FUEL
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2020
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IF 5.578
Xiaohua Zhang,Weikun Jiang,Hao Ma,Shubin Wu
This study investigated the relationship between the formation of oligomers and monophenols and lignin structure during pyrolysis regarding two technical lignins from alkali lignin (AL) and corn cob hydrolysis residue lignin (CHRL). The results showed that the molecular weight distribution and inter-unit linkages varied substantially between AL and CHRL, resulting in profound differences in the content of monophenols and oligomers and their distributions in pyrolysis oil (PO). Thereinto, CHRL-PO containing higher monomers content (20.48%) and lower oligomers content (14.31%) relative to AL-PO (5.02%, 22.4%). This was attributed to the higher proportion of guaiacyl (G) units existed in AL, which tended to form oligomers and char. Additionally, the formation pathways of main monophenols from two POs were also different. In light of these findings, the thermal cracking behavior of lignin was closely bound up with its structural features. On one hand, the formation pathways of lignin-derived dimers and tetramers in PO originated from the breaking of a large amount of β-O-4, α-O-4 and C β -C γ bonds during pyrolysis process. Meanwhile, the interconversion relationship between oligomers and monophenols was also existed. Polycyclic aromatic hydrocarbon (PAH) derivatives, on the other hand, were formed by the continuous growth of smaller free radicals because of the evolutionary components (such as phenols, syringols) could form oxygen-related free radicals during the secondary reaction process. Overall, this work provided the research basis and theoretical guidance for balancing the production of oligomers and monophenols through the selection of specific lignin feedstock.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Hang Chen,Tanglong Liu,Yi Meng,Yi Cheng,Jie Lu,Haisong Wang
Biomass adsorbents applied in the removal of pollutants in wastewater treatment has become a trend. Herein, only 0.1 % graphene oxide was used to modify the aminated lignin aerogels and applied in the removal of dyes. The adsorption capacity of graphene oxide/aminated lignin aerogels (GALA) to malachite green (MG) was compared with different composition, pH, aerogels dosage, reaction temperature and contacting time. The experimental results indicated that the maximum adsorption capacity and efficiency could reach to 113.5 mg/g and 91.72 % under the optimal conditions. Compared to other aerogels in this experiment, the adsorption performance of GALA was significantly improved due to the synergy between the carboxyl group on the surface of graphene oxide and the amine of aminated lignin. Additionally, the fitting results of adsorption isotherm models and adsorption kinetic models conformed to the Langmuir and pseudo-second-order models, respectively. Furthermore, the adsorption efficiency of the GALA was able to keep 89.8 % within 5 cycles of adsorption-desorption. Overall, the GALA reduces costs and reuses waste lignin, which were eco-friendly, regenerate and convenient biomass adsorbents that has the good potential for wastewater treatment.
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高影响因子
CHEMOSPHERE
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2020
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IF 5.778
Qiong Wu,Xiaoxia Ye,Yuancai Lv,Ruihan Pei,Minya Wu,Minghua Liu
It is crucial for water environment security to remove its p -arsanilic acid ( p -ASA) efficiently. Namely, removing p -arsanilic acid from aqueous media through magnetic separation, has become a novel method of removing toxic pollutants from water. Batch adsorption experiments demonstrated a higher adsorption of lignin-based magnetic activated carbon (201.64 mg g −1 ) toward p -ASA. In addition, LMAC nanoparticles exhibited typical magnetism (35.63 emu g −1 of saturation magnetization) and could be easily separated from the aqueous solution. Meanwhile, the endothermic adsorption of p -ASA over LMAC could spontaneously proceed and be well described by the pseudo-first-order and pseudo-second-order model as well as the intra-particle diffusion model. Moreover, the mechanisms during p -ASA adsorption over LMAC included the electrostatic attraction, surface complexation, π-π stacking and hydrogen bonding interaction. Importantly, lignin-based magnetic activated carbon has high absorbability and preferable reusability in real water samples. Consequently, this paper provides insights into preparation of the lignin-based magnetic activated carbon may be potential adsorbents for the remediation of organoarsenic compounds.
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PubMed
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 6
·1591-1604
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IF 2.372
Du Boyu,Chen Changzhou,Sun Yang,Liu Bingyang,Yang Yingying,Gao Si,Zhang Zhenshu,Wang Xing,Zhou Jinghui
Abstract Catalytic depolymerization of lignin to produce bio-oil, liquid fuels, and aromatic chemicals in high yields is important for a biorefinery to remain competitive. In this study, undoped and Ni-doped catalysts for depolymerization of rice husk lignin (RHL) were developed and analyzed. The results showed that the catalysts had hydrotalcite-like structures with lamellar morphology. With suitable Ni-doping amount, the catalysts had high activity, thus better promoted the depolymerization of RHL. Among all catalysts, the Ni1/4MgAl catalyst could best promote the cleavage of the β-O-4 aryl ether bond in RHL molecule and thus could substantially increase the yields of bio-oil. The depolymerization catalyzed by this catalyst was also found to be temperature-, time-, and solvent-dependent. This study provides information that can be beneficial to the biorefinery industries and may help promote the valorization of lignin. Graphic Abstract
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高影响因子
ACS Catalysis
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2019
·
IF 12.221
Huifang Liu,Hongji Li,Nengchao Luo,Feng Wang
Lignin is the largest carrier of aromatics on earth, and its depolymerization can afford value-added aromatic products. Direct cleavage of the C–C bonds in lignin linkages is significant, but it is challenging to obtain low-molecular-weight aromatic monomers. Herein, using vanadium catalysts under visible light, we selectively cleave the C–C bonds in β-1 and β-O-4 interlinkages occluded in lignin models and extracts by an oxidative protocol. Visible light irradiation triggered single electron transfer between the substrate and the catalyst, which further induced the selective Cα–Cβ bond cleavage and generated the final aromatic products through radical intermediates. Using this photocatalytic chemistry, the reactivity of lignin models and the selectivity of Cα–Cβ bond cleavage were significantly improved. More importantly, this protocol affords aromatic monomers through the fragmentation of organosolv lignins even at room temperature, indicating the potential of photocatalytic C–C bond cleavage of lignin linkages under ambient conditions.
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高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2019
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IF 4.191
Mingfu Li,Qingtong Zhang,Bin Luo,Changzhou Chen,Shuangfei Wang,Douyong Min
Lignin-based activated carbon solid (LCS) was prepared by simultaneous carbonization and activation at different temperatures. Lignin-based carbon solid acid (LCSA) was synthesized from LCS via sulfonation by sulfuric acid and used as a catalyst for converting fructose to 5-hydroxymethylfurfural (HMF). The physicochemical properties of LCS and LCSA were determined by scanning electron microscopy, N 2 adsorption–desorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and element analysis. Owing to the microporous structure, LCSA possessed high specific area and could selectively and effectively convert fructose to HMF. Under the optimal conditions, the yield of HMF was 75.7% when dimethyl sulfoxide was used as the solvent. The recovery rate of the LCSA catalyst was nearly 95%, and the catalytic ability was more than 70% after five recycles. The preparation of microporous LCSA and its use as a catalyst are not only a value addition to lignin but are also environmentally friendly strategies for converting carbohydrates into HMF, as LCSA can prevent the pollution caused by the use of conventional mineral acid catalysts.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
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IF 14.229
Qianying Fang,Zhicheng Jiang,Kai Guo,Xudong Liu,Zheng Li,Guiying Li,Changwei Hu
Two-step conversion of pubescens to aromatic monomers and small molecular weight oligomers (mainly dimers and trimers) was studied. Lignin-derived oligomers (LDO) were obtained by formic acid assisted solvo-thermal conversion of pubescens in the H 2 O-ethanol system at 160 ℃. In the second step, hydrogenolysis of LDO on Pd/NbOPO 4 catalyst was carried out over the temperature range of 60–120 ℃. Pd/NbOPO 4 showed acceptable catalytic performance for efficient degradation of oligomers at low temperature. The NbO x species on the catalyst facilitated the breakage of C O C bonds to depolymerize the oligomers toward small molecules, while Pd species accelerated the selective hydrogenation of side chain and furans. The esterification of S (Syringol) unit phenols took place simultaneously with the depolymerization of LDO. The hydrogenated mixture at 100 ℃ and reaction time of 20 h had an average molecular weight of 908 g/mol, and the yield of aromatic monomers was 22.4 wt.% based on lignin contained.
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高影响因子
FUEL
·
2022
·
IF 8.035
Han-Bing Gao,Le-Le Qiu,Fa-Peng Wu,Jian Xiao,Yun-Peng Zhao,Jing Liang,Yong-Hui Bai,Fang-Jing Liu,Jing-Pei Cao
Catalytic hydrogenolysis of C O bonds in lignin provides a promising route to produce high value-added biofuels and chemicals. However, designing highly active and stable catalysts for this process is still a challenge. Herein, a series of Ni/Al 2 O 3 catalysts were synthesized by calcination and reduction of layered double hydroxide precursors, and their activities were evaluated in the catalytic conversion of lignin-derived compounds. Diphenyl ether was completely converted with a 100% monomeric selectivity (cyclohexane and cyclohexanol) over the optimized Ni/Al 2 O 3 -500 under the optimal conditions of 200 ℃, 0.5 MPa H 2 and 1.5 h, indicating the excellent catalytic activity in the cleavage of C O bonds of the catalyst. The excellent catalytic performances of Ni/Al 2 O 3 -500 were originated from its relatively large specific surface area, well-developed porosity, small crystallite size, high Ni 0 concentration and strong interaction between the active metal and support. The reusability experiments show that Ni/Al 2 O 3 -500 possesses a relatively high stability for six reuses. Moreover, various lignin model compounds can be completely converted to corresponding monomeric products over Ni/Al 2 O 3 -500, indicating the applicability of this ingenious catalyst. The application of the hydrotalcite-derived Ni-based catalysts with high activity and stability provides a promising approach for the efficient hydrogenolysis of lignin derivatives.
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高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2023
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IF 7.4
Lanxin Wang,Yuncheng Wang,Jiawen Zhang,Fengjuan Wang,Zhiyong Liu,Jinyang Jiang
Surface protective coatings are prone to cracking and failure due to the deformation of concrete structure itself and harsh service environment factors such as UV, ion erosion, and large temperature differences during the period of service. It is urgently required to develop new types of self-healing coatings to provide long-lasting protection for concrete structures and extend their service life. In this investigation, a lignin-based self-healing agent was prepared using aniline and lignin as raw materials. Its characterization was analyzed by SEM and FT-IR. By introducing the lignin-based healing agent and dynamic disulfide bonds, a new kind of self-healing polyurethane coating was prepared, and its self-healing ability was qualitatively and quantitatively evaluated, indicating that it had excellent self-healing performance. After self-healing process, the crack could withstand bending force. Moreover, with the increased temperature, the self-healing efficiency of tensile strength gradually increased, reaching a maximum of 86.42% at 60 ℃. Meanwhile, the self-healing efficiency of its elongation at break firstly increased and then gradually decreased, reaching a maximum of 93.77% at 40 ℃. This self-healing polyurethane coating had high hydrophobicity (139.4°) and excellent abrasion resistance . After 40 friction cycles , its hydrophobicity only decreased by 10.9% to 124.2°. In addition, this self-healing protective coating also showed excellent resistance to chloride ions, effectively protecting cementitious materials with the damaged surface. This work provides a new method for long-term protection of concrete structures.
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高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Miaolian Ma,Wanpeng Zhou,Yu Zhang,Qisen Huang,Zhixuan Hu,Liuzhang Ouyang
Herein, natural lignin is used for the first time as a catalyst for the methanolysis of NaBH 4 . Lignin exhibits excellent catalytic activity for the methanolysis of NaBH 4 , and the HGR value is as high as 20425 mL H 2 ·g cat −1 ·min −1 at room-temperature. It is still satisfactory even at − 20 ℃, with a HGR of 2182 mL H 2 ·g cat −1 ·min −1 , which is the highest value reported in the literature to date. In addition, the study of kinetic reaction orders for NaBH 4 methanolysis catalyzed by lignin indicates that the catalytic methanolysis of NaBH 4 obeys first-order kinetics with respect to both of NaBH 4 concentration and catalyst dosage. The activation energy for the methanolysis catalysis by lignin is calculated to be 19.5 kJ·mol −1 at low temperature of − 20 ∼ 25 ℃. The lignin retain over 66% of the original catalytic activity at the end of fifth consecutive reuse, and the catalytic activity can be completely recovered through simple acid treatment.
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Molecular Catalysis
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2023
·
IF 4.6
Donglin Huang,Wulin Song,Hongmei Zhao,Meng Li,Liang Wei,Hongxi Zhang
There are limited renewable sources of aromatic chemicals, with lignin being one of the most prominent, accounting for approximately 30% of the planet's organic carbon. Due to its intricate and irregular structure, lignin is recalcitrant to chemical conversion, often resulting in low yields of mixtures of products when it is depolymerized. This study synthesized a CeO 2 /AC catalyst via an impregnation technique and then explored its ability to depolymerize lignin via an oxidation-reduction strategy. The CeO 2 /AC catalyst efficiently depolymerized lignin by an oxidation-reduction strategy. At 200 °C, an argon pressure of 1 MPa, and a reaction time of 4 h, the conversion of the lignin model compound reached 98.5%. When using lignin derived from poplar, birch, pine, and cotton stalk, the total yields of phenolic monomers were 36.2 wt.%, 31.2 wt.%, 17.4 wt.%, and 12.1 wt.%, respectively. The CeO 2 /AC catalyst exhibited a higher surface oxygen vacancy concentration than CeO 2 , which was crucial for facilitating the hydrogenolysis of lignin.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2023
·
IF 19
Yong Zheng,Hai Liu,Li Yan,Haiyue Yang,Lin Dai,Chuanling Si
Room-temperature liquid metals (RTLMs) have excellent shape reconfiguration capabilities, which make them ideal for flexible electrodes, sensors, and energy devices. However, due to the high surface tension and weak adhesion of RTLM, the types of printing substrates, patterning, and recovery processes are limited. It is essential to develop advanced encapsulation techniques for the patterning of RTLMs. Lignin has great potential for promotion as nanodispersants and nanocarriers because of its abundant hydroxyl groups and good self-assembly properties. In this work, a green and facile encapsulation method using industrial lignin is reported for stable, uniform, and reproducible patterning of eutectic gallium–indium (EGaIn). Lignin-encapsulated EGaIn particles exhibit good stability and can be patterned on the surface of various substrates with a simple ballpoint pen. The electrical resistance of the conductive tracks shows little change under bending and twisting (720°) conditions. More importantly, the lignin-encapsulated system can be easily dissolved and regenerated, which is also supported by molecular dynamics simulations and density functional theory calculations. 96.9% of the EGaIn can be recovered from the system. These characteristics make it very environmentally friendly throughout the preparation process and find applications in flexible sensors, transient circuits, and many other areas.
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