The solubility of disperse dyes and their mixture in supercritical carbon dioxide is an important property in study and development of supercritical fluid dyeing technology.In this study,solubilities of C.I.Disperse R...The solubility of disperse dyes and their mixture in supercritical carbon dioxide is an important property in study and development of supercritical fluid dyeing technology.In this study,solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183 and their mixture in supercritical CO2 are measured at temperatures from 343.2 to 383.2 K and pressures from 12 to 28 MPa with a static recirculation method.Under the experimental conditions for the binary(C.I.Disperse Red 73+CO2 or C.I.Disperse Blue 183+CO2) and ternary(C.I.Disperse Red 73+C.I.Disperse Blue 183+CO2) systems,the solubilities increase with pressure.The solubility of C.I.Disperse Blue 183 decreases with the increase of temperature when the pressure is lower than 16 MPa,and the trend is opposite when the pressure is higher than 16 MPa.However,there is no crossover pressure for C.I.Disperse Red 73.The solubilities are also affected by molecular polarity of dyes.The co-solvent effect exhibited in the dissolving process of mixed dyes promotes their dissolution in supercritical CO2.The experimental data of solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183,and their mixture are correlated with the Chrastil model and Mendez-Santiago/Teja model. The former is more accurate.展开更多
Piperine is a member of the lipids family commonly found in peppercorn, ginger and other natural sources and is grouped as an alkaloid. The solubility of piperine has been determined in carbon dioxide at near critical...Piperine is a member of the lipids family commonly found in peppercorn, ginger and other natural sources and is grouped as an alkaloid. The solubility of piperine has been determined in carbon dioxide at near critical and supercritical conditions in a dynamic extraction apparatus. The conditions studied were at pressures ranging from 10 to 20 MPa and temperatures at 293, 300, 313, 323 and 333 K. The results showed that piperine solubility increased with increasing pressure at all temperatures studied. The solubility of plperme in near critical conditions was slightly higher than that at supercritical conditions only at the low-pressure range. Two semi-empirical density dependent correlations, namely the Chrastil model and the Dilute Solution model, were also used to estimate the solubility data. Although both models showed good correlation with the solubility data, the Dilute Solution model performed better prediction than the Chrastil model.展开更多
Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9...Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9%0 with changes in temperature, salinity, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen pool. In February, biological processes decreased because of low temperature, and the mean δ15NO3 near the river mouth was 2.4%0. In May, δ15NO3 was the highest in the surface waters among all seasons. Analysis on the conservative mixing revealed assimilation, and this finding is supported by positive relationship between Chl a and δ15NO3. The fractionation factor of assimilation was estimated to be 2.0‰ by the Rayleigh equation. Nitrification was supported based on the mixing behaviors in November 2010 and the low δ15NO3 values in May and November 2009. The high ammonium concentrations in the adjacent marine area and positive relationships between total organic nitrogen and δ15NO3 in November 2010 indicated that mineralization was taking place.展开更多
In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7...In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method (isocratic method). The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.展开更多
In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South ...In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea. The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’ studies. The results showed that the Qingdao Cold Water Mass has growing and vanishing processes: appears in the last ten days of March; has stable pattern in April; is biggest in its area in May; becomes small in its area in June; vanishes in July. It comes from the northern Shandong Coastal Water and is characterized by low temperature and salinity and high dissolved oxygen. The mass is formed under the joint effects of anticyclonic circulation and solar radiation.展开更多
Nowadays artificial neural networkS (ANNs) with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, cr...Nowadays artificial neural networkS (ANNs) with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility predic- tion of three disperse dyes in supercritical carbon dioxide (SC-C02) and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-C02. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash-Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.展开更多
Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 (SC-CO2) was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil ex...Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 (SC-CO2) was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil extracted increased with pressure at constant temperature. The initial slope of the extraction was considered as the solubility of oil in SC-CO2. Chrastil equation was used to correlate the solubility data of Ligusticum Chuanxiong oil. An improved Chrastil equation was also presented and was employed to correlate the solubility data, The correlation results show that the values of the average absolute relative deviation are 5.94% and 3.33% respectively, indicating the improved version has better correlation accuracy than that of Chrastil equation.展开更多
The solubility of carbon monoxide in phenol+ethanol mixed solvents at elevated pressures is reported in this article. The experimental results revealed the influence of pressure on the solubility of CO in phenol+eth...The solubility of carbon monoxide in phenol+ethanol mixed solvents at elevated pressures is reported in this article. The experimental results revealed the influence of pressure on the solubility of CO in phenol+ethanol mixtures. These mixtures are a poorer solvent for carbon monoxide. The solubility of CO is a linear function of pressure, and the extended Henry's constants were presented at different concentrations of phenol. The cubic Soave-Redlich-Kwong equation of state was used to correlate the experimental gas liquid equilibrium data and to predict the solubility of CO. At the same time, the binary interaction parameters, kO, for CO-phenol, CO-ethanol and phenol-ethanol systems were estimated by fitting experimental GLE data at 303.15 K and at 2.0-9.0 MPa. Hence, a model was suggested for the solubility of CO in phenol+ethanol mixed solvents. The agreement between experimental and calculated solubilities with the proposed model was rather satisfactory.展开更多
To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect...To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.展开更多
In the feeding process of aluminum electrolytic, feeding quantity of alumina affects eventually dissolved quantity at the end of a feeding cycle. Based on the OpenFOAM platform, dissolution model coupled with heat and...In the feeding process of aluminum electrolytic, feeding quantity of alumina affects eventually dissolved quantity at the end of a feeding cycle. Based on the OpenFOAM platform, dissolution model coupled with heat and mass transfer was established. Applying the Rosin-Rammler function, alumina particle size distribution under different feeding quantities was obtained. The temperature response of electrolyte after feeding was included and calculated, and the dissolution processes of alumina with different feeding quantities (0.6, 0.8, 1.0, 1.2, 1.4, 1.6 kg) after feeding were simulated in 300 kA aluminum reduction cell. The results show that with the increase of feeding quantity, accumulated mass fraction of dissolved alumina decreases, and the time required for the rapid dissolution stage extends. When the feeding quantity is 0.6 kg and 1.2 kg, it takes the shortest time for the electrolyte temperature dropping before rebounding back. With the increase of feeding quantity, the dissolution rate in the rapid dissolution stage increases at first and then decreases gradually. The most suitable feeding quantity is 1.2 kg. The fitting equation of alumina dissolution curve under different feeding quantities is obtained, which can be used to evaluate the alumina dissolution and guide the feeding quantity and feeding cycle.展开更多
The Box–Behnken design and desirability approach were used to investigate and optimize the process parameters for aluminum reduction cells related to alumina dissolution. The bath temperature, alumina content, curren...The Box–Behnken design and desirability approach were used to investigate and optimize the process parameters for aluminum reduction cells related to alumina dissolution. The bath temperature, alumina content, current and alumina temperature were chosen as the design parameters. The content of cumulative dissolved alumina(CCDA) and the relative deviation from the target content(RDTC) were adopted as the responses. The interactive influence results show that increasing the bath temperature and alumina temperature, as well as decreasing the alumina content, can increase CCDA. Increasing the bath temperature and lowering the current are beneficial for obtaining a more uniform alumina distribution. The optimal operating parameters were determined to be as follows: bath temperature of 958.8 ℃, alumina content of 2.679 wt.%, current of 300 kA and alumina temperature of 200 ℃.展开更多
Solubility data of carbon dioxide (CO2) (1) in methanol (2), 1-octyl-3-methylimidazolium bis(trifluoro- methylsulfonyl)imide ([omim]+[TfzN]-) (3), and their mixtures (w3 = 0.2, 0.5, and 0.8) at temperat...Solubility data of carbon dioxide (CO2) (1) in methanol (2), 1-octyl-3-methylimidazolium bis(trifluoro- methylsulfonyl)imide ([omim]+[TfzN]-) (3), and their mixtures (w3 = 0.2, 0.5, and 0.8) at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO2 in methanol (w3 = 0), [omim]+[Tf2N]- (w3 = 1.0) and their mixtures follows the order of (w3 = 0)〈(w3 = 0.2)〈 (w3 = 0.5)〈(w3 = 0.8)〈(w3 = 1.0) at the same temperature and pressure, while the magnitude of Henry's constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS (conductor-like screen- ing for real solvents) calculation. The solubility data of CO2 in methanol and [omim]~[Tf2N]- are correlated with the Peng-Robinson equation of state, and the solubility of CO2 in the mixtures of methanol and [omim]+[TfzN] can be well predicted based on the mole fraction average of methanol and [omim]+[Tf2N] over the solubility of CO2 in pure methanol and [omim]+[Tf2N] . The mixtures of methanol and [omim]+[Tf2N]- may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.展开更多
The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's...The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's law is not applicable if the gas phase is a mixture.This problem can be solved by using UNIQUAC model to calculate the activity coefficient of gas dissolved in the membrane.A method was proposed in this study to obtain the gas-membrane interaction parameter for UNIQUAC model.By the experiments of gas permeation through polydimethylsiloxane PDMS membrane,the solubility coefficients of some gases(N2,CO2,CH4) were measured.Through non-linear fitting UNIQUAC model to the experimental results from this study and in literature(H2,O2,C3H8),the gas-membrane interaction parameters for these gases were obtained.Based on these parameters,the activity coefficients of the dissolved gas were calculated by UNIQUAC model,and their values agree well with the experimental data.These results confirm the feasibility and effectiveness of the proposed method,which makes it possible to better predict gas-membrane solution equilibrium.展开更多
The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5-25 MPa and, 313.15-333.15 K and at a fixed scCO2 flow rate of 2.9 g. mn -1 using a full fac...The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5-25 MPa and, 313.15-333.15 K and at a fixed scCO2 flow rate of 2.9 g. mn -1 using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO par- ticle formation using scCO2. The solubility of RPO was 0.5-11.3 mg. (g CO2) -1 and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi-Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R2 of 0.9667, whereas the Peng-Robinson equation of state thermodynamic model recorded deviations of 17%-30%.展开更多
基金Supported by the Natural Science Foundation of Zhejiang Province(M203035)
文摘The solubility of disperse dyes and their mixture in supercritical carbon dioxide is an important property in study and development of supercritical fluid dyeing technology.In this study,solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183 and their mixture in supercritical CO2 are measured at temperatures from 343.2 to 383.2 K and pressures from 12 to 28 MPa with a static recirculation method.Under the experimental conditions for the binary(C.I.Disperse Red 73+CO2 or C.I.Disperse Blue 183+CO2) and ternary(C.I.Disperse Red 73+C.I.Disperse Blue 183+CO2) systems,the solubilities increase with pressure.The solubility of C.I.Disperse Blue 183 decreases with the increase of temperature when the pressure is lower than 16 MPa,and the trend is opposite when the pressure is higher than 16 MPa.However,there is no crossover pressure for C.I.Disperse Red 73.The solubilities are also affected by molecular polarity of dyes.The co-solvent effect exhibited in the dissolving process of mixed dyes promotes their dissolution in supercritical CO2.The experimental data of solubilities of C.I.Disperse Red 73,C.I.Disperse Blue 183,and their mixture are correlated with the Chrastil model and Mendez-Santiago/Teja model. The former is more accurate.
基金Supported by the IRPA Project of the Ministry of Science,Technology and Innovation,Malaysia (09-02-03-0101-EA0001)Fundamental Research Grant 2009 Directorate General of Higher Education,Ministry of National Education,the Republic of Indonesia
文摘Piperine is a member of the lipids family commonly found in peppercorn, ginger and other natural sources and is grouped as an alkaloid. The solubility of piperine has been determined in carbon dioxide at near critical and supercritical conditions in a dynamic extraction apparatus. The conditions studied were at pressures ranging from 10 to 20 MPa and temperatures at 293, 300, 313, 323 and 333 K. The results showed that piperine solubility increased with increasing pressure at all temperatures studied. The solubility of plperme in near critical conditions was slightly higher than that at supercritical conditions only at the low-pressure range. Two semi-empirical density dependent correlations, namely the Chrastil model and the Dilute Solution model, were also used to estimate the solubility data. Although both models showed good correlation with the solubility data, the Dilute Solution model performed better prediction than the Chrastil model.
基金Supported by the National Natural Science Foundation of China(No.41276116)the Fund for Creative Research Groups by NSFC(No.41121064)the National Basic Research Program of China(973 Program)(No.2010CB428706)
文摘Seasonal variations in the nitrogen isotopic composition of dissolved nitrate (δ15NO3) were investigated in the surface waters of the Changjiang River estuary in 2009 and 2010. δ15NO3 varied between -4.6‰ and 8.9%0 with changes in temperature, salinity, dissolved oxygen concentrations, and the composition of the dissolved inorganic nitrogen pool. In February, biological processes decreased because of low temperature, and the mean δ15NO3 near the river mouth was 2.4%0. In May, δ15NO3 was the highest in the surface waters among all seasons. Analysis on the conservative mixing revealed assimilation, and this finding is supported by positive relationship between Chl a and δ15NO3. The fractionation factor of assimilation was estimated to be 2.0‰ by the Rayleigh equation. Nitrification was supported based on the mixing behaviors in November 2010 and the low δ15NO3 values in May and November 2009. The high ammonium concentrations in the adjacent marine area and positive relationships between total organic nitrogen and δ15NO3 in November 2010 indicated that mineralization was taking place.
文摘In this work it presents a strategy to obtain the ozone solubility in water by gradient step method. In this methodology, the ozone in mixture with oxygen is bubbling in a reactor with distilled water at 21℃ and pH 7. The ozone concentration on gas phase is continually increased after the saturation is reached. The method proposed is faster than conventional method (isocratic method). The solubility from the gradient method is compared with that values obtained from correlations founded in the literature.
文摘In this work, the main characteristics of the Qingdao Cold Water Mass were studied by using "the comparison analysis method" based on 1980 temperature,salinity and dissolved oxygen data on the western South Yellow Sea. The formation cause of the water mass was analyzed based on February of 1959 temperature and salinity data for this area and on some other authors’ studies. The results showed that the Qingdao Cold Water Mass has growing and vanishing processes: appears in the last ten days of March; has stable pattern in April; is biggest in its area in May; becomes small in its area in June; vanishes in July. It comes from the northern Shandong Coastal Water and is characterized by low temperature and salinity and high dissolved oxygen. The mass is formed under the joint effects of anticyclonic circulation and solar radiation.
文摘Nowadays artificial neural networkS (ANNs) with strong ability have been applied widely for prediction of non- linear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility predic- tion of three disperse dyes in supercritical carbon dioxide (SC-C02) and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-C02. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash-Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.
基金Supported by Scientific and Technological Development Project of Tianjin (No. 01310861111)
文摘Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 (SC-CO2) was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil extracted increased with pressure at constant temperature. The initial slope of the extraction was considered as the solubility of oil in SC-CO2. Chrastil equation was used to correlate the solubility data of Ligusticum Chuanxiong oil. An improved Chrastil equation was also presented and was employed to correlate the solubility data, The correlation results show that the values of the average absolute relative deviation are 5.94% and 3.33% respectively, indicating the improved version has better correlation accuracy than that of Chrastil equation.
基金Supported by the National Natural Science Foundation of China (20476083, 50576028).
文摘The solubility of carbon monoxide in phenol+ethanol mixed solvents at elevated pressures is reported in this article. The experimental results revealed the influence of pressure on the solubility of CO in phenol+ethanol mixtures. These mixtures are a poorer solvent for carbon monoxide. The solubility of CO is a linear function of pressure, and the extended Henry's constants were presented at different concentrations of phenol. The cubic Soave-Redlich-Kwong equation of state was used to correlate the experimental gas liquid equilibrium data and to predict the solubility of CO. At the same time, the binary interaction parameters, kO, for CO-phenol, CO-ethanol and phenol-ethanol systems were estimated by fitting experimental GLE data at 303.15 K and at 2.0-9.0 MPa. Hence, a model was suggested for the solubility of CO in phenol+ethanol mixed solvents. The agreement between experimental and calculated solubilities with the proposed model was rather satisfactory.
基金Projects PGSD3-334033-2006 supported by the Natural Sciences and Engineering Research Council of Canada2007-2008 by the Canadian Forest Service of Natural Resources
文摘To get a better understanding of the spatial impact of organic discharges on stream water quality,a "scenario-testing" approach was proposed to examine how a change in plant treatment efficiency would affect dissolved oxygen(DO) concentration along a stream.An "upper-lower" boundary technique was applied to conduct sensitivity analysis to observe the responses of DO concentration to different DO-related parameters.The results show a non-linear discrepancy of biochemical oxygen demand(BOD) and DO concentration among different treatment scenarios,which indicates the higher the efficiency of the plant treatment,the shorter the time the stream needs to recover.The sensitivity analysis reveals that the larger the amount of the waste discharge,the more sensitive the BOD to the biological removal parameter.In addition,the DO is more sensitive to the biological removal parameter than to the reaeration parameter.
基金Project(2010AA065201) supported by the High-Tech Research and Development Program of ChinaProject(2018zzts157) supported by the Fundamental Research Funds for the Central Universities,China
文摘In the feeding process of aluminum electrolytic, feeding quantity of alumina affects eventually dissolved quantity at the end of a feeding cycle. Based on the OpenFOAM platform, dissolution model coupled with heat and mass transfer was established. Applying the Rosin-Rammler function, alumina particle size distribution under different feeding quantities was obtained. The temperature response of electrolyte after feeding was included and calculated, and the dissolution processes of alumina with different feeding quantities (0.6, 0.8, 1.0, 1.2, 1.4, 1.6 kg) after feeding were simulated in 300 kA aluminum reduction cell. The results show that with the increase of feeding quantity, accumulated mass fraction of dissolved alumina decreases, and the time required for the rapid dissolution stage extends. When the feeding quantity is 0.6 kg and 1.2 kg, it takes the shortest time for the electrolyte temperature dropping before rebounding back. With the increase of feeding quantity, the dissolution rate in the rapid dissolution stage increases at first and then decreases gradually. The most suitable feeding quantity is 1.2 kg. The fitting equation of alumina dissolution curve under different feeding quantities is obtained, which can be used to evaluate the alumina dissolution and guide the feeding quantity and feeding cycle.
基金Project(2010AA065201)supported by the High Technology Research and Development Program of ChinaProject(2018zzts157)supported by the Fundamental Research Funds for the Central Universities of Central South University,China。
文摘The Box–Behnken design and desirability approach were used to investigate and optimize the process parameters for aluminum reduction cells related to alumina dissolution. The bath temperature, alumina content, current and alumina temperature were chosen as the design parameters. The content of cumulative dissolved alumina(CCDA) and the relative deviation from the target content(RDTC) were adopted as the responses. The interactive influence results show that increasing the bath temperature and alumina temperature, as well as decreasing the alumina content, can increase CCDA. Increasing the bath temperature and lowering the current are beneficial for obtaining a more uniform alumina distribution. The optimal operating parameters were determined to be as follows: bath temperature of 958.8 ℃, alumina content of 2.679 wt.%, current of 300 kA and alumina temperature of 200 ℃.
基金Supported by the National Natural Science Foundation of China (21121064, 21076008), and the Projects in the National Sci ence & Technology Pillar Program During the Twelfth Five-Year Plan Period (2011BAC06B04).
文摘Solubility data of carbon dioxide (CO2) (1) in methanol (2), 1-octyl-3-methylimidazolium bis(trifluoro- methylsulfonyl)imide ([omim]+[TfzN]-) (3), and their mixtures (w3 = 0.2, 0.5, and 0.8) at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique. The solubility of CO2 in methanol (w3 = 0), [omim]+[Tf2N]- (w3 = 1.0) and their mixtures follows the order of (w3 = 0)〈(w3 = 0.2)〈 (w3 = 0.5)〈(w3 = 0.8)〈(w3 = 1.0) at the same temperature and pressure, while the magnitude of Henry's constants follows the reverse order at a given temperature, which is consistent with the COSMO-RS (conductor-like screen- ing for real solvents) calculation. The solubility data of CO2 in methanol and [omim]~[Tf2N]- are correlated with the Peng-Robinson equation of state, and the solubility of CO2 in the mixtures of methanol and [omim]+[TfzN] can be well predicted based on the mole fraction average of methanol and [omim]+[Tf2N] over the solubility of CO2 in pure methanol and [omim]+[Tf2N] . The mixtures of methanol and [omim]+[Tf2N]- may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.
文摘The recovery or capture of one or more components from gas mixture by membrane separation has become a research focus in recent years.This study investigates the gas-membrane solution equilibrium,for which Henry's law is not applicable if the gas phase is a mixture.This problem can be solved by using UNIQUAC model to calculate the activity coefficient of gas dissolved in the membrane.A method was proposed in this study to obtain the gas-membrane interaction parameter for UNIQUAC model.By the experiments of gas permeation through polydimethylsiloxane PDMS membrane,the solubility coefficients of some gases(N2,CO2,CH4) were measured.Through non-linear fitting UNIQUAC model to the experimental results from this study and in literature(H2,O2,C3H8),the gas-membrane interaction parameters for these gases were obtained.Based on these parameters,the activity coefficients of the dissolved gas were calculated by UNIQUAC model,and their values agree well with the experimental data.These results confirm the feasibility and effectiveness of the proposed method,which makes it possible to better predict gas-membrane solution equilibrium.
基金supported by Geran Putra IPS(Vote No.:9469400),University Putra Malaysia
文摘The solubility of red palm oil (RPO) in supercritical carbon dioxide (scCO2) was determined using a dynamic method at 8.5-25 MPa and, 313.15-333.15 K and at a fixed scCO2 flow rate of 2.9 g. mn -1 using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO par- ticle formation using scCO2. The solubility of RPO was 0.5-11.3 mg. (g CO2) -1 and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi-Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R2 of 0.9667, whereas the Peng-Robinson equation of state thermodynamic model recorded deviations of 17%-30%.