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WO2022112425A1 - Procédé de fourniture d'une solution de filage de cellulose alcaline - Google Patents

Procédé de fourniture d'une solution de filage de cellulose alcaline Download PDF

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Publication number
WO2022112425A1
WO2022112425A1 PCT/EP2021/083020 EP2021083020W WO2022112425A1 WO 2022112425 A1 WO2022112425 A1 WO 2022112425A1 EP 2021083020 W EP2021083020 W EP 2021083020W WO 2022112425 A1 WO2022112425 A1 WO 2022112425A1
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Prior art keywords
cellulose
sodium hydroxide
dispersion
aqueous sodium
hydroxide solution
Prior art date
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Ceased
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PCT/EP2021/083020
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English (en)
Inventor
Åsa ÖSTLUND
Hans Grundberg
Matti VIIKILÄ
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Treetotextile AB
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Treetotextile AB
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Publication date
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Priority to EP21819453.8A priority Critical patent/EP4251655A1/fr
Publication of WO2022112425A1 publication Critical patent/WO2022112425A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B16/00—Regeneration of cellulose
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B1/00—Preparatory treatment of cellulose for making derivatives thereof, e.g. pre-treatment, pre-soaking, activation
    • C08B1/003—Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B1/00—Preparatory treatment of cellulose for making derivatives thereof, e.g. pre-treatment, pre-soaking, activation
    • C08B1/08—Alkali cellulose

Definitions

  • the present invention relates to a process for dissolving cellulose, to provide a cellulose dope for extrusion into an aqueous coagulation bath liquid.
  • the process comprises an adaptation step affecting the solubility of the cellulose to be dissolved.
  • Fibers and films have large application areas in the textile and packaging industries.
  • cellulose fibers have for long been used in textile industry for making fabric.
  • the cellulose fibers have been obtained from cotton.
  • other sources of cellulose such as wood.
  • cellulose fibers An interesting alternative for obtaining regenerated cellulose fibers is the regeneration of cellulose fibers from solutions of dissolved non-derivatized cellulose, e.g. dissolving pulp. Such a process is described inter alia in EP3443151B1 and WO2018169479A1.
  • non-derivatized cellulose use of e.g. CS2 (carbon disulphide) which is used in the viscose process, may be avoided.
  • CS2 carbon disulphide
  • non- derivatized cellulose is soluble in cold aqueous sodium hydroxide and aqueous sodium hydroxide has been used as cellulose solvent in experimental procedures, though no industrial process being economically feasible is available so far.
  • cellulose In order to improve the solubility of cellulose, it may be depolymerized by alkaline or acidic depolymerization reducing the degree of polymerization. Further, the depolymerization treatment as such may also physically affect the cellulose and separates the polymer chains, thereby facilitating dissolution. This kind of treatment is typically denoted adaptation or ageing.
  • alkaline as well as acidic processes are known. Both have their pros and cons. If using acidic adaptation, the cellulose has to be washed and neutralized before being dissolved. Furthermore, removal of low molecular weight components of the pulp is limited. Acidic adaptation is a however a robust procedure. The acidity of the pulp during the adaptation treatment, as well as the temperatures used in various stages of the process, may be varied quite a lot, still providing a high quality cellulose dope.
  • the neutralization step may be omitted, and in addition removal of low-molecular weight components is efficient.
  • the resulting quality of cellulose dope is very sensitive to the alkalinity of the pulp during the adaptation treatment, as well as the temperatures used in various stages of the process.
  • the final degree of polymerization of the adapted pulp is highly sensitive to the amount of transition metals either present in the original pulp, leaching from the processing equipment, or being added as a catalyst.
  • a method of treating cellulose pulp for use in regeneration of cellulose comprises heating an alkaline slurry comprising cellulose and a metal hydroxide solution having a concentration of 5 to 8% by weight to a temperature of 60 to 80°C, and dissolving the treated cellulose pulp in an alkaline solution having a temperature within the range of -10°C to 12°C.
  • the alkaline slurry is to be heated for up to 24 hours, such as for 2-8 hours.
  • an accelerator such as Mn 2+ , typically has to be added. Still the residence time in the heating step is long even if performed under an overpressure (5 to 15 bar) of oxygen. Using accelerators may be troublesome, as it may result in discoloration of the cellulose dope.
  • a fairly high concentration of NaOH has to be used in order to keep the reaction time reasonably short.
  • a process for providing an alkaline cellulose spin dope for extrusion into fiber spinning, film forming, or three-dimensional structures Such extrusion is well-known in the art.
  • three-dimensional structures comprises cellulosic sponges, and moisture sorption aerogels.
  • adaptation, or ageing In order to improve the solubility of cellulose, it is typically treated in a process known as adaptation, or ageing, before being dissolved.
  • cellulose is firstly dispersed in a first aqueous sodium hydroxide solution, to form a dispersion of cellulose.
  • This first solution typically comprises 4 to 10 % by weight of sodium hydroxide, such as 5 to 8 % by weight of sodium hydroxide.
  • the cellulose to be dispersed is preferably cellulose pulp, such as dissolving pulp, paper grade pulp, and/or pulp from recycled resources, such as paper, cardboard or textile waste.
  • the cellulose is non- derivatized cellulose.
  • low derivatized cellulose may be used. Such low derivatized cellulose may have a degree of substitution (DS) of not more than 0.1.
  • the low derivatized cellulose may be provided by derivatization processes employing ethylene oxide or propylene oxide.
  • Derivatized cellulose is preferably not derivatized by a process employing carbon disulfide (CS2).
  • the degree of substitution (DS) for low derivatized cellulose is according to an embodiment less than that degree of substitution (DS) that would be required to be able to completely dissolve more than 1 g of substituted cellulose in 50 g of an aqueous sodium hydroxide solution comprising 8 wt% sodium hydroxide, without additional additives, at +10°C.
  • the dispersion of cellulose is heated to adapt the cellulose for its subsequent use in a cellulose spin dope by partly degrading it in a heating step.
  • the dispersion of cellulose is heated to a temperature of more than 100°C.
  • the dispersion of cellulose is heated to a temperature of 101 to 125°C, such as to a temperature of 105 to 115°C.
  • the residence time in the heating step may be within the range of 5 to 90 minutes, such as 7.5 to 60 minutes, or 10 to less than 30 minutes. The residence time is not to be too long, as this may result in a too low degree of polymerization (DP), i.e.
  • DP degree of polymerization
  • the concentration of cellulose may be up to 50 % by weight, such as 15 to 50 % by weight.
  • the adaptation mainly results from heating the cellulose in the presence of alkali. While being performed at high temperature, it may still be of interest to further affect that adaptation, i.e. increase the degradation rate; especially in the absence of addition of accelerators, such as metallic salts of Mn 2+ , Co 2+ , Fe 2+ , Fe 3+ and/or Cu 2+ , or in the case of only minor addition of such salts. Given the high catalytic activity of such metallic salts at high temperatures, they are rather causing difficulties to optimize and control the degradation and can be eliminated from the process.
  • accelerators such as metallic salts of Mn 2+ , Co 2+ , Fe 2+ , Fe 3+ and/or Cu 2+
  • the degradation rate is fairly low at atmospheric pressure, i.e. an oxygen partial pressure of about 0.21 bar.
  • the dispersion of cellulose is hence heated under an over pressure of oxygen, as oxygen affects the adaptation by increasing the degradation rate.
  • the dispersion of cellulose may thus be heated at an oxygen partial pressure exceeding the atmospheric partial pressure of oxygen.
  • the dispersion of cellulose may be heated at an oxygen partial pressure of 0.25 to 10 bar, such as 0.5 to 5 bar, or 1 to 4 bar.
  • the adaption may be controlled and optimized by adjusting the partial pressure of oxygen. Further, also the temperature and the reaction time may be adjusted to control and optimize the adaption.
  • the heat-treated cellulose is to be dissolved in a second aqueous sodium hydroxide solution provide an alkaline cellulose spin dope.
  • the process thus comprises a step of dissolving the heat-treated cellulose in a second aqueous sodium hydroxide solution.
  • the second aqueous sodium hydroxide solution comprises 5 to 12 % by weight of sodium hydroxide, such as 6 to 10 % by weight of sodium hydroxide.
  • the temperature has to be low.
  • the temperature of the second aqueous sodium hydroxide solution in dissolving the heat-treated cellulose is thus +12°C or lower.
  • the temperature of the second aqueous sodium hydroxide solution in dissolving the heat-treated cellulose is -20°C to +10°C, -10°C to +5°C, or - 5°C to +5°C.
  • the process may further comprise a step of quenching the degradation of the cellulose. This can be done by releasing, at least partly, an over pressure of oxygen, by cooling the heat treated cellulose, or a combination thereof.
  • the dispersion of cellulose is heated under an over pressure of oxygen.
  • the adaptation i.e. degradation of the cellulose
  • the over pressure is quenched by, at least partly, releasing the over pressure, such as releasing the pressure to remove the over pressure.
  • the over pressure is decreased to atmospheric pressure within 5 minutes, such as within 2 minutes or even within 1 minute.
  • the adaptation may be quenched by cooling down the heat- treated cellulose before dissolving it in the second aqueous sodium hydroxide solution.
  • cooling the heat-treated cellulose down it may at least be cooled down to temperature of 50°C.
  • the cooling is typically rapid.
  • the temperature of the heat-treated cellulose may be decreased from the adaption temperature, i.e. a temperature of more than 100°C, such as 101 to 125°C, or 105 to 115°C, to 50°C or less in less than 10 minutes, such as in less than 7 minutes, or even in less than 5 minute.
  • the heat-treated cellulose may be cooled down in different ways. It may be cooled down indirectly or directly.
  • the heat-treated cellulose may be cooled down indirectly by subjecting it to a surface being cooled.
  • the vessel in which the heat treatment is performed may be provided with a heating/cooling jacket. This may be used to firstly heat the cellulose by circulating a heated liquid in the heating/cooling jacket. Subsequently, a cooling liquid may be circulated in the heating/cooling jacket to cool the cellulose, whereby quenching the degradation.
  • the vessel in which the heat treatment is performed may be of various kinds.
  • the vessel should allow for heating the cellulose and subjecting it to an over pressure of oxygen. Further, it should preferably allow for rapidly decreasing the pressure to quench the reaction.
  • the heating may for example be performed in a helix dryer, a batch mixer, or a kneader reactor.
  • the heat-treated cellulose may also be cooled down directly by adding and mixing a cooling liquid into the heated dispersion of cellulose.
  • the cooling liquid may have a temperature of 25°C or less.
  • the cooling liquid may be water. Further, the cooling liquid may be a fourth aqueous sodium hydroxide solution.
  • the process may comprise a step of washing the heat-treated cellulose before dissolving it.
  • the washing step will thus provide a narrower molecular weight distribution.
  • the heat-treated cellulose may be washed with a washing liquid, such as water.
  • the heat-treated cellulose may be washed with a fourth aqueous sodium hydroxide solution before being dissolved in the second aqueous sodium hydroxide solution.
  • the washing step may be combined with the step of cooling the heat-treated cellulose.
  • the washing may also serve to lower the temperature of the heat-treated cellulose slurry, such as to a temperature of 50°C or lower.
  • the washing liquid may have a temperature of 25°C or less.
  • the dispersed cellulose is steeped in the first aqueous sodium hydroxide solution before being heated.
  • the steeping may serve to distribute sodium hydroxide evenly into the pulp to provide for a desired, narrow molecular weight distribution and favorable dissolution performance in the heating step. Further, steeping may facilitate removal of unwanted low molecular weight components.
  • the dispersed cellulose may be steeped at a moderate temperature below 100°C, such as at a temperate of 10 to 70°C, such as 10 to 30°C.
  • the residence time in the steeping step may be 5 to 120 minutes, such as 15 to 60 minutes. Before heating the steeped cellulose, it may be dewatered to concentrate it.
  • the concentration of cellulose in the dispersion may be 0.5 to 15 % by weight, such as 2 to 12 % by weight, before the dewatering.
  • the concentration of cellulose in the dispersion may be 15 to 50 % by weight after the dewatering.
  • dispersed, steeped cellulose is diluted before being heated.
  • the dispersed, steeped cellulose to be heated may comprise 3 to 9 % by weight of sodium hydroxide, such as 4 to 8 % by weight of sodium hydroxide.
  • the dispersed cellulose is steeped in the first aqueous sodium hydroxide solution before being heated. Further, the steeped cellulose is dewatered to concentrate it. In dewatering the steeped cellulose, a concentrated dispersion of cellulose is provided. Further, a third aqueous sodium hydroxide solution depleted of cellulose is provided. The third aqueous sodium hydroxide solution may however comprise hemicellulose having been dissolved in the steeping step. Thus, the dewatering, apart from decreasing the volume, which is to be heated, may also serve to remove components, e.g. hemicellulose, which may impair the quality of the extruded objects (i.e. fibers, films, or three-dimensional structures).
  • the dewatering apart from decreasing the volume, which is to be heated, may also serve to remove components, e.g. hemicellulose, which may impair the quality of the extruded objects (i.e. fibers, films, or three-dimensional structures).
  • the third aqueous sodium hydroxide solution may be filtered to remove hemicellulose, whereby providing a filtrate.
  • the resulting filtrate is depleted of hemicellulose and comprises sodium hydroxide.
  • This filtrate may be re-cycled. It may thus be used to form part of the first aqueous sodium hydroxide solution. Further, or alternatively, it may be used to form part of the second aqueous sodium hydroxide solution.
  • the hemicellulose filtered off may be concentrated and purified and valorized. As an example, it may be upgraded to furfural, levulinic acid, xylitol and/related chemicals.
  • the molecular weight distribution of the heat treated cellulose may be affected, as a low molecular weight fraction may be removed already prior to the heating. Further, the steeping may at least partly depolymerize the low molecular weight fraction, facilitating removal thereof.
  • the low molecular weight fraction may be quite substantial and the initial molecular weight distribution may even be bi-modal. Steeping and dewatering may thus serve to provide cellulose with narrower molecular weight distribution being unimodal.
  • the pulp used to prepare the alkaline cellulose spin dope does not necessarily have to be a dissolving pulp as commonly has been the case in art.
  • cellulose to be dispersed is paper grade pulp or pulp from recycled resources, such as paper, cardboard and/or textile waste.
  • the dispersion of cellulose to be heated may further comprise other oxidants comprising oxygen, such as hydrogen peroxide and ozone.
  • the partial pressure of oxygen should not be too high. As already mentioned, it should preferably not exceed 5 bar; more preferably not exceed 2.5 bar.
  • metallic salts of Mn 2+ , Co 2+ , Fe 2+ , Fe 3+ and/or Cu 2+ may be added to be present in heating the dispersion of cellulose. Addition of such salts may serve to further affect that adaptation. As already mentioned, given that the adaptation is performed at relatively high temperature, it may not be necessary to further affect that adaptation. Further, any acceleration should be careful in order to avoid a too drastic effect on the cellulose. Thus, it may according to some embodiments be of interest to not add any metallic salts of Mn 2+ , Co 2+ , Fe 2+ , Fe 3+ and/or Cu 2+ or to only add a minor amount. According to an embodiment:
  • the concentration of Mn 2+ in the dispersion of cellulose to be heated is lower than 50 ppm, such as lower than 25 ppm;
  • the concentration of Co 2+ in the dispersion of cellulose to be heated is lower than 1 ppm, such as lower than 0.5 ppm;
  • the concentration of Fe 2+ in the dispersion of cellulose to be heated is lower than 50 ppm, such as lower than 25 ppm;
  • the concentration of Fe 3+ in the dispersion of cellulose to be heated is lower than 50 ppm, such as lower than 25 ppm;
  • the concentration of Cu 2+ in the dispersion of cellulose to be heated is lower than 25 ppm, such as lower than 10 ppm.
  • the adaptation serves to provide a cellulose suitable for being dissolved in alkali and subsequently extruded into fiber spinning, film forming, or three-dimensional structures.
  • Important properties of cellulose are inter alia the molecular weight, as well as the molecular weight distribution. According to an embodiment:
  • the heat treated cellulose to be dissolved in the second aqueous sodium hydroxide solution has a DP of 140 to 600, such as 180 to 600, 200 to 400, 160 to 400, or 180 to 300 (Intrinsic viscosity may be converted to DP and vice-versa with formulas outlined for example in ASTM D4243 - 16 “ Standard Test Method for Measurement of Average Viscometric Degree of Polymerization of New and Aged Electrical Papers and Boards", and/or
  • an intrinsic viscosity according to IS05351:2010(E) of 115 to 450 such as 150 to 450ml/g, 190 to 300ml/g, 130 to 300 ml/g, or 140 to 230 ml/g; and/or
  • the molecular weight distribution of the heat treated cellulose to be dissolved in the second aqueous sodium hydroxide solution is unimodal.
  • alkaline provides lower polydispersity index Mw/Mn compared to acidic adaptation.
  • the heat-treated cellulose is dissolved in the second aqueous sodium hydroxide solution.
  • This solution may comprise 5 to 12 % by weight of sodium hydroxide, such as 6 to 10 % by weight of sodium hydroxide.
  • the cellulose is dissolved at a temperature of +12°C or lower, such as -20°C to +10°C, -10°C to +5°C, or -5°C to +5°C, to provide the alkaline cellulose spin dope.
  • the second aqueous sodium hydroxide solution comprises zinc oxide (ZnO).
  • the second aqueous sodium hydroxide solution comprises 2.7 % by weight or less of zinc oxide (ZnO), such as 0.1 to 2.7 % by weight, or 0.5 to 1.6 % by weight, of zinc oxide (ZnO).
  • the alkaline cellulose spin dope may comprise 4 to 12 % by weight, preferably 5 to 8 % by weight cellulose.
  • a process for providing an alkaline cellulose spin dope for extrusion into fiber spinning, film forming, or three-dimensional structures is provided.
  • the process according to the second aspect comprises the steps of:
  • the dispersion of cellulose to a temperature of at least 80°C, e.g. more than 100°C, such as 101 to 125°C, or 105 to 115°C, under an over pressure of oxygen to partly degrade the cellulose, in a heating step; preferably the residence time in the heating step being 5 to 90 minutes, such as 7.5 to 60 minutes, or 10 to less than 30 minutes;
  • the over pressure is decreased to atmospheric pressure, within
  • a second aqueous sodium hydroxide solution comprising 5 to 12 % by weight of sodium hydroxide, such as 6 to 10 % by weight of sodium hydroxide, the second aqueous sodium hydroxide solution having a temperature of +12°C or lower, such as -20°C to +10°C, -10°C to +5°C, or -5°C to +5°C, to provide an alkaline cellulose spin dope.
  • Fig. 1 depicts a flow chart
  • Fig. 2 shows the how the viscosity decreases over time according to an embodiment
  • Fig. 3 shows the how the viscosity decreases over time according to an embodiment
  • Fig. 4 shows the how the viscosity decreases over time according to an embodiment.
  • cellulose pulp 20 is dispersed 71 in a first aqueous sodium hydroxide solution 10, typically comprising about 5 to 8 % by weight of sodium hydroxide, to provide a dispersion of cellulose pulp comprising about 2 to 12 % by weight cellulose.
  • a first aqueous sodium hydroxide solution 10 typically comprising about 5 to 8 % by weight of sodium hydroxide
  • the cellulose pulp is steeped 72 in the first aqueous sodium hydroxide solution 10 for some time, such as about 5 to 120 minutes at 10 to 70°C, e.g. 30 minutes at 60°C.
  • the steeped cellulose pulp is dewatered 73 in a e.g. filter press to provide a concentrated dispersion of cellulose pulp comprising about 15 to 50 % by weight of cellulose (e.g. about 30% by weight cellulose) and a third aqueous sodium hydroxide solution 12 comprising hemicellulose, respectively.
  • the third aqueous sodium hydroxide solution 12 is filtered 78 to remove hydrolyzed hemicellulose 30.
  • the resulting filtrate which is depleted of hemicellulose and comprises sodium hydroxide, is routed back to the dispersion 71 of cellulose pulp 20 to supplement the first aqueous sodium hydroxide solution 10.
  • the concentrated dispersion of cellulose pulp is pressurized by oxygen, such as to about 4 bar, and heated 74 to a temperature above 100°C, to adapt the cellulose by partly degrading it. Once the adaptation is completed, the degradation is quenched 75 by releasing the over pressure.
  • the heat-treated cellulose pulp is washed 76 with a fourth aqueous sodium hydroxide solution 13. Subsequently, the heat-treated cellulose pulp is dissolved 77 in a cold (e.g. -5°C), second aqueous sodium hydroxide solution 11 comprising about 8% by weight of sodium hydroxide to provide an alkaline cellulose spin dope 50 comprising about 5 to 10 % by weight of cellulose.
  • the alkaline cellulose spin dope may be filtered. Without further elaboration, it is believed that one skilled in the art may, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the disclosure in any way whatsoever.
  • Dissolving grade cellulose pulp (intrinsic viscosity of about 450 ml/g) was steeped in 8 wt.% NaOH solution under constant mixing for 30 min at 60°C. The consistency of the steeping slurry was 2.5 wt.%. After the steeping, the dispersion was dewatered and its consistency adjusted to 30 wt.%.
  • the dewatered pulp i.e. a concentrated dispersion of cellulose
  • the shredded pulp was transferred to four Teflon-lined autoclaves, which had been pre-heated to 110 °C.
  • the autoclaves were pressurized with 4 bar oxygen, and mounted in a 110°C oil bath and rotated to ensure uniform heating of the pulp. After treatment for 8 minutes, the intrinsic viscosity of the pulps were measured at 4-minute intervals (cf. Fig. 2).
  • Adaptation for 20 minutes provided a pulp in the form of a heat-treated cellulose with intrinsic viscosity of 186 ml/g, i.e. just below the target value 200 ml/g, as can be seen in Fig. 2 (cf. dashed line).
  • Dissolving grade cellulose pulp was steeped and adapted in the same manner as in Example 1, except for that the autoclaves were not pressurized. After treatment for 20 minutes, the intrinsic viscosity of the pulps was measured at 20-minute intervals (cf.
  • the degradation rate was very slow when the autoclaves were not pressurized by oxygen catalyzing the degradation. Thus, it was concluded that the degradation may be quenched by releasing the over pressure.
  • Dissolving grade cellulose pulp (intrinsic viscosity of about 450 ml/g) was steeped in 4.5 wt.% NaOH solution under constant mixing for 30 min at 60°C. The consistency of the steeping slurry was 2.5 wt.%. After the steeping, the dispersion was dewatered and its consistency adjusted to 30 wt.%.
  • the dewatered pulp i.e. a concentrated dispersion of cellulose
  • the autoclaves were pressurized with 4 bar oxygen, and mounted in a 110°C oil bath and rotated to ensure uniform heating of the pulp. After treatment for 25 minutes, the intrinsic viscosity of the pulps were measured at 5-minute intervals (cf. Fig. 4).
  • Adaptation for 30 minutes provided a pulp in the form of a heat-treated cellulose with intrinsic viscosity of 189 ml/g, i.e. just below the target value 200 ml/g, as can be seen in Fig. 4 (cf. dashed line).
  • the degradation rate could be adjusted by lowering the NaOH concentration. Still, efficient degradation could be accomplished in short time.
  • Dissolving grade cellulose pulp was steeped and adapted in the same manner as in Example 1, except for that the treatment temperature was lowered from 110°C to 60°C and that the cellulose concentration was 12 % instead of 30 %. After treatment for 100 minutes (intrinsic viscosity about 360 ml/g), the intrinsic viscosity of the pulps was measured at 50-minute intervals. Even after treatment for 250 min, the intrinsic viscosity still was about 240 ml/g, i.e. well above 200 ml/g. Thus, it seems that also a metallic catalyst (e.g. Mn 2+ ), as taught by EP 3 292244, has to be added in order to accelerate the degradation to operate effectively at lower temperatures.
  • a metallic catalyst e.g. Mn 2+

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Abstract

Procédé de fourniture d'une solution de filage de cellulose alcaline (50) pour l'extrusion dans le filage de fibres, la formation de film ou des structures tridimensionnelles. Le procédé comprend les étapes suivantes : - la dispersion (71) de cellulose (20) dans une première solution aqueuse d'hydroxyde de sodium (10) comprenant de 4 à 10 % en poids d'hydroxyde de sodium, tel que 5 à 8 % en poids d'hydroxyde de sodium, pour former une dispersion de cellulose ; - le chauffage (74) de la dispersion de cellulose à une température supérieure à 100 °C, telle que 101 à 125 °C, ou 105 à 115 °C, pour dégrader partiellement la cellulose, dans une étape de chauffage ; le temps de séjour dans l'étape de chauffage étant de préférence de 5 à 90 minutes, tel que 7,5 à 60 minutes, ou de 5 à moins de 30 minutes ; et la dissolution (77) de la cellulose traitée thermiquement dans une deuxième solution aqueuse d'hydroxyde de sodium (11) comprenant de 5 à 12 % en poids d'hydroxyde de sodium, tel que 6 à 10 % en poids d'hydroxyde de sodium, la deuxième solution aqueuse d'hydroxyde de sodium (111) ayant une température de +12 °C ou moins, telle que de -20 °C à +10 °C, de -10 °C à +5 °C, ou de -5 °C à +5 °C, pour fournir une solution de filage de cellulose alcaline (50).
PCT/EP2021/083020 2020-11-26 2021-11-25 Procédé de fourniture d'une solution de filage de cellulose alcaline Ceased WO2022112425A1 (fr)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4368753A1 (fr) 2022-11-08 2024-05-15 TreeToTextile AB Tissu avec de la cellulose régénérée
WO2024102054A1 (fr) 2022-11-08 2024-05-16 Treetotextile Ab Tissu comportant de la cellulose régénérée
FI20236405A1 (en) * 2023-12-20 2025-06-21 Metsae Spring Oy Pulp composition and process
EP4650499A1 (fr) 2024-05-17 2025-11-19 Aurotec GmbH Dispositif et procédé d'enroulement
EP4650498A1 (fr) 2024-05-17 2025-11-19 Aurotec GmbH Dispositif de contact de fluide

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WO2013124265A1 (fr) * 2012-02-20 2013-08-29 Renewcell Lux S.À.R.L Régénération de cellulose
WO2016177534A1 (fr) * 2015-05-06 2016-11-10 Södra Skogsägarna Ekonomisk Förening Procédé de traitement de pâte de cellulose
WO2018169479A1 (fr) 2017-03-15 2018-09-20 Treetotextile Ab Fibres de cellulose régénérée filées à partir d'une solution à filer alcaline aqueuse
EP3443151B1 (fr) 2016-04-14 2020-01-01 TreeToTextile AB Procédé pour le filage de cellulose dissoute comprenant la récupération du liqueur de coagulation epuisee d'une solution de hydroxide de sodium comme solvant aqueux pour cellulose

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013124265A1 (fr) * 2012-02-20 2013-08-29 Renewcell Lux S.À.R.L Régénération de cellulose
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EP4368753A1 (fr) 2022-11-08 2024-05-15 TreeToTextile AB Tissu avec de la cellulose régénérée
WO2024102054A1 (fr) 2022-11-08 2024-05-16 Treetotextile Ab Tissu comportant de la cellulose régénérée
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EP4650499A1 (fr) 2024-05-17 2025-11-19 Aurotec GmbH Dispositif et procédé d'enroulement
EP4650498A1 (fr) 2024-05-17 2025-11-19 Aurotec GmbH Dispositif de contact de fluide
WO2025238211A1 (fr) 2024-05-17 2025-11-20 Aurotec Gmbh Dispositif d'enroulement et procédé d'enroulement
WO2025238208A1 (fr) 2024-05-17 2025-11-20 Aurotec Gmbh Dispositif de contact par liquide

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