Details of the Researcher

PHOTO

Qingxin Zheng
Section
Graduate School of Engineering
Job title
Specially Appointed Associate Professor(Research)
Degree

  • Ｐｈ．Ｄ．（材料学）（山東大学）

Research History 6

  • 2025/04 - Present
    Tohoku University　Graduate School of Engineering, Research Center of Supercritical Fluid Technology　Associate Professor

  • 2020/08 - 2025/03
    Tohoku University　Graduate School of Engineering Research Center of Supercritical Fluid Technology　Assistant professor (specially appointed)

  • 2019/10 - 2020/07
    Tohoku University　Graduate School of Engineering Research Center of Supercritical Fluid Technology　Researcher

  • 2017/10 - 2019/09
    Nagoya University　Graduate School of Engineering Materials Process Engineering　Researcher

  • 2013/04 - 2017/09
    National Institute of Advanced Industrial Science and Technology　AIST Postdoctoral Researcher

  • 2011/09 - 2013/03
    Kumamoto University　Faculty of Engineering Department of Applied Chemistry and Biochemistry　Researcher

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Education 2

  • Shandong University　National Key Laboratory for Crystal Materials　Materials science

    2006/09 - 2011/06

  • Shandong University of Technology　School of Material s Science and Engineering　Materials Chemistry

    2002/09 - 2006/06

Professional Memberships 4

  • The International Society for the Advancement of Supercritical Fluids (ISASF)

  • The Society of Chemical Engineers, Japan (SCEJ)

  • The Royal Society of Chemistry

  • Japan Institute of Energy

Research Interests 11

  • Catalyst

  • Hydrothermal treatment

  • Hydrothermal extraction

  • Micro-nano materials

  • Microalgae

  • Biomass conversion

  • Low-rank coal

  • Lithium-ion battery recycling

  • Dimethyl ether extraction

  • Hydrothermal synthesis

  • Supercritical fluids

Research Areas 4

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Catalytic processes and resource chemistry /

  • Nanotechnology/Materials / Structural and functional materials /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Chemical reaction and process system engineering /

  • Energy / Earth resource engineering, energy science /

Awards 2

  1. Outstanding Paper Award of 2021

    2022/09　The Society of Chemical Engineers, Japan (SCEJ)　Application of Hydrothermal Leaching Technology to Spent LIB Cathode Materials with Citric Acid Using Batch-type Device and Flow System

  2. Presentation award

    2015/10　The Japan Institute of Energy　Hydrothermal Oxidation and Decarboxylation of Brown Coal

Papers 38

  1. Evaluation of the Corrosion Behavior of Various Metallic Materials for Material Selection of Citric Acid Hydrothermal Leaching Apparatus for Lithium-Ion Battery Recycling Peer-reviewed

    Panpan Wu, Qingxin Zheng, Tian Meng, Xiangyu Zhong, Masaru Watanabe

    ACS Sustainable Chemistry & Engineering　2025/07/28

    DOI： 10.1021/acssuschemeng.5c03729 　

  2. Measurement of Solubility of Terephthalic Acid in Water Under Hydrothermal Conditions Peer-reviewed

    Yu Su, Qingxin Zheng, Yoshiki Suga, Masaru Watanabe

    The Journal of Supercritical Fluids　218　106497(1)-106497(9)　2025/04

    DOI： 10.1016/j.supflu.2024.106497 　

    ISSN： 0896-8446

  3. Simultaneous Material and Chemical Recycling of Waste PET/PE Multi‐Layer Films under Hydrothermal Conditions International-journal Peer-reviewed

    Qingxin Zheng, Yoshiki Suga, Yu Su, Hiroya Yamaguchi, Masaru Watanabe

    Angewandte Chemie International Edition　136　(44)　e202410888-e202410888　2024/07/31

    Publisher: Wiley

    DOI： 10.1002/anie.202410888 　 10.1002/ange.202410888 　

    ISSN： 1433-7851

    eISSN： 1521-3773

    More details Close

    Abstract Multi‐layer plastic films are widely used in various fields especially for packaging, but due to complex composition, it is very difficult to recover single‐material polymers or high‐purity monomers from them after usage. In this study, we proposed a hydrothermal process for recycling PET/PE (PET: Polyethylene terephthalate; PE: Polyethylene) films. PET can be hydrolyzed to monomers of terephthalic acid (TPA) and ethylene glycol (EG). Using a hydrothermal system equipped with two filters, PE, TPA, and EG were collected separately, indicating the simultaneous material and chemical recycling of PET/PE films was firstly achieved. At 300 °C and 10 MPa for 60 min, PET conversion reached around 100 %, and TPA yield of 83.0 % was obtained with a high TPA purity of 96.1 %. In addition, the effect of the holding time on PET conversion, TPA yield, EG yield, and TPA purity was studied. This research opened up a new and sustainable pathway to recycle multi‐layer plastic films in both lab and industry.

  4. Organic Acid‐Based Hydrothermal Leaching of LiFePO4 Cathode Materials Peer-reviewed

    Zixian Li, Qingxin Zheng, Akitoshi Nakajima, Zhengyang Zhang, Masaru Watanabe

    Advanced Sustainable Systems　8　(4)　2300421(1)-2300421(12)　2024

    Publisher: Wiley

    DOI： 10.1002/adsu.202300421 　

    ISSN： 2366-7486

    eISSN： 2366-7486

    More details Close

    Abstract This study conducts hydrothermal leaching of commercial LiFePO4 (LFPO) cathode materials with oxalic acid, citric acid, or glycine without any other oxidants or reductants. Of these acids, glycine exhibits the weakest leaching behavior, with the leaching efficiency of lithium (Li), iron (Fe), or phosphorus (P) less than 15% even at 200 °C and an acid concentration of 0.8 mol L−1 for 10 min. For oxalic acid, at 200 °C for 10 min, with a pulp density of 30 g L−1 and an acid concentration of 0.8 mol L−1, the leaching efficiencies for Li and P are 100% and 97%, respectively, and 98.5% of Fe precipitates as iron oxalate (FeC2O4) that can be used as a precursor for preparing LFPO cathode materials. Citric acid shows the highest leaching efficiency for Li, Fe, and P, reaching 96%, 100%, and 88%, respectively, at 90 °C for 10 min with a pulp density of 10 g L−1 and an acid concentration of 0.8 mol L−1. The continuous hydrothermal leaching of LFPO cathode materials with citric acid is first achieved. These results clarify the superiority of citric acid over oxalic acid and glycine with respect to the leaching efficiency for Li, Fe, and P from LFPO batteries under hydrothermal conditions.

  5. Excellent Performance of Glycine in Isolating Mn during Hydrothermal Leaching of LiMn2O4 Cathode Materials Peer-reviewed

    Qingxin Zheng, Seiya Hirama, Akitoshi Nakajima, Tetsufumi Ogawa, Yuta Nakayasu, Zixian Li, Masaru Watanabe

    ACS Sustainable Chemistry & Engineering　11　(35)　13033-13042　2023/09/04

    DOI： 10.1021/acssuschemeng.3c02854 　

  6. Understanding the reaction behavior of alanine under hydrothermal conditions through a network model Peer-reviewed

    Qingxin Zheng, Keisuke Suzuki, Yuya Hiraga, Masaru Watanabe

    Chemical Engineering Journal　468　143588-143588　2023/07

    Publisher: Elsevier BV

    DOI： 10.1016/j.cej.2023.143588 　

    ISSN： 1385-8947

  7. Production of Solid Fuels by Hydrothermal Treatment of Wastes of Biomass, Plastic, and Biomass/Plastic Mixtures: A Review Peer-reviewed

    Qingxin Zheng, Zixian Li, Masaru Watanabe

    Journal of Bioresources and Bioproducts　7　(4)　221-244　2022/10

    Publisher: Elsevier {BV}

    DOI： 10.1016/j.jobab.2022.09.004 　

    ISSN： 2369-9698

  8. Metal Recovery of LiCoO2/LiNiO2 Cathode Materials by Hydrothermal Leaching and Precipitation Separation Peer-reviewed

    Akitoshi Nakajima, Qingxin Zheng, Tetsufumi Ogawa, Seiya Hirama, Masaru Watanabe

    ACS Sustainable Chemistry & Engineering　10　(38)　12852-12863　2022/09/26

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acssuschemeng.2c04259 　

    ISSN： 2168-0485

    eISSN： 2168-0485

  9. Extraction of Calcium Phosphate Nanoparticles from Cooked Bone Wastes by Supercritical Water Peer-reviewed

    Huadong Zhang, Chengye Zhang, Qingxin Zheng, Xi Zeng

    Waste and Biomass Valorization　13　2287-2294　2022/04

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s12649-021-01667-9 　

    ISSN： 1877-2641

    eISSN： 1877-265X

  10. Bimetallic sulfide ZnMoS4-x/C nanocoral synthesized through glucose-assisted supercritical water system and its high performance for lithium-ion batteries Peer-reviewed

    Ji Zhuang, Mengqi Zhang, Bo Li, He Zhu, Xiangyan Zhao, Qingxin Zheng, Ni Xue, Lei Wang, Yang Liu, Xutang Tao

    Electrochimica Acta　411　140075-140075　2022/02

    Publisher: Elsevier {BV}

    DOI： 10.1016/j.electacta.2022.140075 　

    ISSN： 0013-4686

  11. Dimethyl carbonate (DMC) synthesis from methanol and carbon dioxide in the presence of ZrO2 solid solutions and yield improvement by applying a natural convection circulation system Peer-reviewed

    Qingxin Zheng, Ryo Nishimura, Yoshiyuki Sato, Hiroshi Inomata, Masaki Ota, Masaru Watanabe, Séverine Camy

    Chemical Engineering Journal　429　132378-132378　2022/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.cej.2021.132378 　

    ISSN： 1385-8947

  12. Advances in Low-temperature Extraction of Natural Resources Using Liquefied Dimethyl Ether

    Qingxin Zheng, Masato Watanabe

    Resources Chemicals and Materials　1　(1)　16-26　2022/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.recm.2022.01.001 　

    ISSN： 2772-4433

  13. Sulfonated carbon-catalyzed deamination of alanine under hydrothermal conditions Peer-reviewed

    Qingxin Zheng, Takuma Kato, Yuko Ito, Masayoshi Wagatsuma, Yuya Hiraga, Masaru Watanabe

    The Journal of Supercritical Fluids　175　105275-105275　2021/09

    Publisher: Elsevier {BV}

    DOI： 10.1016/j.supflu.2021.105275 　

    ISSN： 0896-8446

  14. Single-Step Recovery of Divalent Mn Component from LiMn2O4 Cathode Material at Hydrothermal Conditions as an Mn–Citrate Complex Peer-reviewed

    Qingxin Zheng, Kensuke Shibazaki, Tetsufumi Ogawa, Masaru Watanabe

    ACS Sustainable Chemistry & Engineering　9　(33)　10970-10976　2021/08/23

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/acssuschemeng.1c03459 　

    ISSN： 2168-0485

    eISSN： 2168-0485

  15. Application of Hydrothermal Leaching Technology to Spent LIB Cathode Materials with Citric Acid Using Batch-type Device and Flow System Peer-reviewed

    Qingxin Zheng, Kensuke Shibazaki, Tetsufumi Ogawa, Atsushi Kishita, Yuya Hiraga, Masaru Watanabe

    Journal of Chemical Engineering of Japan　54　(6)　344-350　2021/06/20

    Publisher: Society of Chemical Engineers, Japan

    DOI： 10.1252/jcej.20we182 　

    ISSN： 1881-1299

  16. Glycine-Assisted Hydrothermal Leaching of LiCoO2/LiNiO2 Cathode Materials with High Efficiency and Negligible Acid Corrosion Employing Batch and Continuous Flow System Peer-reviewed

    Qingxin Zheng, Kensuke Shibazaki, Seiya Hirama, Yuta Iwatate, Atsushi Kishita, Yuya Hiraga, Yuta Nakayasu, Masaru Watanabe

    ACS Sustainable Chemistry & Engineering　9　(8)　3246-3257　2021/03/01

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/acssuschemeng.0c08703 　

    ISSN： 2168-0485

    eISSN： 2168-0485

  17. Mechanism study on green high-efficiency hydrothermal activation of fly ash and its application prospect Peer-reviewed

    Lingjun Ma, Yu Feng, Man Zhang, Qingxin Zheng, Bing Wang, Lina Han, Yuping Li, Liping Chang, Weiren Bao, Jiancheng Wang

    Journal of Cleaner Production　275　122977-122977　2020/12

    Publisher: Elsevier BV

    DOI： 10.1016/j.jclepro.2020.122977 　

    ISSN： 0959-6526

  18. Hydrothermal leaching of ternary and binary lithium-ion battery cathode materials with citric acid and the kinetic study Peer-reviewed

    Qingxin Zheng, Masaru Watanabe, Yuta Iwatate, Daiki Azuma, Kensuke Shibazaki, Yuya Hiraga, Atsushi Kishita, Yuta Nakayasu

    The Journal of Supercritical Fluids　165　104990-104990　2020/11

    Publisher: Elsevier BV

    DOI： 10.1016/j.supflu.2020.104990 　

    ISSN： 0896-8446

  19. Behavior and Kinetics of Drying, Pyrolysis, Gasification, and Combustion Tested by a Microfluidized Bed Reaction Analyzer for the Staged-Gasification Process Peer-reviewed

    Xi Zeng, Jianling Zhang, Mohammed Haruna Adamu, Fang Wang, Zhennan Han, Qingxin Zheng, Lijuan Zhang, Guangwen Xu

    Energy & Fuels　34　(2)　2553-2565　2020/02/20

    Publisher: American Chemical Society ({ACS})

    DOI： 10.1021/acs.energyfuels.9b03707 　

  20. Room-temperature extraction of direct coal liquefaction residue by liquefied dimethyl ether

    Qingxin Zheng, Yelin Zhang, Wahyudiono, Thierry Fouque, Xi Zeng, Hideki Kanda, Motonobu Goto

    Fuel　262　116528-116528　2020/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2019.116528 　

    ISSN： 0016-2361

  21. Lipid extraction from microalgae covered with biomineralized cell walls using liquefied dimethyl ether Peer-reviewed

    Hideki Kanda, Rintaro Hoshino, Kazuya Murakami, Wahyudiono, Qingxin Zheng, Motonobu Goto

    Fuel　262　116590-116590　2020/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.fuel.2019.116590 　

    ISSN： 0016-2361

  22. Continuous hydrothermal leaching of LiCoO2 cathode materials by using citric acid Peer-reviewed

    Qingxin Zheng, Kensuke Shibazaki, Tetsufumi Ogawa, Atsushi Kishita, Yuya Hiraga, Yuta Nakayasu, Masaru Watanabe

    Reaction Chemistry & Engineering　5　(12)　2148-2154　2020

    Publisher: Royal Society of Chemistry ({RSC})

    DOI： 10.1039/D0RE00286K 　

    ISSN： 2058-9883

    eISSN： 2058-9883

  23. Resolution-enhanced Kendrick mass defect plots for the data processing of mass spectra from wood and coal hydrothermal extracts Peer-reviewed

    Qingxin Zheng, Masato Morimoto, Hiroaki Sato, Thierry Fouquet

    Fuel　235　944-953　2019/01

    Publisher: Elsevier {BV}

    DOI： 10.1016/j.fuel.2018.08.085 　

  24. Effect of hydrothermal conditions on production of coal organic microspheres Peer-reviewed

    Qingxin Zheng, Masato Morimoto, Thierry Fouquet, Hiroaki Sato, Toshimasa Takanohashi

    Fuel　234　1301-1312　2018/12

    DOI： 10.1016/j.fuel.2018.08.002 　

  25. Finding of coal organic microspheres during hydrothermal treatment of brown coal Peer-reviewed

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    Fuel　195　143-150　2017/05

    DOI： 10.1016/j.fuel.2017.01.066 　

  26. Production of carbonaceous microspheres from wood sawdust by a novel hydrothermal carbonization and extraction method Peer-reviewed

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    RSC Advances　7　(67)　42123-42128　2017

    Publisher: Royal Society of Chemistry ({RSC})

    DOI： 10.1039/C7RA07847A 　

  27. Influences of the Support Property and Pd Loading on Activity of Mesoporous Silica-Supported Pd Catalysts in Partial Hydrogenation of Palm Biodiesel Fuel

    Shih-Yuan Chen, Lalita Attanatho, Takehisa Mochizuki, Qingxin Zheng, Makoto Toba, Yuji Yoshimura, Phunthinee Somwongsa, Supranee Lao-Ubol

    Advanced Porous Materials　4　(3)　230-237　2016/12/01

    DOI： 10.1166/apm.2016.1116 　

    ISSN： 2327-3941

    eISSN： 2327-395X

  28. A novel process for the production of aromatic hydrocarbons from brown coal in water medium by hydrothermal oxidation and catalytic hydrothermal decarboxylation Peer-reviewed

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    Fuel　182　437-445　2016/10

    DOI： 10.1016/j.fuel.2016.06.002 　

  29. Property of extract prepared by hydrothermal extraction of brown coal

    Masato Morimoto, Qingxin Zheng, Toshimasa Takanohashi

    33rd Annual International Pittsburgh Coal Conference: Coal - Energy, Environment and Sustainable Development, PCC 2016　2016-　2016

    Publisher: International Pittsburgh Coal Conference

  30. Molecular composition of extracts obtained by hydrothermal extraction of brown coal Peer-reviewed

    Zheng, Qingxin, Morimoto, Masato, Sato, Hiroaki, Takanohashi, Toshimasa

    Fuel　159　751-758　2015/11

    DOI： 10.1016/j.fuel.2015.07.042 　

  31. An efficient production of benzene from benzoic acid in subcritical water using a copper(I) oxide catalyst Peer-reviewed

    Zheng, Qingxin, Morimoto, Masato, Takanohashi, Toshimasa

    Green Chemistry　17　(2)　791-794　2015

    DOI： 10.1039/c4gc01875c 　

  32. Hydrothermal synthesis of CuV2O6 supported on mesoporous SiO2 as SO3 decomposition catalysts for solar thermochemical hydrogen production Peer-reviewed

    Kawada, Takahiro, Yamashita, Hiroaki, Zheng, Qingxin, Machida, Masato

    International Journal of Hydrogen Energy　39　(35)　20646-20651　2014/12

    DOI： 10.1016/j.ijhydene.2014.06.162 　

  33. Polymorphism of BaTeMo2O9: A New Polar Polymorph and the Phase Transformation Peer-reviewed

    Zhang, Junjie, Zhang, Zhonghan, Zhang, Weiguo, Zheng, Qingxin, Sun, Youxuan, Zhang, Chengqian, Tao, Xutang

    Chemistry of Materials　23　(16)　3752-3761　2011/07

    DOI： 10.1021/cm2015143 　

  34. Novel BaTeMo2O9 fine particles synthesized via a supercritical water route Peer-reviewed

    Zheng, Qingxin, Li, Bo, Tao, Xutang

    Crystengcomm　13　(3)　750-752　2011

    DOI： 10.1039/c0ce00778a 　

  35. Preparation of FeIn2S4 nanoparticles in supercritical water Peer-reviewed

    Zhang, H.-D., Li, B., Zheng, Q.-X., Xi, H., Tao, X.-T.

    Rengong Jingti Xuebao/Journal of Synthetic Crystals　38　(6)　1299-1303　2009/12

    ISSN： 1000-985X

  36. Fabrication of YAG mono-dispersed particles with a novel combination method employing supercritical water process Peer-reviewed

    Zheng, Q. X., Li, B., Zhang, H. D., Zheng, J. J., Jiang, M. H., Tao, X. T.

    Journal of Supercritical Fluids　50　(1)　77-81　2009/08

    DOI： 10.1016/j.supflu.2009.04.002 　

  37. Synthesis of YVO4 and rare earth-doped YVO4 ultra-fine particles in supercritical water Peer-reviewed

    Zheng, Q. X., Li, B., Xue, M., Zhang, H. D., Zhan, Y. J., Pang, W. S., Tao, X. T., Jiang, M. H.

    Journal of Supercritical Fluids　46　(2)　123-128　2008/09

    DOI： 10.1016/j.supflu.2008.04.014 　

  38. Synthesis and characterization of monolithic Gd2O3 aerogels Peer-reviewed

    Zhang, H. D., Li, B., Zheng, Q. X., Jiang, M. H., Tao, X. T.

    Journal of Non-Crystalline Solids　354　(34)　4089-4093　2008/09

    DOI： 10.1016/j.jnoncrysol.2008.05.044 　

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Misc. 4

  1. Recycling of valuable monomer materials from plastic waste under hydrothermal conditions Invited Peer-reviewed

    Qingxin Zheng

    89　(4)　237-237　2025/04

  2. 水熱クエン酸浸出プロセスにおけるMn単離条件の探索 Invited Peer-reviewed

    渡邉賢, 鄭慶新, 小川哲史, 中島暉敏

    分離技術　52　(4)　194-200　2022/08

  3. No.1-27 Finding of Coal Organic Microspheres

    ZHENG Qingxin, MORIMOTO Masato, TAKANOHASHI Toshimasa

    Proceedings of Conference on Coal Science　53　(0)　54-55　2016

    Publisher: The Japan Institute of Energy

    DOI： 10.20550/jiesekitanronbun.53.0_54 　

    ISSN： 2423-8295

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    A series of organic microspheres (OM) were prepared from three brown coals directly using a simple treatment in water at 350°C and 20 MPa. The method can be applied to various coals with carbon yields above 20%, which would meet the requirement for industrial application. The diameters of OMs are ranging from 0.2-3.7 μm. The spherical morphology of OMs changes slightly with different resources, and some microcapsules have been found. OMs from coal are expected to be used as carriers and/or supporters. This methodology provides a novel low-cost resource with world-wide abundance and stable supply for OMs, opening up a novel avenue in the conversion of natural fossil fuel to advanced materials.

  4. No.33 Hydrothermal Oxidation and Decarboxylation of Brown Coal

    Zheng Qingxin, Morimoto Masato, Takanohashi Toshimasa

    Proceedings of Conference on Coal Science　52　(0)　66-67　2015

    Publisher: The Japan Institute of Energy

    DOI： 10.20550/jiesekitanronbun.52.0_66 　

    ISSN： 2423-8295

    More details Close

    A novel process composed of hydrothermal oxidation and hydrothermal decarboxylation was proposed and applied to liquefaction of brown coal. Coal is first oxidized under hydrothermal condition at ≤ 240℃ using oxygen with or without alkaline, and then the products of aromatic acids are decarboxylated using subcritical water (SbCW) at 350℃ with Cu_2O. The whole process is performed in water, which must be suitable for brown coal with high moisture content, and produces various light aromatics. This new and green "Cu_2O-SbCW" system showed a high efficiency for the decarboxylation of benzene/naphthalene carboxylic acids. Our proposed method is promising as an efficient brown coal liquefaction process without using hydrogen.

Books and Other Publications 1

  1. The technology of rare metal recovery and recycling from lithium-ion batteries

    2024/04

    ISBN: 9784860438852

Presentations 58

  1. Highly selective separation of lithium from spent LIB leachate using NF membrane and transport model analysis

    Xuesong Yao, Qingxin Zheng, Masaru Watanabe

    24th Summer School of Supercritical Fluid Division　2025/07/18

  2. Polymer and Monomer-Targeted Hydrothermal Recycling of Plastic Waste: A Progress Report Invited

    Qingxin Zheng

    24th Summer School of Supercritical Fluid Division　2025/07/19

  3. Recycling of LFPO Cathode Material using Hydrothermal Leaching with Citric Acid

    Zixian Li, Qingxin Zheng, Masaru Watanabe

    The 29th Annual Green Chemistry & Engineering Conference (GC&E 2025)　2025/06/24

  4. Corrosion Behavior of Citric Acid on Various Steel Materials During the Hydrothermal Leaching of Lithium-ion Battery Cathode materials

    Panpan Wu, Qingxin Zheng, Masaru Watanabe

    14th International Symposium on Supercritical Fluid-9th International Solvothermal and Hydrothermal Association (ISSF-ISHA 2025)　2025/06/18

  5. Hydrothermal Recycling of Polycarbonate Waste: From Batch-type Reactor to Continuous Flow System

    Qingxin Zheng, Rintaro Sato, Masaru Watanabe

    14th International Symposium on Supercritical Fluids-9th International Solvothermal and Hydrothermal Association Conference (ISSF-ISHA 2025)　2025/06/19

  6. Research Advances in the Application of Hydrothermal Leaching Technology for Lithium-Ion Battery Recycling Invited

    Masaru Watanabe, Qingxin Zheng

    13th International Conference on Supercritical Fluids (Supergreen 2024)　2024/12/01

  7. Simultaneous Material and Chemical Recycling of Waste PET/PE Multi-Layer Films under Hydrothermal Conditions

    Qingxin Zheng, Yoshiki Suga, Masaru Watanabe

    13th International Conference on Supercritical Fluids (Supergreen 2024)　2024/12/01

  8. Reaction Behavior Analysis of Polycarbonate Hydrolysis in the Different Type of Apparatus

    Rintaro Sato, Qingxin Zheng, Masaru Watanabe

    The SCEJ 55th Autumn Meeting　2024/09/13

  9. Re-synthesis of LMO from Leachate and Synthesis of Bio-Graphite from Cedar Sawdust for Environmentally Friendly LIBs

    Yuta Nakayasu, Preethi Perianayagam, Wu Panpan, Zheng Qingxin, Yoshiyuki Gambe, Itaru Honma, Masaru Watanabe

    The SCEJ 55th Autumn Meeting　2024/09/12

  10. QM simulations of precipitation mechanism of Mn(II)-citrate complex formed during citric acid hydrothermal leaching of LiMn2O4

    Tian Meng, Qingxin Zheng, Masaru Watanabe

    The SCEJ 55th Autumn Meeting　2024/09/11

  11. Metal Recovery of LFPO Cathode material Using Hydrothermal Leaching with Oxalic Acid

    Zixian Li, Masaru Watanabe, Qingxin Zheng

    10th International Conference on Engineering for Waste and Biomass Valorisation (WasteEng2024)　2024/08/22

  12. Mechanism and kinetic study of hydrothermal recycling of PET/PE multi-layer film using a semi-batch system

    Qingxin Zheng, Yoshiki Suga, Masaru Watanabe

    20th European Meeting on Supercritical Fluids　2024/05/27

  13. Recycling of LiFePO4 cathode material by hydrothermal leaching with glycine, oxalic acid or citric acid and precipitation isolation

    Zixian Li, Qingxin Zheng, Masaru Watanabe

    20th European Meeting on Supercritical Fluids　2024/05/29

  14. Chemical Recycling of Discarded Fishing Nets to Recover Polyamide 6 Monomers using Hydrothermal Method

    Yu Su, Qingxin Zheng, Masaru Watanabe

    SCEJ 89th Annual Meeting　2024/03/19

  15. Measurement of Terephthalic Acid (TPA) solubility under Hydrothermal Condition

    Yu Su, Qingxin Zheng, Masaru Watanabe

    SCEJ 89th Annual Meeting　2024/03/20

  16. Development of hydrothermal leaching technology for recycling of spent lithium-ion batteries Invited

    Qingxin Zheng, Masaru Watanabe

    SCEJ 89th Annual Meeting　2024/03/19

  17. Hydrothermal conversion of PET/PE mixed film by a semi-batch system

    Yoshiki Suga, Qingxin Zheng, Masaru Watanabe

    The SCEJ 54th Autumn Meeting　2023/09/11

  18. Hydrothermal leaching of LiFePO4 using organic acids

    Zixian Li, Qingxin Zheng, Masaru Watanabe

    The SCEJ 54th Autumn Meeting　2023/09/11

  19. Study of hydrothermal degradation behavior of PET/PE mixed film by using a semi-batch system

    Yoshiki Suga, Qingxin Zheng, Masaru Watanabe

    Joint Meeting of the Tohoku Area Chemistry Societies　2023/09/08

  20. Measurement of Terephthalic Acid (TPA) Solubility under Hydrothermal Condition

    Yu Su, Qingxin Zheng, Masaru Watanabe

    Joint Meeting of the Tohoku Area Chemistry Societies　2023/09/08

  21. Hydrothermal conversion of commercial and real waste polycarbonates

    Rintaro Sato, Qingxin Zheng, Masaru Watanabe

    Joint Meeting of the Tohoku Area Chemistry Societies　2023/09/08

  22. Application of hydrothermal leaching process with organic acids on LiFePO4 cathode materials

    Zixian Li, Qingxin Zheng, Masaru Watanabe

    Joint Meeting of the Tohoku Area Chemistry Societies　2023/09/08

  23. Metal recovery of LiMn2O4-based spent lithium-ion battery cathode material using hydrothermal leaching with organic acids and precipitation separation

    Masaru Watanabe, Qingxin Zheng, Akitoshi Nakajima

    19th European Meeting on Supercritical fluids　2023/05/23

  24. Simultaneous material and chemical recycling of PET/PE multi-layer film using a semi-batch hydrothermal system

    Qingxin Zheng, Yoshiki Suga, Hiroya Yamaguchi, Masaru Watanabe

    19th European Meeting on Supercritical fluids　2023/05/23

  25. Application of Hydrothermal Leaching Technology to Spent LIB Cathode Materials with Citric Acid Using Batch-type Device and Flow System Invited

    Masaru Watanabe, Qingxin Zheng, Kensuke Shibazaki, Tetsufumi Ogawa, Atsushi Kishita, Yuya Hiraga

    SCEJ 53rd Autumn Meeting　2022/09/15

  26. Extruder system for direct mixing of melted polyethylene with high temperature high pressure water

    Hiroya Yamaguchi, Yoshiki Suga, Qingxin Zheng, Masaru Watanabe, Takuya Takahata, Keita Akimoto

    SCEJ 53rd Autumn Meeting　2022/09/14

  27. Metal recovery of the leachate obtained from commercial cathode materias by hydrothermal leaching

    Akitoshi Nakajima, Qingxin Zheng, Tetsufumi Ogawa, Yuta Nakayasu, Masaru Watanabe

    9th International Conference on Engineering for Waste and Biomass Valorisation (WasteEng2022)　2022/06

  28. Low/no-corrosion leaching of spent lithium-ion battery cathode materials by hydrothermal method using amino acid or mixed organic acids as the leachantl

    Qingxin Zheng, Tetsufumi Ogawa, Akitoshi Nakajima, Masaru Watanabe

    9th International Conference on Engineering for Waste and Biomass Valorisation (WasteEng2022)　2022/06/30

  29. Hydrothermal leaching of commercial and spent lithium-ion battery cathode materials with citric acid employing batch and continuous flow system Invited

    Qingxin Zheng, Kensuke Shibazaki, Seiya Hirama, Tetsufumi Ogawa, Akitoshi Nakajima, Yuya Hiraga, Atsushi Kishita, Masaru Watanabe

    The 18th European Meeting on Supercritical Fluids　2021/05/06

  30. Glycine-assisted hydrothermal leaching of LiCoO2 cathode materials with a continuous flow system

    Seiya Hirama, Qingxin Zheng, Atsushi Kishita, Yuya Hiraga, Yuta Nakayasu, Masaru Watanabe

    SCEJ 86th Annual Meeting　2021/03/21

  31. 試作プラントを用いた湿潤微細藻類からの油脂の液化ジメチルエーテル抽出

    神田英輝, Ansari Faiz Ahmad, 櫻木優冶, 鄭慶新, Wahyudiono・Rawat Ismail, 後藤元信, Bux Faizal

    2020/03/16

  32. Design of lipids extraction prpcess from microalgae by using liquefied DME

    Masaya, Sakuragi, Naomasa Yamamoto, Qingxin Zheng, Wahyudiono, Hideki Kanda, Motonobu Goto

    2019/11/07

  33. Lipid extraction from wet microalgae by liquefied dimethyl ether in pilot scale

    Qingxin Zheng, Hideki Kanda, Wahyudiono, Motonobu Goto

    18th Asian Pacific Confederation of Chemical Engineering Congress (APCChE 2019)　2019/09

  34. 液化ジメチルエーテルを用いた微細藻類からの油脂抽出プロセスの設計

    櫻木優冶, Wahyudiono, 鄭慶新, 神田 英輝, 後藤 元信

  35. 液化ジメチルエーテルを用いた微細藻類からの油脂抽出プロセスの設計

    櫻木優冶, 山本直将, Wahyudiono, 鄭慶新, 神田 英輝, 後藤 元信

  36. 下水処理水で屋外培養した微細藻類の回収と油脂抽出

    神田 英輝, 櫻木優冶, Wahyudiono, 鄭慶新, 後藤 元信, Ismail Rawa, Faizal Bux

  37. 液化ジメチルエーテルを用いる微細藻類からの油脂抽出プロセスの収支計算

    櫻木 優冶, 山本 直将, 鄭 慶新, Wahyudiono, 神田 英輝, 後藤 元信

    SCEJ 84th Annual Meeting　2019/03/13

  38. Lipid Recovery from Wet Desmodesmus sp for Biofuel Production by Liquefied Dimethyl ether

    Wahyudiono, Qingxin Zheng, Hideki Kanda, Motonobu Goto

    Indonesia Malaysia Research Consortium Seminar 2018

  39. Lipid profile in liquified dimethyl ether extraction from microalgae Chlorella vulgaris

    Naomasa Yamamoto, Qingxin Zheng, Wahyudiono, Hideki Kanda, Motonobu Goto

    The 7th Asia-Oceania Conference on Green and Sustainable Chemistry (AOC7-GSC)

  40. Lipid extraction from wet microalgae by liquefied dimethyl ether

    Qingxin Zheng, Wahyudiono, Motonobu Goto, Ismail Rawat, Faizal Bux, Hideki Kanda

    The 7th Asia-Oceania Conference on Green and Sustainable Chemistry　2018/11

  41. Effects of hydrothermal conditions on production of coal organic microspheres

    Qingxin Zheng, Masato Morimoto, Thierry Fouquet, Hiroaki Sato, Toshimasa Takanohashi

    The 14th Japan-China Symposium on Coal and C1 Chemistry　2018/09

  42. Low-temperature extraction of direct coal liquefaction residue by liquefied dimethyl ether

    Qingxin Zheng, Hideki Kanda, Motonobu Goto

    The 14th Japan-China Symposium on Coal and C1 Chemistry　2018/09

  43. Energy-saving lipid extraction from et microalgae by liquefied dimethy ether

    Hideki Kanda, Qingxin Zheng, Wahyudiono, Motonobu Goto

    Grand renewable exery 2018 international conference and exhibition

  44. Development of biofuel production process from wet microalgae by liquefied dimethylether

    Motonobu Goto, Naomasa Yamamoto, Qingxin Zheng, Masaki Honda, Wahyudiono, Hideki Kanda

    The 14th edition of the International Conference on Renewable Resources & Biorefineries

  45. Finding of coal organic microspheres Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 1st Australia-Japan Symposium on Carbon Resource Utilisation　2016/11

  46. Finding of coal organic microspheres

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 53rd Coal Science Conference　2016/10

  47. Lipid extraction from wet microalgae by liquefied dimethyl ether

    Qingxin Zheng, Hideki Kanda, Wahyudiono, Motonobu Goto

    The 14th Japan-China Symposium on Coal and C1 Chemistry　2016/09

  48. Hydrothermal oxidation and decarboxylation of brown coal

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 52nd Coal Science Conference　2015/10/28

  49. Hydrothermal treatment of brown coal for the production of liquid fuel and chemicals Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 3rd Joint Meeting of Strategic Japanese-Chinese Joint Research Program　2015/10/27

  50. Oxidation and decarboxylation of coal Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    2015 International Conference on Coal Science & Technology (ICCS&T)　2015/09/28

  51. Molecular composition of extract obtained by hydrothermal extraction of brown coal Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 13th China-Japan Symposium on Coal and C1 Chemistry　2015/09/01

  52. Hydrothermal oxidation and decarboxylation of brown coal Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 13th China-Japan Symposium on Coal and C1 Chemistry　2015/09/01

  53. Efficient production of benzene from benzoic acid in subcritical water with Cu2O

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    7th International Conference on Green and Sustainable Chemistry and 4th JACI/GSC Symposium　2015/07/08

  54. Catalyzed decarboxylation of aromatic acids in subcritical water and its practical application in coal industry

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohash

    1st AIST Energy & Environmental Forum　2015/06/25

  55. Hydrothermal extraction of brown coal Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 2nd Joint Meeting of Strategic Japanese-Chinese Joint Research Program　2014/09

  56. Detailed analysis of extract obtained from Loy-yang coal by hydrothermal method Invited

    Qingxin Zheng, Masato Morimoto, Toshimasa Takanohashi

    The 12th Japan-China Symposium on Coal and C1 Chemistry　2013/10

  57. Synthesis and size control of YAG fine particle in supercritical water system

    Qingxin Zheng, Bo Li, Xutang Tao

    8th National Symposium on Supercritical Fluids and Their Applications　2010/09

  58. YAG ultra-fine particles synthesized by a modified supercritical water process

    Qingxin Zheng, Bo Li, Xutang Tao, Minhua Jiang

    The 16th International Conference on Crystal Growth (IDDG-16)　2010/08

Show all Show first 5

Industrial Property Rights 3

  1. A method to produce manganese citrate

    Masaru Watanabe, Qingxin Zheng, Hideki Miyazaki

    特許7565543

    Property Type: Patent

    Holder: Tohoku University; Keiwa Kogyo Co., Ltd

  2. The process for producing an aromatic compound

    Masato Morimoto, Qingxin Zheng, Toshimasa Takanohashi

    特許6433835

    Property Type: Patent

  3. A method to produce benzene and naphthalene

    Masato Morimoto, Qingxin Zheng, Toshimasa Takanohashi

    特許6433801

    Property Type: Patent

Research Projects 3

  1. Proposal of an intra-regional circulation system for LMO-based lithium-ion batteries

    Masaru Watanabe

    Offer Organization: Ministry of the Environment, Environmental Restoration and Conservation Agency (ERCA)

    System: Environment Research and Technology Development Fund (ERDF)

    Institution: Tohoku University

    2022/04 - 2024/03

  2. Low/no-corrosion leaching of spent lithium-ion battery cathode materials in hydrothermal water using amino acid or mixed organic acids as the leachant

    Qingxin Zheng

    Offer Organization: Japan Society for the Promotion of Science (JSPS)

    System: Grant-in-Aid for Scientific Research (C)

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2021/04 - 2024/03

  3. Development of environmentally-friendly hydrometallurgy technology for constructing the recycling process of ternary lithium-ion batteries

    Qingxin Zheng

    Offer Organization: Arai Foundation

    2022/04 - 2023/03