Ammonia(NH_(3))emission has caused serious environment issues and aroused worldwide concern.The emerging ionic liquid(IL)provides a greener way to efficiently capture NH_(3).This paper provides rigorous process simula...Ammonia(NH_(3))emission has caused serious environment issues and aroused worldwide concern.The emerging ionic liquid(IL)provides a greener way to efficiently capture NH_(3).This paper provides rigorous process simulation,optimization and assessment for a novel NH_(3)deep purification process using IL.The process was designed and investigated by simulation and optimization using ionic liquid[C_(4)im][NTF_(2)]as absorbent.Three objective functions,total purification cost(TPC),total process CO_(2)emission(TPCOE)and thermal efficiency(ηeff)were employed to optimize the absorption process.Process simulation and optimization results indicate that at same purification standard and recovery rate,the novel process can achieve lower cost and CO_(2)emission compared to benchmark process.After process optimization,the optimal functions can achieve 0.02726$/Nm~3(TPC),311.27 kg CO_(2)/hr(TP-COE),and 52.21%(ηeff)for enhanced process.Moreover,compared with conventional process,novel process could decrease over$3 million of purification cost and 10000 tons of CO_(2)emission during the life cycle.The results provide a novel strategy and guidance for deep purification of NH_(3)capture.展开更多
Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and to...Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and total ammonia concentration in the solution on the purification of the solution were investigated.The results indicate that total ammonia concentration in the solution had no effect on the purification,but relative amount of metallic impurities,dosage of zinc dust,purification time,temperature and pH value of the solution were the main factors influencing the purification.Keeping appropriate molar ratio of copper to cadmium or nickel to cadmium was beneficial to the cementation of cadmium.Nevertheless,the presence of cobalt went against the cementation of cadmium and cobalt.All metallic impurities could be decreased to acceptable levels under the optimized conditions of 2 g/L of zinc dust dosage,1 h of purification time,35℃,pH value 9.03 of zinc ammoniacal leaching solution.The deeply purified zinc ammoniacal solution obtained by one-stage purification meets the requirements of zinc electrowinning.展开更多
The sequestration of trace hexafluoropropylene(C_(3)F_(6))is a critical yet formidable task in the production of high-purity perfluoropropane(C_(3)F_(8)),an important perfluorinated electronic specialty gas(F-gas)in t...The sequestration of trace hexafluoropropylene(C_(3)F_(6))is a critical yet formidable task in the production of high-purity perfluoropropane(C_(3)F_(8)),an important perfluorinated electronic specialty gas(F-gas)in the advanced electronics industry.Traditional adsorbents struggle with uneven,low-pressure uptake and compromises in selectivity.This work utilizes aperture size-electrostatic potential matching within a robust metal–organic framework(Al-PMA)to facilitate selective,reversible binding of C_(3)F_(6)while excluding larger C_(3)F_(8)molecules.The presence of bridging hydroxyl groups(μ_(2)-OH)in Al-PMA creates positive electrostatic potential traps that securely anchor C_(3)F_(6)through strong hydrogen bonding,evidenced by insitu infrared and^(19)F magic angle spinning nuclear magnetic resonance spectroscopy.Breakthrough experiments demonstrate the efficient removal of trace C_(3)F_(6)from C_(3)F_(8)under ambient conditions,achieving C_(3)F_(8)purity exceeding 99.999%.The scalability of Al-PMA synthesis,remarkable stability,and exceptional performance highlight its potential as a promising adsorbent for industrial C_(3)F_(6)/C_(3)F_(8)separations.展开更多
Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be ...Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be controlled to trace levels of below 10 ppm by in situ reduction of the COconcentration to less than 100 ppm via the aforementioned process. The COadsorption capacity of potassiumpromoted hydrotalcite at elevated temperatures under different adsorption（mole fraction, working pressure） and desorption（flow rate, desorption time, steam effects） conditions was systematically investigated using a fixed bed reactor. It was found that the COresidual concentration before the breakthrough of COmainly depended on the total amount of purge gas and the COmole fraction in the inlet syngas.The residual COconcentration and uptake achieved for the inlet gas comprising CO（9.7 mL/min） and He（277.6 mL/min） at a working pressure of 3 MPa after 1 h of Ar purging at 300 mL/min were 12.3 ppm and0.341 mmol/g, respectively. Steam purge could greatly improve the cyclic adsorption working capacity, but had no obvious benefit for the recovery of the residual COconcentration compared to purging with an inert gas. The residual COconcentration obtained with the adsorbent could be reduced to 3.2 ppm after 12 h of temperature swing at 450 °C. A new concept based on an adsorption/desorption process, comprising adsorption, steam rinse, depressurization, steam purge, pressurization, and high-temperature steam purge, was proposed for reducing the steam consumption during CO/COpurification.展开更多
A hydrometallurgical process for indium extraction and ferric oxide powder preparation for soft magnetic ferrite material was developed. Using reduction lixivium from high-acid reductive leaching of zinc oxide calcine...A hydrometallurgical process for indium extraction and ferric oxide powder preparation for soft magnetic ferrite material was developed. Using reduction lixivium from high-acid reductive leaching of zinc oxide calcine as raw solution, copper and indium were firstly recovered by iron powder cementation and neutralization. The recovery ratios of Cu and In are 99% and 95%, respectively. Some harmful impurities that have negative influences on magnetic properties of soft magnetic ferrite material are deeply removed with sulfidization purification and neutral flocculation method. Under the optimum conditions, the content of impurities like Cu, Pb, As, Al in pure Zn-Fe sulfate solution are less than 0.004 g/L, but those of Cd, Si, Ca and Mg are relatively high. Finally, thermal precipitation of iron is carried out at 210 ℃ for 1.5 h. The precipitation ratio of Fe is 93.33%. Compared with the quality standard of ferric oxide for soft magnetic ferrite materials, the contents of Al and Mg in obtained ferric oxide powder meet the requirement of YHT1 level of ferric oxide, and those of Si, Ca meet the requirement of YHT3 level of ferric oxide. XRD and SEM characterizations confirm that the obtained sample is well-dispersed spindle spherule with regular a-Fe2O3 crystal structure. The length-to-diameter ratio ofa-Fe2O3 powder is （3-4）：1 with an average particle size of 0.5 μm.展开更多
基金supported by the National Natural Science Foundation of China (Nos.21890760 and 21838010)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (No.21921005)the International (Regional)Cooperation and Exchange of the National Natural Science Foundation of China (No.21961160744)。
文摘Ammonia(NH_(3))emission has caused serious environment issues and aroused worldwide concern.The emerging ionic liquid(IL)provides a greener way to efficiently capture NH_(3).This paper provides rigorous process simulation,optimization and assessment for a novel NH_(3)deep purification process using IL.The process was designed and investigated by simulation and optimization using ionic liquid[C_(4)im][NTF_(2)]as absorbent.Three objective functions,total purification cost(TPC),total process CO_(2)emission(TPCOE)and thermal efficiency(ηeff)were employed to optimize the absorption process.Process simulation and optimization results indicate that at same purification standard and recovery rate,the novel process can achieve lower cost and CO_(2)emission compared to benchmark process.After process optimization,the optimal functions can achieve 0.02726$/Nm~3(TPC),311.27 kg CO_(2)/hr(TP-COE),and 52.21%(ηeff)for enhanced process.Moreover,compared with conventional process,novel process could decrease over$3 million of purification cost and 10000 tons of CO_(2)emission during the life cycle.The results provide a novel strategy and guidance for deep purification of NH_(3)capture.
基金Supported by the National Basic Research Program of China (973 Project) (No.2007CB613601)
文摘Deep purification of zinc ammoniacal leaching solution by cementation using zinc dust was studied.The effects of relative amount of metallic impurities,dosage of zinc dust,purification time,temperature,pH value and total ammonia concentration in the solution on the purification of the solution were investigated.The results indicate that total ammonia concentration in the solution had no effect on the purification,but relative amount of metallic impurities,dosage of zinc dust,purification time,temperature and pH value of the solution were the main factors influencing the purification.Keeping appropriate molar ratio of copper to cadmium or nickel to cadmium was beneficial to the cementation of cadmium.Nevertheless,the presence of cobalt went against the cementation of cadmium and cobalt.All metallic impurities could be decreased to acceptable levels under the optimized conditions of 2 g/L of zinc dust dosage,1 h of purification time,35℃,pH value 9.03 of zinc ammoniacal leaching solution.The deeply purified zinc ammoniacal solution obtained by one-stage purification meets the requirements of zinc electrowinning.
基金supported by the National Natural Science Foundation of China(22225802,22288102,22141001,and 21878260)Zhejiang Provincial Natural Science Foundation of China(LZ22B060002 and LQ22B060005)Zhejiang Provincial Innovation Center of Advanced Chemicals Technology(2024SJCZX0020)。
文摘The sequestration of trace hexafluoropropylene(C_(3)F_(6))is a critical yet formidable task in the production of high-purity perfluoropropane(C_(3)F_(8)),an important perfluorinated electronic specialty gas(F-gas)in the advanced electronics industry.Traditional adsorbents struggle with uneven,low-pressure uptake and compromises in selectivity.This work utilizes aperture size-electrostatic potential matching within a robust metal–organic framework(Al-PMA)to facilitate selective,reversible binding of C_(3)F_(6)while excluding larger C_(3)F_(8)molecules.The presence of bridging hydroxyl groups(μ_(2)-OH)in Al-PMA creates positive electrostatic potential traps that securely anchor C_(3)F_(6)through strong hydrogen bonding,evidenced by insitu infrared and^(19)F magic angle spinning nuclear magnetic resonance spectroscopy.Breakthrough experiments demonstrate the efficient removal of trace C_(3)F_(6)from C_(3)F_(8)under ambient conditions,achieving C_(3)F_(8)purity exceeding 99.999%.The scalability of Al-PMA synthesis,remarkable stability,and exceptional performance highlight its potential as a promising adsorbent for industrial C_(3)F_(6)/C_(3)F_(8)separations.
基金financed by Shanxi Province Science and Technology Major Projects of MH2015-06
文摘Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be controlled to trace levels of below 10 ppm by in situ reduction of the COconcentration to less than 100 ppm via the aforementioned process. The COadsorption capacity of potassiumpromoted hydrotalcite at elevated temperatures under different adsorption（mole fraction, working pressure） and desorption（flow rate, desorption time, steam effects） conditions was systematically investigated using a fixed bed reactor. It was found that the COresidual concentration before the breakthrough of COmainly depended on the total amount of purge gas and the COmole fraction in the inlet syngas.The residual COconcentration and uptake achieved for the inlet gas comprising CO（9.7 mL/min） and He（277.6 mL/min） at a working pressure of 3 MPa after 1 h of Ar purging at 300 mL/min were 12.3 ppm and0.341 mmol/g, respectively. Steam purge could greatly improve the cyclic adsorption working capacity, but had no obvious benefit for the recovery of the residual COconcentration compared to purging with an inert gas. The residual COconcentration obtained with the adsorbent could be reduced to 3.2 ppm after 12 h of temperature swing at 450 °C. A new concept based on an adsorption/desorption process, comprising adsorption, steam rinse, depressurization, steam purge, pressurization, and high-temperature steam purge, was proposed for reducing the steam consumption during CO/COpurification.
基金Project(50674104) supported by the National Natural Science Foundation of ChinaProject(2006BA02B04-4-2) supported by the Planned Science and Technology of China
文摘A hydrometallurgical process for indium extraction and ferric oxide powder preparation for soft magnetic ferrite material was developed. Using reduction lixivium from high-acid reductive leaching of zinc oxide calcine as raw solution, copper and indium were firstly recovered by iron powder cementation and neutralization. The recovery ratios of Cu and In are 99% and 95%, respectively. Some harmful impurities that have negative influences on magnetic properties of soft magnetic ferrite material are deeply removed with sulfidization purification and neutral flocculation method. Under the optimum conditions, the content of impurities like Cu, Pb, As, Al in pure Zn-Fe sulfate solution are less than 0.004 g/L, but those of Cd, Si, Ca and Mg are relatively high. Finally, thermal precipitation of iron is carried out at 210 ℃ for 1.5 h. The precipitation ratio of Fe is 93.33%. Compared with the quality standard of ferric oxide for soft magnetic ferrite materials, the contents of Al and Mg in obtained ferric oxide powder meet the requirement of YHT1 level of ferric oxide, and those of Si, Ca meet the requirement of YHT3 level of ferric oxide. XRD and SEM characterizations confirm that the obtained sample is well-dispersed spindle spherule with regular a-Fe2O3 crystal structure. The length-to-diameter ratio ofa-Fe2O3 powder is （3-4）：1 with an average particle size of 0.5 μm.
