Conversion of CO2 into CO using plasma processing powered by renewable energy is a promising method to convert intermittent sustainable electricity into storable chemical energy.Despite extensive research efforts worl...Conversion of CO2 into CO using plasma processing powered by renewable energy is a promising method to convert intermittent sustainable electricity into storable chemical energy.Despite extensive research efforts worldwide,there is currently no process that achieves economically viable values for both CO2 conversion fraction and energy recovery efficiency simultaneously.Here we demonstrate that a process that utilizes the Boudouard reaction,CO^2++C→2 CO,driven by a thermal plasma allows both 95%CO2 conversion to CO and energy recovery efficiency of 70%,values far higher than seen so far.By comparing the conversion process with and without CO2 excitation by a plasma and by using optical emission spectroscopy we show that the improved performance is due to a novel mode of operation where CO2 is pyrolyzed into an active mixture of CO,O and O2 by an arc discharge which is then introduced into a fixed bed to interact with carbon material.In this way,the free oxygen in the mixture combusts with carbon to form CO,and residual plasma excited CO2 is reduced by carbon.In the overall process,the endothermic Boudouard reaction is partially replaced by an exothermic reaction,and the excess electric energy to produce CO2 plasma is reused in the carbon bed.展开更多
The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a ...The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.展开更多
Coal-based ethanol production by hydration of ethylene is limited by the low equilibrium ethylene conversion at elevated temperature.To improve ethylene conversion,coupling hydration of ethylene with a potential ethan...Coal-based ethanol production by hydration of ethylene is limited by the low equilibrium ethylene conversion at elevated temperature.To improve ethylene conversion,coupling hydration of ethylene with a potential ethanol consumption reaction was analyzed thermodyna-mically.Five reactions have been attempted and compared:(1)dehydration of ethanol to ethyl ether(2C2H2OH5■C2H5OC2H5+H2O),(2)dehydrogenation of ethanol to acetaldehyde(C2H2OH5■CH3CHO+H2),(3)esterifica-tion of acetic acid with ethanol(C2H3OH+CH,COOH■CH3COOC2H5+H2O),(4)dehydrogenation of etha-nol to ethyl acetate(2C2H5OH■CH3COOC2H5+2H2),and(5)oxidative dehydrogenation of ethanol to ethyl acetate(2C2H2OH+O2■CH3COOC2H5+2H2O).The equilibrium constants and equilibrium distributions of the coupled reactions were calculated and the effects of feed composition,temperature and pressure upon the ethylene equilibrium conversion were examined.The results show that dehydrogenation of ethanol to acetaldehyde has lttle effect on ethylene conversion,whereas for dehydrogenation of ethanol to acetaldehyde and ethyl acetate,ethylene conversion can be improved from 8%to 12.8%and 18.5%,respectively,under conditions of H2O/C2H4=2,10 atm and 300℃.The esterification of acetic acid with ethanol can greatly enhance the ethylene conversion to 22.5%;in particular,ethylene can be actually completely converted to ethyl acetate by coupling oxidative dehydrogenation of ethanol.展开更多
The control system of a catalytic flow reversal reactor (CFRR) for the mitigation of ventilation air methane was investigated. A one-dimensional heteroge- neous model with a logic-based controller was applied to sim...The control system of a catalytic flow reversal reactor (CFRR) for the mitigation of ventilation air methane was investigated. A one-dimensional heteroge- neous model with a logic-based controller was applied to simulate the CFRR. The simulation results indicated that the controller developed in this work performs well under normal conditions. Air dilution and auxiliary methane injection are effective to avoid the catalyst overheating and reaction extinction caused by prolonged rich and lean feed conditions, respectively. In contrast, the reactor is prone to lose control by adjusting the switching time solely. Air dilution exhibits the effects of two contradictory aspects on the operation of CFRR, i.e., cooling the bed and accumulating heat, though the former is in general more prominent. Lowering the reference temperature for flow reversal can decrease the bed temperature and benefit stable operation under rich methane feed condition.展开更多
基金supported by the National Natural Science Foundation of China(Grants nos.11775155,51561135013,21603202)。
文摘Conversion of CO2 into CO using plasma processing powered by renewable energy is a promising method to convert intermittent sustainable electricity into storable chemical energy.Despite extensive research efforts worldwide,there is currently no process that achieves economically viable values for both CO2 conversion fraction and energy recovery efficiency simultaneously.Here we demonstrate that a process that utilizes the Boudouard reaction,CO^2++C→2 CO,driven by a thermal plasma allows both 95%CO2 conversion to CO and energy recovery efficiency of 70%,values far higher than seen so far.By comparing the conversion process with and without CO2 excitation by a plasma and by using optical emission spectroscopy we show that the improved performance is due to a novel mode of operation where CO2 is pyrolyzed into an active mixture of CO,O and O2 by an arc discharge which is then introduced into a fixed bed to interact with carbon material.In this way,the free oxygen in the mixture combusts with carbon to form CO,and residual plasma excited CO2 is reduced by carbon.In the overall process,the endothermic Boudouard reaction is partially replaced by an exothermic reaction,and the excess electric energy to produce CO2 plasma is reused in the carbon bed.
基金supported by the National Natural Science Foundation of China (Nos. 21901063, U20041101)Young Talents Personnel Fund of Henan Agricultural University (No. 30500604)。
文摘The preparation of intelligent-responsive materials with controllable topology structure has long been a significant objective for chemists in the field of materials science. In this paper, we designed and prepared a linear-cyclic reversible topological structure polymer based on the bistable [1]rotaxane molecular shuttle. A ferrocene-functionalized [1]rotaxane and naphthalimide fluorophore group are introduced into the both ends of the polymer, which exhibit distance-induced photo-electron transfer effect. The structural transformation between linear and cyclic state of polymer is demonstrated by simple acid-base stimuli, accompanying visual fluorescence changes. The transformation process was characterized by 1H NMR spectra and fluorescence spectra. This work provides a novel strategy to construct functionalized polymers with topological structure.
基金This work is supported by the National Key Research and Development Program of China(Grant No.2018YFB0604802)the Strategic Priority Rescarch Program of the Chinese Academy of Sciences(No.XDA21020500)+2 种基金the National Natural Science Foundation of China(Grant Nos.U1862101 and 21773281)the CAS/SAFEA International Partnership Program for Creative Research Teams(No.2015YC901)Natural Science Foundation of Shanxi Province of China(No.201601D202014).
文摘Coal-based ethanol production by hydration of ethylene is limited by the low equilibrium ethylene conversion at elevated temperature.To improve ethylene conversion,coupling hydration of ethylene with a potential ethanol consumption reaction was analyzed thermodyna-mically.Five reactions have been attempted and compared:(1)dehydration of ethanol to ethyl ether(2C2H2OH5■C2H5OC2H5+H2O),(2)dehydrogenation of ethanol to acetaldehyde(C2H2OH5■CH3CHO+H2),(3)esterifica-tion of acetic acid with ethanol(C2H3OH+CH,COOH■CH3COOC2H5+H2O),(4)dehydrogenation of etha-nol to ethyl acetate(2C2H5OH■CH3COOC2H5+2H2),and(5)oxidative dehydrogenation of ethanol to ethyl acetate(2C2H2OH+O2■CH3COOC2H5+2H2O).The equilibrium constants and equilibrium distributions of the coupled reactions were calculated and the effects of feed composition,temperature and pressure upon the ethylene equilibrium conversion were examined.The results show that dehydrogenation of ethanol to acetaldehyde has lttle effect on ethylene conversion,whereas for dehydrogenation of ethanol to acetaldehyde and ethyl acetate,ethylene conversion can be improved from 8%to 12.8%and 18.5%,respectively,under conditions of H2O/C2H4=2,10 atm and 300℃.The esterification of acetic acid with ethanol can greatly enhance the ethylene conversion to 22.5%;in particular,ethylene can be actually completely converted to ethyl acetate by coupling oxidative dehydrogenation of ethanol.
文摘The control system of a catalytic flow reversal reactor (CFRR) for the mitigation of ventilation air methane was investigated. A one-dimensional heteroge- neous model with a logic-based controller was applied to simulate the CFRR. The simulation results indicated that the controller developed in this work performs well under normal conditions. Air dilution and auxiliary methane injection are effective to avoid the catalyst overheating and reaction extinction caused by prolonged rich and lean feed conditions, respectively. In contrast, the reactor is prone to lose control by adjusting the switching time solely. Air dilution exhibits the effects of two contradictory aspects on the operation of CFRR, i.e., cooling the bed and accumulating heat, though the former is in general more prominent. Lowering the reference temperature for flow reversal can decrease the bed temperature and benefit stable operation under rich methane feed condition.