The supercritical antisolvent （SAS） process has been developed in recent years for the tormation of nanoand micro-particles. It is necessary to study the liquid phase volume expansion （LPVE） and find the relations...The supercritical antisolvent （SAS） process has been developed in recent years for the tormation of nanoand micro-particles. It is necessary to study the liquid phase volume expansion （LPVE） and find the relationships between the operating conditions and the LPVE in order to develop a practical method for determining the operation conditions and selecting an organic solvent for SAS process. The PR equation of state with vdW-1 mixing rule is used to calculate the LPVE for CO2/toluene, CO2/acetone and CO2/ethyl acetate systems, and the results show that the LPVE for each CO2/organic solvent system decreases as the temperature increases. The relationship between the LPVE and the solubility of CO2 in the liquid phase for CO2/organic solvent systems is investigated, and the results show that the LPVE is determined directly by the solubility of CO2 in the liquid phase, xCO2, and can be related to xCO2 independently. No matter what system of CO2/organic solvent is and how different the temperature is, the LPVEs have little difference as long as the solubility of CO2 in the liquid phase, xCO2, keeps constant. The lower temperature is always favorable to the SAS process. The higher the solubility of CO2 in an organic solvent under certain operation condition, the more suitable it is to the SAS process.展开更多
The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritic...The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritical fluid crystallization techniques, i.e. rapid expansion of supercritical solutions, supercritical fluid anti-solvent and particles from gas saturated solutions Some questions and the prospect of this technique were also discussed.展开更多
Granular HApB composite adsorbents, with dimensions of 4 mm × 4 mm, were prepared for the removal of lead from an aqueous solution. The effectiveness of the composites for Pb2＋ removal from an aqueous solution w...Granular HApB composite adsorbents, with dimensions of 4 mm × 4 mm, were prepared for the removal of lead from an aqueous solution. The effectiveness of the composites for Pb2＋ removal from an aqueous solution with different initial concentrations, adsorbent doses and reaction times were examined. The Langmuir isotherms, Freundlich isotherm models and pseudo-second order kinetic model were used in this analysis. It was found that the Langmuir model fitted the experimental data better than the Freundlich model, with a maximum adsorption capacity of 93.37 mg.g-1. The pseudo-second order kinetic model also fit the experiment data well with an adsorption capacity of 70.73 mg.g-1 after being reused for 3 times. Furthermore, the composites may possibly be used in processes for industrial water treatment.展开更多
基金Supported by the National Nature Science Foundation of China (No. 20176003)
文摘The supercritical antisolvent （SAS） process has been developed in recent years for the tormation of nanoand micro-particles. It is necessary to study the liquid phase volume expansion （LPVE） and find the relationships between the operating conditions and the LPVE in order to develop a practical method for determining the operation conditions and selecting an organic solvent for SAS process. The PR equation of state with vdW-1 mixing rule is used to calculate the LPVE for CO2/toluene, CO2/acetone and CO2/ethyl acetate systems, and the results show that the LPVE for each CO2/organic solvent system decreases as the temperature increases. The relationship between the LPVE and the solubility of CO2 in the liquid phase for CO2/organic solvent systems is investigated, and the results show that the LPVE is determined directly by the solubility of CO2 in the liquid phase, xCO2, and can be related to xCO2 independently. No matter what system of CO2/organic solvent is and how different the temperature is, the LPVEs have little difference as long as the solubility of CO2 in the liquid phase, xCO2, keeps constant. The lower temperature is always favorable to the SAS process. The higher the solubility of CO2 in an organic solvent under certain operation condition, the more suitable it is to the SAS process.
文摘The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritical fluid crystallization techniques, i.e. rapid expansion of supercritical solutions, supercritical fluid anti-solvent and particles from gas saturated solutions Some questions and the prospect of this technique were also discussed.
文摘Granular HApB composite adsorbents, with dimensions of 4 mm × 4 mm, were prepared for the removal of lead from an aqueous solution. The effectiveness of the composites for Pb2＋ removal from an aqueous solution with different initial concentrations, adsorbent doses and reaction times were examined. The Langmuir isotherms, Freundlich isotherm models and pseudo-second order kinetic model were used in this analysis. It was found that the Langmuir model fitted the experimental data better than the Freundlich model, with a maximum adsorption capacity of 93.37 mg.g-1. The pseudo-second order kinetic model also fit the experiment data well with an adsorption capacity of 70.73 mg.g-1 after being reused for 3 times. Furthermore, the composites may possibly be used in processes for industrial water treatment.
