Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was i...Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was initially adsorbed on the porous ATPs, and then the enriched MB was removed by the H2O2-assisted Fenton-like oxidation with the iron-containing ATP catalyst. Under optimal conditions, the ATP powder exhibits the maximum removal efficiency of 100% with negligible iron leaching(1.5 mg L^(-1)) and no sludge formation. Furthermore,polysulfone/ATP(PSF/ATP) pellets were fabricated through a water-induced phase separation process to construct a fixed-bed reactor(FBR) for continuous contaminant removal. For the first cycle, the maximum adsorption capacity was 15.5 L with an outlet MB concentration of1.973 mg L-1(< 2 mg L^(-1), GB4287-2012) using the PSF/ATP pellets containing 50.0 g of ATP powders, and the maximum Fenton-like oxidation capacity was 35.5 L with the outlet concentration of 0.831 mg L^(-1). After five cycles, the total treated volume of the MB solution was ca. 255 L, and the efficiency remained above 99%. After 10 h of continuous treatment towards practical resin industrial wastewater, the chemical oxygen demand(COD) removal efficiency was still measured at 83.05%, costing 0.398 $ m^(-3). These results demonstrate the practical applicability of iron-containing low-grade ATP clay for textile water treatment.展开更多
Adsorptive reactors(AR),in which an adsorptive functionality is incorporated into the catalytic reactors,offer enhanced performance over their conventional counterparts due to the effective manipulation of concentrati...Adsorptive reactors(AR),in which an adsorptive functionality is incorporated into the catalytic reactors,offer enhanced performance over their conventional counterparts due to the effective manipulation of concentration and temperature profiles.The operation of these attractive reactors is,however,inherently unsteady state,complicating the design and operation of such sorption-enhanced processes.In order to capture,comprehend and capitalize upon the rich dynamic texture of adsorptive reactors,it is necessary to employ cyclic steady state algorithms describing the entire reaction-adsorption/desorption cycle.The stability of this cyclic steady state is of great importance for the design and operation of adsorptive reactors.In this paper,the cyclic steady state of previously proposed novel adsorptive reactor designs has been calculated and then optimized to give maximum space–time yields.The results obtained revealed unambiguously that an improvement potential of up to multifold level could be attained under the optimized cyclic steady state conditions.This additional improvement resulted from the reduction of the regeneration time well below the reaction-adsorption time,which means,in turn,more space–time yield.展开更多
The use of metal-organic frameworks (MOFs) as CO_(2)-gas-capture materials has attracted extensive research attention. In this study, two types of MOFs—Zn-MOF and ZnCe-MOF—were synthesized utilizing the microchannel...The use of metal-organic frameworks (MOFs) as CO_(2)-gas-capture materials has attracted extensive research attention. In this study, two types of MOFs—Zn-MOF and ZnCe-MOF—were synthesized utilizing the microchannel reaction method, with water being employed as the solvent. The specific surface area, pore size, and pore volume of Zn-MOF and ZnCe-MOF were 1566.4 and 15.6 m^(2)·g^(-1), 0.65 and 7.32 nm, as well as 1.65 and 0.03 cm^(3)·g^(-1), respectively. Furthermore, Ce doping not only increased the pore size of ZnCe-MOF but also its adsorption energy from −0.19 eV (Zn-MOF) to −0.53 eV (ZnCe-MOF). At 298 K, the adsorption capacities of Zn-MOF and ZnCe-MOF were 0.66 and 0.74 mmol·g^(-1), respectively. In addition, the CO_(2) adsorption behaviors of Zn-MOF and ZnCe-MOF were linear and logarithmic, respectively. Theoretical calculations show that the results of adsorption thermodynamic simulations were consistent with the experiments. Thus, the preparation of ZnCe-MOF materials using a microchannel reactor provides a new approach for the continuous preparation of MOFs.展开更多
Carbon dioxide(CO2),the main gas emitted from fossil burning,is the primary contributor to global warming.Circulating fluidized bed reactor(CFBR)is proved as an energy-efficient method for post-combustion CO2 capture....Carbon dioxide(CO2),the main gas emitted from fossil burning,is the primary contributor to global warming.Circulating fluidized bed reactor(CFBR)is proved as an energy-efficient method for post-combustion CO2 capture.The numerical simulation by computational fluid dynamics(CFD)is believed as a promising tool to study CO2 adsorption process in CFBR.Although three-dimensional(3D)simulations were proved to have better predicting performance with the experimental results,two-dimensional(2D)simulations have been widely reported for qualitative and quantitative studies on gas-solid behavior in CFBR for its higher computational efficiency recently.However,the discrepancies between 2D and 3D simulations have rarely been evaluated by detailed study.Considering that the differences between the 2D and 3D simulations will vary substantially with the changes of independent operating conditions,it is beneficial to lower computational costs to clarify the effects of dimensionality on the numerical CO2 adsorption runs under various operating conditions.In this work,the comparative analysis for CO2 adsorption in 2D and 3D simulations was conducted to enlighten the effects of dimensionality on the hydrodynamics and reaction behaviors,in which the separation rate,species distribution and hydrodynamic characteristics were comparatively studied for both model frames.With both accuracy and computational costs considered,the viable suggestions were provided in selecting appropriate model frame for the studies on optimization of operating conditions,which directly affect the capture and energy efficiencies of cyclic CO2 capture process in CFBR.展开更多
基金supported by Gansu Cuihua Technology Co.,Ltd.(H2020292)Science and Technology Planning of Baiyin City,Fundamental Research Funds for the Central Universities (buctrc202208)+2 种基金Engineering Research Center of Non-metallic Minerals of Zhejiang Province and the Beijing Engineering Center for Hierarchical Catalysts. Central Government Guiding Funds for Local Science and Technology Development (2022ZY015)Nanjiang Technology Project(2023AB028)Open Laboratory of State Key Laboratory of Organic and Inorganic Composites (oic-202301006)。
文摘Coupling adsorption and in-situ Fenton-like oxidation process was developed for Methylene blue(MB) using refined iron-containing lowgrade attapulgite(ATP) clay, and the removal mechanism was investigated. The MB was initially adsorbed on the porous ATPs, and then the enriched MB was removed by the H2O2-assisted Fenton-like oxidation with the iron-containing ATP catalyst. Under optimal conditions, the ATP powder exhibits the maximum removal efficiency of 100% with negligible iron leaching(1.5 mg L^(-1)) and no sludge formation. Furthermore,polysulfone/ATP(PSF/ATP) pellets were fabricated through a water-induced phase separation process to construct a fixed-bed reactor(FBR) for continuous contaminant removal. For the first cycle, the maximum adsorption capacity was 15.5 L with an outlet MB concentration of1.973 mg L-1(< 2 mg L^(-1), GB4287-2012) using the PSF/ATP pellets containing 50.0 g of ATP powders, and the maximum Fenton-like oxidation capacity was 35.5 L with the outlet concentration of 0.831 mg L^(-1). After five cycles, the total treated volume of the MB solution was ca. 255 L, and the efficiency remained above 99%. After 10 h of continuous treatment towards practical resin industrial wastewater, the chemical oxygen demand(COD) removal efficiency was still measured at 83.05%, costing 0.398 $ m^(-3). These results demonstrate the practical applicability of iron-containing low-grade ATP clay for textile water treatment.
基金the German research council(Deutsche Forschungsgemeinschaft) for their financial support to the project:AG 26/18-1
文摘Adsorptive reactors(AR),in which an adsorptive functionality is incorporated into the catalytic reactors,offer enhanced performance over their conventional counterparts due to the effective manipulation of concentration and temperature profiles.The operation of these attractive reactors is,however,inherently unsteady state,complicating the design and operation of such sorption-enhanced processes.In order to capture,comprehend and capitalize upon the rich dynamic texture of adsorptive reactors,it is necessary to employ cyclic steady state algorithms describing the entire reaction-adsorption/desorption cycle.The stability of this cyclic steady state is of great importance for the design and operation of adsorptive reactors.In this paper,the cyclic steady state of previously proposed novel adsorptive reactor designs has been calculated and then optimized to give maximum space–time yields.The results obtained revealed unambiguously that an improvement potential of up to multifold level could be attained under the optimized cyclic steady state conditions.This additional improvement resulted from the reduction of the regeneration time well below the reaction-adsorption time,which means,in turn,more space–time yield.
基金supported by the Xinjiang Science and Technology Program(Grant No.2023TSYCCX0118).
文摘The use of metal-organic frameworks (MOFs) as CO_(2)-gas-capture materials has attracted extensive research attention. In this study, two types of MOFs—Zn-MOF and ZnCe-MOF—were synthesized utilizing the microchannel reaction method, with water being employed as the solvent. The specific surface area, pore size, and pore volume of Zn-MOF and ZnCe-MOF were 1566.4 and 15.6 m^(2)·g^(-1), 0.65 and 7.32 nm, as well as 1.65 and 0.03 cm^(3)·g^(-1), respectively. Furthermore, Ce doping not only increased the pore size of ZnCe-MOF but also its adsorption energy from −0.19 eV (Zn-MOF) to −0.53 eV (ZnCe-MOF). At 298 K, the adsorption capacities of Zn-MOF and ZnCe-MOF were 0.66 and 0.74 mmol·g^(-1), respectively. In addition, the CO_(2) adsorption behaviors of Zn-MOF and ZnCe-MOF were linear and logarithmic, respectively. Theoretical calculations show that the results of adsorption thermodynamic simulations were consistent with the experiments. Thus, the preparation of ZnCe-MOF materials using a microchannel reactor provides a new approach for the continuous preparation of MOFs.
基金supported by the National Natural Science Foundation of China(21506181,21506179)Natural Science Foundation of Hunan Province(2020JJ3033,2019JJ40281,2018SK2027,2018RS3088,2019SK2112)+1 种基金Research Foundation of Education Bureau of Hunan Province(18B088)Hunan Key Laboratory of Environment Friendly Chemical Process Integration and Hunan 2011 Collaborative Innovation Center of Chemical Engineering&Technology with Environmental Benignity and Effective Resource Utilization,State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2020-KF-11).
文摘Carbon dioxide(CO2),the main gas emitted from fossil burning,is the primary contributor to global warming.Circulating fluidized bed reactor(CFBR)is proved as an energy-efficient method for post-combustion CO2 capture.The numerical simulation by computational fluid dynamics(CFD)is believed as a promising tool to study CO2 adsorption process in CFBR.Although three-dimensional(3D)simulations were proved to have better predicting performance with the experimental results,two-dimensional(2D)simulations have been widely reported for qualitative and quantitative studies on gas-solid behavior in CFBR for its higher computational efficiency recently.However,the discrepancies between 2D and 3D simulations have rarely been evaluated by detailed study.Considering that the differences between the 2D and 3D simulations will vary substantially with the changes of independent operating conditions,it is beneficial to lower computational costs to clarify the effects of dimensionality on the numerical CO2 adsorption runs under various operating conditions.In this work,the comparative analysis for CO2 adsorption in 2D and 3D simulations was conducted to enlighten the effects of dimensionality on the hydrodynamics and reaction behaviors,in which the separation rate,species distribution and hydrodynamic characteristics were comparatively studied for both model frames.With both accuracy and computational costs considered,the viable suggestions were provided in selecting appropriate model frame for the studies on optimization of operating conditions,which directly affect the capture and energy efficiencies of cyclic CO2 capture process in CFBR.
