Effect of Hot-Water Pre-Extraction on Alkaline Pulping Properties of Wheat Straw

2011 ◽  
Vol 236-238 ◽  
pp. 1174-1177 ◽  
Author(s):  
Su Feng Zhang ◽  
Heng Yang
Keyword(s):  
Wheat Straw ◽  
Extraction Process ◽  
Kappa Number ◽  
Cooking Time ◽  
Hot Water ◽  
Maximum Temperature ◽  
Optimum Conditions ◽  
Hot Water Extraction ◽  
Alkaline Pulping ◽  
Effluent Discharge

The alkaline pulping properties of wheat straw, which had been hemicelluloses pre-extracted with hot water, were studied. In this work, the process of hot-water extraction at various temperatures, reaction time and other conditions were investigated. The straws pre-extracted or not were made into pulp with NaOH-AQ at same conditions. Then the effects of pre-extraction on properties of straw pulp were studied. The results show that the yield, Kappa number and viscosity of the pulp are affected significantly by hemicelluloses pre-extraction process. The chemicals charge of the extracted straw in the pulping process is lower and shorter cooking time needed, the maximum pulping temperature reduced. These effects indicate that the action of hot-water pre-extraction before alkaline pulping is able to reduce effluent discharge and chemical demand to pulp, and it would be energy-saving. In this experiment, the optimum conditions of hot-water pre-extraction were: maximum temperature 140°C, heat-up time 30min, time at maximum temperature 60min and liquor ratio 1:10. The optimal pulping conditions were: alkali charge 12%, maximum temperature 155°C, heat-up time 90min, and holding time at maximum temperature 60min.

scholarly journals Potassium hydroxide pulping of four non-woods

2018 ◽  
Vol 53 (1) ◽  
pp. 1-6 ◽  
Author(s):  
S Sutradhar ◽  
M Sarkar ◽  
J Nayeem ◽  
M Sarwar Jahan ◽  
C Tian
Keyword(s):  
Wheat Straw ◽  
Potassium Hydroxide ◽  
Raw Materials ◽  
Kappa Number ◽  
Pulp Yield ◽  
Optimum Conditions ◽  
Corchorus Capsularis ◽  
Sesbania Bispinosa ◽  
Soda Pulping ◽  
Good Substitute

Four non-woods such as, dhaincha (Sesbania bispinosa), jute stick (Corchorus capsularis), wheat straw (Triticum aestivum) and corn stalks (Zea mays) were cooked by potassium hydroxide (KOH) at the optimum conditions of soda pulping. Dhaincha, wheat straw and corn stalks were delignified to kappa number 19.4, 13.6 and 19, respectively, while jute stick was not delignified sufficiently (kappa number 32.5). All these four raw materials maintained good yield in KOH process. Dhaincha produced the highest pulp yield (50.5%) and wheat straw had the lowest pulp yield (44.7). All pulps were bleached by D0EpD1 bleaching sequences in identical bleaching conditions. Final pulp brightness reached to above 80% ISO except jute stick pulp. Jute stick pulp reached to 74.9% brightness only after the consumption of 30 kg ClO2/ ton of pulp. The overall bleaching yields were 92.6%, 88.4%, 90.1 and 90.8% for dhaincha, jute stick, wheat straw and corn stalks pulps, respectively. The oSR of these four non-wood bleached pulps was above 20, consequently improved papermaking in the unrefined state. Beating rapidly increased papermaking properties, as for example, the tensile index of dhaincha pulps increased from 49 N.m/g in the unrefined pulp to 90 N.m/g in the beaten 50 oSR. It can be seen that KOH is a good substitute to soda process for non-wood.Bangladesh J. Sci. Ind. Res.53(1), 1-6, 2018

Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping

2013 ◽  
Vol 135 ◽  
pp. 665-671 ◽  
Author(s):  
Marc Borrega ◽  
Lasse K. Tolonen ◽  
Fanny Bardot ◽  
Lidia Testova ◽  
Herbert Sixta
Keyword(s):  
High Purity ◽  
Dissolving Pulp ◽  
Hot Water ◽  
Water Extraction ◽  
Birch Wood ◽  
Hot Water Extraction ◽  
Alkaline Pulping

Effect of hot-water extraction on alkaline pulping of bagasse

2010 ◽  
Vol 28 (5) ◽  
pp. 609-612 ◽  
Author(s):  
Yichao Lei ◽  
Shijie Liu ◽  
Jiang Li ◽  
Runcang Sun
Keyword(s):  
Hot Water ◽  
Water Extraction ◽  
Hot Water Extraction ◽  
Alkaline Pulping

Search for optimum conditions of wheat straw hemicelluloses cold alkaline extraction process

2013 ◽  
Vol 71 ◽  
pp. 127-133 ◽  
Author(s):  
Juan C. García ◽  
M.J. Díaz ◽  
M.T. Garcia ◽  
M.J. Feria ◽  
D.M. Gómez ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Extraction Process ◽  
Alkaline Extraction ◽  
Optimum Conditions

Bagasse alkaline sulfite-anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Sahab Hedjazi ◽  
Othar Kordsachia ◽  
Rudolf Patt ◽  
Ahmad Jahan Latibari ◽  
Ulrike Tschirner
Keyword(s):  
Hydrogen Peroxide ◽  
Kappa Number ◽  
Cooking Time ◽  
Maximum Temperature ◽  
Oxygen Delignification ◽  
Burst Strength ◽  
Peroxide Bleaching ◽  
Paper Company ◽  
Printing Paper ◽  
Pulp Strength

Abstract Alkaline sulfite/anthraquinone (AS/AQ) pulping and totally chlorine free (TCF) bleaching of bagasse was investigated. Depithed and wet cleaned bagasse was collected from the Pars Paper Company in southern Iran, dried and then pulped. The active alkali charge was chosen between 16 and 20% on oven-dry bagasse and the alkali ratio, Na2SO3/NaOH, was varied from 30/70 to 70/30. The AQ dose was kept constant. While keeping a constant cooking time at maximum temperature for 60 min, the maximum temperature was varied between 155 and 165°C. For bleaching, a pulp with a kappa number of 8.5 was produced under the following conditions: 18% active alkali, alkali ratio 30/70, 60 min cooking at 155°C. TCF bleaching was performed with oxygen and hydrogen peroxide. Oxygen delignification (O) with an alkali charge of 2% NaOH resulted in 50% degree of delignification. A brightness of 80% ISO was achieved with a chelating treatment (Q) and a subsequent oxygen reinforced peroxide bleaching stage (OP) under drastic conditions (4% H2O2, 2.75% NaOH, 90 min at 98°C). With an additional peroxide bleaching stage charging 2% H2O2, the brightness could be further improved to 83.5% ISO. Bleaching led to only small losses in tensile and burst strength at unchanged tear strength. Short beating in a Jokro mill was sufficient to attain good pulp strength. The results indicate that AS/AQ pulping and TCF bleaching can be successfully applied to bagasse to produce pulp for writing and printing paper.

scholarly journals PENGARUH PEMUTIHAN OKSIGEN DUA TAHAP TERHADAP KUALITAS PULP Acacia mangium

2016 ◽  
Vol 1 (02) ◽  
Author(s):  
Paryono ,
Keyword(s):  
Acacia Mangium ◽  
Kappa Number ◽  
Cooking Time ◽  
Maximum Temperature ◽  
Bleaching Process ◽  
Two Stages ◽  
Cooking Conditions ◽  
Unbleached Pulp ◽  
Made In ◽  
Oxygen Bleaching

In this study, the unbleached pulp was made in the laboratory by cooking conditions: Active Alkali (AA) 18%, Sulfidity (S) 32%, ratio 1: 4, maximum temperature 165 oC, with cooking time of 2 + 1.5 hours. Pulp with kappa number of 20.01 and 52.30% yield was produced. Oxygen bleaching process was varied into a single stage bleaching process, a two-stage bleaching process with and without washing. The results showed that the two stages oxygen bleaching processes, without washing with variation of NaOH addition 100:0 and 80:20 gave the higher reduction of kappa number and the increasing of bleaching yield compare to one stage oxygen bleaching. The higher reduction of kappa number gave the higher of reduction of viscosity, but had no effect on fiber composition. Two oxygen stage bleaching without washing is recommended.Key words : oxygen bleaching, kappa number, viscosity, yield filtered  ABSTRAKPada penelitian ini pulp belum putih dibuat di laboratorium dengan kondisi pemasakan : AA 18 %, S 32 %, rasio 1 : 4, temperatur maksimum 165 OC, dan waktu 2 + 1,5 jam. Dihasilkan pulp dengan bilangan kappa 20,01 dan rendemen tersaring 52,30 %. Proses pemutihan oksigen divariasi menjadi proses pemutihan satu tahap, proses pemutihan dua tahap dengan dan tanpa pencucian. Hasil penelitian menunjukkan pemutihan oksigen dua tahap tanpa proses pencucian dengan variasi penambahan NaOH 100 : 0 dan 80 : 20 memberikan penurunan bilangan kappa yang lebih besar dan peningkatan rendemen pemutihan dibanding dengan pemutihan oksigen satu tahap. Penurunan viskositas sebanding dengan penurunan bilangan kappa, dimana semakin besar penurunan bilangan kappa juga mengakibatkan penurunan viskositas yang semakin besar tetapi tidak berpengaruh terhadap komposisi serat. Pemutihan oksigen dua tahap tanpa proses pencucian sangat disarankan. Kata kunci : pemutihan oksigen, bilangan kappa, viskositas, rendemen tersaring  

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