The discharge of textile wastewater into aquatic streams is considered a major challenge due to i... more The discharge of textile wastewater into aquatic streams is considered a major challenge due to its effect on the water ecosystem. Direct blue 78 (DB78) dye has a complex structure. Therefore, it is difficult to separate it from industrial wastewater. In this study, carbon obtained from the pyrolysis of mixed palm seeds under different temperatures (400 °C and 1000 °C) was activated by a thermochemical method by using microwave radiation and an HCl solution in order to improve its adsorption characteristics. The generated activated carbon was used to synthesize a novel activated carbon/chitosan microbead (ACMB) for dye removal from textile wastewater. The obtained activated carbon (AC) was characterized by a physicochemical analysis that included, namely, particle size, zeta potential, SEM, EDX, and FTIR analyses. A series of batch experiments were conducted in terms of the ACMB dose, contact time, pH, and activated carbon/chitosan ratios in synthetic microbeads for enhancing the ad...
Pyrolysis has been demonstrated to be a highly effective thermochemical process for converting co... more Pyrolysis has been demonstrated to be a highly effective thermochemical process for converting complex biomaterials into biochar and syngas rich in hydrogen. The pyrolysis of mixed date palm seeds from Saudi Arabia was conducted using a fixed-bed pyrolyzer that was custom made for the purpose. The influence of the pyrolysis temperature (200–1000 °C) on the various physicochemical parameters of the date seed biochar generated through the pyrolysis process and the hydrogen-rich syngas was investigated. Proximate and ultimate analyses indicated a high carbon content in the lignocellulosic constituents such as cellulose, hemicellulose, and lignin. Using energy-dispersive X-ray (EDX) analysis, it was discovered that the elemental composition of biochar changes with the pyrolysis temperature. The date seeds pyrolyzed at 800 °C were found to have the maximum carbon concentration, with 97.99% of the total carbon content. The analysis of the biochar indicated a high concentration of carbon, ...
Global Journal of Energy Technology Research Updates, 2020
The Ejector refrigeration system can operate using renewable energy such as solar or wasted heat... more The Ejector refrigeration system can operate using renewable energy such as solar or wasted heat. A mathematical model for an ejector refrigeration system powered by solar energy was developed. The Ejector refrigeration system depends on many factors, such as ejector geometry, NXP, and operating conditions. A flat plate solar collector is designed to predict the heat transfer performance for the whole system, and the primary factors affecting the heat transfer performance. Outlet temperature of 134.95 °C was achieved from the setup of five solar collectors (two square meters each) when the solar irradiance was 985.69 W/m2. The water needs total power of 5016 W to reach this temperature.
It all starts or fails with energy managers! No energy manager in a firm means no voice to invest... more It all starts or fails with energy managers! No energy manager in a firm means no voice to invest in energy efficiency. No voice implies no annual budget for energy conservation measures. Having no annual budget means no energy efficiency measures are implemented. No implementation results in less profit and no energy cost reduction. It is expected from an energy manger to follow a sequential and iterative procedure and suggest design improvements in existing energy systems. In line with the Government‟s effort to be more energy efficient as indicated within the Strategic Plans of Saudi Arabia, the Energy Efficiency (EE) programmes would focus especially in the industrial and commercial sectors. With the proposed introduction of Efficient Management of Electrical Energy Regulation, amendments to the Uniform Building By-laws, labelling of electrical appliances and the use of high-efficient motors, the focus on energy efficiency within the commercial and industrial sector would be fur...
The thermochemical processes such as gasification and co-gasification of biomass and coal are pro... more The thermochemical processes such as gasification and co-gasification of biomass and coal are promising route for producing hydrogen-rich syngas. However, the process is characterized with complex reactions that pose a tremendous challenge in terms of controlling the process variables. This challenge can be overcome using appropriate machine learning algorithm to model the nonlinear complex relationship between the predictors and the targeted response. Hence, this study aimed to employ various machine learning algorithms such as regression models, support vector machine regression (SVM), gaussian processing regression (GPR), and artificial neural networks (ANN) for modeling hydrogen-rich syngas production by gasification and co-gasification of biomass and coal. A total of 12 machine learning algorithms which comprises the regression models, SVM, GPR, and ANN were configured, trained using 124 datasets. The performances of the algorithms were evaluated using the coefficient of determination (R2), root mean square error (RMSE), mean square error (MSE), and mean absolute error (MAE). In all cases, the ANN algorithms offer superior performances and displayed robust predictions of the hydrogen-rich syngas from the co-gasification processes. The R2 of both the Levenberg-Marquardt- and Bayesian Regularization-trained ANN obtained from the prediction of the hydrogen-rich syngas was found to be within 0.857-0.998 with low prediction errors. The sensitivity analysis to determine the effect of the process parameters on the model output revealed that all the parameters showed a varying level of influence. In most of the processes, the gasification temperature was found to have the most significant influence on the model output.
Sustainable Energy Technologies and Assessments, 2021
Abstract In this research, numerical study of the effect of curved turbulators on the exergy effi... more Abstract In this research, numerical study of the effect of curved turbulators on the exergy efficiency of solar collector (SC) with two-phase hybrid nanofluid (TPHN) has been addressed. The MWCNT-TiO2-water hybrid nanofluid is modeled as two-phase, and the Eulerian-Eulerian model is used to model it. The numerical study has been performed for different concentrations, Reynolds numbers (Re), turbulator curvature angles, and lateral ratios with respect to the curved turbulator under turbulent flow regime. The k-epsilon turbulence model has been used to model the turbulent flow. Based on the results, an increase in both Re and φ increases the exergy efficiency at both turbulator curvatures. Furthermore, with an increase in the lateral ratio of the curved turbulators, the exergy efficiency decreases. For both turbulator curvatures, At a lateral ratio of 14 mm and φ = 3%, the exergy efficiency intensifies by 23.26% with an increase in Re from 4000 to 18000. On the other hand, the exergy efficiency falls with a rise in the lateral ratio. For instance, at a constant volume fraction of 3% and a Re = 18000, the exergy efficiency reduces by 18.87% with an increase in the lateral ratio from 14 mm to 20 mm.
ABSTRACT Circulating fluidized bed combustion (CFBC) technology is being used for few decades to ... more ABSTRACT Circulating fluidized bed combustion (CFBC) technology is being used for few decades to burn biomass wastes while meeting the stringent emission standards; however, much is needed to be understood about the complex flow patterns that are encountered. This work is aimed at understanding the major fluidization characteristics in a CFB loop for palm shell waste powders. Effects of inlet air on the fluidization behavior were experimentally investigated. The voidage of the bed material was found to be a function of axial distance above the distributor. The CFD modeling has also been done to quantify the riser exit effects. The flow was simulated using the “algebraic slip mixture (ASM)” model. In the simulation results the deviation of velocity contours owing to variation in riser exit geometries is discussed. It was found that the influence is found to be significant in the upper region of the riser column and the velocity contours are also swayed by the exit geometry.
Cold thermal storage can be used to manage peak load when the energy demand is exceeding the capa... more Cold thermal storage can be used to manage peak load when the energy demand is exceeding the capacities of the electric companies. Latent heat thermal storage is more effective because it requires less spacing and has higher thermal capacity than other types. Solidification and melting are taking place in CTS and need more investigation for better performance. Phase change materials properties vary and need more investigation to select the most suitable for a certain application. The analytical equations are needed for design of CTS and get the maximum efficiency out of it. Cost effectiveness is also described.
The robust growth in population and gross domestic product (GDP) for Gulf Countries (GC) has led ... more The robust growth in population and gross domestic product (GDP) for Gulf Countries (GC) has led to negative side-effects such as power shortages and environmental pollution. Therefore, it is necessary for GC to have quick actions to preserve their energy resources and protect their environment. The current paper identifies the main energy conservation strategies that were widely adopted in GC. The efforts that were conducted by GC to manage the energy consumption and to establish the required regulations are presented. The paper also investigates possibilities for the use of alternative sources of clean energy that might avoid the disadvantages of the conventional sources of energy. It is found that in order to protect the environment and the maintain the fossil fuel wealth for longer time, long term strategies must be implemented, and alternative sources of renewable energy must be utilized.
International Journal of Engineering Pedagogy (iJEP)
It is compulsory for final-year undergraduate engineering students to take a senior design class,... more It is compulsory for final-year undergraduate engineering students to take a senior design class, commonly known as the senior capstone design project. This project is set up to help students deeply understand and apply what they have learned since beginning their quest for a bachelor’s degree in science. Capstone preparation involves many elements including the contribution of faculty members and academic programs that give students the technical and management skills needed to establish a career in engineering. Moreover, the capstone usually requires funding, which often comes from the industry sector. The engineering faculty at King Abdulaziz University (KAU) encourages students to complete this course showing high-quality levels of achievement. The university’s mechanical engineering department led the effort in organizing the senior design project course, which meets the Accreditation Board for Engineering and Technology (ABET) requirements. This paper presents an overview of a...
Falling film heat exchanger is widely used in the industry, because of its high heat transfer coe... more Falling film heat exchanger is widely used in the industry, because of its high heat transfer coefficient, low liquid quantity and lower fouling factor. The heat exchanger considered here is a falling film one. It consists of a unique feeding tube, supply liquid such as pure water over seven parallel horizontal tubes which are heated internally. Convection heat transfer takes place outside the tubes surface and it is experimentally investigated. The falling film over the test tubes may be in the form of a droplet, jet or sheet. A combination of these forms is also possible. The tested tubes are made of copper and have 28.5 mm outer diameter and 300 mm length, each. They are arranged in series so that heated water enters each tube with the same flow rate, from bottom to top. The temperatures at the entrance and exit of the hot water flow and the falling film liquid are recorded. Also, the average surface temperature at one test tube is measured using five impeded thermocouples. An in...
The discharge of textile wastewater into aquatic streams is considered a major challenge due to i... more The discharge of textile wastewater into aquatic streams is considered a major challenge due to its effect on the water ecosystem. Direct blue 78 (DB78) dye has a complex structure. Therefore, it is difficult to separate it from industrial wastewater. In this study, carbon obtained from the pyrolysis of mixed palm seeds under different temperatures (400 °C and 1000 °C) was activated by a thermochemical method by using microwave radiation and an HCl solution in order to improve its adsorption characteristics. The generated activated carbon was used to synthesize a novel activated carbon/chitosan microbead (ACMB) for dye removal from textile wastewater. The obtained activated carbon (AC) was characterized by a physicochemical analysis that included, namely, particle size, zeta potential, SEM, EDX, and FTIR analyses. A series of batch experiments were conducted in terms of the ACMB dose, contact time, pH, and activated carbon/chitosan ratios in synthetic microbeads for enhancing the ad...
Pyrolysis has been demonstrated to be a highly effective thermochemical process for converting co... more Pyrolysis has been demonstrated to be a highly effective thermochemical process for converting complex biomaterials into biochar and syngas rich in hydrogen. The pyrolysis of mixed date palm seeds from Saudi Arabia was conducted using a fixed-bed pyrolyzer that was custom made for the purpose. The influence of the pyrolysis temperature (200–1000 °C) on the various physicochemical parameters of the date seed biochar generated through the pyrolysis process and the hydrogen-rich syngas was investigated. Proximate and ultimate analyses indicated a high carbon content in the lignocellulosic constituents such as cellulose, hemicellulose, and lignin. Using energy-dispersive X-ray (EDX) analysis, it was discovered that the elemental composition of biochar changes with the pyrolysis temperature. The date seeds pyrolyzed at 800 °C were found to have the maximum carbon concentration, with 97.99% of the total carbon content. The analysis of the biochar indicated a high concentration of carbon, ...
Global Journal of Energy Technology Research Updates, 2020
The Ejector refrigeration system can operate using renewable energy such as solar or wasted heat... more The Ejector refrigeration system can operate using renewable energy such as solar or wasted heat. A mathematical model for an ejector refrigeration system powered by solar energy was developed. The Ejector refrigeration system depends on many factors, such as ejector geometry, NXP, and operating conditions. A flat plate solar collector is designed to predict the heat transfer performance for the whole system, and the primary factors affecting the heat transfer performance. Outlet temperature of 134.95 °C was achieved from the setup of five solar collectors (two square meters each) when the solar irradiance was 985.69 W/m2. The water needs total power of 5016 W to reach this temperature.
It all starts or fails with energy managers! No energy manager in a firm means no voice to invest... more It all starts or fails with energy managers! No energy manager in a firm means no voice to invest in energy efficiency. No voice implies no annual budget for energy conservation measures. Having no annual budget means no energy efficiency measures are implemented. No implementation results in less profit and no energy cost reduction. It is expected from an energy manger to follow a sequential and iterative procedure and suggest design improvements in existing energy systems. In line with the Government‟s effort to be more energy efficient as indicated within the Strategic Plans of Saudi Arabia, the Energy Efficiency (EE) programmes would focus especially in the industrial and commercial sectors. With the proposed introduction of Efficient Management of Electrical Energy Regulation, amendments to the Uniform Building By-laws, labelling of electrical appliances and the use of high-efficient motors, the focus on energy efficiency within the commercial and industrial sector would be fur...
The thermochemical processes such as gasification and co-gasification of biomass and coal are pro... more The thermochemical processes such as gasification and co-gasification of biomass and coal are promising route for producing hydrogen-rich syngas. However, the process is characterized with complex reactions that pose a tremendous challenge in terms of controlling the process variables. This challenge can be overcome using appropriate machine learning algorithm to model the nonlinear complex relationship between the predictors and the targeted response. Hence, this study aimed to employ various machine learning algorithms such as regression models, support vector machine regression (SVM), gaussian processing regression (GPR), and artificial neural networks (ANN) for modeling hydrogen-rich syngas production by gasification and co-gasification of biomass and coal. A total of 12 machine learning algorithms which comprises the regression models, SVM, GPR, and ANN were configured, trained using 124 datasets. The performances of the algorithms were evaluated using the coefficient of determination (R2), root mean square error (RMSE), mean square error (MSE), and mean absolute error (MAE). In all cases, the ANN algorithms offer superior performances and displayed robust predictions of the hydrogen-rich syngas from the co-gasification processes. The R2 of both the Levenberg-Marquardt- and Bayesian Regularization-trained ANN obtained from the prediction of the hydrogen-rich syngas was found to be within 0.857-0.998 with low prediction errors. The sensitivity analysis to determine the effect of the process parameters on the model output revealed that all the parameters showed a varying level of influence. In most of the processes, the gasification temperature was found to have the most significant influence on the model output.
Sustainable Energy Technologies and Assessments, 2021
Abstract In this research, numerical study of the effect of curved turbulators on the exergy effi... more Abstract In this research, numerical study of the effect of curved turbulators on the exergy efficiency of solar collector (SC) with two-phase hybrid nanofluid (TPHN) has been addressed. The MWCNT-TiO2-water hybrid nanofluid is modeled as two-phase, and the Eulerian-Eulerian model is used to model it. The numerical study has been performed for different concentrations, Reynolds numbers (Re), turbulator curvature angles, and lateral ratios with respect to the curved turbulator under turbulent flow regime. The k-epsilon turbulence model has been used to model the turbulent flow. Based on the results, an increase in both Re and φ increases the exergy efficiency at both turbulator curvatures. Furthermore, with an increase in the lateral ratio of the curved turbulators, the exergy efficiency decreases. For both turbulator curvatures, At a lateral ratio of 14 mm and φ = 3%, the exergy efficiency intensifies by 23.26% with an increase in Re from 4000 to 18000. On the other hand, the exergy efficiency falls with a rise in the lateral ratio. For instance, at a constant volume fraction of 3% and a Re = 18000, the exergy efficiency reduces by 18.87% with an increase in the lateral ratio from 14 mm to 20 mm.
ABSTRACT Circulating fluidized bed combustion (CFBC) technology is being used for few decades to ... more ABSTRACT Circulating fluidized bed combustion (CFBC) technology is being used for few decades to burn biomass wastes while meeting the stringent emission standards; however, much is needed to be understood about the complex flow patterns that are encountered. This work is aimed at understanding the major fluidization characteristics in a CFB loop for palm shell waste powders. Effects of inlet air on the fluidization behavior were experimentally investigated. The voidage of the bed material was found to be a function of axial distance above the distributor. The CFD modeling has also been done to quantify the riser exit effects. The flow was simulated using the “algebraic slip mixture (ASM)” model. In the simulation results the deviation of velocity contours owing to variation in riser exit geometries is discussed. It was found that the influence is found to be significant in the upper region of the riser column and the velocity contours are also swayed by the exit geometry.
Cold thermal storage can be used to manage peak load when the energy demand is exceeding the capa... more Cold thermal storage can be used to manage peak load when the energy demand is exceeding the capacities of the electric companies. Latent heat thermal storage is more effective because it requires less spacing and has higher thermal capacity than other types. Solidification and melting are taking place in CTS and need more investigation for better performance. Phase change materials properties vary and need more investigation to select the most suitable for a certain application. The analytical equations are needed for design of CTS and get the maximum efficiency out of it. Cost effectiveness is also described.
The robust growth in population and gross domestic product (GDP) for Gulf Countries (GC) has led ... more The robust growth in population and gross domestic product (GDP) for Gulf Countries (GC) has led to negative side-effects such as power shortages and environmental pollution. Therefore, it is necessary for GC to have quick actions to preserve their energy resources and protect their environment. The current paper identifies the main energy conservation strategies that were widely adopted in GC. The efforts that were conducted by GC to manage the energy consumption and to establish the required regulations are presented. The paper also investigates possibilities for the use of alternative sources of clean energy that might avoid the disadvantages of the conventional sources of energy. It is found that in order to protect the environment and the maintain the fossil fuel wealth for longer time, long term strategies must be implemented, and alternative sources of renewable energy must be utilized.
International Journal of Engineering Pedagogy (iJEP)
It is compulsory for final-year undergraduate engineering students to take a senior design class,... more It is compulsory for final-year undergraduate engineering students to take a senior design class, commonly known as the senior capstone design project. This project is set up to help students deeply understand and apply what they have learned since beginning their quest for a bachelor’s degree in science. Capstone preparation involves many elements including the contribution of faculty members and academic programs that give students the technical and management skills needed to establish a career in engineering. Moreover, the capstone usually requires funding, which often comes from the industry sector. The engineering faculty at King Abdulaziz University (KAU) encourages students to complete this course showing high-quality levels of achievement. The university’s mechanical engineering department led the effort in organizing the senior design project course, which meets the Accreditation Board for Engineering and Technology (ABET) requirements. This paper presents an overview of a...
Falling film heat exchanger is widely used in the industry, because of its high heat transfer coe... more Falling film heat exchanger is widely used in the industry, because of its high heat transfer coefficient, low liquid quantity and lower fouling factor. The heat exchanger considered here is a falling film one. It consists of a unique feeding tube, supply liquid such as pure water over seven parallel horizontal tubes which are heated internally. Convection heat transfer takes place outside the tubes surface and it is experimentally investigated. The falling film over the test tubes may be in the form of a droplet, jet or sheet. A combination of these forms is also possible. The tested tubes are made of copper and have 28.5 mm outer diameter and 300 mm length, each. They are arranged in series so that heated water enters each tube with the same flow rate, from bottom to top. The temperatures at the entrance and exit of the hot water flow and the falling film liquid are recorded. Also, the average surface temperature at one test tube is measured using five impeded thermocouples. An in...
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