Kyushu University Academic Staff Educational and Research Activities Database
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Shusaku Asano Last modified date:2021.04.28

Graduate School

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 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Ph. D. in Engineering
Country of degree conferring institution (Overseas)
Field of Specialization
Chemical Engineering, Chemical Reaction Engineering
ORCID(Open Researcher and Contributor ID)
Total Priod of education and research career in the foreign country
Research Interests
  • 1 Automated reactor system with dynamic and precise control
    2 Handling of solid materials, liquid catalysts, and particules in a reactor
    3 Chemical reaction engineering for organic synthesis and fine crystal synthesis
    keyword : Flow chemistry, Automated synthesis, Chemical Reaction Engineering, Dynamic Control
Academic Activities
1. Jing Xian Wang, Shusaku Asano, Shinji Kudo, Jun Ichiro Hayashi, Deep Delignification of Woody Biomass by Repeated Mild Alkaline Treatments with Pressurized O2, ACS Omega, 10.1021/acsomega.0c03953, 5, 45, 29168-29176, 2020.11, Delignification is essential in effective utilization of carbohydrates of lignocellulosic biomass. Characteristics of the delignification are important for the yield and property of the resulting carbohydrates. Oxidation with O2 of biomass in alkaline water can potentially produce high-purity cellulose at high yield. The present authors chose a Japanese cedar and investigated its oxidative delignification at 90 °C. The delignification selectivity was determined mainly by the chemical structures of lignin and cellulose. Treatment conditions, except for temperature, hardly changed the relationship between delignification rate and cellulose retention. During the treatment, dissolved lignin underwent chemical condensation in the aqueous phase. This "unfavorable"condensation consumed O2-derived active species, slowing down further delignification. Repeated short-time oxidation with renewal of alkaline water suppressed the condensation, enhancing the delignification. Repetition of 2-h treatments four times achieved 96% delignification, which was 8% higher than a single 8-h treatment at 130 °C..
2. Shusaku ASANO, Yu TAKAHASHI, Taisuke MAKI, Yosuke MURANAKA, Nikolay CHERKASOV, Kazuhiro MAE, Contactless mass transfer for intra-droplet extraction, Scientific Reports, 10.1038/s41598-020-64520-4, 10, 7685, 2020.05, This study demonstrates the possibility of “contactless” mass transfer between two aqueous slugs (droplets) separated by an oil slug in Taylor flow inside milli-channels. Separation of the alternating aqueous slugs at the outlet was performed by switching a couple of solenoid valves at branched outlets according to signals obtained by an optical sensor at the branch. Transfer of bromothymol blue (BTB) from acidic to basic aqueous slugs was performed for demonstration. In some cases, aqueous slugs separated by oil, merged catching on each other due to the velocity difference. Interfacial tension which was affected by the solute concentration was responsible for the velocity difference. Position-specific mass transfer activity at the rear end of the aqueous slugs was found on the course of the experiment. A meandering channel decreased the velocity difference and enhanced mass transfer. Almost complete (93%) transfer of BTB was achieved within a short residence time of several minutes under optimized conditions. The presented system opens a way for advanced separation using minimum amounts of the oil phase and allows concentrating the solute by altering relative lengths of the sender and receiver slugs..
3. Syusaku Asano, S. Yamada, T. Maki, Y. Muranaka, K. Mae, Design protocol of microjet mixers for achieving desirable mixing times with arbitrary flow rate ratios, Reaction Chemistry and Engineering, 10.1039/c7re00051k, 2, 6, 830-841, 2017.12.
4. Syusaku Asano, Taisuke Maki, Ryutaro Nakayama, Ryuji Utsunomiya, Yosuke Muranaka, Toshiharu Kuboyama, Kazuhiro Mae, Precise analysis and control of polymerization kinetics using a micro flow reactor, Chemical Engineering and Processing - Process Intensification, 10.1016/j.cep.2017.05.016, 119, 73-80, 2017.01.
5. Syusaku Asano, Taisuke Maki, Kazuhiro Mae, Evaluation of mixing profiles for a new micromixer design strategy, AIChE Journal, 10.1002/aic.15082, 62, 4, 1154-1161, 2016.04.
6. Shusaku Asano, Taisuke Maki, Victor Sebastian , Klavs F. Jensen, Kazuhiro Mae, Revealing the Formation Mechanism of Alloyed Pd–Ru Nanoparticles: A Conversion Measurement Approach Utilizing a Microflow Reactor, Langmuir, 10.1021/acs.langmuir.8b03516, 35, 6, 2236-2243, 2019.01, [URL], The synthesis of alloyed nanoparticles has been studied extensively; however, the formation mechanisms involved remain unclear. Here, we reveal the detailed formation mechanism of alloyed nano- particles in a Pd−Ru system, using a semibatch polyol method in which the simultaneous rapid reduction of both precursors was assumed to be the critical mechanism. We employed a microflow reactor to realize rapid heating and cooling. A significant difference in the reaction rate between the two precursors was observed. Pd was reduced within seconds, but the reduction of Ru was 2 orders of magnitude slower than that of Pd and was not as rapid as previously assumed. Further investigation of the semibatch method was performed to trace changes in the particle sizes and composition. Through quantitative and multilateral evidence, we concluded that the formation of low-crystallinity seeds, followed by solid-state diffusion, is the governing mechanism for the formation of alloyed Pd−Ru nanoparticles.
7. Shusaku Asano, Shota Yatabe, Taisuke Maki, Kazuhiro Mae, Numerical and Experimental Quantification of the Performance of Microreactors for Scaling-up Fast Chemical Reactions, Organic Process Research & Development, 10.1021/acs.oprd.8b00356, 23, 5, 807-817, 2019.05, [URL], Microreactors have been utilized for controlling fast chemical reactions. However, the scale-up strategy for fast reactions is not established enough due to the difficulty in quantifying the effect of the reactor size on the mixing performance, heat removal, and observable reaction rate. We present a chart for analyzing the effect of the mixing rate on the observable kinetic constant and a chart for estimating the temperature increase in the reactor. By using these charts, the validity of the rate analysis and the maximum reactor diameter, which control the reaction temperature, were determined. Commercial computational fluid dynamics (CFD) software was employed to solve the partial differential equations and to build the charts, and experiments were conducted to validate the results. We demonstrated the concept by using the ultrafast organolithium reaction in milliseconds. The product throughput was increased eight times with a reactor diameter that was twice as wide as the original reactor..
8. Asano Shusaku, Choi Cheolyong, Ishiyama Kentaro, Kudo Shinji, Gao Xiangpeng, Hayashi Jun-ichiro, Re-examination of Thermogravimetric Kinetic Analysis of Lignite Char Gasification, Energy & Fuels, 10.1021/acs.energyfuels.9b02946, 33, 11, 10913-10922, 2019.11, [URL].
1. ASANO Shusaku, INOUE Shogo, MAKI Taisuke, MAE Kazuhiro, Effect of mixing behaviors on fine particle synthesis in a flow microreactor, APCChE 2019 Congress, 2019.09.
Membership in Academic Society
  • The Society of Chemical Engineers, Japan
Educational Activities
Mentoring undergraduate and gratuate students