343 results on '"WOOD"'
Search Results
2. Applications of enzymatic technologies to the production of high-quality dissolving pulp: A review
- Author
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Jaroslav Stavik, Chao Duan, Bo Yang, Darcy Alexandra Fuller, Susmita Paul Chowdhury, Yonghao Ni, Hongjie Zhang, Xinqi Wang, and Shuo Yang
- Subjects
0106 biological sciences ,Environmental Engineering ,Bioengineering ,Cellulase ,010501 environmental sciences ,engineering.material ,01 natural sciences ,stomatognathic system ,010608 biotechnology ,Cellulose ,Dissolving pulp ,Waste Management and Disposal ,Practical implications ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Laccase ,Endo-1,4-beta Xylanases ,biology ,Viscosity ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Pulp (paper) ,General Medicine ,Pulp and paper industry ,Wood ,stomatognathic diseases ,Enzyme ,engineering ,biology.protein ,Xylanase - Abstract
Recently, the worldwide production of dissolving pulp has grown rapidly. Enzymatic technologies play an important role in producing high-quality dissolving pulp, due to their green, mild conditions, high specificity and efficiency. In this review, the relevant publications regarding enzyme applications for dissolving pulp are summarized. Cellulase and xylanase are two major enzymes used for this purpose. Cellulase can improve the quality of dissolving pulp, such as improving the reactivity/accessibility, controlling the intrinsic viscosity and adjusting the molecular weight. Xylanase is mainly used to increase the purity of the dissolving pulp and improve the pulp brightness. Furthermore, in order to increase the enzymatic treatment efficiency, the enzymatic technology can be combined with other techniques, including mechanical refining, fiber fractionations, alkali treatment and use of additives. The advantages, disadvantages and practical implications are analyzed. Also, the potential of other enzymes (such as laccase, mannanase) are discussed.
- Published
- 2019
3. Autohydrolysis prior to poplar chemi-mechanical pulping: Impact of surface lignin on subsequent alkali impregnation
- Author
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Zhen Yue, Qingxi Hou, Wei Liu, Shiyun Yu, Honglei Zhang, and Xiaodi Wang
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0106 biological sciences ,Environmental Engineering ,Stepwise regression analysis ,Biomass ,Bioengineering ,Alkalies ,010501 environmental sciences ,Lignin ,01 natural sciences ,chemistry.chemical_compound ,stomatognathic system ,010608 biotechnology ,Porosity ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Hydrolysis ,fungi ,food and beverages ,General Medicine ,Pulp and paper industry ,Alkali metal ,Wood ,stomatognathic diseases ,Populus - Abstract
Chemi-mechanical pulping, a typical high-yield pulping method, combined with autohydrolysis pretreatment prior to pulping is an efficient and value-added utilization method for biomass in pulp and paper industry. This study investigated the surface lignin changes of poplar sapwood chips in autohydrolysis pretreatment and their effect on the subsequent alkali impregnation for chemi-mechanical pulping. The results showed that the surface lignin content went up with the increase of autohydrolysis intensity, and that the existence of the surface lignin had nearly no impact on the subsequent alkali impregnation in making chemi-mechanical pulps (CMPs) compared to the volume porosity, which was validated by using the stepwise regression analysis. It can be further concluded that autohydrolysis can facilitate the subsequent alkali impregnation of the autohydrolyzed sapwood chips in making CMP, which would be of significance for the combination of biomass refinery and pulp and paper industry.
- Published
- 2019
4. Effect of torrefaction on pinewood pyrolysis kinetics and thermal behavior using thermogravimetric analysis
- Author
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Juntao Wei, Qing He, Lu Ding, Weifeng Li, Guangsuo Yu, and Gong Yan
- Subjects
0106 biological sciences ,Thermogravimetric analysis ,Hot Temperature ,Environmental Engineering ,Materials science ,Biomass ,Bioengineering ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Crystallinity ,010608 biotechnology ,Lignin ,Hemicellulose ,Cellulose ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Pinus ,Torrefaction ,Wood ,Kinetics ,chemistry ,Chemical engineering ,Thermogravimetry ,Pyrolysis - Abstract
Torrefaction is a promising pretreatment technology for biomass thermochemical conversion. In this study, pinewood (PW) and PW250 (torrefied at 250 °C) were prepared for pyrolysis. Torrefaction was carried out in a fixed bed reactor and the pyrolysis was studied by thermogravimetric analyzer using six different heating rates. The results showed that the content of hemicellulose in biomass decreased while cellulose and lignin increased after torrefaction. Moreover, the C-O peaks of torrefied biomass was strengthened in FTIR spectrum and the crystallinity degree was enhanced according to XRD analysis. The performance of devolatilization and heat transfer were improved for PW250 while the volatiles only decreased by only 4%. Activation energy was calculated by three iso-conversion methods. It was found that the PW followed D3 diffusion model, while the PW250 followed D1 diffusion model and tended to higher order reaction model at high conversions. In addition, the thermodynamic parameters were compared.
- Published
- 2019
5. Pyrolysis of blend (oil palm biomass and sawdust) biomass using TG-MS
- Author
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Ryan Man Wai Ting, Yong Kuan Shang, and Arshad Adam Salema
- Subjects
0106 biological sciences ,Thermogravimetric analysis ,Environmental Engineering ,Biomass ,Bioengineering ,Activation energy ,Palm Oil ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,Mass Spectrometry ,010608 biotechnology ,Palm oil ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Temperature ,General Medicine ,Pulp and paper industry ,Wood ,Kinetics ,visual_art ,Thermogravimetry ,visual_art.visual_art_medium ,Sawdust ,Pyrolysis - Abstract
The aim of this study was to pyrolyze individual (oil palm shell, empty fruit bunch and sawdust) as well as blend biomass in a thermogravimetric mass spectrometry (TG-MS) from room temperature to 800 °C at constant heating rate of 15 °C/min. The results showed that the onset TG temperature for blend biomass shifted slightly to lower values. Activation energy values were also found to decrease slightly after blending the biomass. Interestingly, the MS spectra of selected gases (H2O CH4, H2O, C2H2, C2H4 or CO, CH2O, CH3OH, HCl, C3H6, CO2, HCOOH, and C6H12) evolved from blend biomass showed decreased in the intensity as compared to their individual biomass. Overall, the blend biomass showed synergy which provides ways to expand the possibility of utilizing multiple feedstocks in one thermo-chemical system.
- Published
- 2019
6. Bioethanol production from palm wood using Trichoderma reesei and Kluveromyces marxianus
- Author
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Edgard Gnansounou, Gurunathan Baskar, R. Praveenkumar, and E. Raja Sathendra
- Subjects
0106 biological sciences ,Environmental Engineering ,whey ,ethanol-production ,Bioengineering ,Arecaceae ,010501 environmental sciences ,Lignin ,01 natural sciences ,Zymomonas mobilis ,Hydrolysate ,chemistry.chemical_compound ,lignocellulose ,Kluyveromyces marxianus ,010608 biotechnology ,Ethanol fuel ,Cellulose ,Waste Management and Disposal ,Trichoderma reesei ,bioethanol ,0105 earth and related environmental sciences ,Trichoderma ,palm wood ,Ethanol ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Hydrolysis ,high-temperature ,Temperature ,General Medicine ,biology.organism_classification ,Pulp and paper industry ,Wood ,cellulose ,kluyveromyces-marxianus ,sugar ,Biofuel ,Fermentation ,saccharomyces-cerevisiae ,zymomonas-mobilis - Abstract
In the present work, palm wood was pretreated using hydrothermal technique in conjunction with chemical method for removal of lignin. Pretreated palm wood was subjected to hydrolysis using Trichoderma reesei MTCC 4876. Subsequently bioethanol was produced using palm wood hydrolysate by Kluveromyces marxianus MTCC 1389. RSM was used to identify the non-linear relationship and optimize various process parameters such as parameters such as pH, temperature, agitation rate, substrate concentration and inoculum size for bioethanol production. ANN constructed with 5-2-1 topology was also used to optimize process parameters. The experimental bioethanol yield of 22.90 g/l was obtained at ANN optimum conditions of temperature 45 degrees C, agitation rate 156 rpm, pH 5, substrate concentration 8% (v/v) and inoculum size 3.2% (v/v).
- Published
- 2019
7. Correlation between physicochemical characteristics of lignin deposited on autohydrolyzed wood chips and their cellulase enzymatic hydrolysis
- Author
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Wenchao, Jia, Haiqiang, Shi, Xueru, Sheng, Yanzhu, Guo, Pedram, Fatehi, and Meihong, Niu
- Subjects
Environmental Engineering ,Cellulase ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Bioengineering ,Biomass ,General Medicine ,Cellulose ,Lignin ,Wood ,Waste Management and Disposal - Abstract
Enzymatic hydrolysis is a method to generate biofuel from biomass, and autohydrolysis is a popular method to pretreat biomass prior to enzymatic hydrolysis. The primary aim of the present study was to determine the role of lignin produced in the autohydrolysis process on the enzymatic hydrolysis of biomass. The HSQC and
- Published
- 2022
8. Biotransformation of flower waste composting: Optimization of waste combinations using response surface methodology
- Author
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Sunil Kumar, Kunwar D. Yadav, and Dayanand Sharma
- Subjects
Environmental Engineering ,Municipal solid waste ,Central composite design ,Carbon-to-nitrogen ratio ,Nitrogen ,020209 energy ,Bioengineering ,Flowers ,02 engineering and technology ,010501 environmental sciences ,engineering.material ,01 natural sciences ,Nutrient ,0202 electrical engineering, electronic engineering, information engineering ,Animals ,Response surface methodology ,Waste Management and Disposal ,Biotransformation ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Compost ,Composting ,Electric Conductivity ,General Medicine ,Pulp and paper industry ,Wood ,visual_art ,visual_art.visual_art_medium ,engineering ,Environmental science ,Cattle ,Sawdust ,Cow dung - Abstract
Flower waste (FW) is disposed off in the rivers or mixed with solid waste for landfilling that pollutes the environment and causes harmful effects on human health and aquatic life. It is rich in nutrient content and easily converted into the compost. Therefore, the objective of the present research was to optimize the combinations of flower waste and cow dung during agitated pile composting using response surface methodology. Thirteen different agitated piles were used for composting using the central composite design. The optimum combination from central composite design was 65 kg floral waste, 25 kg cattle dung and 10 kg sawdust having 7.10 pH, 3.31 mS cm−1 electrical conductivity, 32.98% total organic carbon and 14 Carbon to Nitrogen ratio during the end phase of the composting period. The nutrient concentrations into the final compost were within the acceptable limit and also found to be beneficial for the growth of plants.
- Published
- 2018
9. Enhanced enzymatic digestibility of mixed wood sawdust by lignin modification with naphthol derivatives during dilute acid pretreatment
- Author
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Qiang Yong, Xin Li, Chenhuan Lai, Xiangyang Song, Bo Yang, Juan He, and Caoxing Huang
- Subjects
0106 biological sciences ,Environmental Engineering ,Bioengineering ,Naphthols ,Lignin ,01 natural sciences ,chemistry.chemical_compound ,Hydrolysis ,Adsorption ,Cellulase ,010608 biotechnology ,Enzymatic hydrolysis ,Cellulose ,Waste Management and Disposal ,chemistry.chemical_classification ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Wood ,0104 chemical sciences ,Enzyme ,chemistry ,visual_art ,Yield (chemistry) ,visual_art.visual_art_medium ,Sawdust ,Nuclear chemistry - Abstract
Effects of the addition of 2-naphthol and 2-naphthol-7-sulfonate on the dilute acid pretreatment of mixed wood sawdust were investigated, respectively. Compared to 2-naphthol, 2-naphtnol-7-sulfonate was more effective to enhance delignification and facilitate the enzymatic hydrolysis. The 72 h hydrolysis yield was improved by 47.8% for 2-naphthol-7-sulfone, while only 9.1% was observed for 2-naphthol. The surface charges, enzyme adsorption, and cellulose accessibility of dilute acid pretreated substrates with or without naphthol derivatives were examined. The improved enzymatic hydrolysis by adding 2-naphthol-7-sulfonate was ascribed to the higher negative surface charges, the lower enzyme non-productive binding, and the higher cellulose accessibility of pretreated substrates. Additionally, the HSQC NMR and 31P NMR analysis were carried out on both decomposed lignins and residual bulk lignins. It indicated that the addition of the naphthol derivatives during pretreatment could suppress the lignin repolymerization, which further mitigated the inhibition of residual lignins on enzymatic hydrolysis.
- Published
- 2018
10. Phosphoric acid-activated wood biochar for catalytic conversion of starch-rich food waste into glucose and 5-hydroxymethylfurfural
- Author
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Iris K.M. Yu, Leichang Cao, Hocheol Song, Eilhann E. Kwon, Daniel C.W. Tsang, Yong Sik Ok, Shicheng Zhang, and Chi Sun Poon
- Subjects
Environmental Engineering ,Starch ,Lignocellulosic biomass ,Bioengineering ,02 engineering and technology ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Biochar ,Furaldehyde ,Phosphoric Acids ,Waste Management and Disposal ,Phosphoric acid ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,food and beverages ,Fructose ,General Medicine ,021001 nanoscience & nanotechnology ,Wood ,0104 chemical sciences ,Glucose ,chemistry ,Charcoal ,visual_art ,visual_art.visual_art_medium ,Sawdust ,0210 nano-technology ,Hydroxymethylfurfural ,Nuclear chemistry - Abstract
The catalytic activity of engineered biochar was scrutinized for generation of glucose and hydroxymethylfurfural (HMF) from starch-rich food waste (bread, rice, and spaghetti). The biochar catalysts were synthesized by chemical activation of pinewood sawdust with phosphoric acid at 400–600 °C. Higher activation temperatures enhanced the development of porosity and acidity (characterized by C O PO3 and C PO3 surface groups), which imparted higher catalytic activity of H3PO4-activated biochar towards starch hydrolysis and fructose dehydration. Positive correlations were observed between HMF selectivity and ratio of mesopore to micropore volume, and between fructose conversion and total acid density. High yields of glucose (86.5 Cmol% at 150 °C, 20 min) and HMF (30.2 Cmol% at 180 °C, 20 min) were produced from rice starch and bread waste, respectively, over H3PO4-activated biochar. These results highlighted the potential of biochar catalyst in biorefinery as an emerging application of engineered biochar.
- Published
- 2018
11. Effects of alkali and alkaline earth metal species on the combustion characteristics of single particles from pine sawdust and bituminous coal
- Author
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Bu Q. Ye, Rui Zhang, Dong Liu, Kai Lei, and Jin Cao
- Subjects
Environmental Engineering ,020209 energy ,Analytical chemistry ,geology ,Biomass ,Bioengineering ,Incineration ,02 engineering and technology ,Alkalies ,Combustion ,law.invention ,law ,Metals, Alkaline Earth ,0202 electrical engineering, electronic engineering, information engineering ,Coal ,Char ,Waste Management and Disposal ,Bituminous coal ,Renewable Energy, Sustainability and the Environment ,Chemistry ,business.industry ,geology.rock_type ,General Medicine ,Alkali metal ,Wood ,Ignition system ,visual_art ,Thermogravimetry ,visual_art.visual_art_medium ,Sawdust ,business - Abstract
Alkali and alkaline earth metal (AAEM) species are the main components of the ash of biomass, and which would influence the combustion of biomass and coal during the co-firing process. The aim of this paper is to investigate the effects of potassium (K), sodium (Na), calcium (Ca), and magnesium (Mg) on the combustion characteristics of pine sawdust (PS) and bituminous coal (BC) by a single particle combustion method. The raw, ash-free and impregnated samples were prepared, and their combustion processes were recorded by a high speed camera. Based on the recorded flame images, the effects of K, Na, Ca and Mg on the combustion characteristics (ignition, volatiles combustion, char combustion) of PS and BC were analyzed. The results reveal that the demineralization treatment brings negative effects on the combustion of PS, which reflects in longer ignition delay time, volatiles and char burnout time, and lower combustion temperature, while the effects on the combustion of BC are opposite. The impregnated samples exhibit shorter ignition delay time, volatiles and char burnout time, and higher combustion temperature than the ash-free samples. In the entire combustion process of PS and BC, K exhibits the strongest promotion effect. When the concentration of K increases from 0 to 2 wt%, the ignition delay time of PS and BC decreases about 5.5 ms and 16.4 ms respectively, the volatiles combustion temperature increases about 41 °C and 77 °C respectively, and the char combustion temperature increases about 226 °C and 141 °C respectively.
- Published
- 2018
12. Co-pyrolysis of microwave-assisted acid pretreated bamboo sawdust and soapstock
- Author
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Yunfeng Zhao, Yayun Zhang, Dengle Duan, Wu Qiuhao, Guiming Fu, Liangliang Fan, Roger Ruan, Zhang Shumei, Yunpu Wang, Leilei Dai, and Yuhuan Liu
- Subjects
Hot Temperature ,Environmental Engineering ,020209 energy ,Bioengineering ,Fraction (chemistry) ,Hydrochloric acid ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Diesel fuel ,Phenols ,0202 electrical engineering, electronic engineering, information engineering ,Microwaves ,Waste Management and Disposal ,Oxygenate ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Temperature ,General Medicine ,Wood ,Product distribution ,Biofuels ,Yield (chemistry) ,visual_art ,visual_art.visual_art_medium ,Sawdust ,Nuclear chemistry - Abstract
Fast microwave-assisted co-pyrolysis of pretreated bamboo sawdust and soapstock was conducted. The pretreatment process was carried out under microwave irradiation. The effects of microwave irradiation temperature, irradiation time, and concentration of hydrochloric acid on product distribution from co-pyrolysis and the relative contents of the major components in bio-oil were investigated. A maximum bio-oil yield of 40.00 wt.% was obtained at 200 °C for 60 min with 0.5 M hydrochloric acid. As pretreatment temperature, reaction time and acid concentration increased, respectively, the relative contents of phenols, diesel fraction (C12 + aliphatics), and other oxygenates decreased. The gasoline fraction (including C5-C12 aliphatics and aromatics) ranged from 55.77% to 73.30% under various pretreatment conditions. Therefore, excessive reaction time and concentration of acid are not beneficial to upgrading bio-oil.
- Published
- 2018
13. Shiitake cultivation as biological preprocessing of lignocellulosic feedstocks – Substrate changes in crystallinity, syringyl/guaiacyl lignin and degradation-derived by-products
- Author
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Feng Chen, Torbjörn A. Lestander, Alejandro Grimm, Shaojun Xiong, and Carlos Martín
- Subjects
Environmental Engineering ,Shiitake Mushrooms ,chemistry.chemical_element ,Bioengineering ,Raw material ,Lignin ,Fungal pretreatment ,chemistry.chemical_compound ,PLS mode ,PLS model ,Hardwood ,Lignocellulose degradation ,Food science ,Bioprocess Technology ,Glucans ,Waste Management and Disposal ,Glucan ,chemistry.chemical_classification ,Mushroom ,biology ,Renewable Energy, Sustainability and the Environment ,Bioprocessteknik ,food and beverages ,Substrate (chemistry) ,VDP::Matematikk og Naturvitenskap: 400 ,General Medicine ,biology.organism_classification ,Wood ,Nitrogen ,Lentinula ,chemistry ,Phenolic components ,Hardwood substrate - Abstract
Formulation of substrates based on three hardwood species combined with modulation of nitrogen content by whey addition (0–2%) was investigated in an experiment designed in D-optimal model for their effects on biological preproceesing of lignocellulosic feedstock by shiitake mushroom (Lentinula edodes) cultivation. Nitrogen loading was shown a more significant role than wood species for both mushroom production and lignocellulose degradation. The fastest mycelial colonisation occurred with no nitrogen supplementation, but the highest mushroom yields were achieved when 1% whey was added. Low nitrogen content resulted in increased delignification and minimal glucan consumption. Delignification was correlated with degradation of syringyl lignin unit, as indicated by a significant reduction (41.5%) of the syringyl-to-guaiacyl ratio after cultivation. No significant changes in substrate crystallinity were observed. The formation of furan aldehydes and aliphatic acids was negligible during the pasteurisation and fungal cultivation, while the content of soluble phenolics increased up to seven-fold.
- Published
- 2022
14. Modeling, experimental validation and optimization of Prosopis juliflora fuelwood pyrolysis in fixed-bed tubular reactor
- Author
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Sethumadhavan Ramachandran, Arunkumar Chandrasekaran, and Senthilmurugan Subbiah
- Subjects
Hot Temperature ,Environmental Engineering ,Materials science ,Moisture ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Temperature ,Biomass ,Bioengineering ,02 engineering and technology ,General Medicine ,Kinetic energy ,Wood ,Heating ,Bioreactors ,Prosopis ,Chemical engineering ,Scientific method ,Yield (chemistry) ,0202 electrical engineering, electronic engineering, information engineering ,Particle size ,Char ,Waste Management and Disposal ,Pyrolysis - Abstract
This work studied the optimal conditions for pyrolysis of Prosopis juliflora wood in fixed-bed tubular reactor. The optimal conditions are measured by performing pyrolysis experiment with respect to wood properties such as particle size, moisture and pyrolysis condition such as, temperatures, heating rates. Higher solid yield (36.8%) was recorded for a slower heating rate of larger particle size at lower temperatures. Further, higher liquid yield (38.3%) was observed while maintaining high heating rate and temperature. It is observed that with increase in particle size, the yield of char and gas decreases and bio-oil increases. The literature reported biomass pyrolysis kinetic model is validated for Prosopis juliflora wood. The kinetic models are able to predict the performance of fixed-bed tubular reactor in terms of pyrolysis product properties. The validated kinetic model may be used for the design of commercial fixed bed pyrolysis reactor to process Prosopis juliflora wood.
- Published
- 2018
15. Role of sawdust and cow dung on compost maturity during rotary drum composting of flower waste
- Author
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Dayanand Sharma, Sunil Kumar, and Kunwar D. Yadav
- Subjects
Environmental Engineering ,020209 energy ,Bioengineering ,Flowers ,02 engineering and technology ,Drum ,010501 environmental sciences ,engineering.material ,complex mixtures ,01 natural sciences ,Soil ,0202 electrical engineering, electronic engineering, information engineering ,Animals ,Organic matter ,Leachate ,Waste Management and Disposal ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Renewable Energy, Sustainability and the Environment ,Compost ,business.industry ,Composting ,fungi ,food and beverages ,Agriculture ,General Medicine ,Pulp and paper industry ,Wood ,Manure ,chemistry ,visual_art ,visual_art.visual_art_medium ,engineering ,Environmental science ,Cattle ,Female ,Sawdust ,business ,Cow dung - Abstract
Flower waste is the good source of organic matter which is beneficial for the growth of plants. It can be extracted from the abundant flower waste resources. The present study was carried out to examine the role of sawdust and cow dung on the compost maturity from six different combinations of waste mixture. Role of cow dung was significant, however, saw dust played a critical role to arrest the leachate and also to maintain the aerobic condition. Addition of sawdust is crucial as flower waste may get converted into a lump (ball like structure) without adding the bulking agent. At the completion of composting period, the concentration of macro and micronutrients, CO2 evolution and C/N ratio showed the stable matured compost which is useful for the purpose of agriculture.
- Published
- 2018
16. Efficient degradation of lignin in raw wood via pretreatment with heteropoly acids in γ-valerolactone/water
- Author
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Ziming Wang, Ling Jiang, Tianfu Wang, Yubo Ma, Wenxiu Zheng, and Libo Zhang
- Subjects
Environmental Engineering ,Bioengineering ,02 engineering and technology ,Raw material ,Silicotungstic acid ,Lignin ,complex mixtures ,01 natural sciences ,Lactones ,chemistry.chemical_compound ,Enzymatic hydrolysis ,Organic chemistry ,Biomass ,Cellulose ,Waste Management and Disposal ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,technology, industry, and agriculture ,Water ,General Medicine ,021001 nanoscience & nanotechnology ,Biorefinery ,Wood ,Refuse Disposal ,0104 chemical sciences ,gamma-Valerolactone ,chemistry ,Cellulosic ethanol ,0210 nano-technology - Abstract
The aim of this work was to study the degradation of lignin in raw wood via pretreatment with heteropoly acids as substitutes for traditional H2SO4 in γ-valerolactone/water. By optimizing catalyst concentration, reaction time and temperature, the optimal lignin degradation conditions are obtained (130 °C, 3 h and 20 mM silicotungstic acid). SEM and FTIR measurements demonstrated the efficient lignin degradation ability of HPAs in the GVL/H2O solvent, with negligible damage to cellulose within the raw wood. Furthermore, an elaborated enzymatic hydrolysis study of the thus obtained cellulosic feedstock revealed its suitability for enzymatic digestion, with great potential as starting material for the production of fermentable sugar from biomass in future biorefinery applications.
- Published
- 2018
17. Assessment of hydrothermal carbonization and coupling washing with torrefaction of bamboo sawdust for biofuels production
- Author
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Xinzhi Liu, Houlei Zhang, Shuguang Zhu, Dan Xu, Shuping Zhang, and Yinhai Su
- Subjects
Bamboo ,Environmental Engineering ,Materials science ,020209 energy ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,Combustion ,Hydrothermal carbonization ,0202 electrical engineering, electronic engineering, information engineering ,Coupling (piping) ,Biomass ,Waste Management and Disposal ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Torrefaction ,Pulp and paper industry ,Wood ,Carbon ,chemistry ,Biofuel ,Biofuels ,visual_art ,visual_art.visual_art_medium ,Sawdust - Abstract
Two kinds of biofuels were produced and compared from hydrothermal carbonization (HTC) and coupling washing with torrefaction (CWT) processes of bamboo sawdust in this study. The mass and energy yields, mass energy density, fuel properties, structural characterizations, combustion behavior and ash behavior during combustion process were investigated. Significant increases in the carbon contents resulted in the improvement of mass energy density and fuel properties of biofuels obtained. Both HTC and CWT improved the safety of the biofuels during the process of handling, storing and transportation. The ash-related issues of the biofuels were significantly mitigated and combustion behavior was remarkably improved after HTC and CWT processes of bamboo sawdust. In general, both HTC and CWT processes are suitable to produce biofuels with high fuel quality from bamboo sawdust.
- Published
- 2018
18. Heteropoly acid catalytic treatment for reactivity enhancement and viscosity control of dissolving pulp
- Author
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Yongjian Xu, Meng Jingru, Duan Chao, Xinqi Wang, Yonghao Ni, Chengxin Zhao, and Xiaoyu Qin
- Subjects
Environmental Engineering ,Bioengineering ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Cellulase ,Specific surface area ,Reactivity (chemistry) ,Fiber ,Phosphotungstic acid ,Cellulose ,Dissolving pulp ,Waste Management and Disposal ,Viscosity ,Renewable Energy, Sustainability and the Environment ,Pulp (paper) ,General Medicine ,021001 nanoscience & nanotechnology ,Wood ,0104 chemical sciences ,Molecular Weight ,chemistry ,Chemical engineering ,engineering ,0210 nano-technology - Abstract
The reactivity enhancement and viscosity control are of practical importance during the manufacture of high-quality cellulose (also known as dissolving pulp). In the study, the concept of using phosphotungstic acid (HPW) for this purpose was demonstrated. The Fock reactivity of resultant pulp increased from 49.1% to 74.1% after the HPW catalytic treatment at a dosage of 86.4 mg HPW/g odp. The improved results can be attributed to the increased fiber accessibility, thanks to the favorable fiber morphologic changes, such as increased pore volume/size, water retention value and specific surface area. HPW can be readily recycled/reused by evaporating method, where maintaining 87.1% catalytic activity after six recycle times. The HPW catalytic treatment concept may provide a green alternative for the manufacture of high-quality dissolving pulp.
- Published
- 2018
19. Combining autohydrolysis and ionic liquid microwave treatment to enhance enzymatic hydrolysis of Eucalyptus globulus wood
- Author
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Mercedes Oliet, Victoria Rigual, Juan Carlos Domínguez, M. Virginia Alonso, Francisco Rodríguez, and Tamara M. Santos
- Subjects
Environmental Engineering ,020209 energy ,Ionic Liquids ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,Lignin ,01 natural sciences ,chemistry.chemical_compound ,Enzymatic hydrolysis ,Lacunarity ,0202 electrical engineering, electronic engineering, information engineering ,Cellulose ,Microwaves ,Waste Management and Disposal ,Chemical composition ,0105 earth and related environmental sciences ,Glucan ,chemistry.chemical_classification ,Eucalyptus ,Chromatography ,biology ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,General Medicine ,biology.organism_classification ,Wood ,chemistry ,Eucalyptus globulus ,Ionic liquid ,Microwave - Abstract
The combination of autohydrolysis and ionic liquid microwave treatments of eucalyptus wood have been studied to facilitate sugar production in a subsequent enzymatic hydrolysis step. Three autohydrolysis conditions (150 °C, 175 °C and 200 °C) in combination with two ionic liquid temperatures (80 °C and 120 °C) were compared in terms of chemical composition, enzymatic digestibility and sugar production. Morphology was measured (using SEM) and the biomass surface was visualized with confocal fluorescence microscopy. The synergistic cooperation of both treatments was demonstrated, enhancing cellulose accessibility. At intermediate autohydrolysis conditions (175 °C) and low ionic liquid temperature (80 °C), a glucan digestibility of 84.4% was obtained. Using SEM micrographs, fractal dimension (as a measure of biomass complexity) and lacunarity (as a measure of homogeneity) were calculated before and after pretreatment. High fractals dimensions and low lacunarities correspond to morphologically complex and homogeneous samples, that are better digested by enzyme cocktails.
- Published
- 2018
20. Pyrolysis kinetics and thermal behavior of waste sawdust biomass using thermogravimetric analysis
- Author
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Kaustubha Mohanty and Ranjeet Kumar Mishra
- Subjects
Thermogravimetric analysis ,Environmental Engineering ,Materials science ,020209 energy ,Kinetics ,Biomass ,Thermodynamics ,Bioengineering ,02 engineering and technology ,Activation energy ,010501 environmental sciences ,Kinetic energy ,01 natural sciences ,Heating ,Thermal ,0202 electrical engineering, electronic engineering, information engineering ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Wood ,visual_art ,Thermogravimetry ,visual_art.visual_art_medium ,Sawdust ,Pyrolysis - Abstract
The present study reports pyrolysis behavior of three waste biomass using thermogravimetric analysis to determine kinetic parameters at five different heating rates. Physiochemical characterization confirmed that these biomass have the potential for fuel and energy production. Pyrolysis experiments were carried out at five different heating rates (5–25 °C min−1). Five model-free methods such as Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), Friedman, Coats-Redfern, and distributed activation energy (DAEM) were used to calculate the kinetic parameters. The activation energy was found to be 171.66 kJ mol−1, 148.44 kJ mol−1, and 171.24 kJ mol−1 from KAS model; 179.29 kJ mol−1, 156.58 kJ mol−1, and 179.47 kJ mol−1 from OFW model; 168.58 kJ mol−1, 181.53 kJ mol−1, and 184.61 kJ mol−1 from Friedman model; and 206.62 kJ mol−1, 171.63 kJ mol−1, and 160.45 kJ mol−1 from DAEM model for PW, SW, AN biomass respectively. The calculated kinetic parameters are in good agreement with other reported biomass.
- Published
- 2018
21. Cellulase pretreatment for enhancing cold caustic extraction-based separation of hemicelluloses and cellulose from cellulosic fibers
- Author
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Yonghao Ni, Jianguo Li, Xinhua Ouyang, Liulian Huang, Hailong Li, Shaokai Zhang, and Lihui Chen
- Subjects
0106 biological sciences ,Environmental Engineering ,Softwood ,Caustics ,Bioengineering ,02 engineering and technology ,Cellulase ,engineering.material ,Polysaccharide ,01 natural sciences ,chemistry.chemical_compound ,Hydrolysis ,Polysaccharides ,010608 biotechnology ,Specific surface area ,Cellulose ,Waste Management and Disposal ,chemistry.chemical_classification ,biology ,Renewable Energy, Sustainability and the Environment ,Pulp (paper) ,General Medicine ,021001 nanoscience & nanotechnology ,Wood ,Cellulose fiber ,chemistry ,Chemical engineering ,engineering ,biology.protein ,0210 nano-technology - Abstract
The effective separations of cellulose and hemicelluloses from cellulosic fibers are the prerequisite for creating high-value to the abundant and green cellulose materials. In this study, the process concept of cellulase pretreatment, followed by a cold caustic extraction (CCE) was investigated for a softwood sulfite pulp. The results showed that the cellulase pretreatment led to favorable fiber morphological changes, including the increases of the specific surface area (SSA), pore volume and diameter, and the water retention value (WVR). These changes can induce more pronounced fiber swelling in the subsequent CCE process so that the hemicelluloses removal is enhanced. After the cellulase pretreatment (cellulase dosage of 1 mg/g) and CCE process, the cellulose purity was as high as 97.49%, while the hemicelluloses removal selectivity reached 76.42%.
- Published
- 2018
22. Bioethanol potential of Eucalyptus obliqua sawdust using gamma-valerolactone fractionation
- Author
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Maazuza Z. Othman, Tony Vancov, Raymond M. Trevorah, and Tien Huynh
- Subjects
Environmental Engineering ,Eucalyptus obliqua ,020209 energy ,Biomass ,Bioengineering ,02 engineering and technology ,Fractionation ,010501 environmental sciences ,01 natural sciences ,Lactones ,chemistry.chemical_compound ,0202 electrical engineering, electronic engineering, information engineering ,Biorefining ,Cellulose ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Eucalyptus ,Ethanol ,biology ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Australia ,General Medicine ,biology.organism_classification ,Pulp and paper industry ,Wood ,gamma-Valerolactone ,chemistry ,Biofuel ,visual_art ,visual_art.visual_art_medium ,Sawdust - Abstract
© 2017 Elsevier Ltd Optimisation of conditions for gamma-valerolactone (GVL) pretreatment of Australian eucalyptus sawdust for high cellulose biomass and bioethanol production was demonstrated. Pretreatment parameters investigated included GVL concentrations of 35-50% w/w, temperatures of 120-180 °C and reaction durations of 0.5-2.0 h. Optimum conditions were determined using the response surface method (RSM) and central composite face-centred design. Cellulose content increased from 39.9% to a maximum of 89.3% w/w using treatments with 50% GVL at 156 °C for 0.5 h. Temperature had the most significant effect (RSM p < .05) on cellulose content of residual biomass and reducing operational duration of < 0.5 h may be viable according to RSM. PSSF fermentations of optimised pretreated eucalyptus sawdust produced up to 94% theoretical ethanol yield, which corresponded to approximately 181 kg of ethanol per dry ton of eucalyptus sawdust. The compositions of both the residual biomass and pretreatment liquors show that GVL pretreatment is a promising solvent for lignocellulosic biorefining.
- Published
- 2018
23. Valorisation of Tectona Grandis tree sawdust through the production of high activated carbon for environment applications
- Author
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I.P.P. Cansado, P.A.M. Mourão, Cristóvão Ramiro Belo, and Pandey, Ashok
- Subjects
Environmental Engineering ,Activated carbon ,020209 energy ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Trees ,chemistry.chemical_compound ,Adsorption ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Production (economics) ,Pesticides ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Pollutant ,Lamiaceae ,biology ,Renewable Energy, Sustainability and the Environment ,General Medicine ,biology.organism_classification ,Pulp and paper industry ,Wood ,Carbon ,chemistry ,Tectona ,Charcoal ,visual_art ,Carbon dioxide ,visual_art.visual_art_medium ,Physical activation ,Environmental science ,East Timor ,Sawdust ,Valorisation ,Tectona Grandis ,medicine.drug - Abstract
This work presents a first approach concerning the use of Tectona Grandis tree sawdust (from East Timor) for high activated carbon production, by physical activation with carbon dioxide at different temperatures. The activated carbons (AC) obtained exhibit a well-developed porous structure with a pore size distribution varying from micro to mesopores. Selected AC was successfully evaluated for pesticide removal, specific to 4-chloro-2-methylphenoxyacetic acid, from the liquid phase. The results presented are very promising, allowing to establish that Tectona Grandis sawdust is as an excellent precursor for the basic AC production and allow to expect good performance of theses adsorbents on the removal of a broad range of pollutants. It should also be noted that, this achievement is very relevant for developing countries, such East Timor, where Tectona Grandis sawdust is available and may constitute a source of income creating a handle to the technical and industrial development of this region.
- Published
- 2018
24. Hydrothermal pretreatment of bamboo sawdust using microwave irradiation
- Author
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Leilei Dai, Zhenting Yu, Liangliang Fan, Chao He, Yuhuan Liu, Yue Zhou, Roger Ruan, Yunpu Wang, Dengle Duan, and Yunfeng Zhao
- Subjects
Thermogravimetric analysis ,Environmental Engineering ,020209 energy ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Hydrothermal circulation ,Crystallinity ,Acetic acid ,chemistry.chemical_compound ,0202 electrical engineering, electronic engineering, information engineering ,Organic chemistry ,Microwaves ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Renewable Energy, Sustainability and the Environment ,Temperature ,General Medicine ,Wood ,Carbon ,Thermogravimetry ,chemistry ,visual_art ,visual_art.visual_art_medium ,Heat of combustion ,Sawdust ,Pyrolysis ,Nuclear chemistry - Abstract
In the present study, the effect of temperature and residence time during microwave hydrothermal pretreatment (MHT) on hydrochar properties and pyrolysis behaviors was investigated. Experimental results indicated that higher heating value (HHV) and fixed carbon content gradually increased with increased pretreatment severity. Obvious reduction of oxygen content was found under MHT at 230°C-15min and 210°C-35min. Although lower mass yield was observed under severe conditions, corresponding energy yield was relatively higher. Crystallinity indexes of hydrochar demonstrated an upward trend with increased residence time. Unlike hydroxyl group, dissociation of acetyls was more favorable under prolonged residence time rather than increased temperature. Peaks in thermogravimetric and derivative thermogravimetric curves shifted to higher temperature region under severe conditions, indicating better thermal stability. Py-GC/MS analysis suggested that acids content was decreased but sugars increased with increased MHT severity. Moreover, compared to temperature, residence time was mainly responsible for acetic acid formation.
- Published
- 2018
25. Integrated microwave and alkaline treatment for the separation between hemicelluloses and cellulose from cellulosic fibers
- Author
-
Jianguo Li, Lingfang Yu, Yuxin Liu, Xuefan Zheng, and Bing Sun
- Subjects
Environmental Engineering ,Bioengineering ,02 engineering and technology ,engineering.material ,01 natural sciences ,chemistry.chemical_compound ,stomatognathic system ,Polysaccharides ,Hardwood ,Cellulose ,Microwaves ,Dissolving pulp ,Waste Management and Disposal ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Pulp (paper) ,Treatment process ,General Medicine ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Wood ,0104 chemical sciences ,Cellulose fiber ,chemistry ,Kraft process ,engineering ,0210 nano-technology ,Microwave - Abstract
In this study, the microwave was employed during the alkaline treatment process, in order to separate the hemicelluloses and cellulose from a delignified hardwood kraft pulp. In relation to hemicelluloses yield, the integrated microwave and alkaline treatment resulted in 9.25% and 12.05% at 50°C and 80°C, respectively. Correspondingly, the resultant pulp fibers presented the increased cellulose content, which was desirable for manufacturing dissolving pulp. Additionally, the effect from mechanical refining pretreatment followed microwave and alkaline treatment, on the separation of hemicelluloses and cellulose, was also investigated.
- Published
- 2018
26. A comparative study of composting the solid fraction of dairy manure with or without bulking material: Performance and microbial community dynamics
- Author
-
Yue-Qin Tang, Xiao-Zhong Zhong, Zhao-Yong Sun, Shi-Peng Wang, Yu Deng, Kenji Kida, Ting-Ting Wang, and Shi-Chun Ma
- Subjects
0301 basic medicine ,Environmental Engineering ,Firmicutes ,Bioengineering ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Nitrospirae ,Soil ,03 medical and health sciences ,Food science ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Bacteria ,biology ,Renewable Energy, Sustainability and the Environment ,Composting ,fungi ,Planctomycetes ,Environmental engineering ,Bacteroidetes ,General Medicine ,biology.organism_classification ,Wood ,Manure ,030104 developmental biology ,Chloroflexi (class) ,Microbial population biology ,Proteobacteria - Abstract
The present study compared the development of various physicochemical properties and the composition of microbial communities involved in the composting process in the solid fraction of dairy manure (SFDM) with a sawdust-regulated SFDM (RDM). The changes in several primary physicochemical properties were similar in the two composting processes, and both resulted in mature end-products within 48days. The bacterial communities in both composting processes primarily comprised Proteobacteria and Bacteroidetes. Firmicutes were predominant in the thermophilic phase, whereas Chloroflexi, Planctomycetes, and Nitrospirae were more abundant in the final mature phase. Furthermore, the succession of bacteria in both groups proceeded in a similar pattern, suggesting that the effects of the bulking material on bacterial dynamics were minor. These results demonstrate the feasibility of composting using only the SFDM, reflected by the evolution of physicochemical properties and the microbial communities involved in the composting process.
- Published
- 2018
27. Hydrothermal extraction of hemicellulose: from lab to pilot scale
- Author
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Pierdomenico Biasi, Enrique Regidor Alfageme, Gianluca Gallina, and Juan García-Serna
- Subjects
Hot Temperature ,Environmental Engineering ,Materials science ,Biomass ,Bioengineering ,02 engineering and technology ,Fractionation ,Xylose ,Raw material ,01 natural sciences ,chemistry.chemical_compound ,Bioreactors ,Polysaccharides ,Hemicellulose ,Waste Management and Disposal ,Chromatography ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Extraction (chemistry) ,Water ,General Medicine ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Wood ,0104 chemical sciences ,Pilot plant ,chemistry ,Yield (chemistry) ,0210 nano-technology - Abstract
A flow-through reactor for hemicelluloses extraction with hot pressurized water was scaled with a factor of 73. System performance was evaluated by comparing the temperature profile, extraction yield and kinetics of the two systems, performing experiments at 160 and 170 °C, 11 barg for 90 min, using catalpa wood as raw material. Hemicellulose yields were 33.9% and 38.8% (lab scale 160 °C and 170 °C) and 35.7% and 41.7% (pilot scale 160 °C and 170 °C). The pilot reactor was upgraded by designing a manifold system capable to provide samples with different liquid residence time during the same experiment. Tests at 140, 150, 160 and 170 °C were carried for 90 min. Increasing yields (9.3–40.6%) and decreasing molecular weights (4078–1417 Da) were obtained at increasing the temperature. Biomass/water ratio of 1/27 gave total average concentration of xylose of 0.4 g/L (140 °C) to 1.8 g/L (170 °C)., MINECO and FEDER Funds, Project CTQ2015-64892-R (BioFraHynery)
- Published
- 2018
28. Simultaneous pyrolysis of microalgae C. vulgaris, wood and polymer: The effect of third component addition
- Author
-
Kolsoom Azizi, Mostafa Keshavarz Moraveji, and Hamed Abedini Najafabadi
- Subjects
Thermogravimetric analysis ,Environmental Engineering ,Polymers ,020209 energy ,Biomass ,Bioengineering ,02 engineering and technology ,Raw material ,Microalgae ,0202 electrical engineering, electronic engineering, information engineering ,Waste Management and Disposal ,chemistry.chemical_classification ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,Chemical process of decomposition ,Thermal decomposition ,Fossil fuel ,General Medicine ,Polymer ,Wood ,Kinetics ,chemistry ,Chemical engineering ,Thermogravimetry ,business ,Pyrolysis - Abstract
Due to the depletion of fossil fuels and their environmental issues, it is necessary to find energy resources which are renewable. Biomass becomes promising feedstock for bio-fuel production. The aim of this study is to investigate thermal decomposition behavior and the effect of third component on the binary mixture pyrolysis using thermogravimetric analysis (TGA). Experiments were carried out at heating rates of 10, 20 and 40°C/min from ambient temperature to 600°C. Two divided groups of peaks were observed in DTG curve of tertiary mixture which the first one was corresponded to microalgae and wood and the second one was belonged to polymer. It is stated that microalgae and wood can improve the degradation process while polymer can delay the decomposition process of mixture. Mentioned positive effect of microalgae and wood could be related to main decomposition temperature and component of microalgae and wood. On the other hand, polymer reduces weight loss of binary mixture and has negative effect of it. The kinetics analysis showed that activation energy (E) and pre-exponential factor (A) of tertiary mixture was slightly lower than that of microalgae-polymer mixture which had the lowest E and A.
- Published
- 2018
29. Unmasking radical-mediated lignin pyrolysis after benzyl hydroxyl shielding
- Author
-
Weicong Xu, Yue Han, Xiangchen Kong, Chao Liu, Rui Xiao, Ming Lei, Zhengxue Zhang, Yuyang Fan, and Ming Li
- Subjects
Hot Temperature ,Environmental Engineering ,Hydroxyl Radical ,Renewable Energy, Sustainability and the Environment ,Radical ,Bioengineering ,Propionaldehyde ,General Medicine ,Lignin ,Wood ,chemistry.chemical_compound ,Phenols ,chemistry ,Yield (chemistry) ,Organic chemistry ,Thermal stability ,Pyrolytic carbon ,Char ,Waste Management and Disposal ,Pyrolysis - Abstract
Whether lignin benzyl hydroxyl shielding could promote its pyrolysis to phenolic compounds was investigated in this paper. Lignin benzyl hydroxyl was first preoxidized by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and stabilized by propionaldehyde respectively, then pyrolysis was conducted with milled wood lignin as a control. Organic stable radicals in pyrolytic chars were further detected to reveal lignin pyrolysis chemistry. Results showed that benzyl hydroxyl shielding process weakened lignin thermal stability, and decreased liquid yields regardless of the frequency of lignin β-O-4 linkages. In addition, char yield grew after benzyl hydroxyl shielding. Radical concentration was inversely proportional to β-O-4 content which indicated the non-negligible impact of shielded benzyl hydroxyl on lignin pyrolysis. Furthermore, gases from propionaldehyde stabilized lignin quenched its radicals. This work confirmed that lignin β-O-4 linkages and shielded benzyl hydroxyl both played the great role in radical-mediated pyrolysis, but the enhancement of liquid products could not be achieved via benzyl hydroxyl shielding.
- Published
- 2021
30. Wood‑feeding termites as an obscure yet promising source of bacteria for biodegradation and detoxification of creosote-treated wood along with methane production enhancement
- Author
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Sameh S. Ali, Ahmed M. Mustafa, and Jianzhong Sun
- Subjects
Environmental Engineering ,Microbial Consortia ,Bioengineering ,Isoptera ,Lignin ,Pseudomonas mosselii ,chemistry.chemical_compound ,Bioremediation ,Pseudomonas ,Animals ,Anaerobiosis ,Food science ,Cellulose ,Waste Management and Disposal ,Creosote ,Bacteria ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,General Medicine ,Biodegradation ,Microbial consortium ,biology.organism_classification ,Wood ,Anaerobic digestion ,Biodegradation, Environmental ,Biofuels ,visual_art ,visual_art.visual_art_medium ,Sawdust ,Methane - Abstract
This study aims to explore distinct bacterial strains from wood-feeding termites and to construct novel bacterial consortium for improving the methane yield during anaerobic digestion by degrading birchwood sawdust (BSD) and removing creosote (CRO) compounds simultaneously. A novel bacterial consortium CTB-4 which stands for the molecularly identified species Burkholderia sp., Xanthomonas sp., Shewanella sp., and Pseudomonas mosselii was successfully developed. The CTB-4 consortium showed high efficiency in the removal of naphthalene and phenol. It also revealed reduction in lignin, hemicellulose, and cellulose by 19.4, 52.5, and 76.8%, respectively. The main metabolites after the CRO degradation were acetic acid, succinate, pyruvate, and acetaldehyde. Pretreatment of treated BSD mixed with CRO enhanced the total methane yield (162 L/kg VS) by 82.7% and biomass reduction by 54.7% compared to the untreated substrate. CRO showed a toxicity decrease of >90%, suggesting the efficiency of constructed bacterial consortia in bioremediation and biofuel production.
- Published
- 2021
31. Fast pyrolysis of holocellulose for the preparation of long-chain ether fuel precursors: Effect of holocellulose types
- Author
-
Huiyan Zhang, Rui Xiao, Shiliang Wu, and Yuan Liu
- Subjects
Thermogravimetric analysis ,Hot Temperature ,Environmental Engineering ,Renewable Energy, Sustainability and the Environment ,Levoglucosan ,Bioengineering ,Ether ,General Medicine ,Mass spectrometry ,Wood ,chemistry.chemical_compound ,chemistry ,Stalk ,Organic chemistry ,Hemicellulose ,Biomass ,Cellulose ,Waste Management and Disposal ,Pyrolysis - Abstract
The pyrolysis behaviors of nine biomass-derived holocelluloses (from seven agricultural and two forestry residues) were studied on a thermogravimetric analyzer (TGA) and pyrolysis–gas chromatography/mass spectrometer (Py-GC/MS). The results illustrated that compared with forestry holocellulose, agricultural holocellulose had quite high ash and hemicellulose contents. Moreover, agricultural holocellulose presented lower initial temperature and maximum mass loss rate. The results of GC/MS revealed that agricultural holocellulose produced more acids, ketones, aldehydes and furans and corn stalk holocellulose led to the highest targeted compounds (ketones, aldehydes and furans with carbonyl group) content of 51.4%. Woody holocellulose was suitable for the production of sugars, particularly levoglucosan, and pine sawdust holocellulose afforded the highest levoglucosan content of 46.55%. Intriguingly, the correlation of sugars/levoglucosan content with a mass ratio of cellulose to hemicellulose (CE/HCE) was put forward.
- Published
- 2021
32. Thermal stability of biochar and its effects on cadmium sorption capacity
- Author
-
Kirk T. Semple, Yanju Liu, Ravi Naidu, Scott W. Donne, Yubo Yan, Dane Lamb, Fangjie Qi, Nanthi Bolan, and Yong Sik Ok
- Subjects
Environmental Engineering ,0208 environmental biotechnology ,Inorganic chemistry ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,Combustion ,01 natural sciences ,Biochar ,medicine ,Organic matter ,Thermal stability ,Waste Management and Disposal ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Cadmium ,Renewable Energy, Sustainability and the Environment ,Sorption ,General Medicine ,Wood ,020801 environmental engineering ,chemistry ,Charcoal ,Environmental chemistry ,Composition (visual arts) ,Adsorption ,Activated carbon ,medicine.drug - Abstract
In this study, the thermal stability of a wood shaving biochar (WS, 650 °C), a chicken litter biochar (CL, 550 °C) and an activated carbon (AC, 1100 °C) were evaluated by combustion at 375 °C for 24 h to remove the labile non-carbonized organic matter. Results showed that WS and CL biochars were not thermally stable and can lose most of the organic C during combustion. The combusted WS and CL biochars retained considerable amounts of negative charge and displayed higher sorption for Cd (from 5.46 to 68.9 mg/g for WS and from 48.5 to 60.9 mg/g for CL). The AC retained 76.5% of its original C and became more negatively chargely after combustion, but its sorption for Cd slightly decreased (from 18.5 to 14.9 mg/g). This study indicated that after potential burning in wildfires (200–500 °C), biochars could have higher sorption capacity for metals by remaining minerals.
- Published
- 2017
33. Characteristics and kinetics study of simultaneous pyrolysis of microalgae Chlorella vulgaris, wood and polypropylene through TGA
- Author
-
Kolsoom Azizi, Hamed Abedini Najafabadi, and Mostafa Keshavarz Moraveji
- Subjects
Thermogravimetric analysis ,Environmental Engineering ,020209 energy ,Chlorella vulgaris ,Kinetics ,Bioengineering ,02 engineering and technology ,Polypropylenes ,chemistry.chemical_compound ,Microalgae ,0202 electrical engineering, electronic engineering, information engineering ,Waste Management and Disposal ,chemistry.chemical_classification ,Polypropylene ,Waste management ,Renewable Energy, Sustainability and the Environment ,Chemical process of decomposition ,Thermal decomposition ,General Medicine ,Polymer ,Wood ,chemistry ,Chemical engineering ,Thermogravimetry ,Pyrolysis - Abstract
Thermal decomposition behavior and kinetics of microalgae Chlorella vulgaris, wood and polypropylene were investigated using thermogravimetric analysis (TGA). Experiments were carried out at heating rates of 10, 20 and 40°C/min from ambient temperature to 600°C. The results show that pyrolysis process of C. vulgaris and wood can be divided into three stages while pyrolysis of polypropylene occurs almost totally in one step. It is shown that wood can delay the pyrolysis of microalgae while microalgae can accelerate the pyrolysis of wood. The existence of polymer during the pyrolysis of microalgae or wood will lead to two divided groups of peaks in DTG curve of mixtures. The results showed that interaction is inhibitive rather than synergistic during the decomposition process of materials. Kinetics of process is studied by the Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The average E values obtained from FWO and KAS methods were 131.228 and 142.678kJ/mol, respectively.
- Published
- 2017
34. Hydrothermal pretreatment of wood by mild steam explosion and hot water extraction
- Author
-
Merima Hasani, Joanna Wojtasz-Mucha, and Hans Theliander
- Subjects
0106 biological sciences ,Pre treatment ,Mass transport ,Environmental Engineering ,Waste management ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Extraction (chemistry) ,Water ,Bioengineering ,General Medicine ,Wood ,complex mixtures ,01 natural sciences ,Hydrothermal circulation ,0104 chemical sciences ,Hot water extraction ,Steam ,Polysaccharides ,010608 biotechnology ,Waste Management and Disposal ,Steam explosion - Abstract
The aim of this work was to compare the two most common hydrothermal pre-treatments for wood - mild steam explosion and hot water extraction - both with the prospect of enabling extraction of hemicelluloses and facilitating further processing. Although both involve autohydrolysis of the lignocellulosic tissue, they are performed under different conditions: the most prominent difference is the rapid, disintegrating, discharge employed in the steam explosion opening up the structure. In this comparative study, the emphasis was placed on local composition of the pre-treated wood chips (of industrially relevant size). The results show that short hot water extraction treatments lead to significant variations in the local composition within the wood chips, while steam explosion accomplishes a comparably more even removal of hemicelluloses due to the advective mass transport during the explosion step.
- Published
- 2017
35. Thermo-mechanical fractionation of yellow poplar sawdust with a low reaction severity using continuous twin screw-driven reactor for high hemicellulosic sugar recovery
- Author
-
Hyun Jin Ryu, Kyeong Keun Oh, Seong Ju Kim, and Won-Il Choi
- Subjects
0106 biological sciences ,Sucrose ,Environmental Engineering ,Liriodendron ,020209 energy ,Carbohydrates ,Bioengineering ,02 engineering and technology ,Fractionation ,01 natural sciences ,chemistry.chemical_compound ,Hydrolysis ,Bioreactors ,010608 biotechnology ,0202 electrical engineering, electronic engineering, information engineering ,Hemicellulose ,Cellulose ,Sugar ,Waste Management and Disposal ,Waste management ,Renewable Energy, Sustainability and the Environment ,Sulfuric acid ,General Medicine ,Pulp and paper industry ,Wood ,chemistry ,visual_art ,visual_art.visual_art_medium ,Sawdust - Abstract
Yellow poplar sawdust (YPS), a wood waste that can be easily collected from a local furniture factory, was fractionated using continuous twin screw-driven reactor for high hemicellulosic sugar recovery. The highest total sugar yields were attained under the following conditions: a barrel temperature of 127°C, sulfuric acid concentration of 0.8wt%, liquid feeding rate of 25mL/min, solid feeding rate of 2.0g/min, screw rotation speed of 25rpm, and residence time of 14.5min. The glucan and hemicellulose contents of the CTSR-fractionated YPS were 47.8% and 10.4%, respectively, and these results indicated that 44.9% of cellulose and 76.3% of the hemicellulose were extracted into liquid hydrolyzate. Meanwhile, the batch fractionation of YPS at the same reaction conditions showed a little fractionation effect, i.e., only 20.5% of hemicellulosic sugar yield was obtained.
- Published
- 2017
36. Superheated steam as carrier gas and the sole heat source to enhance biomass torrefaction
- Author
-
Chen Xuejiao, Wang Hong, Frederik Ronsse, Zhou Wanlai, Dongdong Zhang, Lin Wei, Yang Rui, Li Jie, and Qi Zhiyong
- Subjects
0106 biological sciences ,Hot Temperature ,Environmental Engineering ,Materials science ,Biomass ,Bioengineering ,Heat transfer coefficient ,010501 environmental sciences ,01 natural sciences ,010608 biotechnology ,Char ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Steam explosion ,Renewable Energy, Sustainability and the Environment ,Superheated steam ,Temperature ,General Medicine ,Pulp and paper industry ,Torrefaction ,Wood ,Steam ,Pyrolysis ,Ambient pressure - Abstract
Superheated steam (SHS) has been used as a carrier gas for pressurized steam torrefaction, steam explosion or pyrolysis, but is barely used as a heat source. However, SHS is superior in thermal capacity and heat transfer coefficient resulting in even heating and fast heating rates. Therefore, this work applied SHS as the sole heat source for torrefaction at ambient pressure. A setup was specially designed and capable of heating wood shavings at a rate >120 °C•min−1. Solid products were analyzed in many aspects and demonstrated the enhanced organics conversion owing to SHS torrefaction. Torrefied biomass was comparable to slow pyrolysis char in fuel quality and superior to that of conventional torrefactions. Moreover, SHS torrefaction was super-timesaving. A coal-like product (HHV of 27.84 MJ•kg−1) was achieved in only 15 min at 350 °C. Overall, SHS torrefaction boosted biomass densification and gave rise to greater production efficiency.
- Published
- 2021
37. Co-production of ethanol and cellulose nanocrystals through self-cycling fermentation of wood pulp hydrolysate
- Author
-
Jie Wang, Michael Chae, Dominic Sauvageau, Dawit Beyene, and David C. Bressler
- Subjects
0106 biological sciences ,Environmental Engineering ,Bioengineering ,010501 environmental sciences ,engineering.material ,Ethanol fermentation ,7. Clean energy ,01 natural sciences ,chemistry.chemical_compound ,010608 biotechnology ,Enzymatic hydrolysis ,Ethanol fuel ,Cellulose ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Ethanol ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Pulp (paper) ,General Medicine ,Pulp and paper industry ,Wood ,chemistry ,Cellulosic ethanol ,Fermentation ,engineering ,Nanoparticles ,Acid hydrolysis - Abstract
A promising approach to help offset production costs for the cellulosic ethanol industry is to improve ethanol productivity while simultaneously generating value-added by-products. This study reports integration of an advanced fermentation approach (self-cycling fermentation) with the production of cellulose nanocrystals. Specifically, wood pulp was enzymatically hydrolyzed to yield dissolved sugars, which were fed to a self-cycling fermentation system for ethanol production, and residual solids were used for cellulose nanocrystals production via acid hydrolysis. Self-cycling fermentation achieved stable ethanol production for 10 cycles with significantly greater productivity than batch operation: ethanol volumetric productivity increased by 63–95% and annual ethanol productivity by 96 ± 5%. Additionally, the enzyme hydrolysis approach employed did not impede ethanol fermentation, and the cellulose nanocrystals generated displayed properties consistent with previous studies. Taken together, these results highlight the potential of this co-production strategy to produce both cellulosic ethanol and cellulose nanocrystals from a single feedstock.
- Published
- 2021
38. Optimized removal of oxytetracycline and cadmium from contaminated waters using chemically-activated and pyrolyzed biochars from forest and wood-processing residues
- Author
-
Aylin Aghababaei, Mohamed Chaker Ncibi, and Mika Sillanpää
- Subjects
Environmental Engineering ,chemistry.chemical_element ,Oxytetracycline ,Bioengineering ,02 engineering and technology ,Forests ,010501 environmental sciences ,01 natural sciences ,Water Purification ,Metal ,Adsorption ,Porosity ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Pollutant ,Cadmium ,Aqueous solution ,Renewable Energy, Sustainability and the Environment ,Forestry ,General Medicine ,Contamination ,021001 nanoscience & nanotechnology ,Wood ,chemistry ,Charcoal ,visual_art ,Environmental chemistry ,visual_art.visual_art_medium ,0210 nano-technology ,Pyrolysis ,Water Pollutants, Chemical - Abstract
In the present investigation, the adsorptive removal of the antibiotic drug oxytetracycline (OTC) and toxic heavy metal cadmium (Cd) from aqueous solution was carried out using forest and wood-processing residues. Numerous biochars were prepared using different chemical agents (H 3 PO 4 , H 2 SO 4 , NaOH and KOH) and pyrolysis times and temperatures. Several elemental, chemical and structural characterizations were performed. The optimum conditions for pyrolysis to enable the production of biochars with well-developed porosity was 600 °C for 1 h, for both residues. The adsorption process using selected activated biochars was optimized with respect to reaction time, pH, temperature and initial load of pollutants. Under optimized operating conditions, and based on equilibrium modelling data, the biochars which showed the highest removal efficiencies of OTC and cadmium were “5 M H 3 PO 4 forest” (263.8 mg/g) and “1 M NaOH forest” (79.30 mg/g), respectively. Compared to adsorbents reported in the literature, the efficiencies of those biochars are highly competitive.
- Published
- 2017
39. Biodiesel production from microbial oil derived from wood isolate Trichoderma reesei
- Author
-
D. Yuvaraj, Sridevi Sridharan, R. Praveenkumar, V. Sowmya, J. Jayamuthunagai, and B. Bharathiraja
- Subjects
0106 biological sciences ,Saponification value ,Environmental Engineering ,020209 energy ,Biomass ,Bioengineering ,02 engineering and technology ,complex mixtures ,01 natural sciences ,Iodine value ,010608 biotechnology ,Botany ,0202 electrical engineering, electronic engineering, information engineering ,Food science ,Lipase ,Waste Management and Disposal ,Trichoderma reesei ,Trichoderma ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Fatty Acids ,General Medicine ,Transesterification ,biology.organism_classification ,Lipids ,Wood ,Biofuels ,Biodiesel production ,biology.protein ,Cetane number - Abstract
In the present study Trichoderma reesei, a wood isolate can yield high biomass quantities up to 30g/L, yielding 32.4% of lipids of dry cell weight (DCW). Biodiesel production from Trichoderma reesei involved simple unit operations like filtration and ultrasonication, yet giving good lipid yield with desirable bio-diesel properties. Optimization of ultrasonication conditions was done to ensure maximum lipid extraction. SEM analysis of ultrasonicated samples showed distinct breakage of fungal hyphae. The lipids were found to contain 49.7% saturated fatty acids. Transesterification using chemical and biological catalysts were compared and 96.09% efficiency was observed for lipase-catalyzed transesterification. The bio-diesel properties satisfied ASTM and EN specifications with cetane number: 53.1, iodine value: 63.34g, saponification value: 235.07mg KOH/g, cold flow plugging point: 9.13°C.
- Published
- 2017
40. Proteomic characterization and schizophyllan production by Schizophyllum commune ISTL04 cultured on Leucaena leucocephala wood under submerged fermentation
- Author
-
Madan Kumar, Manoj Kumar Singh, and Indu Shekhar Thakur
- Subjects
Proteomics ,0301 basic medicine ,Environmental Engineering ,Leucaena leucocephala ,biology ,Renewable Energy, Sustainability and the Environment ,Sizofiran ,Schizophyllum commune ,Bioengineering ,General Medicine ,Schizophyllum ,biology.organism_classification ,Wood ,Esterase ,Schizophyllan ,03 medical and health sciences ,030104 developmental biology ,Biochemistry ,Fermentation ,Oxidative enzyme ,Glycoside hydrolase ,Sugar ,Waste Management and Disposal - Abstract
In this study Schizophyllum commune ISTL04 was grown on Leucaena leucocephala wood (LLW) for secretome analysis and schizophyllan production. There is no report on extracellular protein profile and schizophyllan production on woody biomass by this fungus under submerged fermentation conditions. Leucaena leucocephala, a promising bioenergy crop having high holocellulose content was used as substrate without pretreatment. The maximum sugar, extracellular protein and exopolysaccharide (EPS) production during fermentation was found to be 8.53±0.07mgmL-1, 391±7.51mgL-1 and 4.2±0.1gL-1 or 0.21gg-1LLW on day 18 respectively. The secretome profile was dominated by glycoside hydrolases followed by carbohydrate esterase and other oxidative enzymes. EPS was further characterized by FTIR and GC-MS for functional group, monomer composition and linkage analysis and was identified as schizophyllan. The result indicated that LLW can be utilized as a low cost substrate for enzyme cocktail and schizophyllan production.
- Published
- 2017
41. Impact of lignin structure on oil production via hydroprocessing with a copper-doped porous metal oxide catalyst
- Author
-
Paul T. Anastas, Sébastien Gillet, Christophe Blecker, Chun Ho Lam, Mario Aguedo, and Laurence Petitjean
- Subjects
Environmental Engineering ,Ethyl acetate ,Oxide ,Bioengineering ,Fraction (chemistry) ,macromolecular substances ,010402 general chemistry ,Lignin ,complex mixtures ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Organic chemistry ,Waste Management and Disposal ,010405 organic chemistry ,Renewable Energy, Sustainability and the Environment ,Depolymerization ,fungi ,technology, industry, and agriculture ,food and beverages ,Oxides ,General Medicine ,Wood ,0104 chemical sciences ,Monomer ,chemistry ,Yield (chemistry) ,Copper - Abstract
A copper-catalyzed depolymerization strategy was employed to investigate the impact of lignin structure on the distribution of hydroprocessing products. Specifically, lignin was extracted from beech wood and miscanthus grass. The extracted lignins, as well as a commercial lignin (P1000), were then fractionated using ethyl acetate to provide three different portions for each source of lignin [total of 9 fractions]. Each fraction was structurally characterized and treated with a copper-doped porous metal oxide (Cu-PMO) catalyst under 4MPa H2 and at 180°C for 12h. The reaction conditions provided notable yields of oil for each fraction of lignin. Analysis of the oils indicated phenolic monomers of commercial interest. The structure of these monomers and the yield of monomer-containing oil was dependent on the origin of the lignin. Our results indicate that hydroprocessing with a Cu-PMO catalyst can selectively provide monomers of commercial interest by careful choice of lignin starting material.
- Published
- 2017
42. The effects of autohydrolysis pretreatment on the structural characteristics, adsorptive and catalytic properties of the activated carbon prepared from Eucommia ulmoides Oliver based on a biorefinery process
- Author
-
Ming-Qiang Zhu, Ling Qiu, Qin Wei, Zhi-Wen Wang, Ya-Hong Zhu, Jia-Long Wen, Run-Cang Sun, and Yin-Quan Su
- Subjects
Environmental Engineering ,ved/biology.organism_classification_rank.species ,Oligosaccharides ,Glucuronates ,Bioengineering ,Eucommia ulmoides ,02 engineering and technology ,010501 environmental sciences ,Raw material ,01 natural sciences ,Catalysis ,Bioreactors ,Polysaccharides ,medicine ,Organic chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Hydrogen production ,Renewable Energy, Sustainability and the Environment ,Carbonization ,Chemistry ,ved/biology ,Eucommiaceae ,Hydrolysis ,General Medicine ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Biorefinery ,Wood ,Decomposition ,Carbon ,Charcoal ,Adsorption ,0210 nano-technology ,Activated carbon ,medicine.drug - Abstract
Eucommia ulmoides Oliver (EU) wood was consecutively treated by autohydrolysis pretreatment and chemical carbonization post-treatment based on a biorefinery process. Results showed that the optimal condition of the autohydrolysis pretreatment and carbonization process yielded 10.37 kg xylooligosaccharides (XOS), 1.39 kg degraded hemicellulosic products, 17.29 kg other degraded products from hemicelluloses and 40.72 kg activated carbon (S BET of 1534.06 m 2 /g) from the 100 kg raw materials. Simultaneously, 29.14 kg gas products generated from the optimum integrated process was significantly lower than that from the direct carbonization process (68.84 kg). Besides, the optimal activated carbon (AC 170–1.0 ) also showed a moderate catalytic activity and high stability for hydrogen production by catalytic methane decomposition. Overall, the data presented indicated that the integrated process is an eco-friendly and efficient process to produce XOS and activated carbon, which is beneficial for value-added and industrial application of EU wood.
- Published
- 2017
43. Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals
- Author
-
Peter Christie, Yucheng Cao, Minyan Wang, Shengdao Shan, Junwei Jin, Ming Hung Wong, Shengchun Wu, Jianyun Zhang, Yanan Li, Peng Liang, and Jin Zhang
- Subjects
Bamboo ,Environmental Engineering ,020209 energy ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,Raw material ,Waste Disposal, Fluid ,01 natural sciences ,Metals, Heavy ,Spectroscopy, Fourier Transform Infrared ,Biochar ,0202 electrical engineering, electronic engineering, information engineering ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Sewage ,Waste management ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Cumulative effects ,General Medicine ,Pulp and paper industry ,Wood ,Bioavailability ,Charcoal ,visual_art ,visual_art.visual_art_medium ,Sawdust ,Pyrolysis ,Sludge - Abstract
A novel type of biochar was produced by mixing bamboo sawdust with sewage sludge (1:1, w/w) via a co-pyrolysis process at 400-600°C. Changes in physico-chemical properties and the intrinsic speciation of metals were investigated before and after pyrolysis. Co-pyrolysis resulted in a lower biochar yield but a higher C content in the end product compared with use of sludge alone as the raw material. FT-IR analysis indicates that phosphine derivatives containing PH bonds were formed in the co-pyrolyzed biochars. In addition, co-pyrolysis of sludge with bamboo sawdust transformed the potentially toxic metals in the sludge into more stable fractions, leading to a considerable decrease in their direct toxicity and bioavailability in the co-pyrolyzed biochar. In conclusion, the co-pyrolysis technology provides a feasible method for the safe disposal of metal-contaminated sewage sludge in an attempt to minimize the environmental risk from potentially toxic metals after land application.
- Published
- 2017
44. Biological pretreatment of sugarcane bagasse with basidiomycetes producing varied patterns of biodegradation
- Author
-
Angela da Silva Machado and André Ferraz
- Subjects
0106 biological sciences ,Environmental Engineering ,020209 energy ,Bioengineering ,Fraction (chemistry) ,02 engineering and technology ,01 natural sciences ,chemistry.chemical_compound ,Biotreatment ,Cellulase ,010608 biotechnology ,Enzymatic hydrolysis ,Botany ,0202 electrical engineering, electronic engineering, information engineering ,Food science ,Cellulose ,Glucans ,Waste Management and Disposal ,Glucan ,chemistry.chemical_classification ,Xylose ,Enzymatic digestion ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,beta-Glucosidase ,food and beverages ,General Medicine ,Biodegradation ,Wood ,ENZIMAS ,Saccharum ,Biodegradation, Environmental ,Glucose ,chemistry ,Xylans ,Coriolaceae ,Bagasse - Abstract
This work evaluated sugarcane bagasse pretreatment with wood-decay fungi, producing varied patterns of biodegradation. The overall mass balance of sugars released after pretreatment and enzymatic hydrolysis indicated that a selective white-rot was necessary to provide glucose yields similar to the ones observed from leading physico-chemical pretreatment technologies. The selective white-rot Ceriporiopsis subvermispora was selective for lignin degradation in the lignocellulosic material, preserved most of the glucan fraction, and increased the cellulose digestibility of biotreated material. Glucose mass balances indicated that of the potential glucose of untreated bagasse, 47% was recovered as sugar-rich syrup after C. subvermispora biotreatment for 60 days followed by enzymatic digestion of the pretreated material.
- Published
- 2017
45. Anaerobic batch conversion of pine wood torrefaction condensate
- Author
-
Ramasamy Praveenkumar, Henrik Tolvanen, Jukka Konttinen, Marja R.T. Palmroth, Jukka Rintala, and Tharaka Rama Krishna C. Doddapaneni
- Subjects
Hot Temperature ,Environmental Engineering ,020209 energy ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Organic compound ,Methane ,law.invention ,chemistry.chemical_compound ,Bioreactors ,Magazine ,law ,0202 electrical engineering, electronic engineering, information engineering ,Anaerobiosis ,Waste Management and Disposal ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Waste management ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Substrate (chemistry) ,General Medicine ,Pinus ,Torrefaction ,Pulp and paper industry ,Wood ,Anaerobic digestion ,Composition (visual arts) ,Mesophile - Abstract
Organic compound rich torrefaction condensate, owing to their high water content and acidic nature, have yet to be exploited for practical application. In this study, microbial conversion of torrefaction condensate from pine wood through anaerobic batch digestion (AD) to produce methane was evaluated. Torrefaction condensate exhibited high methane potentials in the range of 430–492 mL/g volatile solids (VS) and 430–460 mL/g VS under mesophilic and thermophilic conditions, respectively. Owing to the changes in the composition, the methane yields differed with the torrefaction condensates produced at different temperatures (225, 275 and 300 °C), with a maximum of 492 ± 18 mL/g VS with the condensate produced at 300 °C under mesophilic condition. The cyclic batch AD experiments showed that 0.1 VS substrate :VS inoculum is optimum, whereas the higher substrate loading (0.2–0.5) resulted in a reversible inhibition of the methane production. The results suggest that torrefaction condensate could be practically valorized through AD.
- Published
- 2017
46. Increasing efficiency of enzymatic hemicellulose removal from bamboo for production of high-grade dissolving pulp
- Author
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Lingfeng Zhao, Zhaoyang Yuan, D. Mark Martinez, Heather L. Trajano, Rodger P. Beatson, Xue Feng Chang, and Nuwan Sella Kapu
- Subjects
0106 biological sciences ,Bamboo ,Environmental Engineering ,Bioengineering ,02 engineering and technology ,engineering.material ,01 natural sciences ,chemistry.chemical_compound ,stomatognathic system ,Polysaccharides ,010608 biotechnology ,Hemicellulose ,Cellulose ,Dissolving pulp ,Waste Management and Disposal ,Endo-1,4-beta Xylanases ,Viscosity ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Hydrolysis ,Pulp (paper) ,General Medicine ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Wood ,Kraft process ,Xylanase ,engineering ,Sasa ,0210 nano-technology - Abstract
To improve the efficiency of enzymatic hemicellulose removal from bamboo pre-hydrolysis kraft pulp, mechanical refining was conducted prior to enzyme treatment. Refining significantly improved the subsequent hemicellulose removal efficiency by xylanase treatment. Results showed that when PFI refining was followed by 3 h xylanase treatment, the xylan content of the bamboo pre-hydrolysis kraft pulp (after first stage oxygen delignification) could be decreased to 2.72% (w/w). After bleaching of enzyme treated pulp, the alpha-cellulose content was 93.4% (w/w) while the xylan content was only 2.38%. The effect of refining on fibre properties was investigated in terms of freeness, water retention value, fibre length and fibrillation characteristics. The brightness, reactivity and viscosity were also determined to characterize the quality of final pulp. Results demonstrated the feasibility of combining refining and xylanase treatment to produce high quality bamboo dissolving pulp.
- Published
- 2017
47. Liquid nitrogen pretreatment of eucalyptus sawdust and rice hull for enhanced enzymatic saccharification
- Author
-
Regina de Fátima Peralta Muniz Moreira, Vanesa Gesser Correa, Cristina Giatti Marques de Souza, Rosely A. Peralta, Adelar Bracht, Rafael Castoldi, Rosane Marina Peralta, and Gutierrez Rodrigues de Morais
- Subjects
0106 biological sciences ,Environmental Engineering ,Nitrogen ,Bioengineering ,010501 environmental sciences ,Furfural ,Lignin ,01 natural sciences ,chemistry.chemical_compound ,Hydrolysis ,Polysaccharides ,010608 biotechnology ,Enzymatic hydrolysis ,Hemicellulose ,Biomass ,Cellulose ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Eucalyptus ,Waste management ,Renewable Energy, Sustainability and the Environment ,food and beverages ,Oryza ,General Medicine ,Pulp and paper industry ,Rice hulls ,Wood ,chemistry ,visual_art ,visual_art.visual_art_medium ,Sawdust - Abstract
In this work, liquid nitrogen was used for the first time in the pretreatment of plant biomasses for purposes of enzymatic saccharification. After treatment (cryocrushing), the initial rates of the enzymatic hydrolysis of eucalyptus sawdust and rice hull were increased more than ten-fold. Cryocrushing did not modify significantly the contents of cellulose, hemicellulose and lignin in both eucalyptus sawdust and rice hulls. However, substantial disorganization of the lignocellulosic materials in consequence of the pretreatment could be observed by electron microscopy. Cryocrushing was highly efficient in improving the saccharification of the holocellulose component of the plant biomasses (from 4.3% to 54.1% for eucalyptus sawdust and from 3.9% to 40.6% for rice hull). It is important to emphasize that it consists in a simple operation with low requirements of water and chemicals, no corrosion, no release of products such as soluble phenolics, furfural and hydroxymethylfurfural and no waste generation.
- Published
- 2017
48. Fractionation and cellulase treatment for enhancing the properties of kraft-based dissolving pulp
- Author
-
Yanling Zhang, Yonghao Ni, Xinqi Wang, Chao Duan, and Yongjian Xu
- Subjects
0106 biological sciences ,Environmental Engineering ,Dispersity ,Bioengineering ,02 engineering and technology ,Fractionation ,Cellulase ,engineering.material ,01 natural sciences ,Adsorption ,010608 biotechnology ,Particle Size ,Dissolving pulp ,Waste Management and Disposal ,Chromatography ,biology ,Viscosity ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Pulp (paper) ,General Medicine ,021001 nanoscience & nanotechnology ,Wood ,Molecular Weight ,Kinetics ,engineering ,biology.protein ,Molar mass distribution ,0210 nano-technology ,Kraft paper - Abstract
The aim of this study was to investigate a combined process involving pulp fractionation and cellulase treatment of each fraction for improving the molecular weight distribution (MWD) and reactivity of a kraft-based dissolving pulp. Three pulp fractions, namely long-fiber, mid-fiber and short-fiber fractions (LF, MF and SF, respectively), were used as the substrates. The results showed that the SF had the highest accessibility, lowest viscosity, and highest cellulase adsorption capacity, while the opposite was true for the LF. At a given viscosity, the combined process led to a lower polydispersity index (3.71 vs 4.98) and a higher Fock reactivity (85.6% vs 76.3%), in comparison to the conventional single-stage cellulase treatment.
- Published
- 2017
49. Cobalt-60 gamma-ray irradiation pretreatment and sludge protein for enhancing enzymatic saccharification of hybrid poplar sawdust
- Author
-
Yulin Xiang, Yuxiu Xiang, and Lipeng Wang
- Subjects
Environmental Engineering ,020209 energy ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Hydrolysis ,Cellulase ,Enzymatic hydrolysis ,0202 electrical engineering, electronic engineering, information engineering ,Irradiation ,Cobalt Radioisotopes ,Cellulose ,Waste Management and Disposal ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Sewage ,biology ,Waste management ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Wood ,Enzyme assay ,Reducing sugar ,Enzyme ,chemistry ,visual_art ,Yield (chemistry) ,visual_art.visual_art_medium ,biology.protein ,Sawdust ,Nuclear chemistry - Abstract
In order to improve the enzymatic saccharification of hybrid poplar sawdust, gamma irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein were investigated. The cellulose crystallinity index were significantly decreased after irradiation pretreatment, and adding sludge protein improved enzyme activity and increased the reducing sugar yield. The conditions of irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein were systematically examined. The maximum reducing sugar yield was 519mg/g under an irradiation dose of 300kGy, a sludge protein dosage of 2mg/mL, an enzymatic hydrolysis temperature of 45°C, an enzymatic hydrolysis time of 84h, and a 90FPU/g enzyme loading. This work indicated that the combined method of gamma irradiation pretreatment and enzymatic hydrolysis in the presence of sludge protein was a promising potential for the saccharification of hybrid poplar sawdust.
- Published
- 2016
50. Novel process for the coproduction of xylo-oligosaccharides, fermentable sugars, and lignosulfonates from hardwood
- Author
-
Qiang Yong, Jing Du, Caoxing Huang, Richard Phillips, Ben Jeuck, Hou-min Chang, and Hasan Jameel
- Subjects
0106 biological sciences ,Environmental Engineering ,Carbohydrates ,Oligosaccharides ,Bioengineering ,010501 environmental sciences ,Lignin ,01 natural sciences ,Residue (chemistry) ,Liquidambar ,010608 biotechnology ,Enzymatic hydrolysis ,Hardwood ,Recycling ,Lignosulfonates ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Glucan ,chemistry.chemical_classification ,Renewable Energy, Sustainability and the Environment ,Hydrolysis ,Economic return ,General Medicine ,Biorefinery ,Pulp and paper industry ,Wood ,Glucose ,chemistry ,Steady state simulation - Abstract
Many biorefineries have not been commercialized due to poor economic returns from final products. In this work, a novel process has been developed to coproduce valuable sugars, xylo-oligosaccharides, and lignosulfonates from hardwood. The modified process includes a mild autohydrolysis pretreatment, which enables for the recovery of the xylo-oligosaccharides in auto-hydrolysate. Following enzymatic hydrolysis, the residue is sulfomethylated to produce lignosulfonates. Recycling the sulfomethylation residues increased both the glucan recovery and lignosulfonate production. The glucose recovery was increased from 81.7% to 87.9%. Steady state simulation using 100g of hardwood produced 46.7g sugars, 5.9g xylo-oligosaccharides, and 25.7g lignosulfonates, which were significantly higher than that produced from the no-recycling process with 39.1g sugars, 5.9g xylo-oligosaccharides, and 15.0g lignosulfonates. The results indicate that this novel biorefinery process can improve the production of fermentable sugars and lignosulfonate from hardwood as compared to a conventional biorefinery process.
- Published
- 2016
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