Co-reporter:Qing-yan Liu;Fang Yang;Xiao-feng Sun
Journal of Material Cycles and Waste Management 2017 Volume 19( Issue 1) pp:134-143
Publication Date(Web):2017 January
DOI:10.1007/s10163-015-0392-9
This paper presented a novel process for production of furfural by hydrothermal degradation of corncob over biochar catalyst, in which it was prepared with the recycling degradation solution and lignocellulosic solid residues. The biochar catalyst was papered by lignocellulose residues and concentrated saccharide solution, and then impregnated in 0.5 mol/L sulphuric acid at room temperature for 24 h assisted by the ultrasonic vibration. In the system of recycling, 8.8 % lignocellulose residues and 100 % concentrated saccharide solution from corncob hydrolysis have been recycled. Hydrolysis of corncob was carried out at 180 °C for duration of 170 min over the biochar catalyst. The experimental results have shown that the furfural yield of up to 37.75 % and overall corncob conversion rate of 62.00 % could be achieved under optimum operating conditions for the catalysts preparation and the corncob hydrolysis. It is believed that the acid density of 4.27 mmol/g of biochar catalyst makes the SO3H groups cleave β-1,4 glycosidic linkages effectively and hydrolyze the cellulose and hemicellulose to water-soluble sugars, as well as to facilitate dehydration of xylose to give the product of furfural.
Co-reporter:Guiyu Zhang, Yeqian Wen, Zhihua Liu, Songmei Zhang, Gang Li
Applied Catalysis A: General 2017 Volume 542(Volume 542) pp:
Publication Date(Web):25 July 2017
DOI:10.1016/j.apcata.2017.05.004
•Purification of commercial lignosulfonate by methanol-water solution.•Aggregation behaviors of lignosulfonate.•New explanation of the effect of inorganic acids to lignosulfonate.•Production of low molecular weight value-added chemicals, i.e. isovanillic acid, vanillin, syringaldehyde, acetosyringone, acetovanillone.Commercial sodium lignosulfonate from conifer black liquor (RSL) was used in our study to investigate acid-catalyzed hydrolysis of lignosulfonate (LS) by inorganic acids in aqueous solution. Before the hydrolysis process, RSL was purified by alcohol-water solution. Combustion method and gel permeation chromatography (GPC) of the high performance liquid chromatography system (HPLC) were used to detect the purification efficiency. The results showed that methanol-water solution had better purification effect. In addition, for the purified RSL (PSL-M), 0.5 mol/L NaOH solution was chosen as the best dissolving medium through the comparison of aggregation behaviors of PSL-M in deionized water and various concentrations of NaOH solutions. In the following acid-catalyzed hydrolysis process, the experimental results proved that the three kinds of inorganic acids (HCl, H2SO4 and H3PO4) could catalytically hydrolyze PSL-M to lower molecular weight fractions and other organic chemicals, but HCl had the best efficiency. Moreover, in 0.5 mol/L NaOH solution, PSL-M (solid-liquid ratio, 50 g/L) catalytically hydrolyzed by 0.68 mol/L HCl at 50 °C for 10 min could produce 1.729 g/kg isovanillic acid, 0.088 g/kg vanillin, 0.007 g/kg syringaldehyde, 0.056 g/kg acetosyringone and 0.024 g/kg acetovanillone respectively.Download high-res image (156KB)Download full-size image
Co-reporter:Yi-ming Zhang;Ying Peng;Xiao-lian Yin;Zhi-hua Liu
Journal of Chemical Technology and Biotechnology 2014 Volume 89( Issue 12) pp:1954-1960
Publication Date(Web):
DOI:10.1002/jctb.4282
Abstract
BACKGROUND
Currently, renewable resources such as lignocellulose biomass are explored for valuable chemicals and biofuels. The study of conversion of lignin into valuable products is attracting increasing attention. Electrochemical oxidation has been used as an effective process for lignin degradation owing to its environmental friendliness and high efficiency.
RESULTS
Through analysis using XRD, SEM, and CV patterns, the self-made Pb/PbO2 electrode is shown to have favorable properties as an anode for electrocatalytic degradation of lignin. The proposed sequence of reactions is illustrated for the electrochemical catalysis degradation of lignin to 2,6-bis(1,1-dimethylethyl)-4-methylphenol (BHT) on the Pb/PbO2 electrode surface. The optimum operating conditions for production of BHT (5.61 g L−1) from lignin degradation were found to be current density of 25 mA cm−2 and electrolysis time of 3 h.
CONCLUSION
A new process is proposed to degrade lignin to BHT in alkaline solution with a three electrode system consisting of a Pb/PbO2 working anode, a copper auxiliary cathode and a reference saturated calomel electrode. The sequence reactions for lignin to BHT suggest that the oxidization of lignin on the Pb/PbO2 electrode surface with the required amount of superoxide anion radical (O2•−) results in the effective breakage of the link between the hydroxyphenyl propane unit and benzene ring by the electrolysis. © 2013 Society of Chemical Industry
Co-reporter:Xiao-Na Lv, Gang Li, Fang Yang, Peng Gao, Zhi-hua Liu, Lan Meng, and Xue-Qing Yu
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 1) pp:297-302
Publication Date(Web):December 12, 2012
DOI:10.1021/ie300881k
This study has investigated homogeneous degradation of cotton cellulose into furan derivatives, namely 5-hydroxymethylfurfural (HMF), 1-(furan-2-yl)-2-hydroxyethanone (FHE), and furfural (FF), in concentrated zinc chloride solution under biphasic reaction system with Lewis acids (ZnCl2) as catalysts. Compared with cellulose degradation in pure aqueous phase without any organic solvent, using the integrated reaction and extraction process has shown significant enhancement for the production of HMF, FF, and FHE although the effect on the HMF yield is most significant. However, when dimethyl sulfoxide (DMSO) was added either in the reactive phase or in the extractive phase, the FHE production was inhibited but other product yields were increased. By optimizing the operation conditions, the maximum yields of HMF and FF have been achieved as 79.68 and 17.02 g/kg cellulose. These product yields were, respectively, 130.84 and 3.29 times of those obtained from the systems without any extraction solvent.
Co-reporter:Defa Meng, Gang Li, Zhihua Liu, Fang Yang
Polymer Degradation and Stability 2011 Volume 96(Issue 7) pp:1173-1178
Publication Date(Web):July 2011
DOI:10.1016/j.polymdegradstab.2011.04.021
A novel method of cotton cellulose depolymerization is investigated in this paper. In this work, a three-electrode system, which contains a Pb/PbO2 anode, two copper cathodes and a reference saturated calomel electrode (SCE), is applied to electrocatalytic depolymerization of cotton cellulose. After electrocatalytic depolymerization of cotton cellulose in 0.5M sulfuric acid solution using Pb/PbO2 anode at room temperature (25 °C), the average degree of polymerization (DP) can be reduced to the minimum 367 from 1100. The effects of operating parameters, such as supporting electrolyte, current density and reaction time are investigated as well. The composition of the products in filtrate is characterized by phenol-sulfuric acid method, extraction, NMR, GC–MS and High Performance Liquid Chromatography (HPLC). In addition, the solid sample is analyzed via SEM images, XRD diffractogram, Ubbelohde capillary viscometer and FT-IR spectra. The results suggest that it is effective to convert cotton cellulose to soluble sugar, 5-hydroxymethylfurfural (5-HMF) and other products by electrocatalytic methods. However, the yield of products is low and needs further study. A novel method to significantly convert cotton cellulose to biofuels and biomaterials can be hopefully developed if the selectivity of cotton cellulose electrocatalytic depolymerization is improved in the future.
Co-reporter:Hongxian Fan;Fang Yang;Lei Yang ;Songmei Zhang
Journal of Chemical Technology and Biotechnology 2011 Volume 86( Issue 8) pp:1107-1112
Publication Date(Web):
DOI:10.1002/jctb.2632
Abstract
BACKGROUND: Since natural cellulose is an insoluble, crystalline microfibril, which is difficult to react with other compounds, most reactions related with cellulose are heterogeneous. The methods of cellulose degradation include acid hydrolysis, thermal degradation, alkaline degradation and catalytic degradation. Photocatalysis is a very powerful process.
RESULTS: With 10 g cellulose dissolved in 100 mL ZnCl2 solution (66%), the 5-hydroxymethyl furfural yield in the corrugated plate photocatalytic reactor reached 3.87 g L−1 under the following experimental conditions: 2 h irradiation under ultraviolet (UV) lamp (power—21 W), nine TiO2 coating cycles, and 42° corrugated plate angle.
CONCLUSION: Owing to the enhancement of catalyst surface area illuminated by UV light and the large number of photons captured on the catalyst surface, the energy efficiency per mass (EE/M) of the corrugated plate photocatalytic reactor for photocatalytic degradation of cellulose was 10.9 kWh kg−1. This is therefore an effective technology for 5-HMF preparation from cellulose. Copyright © 2011 Society of Chemical Industry
Co-reporter:Yang Chen, Gang Li, Fang Yang, Song-Mei Zhang
Polymer Degradation and Stability 2011 Volume 96(Issue 5) pp:863-869
Publication Date(Web):May 2011
DOI:10.1016/j.polymdegradstab.2011.02.007
The degradation reactions of cellulose under a combination of heterogeneous Fenton-like reagent with catalyst Mn/ZSM-5 and phosphoric acid media have been investigated. Phosphoric acid solution was selected as the reactive medium for the degradation of cellulose due to its good ability to destroy inter- and intra-molecular hydrogen bond so as to promote cellulose activation. The Fenton-like system, composing of H2O2 and Mn/ZSM-5 in combination with phosphoric acid, can effectively depolymerize cellulose to soluble sugars and partly degraded cellulose with much lower degree of polymerization. Small molecular products, 5-hydroxymethyl furfural and levulinic acid were extracted from the reaction solution. The performance of the catalyst Mn/ZSM-5 and the effect of reaction factors on the molar yield of 5-hydroxymethyl furfural were investigated. A three-step degradation scheme reflecting the main pathways of cellulose degradation in the reaction is proposed.
Co-reporter:Fang Yang;Nian Xu;Rong Liu
Journal of Surfactants and Detergents 2011 Volume 14( Issue 3) pp:339-345
Publication Date(Web):2011 July
DOI:10.1007/s11743-011-1245-8
A series of gemini n-alkylphenol polyoxyethylene surfactants (GAP) were successfully synthesized and their molecular structure were confirmed by NMR and FTIR spectrum. Using the same synthesis route, a gemini nonylphenol polyoxyethylene surfactant (GNP) was synthesized using an industrial nonylphenol product and paraformaldehyde, and its molecular structure was also characterized by 1H-NMR and FTIR spectra. The optimal reaction conditions were established. The critical micelle concentration (CMC) values of GAP were determined by means of Wilhelmy plate method and steady-state fluorescence probe method. The experimental results show how the lengths of the hydrophilic polyoxyethylene chain and the hydrophobic tail alter the CMC values. The CMC values of the GAP are found to be much lower than those of corresponding conventional single tail nonionic surfactants of the polyethoxylated alkylphenol type, which indicates that the gemini species exhibit a better surface activity.
Co-reporter:Lei Yang, Gang Li, Fang Yang, Song-Mei Zhang, Hong-Xian Fan, Xiao-Na Lv
Carbohydrate Research 2011 346(14) pp: 2304-2307
Publication Date(Web):
DOI:10.1016/j.carres.2011.07.005
Co-reporter:Zhong-Xu Wang, Gang Li, Fang Yang, Yu-Lu Chen, Peng Gao
Carbohydrate Polymers 2011 86(4) pp: 1807-1813
Publication Date(Web):
DOI:10.1016/j.carbpol.2011.07.021
Co-reporter:Fang Yang, Gang Li, Jian Qi, Song-Mei Zhang, Rong Liu
Applied Surface Science 2010 Volume 257(Issue 1) pp:312-318
Publication Date(Web):15 October 2010
DOI:10.1016/j.apsusc.2010.06.094
Abstract
A series of trimeric n-alkylphenol polyoxyethylene surfactants (TAP) were successfully synthesized and the molecular structure were confirmed by NMR, FTIR spectrum and elemental analysis. Using the same synthesis route, the trimeric nonylphenol polyoxyethylene surfactant (TNP) was synthesized using industrial product nonylphenol and paraformaldehyde, and its molecular structure was characterized by 1HNMR, FTIR spectrum and elemental analysis. The optimal reaction conditions were established. The surface activity properties of TAP and TNP (such as the critical micelle concentration (cmc), the values of surface tension at the cmc (γcmc), the maximum surface excess concentration (Γcmc), and the minimum surface area per surfactant molecule (Acmc)), were determined by means of Wilhelmy plate method and steady-state fluorescence probe method, respectively. The experimental results show that the lengths of the hydrophilic group oxyethylene (EO) chains and hydrophobic group methylene chains have an influence on the cmc, γcmc, Γcmc, and Acmc of series of surfactants. Furthermore, TAP are arranged to staggered three-dimensional array mode at the air–water interface, which has exhibited better surface properties, such as low cmc values, strong adsorption affinities and wet abilities.
Co-reporter:Fang Yang, Gang Li, Yan-Gang He, Feng-Xia Ren, Gui-xiang Wang
Carbohydrate Polymers 2009 Volume 78(Issue 1) pp:95-99
Publication Date(Web):4 August 2009
DOI:10.1016/j.carbpol.2009.04.004
The synthesis of carboxymethylcellulose (CMC)-g-polyacrylamide (PAM) was carried out in an aqueous medium by using a redox system as an initiator. The effects of reactive conditions on the weigh-average molecular weight of the copolymers (such as initiator concentrations, monomer concentrations, initial reaction temperature, and pH value) were investigated, and the optimal conditions for the grafting reaction were established. The obtained graft copolymers were characterized by Fourier transform infrared spectroscopy, thermal analysis, X-ray diffractometry, intrinsic viscosity, and radius of gyration. An equation relating the radius of gyration of the copolymer influenced by the radius of gyration of PAM and CMC was obtained. The experimental results show how the salt-resistance and heat-resistance of graft copolymers are improved remarkably.
Co-reporter:Gang Li;Fengxia Ren;Yingjun Cui;Fang Yang
Reaction Kinetics, Mechanisms and Catalysis 2008 Volume 93( Issue 1) pp:109-117
Publication Date(Web):2008 January
DOI:10.1007/s11144-008-5097-9
Alkylation of 2-naphthol with tripropylene in the presence of zeolite catalysts HBEA, H-Y and H-MFI was studied. Comparative studies on the catalytic properties of H-BEA, H-Y and H-MFI zeolites were carried out under identical reaction conditions. The results showed that the H-BEA catalyst exhibited outstanding catalytic performance; and the conversion and selectivity of 2-naphthol could be 52.1% and 86.3%, respectively. It was found that the structure and acid strength of zeolite catalysts were the major influencing factors for the conversion and selectivity of 2-naphthol alkylation.
Co-reporter:Gang Li;Chao Yang;Fang Yang;Xueqing Yu;Yangang He
Journal of Applied Polymer Science 2007 Volume 106(Issue 4) pp:2479-2484
Publication Date(Web):27 JUL 2007
DOI:10.1002/app.25645
Copolymer particles consisting of acrylamide (AM) and cationic comonomer 2-methyl acryloyloxyethyl trimethyl ammonium chloride (DMC) were prepared by precipitation polymerization in an solution of potassium citrate using ammonium persulfate ((NH4)2S2O8) and sodium sulfite (Na2SO3) as an initiator. The product poly(acrylamide-2-methyl acryloyloxyethyl trimethyl ammonium chloride) [Poly(DMC-AM)] is a water-soluble cationic polyelectrolyte. The solubility of DMC, AM and Poly(DMC-AM) in potassium citrate solution were measured, combined with the theory of solubility parameter, and the experiment results indicate that the solubility of DMC and AM is much higher than that of Poly(DMC-AM), and also the mechanism of copolymer precipitated in salt solution was discussed. The factors influencing the conversion of comonomers were examined, such as salt mass fraction, polymerization temperature, monomers mass fraction, initiator mass fraction, and so on. The results of experiments indicate that the best conditions are salt mass fraction = 57%, monomers mass fraction = 3%, m(DMC) : m(AM) = 3 : 1, initiator mass fraction = 0.08%, polymerization temperature = 50°C, reaction time = 2 h, and the conversion is 86.4%. And the qualitative analysis experimental method for copolymer by infrared absorption spectrum show that [Poly(DMC-AM)] was successfully synthesized by precipitation polymerization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Co-reporter:Yangang He;Fang Yang;Xueqing Yu;Yingjun Cui;Fengxia Ren
Journal of Applied Polymer Science 2007 Volume 104(Issue 6) pp:4060-4067
Publication Date(Web):27 MAR 2007
DOI:10.1002/app.25649
Precipitation polymerization of 2-(methacryloyloxyethyl) trimethyl ammonium chloride (DMC)-co-acrylamide (AM) [poly(AM-DMC)] has been successfully performed in potassium carbonate (K2CO3)-water media by plasma initiation. K2CO3 solution was selected because not only the higher solubility of AM and DMC comparing with that of poly(AM-DMC), but the higher intrinsic viscosity of poly(AM-DMC) could be obtained. A set of experiments was performed using different K2CO3 concentration (from 50 down to 10% (w/w)), thus the precipitation architecture was not obtained below 20% (w/w). And particles size, particles size distribution (7–120 μm), and intrinsic viscosity of poly(AM-DMC) (ranging up to 455 cm3/g) were also summarized in this article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4060–4067, 2007
Co-reporter:Yan Li, Hongxian Fan, Xueqing Yu, Songmei Zhang, Gang Li
Chinese Journal of Chemical Engineering (December 2016) Volume 24(Issue 12) pp:1786-1792
Publication Date(Web):1 December 2016
DOI:10.1016/j.cjche.2016.05.016
Hemicellulose in corn straw is a group of complex heteropolysaccharides which are composed of different sugar units, including mannans, xylans, arabinans and galactans. This study developed a simple and practical process for production of 5-hydroxymethyl furfural (HMF) using hemicellulose that was extracted from corn straw. In the hemicellulose degradation process HCOOH/HCOONa was used as buffer solution, and the optimum conditions for maximum HMF yield were explored. Various extraction conditions including NaOH concentration, reaction time, temperature, solid-to-liquid ratio and precipitant were tested for hemicellulose obtaining, giving the optimum condition of 55 °C, 4 h, solid-to-liquid ratio of 1:10, 1.5 mol·L− 1 NaOH solution and ethanol as precipitant with the yield of 34.16%. Dehydration of hemicellulose under HCOOH/HCOONa buffer solution process, using solution medium of pH = 0.8 hydrolyzed hemicellulose in corn straw at 190 °C after 190 min and 82% of HMF yield was achieved.This diagram demonstrated the whole experimental process which roughly divided into two steps. In the first step, hemicellulose of corn straw was extracted in alkaline solution and specific precipitant. During this process, several factors had been investigated for the maximum of hemicellulose. The next step was the degradation procedure. Buffer solution and hemicellulose were mixed into the iron batch autoclave under high temperature for a period of time. The products of the mixture were detected by HPLC, NMR, FTIR and other testing means. The buffer solution could be used for recycling for 4 times.Download high-res image (178KB)Download full-size image
Co-reporter:Yong-sheng Wang, Fang Yang, Zhi-hua Liu, Lu Yuan, Gang Li
Catalysis Communications (5 July 2015) Volume 67() pp:49-53
Publication Date(Web):5 July 2015
DOI:10.1016/j.catcom.2015.03.033
•Electrochemical catalysis degradation of aspen lignin in the TDE reactor•The lignin was cracked by OH and hydrogenated by H atom.•Products 4-methylanisole, acetovanillone, 2,6-dimethoxyphenol and so onA novel procedure about electrochemical catalysis degradation of aspen lignin with Pb/PbO2 anode in the three-dimensional electrode (TDE) reactor was investigated. SEM, XRD and cyclic voltammogram tests were employed to study the surface morphology, composition and the electrochemical redox performance of the fabricated Pb/PbO2 electrode. The lignin was cracked by OH and hydrogenated by [H] atom generated from alkaline water electrolysis, leading to the production of 4-methylanisole and other products. Raw material lignin concentration, current density, temperature and time were optimized. The pathway of electrocatalytic degradation and hydrogenation process of lignin in alkaline solution was also discussed.
