scholarly journals Effects of Caustic Extraction on Properties of Viscose Grade Dissolving Pulp

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 122 ◽  
Author(s):  
Cindy Friebel ◽  
Robert Bischof ◽  
Gabriele Schild ◽  
Karin Fackler ◽  
Ireen Gebauer
Keyword(s):  
Viscose Fibre ◽  
Beech Wood ◽  
Fibre Production ◽  
Extraction Yield ◽  
Dissolving Pulp ◽  
High Yield ◽  
Cellulose Content ◽  
Sodium Hydroxide Concentration ◽  
Pulp Temperature ◽  
Extraction Model

Viscose, a cellulose-based commodity fibre, is produced by pulping and bleaching of wood, yielding a high quality “dissolving pulp” which is then spun. During pulping and bleaching, effective hemicellulose extraction is required to allow fibre production. We present a design of experiments (DoE) approach to optimise caustic extraction in a total chlorine free (TCF) bleaching sequence (O-CE-Z-P) of beech wood sulphite pulp. Temperature and sodium hydroxide concentration were varied to identify highest xylan extraction yield, and a maximum xylan removal of 83% was achieved at 20 °C and 120 g/L NaOH. Additionally, caustic extraction conditions were derived from the DoE model that led to pulps with high yield, high alpha cellulose content or uniform cellulose molecular weight distribution. Pulps from verification experiments exhibited good reactivity in viscose application tests. Hence, the presented O-CE-Z-P bleaching sequence can be considered as suitable for integrated viscose fibre production. We assume that the presented caustic extraction model will be useful for pulp and biorefinery researchers who work on caustic biorefinery processes involving hardwood feedstocks.

Preparation of acetate-grade dissolving pulp from eucalyptus by processes including alkaline pretreatment and combined post-treatments with xylanase and alkali

TAPPI Journal ◽  
2013 ◽  
Vol 12 (9) ◽  
pp. 19-24
Author(s):  
WEN LIU ◽  
SHUKE ZHOU ◽  
XIAOHUA QI ◽  
JUNWEN PU
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Degree Of Polymerization ◽  
Kraft Pulping ◽  
Dissolving Pulp ◽  
Alkaline Pretreatment ◽  
Cellulose Content ◽  
Optimal Conditions ◽  
Pulp Bleaching ◽  
Sodium Hydroxide Concentration

In this investigation, alkaline pretreatment before kraft pulping and combined post-treatments with xylanase and alkali after bleaching were applied to obtain an acetate-grade dissolving pulp. Bleaching sequences using oxygen or hydrogen peroxide were also studied. The brightness, α-cellulose content, and degree of polymerization (DP) of the bleached pulps from different bleaching sequences were evaluated. Alkaline pretreatment resulted in a higher α-cellulose content in the pulp. When a D1ED2P bleaching sequence was applied, the pulp obtained had an ISO brightness of 87.5%, a DP of 1050, and an α-cellulose content of 92.7%. The requirements for an acetate-grade dissolving pulp can then be met when followed by combined post-treatments with xylanase and alkali under the optimal conditions of 120 IU•g–1 xylanase dosage and 4% sodium hydroxide concentration.

scholarly journals Optimized Supercritical CO2 Extraction Enhances the Recovery of Valuable Lipophilic Antioxidants and Other Constituents from Dual-Purpose Hop (Humulus lupulus L.) Variety Ella

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 918
Author(s):  
Nóra Emilia Nagybákay ◽  
Michail Syrpas ◽  
Vaiva Vilimaitė ◽  
Laura Tamkutė ◽  
Audrius Pukalskas ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Antioxidant Properties ◽  
Extraction Yield ◽  
Biologically Active ◽  
High Yield ◽  
Acid Extraction ◽  
Supercritical Co2 Extraction ◽  
Bioactive Constituents ◽  
Total Extract

The article presents the optimization of supercritical CO2 extraction (SFE-CO2) parameters using response surface methodology (RSM) with central composite design (CCD) in order to produce single variety hop (cv. Ella) extracts with high yield and strong in vitro antioxidant properties. Optimized SFE-CO2 (37 MPa, 43 °C, 80 min) yielded 26.3 g/100 g pellets of lipophilic fraction. This extract was rich in biologically active α- and β-bitter acids (522.8 and 345.0 mg/g extract, respectively), and exerted 1481 mg TE/g extract in vitro oxygen radical absorbance capacity (ORAC). Up to ~3-fold higher extraction yield, antioxidant recovery (389.8 mg TE/g pellets) and exhaustive bitter acid extraction (228.4 mg/g pellets) were achieved under the significantly shorter time compared to the commercially used one-stage SFE-CO2 at 10–15 MPa and 40 °C. Total carotenoid and chlorophyll content was negligible, amounting to <0.04% of the total extract mass. Fruity, herbal, spicy and woody odor of extracts could be attributed to the major identified volatiles, namely β-pinene, β-myrcene, β-humulene, α-humulene, α-selinene and methyl-4-decenoate. Rich in valuable bioactive constituents and flavor compounds, cv. Ella hop SFE-CO2 extracts could find multipurpose applications in food, pharmaceutical, nutraceutical and cosmetics industries.

Water Prehydrolysis of Moso Bamboo Dissolving Pulp

2013 ◽  
Vol 750-752 ◽  
pp. 1586-1592
Author(s):  
Tao Gu ◽  
Li Qing Weng ◽  
Guo Xin Xue
Keyword(s):  
Retention Rate ◽  
Dissolving Pulp ◽  
Moso Bamboo ◽  
Cellulose Content ◽  
High Grade ◽  
Single Factor ◽  
Optimum Conditions ◽  
Wood Material ◽  
Factor Method ◽  
High Cellulose

The chemical comcomposition and water prehydrolysis of moso bamboo were studied to prepare high grade dissolving pulp. The results indicated that the moso bamboo was an appropriate none-wood material for great dissolving pulp goten as its high cellulose content. By single factor method, the optimum prehydrolysis conditions which were 150°C, 120minutes and 1:8 of liquor-to-wood tatio, were obtained. Based on the optimum conditions, the yield was 90.35%, and the retention rate of cellulose, pentosan, acid accumulator insoluble lignin, and ash were respectively 96.30%, 88.22%, 88.13%, and 11.71%.

scholarly journals PENGGUNAAN XILANASE PADA PEMUTIHAN DISSOLVING PULP Acacia crassicarpa

2015 ◽  
Vol 5 (02) ◽  
Author(s):  
Susi Sugesty ◽  
Teddy Kardiansyah ◽  
Wieke Pratiwi
Keyword(s):  
Chlorine Dioxide ◽  
Dissolving Pulp ◽  
Raw Material ◽  
National Standard ◽  
Cellulose Content ◽  
Pulp Bleaching ◽  
Elemental Chlorine ◽  
Free Process ◽  
Acacia Crassicarpa ◽  
Prehydrolysis Kraft

The use of xylanase in pulp bleaching process is intended to reduce chemicals consumption in pulp industry that still using chlorine compounds (chlorine dioxide), so the bleaching stage needs to be modified without reducing the quality of dissolving pulp. Dissolving pulp was produced from six-year-old Acacia crassicarpa as raw material by the Prehydrolysis-Kraft process, then the pulp was bleached with the ECF (elemental chlorine free) process using xylanase (X) and oxygen (O) as comparison at the early stage of bleaching. The sequences of process include X/ODEDED (xylanase or oxygen; chlorine dioxide; extraction-1; chlorine dioxide-1; extraction-2; chlorine dioxide -2). Results showed that the dissolving pulp with active alkali of 22%, sulphidity of 30%, the temperature of 165oC, and the ratio of 1:4 is the optimal condition. Cellulose content, viscosity and brightness were above 94%, 6.2 cP and 88% ISO, respectively.The dissolving pulp produced with the application of xylanase has better quality than the oxygen one, and meets the requirement according to Indonesia National Standard (SNI 0938:2010, pulp rayon).Keywords: Acacia crassicarpa, xylanase, Prehydrolysis-Kraft, dissolving pulp, rayon pulpABSTRAKPenggunaan xilanase pada proses pemutihan pulp dimaksudkan untuk mengurangi konsumsi bahan kimia yang digunakan selama ini di industri pulp, yang masih menggunakan senyawa klorin (klorin dioksida), untuk itu perlu dilakukan modifikasi pada tahap pemutihannya tanpa mengurangi kualitas dissolving pulp yang dihasilkan. Pembuatan dissolving pulp dilakukan menggunakan bahan baku kayu Acacia crassicarpa berumur 6 tahun dengan proses Prahidrolisa–Kraft, selanjutnya pulp diputihkan dengan proses ECF (Elemental Chlorine Free) menggunakan xilanase (X) dan oksigen (O) sebagai pembanding pada awal pemutihan dengan 6 tahapan proses, yaitu X/ODEDED (xilanase atau oksigen; klorin dioksida; ekstraksi-1; klorin dioksida-1; ekstraksi-2; klorin dioksida-2) dengan perlakuan oksigen sebagai pembanding. Hasil pembuatan dissolving pulp dengan alkali aktif 22%, sulfiditas 30%, suhu 165oC, rasio 1:4 adalah kondisi yang optimal. Kandungan selulosa, viskositas dan derajat cerah yang diperoleh masing-masing yaitu di atas 94%, 6,2 cP dan 88% ISO. Kualitas dissolving pulp hasil pemutihan dengan penambahan xilanase lebih tinggi daripada menggunakan oksigen dan memenuhi persyaratan spesifikasi SNI 0938:2010, pulp rayon. Kata kunci : Acacia crassicarpa, xilanase, Prahidrolisa-Kraft, dissolving pulp, pulp rayon

scholarly journals Technical and environmental improvement of the bleaching sequence of dissolving pulp for fibre production

Cellulose ◽  
2020 ◽  
Vol 27 (7) ◽  
pp. 4079-4090 ◽  
Author(s):  
Carlos Arce ◽  
Tamara Llano ◽  
Pablo García ◽  
Alberto Coz
Keyword(s):  
Fibre Production ◽  
Dissolving Pulp ◽  
Environmental Improvement

Research on hybrid poplars and willow species for fast-growing tree plantations: Its importance for growth and yield, silviculture, policy-making and commercial applications

2013 ◽  
Vol 89 (01) ◽  
pp. 32-41 ◽  
Author(s):  
G.R. Larocque ◽  
A. DesRochers ◽  
M. Larchevêque ◽  
F. Tremblay ◽  
J. Beaulieu ◽  
...  
Keyword(s):  
Hybrid Poplar ◽  
Fibre Production ◽  
Production Costs ◽  
Growth And Yield ◽  
Yield Potential ◽  
High Yield ◽  
Industrial Transformation ◽  
Practical Applications ◽  
Fast Growing ◽  
Commercial Applications

There is a growing interest in fast-growing hybrid poplar and willow plantations in Canada. This interest can be explained both by the rapid growth rate and high yield potential of this type of production system. However, their establishment and maintenance require considerable investments. Research efforts on productivity comparisons between different clones or species, breeding, physiology, nutrition, silviculture, pest management, harvesting methods, social and economic issues and industrial transformation contribute to maximizing fibre production and minimizing production costs. The objective of this paper is to briefly describe a number of current or recently completed research studies on fast-growing hybrid poplar and willow plantations and to discuss their utility and impacts for practical applications.

scholarly journals Extraction of Viral Nucleic Acids with Carbon Nanotubes Increases SARS-CoV-2 RT-qPCR Detection Sensitivity

2021 ◽  
Author(s):  
Sanghwa Jeong ◽  
Eduardo G. Grandio ◽  
Nicole Navarro ◽  
Rebecca L. Pinals ◽  
Francis Ledesma ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Nucleic Acids ◽  
Rna Extraction ◽  
High Sensitivity ◽  
Human Saliva ◽  
Extraction Yield ◽  
Detection Sensitivity ◽  
High Yield ◽  
Acid Extraction ◽  
Chemical Reagents

AbstractThe global SARS-CoV-2 coronavirus pandemic has led to a surging demand for rapid and efficient viral infection diagnostic tests, generating a supply shortage in diagnostic test consumables including nucleic acid extraction kits. Here, we develop a modular method for high-yield extraction of viral single-stranded nucleic acids by using ‘capture’ ssDNA sequences attached to carbon nanotubes. Target SARS-CoV-2 viral RNA can be captured by ssDNA-nanotube constructs via hybridization and separated from the liquid phase in a single-tube system with minimal chemical reagents, for downstream quantitative reverse transcription polymerase chain reaction (RT-qPCR) detection. This nanotube-based extraction method enables 100% extraction yield of target SARS-CoV-2 RNA from phosphate buffered saline in comparison to ∼20% extraction yield when instead using a commercial silica-column kit. Notably, carbon nanotubes enable extraction of nucleic acids directly from 50% human saliva, bypassing the need for further biofluid purification and avoiding the use of DNA/RNA extraction kits. Carbon nanotube-based extraction of viral nucleic acids facilitates high-yield and high-sensitivity identification of viral nucleic acids such as the SARS-CoV-2 viral genome with reduced reliance on reagents affected by supply chain obstacles.Abstract Figure

Dissolving pulp from white press cuttings

TAPPI Journal ◽  
2016 ◽  
Vol 15 (4) ◽  
pp. 277-282 ◽  
Author(s):  
M. SARWAR JAHAN ◽  
RAJESH CHANDRA DEB ◽  
M. MOSTAFIZUR RAHAMAN ◽  
M.A. QUAIYYUM
Keyword(s):  
Acid Treatment ◽  
Ash Content ◽  
Dissolving Pulp ◽  
Pulp Yield ◽  
Cellulose Content ◽  
Alkaline Extraction ◽  
Rayon Production ◽  
Oligomeric Form ◽  
White Press ◽  
Pentose Sugars

Upgrading of white press cuttings into dissolving pulp was carried out by acidification followed by alkaline extraction. Acid treatment decreased ash content of white press cutting pulp from 11.25% to 0.33% at pH 2. The yield after acidification and screening was 87%. Alkaline extraction removed hemicelluloses and increased α-cellulose content to 92% with viscosity value of 4.3 mPa.s. The overall pulp yield after alkaline extraction was 76.6%. Alkaline extracted liquor contains 9.2% total organics, mostly pentose sugars in the oligomeric form. The produced dissolving pulp can be used for rayon production.

Predicting the extraction yield of nimbin from neem seeds in supercritical CO2 using group contribution methods, equations of state and a shrinking core extraction model

2009 ◽  
Vol 51 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Araya Ajchariyapagorn ◽  
Thippawan Kumhom ◽  
Suwassa Pongamphai ◽  
Supaporn Douglas ◽  
Peter L. Douglas ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Equations Of State ◽  
Extraction Yield ◽  
Group Contribution ◽  
Shrinking Core ◽  
Group Contribution Methods ◽  
Core Extraction ◽  
Extraction Model

A new and facile method for isolation of lignin from wood based on complete wood dissolution

Holzforschung ◽  
2008 ◽  
Vol 62 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Mario Fasching ◽  
Philipp Schröder ◽  
R. Petra Wollboldt ◽  
Hedda K. Weber ◽  
Herbert Sixta
Keyword(s):  
Beech Wood ◽  
High Yield ◽  
Resonance Spectroscopy ◽  
Hydroxyl Groups ◽  
Milled Wood Lignin ◽  
Lignin Fraction ◽  
Extraction Step ◽  
Elemental Analyses ◽  
Phenolic Hydroxyl Groups ◽  
Total Dissolution

Abstract A new method for the isolation of lignin in high yield from wood and pretreated wood is presented, avoiding the liquid-solid extraction step of the classical milled wood lignin (MWL) isolation. Dissolved wood lignin (DWL) was obtained by total dissolution of ball milled wood in dimethylsulfoxide and N-methylimidazole (DMSO/NMI) followed by precipitation in dioxane/water in the course of which lignin and carbohydrate fractions were separated. The lignin fraction was purified. High lignin yields and the low number of separation steps belong to the advantages of the described method. DWL lignin was isolated from beech wood (Fagus sylvatica L.) and the sample was compared to MWL obtained by the classical Björkman method. Elemental analyses, methoxyl group content, potassium permanganate oxidation, infrared spectroscopy, and 1D and 2D nuclear magnetic resonance spectroscopy indicated that both lignin preparations are quite similar. However, MWL contained significantly more phenolic hydroxyl groups than DWL. The results indicated that MWL contains higher amounts of smaller fractions with broken β-O-4 linkages than DWL.

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