saumitra saxena - Academia.edu (original) (raw)
Papers by saumitra saxena
Routledge eBooks, Apr 5, 2024
This chapter has been made available under a CC-BY-NC-ND 4.0 license. Introduction: coupling poll... more This chapter has been made available under a CC-BY-NC-ND 4.0 license. Introduction: coupling pollution mitigation with climate goals The environmental degradation of life-sustaining natural ecosystems and resources due to air pollution is closely interlinked with the adverse outcomes of climate change. While climate change is predominantly a result of air pollution from human activities (anthropogenic), it worsens air pollution at the same time, thereby creating a vicious cycle (Fuglestvedt et al. 2003; Jacob and Winner 2009; Masson-Delmotte et al. 2021; Watts et al. 2019). Natural emissions, dust, and wildfires, often the result of aggravated climate warming, affect air quality immensely. However, although climate change and air pollution are extensively discussed separately, their interactions and a holistic approach to tackle them are overlooked (Allan et al. 2021; OECD 2016; Rao et al. 2017). Anthropogenic air pollution is regulated worldwide by limiting criteria pollutants, hazardous air pollutants, and air toxic substances; however, greenhouse gases (GHGs) such as CO 2 and methane are excluded from this category. This leaves little motivation or financial incentive for those industries responsible for air pollution (e.g., emissions of particulate matter (PM), ozone, NO x , and SO 2) to reduce CO 2 emissions. Conversely, much of the discourse on reducing the carbon footprint and meeting net-zero targets does not consider air pollution aspects (Dreyfus et al. 2022; Masson-Delmotte et al. 2021; Sun et al. 2019). The imperative to address climate change and air pollution simultaneously is existential and necessary for all countries globally, irrespective of their development status or historic contribution to overall climate warming. Atmospheric aerosols and surface ozone (tropospheric) constitute the most climate-relevant air pollutants and act as near-term climate forcers (Fu and Tian 2019). The radiative forcing (RF) of these two primary forcing agents is the
Journal of Energy Resources Technology-transactions of The Asme, Apr 9, 2021
Waste heat recovery from power plants and industries requires a new type of electricity generator... more Waste heat recovery from power plants and industries requires a new type of electricity generator and related technological developments. The current research work is aimed at the design of a multi-kilowatt thermoacoustic electric generator, which can be employed as the bottoming cycle of a gas-turbine power plant or for industrial waste heat recovery. The proposed device converts thermal energy into acoustic power and subsequently uses a piezoelectric alternator to convert acoustic power into electricity. The challenge in designing such a device is that it has to be acoustically balanced. The performance of the device is greatly affected by numerous parameters such as frequency of the traveling acoustic wave, heat exchanger parameters, regenerator dimensions, acoustic feedback loop, etc. The proposed device is a lab-scale demonstration targeted to produce few kilowatts of electric power from a 20 kWth heat source. DeltaEC software is used to achieve the acoustically balanced configuration of the device. The DeltaEC model outcomes are used to arrive at the optimized design of the device and its components. The analytical method, the optimized geometrical dimensions of thermoacoustic components, and the minimum required conditions of heat source input are presented in this paper. 1
Separation and Purification Technology
Journal of Thermal Analysis and Calorimetry
Catalysis Today
Molecular characteristics of sulfur compounds in oxidative desulfurization for heavy fuel oil bas... more Molecular characteristics of sulfur compounds in oxidative desulfurization for heavy fuel oil based on APPI FT-ICR MS analysis. Catalysis Today.
Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power, 2021
Thermoacoustics (TA) engines and refrigerators typically run on the Stirling cycle with acoustic ... more Thermoacoustics (TA) engines and refrigerators typically run on the Stirling cycle with acoustic networks and resonators replacing the physical pistons. Without moving parts, these TA machines achieve a reasonable fraction of Carnot’s efficiency. They are also scalable, from fractions of a Watt up to kW of cooling. Despite their apparent promise, TA devices are not in widespread use, because outside of a few niche applications, their advantages are not quite compelling enough to dislodge established technology. In the present study, the authors have evaluated a selected group of applications that appear suitable for utilization of industrial waste heat using TA devices and have arrived at a ranked order. The principal thought is to appraise whether thermoacoustics can be a viable path, from both an economic and energy standpoint, for carbon mitigation in those applications. The applications considered include cryogenic carbon capture for power plant exhaust gases, waste-heat powered...
Journal of Fluid Mechanics, 2022
This study presents computational simulations of multicomponent and multiphase flows to reproduce... more This study presents computational simulations of multicomponent and multiphase flows to reproduce the physical phenomena in the secondary atomization of a droplet induced by a hot temperature environment. The computational fluid dynamics model is based on the geometric volume of fluid method, with piecewise linear interface calculation reconstruction for accurate determination of the curvature and evaporation fluxes at the interface. The purpose of the model was to faithfully reproduce complex physical processes, such as internal gas cavity formation, liquid–vapour interface instability, cavity collapse and liquid jet ejection, and the pinch-off of a secondary droplet, leading to the microexplosion phenomenon that greatly enhances the evaporation rate of non-volatile liquid droplets. The solver was validated against the analytical solution in benchmark cases, and experimental data with bicomponent droplets reported in the literature. The developed model was used to predict the atomi...
International Journal of Heat and Mass Transfer, 2021
Clean and efficient processing of heavy fuels is a major challenge for several combustion driven ... more Clean and efficient processing of heavy fuels is a major challenge for several combustion driven prime movers like internal combustion engines, used in marine or power generation sectors. Emulsification was recognized in the past as practical technology for heavy fuels combustion since it engenders an enabling phenomenon called micro-explosion that proceeds during the spray process. Micro-explosions allow finer secondary break-up, leading to improved mixing, and subsequent cleaner and fuller burning. However, the translation of this technology to real applications is still not fully exploited due to lack of basic understanding and characterization of the evaporation process which includes both micro-explosions and puffing. Ultrasonically induced cavitation is a promising technology for the production of water-in-oil emulsions at industrial scale. Fundamental research performed in the field of liquid fuels gasification and combustion mostly regards ideal or simple mixtures and not all the considerations made in these cases apply for real fuels. In this work, we investigated the evaporation characteristics of ultrasonically produced heavy fuel oil (HFO) emulsions with a set of newly developed methodologies. We characterized the emulsions by using a state-of-the-art microscopy technique, the Cryogenic Scanning Electron Microscopy, Cryo-SEM and obtained accurate droplet size distribution up to nano-scale. We tested the fuel emulsion in a suspended droplet experiment and reconstructed the interface from the obtained images. The normalized squared diameter profile is not representative of the complex physics involved in heavy fuel evaporation; therefore, it was substituted with the normalized distance of the interface from the centroid of the droplet. By using this procedure, it is possible to highlight both evaporation and stochastic events like puffing and ejections. A dimensionality reduction algorithm, the dynamic mode decomposition (DMD), was then performed on the evolving interface to highlight the main modes describing the emulsion system and the dynamics. The overall objective was to develop a strategy for optimizing emulsions for improved combustion performance. From the experimental data, it was observed that a water concentration of 5% by mass decreases the vaporization time of the mixture and that the presence of water favors puffing and ejections with different intensity depending on the percentage of water enhancing the volatilization of the fuel.
Waste heat recovery from power plants and industries requires a new type of electricity generator... more Waste heat recovery from power plants and industries requires a new type of electricity generators and related technological developments. The current research work is aimed at the design of a multi-kilowatt thermoacoustic electric generator, which can be employed as the bottoming cycle of a gas-turbine power plant or for industrial waste heat recovery. The proposed device converts thermal energy into acoustic power and subsequently uses a piezoelectric alternator to convert acoustic power into electricity. The challenge in designing such a device is that it has to be acoustically balanced and the performance of the device is greatly affected by numerous parameters such as frequency of the traveling acoustic wave, heat exchanger parameters, regenerator dimensions, acoustic feedback loop, etc. The proposed device is a lab-scale demonstration targeted to produce a few kilowatts of electric power from a 20 kWth heat source. To achieve the acoustically balanced configuration of the device, DeltaEC software is used. The DeltaEC model outcomes are used to arrive at the optimized design of the device and its components. The analytical method, the optimized geometrical dimensions of thermoacoustic components and the minimum required conditions of heat source input are presented in this paper.
The spray formation precedes combustion in all practical burners and constitutes the critical sta... more The spray formation precedes combustion in all practical burners and constitutes the critical stage, which eventually determines the efficiency of the combustion process and level of emissions. Modern CFD simulations of combustion resolve simplified sub-models for droplet evaporation and combustion within a Lagrangian framework. Break-up effects like puffing and microexplosions are usually neglected but they eventually influence the evaporation and combustion behavior of heavy fuel sprays. We are developing a Volume of Fluid (VoF)-based CFD solver that allows us to model single droplet differential evaporation with the break-up effects. Puffing/micro-explosion and droplet ejection proceed in three steps: nucleation of a bubble of a light component within the droplet, expansion/coalescence of the bubbles and finally eruption with sub-droplets formation. Our goal is to individually model each event and then combine them in a composite simulation. Henceforth we can get data in realistic conditions to be used in Lagrangian spray simulations. We identified three relevant features which are necessary to create a reliable representation: interface tracking, differential evaporation, and compressibility effect. The solver is based on the Volume of Fluid (VoF) technique and coded within the open-source OpenFOAM framework. VoF technique consists in transporting the volume fraction of one of the two phases (liquid or gas). The Navier-Stokes equations are solved for a single-phase but adapting the * Address all correspondence to this author. physical properties to the volume fraction value. A state-of-theart method called iso-Advector is used to reconstruct the interface from the volume fraction field. The evaporation has been implemented as a source term in the volume fraction equation, and the conservation equations have been modified accordingly. In order to calculate the vapour and liquid physical properties, we implemented RKS equation of state (EOS). The droplet is assumed to have 2 phases: light and heavy, having physical properties comparable to diesel and heavy fuel oil (HFO), respectively. The pressure closure equation has been modified to handle large pressure differences during internal evaporation of light component. The validation of the solver is performed through benchmark cases as multiphase shock-tube, droplet oscillation and boiling interface either with experimental works and analytical solutions. Single suspended droplet experiment was performed to measure the velocity of an ejected micro-droplet during puffing using a shadowgraphy technique. The code is able to predict ejection velocity within a 15% error, which seems to be promising. The present article documents part of the algorithm development and its validation for the aforementioned methodology.
Energy & Fuels, 2021
The research reported in this publication was partially supported by the Saudi Electricity Compan... more The research reported in this publication was partially supported by the Saudi Electricity Company (SEC) and the Clean Combustion Research Center (CCRC) of the King Abdullah University of Science and Technology (KAUST). The authors thank Drs. Long Jiang and Aiping Chen for their work on asphaltene separation and analytical chemistry. This research used resources of the Core Labs at the KAUST. We also thank Dr Wen Zhang for the FT ICR-MS analysis and Dr Salvedin Telalovic for the TGA–MS.
The environmental impact of the re-manufactured aluminium alloy (LM6) street lamp has been analys... more The environmental impact of the re-manufactured aluminium alloy (LM6) street lamp has been analysed. The results have been compared to the new housing lamp made of aluminium alloy (Al Si12Cu1{Fe}). The methodology used to calculate life cycle inventory and environmental impact is BEES V4.07 and Ecoinvent V3 was used as reference since it is the most updated database. The results show that the reworked aluminium lamp has an environmental impact of 2.38 pts and compared to that of alloy (Al Si12Cu1{Fe}) which has an impact of 2.56 pts. The first major factor is that the housing remanufacturing process does not consider the primary production processes of mining, extraction and casting. The new housing includes the primary production processes and casting thus impacting heavily on the environment. The second major factor that contributes to the lower impact of the remanufactured housing than the new housing is the low energy use since the housing is not remanufactured by re-casting whi...
Journal of Energy Resources Technology, 2020
In the present work, an experimental investigation on the effect of sulfur content in heavy fuel ... more In the present work, an experimental investigation on the effect of sulfur content in heavy fuel oil (HFO) on the gaseous emissions under swirling flame conditions was carried out. The sulfur content in HFO was varied by blending with ultra-low sulfur diesel and four fuel samples containing 3.15, 2.80, 1.97, and 0.52% sulfur (by mass) were prepared. Pure asphaltenes were added to the blends to ensure that the asphaltene content in the fuel remained the same. The fuels were then fired in a high-swirl stabilized, turbulent spray flame. The combustion performance of the fuels was evaluated by measuring flame temperature distribution, gaseous emissions (SOx, NOx, CO, CO2, and flue gas pH), and particulate matter (PM) emissions (morphology, composition, and pH). The results showed a significant reduction in the SO2 emissions and acidity of the flue gas when the sulfur content in the fuel was reduced, as expected. The reduction was more than would be expected based on sulfur content, howe...
Fuel Processing Technology, 2021
Abstract Heavy fuel oil (HFO) is a good alternative and economical fuel for power generation and ... more Abstract Heavy fuel oil (HFO) is a good alternative and economical fuel for power generation and marine transport industry because of its low price and high energy density. However, HFO's incomplete and complex combustion results in high levels of emissions. One way to improve HFO combustion and reduce its high-level pollutant emissions is by emulsifying HFO with water to form water-in-oil emulsion fuel by virtue of its characteristic of the micro-explosion phenomenon of emulsion fuel. In this work, we tested HFO samples with water contents of 0% (normal HFO), 5%, 10%, 20%, and 30% in mass. A lab-scale burner with an air-blast nozzle and swirling airflow was applied to simulate the industrial boiler's typical features. The properties of various water contents emulsion fuel, including composition, water droplet size distribution, heating value, density, viscosity, and TGA were analyzed. The influence of water-HFO emulsion on the swirling flame combustion performance and the primary pollutant emissions, listed as CO, CO2, NOx, SOx, particulate matter (PM), and its composition, was studied. The results show that, in general, multiple various beneficial processes come into effect when water-in-HFO emulsion augments the combustion. HFO emulsion technology offers tremendous potential to enhance combustion processes' efficiency with reduced SOx, NOx, and particulate matter emissions. The emulsion fuel has a considerable effect on the formation process of cenospheres. This effect varies with different water levels in HFO due to the different intensities of secondary atomization of emulsion fuel combustion.
Routledge eBooks, Apr 5, 2024
This chapter has been made available under a CC-BY-NC-ND 4.0 license. Introduction: coupling poll... more This chapter has been made available under a CC-BY-NC-ND 4.0 license. Introduction: coupling pollution mitigation with climate goals The environmental degradation of life-sustaining natural ecosystems and resources due to air pollution is closely interlinked with the adverse outcomes of climate change. While climate change is predominantly a result of air pollution from human activities (anthropogenic), it worsens air pollution at the same time, thereby creating a vicious cycle (Fuglestvedt et al. 2003; Jacob and Winner 2009; Masson-Delmotte et al. 2021; Watts et al. 2019). Natural emissions, dust, and wildfires, often the result of aggravated climate warming, affect air quality immensely. However, although climate change and air pollution are extensively discussed separately, their interactions and a holistic approach to tackle them are overlooked (Allan et al. 2021; OECD 2016; Rao et al. 2017). Anthropogenic air pollution is regulated worldwide by limiting criteria pollutants, hazardous air pollutants, and air toxic substances; however, greenhouse gases (GHGs) such as CO 2 and methane are excluded from this category. This leaves little motivation or financial incentive for those industries responsible for air pollution (e.g., emissions of particulate matter (PM), ozone, NO x , and SO 2) to reduce CO 2 emissions. Conversely, much of the discourse on reducing the carbon footprint and meeting net-zero targets does not consider air pollution aspects (Dreyfus et al. 2022; Masson-Delmotte et al. 2021; Sun et al. 2019). The imperative to address climate change and air pollution simultaneously is existential and necessary for all countries globally, irrespective of their development status or historic contribution to overall climate warming. Atmospheric aerosols and surface ozone (tropospheric) constitute the most climate-relevant air pollutants and act as near-term climate forcers (Fu and Tian 2019). The radiative forcing (RF) of these two primary forcing agents is the
Journal of Energy Resources Technology-transactions of The Asme, Apr 9, 2021
Waste heat recovery from power plants and industries requires a new type of electricity generator... more Waste heat recovery from power plants and industries requires a new type of electricity generator and related technological developments. The current research work is aimed at the design of a multi-kilowatt thermoacoustic electric generator, which can be employed as the bottoming cycle of a gas-turbine power plant or for industrial waste heat recovery. The proposed device converts thermal energy into acoustic power and subsequently uses a piezoelectric alternator to convert acoustic power into electricity. The challenge in designing such a device is that it has to be acoustically balanced. The performance of the device is greatly affected by numerous parameters such as frequency of the traveling acoustic wave, heat exchanger parameters, regenerator dimensions, acoustic feedback loop, etc. The proposed device is a lab-scale demonstration targeted to produce few kilowatts of electric power from a 20 kWth heat source. DeltaEC software is used to achieve the acoustically balanced configuration of the device. The DeltaEC model outcomes are used to arrive at the optimized design of the device and its components. The analytical method, the optimized geometrical dimensions of thermoacoustic components, and the minimum required conditions of heat source input are presented in this paper. 1
Separation and Purification Technology
Journal of Thermal Analysis and Calorimetry
Catalysis Today
Molecular characteristics of sulfur compounds in oxidative desulfurization for heavy fuel oil bas... more Molecular characteristics of sulfur compounds in oxidative desulfurization for heavy fuel oil based on APPI FT-ICR MS analysis. Catalysis Today.
Volume 4: Controls, Diagnostics, and Instrumentation; Cycle Innovations; Cycle Innovations: Energy Storage; Education; Electric Power, 2021
Thermoacoustics (TA) engines and refrigerators typically run on the Stirling cycle with acoustic ... more Thermoacoustics (TA) engines and refrigerators typically run on the Stirling cycle with acoustic networks and resonators replacing the physical pistons. Without moving parts, these TA machines achieve a reasonable fraction of Carnot’s efficiency. They are also scalable, from fractions of a Watt up to kW of cooling. Despite their apparent promise, TA devices are not in widespread use, because outside of a few niche applications, their advantages are not quite compelling enough to dislodge established technology. In the present study, the authors have evaluated a selected group of applications that appear suitable for utilization of industrial waste heat using TA devices and have arrived at a ranked order. The principal thought is to appraise whether thermoacoustics can be a viable path, from both an economic and energy standpoint, for carbon mitigation in those applications. The applications considered include cryogenic carbon capture for power plant exhaust gases, waste-heat powered...
Journal of Fluid Mechanics, 2022
This study presents computational simulations of multicomponent and multiphase flows to reproduce... more This study presents computational simulations of multicomponent and multiphase flows to reproduce the physical phenomena in the secondary atomization of a droplet induced by a hot temperature environment. The computational fluid dynamics model is based on the geometric volume of fluid method, with piecewise linear interface calculation reconstruction for accurate determination of the curvature and evaporation fluxes at the interface. The purpose of the model was to faithfully reproduce complex physical processes, such as internal gas cavity formation, liquid–vapour interface instability, cavity collapse and liquid jet ejection, and the pinch-off of a secondary droplet, leading to the microexplosion phenomenon that greatly enhances the evaporation rate of non-volatile liquid droplets. The solver was validated against the analytical solution in benchmark cases, and experimental data with bicomponent droplets reported in the literature. The developed model was used to predict the atomi...
International Journal of Heat and Mass Transfer, 2021
Clean and efficient processing of heavy fuels is a major challenge for several combustion driven ... more Clean and efficient processing of heavy fuels is a major challenge for several combustion driven prime movers like internal combustion engines, used in marine or power generation sectors. Emulsification was recognized in the past as practical technology for heavy fuels combustion since it engenders an enabling phenomenon called micro-explosion that proceeds during the spray process. Micro-explosions allow finer secondary break-up, leading to improved mixing, and subsequent cleaner and fuller burning. However, the translation of this technology to real applications is still not fully exploited due to lack of basic understanding and characterization of the evaporation process which includes both micro-explosions and puffing. Ultrasonically induced cavitation is a promising technology for the production of water-in-oil emulsions at industrial scale. Fundamental research performed in the field of liquid fuels gasification and combustion mostly regards ideal or simple mixtures and not all the considerations made in these cases apply for real fuels. In this work, we investigated the evaporation characteristics of ultrasonically produced heavy fuel oil (HFO) emulsions with a set of newly developed methodologies. We characterized the emulsions by using a state-of-the-art microscopy technique, the Cryogenic Scanning Electron Microscopy, Cryo-SEM and obtained accurate droplet size distribution up to nano-scale. We tested the fuel emulsion in a suspended droplet experiment and reconstructed the interface from the obtained images. The normalized squared diameter profile is not representative of the complex physics involved in heavy fuel evaporation; therefore, it was substituted with the normalized distance of the interface from the centroid of the droplet. By using this procedure, it is possible to highlight both evaporation and stochastic events like puffing and ejections. A dimensionality reduction algorithm, the dynamic mode decomposition (DMD), was then performed on the evolving interface to highlight the main modes describing the emulsion system and the dynamics. The overall objective was to develop a strategy for optimizing emulsions for improved combustion performance. From the experimental data, it was observed that a water concentration of 5% by mass decreases the vaporization time of the mixture and that the presence of water favors puffing and ejections with different intensity depending on the percentage of water enhancing the volatilization of the fuel.
Waste heat recovery from power plants and industries requires a new type of electricity generator... more Waste heat recovery from power plants and industries requires a new type of electricity generators and related technological developments. The current research work is aimed at the design of a multi-kilowatt thermoacoustic electric generator, which can be employed as the bottoming cycle of a gas-turbine power plant or for industrial waste heat recovery. The proposed device converts thermal energy into acoustic power and subsequently uses a piezoelectric alternator to convert acoustic power into electricity. The challenge in designing such a device is that it has to be acoustically balanced and the performance of the device is greatly affected by numerous parameters such as frequency of the traveling acoustic wave, heat exchanger parameters, regenerator dimensions, acoustic feedback loop, etc. The proposed device is a lab-scale demonstration targeted to produce a few kilowatts of electric power from a 20 kWth heat source. To achieve the acoustically balanced configuration of the device, DeltaEC software is used. The DeltaEC model outcomes are used to arrive at the optimized design of the device and its components. The analytical method, the optimized geometrical dimensions of thermoacoustic components and the minimum required conditions of heat source input are presented in this paper.
The spray formation precedes combustion in all practical burners and constitutes the critical sta... more The spray formation precedes combustion in all practical burners and constitutes the critical stage, which eventually determines the efficiency of the combustion process and level of emissions. Modern CFD simulations of combustion resolve simplified sub-models for droplet evaporation and combustion within a Lagrangian framework. Break-up effects like puffing and microexplosions are usually neglected but they eventually influence the evaporation and combustion behavior of heavy fuel sprays. We are developing a Volume of Fluid (VoF)-based CFD solver that allows us to model single droplet differential evaporation with the break-up effects. Puffing/micro-explosion and droplet ejection proceed in three steps: nucleation of a bubble of a light component within the droplet, expansion/coalescence of the bubbles and finally eruption with sub-droplets formation. Our goal is to individually model each event and then combine them in a composite simulation. Henceforth we can get data in realistic conditions to be used in Lagrangian spray simulations. We identified three relevant features which are necessary to create a reliable representation: interface tracking, differential evaporation, and compressibility effect. The solver is based on the Volume of Fluid (VoF) technique and coded within the open-source OpenFOAM framework. VoF technique consists in transporting the volume fraction of one of the two phases (liquid or gas). The Navier-Stokes equations are solved for a single-phase but adapting the * Address all correspondence to this author. physical properties to the volume fraction value. A state-of-theart method called iso-Advector is used to reconstruct the interface from the volume fraction field. The evaporation has been implemented as a source term in the volume fraction equation, and the conservation equations have been modified accordingly. In order to calculate the vapour and liquid physical properties, we implemented RKS equation of state (EOS). The droplet is assumed to have 2 phases: light and heavy, having physical properties comparable to diesel and heavy fuel oil (HFO), respectively. The pressure closure equation has been modified to handle large pressure differences during internal evaporation of light component. The validation of the solver is performed through benchmark cases as multiphase shock-tube, droplet oscillation and boiling interface either with experimental works and analytical solutions. Single suspended droplet experiment was performed to measure the velocity of an ejected micro-droplet during puffing using a shadowgraphy technique. The code is able to predict ejection velocity within a 15% error, which seems to be promising. The present article documents part of the algorithm development and its validation for the aforementioned methodology.
Energy & Fuels, 2021
The research reported in this publication was partially supported by the Saudi Electricity Compan... more The research reported in this publication was partially supported by the Saudi Electricity Company (SEC) and the Clean Combustion Research Center (CCRC) of the King Abdullah University of Science and Technology (KAUST). The authors thank Drs. Long Jiang and Aiping Chen for their work on asphaltene separation and analytical chemistry. This research used resources of the Core Labs at the KAUST. We also thank Dr Wen Zhang for the FT ICR-MS analysis and Dr Salvedin Telalovic for the TGA–MS.
The environmental impact of the re-manufactured aluminium alloy (LM6) street lamp has been analys... more The environmental impact of the re-manufactured aluminium alloy (LM6) street lamp has been analysed. The results have been compared to the new housing lamp made of aluminium alloy (Al Si12Cu1{Fe}). The methodology used to calculate life cycle inventory and environmental impact is BEES V4.07 and Ecoinvent V3 was used as reference since it is the most updated database. The results show that the reworked aluminium lamp has an environmental impact of 2.38 pts and compared to that of alloy (Al Si12Cu1{Fe}) which has an impact of 2.56 pts. The first major factor is that the housing remanufacturing process does not consider the primary production processes of mining, extraction and casting. The new housing includes the primary production processes and casting thus impacting heavily on the environment. The second major factor that contributes to the lower impact of the remanufactured housing than the new housing is the low energy use since the housing is not remanufactured by re-casting whi...
Journal of Energy Resources Technology, 2020
In the present work, an experimental investigation on the effect of sulfur content in heavy fuel ... more In the present work, an experimental investigation on the effect of sulfur content in heavy fuel oil (HFO) on the gaseous emissions under swirling flame conditions was carried out. The sulfur content in HFO was varied by blending with ultra-low sulfur diesel and four fuel samples containing 3.15, 2.80, 1.97, and 0.52% sulfur (by mass) were prepared. Pure asphaltenes were added to the blends to ensure that the asphaltene content in the fuel remained the same. The fuels were then fired in a high-swirl stabilized, turbulent spray flame. The combustion performance of the fuels was evaluated by measuring flame temperature distribution, gaseous emissions (SOx, NOx, CO, CO2, and flue gas pH), and particulate matter (PM) emissions (morphology, composition, and pH). The results showed a significant reduction in the SO2 emissions and acidity of the flue gas when the sulfur content in the fuel was reduced, as expected. The reduction was more than would be expected based on sulfur content, howe...
Fuel Processing Technology, 2021
Abstract Heavy fuel oil (HFO) is a good alternative and economical fuel for power generation and ... more Abstract Heavy fuel oil (HFO) is a good alternative and economical fuel for power generation and marine transport industry because of its low price and high energy density. However, HFO's incomplete and complex combustion results in high levels of emissions. One way to improve HFO combustion and reduce its high-level pollutant emissions is by emulsifying HFO with water to form water-in-oil emulsion fuel by virtue of its characteristic of the micro-explosion phenomenon of emulsion fuel. In this work, we tested HFO samples with water contents of 0% (normal HFO), 5%, 10%, 20%, and 30% in mass. A lab-scale burner with an air-blast nozzle and swirling airflow was applied to simulate the industrial boiler's typical features. The properties of various water contents emulsion fuel, including composition, water droplet size distribution, heating value, density, viscosity, and TGA were analyzed. The influence of water-HFO emulsion on the swirling flame combustion performance and the primary pollutant emissions, listed as CO, CO2, NOx, SOx, particulate matter (PM), and its composition, was studied. The results show that, in general, multiple various beneficial processes come into effect when water-in-HFO emulsion augments the combustion. HFO emulsion technology offers tremendous potential to enhance combustion processes' efficiency with reduced SOx, NOx, and particulate matter emissions. The emulsion fuel has a considerable effect on the formation process of cenospheres. This effect varies with different water levels in HFO due to the different intensities of secondary atomization of emulsion fuel combustion.