Article
Chemistry, Physical
Yuichiro Onishi, Shuji Adachi, Fumito Tani, Takashi Kobayashi
Summary: This study found that under high temperature and pressure conditions, various sugars can be isomerized or epimerized into rare sugars. The yields vary slightly between different sugars, with higher yields observed for rare disaccharides than rare monosaccharides, and higher yields for hexose compared to pentose. Additionally, the formation of organic acids during the process leads to a decrease in pH, and the isomerization and epimerization reactions hardly occur at pH levels lower than 6.3.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Chemistry, Multidisciplinary
Jing-Xian Wang, Jun-ichiro Hayashi, Shusaku Asano, Shinji Kudo
Summary: The study investigated the oxidation of pulverized Japanese cedar using O-2 in hot-compressed alkaline water, revealing that the cedar consisted of three kinetic components undergoing extraction in parallel following first-order kinetics. Further analysis uncovered that these components were mixtures of carbohydrates and lignin, with C1 and C2 being converted at different rates while maintaining steady product distributions, and C3 being the most refractory component mainly composed of glucan.
Article
Chemistry, Multidisciplinary
Masahide Sasaki, Kurumi Ohsawa
Summary: The study found that adding CO2 under hydrothermal and hydrolysis conditions significantly increased the yield of glucan degradation products, and the efficiency of degradation was higher when CO2 was present at a similar reaction rate. Additionally, increasing the fluid velocity of the hydrothermal reaction accelerated the solubilization rate, but did not affect the ultimate yield.
Article
Engineering, Chemical
Mian Hu, Xiaotong Huang, Letao Sun, Weicheng Zheng, I-Ming Chou, Libo Wu, Jinling Wan, Zhiyan Pan, Junliang Wang
Summary: The catalytic oxidation of o-chloroaniline (o-ClA) in hot compressed water was studied in a fused quartz tube reactor to determine the effects of catalyst, temperature, oxygen stoichiometric ratio (OSR), and reaction time on o-ClA mineralization and total nitrogen (TN) removal rate. The results showed that ammonia-N was the main nitrogen-containing intermediate product of o-ClA degradation, which could be oxidized to nitrate-N with excessive oxidant. The addition of Mn2O3 as a catalyst promoted the removal of ammonia-N, improved the degradation of ammonia-N, and inhibited the production of nitrate-N.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
Ying-Jie Xu, Yun-Fei Sun, Jing-Yi Yang, Zi-Bin Huang, Pei-Qing Yuan
Summary: In this study, the dealkylation-based visbreaking of heavy oil in a hot compressed water environment was investigated. It was found that the solubilization of water reduces the viscosity of heavy oil, leading to an increase in the reaction rate of dealkylation. The hydration reaction with solubilized water suppresses condensation and extends the reaction time window for dealkylation, resulting in higher yields and lower viscosity of the products.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Nutrition & Dietetics
Liang Feng, Yan Yang, Ya-ting Xie, Shuang-shuang Liu, Xuan Peng, Sheng Hu, Ai-nong Yu
Summary: The study investigated the degradation of L-ascorbic acid (ASA) and the generation of browning products (BPs) in hot-compressed water (HCW) by adjusting the reaction conditions. It was found that ASA degradation followed pseudo-first-order kinetics and the formation of BPs was closely related to the concentration of H3O+ in HCW. The acidic condition (pH=5.0) and lower concentration of ASA (0.03 mol/L) were found to be more favorable for ASA degradation.
FRONTIERS IN NUTRITION
(2023)
Article
Chemistry, Multidisciplinary
Qianli Wang, Shinji Kudo, Shusaku Asano, Jun-ichiro Hayashi
Summary: This study investigates the method and properties of converting rice husk into high-strength material through hot-compressed water treatment. The research finds that the plates of hot-compressed water-treated rice husk have higher tensile and flexural strengths, as well as lower water absorptivity and swellability, compared to the original rice husk. These improvements are mainly attributed to improved pulverizability, the occurrence of fibrous reinforcement material, and optimized fractions of cellulose, silica, hemicellulose, and lignin.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Applied
Liang Feng, Yan Yang, Shuang-shuang Liu, Ding-yun Tan, Chun Tan, Ai-nong Yu
Summary: The formation of volatile products (VPs) from the self-degradation of L-ascorbic acid (ASA) in hot compressed water (HCW) was investigated through varying reaction parameters, with initial pH of the solution being the most significant factor. Different pH conditions led to different types of products, showing that pH played a dominant role in the yields and distribution of VPs in HCW. The experimental results proposed a possible formation mechanism for VPs from the self-degradation of ASA in HCW.
Review
Chemistry, Multidisciplinary
Si Woo Lee
Summary: Catalysis is enhanced by electron transfer between catalyst surface and reaction intermediate. Charge transfer in metal-oxide systems is crucial for catalytic performance. This review focuses on the detection of hot electrons in catalytic reactions and the relationship between electron transfer and reactivity. Coupling a catalytic nanodiode with metal-oxide heterogeneous catalysts allows studying the dynamics of hot electrons on metal surfaces.
TRENDS IN CHEMISTRY
(2023)
Article
Agriculture, Multidisciplinary
Xiaomei Lyu, Ruijin Yang, Lu Wang, Jiali Gu, Wei Zhao, Mingming Wang, Kuan Rei Ng
Summary: By reshaping the binding domain, the mutant CsCE/Q371E showed enhanced isomerization activity and substrate affinity, making it a potential candidate for industrial lactulose production.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2022)
Article
Chemistry, Physical
Rui Liu, Zhiyuan Zhang, Longxiang Yan, Xinrui Yang, Yu Zhu, Peifeng Su, Huajie Song, Zhigang Wang
Summary: This study reports the roaming process of nitrobenzene influenced by hydrogen bonds between nitro- and phenyl radicals and water molecules. Notably, despite the influence of the hydrogen bonds on the barrier and reaction rates, the roaming reaction still occurs, providing a new approach to modulate the roaming reaction by introducing environmental molecules.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Tien Pham, Hoang T. Tue Trang
Summary: Theoretical study on the mechanisms and kinetics of the C4H6 system shows the major products and key reaction paths in different reactions. The calculated results are in excellent agreement with experimental data.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Agriculture, Multidisciplinary
Lu Wang, Jiali Gu, Yinghui Feng, Mingming Wang, Yanjun Tong, Yingjie Liu, Xiaomei Lyu, Ruijin Yang
Summary: This study aimed to optimize the catalytic performances of CEs by flexible loop exchange, resulting in mutants with improved isomerization activity and thermostability. Molecular dynamics simulations showed that loop exchange enlarged the entrance of the active site for substrate binding and benefited proton transfer. This work demonstrated the importance of the flexible loop surrounding the active site in determining the isomerization activity and thermostability of CEs.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2021)
Article
Energy & Fuels
Rashedul Hasan Khondakar, Yun Yu, Hongwei Wu
Summary: This study systematically investigated the fundamental reaction mechanism of GF hydrothermal decomposition for the first time, revealing that hydrolysis, isomerization, and retro-aldol condensation are the primary reactions during GF decomposition. Hydrolysis plays a key role in GF decomposition, while the resulting primary products further decompose into various secondary products.
Article
Chemistry, Applied
Mohd Sharizan Md Sarip, Noor Azian Morad, Mustafa Kamal Tun Abd Aziz, Norliza Saparin, Mohd Al Hafiz Mohd Nawi
Summary: This study utilized hot compressed water extraction (HCWE) for the extraction of crude palm oil (CPO). The quality of the extracted CPO was analyzed to evaluate possible product degradation. The results showed that the CPO extracted using HCWE had low FFA and low DAG, indicating higher quality. The fatty acid composition of the extracted CPO was similar to commercial CPO, suggesting no undesired reaction occurred during the extraction process. HCWE has the potential to replace screw press systems, but further economic analysis is needed to evaluate its prospects.
JOURNAL OF OLEO SCIENCE
(2023)
Article
Thermodynamics
Jingchun Huang, Zhenqi Wang, Yu Qiao, Bo Wang, Yun Yu, Minghou Xu
Summary: Temperature significantly affects the transformation of nitrogen during sludge hydrothermal carbonization, with different distributions of nitrogen in different products at different temperatures. The transformation pathways of protein-N and amino acid species are also influenced by temperature and the addition of CaAc and NaAc.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Jinxiu Cao, Sui Boon Liaw, Yu Long, Yun Yu, Hongwei Wu
Summary: This study aims to understand the fundamental reaction mechanisms during fast pyrolysis of acid-impregnated cellulose, showing how different temperatures affect the formation of key compounds in the reaction intermediates and primary volatiles. The results indicate that acid impregnation reduces the onset reaction temperature of cellulose pyrolysis, leading to the production of different major products at varying temperatures. The study also suggests that condensation reactions play an important role during acid-catalysed cellulose pyrolysis, with char formation becoming the favored pathway at higher temperatures.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Review
Energy & Fuels
Jun Xu, Qichen He, Zhe Xiong, Yun Yu, Shu Zhang, Xun Hu, Long Jiang, Sheng Su, Song Hu, Yi Wang, Jun Xiang
Summary: Raman spectroscopy is a powerful tool for analyzing various samples, covering the entire thermochemical processing of coal, biomass, and wastes. It can be used for characterizing and diagnosing feedstock and products, providing important support for studying thermochemical processes.
Article
Green & Sustainable Science & Technology
Bing Song, Richen Lin, Chun Ho Lam, Hao Wu, To-Hung Tsui, Yun Yu
Summary: This paper provides an overview of the opportunities for biomass valorization through the combination of hydrothermal and biological techniques, reviews recent advances in treatment conditions and optimal performances, compares energy balance and economic feasibility of different integrated options, and concludes the challenges and perspectives for advancing complete biomass valorization using integrated hydrothermal and biological techniques.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Materials Science, Multidisciplinary
Geyi Wang, Huan Liu, Tongzhou Chen, Xiuju Zhang, Haiyan Li, Yun Yu, Hong Yao
Summary: The study quantified the corrosion resistance of coatings prepared by different technologies under high temperature conditions through thermal corrosion and ash adhesion tests. Results showed that TWAS coatings had poor corrosion resistance, while PTA and HVOF coatings performed well at higher temperatures. Furthermore, the study on HVOF-NiCr coatings revealed a linear enhancement in corrosion resistance with the increase of Cr content.
Article
Energy & Fuels
Rashedul Hasan Khondakar, Yun Yu, Hongwei Wu
Summary: This study systematically investigated the fundamental reaction mechanism of GF hydrothermal decomposition for the first time, revealing that hydrolysis, isomerization, and retro-aldol condensation are the primary reactions during GF decomposition. Hydrolysis plays a key role in GF decomposition, while the resulting primary products further decompose into various secondary products.
Article
Energy & Fuels
Jinxiu Cao, Yun Yu, Hongwei Wu
Summary: This study proposes a new method using tracers to determine the true yields of ejected aerosols and evaporated vapors in condensable volatiles produced from cellulose pyrolysis. The results show the key role of thermal ejection in the formation of condensable volatiles, significantly influencing the yield and composition of tar generated from cellulose pyrolysis.
Article
Energy & Fuels
Jingchun Huang, Chao Feng, Yun Yu, Di Xie, Zhenqi Wang, Wei Hu, Yu Qiao
Summary: Steam gasification of leftover rice involves pyrolysis, volatile reforming, and char gasification stages. Experiments conducted at temperatures ranging from 600 to 1000 degrees C show that raw leftover rice can be cracked into volatile products at 600 degrees C, generating high yields of tar and gas. The study also demonstrates that torrefied leftover rice generates lower gas yields at all pyrolysis temperatures. This research provides valuable data for designing suitable gasification reactors for food waste.
Article
Energy & Fuels
Erwei Leng, Yilin Guo, Yanshan Yin, Yun Yu, Xun Gong, Jingwei Chen, Yuan Xue, E. Jiaqiang
Summary: In this study, a combination of spectroscopic techniques was used to reveal the catalytic mechanism of KCl and CaCl2 on cellulose char evolution during slow pyrolysis, providing insights into the evolution of functional groups in pyrolysis char. The results of this research are significant for understanding biomass pyrolysis mechanism and industrial production of biochar.
Article
Thermodynamics
Samreen Hameed, Adhirath S. Wagh, Abhishek Sharma, Vishnu Pareek, Yun Yu, Jyeshtharaj B. Joshi
Summary: This study investigates the effect of salt on cellulose pyrolysis behavior using the chemical percolation devolatilization (CPD) model. The experimental results show that salt has a pronounced effect on the primary pyrolysis reactions of cellulose, accelerating its decomposition and favoring the formation of gases and char.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Review
Energy & Fuels
Md. Maksudur Rahman, Yun Yu, Hongwei Wu
Summary: This paper reviews the environmental concerns and waste management due to the increase in waste tyre globally and emphasizes the importance of pyrolysis as an attractive technical route for waste tyre valorization. The paper summarizes the pyrolysis reaction chemistry, discusses the key factors influencing the properties and distribution of pyrolysis products and impurity removal, and surveys the potential applications of pyrolysis products. It also covers the important role of impurities and their remediation strategies, the progress in process development and analysis, and identifies the remaining challenges and research gaps in the field of waste tyre pyrolysis.
Article
Energy & Fuels
Zhiliang Wu, Yun Yu, Hongwei Wu
Summary: This study investigates the reaction mechanisms of hydrothermal decomposition of glucose and fructose to understand the formation of 5-HMF. The results show that 5-HMF is not directly produced from glucose or fructose in water. However, in the presence of formic acid, dehydration to produce 5-HMF becomes a primary reaction. The selectivity of this reaction increases with reducing the initial pH.
Article
Materials Science, Multidisciplinary
Haiyan Li, Huan Liu, Mingwen Bai, Xiuju Zhang, Hetian Chi, Tongzhou Chen, Yun Yu, Hong Yao
Summary: The corrosion resistance of Ni40AA and Ni40AA-Mo coatings on 304SS substrate was evaluated in molten NaClNa2SO4-KCl-K2SO4 salts at 600 degrees C. Results showed that in the oxidizing-chloridizing environment, the addition of Mo significantly reduced the dissolved Cr in soluble corrosion products. Mo substituted Cr to react with molten salts, reducing the depletion of Cr and enhancing the accumulation of Cr-rich oxides. As a result, the corrosion resistance of Ni40AA was improved, with a reduction in corrosion weight gain by approximately 50% and thickness loss by 1/3.
Article
Energy & Fuels
Xiuju Zhang, Huan Liu, Tongzhou Chen, Haiyan Li, Zifeng Huang, Yun Yu, Hong Yao
Summary: Municipal solid waste incineration technology has rapidly developed for waste disposal and energy conversion. However, the high content of alkali salts, especially chlorides, in the waste causes severe high-temperature corrosion. High-velocity oxy-fuel spray (HVOF) coating shows promise in mitigating this issue, but the corrosion process involving flue gas and deposits is not well understood. This study investigates the in-service performance and coupling corrosion mechanism. The results provide insights into the corrosion mechanism induced by deposits and flue gas and clarify the resistance of HVOF-NiCr coating through staged characterization.
Article
Energy & Fuels
Ben He, Yun Yu, Xun Gong, Shuai Liu, Hong Tian, Erwei Leng
Summary: This study investigates the possible reaction mechanisms for the polymerization of levoglucosan to produce various anhydro-disaccharides and beta-D-glucose under H2SO4 catalysis using density functional theory calculation. Thermodynamic and kinetic analysis reveal that anhydro-disaccharides with beta linkages are most likely formed by direct polymerization of two levoglucosan molecules, while different anhydro-disaccharides with alpha linkages are formed by different reaction mechanisms. The addition of H2SO4 as a catalyst significantly reduces the activation energy for various reactions and promotes the production of anhydro-disaccharides and beta-D-glucose.