Modified Ca-based sorbents were obtained by adding sodium alkali into Ca(OH)2 and CaCO3. Reactive properties of modified Ca-based sorbents with acidic gases were investigated through reacting with gaseous HC1 at 450-...Modified Ca-based sorbents were obtained by adding sodium alkali into Ca(OH)2 and CaCO3. Reactive properties of modified Ca-based sorbents with acidic gases were investigated through reacting with gaseous HC1 at 450-760℃, and SEM and XRD technologies were adopted to get information on the reaction mechanism. Experimental data showed that HC1 dry removal efficiencies increased with temperature before 700℃ for all of the investigated sorbents, and there existed improved sorbents that corresponded to the highest removal efficiencies under the similar conditions. SEM photographs exhibited morphology difference between original and improved sorbents both before and after the reaction; and displayed that improved sorbents formed more porous product layers than original sorbents especially at higher temperature when product sintering became heavier, which is favorable to HC1 dry removal. XRD analysis showed that (1) improved Ca(OH)2 and CaCO3 were less crystalline than original lime and limestone; (2) the reaction product species of improved Ca(OH)2 changed with reaction temperature, while for original Ca(OH)2 the same product species appeared for all of the tested temperatures; and (3) for improved CaCO3, the only product at lower temperatures was CaCl2.2H2O and more product species were produced when temperature was higher than 650℃, but no CaCl2.Ca(OH)2.H2O formed at 700℃, while for the case of original CaCO3, the undesired CaCl2.Ca(OH)2.H2O appeared at 700℃. Presently, reaction temperature interval of 650-700℃ is recommended for improved Ca(OH2) to get the highest efficiency, for improved CaCO3 reaction at higher temperature deserves further investigation to make a good choice.展开更多
Wastewater plays a crucial role in deteriorating water quality and can significantly affect human health and ecosystems if discharged without proper treatment.Among available treatment methods,adsorption is often cons...Wastewater plays a crucial role in deteriorating water quality and can significantly affect human health and ecosystems if discharged without proper treatment.Among available treatment methods,adsorption is often considered an effective,relatively inexpensive,and environmentally friendly purification technique,but its efficiency depends on the sorbents used.The use of low-cost biosorbents with high adsorption capacity is widely studied.These include various biomaterials such as microalgae,cyanobacteria,fungi,and plant materials.The utilization of different biosorbents derived from plant waste,such as Paulownia wood,aspen,hickory,Ziziphus bark,peach tree shavings,as well as grasses such as red fescue and reed,and Sargassum algae in natural and modified forms,is a crucial research direction.Such studies highlight the potential to address waste issues by repurposing it as biosorbents.Several studies have examined the ability of different biosorbents to treat wastewater and suggested that the physicochemical properties of the material's surface,such as specific surface area,pore size,and pore volume,play a decisive role in adsorption capacity.A quantitative analysis of plant-based biosorbents will significantly aid in developing water treatment systems and achieving optimal adsorption through modifications of their physicochemical properties.Furthermore,the analysis will help understand the relative importance of each physicochemical property in determining adsorption capacity,thereby contributing to the implementation of treatment methods targeting specific pollutants.展开更多
Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,...Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.展开更多
Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both techn...Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.展开更多
A kind of industrial solid waste, i.e., carbide slag, was used as CaO precursor to synthesize CO2 sorbent. The highly reactive synthetic sorbent was prepared from carbide slag, aluminum nitrate hydrate and glycerol wa...A kind of industrial solid waste, i.e., carbide slag, was used as CaO precursor to synthesize CO2 sorbent. The highly reactive synthetic sorbent was prepared from carbide slag, aluminum nitrate hydrate and glycerol water solution by the combustion synthesis method. The results show that the synthetic sorbent exhibits a much higher CO2 capture capacity compared with carbide slag. The CO2 capture capacity and the carbonation conversion of the synthetic sorbent are 0. 38 g/g and 0. 70 after 50 cycles, which are 1.8 and 2. 1 times those of carbide slag. The average carbonation conversion and the CO2 capture efficiency of the synthetic sorbent are higher than those of carbide slag with the same sorbent flow ratios. The required sorbent flow ratios are lower for synthetic sorbent to achieve the same CO2 capture efficiency compared with carbide slag. With the same sorbent flow ratio and CO2 capture efficiency, the energy requirement in calciner for the synthetic sorbent is less than that for carbide slag.展开更多
Under the Paris agreement, China has committed to reducing CO_2 emissions by 60%–65% per unit of GDP by 2030.Since CO_2 emissions from coal-fired power plants currently account for over 30% of the total carbon emissi...Under the Paris agreement, China has committed to reducing CO_2 emissions by 60%–65% per unit of GDP by 2030.Since CO_2 emissions from coal-fired power plants currently account for over 30% of the total carbon emissions in China, it will be necessary to mitigate at least some of these emissions to achieve this goal. Studies by the International Energy Agency(IEA) indicate CCS technology has the potential to contribute 14% of global emission reductions, followed by 40% of higher energy efficiency and 35% of renewable energy, which is considered as the most promising technology to significantly reduce carbon emissions for current coal-fired power plants.Moreover, the announcement of a Chinese national carbon trading market in late 2017 signals an opportunity for the commercial deployment of CO_2 capture technologies.Currently, the only commercially demonstrated technology for post-combustion CO_2 capture technology from power plants is solvent-based absorption. While commercially viable, the costs of deploying this technology are high. This has motivated efforts to develop more affordable alternatives, including advanced solvents, membranes,and sorbent capture systems. Of these approaches, advanced solvents have received the most attention in terms of research and demonstration. In contrast, sorbent capture technology has less attention, despite its potential for much lower energy consumption due to the absence of water in the sorbent. This paper reviews recent progress in the development of sorbent materials modified by amine functionalities with an emphasis on material characterization methods and the effects of operating conditions on performance. The main problems and challenges that need to be overcome to improve the competitiveness of sorbent-based capture technologies are discussed.展开更多
Oxides of silicon, aluminium and calcium are normally dominant minerals during municipal solid waste(MSW)combustion. In flue gas, Si O2, Al2O3 and Ca O all act as sorbents capturing heavy metals(and semi-volatile orga...Oxides of silicon, aluminium and calcium are normally dominant minerals during municipal solid waste(MSW)combustion. In flue gas, Si O2, Al2O3 and Ca O all act as sorbents capturing heavy metals(and semi-volatile organics). To further understand the effect of sorbents during MSW combustion, the effects of Si O2, Al2O3 and Ca O on Cu partitioning were experimentally investigated by the combustion of synthetic MSW in a tubular furnace and their effects on Cu speciation were studied by thermodynamic equilibrium calculations using Chem Kin software. The experiments show that Ca O has the highest Cu sorption efficiency at 900 °C, followed by Al2O3 and Si O2. Thermodynamic equilibrium calculations show that for Cu the addition of Si O2 and Al2O3reduces the amount of liquid Cu Cl, which is more volatile. However, the addition of Ca O has little influence on chemical sorption of Cu, indicating that the sorption of Ca O is resulted from physical sorption.展开更多
In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic ...In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions （SO4^2-, H2PO4^-, NO3^-, and NO2^-） were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.展开更多
Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearl...Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearly detected in the outlet gas before 20 h breakthrough time.The effects of the main operational conditions and the particle size of Z20SC sorbent on its desulfurization performances sorbent were investigated in a fixed-bed reactor and the desulfurization kinetics of Z20SC sorbent removing H2 S from hot coal gas was calculated based on experimental data.Results showed that the conversion of Z20SC sorbent desulfurization reaction increased with the decrease of the particle size of the sorbent and the increases of gas volumetric flow rate,reaction temperature and H 2 S content in inlet gas.Z20SC sorbent obtained from hydrothermal synthesis by high-pressure impregnation possessed much larger surface area and pore volume than semi-coke support,and they were significantly reduced after the desulfurization reaction.The equivalent grain model was reasonably used to analyze experimental data,in which k s=4.382×10-3 exp（-8.270×103/RgT） and Dep=1.262×10-4exp（1.522×104/RgT）.It suggests that the desulfurization reaction of the Z20SC sorbent is mainly controlled by the chemical reaction in the initial stage and later by the diffusion through the reacted sorbent layer.展开更多
Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from ...Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from coal gasifier gas to very low levels. In this paper, zinc ferrites prepared by co-precipitation were identified as a novel coal gas desulfurization sorbent at high temperature. Preparation of zinc ferrite and effects of binders on pore volume, strength and desulfurization efficiency of zinc ferrite desulfurizer were studied. Moreover, the behavior of zinc ferrite sorbent during desulfurization and regeneration under the temperature range of 350-400 ℃ are investigated. Effects of binders on the pore volume, mechanical strength and desulfurization efficiency of zinc ferrite sorbents indicated that the addition of kaolinite to zinc ferrite desulfurizer seems to be superior to other binders under the experimental conditions.展开更多
With lignite after vacuum drying as the raw material,a series of Zn-based sorbents were prepared by static impregnation,ultrasonic-assisted impregnation,bubbling-assisted impregnation and high-pressure impregnation.Th...With lignite after vacuum drying as the raw material,a series of Zn-based sorbents were prepared by static impregnation,ultrasonic-assisted impregnation,bubbling-assisted impregnation and high-pressure impregnation.The physical properties and the desulfurization performances of Zn-based sorbents were studied systematically by XRD,BET,AAS characterization techniques and the fixed-bed desulfurization evaluation apparatus.The sorbents obtained by high-pressure impregnation method have a larger specific surface area,pore volume and pore diameter comparing with other methods,which is conducive to the sulfidation reaction of hydrogen sulfide gas in the sorbent.The effects of pressure during the high-pressure impregnation and concentration of Zn(NO3)2 precursor solution on the sorbents properties and desulfurization behavior were investigated.The higher the impregnation pressure and the concentration of impregnation solution are,the greater the amount of the active components are uploaded.However,overhigh impregnation pressure can cause collapse and blocking of the carrier pore.The optimal operating condition of high-pressure impregnation method for preparing the sorbents was the impregnation pressure of 20 atm and the solution concentration of 41%.Under that condition,the sorbent had the best desulfurization ability with a sulfur capacity of 13.94 gS/100 gsorbent and a breakthrough time of 54 h.Its desulfurization precision and efficiency of removing H2S before sorbent breakthrough from the middle temperature gases of 400℃ can reach【5 ppm and】99%,respectively.Sorbents could be regenerated under the condition of 1 vol%O2,20 vol% H2O,0.5 vol% NH3,and N2balance gas.The regenerated sorbent could be used for repeated absorption of H2S with a slight decrease in desulfurization effect.展开更多
A new industrial S Zorb sorbent(Ni/Zn O-P) was prepared by using the spray drying technique. The other two traditional sorbents(Ni/Zn O-M and Ni/Zn O-H) were prepared in exactly the same way except the use of differen...A new industrial S Zorb sorbent(Ni/Zn O-P) was prepared by using the spray drying technique. The other two traditional sorbents(Ni/Zn O-M and Ni/Zn O-H) were prepared in exactly the same way except the use of different silica-alumina binder matrices. The XRD, Rietveld quantitative phase analysis, BET, and laser particle size analysis were employed to characterize their physico-chemical properties. The deactivation mechanism and desulfurization kinetics of sorbent was investigated on a water vapor aging treatment device. It was shown that both the water vapor pressure and reaction temperature significantly could influence the formation rate of inactive Zn2 Si O4, which could decrease the sulfur storage capacity of sorbents. The Zn2 Si O4 content profiles could be fitted into the zero order equation, from which the apparent rate constant k and the activation energy E a were calculated. The matrix P greatly raised the E a of Zn2 Si O4 formation due to the less bridged hydroxyl silanol groups on its surface, which accounted for the high stability of Ni/Zn O-P. The desulfurization performance of the fresh and aged sorbents showed that the overall average sulfur conversion of Ni/Zn O-P(aged) was 92%, which was close to that of fresh sorbents(95%), and was higher than that of Ni/Zn O-M(aged)(86%) and Ni/Zn O-H(aged)(90%). Based on these findings, the application of Ni/Zn O-P can greatly improve the long-term running stability of the industrial unit.展开更多
Zn-Mn-Cu/SC（U） sorbent was hydrothermally synthesized by ultrasound-assisted high-pressure impregnation method with semi-coke（SC）as support and the mixed solution of zinc nitrate,manganese nitrate and copper nitra...Zn-Mn-Cu/SC（U） sorbent was hydrothermally synthesized by ultrasound-assisted high-pressure impregnation method with semi-coke（SC）as support and the mixed solution of zinc nitrate,manganese nitrate and copper nitrate as active component precursors.The desulfurization performances of hot coal gas on the prepared sorbent at a mid-temperature of 500°C were tested in fixed-bed reactor.Morphology and pore structure of the prepared sorbent were also characterized by TEM,N2adsorption/desorption isotherms and XRD.For comparison,the sorbent of Zn-Mn-Cu/SC prepared by conventional high-pressure impregnation was also evaluated and characterized in order to study the effects of ultrasound treatment.Zn-Mn-Cu/SC（U） sorbent prepared by high-pressure impregnation under ultrasound-assisted condition showed a better desulfurization performance than Zn-Mn-Cu/SC.It could remove H2 S from 1000×10-6m3/m3 to 0.1×10-6m3/m3 at 500°C and maintained for 12.5 h with the sulfur capacity of 7.74%,in which both the breakthrough time and sulfur capacity were about 32% and 51% higher than those of Zn-Mn-Cu/SC sorbent.The introduction of ultrasound during high-pressure impregnation process greatly improved the morphology and pore structure of the sorbent.The ultrasonic treatment made particle size of active components smaller and made them more evenly disperse on semi-coke support,which provided more opportunities to contact with H2S in coal-based gases.However,there were no any difference in compositions and existing forms of active components on the Zn-Mn-Cu/SC and Zn-Mn-Cu/SC（U） sorbents.展开更多
Iodine-modified calcium-based rice husk ash sorbents(I2/CaO/RHA)were synthesized and characterized by X-ray diffraction,X-ray fluorescence,and N2 isotherm adsorption/desorption.Adsorption experiments of vapor-phase el...Iodine-modified calcium-based rice husk ash sorbents(I2/CaO/RHA)were synthesized and characterized by X-ray diffraction,X-ray fluorescence,and N2 isotherm adsorption/desorption.Adsorption experiments of vapor-phase elemental mercury(Hg^0)were performed in a laboratory-scale fixed-bed reactor.I2/CaO/RHA performances on Hg^0 adsorption were compared with those of modified Cabased fly ash sorbents(I2/CaO/FA)and modified fly ash sorbents(I2/FA).Effects of oxidant loading,supports,pore size distribution,iodine impregnation modes,and temperature were investigated as well to understand the mechanism in capturing Hg^0.The modified sorbents exhibited reasonable efficiency for Hg^0 removal under simulated flue gas.The surface area,pore size distribution,and iodine impregnation modes of the sorbents did not produce a strong effect on Hg^0 capture efficiency,while fair correlation was observed between Hg^0 uptake capacity and iodine concentration.Therefore,the content of 12 impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg^0 uptake.Increasing temperature in the range of 80-140℃caused a rise in Hg^0 removal.A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study.展开更多
Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrol...Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrolyte was as follows： white sand 〈 anionic resin 〈 zeolite 〈 kaolin 〈 activated carbon 〈 bentonite. Bentonite was characterized using FTIR, XRF, XRD, SEM and BET methods. The results show specific surface area of 95 m2/g and particles size of 175 nm for bentonite. The optimum conditions for the maximum removal of Sb are contact time 10 min, 4 g bentonite and temperature of 40 ° C. The adsorption of Sb（V） on bentonite is followed by pseudo-second-order kinetic （R2=0.996 and k=9×10？5 g/（mg· min））. Thermodynamic results reveal that the adsorption of Sb（V） onto bentonite from copper electrolyte is endothermic and spontaneous process （ΔGΘ=？4806 kJ/（mol· K）. The adsorption data fit both the Freundlich and Langmuir isotherm models. Bentonite has the maximum adsorption capacity of 10000 mg/g for adsorption of Sb（V） in copper electrolyte. The adsorption of Zn, Co, Cu and Bi that present in the copper electrolyte is very low and insignificant.展开更多
文摘Modified Ca-based sorbents were obtained by adding sodium alkali into Ca(OH)2 and CaCO3. Reactive properties of modified Ca-based sorbents with acidic gases were investigated through reacting with gaseous HC1 at 450-760℃, and SEM and XRD technologies were adopted to get information on the reaction mechanism. Experimental data showed that HC1 dry removal efficiencies increased with temperature before 700℃ for all of the investigated sorbents, and there existed improved sorbents that corresponded to the highest removal efficiencies under the similar conditions. SEM photographs exhibited morphology difference between original and improved sorbents both before and after the reaction; and displayed that improved sorbents formed more porous product layers than original sorbents especially at higher temperature when product sintering became heavier, which is favorable to HC1 dry removal. XRD analysis showed that (1) improved Ca(OH)2 and CaCO3 were less crystalline than original lime and limestone; (2) the reaction product species of improved Ca(OH)2 changed with reaction temperature, while for original Ca(OH)2 the same product species appeared for all of the tested temperatures; and (3) for improved CaCO3, the only product at lower temperatures was CaCl2.2H2O and more product species were produced when temperature was higher than 650℃, but no CaCl2.Ca(OH)2.H2O formed at 700℃, while for the case of original CaCO3, the undesired CaCl2.Ca(OH)2.H2O appeared at 700℃. Presently, reaction temperature interval of 650-700℃ is recommended for improved Ca(OH2) to get the highest efficiency, for improved CaCO3 reaction at higher temperature deserves further investigation to make a good choice.
文摘Wastewater plays a crucial role in deteriorating water quality and can significantly affect human health and ecosystems if discharged without proper treatment.Among available treatment methods,adsorption is often considered an effective,relatively inexpensive,and environmentally friendly purification technique,but its efficiency depends on the sorbents used.The use of low-cost biosorbents with high adsorption capacity is widely studied.These include various biomaterials such as microalgae,cyanobacteria,fungi,and plant materials.The utilization of different biosorbents derived from plant waste,such as Paulownia wood,aspen,hickory,Ziziphus bark,peach tree shavings,as well as grasses such as red fescue and reed,and Sargassum algae in natural and modified forms,is a crucial research direction.Such studies highlight the potential to address waste issues by repurposing it as biosorbents.Several studies have examined the ability of different biosorbents to treat wastewater and suggested that the physicochemical properties of the material's surface,such as specific surface area,pore size,and pore volume,play a decisive role in adsorption capacity.A quantitative analysis of plant-based biosorbents will significantly aid in developing water treatment systems and achieving optimal adsorption through modifications of their physicochemical properties.Furthermore,the analysis will help understand the relative importance of each physicochemical property in determining adsorption capacity,thereby contributing to the implementation of treatment methods targeting specific pollutants.
基金supported by the National Natural Science Foundation of China(Nos.42022051,U21A2028,and 42305124)the Youth Innovation Promotion Association CAS(No.Y202089)the HFIPS Director’s Fund(Nos.BJPY2023A02,YZJJ202101,and YZJJ2023QN01).
文摘Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.
基金financial support from Business Finland 8205/31/2022the Magnus Ehrnrooth Foundation for financial support.
文摘Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.
基金The National Natural Science Foundation of China(No.51376003)
文摘A kind of industrial solid waste, i.e., carbide slag, was used as CaO precursor to synthesize CO2 sorbent. The highly reactive synthetic sorbent was prepared from carbide slag, aluminum nitrate hydrate and glycerol water solution by the combustion synthesis method. The results show that the synthetic sorbent exhibits a much higher CO2 capture capacity compared with carbide slag. The CO2 capture capacity and the carbonation conversion of the synthetic sorbent are 0. 38 g/g and 0. 70 after 50 cycles, which are 1.8 and 2. 1 times those of carbide slag. The average carbonation conversion and the CO2 capture efficiency of the synthetic sorbent are higher than those of carbide slag with the same sorbent flow ratios. The required sorbent flow ratios are lower for synthetic sorbent to achieve the same CO2 capture efficiency compared with carbide slag. With the same sorbent flow ratio and CO2 capture efficiency, the energy requirement in calciner for the synthetic sorbent is less than that for carbide slag.
基金Supported by the National Key Research and Development Program of China(2017YFB0603301)
文摘Under the Paris agreement, China has committed to reducing CO_2 emissions by 60%–65% per unit of GDP by 2030.Since CO_2 emissions from coal-fired power plants currently account for over 30% of the total carbon emissions in China, it will be necessary to mitigate at least some of these emissions to achieve this goal. Studies by the International Energy Agency(IEA) indicate CCS technology has the potential to contribute 14% of global emission reductions, followed by 40% of higher energy efficiency and 35% of renewable energy, which is considered as the most promising technology to significantly reduce carbon emissions for current coal-fired power plants.Moreover, the announcement of a Chinese national carbon trading market in late 2017 signals an opportunity for the commercial deployment of CO_2 capture technologies.Currently, the only commercially demonstrated technology for post-combustion CO_2 capture technology from power plants is solvent-based absorption. While commercially viable, the costs of deploying this technology are high. This has motivated efforts to develop more affordable alternatives, including advanced solvents, membranes,and sorbent capture systems. Of these approaches, advanced solvents have received the most attention in terms of research and demonstration. In contrast, sorbent capture technology has less attention, despite its potential for much lower energy consumption due to the absence of water in the sorbent. This paper reviews recent progress in the development of sorbent materials modified by amine functionalities with an emphasis on material characterization methods and the effects of operating conditions on performance. The main problems and challenges that need to be overcome to improve the competitiveness of sorbent-based capture technologies are discussed.
基金Supported by the National Basic Research Program of China(2011CB201502)
文摘Oxides of silicon, aluminium and calcium are normally dominant minerals during municipal solid waste(MSW)combustion. In flue gas, Si O2, Al2O3 and Ca O all act as sorbents capturing heavy metals(and semi-volatile organics). To further understand the effect of sorbents during MSW combustion, the effects of Si O2, Al2O3 and Ca O on Cu partitioning were experimentally investigated by the combustion of synthetic MSW in a tubular furnace and their effects on Cu speciation were studied by thermodynamic equilibrium calculations using Chem Kin software. The experiments show that Ca O has the highest Cu sorption efficiency at 900 °C, followed by Al2O3 and Si O2. Thermodynamic equilibrium calculations show that for Cu the addition of Si O2 and Al2O3reduces the amount of liquid Cu Cl, which is more volatile. However, the addition of Ca O has little influence on chemical sorption of Cu, indicating that the sorption of Ca O is resulted from physical sorption.
基金Project supported by the Key Science Project of Environmental Protection Foundation of Shandong Government(No.(2006)005).
文摘In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions （SO4^2-, H2PO4^-, NO3^-, and NO2^-） were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.
基金supported by the National Basic Research Program of China (2012CB723105)the National Natural Science Foundation of China(20976117)+1 种基金Shanxi Province Natural Science Foundation (2010011014-3)Shanxi Province Basic Conditions Platform for Science and Technology Project(2010091015)
文摘Zn-based sorbent （Z20SC） prepared through semi-coke support in 20 wt% zinc nitrate solution by high-pressure impregnation presents an excellent desulfurization capacity in hot coal gas,in which H2 S can not be nearly detected in the outlet gas before 20 h breakthrough time.The effects of the main operational conditions and the particle size of Z20SC sorbent on its desulfurization performances sorbent were investigated in a fixed-bed reactor and the desulfurization kinetics of Z20SC sorbent removing H2 S from hot coal gas was calculated based on experimental data.Results showed that the conversion of Z20SC sorbent desulfurization reaction increased with the decrease of the particle size of the sorbent and the increases of gas volumetric flow rate,reaction temperature and H 2 S content in inlet gas.Z20SC sorbent obtained from hydrothermal synthesis by high-pressure impregnation possessed much larger surface area and pore volume than semi-coke support,and they were significantly reduced after the desulfurization reaction.The equivalent grain model was reasonably used to analyze experimental data,in which k s=4.382×10-3 exp（-8.270×103/RgT） and Dep=1.262×10-4exp（1.522×104/RgT）.It suggests that the desulfurization reaction of the Z20SC sorbent is mainly controlled by the chemical reaction in the initial stage and later by the diffusion through the reacted sorbent layer.
基金the Ministry of Science and Technology of China under the Grant No. G2005CB221203the Natural Science Foundation of China under Contract No. 20576087.
文摘Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from coal gasifier gas to very low levels. In this paper, zinc ferrites prepared by co-precipitation were identified as a novel coal gas desulfurization sorbent at high temperature. Preparation of zinc ferrite and effects of binders on pore volume, strength and desulfurization efficiency of zinc ferrite desulfurizer were studied. Moreover, the behavior of zinc ferrite sorbent during desulfurization and regeneration under the temperature range of 350-400 ℃ are investigated. Effects of binders on the pore volume, mechanical strength and desulfurization efficiency of zinc ferrite sorbents indicated that the addition of kaolinite to zinc ferrite desulfurizer seems to be superior to other binders under the experimental conditions.
基金supported by the National Basic Research Program of China(2012CB723105)the National Natural Science Foundation of China(20976117)Shanxi Graduates Excellent Innovation Project of China(tyut-rc201018a)
文摘With lignite after vacuum drying as the raw material,a series of Zn-based sorbents were prepared by static impregnation,ultrasonic-assisted impregnation,bubbling-assisted impregnation and high-pressure impregnation.The physical properties and the desulfurization performances of Zn-based sorbents were studied systematically by XRD,BET,AAS characterization techniques and the fixed-bed desulfurization evaluation apparatus.The sorbents obtained by high-pressure impregnation method have a larger specific surface area,pore volume and pore diameter comparing with other methods,which is conducive to the sulfidation reaction of hydrogen sulfide gas in the sorbent.The effects of pressure during the high-pressure impregnation and concentration of Zn(NO3)2 precursor solution on the sorbents properties and desulfurization behavior were investigated.The higher the impregnation pressure and the concentration of impregnation solution are,the greater the amount of the active components are uploaded.However,overhigh impregnation pressure can cause collapse and blocking of the carrier pore.The optimal operating condition of high-pressure impregnation method for preparing the sorbents was the impregnation pressure of 20 atm and the solution concentration of 41%.Under that condition,the sorbent had the best desulfurization ability with a sulfur capacity of 13.94 gS/100 gsorbent and a breakthrough time of 54 h.Its desulfurization precision and efficiency of removing H2S before sorbent breakthrough from the middle temperature gases of 400℃ can reach【5 ppm and】99%,respectively.Sorbents could be regenerated under the condition of 1 vol%O2,20 vol% H2O,0.5 vol% NH3,and N2balance gas.The regenerated sorbent could be used for repeated absorption of H2S with a slight decrease in desulfurization effect.
基金supported by the Science and Technology Development projects of SINOPEC, China (Nos. 113138, 112008 and 110099)
文摘A new industrial S Zorb sorbent(Ni/Zn O-P) was prepared by using the spray drying technique. The other two traditional sorbents(Ni/Zn O-M and Ni/Zn O-H) were prepared in exactly the same way except the use of different silica-alumina binder matrices. The XRD, Rietveld quantitative phase analysis, BET, and laser particle size analysis were employed to characterize their physico-chemical properties. The deactivation mechanism and desulfurization kinetics of sorbent was investigated on a water vapor aging treatment device. It was shown that both the water vapor pressure and reaction temperature significantly could influence the formation rate of inactive Zn2 Si O4, which could decrease the sulfur storage capacity of sorbents. The Zn2 Si O4 content profiles could be fitted into the zero order equation, from which the apparent rate constant k and the activation energy E a were calculated. The matrix P greatly raised the E a of Zn2 Si O4 formation due to the less bridged hydroxyl silanol groups on its surface, which accounted for the high stability of Ni/Zn O-P. The desulfurization performance of the fresh and aged sorbents showed that the overall average sulfur conversion of Ni/Zn O-P(aged) was 92%, which was close to that of fresh sorbents(95%), and was higher than that of Ni/Zn O-M(aged)(86%) and Ni/Zn O-H(aged)(90%). Based on these findings, the application of Ni/Zn O-P can greatly improve the long-term running stability of the industrial unit.
基金supported by the National Basic Research Program of China(2012CB723105)the National Natural Science Foundation of China(20976117)the Technological Innovation Programs of Higher Education Institutions in Shanxi(2013JYT113)
文摘Zn-Mn-Cu/SC（U） sorbent was hydrothermally synthesized by ultrasound-assisted high-pressure impregnation method with semi-coke（SC）as support and the mixed solution of zinc nitrate,manganese nitrate and copper nitrate as active component precursors.The desulfurization performances of hot coal gas on the prepared sorbent at a mid-temperature of 500°C were tested in fixed-bed reactor.Morphology and pore structure of the prepared sorbent were also characterized by TEM,N2adsorption/desorption isotherms and XRD.For comparison,the sorbent of Zn-Mn-Cu/SC prepared by conventional high-pressure impregnation was also evaluated and characterized in order to study the effects of ultrasound treatment.Zn-Mn-Cu/SC（U） sorbent prepared by high-pressure impregnation under ultrasound-assisted condition showed a better desulfurization performance than Zn-Mn-Cu/SC.It could remove H2 S from 1000×10-6m3/m3 to 0.1×10-6m3/m3 at 500°C and maintained for 12.5 h with the sulfur capacity of 7.74%,in which both the breakthrough time and sulfur capacity were about 32% and 51% higher than those of Zn-Mn-Cu/SC sorbent.The introduction of ultrasound during high-pressure impregnation process greatly improved the morphology and pore structure of the sorbent.The ultrasonic treatment made particle size of active components smaller and made them more evenly disperse on semi-coke support,which provided more opportunities to contact with H2S in coal-based gases.However,there were no any difference in compositions and existing forms of active components on the Zn-Mn-Cu/SC and Zn-Mn-Cu/SC（U） sorbents.
基金supported by the National Natural Science Foundation of China(NSFC)(No.50506011,50936004)the partial funding from the Science Foundation of Huazhong University of Science and Technology(No.M2009009)the Ministry of Science and Technology of China(No.2006CB705806)
文摘Iodine-modified calcium-based rice husk ash sorbents(I2/CaO/RHA)were synthesized and characterized by X-ray diffraction,X-ray fluorescence,and N2 isotherm adsorption/desorption.Adsorption experiments of vapor-phase elemental mercury(Hg^0)were performed in a laboratory-scale fixed-bed reactor.I2/CaO/RHA performances on Hg^0 adsorption were compared with those of modified Cabased fly ash sorbents(I2/CaO/FA)and modified fly ash sorbents(I2/FA).Effects of oxidant loading,supports,pore size distribution,iodine impregnation modes,and temperature were investigated as well to understand the mechanism in capturing Hg^0.The modified sorbents exhibited reasonable efficiency for Hg^0 removal under simulated flue gas.The surface area,pore size distribution,and iodine impregnation modes of the sorbents did not produce a strong effect on Hg^0 capture efficiency,while fair correlation was observed between Hg^0 uptake capacity and iodine concentration.Therefore,the content of 12 impregnated on the sorbents was identified as the most important factor influencing the capacity of these sorbents for Hg^0 uptake.Increasing temperature in the range of 80-140℃caused a rise in Hg^0 removal.A reaction mechanism that may explain the experimental results was presumed based on the characterizations and adsorption study.
基金Kerman-Sarcheshmeh copper electrorefining(Iran)and Islamic Azad University,Yazd Brunch for support to carry out this work
文摘Removal of Sb（V） from copper electrolyte by different sorbents such as activated carbon, bentonite, kaolin, resin, zeolite and white sand was investigated. Adsorption capacity of Sb（V） removal from copper electrolyte was as follows： white sand 〈 anionic resin 〈 zeolite 〈 kaolin 〈 activated carbon 〈 bentonite. Bentonite was characterized using FTIR, XRF, XRD, SEM and BET methods. The results show specific surface area of 95 m2/g and particles size of 175 nm for bentonite. The optimum conditions for the maximum removal of Sb are contact time 10 min, 4 g bentonite and temperature of 40 ° C. The adsorption of Sb（V） on bentonite is followed by pseudo-second-order kinetic （R2=0.996 and k=9×10？5 g/（mg· min））. Thermodynamic results reveal that the adsorption of Sb（V） onto bentonite from copper electrolyte is endothermic and spontaneous process （ΔGΘ=？4806 kJ/（mol· K）. The adsorption data fit both the Freundlich and Langmuir isotherm models. Bentonite has the maximum adsorption capacity of 10000 mg/g for adsorption of Sb（V） in copper electrolyte. The adsorption of Zn, Co, Cu and Bi that present in the copper electrolyte is very low and insignificant.
