Short Process TCF And ECF Bleaching Of Organic Acid Biorefinery Corn Stalk Rind Pulp

Corn straw are abundant and excellent biomass resources and natural fiber raw materials.Lignocellulose biomass organic acid pulping process is a promising biological process.Development of short bleaching process for organic acid biorefinery Corn Stalk rind pulp(OABCSRP) technology is valuable. To obtain the bleaching process towards a reasonablebrightness, fiber resource-saving and reduction energy consumption and pollution, theproperties of alkali treatment (E), O₂delignification (O) and xylanase pretreatment (X),hydrogen peroxide bleaching(P), pressure hydrogen peroxide bleaching (PO),short TCF andECF bleaching processes of OABCSRP were studied. The main results are as follows:Preteatment E is a selective delignification for OABCSRP and a pulp with95.4%ofyield,23.5%of delignification,115mPa·s of viscosity and44.2%ISO of brightness could beobtained by the extraction of10.0%pulp consistency,4.0%NaOH for1.5h at70℃; a pulpwith99.8%of yield,6.75%of delignification and95.7mPa·s of viscosity of brightness couldbe obtained by X at10.0%of pulp consistency and2.5IU/g of X dosage at70℃for1.5h; Ohad a good preteatment effect, a pulp with91.8%of yield,43.4%of delignification,92.7mPa·sof viscosity and48.8%(ISO) of brightness obtained by delignification at10.0%pulpconsistency and3.0%NaOH at0.75MPa and110oC for50min; the ester linkages of thelignin and carbohydrate in the pulp were hydrolyzed in E and O processes; the fible cellulosecrystallinity was decreased in X processes; the fiber surface morphology chang in the E and Opretreatments was more obviously than that in X processes.TCF P bleaching was efficient for OABCSRP, a pulp with91.7%of yield,94.3mPa·s ofviscosity and62.8%(ISO) of brightness was abtained by P bleaching; compared to P,(PO)bleaching has better bleaching performance, the bleaching could obtained91.8%of yield,67.5mPa·s of viscosity and68.1%ISO of brightness, but cellulose degradation was moreseriously in (PO) bleaching; EP improved bleaching performance further, which could easilyachieve a pulp with92.2%of yield,74.1mPa·s of viscosity and75.6%ISO; E(PO) could easilyachieve a pulp with91.8%of yield,53.5mPa·s of viscosity and79.9%ISO; a pulp with a81.7%of yield,72.0mPa·s of viscosity and81.4%(ISO) of brightness could be obtained after EP₁P₂;and E(PO)P could achieve the pulp which was a87.4%of yield,39.1mPa·s of viscosity and84.5%(ISO) of brightness. Two stages E(PO) bleaching could save chemials than EP, but energyconsumption in E(PO) is more than that in EP. The pulp with a brightness around75%(ISO) bymentioned processes above could be used for the production of writing paper; The EPP andE(PO)P processes can bleach OABCSRP to over80%(ISO) of brightness and the pulp can be used for mamufacture of fine paper.ECF A short ED₁D₂process, which get a pulp with a yield88.0%, viscosity124mPa·s andbrightness75%(ISO), is suitable for the pulp bleaching to produce a fine paper; a pulp with ayield87.1%, viscosity124mPa·s and brightness75.4%(ISO) could be obtained by OD₁D₂process; A short XD₁D₂process bleach can OABCSRP to a pulp with a yield90.3%, viscosity101mPa·s and brightness74.7％(ISO). The yield of XD₁D₂bleaching pulp was higher than thatof ED₁D₂and XD₁D₂, and the other XD₁D₂performance are simier with ED₁D₂and XD₁D₂, thusE is a better pretreatment for OABCSRP.Paper performance E(PO) pulp is easily to be refined by PFI mill, which characteristicsin refining was similar to that in wheat straw pulp refining; when the rpm was increaseed from0to1500, the beating degree increased from16.7oSR to37.2oSR linearly; The bleached pulp cangreatly improve the paper air permeabibly; The handsheet strength and optical properties weresimiler to the wheat straw's properties, which could instead of wheat straw bleached pulp for therelated paper production.