M. Zeppilli, Edoardo Dell’Armi, M. P. Papini, M. Majone
Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants, microbial communities naturally present in groundwater can reduce CAHs as perchloroethylene (PCE) and trichloroethylene (TCE) to ethylene through reductive dechlorination (RD) reaction while low chlorinated CAHs like cis-dichloroethylene (cis DCE) and vinyl chloride (VC) can be oxidized by aerobic pathways. A combination of reductive and oxidative dechlorination results an effective strategy for the complete mineralization of CAHs. Bioelectrochemical systems (BES) are innovative processes which can be adopted to stimulate both reductive and oxidative dechlorination biomass through polarized electrodes. The present study describes the performances of a an oxidative bioelectrochemical reactor composed by a membrane-less microbial electrolysis cell (MEC) equipped with an internal graphite counterelectrode. In the oxidative reactor the oxygen provided by a mixed metal oxides (MMO) anode stimulated the oxidative dechlorination of the cisDCE contained in synthetic groundwater. Throughout the experimental period, both reductive and oxidative dechlorination pathways were identified due to presence of an internal counter electrode that acted as electron donor. Reductive and oxidative bioelectrochemical reactions, including anions reduction were determined and their relative contribution to the overall flowing current has been quantified in terms of oxidative and reductive coulombic efficiencies.
{"title":"Sequential Reductive/oxidative Bioelectrochemical Process for Groundwater Perchloroethylene Removal","authors":"M. Zeppilli, Edoardo Dell’Armi, M. P. Papini, M. Majone","doi":"10.3303/CET2186063","DOIUrl":"https://doi.org/10.3303/CET2186063","url":null,"abstract":"Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants, microbial communities naturally present in groundwater can reduce CAHs as perchloroethylene (PCE) and trichloroethylene (TCE) to ethylene through reductive dechlorination (RD) reaction while low chlorinated CAHs like cis-dichloroethylene (cis DCE) and vinyl chloride (VC) can be oxidized by aerobic pathways. A combination of reductive and oxidative dechlorination results an effective strategy for the complete mineralization of CAHs. Bioelectrochemical systems (BES) are innovative processes which can be adopted to stimulate both reductive and oxidative dechlorination biomass through polarized electrodes. The present study describes the performances of a an oxidative bioelectrochemical reactor composed by a membrane-less microbial electrolysis cell (MEC) equipped with an internal graphite counterelectrode. In the oxidative reactor the oxygen provided by a mixed metal oxides (MMO) anode stimulated the oxidative dechlorination of the cisDCE contained in synthetic groundwater. Throughout the experimental period, both reductive and oxidative dechlorination pathways were identified due to presence of an internal counter electrode that acted as electron donor. Reductive and oxidative bioelectrochemical reactions, including anions reduction were determined and their relative contribution to the overall flowing current has been quantified in terms of oxidative and reductive coulombic efficiencies.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"94 1","pages":"373-378"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86255436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alessandro Marson, A. Manzardo, Mirco Piron, A. Fedele, A. Scipioni
The plastics and construction sectors are at the heart of European policies for the circular economy. Polyvinyl chloride (PVC) is the most used polymer in construction products and one of the major applications is piping systems for water distribution. The PVC-A polymer alloy is made blending PVC with chlorinated polyethylene and it is characterized by improved physical properties that allow a reduction in pipe’s thickness. These characteristics enable a reduction in the consumption of resources, but a comprehensive analysis of environmental performance is needed to identify any trade-offs. The aim of this work is to apply Life Cycle Assessment to evaluate two PVC-A piping systems with different gaskets. The study was conducted according to the EN 15804 standard and primary data from an industrial-scale production process were used. An extensive comparison with the main alternatives on the market (PVC-U, PVC-O, PVC-M, and PE) is reported, both referred to 1 kg and 1 meter of pipe.
{"title":"Life Cycle Assessment of Pvc-a Polymer Alloy Pipes for the Impacts Reduction in the Construction Sector","authors":"Alessandro Marson, A. Manzardo, Mirco Piron, A. Fedele, A. Scipioni","doi":"10.3303/CET2186121","DOIUrl":"https://doi.org/10.3303/CET2186121","url":null,"abstract":"The plastics and construction sectors are at the heart of European policies for the circular economy. Polyvinyl chloride (PVC) is the most used polymer in construction products and one of the major applications is piping systems for water distribution. The PVC-A polymer alloy is made blending PVC with chlorinated polyethylene and it is characterized by improved physical properties that allow a reduction in pipe’s thickness. These characteristics enable a reduction in the consumption of resources, but a comprehensive analysis of environmental performance is needed to identify any trade-offs. The aim of this work is to apply Life Cycle Assessment to evaluate two PVC-A piping systems with different gaskets. The study was conducted according to the EN 15804 standard and primary data from an industrial-scale production process were used. An extensive comparison with the main alternatives on the market (PVC-U, PVC-O, PVC-M, and PE) is reported, both referred to 1 kg and 1 meter of pipe.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"39 1","pages":"721-726"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88412663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dimethyl ether is classified as an alternative material that can be renewed and used for diesel engines, diesel fuel, and gas stoves as a household fuel. Dimethyl ether production was carried out by dehydration of methanol. The catalyst used in this process was dealuminated zeolite Y. This study aims to determine the effect of temperature on conversion, reaction rate constants, activation energy, and collision factor (A) in the synthesis of dimethyl ether. The reaction was carried out in a fixed bed catalytic reactor where the temperature was varied at 225-325 oC. The gas product was analysed by Gas Chromatography-Mass Spectrometry (GCMS), while the liquid product was analysed by High-Performance Liquid Chromatography (HPLC). The calculation of reaction kinetics was carried out using MATLAB. The results showed that the highest conversion was obtained at a reaction temperature of 225 oC which was 75.58 %. The reaction rate constant was obtained at 0.1795 l/mol.h with the activation energy and the collision factor values are 1.044 x 103 cal/mol and 0.0589, respectively.
{"title":"Reaction Kinetics Study of Methanol Dehydration for Dimethyl Ether (dme) Production Using Dealuminated Zeolite Y Catalyst","authors":"L. Buchori, D. Anggoro","doi":"10.3303/CET2186251","DOIUrl":"https://doi.org/10.3303/CET2186251","url":null,"abstract":"Dimethyl ether is classified as an alternative material that can be renewed and used for diesel engines, diesel fuel, and gas stoves as a household fuel. Dimethyl ether production was carried out by dehydration of methanol. The catalyst used in this process was dealuminated zeolite Y. This study aims to determine the effect of temperature on conversion, reaction rate constants, activation energy, and collision factor (A) in the synthesis of dimethyl ether. The reaction was carried out in a fixed bed catalytic reactor where the temperature was varied at 225-325 oC. The gas product was analysed by Gas Chromatography-Mass Spectrometry (GCMS), while the liquid product was analysed by High-Performance Liquid Chromatography (HPLC). The calculation of reaction kinetics was carried out using MATLAB. The results showed that the highest conversion was obtained at a reaction temperature of 225 oC which was 75.58 %. The reaction rate constant was obtained at 0.1795 l/mol.h with the activation energy and the collision factor values are 1.044 x 103 cal/mol and 0.0589, respectively.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"107 1","pages":"1501-1506"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86459982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Reverberi, M. Vocciante, A. Bruzzone, B. Fabiano
Carbon nanoparticles (CNPs) gained a growing attention for a wide multiplicity of applications. CNPs offer the basic advantage of being well tolerated by living organisms and they are much more environmental friendly than many other inorganic NPs for analogous purposes. In this short review, several techniques are described and compared, enlighting their strenghts and drawbacks in terms of easy of deployment, possibility of transfer on a large scale, plant safety and environmental soundness. The latter aspect is now one of the basic paradigms for the chemical production tout court and this target can be achieved by acting on different fronts, namely energy saving, cleaner processes and reagents substitution. Some techniques are still confined to a laboratory scale and they need deeper investigations before being transferred to an industrial production, while some other have reached a technological maturity to make them competitive on the market. The methods for the synthesis of CNPs have been grouped according to a scheme different from the usual classification in top-down and bottom-up processes. A greater emphasis has been given to the simplicity of unit operations and to the corresponding energy burden.
{"title":"A Critical Analysis on Green and Low-temperature Methods for the Production of Carbon Nanoparticles","authors":"A. Reverberi, M. Vocciante, A. Bruzzone, B. Fabiano","doi":"10.3303/CET2186135","DOIUrl":"https://doi.org/10.3303/CET2186135","url":null,"abstract":"Carbon nanoparticles (CNPs) gained a growing attention for a wide multiplicity of applications. CNPs offer the basic advantage of being well tolerated by living organisms and they are much more environmental friendly than many other inorganic NPs for analogous purposes. In this short review, several techniques are described and compared, enlighting their strenghts and drawbacks in terms of easy of deployment, possibility of transfer on a large scale, plant safety and environmental soundness. The latter aspect is now one of the basic paradigms for the chemical production tout court and this target can be achieved by acting on different fronts, namely energy saving, cleaner processes and reagents substitution. Some techniques are still confined to a laboratory scale and they need deeper investigations before being transferred to an industrial production, while some other have reached a technological maturity to make them competitive on the market. The methods for the synthesis of CNPs have been grouped according to a scheme different from the usual classification in top-down and bottom-up processes. A greater emphasis has been given to the simplicity of unit operations and to the corresponding energy burden.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"1 1","pages":"805-810"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90363074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Moliner, Beatrice Antonucci, Simona Focacci, J. M. Heap, Aldo Moreno Martel, F. Hamzah, C. Martín, A. Martinez-Felipe
Paper Received: 23 September 2020; Revised: 24 February 2021; Accepted: 2 May 2021 Please cite this article as: Moliner C., Antonucci B., Focacci S., Maclean Heap J., Moreno Martel A., Hamzah F., Martin C., Martinez-Felipe A., 2021, Molecular Dynamics Simulation of the Interactions Between Carbon Dioxide and a Natural-based Carbonaceous Microporous Material, Chemical Engineering Transactions, 86, 1111-1116 DOI:10.3303/CET2186186 CHEMICAL ENGINEERING TRANSACTIONS
{"title":"Molecular dynamics simulation of the interactions between carbon dioxide and a natural-based carbonaceous microporous material","authors":"C. Moliner, Beatrice Antonucci, Simona Focacci, J. M. Heap, Aldo Moreno Martel, F. Hamzah, C. Martín, A. Martinez-Felipe","doi":"10.3303/CET2186186","DOIUrl":"https://doi.org/10.3303/CET2186186","url":null,"abstract":"Paper Received: 23 September 2020; Revised: 24 February 2021; Accepted: 2 May 2021 Please cite this article as: Moliner C., Antonucci B., Focacci S., Maclean Heap J., Moreno Martel A., Hamzah F., Martin C., Martinez-Felipe A., 2021, Molecular Dynamics Simulation of the Interactions Between Carbon Dioxide and a Natural-based Carbonaceous Microporous Material, Chemical Engineering Transactions, 86, 1111-1116 DOI:10.3303/CET2186186 CHEMICAL ENGINEERING TRANSACTIONS","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"10 1","pages":"1111-1116"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84673602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes a functional modelling method, called Multilevel Flow Modelling (MFM) for identification of safety objectives and functions of emergency shutdown (ESD) system in the design phase for emergency shutdown safely. Firstly, the required information for designing safety objectives and functions for an emergency shutdown is analysed. The information includes process topology, the initial state of the process, the shutdown objectives, and other constraints, such as design and operational limits of unit operations and hazardous and environmental constraints. Secondly, a procedure is proposed based on the required information by using MFM. The procedure incorporates steps: 1) The MFM model of the process in normal operations are built by following modelling procedures, 2) Initiate states are defined and changing conditions are identified of the process when it shuts down unplanned by using the objective-function tree in the MFM modelling, 3) The goals of the shutdown operation are defined, 4) With the consideration of the shutdown operating goals and changing conditions, the first safety function during shutdown process are identified by using MFM causal reasoning, 5) By using MFM consequence reasoning based on the first identified safety function represented in the MFM model, the rest of the safety functions are identified, and the emergency shutdown procedures are generated. This procedure is demonstrated by designing safety functions in an emergency shut down of a seawater deaeration process in a seawater injection system. The results show that the produced emergency shut down procedure based on the proposed method is feasible and that it can be validated against the real operating procedure.
{"title":"Identifying Safety Objectives and Functions for Emergency Shutdown in the Design Phase by Using Functional Modelling","authors":"Jing Wu, Mengchu Song, Xinxin Zhang, M. Lind","doi":"10.3303/CET2186162","DOIUrl":"https://doi.org/10.3303/CET2186162","url":null,"abstract":"This paper proposes a functional modelling method, called Multilevel Flow Modelling (MFM) for identification of safety objectives and functions of emergency shutdown (ESD) system in the design phase for emergency shutdown safely. Firstly, the required information for designing safety objectives and functions for an emergency shutdown is analysed. The information includes process topology, the initial state of the process, the shutdown objectives, and other constraints, such as design and operational limits of unit operations and hazardous and environmental constraints. Secondly, a procedure is proposed based on the required information by using MFM. The procedure incorporates steps: 1) The MFM model of the process in normal operations are built by following modelling procedures, 2) Initiate states are defined and changing conditions are identified of the process when it shuts down unplanned by using the objective-function tree in the MFM modelling, 3) The goals of the shutdown operation are defined, 4) With the consideration of the shutdown operating goals and changing conditions, the first safety function during shutdown process are identified by using MFM causal reasoning, 5) By using MFM consequence reasoning based on the first identified safety function represented in the MFM model, the rest of the safety functions are identified, and the emergency shutdown procedures are generated. This procedure is demonstrated by designing safety functions in an emergency shut down of a seawater deaeration process in a seawater injection system. The results show that the produced emergency shut down procedure based on the proposed method is feasible and that it can be validated against the real operating procedure.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"25 1","pages":"967-972"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87230909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yerkanat N. Kanafin, A. Satayeva, E. Arkhangelsky, S. Poulopoulos
Emerging pollutants like metronidazole (MNZ) affect the removal efficiency of conventional activated sludge (CAS) based wastewater treatment plants and can escape traditional treatment facilities. Advanced oxidation processes (AOPs) and membrane filtration could complement the existing processes to completely eliminate pollutants of emerging concern in wastewaters. This work investigated the application of photochemical processes for treating a synthetic wastewater effluent from CAS treatment and membrane filtration of the biological effluents after CAS experiments with MNZ, caffeine (CAF) and ibuprofen (IBU). Photochemical experiments were conducted in a batch photochemical reactor. The influence of different chemical species such as H2O2, Fe(II), K2S2O8 and TiO2 and of pH value in the system were studied in terms of TOC removal and MNZ degradation. The application of UV/K2S2O8/Fe(II) resulted in 78 % TOC removal in the effluent. Complete degradation of MNZ was observed after 30 min of treatment in the following experiments: UV/H2O2/Fe(II) at pH 3 and UV/K2S2O8. Moreover, the effluents were treated by means of a membrane bioreactor (MBR). Polycarbonate track-etch membranes of 50 and 100 nm pore size were used. The results obtained showed that the carbon removal by the MBR was comparable with the conventional biological treatment. Rejection of MNZ depends on the presence/absence of other emerging contaminants in the wastewater effluents.
{"title":"Treatment of a Biological Effluent Containing Metronidazole","authors":"Yerkanat N. Kanafin, A. Satayeva, E. Arkhangelsky, S. Poulopoulos","doi":"10.3303/CET2186100","DOIUrl":"https://doi.org/10.3303/CET2186100","url":null,"abstract":"Emerging pollutants like metronidazole (MNZ) affect the removal efficiency of conventional activated sludge (CAS) based wastewater treatment plants and can escape traditional treatment facilities. Advanced oxidation processes (AOPs) and membrane filtration could complement the existing processes to completely eliminate pollutants of emerging concern in wastewaters. This work investigated the application of photochemical processes for treating a synthetic wastewater effluent from CAS treatment and membrane filtration of the biological effluents after CAS experiments with MNZ, caffeine (CAF) and ibuprofen (IBU). Photochemical experiments were conducted in a batch photochemical reactor. The influence of different chemical species such as H2O2, Fe(II), K2S2O8 and TiO2 and of pH value in the system were studied in terms of TOC removal and MNZ degradation. The application of UV/K2S2O8/Fe(II) resulted in 78 % TOC removal in the effluent. Complete degradation of MNZ was observed after 30 min of treatment in the following experiments: UV/H2O2/Fe(II) at pH 3 and UV/K2S2O8. Moreover, the effluents were treated by means of a membrane bioreactor (MBR). Polycarbonate track-etch membranes of 50 and 100 nm pore size were used. The results obtained showed that the carbon removal by the MBR was comparable with the conventional biological treatment. Rejection of MNZ depends on the presence/absence of other emerging contaminants in the wastewater effluents.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"6 1","pages":"595-600"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78831488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The valorization of municipal waste represents one of the major opportunities for the next future. In particular, the Organic Fraction of Municipal Solid Waste (OFMSW) can be used in anaerobic digesters to produce biogas/biomethane. Furthermore, a fraction of Municipal Solid Waste (e.g. non-recyclable plastics, paper cardboard, etc.) can be converted to Refuse Derived Fuel (RDF). Both biogas/biomethane and RDF may be further converted in syngas (a mixture of H2, CO and CO2) by using several technologies, such as steam reforming for the former, and gasification for the latter. Syngas may be used as fuel in CHP plants or for the production of chemical intermediates and fuel. The digestate derived from anaerobic digestion, as well as CO2 from biogas, can be used as nutrients source to grow microalgae, which are feedstock suitable for supercritical water gasification (SWG). In this paper, an integrated process is proposed, by coupling an anaerobic digestion plant for biomethane production with (i) high-temperature gasification of RDF and (ii) SWG of algae grown up with digestate and CO2 from biogas. The biomethane is assumed to be converted in syngas by steam reforming. Considering its importance for the chemical industry chain, methanol is considered as a target product. Methanol synthesis is assessed in terms of mass and energy balances and direct CO2 emissions. The results show that high-temperature endothermic processes require the use of purge gas as a fuel in a burner to sustain itself. The lowest direct CO2 emission value per kg of methanol produced is obtained in the case of high use of RDF, minimum recycling of CO2 to algae production and minimum purge ratio.
{"title":"Waste-to-methanol: Direct CO2 Emissions Assessment for the Methanol Production from Municipal Waste-derived Syngas","authors":"E. Catizzone, A. Giuliano, D. Barletta","doi":"10.3303/CET2186086","DOIUrl":"https://doi.org/10.3303/CET2186086","url":null,"abstract":"The valorization of municipal waste represents one of the major opportunities for the next future. In particular, the Organic Fraction of Municipal Solid Waste (OFMSW) can be used in anaerobic digesters to produce biogas/biomethane. Furthermore, a fraction of Municipal Solid Waste (e.g. non-recyclable plastics, paper cardboard, etc.) can be converted to Refuse Derived Fuel (RDF). Both biogas/biomethane and RDF may be further converted in syngas (a mixture of H2, CO and CO2) by using several technologies, such as steam reforming for the former, and gasification for the latter. Syngas may be used as fuel in CHP plants or for the production of chemical intermediates and fuel. The digestate derived from anaerobic digestion, as well as CO2 from biogas, can be used as nutrients source to grow microalgae, which are feedstock suitable for supercritical water gasification (SWG). In this paper, an integrated process is proposed, by coupling an anaerobic digestion plant for biomethane production with (i) high-temperature gasification of RDF and (ii) SWG of algae grown up with digestate and CO2 from biogas. The biomethane is assumed to be converted in syngas by steam reforming. Considering its importance for the chemical industry chain, methanol is considered as a target product. Methanol synthesis is assessed in terms of mass and energy balances and direct CO2 emissions. The results show that high-temperature endothermic processes require the use of purge gas as a fuel in a burner to sustain itself. The lowest direct CO2 emission value per kg of methanol produced is obtained in the case of high use of RDF, minimum recycling of CO2 to algae production and minimum purge ratio.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"105 1","pages":"511-516"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77006400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present work, CFD simulations of transient temperature increase in a pool of water due to indirect contact heating in the middle of the pool has been presented. CFD simulations have been able to mimic the transient phenomena of increase in temperature throughout the pool eventually leading to evaporation of water at the top surface and decrease in the level of the pool due to thermal stratification after several hours of operation. The CFD model is first validated with experimental temperature and water vapour volume fraction profiles at a particular level of the pool from the literature. Predictions show good agreement of less than 10% variation is observed. Spatial temperature profiles for different times are analysed to understand the pool boiling in such pools. The profiles indicate thermal stratification after 10000 seconds. Further, analysis transient variation of stratification parameter confirms the strong thermal stratification after 10000 seconds. The evaporation rate after 10000 seconds from top surface have been measured and compared with empirical models from liter
{"title":"Two Phase CFD Simulations in Stagnant Water Pools: Unsteady Temperature and Level Variation","authors":"A. Ganguli, A. Pandit","doi":"10.3303/CET2186253","DOIUrl":"https://doi.org/10.3303/CET2186253","url":null,"abstract":"In the present work, CFD simulations of transient temperature increase in a pool of water due to indirect contact heating in the middle of the pool has been presented. CFD simulations have been able to mimic the transient phenomena of increase in temperature throughout the pool eventually leading to evaporation of water at the top surface and decrease in the level of the pool due to thermal stratification after several hours of operation. The CFD model is first validated with experimental temperature and water vapour volume fraction profiles at a particular level of the pool from the literature. Predictions show good agreement of less than 10% variation is observed. Spatial temperature profiles for different times are analysed to understand the pool boiling in such pools. The profiles indicate thermal stratification after 10000 seconds. Further, analysis transient variation of stratification parameter confirms the strong thermal stratification after 10000 seconds. The evaporation rate after 10000 seconds from top surface have been measured and compared with empirical models from liter","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"101 1","pages":"1513-1518"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77629909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Primerano, Concetta Saja, M. Milazzo, F. Lanuzza
The unextracted residue, obtained after an extractive process from glass cullet with sodium hydroxide aqueous solution at 140°C for 2 hours, is mainly made of calcium and sodium silicate. It shows a high porosity and a large surface area. It could be active as an agent for the removal dyes from wastewater. In this paper Methyl Red (MR) was employed to evaluate the adsorbent properties of above residue. Aliquots of this residue were maintained at room temperature under constant stirring with 0.025-0.5 g/L of MR aqueous solution by using a liquid/solid ratio from 50 to 500 mL/g and up to 24 hours. The results have shown an effective removal of MR within one hour for MR concentration of 0.5 g/L and within 30 minutes and for MR concentration = 0.25 g/L with liquid/solid ratio < 100 mL/g. The performance of the residue as an adsorbent contributes to increase the environmental sustainability of glass recycling treatment and further decreases the amount of waste to be delivered to landfill.
{"title":"Removal of Dyes from Wastewater Using the Residue from the Chemical Recycling of Glass Cullet","authors":"P. Primerano, Concetta Saja, M. Milazzo, F. Lanuzza","doi":"10.3303/CET2186105","DOIUrl":"https://doi.org/10.3303/CET2186105","url":null,"abstract":"The unextracted residue, obtained after an extractive process from glass cullet with sodium hydroxide aqueous solution at 140°C for 2 hours, is mainly made of calcium and sodium silicate. It shows a high porosity and a large surface area. It could be active as an agent for the removal dyes from wastewater. In this paper Methyl Red (MR) was employed to evaluate the adsorbent properties of above residue. Aliquots of this residue were maintained at room temperature under constant stirring with 0.025-0.5 g/L of MR aqueous solution by using a liquid/solid ratio from 50 to 500 mL/g and up to 24 hours. The results have shown an effective removal of MR within one hour for MR concentration of 0.5 g/L and within 30 minutes and for MR concentration = 0.25 g/L with liquid/solid ratio < 100 mL/g. The performance of the residue as an adsorbent contributes to increase the environmental sustainability of glass recycling treatment and further decreases the amount of waste to be delivered to landfill.","PeriodicalId":9695,"journal":{"name":"Chemical engineering transactions","volume":"1074 1","pages":"625-630"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73981147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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