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  

scholarly journals Formic Acid Pulping of Bagasse

1970 ◽  
Vol 41 (3) ◽  
pp. 245-250 ◽  
Author(s):  
M Sarwar Jahan
Keyword(s):  
Formic Acid ◽  
Acid Concentration ◽  
Strength Properties ◽  
Kappa Number ◽  
Cooking Time ◽  
Pulp Yield ◽  
Cooking Conditions

Atmospheric formic acid pulping of bagasse was done with varying formic acid concentration and cooking time. Pulp yield and kappa number decreased with increasing formic acid concentration or cooking time. The optimal cooking conditions were 90 % formic acid and 90 min of cooking at 95°C. The pulp yield at this condition was 44.4 % and kappa number 26.1. The strength properties were acceptable in formic acid pulping of bagasse. Addition of H2SO4 catalyst in formic acid degraded carbohydrate, resulting lower pulp yield and inferior strength properties. The strength properties were improved slightly after bleaching. Bangladesh J. Sci. Ind. Res. 41(3-4), 245-250, 2006

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.

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.

Organic material dissolved during oxygen-alkali pulping of hot water extracted birch sawdust

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN
Keyword(s):  
Acetic Acid ◽  
Betula Pendula ◽  
Cooking Time ◽  
Hot Water ◽  
Partial Hydrolysis ◽  
Chemical Pulping ◽  
Black Liquors ◽  
Aliphatic Carboxylic Acids ◽  
Hydrolysis Of ◽  
Cooking Conditions

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.

The first two decades of Circular Economy in the 21st century: a bibliographic review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
João Francisco Pinto Anaruma ◽  
Jorge Henrique Caldeira de Oliveira ◽  
Francisco Anaruma Filho ◽  
Wesley Ricardo de Souza Freitas ◽  
Adriano Alves Teixeira
Keyword(s):  
21St Century ◽  
Circular Economy ◽  
Review Of Literature ◽  
Content Type ◽  
Time Period ◽  
Number Of Publications ◽  
Two Stages ◽  
Academic Area ◽  
Practical Implications ◽  
Made In

PurposeThe purpose of this paper is to analyze and map the main areas of the Circular Economy literature of the first two decades of 21st century, offering a broad vision about the growth of the theme during these years.Design/methodology/approachThe research was divided into two stages: the first was a systematic review of literature and the second consisted on generation and analysis of bibliographic maps.FindingsThe publication indicates the prominence of China and European Union countries in the production of articles about Circular Economy. Furthermore, the topic is restricted to academic area, and that research on Circular Economy is still very focused on theory studies, even with exponential growth in the number of published articles about the theme since 2015. Finally, it also provides a collection of information as the principal authors, the most cited publications, citations, co-citations and countries that have most published beyond which are the most discussed topics.Research limitations/implicationsA possible limitation of the research is that it was performed only in the Scopus database. It may be suggested as future searches that other databases are included as well, and another suggestion is to reduce the time period between research samples due to the exponential increase in the number of publications and topics discussed lately.Practical implicationsThe results of this paper can guide future researches about the development of Circular Economy during the next decades or years and serve as a facilitator for researchers and for managers that want to know more about the topic.Originality/valueA mapping of the principal players and main discussions about Circular Economy made in the first two decades of the 21st century and an analysis about the growth and changes about the theme.

Kraft pulping and bleaching of Eichhornia crassipes (Mart.) Solms (water hyacinth)

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9243-9264
Author(s):  
Luis Fernando Pintor-Ibarra ◽  
José de Jesús Rivera-Prado ◽  
Sarai Ramos-Vargas ◽  
Teófilo Escoto-García ◽  
Nancy Eloisa Rodríguez-Olalde ◽  
...  
Keyword(s):  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Inorganic Elements ◽  
Wood Fibers ◽  
Pulp Bleaching ◽  
Cellulosic Pulp ◽  
Unbleached Pulp

Eichhornia crassipes (water hyacinth) was pulped by means of a kraft pulping process with reagent loads of 10 and 20% on a dry matter basis to determine yield, rejects, kappa number, and ash. Fiber classification, brightness, opacity, and viscosity were measured in the brown pulp. Bleaching was performed by means of an O1O2D1(PO)D2HD3 sequence. Yield, kappa number, pH, ash, brightness, opacity, and viscosity were evaluated in the bleached pulp. Finally, a microanalysis of inorganic elements was carried out in both the bleached and unbleached pulp ash. The highest kraft pulp yield was 26.4%, with a 10% reagent load at 120 °C and 30 minutes cooking. It was determined that E. crassipes cellulosic pulp contains large amounts of fines. Results of the bleaching sequence indicate low brightness (58.0 %) and low viscosity (6.43 cP). The most abundant inorganic elements in the ash of both bleached and unbleached pulp were Ca, Mg, P, and Si. These results suggest that E. crassipes biomass might complement cellulosic fibers in pulping processes of low yield, such as the wood fibers used to produce handmade paper.

scholarly journals Extraction of γ-Alumina from Low-Cost Kaolin

Resources ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 63
Author(s):  
Khalil Ibrahim ◽  
Mohammad Moumani ◽  
Salsabeela Mohammad
Keyword(s):  
Low Cost ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminum Metal ◽  
Alumina Particles ◽  
Two Stages ◽  
Method Of Extraction ◽  
Microcrystalline Powder ◽  
Made In

A combined process is proposed for the utilization of local kaolin to produce alumina particles. The applied process is made in two stages: calcination at 700 °C with sodium chloride and leaching with sulfuric followed by hydrochloric acids. The optimal extraction efficiency can be obtained when the conditions are as follows: leaching temperature is at 140 °C, leaching time is 3 h 45 min and concentration of sulfuric acid is 40 wt.%. The results show that the purity of alumina reaches 79.28%, which is suitable for the production of aluminum metal. It is evident that this method of extraction of alumina from the kaolin ash is practical and feasible. The structural and morphological properties of the calcined microcrystalline powder was characterized by X-ray diffraction and scanning electron microscope (SEM).

Positioning the Tata Nano (B)

2017 ◽  
pp. 1-2
Author(s):  
Alice M. Tybout ◽  
Natalie Fahey
Keyword(s):  
Production Capacity ◽  
Frame Of Reference ◽  
Product Launch ◽  
Limited Capacity ◽  
Brand Positioning ◽  
Decision Point ◽  
Safety Issues ◽  
Indian Consumers ◽  
Two Stages ◽  
Made In

The case focuses on positioning a new brand, the Tata Nano. The car has been widely publicized as the world's cheapest car at Rs.1 lakh. Students must consider the gap between the ultimate target, the huge emerging middle class of Indian consumers, and the limited capacity and distribution available in choosing a target. They also must select between alternative competitive frames and the various points of difference they highlight. The case unfolds in two stages. The first decision point is in 2009, at the launch of the time of the product launch. The second decision point is 18 months later, after production capacity has increased and some product safety issues have arisen.The primary goal of the case is to illustrate the choices made in developing a strong brand positioning and the interrelationship between these choices. Students select a target and an appropriate competitive frame of reference and point of difference for that target and summarize these elements in a positioning statement. The case also highlights importance of making promotion and distribution decisions that are consistent with the positioning.

Pre-bleaching of kraft acacia pulp

2019 ◽  
Vol 34 (2) ◽  
pp. 165-172 ◽  
Author(s):  
Moinul Haque ◽  
Moumita Nanjiba ◽  
M. Sarwar Jahan ◽  
M. A. Quaiyyum ◽  
M. Zahangir Alam ◽  
...  
Keyword(s):  
Acacia Mangium ◽  
Kappa Number ◽  
Acacia Auriculiformis ◽  
Kraft Pulps ◽  
Oxygen Delignification ◽  
Acid Pretreatment ◽  
Acacia Hybrid ◽  
Pre Treatment ◽  
Hexenuronic Acid ◽  
Peroxyformic Acid

Abstract Kraft pulps from acacia hybrid, Acacia mangium of 8 years old and Acacia auriculiformis of 6, 8 and 10 years old were pre-treated with oxygen, peroxyformic acid and acid treatment prior to bleaching. The kappa number reduction was 52–63 % by oxygen delignification, 31–35 % by peroxyformic acid (PFA) pre-treatment and 11–13 % by acid pre-treatment. Oxygen delignified pulp required less chlorine dioxide charge to reach target brightness. At the consumption of 30 kg ClO2/ton of pulp, the pulp brightness reached to 65–71 % for the untreated pulp, 81–85 % for the oxygen delignified pulp, 81–82 % for the PFA treatment and 79–80 % for acid pre-treated pulp. COD load in bleached effluent was much lower in oxygen delignified pulp. Cold alkali extraction of unbleached and oxygen delignified pulps was also carried out with varying alkali charge to remove hexenuronic acid (HexA) from the pulp. Xylan removal from the pulp was insignificant and resulted in no removal of HexA. Acid pretreatment removed 55.7 % to 17.8 % HexA from acacia hybrid, 57.5 % to 16.3 % from A. auriculiformis of 10 years and 58.6 % to 20.1 % from A. auriculiformis of 6 years old, resulting in improved final pulp brightness.

Study on Preparation of Dissolving Grade Pulp and its Kinetics of Prehydrolysis

2011 ◽  
Vol 233-235 ◽  
pp. 1479-1484
Author(s):  
Ke Xin Hu ◽  
Guang Ming Zeng ◽  
Hai Chao Zhang
Keyword(s):  
Quality Standards ◽  
Kraft Pulping ◽  
Cooking Time ◽  
Bleaching Process ◽  
First Order ◽  
Pseudo First Order ◽  
P Factor ◽  
Prehydrolysis Kraft ◽  
Kinetics Of ◽  
Pulp Production

The possibilities of dissolving grade pulp production from reed were investigated in this paper. Two – stage prehydrolysis – kraft pulping and CEHA bleaching process of reed for preparation of dissolving grade pulp were studied in laboratory. The optimum cooking and bleaching conditions were found out. The mechanism and its kinetics of reed in prehydrolysis process were also discussed. The results showed that under the laboratory conditions the rate for removal of materials at about 175°C follow approximately a pseudo first order law with two distinct phrases: the bulk removal and the residual removal of the materials. The prehydrolysis-factor (P-factor) was established. The advantage of using P-factor is predict compensating adjustments in cooking time and/or temperature to give the same degree of pulping and to produce pulp with predetermined characteristics. It is found that three distinct delignification rate stages about 75% of pentosans and about 50% of lignin were removed. A CEHA four stage bleaching is used for dissolving grade pulp. Total chlorine charge in bleaching is 6% (to oven-dry pulp). The results show that all of the indices fitted the quality standards of dissolving grade pulp.

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