Table of Content

30 September 2017, Volume 51 Issue 5 Previous Issue    Next Issue

Select

Synthesis of Renewable Bio-diesel Precursors with Angelica Lactone and 2-Methylfuran WANG Wei, JI Xiaohui, GE Hongguang, LI Zhizhou, SHAO Xianzhao, ZHANG Qiang 2017, 51 (5):  1-6.  doi: 10.3969/j.issn.1673-5854.2017.05.001 Abstract ( 868 )   PDF (760KB) ( 876 )   Save Hydroxylalkylation/alkylation of angelica lactone and 2-methylfuran derived from biomass was processed with heteropoly acid as catalyst to obtained 4,4-bis(5-methylfuran-2-yl)pentanoic acid. Renewable bio-diesel precursors, 4,4-bis(5-methyl-tetrahydrofuran-2-yl)pentan-1-ol and bis(5-methyl-tetrahydrofuran-2-yl)ethane, were produced by hydrogenation of the 4,4-bis(5-methylfuran-2-yl)pentanoic acid. First of all, the effects of silicotungstic acid, phosphomolybdic acid and silicomolybdic acid catalyst on hydroxylalkylation/alkylation yield were studied. Reaction temperature, catalyst dosage and reaction time were optimized. The yield of 4,4-bis(5-methylfuran-2-yl)pentanoic acid reached 70.5% under the reaction temperature 60 ℃, the dosage of silicotungstic acid 0.05 g, and the reaction time 60 min. Afterwards, the hydrogenation of hydroxylalkylation/alkylation product of angelica lactone and 2-methylfuran on the Pd/C, Ru/C and Pt/C catalyst was also investigated. Ru/C catalyst showed the best activity and selectivity. Yields of 4,4-bis(5-methyl-tetrahydrofuran-2-yl)pentan-1-ol and bis(5-methyl-tetrahydrofuran-2-yl)ethane were 60.5% and 24.6%, respectively. Finally, the stability of Ru/C catalyst was investigated, and the reaction time of 24 h showed good stability. The obtained mixture of 4,4-bis(5-methyl-tetrahydrofuran-2-yl)pentan-1-ol and bis(5-methyl-tetrahydrofuran-2-yl)ethane can be used as bio-diesel precursors. References | Related Articles | Metrics

Select

GC-MS Analysis of Pine Needles Extracts and Toxic Effect of Their Complex Agent on Ambrostoma quadriimopressum Motschulsky CUI Yi, WANG Haiying, HU Jiayi, FANG Jiaoyang, WANG Tingting 2017, 51 (5):  7-14.  doi: 10.3969/j.issn.1673-5854.2017.05.002 Abstract ( 835 )   PDF (863KB) ( 862 )   Save Fresh needle leaves extracts of Pinus sylvestris L. var. mongolica Litv.and Pinus tabuliformis Carr. var. mukdensis Uyeki were respectively obtained by Soxhlet extraction method with hexane as solvent and analyzed by gas chromatography-mass spectrometry(GC-MS). The insecticidal activities of the extracts of the two needle leaves mixed pine sawdust wood vinegar on Ambrostoma quadriimopressum imago and larvae were studied separately.The results showed that 16 components were identificated from the extracts of Pinus sylvestris L. var. mongolica Litv. and the highest GC content compound was 2,2,4,4,6,8,8-heptamethyl-nonane(23.72%),followed by phenyl-acetic acid-3-hexenyl ester(8.56%).41 components were identificated from extracts of Pinus tabuliformis Carr. var. mukdensis Uyeki, and the highest GC content compound was caryophyllene(23.29%), followed by 4-epi-cubedol(11.24%). The insecticidal effects of five times diluted mixture of extracts of the two needle leaves and wood vinegar(volume ratio 1:9) on Ambrostoma quadriimopressum imago were poor, and the insecticidal effect of five times diluted mixture of extracts of needle leaves of Pinus tabuliformis Carr. var. mukdensis Uyeki and wood vinegar(volume ratio 1:9) on Ambrostoma quadriimopressum imago was better than that of wood vinegar. In the first four days, the insecticidal effect of five times diluted wood vinegar on Ambrostoma quadriimopressum larvae was better than the five times diluted mixture of extracts of Pinus tabuliformis Carr. var. mukdensis Uyeki fresh needle leaves and wood vinegar(volume ratio 1:9),the results were opposite on the fifth day. References | Related Articles | Metrics

Select

Production Process of Resinous Foam Material Made From Poplar Wood Powder ZHENG Jiayan, CHU Chenghao, SUN Fengwen 2017, 51 (5):  15-22.  doi: 10.3969/j.issn.1673-5854.2017.05.003 Abstract ( 901 )   PDF (1097KB) ( 840 )   Save With poplar wood powder as raw material, the liquefied resin was prepared by liquefaction experiment system and then the resin was used to foam by low temperature foaming system. In addition,the effects of foaming temperature, viscosity and solid mass fraction of resin, surfactant, curing agent and foaming agent dosage and kinds on preparation process were studied. The results showed that the appropriate viscosity of resin was about 6 000 mPa/s with the solid mass fraction of 75% and the foaming temperature was set at 75 ℃, with Twain-80 and OP-10(mass ratio of 1:1) as surfactant, n-pentane as foaming agent and 1,4-butyrolactone as curing agent at the dosages of 8%-12%. Under these conditions, the foaming process was stable and the pore of foaming material was fine and even. What's more, the foaming material had high percentage of close area, good surface quality, low density(0.12-0.16 g/cm3) and high foaming ratio(5-8). References | Related Articles | Metrics

Select

Steam Gasification of Sawdust-char for Syngas JIA Shuang, YING Hao, SUN Yunjuan, SUN Ning, XU Wei, XU Yu, NING Siyun 2017, 51 (5):  23-28.  doi: 10.3969/j.issn.1673-5854.2017.05.004 Abstract ( 1254 )   PDF (1009KB) ( 889 )   Save Steam gasification of sawdust-char was studied in updraft fixed bed reactor to prepare syngas. The effects of temperature and steam flow rate on products distribution, char conversion rate, gas yield, gas composition and the ratio of H2/CO were investigated. The results showed that temperature had a positive effect on sawdust-char steam gasification, the maximum char conversion rate and gas yield of 99.2% and 4.16 L/g were obtained at 950 ℃. However, the increase of temperature would cause the decrease of H2 concentration from 65.8% to 61.2%. In the meantime, the ratio of H2/CO decreased from 10.3 to 3.35. Increasing steam flow rate could improve H2 concentration from 59.8% to 62%, but there was no change in gasification consequences with the steam flow rate higher than 0.6 g/min. In addition, the temperature of 900 ℃and the steam flow rate of 0.6 g/min were the optimum operating conditions, and the char conversion rate of 93.3% and gas yield of 4.06 L/g could be obtained. Furthermore, the ratio of H2/CO could arrive to 4.11, meeting the requirement of methanation. References | Related Articles | Metrics

Select

Kinetics of Butanone Adsorption on Activated Carbon HUANG Li, YANG Hua, SUN Kang, LIU Shicai 2017, 51 (5):  29-35.  doi: 10.3969/j.issn.1673-5854.2017.05.005 Abstract ( 1709 )   PDF (996KB) ( 944 )   Save Two kinds of activated carbons(wooden activated carbon and coaly activated carbon) were used to study the butanone adsorption. The effects of adsorption time, adsorption temperature and the carrier gas flow of butanone on the adsorption performance were discussed. The adsorption kinetics at different temperatures were studied. Equilibrium data were analyzed by four kinetic models which were pseudo-first-order kinetic model, pseudo-second-order kinetic model, Elovich kinetic model and Bangham kinetic model, thus the kinetic model on the butanone adsorption was established. The results showed that the different kinds of activated carbons showed different adsorption performance. Meanwhile, the adsorption and desorption happened at the same time during the process of butanone adsorption on activated carbon. When the adsorption rate equaled the desorption rate, the equilibrium was established. The equilibrium adsorption amount of butanone decreased with the increase of temperature, which also indicated that the butanone adsorption on activated carbon was an exothermic reaction. The carrier gas flow influenced the adsorption time and rate, and the saturated adsorption amount of butanone of AC-1 was influenced and that of AC-2 was not. The optimal adsorption temperature was 303 K and the ideal carrier gas flow was 400 mL/min. It was also found that the R2 of Bangham model was more than 0.99, therefore it could be concluded that the adsorption of butanone on activated carbon followed Bangham kinetic model. References | Related Articles | Metrics

Select

Influence of Temperature of Pressurized Hot Water Treatment on Structure and Enzymatic Efficiency of Chinese White Poplar Wood XING Jinchen, YU Lili, MA Xiaojun 2017, 51 (5):  36-40.  doi: 10.3969/j.issn.1673-5854.2017.05.006 Abstract ( 921 )   PDF (4338KB) ( 801 )   Save Chinese white poplar(Populustomentosa Carr.) was pretreated by pressurized hot water treatment. The influences of pretreatment temperature on the structure and enzymatic efficiency of wood were discussed by scanning electron microscopy(SEM), X-ray diffraction(XRD), and Fourier transform infrared spectroscopy(FT-IR), and the effect of pretreatment temperature on the sugars yield was also investigated. Results showed that the structure of wood was loose after the pressurized hot water treatment, the morphology and structure of fiber were changed. It was also found that when the pretreatment temperature during pressurized hot water treatment was more than 180 ℃, the crystallinity of the material decreased obviously after enzymolysis, and the maximum reduction rate reached 74%. With increasing the pretreatment temperature, the reducing sugars yields of the enzymolysis of pretreated wood increased firstly and then decreased. As the pretreating temperature was 200 ℃, the reducing sugars yield of wood could reach 38.3%. References | Related Articles | Metrics

Select

Kinetic Study of Tobacco Stem Waste Pyrolysis WU Wentao, LI Zhihua, ZHAO Beibei 2017, 51 (5):  41-48.  doi: 10.3969/j.issn.1673-5854.2017.05.007 Abstract ( 952 )   PDF (1285KB) ( 853 )   Save The pyrolysis kinetic of tobacco stem waste(TSW) was investigated by using single reaction model and three-parallel-reaction (TPR) model via thermogravimetric analysis(TGA). In single reaction model, the reaction mechanism of TSW pyrolysis presented as 14th order reaction f(α)=(1-α)14, with the apparent activation energy of 182.4 kJ/mol. According to the energy compensation effect results, the pyrolysis process of TSW could be divided into three stages which successively covered the conversion range of α=0-0.32, α=0.32-0.80, α=0.80-1 with the pre-exponential factor of 2.88×1010, 4.33×1014 and 9.76×1016, respectively. The single reaction model could not describe the pyrolytic mechanism of TSW reasonably. And then, the pyrolytic kinetic of TSW was investigated by using mixture Weibull distributed activation energy model(DAEM). Results showed that the mix-Weibull DAEM fitted the experimental data very well with correlation coefficients of R2≥0.997 6. According to the results of mix-Weibull DAEM, the apparent activation energy of three pseudo components followed the order of E0(lignin, 195.26 kJ/mol)>E0 (cellulose, 152.54 kJ/mol)> E0(hemicelluloses, 121.18 kJ/mol). The pyrolytic mechanism for pseudo hemicelluloses was first-order reaction f(α)=1-α. And nucleation mechanism could be used to explain the pseudo cellulose pyrolysis. Order-based reaction mechanism was also suitable for pseudo lignin pyrolysis, however, the reaction order was between 3-4, which indicated that the pyrolytic mechanism of pseudo lignin was complex and might be a multiple steps reaction. References | Related Articles | Metrics

Select

Characteristics of High-temperature Carbon Dioxide Gasification of Sawdust-derived Char XU Wei, SUN Ning, YING Hao, SUN Yunjuan, XU Yu, JIA Shuang 2017, 51 (5):  49-53.  doi: 10.3969/j.issn.1673-5854.2017.05.008 Abstract ( 836 )   PDF (571KB) ( 810 )   Save The characteristics of carbon dioxide(CO2) gasification of sawdust-derived char were studied in high-temperature fixed bed reactor. The effects of temperature and CO2 flow rate on the volume fraction of gas compositions, low heating value(QLHV), gas yield, and solid yield were investigated. The results showed that with the temperature increasing from 750 ℃ to 950 ℃, the volume fraction of CO increased and that of CO2 reduced, and the QLHV of the fuel gas increased obviously, the change trend of QLHV was not obvious from 950 ℃ to 1 050 ℃. With the increase of CO2 flow rate, which was used as the gasification agent, the solid yield reduced, the gas yield increased, and the volume fraction of CO2 increased obviously, while the volume fraction of CO and QLHV increased firstly and then reduced. When the flow rate of CO2 was 15 mL/(min·g), the QLHV was up to the largest. The optimized conditions were the gasification temperature 950 ℃ and CO2 flow rate 15 mL/(min·g). Under these conditions,the volume fraction of CO was 51.51%, the volume fraction of CO2 was 37.99%, the QLHV was 8.03 MJ/m3, and the gas yield was 0.78 L/g. References | Related Articles | Metrics

Select

Research Progress of Main Sesquiterpenes from Heavy Turpentine MIN Denghao, ZHAO Jiaping, CHEN Yuxiang, ZHAO Zhendong 2017, 51 (5):  54-60.  doi: 10.3969/j.issn.1673-5854.2017.05.009 Abstract ( 1168 )   PDF (1040KB) ( 931 )   Save Heavy turpentine is a by-product in the production of rosin and turpentine from Pinus massoniana, which mainly contains longifolene and β-caryophyllene. The separation of heavy turpentine, as well as the research progress of longifolene and β-caryophyllene in heavy turpentine were reviewed. For longifolene, the research situation of its isomerization and aromatization was mainly introduced. For β-caryophyllene, the information of its biological activity and the research and utilization of its derivative, caryophyllenol, were introduced. References | Related Articles | Metrics

Select

Research Progress on Activation Method of Cellulose MA Panpan, HE Shanshan, DI Mingwei 2017, 51 (5):  61-66.  doi: 10.3969/j.issn.1673-5854.2017.05.010 Abstract ( 1258 )   PDF (875KB) ( 958 )   Save There were numerous strong intramolecular and intermolecular hydrogen bonds in the molecular structure of cellulose, which restricted the application of cellulose. To improve the reactivity and accessibility of cellulose, the activation pretreatment should be carried on the cellulose. And the research development of activation method for cellulose was reviewed mainly from three aspects of physical activation, chemical activation and physical-chemical activation. The action mechanisms of various activation methods were expounded, and the research results of recent cellulose activation pretreatment were also summarized. The different activation method for cellulose should be chosen according to different process in practical application. References | Related Articles | Metrics