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The highest economic and environmental costs of wastewater treatment plants are related to waste disposal, which is mainly sludge disposal, and energy supply. Such challenges are even more critical in islands, where there are many environmental, landscape, and geographical constraints that make the use of conventional technologies difficult. For this reason, a geothermal energy system for wastewater and sludge treatment, and power production is proposed. Such a system is assessed through an exergoeconomic analysis, performed in Engineering Equation Solver environment, that allows determining the exergoeconomic costs of geo-fluid, electricity production, and sludge drying. The sensitivity analyses, carried out to assess the effect of several design parameters, have highlighted that the geothermal source temperature significantly affects the system operation and consequently the exergoeconomic costs, which range 77–95 c€/kWhex for sludge treatment and between 4.8 and 6.6c€/kWhex for electricity production. Finally, multivariate optimization has been carried out to find the conditions that minimize the exergoeconomic costs of the system. The total hourly exergoeconomic cost of the system products, namely sludge and electricity, is minimized when the geothermal source temperature is equal to 110 °C and the 58.91% of the desiccant flow is recycled. Overall, this study outlines that an exergy-based economic analysis is fundamental to assess the economic viability of innovative integrated solutions based on renewables.
Simona Di Fraia; Adriano Macaluso; Nicola Massarotti; Laura Vanoli. Geothermal energy for wastewater and sludge treatment: An exergoeconomic analysis. Energy Conversion and Management 2020, 224, 113180 .
AMA StyleSimona Di Fraia, Adriano Macaluso, Nicola Massarotti, Laura Vanoli. Geothermal energy for wastewater and sludge treatment: An exergoeconomic analysis. Energy Conversion and Management. 2020; 224 ():113180.
Chicago/Turabian StyleSimona Di Fraia; Adriano Macaluso; Nicola Massarotti; Laura Vanoli. 2020. "Geothermal energy for wastewater and sludge treatment: An exergoeconomic analysis." Energy Conversion and Management 224, no. : 113180.
According to the Italian national Energy strategy elaborated in 2017, the biomass sector has one of the most important strategic roles in energy renewables policy. Thus estimating the potential of this resource is crucial for its energy valorization. Therefore, in this paper, a method to assess the energy potential from residual biomass is presented. The availability of residual biomass and its energy potential are estimated by using statistical and literature data. To account for the variability of the factors taken into account a comprehensive literature review is carried out focusing on the case studies related to Mediterranean areas. Based on the collected data uncertainty analysis and sensitivity analyses are performed to provide reliable results. As a case study, the energy potential of residual biomass from agro-industry in the Campania region (southern Italy) is considered. The proposed method allows estimating a total of about 14.5 PJ per year of recoverable primary energy potential in the Campania region, which may cover around 14% of its thermal demand. The analysis carried out is intended to be a useful tool for policymakers of Mediterranean regions, to integrate energy recovery from agro-industrial biomass in the regulatory and investment strategies of the energy sector.
Simona Di Fraia; Salvatore Fabozzi; Adriano Macaluso; Laura Vanoli. Energy potential of residual biomass from agro-industry in a Mediterranean region of southern Italy (Campania). Journal of Cleaner Production 2020, 277, 124085 .
AMA StyleSimona Di Fraia, Salvatore Fabozzi, Adriano Macaluso, Laura Vanoli. Energy potential of residual biomass from agro-industry in a Mediterranean region of southern Italy (Campania). Journal of Cleaner Production. 2020; 277 ():124085.
Chicago/Turabian StyleSimona Di Fraia; Salvatore Fabozzi; Adriano Macaluso; Laura Vanoli. 2020. "Energy potential of residual biomass from agro-industry in a Mediterranean region of southern Italy (Campania)." Journal of Cleaner Production 277, no. : 124085.
Waste vegetable oil is generated from different sources, such as domestic, commercial and industrial activities, and it requires proper management. Due to the increase in the generation of waste vegetable oil, concern for its management has intensified. The most common management option for waste vegetable oil is the conversion into biodiesel, which improves the chemical-physical characteristics of raw waste vegetable oil for its use but is characterized by significant energy consumption and environmental impact. Therefore, straight waste vegetable oil as fuel, after mechanical pre-treatments and with suitable operational strategy, is suggested in the available literature. In this work, waste vegetable oil from the separate collection is proposed as a source to fuel a combined heat and power unit producing energy for wastewater and sludge treatment plants, which is high energy-demanding. The operation of the combined heat and power unit is analyzed considering data from an experimental campaign carried out to investigate the performance of internal combustion engines powered by waste vegetable oil. Such experimental data are used to carry out the feasibility analysis of a combined heat and power system for an actual wastewater treatment plant located in the Campania region, southern Italy. The system appears to be economically feasible with a simple payback around 3.44 years, a net present value higher than 19.0 M€ and an interest rate of return of 26.7%. Moreover, it produces 70.0% less equivalent carbon dioxide emissions, with respect to a similar system powered by fossil fuels. Therefore, waste vegetable oil as a locally available and renewable energy source may contribute to realize smart and resilient communities, since it improves securing domestic energy supply and waste valorization.
S. Di Fraia; N. Massarotti; M.V. Prati; L. Vanoli. A new example of circular economy: Waste vegetable oil for cogeneration in wastewater treatment plants. Energy Conversion and Management 2020, 211, 112763 .
AMA StyleS. Di Fraia, N. Massarotti, M.V. Prati, L. Vanoli. A new example of circular economy: Waste vegetable oil for cogeneration in wastewater treatment plants. Energy Conversion and Management. 2020; 211 ():112763.
Chicago/Turabian StyleS. Di Fraia; N. Massarotti; M.V. Prati; L. Vanoli. 2020. "A new example of circular economy: Waste vegetable oil for cogeneration in wastewater treatment plants." Energy Conversion and Management 211, no. : 112763.
In this study, the sustainability of low-temperature geothermal field exploitation in a carbonate reservoir near Mondragone (CE), Southern Italy, is analyzed. The Mondragone geothermal field has been extensively studied through the research project VIGOR (Valutazione del potenzIale Geotermico delle RegiOni della convergenza). From seismic, geo-electric, hydro-chemical and groundwater data, obtained through the experimental campaigns carried out, physiochemical features of the aquifers and characteristics of the reservoir have been determined. Within this project, a well-doublet open-loop district heating plant has been designed to feed two public schools in Mondragone town. The sustainability of this geothermal application is analyzed in this study. A new exploration well (about 300 m deep) is considered to obtain further stratigraphic and structural information about the reservoir. Using the derived hydrogeological model of the area, a numerical analysis of geothermal exploitation was carried out to assess the thermal perturbation of the reservoir and the sustainability of its exploitation. The effect of extraction and reinjection of fluids on the reservoir was evaluated for 60 years of the plant activity. The results are fundamental to develop a sustainable geothermal heat plant and represent a real case study for the exploitation of similar carbonate reservoir geothermal resources.
Marina Iorio; Alberto Carotenuto; Alfonso Corniello; Simona Di Fraia; Nicola Massarotti; Alessandro Mauro; Renato Somma; Laura Vanoli. Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy). Energies 2020, 13, 1237 .
AMA StyleMarina Iorio, Alberto Carotenuto, Alfonso Corniello, Simona Di Fraia, Nicola Massarotti, Alessandro Mauro, Renato Somma, Laura Vanoli. Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy). Energies. 2020; 13 (5):1237.
Chicago/Turabian StyleMarina Iorio; Alberto Carotenuto; Alfonso Corniello; Simona Di Fraia; Nicola Massarotti; Alessandro Mauro; Renato Somma; Laura Vanoli. 2020. "Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy)." Energies 13, no. 5: 1237.
In the present study, a modified equilibrium model was developed by Aspen Plus® to simulate the gasification of biosolids (treated sewage sludge) in an atmospheric fluidized bed reactor (FBR) using air as a gasification agent. The model, which is based on the Gibbs free energy minimization applying the restricted equilibrium method, was calibrated and validated against a set of experimental data obtained in a pre-pilot scale FBR. The comparison between the simulation results and the experimental data showed a satisfactory agreement; in particular, with respect to the content of combustible gases in the syngas and the heating value. The main objective is to assess the impact of different sludge pretreatment methods (i.e., torrefaction, anaerobic digestion and co-pelletization of sewage sludge with wood waste) and the key operating conditions (gasification temperature and equivalence ratio) on both the syngas quality (composition and heating value) and the performance of the gasifier in terms of carbon conversion efficiency (Xc), syngas yield (YG) and cold gas efficiency (CGE) under the same operating conditions. A global sensitivity analysis was first performed by varying the gasification temperature and the equivalence ratio (ER). Then, the impact of sludge pretreatments was evaluated by changing the sludge composition in the model in line with experimental data from pertinent literature. Results point out the torrefaction pretreatment in combination of gasification exhibited promising results in terms of gas quality and energy efficiency of the process (e. g. heating value and CGE).
Ashraf Abdelrahim; Paola Brachi; Giovanna Ruoppolo; Simona Di Fraia; Laura Vanoli. Experimental and Numerical Investigation of Biosolid Gasification: Equilibrium-Based Modeling with Emphasis on the Effects of Different Pretreatment Methods. Industrial & Engineering Chemistry Research 2019, 59, 299 -307.
AMA StyleAshraf Abdelrahim, Paola Brachi, Giovanna Ruoppolo, Simona Di Fraia, Laura Vanoli. Experimental and Numerical Investigation of Biosolid Gasification: Equilibrium-Based Modeling with Emphasis on the Effects of Different Pretreatment Methods. Industrial & Engineering Chemistry Research. 2019; 59 (1):299-307.
Chicago/Turabian StyleAshraf Abdelrahim; Paola Brachi; Giovanna Ruoppolo; Simona Di Fraia; Laura Vanoli. 2019. "Experimental and Numerical Investigation of Biosolid Gasification: Equilibrium-Based Modeling with Emphasis on the Effects of Different Pretreatment Methods." Industrial & Engineering Chemistry Research 59, no. 1: 299-307.
Purpose This study aims at developing a comprehensive model for the analysis of electro-osmotic flow (EOF) through a fluid-saturated porous medium. To fully understand and exploit a number of applications, such a model for EOF through porous media is essential. Design/methodology/approach The proposed model is based on a generalised set of governing equations used for modelling flow through fluid saturated porous media. These equations are modified to incorporate appropriate modifications to represent electro-osmosis (EO). The model is solved through the finite element method (FEM). The validity of the proposed numerical model is demonstrated by comparing the numerical results of internal potential and velocity distribution with corresponding analytical expressions. The model introduced is also used to carry out a sensitivity analysis of the main parameters that control EOF. Findings The analysis carried out confirms that EO in free channels without porous obstruction is effective only at small scales, as largely discussed in the available literature. Using porous media makes EO independent of the channel scale. Indeed, as the channel size increases, the presence of the charged porous medium is essential to induce fluid flow. Moreover, results demonstrate that flow is significantly affected by the characteristics of the porous medium, such as particle size, and by the zeta potential acting on the charged surfaces. Originality/value To the best of the authors’ knowledge, a comprehensive FEM model, based on the generalised equations to simulate EOF in porous media, is proposed here for the first time.
Simona Di Fraia; P. Nithiarasu. A generalised model for electro-osmotic flow in porous media. International Journal of Numerical Methods for Heat & Fluid Flow 2019, 29, 4895 -4924.
AMA StyleSimona Di Fraia, P. Nithiarasu. A generalised model for electro-osmotic flow in porous media. International Journal of Numerical Methods for Heat & Fluid Flow. 2019; 29 (12):4895-4924.
Chicago/Turabian StyleSimona Di Fraia; P. Nithiarasu. 2019. "A generalised model for electro-osmotic flow in porous media." International Journal of Numerical Methods for Heat & Fluid Flow 29, no. 12: 4895-4924.
An integrated system for sewage sludge drying and electricity production is proposed. The system is powered by waste vegetable oil from separate collection. The system significantly reduces the sludge to be disposed of and the electricity to be supplied by the grid.
Simona Di Fraia; Nicola Massarotti; Laura Vanoli; Riccardo Bentivoglio; Gianfranco Milani. Techno-Economic Assessment of Combined Heat and Power Units Fuelled by Waste Vegetable Oil for Wastewater Treatment Plants: A Real Case Study. Plant-Microbes-Engineered Nano-particles (PM-ENPs) Nexus in Agro-Ecosystems 2019, 345 -348.
AMA StyleSimona Di Fraia, Nicola Massarotti, Laura Vanoli, Riccardo Bentivoglio, Gianfranco Milani. Techno-Economic Assessment of Combined Heat and Power Units Fuelled by Waste Vegetable Oil for Wastewater Treatment Plants: A Real Case Study. Plant-Microbes-Engineered Nano-particles (PM-ENPs) Nexus in Agro-Ecosystems. 2019; ():345-348.
Chicago/Turabian StyleSimona Di Fraia; Nicola Massarotti; Laura Vanoli; Riccardo Bentivoglio; Gianfranco Milani. 2019. "Techno-Economic Assessment of Combined Heat and Power Units Fuelled by Waste Vegetable Oil for Wastewater Treatment Plants: A Real Case Study." Plant-Microbes-Engineered Nano-particles (PM-ENPs) Nexus in Agro-Ecosystems , no. : 345-348.
Wastewater treatment is one of the most energy-consuming processes in the water sector, requiring both electric and thermal energy. In order to improve their sustainability, renewable energy sources can supply such energy demands in wastewater treatment plants, especially in small islands, where the lack of connections with mainland and environmental restrictions promote the use of unconventional fuels and technologies for energy production and waste treatment. For this reason, in this work, the use of geothermal energy is proposed for electric and thermal energy generation for wastewater and sludge treatment. An energy, exergy and economic analysis for the developed system is carried out. The study is carried out for a district wastewater treatment plant on the island of Ischia, in southern Italy, which presents diffused low-medium enthalpy geothermal sources, considered in this work to power an organic Rankine cycle system for electric energy production and to heat the desiccant flow for sludge drying. The proposed system reduces sludge to be disposed by around 70% and it covers 100% of the electrical energy demand of the wastewater treatment plant, with a production of 1.68 kWh per kg of processed sludge. Despite the high investment, the revenues deriving from the avoided sludge disposal and the electricity production, make the system convenient, with a simple payback of about 5 years and a saving of CO2 equivalent emissions equal to 628 tons/year. Therefore, the energy, exergy and economic analysis of the proposed system shows that the geothermal source is a viable and environmentally sustainable solution to produce electrical and thermal energy for wastewater and sludge treatment plants, especially in small islands or energy isolated systems, where electric energy supply and sewage sludge treatment are commonly critical challenges.
Simona Di Fraia; Adriano Macaluso; Nicola Massarotti; Laura Vanoli. Energy, exergy and economic analysis of a novel geothermal energy system for wastewater and sludge treatment. Energy Conversion and Management 2019, 195, 533 -547.
AMA StyleSimona Di Fraia, Adriano Macaluso, Nicola Massarotti, Laura Vanoli. Energy, exergy and economic analysis of a novel geothermal energy system for wastewater and sludge treatment. Energy Conversion and Management. 2019; 195 ():533-547.
Chicago/Turabian StyleSimona Di Fraia; Adriano Macaluso; Nicola Massarotti; Laura Vanoli. 2019. "Energy, exergy and economic analysis of a novel geothermal energy system for wastewater and sludge treatment." Energy Conversion and Management 195, no. : 533-547.
The authors would like to add some corrections to the published paper “An integrated system for sewage sludge drying through solar energy and a combined heat and power unit fuelled by biogas”, Energy Conversion and Management, Volume 171, 1 September 2018, Pages 587-603. The corrections provided here do not affect main findings and conclusions of the original paper.
Simona Di Fraia; Rafal Damian Figaj; Nicola Massarotti; Laura Vanoli. Corrigendum to “An Integrated System For Sewage Sludge Drying through Solar Energy and a Combined Heat and Power Unit fuelled by Biogas” [Energy Conversion and Management 171 (2018) 587-603]. Energy Conversion and Management 2019, 185, 892 -893.
AMA StyleSimona Di Fraia, Rafal Damian Figaj, Nicola Massarotti, Laura Vanoli. Corrigendum to “An Integrated System For Sewage Sludge Drying through Solar Energy and a Combined Heat and Power Unit fuelled by Biogas” [Energy Conversion and Management 171 (2018) 587-603]. Energy Conversion and Management. 2019; 185 ():892-893.
Chicago/Turabian StyleSimona Di Fraia; Rafal Damian Figaj; Nicola Massarotti; Laura Vanoli. 2019. "Corrigendum to “An Integrated System For Sewage Sludge Drying through Solar Energy and a Combined Heat and Power Unit fuelled by Biogas” [Energy Conversion and Management 171 (2018) 587-603]." Energy Conversion and Management 185, no. : 892-893.
Simona Di Fraia; Rafal Damian Figaj; Nicola Massarotti; Laura Vanoli. An integrated system for sewage sludge drying through solar energy and a combined heat and power unit fuelled by biogas. Energy Conversion and Management 2018, 171, 587 -603.
AMA StyleSimona Di Fraia, Rafal Damian Figaj, Nicola Massarotti, Laura Vanoli. An integrated system for sewage sludge drying through solar energy and a combined heat and power unit fuelled by biogas. Energy Conversion and Management. 2018; 171 ():587-603.
Chicago/Turabian StyleSimona Di Fraia; Rafal Damian Figaj; Nicola Massarotti; Laura Vanoli. 2018. "An integrated system for sewage sludge drying through solar energy and a combined heat and power unit fuelled by biogas." Energy Conversion and Management 171, no. : 587-603.
Waste management and energy production are becoming critical issues in geographically disadvantaged areas, like small islands. For waste disposal the most common strategy is shipping to the mainland, due to the scarcity of land and local suitable treatments. Electricity generation is based on the importation of fossil fuels for local production, due to the lack of connections with continental energy networks. Both, waste shipping and fuels importation determine strong dependence on the mainland, as well as high economic and environmental cost for small islands. Therefore, using local renewable energy sources is extremely attracting. In this work, geothermal energy is considered for thermal drying of wastewater sludge and electricity supply of the whole wastewater treatment. The system is analysed for the case study of Pantelleria, a small island in Southern Italy, where sludge is currently dewatered to a final water content of 70–80%, and then shipped to mainland. The proposed system decreases wastewater sludge to be transported and disposed by 73.3%. Its profitability is demonstrated by several economic indicators, showing a Simple Payback time equal to 8.34 years and a Net Present Value of 502 k€. In addition, a sensitivity analysis for the main parameters affecting plant operation is carried out.
F. Calise; S. Di Fraia; A. Macaluso; Nicola Massarotti; L. Vanoli. A geothermal energy system for wastewater sludge drying and electricity production in a small island. Energy 2018, 163, 130 -143.
AMA StyleF. Calise, S. Di Fraia, A. Macaluso, Nicola Massarotti, L. Vanoli. A geothermal energy system for wastewater sludge drying and electricity production in a small island. Energy. 2018; 163 ():130-143.
Chicago/Turabian StyleF. Calise; S. Di Fraia; A. Macaluso; Nicola Massarotti; L. Vanoli. 2018. "A geothermal energy system for wastewater sludge drying and electricity production in a small island." Energy 163, no. : 130-143.
Wastewater treatment is a high energy consuming process, and its energy demand is considerably increasing due to the introduction of more restrictive standards on the quality of water effluents, that require advanced technologies for pollutant removal. Energy audits are carried out in order to improve energy efficiency of wastewater treatment plants, by introducing some measures, such as adjustments of the treatment scheme, or optimization of existing operational units. At the same time, energy recovery from wastewater treatment and its by-products is being implemented in order to reduce economic costs and environmental impact of the process. In order to assess the benefits resulting from implementation of these interventions, procedures for evaluation of energy performance of wastewater treatment plants are being developed. In this work, a novel method is proposed for assessing energy performance of wastewater treatment plants by coupling simple energy performance indicators with specific pollution removal efficiencies. This procedure is applied to a large database of wastewater treatment plants, in order to define some classes of energy performance depending on removal efficiency. The method is also used to analyse some Italian plants, representative of different design and management conditions. As a result, only 8.2% of around 300 plants presents the highest class of performance, considering the energy consumption related to the organic matter removal.
S. Di Fraia; Nicola Massarotti; L. Vanoli. A novel energy assessment of urban wastewater treatment plants. Energy Conversion and Management 2018, 163, 304 -313.
AMA StyleS. Di Fraia, Nicola Massarotti, L. Vanoli. A novel energy assessment of urban wastewater treatment plants. Energy Conversion and Management. 2018; 163 ():304-313.
Chicago/Turabian StyleS. Di Fraia; Nicola Massarotti; L. Vanoli. 2018. "A novel energy assessment of urban wastewater treatment plants." Energy Conversion and Management 163, no. : 304-313.
Purpose This paper aims to provide a comprehensive literature review on modelling electro-osmotic flow in porous media. Design/methodology/approach Modelling electro-osmosis in fluid systems without solid particles has been first introduced. Then, after a brief description of the existing approaches for porous media modelling, electro-osmotic flow in porous media has been considered by analysing the main contributions to the development of this topic. Findings The analysis of literature has highlighted the absence of a universal model to analyse electro-osmosis in porous media, whereas many different methods and assumptions are used. Originality/value For the first time, the existing approaches for modelling electro-osmotic flow in porous have been collected and analysed to provide detailed indications for future works concerning this topic.
Simona Di Fraia; Nicola Massarotti; Perumal Nithiarasu. Modelling electro-osmotic flow in porous media: a review. International Journal of Numerical Methods for Heat & Fluid Flow 2018, 28, 472 -497.
AMA StyleSimona Di Fraia, Nicola Massarotti, Perumal Nithiarasu. Modelling electro-osmotic flow in porous media: a review. International Journal of Numerical Methods for Heat & Fluid Flow. 2018; 28 (2):472-497.
Chicago/Turabian StyleSimona Di Fraia; Nicola Massarotti; Perumal Nithiarasu. 2018. "Modelling electro-osmotic flow in porous media: a review." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 2: 472-497.
Purpose In this work, a new two-phase version of the finite element-based Artificial Compressibility (AC) Characteristic-Based Split (CBS) algorithm is developed and applied for the first time to heat and mass transfer phenomena in porous media with associated phase change. The purpose of this study is to provide an alternative for the theoretical analysis and numerical simulation of multiphase transport phenomena in porous media. Traditionally, the more complex Separate Flow Model was used in which the vapour and liquid phases were considered as distinct fluids and mathematically described by the conservation laws for each phase separately, resulting in a large number of governing equations. Design/methodology/approach Even though the adopted mathematical model presents analogies with the conventional multicomponent mixture flow model, it is characterized by a considerable reduction in the number of the differential equations for the primary variables. The fixed-grid numerical formulation can be applied to the resolution of general problems that may simultaneously include a superheated vapour region, a two-phase zone and a sub-cooled liquid region in a single physical domain with irregular and moving phase interfaces in between. The local thermal non-equilibrium model is introduced to consider the heat exchange between fluid and solid within the porous matrix. Findings The numerical model is verified considering the transport phenomena in a homogenous and isotropic porous medium in which water is injected from one side and heated from the other side, where it leaves the computational domain in a superheated vapour state. Dominant forces are represented by capillary interactions and two-phase heat conduction. The obtained results have been compared with the numerical data available in the scientific literature. Social implications The present algorithm provides a powerful routine tool for the numerical modelling of complex two-phase transport processes in porous media. Originality/value For the first time, the stabilized AC-CBS scheme is applied to the resolution of compressible viscous flow transport in porous materials with associated phase change. A properly stabilized matrix inversion-free procedure employs an adaptive local time step that allows acceleration of the solution process even in the presence of large source terms and low diffusion coefficients values (near the phase change point).
Gino Cortellessa; Fausto Arpino; Simona Di Fraia; Mauro Scungio. Two-phase explicit CBS procedure for compressible viscous flow transport in porous materials. International Journal of Numerical Methods for Heat & Fluid Flow 2018, 28, 336 -360.
AMA StyleGino Cortellessa, Fausto Arpino, Simona Di Fraia, Mauro Scungio. Two-phase explicit CBS procedure for compressible viscous flow transport in porous materials. International Journal of Numerical Methods for Heat & Fluid Flow. 2018; 28 (2):336-360.
Chicago/Turabian StyleGino Cortellessa; Fausto Arpino; Simona Di Fraia; Mauro Scungio. 2018. "Two-phase explicit CBS procedure for compressible viscous flow transport in porous materials." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 2: 336-360.
Simona Di Fraia; Nicola Massarotti; Alessandro Mauro; Perumal Nithiarasu. Heat and fluid flow in electro-osmotically driven systems. Energy Procedia 2017, 126, 91 -98.
AMA StyleSimona Di Fraia, Nicola Massarotti, Alessandro Mauro, Perumal Nithiarasu. Heat and fluid flow in electro-osmotically driven systems. Energy Procedia. 2017; 126 ():91-98.
Chicago/Turabian StyleSimona Di Fraia; Nicola Massarotti; Alessandro Mauro; Perumal Nithiarasu. 2017. "Heat and fluid flow in electro-osmotically driven systems." Energy Procedia 126, no. : 91-98.
In this paper the influence of obstructions on microchannel electro-osmotic flow is investigated for the first time. To carry out such a study, regular obstructions are introduced into microchannels and flow rates are numerically calculated. The effect of channel width on flow rates is analysed on both free and obstructed channels. The solid material considered for channel walls and obstructions is silicon, and the electrolyte is deionised water. The parameters studied include channel width, obstruction size and effective porosity of the channel. The effective porosity is varied between 0.4 and 0.8 depending on other chosen parameters. The results clearly demonstrate that, under the analysed conditions, introduction of obstructions into channels wider than \(100\,\upmu \hbox {m}\) enhances the flow rate induced by electro-osmosis.
S. Di Fraia; N. Massarotti; Perumal Nithiarasu. Effectiveness of flow obstructions in enhancing electro-osmotic flow. Microfluidics and Nanofluidics 2017, 21, 46 .
AMA StyleS. Di Fraia, N. Massarotti, Perumal Nithiarasu. Effectiveness of flow obstructions in enhancing electro-osmotic flow. Microfluidics and Nanofluidics. 2017; 21 (3):46.
Chicago/Turabian StyleS. Di Fraia; N. Massarotti; Perumal Nithiarasu. 2017. "Effectiveness of flow obstructions in enhancing electro-osmotic flow." Microfluidics and Nanofluidics 21, no. 3: 46.
Wastewater treatment plants are high energy-consuming systems, and their electric energy consumption contributes to 25–30% of the total operating costs. A significant part of thermal energy is needed for management of the sludge produced during the process. Sludge drying by Combined Heat and Power (CHP) systems is attractive to obtain substantial economic and energy savings, especially if all the waste heat can be used. Since biogas production, where available, is insufficient for sludge drying, the direct use of the exhaust gases of a CHP system fuelled with syngas derived from sludge gasification and waste vegetable oil, is proposed. The profitability of this system is comparable with that of the systems currently employed in advanced wastewater treatment plants. The economic convenience derives from the reduction of sludge to be disposed and the overall energy saving in the plant. The simple payback of the proposed system, equal to 6.8 years, is only one year higher than that found for of an analogue conventional system, while the Net Present Value is 30% higher than that calculated for a conventional system. In terms of environmental impact, the layout presented is more efficient as biomass-derived fuels are used instead of fossil fuels.
S. Di Fraia; N. Massarotti; L. Vanoli; Michela Costa. Thermo-economic analysis of a novel cogeneration system for sewage sludge treatment. Energy 2016, 115, 1560 -1571.
AMA StyleS. Di Fraia, N. Massarotti, L. Vanoli, Michela Costa. Thermo-economic analysis of a novel cogeneration system for sewage sludge treatment. Energy. 2016; 115 ():1560-1571.
Chicago/Turabian StyleS. Di Fraia; N. Massarotti; L. Vanoli; Michela Costa. 2016. "Thermo-economic analysis of a novel cogeneration system for sewage sludge treatment." Energy 115, no. : 1560-1571.