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Advancements in biomass gasification research utilizing iron-based oxygen carriers in chemical looping:A review
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作者 Yonghong Niu Zhengyang Chi Ming Li 《Materials Reports(Energy)》 EI 2024年第3期35-48,共14页
Biomass,recognized as renewable green coal,is pivotal for energy conservation,emission reduction,and dualcarbon objectives.Chemical looping gasification,an innovative technology,aims to enhance biomass utilization eff... Biomass,recognized as renewable green coal,is pivotal for energy conservation,emission reduction,and dualcarbon objectives.Chemical looping gasification,an innovative technology,aims to enhance biomass utilization efficiency.Using metal oxides as oxygen carriers regulates the oxygen-to-fuel ratio to optimize synthesis product yields.This review examines various oxygen carriers and their roles in chemical looping biomass gasification,including natural iron ore types,industrial by-products,cerium oxide-based carriers,and core-shell structures.The catalytic,kinetic,and phase transfer properties of iron-based oxygen carriers are analyzed,and their catalytic cracking capabilities are explored.Molecular interactions are elucidated and system performance is optimized by providing insights into chemical looping reaction mechanisms and strategies to improve carrier efficiency,along with discussing advanced techniques such as density functional theory(DFT)and reactive force field(ReaxFF)molecular dynamics(MD).This paper serves as a roadmap for advancing chemical looping gasification towards sustainable energy goals. 展开更多
关键词 chemical looping gasification Iron based oxygen carrier Preparation of oxygen carrier system
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Microscopic mechanism study and process optimization of dimethyl carbonate production coupled biomass chemical looping gasification system 被引量:1
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作者 Wende Tian Jiawei Zhang +2 位作者 Zhe Cui Haoran Zhang Bin Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第6期291-305,共15页
Biomass chemical looping gasification technology is one of the essential ways to utilize abundant biomass resources.At the same time,dimethyl carbonate can replace phosgene as an environmentfriendly organic material f... Biomass chemical looping gasification technology is one of the essential ways to utilize abundant biomass resources.At the same time,dimethyl carbonate can replace phosgene as an environmentfriendly organic material for the synthesis of polycarbonate.In this paper,a novel system coupling biomass chemical looping gasification with dimethyl carbonate synthesis with methanol as an intermediate is designed through microscopic mechanism analysis and process optimization.Firstly,reactive force field molecular dynamics simulation is performed to explore the reaction mechanism of biomass chemical looping gasification to determine the optimal gasification temperature range.Secondly,steady-state simulations of the process based on molecular dynamics simulation results are carried out to investigate the effects of temperature,steam to biomass ratio,and oxygen carrier to biomass ratio on the syngas yield and compositions.In addition,the main energy indicators of biomass chemical looping gasification process including lower heating value and cold gas efficiency are analyzed based on the above optimum parameters.Then,two synthesis stages are simulated and optimized with the following results obtained:the optimal temperature and pressure of methanol synthesis stage are 150℃ and 4 MPa;the optimal temperature and pressure of dimethyl carbonate synthesis stage are 140℃ and 0.3 MPa.Finally,the pre-separation-extraction-decantation process separates the mixture of dimethyl carbonate and methanol generated in the synthesis stage with 99.11%purity of dimethyl carbonate.Above results verify the feasibility of producing dimethyl carbonate from the perspective of multi-scale simulation and realize the multi-level utilization of biomass resources. 展开更多
关键词 Biomass chemical looping gasification Reactive force field molecular dynamics simulation SEPARATION Multi-scale simulation
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Chemical looping gasification of sewage sludge using copper slag modified by NiO as an oxygen carrier 被引量:3
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作者 Nanhang Dong Ruiqiang Huo +5 位作者 Ming Liu Lisheng Deng Zhengbing Deng Guozhang Chang Zhen Huang Hongyu Huang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第1期335-343,共9页
Chemical looping gasification(CLG) provides a novel approach to dispose the sewage sludge.In order to improve the reactivity of the calcined copper slag,NiO modification is considered as one of the good solutions.The ... Chemical looping gasification(CLG) provides a novel approach to dispose the sewage sludge.In order to improve the reactivity of the calcined copper slag,NiO modification is considered as one of the good solutions.The copper slag calcined at 1100℃ doped with 20 wt% NiO(Ni20-CS) was used as an oxygen carrier(OC) in sludge CLG in the work.The modification of NiO can evidently enhance the reactivity of copper slag to promote the sludge conversion,especially for sludge char conversion.The carbon conversion and valid gas yield(V_(g)) increase from 67.02% and 0.23 m^(3)·kg^(-1) using the original OC to 78.34% and 0.29 m^(3)·kg^(-1) using the Ni20-CS OC, respectively.The increase of equivalent coefficient(Ω) facilitates the sludge conversion and a suitable Ω value is determined at 0.47 to obtain the highest valid gas yield(0.29 m^(3)·kg^(-1)).A suitable steam content is assigned at 27.22% to obtain the maximum carbon conversion of 87.09%,where an acceptable LHV of 12.63 MJ·m^(-3) and Vg of 0.39 m^(3)·kg^(-1)are obtained.Although the reactivity of Ni20-CS OC gradually decreases with the increase in cycle numbers because of the generation of NiFe_(2) O_(4-δ) species,the deposition of sludge ash containing many metallic elements is beneficial to the sludge conversion.As a result,the carbon conversion shows a slight uptrend with the increase of cycle numbers in sludge CLG.It indicates that the Ni20-CS sample is a good OC for sludge CLG. 展开更多
关键词 chemical looping gasification(clg) Copper slag NIO SLUDGE Oxygen carrier(OC)
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Effect of Gasifying Medium on the Coal Chemical Looping Gasification with CaSO_4 as Oxygen Carrier 被引量:2
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作者 刘永卓 贾伟华 +1 位作者 郭庆杰 Hojung Ryu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第Z1期1208-1214,共7页
The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with Ca SO4 as ox... The chemical looping gasification uses an oxygen carrier for solid fuel gasification by supplying insufficient lattice oxygen. The effect of gasifying medium on the coal chemical looping gasification with Ca SO4 as oxygen carrier is investigated in this paper. The thermodynamical analysis indicates that the addition of steam and CO2 into the system can reduce the reaction temperature, at which the concentration of syngas reaches its maximum value.Experimental result in thermogravimetric analyzer and a fixed-bed reactor shows that the mixture sample goes through three stages, drying stage, pyrolysis stage and chemical looping gasification stage, with the temperature for three different gaseous media. The peak fitting and isoconversional methods are used to determine the reaction mechanism of the complex reactions in the chemical looping gasification process. It demonstrates that the gasifying medium(steam or CO2) boosts the chemical looping process by reducing the activation energy in the overall reaction and gasification reactions of coal char. However, the mechanism using steam as the gasifying medium differs from that using CO2. With steam as the gasifying medium, parallel reactions occur in the beginning stage, followed by a limiting stage shifting from a kinetic to a diffusion regime. It is opposite to the reaction mechanism with CO2 as the gasifying medium. 展开更多
关键词 chemical looping gasification Ca SO4 oxygen CARRIER Reaction mechanism SYNGAS generation
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Chemical looping catalytic gasification of biomass over active LaNixFe1-xO_(3)perovskites as functional oxygen carriers 被引量:4
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作者 Jingchun Yan Weidong Liu +3 位作者 Rong Sun Shouxi Jiang Shen Wang Laihong Shen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第8期146-156,共11页
Oxygen carriers(OCs)with perovskite structure are attracting increasing interests due to their redox tunability by introducing various dopants in the structure.In this study,LaNixFe1-xO3(x=0,0.1,0.3,0.5,0.7,1.0)perovs... Oxygen carriers(OCs)with perovskite structure are attracting increasing interests due to their redox tunability by introducing various dopants in the structure.In this study,LaNixFe1-xO3(x=0,0.1,0.3,0.5,0.7,1.0)perovskite OCs have been prepared by a citric acid–nitrate sol–gel method,characterized by means of X-ray diffraction(XRD)analysis and tested for algae chemical looping gasification in a fixed bed reactor.The effects of perovskite types,OC/biomass mass ratio(O/B),gasification temperature and water injection rate on the gasification performance were investigated.Lower Ni-doped(0≤x≤0.5)perovskites crystalized in the rhombohedra system which was isostructural with LaNiO3,while those with composition 0.5≤x≤1 crystalized in the orthorhombic system.Despite the high reactivity for LaNiO_(3),LaNi_(0.5)Fe_(0.5)O_(3)(LN5F5)was found to be more stable at a high temperature and give almost as good results as LaNiO_(3)in the formation of syngas.The relatively higher syngas yield of 0.833 m^(3)·kg^(-1) biomass was obtained under the O/B of 0.4,water injection rate of 0.3 ml·min^(-1) and gasification temperature at 850C.Continuous high yield of syngas was achieved during the first 5 redox cycles,while a slight decrease in the reactivity for LN5F5 after 5 cycles was observed due to the adhesion of small grains occurring on the surface of OCs.However,an obvious improvement in the gasification performance was attained for LN5F5 compared to raw biomass direct gasification,indicating that LN5F5 is a promising functional OC for chemical looping catalytic gasification of biomass. 展开更多
关键词 BIOMASS chemical looping gasification Oxygen carrier La-Ni-Fe perovskite CATALYSIS
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Experimental and numerical simulation of lignite chemical looping gasification with phosphogypsum as oxygen carrier in a fluidized bed 被引量:2
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作者 Wang Du Liping Ma +2 位作者 Jing Yang Wei Zhang Ran Ao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第9期197-207,共11页
Phosphogypsum(PG)is a solid waste produced in the wet process of producing phosphoric acid.Lignite is a kind of promising chemical raw material.However,the high sulfur of lignite limits the utilization of lignite as a... Phosphogypsum(PG)is a solid waste produced in the wet process of producing phosphoric acid.Lignite is a kind of promising chemical raw material.However,the high sulfur of lignite limits the utilization of lignite as a resource.Based on fluidized bed experiments,the optimal reaction conditions for the production syngas by lignite chemical looping gasification(CLG)with PG as oxygen carrier were studied.The study found that the optimal reaction temperature should not exceed 1123 K;the mole ratio of water vapor to lignite should be about 0.2;the mole ratio of PG oxygen carrier to lignite should be about 0.6.Meanwhile,commercial software Comsol was used to establish a fuel reaction kinetics model.Through computational fluid dynamics(CFD)numerical simulation,the process of reaction in fluidized bed were well captured.The model was based on a two-fluid model and coupled mass transfer,heat transfer and chemical reactions.This study showed that the fluidized bed presents a flow structure in which gas and solid coexist.There was a high temperature zone in the middle and lower parts of the fluidized bed.It could be seen from the results of the flow field simulated that the fluidized bed was beneficial to the progress of the gasification reaction. 展开更多
关键词 PHOSPHOGYPSUM LIGNITE chemical looping gasification FLUIDIZED-BED SYNGAS Computational fluid dynamics
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Chemical looping gasification of maceral from low-rank coal: Products distribution and kinetic analysis on vitrinite 被引量:2
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作者 Bo Zhang Bolun Yang +3 位作者 Wei Guo Song Wu Jie Zhang Zhiqiang Wu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第8期233-241,共9页
The product distribution and kinetic analysis of low-rank coal vitrinite were investigated during the chemical looping gasification(CLG)process.The acid washing method was used to treat low-rank coal,and the density g... The product distribution and kinetic analysis of low-rank coal vitrinite were investigated during the chemical looping gasification(CLG)process.The acid washing method was used to treat low-rank coal,and the density gradient centrifugation method was adopted to obtain the coal macerals.By combining thermogravimetric analysis and online mass spectrometry,the influence of the heating rate and oxygen carrier(Fe2O3)blending ratio on product distribution was discussed.The macroscopic kinetic parameters were solved by the Kissinger-Akahira-Sunose(KAS)method,and the main gaseous product formation kinetic parameters were solved by the iso-conversion method.The results of vitrinite during slow heating chemical looping gasification showed that the main weight loss interval was 400–600℃,and the solid yield of sample vitrinite-Fe-10 at different heating rates was 64.30%–69.67%.When b=20℃·min^(-1),the maximum decomposition rate of vitrinite-Fe-10 was 0.312%min1.The addition of Fe2O_(3)reduced the maximum decomposition rate,but by comparing the chemical looping conversion characteristic index,it could be inferred that the chemical looping gasification of vitrinite might produce volatile substances higher than the pyrolysis process of vitrinite alone.The average activation energy of the reaction was significantly reduced during chemical looping gasification of vitrinite,which was lower than the average activation energy of 448.69 kJ·mol^(-1) during the pyrolysis process of vitrinite alone.The gaseous products were mainly CO and CO_(2).When the heating rate was 10℃·min^(-1),the highest activation energy for CH4 formation was 21.353 kJ·mol^(-1),and the lowest activation energy for CO formation was 9.7333 kJ·mol^(-1).This study provides basic data for exploring coal chemical looping gasification mechanism and reactor design by studying the chemical looping gasification process of coal macerals。 展开更多
关键词 COAL VITRINITE chemical looping process gasification Products distribution Reaction kinetics
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Ca-and Mg-rich waste as high active carrier for chemical looping gasification of biomass 被引量:1
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作者 Xin Niu Laihong Shen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期145-154,共10页
Chemical looping gasification(CLG)is a promising technology for high-quality syngas production.One key issue to successful CLG is the selection of high-performance oxygen carrier.In this study,several Ca-and Mg-rich s... Chemical looping gasification(CLG)is a promising technology for high-quality syngas production.One key issue to successful CLG is the selection of high-performance oxygen carrier.In this study,several Ca-and Mg-rich steelmaking wastes from steel industry,such as blast furnace slag(BF slag),blast furnace dust(BF dust)and Linz-Donawitz converter slag(LD slag),were used as oxygen carriers in chemical looping gasification of biomass.The results showed that the reducibility of Ca-and Mg-rich waste,especially LD slag and BF dust,was superior to that of hematite.Considering long-term operation,the cyclic stability of steelmaking waste was tested.BF dust showed a poor stability,while the other carrier(hematite,BF slag or LD slag)presented an excellent stability during multiple redox cycles in spite of partial sintering and agglomeration.Moreover,the effects of supply oxygen coefficient(O/B ratio)and reaction temperature on CLG of biomass were investigated.The results revealed that Ca-and Mg-rich waste exhibited a higher syngas production compared to hematite.The higher performance could be attributed to the improved reduction rate of Fe2O3 and gasification rate of biomass by Ca or Mg in steelmaking waste.In addition,LD slag exhibited the higher gas value at the O/B ratio of 1 at 900℃.As a consequence,LD slag was an appropriate oxygen carrier for CLG of biomass in terms of perfect reducibility,superior cyclic stability and high reactivity. 展开更多
关键词 BIOMASS SYNGAS gasification Ca-and Mg-rich waste chemical looping
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Chemical-looping gasification of biomass in a 10 kW_(th) interconnected fluidized bed reactor using Fe_2O_3/Al_2O_3 oxygen carrier 被引量:9
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作者 HUSEYIN Sozen WEI Guo-qiang +2 位作者 LI Hai-bin HE Fang HUANG Zhen 《燃料化学学报》 EI CAS CSCD 北大核心 2014年第8期922-931,共10页
Abstract:The aim of this research is to design and operate a 10 kW hot chemical-looping gasification(CLG)unit using Fe2O3/Al2O3as an oxygen carrier and saw dust as a fuel.The effect of the operation temperature on gas... Abstract:The aim of this research is to design and operate a 10 kW hot chemical-looping gasification(CLG)unit using Fe2O3/Al2O3as an oxygen carrier and saw dust as a fuel.The effect of the operation temperature on gas composition in the air reactor and the fuel reactor,and the carbon conversion of biomass to CO2and CO in the fuel reactor have been experimentally studied.A total60 h run has been obtained with the same batch of oxygen carrier of iron oxide supported with alumina.The results show that CO and H2concentrations are increased with increasing temperature in the fuel reactor.It is also found that with increasing fuel reactor temperature,both the amount of residual char in the fuel reactor and CO2concentration of the exit gas from the air reactor are degreased.Carbon conversion rate and gasification efficiency are increased by increasing temperature and H2production at 870℃reaches the highest rate.Scanning electron microscopy(SEM),X-ray diffraction(XRD)and BET-surface area tests have been used to characterize fresh and reacted oxygen carrier particles.The results display that the oxygen carrier activity is not declined and the specific surface area of the oxygen carrier particles is not decreased significantly. 展开更多
关键词 chemical-looping gasification hot model BIOMASS Fe2O3/Al2O3 dual circulating fluidized bed
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Thermodynamic Analysis and Synthesis Gas Generation by Chemical-Looping Gasification of Biomass with Nature Hematite as Oxygen Carriers 被引量:2
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作者 Zhen Huang Fang He +5 位作者 Anqing Zheng Kun Zhao Sheng Chang Xinai Li Haibin Li Zengli Zhao 《Journal of Sustainable Bioenergy Systems》 2013年第1期33-39,共7页
Thermodynamic parameters of chemical reactions in the system were carried out through thermodynamic analysis. According to the Gibbs free energy minimization principle of the system, equilibrium composition of the rea... Thermodynamic parameters of chemical reactions in the system were carried out through thermodynamic analysis. According to the Gibbs free energy minimization principle of the system, equilibrium composition of the reactions of chemical-looping gasification (CLG) of biomass with natural hematite (Fe2O3) as oxygen carrier were analyzed using commercial software of HSC Chemistry 5.1. The feasibility of the CLG of biomass with hematite was experimental verified in a lab-scale bubbling fluidized bed reactor using argon as fluidizing gas. It was indicated the experimental results were consistent with the theoretical analysis. The presence of oxygen carrier gave a significant effect on the biomass conversion and improved the synthesis gas yield obviously. It was observed that the gas content of CO and H2 was over 70% in CLG of biomass. The reduced hematite particles mainly existed in form of FeO. It was showed that the reduction of natural hematite with biomass proceeds in a stepwise manner from Fe2O3 →Fe3O4→ FeO. Reduction product of natural hematite can be restored the lattice oxygen by oxidation with air. 展开更多
关键词 THERMODYNAMICS Synthesis Gas Natural HEMATITE Oxygen Carriers BIOMASS chemical looping gasification
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Study on the mechanism and reaction characteristics of metal-supported phosphogypsum as oxygen carrier in a chemical looping gasification application
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作者 Jing Yang Yujie Ren +1 位作者 Shuoyu Chen Jinsuo Lu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第4期428-438,共11页
This study aimed to explore the chemical looping gasification(CLG)reaction characteristics of the metal-supported composite phosphogypsum(PG)oxygen carriers(OCs)and the thermodynamic mechanism.The FactSage 7.1 thermod... This study aimed to explore the chemical looping gasification(CLG)reaction characteristics of the metal-supported composite phosphogypsum(PG)oxygen carriers(OCs)and the thermodynamic mechanism.The FactSage 7.1 thermodynamic simulation was used to explore the oxygen release and H_(2)S removal mechanisms.The experimental results showed that the syngas yield of CLG with PG-CuFe_(2)O_(4)was more than that with PG-Fe_(2)O_(3)20/CuO40 or PG-Fe_(2)O_(3)30/CuO30 OC at 1023 K when the water vapor content was 0.3.Furthermore,the maximum syngas yield of the CO selectivity was 70.3% and of the CO_(2)selectivity was 23.8%.The H_(2)/CO value was 0.78,and the highest carbon conversion efficiency was 91.9% in PG-CuFe_(2)O_(4)at the gasification temperature of 1073 K.The metal-supported PG composite oxygen carrier was proved not only as an oxygen carrier to participate in the preparation of syngas but also as a catalyst to catalyze coal gasification reactions.Furthermore,both the experimental results and FactSage 7.1 thermodynamic analysis revealed that the trapping mechanism of H_(2)S by composite OCs was as follows:CuO first lost lattice oxygen as an oxygen carrier to generate Cu_(2)O,which,in turn,reacted with H_(2)S to generate Cu_(2)S.This study provided efficient guidance and reference for OC design in CLG. 展开更多
关键词 Metal-supported composite PHOSPHOGYPSUM Reaction characteristics Thermodynamic mechanism chemical looping gasification
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CuFe_(2)O_(4)氧载体与小麦秆-煤化学链共气化研究
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作者 林德顺 丁宁 +1 位作者 李炜光 王保文 《动力工程学报》 CAS CSCD 北大核心 2024年第2期188-195,共8页
以小麦秆与印尼褐煤为原料,制备具有尖晶石结构的CuFe_(2)O_(4)复合氧载体,在自制多功能反应器上,系统研究了CuFe_(2)O_(4)氧载体反应活性及小麦秆和印尼褐煤化学链共气化特性,重点关注小麦秆和煤不同掺混比、气化温度、氧载体过量系数... 以小麦秆与印尼褐煤为原料,制备具有尖晶石结构的CuFe_(2)O_(4)复合氧载体,在自制多功能反应器上,系统研究了CuFe_(2)O_(4)氧载体反应活性及小麦秆和印尼褐煤化学链共气化特性,重点关注小麦秆和煤不同掺混比、气化温度、氧载体过量系数和水蒸气输入量这4个关键运行参数的影响。结果表明:CuFe_(2)O_(4)复合氧载体中Cu-Fe的协同作用有助于晶格氧的有效传递和反应活性的提升,而小麦秆和印尼褐煤化学链共气化时碳转化率及冷煤气效率比单一燃料的大,促进了高品质合成气的形成;小麦秆和褐煤在与CuFe_(2)O_(4)化学链气化过程中的最优运行参数为共气化温度950℃、氧载体过量系数0.2、水蒸气通入体积流量0.125 mL/min、小麦秆-印尼褐煤掺混质量比1∶1,在此最优条件下,合成气产量高达1.262 m^(3)/kg,H_(2)与CO体积比为1.69,碳转化率为89.7%,合成气选择性为63.2%。 展开更多
关键词 化学链 共气化 小麦秆 褐煤 CuFe_(2)O_(4)氧载体
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Aspen Plus在生物质化学链气化技术中的应用进展
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作者 万鹏程 赵雪露 +1 位作者 刘玉海 马晶晶 《当代化工研究》 CAS 2024年第13期18-23,共6页
目前世界能源结构仍以化石能源为主,面对能源紧缺与环境恶化的局面,开发可再生能源不仅能够调节能源结构,缓解能源压力,同时可以改善因化石能源过度使用而带来的环境问题。生物质为生活中最常见的可再生能源,对于生物质的合理利用是目... 目前世界能源结构仍以化石能源为主,面对能源紧缺与环境恶化的局面,开发可再生能源不仅能够调节能源结构,缓解能源压力,同时可以改善因化石能源过度使用而带来的环境问题。生物质为生活中最常见的可再生能源,对于生物质的合理利用是目前研究的主要方向。生物质的高质化利用有直接燃烧、生物转换和热化学转换等方式,但普遍存在产生大量污染物及生物质利用效率不高等问题。因此,发展清洁高效的可再生能源利用技术显得至关重要。化学链气化技术不仅可以从CO_(2)捕集和载氧体的循环使用等方面降低环境污染,还能从产生的合成气等化学用品中提升经济效益。通过Aspen Plus模拟软件还可以对生物质耦合化学链气化过程进行实时监控、优化,并对后续的工艺开发提供理论和数据支持。因此,本文从生物质种类与过程能量供给方式出发,对不同类型的生物质化学链气化过程Aspen Plus模拟研究进行了系统论述,综述了Aspen Plus模拟软件在生物质化学链气化技术领域中的工艺模拟、反应器优化、生产过程中能耗问题的应用情况,并提出了该软件的应用前景和发展方向,为我国化学链技术的应用和模拟研究提供了一定的参考。 展开更多
关键词 化学链气化 Aspen Plus模拟 生物质
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Biomass chemical looping gasification for syngas production using modified hematite as oxygen carriers 被引量:2
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作者 Cong Jiang Xiaoyu Jin +3 位作者 Tingting Xu Bo Xiao Zhiquan Hu Xun Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第3期171-184,共14页
Syngas is a clean energy carrier and a major industrial feedstock. In this paper, syngas was produced via biomass chemical looping gasification(CLG) process. Hematite, the most common Fe-based oxygen carrier(OC), was ... Syngas is a clean energy carrier and a major industrial feedstock. In this paper, syngas was produced via biomass chemical looping gasification(CLG) process. Hematite, the most common Fe-based oxygen carrier(OC), was modified with different metal oxides(CeO_(2), CaO and MgO) by the impregnation method. The hematite modified by CeO_(2), CaO and MgO was namely as CeO_(2)-hematite(CeO_(2)-H), CaO-hematite(CaO-H) and MgO-hematite(MgO-H), respectively. The introduction of CeO_(2), CaO and MgO enhanced the reactivity of lattice oxygen of hematite. The optimum condition for syngas production had been explored as the mass ratio of oxygen carrier to biomass(O/B) of 0.2, the mass ratio of steam to biomass(S/B) of0.75 and temperature of 800℃in the biomass CLG process. The CeO_(2)-H exhibited the most wonderful performance compared to that for CaO-H and MgO-H. The crystal composition of OC influenced greatly in the CLG process. CeFeO_(3)had a good oxygen mobility property and lattice oxygen releasing capacity due to the most oxygen vacancy distributed on the OC surface and the most active lattice oxygen, which is conducive to the biomass chemical looping gasification process for syngas production, leading to the highest gasification efficiency of 95.86% and gas yield of 1.20 m^(3)/kg of the three. Cyclic test proved that CeO_(2)-H had well sintering resistance and cyclic performance. 展开更多
关键词 chemical looping gasification Oxygen carrier SYNGAS Modified hematite Pine sawdust
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碱木质素强化煤焦粉化学链气化实验研究
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作者 高行龙 安风霞 +6 位作者 胡耘 陈国庆 易群 武小燕 曹晋曾 姚炜珊 魏国强 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2024年第7期995-1005,共11页
中国煤炼焦工业副产物煤焦粉产量大、活性低,难以被直接回收利用,常规热化学利用方式反应条件苛刻、催化剂易失活且存在动力学限制。本研究通过造纸副产物碱木质素作为可弃型催化剂,构建碱木质素强化化学链气化的方式来处理煤焦粉,实现... 中国煤炼焦工业副产物煤焦粉产量大、活性低,难以被直接回收利用,常规热化学利用方式反应条件苛刻、催化剂易失活且存在动力学限制。本研究通过造纸副产物碱木质素作为可弃型催化剂,构建碱木质素强化化学链气化的方式来处理煤焦粉,实现工业副产物协同资源化利用。热转化实验和动力学分析研究表明,碱木质素可强化煤焦粉化学链气化过程,促进煤焦粉热解峰向低温方向移动。当煤焦粉与碱木质素质量比为1∶3时,反应活化能比单独煤焦粉反应降低87.56%。固定床实验证实气化温度提高、碱木质素以及载氧体赋存量增加,可以有效提高燃料碳转化率及合成气产物选择性,促进气化反应进行,但氧载体过量会导致合成气转化为终端产物,降低合成气选择性。在气化温度为950℃,煤焦粉与碱木质素质量比为1∶2,氧载体与煤焦粉/碱木质素混合体系质量比为1∶1的最佳反应条件下,基于NiFe2O4的碱木质素/煤焦粉化学链气化合成气选择性高达82.85%。该研究为碱木质素与煤焦粉的资源化利用提供科学依据。 展开更多
关键词 化学链气化 碱木质素 煤焦粉 氧载体 可弃型催化剂
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煤直接化学链气化合成尿素过程建模与性能分析
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作者 崔富俊 刘旌江 周怀荣 《当代化工研究》 CAS 2024年第5期34-36,共3页
本文针对传统煤制尿素过程碳利用率低及二氧化碳捕集能耗高的问题,提出了煤直接化学链气化合成尿素的新工艺。本文对新工艺关键单元进行建模、模拟和性能分析。新工艺中CO_(2)、H2和N2分别来自于化学链技术的燃烧反应器,水蒸气反应器和... 本文针对传统煤制尿素过程碳利用率低及二氧化碳捕集能耗高的问题,提出了煤直接化学链气化合成尿素的新工艺。本文对新工艺关键单元进行建模、模拟和性能分析。新工艺中CO_(2)、H2和N2分别来自于化学链技术的燃烧反应器,水蒸气反应器和空气反应器,避免了高能耗的空分单元和气体分离单元,H2和N2用于合成氨,氨进一步与CO_(2)合成尿素。采用碳利用率和二氧化碳捕集能耗分析新艺的技术性能,生产成本和投资回收期分析其经济性能。结果表明煤直接化学链气化合成尿素工艺碳利用率为30.11%,相比于传统煤制尿素提高约7%,二氧化碳捕集能耗下降了97.04%。新工艺单位尿素成本相比传统工艺下降了12.18%,投资回收期缩短了4年。 展开更多
关键词 煤直接化学链气化 化学链制氢 煤制尿素 参数优化 性能分析
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Retention mechanism of calcium ferrite and compositions of ash on selenium during chemical looping gasification
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作者 Ziheng Han Huifen Kang +3 位作者 Nini Yuan Xintong Guo Jingjing Ma Qingjie Guo 《Particuology》 SCIE EI CAS CSCD 2023年第8期143-152,共10页
Selenium pollution by coal utilization is of increasing concern.Calcium-iron(Ca-Fe)oxygen carriers(OCs)and alkali metal ions have strong inhibitory effects on selenium,which can reduce the emissions of selenium vapor.... Selenium pollution by coal utilization is of increasing concern.Calcium-iron(Ca-Fe)oxygen carriers(OCs)and alkali metal ions have strong inhibitory effects on selenium,which can reduce the emissions of selenium vapor.The retention mechanisms of selenium by Fe_(2)O_(3),CaFe_(2)O_(4),Ca_(2)Fe_(2)O_(5) and bottom ash are investigated during chemical looping gasification(CLG).Iron-based OC can oxidize H_(2)Se(g)to SeO_(2)(g);furthermore,lattice oxygen is released by Fe_(2)O_(3),contributing to the formation of an Fe-O-Se structure to retain selenium and form selenite.Because calcium ferrite is poorly oxidizing,it cannot oxidize H_(2)Se(g),but the CaO produced when OCs are reduced can react with H_(2)Se(g)to form CaSe(s),and this process can be promoted by H_(2)S(g).The best retention rates reached 32.301%when Ca_(2)Fe_(2)O_(5) was used.In the cyclic experiment,the selenium retention of the bottom ash gradually increases.Alkali metal ions in bottom ash are the main factor in retaining selenium.Ca^(2+) and Mg^(2+) do not easily vaporize due to their high melting points;therefore,their selenium retention is significantly better than that of K^(+) and Na^(+).This research provided a new idea for the removal of selenium by using OCs and bottom ash par-ticles during CLG. 展开更多
关键词 SELENIUM chemical looping gasification Oxygen carrier Retention mechanism Ashcomposition
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A novel hybrid digestion-gasification process integrated with membranes for efficient conversion of biomass to bio-alcohols
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作者 Xuezhong He 《Green Energy & Environment》 SCIE CSCD 2021年第1期15-21,共7页
There is an urgent need to develop technologies which enable the conversion of biomass into liquid biofuels to fill the gap between limited fossil fuel supplies and increasing worldwide demand.In order to achieve the ... There is an urgent need to develop technologies which enable the conversion of biomass into liquid biofuels to fill the gap between limited fossil fuel supplies and increasing worldwide demand.In order to achieve the EU 2030 vision of at least 15%of the fuels used in the road transportation sector will be biofuels derived from non-food biomass feedstocks,the R&D of clean,inexpensive,highly end-user compatible biofuels from a virtually inexhaustible source of biomass should be pursued to make breakthroughs in cost-effective biomass to liquid biofuels(BTL)technologies.Thus,an innovative,consolidated,and sustainable technology using a hybrid digestion-gasification process integrated with membranes to produce next generation bio-alcohols from different biomass feedstocks was designed.The proposed concept was theoretically estimated to achieve an overall BTL efficiency of 44%and a cost reduction for bioalcohol production of 18.6%.Moreover,this technology can potentially achieve an overall CO2 emission reduction of>75%for road transport based on the preliminary analysis. 展开更多
关键词 Biofuels BIOMASS chemical looping gasification MEMBRANE Anaerobic digestion
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Simulation study on the gasification process of Ningdong coal with iron-based oxygen carrier
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作者 Fei Xie Mei An +3 位作者 Ping Li Xiude Hu Hongcun Bai Qingjie Guo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第1期326-334,共9页
Chemical looping gasification(CLG) of Ningdong coal by using Fe_(2) O_(3) as the oxygen carriers(OCs) was studied,and the gasification characteristics were obtained.A computation fluid dynamics(CFD) model based on Eul... Chemical looping gasification(CLG) of Ningdong coal by using Fe_(2) O_(3) as the oxygen carriers(OCs) was studied,and the gasification characteristics were obtained.A computation fluid dynamics(CFD) model based on Eulerian--Lagrangian multiphase framework was established,and a numerical simulation the coal chemical looping gasification processes in fuel reactor(FR) was investigated.In addition,the heterogeneous reactions,homogeneous reactions and Fe_(2) O_(3) oxygen carriers' reduction reactions were considered in the gasification process.The characteristics of gas flow and gasification in the FR were analyzed and it was found that the experiment results were consistent with the simulation values.The results show that when the O/C mole rate was 0.5:1,the gasification temperature was 900℃ and the water vapor volume flow rate was 2.2 ml·min^(-1),the mole fraction of syngas reached a maximum value of the experimental result and simulation value were 71.5% and 70.2%,respectively.When the O/C mole rate was 0.5:1,the gasification temperature was 900℃,and the water vapor volume flow was 1.8 ml·min^(-1);the gasification efficiency reached the maximum value was 62.2%,and the maximum carbon conversion rate was 84.0%. 展开更多
关键词 chemical looping gasification Fuel reactor gasification characteristics Fe_(2)O_(3)oxygen carrier
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生物质化学链气化-燃气轮机-有机朗肯循环发电
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作者 穆林 胡天才 +3 位作者 王震 黄贤坤 赵亮 尹洪超 《洁净煤技术》 CAS CSCD 北大核心 2023年第5期11-20,共10页
生物质化学链气化(BCLG)是具有发展前景的生物质利用和碳捕集技术,有机朗肯循环(ORC)是可提高能源品位的能源转化技术。为实现生物质能源高值化利用,提出了一种生物质化学链气化联合燃气轮机(GT)并耦合有机朗肯循环(ORC)的新型发电系统... 生物质化学链气化(BCLG)是具有发展前景的生物质利用和碳捕集技术,有机朗肯循环(ORC)是可提高能源品位的能源转化技术。为实现生物质能源高值化利用,提出了一种生物质化学链气化联合燃气轮机(GT)并耦合有机朗肯循环(ORC)的新型发电系统。该系统通过子系统间物质/能源交换实现了不同品位能源的梯级利用。采用Aspen Plus软件进行模拟,研究以玉米秸秆、稻秆及麦秆为气化燃料时,氧与生物质比(λ)和压气机压比(PR)等对BCLG-GT系统发电效率的影响。模拟结果表明,麦秆是3种生物质中应用于BCLG-GT系统的最优气化燃料,最佳模拟工况为:λ=0.05,P_(R)=13。在BCLG-GT子系统运行最佳工况基础上耦合ORC子系统,研究了4种不同有机流体工质(R245fa、R134a、HCFC-123和R-404A)和有无回热装置对ORC子系统发电效率的影响。结果表明:R245fa具有更高的实用价值与较好的环境友好性,相较其他3种有机流体工质具有明显优势;另外,加装回热装置后,ORC系统的净输出功率提高了13.37%,新型具有回热装置的BCLG-GT-ORC发电系统的净能量效率达35.48%。本研究为工业规模的生物质化学链气化装置的设计和优化提供思路和理论指导。 展开更多
关键词 生物质化学链气化 燃气轮机发电 有机朗肯循环 效率分析 Aspen Plus
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