Article
Chemistry, Physical
Satoru Sakama, Merika Chanthanumataporn, Katsunori Hanamura
Summary: This study experimentally investigated the influence of electrochemical reactions on carbon deposition in solid oxide fuel cells using methane as fuel. The results showed that electrochemical reactions play an important role in suppressing carbon deposition by providing oxygen ions and increasing water concentration inside the anode. The amount of H2O supplied in fuel and the amount of oxygen ion produced by electrochemical reaction are the determining factors for carbon deposition.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Qingshan Li, Kunbin Kuang, Yuanna Sun, Yifeng Zheng, Qinglin Liu, Siew Hwa Chan, Hui Zhang, Weiguo Wang, Tingshuai Li, Junbo Wang
Summary: Deficient or non-linear hydrogen production is observed for the first time in large-scale steam electrolysis cells. Steam starvation affects the linearity of hydrogen production, with the Ni/NiO redox process playing a role in SOEC operations. The SOEC shows endurance to 10 hours of extreme polarization through electric conduction and oxygen vacancy transportation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Applied
Yikyeom Kim, Hyun Suk Lim, Minbeom Lee, Jae W. Lee
Summary: The study achieved complete methane conversion using abundant metal oxide particles by utilizing deposited surface carbon as a reaction intermediate. Incorporating Ni into the Fe-Al oxide overcame agglomeration and performance decline issues, while also improving CH4 activation and carbon gasification kinetics.
Article
Energy & Fuels
Shou-Han Zhou, Elwyn Omanga, Asif Nadeem Tabish, Weiwei Cai, Liyuan Fan
Summary: This study aims to find an appropriate kinetic model to describe the effect of current density on steam adsorption behavior in solid oxide fuel cells. The formation of catalyst-hydroxide complexes in the fuel cell is directly influenced by the steam concentration and the current drawn through non-faradaic electrochemical modification.
Article
Energy & Fuels
Dmitry Pashchenko
Summary: This work evaluates the diffusion limitation in the steam methane reforming process over spherical catalyst particles (Ni/α-Al2O3). A CFD model is used for numerical calculations that determine the intrinsic and actual reaction rates. The model is validated with experimental results. The effectiveness factor is used to express the diffusion limitation within the porous catalyst particle, and its relationship with operational parameters is established. The results show that the effectiveness factor depends on the catalyst particle diameter, temperature, and steam-to-methane ratio, with an inverse relation to particle size and direct relations to temperature and ratio.
Article
Energy & Fuels
Fatemeh Salahi, Fatemeh Zarei-Jelyani, Maryam Meshksar, Mohammad Farsi, Mohammad Reza Rahimpour
Summary: This study focuses on the application of Y-promoted Ni-based catalysts supported on bulk and hollow Al2O3 supports in the steam reforming of methane process. Various characterizing techniques were employed to analyze the catalysts. The 20Ni-3.0Y/HAl catalyst showed the highest methane conversion, hydrogen yield, and H2/CO molar ratio at 700 degrees C, possibly due to the larger surface area of the hollow alumina support compared to the bulk one.
Article
Thermodynamics
Dmitry Pashchenko, Ravil Mustafin, Igor Karpilov
Summary: Improving the energy efficiency of gas turbines is a crucial task for the global energy industry. This paper presents a thermodynamic analysis of a gas turbine unit with thermochemical exhaust heat recuperation, and the results show that it provides higher efficiency compared to steam injection systems.
Article
Chemistry, Applied
Shiwei Ma, Fang Cheng, Junguang Meng, Huijun Ge, Ping Lu, Tao Song
Summary: The feasibility of using Ni-enhanced red mud in chemical looping steam methane reforming (CL-SMR) was evaluated. It was found that the Ni-enhanced red mud displayed desirable reactivity and cyclic stability, with CO selectivity reaching 94.1% and H-2/CO ratio of 2.01 at the most suitable temperature of 900 C. The Ni species effectively activated the C-H bond of methane and facilitated the transfer of lattice oxygen.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Green & Sustainable Science & Technology
A. O. Oni, T. Giwa, C. Font-Palma, D. A. Fadare
Summary: This study compares the greenhouse gas emissions and economic feasibility of thermal decomposition of methane (TDM) technology and conventional steam methane reforming (SMR) technology for ammonia production. The results show that TDM has lower fuel consumption and emits less greenhouse gases than SMR. However, SMR has lower production costs and is more economically attractive. Integrating a carbon capture unit into TDM improves its economic performance when considering the sale of oxygen. SMR is more economically preferable without a carbon capture unit when the carbon price is below $99/t CO2, but above this price, integrating a carbon capture unit into TDM becomes economically preferable.
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2023)
Article
Chemistry, Inorganic & Nuclear
Cong Suo, Yang Liu, Xiao Zhang, Haiyan Wang, Bingbing Chen, Jiancong Fang, Zhenguo Zhang, Ruoyu Chen, Rui Chen, Chuan Shi
Summary: This study presents a method of preparing embedded Ni@PSi catalysts by adjusting the reduction temperature, which effectively prevents the sintering of Ni nanoparticles and maintains stability. The optimized reduction temperature of 600 degrees C results in a catalyst with high reaction rate and stability.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2022)
Article
Thermodynamics
Dmitry Pashchenko, Ivan Makarov
Summary: The experimental investigation focused on steam methane reforming process over an industrial Ni-based catalyst to understand the impact of carbon deposition on methane conversion and pressure drop. Results showed that methane conversion rates varied with different operating conditions, with the most significant decrease observed at a steam-to-methane ratio of 0.5.
Article
Chemistry, Multidisciplinary
Qi Song, Rui Ran, Xiaodong Wu, Zhichun Si, Duan Weng
Summary: Dry reforming of methane is an efficient way to utilize carbon dioxide. This study utilized mesoporous silica support SBA-15 and microporous silica support beta as catalyst supports, and obtained highly dispersed Ni nanoparticles on Ni-SBA-15 and Ni-beta catalysts prepared by ammonia evaporation method. The Ni-SBA-15 and Ni-beta catalysts showed excellent catalytic activity, with a CO2 conversion of ca. 89 % and a CH4 conversion of ca. 84 % at 700 degrees C and nearly 100 % conversions at 800 degrees C. The mesopores of SBA-15 provided confinement for Ni nanoparticles, preventing Ni sintering and carbon deposition. However, the smaller pore size of beta hindered the introduction of Ni into its micropores, leading to more intensive Ni sintering and carbon deposition.
JOURNAL OF CO2 UTILIZATION
(2023)
Article
Energy & Fuels
Azita Etminan, S. K. Sadrnezhaad
Summary: In this study, mesoporous monometallic and bimetallic catalysts were synthesized and characterized. The results showed that the bimetallic catalyst had higher conversion and lower carbon deposition in methane steam reforming. The study also suggested that highly dispersed active Ni species might play an important role in the catalyst activity and resistance to coking in the reaction.
Article
Chemistry, Physical
Liyuan Fan, Anatoli Mokhov, S. Ali Saadabadi, Nigel Brandon, Purushothaman Vellayani Aravind
Summary: This study experimentally investigated the influence of operation temperature, inlet gas composition, current density, and anode thickness on the methane steam reforming reaction over nickel yttria-stabilized zirconia anodes in solid oxide fuel cells. The results were analyzed using two kinetic models, with positive methane reaction order and negative impact of steam partial pressure on the reaction rate being observed. The evaluation of the models suggested that the Langmuir-Hinshelwood kinetic model performed better due to its additional parameters.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Applied
Dongxu Cui, Anna Sciazko, Yosuke Komatsu, Akiko Nakamura, Toru Hara, Shiliang Wu, Rui Xiao, Naoki Shikazono
Summary: In this study, two Ni/YSZ anodes with different volume ratios of Ni and YSZ were operated in dry methane under open circuit and polarized conditions. The reconstructed microstructures showed that the Ni surface near the active TPB did not have carbon deposition, while the remaining Ni surface away from the TPB exhibited severe carbon deposition. The results indicate a complex interplay between electrochemical steam generation and methane cracking on Ni surface.
JOURNAL OF ENERGY CHEMISTRY
(2023)
