Article
Chemistry, Multidisciplinary
Michael Zirbes, Tobias Grassl, Rieke Neuber, Siegfried R. R. Waldvogel
Summary: In this study, the oxidative depolymerization of Kraft lignin at 180℃ was demonstrated to produce vanillin with a yield of up to 6.2 wt% and 92% relative to the maximum yield from the quantification reaction using nitrobenzene. The use of peroxodicarbonate as a green oxidizer prevents the use of toxic and/or harmful reagents, and the resulting waste can be used as a makeup chemical in the pulping process. The oxidation and degradation of Kraft lignin were analyzed through UV/Vis and NMR spectroscopy.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Biochemistry & Molecular Biology
Xuewen Xu, Penghui Li, Yidan Zhong, Jiangdong Yu, Chen Miao, Guolin Tong
Summary: Vanillin plays a crucial role in food and flavoring as well as serves as a platform for synthesizing other valuable compounds. In light of the depletion of petroleum resources, the conversion of lignin into vanillin has emerged as an environmentally sustainable option. However, the production of vanillin from lignin still faces challenges. This paper provides a comprehensive review of four methods for preparing vanillin from lignin: alkaline (catalytic) oxidation, electrochemical (catalytic) oxidation, Fenton (catalytic) oxidation, and photo (catalytic) oxidative degradation of lignin. The working principles, influencing factors, vanillin yields, advantages and disadvantages, and future development trends of these methods are systematically summarized, and several methods for the separation and purification of lignin-based vanillin are briefly discussed.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Engineering, Environmental
Ruijin Li, Danlian Huang, Yashi Chen, Guangfu Wang, Zhen Wei, Wei Zhou, Ruihao Xiao
Summary: In this study, carboxylated multi-walled carbon nanotubes were utilized as the support to encapsulate MOFs, forming a multiphase catalytic system. The addition of carbon nanotubes improved the stability and thermal conductivity of the catalyst, leading to high conversion of VAL to VN. The catalyst showed good reusability with an efficiency of more than 85% after five cycles.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Kaili Zhang, Qinglei Meng, Haihong Wu, Jiang Yan, Xuelei Mei, Pengfei An, Lirong Zheng, Jing Zhang, Mingyuan He, Buxing Han
Summary: CeO2-supported Ru single-atom catalysts enable the hydrogenation of the benzene ring and catalyze etheric C-O(R) bond cleavage, leading to high yields of cyclohexanols.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Biochemistry & Molecular Biology
Ajinkya More, Thomas Elder, Zhihua Jiang
Summary: This study investigates the influence of oxygen on the oxidative conversion of lignin to aromatic aldehydes and acids, demonstrating that optimizing the duration of oxygen charging can significantly improve the yield. Factors such as reaction chemistry, time, temperature, and lignin feedstock were found to play a crucial role in determining the yield.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Energy & Fuels
Apisit Manassa, Phisit Seesuriyachan
Summary: The study shows that the concentrations of Fe-0, Fe2+, Fe3+, and H(2)O(2) have a significant impact on vanillin yield in heterogeneous Fenton oxidation, while reaction temperature and time have positive effects on the process. Under optimal conditions, the vanillin yield increased by 2.59-fold from lignin.
BIOMASS CONVERSION AND BIOREFINERY
(2021)
Article
Biochemistry & Molecular Biology
Dingliang Dai, Jianhao Qiu, Guanglu Xia, Lu Zhang, Hong Ma, Luan Yang, Jianfeng Yao
Summary: Flower-like BiOI decorated with CdS nanodots and iodine vacancies (VI) was used as a photocatalyst for the valorization of sodium lignosulfonate (SLS) under visible light. The introduction of iodine vacancies adjusted the band configuration, enhanced light absorption, and acted as electron traps. The intimate contact between BiOI and CdS nanodots facilitated charge transfer, significantly improving the photocatalytic performance. The CdS/BiOI-VI heterostructure exhibited the highest yield of vanillin, surpassing other photocatalysts and showing great potential for lignin valorization.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Biochemistry & Molecular Biology
Jie Xu, Ming Li, Jianhao Qiu, Xiong-Fei Zhang, Jianfeng Yao
Summary: The study successfully utilized the CdxZn1-xS photocatalyst to degrade alkaline lignin into vanillin, with each gram of lignin producing 46.5 mg of vanillin; Fine-tuned CdxZn1-xS can effectively cleave the C β-O-4 bond in PP-ol; Under simulated sunlight, the highest conversion rate of PP-ol reached 89.5%.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Chemistry, Multidisciplinary
Wenbo Peng, Hanxi Bao, Yigui Wang, Elizabeth Cote, William J. Sagues, Halena Hagelin-Weaver, Ji Gao, Dequan Xiao, Zhaohui Tong
Summary: This study demonstrates an effective route to selectively convert lignin into isolated phenolic acids using a low-cost graphene oxide-urea hydrogen peroxide catalyst under mild conditions. It opens a new way to selectively cleave lignin side chains to isolated biochemicals under mild conditions.
Article
Chemistry, Multidisciplinary
Jana Klein, Siegfried R. R. Waldvogel
Summary: A sustainable electrochemical pathway for the degradation and thermal treatment of technical lignosulfonate is proposed. This method allows for the production of significant quantities of low molecular weight compounds, including vanillin and acetovanillone. The electrochemical degradation is carried out using a simple two-electrode setup in aqueous media, which can be easily scaled up. The biopolymer is oxidized at the anode, while hydrogen is evolved at the cathode. Subsequent thermal treatment further degrades the robust chemical structure of lignosulfonates. Under optimized electrolytic conditions, vanillin can be obtained in a yield of 9.7 wt% relative to the dry mass of lignosulfonate used. By-products such as acetovanillone or vanillic acid are also observed but in lower yields. Overall, this study establishes a new and reliable one-pot, two-step degradation process for various technically relevant lignosulfonates, offering the advantage of using electrons as an oxidizing agent and resulting in minimal reagent waste.
Article
Chemistry, Physical
Valery E. Tarabanko, Dmitrii O. Vigul, Konstantin L. Kaygorodov, Yulia Chelbina, Elena Mazurova
Summary: This research found that catalytic oxidation of flax shives with molecular oxygen can produce vanillin and pulp, with minimum alkali consumption achieved at a mild stirring speed.
Review
Forestry
Ajinkya More, Thomas Elder, Zhihua Jiang
Summary: This review mainly discusses the main factors governing the oxidation of lignins into aromatic aldehydes and acids using hydrogen peroxide, and the impact of the stability of hydrogen peroxide under the reaction conditions on the product yield. The paper also highlights the different reaction patterns and product distributions of hydrogen peroxide under different pH conditions.
Article
Materials Science, Multidisciplinary
Archana Bansode, Lorena Alexandra Portilla Villarreal, Yuyang Wang, Osei Asafu-Adjaye, Brian K. Via, Ramsis Farag, Iris Beatriz Vega Erramuspe, Maria L. Auad
Summary: In this study, biobased novolacs phenol-formaldehyde (BNPF) resins were developed by partially replacing petroleum-derived phenol and formaldehyde with lignin derived from kraft biorefinery and modified kraft biorefinery-derived lignin, respectively. The lignin was chemically modified through the periodate oxidation process, and a series of BNPF resins were synthesized by replacing phenol and formaldehyde with lignin and oxidized lignin. The NPF resins exhibited the formation of methylene linkages in the phenolic rings. The bonding performance tests showed that BNPF resin adhesives have high adhesion strengths (>0.7 MPa). This research provides a promising perspective for utilizing natural polymers such as lignin for the synthesis of biobased wood adhesives.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Agriculture, Multidisciplinary
Takuya Hayashi, Takashi Hosoya, Hisashi Miyafuji
Summary: Alkaline nitrobenzene oxidation (AN oxidation) is an important method for analyzing lignin chemistry, but the detailed chemical reactions involved in this process are not fully understood. Specifically, the reaction pathways in the AN oxidation of a common model compound in lignin chemistry, guaiacyl glycerol-beta-guaiacyl ether (GG), have not been experimentally supported. This study investigates the formation pathway of vanillin in the AN oxidation of GG and proposes a vanillin formation pathway involving an enol ether intermediate called C2EE. The comparison of vanillin yields suggests that there are unknown pathways involved in vanillin formation from GG where C2EE is not an intermediate.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Chemistry, Applied
Ivana Maric, Yiming Guo, Maximilian J. L. J. Furst, Korneel Van Aelst, Sander Van den Bosch, Mario De Simone, Ligia O. Martins, Bert F. Sels, Marco W. Fraaije
Summary: This study successfully produced high-yield vanillin from 4-n-propylguaiacol in lignin oil using recombinant Escherichia coli cells. It provides an environmentally friendly, efficient, and sustainable route for vanillin production and demonstrates the robustness and applicability of the employed biocatalysts.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
