To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
MXene has given great promises to superca-pacitor electrode material due to its high conductivity and redox properties.However,the self-agglomeration of the MXene lamella will reduce its contact area with the elec-tro...MXene has given great promises to superca-pacitor electrode material due to its high conductivity and redox properties.However,the self-agglomeration of the MXene lamella will reduce its contact area with the elec-trolyte and generate a tortuous transportation pathway of the electrolyte ions,thereby reducing its capacitive per-formance and rate capability.In this work,we engineered the electrolyte ion channels by adjusting the MXene lamella size and inserting holey graphene(HG)nanosheets into the interlayer of the MXene flakes.The developed MXene/HG electrode can not only avoid the self-restack-ing of MXene but also provide unimpeded ion transport channels.As a result,the supercapacitive and rate perfor-mances of the small MXene lamella-based MXene/HG(S-MXene/HG)supercapacitor are prominently ameliorated.By adjusting the content of HG,the S-MXene/HG0.05 electrode exhibits excellent gravimetric capacitance of 446 F·g^(-1)and a rate capability of 77.5%.The S-MXene/HG0.05-based symmetric supercapacitor provides an impressive energy density of 14.84 Wh·kg^(-1)with excellent cyclic stability of 96%capacitance retention after 10,000 cycles.This demonstration of the engineering of the ion channels shows great potential in two-dimensional mate-rial-based supercapacitor electrodes.展开更多
The extrartion of aluminum from coal mining waste(CMW) is an important industrial process.The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material,which ...The extrartion of aluminum from coal mining waste(CMW) is an important industrial process.The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material,which affect the quantity and quality of products.To improve the aluminum recovery process,the leaching kinetics of CMW with hydrochloric acid was studied.A shrinking core model was used to investigate aluminum and iron dissolution kinetics.Based on the kinetic characteristics,a process for recovering aluminum was proposed and tested experimentally.It is found that the aluminum leaching reaction is controlled by surface reaction at low temperatures(40-80℃) and by diffusion process at higher temperatures(90-106℃).The iron dissolution process is dominated by surface reaction at 40-100℃.The results show that iron could be dissolved or separated by concentrated hydrochloric acid.Fine grinding will improve aluminum dissolution significantly.展开更多
The co-liquefaction behaviors of cotton seed(CS)and flos populi(FP)were investigated in the sub-critical water/ethanol mixed solvent using the medical stone(MS)based additives.Oil products were characterized using FTI...The co-liquefaction behaviors of cotton seed(CS)and flos populi(FP)were investigated in the sub-critical water/ethanol mixed solvent using the medical stone(MS)based additives.Oil products were characterized using FTIR,GC-MS,1HNMR,and 13CNMR techniques.The test results showed that the synergistic effect of co-liquefaction was obvious when the ratio of cotton seed and flospopuli was 1:1 without additives.The additives,such as 12-phosphotungstic acid(PW12),HZSM-5,PW12/HZSM-5 and modified medical stone(MS),PW12/MS,Ni/MS,Co/MS,Mo/MS and Co-Mo/MS,could increase the bio-oil yield;and the modified MS resulted in higher liquefied oil yield than that achieved by MS.Furthermore,additives such as Ni/MS,Mo/MS,and Co-Mo/MS also could increase the yield of aliphatic hydrocarbons in liquefied oil.The addition of Co-Mo/MS could lead to a highest liquefied oil yield of 28.8%,while the additive of PW12/HZSM-5 could result in a highest total conversion of 81.6%.Results also revealed that additives,such as PW12/MS,PW12,PW12/HZSM-5,Ni/MS,Co/MS,Mo/MS,and Co-Mo/MS,could increase the H2 production and decrease the CO2 production in gas products.展开更多
Taking a three-year fertilization trial in mine reclamation soil from Shanxi Province, China as an example, the effects of different fertilization treatments on soil carbon storage and carbon fixation by corn were stu...Taking a three-year fertilization trial in mine reclamation soil from Shanxi Province, China as an example, the effects of different fertilization treatments on soil carbon storage and carbon fixation by corn were studied in this paper. Four treatments were designed in the experiment, including fertilizer （ F）, organic manure （ M）, half organic manure plus half fertilizer （ FM） and control （CK）. The results showed that fertilization had certain roles in increasing organic carbon storage of mine reclamation soil, and the application of single or combined organic and inorganic fertilizers had the most remarkable influence. Meanwhile, the treatment of single or combined organic and inorganic fertilizers could improve the carbon fixation capacity of corn prominently, and increased soil organic matter input. Thus, the application of organic manure or combined organic and inorganic fertilizer has great contribution to enhancing soil carbon sink and sustainable development of agriculture. However, the combined application of organic and inorganic fertilizer is the best choice for agricultural field based on economic consideration.展开更多
In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(...In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(NO_x)emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises.While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction effciency above 800℃,their elevated levels of chlorine(Cl)and alkali metals pose potential risks to boiler equipment integrity.Therefore,this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations.Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass.Specifically,it was determined that biomass char produced through deeply pyrolysis at 300℃achieves the highest NO reduction efficiency while minimizing the presence of harmful components.At a reduction temperature of 700℃,both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90%and 62.22%,which is already an ideal deficiency at low temperatures.The addition of water vapor at 700-800℃obviously avoids the oxidation of ammonia to NO in advanced reburning.Upon further analysis,denitrification efficiency in biomass char re-burning and advanced reburning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions.This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants,offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.展开更多
Lithium(Li)is an important energy metal in the 21st century.However,the selective recovery of Li is still a big challenge,especially from acidic solutions with multiple metal ions existence.Herein we report a new ion ...Lithium(Li)is an important energy metal in the 21st century.However,the selective recovery of Li is still a big challenge,especially from acidic solutions with multiple metal ions existence.Herein we report a new ion pair induced mechanism for selectively extracting Li^(+)from acidic chloride solutions by tributyl phosphate(TBP).It is shown that the acidity and the chloride ions in the aqueous phase have great effects on the extraction of Li^(+).The FT-IR,UV-Vis and ESI-MS experiments provide solid evidence for the formation of ion-pair complex[Li(TBP)_n(H_(2)O)_(m)]^(+)[FeCl_(4)]^(-)(n-1,2,3;m-0,1)in the organic phase,which brings about the effective and efficient extraction of Li^(+).This mechanism can overcome the Hofmeister bias and allow for the selective extraction of Li^(+) from the extremely hydrophilic chlorides.It has also been proved that the loaded Li in TBP can be effectively stripped by concentrated HCl solution with a Li/Fe separation factor>500.The understanding of the ion-pair transport mechanism is helpful for optimizing the recovery process or further advancing more efficient recovery techniques for Li from acidic liquor.展开更多
The influence of Co Mo P/medical stone and SO_4^(2-)/medical stone on sulfur behavior during the Longma coal pyrolysis was investigated in a fixed bed reactor. Moreover, the kinetics was also studied. It is found that...The influence of Co Mo P/medical stone and SO_4^(2-)/medical stone on sulfur behavior during the Longma coal pyrolysis was investigated in a fixed bed reactor. Moreover, the kinetics was also studied. It is found that adding SO_4^(2-)/medical stone was favorable to removal of volatile matter, while adding Co Mo P/medical stone could inhibit the emission of volatiles. Moreover, the results also showed that adding Co Mo P/medical stone made the total sulfur retention higher, while adding SO_4^(2-)/medical stone made the total sulfur retention lower. Adding modified medical stone was beneficial to removal of sulfate sulfur and pyritic sulfur, while it was beneficial to retaining organic sulfur in the residue. Furthermore, adding Co Mo P/medical stone and SO_4^(2-)/medical stone all could increase the emission of H_2S when the temperature was higher than 450℃. Judging from the kinetics study, it also can be known that addition of the natural minerals could result in a decrease of the pre-exponential factor and also change the apparent activation energy upon comparing the apparent activation energy and the pre-exponential factor of raw Longma coal at 435—537℃.展开更多
of main observation and conclusion The extraction of Li^+from the high Mg/Li ratio brine was performed using hydroxyl functional ionic lic-uids(ILs)as the coextractant and tributyl phosphate(TBP)as the extractant.irst...of main observation and conclusion The extraction of Li^+from the high Mg/Li ratio brine was performed using hydroxyl functional ionic lic-uids(ILs)as the coextractant and tributyl phosphate(TBP)as the extractant.irsty the extractive system,1-2-hydroxyethyl-3-mnethylimidazolumbis(trifuoromethylsulfonyl)imide([HOEmim][NTf2])+TBP was proved to exhibit the highest extraction efficiency of Li^+(88.15%)from LiCl aqueous solutions among the extractants composed of differents TB P,and ls+TBP.Effects of various extraction parameters on the extraction eficiencies of Li^+and Mg^2+were then investigated.95.01%of Li^+was extracted and the Li^+/Mg^2+separation factor reached 405.76 in a singl-stage at 278.15 Kand O/A of 2:1.The extraction complexes were determined by the slope analysis method and ESI-MS analysis,and the metal complexes in the organic phase were indcated to be mainly[L-2TBP][NTf;J.The striping study showed that 92.86%of i*was stripped with 1.0 mol·L^-1 HCl.98%extraction capacity of the synergyextractants was remained after 5 regeneration cycles.The thermodynamic parameters(△G°,△H°,and△S°),together with the mechanism of the Li^+extraction were further demonstrated finally,According to the results,[HOEmim][NTf2]+TBP extraction system showed promising performance in extracting lithium from salt lake brine with high Mg/Li ratio.展开更多
Solid-liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baff...Solid-liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baffled stirred tank and punched baffled stirred tank(Pun-BST) were studied by using the computational fluid dynamic analysis. Results showed that perforating holes in the baffles could reduce power consumption of mixing. Meanwhile, the punched baffle system could maintain the solids in suspension as traditional baffle system. The results also showed that the baffles could increase the “effective flow” of stirred tank even though the whole velocity of the vessel is lower than un-baffled vessel. In addition, both the solid-liquid suspension and “effective flow” were related to instability of the flow field.Perfect solid-liquid suspension results always along with obvious instability of the flow field. But, the strengthening effect of punched baffle on flow field instability mainly happened in the near-wall area.It's because the collision and aggregation among sub-streams induced by holes intensified the unstable fluid flow. On the whole, the Pun-BST system provided much better mixing characteristics and recommended to apply in the industrial process.展开更多
Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization approaches.Mesoporous silica could not be synthesized on a large-scale by conventional sol-gel method.I...Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization approaches.Mesoporous silica could not be synthesized on a large-scale by conventional sol-gel method.In this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was proposed.The influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure formation.The results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline structure.By controlling the degree of acid etching,mesoporous silica materials with different pore structures can be obtained.This paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.展开更多
Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high...Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high condensate content,high temperature,and high salinity)often affect foaming agent performance.In this study,surfactants were screened using an airflow method that closely resembles field treatment method.Notably,alcohol ether sulfates(AE_(n)S)with various polyoxyethylene(EO)units demonstrated exceptional performance in terms of liquid unloading efficiency and foam stability.At 80℃,the unloading efficiency of AE_(n)S with two EO units(AE_(2)S)in a high NaCl mass concentration(up to 200 g/L)and high condensate volume fraction(up to 20%)reached 84%.The dynamic surface tension and interfacial tension measured at the same temperature were used to analyze the influence of the diffusion rate and interfacial characteristics on the AE_(n)S foam,while the viscosity and liquid film thickness measurements reflected the mechanical strength and liquid-carrying capacity.In addition,transmission electron microscopy(TEM)revealed that AE_(2)S formed“dendritic”micellar aggregates at a high NaCl mass concentration,which significantly enhanced the viscosity and stability of the foam.The interactions among AE_(n)S,NaCl,and H2O were analyzed using molecular dynamics,and it was confirmed from a molecular mechanics perspective that a stable structure can form among the three,contributing to the foam stability.These findings demonstrate the significant potential of the AE_(2)S foam for gas well deliquification.展开更多
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金financially supported by the National Key R&D Program of China (No.2017YFA0304203)the National Natural Science Foundation of China (Nos.21805174 and 51902190)+5 种基金the Key Research and Development Program of Shanxi Province for International Cooperation (No.201803D421082)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (Nos.2019L0013 and 2019L0018)Shanxi Scholarship Council of China (No.2021-004)the Program of Introducing Talents of Discipline to Universities (No.D18001)the Changjiang Scholars and Innovative Research Team at the University of Ministry of Education of China (No.IRT_17R70)the Fund for Shanxi “1331 Project”
文摘MXene has given great promises to superca-pacitor electrode material due to its high conductivity and redox properties.However,the self-agglomeration of the MXene lamella will reduce its contact area with the elec-trolyte and generate a tortuous transportation pathway of the electrolyte ions,thereby reducing its capacitive per-formance and rate capability.In this work,we engineered the electrolyte ion channels by adjusting the MXene lamella size and inserting holey graphene(HG)nanosheets into the interlayer of the MXene flakes.The developed MXene/HG electrode can not only avoid the self-restack-ing of MXene but also provide unimpeded ion transport channels.As a result,the supercapacitive and rate perfor-mances of the small MXene lamella-based MXene/HG(S-MXene/HG)supercapacitor are prominently ameliorated.By adjusting the content of HG,the S-MXene/HG0.05 electrode exhibits excellent gravimetric capacitance of 446 F·g^(-1)and a rate capability of 77.5%.The S-MXene/HG0.05-based symmetric supercapacitor provides an impressive energy density of 14.84 Wh·kg^(-1)with excellent cyclic stability of 96%capacitance retention after 10,000 cycles.This demonstration of the engineering of the ion channels shows great potential in two-dimensional mate-rial-based supercapacitor electrodes.
基金Supported by the National High Technology Research and Development Program of China(2011AA06A103)the National Natural Science Foundation of China(21306109)
文摘The extrartion of aluminum from coal mining waste(CMW) is an important industrial process.The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material,which affect the quantity and quality of products.To improve the aluminum recovery process,the leaching kinetics of CMW with hydrochloric acid was studied.A shrinking core model was used to investigate aluminum and iron dissolution kinetics.Based on the kinetic characteristics,a process for recovering aluminum was proposed and tested experimentally.It is found that the aluminum leaching reaction is controlled by surface reaction at low temperatures(40-80℃) and by diffusion process at higher temperatures(90-106℃).The iron dissolution process is dominated by surface reaction at 40-100℃.The results show that iron could be dissolved or separated by concentrated hydrochloric acid.Fine grinding will improve aluminum dissolution significantly.
基金This work was supported by the NSFCShanxi coal based low carbon joint fund(U1810209)the Natural Science Foundation of Shanxi Province(201901D111006).
文摘The co-liquefaction behaviors of cotton seed(CS)and flos populi(FP)were investigated in the sub-critical water/ethanol mixed solvent using the medical stone(MS)based additives.Oil products were characterized using FTIR,GC-MS,1HNMR,and 13CNMR techniques.The test results showed that the synergistic effect of co-liquefaction was obvious when the ratio of cotton seed and flospopuli was 1:1 without additives.The additives,such as 12-phosphotungstic acid(PW12),HZSM-5,PW12/HZSM-5 and modified medical stone(MS),PW12/MS,Ni/MS,Co/MS,Mo/MS and Co-Mo/MS,could increase the bio-oil yield;and the modified MS resulted in higher liquefied oil yield than that achieved by MS.Furthermore,additives such as Ni/MS,Mo/MS,and Co-Mo/MS also could increase the yield of aliphatic hydrocarbons in liquefied oil.The addition of Co-Mo/MS could lead to a highest liquefied oil yield of 28.8%,while the additive of PW12/HZSM-5 could result in a highest total conversion of 81.6%.Results also revealed that additives,such as PW12/MS,PW12,PW12/HZSM-5,Ni/MS,Co/MS,Mo/MS,and Co-Mo/MS,could increase the H2 production and decrease the CO2 production in gas products.
基金Supported by the International Science and Technology Cooperation Program of China(2011DFR31230)Major Science and Technology Project of Shanxi Province,China(20121101009)Key Project of Shanxi Academy of Agricultural Sciences,China(2013zd12)
文摘Taking a three-year fertilization trial in mine reclamation soil from Shanxi Province, China as an example, the effects of different fertilization treatments on soil carbon storage and carbon fixation by corn were studied in this paper. Four treatments were designed in the experiment, including fertilizer （ F）, organic manure （ M）, half organic manure plus half fertilizer （ FM） and control （CK）. The results showed that fertilization had certain roles in increasing organic carbon storage of mine reclamation soil, and the application of single or combined organic and inorganic fertilizers had the most remarkable influence. Meanwhile, the treatment of single or combined organic and inorganic fertilizers could improve the carbon fixation capacity of corn prominently, and increased soil organic matter input. Thus, the application of organic manure or combined organic and inorganic fertilizer has great contribution to enhancing soil carbon sink and sustainable development of agriculture. However, the combined application of organic and inorganic fertilizer is the best choice for agricultural field based on economic consideration.
基金supported by the Open Topics of State Key Laboratory of Clean and Efficient Coal-Fired Power Generation and Pollution Control(D2022FK103)National Natural Science Foundation of China(22278250)+1 种基金the Shanxi Province Science and Technology Cooperation and Exchange Special Program(202104041101014)the Shanxi Province Scholarship Council。
文摘In the current era of renewable energy prominence,the wide operational capacity of coal-fired boilers has emerged as crucial for ensuring the sustainability of power plants.However,attaining ultra-low nitrogen oxides(NO_x)emissions during periods of low-load operations presents a significant and persistent challenge for coal power enterprises.While techniques such as biomass re-burning and advanced re-burning have shown promise in enhancing NO reduction effciency above 800℃,their elevated levels of chlorine(Cl)and alkali metals pose potential risks to boiler equipment integrity.Therefore,this study proposes the utilization of biomass char derived from pyrolysis as a dual-purpose solution to enhance NO reduction efficiency while safeguarding boiler integrity during low-load operations.Findings indicate that pyrolysis treatment effectively reduces the Cl and alkali metal content of biomass.Specifically,it was determined that biomass char produced through deeply pyrolysis at 300℃achieves the highest NO reduction efficiency while minimizing the presence of harmful components.At a reduction temperature of 700℃,both re-burning and advanced re-burning techniques exhibit NO reduction efficiencies of 55.90%and 62.22%,which is already an ideal deficiency at low temperatures.The addition of water vapor at 700-800℃obviously avoids the oxidation of ammonia to NO in advanced reburning.Upon further analysis,denitrification efficiency in biomass char re-burning and advanced reburning is influenced not only by volatile content but also by physicochemical properties such as porosity and surface functional group distribution under certain reaction conditions.This study provides a theoretical framework for the industrial implementation of biomass char for NO control in coal-fired power plants,offering insights into optimizing NO reduction efficiency while mitigating potential risks to boiler equipment.
基金supported by the National Natural Science Foundation of China(21706257,21878180)the Shanxi Province Coal Based Low-carbon Technology Major Projects(MC2016-05)the Xiangyuan Key Technology Research Projects(2018XYSDYY-02)。
文摘Lithium(Li)is an important energy metal in the 21st century.However,the selective recovery of Li is still a big challenge,especially from acidic solutions with multiple metal ions existence.Herein we report a new ion pair induced mechanism for selectively extracting Li^(+)from acidic chloride solutions by tributyl phosphate(TBP).It is shown that the acidity and the chloride ions in the aqueous phase have great effects on the extraction of Li^(+).The FT-IR,UV-Vis and ESI-MS experiments provide solid evidence for the formation of ion-pair complex[Li(TBP)_n(H_(2)O)_(m)]^(+)[FeCl_(4)]^(-)(n-1,2,3;m-0,1)in the organic phase,which brings about the effective and efficient extraction of Li^(+).This mechanism can overcome the Hofmeister bias and allow for the selective extraction of Li^(+) from the extremely hydrophilic chlorides.It has also been proved that the loaded Li in TBP can be effectively stripped by concentrated HCl solution with a Li/Fe separation factor>500.The understanding of the ion-pair transport mechanism is helpful for optimizing the recovery process or further advancing more efficient recovery techniques for Li from acidic liquor.
基金Upon undertaking the Key Research and Development Program (International Cooperation) of Shanxi (Project Number: 201603D421041)the financial supports of this work by the Provincial Key Scientific Research Projects on Coal-based Low Carbon Energy of Shanxi Province (Project Number: MD2015-01)+1 种基金the National Natural Science Foundation of China-Shanxi Coal-based Low Carbon Joint Fund (U1610254)the NSFC-National Natural Science Foundation of China (No. 51476109)are gratefully acknowledged
文摘The influence of Co Mo P/medical stone and SO_4^(2-)/medical stone on sulfur behavior during the Longma coal pyrolysis was investigated in a fixed bed reactor. Moreover, the kinetics was also studied. It is found that adding SO_4^(2-)/medical stone was favorable to removal of volatile matter, while adding Co Mo P/medical stone could inhibit the emission of volatiles. Moreover, the results also showed that adding Co Mo P/medical stone made the total sulfur retention higher, while adding SO_4^(2-)/medical stone made the total sulfur retention lower. Adding modified medical stone was beneficial to removal of sulfate sulfur and pyritic sulfur, while it was beneficial to retaining organic sulfur in the residue. Furthermore, adding Co Mo P/medical stone and SO_4^(2-)/medical stone all could increase the emission of H_2S when the temperature was higher than 450℃. Judging from the kinetics study, it also can be known that addition of the natural minerals could result in a decrease of the pre-exponential factor and also change the apparent activation energy upon comparing the apparent activation energy and the pre-exponential factor of raw Longma coal at 435—537℃.
基金This work was supported by the National Natural Science Foundation of china(Nos.21978302,21706257 and 21776292)Innovation Academy for Green Manufacture(IAGM2020DB05)Major Program of National Natural Science Foundation of China(No.21890762).This paper was completed under the guid-ance of Professor Suojiang Zhang.
文摘of main observation and conclusion The extraction of Li^+from the high Mg/Li ratio brine was performed using hydroxyl functional ionic lic-uids(ILs)as the coextractant and tributyl phosphate(TBP)as the extractant.irsty the extractive system,1-2-hydroxyethyl-3-mnethylimidazolumbis(trifuoromethylsulfonyl)imide([HOEmim][NTf2])+TBP was proved to exhibit the highest extraction efficiency of Li^+(88.15%)from LiCl aqueous solutions among the extractants composed of differents TB P,and ls+TBP.Effects of various extraction parameters on the extraction eficiencies of Li^+and Mg^2+were then investigated.95.01%of Li^+was extracted and the Li^+/Mg^2+separation factor reached 405.76 in a singl-stage at 278.15 Kand O/A of 2:1.The extraction complexes were determined by the slope analysis method and ESI-MS analysis,and the metal complexes in the organic phase were indcated to be mainly[L-2TBP][NTf;J.The striping study showed that 92.86%of i*was stripped with 1.0 mol·L^-1 HCl.98%extraction capacity of the synergyextractants was remained after 5 regeneration cycles.The thermodynamic parameters(△G°,△H°,and△S°),together with the mechanism of the Li^+extraction were further demonstrated finally,According to the results,[HOEmim][NTf2]+TBP extraction system showed promising performance in extracting lithium from salt lake brine with high Mg/Li ratio.
基金supported by the National Natural Science Foundation of China (22078030, Z20200804)National Key Research and Development Program of China (2019YFC1905802)+1 种基金Key Project of Independent Research Project of State Key Laboratory of Coal Mine Disaster Dynamics and Control (2011DA105287zd201902)Hubei Three Gorges Laboratory Open/Innovation Fund (SK211009, SK215001)。
文摘Solid-liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baffled stirred tank and punched baffled stirred tank(Pun-BST) were studied by using the computational fluid dynamic analysis. Results showed that perforating holes in the baffles could reduce power consumption of mixing. Meanwhile, the punched baffle system could maintain the solids in suspension as traditional baffle system. The results also showed that the baffles could increase the “effective flow” of stirred tank even though the whole velocity of the vessel is lower than un-baffled vessel. In addition, both the solid-liquid suspension and “effective flow” were related to instability of the flow field.Perfect solid-liquid suspension results always along with obvious instability of the flow field. But, the strengthening effect of punched baffle on flow field instability mainly happened in the near-wall area.It's because the collision and aggregation among sub-streams induced by holes intensified the unstable fluid flow. On the whole, the Pun-BST system provided much better mixing characteristics and recommended to apply in the industrial process.
基金supported by the National Natural Science Foundation of China(grant Nos.U21A20321 and 21908138)Shanxi Province Central Government Guided Local Science and Technology Development Fund Project(grant No.YDZJSX2022A004)Shanxi Province Scientific and Technological Innovation Project of Colleges and Universities(grant No.2020L0009).
文摘Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization approaches.Mesoporous silica could not be synthesized on a large-scale by conventional sol-gel method.In this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was proposed.The influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure formation.The results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline structure.By controlling the degree of acid etching,mesoporous silica materials with different pore structures can be obtained.This paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.
文摘Gas wells often encounter blockages in gas recovery channels owing to fluid accumulation during the later stages of extraction,which adversely affects subsequent recovery efforts.These undesirable conditions(e.g.,high condensate content,high temperature,and high salinity)often affect foaming agent performance.In this study,surfactants were screened using an airflow method that closely resembles field treatment method.Notably,alcohol ether sulfates(AE_(n)S)with various polyoxyethylene(EO)units demonstrated exceptional performance in terms of liquid unloading efficiency and foam stability.At 80℃,the unloading efficiency of AE_(n)S with two EO units(AE_(2)S)in a high NaCl mass concentration(up to 200 g/L)and high condensate volume fraction(up to 20%)reached 84%.The dynamic surface tension and interfacial tension measured at the same temperature were used to analyze the influence of the diffusion rate and interfacial characteristics on the AE_(n)S foam,while the viscosity and liquid film thickness measurements reflected the mechanical strength and liquid-carrying capacity.In addition,transmission electron microscopy(TEM)revealed that AE_(2)S formed“dendritic”micellar aggregates at a high NaCl mass concentration,which significantly enhanced the viscosity and stability of the foam.The interactions among AE_(n)S,NaCl,and H2O were analyzed using molecular dynamics,and it was confirmed from a molecular mechanics perspective that a stable structure can form among the three,contributing to the foam stability.These findings demonstrate the significant potential of the AE_(2)S foam for gas well deliquification.
