• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:

    公开号:SE1200136A1
    申请号:SE1200136
    申请日:2012-03-02
    公开日:2012-09-04
    发明作者:Lars Stigsson
    申请人:Cellray Ab；
    IPC主号:
    专利说明:

    10invention in the present invention is to start with debarking and mechanical refinementor the eller berisation of wood to wood fi brer, fi berbunter or fi brös trassassa to a me-partial milling condition (CSF) over about 40 ml, preferably higher than 100 ml and mostpreferred to a grinding condition level above 200ml. The grinding condition level is adjustedwith the energy input (steam and / or electrical energy) to operators or distributorsand / or by adding chemicals to the wood material used in the process(sul fl t, sulfur dioxide).
    In a further alternative process with respect to the first step, a fi fracture is producedpulp comprising recycled cellulose (newsprint, occ. and the like) such ashas a lignin excess of more than about 1% by weight in relation to the dry mass (afterremoval of ink) as a feed to the second stage according to the present invention.ningen.
    In an optional second step, small wood particles, wood fibers, fiber bundle steps are treatedor fi broth mass obtained directly, or indirectly, from the first step of steamingand / or an acidic solution to dissolve, break down and separate hemicellulose from wood fi-the bundles or the fragile wood pulp. Such steam treatment is advantageously performed duringpressure in reactor (STEX steam explosion reactor). The pressure is abruptly removed and the materialal, from which fiber has been removed, is taken out of the STEX reactor. The STEX treatment gives onecurrent rich in hemicellulose and a current rich in small wood particles and lignocellulosicenn bennassa. In a third step, wood particles, fi brittle wood pulp or fi brittle pulp are dischargedrecovered fi requests from the previous step, directly or indirectly, to a reaction zone in areactor operating at a temperature in the range 20-220 ° C, preferably in the range 20-150 ° C, most preferably in the spar 20-130 ° C. A cooking liquid is charged to the reactor, theresaid cooking liquid comprises at least one chemical capable of dissolving a lignin,wherein said chemical is either ofi) an organic solvent comprising methanol, ethanol, acetic acid or formic acidraii) a hydrotropic pulp preparation chemical, such as sodium xylene sulfonate(iii) liquids containing sul fi t, sul fi d or hydroxide ionsIn a third step, lignin is released from the cellulose and dissolved in the cooking liquid to forman aqueous, spent cooking liquid.
    The aqueous spent liquor comprising dissolved lignin is separatedfrom the stripped cellulose pulp through one or more periods of filtration, sieving andcentrifugation, to give a first stream of ös brittle mass rich in alpha-cellulose with onelignin content corresponding to a kappa number lower than about 30, preferably lower thanabout 20, and most preferably to a kappa number lower than about 10, and a secondstream of spent cooking liquor containing dissolved lignin. Kappatalet is a measure ofthe lignin content of cellulose pulp, a measure well known to the skilled user.
    In a fourth step, said first current is treated with a mass rich in alpha cellsolve with one or fl era of washing with a solution comprising a hydrotropic mediumpart, washing with water, treatment with oxygen, hydrogen peroxide or ozone, bleaching with sub-punches containing chlorine, treatment with enzymes to remove hemicellulose andextraction of hemicelluloses by treating the pulp with cold or aqueous sodiumhydroxide, in which the corresponding treatments are carried out to give a pure, soluble mass,with high alpha cellulose content.
    In an optional fifth step, pulp is dissolved, which can be dissolved and which has onehigh alpha cellulose content, in a cellulose solvent to form a cellulose doping,which comprises at least 5% cellulose by weight. The cellulose doping is used toto form new cellulose fibers, either by removing the cellulose solutionthe agent to form a fi tissue or by treating the cellulose doping with acellulose solvent, whereby regenerated cellulose, in the form of lamentationsor a cellulose film, is formed.
    Lignin is removed from the spent cooking liquid with either of;a) Dilution of a spent cooking liquid, which comprises a hydrotropicby water and separating the precipitated and substantially sulfur-free lignin fromvästkan,b) Distillation of the spent cooking liquid, which includes organicsolvent (ethanol, acetic acid, formic acid), and recovery of organic solventand a substantially sulfur-free lignin.c) Oxidation, or partial oxidation, of spent cooking liquid, which containssulfur-containing chemicals (sulphate, sul fi t, sul fi d) in a gas generator or a recyclableboilers, wherein said removal of lignin is carried out to produce fresh cooking liquidfor recycling to treat new cellulose particles or fi brittle pulp in step b) and forto recover the lignin value as fuel / energy or as a starting material for chemicallie manufacturing.
    After removal of lignin, the spent cooking liquid is restored and recycledas fresh cooking liquid to the cooking step.
    The mechanical size reduction of wood in the first step can be performed in oneor steg your steps, which include icing and unification in refiners and debraters. Beneficiallaktigen is performed for the eller or de ellerbration in the presence of steam. Optionally, the fi b-or compounding in the presence of (or after treatment with) sulfur dioxide or salt.
    In an optional second step, an acid stream comprising degraded heat is removed.micellulose (pentosanes) before the treatment with the cooking liquid in the third step.
    The second and / or third stage is carried out in continuous or batch boilers,tank reactors or tube reactors, which include static mixers. Continuous hydraulicboilers or vapor phase boilers, as well as MD boilers, STX reactors or Pan-deacokers can be advantageously used for the thermal treatments and / orings the reactions described herein.
    The invention is particularly characterized by the fact that the alignment procedure in the thirdThis step is significantly shorter in time compared to traditional wood leveling processes.cesser. The residence time at temperature in the boiler or reactor is shorter than about 2hours, preferably less than about 1 hour and most preferably for aboutminutes. The short residence time, which is made possible by the previous treatment ofthe wood material in the first and second stage, is a significant advantage compared to thoselong times used for alignment in traditional pulp production ascan be dissolved. The temperature and time of boiling / alignment in the pulping processis traditionally expressed by the H-factor. The H-factor is a kinetic model for the speed ofthe alignment in the mass production. It is a single variable model thatcombines the temperature (T) and time (t) assuming that the equalization is a one-stepaction.16115) dTrH = I0 exp <43.2 - T:As a result of the small sizes of wood particles or fiber bundles thatproduced in the first step of the present invention requires the third alignmentthe step of the present invention substantially less time than that usedalignment in traditional alignment processes. The H-factor used is dependent onthose of the wood raw material (hard wood or soft wood) and whether any chemical pre-treatment(steam and / or acid) made before delignification. The H-factor used is therefore keptlower than 1500, more preferably lower than about 1000 and most preferably lower thanabout 600.
    During the second and third stages, gaseous substances (carbon dioxide,acetic acid, formic acid) are developed, which gases are intermittently removed to keep the pressure inthe reactor or reactor at the desired level.
    For the third step, the hydrotropic pulp production pathway ortic acid pulp preparation method to be preferred. Most preferred is the hydrotropic onethe mass road, which has the least complicated recycling system for spentcooking chemicals.
    Hydrotropic solvents are preferably alkali metal salts, whichobtained from aromatic single ring systems. Particularly preferred as a hydrotropic agentis sodium xylene sulfonate. The concentration of the hydrotropic agents in the freshthe liquid is from about 20% to about 60% by weight in water.
    The third ligation step is performed until the lignin content of the remainderthe mass is lower than about 5%, preferably lower than about 3% and preferablyuntil the lignin content is less than 1% by weight in relation to the dry mass.
    Alignment of cellulose pulp from the third alignment step is treatedwith one or more periods of oxygen depletion, peroxide or peracetic acid treatment, cold orhot alkali extraction and / or treatment with a hydrotropic agent to form aquality cellulose pulp that can be dissolved, which has a lignin content lower than theabout 1% by weight in terms of mass and an alpha-cellulose content exceeding 90% by weight.
    In addition to removing lignin to levels below 1% by weight, hemicellulosethe content of the quality mass, which can be dissolved, in the lignin removal treatments.
    The hemicellulose content is advantageously lower than 5% in the product mass, which is rich inalphacellulose.
    Mass, which is rich in high alpha and can be dissolved, prepared accordinglythe present invention, any good cellulose solvent, such as sodiumumhydroxide, NMMO, or ionic liquids. Before dissolution, the mass, which can be dissolvedalso reacted with acetic acid, urea or carbon disul fi d to form a cellulose ester,a cellulose axanthate or a cellulose carbamate, which cellulose derivatives are more soluble inagents such as sodium hydroxide.
    The cellulose doping formed by dissolving alpha-cellulose-rich pulp, which candissolved, can be converted into new cellulose fibers by injecting the cellulose doping intoa solvent with poor ability to dissolve cellulose. Solvents with low orno ability to dissolve cellulose is well known to the skilled user in wet fi-berspinning. Alternatively, the solvent is removed from the cellulose doping by removingevaporation or washing whereby a cellulosic tissue material is formed.
    The present invention thus describes a cheap and efficient processto produce a quality pulp, which can be dissolved, from recycled celluloseor from wood by a thermomechanical treatment, size reduction of the wood materialto small particles, fi berb bundles or fi ber that form a ös brittle cellulose mass, treatthe brittle cellulose mass at a low H-factor with a leveling agent toform a cellulose pulp with a low lignin content, further to treat the cellulose pulpwith low lignin content to obtain a quality cellulose mass, which can be dissolved andhas a high alpha-cellulose content, and optionally loose cellulose rich in high alpha-cellulose ina solvent to form a cellulose doping, which doping is used for regeneration.new cellulose fibers, films or a fabric.
    Such regenerated celluloses are particularly advantageous in order to partially orreplace all viscose or cotton in the manufacture of woven fabrics for applications inhome and clothes.
    权利要求:
    Claims (9)
    [1]
    A process for producing a quality cellulose pulp which can be dissolved, with a low lignin content in a sequence of steps characterized in that: a) Wood treated with a thermomechanical or steam explosion process and / or recycled cellulose pulp having a lignin content above about 1% constitutes a feed stream consisting of a brittle mass having a grinding state (CSF) level of about 40 ml b) Fibrous mass from step a) is boiled in the presence of an active cooking chemical using an H-factor lower than about 1500 to form a stream of stripped cellulose pulp and a stream of spent cooking liquor sa, which can be dissolved, with a lignin content of less than about 1% by mass and an alpha-cellulose content exceeding 90 v d) Consumed cooking liquid taken from step b) is treated with at least one of combustion, gasification, distillation, washing or dilution to an aqueous solution, filtration and centrifugation to separate lignin from the consumed cooking liquid. can.
    [2]
    Process according to claim 1, characterized in that the H-factor used to complete the cooking in step b) is lower than 1000, preferably lower than about 600.
    [3]
    Process according to claim 1, characterized in that the active cooking chemical is an organic acid, an alcohol or a hydrotropic agent.
    [4]
    Process according to claim 1, characterized in that the level of grinding condition in the brittle mass prepared in step a) is higher than about 100 ml, preferably higher than about 200 ml.
    [5]
    Process according to claim 1, characterized by the aligned cellulose pulp prepared in step b) has a kappa number lower than about 30, preferably lower than about 20 and most preferably a kappa number lower than about 10.
    [6]
    Process according to claim 1, characterized in that the quality pulp which can be dissolved and which is produced in step c) has a hemicellulose content lower than about 5% by weight in terms of the pulp.
    [7]
    Process according to claim 1, characterized in that the quality mass which can be dissolved from step c) is dissolved in a solvent which forms a cellulose doping having a cellulose content of more than about 5%.
    [8]
    Process according to Claim 7, characterized in that the cellulose doping is regenerated into new cellulose by treatment with a solvent with a poor capacity to dissolve cellulose.
    [9]
    Process according to claim 7, characterized in that the cellulose doping is transferred to a fi tissue by removing the cellulose solvent.
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    同族专利:
    公开号 | 公开日
    SE536786C2|2014-08-12|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    US201161457338P| true| 2011-03-03|2011-03-03|
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