Magnesium bicarbonate, prepared by the carbonation of magnesium hydroxide slurry, was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process. The effect ...Magnesium bicarbonate, prepared by the carbonation of magnesium hydroxide slurry, was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process. The effect of impurity ions introduced by system on the carbonation reaction of magnesium hydroxide was studied in the work. The results showed that the presence of Ca2＋could lead to side reactions so as to reduce the conversion rate of magnesium hydroxide, and a small number of rare earth ions would have great influence on the carbonation reaction. What’s more, there was no influence on carbonation reaction with the low concen-tration of Na＋or Mg2＋, the conversion rate of magnesium hydroxide could reach above 96%. This paper showed a practical theory which could provide scientific guidance for the preparation of novel saponifier in rare earth extraction separation process.展开更多
A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. ...A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. The recovery process involved three steps：（1） leaching REs（mainly lanthanum and cerium）;（2） solvent extraction by applying saponified P507-kerosene system;（3） stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl（1 mol/L） could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio（O/A ratio） of 2：1 with an extractants＇ saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1：1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.展开更多
The microemulsion system of HA(2-ethylhexylphosphonic acid mono 2-ethylhexyl ester) / kerosene not containing cosurfactant has been investigated.The physico-chemical properties,such as phase behaviour, conductivity et...The microemulsion system of HA(2-ethylhexylphosphonic acid mono 2-ethylhexyl ester) / kerosene not containing cosurfactant has been investigated.The physico-chemical properties,such as phase behaviour, conductivity etc. of microemulsion formed by HA-kerosene saponified by different concentrations of sodium hydroxide have been measured . The results show that the properties are different from the microemulsion system containing cosurfactant. The structure of the microemulsion has been discussed. Furthermore, the effect of H2O、 NaCl、 NH4Cl on the properties of microemulsion have also been studied.展开更多
Microalgae biomass has been reported in the literature as one of the most promising sources for obtaining different products of industrial interest such as lipids, fatty acids, carotenoids, proteins and fibers. The li...Microalgae biomass has been reported in the literature as one of the most promising sources for obtaining different products of industrial interest such as lipids, fatty acids, carotenoids, proteins and fibers. The lipid fraction of microalgae comprises neutral lipids, free fatty acids and polar lipids. It is of great importance to estimate the composition of the lipid fraction to define the potential for use, either as a raw material for the production of biofuels or for use for nutraceuticals and/or food purposes. The microalgae </span><i><span style="font-size:12px;font-family:Verdana;">Scenedesmus</span></i><span style="font-size:12px;font-family:Verdana;"> sp. cultivated in a photobioreactor</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">,</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> the sky open raceway type</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">,</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> was evaluated for lipid content, identification and quantification of lipid components obtained from different extracts. In the quantification of the lipid content, extraction methods were proposed without chemical treatment (use of solvents only) such as chloroform:methanol (2:1 v/v)—Bligh & Dyer, Ethanol, Ethyl acetate:Hexane (1:1 v/v) and others with chemical treatment such as J-Schmid-Bondzynski-Ratzlaff (acid) and saponification (basic). For the identification of the main lipid components present in the extracts, the Thin layer chromatography (TLC) technique was used. This made it possible, using a simple and inexpe展开更多
In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mon...In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000 mol·L^(-1); EHEHPA in a range of 0.2877–0.8631 mol·L^(-1) with saponification rate of 0.3(mole fraction), and the initial aqueous p H in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with.The calculation results are in good agreement well with the experimental data.展开更多
The solubization of the W/O microemulsion of NA（naphthenic acid）/kerosene/NH3· H2O system has been investigated.The effect of salt,cosurfactant （- alcohol） on solubization of the microemulsion has been studie...The solubization of the W/O microemulsion of NA（naphthenic acid）/kerosene/NH3· H2O system has been investigated.The effect of salt,cosurfactant （- alcohol） on solubization of the microemulsion has been studied by the theory of cohesive energies（theory of R- ratio）.The results show that theory of R- ratio may explain the effect of concentration of salt,such as LiCl,NaCl,KCl,NaNO3,Na2SO4,NH4Cl,on maximum solubization （Φ m） of the microemulsion,but can not explain the differences of the effect of these salt onΦ m（to see Fig.1）.We have found that,the rateQ（Q=z/r） of salt was correlated with the effect of salt on Φ m（to see Tab.1）.Theory of R- ratio can only explain the effect of fraction mass of part alconols,such as n- octyl and n- heptyl and n- hexyl alcohol onΦ m,but can not explain the effect of isobutyl alcohol,n- butyl alcohol,n- pentanol and isoamyl alconol onΦ m （to see Fig.2）.So theory of R- ratio has it’s limitations in explaination of the phenomenons of solubization of W/O microemulsion.展开更多
The extraction of zinc from zinc sulfate solution was investigated, using 20% saponified D2EHPA as an extractam and 260^# sulfonate kerosene as a diluent. The solution was stirred for 8 min at phase ratio （Vσ/Va） o...The extraction of zinc from zinc sulfate solution was investigated, using 20% saponified D2EHPA as an extractam and 260^# sulfonate kerosene as a diluent. The solution was stirred for 8 min at phase ratio （Vσ/Va） of 1.0：1.0, initial pH of 2.0 and stirring speed of 200 r/min. The results show that 75% zinc can be extracted from the zinc sulfate solution when the concentration of zinc is 18.7 g/L after being settled for 10 min. 88.60% zinc can be stripped by 196 g/L sulfuric acid, and zinc ion can be separated from ferric ion.展开更多
In the current study,the potentiality and optimization of lipid extraction from secondary sludge for biodiesel production were investigated.Four lipid extraction parameters were examined and used for process optimizat...In the current study,the potentiality and optimization of lipid extraction from secondary sludge for biodiesel production were investigated.Four lipid extraction parameters were examined and used for process optimization and model development using Design of Experiment(DoE)method(namely methanol to hexane ratio-%,solvent to sludge ratio-ml/g,temperature-oC and extraction time-h).During the optimization process,free fatty acid(FFA)and saponifiable lipids(SLs)content of the extracted lipid were analyzed.The results revealed that,the maximum lipid extraction yield(Ylipid)predicted through numerically optimized conditions by the model for highest desirability(0.99)was 16.5%at methanol to hexane ratio(%)of 84%,solvent to sludge ratio(v/wt)of 45 ml/g,temperature at 90℃ for 6 hours extraction time.The extracted lipid contained a maximum amount of 31%(wt/wt)FFA,where palmatic acid was predominant.The FAMEs yield produced from ex-situ acid-catalyzed esterification/transesterification of the methanol-hexane co-solvent extracted lipid ranged between 4.5-5%(wt/wt)based on sludge weight.Fatty acid profile of FAMEs was found to be dominated by methyl palmitate(C16:0)representing 36%of FAMEs composition,followed by palmitoleic acid methyl ester(C16:1),oleic acid methyl ester(C18:1)and stearic acid methyl ester(C18:1)representing 24%,18%and 10%of the FFA composition respectively.PCA analysis showed that solvent to sludge ratio(ml/g)has the highest significant positive effect on FAMEs yield(p-value<0.05)where methanol to hexane ratio(X1),temperature(X3)and extraction time(X4)were inversely correlated with FAMEs yield.The results indicated the feasibility of using secondary sludge as an alternative feedstock for biodiesel production.However,the optimized conditions for maximizing extracted lipid content should not be considered suitable for FAMEs yield as well.展开更多
基金Project supported by Key Program of National Natural Science Foundation of China(50934004)National High Technology Research and Development Program of China(2010AA03A405)National Science and Technology Support Program of China(2012BAE01B02)
文摘Magnesium bicarbonate, prepared by the carbonation of magnesium hydroxide slurry, was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process. The effect of impurity ions introduced by system on the carbonation reaction of magnesium hydroxide was studied in the work. The results showed that the presence of Ca2＋could lead to side reactions so as to reduce the conversion rate of magnesium hydroxide, and a small number of rare earth ions would have great influence on the carbonation reaction. What’s more, there was no influence on carbonation reaction with the low concen-tration of Na＋or Mg2＋, the conversion rate of magnesium hydroxide could reach above 96%. This paper showed a practical theory which could provide scientific guidance for the preparation of novel saponifier in rare earth extraction separation process.
基金Project supported by the National Key Basic Research Program of China(2012CBA01203)the Specialized Research Fund for Doctoral Programme of Higher Education of MOE of China(20130002110018)in the State Key Laboratory of Chemical Engineering of Tsinghua University
文摘A process to recover rare earth（RE） metals from spent fluid catalytic cracking（FCC） catalysts by solvent extraction was studied, using saponified 2-ethylhexyl phosphoric acid-2-ethylhexyl ester（EHEHPA or P507）. The recovery process involved three steps：（1） leaching REs（mainly lanthanum and cerium）;（2） solvent extraction by applying saponified P507-kerosene system;（3） stripping. Experiments to assure optimal operating conditions were conducted. Results indicated that RE metals could be recovered effectively from spent catalyst with saponified P507-kerosene-HCl system. At room temperature of 25 oC, 10 g spent catalyst with 110 m L of HCl（1 mol/L） could achieve a leaching efficiency of 85%. For extraction, initial pH value of 3.17, organic/aqueous ratio（O/A ratio） of 2：1 with an extractants＇ saponification rate of 20% could obtain 100% efficiency. In the stripping process, 1 mol/L HCl with O/A ratio of 1：1 led to a stripping efficiency of 96%. In the present study, RE metals from spent FCC catalysts were effectively recovered, which avoided wasting a large amount of RE resources. It provides a theoretical support for commercial recycling of RE resources.
文摘The microemulsion system of HA(2-ethylhexylphosphonic acid mono 2-ethylhexyl ester) / kerosene not containing cosurfactant has been investigated.The physico-chemical properties,such as phase behaviour, conductivity etc. of microemulsion formed by HA-kerosene saponified by different concentrations of sodium hydroxide have been measured . The results show that the properties are different from the microemulsion system containing cosurfactant. The structure of the microemulsion has been discussed. Furthermore, the effect of H2O、 NaCl、 NH4Cl on the properties of microemulsion have also been studied.
文摘Microalgae biomass has been reported in the literature as one of the most promising sources for obtaining different products of industrial interest such as lipids, fatty acids, carotenoids, proteins and fibers. The lipid fraction of microalgae comprises neutral lipids, free fatty acids and polar lipids. It is of great importance to estimate the composition of the lipid fraction to define the potential for use, either as a raw material for the production of biofuels or for use for nutraceuticals and/or food purposes. The microalgae </span><i><span style="font-size:12px;font-family:Verdana;">Scenedesmus</span></i><span style="font-size:12px;font-family:Verdana;"> sp. cultivated in a photobioreactor</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">,</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> the sky open raceway type</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;">,</span></span></span><span style="font-size:12px;font-family:Verdana;"><span style="font-size:12px;font-family:Verdana;"><span style="font-family:Verdana;font-size:12px;"> was evaluated for lipid content, identification and quantification of lipid components obtained from different extracts. In the quantification of the lipid content, extraction methods were proposed without chemical treatment (use of solvents only) such as chloroform:methanol (2:1 v/v)—Bligh & Dyer, Ethanol, Ethyl acetate:Hexane (1:1 v/v) and others with chemical treatment such as J-Schmid-Bondzynski-Ratzlaff (acid) and saponification (basic). For the identification of the main lipid components present in the extracts, the Thin layer chromatography (TLC) technique was used. This made it possible, using a simple and inexpe
基金Supported by the National Basic Research Program of China(2012CBA01203)the National Natural Science Foundation of China(9021003420221603)
文摘In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements(REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester(EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000 mol·L^(-1); EHEHPA in a range of 0.2877–0.8631 mol·L^(-1) with saponification rate of 0.3(mole fraction), and the initial aqueous p H in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with.The calculation results are in good agreement well with the experimental data.
文摘The solubization of the W/O microemulsion of NA（naphthenic acid）/kerosene/NH3· H2O system has been investigated.The effect of salt,cosurfactant （- alcohol） on solubization of the microemulsion has been studied by the theory of cohesive energies（theory of R- ratio）.The results show that theory of R- ratio may explain the effect of concentration of salt,such as LiCl,NaCl,KCl,NaNO3,Na2SO4,NH4Cl,on maximum solubization （Φ m） of the microemulsion,but can not explain the differences of the effect of these salt onΦ m（to see Fig.1）.We have found that,the rateQ（Q=z/r） of salt was correlated with the effect of salt on Φ m（to see Tab.1）.Theory of R- ratio can only explain the effect of fraction mass of part alconols,such as n- octyl and n- heptyl and n- hexyl alcohol onΦ m,but can not explain the effect of isobutyl alcohol,n- butyl alcohol,n- pentanol and isoamyl alconol onΦ m （to see Fig.2）.So theory of R- ratio has it’s limitations in explaination of the phenomenons of solubization of W/O microemulsion.
基金Project(50774094) supported by the National Natural Science Foundation of China
文摘The extraction of zinc from zinc sulfate solution was investigated, using 20% saponified D2EHPA as an extractam and 260^# sulfonate kerosene as a diluent. The solution was stirred for 8 min at phase ratio （Vσ/Va） of 1.0：1.0, initial pH of 2.0 and stirring speed of 200 r/min. The results show that 75% zinc can be extracted from the zinc sulfate solution when the concentration of zinc is 18.7 g/L after being settled for 10 min. 88.60% zinc can be stripped by 196 g/L sulfuric acid, and zinc ion can be separated from ferric ion.
文摘In the current study,the potentiality and optimization of lipid extraction from secondary sludge for biodiesel production were investigated.Four lipid extraction parameters were examined and used for process optimization and model development using Design of Experiment(DoE)method(namely methanol to hexane ratio-%,solvent to sludge ratio-ml/g,temperature-oC and extraction time-h).During the optimization process,free fatty acid(FFA)and saponifiable lipids(SLs)content of the extracted lipid were analyzed.The results revealed that,the maximum lipid extraction yield(Ylipid)predicted through numerically optimized conditions by the model for highest desirability(0.99)was 16.5%at methanol to hexane ratio(%)of 84%,solvent to sludge ratio(v/wt)of 45 ml/g,temperature at 90℃ for 6 hours extraction time.The extracted lipid contained a maximum amount of 31%(wt/wt)FFA,where palmatic acid was predominant.The FAMEs yield produced from ex-situ acid-catalyzed esterification/transesterification of the methanol-hexane co-solvent extracted lipid ranged between 4.5-5%(wt/wt)based on sludge weight.Fatty acid profile of FAMEs was found to be dominated by methyl palmitate(C16:0)representing 36%of FAMEs composition,followed by palmitoleic acid methyl ester(C16:1),oleic acid methyl ester(C18:1)and stearic acid methyl ester(C18:1)representing 24%,18%and 10%of the FFA composition respectively.PCA analysis showed that solvent to sludge ratio(ml/g)has the highest significant positive effect on FAMEs yield(p-value<0.05)where methanol to hexane ratio(X1),temperature(X3)and extraction time(X4)were inversely correlated with FAMEs yield.The results indicated the feasibility of using secondary sludge as an alternative feedstock for biodiesel production.However,the optimized conditions for maximizing extracted lipid content should not be considered suitable for FAMEs yield as well.
