FUEL PROCESSING TECHNOLOGY
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2024
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IF 7.2
Xinxu Zhao,Chaoqun You,Xun Li,Yu Zhang,Fei Wang
The limited solubility of lignin in commonly used solvents poses a challenge for its depolymerization into high-value monomers. This paper investigates the solubility of alkali lignin in water, methanol, ethanol, acetone, 1,4-dioxane, and their binary solution, and examines their impact on lignin depolymerization. The distribution of depolymerization products was correlated with the chemical structure changes in various solvent. Among the solvents tested, water-acetone mixtures demonstrated exceptional solubility for alkali lignin (95.24%) and provide the highest yield of bio-oil and phenolic monomers. The enhanced solubility of guaiacol units in acetone, combined with the addition of water in the co-solvent system dramatically improved the solubility of alkali lignin. Moreover, formic acid donated hydrogen protons to facilitate lignin depolymerization and prevented the repolymerization of unstable intermediates. Optimal reaction conditions were achieved at 300 °C for 120 mins using a mixed solvent composed of water, acetone, and formic acid in a ratio of 5:5:1 ( v /v/v), corresponding to the highest yield of bio-oil with 81.45 wt%, the lowest yield of residue with 6.20 wt%, and a phenolic monomer content of 57.48%. Furthermore, this co-solvent system revealed satisfactory adaptability for converting various lignin into phenolic monomers.
研究领域:
化学工程
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生物质能
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2024
·
IF 2.7
Yucheng Zi,Dong Chen,Guochen Wang,Yuhong Ma,Wantai Yang
A simple strategy is proposed to offer styrene (St) copolymer with intrinsic and catalyst-free upcycling capability by incorporating α -methylstyrene (AMS) units into the copolymer poly(AMS -co- St) (PAS). Compared to polystyrene (PS), the PAS is more susceptible to depolymerizing into St and AMS monomers with higher yields at relatively lower temperature. The yield of liquid chemicals of PAS-4 (26.1 mol% AMS) is up to 93 wt% at 380°C, whereas that PS as control is 78 wt%. The reclaimed liquid chemicals of PAS-4 contain 58.4 wt% St and 37.7 wt% AMS, while the chemicals of PS contain 81.8 wt% St and 4.1 wt% AMS. The introduction of AMS units in PAS leads to a reduction in the liquid chemicals other than St and AMS monomers. The blends of PS and PAMS do not demonstrate the synergistic effect regarding facilitating the PS depolymerization. In addition, the properties of the new PASs prepared with the reclaimed monomers are comparable with those of the virgin PASs. This work proves the concept that recycling efficiency could be boosted by incorporating liable structural units into the copolymer chains and demonstrates a closed-loop of PS up-cycling.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Polymers
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2017
·Vol. 9
·期 3
·83
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IF 3.364
Shaofeng Liu,Jie Zhang,Weiwei Zuo,Wenjuan Zhang,Wen-Hua Sun,Hongqi Ye,Zhibo Li
The stoichiometric reactions of 8-(2,6-R1-4-R2-anilide)-5,6,7-trihydroquinoline (LH) with AlR3(R = Me or Et) afforded the aluminum complexesLAlR2(Al1–Al5,Al1: R1=iPr, R2= H, R = Me;Al2: R1= Me, R2= H, R = Me;Al3: R1= H, R2= H, R = Me;Al4: R1= Me, R2= Me, R = Me;Al5: R1= Me, R2= Me, R = Et) in high yields. All aluminum complexes were characterized by NMR spectroscopy and elemental analysis. The molecular structures of complexesAl4andAl5were determined by single-crystal X-ray diffractions and revealed a distorted tetrahedral geometry at aluminum. In the presence of BnOH, complexesAl1–Al5efficiently initiated the ring-opening homopolymerization ofε-caprolactone (ε-CL) andrac-lactide (rac-LA), respectively, in a living/controlled manner.Keywords:aluminum complexes;crystal structures;ring-opening polymerization;biodegradable polyesters
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
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IF 5.807
Ligang Luo,Jing Yang,Guodong Yao,Fangming Jin
Catalytic depolymerization of kraft lignin was successfully carried out in isopropanol/water mixture system over Rh/La 2 O 3 /CeO 2 -ZrO 2 catalyst at 373 °C for 2 h with Fe as reductant. The selectivity of in-situ H 2 was increasing from 67 wt% to 98 wt% by changing the proportion of isopropanol and water with metal Fe. A one-to-one correspondence was established between liquid products distribution and H 2 . It was an efficient method for predicting the composition of the liquid oil by H 2 selectivity detection or converting kraft lignin to desirable liquid products optionally, which administered to reduce the dependence on the specific catalysts. Other temperatures and catalysts were a viable option for the relationship.
研究领域:
化学工程
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生物质能
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DOI
PubMed
高影响因子
Sustainable Energy & Fuels
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2024
·Vol. 8
·期 19
·4496-4506
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IF 5
Jifang Zhang,Jinde Sun,Chengcheng Suo,Wei Li,Sha Luo,Bing Tian,Chunhui Ma,Shouxin Liu
The low efficiency of photogenerated charge transfer to generate reactive oxygen species is the main factor that limits the photocatalytic activity of ZnIn2S4 (ZIS)-based materials in lignin depolymerization. In this work, we prepared an efficient ZIS catalyst with a hexagonal crystal structure and three-dimensional flower-like micromorphology by a solvothermal method. The ZIS catalyst possessed abundant active sites and efficient light-harvesting ability. Sulfur vacancies (Sv) were introduced into the ZIS photocatalyst (ZIS-Sv) to enhance its electron-withdrawing ability and promote the separation and transfer of photogenerated charges. Using the ZIS-Sv photocatalyst, the conversion rate of Cα–Cβ bonds in the β-O-4 dimer reached 96.31% and the molar yields (selectivity) of phenol and acetophenone were 695.17 μmol g−1 h−1 (85.14%) and 610.66 μmol g−1 h−1 (74.73%), respectively (with a ZIS-Sv0.6 concentration of 1 mg ml−1, irradiation time of 6 h, ethanol content of 90%, pH of 5, and 2-phenoxyacetophenone concentration of 1 mg ml−1). The photocatalytic depolymerization of dioxane lignin by the ZIS-Sv photocatalyst reached an efficiency of 80.42%. Catalyst characterization results and mechanism studies indicated that Sv promoted effective electron adsorption to generate oxygen radicals ˙OH and ˙O2− through O2 single-electron reduction and H2O decomposition, respectively. Then, the oxygen radicals combined with C-centered radicals to form unstable intermediates, further breaking lignin linkages, which finally formed an efficient indirect oxidation process. It is expected that introducing Sv into ZIS materials is a useful strategy to obtain photocatalysts for Cα–Cβ cleavage to realize efficient photocatalytic lignin depolymerization.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2025
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IF 6.2
Dingkai Wang,Mingyu Cui,Wei Zhao,Jin Zhang,Meiling Liu,Shanglong Chen,Xutang Liu,Yanjun Li,Shangshang Ma,Xian-Yong Wei
Lignin, the most abundant renewable resource of aromatics in nature, is recognized as an alternative to fossil-based fuels and chemicals. In this study, a phosphomolybdic acid-ionic liquid (PMA-IL) [BSHMIM]H2PMo12O40 was synthesized and used as a catalyst for further oxidative depolymerization of extracted lignin to prepare valuable chemicals. Under optimized conditions, the conversion of lignin reached 61.33%, and the total yield of target products (vanillin, vanillic acid, and methyl vanillate) was 28.00 mg·g–1, where the selectivity of methyl vanillate reached 56.43%. The liquid products and residues obtained under the optimum conditions were analyzed, further confirming the advantages of PMA-IL compared with single PMA. In addition, this method also has an excellent catalytic effect for other types of lignin and presents a good substrate applicability. Finally, based on the research results of model compounds, the possible reaction pathway of the formation of vanillin, vanillic acid, and methyl vanillate was proposed.
研究领域:
化学工程
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可再生资源
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催化反应
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产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
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2023
·Vol. 13
·期 22
·6561-6569
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IF 5
Songlei Mo,Yong Guo,Xiaohui Liu,Yanqin Wang
The glycolysis of polyethylene terephthalate (PET) is considered as the most promising PET recycling strategy due to its mild reaction conditions and circularity. Herein, several metal-doped SBA-15 (M/SBA-15) as heterogeneous Lewis acid catalysts were investigated to screen the best catalyst and to understand the essence for their differences in PET glycolysis. It is found that the catalytic activity is positively correlated with the acid amount in different metal-doped SBA-15 and Ti/SBA-15 with different Ti loadings, with the exception of Nb/SBA-15. 4Ti/SBA-15 with abundant Lewis acid sites shows excellent PET glycolysis ability, with the yield of bis(2-hydroxyethyl) terephthalate (BHET) reaching 87.2% within 45 min at 190 °C (isolated yield 73%). While 4Nb/SBA-15 has a similar acid amount as that in 4Ti/SBA-15, but it has very low catalytic activity probably due to its strong oxygen affinity. Acetone–methanol-adsorption DRIFTS confirms its strong oxygen affinity, which would poison the acid sites by ethylene glycol (EG) and result in very low activity. This study demonstrates that PET glycolysis activity is really correlated with the amount of Lewis acid sites, but species with very strong oxygen affinity would lower its activity. Further diffuse reflection ultraviolet-visible (DR UV-vis) spectra analysis confirms that tetrahedral Ti4+ species in Ti/SBA-15 is the real active center. In addition, 4Ti/SBA-15 has good reusability and can be used in common real PET (dyed polyester fabric, PET bottles) glycolysis. These results indicate that increasing the amount of Lewis acid sites is a promising way to enhance PET glycolysis and 4Ti/SBA-15 with high activity and stability is a potential catalyst for industrial application.
研究领域:
材料科学
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催化化学
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环境科学
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产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
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2025
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IF 4.3
Jiao Li,Shuai Tang,Yonglai Lu,Zhao Wang,Liqun Zhang
Conventional chewing gum (CG) consisting of sweeteners and unbiodegradable chewing gum base (CGB) has caused severe pollution to the environment. To address this issue, this work designs and synthesizes a partially crosslinked biobased and biodegradable polyester elastomer to replace the high molecular weight rubber in traditional CG for elasticity, along with a biobased biodegradable polyester resin with a glass transition temperature ( T g ) of ≈38 °C to provide plasticity for CG. Subsequently, biobased biodegradable CG is prepared. Poly(1,3-propanediol/glycerol/sebacate/succinate) (PPGSeSu) elastomers with adjustable gel content and good elasticity are synthesized by adjusting the content of glycerol, and poly(2,3-butanediol/isosorbide/succinate) (PBIS) resins with a T g of 8–65 °C are prepared by tuning the molar ratio of isosorbide and 2,3-butanediol. As a result, fully biobased, biodegradable CG with similar performance to that of commercially available ones is achieved by using PPGSeSu-25%P (with 8.58% gel content) and PB 50 I 50 S ( T g = 38 °C). The biodegradation rate of the new CG is 75.52% after 97 d, and its chewing properties are comparable to those of commercially available CG according to the texture profile analysis results.
研究领域:
材料科学
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环境科学
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高分子化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
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2025
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IF 6.5
Jifang Zhang,Chengcheng Suo,Xinchi Hao,Xingyu Zhu,Yiheng Zhuang,Cunyuan Hu,Wei Li,Sha Luo,Bing Tian,Chunhui Ma,Shouxin Liu
The selective cleavage of lignin specific linkages for production of high-value chemicals remains a significant challenge due to inherent inertness and complex structure. In this study, we developed a Photo-Electro-Catalysis (PEC) strategy utilizing radicals, which achieved high catalytic efficiency for lignin depolymerization at room temperature (from 10 °C to 35 °C). A heterojunction material composed of 2D ZnIn 2 S 4 nanosheets and carbon nanoparticles was synthesized to facilitate efficient electron transfer and radical generation. The quantum yield (2.1858) exceeding 1 suggested a radical chain mechanism in the PEC process. Mechanistic studies revealed that oxygen radical combine with C-centered radicals to form a C β -OOH peroxide intermediate, leading to C C bond cleavage. Notably, chlorine radicals (•Cl) were introduced for the first time in lignin PEC depolymerization, initiating C β -H functionalization, cyclization and ring-opening reactions. This approach achieved 100 % C α -C β cleavage and over 90 % mass conversion of native G-units lignin. The highest product yields were 233.34 mg g −1 (benzaldehyde), 66.03 mg g −1 (acetophenone), and 54.98 mg g −1 (phenol) from the β-O-4 dimer. This study provides novel insights into radical mechanisms and catalytic strategies for lignin depolymerization into high-value chemicals.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Meixin Wang,Yawei Zhan,Jiayue Zhao,Zhiqiang Li
Bamboo and its mechanical processing residues have broad prospects for high value-added utilization. In this research, p-toluenesulfonic acid was used for the pretreatment of bamboo to investigate the effects of extraction and depolymerization of hemicellulose. The response and behavior of changes of cell-wall chemical components were investigated after different solvent concentration, time, and temperature pretreatment. Results indicated that the maximum extraction yield of hemicellulose was 95.16 % with 5 % p-toluenesulfonic acid at 140 °C for 30 min. The depolymerized components of hemicellulose in the filtrate were mainly xylose and xylooligosaccharide, with xylobiose accounting for 30.77 %. The extraction of xylose from the filtrate reached a maximum of 90.16 % with 5 % p-toluenesulfonic acid at 150 °C for 30 min pretreatment. This research provided a potential strategy for the industrial production of xylose and xylooligosaccharide from bamboo and for the future conversion and utilization.
研究领域:
生物质利用
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化学工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2023
·
IF 7.5
Xiaoyu Lin,Wenbin Ding,Gaojie Shi,Bochao Yan,Suping Zhang
Lignosulfonate (LS), as the most abundant technical lignin, is hard to depolymerize due to highly condensed structure. To overcome the limitation, in this work, NiMoO 4 /Al 2 O 3 catalyst with regulated acidity/hydrogenation activity was developed for highly efficient LS depolymerization . Results show that the performance of NiMoO 4 /Al 2 O 3 was improved by sulfur migration. Meanwhile Ni Mo alloy contributed to the good stability during LS depolymerization . The NiMoO 4 /Al 2 O 3 was favor for the intermediate compounds production by the cleavage of C O and C C bonds, which intermediate compounds were eventually hydrogenated to monomers by highly active MoS 2 . Also, NiMoO 4 /Al 2 O 3 and sulfonic groups play a synergistic role in the sulfur migration (only 39.1% bio-oil yield obtained by MoS 2 /Al 2 O 3 ). After reacting at 300 °C for 4 h, 81.7% of bio-oil yield with 95% desulfurization rate were obtained. Thus, it was demonstrated that an inexpensive catalyst was developed which can efficiently catalyze the depolymerization of lignosulfonate.
研究领域:
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2020
·
IF 7.539
Zhongzhi Yang,Junfeng Feng,Haowen Cheng,Yongxiang Liu,Jianchun Jiang
This work exploits a one-pot method for directional depolymerizing organosolv lignin into high added-value phenolic monomers with synergistic reaction system consisted of methanol-dimethoxymethane binary solvents and acid catalyst. The influence of solvent composition and reaction parameters such as different catalyst, binary solvents ratio, time, and temperature on the conversion of lignin and yield of products were investigated carefully, the optimum yield of liquid products and phenolic monomers were achieved at 67.39% and 27.67% at 200 °C kept for 60 min with low amount of acid catalyst. The plausible mechanism on the depolymerization of lignin was proposed in view of product distributions. Moreover, the combination of co-solvents and acidic catalyst was also suitable for converting different types of lignin into phenolic monomers, and the recyclability of joint reaction system was satisfactory. These results can provide promising prospects on developing an effective method for achieving high added-value phenolic compounds from lignin.
研究领域:
生物化学
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可再生资源利用
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）