Andrea Sliepcevich - Academia.edu (original) (raw)

Papers by Andrea Sliepcevich

Isophorone (3,5,5-Trimethyl-2-cyclohexene1-one) is an α,β-unsaturated ketone of remarkable indust... more Isophorone (3,5,5-Trimethyl-2-cyclohexene1-one) is an α,β-unsaturated ketone of remarkable industrial interest, produced as a consequence of the aldolic condensation of three acetone molecules. Isophorone is used extensively as a solvent in some printing inks, paints, lacquers, adhesives, vinyl resins, copolymers, coatings, finishes, and pesticides, in addition to being used as a chemical intermediate of organic synthesis. This important chemical molecule is produced both by an homogeneous catalytic process as well as an heterogeneous one. In the homogeneous catalysis isophorone is produced in liquid phase with a mixture of acetone, water and KOH (0.1%) at about 200 °C and 35 bar. In the heterogeneous process, acetone reacts over a catalytic bed at temperatures comprised between 200 and 300 °C and pressure of about 5 bar. The main advantages to operate in heterogeneous phase consist in the absence of a corrosive alkaline atmosphere, in the facility of separation of the catalyst from...

This paper addresses the final results of the "ISRU Architecture and Technology Study",... more This paper addresses the final results of the "ISRU Architecture and Technology Study", an ESA Study performed by an Italian-Belgian consortium, consisting of Compagnia Generale per lo Spazio (formerly Carlo Gavazzi Space), Politecnico di Milano and Space Applications Services, aimed at assessing the feasibility of producing oxygen in lunar environment extracting it from regolith. The study concentrated its effort on the Carbothermal Reduction process with non-molten phase using Methane. The paper focuses on the results obtained from an experimental test campaign on a process breadboard. The activities have been conducted by Politecnico di Milano, Chemistry, Material and Chemical Engineering Department. Here, the tests were aimed, at first, at understanding the behaviour of the Carbothermal Reduction with Methane when a solid-gas reaction is implemented and, then, at verifying the efficiency, in terms of capability to extract oxygen (via water) from the raw material, of such a process. Extensive preliminary investigations have been performed also in TGA (Thermal Gravimetric Analysis) in order to drive the experimentation on the breadboard. For the tests, two different lunar simulants, the NU-LHT-2M and the JSC-IA, have been used in order to have representative material of both the main lunar regions, Highlands and Maria, and then to be able to estimate the behaviour of the process also with respect to the different lunar soil compositions. The paper addresses also the results of the definition of a Lunar ISRU System based on the results of the testing on the mentioned process. Technology developments identified during the study have been investigated to assess their criticality and to define the conceptual approach to their solution. This activity led to the definition of the requirements for a Lunar ISRU Demonstrator. Particular emphasis is given in the paper to the conceptual design of such a Demonstrator. Here, it has been conceived in order to be compatible with the ESA Lunar Lander currently in Phase B1 of its development

SAE International Journal of Materials and Manufacturing, 2017

ACS Symposium Series, 2001

Journal of Biotechnology, 2010

Environmental Science and Pollution Research, 2013

Candle composition is expected to influence the air pollutants emissions, possibly leading to imp... more Candle composition is expected to influence the air pollutants emissions, possibly leading to important differences in the emissions of volatile organic compounds and polycyclic aromatic hydrocarbons. In this regard, the purity of the raw materials and additives used can play a key role. Consequently, in this work emission factors for some polycyclic aromatic hydrocarbons, aromatic species, short-chain aldehydes and particulate matter have been determined for container candles constituted by different paraffin waxes burning in a test chamber. It has been found that wax quality strongly influences the air pollutant emissions. These results could be used, at least at a first glance, to foresee the expected pollutant concentration in a given indoor environment with respect to health safety standards, while the test chamber used for performing the reported results could be useful to estimate the emission factors of any other candle in an easy-to-build standardised environment.

Atmospheric Environment, 2012

Burning of scented candles in indoor environment can release a large number of toxic chemicals. H... more Burning of scented candles in indoor environment can release a large number of toxic chemicals. However, in spite of the large market penetration of scented candles, very few works investigated their organic pollutants emissions. This paper investigates volatile organic compounds emissions, with particular reference to the priority indoor pollutants identified by the European Commission, from the burning of scented candles in a laboratory-scale test chamber. It has been found that BTEX and PAHs emission factors show large differences among different candles, possibly due to the raw paraffinic material used, while aldehydes emission factors seem more related to the presence of additives. This clearly evidences the need for simple and cheap methodologies to measure the emission factors of commercial candles in order to foresee the expected pollutant concentration in a given indoor environment and compare it with health safety standards.

Environmental Science and Pollution Research, 2014

Burning of scented candles in indoor environment can release a large number of toxic chemicals. H... more Burning of scented candles in indoor environment can release a large number of toxic chemicals. However, in spite of the large market penetration of scented candles, very few works investigated their organic pollutants emissions. This paper investigates volatile organic compounds emissions, with particular reference to the priority indoor pollutants identified by the European Commission, from the burning of scented candles in a laboratory-scale test chamber. It has been found that BTEX and PAHs emission factors show large differences among different candles, possibly due to the raw paraffinic material used, while aldehydes emission factors seem more related to the presence of additives. This clearly evidences the need for simple and cheap methodologies to measure the emission factors of commercial candles in order to foresee the expected pollutant concentration in a given indoor environment and compare it with health safety standards.

Industrial & Engineering Chemistry Research, 2014

Polymer, 2005

Poly(vinyl alcohol) is often used in vinyl acetate emulsion polymerization as a protective colloi... more Poly(vinyl alcohol) is often used in vinyl acetate emulsion polymerization as a protective colloid, but its role is complex and controversial since it partakes in grafting reactions with the monomer, influencing process mechanisms, and affecting the colloidal properties of the latex. Furthermore, in industrial operations, the wide scatter of macromolecular properties of the commercial types of poly(vinyl alcohol) causes process irreproducibilities. In this work different types of polyvinyl alcohol were used to perform a series of polymerizations, and their kinetics were compared. A selective solubilization procedure was applied to separate the three fractions of poly(vinyl alcohol) in the final latex: free in the water phase, physically adsorbed onto the polymer particles and chemically grafted. These results were compared with those obtained from pure adsorption measurements of polyvinyl alcohol onto 'emulsifier-free' polyvinyl acetate dispersions. The rheological behavior of the different latexes was also compared, and the results were used to formulate an hypothesis on the interaction mechanisms acting in these systems. q

Journal of Biotechnology, 2010

Journal of Applied Polymer Science, 1998

The use of self-propagating frontal polymerization to produce polymer blends has been investigate... more The use of self-propagating frontal polymerization to produce polymer blends has been investigated. A homogeneous solution of monomer, polymer (of a second monomer), and initiator is initially heated at a specific location to start a polymerization front that propagates along the system. The obtained polymerization reaction is very fast compared with diffusion, so that the two types of macromolecules remain homogeneously distributed, as in the original monomer/polymer solution. In the case of two incompatible polymers, the system has no time to reach the equilibrium condition where phase separation occurs and a polymer blend is obtained in the form of a metastable solution. Applications to two incompatible pairs (methyl methacrylatestyrene and methyl methacrylate-methacrylic acid) are discussed. Moreover, it has been found that the presence of inert polymer in the initial mixture improves the process performance, leading to more stable propagation fronts, lower front temperatures, and higher monomer conversions.

Journal of Applied Polymer Science, 2000

Industrial & Engineering Chemistry Research, 2006

The possibility of introducing, as a desorbent in a chromatographic reactor, a reactive desorbent... more The possibility of introducing, as a desorbent in a chromatographic reactor, a reactive desorbent that removes the most strongly retained component by chemical reaction and not by purely physical desorption has been investigated. The principle is demonstrated in the case of the esterification of glycerol with acetic acid using a mixture of acetic acid and acetic anhydride as the desorbent and a polymeric acidic resin as the stationary phase. It is shown that reacting the most strongly retained component, water, with acetic anhydride allows for a significant improvement in the column regeneration process, thus improving the process performance in terms of both productivity and desorbent requirements.

Isophorone (3,5,5-Trimethyl-2-cyclohexene1-one) is an α,β-unsaturated ketone of remarkable indust... more Isophorone (3,5,5-Trimethyl-2-cyclohexene1-one) is an α,β-unsaturated ketone of remarkable industrial interest, produced as a consequence of the aldolic condensation of three acetone molecules. Isophorone is used extensively as a solvent in some printing inks, paints, lacquers, adhesives, vinyl resins, copolymers, coatings, finishes, and pesticides, in addition to being used as a chemical intermediate of organic synthesis. This important chemical molecule is produced both by an homogeneous catalytic process as well as an heterogeneous one. In the homogeneous catalysis isophorone is produced in liquid phase with a mixture of acetone, water and KOH (0.1%) at about 200 °C and 35 bar. In the heterogeneous process, acetone reacts over a catalytic bed at temperatures comprised between 200 and 300 °C and pressure of about 5 bar. The main advantages to operate in heterogeneous phase consist in the absence of a corrosive alkaline atmosphere, in the facility of separation of the catalyst from...

This paper addresses the final results of the "ISRU Architecture and Technology Study",... more This paper addresses the final results of the "ISRU Architecture and Technology Study", an ESA Study performed by an Italian-Belgian consortium, consisting of Compagnia Generale per lo Spazio (formerly Carlo Gavazzi Space), Politecnico di Milano and Space Applications Services, aimed at assessing the feasibility of producing oxygen in lunar environment extracting it from regolith. The study concentrated its effort on the Carbothermal Reduction process with non-molten phase using Methane. The paper focuses on the results obtained from an experimental test campaign on a process breadboard. The activities have been conducted by Politecnico di Milano, Chemistry, Material and Chemical Engineering Department. Here, the tests were aimed, at first, at understanding the behaviour of the Carbothermal Reduction with Methane when a solid-gas reaction is implemented and, then, at verifying the efficiency, in terms of capability to extract oxygen (via water) from the raw material, of such a process. Extensive preliminary investigations have been performed also in TGA (Thermal Gravimetric Analysis) in order to drive the experimentation on the breadboard. For the tests, two different lunar simulants, the NU-LHT-2M and the JSC-IA, have been used in order to have representative material of both the main lunar regions, Highlands and Maria, and then to be able to estimate the behaviour of the process also with respect to the different lunar soil compositions. The paper addresses also the results of the definition of a Lunar ISRU System based on the results of the testing on the mentioned process. Technology developments identified during the study have been investigated to assess their criticality and to define the conceptual approach to their solution. This activity led to the definition of the requirements for a Lunar ISRU Demonstrator. Particular emphasis is given in the paper to the conceptual design of such a Demonstrator. Here, it has been conceived in order to be compatible with the ESA Lunar Lander currently in Phase B1 of its development

SAE International Journal of Materials and Manufacturing, 2017

ACS Symposium Series, 2001

Journal of Biotechnology, 2010

Environmental Science and Pollution Research, 2013

Candle composition is expected to influence the air pollutants emissions, possibly leading to imp... more Candle composition is expected to influence the air pollutants emissions, possibly leading to important differences in the emissions of volatile organic compounds and polycyclic aromatic hydrocarbons. In this regard, the purity of the raw materials and additives used can play a key role. Consequently, in this work emission factors for some polycyclic aromatic hydrocarbons, aromatic species, short-chain aldehydes and particulate matter have been determined for container candles constituted by different paraffin waxes burning in a test chamber. It has been found that wax quality strongly influences the air pollutant emissions. These results could be used, at least at a first glance, to foresee the expected pollutant concentration in a given indoor environment with respect to health safety standards, while the test chamber used for performing the reported results could be useful to estimate the emission factors of any other candle in an easy-to-build standardised environment.

Atmospheric Environment, 2012

Burning of scented candles in indoor environment can release a large number of toxic chemicals. H... more Burning of scented candles in indoor environment can release a large number of toxic chemicals. However, in spite of the large market penetration of scented candles, very few works investigated their organic pollutants emissions. This paper investigates volatile organic compounds emissions, with particular reference to the priority indoor pollutants identified by the European Commission, from the burning of scented candles in a laboratory-scale test chamber. It has been found that BTEX and PAHs emission factors show large differences among different candles, possibly due to the raw paraffinic material used, while aldehydes emission factors seem more related to the presence of additives. This clearly evidences the need for simple and cheap methodologies to measure the emission factors of commercial candles in order to foresee the expected pollutant concentration in a given indoor environment and compare it with health safety standards.

Environmental Science and Pollution Research, 2014

Burning of scented candles in indoor environment can release a large number of toxic chemicals. H... more Burning of scented candles in indoor environment can release a large number of toxic chemicals. However, in spite of the large market penetration of scented candles, very few works investigated their organic pollutants emissions. This paper investigates volatile organic compounds emissions, with particular reference to the priority indoor pollutants identified by the European Commission, from the burning of scented candles in a laboratory-scale test chamber. It has been found that BTEX and PAHs emission factors show large differences among different candles, possibly due to the raw paraffinic material used, while aldehydes emission factors seem more related to the presence of additives. This clearly evidences the need for simple and cheap methodologies to measure the emission factors of commercial candles in order to foresee the expected pollutant concentration in a given indoor environment and compare it with health safety standards.

Industrial & Engineering Chemistry Research, 2014

Polymer, 2005

Poly(vinyl alcohol) is often used in vinyl acetate emulsion polymerization as a protective colloi... more Poly(vinyl alcohol) is often used in vinyl acetate emulsion polymerization as a protective colloid, but its role is complex and controversial since it partakes in grafting reactions with the monomer, influencing process mechanisms, and affecting the colloidal properties of the latex. Furthermore, in industrial operations, the wide scatter of macromolecular properties of the commercial types of poly(vinyl alcohol) causes process irreproducibilities. In this work different types of polyvinyl alcohol were used to perform a series of polymerizations, and their kinetics were compared. A selective solubilization procedure was applied to separate the three fractions of poly(vinyl alcohol) in the final latex: free in the water phase, physically adsorbed onto the polymer particles and chemically grafted. These results were compared with those obtained from pure adsorption measurements of polyvinyl alcohol onto 'emulsifier-free' polyvinyl acetate dispersions. The rheological behavior of the different latexes was also compared, and the results were used to formulate an hypothesis on the interaction mechanisms acting in these systems. q

Journal of Biotechnology, 2010

Journal of Applied Polymer Science, 1998

The use of self-propagating frontal polymerization to produce polymer blends has been investigate... more The use of self-propagating frontal polymerization to produce polymer blends has been investigated. A homogeneous solution of monomer, polymer (of a second monomer), and initiator is initially heated at a specific location to start a polymerization front that propagates along the system. The obtained polymerization reaction is very fast compared with diffusion, so that the two types of macromolecules remain homogeneously distributed, as in the original monomer/polymer solution. In the case of two incompatible polymers, the system has no time to reach the equilibrium condition where phase separation occurs and a polymer blend is obtained in the form of a metastable solution. Applications to two incompatible pairs (methyl methacrylatestyrene and methyl methacrylate-methacrylic acid) are discussed. Moreover, it has been found that the presence of inert polymer in the initial mixture improves the process performance, leading to more stable propagation fronts, lower front temperatures, and higher monomer conversions.

Journal of Applied Polymer Science, 2000

Industrial & Engineering Chemistry Research, 2006

The possibility of introducing, as a desorbent in a chromatographic reactor, a reactive desorbent... more The possibility of introducing, as a desorbent in a chromatographic reactor, a reactive desorbent that removes the most strongly retained component by chemical reaction and not by purely physical desorption has been investigated. The principle is demonstrated in the case of the esterification of glycerol with acetic acid using a mixture of acetic acid and acetic anhydride as the desorbent and a polymeric acidic resin as the stationary phase. It is shown that reacting the most strongly retained component, water, with acetic anhydride allows for a significant improvement in the column regeneration process, thus improving the process performance in terms of both productivity and desorbent requirements.