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
Thermodynamics
Junjie Lin, Kun Luo, Shuai Wang, Liyan Sun, Jianren Fan
Summary: The hydrodynamic and thermochemical characteristics in the coal-direct chemical looping combustion (CLC) process were studied using a self-developed computational fluid dynamics - discrete element method (CFD-DEM) approach. The results showed that increasing the coal feeding rate improved the combustion efficiency, while finer oxygen carriers promoted the conversion of gas products. In addition, a dual-side coal feeding arrangement significantly improved the system's uniformity.
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
Engineering, Environmental
Ming Luo, Yanjun Qin, Jianjun Cai, Lili Qian, Shuxiang Wang, Haiyan Zhang, Lunzheng Zhou, Peng Liu
Summary: This study investigated the release and migration characteristics of sulfur in the chemical looping combustion of coal with two different synthetic oxygen carriers. The results showed that sulfur behavior varied under different conditions, with sulfur mainly migrating to metal sulfides at lower temperatures and peroxide coefficients.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Engineering, Environmental
Jinchen Ma, Daofeng Mei, Chaoquan Wang, Xin Tian, Zhaohui Liu, Haibo Zhao
Summary: This study investigated the fate of sulfur during in-situ gasification chemical looping combustion of coal, highlighting the resistance of Fe2O3/Al2O3 to sulfur and the positive effects of temperature and oxygen/fuel ratio on the conversion of sulfur compounds. Additionally, the research demonstrated the desulfurization function of coal ash and the effective conversion of sulfur-containing gases into SO2 using oxygen carrier materials.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Applied
Doki Yamaguchi, Liangguang Tang, Jose Orellana, Trevor D. Hadley, Sankar Bhattacharya, Kok-Seng Lim
Summary: The study developed a compact fully looped chemical looping reactor and found that the CLC performance increased with increasing operation time over 36 hours, as indicated by the increase in the CO2/CO molar ratio. The morphology changes and ash interaction of the Australian ilmenite did not noticeably affect the CLC performance or operation during continuous operation.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
K. Sekar Pragadeesh, Iyyaswami Regupathi, D. Ruben Sudhakar
Summary: Utilizing large solid fuel particles in fluidized bed Chemical Looping Combustion (CLC) can reduce the energy penalty associated with carbon capture. This study suggests using large particles of all fuels, including high-ash coals, in CLC systems without prior size reduction, with fuel type found to be the prime influencer of char conversion time and fragmentation phenomena.
Article
Chemistry, Applied
Jinchen Ma, Xin Tian, Chaoquan Wang, Haibo Zhao, Zhaohui Liu, Chuguang Zheng
Summary: The study focused on the nitrogen conversion and distribution characteristics in the two elementary stages of coal conversion during the iG-CLC process. It was found that HCN was the dominant precursor of NOx in iG-CLC, and most NOx precursors were released during coal pyrolysis. The high CO2 concentration and reducing reaction atmosphere in the fuel reactor were found to inhibit the formation of NO.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Engineering, Environmental
Shuyue Li, Yuting Zhuo, Yansong Shen
Summary: For the first time, a multi-fluid CFD model is developed to describe the gas-solid-powder reactive flow in a full-loop CDCL unit. The model is validated by comparing with experimental data. This work provides a useful tool for designing and optimizing CLC processes.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Lei Liu, Zhenshan Li, Zuoan Li, Yngve Larring, Ningsheng Cai
Summary: This study investigates the effect of SO2 on the redox kinetics of a CaMn0.375Ti0.5Fe0.125O3-delta perovskite oxygen carrier, revealing that SO2 has minimal impact on reduction reactivity at high temperatures but decreases oxidation reactivity. The sulfur mainly exists in the form of sulfates/sulfides on the particle surface, leading to sulfur poisoning effect during oxidation and reduction processes.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Barnali Bhui, Banabir Das, V Prabu
Summary: Electronic waste poses a serious threat to the environment, but the metals and polymers in PCB boards can be used as potential oxygen carriers in the chemical looping combustion process. Experimental studies demonstrate the feasibility of utilizing PCB based oxygen carriers in CLC for environmental sustainability.
Article
Chemistry, Applied
Yunchang Dong, Yanan Wang, Jinchen Ma, Hengfeng Bu, Chuanbao Zheng, Haibo Zhao
Summary: In this study, composite oxygen carriers were prepared using extrusion-spheronization method with fine iron and copper ores as raw materials and inert aluminosilicates as binders. After optimization, the oxygen carriers showed good performance in terms of reactivity and stability, indicating the suitability of the method for large-scale preparation of oxygen carrier particles.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
Yanan Wang, Hengfeng Bu, Haibo Zhao, Kunlei Liu
Summary: Solid fuel chemical looping gasification technology requires the development of low-cost, easily available oxygen carrier particles, with Cu/Fe-based OCs from waste ore particles and bauxite residues showing promise for coal gasification. Among these OCs, red mud and Cu20Fe80@C exhibit better gasification performance and potential for Fischer-Tropsch synthesis and H-2-rich chemical synthesis. The study also reveals the importance of lattice oxygen donation capacity and alkali metal content in determining coal and char gasification rates.
Article
Engineering, Chemical
Rushikesh Joshi, Yaswanth Pottimurthy, Vedant Shah, Pinak Mohapatra, Sonu Kumar, Omari Jones, Marianna Beard, Ibiada Harry, Albany Hornbuckle, Mandar Kathe, Liang-Shih Fan
Summary: The CDCL-SR process proposed in this study utilizes a multimetal oxide as the oxygen carrier to combust coal and capture sulfur in situ, resulting in high thermal and exergy efficiencies. The process eliminates the need for downstream processing units by producing separate streams of CO2 and SO2 during combustion.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
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
Environmental Sciences
Xinmin Liu, Yanjie Niu, Yuqing Huang, Xuexia Qiu, Qingjie Guo
Summary: Two new types of solid adsorption materials were prepared from waste television plastics and used to capture CO2 in flue gas from coal-fired power plants. The results showed that these materials had different CO2 adsorption capacities and mechanisms.
ENVIRONMENTAL TECHNOLOGY
(2023)
Article
Engineering, Chemical
Huifen Kang, Jingjing Ma, Xintong Guo, Ziheng Han, Jian Hao, Qingjie Guo
Summary: This study investigated the emissions and migration of selenium using an iron-based oxygen carrier in chemical looping combustion. The results showed that the presence of the oxygen carrier significantly reduced the emissions of selenium and promoted its conversion from gaseous form to solid form. Additionally, the temperature of the fuel reactor and the number of oxygen carrier re-oxidation cycles played a crucial role in the emissions and retention of selenium.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Review
Energy & Fuels
Mei An, Qingjie Guo, Xianyong Wei
Summary: The reaction mechanism of H2S and Hg0 on CuFe2O4 with oxygen vacancy structure was investigated using X-ray photoelectron spectroscopy (XPS) characterization and Density Functional Theory (DFT) calculations. The results showed that oxygen vacancies enhanced the adsorption capacity of CuFe2O4 towards Hg, H2S, and HgS, and improved the energy barrier and thermodynamic stability of key intermediates.
Article
Green & Sustainable Science & Technology
Hongjing Tian, Yixing Che, Shengnan Xu, Jixing Tang, Hui Wang, Man Wu, Qingjie Guo
Summary: The catalysts using cobalt ferrite (CoxFe(3-x)O(4)) and sphere mesoporous silica (MCM-41) nanoparticles as support were found to enhance the oxidation rate of MgSO3 under moderate temperatures. The combination of electric field and CoFe2O4/MCM-41 showed a synergistic effect, significantly increasing the oxidation rate of MgSO3 compared to when only one factor was present. The study also revealed the mechanism of the catalytic oxidation of MgSO3, involving the reduction of oxidation potential and increased electron transfer rate.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Chemical
Zhuangmei Li, Ying Zhu, Na Li, Hui Zhang, Yuhua Wu, Ping Li, Qingjie Guo, Hongcun Bai
Summary: Understanding the reactive mechanism of coal thermochemical conversion is crucial for the efficient utilization of coal. However, the evolution of coal macromolecular structure, reactants, and products at particle and molecular scales remains unclear. This study used reactive force field molecular dynamics to uncover the reactive mechanism and nitrogen transformation during the combustion of HSW coal at microscopic scales. The effects of chemical equivalent and combustion temperature were investigated to explore the structural evolution, combustion reactants, and products. The results revealed observable changes in coal structure fracture during the continuous reaction. Furthermore, the study established the transformation networks of organic nitrogen in combustion and identified the pathway for the formation of HCN, NO, and NO2.
Article
Engineering, Chemical
Yunlei Zhao, Bo Jin, Zhineng Zhang, Kun Huang, Yakun Wang, Xiao Luo, Qingjie Guo, Zhiwu Liang
Summary: Using self-templated metal-organic framework (MOF) to develop efficient iron-based oxygen carriers is an effective way, but the effect of metal oxide-support interaction and crystal structure on the reactivity of MOF-derived iron-based materials is still unclear.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Environmental Sciences
Hui Huang, Zhaoxi Wei, Qingru Ge, Qingjie Guo
Summary: This study focuses on 278 cities in China from 2000 to 2017 and uses the SBM model to measure carbon emission efficiency. The results show that the average carbon emission efficiency in China gradually dropped from 0.6 to 0.5 during the research period. The classification of cities based on carbon emission efficiency reveals a decrease in high-efficiency cities and an increase in medium-low- and low-efficiency cities. The spatial-temporal evolution of carbon emission efficiency follows a certain pattern and has spatial auto-correlation. The study also identifies factors such as improving urban development quality and technological innovation, government intervention, and attracting high-quality foreign capital to improve the low efficiency of carbon emissions in cities.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Shengnan Xu, Yun lu Han, Chao Ma, Yanxia Guo, Man Wu, Qingjie Guo, Hongjing Tian
Summary: Mixtures of shell-biochar and calcium silicate slag were impregnated with pentaethylenehexamine and then mixed with wet flue gas desulfurization gypsum to prepare adsorbents. The presence of crystalline water in FGDG slag affected the CO2 adsorption mechanisms of the amine groups. The FGDG modified adsorbents showed comparable cyclic recyclability and a minimal decrease in adsorption capacity after 12 cycles.
Article
Engineering, Chemical
Ziheng Han, Huifen Kang, Nini Yuan, Xintong Guo, Jingjing Ma, Qingjie Guo
Summary: Selenium pollution from coal utilization is a growing concern. Calcium-iron oxygen carriers and alkali metal ions have inhibitory effects on selenium, reducing its emissions. The retention mechanisms of selenium by Fe2O3, CaFe2O4, Ca2Fe2O5, and bottom ash were investigated. Iron-based oxygen carriers can oxidize H2Se(g) to SeO2(g) and release lattice oxygen to form an Fe-O-Se structure and retain selenium. CaFe2O5 showed the highest retention rate of 32.301%. Bottom ash gradually increased selenium retention, with alkali metal ions playing a crucial role. This study provides a new approach to selenium removal using oxygen carriers and bottom ash during chemical looping gasification.
Article
Chemistry, Physical
Wenlong Song, Qiqi Zhu, Kangzhou Wang, Rui Zhu, Qingxiang Ma, Tiansheng Zhao, Qingjie Guo, Xinhua Gao, Jianli Zhang
Summary: This study reports the positive role of residual sodium on the structural properties and catalytic performance of FeAlNa catalysts for olefins synthesis. The residual sodium improves the reduction behavior of Fe species and CO adsorption, inhibits secondary hydrogenation, and also inhibits the interaction between Fe and Al. The modified catalyst achieves a high olefins/paraffins ratio and low CH4 selectivity.
Article
Chemistry, Multidisciplinary
Mengdong Nie, Aixin Cui, Man Wu, Tuo Guo, Qingjie Guo
Summary: This study elucidates the correlation of metal-support interactions in CuO/LaCeOx catalysts and the promotion of catalytic activity. It is found that the introduction of La enhances the conversion of Ce4+ into Ce3+ in the catalyst and activates the formate reaction pathway of CO2 hydrogenation.
JOURNAL OF CO2 UTILIZATION
(2023)
Article
Engineering, Environmental
Chenglong Wang, Lerao Wang, Xumei Tao, Liang Huang, Zaiqing Yang, Qingjie Guo
Summary: Fe-MOFs@Fe2O3 composites were prepared using BDB plasma method with recycle of waste PET, showing high specific surface areas and a low electron-hole complexation rate. These composites exhibited good photocatalytic performance, degrading 99.3% of malachite green within 30 min under visible light. This method provides a new approach for recycling waste PET plastics and preparing new energy functional materials.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Engineering, Environmental
Zhaoxin Wan, Xiude Hu, Chengbo Li, Jiawei Zhang, Qi Wang, Long Fang, Linlin Zhang, Qingjie Guo, Deshuai Sun
Summary: SO2 and NO, the main precursors of acid rain, regional haze, and photochemical smog from coal combustion, can be simultaneously removed through advanced oxidation strategies. Two metal-organic frameworks (MOFs), FeBDC and CuFeBDC, were synthesized to activate peroxymonosulfate (PMS) for the oxidation and absorption of flue pollutants. CuFeBDC exhibited efficient catalytic properties for the removal of NO and SO2 in PMS solution and could be recycled and regenerated.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Energy & Fuels
Liangliang Meng, Ying Zhu, Meilin Zhu, Ge Wu, Wenqian Guo, Chang Geng, Na Li, Rou Feng, Hui Zhang, Qingjie Guo, Hongcun Bai
Summary: Uncovering the reaction mechanism of various fuels to chemical looping combustion (CLC), especially depolymerization of solids in a complex environment, is an important scientific issue. This work presents molecular insights into the reaction behaviors and mechanism for several aromatic structures in the fuel reactor of CLC. It is found that the reaction process of aromatic fuels reacted with Fe2O3 as oxygen carriers in CLC can be divided into four stages, and the decomposition rate of fuel molecules is relevant to the reaction temperature and aromatic sizes.
JOURNAL OF THE ENERGY INSTITUTE
(2023)
Article
Chemistry, Multidisciplinary
Mengdong Nie, Tuo Guo, Fangyuan Qiang, Man Wu, Yongzhuo Liu, Qingjie Guo, Yurong He
Summary: Controlling the metal-support interaction is crucial for the construction of efficient catalytic systems. In this study, different Cu-CeOx interactions were achieved by preparing CuO/MnCeOx catalysts with varying Mn content. The influence of Mn content on the performance of the catalysts during CO2 hydrogenation to CH3OH was analyzed, and the optimal Mn content was determined to be 20%. The catalyst with 20% Mn content (CuO/Mn0.2CeOx) showed the best catalytic behavior, with a methanol space-time yield of 0.25 gCH3OH gcat-1 h-1 at 260 degrees C. It had the highest concentration of oxygen vacancies and Cu0, as well as medium-to-strong basic sites, which were generated by the strongest metal-support interactions between CuO and MnCeOx solid solution. In situ diffuse reflectance infrared Fourier-transform spectroscopy evidence indicated that the CO2 methanolization over CuO/MnCeOx catalysts proceeded via a formate mechanism. These findings are highly significant for the development of new, efficient CO2 hydrogenation catalysts by controlling oxygen vacancies and surface basic sites through rational alteration of the metal-support interaction.
REACTION CHEMISTRY & ENGINEERING
(2023)