Article
Thermodynamics
Yuan Yao, Aidin Panahi, Martin Schiemann, Yiannis A. Levendis
Summary: This research focuses on the size and overall porosity of carbonaceous chars produced during the pyrolysis and combustion of biomass under high-heating rates and temperatures. The study found that the generated chars were highly porous with large cavities.
COMBUSTION AND FLAME
(2022)
Article
Engineering, Chemical
Dezhi Chen, Xinyu Ning, Wen Tang, Jun Xu, Kai Xu, Limo He, Hengda Han, Sheng Su, Long Jiang, Yi Wang, Song Hu, Jun Xiang
Summary: This study utilized micro-Raman spectroscopy to investigate the chemical structures of pyrolytic chars prepared from 32 kinds of Chinese coals, finding that the aromatization degree is the key distinguishable factor for chars prepared from coals of different ranks. A comprehensive coal property index was proposed to predict the chemical structure of pyrolytic char effectively.
Article
Crystallography
Yanshan Yin, Zihua Wu, Jianhang Tao, Caiwen Qi, Wei Zhang, Shan Cheng
Summary: This paper investigates the evolution of the chemical structure of coal char during pyrolysis. The results show that the degree of order and the content of graphite-like microcrystalline carbon in coal char vary with pyrolysis temperatures. The relative content of C=O and COOH in coal char decreases with increasing temperature, indicating an increase in the degree of order at higher temperatures.
Article
Thermodynamics
Changya Deng, Hongwei Wu
Summary: This paper investigates the char formation and inorganic transformation during rapid pyrolysis of various biomass model components. It is found that xylan and water-washed lignin produce char, while water-washed cellulose does not. Loading K2CO3 into the biomass components increases the char yield. The micromorphology analysis reveals that the formed char particles have a cenospheric structure and a rough surface with bubbles and pores.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
Jiangyong He, Chong Zou, Junxue Zhao, Jiale Xi, Yuan She, Mengmeng Ren, Yufen Xu
Summary: This study investigates the variability in in situ Raman spectroscopy for determining the chemical structure of chars. The study explores the rationality of Raman's original peak spectrum fitting method, the influence of objective lens magnification, particle size, and number of measurements on peak shape and characteristic parameters.
Article
Engineering, Environmental
Qingqi Zheng, Dequan Zhang, Peng Fu, Aixia Wang, Yongmei Sun, Zhiyu Li, Qingwen Fan
Summary: Understanding the role of volatile evolving, char structural evolution, and pyrolysis reaction pathway is crucial for effective utilization of lignin through a pyrolysis-based biorefinery approach. Fast pyrolysis of lignin at different temperatures revealed the release characteristics of volatile compounds and their connection with char structure evolution. The results showed that the release of simple substituted aryl compounds was promoted by the cleavage of beta-O-4 and alpha-O-4. The study also found that high temperatures contributed to the formation of aromatic monomers, and the aromaticity can be evaluated based on the atom ratio of H/C and the degree of ring condensation.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Song Qianshi, Wang Xiaohan, Li Haowen, Yang Zixin, Ye Yue, Huo Jiepeng
Summary: The study found that the self-developed char reactivity model accurately predicted the reaction rate of char samples under different gasification temperatures, providing a valuable reference for predicting char gasification reaction rate.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Energy & Fuels
Dikun Hong, Yajing Guo, Chunbo Wang, Riguang Wei
Summary: The interactions between NH3 and coal during co-pyrolysis were investigated using ReaxFF MD simulations. It was found that coal promotes the thermal decomposition of NH3 and NH3 influences the primary and secondary reactions in coal pyrolysis. The physicochemical properties of the char produced from coal/NH3 co-pyrolysis were also analyzed. Finally, the reactivity of the char for NO reduction was examined, showing that coal/NH3 co-pyrolysis char is more conducive to NO chemisorption and N-2 generation than coal pyrolysis char.
Article
Thermodynamics
Xujun Chen, Hongwei Wu
Summary: This study investigates the effect of phosphorus on the char structure and reactivity of biomass during fast pyrolysis. Experimental results show that the presence of phosphorus significantly increases char yield and C/H content, while decreasing O content. The form and content of phosphorus play an important role in the evolution of char structure and reactivity.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Chemistry, Applied
Shasha Liu, Yuhui Wang, Juan Wang, Jianbin Zhou, Xun Hu, Hongqi Sun, Muhammad Asif Akhtar, Hong Zhang, Yong Huang, Shu Zhang
Summary: The effects of char-supported Ni catalysts on the decomposition of lignin model compounds were studied at different preparation temperatures, showing that higher temperature char supports can enhance the activity of the metal catalyst, leading to efficient conversion of the substrate and increased product formation. The synergistic effect of char support and Ni on BPE decomposition was demonstrated, highlighting the potential of char-supported metals as effective catalysts for biomass conversion.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
Jianan Qi, Cuigang Fan, Songgeng Li
Summary: The impacts of temperature and oxygen concentration on char structure evolution during pyrolysis were revealed using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and BET characterization techniques. Char prepared under oxygen atmosphere showed higher reactivity compared to that under inert (N2) atmosphere, with the presence of oxygen reducing char graphitization at high temperatures. The presence of oxygen in pyrolysis improved pore volume and specific surface area, with a critical oxygen concentration observed at high pyrolysis temperatures.
Article
Chemistry, Applied
Lin Li, Shuai Tong, Lunbo Duan, Changsui Zhao, Zhipeng Shi
Summary: By comparing chars produced under different atmospheres, it was found that the pore structure and specific surface area of chars are significantly affected by the gasification environment, while the presence of chemical groups has a minor impact on the chars. The best gasification reactivities were obtained on the chars produced under 50%CO2/50%N2 and 50%H2O/50%N2 atmospheres, largely influenced by the porosity of the chars.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Analytical
T. B. Y. Chen, A. C. Y. Yuen, B. Lin, L. Liu, A. L. P. Lo, Q. N. Chan, J. Zhang, S. C. P. Cheung, G. H. Yeoh
Summary: This study proposes a methodology using molecular dynamics simulation to characterize the thermal degradation process of polymer composites, successfully predicting the chemical distribution and charring kinetics of three common engineering polymers. The results were validated against experimental data and demonstrated good agreement, showing the potential for enhancing the reliability of predictions related to toxic gas emissions, charring, and smoke particulates in fire modeling.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2021)
Article
Polymer Science
Hui Kun, Jiang Li, Kang Li, Ning Yan, Cheng Bian, Yiwen Guan, Yanjing Yang, Hongyan Li
Summary: The char layer acts as a crucial barrier that resists ablation by improving its mechanical properties and ability to resist erosion. Investigating the deposition characteristics of pyrolysis gases in the char layer is of great significance for establishing models related to the strength and ablation of polymer composites.
POLYMER DEGRADATION AND STABILITY
(2022)
Article
Energy & Fuels
Han Zhang, Ming Liu, Haiping Yang, Hao Jiang, Yingquan Chen, Shihong Zhang, Hanping Chen
Summary: This study investigates the mechanism of interaction among biomass constituents during the pyrolysis process by examining product distribution, bio-oil and bio-gas composition, organic functional groups, and the two-dimensional correlation infrared spectrum characteristic of char. The primary and secondary interactions influence the evolution of char, with the former aiding depolymerization and side chain breaking, and the latter stimulating cyclization and intramolecular dehydration of specific molecules.
Article
Energy & Fuels
Shitong Fang, Houfan Du, Tao Yan, Keyu Chen, Zhiyuan Li, Xiaoqing Ma, Zhihui Lai, Shengxi Zhou
Summary: This paper proposes a new type of nonlinear VIV energy harvester (ANVEH) that compensates for the decrease in peak energy output at low wind speeds by introducing an auxiliary structure. Theoretical and experimental results show that ANVEH performs better than traditional nonlinear VIV energy harvesters under various system parameter variations.
Article
Energy & Fuels
Wei Jiang, Shuo Zhang, Teng Wang, Yufei Zhang, Aimin Sha, Jingjing Xiao, Dongdong Yuan
Summary: A standardized method was developed to evaluate the availability of solar energy resources in road areas, which combined the Analytic Hierarchy Process (AHP) and the Geographic Information System (GIS). By analyzing critical factors and using a multi-indicator evaluation method, the method accurately evaluated the utilization of solar energy resources and guided the optimal location selection for road photovoltaic (PV) projects. The results provided guidance for the application of road PV projects and site selection for route corridors worldwide, promoting the integration of transportation and energy.
Article
Energy & Fuels
Chang Liu, Jacob A. Wrubel, Elliot Padgett, Guido Bender
Summary: The study investigates the effects of coating defects on the performance of the anode porous transport layer (PTL) in water electrolyzers. The results show that an increasing fraction of uncoated regions on the PTL leads to decreased cell performance, with continuous uncoated regions having a more severe impact compared to multiple thin uncoated strips.
Article
Energy & Fuels
Marcos Tostado-Veliz, Xiaolong Jin, Rohit Bhakar, Francisco Jurado
Summary: In this paper, a coordinated charging price mechanism for clusters of parking lots is proposed. The research shows that enabling vehicle-to-grid characteristics can bring significant economic benefits for users and the cluster coordinator, and vehicle-to-grid impacts noticeably on the risk-averse character of the uncertainty-aware strategies. The developed pricing mechanism can reduce the cost for users, avoiding to directly translate the energy cost to charging points.
Article
Energy & Fuels
Duan Kang
Summary: Building an energy superpower is a key strategy for China and a long-term goal for other countries. This study proposes an evaluation system and index for measuring energy superpower, and finds that China has significantly improved its ranking over the past 21 years, surpassing other countries.
Article
Energy & Fuels
Fucheng Deng, Yifei Wang, Xiaosen Li, Gang Li, Yi Wang, Bin Huang
Summary: This study investigated the synergistic blockage mechanism of sand and hydrate in gravel filling layer and the evolution of permeability in the layer. Experimental models and modified permeability models were established to analyze the effects of sand particles and hydrate formation on permeability. The study provided valuable insights for the safe and efficient exploitation of hydrate reservoirs.
Article
Energy & Fuels
Hao Wang, Xiwen Chen, Natan Vital, Edward Duffy, Abolfazl Razi
Summary: This study proposes a HVAC energy optimization model based on deep reinforcement learning algorithm. It achieves 37% energy savings and ensures thermal comfort for open office buildings. The model has a low complexity, uses a few controllable factors, and has a short training time with good generalizability.
Article
Energy & Fuels
Moyue Cong, Yongzhuo Gao, Weidong Wang, Long He, Xiwang Mao, Yi Long, Wei Dong
Summary: This study introduces a multi-strategy ultra-wideband energy harvesting device that achieves high power output without the need for external power input. By utilizing asymmetry, stagger array, magnetic coupling, and nonlinearity strategies, the device maintains a stable output voltage and high power density output at non-resonant frequencies. Temperature and humidity monitoring are performed using Bluetooth sensors to adaptively assess the device.
Article
Energy & Fuels
Tianshu Dong, Xiudong Duan, Yuanyuan Huang, Danji Huang, Yingdong Luo, Ziyu Liu, Xiaomeng Ai, Jiakun Fang, Chaolong Song
Summary: Electrochemical water splitting is crucial for hydrogen production, and improving the hydrogen separation rate from the electrode is essential for enhancing water electrolyzer performance. However, issues such as air bubble adhesion to the electrode plate hinder the process. Therefore, a methodology to investigate the two-phase flow within the electrolyzer is in high demand. This study proposes using a microfluidic system as a simulator for the electrolyzer and optimizing the two-phase flow by manipulating the micro-structure of the flow.
Article
Energy & Fuels
Shuo Han, Yifan Yuan, Mengjiao He, Ziwen Zhao, Beibei Xu, Diyi Chen, Jakub Jurasz
Summary: Giving full play to the flexibility of hydropower and integrating more variable renewable energy is of great significance for accelerating the transformation of China's power energy system. This study proposes a novel day-ahead scheduling model that considers the flexibility limited by irregular vibration zones (VZs) and the probability of flexibility shortage in a hydropower-variable renewable energy hybrid generation system. The model is applied to a real hydropower station and effectively improves the flexibility supply capacity of hydropower, especially during heavy load demand in flood season.
Article
Energy & Fuels
Zhen Wang, Kangqi Fan, Shizhong Zhao, Shuxin Wu, Xuan Zhang, Kangjia Zhai, Zhiqi Li, Hua He
Summary: This study developed a high-performance rotary energy harvester (AI-REH) inspired by archery, which efficiently accumulates and releases ultralow-frequency vibration energy. By utilizing a magnetic coupling strategy and an accumulator spring, the AI-REH achieves significantly accelerated rotor speeds and enhanced electric outputs.
Article
Energy & Fuels
Yi Yang, Qianyi Xing, Kang Wang, Caihong Li, Jianzhou Wang, Xiaojia Huang
Summary: In this study, a novel hybrid Quantile Regression (QR) model is proposed for Probabilistic Load Forecasting (PLF). The model integrates causal dilated convolution, residual connection, and Bidirectional Long Short-Term Memory (BiLSTM) for multi-scale feature extraction. In addition, a Combined Probabilistic Load Forecasting System (CPLFS) is proposed to overcome the inherent flaws of relying on a single model. Simulation results show that the hybrid QR outperforms traditional models and CPLFS exceeds the best benchmarks in terms of prediction accuracy and stability.
Article
Energy & Fuels
Wen-Jiang Zou, Young-Bae Kim, Seunghun Jung
Summary: This paper proposes a dynamic prediction model for capacity fade in vanadium redox flow batteries (VRFBs). The model accurately predicts changes in electrolyte volume and capacity fade, enhancing the competitiveness of VRFBs in energy storage applications.
Article
Energy & Fuels
Yuechao Ma, Shengtie Wang, Guangchen Liu, Guizhen Tian, Jianwei Zhang, Ruiming Liu
Summary: This paper focuses on the balance of state of charge (SOC) among multiple battery energy storage units (MBESUs) and bus voltage balance in an islanded bipolar DC microgrid. A SOC automatic balancing strategy is proposed considering the energy flow relationship and utilizing the adaptive virtual resistance algorithm. The simulation results demonstrate the effectiveness of the proposed strategy in achieving SOC balancing and decreasing bus voltage unbalance.
Article
Energy & Fuels
Raad Z. Homod, Basil Sh. Munahi, Hayder Ibrahim Mohammed, Musatafa Abbas Abbood Albadr, Aissa Abderrahmane, Jasim M. Mahdi, Mohamed Bechir Ben Hamida, Bilal Naji Alhasnawi, A. S. Albahri, Hussein Togun, Umar F. Alqsair, Zaher Mundher Yaseen
Summary: In this study, the control problem of the multiple-boiler system (MBS) is formulated as a dynamic Markov decision process and a deep clustering reinforcement learning approach is applied to obtain the optimal control policy. The proposed strategy, based on bang-bang action, shows superior response and achieves more than 32% energy saving compared to conventional fixed parameter controllers under dynamic indoor/outdoor actual conditions.