 nm, preferably of less than 300 nm, even more preferably below 250 nm, even more preferably below 200 nm, in particular below 100 nm.
    [28]
    28. The method according to any one of claims 1 to 27, characterized in that the precipitant is a liquid precipitant and is added such that the concentration of a solvent in the lignin-containing solution in the range of 1 to 10,000 wt% / s, preferably 10 to 5,000 % By weight, preferably 10 to 1000% by weight, preferably 10 to 100% by weight, in particular 50 to 90% by weight, in the mixer or in the mixing device.
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    同族专利:
    公开号 | 公开日
    CA3104550A1|2020-01-02|
    JP2021529849A|2021-11-04|
    AT521393B1|2021-02-15|
    EP3814401A1|2021-05-05|
    WO2020000008A1|2020-01-02|
    AU2019295395A1|2021-01-21|
    CN112543782A|2021-03-23|
    KR20210054503A|2021-05-13|
    US20210261742A1|2021-08-26|
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    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50527/2018A|AT521393B1|2018-06-27|2018-06-27|Process for the production of lignin particles as part of a continuous process|ATA50527/2018A| AT521393B1|2018-06-27|2018-06-27|Process for the production of lignin particles as part of a continuous process|
    EP19739851.4A| EP3814401A1|2018-06-27|2019-06-27|Process for producing lignin particles|
    CA3104550A| CA3104550A1|2018-06-27|2019-06-27|Process for producing lignin particles|
    JP2020571442A| JP2021529849A|2018-06-27|2019-06-27|Process for producing lignin particles|
    AU2019295395A| AU2019295395A1|2018-06-27|2019-06-27|Process for producing lignin particles|
    CN201980049029.XA| CN112543782A|2018-06-27|2019-06-27|Method for producing lignin particles|
    KR1020217002802A| KR20210054503A|2018-06-27|2019-06-27|Method for producing lignin particles|
    PCT/AT2019/060209| WO2020000008A1|2018-06-27|2019-06-27|Process for producing lignin particles|
    US17/255,847| US20210261742A1|2018-06-27|2019-06-27|Process for producing lignin particles|
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