RENEWABLE ENERGY
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2019
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IF 5.439
Qing-Lu Song,Yun-Peng Zhao,Fa-Peng Wu,Guo-Sheng Li,Xing Fan,Rui-Yu Wang,Jing-Pei Cao,Xian-Yong Wei
Low aromaticity and a large number of oxygen-bridged bonds among the aromatic structural units of lignin make it possible to obtain chemicals directly. A novel Co/ [email protected] catalyst with high activity towards hydrogenolysis of lignin-derived aryl ethers was synthesized according to the pyrolysis process of a predesigned ZIF-67. According to the results of characterization by powder X-ray diffraction (XRD), N 2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), Co was reduced by the carbonized organic linker of ZIF-67, and N was doped into the carbon skeleton of the catalyst. The effects of holding time, temperature, and initial H 2 pressure on the catalytic performance of Co/ [email protected] were evaluated in the selective hydrogenolysis of benzyl phenyl ether (BPE). BPE was completely converted and the selectivity of monomer reached to 98.2% under optimized reaction conditions. The C alk -O bond in BPE was first dissociated to form toluene and phenol, and then phenol was rapidly hydrogenated to form cyclohexanol. Furthermore, the Co/ [email protected] catalyst shows high activity for hydroprocessing and selective cleavage of other lignin-derived aryl ethers, including phenylethyl phenyl, diphenyl ether, dibenzyl ether, dinaphthalene ether, guaiacol, anisole and veratrole.
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高影响因子
MOLECULES
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2019
·Vol. 24
·期 15
·2704
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IF 3.06
Chao Liu,Youming Li,Yi Hou
Carboxymethyl lignin nanospheres (CLNPs) were synthesized by a two-step method using microwave irradiation and antisolvent. The morphology and structure of CLNPs were characterized by31P-NMR, FTIR, and SEM, and the results showed that they had an average diameter of 73.9 nm, a surface area of 8.63 m2or 3.2 times larger than the original lignin, and abundant carboxyl functional groups of 1.8 mmol/g. The influence of dosage, pH, contact time, and concentration on the adsorption of metal ions onto CLNPs were analyzed, and the maximum adsorption capacity of CLNPs for Pb(II) was found to be 333.26 mg/g, which is significantly higher than other lignin-based adsorbents and conventional adsorbents. Adsorption kinetics and isotherms indicated that the adsorption of lead ions in water onto CLNPs followed the pseudo-second-order model based on monolayer chemisorption mechanism. The main chemical interaction between CLNPs and lead ions was chelation. CLNPs also showed an excellent recycling performance, with only 27.0% adsorption capacity loss after 10 consecutive adsorption–desorption cycles.Keywords:lignin;carboxymethyl;nanosphere;adsorption;lead
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PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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2018
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IF 5.807
Lupeng Shao,Qilin Zhang,Tingting You,Xueming Zhang,Feng Xu
Microwave-assisted degradation of alkaline lignin in methanol/formic acid media was investigated, concerning the effect of formic acid (FA) amount, reaction temperature, and reaction time on lignin depolymerization. The highest bio-oil yield of 72.0 wt% including 6.7 wt% monomers was achieved at 160 °C and a FA-to-lignin mass ratio of 4 after a reaction time of 30 min. Among the monomers, the yield of 2,3-dihydrobenzofuran was the highest (3.00 wt%), followed by p -coumaric acid (1.59 wt%). Formic acid acted mainly through acid-catalyzed cleavage of the linkages in lignin. Oligomers in bio-oil were mainly composed of dimers (molecular weight: 253–378) and trimers (molecular weight: 379–510) according to the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) analysis. A possible mechanism about microwave-assisted depolymerization of lignin in methanol/formic acid media was proposed. This study will provide an efficient approach for lignin depolymerization.
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PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2018
·
IF 3.849
Tao Li,Shaoyu Lü,Shaofei Zhang,Chunmei Gao,Mingzhu Liu
Excessive application of fertilizers and their losses have exerted a great threat on soil environment. Slow- or controlled-release fertilizers have been widely produced to alleviate the problem. However, most of them can not remedy contaminated soil environment, and even make it worse. To improve nutrient use efficiency and reduce soil environmental pollution, lignin, an extensive biomass source, was used to synthesize a lignin-based superabsorbent (LPA), which was then introduced into the fertilizer as an outer coating material to obtain lignin-based multifunctional fertilizer (LMF). Results showed that the introduction of LPA can improve water-holding and water-retention capacity of soil and nutrients release behavior of fertilizers. The cumulative release rates of nitrogen, phosphorus and zinc were 79.5%, 46.7% and 60.1% after 25 days, respectively. Additionally, LMF can efficiently immobilize and restrict the migration of bivalent lead (Pb(II)) by complexation with lignin. About 91.7% of Pb(II) was immobilized after soil-sand mixture with Pb(NO 3 ) 2 was treated by LMF. The pot experiments indicated that the LMF exhibited a positive effect on the growing of corn in Pb(II)-contaminated soil. Therefore, this work provides a promising fertilizer to improve the utilization efficiency of water, sustained release of nutrients, and immobilization of Pb (II) in contaminated soil.
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高影响因子
Molecular Catalysis
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2018
·
IF 0
Xiaoqing Gao,Shanhui Zhu,Yongwang Li
The mild depolymerization of lignin into aromatic monomer is a grand challenge owing to the various aryl ether C–O bonds, particularly for the most abundant β-O-4, α-O-4 and 4-O-5 linkages. Rod-shaped CeO 2 supported AuPd bimetallic catalysts fabricated by sol-immobilization method presented robust alloy structure, as evidenced by TEM, XPS, UV–vis, and CO-DRIFTS. For the hydrogenolysis of C O bond model compound with formic acid, Au 1 Pd 1 /CeO 2 showed about 23.5 and 6 folds increase in activity compared with its monometallic counterparts Au/CeO 2 and Pd/CeO 2 , respectively. The outstanding performance was mainly ascribed to the increased adsorption ability of electron-deficient Pd for aromatic C–O bond. Additionally, formic acid-mediated Au 1 Pd 1 /CeO 2 has efficiently performed hydrogenolysis of real lignin into a variety of valuable monophenols, achieving 44.1% yield at low temperature.
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ENERGY & FUELS
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2014
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IF 2.733
Jingying Pan,Jie Fu,Shuguang Deng,Xiuyang Lu
A systematic study of microwave-assisted degradation of lignin model compounds such as benzyl phenyl ether (BPE) and guaiacol, in imidazolium-based ionic liquids, was performed by evaluating the catalytic activity of 29 types of ionic liquids as both solvent and catalyst. After measuring and comparing the acidity of each ionic liquid solution for BPE and guaiacol degradation under the microwave irradiation and conventional heating conditions, it was found that the ionic liquid 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO4) was the most effective for decomposing the lignin model compounds. The experimental results indicate that ionic liquid acidity is in favor of the catalytic activity for BPE and guaiacol degradation, microwave irradiation could accelerate the degradation rate by 650% for BPE and 1120% for guaiacol and significantly increase the reaction selectivity. It was also found in experiments that the ionic liquid [BMIM]HSO4 could be used for 5 times without any loss of catalytic activity. The possible mechanisms for BPE and guaiacol degradation are proposed based on the product distributions.
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高影响因子
FUEL PROCESSING TECHNOLOGY
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2015
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IF 3.352
Jingying Pan,Jie Fu,Shuguang Deng,Xiuyang Lu
A study on extraction of 15 kinds of possible lignin degradation products from aqueous solutions was performed by evaluating the distribution coefficients of five different organic-H 2 O systems under different conditions. The experimental results show that the extraction of lignin degradation products from aqueous solutions achieved equilibrium within 30 min; the concentration of the extracted materials and the amount of extractant had a negligible effect on the distribution coefficients. Among the five kinds of extractants investigated in this work, n-butanol was the best solvent for extracting the lignin degradation products, and chloroform had a good selectivity for the extraction of aldehyde. The temperature greatly influenced the distribution coefficients because the distribution coefficients decreased considerably with the extraction temperature. These results provide insights for the degradation of the lignin in a two-phase system.
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高影响因子
ACS Sustainable Chemistry & Engineering
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2015
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IF 4.642
Yonghong Deng,Youfa Liu,Yong Qian,Weijian Zhang,Xueqing Qiu
Lignin-based azo polymers are prepared from alkali lignin, a byproduct in spent liquor from the pulping and papermaking industry, and their structures and photochromic effects are characterized by elemental analysis, Fourier transform infrared, 1H nuclear magnetic resonance, and ultraviolet–visible spectroscopy. Results show that only the 2-(4-nitrophenyl azo) phenol lignin-modified polymer (AL-azo-NO2) shows a significant photochromic effect, and its photoresponsive behavior is evidently slower than that of the synthetic polymer with a similar azo chromophore. For the 2-(4-methoxyphenyl azo) phenol lignin-modified polymer, its photoisomerization behavior was expected to be similar to that of azobenzene-type molecules, but its photoresponse is not obvious. The abnormal photochromic effect of AL-azo polymers is related to strong steric hindrance of lignin backbones. With addition of water (poor solvent), AL-azo-NO2 shrinks gradually, which prevents azobenzene groups from isomerizing and results in a lower isomerization efficiency at higher water contents. Preparation of lignin-based azo polymers offers a novel source of azo polymers and provides a green and sustainable pathway for value-added utilization of lignin biomass recovered from the pulping industry.
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高影响因子
ENERGY & FUELS
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2014
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IF 2.733
Jun Hu,Dekui Shen,Shiliang Wu,Huiyan Zhang,Rui Xiao
The structural analysis and catalytic solvolysis performance of organosolv lignins from Chinese fir (softwood) and maple (hardwood) were investigated. Fourier transformation infrared spectroscopy (FTIR) analysis revealed that both Chinese fir lignin and maple lignin exhibited a guaiacyl–syringyl structure. Chinese fir lignin consisted of guaiacyl units principally, while maple lignin consisted of syringyl units mainly. The ratios of guaiacol-/syringol-type products obtained by pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) were 2.53 for Chinese fir lignin and 0.29 for maple lignin, respectively. The catalytic solvolysis degradation was studied in supercritical ethanol/1-butanol at 300 °C with Ru/C to produce phenolic compounds. The degradation products of Chinese fir lignin were mainly guaiacol-type products, while the products of maple lignin consisted of both guaiacol- and syringol-type compounds. The yields of most products of maple lignin were much higher than those of Chinese fir lignin. The results show that the organosolv maple lignin is a potential feedstock for producing phenolic products through the solvolytic method.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2015
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IF 4.321
Zhili Li,Yan Kong,Yuanyuan Ge
A new lignin xanthate resin (LXR) was synthesized by a two-step reaction from alkaline lignin and carbon disulfide. It was characterized by FT-IR, SEM and element analysis. An ordered porous structure is observed on LXR. Batch adsorption including equilibrium isotherms, kinetics, and the effects of pH, dosage and temperature on the adsorption of Pb 2+ by LXR were systematically studied. LXR shows a 4.8 times higher adsorption capacity than alkaline lignin at 30 °C that is attributed to the incorporation of xanthate groups and porous structure. Thermodynamic parameters, involving Δ H °, Δ S ° and Δ G ° were also calculated from graphical interpretation of the experimental data. Negative values of Δ G ° indicate the adsorption process of Pb 2+ by LXR is spontaneous. The positive value of Δ H ° confirms the endothermic adsorption in nature. The high adsorption capacity of LXR, together with its feasible preparation, biocompatibility and environmentally friendliness, open new perspectives in the potential use for wastewater treatment.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 131
·期 18
·
IF 1.64
Yan Zhou,Jianping Zhang,Xuegang Luo,Xiaoyan Lin
A novel adsorbent for Hg(II), mercapto-functionalized alkali lignin (AL-SH) was synthesized by Friedel–Crafts alkylation reaction and nucleophilic substitution reactions. The adsorbent was characterized by the techniques of Fourier transform-infrared spectroscopy (FT-IR), elementary analysis and thermogravimetric analysis, and N 2 adsorption techniques. The effect of various parameters on Hg(II) adsorption process such as initial pH, contact time, ionic strength, initial Hg(II) concentration, temperature, and adsorbent dosage were investigated in detail through batch static experiments. The results indicated that the adsorption process of Hg(II) on AL-SH was mainly dependent on the pH and the optimal pH value was at pH ranging from 4.0 to 6.0. The adsorption process was found to follow pseudosecond-order kinetics and the main process was chemical adsorption, which equilibrated at 8 h. The adsorption isotherm was better described by Langmuir and Temkin isotherm equations compared to Freundlich isotherm equation and the maximum adsorption capacity obtained was 101.2 mg g −1 (pH = 4.0, 20°C, initial Hg(II) concentration was 200 mg L −1 ). The thermodynamic parameters of and were positive while was negative, revealed that the adsorption of Hg(II) onto AL-SH was a spontaneous and endothermic process with increased entropy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40749.
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ChemCatChem
·
2017
·Vol. 10
·期 2
·415-421
·
IF 4.803
Jianwei Ji,Haiwei Guo,Changzhi Li,Zaojuan Qi,Bo Zhang,Tao Dai,Min Jiang,Chuanqing Ren,Aiqin Wang,Tao Zhang
Graphical Chop up the wood : Tungsten-based bimetallic catalysts exhibit high activity and selectivity in the hydrogenolysis of typical model compounds of the α-O-4 linkage in lignin and deconstruction of lignin feedstock for the production of aromatic chemicals. High yields of C−O cleavage products are obtained without destroying the aromatic rings. Tungsten-based bimetallic catalysts M–W/AC (M=Ru, Pt, and Pd; AC=activated carbon) exhibited high activity and selectivity in the hydrogenolysis of typical α-O-4 model compounds and deconstruction of lignin feedstock for the production of aromatic chemicals. Synergy effect was observed between tungsten and noble-metal species, which on the one hand modulated the hydrogenolysis activity of tungsten and improved the activity of catalyst, and on the other hand suppressed overhydrogenation that avoided the formation of cycloalkanes. The conversion of α-O-4 model compounds with different substituents showed that electronic effects play an important role in stabilizing the reaction intermediates, and the electron-donating methoxy group on the aromatic ring accelerated the hydrogenolysis efficiency. Solvent effect was another factor that determined hydrogenolysis efficiency; dipolar aprotic solvents such as n -hexane provided the high yields of target aromatics. In the conversion of realistic lignins, the bimetallic catalyst showed excellent activity not only in α-O-4 cleavage but also in the hydrogenolysis of other major linkages such as β-O-4 and β−β between aromatic units, so that a high yield of liquid oil was obtained from lignin.
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危险品化学品经营许可证（带存储）