scholarly journals Effect of mechanical and chemical pulping on ionic liquid fractionation of wood chips

2019 ◽  
Author(s):  
◽  
Nhlanhla Hlongwa

In this study, a comparison of two pulping methods namely mechanical and chemical, on the dissolution of Eucalyptus grandis (E. grandis) wood chips was undertaken. The wood chip pulp was treated with an ionic liquid (IL): 1-allyl-3-methylimidazolium chloride to extract the cellulose. The IL was mixed with unbleached mechanical pulp (UBMP), bleached mechanical pulp (BMP), unbleached kraft pulp (UBKP) and bleached kraft pulp (BKP) in ratios of 10%, 20%, 30%. Each solution contained IL, wood pulp and 2-mL of 16 v/v % of dimethyl sulfoxide (DMSO). The 30 % IL pretreatment was the most effective IL pretreatment. The cellulose yield at 30 % IL pretreatment for UBMP, BMP, UBKP and BKP was 65.12%, 63.82%, 67.43%, 67.15%, respectively. This indicated that the kraft pulping method was more effective than the mechanical pulping method for the yield of cellulose after the IL pretreatment. The Crl value at 30 % IL pretreatment was highest for UBMP (72.03%) indicating that the pretreatment used was the least effective in reducing the cellulose crystallinity. The fractions of E. grandis wood chip namely, lignin, regenerated cellulose and hemicelluloses before and after the IL pretreatment, were characterized by a variety of analytical techniques such as High-Performance Liquid Chromatography (HPLC) (carbohydrates), Fourier Transform Infra-Red Attenuated Total Reflection (FTIR-ATR) (functional groups), Pyrolysis-Gas Chromatography /Mass Spectroscopy (Py-GC/MS) (lignin fractions), Ultraviolet/Visible spectroscopy (UV/Vis) (acid soluble lignin), Thermo Gravimetric Analysis (TGA) (degradation of pulp), X-Ray Diffraction (XRD) (crystallinity) and high resolution Scanning Electron Microscopy (SEM) (morphology). Kraft pulping was the most effective method for the yield of cellulose after the [AMIM][Cl]/DMSO pretreatment. The 30% [AMIM][Cl]/DMSO pretreatment gave the highest S/G ratio indicating that minimal bleaching was required.

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 31-39 ◽  
Author(s):  
HANNA HÖRHAMMER ◽  
OKSANA BEREZINA ◽  
EERO HILTUNEN ◽  
TOM GRANSTRÖM ◽  
ADRIAAN VAN HEININGEN

This study was focused on the products from a larch biorefinery, specifically bleached paper and different fermentation products. Siberian larch (Larix sibirica Lebed.) wood chips were treated with water in a pre-extraction (PE) stage. The larch extract was removed by drainage and fermented into different products. Eight different bacteria strains were tested. The extracted wood chips were mildly washed before kraft pulping with polysulfide (PS) and anthraquinone (AQ). The PE-PSAQ pulps were bleached to about 80% brightness. Laboratory paper sheets were made and tested for different paper properties, and a conventional larch kraft pulp was also prepared as reference. The larch PE-PSAQ paper and the larch kraft paper had similar properties. The removal of a significant amount of hemicelluloses from the wood chips before pulping was not a detriment to the paper properties.


Holzforschung ◽  
2012 ◽  
Vol 66 (7) ◽  
pp. 801-808 ◽  
Author(s):  
Esa Saukkonen ◽  
Jesse Kautto ◽  
Irina Rauvanto ◽  
Kaj Backfolk

Abstract To clarify the influence of prehydrolysis on fiber characteristics, Scots pine (Pinus sylvestris L.) wood chips were subjected to pressurized hot-water and dilute-acid prehydrolysis (0.5% H2SO4) prior to kraft pulping to partially remove hemicelluloses as hydrolyzate. After the prehydrolysis, the wood chips were submitted to kraft pulping and the pulp was fully bleached in oxygen (O), chlorine dioxide (D), alkaline extraction (E) and chlorine dioxide (D)-sequence. Measurements with an automated optical fiber analyzer showed that prehydrolysis prior to kraft pulping caused significant changes in the fiber dimensions and morphology of the final bleached pulp. Especially, a decrease in fiber width and an increase in fiber deformations were observed compared to a reference kraft pulp. The scanning electron microscopy of handsheets supported the morphology analyses and revealed alterations also in the fiber ultrastructure. The changes in both chemical and physical fiber characteristics require attention when considering the correct processing and end-use of prehydrolysis-kraft pulp fibers.


2015 ◽  
Vol 10 (4) ◽  
pp. 221-228 ◽  
Author(s):  
Syed Nasir Shah ◽  
Kallidanthiyil Chellappan Lethesh ◽  
M. I. Abdul Mutalib ◽  
Rashidah Binti Mohd Pilus

Abstract In this study, functionalized silica supported ionic liquids phases (SILPs) were synthesized and characterized using Fourier Transform infrared (FTIR) spectroscopy, CHNS elemental analysis, thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption of model naphthenic acid such as hexanoic acid, benzoic acid and commercial naphthenic acid from dodecane/kerosene was also investigated. The silica supported ionic liquids are good adsorbent for the removal of naphthenic acid from highly acidic model oil. The regeneration of supported ionic liquid phases as well as recovery of naphthenic acids from the supported ionic liquid phases (SILPs) was investigated.


2013 ◽  
Vol 89 (04) ◽  
pp. 490-501 ◽  
Author(s):  
Paul Bicho ◽  
Elmer Portillo ◽  
Bernard Yuen ◽  
Dongbo Yan ◽  
Doug G. Pitt

Forty-eight years after application, three nominal precommercial thinning (PCT) spacings of 4 ft (1.2 m), 6 ft (1.8 m) and 8 ft (2.4 m) were compared to an unthinned control in six replicate, balsam fir (Abies balsamea [L.] Mill.)-dominated stands. Following the clearcut harvest of three of these replicates in 2008, chips produced from sawmilling trials (slab-wood) and from the top logs of the sampled trees (top-log) were kraft and thermomechanically (TMP) pulped. In general, top-log chips took longer to kraft pulp, had lower yields, and produced pulps with shorter, finer fibres than the corresponding slab-wood chips, across all PCT treatment levels. The main effects of PCT on pulping occurred with slab-wood chips and not top-log chips. While end-product quality in either kraft or TMP production was generally unaffected by wood from the range of thinnings tested, slight reductions in slab-wood chip density and H-factor suggest that kraft pulping productivity may be reduced by 1.8% with furnish from thinned stands. While these losses could be offset somewhat by lower chip consumption, the economic benefits for a kraft mill are marginal at best, and sharing of fiscal gains across the fibre value chain needs to be explored. Specific refining energy required in TMP production was, however, reduced by 4% with furnish from thinned stands. These results suggest that value-chain optimization is ultimately dependent on the segregation of fibre from different sources, including within-tree and among silvicultural treatments and sites.


Author(s):  
Waleed K. Ahmed

This study presents an experimental laboratory investigation done on the Polyethylene terephthalate – PET that is used for food grade (water bottle) by mixing with ionic liquid. Both thermal and mechanical properties with a varying weight percentage of ionic liquid are investigated. Mainly, at different mixing ratios of PET-Ionic liquid of (2, 3, 5, 7 and 10%), impact of the ionic liquid on the characteristics of the PET are examined through MFI (melt flow index), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), nanoindentation methods as well as Fourier Transform Infrared (FTIR) spectroscopy. In general, the estimated results indicated that the stiffness as well as the hardness acquired from nanoindentation test for the PET blends, decrease as long as the concentration increases.


2020 ◽  
Vol 11 (3) ◽  
pp. 10278-10292

This study intends to synthesis novel compound phenolic chitosan-based via reaction of chitosan with 2-Chloro-N-phenylacetamide in 1-butyl-3-methylimidazolium chloride ionic liquid in the presence of pyridine at 80 °C for 4 h. The alterations in the chemical structure and morphology of the chitosan-N-phenylacetamide biopolymer were verified using IR spectroscopy, XRD, and SEM analyses. Chitosan and Chitosan-N-phenyacetamide were subjected to thermo-gravimetric analysis under an inert atmosphere in the temperature range of room temperature - 600 °C at a heating rate of 20 °C.min-1. The kinetic parameters were determined by the Coats-Redfern method. The corresponding kinetic parameters of the main degradation stages were also determined. The energy required for the degradation of pure chitosan was lower than that of chitosan-N-phenylacetamide in the first region of thermal degradation where the main pyrolysis reaction took place, and the largest weight loss occurred. Energy values in this region are running from 40.25 to 151.07 kJ/mol and 58.45 to 210.99 kJ/mol, respectively. The most probable reaction functions have thus been determined for these two stages by Coats-Redfern and Criado method, leading to greatly improved calculation performance over the entire conversion range. The pyrolysis reaction models of both pure chitosan and chitosan-N-phenylacetamide are described by the reaction, second-order F2.


BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 979-986
Author(s):  
Mehmet Akgül ◽  
Mehmet Onurhan Gücüş ◽  
Birol Üner ◽  
Celil Atik

This study aimed to determine the influence of prehydrolysis of wood chips on the kraft pulping of Populus x euramericana. Optimum cooking conditions were determined by evaluating different alkali concentrations and cooking periods. Xylanase was used to hydrolyze chips before cooking. Prehydrolysis process increased the yield and viscosity of pulp. Consequently, the mechanical properties of paper changed remarkably. In contrast, the optical properties of the unbleached kraft pulp declined due to lignin content.


2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.


2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Madalina Angelusiu ◽  
Maria Negoiu ◽  
Stefania-Felicia Barbuceanu ◽  
Tudor Rosu

The paper presents the synthesis and characterization of Cu(II), Co(II), Ni(II), Cd(II), Zn(II) and Hg(II) complexes with N1-[4-(4-bromo-phenylsulfonyl)-benzoyl]-N4-(4-methoxyphenyl)-thiosemicarbazide. The new compounds were characterized by IR, EPR, electronic spectroscopy, magnetic moments, thermo-gravimetric analysis and elemental analysis.


2020 ◽  
Vol 13 ◽  
Author(s):  
Inbasekaran S. ◽  
G. Thiyagarajan ◽  
Ramesh C. Panda ◽  
S. Sankar

Background:: Chrome shavings, a bioactive material, are generated from tannery as waste material. These chrome shaving can be used for the preparation of many value-added products. Objective:: One such attempt is made to use these chrome shaving wastes as a composite bio-battery to produce DC voltage, an alternate green energy source and cleaner technology. Methods:: Chrome shavings are hydrolyzed to make collagen paste and mixed with the ferrous nanoparticles of Moringa oleifera leaves and Carbon nanoparticles of Onion peels to form electrolyte paste as base. Then, the electrolyte base was added to the aluminum paste and conducting gel, and mixed well to form composite material for bio-battery. Results:: The composite material of bio-battery has been characterized using Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). Series and parallel circuit testing were done using Copper and Zinc electrodes or Carbon and Zinc electrodes as the battery terminals in the electrolyte paste. The surface area of these electrodes needs standardization from bench to pilot scale. The power generated, for an AA battery size, using a single bio-battery cell has produced a DC voltage of 1.5 V; current of 900 mA. Circuit testing on 1 ml of 80 well-cells connected in series has produced DC output of 18 V and 1100 mA whereas 48 V and 1500 mA were obtained from a series-parallel connection. Conclusion:: The glass transition temperature (Tg) of electrolyte of the bio-battery at 53°C indicates that, at this temperature, all the substances present in the bio-battery are well spread and contributing consistently to the electrolyte activity where Fe-C-Nano-Particles were able to form strong chemical bonds on the flanking hydroxyl group sites of the Collagen leading to reduced mobility of polymers and increase Tg. The results instigate promising trends for commercial exploitation of this composite for bio-battery production.


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