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30 May 2017, Volume 51 Issue 3 Previous Issue    Next Issue

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Synthesis of Sulfur-modified Chitosan Aerogel and Its Adsorption Properties for Cu2+ ZHU Xuehuan, YANG Rendang, LIU Xiao 2017, 51 (3):  1-6.  doi: 10.3969/j.issn.1673-5854.2017.03.001 Abstract ( 668 )   PDF (1077KB) ( 1013 )   Save Chitosan was reacted with dimethyl 3,3'-dithiodipropionate to obtain chitosan derivative through acetylation modification. With chitosan/chitosan derivative as raw materials,potassium persulfate(KPS) as initiator and N,N'-methylene diacrylamide(NMBA) as crosslinking agent,the chitosan aerogel and chitosan derivative aerogel were synthesized. The structure and properties of chitosan and its derivative were characterized and analyzed by FT-IR,XRD and TG. Meanwhile,chitosan aerogel and chitosan derivative aerogel were characterized by SEM. In addition,the static adsorption of Cu2+ ions on chitosan aerogel and chitosan derivative aerogel were also investigated. The FT-IR showed that the chitosan derivative was successfully synthesized. The XRD and TG analysis showed that the crystallinity and thermal stability of chitosan derivative decreased compared with those of chitosan. The SEM showed that the number of pores in the chitosan derivative aerogel increased. The results of adsorption experiment indicated that the chitosan derivative aerogel showed noticeable improvements in the adsorption capacity of Cu2+ ions. And under the conditions of 25℃,chitosan derivative aerogel 50mg,initial mass concentration of Cu2+ 100mg/L and pH value 5,the adsorption reached equilibrium at 60min with the maximum adsorption capacity of 48.26mg/g,which increased by 63.37% than that of unmodified chitosan aerogel. References | Related Articles | Metrics

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Preparation,Characterization and Photocatalytic Property of Wintermelon-based TiO2 Carbonaceous Aerogels WEI Wei, CENG Qian, LU Junwei, HAN Hekun, ZHU Jianjun, XIE Jimin 2017, 51 (3):  7-13.  doi: 10.3969/j.issn.1673-5854.2017.03.002 Abstract ( 922 )   PDF (2503KB) ( 870 )   Save Wintermelon-based TiO2 carbonaceous aerogel(WTCA) composites were prepared by hydrothermal reaction and freeze drying process with wintermelon and tetrabutyl titanate as precursor. The Rhodamine B(RhB) wastewater was photodegraded by WTCA under visible light irradiation. The effects of various common inorganic salt ions in water on the photodegradation were also studied systematically. The morphology structure and properties of as-prepared samples were characterized by using X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman spectrometer,and fluorescence spectroscopy(FL). XRD,Raman and EDS analysis results showed that anatase titanium oxide and carbon element appeared in the WTCA. SEM and TEM analysis results showed that TiO2 nanoparticles were homogeneously anchored on the skeleton surface of hierarchical carbonaceous aerogels. Meanwhile the composite aerogels exhibited better photodegradation capacities for the RhB than pure TiO2. The photocatalytic effect of WTCA had the best photocatalytic efficiency(96.11%) when TiO2 load up to 30%. Moreover,the inorganic salt anion ions had the negative effect on photodegradation effect with the order of CO32- > SO42- > Cl- > NO3- while the inhibitory effects of cationic ions(Na+,K+,Ca2+ and Mg2+) were not obvious. References | Related Articles | Metrics

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Simulation of Pine Sawdust Gasification with Oxygen,Steam and Carbon Dioxide as Gasifying Agents CAO Binqi, LIU Yunquan, WANG Duo 2017, 51 (3):  14-20.  doi: 10.3969/j.issn.1673-5854.2017.03.003 Abstract ( 870 )   PDF (525KB) ( 1073 )   Save Using Aspen Plus software,a model was developed to simulate the gasification of pine sawdust with steam-oxygen-carbon dioxide as gasifying agent. At first,the model was verified by the data of literature and the results showed that the model was reliable. And then,the effects of gasification temperature,oxygen equivalence ratio(cER),the mass ratio of steam to biomass(mS/mB) as well as the mass ratio of carbon dioxide to biomass(mCO2/mB) on gas composition,low heating value,yield,gasification efficiency and H/C ratio(nH2/nCO) in the produced gas were studied. The low heating value,yield,gasification efficiency and H/C ratio of the produced gas reached 7.45MJ/m3,1.78m3/kg,73.3%,1.79 respectively under the optimum reaction conditions of 850℃,101.325kPa,cER=0.2,mS/mB=1,mCO2/mB=0.6. Higher gasification temperature was favorable to the process of biomass gasification. With the increased cER,the low heating value,gas yield and gasification efficiency decreased rapidly,while H/C ratio was basically keeping stable. The amount of steam added into gasification agent enhanced H2 content in the produced gas;while appropriate amount of CO2 added would improve the CO content. Therefore,either of the above two measures could effectively adjust the H/C ratio in the produced gas. References | Related Articles | Metrics

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Preparation and Characterization of Rubber Seed Oil Based Polyol HUANG Yuanbo, ZHENG Zhifeng, MA Huan, ZHENG Yunwu, LIU Can, GONG Huiying, YANG Xiaoqin 2017, 51 (3):  21-26.  doi: 10.3969/j.issn.1673-5854.2017.03.004 Abstract ( 985 )   PDF (849KB) ( 946 )   Save Rubber seed oil based polyol was prepared by using epoxidized rubber seed oil(ERSO) as raw materials,methanol and isopropanol as ring-opening reagents,and fluoboric acid as catalyst,the preparation conditions were investigated with the hydroxyl value of product as index,and the characterization of product was also studied. The results showed that the optimum reaction conditions were reaction time 30min,reaction temperature 70℃,the mass ratio of to alcohol to ERSO 4:1,the amount of fluoboric acid 1%(based on the mass of ERSO),the mass ratio of isopropanol to methanol 1:1. The results of verification experiment showed that the acid value,hydroxyl value,average molecular weight,moisture content and viscosity of rubber seed oil based polyol prepared under the optimum reaction conditions were 2.68mg/g,219.32mg/g,870.21,0.08% and 4791mPa·s,respectively. Furthermore,the chemical structure of rubber seed oil based polyol was characterized by FT-IR,1H NMR and 13C NMR,the results showed that the polyol was formed by the ring-opening reaction of epoxy group of ERSO. References | Related Articles | Metrics

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Preparation of Biomass Based Efficient Deinking Agent and Its Application ZHANG Ming, YE Jianping, YANG Rendang 2017, 51 (3):  27-32.  doi: 10.3969/j.issn.1673-5854.2017.03.005 Abstract ( 742 )   PDF (1276KB) ( 881 )   Save The biomass based deinking agent was prepared by using cheap and renewable coconut fatty acid,palmitic acid and gum rosin as raw materials. The raw materials were characterized by FT-IR;the technology of preparation was optimized;the optimum addition amount of deinking agent and the deinking properties were discussed. The deinking properties were also compared with the traditional deinking agents. The FT-IR results showed that the raw materials were both saturated fatty acids and unsaturated fatty acids,and the optimized preparation conditions of biomass deinking agent were 30min,90℃,m(gum rosin):m(coconut fatty acid):m(palmitic acid) of 2.5:3.5:4.0,NaOH mass fraction of 40%. The obtained biomass based deinking agent was a kind of high efficient deinking agent,and the optimum addition amount was 0.2%. After deinking under the addition amount 0.2%,40℃,the mass fraction of pulp 1.0% and pH value 9 for 20min,the brightness of deinking pulp was 58.67%(ISO),the residual ink concentration was 274.42mm2/m2,and the removal rate of ink was 57.81%. Practical application results showed that the deinking effect of biomass based deinking was superior to that of the traditional type S and tian xiao deinking agents. References | Related Articles | Metrics

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Characteristic of Alkali Lignin Filling Natural Rubber ZHANG Cuimei, CUI Xuejing, SUN Yanni, JIANG Ruiyu, ZHAO Jiruo, FENG Ying 2017, 51 (3):  33-40.  doi: 10.3969/j.issn.1673-5854.2017.03.006 Abstract ( 825 )   PDF (2218KB) ( 927 )   Save The performance of alkali lignin filling natural rubber was studied. The characteristic of network structure of filler in rubber compound and its influence on dynamic mechanical properties were investigated. The vulcanizate was observed and analyzed by scanning electron microscopy(SEM),mechanical properties and dynamic mechanical properties test. The results showed that there was almost no filler-filler interactions in alkali lignin filled vulcanizate,the rubber-filler interactions was very weak,and the alkali lignin particles agglomerated when the filling amounts of alkali lignin were 10%-50%. The mechanical properties of vulcanizate were not decreased largely after filling alkali lignin. The tensile strength of 10% alkali lignin filled vulcanizate was 30MPa,higher than that of no alkali lignin filled sample(28.7MPa). The filling of alkali lignin partly accelerated the vulcanization of rubber. The crosslinking density was increased with the addition of alkali lignin and it decreased when the filling amount of alkali lignin was 50%,with the tensile strength of 20.1MPa. The aging resistance was improved with the increase of the amount of alkali lignin. And there was no obvious impact on the vulcanizate's wet skid resistance and rolling resistance with the filling of alkali lignin. References | Related Articles | Metrics

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Effect of Final Pyrolysis Temperature on Pyrolysis Products of Peanut Shells TIAN Yishui, WANG Ru 2017, 51 (3):  41-47.  doi: 10.3969/j.issn.1673-5854.2017.03.007 Abstract ( 924 )   PDF (571KB) ( 1010 )   Save The pyrolysis experiments of peanut shells under different temperatures were carried on the fixed bed pyrolysis device,which was manufactured by Chinese Academy of Agricultural Engineering. The results showed that with the increase of the final pyrolysis temperature,the yields of bio-char and energy reduced gradually;the yields of tar and pyrolysis gas were raised,as well as the heat value. And the yields of tar reached the maximum at 550℃. The fixed carbon,ash and carbon element of the bio-char increased,the hydrogen element and oxygen element decreased,and the aromatic structure and chemical biological stability improved with the increase of final pyrolysis temperature. And the heat value of bio-char achieved the maximum(24.346MJ/kg) at 500℃. The bio-char combustion process included evaporation,fixed carbon and volatile combustion,and its ignition time was significantly later than that of peanut shells. The order of comprehensive combustion characteristic index(S) of bio-char from large to small was C500 > C350 > C600 > C400 > C450 > C550. When the final pyrolysis temperature was 550℃,the specific surface area,microporous surface area,total pore volume and microporous volume of bio-char were the highest,which were 50.58m2/g and 29.56m2/g,0.01543cm3/g,and 0.01111cm3/g,respectively. However,there was still a big gap between the results of activated carbon. This required further processing. References | Related Articles | Metrics

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Accumulation Characteristics and Eating Health Risk Assessment of Lead in Walnut from Panxi Production Areas YANG Xuebing, WU Bin, LUO Yachuan, YANG Ling, ZHANG Sibi, XIE Jinhua, FU Zhuorui 2017, 51 (3):  48-54.  doi: 10.3969/j.issn.1673-5854.2017.03.008 Abstract ( 770 )   PDF (522KB) ( 780 )   Save The contents of lead(Pb) in the soil,bark,leaf,walnut peel,shell,and kernel in Panxi region's walnut were determined by using the atomic absorption spectrometry to study the accumulation characteristics and consumption risk. The results showed that the contents of Pb in the soil were significantly higher than those in the organs of the walnut tree,and one of the soil samples was exceed the national standard;the contents of Pb in the leaves were significantly higher than those in the walnut peel,shell,and kernel;with the increase of Pb content in the soil,the Pb contents in bark,leaf,walnut peel,shell,and kernel didn't show an obvious enrichment regularity,and the accumulation ability of Pb in the walnut kernel was weaker compared with the other main organs. The results of the Nemerow Index Method showed that the pollution index of Pb in the walnut kernel was less than 1,which indicated that the kernel samples of the experimental point in Panxi production base were out of Pb pollution. Referring to China's current standards,the target risk factor of Pb in the walnut was figured out by extending the tree nuts consumption of Chinese residents to the recommended value and much lower than 1.0, which meant the content of heavy metal Pb in the edible parts of walnut was temporarily risk-free for Chinese consumers' health. References | Related Articles | Metrics

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Hydrodeoxygenation Mechanism of Oxygenated Compounds in Bio-oils XU Dongmei, JI Daoyu, MENG Fanyu, ZHANG Huaqian, NIE Xiaolei, LIU Di 2017, 51 (3):  55-64.  doi: 10.3969/j.issn.1673-5854.2017.03.009 Abstract ( 1098 )   PDF (827KB) ( 1356 )   Save The differences in the composition of the oxygenated compounds in bio-oil prepared by different biomass were presented. Then the reaction mechanisms of hydrodeoxygenation(HDO) of the main oxygenated compounds(phenols,furans,ethers,acids and esters) were reviewed,and the HDO kinetic data and reaction pathways were described in detail. Meanwhile,the HDO reaction processes of real bio-oil feeds were sketched,and the removal activities of heteroatoms O,N,S catalyzed by different catalysts were also discussed. Moreover,the problem of the hydrotreating of bio-oil was pointed out that we know little about the reaction mechanism of real bio-oil,and the HDO of model compounds can not reflect the reaction process of real bio-oil,thus the interaction of different types of oxygenated compounds and the reaction mechanism of real bio-oil should emphasically be studied. References | Related Articles | Metrics

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Research Progress of Common Co-catalysts and Supports of Ni Based Catalysts for Catalytic Reforming of Biomass Tar SUN Guanwu, WANG Yangang, XUE Yanan, CUI Lifeng 2017, 51 (3):  65-70.  doi: 10.3969/j.issn.1673-5854.2017.03.010 Abstract ( 727 )   PDF (465KB) ( 1146 )   Save Ni as an ideal catalyst applied in catalytic reforming of biomass tar has some problems such as easy sintering and coke deposition,which makes it difficult to guarantee the activity and stability. Research shows that the sintering and coke deposition of Ni-based catalyst can be effectively alleviated by adding appropriate co-catalyst and using catalyst supporter. This paper introduces research progress of rare earth elements Ce,magnetic elements Fe and Co,alkaline earth elements Ca and Mg as co-catalysts,as well as natural mineral materials dolomite and olivine,natural processed materials calcined shells and rice husks,synthetic materials β-Al2O3 and SBA-15 as the carrier of Ni-based catalyst,and the prospects for future research. References | Related Articles | Metrics