Article
Thermodynamics
Agnieszka Korus, Adam Klimanek, Slawomir Sladek, Andrzej Szlek, Airy Tilland, Stephane Bertholin, Nils Erland L. Haugen
Summary: The process of petcoke conversion in chemical looping combustion technology requires detailed knowledge about the reactions with O-2, CO2, and H2O. Experimental results showed that the reaction with CO2 was slow, and kinetic parameters of petcoke gasification were determined by applying different models to the data obtained from a custom test rig.
Article
Energy & Fuels
Ashwani Kumar Dubey, Arunkumar Samanta, Pinaki Sarkar, Vinod Kumar Saxena
Summary: The study examined the effectiveness of CuO as an oxygen carrier in the chemical looping with oxygen uncoupling (CLOU) process using three Indian coals. It was found that the combustion reaction was most suitable at a mass ratio of 1:30 and 850 degrees C, with good repeatability over multiple cycles and minor agglomeration. Additionally, the kinetic analysis indicates that the combustion reaction kinetics is likely diffusion-dominated, with apparent activation energies in the range of 38.3-60.1 kJ/mol and 102.6-129.0 kJ/mol for different temperature zones.
Article
Energy & Fuels
Jingchun Yan, Tianxu Shen, Peng Wang, Xianglei Yin, Xiao Zhu, Shouxi Jiang, Laihong Shen
Summary: An innovative fluidized bed thermogravimetric analyzer was designed to study the performance of oxygen carriers in chemical looping combustion processes, revealing that high-grade manganese ore with less silicon content is more suitable for industrial CLC pilots.
Article
Energy & Fuels
Richard A. Newby, Dale L. Keairns, Robert W. Stevens
Summary: The objective of this study was to estimate the cost of commercial production of oxygen carriers (OCs) for large-scale application in the chemical looping combustion (CLC) power generation industry. Two production facility scenarios were considered, and two OC production techniques were addressed. The estimated OC product costs can be used to guide development and determine the maximum OC makeup rate for achieving a designated cost-of-electricity (COE) reduction goal.
Article
Energy & Fuels
Fenghua Shen, Shimin Qu, Junyuan Li, Zhenghua Yang, Chungang Zhou, Fei Yang, Ziqi He, Kaisong Xiang, Meiqing Shi, Hui Liu
Summary: This study proposes a chemical looping oxidation method using Fe2O3/Al2O3 composite as an oxygen carrier to remove sulfur from petroleum coke. The Fe2O3/Al2O3 oxygen carrier effectively oxidizes organic sulfur and achieves a removal efficiency of 63%. The used oxygen carrier can be conveniently separated and regenerated for another desulfurization cycle.
Article
Engineering, Environmental
Zhenwu Miao, Laihong Shen, Haibo Zhao
Summary: A study found that a single natural ore oxygen carrier (OC) is limited in its industrial application due to its weak reactivity and cyclic stability. Chemical looping combustion (CLC) cycle tests were conducted on a composite hematite and copper ore OC prepared by spray drying granulation using a fluidized bed thermogravimetric analyzer (FB-TGA). The results revealed a high attrition rate of OC in the early stage of fluidization, which stabilized after 6 minutes at 0.28%/h. The redox cycle reaction subjected the OC to chemical and thermal stresses, leading to decreased mechanical strength, increased particle attrition and sintering. This hindered the oxidation stage and resulted in deep reduction of OC, causing particle agglomeration and loss of fluidization. Therefore, reducing the oxygen transfer capacity and residence time in the fuel reactor is beneficial for the safe operation of OC in industry.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Giovanny S. de Oliveira, Ciro E. S. Lobo, Carlos E. A. Padilha, Domingos F. S. Souza, Juan A. C. Ruiz
Summary: Brazil aims to reduce its CO2 emissions by utilizing glycerin in Chemical Looping Combustion (CLC). The study evaluates the feasibility of using glycerin in CLC and finds that the addition of ethanol improves combustion efficiency, while the addition of methanol reduces efficiency.
Article
Energy & Fuels
Pietro Bartocci, Alberto Abad, Arturo Cabello Flores, Margarita de las Obras Loscertales
Summary: To address the scale-up challenges of Chemical Looping Processes, the development of efficient and affordable oxygen carriers is crucial. Ilmenite, an ore-derived oxygen carrier, has been identified as an abundant and low-cost option. This paper provides insights into its preparation, reactivity, and performance compared to other carriers, along with its thermodynamic properties and kinetics. The paper also explores its compatibility with various fuels (solid, liquid, gaseous, including biofuels) and discusses important considerations such as cost, environmental sustainability, oxygen transport capacity, as well as issues related to fluidized bed reactors, such as agglomeration and attrition behavior. Furthermore, the paper investigates the interaction between ilmenite and fuels, including the impact of impurities and coke deposition on the gasification rate of solid fuels.
Review
Energy & Fuels
Dunyu Liu, Chaoran Wang, Yunpei Fan, Qiuqi Liu, Xudong Wang, Kailong Xu, Jing Jin, Jingjing Ma, Jinchen Ma
Summary: Chemical looping combustion (CLC) of coal for carbon capture utilization and storage is an effective technology to reduce carbon emission. However, there is uncertainty in mercury emission from both air and fuel reactor. This paper aims to reveal the mechanisms for the transformation of mercury-related species.
Article
Thermodynamics
Haodong Huang, Jinchen Ma, Haibo Zhao, Chuguang Zheng
Summary: This work investigates the behavior of coal-derived chlorine in chemical looping combustion (CLC) and the potential adverse impacts of primary gaseous chlorine (HCl) on a Cu-based oxygen carrier (OC). The inactivation mechanism of the sol-gel-derived CuO/Al2O3 OC is studied. It is found that HCl is the main gaseous chlorine in coal CLC and shows high reactivity towards CuO. The presence of HCl can result in corrosion and degradation of the OC.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Chemistry, Physical
Guohui Gao, Yuhua Lai, Shuai Wang
Summary: This study conducts particle-scale simulation to investigate the performance of oxygen carriers in the chemical looping hydrogen generation process, taking into account the effect of coke deposition on pore structures. The results show that particle porosity and active component distribution have a significant impact on the performance of chemical looping hydrogen generation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Applied
Li Yang, Dan Zhu, Xin Wu, Chen Song, Caifu Li, Fang Liu, Zhengchang Song
Summary: Chemical looping combustion relies on high performance oxygen carriers (OCs). Iron-based OCs have excellent overall properties, but the disadvantage of low reduction reactivity limits their application prospects. Clarification of oxygen transfer pathways and bulk phase properties is essential to improve oxygen transfer rates and increase the reactivity of OCs.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Engineering, Environmental
Tianxu Shen, Jingcun Yan, Xiao Zhu, Lulu Wang, Laihong Shen
Summary: MFB-TGA is a micro fluidized bed thermogravimetric analysis technique with high accuracy and stability, which has the potential for extensive application in evaluating catalytic combustion and deducing oxidation mechanisms, oxygen migration pathways, and combustion kinetics. The measurement stability of MFB-TGA is influenced by various factors such as temperature distribution and gas disturbance.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Thermodynamics
Feng Liu, Jing Liu, Yu Li, Ruixue Fang, Yingju Yang
Summary: The study found that spinel NiFe2O4 can be directly reduced into Ni-Fe alloy in CO atmosphere, with a reaction rate two times faster than Fe2O3. Factors such as reaction temperature, CO concentration, and heating rate can enhance the reactivity of NiFe2O4. The reactivity of lattice oxygen in NiFe2O4 is primarily influenced by the coordination environment of oxygen formed by different Ni/Fe atoms.
Article
Engineering, Environmental
Zhenwu Miao, Laihong Shen, Zhenshan Li, Tianxu Shen
Summary: The development of oxygen carrier particles with good cycling stability on an industrial scale remains a challenge in the field of chemical looping. In this study, a perovskite oxygen carrier was prepared using an industrial-scale spray drying granulation method and tested for long-term chemical looping combustion. The results showed that attrition and sintering of the particles increased with the number of redox cycles, and the perovskite structure was destroyed over time. Agglomeration mainly occurred in the reduction stage, leading to defluidization of the bed. Particle activation was found to increase the active area of the particles during the cycle, whether they were fluidized or not. Agglomeration started at the contact surface between the air distribution plate and the particles, resulting in blocked oxidation and deepening agglomeration.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Chaohe Zheng, Hengfeng Bu, Fan Yang, Zuwei Xu, Haibo Zhao
Summary: In this study, the photocatalytic properties of TiO2-supported CuO nanoclusters with different sizes were investigated using an ab initio method. Small clusters were found to have higher charge separation efficiency, while large clusters showed better light-absorption performance. The research highlights the importance of cluster size in promoting photocatalytic reactions.
Article
Energy & Fuels
Dingyi Qin, Qianyun Chen, Jing Li, Zhaohui Liu
Summary: In this study, a visual pressurized flat-flame reaction system was used to investigate the ignition and combustion characteristics of coal particles of different sizes. The results showed that pressure greatly affected the ignition delay time and pyrolysis process of coal.
Article
Environmental Sciences
Sili Zhou, Bin Chen, Wendong Wei, Zhaohui Liu, Song Song, Kuishuang Feng, Jiashuo Li
Summary: The restructuring of China's power sector has had significant impacts on employment, with direct employment increasing while jobs in upstream sectors have been lost. The share of employment driven by solar and wind power has significantly increased. In the future, the power sector is expected to rely more on renewable energy and provide millions of job opportunities.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Chemistry, Applied
Qianyun Chen, Dingyi Qin, Jing Li, Zhaohui Liu
Summary: A particle-tracking image pyrometer system was proposed to investigate the ignition characteristics of pulverized coal particles, providing reliable simultaneous measurements of velocity, diameter, and temperature of individual burning particles. Experimental validation was conducted under specific conditions to accurately measure the combustion state and time parameters of the particles.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Chenghao Luo, Long Huang, Yikun Chen, Zean Wang, Hao Ren, Hao Liu, Zhaohui Liu
Summary: Heat-not-burn tobacco with an external heating source is a cleaner alternative to conventional cigarettes. This study investigated the effects of blending ratio of graphite carbon and K2CO3 on the co-combustion characteristics of the carbon source. The results showed that the minimum ignition temperature was mainly controlled by the biochar, while the burnout temperature was dominated by the graphite. The presence of K2CO3 improved the burnout temperature but had limited effect on the ignition temperature.
Article
Energy & Fuels
Lulu Li, Yanan Wang, Hengfeng Bu, Zuwei Xu, Haibo Zhao
Summary: In order to achieve carbon peak and carbon neutrality, low-carbon combustion technologies are urgently needed in China. Chemical looping combustion has been identified as one of the most promising methods for low-carbon, efficient, and clean utilization of coal. This study developed a low-cost composite oxygen carrier and evaluated its performance in combustion tests using lignite as fuel. The results showed that the composite oxygen carrier exhibited better combustion performance compared to pure red mud. Additionally, increasing the temperature improved carbon capture efficiency, while the effect on CO2 yield was relatively small. Furthermore, increasing the oxygen/fuel ratio led to higher carbon capture efficiency and CO2 yield.
Editorial Material
Energy & Fuels
Haibo Zhao
Article
Computer Science, Interdisciplinary Applications
Kuang Ma, Yaning Wang, Maoqiang Jiang, Zhaohui Liu
Summary: We proposed a simple one-step index (OSI) algorithm for solving the lattice Boltzmann equation, which achieves the streaming of particle distribution functions (PDFs) on a single grid system. The algorithm is derived from the conventional A-B pattern and has fixed memory addresses for the PDFs in accordance with collision principles. It reassigns their indexes to implicitly compute the streaming process. The algorithm is simple to program and suitable for GPUs, showing good performance and efficiency.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Thermodynamics
Fan Hu, Biao Xiong, Xuhui Liu, Xiaohong Huang, Yu Li, Zhaohui Liu
Summary: Accurate assessment of coal char oxidation kinetics under moderate or intense low-oxygen dilution oxy-fuel conditions is essential for efficient combustion system design. This study conducted experimental and modeling studies to analyze the intrinsic kinetic properties of coal char oxidation. The results showed small reactivity differences between the atmospheres and indicated that the random pore model correlated the best with experimental results. The activation energies of coal char under the optimal conditions in different atmospheres were much higher than those obtained by the conventional method, and the reaction orders were close to 1.0.
Article
Engineering, Chemical
Cheng Shang, Zhijing Su, Song He, Zuwei Xu, Frank Einar Kruis, Haibo Zhao
Summary: This study combines computational fluid dynamics and population balance-Monte Carlo method (CFD-PBMC) to develop an accurate method for describing the spatiotemporal evolution and characteristics of dispersed systems. A efficient sub-model for particle migration is proposed to simulate the convection and diffusion processes. Several classical cases are simulated and compared with the classical weighted random walk method, showing good agreements except for radial migration. The measured speedups on the GPU are significantly higher compared to a standard high-performance computer, with a factor of about 450 for pure migration and about 50 for the CFD-PBMC method.
Article
Thermodynamics
Xudong Jiang, Junjun Guo, Zhengyun Wei, Erica Quadarella, Hong G. Im, Zhaohui Liu
Summary: A flamelet/progress variable model accounting for differential diffusion effects is proposed and applied to LES of turbulent oxy-fuel flames. The model incorporates the influences of combustion progress, mixture fraction, and turbulence on variable Lewis numbers. The model is evaluated on a laminar coflow flame and implemented in a fully coupled LES of oxy-fuel jet flames, showing accurate capture of the effects of differential diffusion and good predictions on temperature and species distribution.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Fan Hu, Pengfei Li, Pengfei Cheng, Yaowei Liu, Guodong Shi, Yan Gao, Zhaohui Liu
Summary: The experimental study on the incineration treatment of sawdust and residual char blend in a tubular-furnace reactor and a 200-kW pilot-scale furnace is conducted. The influence of temperature and oxygen concentration on NO release characteristics is examined, indicating that the released NO mainly originates from fuel-NO under medium temperature and low oxygen environments. The results demonstrate that stable combustion and emission reduction can be achieved through MILD combustion of the solid waste blend.
Article
Engineering, Chemical
Shenxu Qin, Maoqiang Jiang, Kuang Ma, Jin Su, Zhaohui Liu
Summary: An efficient immersed boundary-lattice Boltzmann method (IB-LBM) is proposed for fully resolved simulations of suspended solid particles in viscoelastic flows. The method is validated and applied to various scenarios, demonstrating its capability in studying the complex behaviors of viscoelastic particle suspensions.
Review
Energy & Fuels
Pengfei Li, Pengfei Cheng, Guochang Wang, Feifei Wang, Kin-Pang Cheong, Zhaohui Liu, Jianchun Mi
Summary: Moderateor intense low-oxygen dilution (MILD) combustion has the advantages of high thermal efficiency and ultralow NOx emissions. This technology has attracted extensive attention since 1990. Initially, the development of MILD combustion technologies required preheating the combustion air externally, limiting its industrial applications for burning solid fuels. However, this limitation has been overcome, and significant progress has been made in solid-fuel MILD combustion, including the development of burners utilizing different types of solid fuels and the reduction of pollutant emissions.
Article
Energy & Fuels
Xinyi Chen, Guangsheng Zou, Yanliang Yuan, Zuwei Xu, Haibo Zhao
Summary: The research investigates the use of Ni-doped nano-Fe/Ce oxygen carriers for the chemical looping dry reforming of methane. Thermodynamic analysis and reaction simulation are conducted on the CL-DRM process with iron-based oxygen carriers. The experimental results show that the Ni-doped Fe/Ce oxygen carriers achieve high performance and stable cyclic stability due to the high dispersion of Ni and the transformation of Fe oxides and CeO2.
