Catalysts
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2023
·Vol. 13
·期 5
·878
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IF 3.9
Yue Huang,Renhao Si,Yi Wei
Lignin is a crucial raw material for the synthesis of phenol due to its high oxygen concentration; however, the selectivity of phenol in pyrolysis products is low. This study chose cerium oxide as the coupling agent for molten salts, and the reaction’s process conditions—including temperature and catalyst dosage—were examined. The influence of metal loading on the reaction and byproducts of catalytic pyrolysis was examined. The outcomes demonstrated that the best monophenol production was accomplished at 550 °C and an Fe loading of 15 wt.%, with 93.93 wt.% monophenols in the bio-oil. While methoxy was more easily broken and rearranged, producing more monophenols, the presence of the catalyst enhanced the oxidation of Cα-OH and the breaking of β-O-4 bonds, which is significant for the study of lignin pyrolysis.Keywords:molten carbonates;pyrolysis;deoxidation;monophenols;lignin
研究领域:
化学工程
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生物质能研究
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DOI
高影响因子
FUEL
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2023
·
IF 7.4
Ziyu Jia,Jun Hu,Ping Lu,Yahui Sun,Yunjun Wang
Herein, using Ru/C and H 2 WO 4 as the catalysts, native lignin in biomass was efficiently depolymerized into monophenols following the lignin-first strategy at mild conditions. Upon the co-presence of Ru/C and H 2 WO 4 , birch lignin afforded monophenols in 40.4 wt% yield at 200 °C, which was 2.5 times that upon Ru/C and 7.5 times that upon H 2 WO 4 . 4-Propylsyringol and 4-propylguaiacol were two major products with a combined selectivity of 73%. 2D HSQC NMR of liquid product reveals that β-O-4 bonds in the soluble lignin fragments had been thoroughly disrupted. H 2 WO 4 dissolving at high temperatures promoted the solvolysis of lignin from the biomass matrix, and Ru/C enhanced the following reductive depolymerization. The solid catalysts can be readily recovered for reuse at room temperature after the hydrolysis of carbohydrates, and the catalysts exhibited high activity after four recycles.
研究领域:
生物化学
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催化化学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2015
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IF 4.642
Yong Liu,Lungang Chen,Tiejun Wang,Qi Zhang,Chenguang Wang,Jinyue Yan,Longlong Ma
Lignocellulosic biomass is a renewable feedstock that has the potential to replace the diminishing fossil fuels. Herein, we reported the simultaneous conversion of cellulose, hemicellulose and lignin from raw biomass into gasoline alkanes (hexanes and pentanes) and monophenols and related hydrocarbons over layered LiTaMoO6 and Ru/C in aqueous phosphoric acid medium. Specifically, gasoline alkanes were directly yielded from the carbohydrate components, based on hemicellulose and cellulose, and the total yield could be up to 82.4%. Notably, the lignin fraction could also be transformed into monophenols, related alcohols and hydrocarbons by the one-pot reaction. It suggested that the hydrocracking of monophenol fraction could be performed in this catalytic system. The total yield of volatile products was 53% based on the lignin fraction. In this paper, the influences of phosphoric acid concentration, substrate ash and the amino acids derived from the biogenic impurities were investigated and different raw biomass substrates were tested. Furthermore, the catalysts could be reused for several runs to convert raw biomass without pretreatment.
研究领域:
能源生物学
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催化化学
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2023
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IF 4.7
Ying Gao,Hongwei Ma,Yinan Rao,Kaiqi Lv,Fenghao Shu,Jinxing Long
Lignin is a promising renewable starting material for various value-added petrochemicals and high-quality fuels. However, current techniques for utilization of this natural aromatic biopolymer are challenging by the poor selectivity of desired products and the serious char formation. In this study, we provide a novel and efficient approach for selective hydrogenolysis of lignin using the cost-effective catalyst of Ni 3 Fe 1 nanoparticles supported on zirconium phosphates. 77.0 % of lignin is converted, yielding 19.6 % monophenols, whereas, the formation of biochar is insignificant (1.7 %) at the conditions of 260 °C for 5 h in a 2.0 MPa hydrogen. Importantly, 42.1 % of these obtained monophenols are identified to be a versatile bulk chemical of para ethyl phenol (yield of 8.2 %), because of the selective cleavage of the p -coumaryl units of the lignin. The results of catalyst characterization further reveal that the formation of Ni 3 Fe 1 nanoparticle facilitates the breakage of the specific structure of lignin and suppresses the phenolic oligomer's recondensation, which consequently enhance the lignin hydrogenolysis and char inhibition. These insights unveil that the production of bulk chemicals from sustainable resources is realizable through the rational design of catalytic processes, which substantially increase the economic feasibility of biomass biorefinery.
研究领域:
化学工程
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可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Shirong Sun,Erhu Li,Xuliang Lin,Xueqing Qiu
Efficient biomass fractionation is key to enhancing the productivity and profitability of biorefining but faces challenges such as strong carbon–carbon bonds in lignin and irreversible condensation reactions during extraction. In this study, hydroxyl-containing nucleophilic reagents are integrated into acidic deep eutectic solvents (DESs) for wheat straw pretreatment, achieving over 74.3 % lignin removal and 94.3 % cellulose retention. This method preserves more than 98.6 % of the β –O–4 linkages in lignin, and the nucleophilic reagents, introduced in-situ at the benzylic position of lignin, act as both a surfactant on cellulose and a stabilizer for isolated lignin. This dual functionality enhances enzymatic hydrolysis, resulting in 75.3 wt% glucose and 51.0 wt% xylose yields. Additionally, the pyrolysis yield of methoxy-deficient monophenols increases from 27.7 wt% to 38.6 wt%. This approach effectively addresses key challenges in biomass fractionation, improving carbon efficiency and facilitating the full valorization of lignocellulose.
研究领域:
生物化学
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生物质能
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yishuai Fu,Wenliang Wang,Hui Miao,Yangyi Cui,Yutong Chen,Ziwei Wang,Guowei Xiao,Bailiang Xue,Weikun Jiang
Obtaining key platform chemicals from lignin is a sustainable refining concept of the non-petroleum route. Rapid pyrolysis is a potential refining technology, and microwave-assisted catalytic depolymerization with low energy consumption is preferred. Herein, we reported the strategy of microwave-initiated depolymerization using a self-designed dynamic vapor flow reaction system with a facilely prepared CMF@Co-MoS 2 -0.18 catalyst, achieving efficient conversion of lignin (Dealkalize) to monophenol. Under constant microwave irradiation (2.45 GHz), the CMF@Co-MoS 2 -0.18 catalyst had excellent dielectric properties (Dielectric loss factor: 0.56) and microwave heating properties (∼140 s rise to ∼ 600℃). Therefore, microwave-initiated depolymerization of lignin showed that the CMF@Co-MoS 2 -0.18 catalyst can improve the monophenol content (54.72 %) and phenol selectivity (35.84 %) under the synergistic effect of microwave absorptivity and catalysis. The reaction of the lignin model and kinetics analysis show that the CMF@Co-MoS 2 -0.18 catalyst increases the yield of monophenol by reducing depolymerization activation energy and selectively breaking the β -O-4 bond. The finite element analysis pointed out that under microwave irradiation, CMF@Co-MoS 2 -0.18 continuously conducted heat to lignin and the lignin vapor would have sufficient energy to collide with the catalyst active site at a high frequency, which led to an increase in the pre-exponential factor and initiated catalytic depolymerization lignin. In summary, we provide a potential pathway for the rapid conversion of lignin into key platform chemicals.
研究领域:
化学工程
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可再生资源利用
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DOI
高影响因子
Bioresource Technology Reports
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2023
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IF 0
Shaoqing Wang,Gaixiu Yang,Juntao Yang,Zhen Wan,Zhihe Li,Weiming Yi
In this paper, the ternary molten salt (Li 2 CO 3 -Na 2 CO 3 -K 2 CO 3 ) was introduced into the lignin pyrolysis process for the co-production of monophenols and value-added carbon materials. The effect of lignin/molten salt ratios (i.e., 3:1, 1:1, and 1:3) on lignin pyrolysis behaviour was investigated herein. The pyrolytic products were characterized by gas chromatography–mass spectrometry, ultimate analyses, scanning electron microscopy, nitrogen adsorption analyses, and Raman analyses. Results showed that molten salt media can promote the conversion of bulky phenolic oligomers into mono-phenols by enhancing the cracking and deoxygenation reactions. P-type phenols (49.76 %) were produced when the lignin/molten salt mass ratio was 1:3. The porosity and aromaticity of biochar were regulated in-situ using molten salt. The possible catalytic effect of molten salt on lignin pyrolysis was proposed. This study provides a case reference for lignin waste resource utilization.
研究领域:
生物质转化
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能源化工
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材料科学
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DOI
JOURNAL OF MEMBRANE SCIENCE
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2016
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IF 5.557
Hang Lyu,Yan Fang,Shuang Ren,Kaifei Chen,Gang Luo,Shicheng Zhang,Jianmin Chen
Through hydrothermal liquefaction (HTL), lignocellulosic biomass is directly hydrolyzed into small organics like monosaccharides, monophenols and acids, which can be used as valuable chemicals by further purification. This study aims at investigating the feasibility of simultaneous separation of monophenols from sugar and acids in model lignocellulosic hydrolysate solution through two-stage nanofiltration (NF) and reverse osmosis (RO) process. The effects of pressure, temperature and pH on the solute retentions and permeate flux were examined with an eight-solute sugar-monophenols-acids model solution. NF-RO (DK-SE) two-stage membrane process was performed to confirm the multistage separation performance of model hydrolysates under an optimal operation condition. Results showed that membranes with higher water permeability had better performance in separation of sugar from monophenols. The decrease in temperature promoted separation of both acetic acid and monophenols from sugar, while higher pressure and lower temperature favored separation of acetic acid from phenols . The pH should be kept at low values to maintain good monophenols simultaneous separation of from sugar and acids. The maximum separation factors of acetic acid over 2,6-dimethoxyphenol and 2,6-dimethoxyphenol over glucose were 99.59 by RO membrane SE and 29.99 by NF membrane DK, respectively. Two-stage membrane process (DK NF+SE RO) was proven to be a feasible way to fractionate model HTL hydrolysates into three parts: incomplete hydrolyzed biomass fragments, monophenols riched concentrate, and acetic acid permeate.
研究领域:
生物工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Jiubing Zhang,Yuanyuan Ge,Zhili Li
Constructing an advanced catalytic system for the purposeful liquefaction of lignin into chemicals has presented a significant prospect for sustainable development. In this work, the catalytic process of mesoporous homologous biochar (HBC) derived from alkali lignin supported copper catalysts (Cu/HBC) was reported for catalytic liquefaction of alkali lignin to monophenols. The characterization results revealed HBC promoted the formation of metal-support strong interaction and the generation of oxygen vacancies , enhancing the acid sites of Cu/HBC. Under the optimal conditions (0.2 g alkali lignin, 280 °C, 0.05 g Cu/HBC, 6 h, 18 mL water), the monophenol yield reached 75.01 ± 0.76 mg/g, and the bio-oil yield was 57.98 ± 1.76%. The copious mesopores, high surface area, and rich acidic sites were responsible for the high activity of Cu/HBC, which significantly outperformed the controlled catalysts, such as HBC, commercial activated carbon (AC), and reported Ni/AC, Ni/MCM-41, etc. In four consecutive runs, the catalytic performance of Cu/HBC was only reduced by 3.65% per cycle. Interestingly, catechol was selectively produced with Cu/HBC, which provided an effective strategy for the conversion of G/S-type lignin to catechyl phenolics (C-type). These findings indicate that the Cu/HBC will be a promising substitution of noble metal-supported catalysts for conversion biomass into high value-added phenolics.
研究领域:
生物质能
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催化化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY
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2016
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IF 1.83
Zhijie Du,Wenzhi Li,Zhiping Xu,Hao Wu,Hasan Jameel,Hou-Min Chang,Long-Long Ma
Effects of a photocatalyst, C60-modified Bi2TiO4F2, on pine kraft lignin under visible light irradiation were investigated, along with those of Bi2TiO4F2 and C60/TiO2 as references. The influences of pH, C60 mass fraction, and the initial lignin concentration on lignin conversion and yields of mono-phenolic products were investigated. Seven products were determined by GC/MS, including phenol, 2-methoxyphenol, 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol, vanillin, acetovanillone, and homovanillic acid. The yields of products and lignin conversion were higher by C60/Bi2TiO4F2 than Bi2TiO4F2 and C60/TiO2. C60/Bi2TiO4F2 and C60/TiO2 were more stable than Bi2TiO4F2 upon repetitive recycling of catalyst. The effectiveness of C60/Bi2TiO4F2 declines 25%, whereas that of Bi2TiO4F2 declines 56.4% after being recycled five times. FTIR and HRTEM indicated that the deactivation of photocatalysts might be caused by lignin adsorbed on the surface of photocatalysts and the change in the crystal structure.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Xiaolin Luo,Zhenggang Gong,Guangxu Yang,Liulian Huang,Lihui Chen,Li Shuai
Practical, high-yield conversion of lignocellulosic biomass to bulk chemicals is the goal of a profitable biorefinery. However, the development of current biorefining industries is highly restricted by process complexity and processing cost. In this article, we developed a one-pot oxidative process and a one-pot reductive process that allowed selective conversion of lignocellulosic biomass (e.g. hardwood) to multiple bulk chemicals such as monophenolics, diols, and organic acids in total yields of up to 96.8 wt%. Alkali was used to catalyze the disruption of biomass components via retro -aldol reactions to small active intermediate molecules, which were in-situ oxidized or reduced to stable products. As a result, monophenolics, which were derived from lignin, reached an unprecedented yield of 59.3 wt% (71.9 mol%, on the basis of lignin content). Organic acids also reached an unprecedented yield of 111.7 wt% (77.8 C%, on the basis of polysaccharide content). The diverse chemicals could meet broad needs of our society. Cost analysis indicates that the current processes could be profitable in the petrochemical-dominated market.
研究领域:
化学工程
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可再生资源
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产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2023
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IF 5.9
Xiaohui Yang,Chengjun Tang,Lihong Hu,Yonghong Zhou,Minghao Zhou
The industrial production of monophenols was mainly dependent on fossil resources, due to growing energy demand and escalating environmental issues, more efficient and sustainable strategy, such as utilization of biomass as raw materials to economically produce monophenols, was desired, which could liberate us from the reliance on fossil resource and was of great industrial and social significance. Herein, a novel strategy was reported to produce biomass-derived monophenols from lignin by directly deconstructing C-O bond under mild conditions. A series of NiM-MOFs (M=Co, Mo, and Cu) derived bimetallic catalysts were synthesized via a simple hydrothermal method, which were characterized by XRD , SEM , TEM , XPS and NH 3 -TPD. The synergistic effect between the Ni and Mo greatly improved the catalytic activity and inhibited the transformation to by-products. In addition, we explored a new binary solvents system of MeOH-THF to effectively enhance the selectivity of monophenols. Under optimal catalytic conditions, Ni4Mo1/C-BN catalyst could break the C-O bonds in lignin dimer under 160 ℃ to afford phenol and benzoic acid , and the possible reaction pathway was proposed. The high yield of lignin oil from the oxidation of various realistic lignin also confirmed the superiority of this catalytic system. The lignin depolymerization products were characterized by element analysis, GPC and GC-MS, confirming the presence of mainly guaiacyl-type (G) products, while the highest yield was assigned to vanillin.
研究领域:
生物质化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）