The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Giovanna Della Porta - One of the best experts on this subject based on the ideXlab platform.
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Continuous Supercritical Emulsions Extraction: Packed Tower Characterization and Application to Poly(lactic-co-glycolic Acid) + Insulin Microspheres Production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
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continuous supercritical emulsions extraction Packed Tower characterization and application to poly lactic co glycolic acid insulin microspheres production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
Ernesto Reverchon - One of the best experts on this subject based on the ideXlab platform.
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continuous supercritical emulsions extraction Packed Tower characterization and application to poly lactic co glycolic acid insulin microspheres production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
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Continuous Supercritical Emulsions Extraction: Packed Tower Characterization and Application to Poly(lactic-co-glycolic Acid) + Insulin Microspheres Production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
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Hexane elimination from soybean oil by continuous Packed Tower processing with supercritical CO_2
Journal of the American Oil Chemists' Society, 2000Co-Authors: Ernesto Reverchon, L. Sesti Osséo, Massimo Poletto, Michele De SommaAbstract:Hexane elimination is the most energy-consuming step in the industrial extraction of soybean oil. It utilizes three sets of equipment: two evaporation stages in series followed by a stripper at a pressure of about 0.07 bar. The final hexane residue in the oil is about 1000 ppm. We propose an alternative to the present process for hexane elimination, based on the extraction of the soybean oil/hexane mixture with supercritical CO_2 in a continuous countercurrent Packed Tower. In this work, we tested a soybean oil/hexane mixture feed containing 10% by weight of hexane. Various pressures and temperatures of the column were tested to reduce hexane residue in the oil. The extraction process was demonstrated to be very effective for hexane separation. Indeed, at the bottom of the column we recovered soybean oil containing quantities of hexane as low as 20 ppm when we operated at 120 bar, 40°C. The effect of process parameters is also discussed.
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Hexane elimination from soybean oil by continuous Packed Tower processing with supercritical CO2
Journal of the American Oil Chemists' Society, 2000Co-Authors: Ernesto Reverchon, L. Sesti Osséo, Massimo Poletto, Michele De SommaAbstract:Hexane elimination is the most energy-consuming step in the industrial extraction of soybean oil. It utilizes three sets of equipment: two evaporation stages in series followed by a stripper at a pressure of about 0.07 bar. The final hexane residue in the oil is about 1000 ppm. We propose an alternative to the present process for hexane elimination, based on the extraction of the soybean oil/hexane mixture with supercritical CO2 in a continuous countercurrent Packed Tower. In this work, we tested a soybean oil/hexane mixture feed containing 10% by weight of hexane. Various pressures and temperatures of the column were tested to reduce hexane residue in the oil. The extraction process was demonstrated to be very effective for hexane separation. Indeed, at the bottom of the column we recovered soybean oil containing quantities of hexane as low as 20 ppm when we operated at 120 bar, 40°C. The effect of process parameters is also discussed.
Nunzia Falco - One of the best experts on this subject based on the ideXlab platform.
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Continuous Supercritical Emulsions Extraction: Packed Tower Characterization and Application to Poly(lactic-co-glycolic Acid) + Insulin Microspheres Production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
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continuous supercritical emulsions extraction Packed Tower characterization and application to poly lactic co glycolic acid insulin microspheres production
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nunzia Falco, Ernesto Reverchon, Giovanna Della PortaAbstract:The continuous supercritical emulsions extraction (SEE-C) process uses a countercurrent Packed Tower for the continuous extraction of the organic solvents from emulsions. The continuous operation allows the formation of microspheres that are recovered at the bottom of the Tower in the form of a water suspension, avoiding coalescence problems and batch-to-batch repeatability, typical of traditional processes. In this work, the Packed Tower used for SEE-C was characterized from a fluidodynamic point of view: flooding conditions and the allowable density difference were calculated from the experimental data. Then, an active principle (insulin) was tested for its encapsulation in poly(lactic-co-glycolic acid) (PLGA) microspheres, starting from a double emulsion: particle size, morphology, and encapsulation efficiency of the produced microdevices were evaluated. Spherical, not collapsed microspheres with a mean diameter between 1.8 μm (SD ± 0.9) and 4.8 μm (SD ± 2.8) and encapsulation efficiencies up to 70% were obtained. The very fast solvent extraction rate did not influence the particle morphology but had a significant effect on the size distribution of the precipitates which were always smaller than the starting droplets. A solvent residue (ethyl acetate) lower than about 600 ppm was obtained in all the experiments performed.
Giovanni Antonio Longo - One of the best experts on this subject based on the ideXlab platform.
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experimental analysis on chemical dehumidification of air by liquid desiccant and desiccant regeneration in a Packed Tower
Journal of Solar Energy Engineering-transactions of The Asme, 2004Co-Authors: Giovanni Antonio Longo, Andrea GasparellaAbstract:This paper presents the experimental tests on the chemical dehumidification of air by a liquid desiccant and desiccant regeneration carried out in an absorption/desorption Tower with random packing. The experimental set-up is fully described together with measurements, procedures, data reduction, and accuracy. The experimental tests include 46 dehumidification runs and 38 desiccant regeneration runs carried out with the traditional hygroscopic solution H 2 O/LiBr and the new solution H 2 O/KCOOH in the typical operative ranges of air conditioning applications. The experimental results are reported in terms of humidity reduction, desiccant concentration change, and Tower efficiency. The experimental tests show that chemical dehumidification of air by liquid desiccants ensures consistent reduction in humidity ratio, which is suitable for the application to air conditioning or drying processes. The experimental results are also compared to a one-dimensional simulation code of a Packed Tower: a fair agreement was found between experimental and calculated performance.
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chemical dehumidification by liquid desiccants theory and experiment
International Journal of Refrigeration-revue Internationale Du Froid, 1999Co-Authors: Renato Lazzarin, Andrea Gasparella, Giovanni Antonio LongoAbstract:Chemical dehumidification of air by a liquid desiccant in a Packed Tower has been investigated both theoretically and experimentally for air conditioning and industrial applications. A computer model of a Packed Tower, able to determine heat and mass transfer between air and desiccant, has been developed and a parametrical study was carried out considering the solutions H2O/LiBr and H2O/CaCl2 to determine the optimum operative conditions. An experimental apparatus including a Packed Tower and a desiccant regenerator has been described together with experimental results: a set of 70 experimental runs with H2O/LiBr. Data have been reported and compared against the results of the computer code simulations.
Gunter Wozny - One of the best experts on this subject based on the ideXlab platform.
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experimental investigations of foaming in a Packed Tower for sour water stripping
Industrial & Engineering Chemistry Research, 2003Co-Authors: Robin Thiele, Ole Brettschneider, Jensuwe Repke, Holger Thielert, Gunter WoznyAbstract:A foaming problem in an industrial-size deacidifier (Packed column) within the ammonia−hydrogen sulfide circulation scrubbing process (AS process) on a specific site is experimentally investigated. The foamability of solutions is successfully assessed in a small test cell, and the Bikermann coefficient is calculated to characterize the foaminess behavior. The investigations revealed that filtration of the real sour water taken from the specific site does not alter foaming characteristics. Impurities, especially phenol and its derivatives, cresols, are found to highly contribute to foaminess behavior. Experiments in a pilot plant revealed higher pressure drop and lower flood point data. Critical spots of foam formation are identified, and design suggestions for column internals are given.
