Alberto de Angelis - Academia.edu (original) (raw)

Papers by Alberto de Angelis

Computer-aided chemical engineering, 2023

Journal of polymer science, Aug 9, 2022

Macromolecules, Oct 14, 2020

An investigation of the copolymerization of cyclohexene sulfide and carbon disulfide using salphe... more An investigation of the copolymerization of cyclohexene sulfide and carbon disulfide using salphen and salen Cr complexes as catalysts and [PPN] + X − salts as cocatalysts, at different temperatures and reaction times, is reported. Both catalytic systems produce both polymer and cyclic products. For the first time, poly(trithiocyclohexylcarbonates) (PCS) have been synthetized in high yields and high molecular weights. Salphen-based catalysts, in comparison with salen-based ones, show higher productivity and selectivity for polymers with high molecular weight up to 18 kg/mol when the reaction is carried out at 25°C. At a higher temperature with (salphen)CrCl, the maximum value of selectivity for copolymers (72%) was obtained at a short reaction time (3 h). At long reaction times, great amounts of cyclic by-product are observed, thus evidencing the tendency for cyclohexene sulfide and CS 2 to provide cyclic products due to the stability of the trithiocyclohexylcarbonate. PCS possesses high refractive index (n > 1.72), and antimicrobial assays reveal that these materials are active against Escherichia coli and moderately active against Staphylococcus aureus. These properties along with the T g values of 80°C make these polymers suitable for interesting applications different from those of poly(trithiopropylencarbonate).

Industrial & Engineering Chemistry Research, Jul 10, 2023

International Journal of Hydrogen Energy, Jul 1, 2023

ACS Sustainable Chemistry & Engineering, Apr 5, 2023

ChemBioEng Reviews

The growing energy demand, together with the depletion of sweet gas reservoirs, impose the moneti... more The growing energy demand, together with the depletion of sweet gas reservoirs, impose the monetization of ultra‐sour natural gas fields with a high H2S content. To date, in large scale facilities, H2S is removed from natural gas through amine washing and it is converted to sulphur in the Claus process. The Claus process is the leading H2S conversion technology for large scale applications. Regarding small scale plants, scavengers are the most efficient and widely spread choice. On the other hand, present middle scale options show quite high operating costs. Therefore, research efforts are devoted to developing new intermediate scale alternatives with lower costs and easier operability. When developing a new process, the study of the state‐of‐the‐art is the first essential step. No systematic review of H2S valorisation technologies is available in literature. To fill this gap, the aim of this work is to summarize the available processes considering both commercial and novel tendenci...

International Journal of Hydrogen Energy

ACS Omega, 2021

Polythionic acids, whose general formula is H 2 S n O 6 , with n greater than 2, were discovered ... more Polythionic acids, whose general formula is H 2 S n O 6 , with n greater than 2, were discovered in the aqueous solution of SO 2 and H 2 S, known as the Wackenroder liquid. Their reactions with each other and with other reagents are, mostly, difficult to characterize, since such compounds readily decompose and interconvert, especially in solution. Nevertheless, they play an important role in technical applications (e.g., gold leaching, magnesium milling, cooling in metal processing) and in reactions of inorganic chemistry of sulfur. A few years ago, Shell−Paques/ Paqell patented the first industrial process for the biological conversion of H 2 S into a colloidal mixture of sulfur and polythionates. Such hydrophilic sulfur can be used as a fertilizer and soil improver in agriculture in all but alkaline soils. Recently, Eni S.p.A. has developed to bench plant scale a new process, the HydroClaus process for the conversion of H 2 S into an acidic hydrophilic slurry of sulfur and polythionate ions. Such a slurry can be used as a soil improver where the very alkaline soil pH hinders the cultivation. The aim of this work is to study the laboratory-scale production of polythionates in view of the novel HydroClaus process scale-up at the industrial level. After the literature related to polythionates and their characterization has been revised, the sulfur-based mixture has been synthesized and the polythionate ions concentration has been determined. Also, the effect of the reaction operating conditions has been investigated to assess how they can influence the nature and the distribution of products in solution.

Day 2 Tue, November 16, 2021

During production from sour gas reservoirs, precipitation of elemental sulfur can take place in p... more During production from sour gas reservoirs, precipitation of elemental sulfur can take place in production tubing, resulting in plugging of the well and stop of production. Injection in tubing of products devoted to dissolving sulfur can be an efficient solution for plug removal and production restoring. Traditionally, organic solvents (like toluene) are employed for solid sulfur dissolution. In the present work, experimental investigations have been performed on a particular innovative liquid product designed as active phase for wellbore injection or near wellbore applications. The analyses about the behavior of the considered product were conducted at HP-HT conditions. For this purpose, PVT laboratory equipment was employed, being able to reproduce the conditions of interest for the formation of elemental sulfur plug in well. An important preliminary optimization phase on the experimental setup was necessary to assure the correct management of studied liquid substance and solid su...

ACS Sustainable Chemistry & Engineering, 2017

Hydrolysis and subsequent degradation of microcrystalline cellulose in five ionic liquids (ILs) u... more Hydrolysis and subsequent degradation of microcrystalline cellulose in five ionic liquids (ILs) using metal salts and/or Brønsted acids as catalysts allowed for the direct access to 5-hydroxymethylfurfural (HMF), an important renewable biofuel precursor and a useful building-block. For each catalytic system, several reaction parameters (temperature, reaction time, catalyst, and cellulose loading) have been selectively changed. Four systems ([BMIM]Cl-CrCl 3 , [BMIM]Cl-FeCl 3 , [BMIM]Cl-[MIMC 4 SO 3 H][HSO 4 ] and the not yet investigated Page 1 of 28 ACS Paragon Plus Environment ACS Sustainable Chemistry & Engineering 2 [BMIM]Cl-TiOSO 4) were found to be effective for cellulose degradation into HMF. The extraction of HMF from the reaction media represents however the weak point of all these processes being able to affect negatively both HMF recovery and IL recyclability. The critical step which causes the drastic decrease in HMF yield starting from the first recycle has been clearly identified. Furthermore, the possibility to use TiOSO 4 as a sustainable and robust catalyst for the conversion of saccharides (or polysaccharides) in HMF has been shown. The present study could open new perspectives for the one-pot synthesis of HMF starting from cellulose and/or other sugars.

Studies in Surface Science and Catalysis, 2005

Environmental legislation will restrict the total aromatic content in gasoline. Consequently, the... more Environmental legislation will restrict the total aromatic content in gasoline. Consequently, the amount of heavy pyrolysis gasoline (a by-product from steam cracker, mainly composed of C 7 –C 9 aromatics) blended into motor gasoline will be limited. Hydrocracking into premium stream cracker feed has been suggested as a possible way to get value from pyrolysis gasoline. Pd/LaH-Y proved to be an effective catalyst not only in the hydrocracking of C 7 –C 9 aromatics, but also of polynuclear aromatics (e.g. naphtalenes). Feed with relevant sulphur content can be successfully hydrotreated too.

Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate,... more Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate, epoxy–resins, phenolic resins, nylon). Its conventional production starts from benzene and propylen...

Angewandte Chemie, 2021

The production of elemental sulfur from petroleum refining has created a technological opportunit... more The production of elemental sulfur from petroleum refining has created a technological opportunity to increase the valorization of elemental sulfur by the creation of high performance sulfur based plastics with improved thermomechanical properties, elasticity and flame retardancy. We report on a synthetic polymerization methodology to prepare the first example of sulfur based segmented multi-block polyurethanes (SPUs) and thermoplastic elastomers that incorporate an appreciable amount of sulfur into the final target material. This approach applied both the inverse vulcanization of S 8 with olefinic alcohols and dynamic covalent polymerizations with dienes to prepare sulfur polyols and terpolyols that were used in polymerizations with aromatic diisocyanates and short chain diols. Using these methods a new class of high molecular weight, soluble block copolymer polyurethanes were prepared as confirmed by Size Exclusion Chromatography, NMR spectroscopy, thermal analysis and microscopic imaging. These sulfur based polyurethanes were readily solution processed into large area free standing films where both the tensile strength and elasticity of these materials were controlled by variation of the sulfur polyol composition. SPUs with both high tensile strength (13-23 MPa) and ductility (348% strain at break) were prepared, along with SPU thermoplastic elastomers (578% strain at break) which are comparable values to classical thermoplastic polyurethanes (TPUs). The incorporation of sulfur into these polyurethanes, we observe enhanced flame retardancy in comparison to classical TPUs, which points to the opportunity to impart new properties to polymeric materials as a consequence of using elemental sulfur.

Journal of Molecular Catalysis A: Chemical, 1999

A new kind of solid acid based on heteropolyacids has been proved to be a useful catalyst in alky... more A new kind of solid acid based on heteropolyacids has been proved to be a useful catalyst in alkylation of benzene with propylene to obtain cumene. The new catalysts are based on a heteropolyacid supported on zirconia treated with very low contents of sulphate anions. Two different ...

ChemSusChem, 2010

Several different technologies are available for H(2)S removal from the gas stream of medium capa... more Several different technologies are available for H(2)S removal from the gas stream of medium capacity. Among them, the most widely used is Locat with more than 120 plants worldwide. In the last decade, many new processes, such as Sulfatreat-DO, Crystasulf, Caltech, and UCSR, were proposed to overcome the drawbacks of the state-of-the-art processes (low sulfur purity, chemical degradation, thiosulfate formation). We have developed a new H(2)S conversion method based on acid ferric nitrate solution, co-catalyzed by a heteropolyacid. H(2)S was converted to pure sulfur (>99.9 %), with no traces of organic compounds. Due to the acid pH of the solution, no chelant or surfactant was needed and iron content in the solution could reach very high levels. Keggin heteropolyacid (H(6)PW(9)V(3)O(40)) catalyzed the reoxidation of reduced ferrous solution with air at mild temperature and at very high reaction rate. The undesired side reaction (NO(x) formation) could be avoided by simply increasing the oxygen partial pressure.

Journal of Cleaner Production, 2022

In this work, hydrogen sulphide methane reformation is analysed for the hydrogen production from ... more In this work, hydrogen sulphide methane reformation is analysed for the hydrogen production from H 2 S. The process allows the H 2 S valorisation recovering its intrinsic hydrogen content. For the technology scale up to the industrial level, a process simulation is set up in Aspen Plus V11®. Its performances are evaluated as a function of the CH 4 /H 2 S inlet molar ratio. Material and energy balances are presented for each considered case. A detailed process economic assessment is provided to identify the best operating conditions. Results in terms of hydrogen cost show the strong system's dependence on the CH 4 /H 2 S inlet molar ratio. If opportunely optimized, the present process can be competitive with respect to the traditional methane steam reforming, also considering that no direct CO 2 emissions are produced. The advantages of the H 2 S methane reformation are discussed, to pave the way for future process optimization.

Pure and Applied Chemistry, 2007

This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), bot... more This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum-and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).

Computer-aided chemical engineering, 2023

Journal of polymer science, Aug 9, 2022

Macromolecules, Oct 14, 2020

An investigation of the copolymerization of cyclohexene sulfide and carbon disulfide using salphe... more An investigation of the copolymerization of cyclohexene sulfide and carbon disulfide using salphen and salen Cr complexes as catalysts and [PPN] + X − salts as cocatalysts, at different temperatures and reaction times, is reported. Both catalytic systems produce both polymer and cyclic products. For the first time, poly(trithiocyclohexylcarbonates) (PCS) have been synthetized in high yields and high molecular weights. Salphen-based catalysts, in comparison with salen-based ones, show higher productivity and selectivity for polymers with high molecular weight up to 18 kg/mol when the reaction is carried out at 25°C. At a higher temperature with (salphen)CrCl, the maximum value of selectivity for copolymers (72%) was obtained at a short reaction time (3 h). At long reaction times, great amounts of cyclic by-product are observed, thus evidencing the tendency for cyclohexene sulfide and CS 2 to provide cyclic products due to the stability of the trithiocyclohexylcarbonate. PCS possesses high refractive index (n > 1.72), and antimicrobial assays reveal that these materials are active against Escherichia coli and moderately active against Staphylococcus aureus. These properties along with the T g values of 80°C make these polymers suitable for interesting applications different from those of poly(trithiopropylencarbonate).

Industrial & Engineering Chemistry Research, Jul 10, 2023

International Journal of Hydrogen Energy, Jul 1, 2023

ACS Sustainable Chemistry & Engineering, Apr 5, 2023

ChemBioEng Reviews

The growing energy demand, together with the depletion of sweet gas reservoirs, impose the moneti... more The growing energy demand, together with the depletion of sweet gas reservoirs, impose the monetization of ultra‐sour natural gas fields with a high H2S content. To date, in large scale facilities, H2S is removed from natural gas through amine washing and it is converted to sulphur in the Claus process. The Claus process is the leading H2S conversion technology for large scale applications. Regarding small scale plants, scavengers are the most efficient and widely spread choice. On the other hand, present middle scale options show quite high operating costs. Therefore, research efforts are devoted to developing new intermediate scale alternatives with lower costs and easier operability. When developing a new process, the study of the state‐of‐the‐art is the first essential step. No systematic review of H2S valorisation technologies is available in literature. To fill this gap, the aim of this work is to summarize the available processes considering both commercial and novel tendenci...

International Journal of Hydrogen Energy

ACS Omega, 2021

Polythionic acids, whose general formula is H 2 S n O 6 , with n greater than 2, were discovered ... more Polythionic acids, whose general formula is H 2 S n O 6 , with n greater than 2, were discovered in the aqueous solution of SO 2 and H 2 S, known as the Wackenroder liquid. Their reactions with each other and with other reagents are, mostly, difficult to characterize, since such compounds readily decompose and interconvert, especially in solution. Nevertheless, they play an important role in technical applications (e.g., gold leaching, magnesium milling, cooling in metal processing) and in reactions of inorganic chemistry of sulfur. A few years ago, Shell−Paques/ Paqell patented the first industrial process for the biological conversion of H 2 S into a colloidal mixture of sulfur and polythionates. Such hydrophilic sulfur can be used as a fertilizer and soil improver in agriculture in all but alkaline soils. Recently, Eni S.p.A. has developed to bench plant scale a new process, the HydroClaus process for the conversion of H 2 S into an acidic hydrophilic slurry of sulfur and polythionate ions. Such a slurry can be used as a soil improver where the very alkaline soil pH hinders the cultivation. The aim of this work is to study the laboratory-scale production of polythionates in view of the novel HydroClaus process scale-up at the industrial level. After the literature related to polythionates and their characterization has been revised, the sulfur-based mixture has been synthesized and the polythionate ions concentration has been determined. Also, the effect of the reaction operating conditions has been investigated to assess how they can influence the nature and the distribution of products in solution.

Day 2 Tue, November 16, 2021

During production from sour gas reservoirs, precipitation of elemental sulfur can take place in p... more During production from sour gas reservoirs, precipitation of elemental sulfur can take place in production tubing, resulting in plugging of the well and stop of production. Injection in tubing of products devoted to dissolving sulfur can be an efficient solution for plug removal and production restoring. Traditionally, organic solvents (like toluene) are employed for solid sulfur dissolution. In the present work, experimental investigations have been performed on a particular innovative liquid product designed as active phase for wellbore injection or near wellbore applications. The analyses about the behavior of the considered product were conducted at HP-HT conditions. For this purpose, PVT laboratory equipment was employed, being able to reproduce the conditions of interest for the formation of elemental sulfur plug in well. An important preliminary optimization phase on the experimental setup was necessary to assure the correct management of studied liquid substance and solid su...

ACS Sustainable Chemistry & Engineering, 2017

Hydrolysis and subsequent degradation of microcrystalline cellulose in five ionic liquids (ILs) u... more Hydrolysis and subsequent degradation of microcrystalline cellulose in five ionic liquids (ILs) using metal salts and/or Brønsted acids as catalysts allowed for the direct access to 5-hydroxymethylfurfural (HMF), an important renewable biofuel precursor and a useful building-block. For each catalytic system, several reaction parameters (temperature, reaction time, catalyst, and cellulose loading) have been selectively changed. Four systems ([BMIM]Cl-CrCl 3 , [BMIM]Cl-FeCl 3 , [BMIM]Cl-[MIMC 4 SO 3 H][HSO 4 ] and the not yet investigated Page 1 of 28 ACS Paragon Plus Environment ACS Sustainable Chemistry & Engineering 2 [BMIM]Cl-TiOSO 4) were found to be effective for cellulose degradation into HMF. The extraction of HMF from the reaction media represents however the weak point of all these processes being able to affect negatively both HMF recovery and IL recyclability. The critical step which causes the drastic decrease in HMF yield starting from the first recycle has been clearly identified. Furthermore, the possibility to use TiOSO 4 as a sustainable and robust catalyst for the conversion of saccharides (or polysaccharides) in HMF has been shown. The present study could open new perspectives for the one-pot synthesis of HMF starting from cellulose and/or other sugars.

Studies in Surface Science and Catalysis, 2005

Environmental legislation will restrict the total aromatic content in gasoline. Consequently, the... more Environmental legislation will restrict the total aromatic content in gasoline. Consequently, the amount of heavy pyrolysis gasoline (a by-product from steam cracker, mainly composed of C 7 –C 9 aromatics) blended into motor gasoline will be limited. Hydrocracking into premium stream cracker feed has been suggested as a possible way to get value from pyrolysis gasoline. Pd/LaH-Y proved to be an effective catalyst not only in the hydrocracking of C 7 –C 9 aromatics, but also of polynuclear aromatics (e.g. naphtalenes). Feed with relevant sulphur content can be successfully hydrotreated too.

Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate,... more Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate, epoxy–resins, phenolic resins, nylon). Its conventional production starts from benzene and propylen...

Angewandte Chemie, 2021

The production of elemental sulfur from petroleum refining has created a technological opportunit... more The production of elemental sulfur from petroleum refining has created a technological opportunity to increase the valorization of elemental sulfur by the creation of high performance sulfur based plastics with improved thermomechanical properties, elasticity and flame retardancy. We report on a synthetic polymerization methodology to prepare the first example of sulfur based segmented multi-block polyurethanes (SPUs) and thermoplastic elastomers that incorporate an appreciable amount of sulfur into the final target material. This approach applied both the inverse vulcanization of S 8 with olefinic alcohols and dynamic covalent polymerizations with dienes to prepare sulfur polyols and terpolyols that were used in polymerizations with aromatic diisocyanates and short chain diols. Using these methods a new class of high molecular weight, soluble block copolymer polyurethanes were prepared as confirmed by Size Exclusion Chromatography, NMR spectroscopy, thermal analysis and microscopic imaging. These sulfur based polyurethanes were readily solution processed into large area free standing films where both the tensile strength and elasticity of these materials were controlled by variation of the sulfur polyol composition. SPUs with both high tensile strength (13-23 MPa) and ductility (348% strain at break) were prepared, along with SPU thermoplastic elastomers (578% strain at break) which are comparable values to classical thermoplastic polyurethanes (TPUs). The incorporation of sulfur into these polyurethanes, we observe enhanced flame retardancy in comparison to classical TPUs, which points to the opportunity to impart new properties to polymeric materials as a consequence of using elemental sulfur.

Journal of Molecular Catalysis A: Chemical, 1999

A new kind of solid acid based on heteropolyacids has been proved to be a useful catalyst in alky... more A new kind of solid acid based on heteropolyacids has been proved to be a useful catalyst in alkylation of benzene with propylene to obtain cumene. The new catalysts are based on a heteropolyacid supported on zirconia treated with very low contents of sulphate anions. Two different ...

ChemSusChem, 2010

Several different technologies are available for H(2)S removal from the gas stream of medium capa... more Several different technologies are available for H(2)S removal from the gas stream of medium capacity. Among them, the most widely used is Locat with more than 120 plants worldwide. In the last decade, many new processes, such as Sulfatreat-DO, Crystasulf, Caltech, and UCSR, were proposed to overcome the drawbacks of the state-of-the-art processes (low sulfur purity, chemical degradation, thiosulfate formation). We have developed a new H(2)S conversion method based on acid ferric nitrate solution, co-catalyzed by a heteropolyacid. H(2)S was converted to pure sulfur (>99.9 %), with no traces of organic compounds. Due to the acid pH of the solution, no chelant or surfactant was needed and iron content in the solution could reach very high levels. Keggin heteropolyacid (H(6)PW(9)V(3)O(40)) catalyzed the reoxidation of reduced ferrous solution with air at mild temperature and at very high reaction rate. The undesired side reaction (NO(x) formation) could be avoided by simply increasing the oxygen partial pressure.

Journal of Cleaner Production, 2022

In this work, hydrogen sulphide methane reformation is analysed for the hydrogen production from ... more In this work, hydrogen sulphide methane reformation is analysed for the hydrogen production from H 2 S. The process allows the H 2 S valorisation recovering its intrinsic hydrogen content. For the technology scale up to the industrial level, a process simulation is set up in Aspen Plus V11®. Its performances are evaluated as a function of the CH 4 /H 2 S inlet molar ratio. Material and energy balances are presented for each considered case. A detailed process economic assessment is provided to identify the best operating conditions. Results in terms of hydrogen cost show the strong system's dependence on the CH 4 /H 2 S inlet molar ratio. If opportunely optimized, the present process can be competitive with respect to the traditional methane steam reforming, also considering that no direct CO 2 emissions are produced. The advantages of the H 2 S methane reformation are discussed, to pave the way for future process optimization.

Pure and Applied Chemistry, 2007

This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), bot... more This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum-and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).