Article
Thermodynamics
In Seop Lim, Byeonghyun Kang, Jin Young Park, Min Soo Kim
Summary: This study aims to improve the performance of polymer electrolyte membrane fuel cells in low humidity conditions by modifying the gas diffusion layer with HfO2 deposition. Among the different deposition cycles of HfO2, Hf_25 showed the highest peak power due to better water management and lower resistances in both low and high humidity conditions compared to Hf_50, Hf_100, and Hf_200.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Chemistry, Physical
Minsoo Kang, Jaebong Sim, Kyoungdoug Min
Summary: The effects of surface and interior degradation of the gas diffusion layer (GDL) on the performance and durability of polymer electrolyte membrane fuel cells (PEMFCs) were investigated using three freeze-thaw accelerated stress tests. The results showed that surface degradation of GDL caused a decrease in capillary pressure, while interior degradation increased mass transport resistance, affecting the performance of the fuel cells.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Jaebong Sim, Minsoo Kang, Kyoungdoug Min
Summary: The design of the gas diffusion layer (GDL) plays a crucial role in the performance of polymer electrolyte membrane fuel cells (PEMFC), especially in terms of water discharge and capillary pressure gradient. By adjusting different element contents in GDL, the performance of PEMFC can be significantly affected, with differences observed under various conditions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Hyunsoo Chun, Do-Hyung Kim, Hyeon-Seung Jung, Jaebong Sim, Chanho Pak
Summary: The role of gas-diffusion layer (GDL) in high-temperature polymer electrolyte fuel cell (HT-PEMFC) is different from that in low-temperature PEMFC due to operating conditions and environment. This study analyzed the structural parameters and characteristics of four commercial GDLs in the HT-PEMFC cathode using various methods. It was found that the porosity of GDL, influenced by the crack region of the MPL, had a greater impact on gas transmission than its thickness. The correlation between HT-PEMFC cathode performance and GDL porosity and theoretical gas transmission properties was established.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Green & Sustainable Science & Technology
Jin Young Park, In Seop Lim, Eun Jung Choi, Yeong Ho Lee, Min Soo Kim
Summary: As fuel cell technology enters the commercialization stage, issues regarding activation time and fuel consumption become prominent with the increase in fuel cell capacity. A new method of reverse-flow activation has been proposed to reduce activation time and fuel consumption in polymer electrolyte membrane fuel cells, demonstrating significant improvement in experimental results compared to conventional methods.
Article
Chemistry, Physical
Donghwan Park, Seonghyeon Ham, Young-Jun Sohn, Yoon-Young Choi, Minjin Kim
Summary: Recently, metallic bipolar plates are being considered for large-capacity stationary fuel cells to reduce unit costs. The operating conditions for stationary fuel cells differ from those for vehicle applications, requiring a different plate shape. This study analyzed the mass transfer characteristics of fuel cells for stationary applications based on the geometry of the bipolar plate flow field and gas diffusion layer, using computational fluid dynamics modeling and experimental verification.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Jonghyun Son, Sukkee Um, Young-Beom Kim
Summary: This study used computational fluid dynamics to analyze the impact of directional permeability of the gas diffusion layer on PEMFC performance in models with three types of channels. Results showed that x direction permeability had the most influence on performance, particularly for the serpentine channel type.
Article
Chemistry, Physical
Eugen Hoppe, Holger Janssen, Martin Mueller, Werner Lehnert
Summary: The study investigated the impact of misalignment of flow field plates on fuel cell performance, revealing that misalignment can cause shear stress on MEA and GDL intrusion issues. Experimental findings showed that misalignment can result in changes in membrane shape and intrusion depth, but within a certain range, the performance impact is minimal.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Christoph Csoklich, Hong Xu, Federica Marone, Thomas J. Schmidt, Felix N. Buechi
Summary: By modifying GDLs with laser perforation, fuel cell performance can be enhanced and flooding can be avoided; Using XTM technology to understand water transport can guide future advanced pattern design; This approach can serve as a model system for next-generation GDLs, leading to a more rational design of transport layers.
ACS APPLIED ENERGY MATERIALS
(2021)
Article
Electrochemistry
Satoshi Yamaguchi, Satoru Kato, Akihiko Kato, Yoriko Matsuoka, Yasutaka Nagai, Takahisa Suzuki
Summary: Liquid water behavior in the microporous layer (MPL) of a polymer electrolyte fuel cell (PEFC) was investigated using time-resolved X-ray computed micro-tomography (CT) to elucidate the unsteady flow during flooding. Dynamic water transport from a hydrophobic MPL pore to the hydrophilic carbonaceous binder that bonds the substrate fibers was observed.
ELECTROCHEMISTRY COMMUNICATIONS
(2021)
Article
Chemistry, Physical
F. A. Aroge, B. S. Parimalam, J. A. MacDonald, F. P. Orfino, M. Dutta, E. Kjeang
Summary: Rapid X-ray radiographic imaging is proposed as a complement to 3D X-ray computed tomography for operando liquid water visualization in polymer electrolyte fuel cells. Breakthrough patterns and time-dependent characteristics of liquid water dynamics are revealed through a sequence of microscale radiographs and analysis framework. The proposed workflow combines rapid imaging at high resolution with minimal intrusiveness and exposure damage, extending the capabilities of X-ray imaging for future liquid water visualization efforts in fuel cells.
JOURNAL OF POWER SOURCES
(2023)
Article
Green & Sustainable Science & Technology
In Seop Lim, Yeong Ho Lee, Yoo Lee, Byeonghyun Kang, Jin Young Park, Min Soo Kim
Summary: In a polymer electrolyte membrane fuel cell (PEMFC), a non-uniform current distribution due to concentration changes along the flow direction poses a challenge for its development. A suggested in-plane design strategy of the gas diffusion layer (GDL) is used to overcome this barrier, improve performance, and address non-uniformity. The electrochemical experiments and optimization show higher power density and improved current distribution uniformity in the PEMFC using this in-plane design strategy.
Article
Thermodynamics
Jonghyun Son, Daye Lee, Sukkee Um, Young-Beom Kim
Summary: This study investigated the effect of different stacking pressures on PEMFC performance and concluded that stacking pressure should be determined based on channel type and operating voltage to improve performance.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Chemistry, Physical
Hassan Moydien, Pieter Levecque, Darija Susac
Summary: This study compares titanium fibre felts and conventional carbon gas diffusion layers as cathode GDLs for PEMFCs, and finds that titanium fibre felts exhibit improved performance and higher air permeability than carbon GDLs across different thicknesses.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Materials Science, Multidisciplinary
L. M. G. Silva, G. N. Leocadio, R. F. B. de Souza, J. C. Mierzwa, A. Duong, E. C. Venancio, A. O. Neto
Summary: In this study, the performance of the electrospray technique was utilized to obtain a gas diffusion layer (GDL) for a proton exchange membrane fuel cell. The PTFE layer impregnated into the backbone was characterized by infrared spectroscopy and thermogravimetric analysis. The use of the GDL prepared by electrospray was shown to increase the maximum power of the H-2/O-2 fuel cell by about 10% and decrease the diffusion loss of the electrode.
MATERIALS TODAY ADVANCES
(2021)
Article
Agriculture, Dairy & Animal Science
Jordan Si, Shelley Kirychuk, Yingjie Yang, Myra Martel, Brooke Thompson, Lifeng Zhang, Bernardo Predicala, Huiqing Guo
Summary: Methods to control microbial contamination in confined livestock facilities are important for the health of animals and workers, as well as for food safety. This study investigated the efficacy of engineered water nanostructures (EWNS) generated using an electrospray system in inactivating bacteria found in poultry facilities. The results suggest that EWNS could be a potential chemical-free alternative to conventional disinfection methods.
Article
Agricultural Engineering
Yingjie Yang, Shelley P. Kirychuk, Yuchen Si, Myra C. Martel, Huiqing Guo, Bernardo Z. Predicala, Lifeng Zhang
Summary: Animal buildings are a significant contributor to particulate matter pollution, but a laboratory-scale electrospray system has been developed to generate highly-charged nano sized water droplets called engineered water nanostructures (EWNS), which have shown effectiveness in reducing livestock particulate matter. The study found that negative voltages generated higher numbers of EWNS, and the water consumption of the developed electrospray was relatively low compared to other methods, achieving reduction efficiencies comparable to wet electrostatic scrubbers.
BIOSYSTEMS ENGINEERING
(2022)
Article
Chemistry, Applied
Arash Yahyazadeh, Venu Babu Borugadda, Ajay K. Dalai, Lifeng Zhang
Summary: In this study, a synthesis gas-based Fischer-Tropsch synthesis process was used to produce light olefins, such as ethylene, propylene, and butylene, using an iron catalyst supported on carbon nanotubes (CNTs). The synthesized catalyst showed better dispersion and higher catalytic activity compared to the commercial catalyst. The experimental results indicate that CNTs-supported iron catalysts have potential applications in the production of light olefins.
Article
Food Science & Technology
Jingsi Yang, Lifeng Zhang, Venkatesh Meda, Michael Nickerson
Summary: Triboelectrostatic separation (TES) has great potential in dry fractionation of food ingredients. However, optimizing TES efficiency is complex due to unclear understandings and unknown factors in the charging mechanism. In this study, experiments were conducted to investigate the chargeability of pulses particles using a vortex flow tribocharger made of three different materials. The goal was to shed light on the charging mechanism and expand the design and applications of TES technique.
FOOD RESEARCH INTERNATIONAL
(2022)
Article
Engineering, Chemical
Jingsi Yang, Venkatesh Meda, Lifeng Zhang, Michael Nickerson
Summary: The urgent need for sustainable sources of nutrients due to the worldwide pressure on food consumption has led to the development of the tribo-electrostatic separation (T-ES) technique. This technique, which charges particles through physical contact and separates them in an electric field, has shown promise in fractionation of protein and starch in various crops. However, challenges and gaps in the understanding of the charging mechanism and conflicting conclusions in published papers highlight the need for further research.
JOURNAL OF FOOD ENGINEERING
(2022)
Article
Chemistry, Physical
Arash Yahyazadeh, Venu Babu Borugadda, Ajay K. Dalai, Lifeng Zhang
Summary: The production of light olefins (C2-C4) from syngas through Fischer-Tropsch synthesis benefits from Fe-based catalysts supported on carbon nanotubes (CNTs). This study investigated the effects of synthesis conditions and the influence of Mo and K as promoters on the performance of the Fe/CNTs catalyst. The addition of Mo increased olefins' selectivity, while potassium improved CO conversion.
APPLIED CATALYSIS A-GENERAL
(2022)
Article
Engineering, Chemical
Chen Li, Carter Blocka, Lifeng Zhang
Summary: This study experimentally investigated the drying performance of pharmaceutical granules in a pulsation-assisted fluidized bed dryer. It was found that pulsed airflow is effective in enhancing the drying rate at higher superficial gas velocity. A lower pulsation frequency is more favorable to improve the drying rate. In addition, a pulsed fluidized bed dryer has shown a higher energy efficiency than a conventional one.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Engineering, Chemical
Sima Zeinali Danalou, Carter Blocka, Jingsi Yang, Ning Zhu, Heather N. N. Emady, Ellen Wasan, Lifeng Zhang
Summary: Monitoring the microstructure of wet granules is crucial for obtaining high-quality granules. This study used synchrotron x-ray imaging to investigate the real-time pore evolution during granule formation. It was found that granules from coarser and more homogenous powders had a higher rate of pore evolution and a more uniform pore distribution. The physical tests showed that granules with lower porosity and finer pores exhibited higher hardness and a slower dissolution rate.
Article
Engineering, Chemical
Arash Yahyazadeh, Philip Boahene, Tolu Emiola-Sadiq, Ajay K. Dalai, Lifeng Zhang
Summary: The kinetics of the Fischer-Tropsch (FT) reaction was studied on a KMo bimetallic promoted Fe catalyst supported on carbon nanotubes (CNTs). The mechanism of CO activation and the rate equation for CO consumption during FT reactions were investigated. Fresh and spent catalysts were characterized to evaluate the synergistic effects of Fe, Mo, and K phases on catalyst activity. The best fit kinetic model based on carbide formation approach was identified. The effects of reaction temperature and pressure on Fischer-Tropsch synthesis product distribution were assessed, and the kinetic model was compared with the Anderson-Schulz-Flory model.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Mojtaba Nabipoor Hassankiadeh, Jingsi Yang, Mark Berrey, Dave Jordison, Lifeng Zhang, Donald Bergstrom, Raymond J. Spiteri
Summary: Most existing models for predicting bubble size and bubble frequency have been developed for freely bubbling fluidized beds. In this study, the bubbling and fluidization behavior of potash particles in deep fluidized beds were investigated using a twin-plane electrical capacitance tomography (ECT) system. The results showed that the bubble diameter and rising velocity increased with increasing superficial gas velocity, with larger values observed in deeper beds. Good agreement was achieved between the predicted values from previous models and the experimental data for bubble diameter and rise velocity.
Article
Energy & Fuels
Tolu Emiola-Sadiq, Lifeng Zhang, Ajay Dalai, Regan Gerspacher, Bill Campbell, Richard Evitts
Summary: Gasification of soy hull pellets in a fluidized bed gasifier was investigated under different operating conditions to study the effect of various parameters on syngas quality. Statistical analysis and optimization techniques were used to determine the interaction between operating parameters and their impact on the quality of syngas. Results showed that temperature had the most significant effect on syngas quality, with higher temperatures favoring higher H-2:CO ratio and gas composition. The modified nature of the biomass allowed for high loading and increased gas yields. The achieved gas yields and carbon conversion were approximately 4 m(3)/kg and 90%, respectively, for different combinations of operating parameters.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Instruments & Instrumentation
Xiao Fan Ding, Sima Zeinali Danalou, Lifeng Zhang, Ning Zhu
Summary: Synchrotron radiation based dynamic micro-CT is a powerful technique for investigating evolving microstructures. Wet granulation is widely used in pharmaceutical granule production, and dynamic CT can provide insights into this process. The superior X-ray photon flux from synchrotron light sources allows for sub-second data acquisition and non-destructive imaging, enhancing image contrast. Dynamic CT can provide quantitative analysis of how the internal microstructure of a granule evolves during wet granulation.
JOURNAL OF SYNCHROTRON RADIATION
(2023)
Article
Pharmacology & Pharmacy
Carter Blocka, Mojtaba Nabipoor Hassankiadeh, Lifeng Zhang, Oon-Doo Baik
Summary: This study used a transient line heat source method to determine the thermal conductivity and volumetric specific heat capacity of common pharmaceutical components and binary mixtures. A regression model was evaluated and relationships were established between thermal properties and moisture content for pharmaceutical ingredients.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Engineering, Chemical
Mojtaba Nabipoor Hassankiadeh, Raymond J. Spiteri, Mark Berrey, Dave Jordison, Lifeng Zhang, Donald Bergstrom
Summary: Pulsed airflow was used to improve the fluidization behavior of wet potash particles in a fluidized bed by breaking agglomeration and eliminating channeling. The study investigated the effects of pulsation frequency, pulsed air to continuous flow ratio, and inlet relative humidity on bubbling behavior. The optimal condition was found to be a frequency of 1.0 Hz, an r of 0.33, and an opening time of 0.1 s, resulting in the lowest minimum fluidization velocity and generation of homogeneous bubbles. A new theoretical model considering liquid bridge force and resonant force was developed to predict the umf of wet particles in a fluidized bed, with good agreement between the predicted and experimental data.
Article
Energy & Fuels
Tolu Emiola-Sadiq, Lifeng Zhang, Ajay Dalai
Summary: The catalytic effects of alkali-based metal catalysts on biomass pellets were studied. Gasification experiments were conducted in a fluidized bed gasifier with the presence of alkali metal catalysts. The results showed that lower temperature and lower steam-to-biomass ratio led to increased tar yield, while the addition of catalyst significantly reduced tar residue. The results provide insight into the co-pelletization of catalysts during pellet production for improved gasification performance.
JOURNAL OF THE ENERGY INSTITUTE
(2023)
