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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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Journal of Environmental Sciences 2024年第4期138卷 428-438页

作者： Jing Yang Yujie ren Shuoyu Chen Jinsuo lu School of Environmental and Municipal Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

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.

关键词： Metal-supported composite phosphogypsum Reaction characteristics Thermodynamic mechanism Chemical looping gasification

Effect of low-temperature treatment on bacterial cultivation in bacterial induced mineralization

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Science China(Technological Sciences) 2022年第4期65卷 870-881页

作者： WANG lu LIU ShuHua ren Jun State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China School of Architecture and Planning Yunnan UniversityKunming 650051China

In this paper,the effect of low-temperature treatment on bacterial activity was investigated and its performance in preparing the consolidated sand was accessed.Four factors,including absorbance(OD600),p H,electric conductivity(EC)and urease activity(UA)were monitored to evaluate the bacterial activity.Moreover,the calcium carbonate yields under different bacterial solution and cementation solution volume ratios were determined.Finally,the compressive strength and microstructure of consolidated sand were investigated and the mechanism was explored by characterising the products among sand particles.The results showed that for both continuous and interval cultivation of bacteria,stable bacterial solution was harvested within the cultivation period of 30 h.Low-temperature treatment showed limited inhibition at early cultivation stage,while it had strong inhibition at middle cultivation stage.The interval cultivation improved the cultivation efficiency of bacteria.It was observed that the low-temperature preservation for a stable bacterial solution has little influence on UA before 4 days,while UA decreased seriously after its preservation time was extended to over 8 days.The optimal volume ratio of bacterial solution and substrate solution was 1:1,resulting in the highest calcium carbonate yield.The improved compressive strength of consolidated sand after 3 injections was attributed to the irregular-shaped calcite products,which coated and bonded the sand grains together.

关键词： microbial mineralization cultivation methods low-temperature treatment bacterial activity microstructure

Partners in Epoxide Copolymerization Catalysis:Approach to High Activity and Selectivity

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Chinese Journal of Polymer Science 2022年第11期40卷 1331-1348页

作者： Xiao-Bing lu Bai-Hao ren State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

The ring-opening alternating copolymerization processes of epoxides with small-molecule monomers,such as carbon dioxide(CO_(2)),carbonyl sulfide(COS)and cyclic anhydrides,are powerful strategies for preparing polymeric materials with degradable carbonate/ester/thiocarbonate main-chain backbone units.The catalysts selected for copolymerization processes play crucial roles in determining their reaction rates and productivities,as well as the selectivity,regio-and stereochemistry,compositions,and the molecular weights of their resultant copolymers.These processes often generate undesirable byproducts such as polyether or ether linkages dispersed randomly within the copolymer's chain,and/or more thermodynamically stable cyclic products.In this account,we outline our efforts of over a dozen years on developing highly active well-defined metal catalysts based on inter-and intra-molecular synergistic strategies to selectively produce completely alternating copolymers from epoxides and various small-molecule monomers.Much attention was paid to the enantioselective resolution copolymerization processes of racemic epoxides via regioselective ring-openings,and the asymmetric copolymerization processes of meso-epoxides with CO_(2),COS,or cyclic anhydrides via dissymmetrical ring-openings using multichiral catalytic systems,and affording isotactic copolymers with main-chain chirality.In addition,this account provides a thorough mechanistic understanding of the high reactivities,excellent selectivity,and unprecedented stereochemical controls of these copolymerization systems,mediated by interand intramolecular synergistic catalysis.

关键词： Epoxide Ring-opening copolymerization Synergistic catalysis CO_(2) Stereochemistry control

Utilization of porous liquids for catalytic conversion

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Chinese Journal of Structural Chemistry 2023年第4期42卷 7-9页

作者： Yewei ren Guosheng Zhou Ziyang lu Institute of Environmental Health and Ecological Security School of the Environment and Safety EngineeringJiangsu UniversityZhenjiangJiangsu212013China Institute of the Green Chemistry and Chemical Technology School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiangJiangsu212013China Jiangsu Collaborative Innovation Center of Technol0gy and Material of Water Treatment Suzhou University of Science and Technology SuzhouJiangsu215009China

Porous liquids,an emerging type of flowing liquid materials,are composed of porous solids and polymer chains/sterically hindered sol-vents,combining the advantages of porous solids'permanent porosity and liquid's fluidity.Therefore,porous liquids have shown enormous potentials in many applications.However,these applications are limited to gas adsorption[1],transport[2]and separation[3],which is unfa-vorable for the development of porous liquids.Therefore,expanding the application of porous liquids in other fields is quite meaningful.

关键词： porous liquids solids

A disturbance observer based intelligent control for nonstrict-feedback nonlinear systems

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Science China(Technological Sciences) 2023年第2期66卷 456-467页

作者： ren HongRu MA Hui LI HongYi Lu RenQuan School of Automation and Guangdong Province Key Laboratory of Intelligent Decision and Cooperative Control Guangdong University of TechnologyGuangzhou 510006China Department of New Networks Peng Cheng LaboratoryShenzhen 518055China School of Mathematics and Statistics Guangdong University of TechnologyGuangzhou 510006China

Focusing on one class of nonlinear systems with input saturation,the adaptive fuzzy dynamic event-triggered control problem is successfully solved.A dynamic event-triggered mechanism is adopted to save the communication burden of the system,and is integrated into the controller design process based on the backstepping technique.For handling the asymmetric input saturation,an auxiliary system with the same order as the considered system is constructed.Analysis problems caused by unknown continuous functions are efficiently tackled by applying the approximation theory of fuzzy logic systems.It is proven that all the signals of the resulting closed-loop system are bounded via Lyapunov stability analysis.Both numerical and practical simulations are presented to demonstrate the effectiveness of the theoretical results.

关键词： intelligent control dynamic event-triggered mechanism disturbance observer

Improving SINR via Joint Beam and Power Management for GEO and LEO Spectrum-Sharing Satellite Communication Systems

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China Communications 2022年第7期19卷 25-36页

作者： Xiaojin Ding Zhuangzhuang ren Huanbin lu Gengxin Zhang Telecommunication and Networks National Engineering Research Center Nanjing University of Posts and TelecommunicationsNanjing 210003China

In this paper,we investigate a geosynchronous earth orbit(GEO)and low earth orbit(LEO)coexisting satellite communication system.To decrease the interference imposed on the GEO user caused by LEO satellites,we propose a joint beammanagement and power-allocation(JBMPA)scheme to maximize signal-to-interference plus noise ratio(SINR)at the GEO user,whilst maintaining the ongoing wireless links spanning from LEO satellites to their corresponding users.Specifically,we first analyze the overlapping coverage among GEO and LEO satellites,to obtain the LEO-satellite set in which their beams impose interference on the GEO user.Then,considering the traffic of LEO satellites in the obtained set,we design a beam-management method to turn off and switch interference beams of LEO satellites.Finally,we further propose a deep Q-network(DQN)aided power allocation algorithm to allocate the transmit power for the ongoing LEO satellites in the obtained set,whose beams are unable to be managed.Numerical results show that comparing with the traditional fixed beam with power allocation(FBPA)scheme,the proposed JBMPA can achieve a higher SINR and a lower outage probability,whilst guaranteeing the ongoing wireless transmissions of LEO satellites.

关键词： beam management deep Q-network GEO-LEO coexisting power allocation

Modification of Melting Combustion Kinetic Model of Fine Ash from Entrained-Flow Gasifier

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Journal of Thermal Science 2024年第1期33卷 300-310页

作者： WANG Wenyu LI Wei lu Yu ren Qiangqiang LYU Qinggang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Dalian National Laboratory for Clean Energy Chinese Academy of SciencesDalian 116023China

Coal gasification technology is a prominent technology in the coal chemical industry and serves as the fundamental basis for various process industries,including coal-based chemicals,coal-based liquid fuels,Integrated Gasification Combined Cycle(IGCC) power generation,multi-generation systems,hydrogen production,and fuel cells.The gasification process generates significant quantities of ash residue,with annual emissions exceeding tens of millions of tons and accumulation reaching hundreds of millions of tons.Accordingly,there is an urgent need to investigate methods for its disposal.The combustion of gasified fine ash(GFA) was conducted in a tube furnace,and the conventional shrinking core model was modified to accurately predict the combustion behaviors at different temperatures(900℃-1500℃).We divided the reaction temperatures into three ranges,which is defined as unmelted combustion(TFT) and mixed combustion(DTFT),the surface ash of GFA grains fell off,and the residual carbon and gas-phase reactants were nearly no longer affected by the diffusion resistance,thus significantly accelerated the reaction of internal residual carbon.In order to predict the melt combustion process more accurately,the time term of the shrinkage core model(SCM) is modified,and the effective diffusion coefficient of T>FT is defined.

关键词： fine ash melting combustion kinetic model combustion characteristics

Neuronal autophagy aggravates microglial inflammatory injury by downregulating CX3CL1/fractalkine after ischemic stroke

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Neural Regeneration Research 2019年第2期14卷 280-288页

作者： Hong-Yun He Lu Ren Tao Guo Yi-Hao Deng Department of Basic Medicine Medical School Kunming University of Science and Technology

Ischemic stroke often induces excessive neuronal autophagy, resulting in brain damage; meanwhile, inflammatory responses stimulated by ischemia exacerbate neural injury. However, interactions between neuronal autophagy and microglial inflammation following ischemic stroke are poorly understood. CX3CL1/fractalkine, a membrane-bound chemokine expressed on neurons, can suppress microglial inflammation by binding to its receptor CX3CR1 on microglia. In the present study, to investigate whether autophagy could alter CX3CL1 expression on neurons and consequently change microglial inflammatory activity, middle cerebral artery occlusion(MCAO) was established in Sprague-Dawley rats to model ischemic stroke, and tissues from the ischemic penumbra were obtained to evaluate autophagy level and microglial inflammatory activity. MCAO rats were administered 3-methyladenine(autophagy inhibitor) or Tat-Beclin 1(autophagy inducer). Western blot assays were conducted to quantify expression of Beclin-1, nuclear factor kappa Bp65(NF-κB), light chain 3B(LC3B), and CX3CL1 in ischemic penumbra. Moreover, immunofluorescence staining was performed to quantify numbers of LC3B-, CX3CL1-, and Iba-1-positive cells in ischemic penumbra. In addition, enzyme linked immunosorbent assays were utilized to analyze concentrations of tumor necrosis factor alpha(TNF-α), interleukin 6(IL-6), interleukin 1 beta(IL-1β), and prostaglandin E2(PGE2). A dry/wet weight method was used to detect brain water content, while 2,3,5,-triphenyltetrazolium chloride staining was utilized to measure infarct volume. The results demonstrated that autophagy signaling(Beclin-1 and LC3B expression) in penumbra was prominently activated by MCAO, while CX3CL1 expression on autophagic neurons was significantly reduced and microglial inflammation was markedly activated. However, after inhibition of autophagy signaling with 3-methyladenine, CX3CL1 expression on neurons was obviously increased, whereas Iba-1 and NF-κB expression was downregulated; TNF-α, IL-6, IL-1β, and PGE2 leve

关键词： nerve regeneration ischemic stroke neuronal autophagy microglial inflammation CX3CL1 autophagic neurons autophagy induction autophagy inhibition neural regeneration

The risk factors and threshold level of subchronic inhalation exposure of reclaimed water

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Journal of Environmental Sciences 2024年第3期137卷 639-650页

作者： Jiayang Kong Yun lu Yunru ren Menghao Chen Gang Liu Liangliang Shi State Key Joint Laboratory of Environment Simulation and Pollution Control State Environment Protection Key Laboratory of Microorganism Application and Risk ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China

Inhalation of reclaimed water is known to cause lung infammation,and free endotoxins have been shown to be a major risk factor for acute exposure.Subchronic exposure has also been shown to induce infammatory responses with visible tissue damage.However,subchronic risk factors have yet to be identified,and a threshold for the protection of occupational populations during urban reuse is necessary.In this study,potential risk factors in reclaimed water were examined by subchronic exposure with fractionated reclaimed water,and the health risk threshold was tested with a series of diluted reclaimed water.Accordingly,following a 12-week exposure,macromolecules and microorganisms were found to be two major risk factors in reclaimed water that could cause pulmonary infammation,including increased proportion of polymorphonuclear leukocytes in bronchoalveolar fuid,formation of inducible bronchus-associated lymphoid tissue,and elevation of Immunoglobulin A levels.Moreover,infammation persisted after a 4-week recovery period.The calculated threshold of reclaimed water exposure for mice was 31.8 Endotoxin Unit(EU)/(kg·day)under when exposed to 50%additional relative humidity from reclaimed water at 25℃ for 2 hr/day.Meanwhile,the subchronic threshold estimate for humans under the same exposure conditions was found to be 12.2 EU/(kg·day),corresponding to endotoxin levels of 61.7 EU/mL in reclaimed water.The threshold level of endotoxin was lower than that in most non-potable reclaimed water.The findings of this study suggest that occupational exposure of reclaimed water can serve as a potential risk to workers.

关键词： Reclaimed water Inhalation exposure Risk factor Threshold Infammation Endotoxin