Table of Content

25 August 2016, Volume 36 Issue 4 Previous Issue    Next Issue

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Application of Ionic Liquid [Hmim] [CF3SO3] in Biodegradation of Lignin & Lignin Model Compounds CUI Jing-jing, LI Yun-hua, CHEN Bing-hui 2016, 36 (4):  1-6.  doi: 10.3969/j.issn.0253-2417.2016.04.001 Abstract ( 893 )   PDF (957KB) ( 590 )   Save The ternary liquid-liquid equilibrium system composed of ionic liquid [Hmim] [CF3SO3] which dissolved lignin with enzyme solution and the organic acid was investigated in present study. The enzymatic reactions in the system were also studied. The transformation from water-ionic two phase system to homogeneous system should be attributed to the function of carboxylic acid groups in small molecule organic acids. [Hmim] [CF3SO3] with dissolved lignin could also compose the ternary system with water and organic acid. In the degradation reaction, formic acid played two roles in balancing the hydrophobic phase ([Hmim] [CF3SO3] with dissolved lignin), and aqueous phase (enzyme solution), and acting as radical stabilizer for lignin degrading enzymatic reaction. The degradation rates of alkali lignin and dehydrogenation polymers of lignin (DHPs) were 56.5% and 66.5%, and the content of methoxyl group decreased by 46.7% and 45.3%, respectively. The generated phenolic compounds were 204.7 and 207.0 mg/L, and the formic acid consumption were 0.57 and 0.76 g, respectively. In the DHPs degradation process, the ternary equilibrium was disintegrated due to the excessive consumption of formic acid. References | Related Articles | Metrics

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Evaluation of the Factors Contributing to Declining Enzymatic Hydrolysis Rates of Steam Pretreated Corn Stover LAI Chen-huan, YANG Lei, GAO Zi-qi, YU Shi-yuan, YONG Qiang 2016, 36 (4):  7-13.  doi: 10.3969/j.issn.0253-2417.2016.04.002 Abstract ( 836 )   PDF (415KB) ( 593 )   Save To evaluate the factors contributing to the decreasing enzymatic hydrolysis rates, the potential factors, including substrate reactivity, enzyme non-productive binding, enzyme deactivation and end-product inhibition, were investigated in enzymatic hydrolysis of steam pretreated corn stover (SPCS), with solid concentration of 50 g/L glucan and enzyme loading including 20 FPIU/g glucan of filter paper activity and 10 IU/g glucan of β-glucosidase activity. The results showed that the substrate reactivity of SPCS decreased 16.0% and 23.7%, respectively, after hydrolysis for 6 h and 12 h. But the effects of the decline in substrate reactivity on enzymatic hydrolysis rates were limited, with enzyme loading including 20 FPIU/g glucan of filter paper activity and 10 IU/g glucan of β-glucosidase activity. The enzymatic residual lignin addition reduced the enzyme concentration in supernatant by 20.8% at 1 h, but this did not reduce the initial hydrolysis rates. This indicated that enzyme non-productive binding on lignin did not influence the enzymatic hydrolysis rates obviously. Enzyme renewal in two-stage hydrolysis increased hydrolysis rate for 7 h from 1.30 g/(L·h) in one-stage hydrolysis to 1.83 g/(L·h). While the end-product removal in two-stage hydrolysis raised hydrolysis rate for 7 h to 4.76 g/(L·h), which was 3.66 folds higher than that in one-stage hydrolysis. Generally, the results revealed that the enzyme deactivation and the end-product inhibition showed the obvious effects on enzymatic hydrolysis rates. Moreover, the end-product inhibition was the dominating factors for the declining hydrolysis rates of SPCS. References | Related Articles | Metrics

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Preparation and Shape Recovery Property of the Nanocellulose Aerogels WANG Meng-meng, WANG Ai-ting, LIU He, LIU Shi-wei, YU Shi-tao 2016, 36 (4):  14-22.  doi: 10.3969/j.issn.0253-2417.2016.04.003 Abstract ( 1162 )   PDF (1832KB) ( 853 )   Save The porous nanocellulose aerogels were obtained by the cross-linked reaction of 1,4-butanediol diglycidyl ether(BDGE) and nanocellulose fibers (NCFs) with the catalyst of SnCl4. The morphological feature, chemical characterization, crystal structure, thermostability, element of nanocellulose aerogels and surface aera were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermo gravimetric analysis, scanning electron microscopy, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller analysis, respectively. The density, solvent absorption ability, shape recovery property and reusability of nanocellulose aerogels were investigated. The results showed that aerogels with continuous network pore structure still maintain the cellulose I crystalline structure and the aerogels started to degrade above 300℃. When the amount of BDGE was 2 times as much as the mass of NCFs, the density of aerogels was 0.020 2 mg/cm3, and aerogels could absorb water by 36.5 g/g of their own weight. The recovery degree of aerogels immersed in water and DMSO could reach 90%. After reusing for 5 times, the water absorption ability of aegrogel was still up to 30.4 g/g. References | Related Articles | Metrics

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Preparation of Methyl-α-D-glucoside from Fractionation of Direct Liquefied Lignocellulosic Biomass FENG Jun-feng, JIANG Jian-chun, XU Jun-ming, WANG Kui, SU Qiu-li, YANG Zhong-zhi 2016, 36 (4):  23-30.  doi: 10.3969/j.issn.0253-2417.2016.04.004 Abstract ( 840 )   PDF (1269KB) ( 642 )   Save Directional liquefaction(methlysis) of lignocellulosic biomass(bamboo, bagasse, poplar, eucalyptus, pine and wheat straw) were investigated in the presence of sulfuric acid as catalyst at 200℃ for 10 min. The methyl glycosides (MG) in liquid products could be obtained via stepwise treatments of filtering neutralization, and extracting,followed by rotary evaporation. Both hemicellulose and cellulose (holocellulose) in the lignocellulosic biomass could convert into methyl glycosides, mainly methyl-α-D-xyloside and methyl-α-D-glucoside (MLG), and the yield of MG was about 40%. GC content of MG could reach 86.81%. At the same time, decolorization and purification of MG was also investigated for preparation of pure MG crystals. According to the results of HSQC NMR, FT-IR and X-ray diffraction by a single crystal, the prepared MLG had high purity dose to the standard sample and regular crystal structure of orthorhombic system and space group P212121. References | Related Articles | Metrics

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Kinetic Analysis of Palm Kernel Shell during Pyrolysis Reaction CHANG Guo-zhang, HUANG Yan-qin, XIE Jian-jun, YIN Xiu-li, WU Chuang-zhi 2016, 36 (4):  31-40.  doi: 10.3969/j.issn.0253-2417.2016.04.005 Abstract ( 744 )   PDF (1401KB) ( 775 )   Save The pyrolysis characteristics, mechanism, and products properties of palm kernel shell (PKS) in a bench-scaled fixed bed reactor were investigated by using thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR), pyrolysis-gas chromatography and mass spectrometry (Py-GC/MS). TG results showed that the pyrolysis of PKS could be devided into three steps, which included drying(25-236℃, 3.42%), main weight loss(236-400℃, 52.31%), and carbonization (400-850℃, 14.90%) stage. The main mass loss stage of PKS pyrolysis was controlled by 1.5 or 2 order reaction model, and the apparent activation energies at heating rates of 10-30 K/min were 67.63-76.47 kJ/mol. The gaseous products were evolved with the sequence of CO2, H2O, CH4, and CO. The quantitative results showed that liquid was the primary pyrolysis product at 600-850℃, with the mass yield of 36.8%-50.9% and energy yield of 41.3%-58.9% according to original material. Py-GC/MS results indicated that the main components of liquid products were phenol, acetic acid, octadecanoic acid, n-hexadecanoic acid, 4-allyl-2,6-dimethoxyphenol, etc.. It was notable that phneols had a higher relative content, accounting for about 12.56%-15.49%. Biochar was an important by-product of PKS pyrolysis, with the mass and energy yield of 20.6%-26.7% and 27.4%-35.0%, respectively. The CO2 gasification reactivity of PKS char was lower than that of rice straw char and wood char. References | Related Articles | Metrics

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Sodium Ligninsulfonate and Its Blendings with Polycarboxylic Superplasticizer WANG Jin-zhi, WANG Wen-jun, HE Ming, LI Ben-gang, ZHU Li-jun, LUO Zhen-yang 2016, 36 (4):  41-48.  doi: 10.3969/j.issn.0253-2417.2016.04.006 Abstract ( 918 )   PDF (1184KB) ( 622 )   Save Sodium lignosulfonate (SLS) was obtained by oxidation and sulfomethylation from pulp black liquor, and the sulfonation degree and weight-average molecular weight (Mw) were 1.023 7 mmol/L and 26 320, respectively. A series of complex superplasticizers(BPCE1,BPCE2,BPCE3 and BPCE4) were prepared by blending SLS and polycarboxylate superplasticizer (PCE) with various ratio. The adsorption layer thickness on cement particle surface and slurry Zeta potential of complex superplasticizer were studied. The results showed that the thickness increased with the SLS content increase. The Zeta potential of slurry showed the greatest absolute value when the mass fraction of SLS was 20%. The cement and concrete was prepared with the complex superplasticizer dosage 0.18% and SLS 1% of the total dosage. The research results of paste fluidity, mortar fluidity, bleeding rate, the water reducing ratio and compressive strength of concrete showed that the optimal performance was realized as the 20% SLS was used in the complex superplasticizer BPCE2. References | Related Articles | Metrics

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Influence of Removal of Potassium from Activated Carbon by Using Oxidation-ultrasonic Method on Its Electrochemical Properties HOU Min, SUN Kang, DENG Xian-lun, XIAO Feng-long, LIN Guan-feng 2016, 36 (4):  49-54.  doi: 10.3969/j.issn.0253-2417.2016.04.007 Abstract ( 814 )   PDF (807KB) ( 645 )   Save The activated carbon(AC1)was prepared from moso bamboo carbide by KOH activation and hydrochloric acid solution washing. Then AC1 sample was further treated with H2O2 oxidation-ultrasonic method to deeply remove the K+. The effects of different experimental conditions on the removal of K+ content of ACs were studied. The pore structures of the AC samples were characterized by N2 adsorption-desorption isotherm, and electrochemical properties were characterized by cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy. The results showed that high quality activated carbon(AC2)could be obtained under the conditions of mass fraction of H2O2 solution 0.6%, ultrasonic reaction temperature 60℃ and ultrasonic reaction time 8 h. And the K+ content was 52 mg/kg, specific surface area was 3 156 m2/g, pore volume was 1.625 cm3/g, ratio of mesopore was 79.8% and average pore size was 2.208 nm. For the electrochemical properties, it displayed a specific capacitance of 297 F/g and a high capacitance retention of 95% after 3 000 cycles. They increased by 28% and 6 percentage points, respectively, compared with AC1 sample. They indicated excellent capacitive behavior. References | Related Articles | Metrics

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Optimization of Online Upgrading of Bio-oil with MCM-41 and Catalyst Durability Analysis LIU Sha, CAI Yi-xi, FAN Yong-sheng, LI Xiao-hua, WANG Jia-jun 2016, 36 (4):  55-63.  doi: 10.3969/j.issn.0253-2417.2016.04.008 Abstract ( 621 )   PDF (1191KB) ( 734 )   Save Online catalytic upgrading of vapors from vacuum pyrolysis of biomass was performed on MCM-41. The effects of operating parameters including catalyzing temperature, catalyzing bed height and system pressure on the organic yields were inverstigated. The optimization of organic phase yield was further conducted by employing response surface methodology (RSM). Analysis of physicochemical properties, composition of organic phase in bio-oil and durability analysis of catalyst were also carried out. The results showed that operating parameters had significant effects on the yield of organic phase. The yield firstly increased and then decreased with the increment of catalyzing temperature and catalyzing bed height, and decreased as system pressure increased. When catalyzing temperature was 502℃, catalyzing bed height was 2.7 cm and system pressure was 7 kPa, the yield of organic phase reached 15.84% and the high heat value of organic phase was 31.08 MJ/kg. After catalytic pyrolysis of biomass with MCM-41, the aliphatic hydrocarbons and alcohols in organic phase increased significantly, while the contents of aromatic and carbonyl compounds reduced at the same time. Durable research of MCM-41 zeolite found that when the catalyst used for 100 min, the index of physical and chemical properties of bio-oil had decreased dramatically. This indicated that the quality of bio-oil had deteriorated significantly. Meanwhile, the weightlessness of catalyst had significantly increased. It suggested that the coke deposited on the catalyst had increased gradually and the catalytic activity had decreased significantly till the catalyst completely lost its activity. References | Related Articles | Metrics

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Aqueous Two-phase Extraction of Total Flavonoids in Fruit of Rosa davurica Pall. and Its Antioxidant Ability ZHONG Fang-li, WANG Wen-jiao, WANG Xiao-lin, CHEN Ye, LUO Ya-hong 2016, 36 (4):  64-72.  doi: 10.3969/j.issn.0253-2417.2016.04.009 Abstract ( 815 )   PDF (1313KB) ( 684 )   Save In order to study the aqueous two-phase extraction of total flavonoids in fruit of Rosa davurica Pall., both single factor and orthogonal test methods were applied to optimize the extraction conditions. The antioxidant ability of total flavonoids was evaluated according to the clearance ratio and reducing power to superoxide anion free radicals, DPPH free radical, hydroxyl free radical, sodium nitrite and ABTS radical cations. The results showed that the optimum extraction conditions were the volume fraction of absolute ethyl alcohol 27%, mass concentration of ammonium sulfate 0.21 g/mL, volume fraction of extraction solution 22%, and addition of sodium hydroxide 2.0 g, respectively. The average extraction ratio could reach 91.81% under the optimum extraction conditions. The extraction solution showed significant clearance ability to ABTS radical cations, hydroxyl free radical, superoxide anion free radicals with the clearance rates of 90.27%, 89.60% and 96.73% as the mass concentrations of total flavonoids 0.12, 0.30 and 0.60 g/L, respectively. They were stronger than those of Vc. The clearance ability of extraction solution to DPPH free radical and nitrite was weaker than that of Vc. The extraction solution also had some reducing power. References | Related Articles | Metrics

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Preparation and Swelling Property of pH-Sensitive Glucose-based Hydrogels LIN Yan, FANG Gui-gan 2016, 36 (4):  73-78.  doi: 10.3969/j.issn.0253-2417.2016.04.010 Abstract ( 798 )   PDF (972KB) ( 663 )   Save Glucose, as the template compound, was modified by glycidyl methacrylate and copolymerized with acrylic acid and acrylamide. After freeze drying, the pH-sensitive glulose-based hydrogels were obtained. The experimental conditions were studied and the optimal conditions were the 1:4:4 mass ratio of glucose/acrylic acid/acrylic amide, the 0.5% dosage of cross-linking agent, initiator and reaction temperature at 65℃. And the swelling ratio of hydrogel obtained under these conditions was about 90.5 g/g. Additionally, it was found that the swelling ratio of the glulose-based hydrogel increased with time extension and finally approached equilibrium in certain pH medium. And the swelling ratio of the hydrogels in the intestinal fluid without enzymes (pH=7.4) was significantly higher than that in the gastric fluid without enzymes (pH=1.2). Moreover, the hydrogels could keep basically no degradation in the two kinds of medium. This showed certain application prospect in tissue engineering materials. References | Related Articles | Metrics

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Adsorption Behavior of AB-8 Resin for Anthocyanins from Lycium ruthenicum Murray WANG Hong, FU Yan-qiu, HAN Jing, ZHAO Yu-ming, LIU Dong 2016, 36 (4):  79-86.  doi: 10.3969/j.issn.0253-2417.2016.04.011 Abstract ( 868 )   PDF (1155KB) ( 577 )   Save The adsorption performance of AB-8 resin for anthocyanin from Lycium ruthenicum Murray and adsorption mechanism were analyzed by equilibrium adsorption experiment, isothermal adsorption experiment and column adsorption experiment. The results showed that the adsorption kinetics process of AB-8 resin for anthocyanin could well fit with Elovich kinetic model. The linear straight of regression displayed that the Freundlich model was more suitable. Moreover, the enthalpy changes were positive and the absolute value was less than 40 kJ/mol. This indicated the adsorptions of AB-8 resin for anthocyanins were endothermic and physical changes. The Gibbs free energy changes were negative. It indicated that the adsorption process occurred spontaneously. The positive value of entropy changes indicated the increased randomness during the adsorption process. The adsorption mechanism was complicated and the adsorption process was mainly affected by particle diffusion. Adams-Bohart model analysis showed that in the process of column adsorption purification anthocyanins, the flow of mobile phase and the bed height should be reduced and the quality of anthocyanin concentrations should be increased. References | Related Articles | Metrics

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Preparation and Characterization of Poly(lactic acid)/Wood Flour Composites Modified with Polyurethane Prepolymer YANG Lin-qiang, JIN Li-wei 2016, 36 (4):  87-92.  doi: 10.3969/j.issn.0253-2417.2016.04.012 Abstract ( 757 )   PDF (1962KB) ( 658 )   Save Poly(lactic acid)/wood flour (PLA/WF) composites modified with polyurethane prepolymer (PUP) were prepared by blending extrusion, and followed by the test of their mechanical properties, dynamic mechanical analysis (DMA), contact angle measurements, and scanning electron microscope (SEM) analysis on fracture surface. The mechanical property tests showed that flexural strain at break and impact strength of the composites containing 20% PUP calculated by mass fraction of PLA and WF were 5.78% and 18.3 kJ/m2 which were 209% and 123% more than that of untreated sample, respectively. The results indicated that PUP had great effect on toughening the composites. DMA analysis revealed that with the increase of PUP. This two distinct glass transition temperatures corresponding to PLA and PUP phases all decreased, the storage modulus also decreased siginficantly and the toughness of the composites improved. The contact angle test towards water increased obviously with the addition of PUP. This showed the increse of hydrophobic performance. The contact angle of the composites reached to 83.7° with 25% PUP and the value increased by 25.7% comparing with that of non-toughened composites (66.6°). SEM examination on the composite fractured surface showed more wood powder was pulled out and the section was more uneven with the addition of PUP. This presented the characteristic of ductile fracture. References | Related Articles | Metrics

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Alkaline Extraction for Upgrading Bleached Bamboo Pulp to Dissolving Pulp CHEN Qiu-yan, MIAO Qing-xian, CAO Shi-lin, CHEN Li-hui, HUANG Liu-lian 2016, 36 (4):  93-98.  doi: 10.3969/j.issn.0253-2417.2016.04.013 Abstract ( 761 )   PDF (1675KB) ( 613 )   Save Bamboo dissolving pulp was prepared by alkaline extraction method with bleached bamboo pulp as raw material. The cellulose crystalline structure and the fiber surface morphology from the samples treated before and after the extraction were observed by X-ray diffraction and field emission scanning electron microscope (FE-SEM). The changes of molecular weight distribution (MWD) of carbohydrate were studied by the technology of gel permeation chromatography (GPC). The bamboo dissolving pulp was obtained by hydrochloric acid treatment after alkaline extraction. The results showed that the removal rate of hemicellulose was up to 66.71% after treated by 10% of pulp concentration and 10% of sodium hydroxide concentration at 30℃ for 60 min. The FE-SEM results showed that the phenomenon of surface-fibrillated fiber resuced, the fiber lateral width widened and the softness of fiber increased with the removal of hemicellulose. The GPC showed that the polydispersity with the removal of hemicellulose reduced, decreased polydispersity index(PDI) from 7.71 to 4.43, molecular weight of cellulose samples increased. Thus, the uniformity of the molecular weight distribution was improved. And the pulp after optimal alkaline extraction was subjected to subsequent acid treatment which led to 7.02% of hemicellulose, the α-cellulose of bamboo dissolving pulp was 94.25%. References | Related Articles | Metrics

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RAFT Polymerization and Characterization of Rosin Derived Monomer LIU Shao-feng, WANG Chun-peng, CHU Fu-xiang, YU-Juan, WANG Ji-fu 2016, 36 (4):  99-104.  doi: 10.3969/j.issn.0253-2417.2016.04.014 Abstract ( 825 )   PDF (973KB) ( 557 )   Save Rosin derived monomer blend was synthesized by chloridization and esterification in turn, and characterized by FT-IR, GC/MS and 13C NMR, respectively. Rosin derived monomer blend, reversible addition-fragmentation chain transfer (RAFT) agent CDB and initiator AIBN with molar ratio of 100:1:0.1 were then used to perform RAFT polymerization. In order to further investigate the RAFT polymerization of rosin derived monomer blend, high purity dehydroabietic acid was also employed to perform RAFT polymerization. The results showed that dehydroabietic acid derived monomer accounted for 14.3% in rosin derived monomer, and the RAFT polymerization of dehydroabietic acid derived monomer was well controlled and achieved a well-defined dehydroabietic acid based polymer with polydispersity index (PDI) of 1.28. And PDI of rosin derived monomer based polymer was 1.85 which was relative higher than that of dehydroabietic acid based polymer. However, its polymer structure was still regarded well-defined. The rosin based polymer obtained by RAFT polymerization was also a novel Marco-RAFT agent, which could be used as RAFT agent for next step RAFT polymerization with purpose of polymer chain extension. Additionally, the synthesized rosin based polymers were all demonstrated with good thermal stability, temperature of the mass loss at 10% and maximum decomposing temperature was 250℃ and 350℃, respectively. References | Related Articles | Metrics

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Liquefaction of Bamboo Powder in Ethanol-phenol under High Pressure and Product Characterization MA Yan, TAN Wei-hong, FENG Guo-dong, XU Jun-ming, WANG Kui, YING Hao, JIANG Jian-chun 2016, 36 (4):  105-112.  doi: 10.3969/j.issn.0253-2417.2016.04.015 Abstract ( 743 )   PDF (1386KB) ( 626 )   Save The liquefaction of bamboo powder was investigated in ethanol-phenol under high pressure using H2SO4 as catalyst. The liquefaction conditions were optimized by response surface analysis and its result was analyzed using Design-Expert 8.0.6 software. The effects conditions were investigated by a five level three-factor Box-Behnken design. The results showed that the liquefaction rate reached 98.5% under the optimum conditions, i.e., mass ratio of phenol and bamboo powder 1:1, ethanol and bamboo powder 18:1, sulfuric acid amount 5％,reaction temperature 200℃ and reaction time 70 min.The product analysis showed that the bamboo powder could be effectively degraded in blended solvents. The FT-IR, SEM and TG results of residue indicated that the molecular structure of bamboo powder present significant change via liquefaction and the compounds with different substituent on aromatic ring were obtained. The GC-MS analysis showed that the oil produced by this way was complex in composition with some major compounds such as alcohols, phenols, ketones and esters, and the GC content of ethyl levulinate reached 10.11%. References | Related Articles | Metrics

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Organic Acids Variations during Circulation-enhanced Pre-hydrolysis of Eucalyptus GUO Huai-ze, MA Ming-shuai, LI Hai-ming, GUO Yan-zhu, ZHOU Jing-hui, CUI Jing-long 2016, 36 (4):  113-120.  doi: 10.3969/j.issn.0253-2417.2016.04.016 Abstract ( 1135 )   PDF (1157KB) ( 548 )   Save The generation and variations of organic acids during circulation-enhanced pre-hydrolysis of eucalyptus were in present study. The time effects of eucalyptus circulation-enhanced pre-hydrolysis were examined with a 6:1 (mL:g) liquid-solid ratio at 190℃ under varied holding time, and then the hot water pre-hydrolysate obtained under the corresponding conditions was used in the circulation-enhanced pre-hydrolysis process with different ratios. The results showed that formic acid and levulic acid contents in the circulation-enhanced pre-hydrolysate firstly increased with the prolonged time and acetic acid content , and then fluctuated at a relative high level. At the same time, total sugars in pre-hydrolysate show a trend of firstly increasing and then declining.The eucalyptus circulation-enhanced pre-hydrolysis was conducted with a 6:1 liquid-solid ratio for 60 min under different temperature, and then the obtained pre-hydrolysates were used in the circulation-enhanced pre-hydrolysis process with different ratios. The results showed that formic acid, acetic acid , levulic acid and total sugars contents in the circulation-enhanced pre-hydrolysate increased with the increase of hydrolytic temperature. Among the studies mentioned above, organic acid contents increased with the rising of circulation ratio. Enrichment of organic acids during circulation-enhanced pre-hydrolysis process was beneficial for their utilization and their catalytic actions of pre-hydrolysis process. References | Related Articles | Metrics

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Synthesis of a Novel Quinazoline Derivative from Isolongifolanone RUI Jian, XU Xu, YANG Yi-qin, HUANG Jian-feng, XU Hai-jun, WANG Shi-fa 2016, 36 (4):  121-127.  doi: 10.3969/j.issn.0253-2417.2016.04.017 Abstract ( 785 )   PDF (885KB) ( 523 )   Save 4-(4'-Fluorophenyl)-6,6,10,10-tetramethyl-6a,9-methano-5,6,6a,7,8,9,10,10a-octahydrobenzo[h] quinazolin-2-ylamine (FBQ) was synthesized by aldol condensation, to obtain 7-(4'-fluoro-benzylidene)-isolongifolanone (FBI) from isolongifolanone, and then cyclization with guanidine hydrochloride using t-BuOK as the catalyst in t-butanol. The effects of the sort and dosage of catalysts, reaction time, reaction temperature, and the molar ratio of FBI and guanidine hydrochloride on the cyclization were investigated. The optimum cyclization conditions were determined according to the orthogonal experiments. The results were as follows: n(t-BuOK):n(FBI) was 2.9:1, reaction temperature 75℃, reaction time 14 h, the molar ration of FBI and guanidine hydrochloride 1:4. The yield of final product reached 79.51% under the above conditions. The chemical structure of FBQ was determined by FT-IR, MS, 1H NMR, and 13C NMR, respectively. Its spatial structure was examined by X-ray single crystal diffraction. According to single-crystal X-ray diffraction analysis, the target compound was of triclinic system, space group P-1 with a=0.660 85(9)nm,b=1.175 27(16)nm, c=1.340 65(17)nm, α=86.229(3)°, β=83.094(4)°, γ=77.558(4)°, V=1.008 6(2)nm3, Z=2, DC=1.203 g/cm3, F(000)=392, Mr=365.48, μ=0.078 mm-1, R=0.099 3 and wR=0.156 5. References | Related Articles | Metrics

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Preliminary Study on Pressurized Liquefaction of Three Crops Straw for Preparation of Ethyl Levulinate GUAN Qian, JIANG Jian-chun, XU Jun-ming, WANG Kui, FENG Jun-feng 2016, 36 (4):  128-134.  doi: 10.3969/j.issn.0253-2417.2016.04.018 Abstract ( 884 )   PDF (1241KB) ( 613 )   Save Three kinds of crops (wheat, corn and rice) straw were selected as raw materials for pressurized liquefaction. Ethanol and concentrated sulfuric acid (98%) were used as solvent and catalyst, respectively. The liquefaction was carried out under the conditions of reaction temperature 200℃, the dosage of catalyst 5%, the reaction time 60 min and the solid-liquid ratio 1:15. Products of liquefaction were analyzed, and ethyl levulinate (EL) was isolated from the liquefaction products. The results showed that under the same liquefaction conditions, wheat straw performed high liquefied performance. The structure of straw components was changed and degraded. Ethyl levulinate was the main component of liquefaction products. The purity and recovery rate of ethyl levulinate isolated by distillation were 92.71% and 89.93%, respectively. References | Related Articles | Metrics

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Composition of Polyphenols in Bark of Castanopsis fargesii Franch. HUANG Yong-lin, CHEN Yue-yuan, YAN Xiao-jie, LIU Jin-lei, WANG Ya-feng, HE Rui-jie, LI Dian-peng 2016, 36 (4):  135-139.  doi: 10.3969/j.issn.0253-2417.2016.04.019 Abstract ( 806 )   PDF (572KB) ( 708 )   Save The ethanol extract from the bark of Castanopsis fargesii Franch. was purified by column chromatography through Sephadex LH-20, MCI gel CHP 20P and Toyopearl Butyl-650C. Ten compounds were obtained. The structures were identified to be benzoic acid, protocatechuic acid, gallic acid, 5-O-galloyl-(-)-shikimic acid, 3,5-di-O-galloylquinic acid,(-)-epicatechin, catechin, gallocatechin, casuarinas tannin, castalagin. All compounds were isolated from C. fargesii for the first time. References | Related Articles | Metrics

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Research Progress on Biosynthesis of Long Chain Fuel Alcohol XU Jing-liang, CHEN Xiao-yan, XIAO Shi-yuan, YUAN Zhen-hong 2016, 36 (4):  140-146.  doi: 10.3969/j.issn.0253-2417.2016.04.020 Abstract ( 735 )   PDF (1196KB) ( 654 )   Save This paper briefly introduced the excellent properties of long chain alcohols as liquid fuels and reviewed the three main biosynthesis pathways of long chain alcohols, i.e., Ehrlich pathway, non-fermentation pathway and photosynthetic pathway. The methods of improving the yield of long chain alcohol were summarized, such as choice of host strains, screening and breeding of tolerant strains, reconstruction of metabolic pathway, and optimization of long chain alcohol production process. And the future development direction of long chain alcohol was also suggested. References | Related Articles | Metrics