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WO2018147784A1 - Système et procédé d'élimination de silice dans un procédé de dépulpage - Google Patents

Système et procédé d'élimination de silice dans un procédé de dépulpage Download PDF

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Publication number
WO2018147784A1
WO2018147784A1 PCT/SE2018/050072 SE2018050072W WO2018147784A1 WO 2018147784 A1 WO2018147784 A1 WO 2018147784A1 SE 2018050072 W SE2018050072 W SE 2018050072W WO 2018147784 A1 WO2018147784 A1 WO 2018147784A1
Authority
WO
WIPO (PCT)
Prior art keywords
chip slurry
chip
fluid
silica
vessel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SE2018/050072
Other languages
English (en)
Inventor
Fredrik Wilgotson
Stefan ANTONSSON
Lars Eriksson
Bengt WERNERSSON ÖSTBERG
Krister Olsson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Valmet Technologies Oy
Valmet AB
Original Assignee
Valmet Oy
Valmet AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Valmet Oy, Valmet AB filed Critical Valmet Oy
Priority to BR112019014396-3A priority Critical patent/BR112019014396B1/pt
Priority to CN201880009957.9A priority patent/CN110249092A/zh
Priority to FIEP18750677.9T priority patent/FI3580388T3/fi
Priority to EP18750677.9A priority patent/EP3580388B1/fr
Priority to ES18750677T priority patent/ES2947013T3/es
Priority to PL18750677.9T priority patent/PL3580388T3/pl
Publication of WO2018147784A1 publication Critical patent/WO2018147784A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/02—Pretreatment of the raw materials by chemical or physical means
    • D21B1/023—Cleaning wood chips or other raw materials
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C1/00—Pretreatment of the finely-divided materials before digesting
    • D21C1/02—Pretreatment of the finely-divided materials before digesting with water or steam
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C1/00—Pretreatment of the finely-divided materials before digesting
    • D21C1/04—Pretreatment of the finely-divided materials before digesting with acid reacting compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/08—Removal of fats, resins, pitch or waxes; Chemical or physical purification, i.e. refining, of crude cellulose by removing non-cellulosic contaminants, optionally combined with bleaching
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/0007—Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/0021—Introduction of various effluents, e.g. waste waters, into the pulping, recovery and regeneration cycle (closed-cycle)

Definitions

  • the present invention relates generally to a system and a method for the removal of silica contaminants from wood chips in a prehydrolysis kraft cooking pulp production process, and in particular to a system and a method in which silica is removed from a warm chip slurry containing chips that have been soaked in fluid for an extended soaking time at an elevated temperature.
  • the system disclosed in this patent is rather complex and comprises many moving parts, which are exposed to wear. In effect, also this system is difficult to scale to match the requirements of today's large-scale pulp mills, at least in a cost-effective way.
  • An object of the present invention is therefore to provide an improved system and an improved method for removing contaminants in a pulp production process.
  • the system and the method should thereby be easy to implement in large-scale pulp production processes in a cost-effective way.
  • the system and the method should in particular be effective for removing silica, and should also be particularly suitable for use in the production of dissolving pulp.
  • a system for silica removal in a process for pulp production for example a process for the production of dissolving pulp, comprises a vessel; a chip inlet and a steam inlet, which both are arranged in a top section of the vessel; a first fluid inlet arranged below the top section and adapted for inlet of a fluid, such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid to provide a chip slurry having a specified chip slurry temperature in a chip soaking zone disposed below the top section; a chip slurry outlet arranged in a bottom section of the vessel and connected to a chip slurry transportation pipe, which extends out from the vessel for transport of the chip slurry for further processing outside of the vessel; a second fluid inlet arranged in the bottom section of the vessel for dilution of the chip slurry transported (or to be transported) in the chip slurry transportation pipe to a liquor-to-wood ratio of at least 10: 1 with a dilution fluid, such as water or a diluted mineral acid, e.g.
  • a dilution fluid such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid having a specified dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device connected to the chip slurry transportation pipe for dewatering of the chip slurry transported therein and for providing a first flow of chip slurry having a liquor- to-wood ratio of less than 3 : 1 and for providing a second flow of silica-containing fluid; a return pipe connected to the dewatering device for transport of the second flow of silica- containing fluid and connected to the first fluid inlet or to the second fluid inlet; and at least one silica separator, which is arranged in the return pipe.
  • a chip soaking zone is a zone disposed below a top section of the vessel, and in which chips introduced into the vessel via the chip inlet are submerged in or covered by fluid, e.g. water or a diluted mineral acid, e.g. diluted sulphuric acid, which is introduced into the vessel via the first fluid inlet and/or the second fluid inlet.
  • fluid e.g. water or a diluted mineral acid, e.g. diluted sulphuric acid
  • the chips should dwell in this chip soaking zone for a specified soaking time of about 30 minutes to 120 minutes. Within this time interval, silica-containing contaminants, such as sand and clay, which adhere to the surfaces of the chips or which are more or less embedded in the chips, should be dissolved and released from the chips.
  • the method and the system according to the invention are particularly suited for use in an open system, i.e. the vessel containing the chip slurry, is an open, i.e. non-pressurized, vessel, which means that the temperature of the chip slurry in the soaking zone cannot be too high, to avoid excessive boiling of the chip slurry, and the chip slurry temperature should therefore preferably be about 95 °C to about 105 °C.
  • the dilution fluid temperature should be chosen such that the dilution fluid, when added to the chip slurry contained in the vessel, does not cause excessive boiling of the chip slurry, and in practice a dilution fluid temperature of about 110 °C to about 130 °C is useful.
  • the chip slurry is typically pumped out from the vessel, and the consistency of the chip slurry being transported in the chip slurry transportation pipe, or being contained in the bottom section of the vessel for transport in the chip slurry transportation pipe, should therefore allow effective pumping, whereby a liquor-to-wood ratio of at least 10: 1 is useful for the chip slurry in the chip slurry transportation pipe, i.e. the liquor-to-wood ratio of at least 10: 1 relates to the consistency of the chip slurry in the transportation pipe, where the liquor-to-wood ratio - if one so wishes - can be measured.
  • said second fluid inlet which alternatively may be referred to as a dilution fluid inlet, is not arranged in a bottom section of the vessel, but is instead arranged in the chip slurry transportation pipe.
  • said second fluid inlet is divided, such that a second fluid inlet is arranged both in a bottom section of the vessel and in the chip slurry transportation pipe.
  • the return pipe for transport of the second flow of silica containing fluid is connected to both the first fluid inlet and to the second fluid inlet.
  • a mixer can be arranged in the chip slurry transportation pipe; and to enhance the silica-separating action of said at least one silica separator, an inlet for adding an agglomerating and/or flocculating agent, such as polyacrylamide, can be arranged in the return pipe before, as seen in flow direction, the first one of said at least one silica separator.
  • an agglomerating and/or flocculating agent such as polyacrylamide
  • these silica separators can be arranged in parallel or in series; and to ensure effective heating of the dilution fluid, the return pipe can be provided with a heater, e.g. a heat exchanger.
  • FIG. 1 is a schematic illustration of a first embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 2 is a schematic illustration of a second embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 3 is a schematic illustration of a third embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 4 is a schematic illustration of a fourth embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 5 is a schematic illustration of a fifth embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 6 is a schematic illustration of a sixth embodiment of a system for silica removal in a pulp production process according to the present invention.
  • Fig. 1 illustrates schematically a first embodiment of a system 1 for silica removal in a pulping process according to the present invention.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g. diluted sulphuric acid, coming from a fluid source 19, e.g.
  • a fluid such as water or a diluted mineral acid, e.g. diluted sulphuric acid
  • a fluid tank 19 to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time; a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2; a second fluid inlet 11 arranged in the slurry transportation pipe 10 for dilution of the chip slurry to a liquor-to-wood ratio of at least 10: 1, as measured in the chip slurry transportation pipe 10, with a dilution fluid, such as water or a diluted mineral acid, e.g.
  • a dilution fluid such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a dilution fluid source 18, e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a second flow 14 of silica-containing fluid; a return pipe 15 connected to the dewatering device 12 for transport of the second flow 14 of silica-containing fluid and connected to the second fluid inlet 11; and at least one silica separator 16 provided in the return pipe 15.
  • a dilution fluid source e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature
  • a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-105 °C
  • the dilution fluid temperature is about 1 10-130 °C.
  • a heater 17, e.g. heat exchanger 17, can be provided in the return pipe 15, to warm the dilution fluid to the specified dilution fluid temperature, if needed.
  • the heater 17 is disposed close to the dilution fluid source 18, such that the heater 17 essentially only warm up the dilution fluid coming from the dilution fluid source 18 and does not warm up the second flow 14 of silica-containing fluid.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • the first flow 13 of chip slurry has a liquor-to-wood ratio of at least 3 : 1.
  • This rather low value i.e. a relatively large amount of wood in relation to fluid, indicates that the dewatering device is effective and that the first flow 13 contains a relatively small amount of silica.
  • a low value also implies that the chip slurry contains a relatively small amount of fluid that has to be heated in following processing steps. Such processing steps are not part of the present invention, but should nevertheless be considered when designing an efficient system for silica removal.
  • Dewatering devices that are suitable for use in all embodiments presented herein are the dewatering devices manufactured and marketed by the company Valmet AB, for example the top separators marketed by Valmet AB.
  • a second embodiment of a system 1 for silica removal according to the invention is schematically illustrated.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a fluid source 19, e.g. a fluid tank 19, to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time; a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2; a second fluid inlet 11 arranged in the bottom section 4 for dilution of the chip slurry to a liquor-to-wood ratio of at least 10: 1, as measured in the chip slurry transportation pipe 10, with a dilution fluid, such as water or a diluted mineral acid, e.g.
  • a dilution fluid such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a dilution fluid source 18, e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a second flow 14 of silica-containing fluid; a return pipe 15 connected to the dewatering device 12 for transport of the second flow 14 of silica-containing fluid and connected to the second fluid inlet 11; and at least one silica separator 16 provided in the return pipe 15.
  • a dilution fluid source e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature
  • a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-150 °C
  • the dilution fluid temperature is about 1 10-130 °C.
  • a heater 17, e.g. heat exchanger 17, can be provided in the return pipe 15, to warm the dilution fluid to the specified dilution fluid temperature, if needed.
  • the heater 17 is disposed in a position such that the heater 17 warm up both the dilution fluid coming from the dilution fluid source 18 and also the second flow 14 of silica-containing fluid.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • Fig. 3 illustrates schematically a third embodiment of a system 1 for silica removal in a pulping process according to the present invention.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g. diluted sulphuric acid, coming from a fluid source 19, e.g.
  • a fluid such as water or a diluted mineral acid, e.g. diluted sulphuric acid
  • a fluid tank 19 to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time; a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2; a second fluid inlet 11 arranged in the slurry transportation pipe 10 for dilution of the chip slurry to a liquor-to-wood ratio of at least 10: 1, as measured in the chip slurry transportation pipe 10, with a dilution fluid having a dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a second flow
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-105 °C
  • the dilution fluid temperature is about 110-130 °C.
  • a heater 17, e.g. heat exchanger 17 can be provided in the return pipe 15, to warm the dilution fluid to the specified dilution fluid temperature, if needed.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • Fig. 4 illustrates schematically a fourth embodiment of a system 1 for silica removal in a pulping process according to the present invention.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g. diluted sulphuric acid, coming from a fluid source 19, e.g.
  • a fluid such as water or a diluted mineral acid, e.g. diluted sulphuric acid
  • a fluid tank 19 to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time;
  • a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2;
  • a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-105 °C
  • the dilution fluid temperature is about 110-130 °C.
  • a heater 17, e.g. heat exchanger 17 can be provided in the return pipe 15, to warm the dilution fluid to the specified dilution fluid temperature, if needed.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • a fifth embodiment of a system 1 for silica removal according to the invention is schematically illustrated.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a fluid source 19, e.g. a fluid tank 19, to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time; a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2; a second fluid inlet 11 arranged in the chip slurry transportation pipe 10 for dilution of the chip slurry to a liquor-to-wood ratio of at least 10: 1, as measured in the chip slurry transportation pipe 10, with a dilution fluid, such as water or a diluted mineral acid, e.g.
  • a dilution fluid such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a dilution fluid source 18, e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a second flow 14 of silica-containing fluid; a return pipe 15 connected to the dewatering device 12 for transport of the second flow 14 of silica-containing fluid and connected to the first fluid inlet 7; and at least one silica separator 16 provided in the return pipe 15.
  • a dilution fluid source e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature
  • a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-150 °C
  • the dilution fluid temperature is about 1 10-130 °C.
  • a heater 17, e.g. heat exchanger 17 can be provided before the second fluid inlet 1 1, to warm the dilution fluid coming from the dilution fluid source 18 to the specified dilution fluid temperature, if needed.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • a sixth embodiment of a system 1 for silica removal according to the invention is schematically illustrated.
  • the silica-removal system 1 comprises at least a vessel 2, which has a top section 3 and a bottom section 4; a chip inlet 5 provided in the top section 3 for introduction of wood chips, a steam inlet 6 provided in the top section 3 for introduction of steam; a first fluid inlet 7 provided in the vessel and disposed below the top section 3 for introduction of a fluid, such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid to provide a chip slurry having a chip slurry temperature in a chip soaking zone 8, which is disposed below the top section 3, the chip soaking zone 8 being a zone in which chips are submerged in or covered by fluid for a specified soaking time; a chip slurry outlet 9 provided in the bottom section 4 and connected to a chip slurry transportation pipe 10 for transport of the chip slurry out from the vessel 2; a second fluid inlet 1 1 arranged in the bottom section 4 for dilution of the chip slurry to a liquor-to-wood ratio of at least 10: 1, as measured in the chip slurry transportation pipe 10, with a dilution fluid, such as water or a diluted mineral acid, e.g.
  • a dilution fluid such as water or a diluted mineral acid, e.g.
  • diluted sulphuric acid coming from a dilution fluid source 18, e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature; a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry contained therein and for providing a first flow 13 of chip slurry having a liquor-to-wood ration less than 3 : 1 and providing a second flow 14 of silica-containing fluid; a return pipe 15 connected to the dewatering device 12 for transport of the second flow 14 of silica-containing fluid and connected to the first fluid inlet 7; and at least one silica separator 16 provided in the return pipe 15.
  • a dilution fluid source e.g. a dilution fluid tank 18, and having a dilution fluid temperature that is higher than the chip slurry temperature
  • a dewatering device 12 connected to the chip slurry transportation pipe 10 for dewatering of the chip slurry
  • the soaking time for the chips in the chip soaking zone 8 is about 30 minutes to 120 minutes
  • the chip slurry temperature in the chip soaking zone 8 is about 95-105 °C
  • the dilution fluid temperature is about 110-130 °C.
  • a heater 17, e.g. heat exchanger 17 can be provided before the second fluid inlet 11 to warm the dilution fluid coming from the dilution fluid source 18 to the specified dilution fluid temperature, if needed.
  • a mixer 20 can be provided in the chip slurry transportation pipe 10 before - as seen in flow direction - the dewatering device 12, to ensure efficient mixing of the dilution fluid and the chip slurry.
  • a return pipe in both a first fluid inlet and a second fluid inlet, which is connected to a bottom section of a vessel and/or connected to a chip slurry transportation pipe.
  • an inlet for adding an agglomerating and/or flocculating agent, such as polyacrylamide, can be arranged in the return pipe 15 before, as seen in flow direction, the first one of said at least one silica separator 16.
  • Such an agglomerating agent can enhance the efficiency of the silica separator.
  • the common feature for all embodiments presented herein is that the efficiency of the silica removal is enhanced by soaking the chips for a predetermined chip soaking time at rather high, specified temperature.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Mechanical Engineering (AREA)
  • Paper (AREA)
  • Silicon Compounds (AREA)

Abstract

La présente invention concerne de manière générale un système et un procédé pour l'élimination de contaminants de silice de copeaux de bois dans un processus de production de pâte de cuisson kraft à pré-hydrolyse, et en particulier un système et un procédé dans lesquels de la silice est éliminée d'une bouillie de copeaux chaude contenant des copeaux qui ont été trempés dans un fluide pendant un temps de trempage prolongé à une température élevée.
PCT/SE2018/050072 2017-02-07 2018-01-31 Système et procédé d'élimination de silice dans un procédé de dépulpage Ceased WO2018147784A1 (fr)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BR112019014396-3A BR112019014396B1 (pt) 2017-02-07 2018-01-31 Sistema e método para remoção de sílica em um processo para produção de polpa kraft com pré-hidrólise
CN201880009957.9A CN110249092A (zh) 2017-02-07 2018-01-31 用于在制浆工艺中去除二氧化硅的系统和方法
FIEP18750677.9T FI3580388T3 (fi) 2017-02-07 2018-01-31 Järjestelmä ja menetelmä piioksidin poistamiseksi sellunkeittoprosessissa
EP18750677.9A EP3580388B1 (fr) 2017-02-07 2018-01-31 Système et procédé d'élimination de silice dans un procédé de dépulpage
ES18750677T ES2947013T3 (es) 2017-02-07 2018-01-31 Sistema y método para la eliminación de sílice en un proceso de pulpación
PL18750677.9T PL3580388T3 (pl) 2017-02-07 2018-01-31 Układ i sposób usuwania krzemionki w procesie roztwarzania

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1750106A SE540305C2 (en) 2017-02-07 2017-02-07 System and method for silica removal in a pulping process
SE1750106-5 2017-02-07

Publications (1)

Publication Number Publication Date
WO2018147784A1 true WO2018147784A1 (fr) 2018-08-16

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Application Number Title Priority Date Filing Date
PCT/SE2018/050072 Ceased WO2018147784A1 (fr) 2017-02-07 2018-01-31 Système et procédé d'élimination de silice dans un procédé de dépulpage

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Country Link
EP (1) EP3580388B1 (fr)
CN (1) CN110249092A (fr)
CL (1) CL2019002201A1 (fr)
ES (1) ES2947013T3 (fr)
FI (1) FI3580388T3 (fr)
PL (1) PL3580388T3 (fr)
PT (1) PT3580388T (fr)
SE (1) SE540305C2 (fr)
WO (1) WO2018147784A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199399A (en) * 1976-04-19 1980-04-22 Process Evaluation & Development Corp. Method for preparing bagasse dissolving pulps and producing rayon having a degree of polymerization of at least 800 therefrom
US4436586A (en) * 1982-01-22 1984-03-13 Kamyr, Inc. Method of producing kraft pulp using an acid prehydrolysis and pre-extraction
WO1998059107A1 (fr) * 1997-06-25 1998-12-30 Kvaerner Pulping Ab Procede concernant le pretraitement d'une matiere fibreuse hachee
US6214164B1 (en) * 1996-01-31 2001-04-10 Sunds Defibrator Woodhandling Oy Process for pretreating wood chips for pulping
EP1969175B1 (fr) * 2005-12-07 2012-04-11 O'Flynn, Kelly Anthony Nouveau procédé à réacteur catalytique pour la production de pâte de qualité commerciale, de lignine native et d une protéine unicellulaire
JP2015030954A (ja) * 2013-08-06 2015-02-16 日本製紙株式会社 溶解クラフトパルプの製造方法。

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IN154386B (fr) * 1979-12-10 1984-10-20 Dorr Oliver Inc
US4668340A (en) * 1984-03-20 1987-05-26 Kamyr, Inc. Method of countercurrent acid hydrolysis of comminuted cellulosic fibrous material
ZA974836B (en) * 1997-06-02 1998-06-24 Bountiful Applied Res Corp Process for treating spent, waste, alkaline digestion liquor from paper pulping operations and product.
CN101255664B (zh) * 2008-02-02 2010-10-20 山东太阳纸业股份有限公司 一种非木材纤维制浆方法
FI123100B (fi) * 2010-03-11 2012-11-15 Metso Paper Inc Menetelmä sivutuotteiden talteenottamiseksi
WO2013149913A1 (fr) * 2012-04-03 2013-10-10 Ovivo Luxembourg S.a.r.l. Procédé pour l'élimination de matière non fibreuse solide à partir d'une pâte
US9333468B2 (en) * 2012-09-24 2016-05-10 Abengoa Bioenergy New Technologies, Llc Soak vessels and methods for impregnating biomass with liquid
CN203429499U (zh) * 2013-09-11 2014-02-12 江苏飞翔纸业有限公司 一种防堵塞制浆废水循环利用系统
CA2941083C (fr) * 2014-03-21 2020-07-28 Iogen Energy Corporation Procede de traitement d'une charge de depart cellulosique a haute consistance
SE539706C2 (en) * 2014-11-07 2017-11-07 Valmet Oy Method for recovering hydrolyzate

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4199399A (en) * 1976-04-19 1980-04-22 Process Evaluation & Development Corp. Method for preparing bagasse dissolving pulps and producing rayon having a degree of polymerization of at least 800 therefrom
US4436586A (en) * 1982-01-22 1984-03-13 Kamyr, Inc. Method of producing kraft pulp using an acid prehydrolysis and pre-extraction
US6214164B1 (en) * 1996-01-31 2001-04-10 Sunds Defibrator Woodhandling Oy Process for pretreating wood chips for pulping
WO1998059107A1 (fr) * 1997-06-25 1998-12-30 Kvaerner Pulping Ab Procede concernant le pretraitement d'une matiere fibreuse hachee
EP1969175B1 (fr) * 2005-12-07 2012-04-11 O'Flynn, Kelly Anthony Nouveau procédé à réacteur catalytique pour la production de pâte de qualité commerciale, de lignine native et d une protéine unicellulaire
JP2015030954A (ja) * 2013-08-06 2015-02-16 日本製紙株式会社 溶解クラフトパルプの製造方法。

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YUAN, ZHAOYANG ET AL.: "Effect of alkaline pre-extraction of hemicelluloses and silica on kraft pulping of bamboo (Neosinocalamus affinis Keng", INDUSTRIAL CROPS AND PRODUCTS, vol. 91, 2016, pages 66 - 75, XP029681335 *

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PT3580388T (pt) 2023-06-05
ES2947013T3 (es) 2023-07-31
SE540305C2 (en) 2018-06-05
CL2019002201A1 (es) 2019-11-08
EP3580388A1 (fr) 2019-12-18
CN110249092A (zh) 2019-09-17
EP3580388A4 (fr) 2020-12-23
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