1,752 results on '"Alkaline peroxide"'
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2. Extraction of allelochemicals from poplar alkaline peroxide mechanical pulping effluents and their allelopathic effects on Microcystis aeruginosa
- Author
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Yanyan Wang, Mengxing Zhao, and Tingzhi Liu
- Subjects
Allelopathic inhibition ,Allelochemicals ,Organic solvent extraction ,Microcystis aeruginosa ,Alkaline peroxide mechanical pulping (APMP) effluents ,Biochemistry ,QD415-436 - Abstract
In this study, allelochemicals were extracted from pulping effluents rather than from the raw material of plants. Herein, five organic solvents (ethyl acetate (EAC), methyl tert-butyl ether (MTBE), dichloromethane (DCM), carbon tetrachloride (CTC), and petroleum (PE)) were applied to separately extracting the allelochemicals from alkaline peroxide mechanical pulp (APMP) effluents. The results from the algal density, inhibition ratio, and optical density of 446 nm (OD446nm) concluded that the extractives from the APMP effluents can act as effective allelochemicals and showed noticeable allelopathic inhibition effects on Microcystis aeruginosa growth. The results indicated that organic solvent extraction could be a practical approach to isolate the allelochemicals from the APMP effluents, which would broaden the potential application of the APMP effluents in the production of antimicrobial agents and other value-added materials.
- Published
- 2020
- Full Text
- View/download PDF
3. Thermomechanical and Alkaline Peroxide Mechanical Pulping of Lignocellulose Residue Obtained from the 2-Furaldehyde Production Process
- Author
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Maris Puke, Daniela Godina, Prans Brazdausks, Janis Rizikovs, and Velta Fridrihsone
- Subjects
birch wood ,lignocellulose ,thermomechanical pulping process ,alkaline peroxide mechanical pulping process ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
The necessity for the reduction in greenhouse gas emissions, the growing demand for the improvement of biorefinery technologies, and the development of new biorefining concepts oblige us as a society, and particularly us, as scientists, to develop novel biorefinery approaches. The purpose of this study is to thoroughly evaluate the leftover lignocellulosic (LC) biomass obtained after the manufacture of 2-furaldehyde, with the intention of further valorizing this resource. This study demonstrates that by using thermomechanical and alkaline peroxide mechanical pulping techniques, birch wood chips can be used in the new biorefinery processing chain for the production of 2-furaraldehyde, acetic acid, and cellulose pulp. In addition, the obtained lignocellulosic residue is also characterized. To produce a lignocellulosic material without pentoses and with the greatest amount of cellulose fiber preserved for future use, a novel bench-scale reactor technology is used. Studies were conducted utilizing orthophosphoric acid as a catalyst to deacetylate and dehydrate pentose monosaccharides found in birch wood, converting them to 2-furaldehyde and acetic acid. The results showed that, with the least amount of admixtures, the yields of the initial feedstock’s oven-dried mass (o.d.m.) of 2-furaldehyde, acetic acid, and lignocellulose residue ranged from 0.04 to 10.84%, 0.51 to 6.50%, and 68.13 to 98.07%, respectively, depending on the pretreatment conditions utilized. The ideal 2-furaldehyde production conditions with reference to the purity and usability of cellulose in residual lignocellulosic material were also discovered through experimental testing. The experiment that produced the best results in terms of 2-furaldehyde yield and purity of residual lignocellulose used a catalyst concentration of 70%, a catalyst quantity of 4%, a reaction temperature of 175 °C, and a treatment period of 60 min. It was possible to create pulp with a tensile index similar to standard printing paper by mechanically pulping the necessary LC residue with alkaline peroxide, proving that stepwise 2-furaldehyde production may be carried out with subsequent pulping to provide a variety of value-added goods.
- Published
- 2022
- Full Text
- View/download PDF
4. Extraction of allelochemicals from poplar alkaline peroxide mechanical pulping effluents and their allelopathic effects on Microcystis aeruginosa
- Author
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Wang, Yanyan, Zhao, Mengxing, and Liu, Tingzhi
- Published
- 2020
- Full Text
- View/download PDF
5. Optimization of the removal of lignin and silica from rice husks with alkaline peroxide
- Author
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Bazargan, Alireza, Wang, Zhixuan, Barford, John P., Saleem, Junaid, and McKay, Gordon
- Published
- 2020
- Full Text
- View/download PDF
6. Valorization of Lignocellulosic Waste (Crotalaria juncea) Using Alkaline Peroxide Pretreatment under Different Process Conditions: An Optimization Study on Separation of Lignin, Cellulose, and Hemicellulose
- Author
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Sibashish Baksi, Sudeshna Saha, Cansu Birgen, Ujjaini Sarkar, Heinz A Preisig, Sidsel Markussen, Bernd Wittgens, and Alexander Wentzel
- Subjects
crotalaria juncea fiber ,alkaline peroxide pretreatment ,ultrasound-assisted pretreatment ,lignin content ,hemicellulose isolation ,crystallinity index ,Science ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
Lignocellulose materials, essentially consisting of lignin, cellulose and hemicelluloses, are abundant sources of fermentable sugars. The bast fiber of Crotalaria juncea (Sunn hemp), a native cover crop of India, was used as feedstock for this study. The primary objective of this study was to add value to the waste C. juncea bast fiber. The same was achieved by pretreating the waste fiber using alkaline peroxide solution at various process conditions. The optimal process condition for alkaline peroxide pretreatment was identified for the fiber to pretreatment solution (S/S) ratio of 1/40 at 50°C for 5h with respect to all response variables (lignin removal, hemicellulose recovery, recovery of solid pretreated material, and crystallinity of lignocellulose). Three-way ANOVA results revealed that S/S ratio had no significant effect; whereas, both temperature and time, and the combination of parameters, exhibited significant effect on response variables. The characteristic peaks associated with lignin and cellulose demonstrated a higher amount of lignin removal and increased cellulose content with elevated treatment time. Autoclave assisted pretreatment proved to be inefficient due to removal of lower amount of lignin in addition to higher hemicellulose degradation. On the other hand, pretreatment using ultrasound was found to be most effective in removing lignin, liberating hemicelluloses along with diminition in cellulose crystallinity.
- Published
- 2019
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7. Studies on delignification and inhibitory enzyme kinetics of alkaline peroxide pre-treated pine and deodar saw dust
- Author
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Baksi, Sibashish, Sarkar, Ujjaini, Saha, Sudeshna, Ball, Akash K., Chandra Kuniyal, Jagdish, Wentzel, Alexander, Birgen, Cansu, Preisig, Heinz A, Wittgens, Bernd, and Markussen, Sidsel
- Published
- 2019
- Full Text
- View/download PDF
8. A comparative evaluation of fermentable sugars production from oxidative, alkaline, alkaline peroxide oxidation, dilute acid, and molten hydrate salt pretreatments of corn cob biomass
- Author
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Augustine O. Ayeni, Michael O. Daramola, Oluranti Agboola, Ayodeji A. Ayoola, Rasheed Babalola, Babalola A. Oni, Julius O. Omodara, and Deinma T. Dick
- Subjects
pretreatment ,lignocellulose ,polysaccharide ,enzymatic hydrolysis ,reducing sugars ,scanning electron microscope ,Production of electric energy or power. Powerplants. Central stations ,TK1001-1841 ,Renewable energy sources ,TJ807-830 - Abstract
Production of high value-added products from lignocelluloses is an economically sustainable alternative to decreasing dependence on fossil fuels and making the chemical processes environmentally friendly. In this study, different methodologies of alkaline (Ca(OH)2 and NaOH), dilute acid (10%w/w H2SO4), hydrogen peroxide (H2O2), alkaline peroxide oxidation (H2O2/Ca(OH)2 and H2O2/NaOH), and molten hydrated salt (MHS) mediated (ZnCl2.4H2O) pretreatments were employed in the hydrolysis of corncob amenable to enzymatic hydrolysis. Optimal enzyme hydrolysis temperature (considering 45 and 50 ℃) and time (2, 24, 72, and 96 h) were investigated for each pretreatment procedure to ascertain the concentrations of glucose, xylose, and total sugar present in the corncob. At 45 ℃ and 96 h, NaOH alkaline pretreatment achieved the best optimum total sugar production of 75.54 mg/mL (about 54% and 88% increments compared to dilute acid pretreatment (35.06 mg/mL total sugars) and MHS (9.32 mg/mL total sugar) pretreatment respectively). In this study, total sugars production increased appreciably at 45 ℃ and longer hydrolysis period (96 h) compared to hydrolysis at 50 ℃ (with maximum total sugars production of 18.00 mg/mL at 96 h). Scanning electron microscopic imaging of the untreated and treated samples displayed cell wall distortion and surface disruptions.
- Published
- 2021
- Full Text
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9. Impact of double alkaline peroxide pretreatment on enzymatic hydrolysis of palm fibre
- Author
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Chang, Shengqiang, Li, Wangliang, and Zhang, Yuming
- Published
- 2018
- Full Text
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10. Extraction and Characterization of Fiber and Cellulose from Ethiopian Linseed Straw: Determination of Retting Period and Optimization of Multi-Step Alkaline Peroxide Process
- Author
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Kibrom Feleke, Ganesh Thothadri, Habtamu Beri Tufa, Ali A. Rajhi, and Gulam Mohammed Sayeed Ahmed
- Subjects
linseed straw ,fiber ,cellulose ,retting ,extraction ,optimization ,Organic chemistry ,QD241-441 - Abstract
Flax is a commercial crop grown in many parts of the world both for its seeds and for its fibers. The seed-based flax variety (linseed) is considered less for its fiber after the seed is extracted. In this study, linseed straw was utilized and processed to extract fiber and cellulose through optimization of retting time and a multi-step alkaline peroxide extraction process using the Taguchi design of experiment (DOE). Effects of retting duration on fiber properties as well as effects of solvent concentration, reaction temperature, and time on removal of non-cellulosic fiber components were studied using the gravimetric technique, Fourier transform infrared (FTIR) spectroscopy and thermal studies. Based on these findings, retting for 216 h at room temperature should offer adequate retting efficiency and fiber characteristics; 70% cellulose yield was extracted successfully from linseed straw fiber using 75% ethanol–toluene at 98 °C for 4 h, 6% NaOH at 75 °C for 30 min, and 6% H2O2 at 90 °C for 120 min.
- Published
- 2023
- Full Text
- View/download PDF
11. Delignification of Oil Palm Empty Fruit Bunch using Peracetic Acid and Alkaline Peroxide Combined with the Ultrasound
- Author
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Heri Hermansyah, Dwini Normayulisa Putri, Andiko Prasetyanto, Zhofran Bintang Chairuddin, Meka Saima Perdani, Muhamad Sahlan, and Masafumi Yohda
- Subjects
delignification ,pretreatment ,oil palm empty fruit bunch ,ultrasound ,Technology ,Technology (General) ,T1-995 - Abstract
Lignocellulosic biomass has great potential as a low-cost source of fermentable sugar for the production of biofuels and high value organic acids. One potential biomass is oil palm empty fruit bunch, since it has high cellulose and hemicellulose content. However, its lignin content can hinder the access of cellulose and hemicellulose during the hydrolysis process. Therefore, an effective pretreatment for the delignification of lignocellulose biomass should be considered to reduce the lignin content. In this study, delignification of oil palm empty fruit bunch using peracetic acid and alkaline peroxide solution combined with the ultrasound method is investigated as a novel combination method of biomass pretreatment. The effect of pretreatment time was observed by using a peracetic acid solution for 1, 3, 5, 7 and 9 hours, followed by an alkaline peroxide solution for 4, 6, 8 and 10 hours. Based on the results, the best delignification was achieved by pretreatment using peracetic acid pretreatment for 3 hours, followed by alkaline peroxide pretreatment for 10 hours. Both pretreatments were assisted by the ultrasound method. The results show hemicellulose, cellulose and lignin content of 14.13%, 77.27% and 8.6% respectively. The lignin content was reduced by 68.73% and the cellulose content increased by 121.85%, relative to the untreated EFB. This result was considered as the best pretreatment, since the pretreatment time was shorter and high cellulose content together with low lignin content was achieved, which will improve the hydrolysis process.
- Published
- 2019
- Full Text
- View/download PDF
12. Thermomechanical and Alkaline Peroxide Mechanical Pulping of Lignocellulose Residue Obtained from the 2-Furaldehyde Production Process.
- Author
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Puke, Maris, Godina, Daniela, Brazdausks, Prans, Rizikovs, Janis, and Fridrihsone, Velta
- Subjects
- *
LIGNOCELLULOSE , *MANUFACTURING processes , *GREENHOUSE gas mitigation , *MECHANICAL pulping process , *PEROXIDES , *WOOD chips - Abstract
The necessity for the reduction in greenhouse gas emissions, the growing demand for the improvement of biorefinery technologies, and the development of new biorefining concepts oblige us as a society, and particularly us, as scientists, to develop novel biorefinery approaches. The purpose of this study is to thoroughly evaluate the leftover lignocellulosic (LC) biomass obtained after the manufacture of 2-furaldehyde, with the intention of further valorizing this resource. This study demonstrates that by using thermomechanical and alkaline peroxide mechanical pulping techniques, birch wood chips can be used in the new biorefinery processing chain for the production of 2-furaraldehyde, acetic acid, and cellulose pulp. In addition, the obtained lignocellulosic residue is also characterized. To produce a lignocellulosic material without pentoses and with the greatest amount of cellulose fiber preserved for future use, a novel bench-scale reactor technology is used. Studies were conducted utilizing orthophosphoric acid as a catalyst to deacetylate and dehydrate pentose monosaccharides found in birch wood, converting them to 2-furaldehyde and acetic acid. The results showed that, with the least amount of admixtures, the yields of the initial feedstock's oven-dried mass (o.d.m.) of 2-furaldehyde, acetic acid, and lignocellulose residue ranged from 0.04 to 10.84%, 0.51 to 6.50%, and 68.13 to 98.07%, respectively, depending on the pretreatment conditions utilized. The ideal 2-furaldehyde production conditions with reference to the purity and usability of cellulose in residual lignocellulosic material were also discovered through experimental testing. The experiment that produced the best results in terms of 2-furaldehyde yield and purity of residual lignocellulose used a catalyst concentration of 70%, a catalyst quantity of 4%, a reaction temperature of 175 °C, and a treatment period of 60 min. It was possible to create pulp with a tensile index similar to standard printing paper by mechanically pulping the necessary LC residue with alkaline peroxide, proving that stepwise 2-furaldehyde production may be carried out with subsequent pulping to provide a variety of value-added goods. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
13. Pilot-Scale Investigation into the Effects of Alkaline Peroxide Pre-Treatments on Low-Consistency Refining of Primary Refined Softwood TMP
- Author
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Xue Feng Chang, Antti Luukkonen, James Olson, and Rodger Beatson
- Subjects
Alkaline peroxide treatment ,TMP ,Low-consistency refining ,Refining intensity ,Energy saving ,Fibre cutting ,Acid group generation ,Tensile strength ,Biotechnology ,TP248.13-248.65 - Abstract
Primary refined coarse softwood thermomechanical pulp was treated with alkaline peroxide prior to low-consistency (LC) refining. The effects of the pre-treatments on pulp quality, refinability, and electrical energy consumption were assessed. Four pre-treatments were conducted with alkali charges of 2.5 and 6% and peroxide charges of 3 and 4%. The pulps were refined to specific energies up to 600 kWh/t by multiple passes through an LC refiner at intensities of 90 and 150 kWh/t. It was found that alkaline peroxide treatments increased tear strength and protected the fibre from cutting, especially during high intensity refining below a specific energy of 300 kWh/t. Treatment with 6% NaOH and 4% or 3% H2O2 led to lower brightness gains and scattering coefficients but increased the tensile strength index by 31%, potentially lowering the total electrical energy required to achieve strong pulp. The enhancement of tensile strength caused by the highly alkaline peroxide mostly resulted from increased bonding, which was attributable to acid group generation rather than the promotion of further fibrillation during LC refining.
- Published
- 2016
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14. Recycled Polypropylene/Peanut Shell Powder Composites: Pre-Treatment of Lignin Using Alkaline Peroxide
- Author
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Nor Fasihah Zaaba, Hanafi Ismail, and Mariatti Jaafar
- Subjects
Lignocellulosic ,Peanut shell powder ,Alkaline peroxide ,Lignin removal ,Recycled polypropylene ,Biotechnology ,TP248.13-248.65 - Abstract
This study investigated the performance of recycled polypropylene (RPP)/peanut shell powder (PSP) composites with untreated PSP and treated PSP with alkaline peroxide. The RPP/PSP and RPP/PSP-H2O2 composites were prepared by melt mixing and compression molding at different PSP loadings (10 wt.% to 40 wt.%). The samples were characterized by processing properties, tensile properties, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and water absorption behavior. The treated PSP enhanced the stabilization torque, tensile strength, elongation at break, tensile modulus, and water absorption of RPP/PSP-H2O2 composites. FTIR spectra and SEM showed that the elimination of lignin content strongly influenced the fractured surface and chemical characteristics of the RPP/PSP-H2O2 composites.
- Published
- 2016
- Full Text
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15. Effect of Alkaline peroxide denture cleansers on surface roughness and hardness of Conventional heat cured and CAD/CAM denture base resins
- Author
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Mahmoud Darwish Aly
- Subjects
Materials science ,Distilled water ,Independent samples ,Surface roughness ,Denture base ,Alkaline peroxide ,Composite material ,Denture Cleansers ,Hardness ,After treatment - Abstract
Objectives: This study aimed to evaluate the changes of surface roughness and hardness of conventional heat-cured (CHC) and CAD/CAM PMMA after immersion in alkaline peroxide chemical denture cleansers (DC), simulating one -year of use. Materials and Methods: 30 specimens of CHC, and another 30 specimens of CAD/CAM PMMA were divided into three groups (n= 10), each were immersed in two commercially available alkaline peroxide DC (Corega tablets and Polident tablets) as well as distilled water (control group). The mean surface roughness (Ra) of the specimens was recorded using contact stylus surface analyzer device. The surface hardness (VHN) was recorded using Vickers micro-hardness tester. T‑test for paired observation and independent samples T-test were used to indicate and compare any changes in Ra and hardness between the baseline and after simulated daily immersion in DC for one-year. Results: The tested DC had no significant effect on the Ra and hardness of CAD/CAM PMMA specimens. But both types of DC produced significant increase in Ra and significant decrease in VHN of the CHC PMMA specimens (P < 0.05). The Ra of the CAD/CAM PMMA specimens was significantly lower and the VHN was significantly higher than that of the CHC PMMA after treatment with DC. Conclusions: Alkaline peroxide DC appears not to affect the Ra and hardness of CAD/CAM PMMA. Alkaline peroxide DC produced negative effect on the Ra and hardness of CHC PMMA. CAD/CAM denture base resins might be considered the material of choice to produce more durable dentures.
- Published
- 2021
16. Influence of Alkaline-Peroxide Treatment of Fiber on the Mechanical Properties of Oil Palm Mesocarp Fiber/Poly(butylene succinate) Biocomposite
- Author
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Yoon Yee Then, Nor Azowa Ibrahim, Norhazlin Zainuddin, Buong Woei Chieng, Hidayah Ariffin, and Wan Md Zin Wan Yunus
- Subjects
Alkaline-peroxide ,Biocomposite ,Oil palm mesocarp fiber ,Poly(butylene succinate) ,Biotechnology ,TP248.13-248.65 - Abstract
In this work, the surface of oil palm mesocarp fiber (OPMF) was modified via alkaline-peroxide treatment with hydrogen peroxide under alkaline conditions. The effect of the treatment on the chemical composition and microstructure of the fiber was examined using chemical analysis, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The treatment resulted in the removal of lignin, hemicellulose, and waxy substances from the fiber and increased its surface roughness and crystallinity. The eco-friendly biocomposite was made from poly(butylene succinate) (PBS) and chemically treated fiber at a weight ratio of 30:70, and was fabricated via a melt-blending technique followed by hot-pressed moulding. The results indicated that alkaline-peroxide treatment of the fiber improved the tensile strength, tensile modulus, and elongation at break of the OPMF/PBS biocomposite by 54, 830, and 43%, respectively. The SEM analysis revealed improvement of the interfacial adhesion between the chemically treated fiber and the PBS. This work demonstrates that alkaline-peroxide treatment of fiber is beneficial prior to its use in fabricating biocomposites.
- Published
- 2015
- Full Text
- View/download PDF
17. Effects of Supplementary Alkali after Alkaline Peroxide Treatment on the Properties of Bleached Kraft Pine Fluff Pulp
- Author
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Yongjian Xu, Jiayong Wang, Xin Qian, Leigang Zuo, and Xiaopeng Yue
- Subjects
Fluff pulp ,Alkaline-peroxide bleaching ,Bonding strength ,Absorbability ,Biotechnology ,TP248.13-248.65 - Abstract
Effects of dual-treatment on cellulose fiber quality, micro-structure appearance, crystalline structure, hydrogen bonds, and surface elements were analyzed using a fiber quality analyzer (FQA), scanning electron microscope (SEM), wide-angle X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS), respectively. In comparison to the untreated pulp, the brightness of pulp increased by 51.71%, whereas the apparent density and burst strength index of the pulpboard decreased by 11.76% and 48.18%, respectively. The absorption time, absorbability, and bulk of the fiber obtained by defibering the pulpboard decreased by 47.40%, 8.33%, and 5.32%, respectively, when it had been subjected to supplementary alkali. With the analysis of FQA and SEM, fiber swelled and curled, its surface was relatively smooth, and filaments of its partial surface area were exposed as a result of the supplementary alkali. Additionally, XRD analysis, FT-IR analysis, and XPS scanning spectra all showed that the crystallinity degree of fiber decreased by 45.10%, indicating more crystal structures were converted into amorphous structures. The proportion of total intra-molecular hydrogen bond intensity to total hydrogen bonds increased. The –OH content on fiber surface only decreased by 4.15%, compared with those of the untreated pulp, when the fiber was subjected to the two-step chemical treatment.
- Published
- 2015
- Full Text
- View/download PDF
18. Combination of Low-pressure Steam Explosion and Alkaline Peroxide Pretreatment for Separation of Hemicellulose
- Author
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Yang Xing, Zhaoqin Su, Kun Wang, Lihong Deng, and Jianxin Jiang
- Subjects
Lespedeza stalk ,Hemicelluloses ,Combined pretreatment ,Steam explosion ,Alkaline peroxide ,Biotechnology ,TP248.13-248.65 - Abstract
Low-pressure steam explosion (LPSE) combined with alkaline peroxide (AP) pretreatment was first employed to separate hemicellulose from Lespedeza stalks. The monosaccharide composition and molecular weight distribution of the obtained hemicellulose fractions were characterized in this study. The results show that the hemicellulose extracted from Lespedeza stalks consisted of xylose, glucose, galactose, and mannose, which was a mixture of arabinoxylans and xyloglucans or β-glucans. The yield of hemicellulose fractions after AP pretreatment ranged from 11.2% (2.5% hydrogen peroxide (H2O2), w/v for 12 h) to 12.2% (3.3% H2O2, w/v for 72 h). The molecular weight of hemicellulose decreased from 2,458 g/mol to 1,984 g/mol after AP pretreatment, indicating its degradation reaction. The structure of hemicellulose was analyzed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and heteronuclear single quantum coherence. The AP pretreatment partially cleaved the backbone and the ether linkage between lignin and hemicelluloses. Also, branched-chain α-D-arabinofuranosyl in which β-D-xylose substituted at the C-3 position (monosubstituted) was removed, illustrating a partial debranching reaction. Therefore, the combination of low-pressure steam explosion and alkaline peroxide pretreatment (LPSE-AP) is an effective pretreatment method to separate hemicellulose from Lespedeza stalk.
- Published
- 2014
- Full Text
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19. Biomass Sorghum: Effect of Acid, Basic and Alkaline Peroxide Pretreatments on the Enzymatic Hydrolysis and Ethanol Production
- Author
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Beatriz Vieira dos Santos, Rodolfo Travaini, Ana Lorenzo-Hernando, Daniel Pasquini, and Milla Alves Baffi
- Subjects
biomass sorghum ,chemical pretreatment ,enzymatic hydrolysis ,ethanol production ,Biotechnology ,TP248.13-248.65 - Abstract
Abstract This study evaluated the effects of three chemical pretreatments of biomass sorghum (BS): dilute alkaline (PTA1 and PTA2), dilute acid (PTB1 and PTB2) and alkaline hydrogen peroxide (PTC1 and PTC2) in the enzymatic hydrolysis and ethanol production. Among the six investigated conditions, the pretreatment with 7.36% H2O2 (PTC2) was the most efficient in the lignin removal and preservation of the polysaccharide fraction. After the enzymatic hydrolysis, increases in the glucose and xylose concentrations were observed in the pretreated BS hydrolysates, mainly in PTB1 and PTC1. All the hydrolysates obtained low concentrations of inhibitors. In the alcoholic fermentations with Pichia stiptis, the greatest ethanol yield was obtained in PTB1 hydrolysate (3.84 g L-1), corresponding to 16.15% of yield. The highest ethanol yield in PTB1 hydrolysate can be justified by the maximum concentration of xylose obtained in this hydrolysate, demonstrating the potential of P. stiptis in the fermentation of pentose to ethanol. The results indicated that biomass sorghum is an alternative lignocellulose source with potential for the production of second generation ethanol, opening up prospects for additional studies.
- Published
- 2021
- Full Text
- View/download PDF
20. Extraction and Characterization of Fiber and Cellulose from Ethiopian Linseed Straw: Determination of Retting Period and Optimization of Multi-Step Alkaline Peroxide Process.
- Author
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Feleke K, Thothadri G, Beri Tufa H, Rajhi AA, and Ahmed GMS
- Abstract
Flax is a commercial crop grown in many parts of the world both for its seeds and for its fibers. The seed-based flax variety (linseed) is considered less for its fiber after the seed is extracted. In this study, linseed straw was utilized and processed to extract fiber and cellulose through optimization of retting time and a multi-step alkaline peroxide extraction process using the Taguchi design of experiment (DOE). Effects of retting duration on fiber properties as well as effects of solvent concentration, reaction temperature, and time on removal of non-cellulosic fiber components were studied using the gravimetric technique, Fourier transform infrared (FTIR) spectroscopy and thermal studies. Based on these findings, retting for 216 h at room temperature should offer adequate retting efficiency and fiber characteristics; 70% cellulose yield was extracted successfully from linseed straw fiber using 75% ethanol-toluene at 98 °C for 4 h, 6% NaOH at 75 °C for 30 min, and 6% H
2 O2 at 90 °C for 120 min.- Published
- 2023
- Full Text
- View/download PDF
21. Hydrophobically Associating Polyethylenimine for Controlling Dissolved and Colloidal Substances of Alkaline Peroxide Mechanical Pulp
- Author
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Guang-lei Zhao, Jun-rong Li, Bei-hai He, and He Xiao
- Subjects
DCS ,PEI ,Alkaline peroxide mechanical pulp ,Fixing agent ,Biotechnology ,TP248.13-248.65 - Abstract
In a paper mill’s water circuit, normal runnability of the paper machine is often disturbed due to buildup of hydrophobic dissolved and colloidal substances (DCS), such as wood pitch, white pitch, and stickies. General cationic fixing agents such as hydrophilic polymers do not always work to minimize these problems. In the present study, two kinds of novel hydrophobically associating polyethylenimine (PEI) coagulants grafted by acetic anhydride and 1,2-epoxydodecane, named PEI-Ac and PEI-Ed, respectively, were synthesized to remove hydrophobic DCS. The performances of the modified PEI samples were evaluated using a model suspension containing alkaline peroxide mechanical pulp (APMP) and styrene-butadiene latex. The results showed that the modified PEI was more inclined to interact with hydrophobic substances than was non-modified PEI. The relationship between DCS removal and non-modified or modified PEI content was not linear, but there was a maximum. The turbidity and particle counts of model suspensions decreased 30% and 80%, respectively, when the dosage of PEI-Ed(a) was 0.025%. Compared with the 72.8% decrease in the case of non-modified PEI, cationic demand decreased by 67.7% when the PEI-Ed(a) concentration was 0.2%. It was also found that PEI-Ed had a better affinity for DCS than PEI-Ac, which may be because the PEI-Ed had a long hydrophobic chain.
- Published
- 2014
- Full Text
- View/download PDF
22. Impact of double alkaline peroxide pretreatment on enzymatic hydrolysis of palm fibre
- Author
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Shengqiang Chang, Wangliang Li, and Yuming Zhang
- Subjects
Chemical technology ,TP1-1185 - Abstract
A double pretreatment was developed to improve the efficiency of enzymatic hydrolysis and to increase the sugars production from palm fibre in batch and fed-batch systems. After alkaline peroxide pretreatment using NaOH-H2O2 solution, rigid structure of palm fibre was broken and partial of the hemicelluloses and lignin were removed. Compared with cellulase Accellerase® 1500, when using the conjunction of Accellerase® 1500 and Optimash BG, the conversion ratio increased from 35.9% to 45.0% and the reducing sugar yield increased from 245 mg/g substrate to 307 mg/g substrate. To further increase the hydrolysis efficiency, double pretreatment with NaOH-H2O2 solution was used to treat the hydrolysized residues. Then, the hydrolysis ratio reached 93% and reducing sugar yield was 752 mg/g substrate. Fed-batch enzymatic hydrolysis was carried out with 7% (w/v) solids loading and 0.3 mL/g substrate. Then, 7% solids were fed consecutively at 12 h, 24 h, 36 h and 48 h. After 144 h, the final concentration of reducing sugar reached 214.0 g/L and total biomass conversion ratio was 75.23%. Keywords: Cellulase, Palm fibre, Reducing sugar, Lignin, Alkaline peroxide pretreatment
- Published
- 2018
- Full Text
- View/download PDF
23. ALKALINE PEROXIDE MECHANICAL PULPING OF NOVEL BRAZILIAN EUCALYPTUS HYBRIDS
- Author
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Marcelo Coelho dos Santos Muguet,, Jorge Luiz Colodette,, and Anna-Stiina Jääskeläinen
- Subjects
Alkaline peroxide mechanical pulping ,Defibration ,Energy consumption ,Eucalyptus ,Lignin structure ,Pulp properties ,Biotechnology ,TP248.13-248.65 - Abstract
Eucalyptus wood is among the most important biomass resource in the world. Wood mechanical defibration and fibrillation are energy-intensive processes utilized not only to produce pulp for papermaking, but also to produce reinforcement fibers for biocomposites, nanocellulose, or pretreat lignocellulosic material for biofuels production. The structural features of different Eucalyptus hybrids affecting the refining energy consumption and produced fiber furnish properties were evaluated. The defibration and fiber development were performed using an alkaline peroxide mechanical pulping (APMP) process, which included chelation followed by an alkaline peroxide treatment prior to wood chip defibration. Despite the similar wood densities and chemical compositions of different Eucalyptus hybrids, there was a clear difference in the extent of defibration and fibrillation among the hybrids. The high energy consumption was related to a high amount of guaiacyl lignin. This observation is of major importance when considering the optimal wood hybrids for mechanical wood defibration and for understanding the fundamental phenomena taking place in chemi-mechanical defibration of wood.
- Published
- 2012
24. Retention of hemicellulose during delignification of oil palm empty fruit bunch (EFB) fiber with peracetic acid and alkaline peroxide
- Author
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Palamae, Suriya, Palachum, Wilawan, Chisti, Yusuf, and Choorit, Wanna
- Published
- 2014
- Full Text
- View/download PDF
25. A COMPARISON BETWEEN THE EFFECTS OF OZONE AND ALKALINE PEROXIDE TREATMENTS ON TMP PROPERTIES AND SUBSEQUENT LOW CONSISTENCY REFINING
- Author
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James A. Olson, Xue Feng Chang, and Rodger P. Beatson
- Subjects
Ozone ,Alkaline peroxide ,Low consistency refining ,Energy ,TMP ,Biotechnology ,TP248.13-248.65 - Abstract
As part of a program to reduce electrical energy consumption in the refining process, the effects of the ozone and alkaline peroxide treatments on fibre and handsheet properties, prior and subsequent to low consistency (LC) refining, were assessed and compared by applying different levels of ozone and a range of peroxide and alkali charges to a primary stage hemlock thermomechanical pulp (TMP). Both highly alkaline peroxide treatments and ozone treatments decreased the specific energy required for strong mechanical pulp. The improvement in pulp strength through alkaline peroxide treatment mainly resulted from pulp surface changes caused by generation of acid groups. The highly alkaline peroxide treatments significantly increased pulp brightness but did not promote the further fibrillation during the subsequent LC refining. On the other hand, ozone treatments provided tensile strength increases, along with small brightness enhancements for the dark hemlock TMP, and increased the tensile gains obtained through LC refining. The effects of ozone treatments on tensile strength before and after LC refining were the result of pulp surface modifications, fibre swelling, and loss of fibre wall integrity due to non-selective chemical attack. High levels of ozone treatment caused tear strength to decrease during subsequent LC refining.
- Published
- 2011
26. USING A MEMBRANE FILTRATION PROCESS TO CONCENTRATE THE EFFLUENT FROM ALKALINE PEROXIDE MECHANICAL PULPING PLANTS
- Author
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Yong Zhang, Chun-Yu Cao, Qing-Xi Hou, Wen-Ying Feng, Ming Xu, Zhen-Hua Su, Qiao-Yuan Lin, Jin-Feng Zhuang, and Wei-Jun Lv
- Subjects
Alkaline peroxide mechanical pulping ,Effluent ,Polyethersulfone membrane ,Concentrating ,Orthogonal experiment ,Mathematical model ,Energy and water saving ,Biotechnology ,TP248.13-248.65 - Abstract
Using a multi-effect evaporation system to concentrate the effluent from alkaline peroxide mechanical pulping (APMP) plants is known to require a high energy consumption. In order to improve the situation, a polyethersulfone membrane was used to concentrate the effluent of APMP plants beforehand. An orthogonal experimental design was applied and a mathematical model was established to optimize the filtration parameters. An estimation of potential energy and water savings from this new concentration process was developed. The optimal filtration conditions obtained were: molecular weight cut-off at 10,000 Dalton, trans-membrane pressure at 3 bar, feed temperature at 50oC, cross-flow velocity at 420 rpm, and volume reduction factor at 0.93. The average permeate flux under these conditions was 45.31 l/m2.h. The total solids content was increased from 14.74 g/l in the feed to 95.04 g/l in the concentrate. The permeate had low total solid contents of 8.75 g/l, Chemical Oxygen Demand of 6696 mg/l, and Biochemical Oxygen Demand of 4383 mg/l. Such qualities would allow the permeate to be reused in the alkaline peroxide mechanical pulping process. With this new concentration process, about 4840.6 kwh energy can be saved and 23.3 m3 effluent discharge can be reduced for each ton of pulp produced.
- Published
- 2010
27. EVALUATION OF THE STRUCTURAL AND MOLECULAR WEIGHT CHANGES OF LIGNIN DURING THE TREATMENT OF HARDWOOD ALKALINE PEROXIDE MECHANICAL PULP WITH LACCASE AND A LACCASE-MEDIATOR-SYSTEM
- Author
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Yu Liu,, Zhen Wang,, Juan Wang,, Guihua Yang,, Feng Huang,, and Lucian Lucia
- Subjects
Laccase ,Alkaline peroxide mechanical pulp ,Lignin structure ,31P-NMR spectra ,Molecular weight ,GPC ,Biotechnology ,TP248.13-248.65 - Abstract
Alkaline Peroxide Mechanical Pulp (APMP) of triploid of Populus tomentosa was modified by laccase and a Laccase-Mediator-System (LMS). The influence of the following main variables on the pulp physical properties were studied: enzyme dosage, reaction time, treatment temperature, and pH. Under the optimum conditions of laccase treatment – pH 5, temperature 50 °C, pulp consistency 4%, and a reaction time of 60 min – the optimum charge of laccase was 2u/g. It was also found that the tensile strength and tear indices of the pulps treated with laccase increased significantly. The two-stage method of enzyme-mild acidic hydrolysis was adopted to isolate lignin from the APMP pulps both before and after enzymatic treatments. The functional groups in all lignin samples were qualitatively and quantitatively analyzed with 31P-NMR spectra. The molecular weight distributions of all the lignin samples were obtained through Gel Permeation Chromatography (GPC) after the lignin samples were benzoylated.
- Published
- 2012
28. The effects of pre-treatment and consistency on treatment time and brightness of bagasse alkaline peroxide mechanical pulp
- Author
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Saeideh Sharifi, Ahmad reza Saraeyan, and Hossein Resalati
- Subjects
Bagasse ,Alkaline Peroxide Mechanical Pulping ,consistency ,Pretreatment ,residual peroxide ,brightness ,Forestry ,SD1-669.5 - Abstract
Preparation and pre-treatment of raw material influences the pulp production time and color elimination. Pulp consistency during the treatment also influences the color reaction. In the preparation of the APMP pulp, bagasse was pretreated by either boiling water, 1% NaOH as well as 1% NaOH + 1% H2O2. The liquor to bagasse ratio, treatment time and temperature of alkaline peroxide treatment were constant as 10:1, 30 min, and 70 °C respectively. The treatment duration was determined so that at least five percent of the initial hydrogen peroxide remained at the end of chemical treatment. Characteristics of hand sheets were determined according to the TAPPI standard. The results showed that, the duration of the treatment for pulp consistency of 10, 15 and 20% was 50, 30 and 10 minute, for sample pretreated with boiling water and 290, 230 and 170 minute for the sample pretreated with 1% NaOH + 1% H2O2. The highest brightness of the paper reached with bagasse pretreated in boiling water at 20 % consistency.
- Published
- 2012
- Full Text
- View/download PDF
29. Impact of continuous electrochemical degradation of eucalyptus alkaline peroxide mechanical pulping wastewater
- Author
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Ming Li
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Levels of pollutants in pulp and papermaking wastewater are an important issue for environmental protection. High concentrations of contaminants can seriously affect the environment if they are not processed. Therefore, treating paper wastewater is a necessary option for governments to select appropriate treatment methods to remove the multi-component pollutants. In this study, the impact of continuous electro-degradation of eucalyptus alkaline peroxide mechanical pulping wastewater was studied. An electrolytic treatment method performed at a low voltage was used. Through the electrolysis method, the wastewater chemical oxygen demand was decreased by 98%, and color-generating groups were nearly all destroyed. During the electrolysis process, the pH value of wastewater continuously decreased and finally reached 2.5. Lowering the pH of the waste solution will help increase the electrolysis efficiency of the wastewater. A total of 5.8 g of alkali was obtained. The wastewater precipitation before and after electrolysis was analyzed by X-ray photoelectron, Fourier transform infrared, and energy-dispersive X-ray spectroscopies.
- Published
- 2022
30. PERFORMANCE OF A PILOT-SCALE MEMBRANE PROCESS FOR THE CONCENTRATION OF EFFLUENT FROM ALKALINE PEROXIDE MECHANICAL PULPING PLANTS
- Author
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Yong Zhang, Chun-Yu Cao, Wen-Ying Feng, Guo-Xin Xue, and Ming Xu
- Subjects
Pilot-scale membrane process ,Concentrating ,Alkaline peroxide mechanical pulping ,Effluent ,Mathematical model ,Energy and water saving ,Discharge reduction ,Biotechnology ,TP248.13-248.65 - Abstract
A pilot-scale membrane process for the concentration of effluent from an alkaline peroxide mechanical pulping (APMP) plant was investigated. Specifically, the cross-flow velocity and volume reduction were optimized again for a higher flux and a lower system energy consumption. A mathematical model was established to obtain the optimal parameters. Estimates were obtained of the expected savings in energy and water. The obtained optimal concentration conditions were: molecular weight cut-off at 10,000 Dalton, trans-membrane pressure at 3 bar, feed temperature at 50 oC, cross-flow velocity at 2 m/s, and volume reduction at 0.9. The average permeate flux under these conditions was 43.21 l/m2.h. The total solids content was increased from 25.47 g/L in the feed to 128.36 g/L in the concentrate. The permeate had low total solids content of 11.03 g/L, Chemical Oxygen Demand of 9180 mg/l, and Biochemical Oxygen Demand of 5870 mg/L. Such qualities would allow the permeate to be reused in the APMP process after a light biochemical treatment. With this new membrane concentration process, about 1402 kWh energy can be saved and 22 m3 effluent discharge can be reduced for each ton of pulp produced.
- Published
- 2011
31. Effect of xylanase treatment on properties of alkaline peroxide mechanical pulp from poplar (Populus nigra) wood
- Author
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Amir hooman Hamasi, Mehdi Sabor, Mohammad Talaeipoor, and Mohammad Azadfallah
- Subjects
Xylanase Enzyme ,POPLAR ,Alkaline Peroxide Mechanical Pulping ,Forestry ,SD1-669.5 - Abstract
The aim of present study was to investigate the effects of xylanase enzyme obtained from Trichoderma viride on APMP pulp from Populus nigra wood. Treatment temperature, time, enzyme dosage and pulp consistency were varied. The results demonstrated that treating by xylanase has considerable effects on pulp. Paper brightness improved in average 2.5% ISO and the highest gain was 4.5%. Also, using enzyme resulted in enhancement of tear and burst indices. Breaking length of paper from enzyme treated pulp was increased to 4098 meters. Further treatment by xylanase reduced the pulp yield by 2.78% as compared to sample without enzyme treatment. The impact of other treatment such as washing by distilled water and alkaline extraction revealed that these treatments did not have significantly effect on the results of enzyme treatment. The optimum temperature, time, enzyme dosage and pulp consistency were 40-50° C, 70 minutes, 10 U/g of oven dried pulp and 10% respectively.
- Published
- 2012
- Full Text
- View/download PDF
32. Controlled Release Chromic Oxide and Alkaline Peroxide Lignin Marker Methods
- Author
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Pritchard, R. H.
- Published
- 1994
- Full Text
- View/download PDF
33. The alkaline peroxide oxidation of quinolinium salts
- Author
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Apple, Ian Allan
- Subjects
547 ,Organic chemistry - Published
- 2003
34. Studying from the Properties of Chemi-Mechanical Pulping and Alkaline Peroxide Mechanical Pulping of Wheat Straw Golestan province
- Author
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Saeid Kamrani, Ahmad reza Saraeyan, and Eyman Akbarpoor
- Subjects
Tajan wheat straw ,Chemi-mechanical Pulping ,Alkaline Peroxide Mechanical Pulping ,MECHANICAL PROPERTIES ,Optical properties ,yield ,Forestry ,SD1-669.5 - Abstract
In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length , diameter cell , lumen and fiber wall thickness were assessed at 1.18mm, 18.156, 11.461 and 3.396 microns, respectively. chemical components such as cellulose , lignin , ash and extractives were assessed at 53.7, 21.1, 5.1 and 8.5 percent, respectively. Based on the preliminary experiment results, impregnation temperature was 950C, impregnation times of 10, 20, 30, 40 minutes, caustic charge 10% and peroxide charge was 3% in CMP ,one stage APMP and two stages APMP pulps. Considering pulp properties and treatment conditions, many treatments including 20 and 40 minutes treatments were selected for making of handsheet. The selected pulps were refined up to 350 ml (CSF) freeness prior to making of hasndsheet. Final results indicated that two stages APMP pulp (impregnation in time 40 minutes) had the highest burst strength, breaking length and brightness. Also, the results of yield and tear strength showed that, there was no meaningful difference at the 5% level between three methods CMP, one and two stages of APMP pulps.
- Published
- 2010
- Full Text
- View/download PDF
35. Data on the enzymatic conversion of alkaline peroxide oxidative pretreated sugarcane bagasse for the production of fermentable sugars
- Author
-
Augustine O. Ayeni, Daniel T. Oyekunle, Oluwajimi C. Shodipe, and Johnson A. Folayan
- Subjects
Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
Central composite design (CCD) approach of the response surface methodology design of experiment was adopted to determine the production of fermentable sugars after enzymatic conversion of alkaline peroxide oxidative pretreated sugarcane bagasse lignocellulose. MINITAB 16 statistical software was used to design the experiments, evaluate and interpret data generated during the process. The effects of factors such as time, hydrogen peroxide concentration, and temperature on treated biomass for reducing sugars (RS) production were investigated. Operating pretreatment conditions (low–high design levels) were reaction time (6–10 h), hydrogen peroxide concentrations (1–3%v/v), and reaction temperature (60–90 °C). With the desirability of optimization of 1.000, optimal reducing sugar yield after enzymatic hydrolysis was validated to be at 100.2 °C, reaction time of 4.6 h, and hydrogen peroxide concentration of 0.3% with optimum RS yield of 153.74 mg equivalent glucose/g biomass. Keywords: Fermentable sugars, Central composite design, Pretreatment, Enzymatic hydrolysis, Optimization
- Published
- 2019
- Full Text
- View/download PDF
36. Effect of Alkaline Peroxide Pre-treatment on Microfibrillated Cellulose from Oil Palm Fronds Rachis Amenable for Pulp and Paper and Bio-composite Production
- Author
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Abdul Wahab Taiwo Owolabi, Ghazali Arniza, Wanrosli wan Daud, and Abbas F. M. Alkharkhi
- Subjects
Cellulose fibre ,Vascular bundles ,Oil palm frond rachis ,DMRT ,TGA ,FTIR ,XRD ,Micro-fibrillated celluloses ,Biotechnology ,TP248.13-248.65 - Abstract
Effects of alkaline peroxide (AP) pre-treatment were investigated with respect to the extracted cellulose fibres from the vascular bundles of oil palm (Elaeis guineensis) fronds (OPF) rachis at different AP concentrations. The extracted fibres were prepared through the mechanical fibrillation resulting from the AP pre-treatment concentrations of the rachis. The cellulose fibres obtained were characterized using microscopic (SEM), spectroscopic (FTIR), thermal (TGA-DTG), and X-ray diffraction (XRD) techniques. The screen pulp yield was between 38.07% and 42.69%, which increased with the increase in the AP concentrations. The SEM showed a significant separation of the fibres after the AP pretreatment. FTIR spectroscopy and TGA showed significant dissolution of both lignin and hemicellulose molecules from the treated biomass at higher alkaline peroxide concentrations. The thermal stability of the extracted fibres ranged from 366 oC to 392 oC while the XRD results showed that the cellulose fibre extracted at H2O2/NaOH ratio of 2.5%: 2.0%,w/v AP concentrations gave the highest percentage crystallinity (35.7%). The handsheet made from the cellulose fibre showed that tensile, burst, and tear indexes increased with an increase in AP concentration. Duncan Multiple Range Test shows that mild alkaline peroxide pretreatment (medium concentrations) is best favoured for paper making pulp and bio-composite production.
- Published
- 2016
- Full Text
- View/download PDF
37. Impact of continuous electrochemical degradation of eucalyptus alkaline peroxide mechanical pulping wastewater
- Author
-
Li, Ming, primary
- Published
- 2022
- Full Text
- View/download PDF
38. Influence of alkaline peroxide assisted and hydrothermal pretreatment on biodegradability and bio-hydrogen formation from citrus peel waste
- Author
-
Franciele Pereira Camargo, Maria Bernadete Amâncio Varesche, Isabel Kimiko Sakamoto, and Iolanda Cristina Silveira Duarte
- Subjects
biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Hydrogen formation ,Energy Engineering and Power Technology ,Alkaline peroxide ,02 engineering and technology ,Biodegradation ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,biology.organism_classification ,01 natural sciences ,Hydrothermal circulation ,0104 chemical sciences ,HIDROGÊNIO ,Acetic acid ,chemistry.chemical_compound ,Fuel Technology ,Clostridium ,Fermentation ,0210 nano-technology ,Bacteria ,Nuclear chemistry - Abstract
The effect of pretreatments by hydrothermolysis (180 °C; 15 min) and alkaline delignification (NaOH 5M; H2O2 1%; 24 h) in citrus peel waste (CPW) was evaluated, as well as the effect on H2, organic acids and alcohols production, in addition to characterization of the microbial community involved in fermentation. Batch reactors at 37 °C were operated with 3 gTVS/L of CPW with allochthonous consortium (UASB reactor sludge; 2 gTVS/L) and autochthonous of CPW (1.5 gTVS/L) as inocula. H2 production was higher in reactors with in natura CPW (13.31 mmol/L) compared to hydrothermolysis (8.19 mmol/L) and alkaline delignification (7.27 mmol/L). The acetogenic pathway was predominant in the in natura CPW (4,355 mg/L acetic acid). The most abundant genera in the in natura CPW and after hydrothermolysis were Clostridium (18.97 and 12.90%, respectively) and Ruminiclostridium (16.65 and 1.04%, respectively) commonly related to cellulolytic bacteria and/or H2 production.
- Published
- 2019
39. Structural Analysis of Fast-Growing Aspen Alkaline Peroxide Mechanical Pulp Lignin: A Post-Enzymatic Treatment
- Author
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Huimei Wang, Yu Liu, Zhen Wang, Guihua Yang, and Lucian A. Lucia
- Subjects
31P-NMR ,Lignin ,Laccase ,GPC ,LMS ,13C-NMR ,Biotechnology ,TP248.13-248.65 - Abstract
An enzymatic mild acidic hydrolysis was used to separate and purify residual lignin from alkaline peroxide mechanical pulp (APMP). Using the optimum conditions for the laccase treatment (pH 4.5, temperature 50 °C, lignin consistency of 1%, a reaction time of 60 min, and a laccase dosage of 8 μ/g), oven-dried lignin was treated with laccase and in a laccase mediator system (LMS) to explore the mechanism for laccase and the LMS modification of APMP. The changes of functional groups in lignin were analyzed using nuclear magnetic resonance (31P-NMR and 13C-NMR). The molecular weight distributions of the lignin samples were confirmed by gel permeation chromatography (GPC). The 31P-NMR and 13C-NMR spectra revealed that the lignin structure changed significantly with the laccase and the LMS treatments. Meanwhile, GPC demonstrated that laccase without a mediator could lead to the polymerization of lignin, while the LMS could degrade the lignin. Hence, it was concluded that laccase is an attractive enzyme for lignin modification.
- Published
- 2016
- Full Text
- View/download PDF
40. Soft Sensors for Pulp Freeness and Outlet Consistency Estimation in the Alkaline Peroxide Mechanical Pulping (APMP) High-Consistency Refining Process
- Author
-
Xiangyu Zhang, Jigeng Li, Huanbin Liu, and Ping Zhou
- Subjects
APMP pulping ,Soft sensor ,Case-based reasoning ,Pulp quality ,Biotechnology ,TP248.13-248.65 - Abstract
In the mechanical pulping process, some process state and product quality variables are difficult to measure on-line. In this paper, soft sensors were used to estimate Canadian Standard Freeness (CSF) and outlet consistency (Cout) after the high consistency refining stage of the alkaline peroxide mechanical pulping (APMP) process. After the secondary variables for modeling that are readily available processed measurements in pre-treatment and the HC refining stage was selected, models based on the case-based reasoning (CBR) method were developed to estimate CSF and Cout. The ability of CBR soft sensors to predict CSF and Cout was tested using data collected from an APMP mill, and the results were satisfactory. Additionally, two typical soft sensor methods that back propagation network (BP) algorithms and support vector regression algorithms (SVR) were employed to predict CSF and Cout and evaluate the performance of the CBR soft sensor. As a result, the proposed soft sensor demonstrated a better performance than the BP method and can be regarded as of comparable quality to the SVR method.
- Published
- 2016
- Full Text
- View/download PDF
41. Chemical Evaluation of Eumelanin Maturation by ToF-SIMS and Alkaline Peroxide Oxidation HPLC Analysis
- Author
-
Martin Jarenmark, Peter Sjövall, Shosuke Ito, Kazumasa Wakamatsu, and Johan Lindgren
- Subjects
alkaline hydrogen peroxide oxidation ,eumelanin ,maturation ,principal component analysis ,time-of-flight secondary ion mass spectrometry ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Residual melanins have been detected in multimillion-year-old animal body fossils; however, confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Here, we simulate this post-burial process through artificial maturation experiments using three synthetic and one natural eumelanin exposed to mild (100 °C/100 bar) and harsh (250 °C/200 bar) environmental conditions, followed by chemical analysis employing alkaline hydrogen peroxide oxidation (AHPO) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results show that AHPO is sensitive to changes in the melanin molecular structure already during mild heat and pressure treatment (resulting, e.g., in increased C-C cross-linking), whereas harsh maturation leads to extensive loss of eumelanin-specific chemical markers. In contrast, negative-ion ToF-SIMS spectra are considerably less affected by mild maturation conditions, and eumelanin-specific features remain even after harsh treatment. Detailed analysis of ToF-SIMS spectra acquired prior to experimental treatment revealed significant differences between the investigated eumelanins. However, systematic spectral changes upon maturation reduced these dissimilarities, indicating that intense heat and pressure treatment leads to the formation of a common, partially degraded, eumelanin molecular structure. Our findings elucidate the complementary nature of AHPO and ToF-SIMS during chemical characterization of eumelanin traces in fossilized organismal remains.
- Published
- 2020
- Full Text
- View/download PDF
42. Impact of double alkaline peroxide pretreatment on enzymatic hydrolysis of palm fibre
- Author
-
Wangliang Li, Yuming Zhang, and Shengqiang Chang
- Subjects
0106 biological sciences ,020209 energy ,Materials Science (miscellaneous) ,Biomass ,Alkaline peroxide ,02 engineering and technology ,Cellulase ,lcsh:Chemical technology ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Hydrolysis ,010608 biotechnology ,Enzymatic hydrolysis ,0202 electrical engineering, electronic engineering, information engineering ,Lignin ,lcsh:TP1-1185 ,chemistry.chemical_classification ,biology ,Process Chemistry and Technology ,Reducing sugar ,Fuel Technology ,chemistry ,Yield (chemistry) ,biology.protein ,Nuclear chemistry - Abstract
A double pretreatment was developed to improve the efficiency of enzymatic hydrolysis and to increase the sugars production from palm fibre in batch and fed-batch systems. After alkaline peroxide pretreatment using NaOH-H2O2 solution, rigid structure of palm fibre was broken and partial of the hemicelluloses and lignin were removed. Compared with cellulase Accellerase® 1500, when using the conjunction of Accellerase® 1500 and Optimash BG, the conversion ratio increased from 35.9% to 45.0% and the reducing sugar yield increased from 245 mg/g substrate to 307 mg/g substrate. To further increase the hydrolysis efficiency, double pretreatment with NaOH-H2O2 solution was used to treat the hydrolysized residues. Then, the hydrolysis ratio reached 93% and reducing sugar yield was 752 mg/g substrate. Fed-batch enzymatic hydrolysis was carried out with 7% (w/v) solids loading and 0.3 mL/g substrate. Then, 7% solids were fed consecutively at 12 h, 24 h, 36 h and 48 h. After 144 h, the final concentration of reducing sugar reached 214.0 g/L and total biomass conversion ratio was 75.23%. Keywords: Cellulase, Palm fibre, Reducing sugar, Lignin, Alkaline peroxide pretreatment
- Published
- 2018
43. Fiber Characteristics and Bonding Strength of Poplar Refiner-Chemical Preconditioned Alkaline Peroxide Mechanical Pulp Fractions
- Author
-
Jiehui Li, Hongjie Zhang, Jianguo Li, Huiren Hu, and Zhenlei Cao
- Subjects
Fiber fractions ,Fiber characteristics ,Poplar P-RC APMP ,Bonding strength properties ,Biotechnology ,TP248.13-248.65 - Abstract
In China, alkaline peroxide mechanical pulping performed with refiner-chemical preconditioning (P-RC APMP) is well known to produce fiber with high bulk, opacity, and light scattering coefficient but weak bonding and strength properties. In this study, the characteristics of different P-RC APMP fiber fractions were investigated, and their effects on bonding strength properties were determined. The results showed that there was only 5.8% R30 fiber fraction and 14.1% P100/R200 fiber fraction, and the specific surface area increased from R30 to P100/R200. The tensile index increased by 51.85% and the bonding index increased by 15.35%, when the fibers were changed from the R30 fraction to the P100/R200 fraction. The short fiber fraction (P100/R200 fraction) had smaller fiber length and coarseness but larger specific surface area and greater surface charge density than the long fiber fraction (R30 fraction). The fiber specific surface area and surface charge density made significant contributions to the bonding capacity, whereas fiber coarseness and length were negatively correlated with the tensile index.
- Published
- 2015
- Full Text
- View/download PDF
44. Morphological modification of Chromolaena odorata cellulosic biomass using alkaline peroxide oxidation pretreatment methodology and its enzymatic conversion to biobased products
- Author
-
Augustine O. Ayeni, Michael O. Daramola, Adeola Awoyomi, Francis B. Elehinafe, Ajibola Ogunbiyi, Patrick T. Sekoai, and Johnson A. Folayan
- Subjects
bioenergy ,lignocellulose ,pretreatment ,enzymatic conversion ,stereomicrograph ,sem ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
In this study, the structural modification of Siam weed (Chromolaena odorata) was performed using NaOH–H2O2- and Ca(OH)2–H2O2-based oxidative pretreatment for the enzymatic conversion of the biomass to a biocommodity, reducing sugar (RS). Pretreatment of raw sample was evaluated at temperatures of 60°C, 70°C, 80°C, 90°C for different time intervals of 3, 6, 9, 12 h in alkaline medium (NaOH or Ca(OH)2). The effects of pretreatment time and temperature were considered in obtaining the optimum conditions. The optimum conditions for NaOH–H2O2 was obtained at 70°C and 3 h with a maximum cellulose content of 44.29%(w/w), lignin content reduced to 21.09% from the initial raw value of 24.2%. Pretreatment with Ca(OH)2–H2O2 resulted in the optimum conditions obtained to be 70°C for 3 h with a cellulose content of 47.18%. Enzymatic hydrolysis on the pretreated biomass at the optimum conditions showed NaOH–H2O2-treated sample yielded 424.35 mg equivalent glucose/g biomass of RS while Ca(OH)2–H2O2-treated sample yielded 335.81 mg equivalent glucose/g biomass of RS. The untreated raw sample yielded 68.75 mg equivalent glucose/g biomass of RS. Consequently, NaOH–H2O2 pretreatment displayed a higher efficiency than Ca(OH)2–H2O2 pretreatment. Stereomicroscopic and scanning electron microscopic imaging of the treated and untreated samples revealed morphological disruptions brought about by the treatments.
- Published
- 2018
- Full Text
- View/download PDF
45. Saccharification of microalgae biomass obtained from wastewater treatment by enzymatic hydrolysis. Effect of alkaline-peroxide pretreatment
- Author
-
Martín Juarez, Judit and Martín Juarez, Judit
- Abstract
An enzymatic method for the carbohydrate hydrolysis of different microalgae biomass cultivated in domestic (DWB) and pig manure (PMWB) wastewaters, at different storage conditions (fresh, freeze-dried and reconstituted), was evaluated. The DWB provided sugars yields between 40 and 63%, although low xylose yields (< 23.5%). Approximately 2% of this biomass was converted to byproducts as succinic, acetic and formic acids. For PMWB, a high fraction of the sugars (up to 87%) was extracted, but mainly converted into acetic, butyric and formic acids, which was attributed to the bacterial action. In addition, the performance of an alkaline-peroxide pretreatment, conducted for 1 hour, 50ºC and H2O2 concentrations from 1 to 7.5% (w/w), was essayed. The hydrolysis of pretreated microalgae supported a wide range of sugars extraction for DWB (55-90%), and 100% for PMWB. Nevertheless, a large fraction of these sugars (~30% for DWB and 100% for PMWB) was transformed to byproducts., INIA MICINN Junta de Castilla y León
- Published
- 2016
46. Production of natural cellulose-based microfibres, from oil palm mesocarp fibres and pineapple leaf wastes, as porous supports for further applications
- Author
-
G.D. Anukwah and V.P.Y. Gadzekpo
- Subjects
Purification ,Eco-friendly ,Cellulosic nature ,Gauze bandage ,Alkaline-peroxide ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Natural cellulose-based microfibers were obtained through an economical and environmentally sustainable process called alkaline-peroxide purification, from the waste products of oil palm mesocarp fibres (OPMF) and pineapple leaves (PL), with the intention of creating porous, biodegradable, biocompatible, and non-toxic solid supports for use in future processes. The extracted microfibres were then taken through microscopic, spectroscopic and thermal characterisation to establish their cellulosic nature. The scanning electron microscopic (SEM) images of the bleached microfibres (B-OPMF and B-PLF) were cleaner, smoother and porous as compared with that of the unrefined fibres (Ur-OPMF and Ur-PLF). The bleached fibres (B-OPMF and B-PLF) exhibited peaks of C and O, which are indicative of pure cellulose, in the energy-dispersive X-ray spectroscopy (EDS) analysis. The FTIR spectral analysis of the extracted cellulose-based fibres (B-OPMF and B-PLF) exhibited peaks that were similar in composition to the reference cellulose (P-GB). For the thermogravimetric analysis (TGA) analysis, the maximum weight degradation in the reference cellulose (P-GB), occurred at 363.11 °C, in the bleached palm fibres (B-OPMF) at 334.55 °C and in the bleached pineapple leaf fibres (B-PLF) at 375.68 °C which, corresponds to cellulose decomposition. The differential scanning calorimetry (DSC) test verified the microfibers' thermally induced transitions. Therefore, these cellulose-based microfibres could be applied as functionalised microfibre supports for future applications.
- Published
- 2024
- Full Text
- View/download PDF
47. Alkaline Peroxide and Laccase Treatment for the Delignification of Ricinus Communis Biomass to Enhance Saccharification
- Author
-
Narkhede Yogesh
- Subjects
Laccase ,biology ,Chemistry ,Ricinus ,Biomass ,Alkaline peroxide ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,biology.organism_classification ,01 natural sciences ,Hydrolysis ,0210 nano-technology ,0105 earth and related environmental sciences - Published
- 2018
48. Comparison of Interfiber Bonding Ability of Different Poplar P-RC Alkaline Peroxide Mechanical Pulp (APMP) Fiber Fractions
- Author
-
Hailong Li, Hongjie Zhang, Jianguo Li, and Fang Du
- Subjects
Poplar P-RC APMP ,Fiber fractions ,Interfiber bonding ,Relative bonded area (RBA) ,Biotechnology ,TP248.13-248.65 - Abstract
In recent years, the alkaline peroxide mechanical pulping performed with refiner-chemical preconditioning (P-RC APMP) has obtained a wide application in many paper grades in China. This is due to such desirable pulp characteristics as its high bulk, opacity, and light scattering coefficient. However, compared with its bleached chemical pulps, the poplar P-RC APMP has weak bonding strength, which limits its application in value-added products. Usually, the interfiber bonding abilities of different fiber fractions are quite different. In this study, the page bonding strength index (B) and the interfiber bonding abilities (shear bond strength per unit area (b) and relative bonding area (RBA)) of different P-RC APMP fiber fractions were extrapolated by the traditional Page Equation. The results show that the higher B could be obtained when the fiber fraction was shorter or smaller. The same trend was observed for b and RBA. Wet pressing was used to improve the bonding ability, and higher pressure of wet pressing or shorter fiber fraction can lead to obviously higher tensile strength.
- Published
- 2014
- Full Text
- View/download PDF
49. Alkaline Peroxide Extrusion Pulping of Cotton Bast and Cotton Stalk
- Author
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Zhijun Hu and Xunzai Nie
- Subjects
Cotton stalk ,Cotton bast ,Pulping ,Screw extrusion ,Biotechnology ,TP248.13-248.65 - Abstract
The chemical compositions of cotton stalk and bast are similar to those of hardwood and superior to those of grass fiber. With respect to the morphological characteristics of their fibers, cotton stalk is similar to hardwood and cotton bast is similar to softwood. The average length of cotton bast fibers is nearly triple that of cotton stalk fibers, and the length-to-width ratio is almost quadruple. Traditionally, cotton stalk and cotton bast are pulped together, which affects the quality and homogeneity of the pulp and complicates bleaching, limiting its use to low-grade paper. In this study, cotton bast and cotton stalk were separated and pulped individually by alkaline peroxide extrusion pulping (APEP). The orthogonal analytical method was used to determine the optimal pulping parameters. Compared to those obtained via the kraft pulp (KP) of cotton stalk as a whole, far superior yield and whiteness were obtained in APEP. Further, with APEP, lower amounts of chemicals and less energy were consumed and there was little pollution. The physical performance of APEP was slightly lower than that of KP. With respect to bast alone, the physical performance of APEP was almost as good as that of KP.
- Published
- 2014
- Full Text
- View/download PDF
50. Removal of fermentation inhibitors from alkaline peroxide pretreated and enzymatically hydrolyzed wheat straw: Production of butanol from hydrolysate using Clostridium beijerinckii in batch reactors
- Author
-
Qureshi, Nasib, Saha, Badal C., Hector, Ronald E., and Cotta, Michael A.
- Published
- 2008
- Full Text
- View/download PDF
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