Seham El-Temtamy | EPRI - Academia.edu (original) (raw)

Papers by Seham El-Temtamy

European journal of applied microbiology and biotechnology, 1982

Baker's yeast was aerobically grown in gaseous fluidized beds in the form of solid particles. Air... more Baker's yeast was aerobically grown in gaseous fluidized beds in the form of solid particles. Air was used as the fiuidizing fluid and as a source of oxygen, while the concentrated nutrient solution was sprayed at the top of the bed. Five glucose concentrations 125,160, 200,250 und 350 g 1-1 were used. A maximum in the growth rate and in the yield coefficient occurred at 250 and 200 g 1-1 , respectively. The calculated growth rates are one order of magnitude less than the growth rates in submerged cultures, but the maintenance energy coefficient is the same in both systems. Alcohol ppm level in the exhaust gases increased with increasing glucose concentration in the nutrient solution. Oscillations in the alcohol produc

Chemical Engineering & Technology, Apr 19, 2022

The Box‐Behnken experimental design method was applied to study optimization of dry reforming of ... more The Box‐Behnken experimental design method was applied to study optimization of dry reforming of methane over a magnesia‐supported nickel catalyst (Ni/MgO). The catalyst was prepared by impregnation method and characterized using Brunauer‐Emmett‐Teller analysis, X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy. Response surface methodology (RSM) modified by the Box‐Cox method was applied to investigate the effect of different operating parameters on conversion and formation of the different components of the reaction system. The RSM‐generated predictive models verified by analysis of variance were used to simulate the responses of the operating variables. This study revealed that the reaction temperature has the most pronounced effect followed by the CO2/CH4 mole ratio while the gas hourly space velocity had a negligible impact.

Process integration (PI) techniques is an efficient approach to increase the profitability due to... more Process integration (PI) techniques is an efficient approach to increase the profitability due to reduction in energy, water and raw materials consumption, reduction in greenhouse gas (GHG) emissions, and in waste generation. The PI method, pinch technology is certainly the most widely used in industrial processes. When planning a new plant or revamping an existing plant it is very important to understand and select the right process to minimize capital and operating costs. This research was directed to investigate the reduction of energy consumption in propane recovery units that process natural gas produced from wells existing in the Egyptian western desert fields. The first step was process simulation of the existing gas processing plant using AspenHysys8.3 steady state process simulation program. Next, pinch technology has been adopted in order to achieve minimum hot and cold utilities and save capital cost of the process. Target utilities were calculated using pinch analysis in...

Petroleum Science and Technology, 2009

Abstract The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO + H2) has been... more Abstract The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO + H2) has been investigated using 2 g of 0.5% wt of each of the catalysts; rhodium, ruthenium and iridium supported on γ-alumina. The experiments were carried out in a tubular reactor at three temperature levels namely 600, 700, 800°C and four gas weight hourly space velocities; 18000, 36000, 45000, and 60000 ml g−1 h−1. The reaction was found to obey first-order kinetics for the depletion of both of the reacting components; CH4 and CO2 on all the investigated catalysts. At the same temperature, CO2 had a higher reaction rate constant, k', as compared to CH4 for all the catalysts. This was more pronounced for Rh/γ-alumina catalyst, which occupied the highest reaction rates. Activation Energies were calculated from the Arrhenius relation.

Egyptian Journal of Petroleum, 2013

Biofuels are particularly important as an alternative fuel option for transportation. The sustain... more Biofuels are particularly important as an alternative fuel option for transportation. The sustainability of biofuels will depend on the development of viable, sustainable technologies that do not appear to be yet commercially viable. Successful development of algae-based biofuels and coproducts industry requires the optimum combination of technical innovations in systems and processes, coupled with economic feasibility in the practical implementation and integrated scale-up for commercial production and marketing. This article discusses the importance of algae-based biofuels together with the different opinions regarding its future. Advantages and disadvantages of these types of biofuels are presented. Algal growth drives around the world with special emphasis to Egypt are outlined. The article includes a brief description of the concept of algal biorefineries. It also declares the five key strategies to help producers to reduce costs and accelerate the commercialization of algal biodiesel. The internal strengths and weaknesses, and external opportunities, and threats are manifested through the SWOT analysis for micro-algae. Strategies for enhancing algae based-fuels are outlined. New process innovations and the role of genetic engineering in meeting these strategies are briefly discussed. To improve the economics of algal biofuels the concept of employing algae for wastewater treatment is presented.

3 Abstract: In this study, the effect of different C-sources as a co-substrate to enhance DBT-bio... more 3 Abstract: In this study, the effect of different C-sources as a co-substrate to enhance DBT-biodesulfurization using the newly isolated strain, Brevibacillus invocatusC19 and Rhodococcus erythropolis IGTS8 showed that glucose and glycerol expressed the highest biodesulfurization efficiency of 1000 ppm DBT, respectively. Based on five levels full factorial design, a statistical design of experiments was used to investigate two cases of DBT-biodesulfurization in batch processes, involving as factors yeast extract and glucose or glycerol for C19 and IGTS8, respectively. Cubic and quadratic predictive models significantly describing the interactive relationships between dependent and independent variables were established for C19 and IGTS8, respectively.

The Egyptian Journal of Chemistry, 2021

Biosciences, Biotechnology Research Asia, 2019

Fluidization, 1980

Particle entrainment in the freeboard region above a cocurrent gas-liquid fluidized bed arises la... more Particle entrainment in the freeboard region above a cocurrent gas-liquid fluidized bed arises largely as a result of the solids carried in the wakes of the gas bubbles leaving the bed. It is by the periodic wake-shedding which takes place in the freeboard that de-entrainment gradually occurs. This freeboard phenomenon is modelled as a stagewise partition process. The predictions of the model are compared with solids entrainment as obtained from measured axial pressure profiles in the freeboard of air-water fluidized beds of glass beads, for three bead sizes and different air and water velocities. Agreement with the experimental data is good.

World Renewable Energy Congress VI, 2000

Publisher Summary This chapter discusses the transportation cost of natural gas. The cost include... more Publisher Summary This chapter discusses the transportation cost of natural gas. The cost includes the construction costs of pipelines, and gas pressure reduction stations. Actual cost data for pipelines and pressure reduction stations are collected and processed. Empirical equations describing the construction cost are also obtained. Comparison between calculated and actual values reveals the reasonable accuracy of the proposed equations for such projects. Split of the capital investment indicates that pipelines cut out the lion's share (93%) against 7% for the pressure reduction stations. Pipelines material represents 49% of the total construction cost, followed by labors cost (28%), and wrapping cost (18%). All other items together represent around 5%.

Petroleum Science and Technology, 2009

The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO C H2) has been investig... more The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO C H2) has been investigated using 2 g of 0.5% wt of each of the catalysts; rhodium, ruthenium and iridium supported on -alumina. The experiments were carried out in a tubular reactor at three temperature levels namely 600, 700, 800ıC and four gas weight hourly space velocities; 18000, 36000, 45000, and 60000 ml g􀀀1 h􀀀1. The reaction was found to obey first-order kinetics for the depletion of both of the reacting components; CH4 and CO2 on all the investigated catalysts. At the same temperature, CO2 had a higher reaction rate constant, k0, as compared to CH4 for all the catalysts. This was more pronounced for Rh/-alumina catalyst, which occupied the highest reaction rates. Activation Energies were calculated from the Arrhenius relation

International Journal of Energy Research

International Journal of Hydrogen Energy

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Journal of applied microbiology, Jan 19, 2018

Marine seaweeds (macroalgae) cause eutrophication problem and affects the touristic activities. T... more Marine seaweeds (macroalgae) cause eutrophication problem and affects the touristic activities. The success of the production of the third generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes. Different marine macroalgal strains; red Jania rubens, green Ulva lactuca. and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermo-chemical hydrolysis with diluted acids (HCl and H SO ) and base (NaOH), hydrothermal hydrolysis followed by saccharification wit...

World Applied Sciences Journal

Renewable Energy, 1994

The thermal performance of a laboratory-scale salt gradient solar pond has been modeled as a one-... more The thermal performance of a laboratory-scale salt gradient solar pond has been modeled as a one-dimensional unsteady conduction heat transfer problem with heat generation. The pond is assumed to be cut into horizontal slices and finite difference heat balance equations are solved simultaneously to predict the temperature of each slice at any time. The initial conditions were the temperature profile data. The boundary conditions were determined by studying the heat balance at the bottom of the pond and by assuming the pond surface temperature to be equal to the ambient temperature. Solar radiation attenuation is calculated by the Bryant and Colbeck formula. A computer program is constructed to perform the calculations. In addition, Kooi's model was compared with our model. Similarly the salinity behavior was studied by writing the one-dimensional differential mass balance equation over a small slice with the appropriate boundary and initial conditions. The resultant set of linear equations was solved simultaneously for the unknown new concentrations. A computer program has been constructed to perform the calculations. Fair agreement between experimental and predicted profiles was obtained.

European journal of applied microbiology and biotechnology, 1982

Baker's yeast was aerobically grown in gaseous fluidized beds in the form of solid particles. Air... more Baker's yeast was aerobically grown in gaseous fluidized beds in the form of solid particles. Air was used as the fiuidizing fluid and as a source of oxygen, while the concentrated nutrient solution was sprayed at the top of the bed. Five glucose concentrations 125,160, 200,250 und 350 g 1-1 were used. A maximum in the growth rate and in the yield coefficient occurred at 250 and 200 g 1-1 , respectively. The calculated growth rates are one order of magnitude less than the growth rates in submerged cultures, but the maintenance energy coefficient is the same in both systems. Alcohol ppm level in the exhaust gases increased with increasing glucose concentration in the nutrient solution. Oscillations in the alcohol produc

Chemical Engineering & Technology, Apr 19, 2022

The Box‐Behnken experimental design method was applied to study optimization of dry reforming of ... more The Box‐Behnken experimental design method was applied to study optimization of dry reforming of methane over a magnesia‐supported nickel catalyst (Ni/MgO). The catalyst was prepared by impregnation method and characterized using Brunauer‐Emmett‐Teller analysis, X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy. Response surface methodology (RSM) modified by the Box‐Cox method was applied to investigate the effect of different operating parameters on conversion and formation of the different components of the reaction system. The RSM‐generated predictive models verified by analysis of variance were used to simulate the responses of the operating variables. This study revealed that the reaction temperature has the most pronounced effect followed by the CO2/CH4 mole ratio while the gas hourly space velocity had a negligible impact.

Process integration (PI) techniques is an efficient approach to increase the profitability due to... more Process integration (PI) techniques is an efficient approach to increase the profitability due to reduction in energy, water and raw materials consumption, reduction in greenhouse gas (GHG) emissions, and in waste generation. The PI method, pinch technology is certainly the most widely used in industrial processes. When planning a new plant or revamping an existing plant it is very important to understand and select the right process to minimize capital and operating costs. This research was directed to investigate the reduction of energy consumption in propane recovery units that process natural gas produced from wells existing in the Egyptian western desert fields. The first step was process simulation of the existing gas processing plant using AspenHysys8.3 steady state process simulation program. Next, pinch technology has been adopted in order to achieve minimum hot and cold utilities and save capital cost of the process. Target utilities were calculated using pinch analysis in...

Petroleum Science and Technology, 2009

Abstract The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO + H2) has been... more Abstract The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO + H2) has been investigated using 2 g of 0.5% wt of each of the catalysts; rhodium, ruthenium and iridium supported on γ-alumina. The experiments were carried out in a tubular reactor at three temperature levels namely 600, 700, 800°C and four gas weight hourly space velocities; 18000, 36000, 45000, and 60000 ml g−1 h−1. The reaction was found to obey first-order kinetics for the depletion of both of the reacting components; CH4 and CO2 on all the investigated catalysts. At the same temperature, CO2 had a higher reaction rate constant, k', as compared to CH4 for all the catalysts. This was more pronounced for Rh/γ-alumina catalyst, which occupied the highest reaction rates. Activation Energies were calculated from the Arrhenius relation.

Egyptian Journal of Petroleum, 2013

Biofuels are particularly important as an alternative fuel option for transportation. The sustain... more Biofuels are particularly important as an alternative fuel option for transportation. The sustainability of biofuels will depend on the development of viable, sustainable technologies that do not appear to be yet commercially viable. Successful development of algae-based biofuels and coproducts industry requires the optimum combination of technical innovations in systems and processes, coupled with economic feasibility in the practical implementation and integrated scale-up for commercial production and marketing. This article discusses the importance of algae-based biofuels together with the different opinions regarding its future. Advantages and disadvantages of these types of biofuels are presented. Algal growth drives around the world with special emphasis to Egypt are outlined. The article includes a brief description of the concept of algal biorefineries. It also declares the five key strategies to help producers to reduce costs and accelerate the commercialization of algal biodiesel. The internal strengths and weaknesses, and external opportunities, and threats are manifested through the SWOT analysis for micro-algae. Strategies for enhancing algae based-fuels are outlined. New process innovations and the role of genetic engineering in meeting these strategies are briefly discussed. To improve the economics of algal biofuels the concept of employing algae for wastewater treatment is presented.

3 Abstract: In this study, the effect of different C-sources as a co-substrate to enhance DBT-bio... more 3 Abstract: In this study, the effect of different C-sources as a co-substrate to enhance DBT-biodesulfurization using the newly isolated strain, Brevibacillus invocatusC19 and Rhodococcus erythropolis IGTS8 showed that glucose and glycerol expressed the highest biodesulfurization efficiency of 1000 ppm DBT, respectively. Based on five levels full factorial design, a statistical design of experiments was used to investigate two cases of DBT-biodesulfurization in batch processes, involving as factors yeast extract and glucose or glycerol for C19 and IGTS8, respectively. Cubic and quadratic predictive models significantly describing the interactive relationships between dependent and independent variables were established for C19 and IGTS8, respectively.

The Egyptian Journal of Chemistry, 2021

Biosciences, Biotechnology Research Asia, 2019

Fluidization, 1980

Particle entrainment in the freeboard region above a cocurrent gas-liquid fluidized bed arises la... more Particle entrainment in the freeboard region above a cocurrent gas-liquid fluidized bed arises largely as a result of the solids carried in the wakes of the gas bubbles leaving the bed. It is by the periodic wake-shedding which takes place in the freeboard that de-entrainment gradually occurs. This freeboard phenomenon is modelled as a stagewise partition process. The predictions of the model are compared with solids entrainment as obtained from measured axial pressure profiles in the freeboard of air-water fluidized beds of glass beads, for three bead sizes and different air and water velocities. Agreement with the experimental data is good.

World Renewable Energy Congress VI, 2000

Publisher Summary This chapter discusses the transportation cost of natural gas. The cost include... more Publisher Summary This chapter discusses the transportation cost of natural gas. The cost includes the construction costs of pipelines, and gas pressure reduction stations. Actual cost data for pipelines and pressure reduction stations are collected and processed. Empirical equations describing the construction cost are also obtained. Comparison between calculated and actual values reveals the reasonable accuracy of the proposed equations for such projects. Split of the capital investment indicates that pipelines cut out the lion's share (93%) against 7% for the pressure reduction stations. Pipelines material represents 49% of the total construction cost, followed by labors cost (28%), and wrapping cost (18%). All other items together represent around 5%.

Petroleum Science and Technology, 2009

The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO C H2) has been investig... more The Kinetics of CO2 reforming of natural gas to produce synthesis gas (CO C H2) has been investigated using 2 g of 0.5% wt of each of the catalysts; rhodium, ruthenium and iridium supported on -alumina. The experiments were carried out in a tubular reactor at three temperature levels namely 600, 700, 800ıC and four gas weight hourly space velocities; 18000, 36000, 45000, and 60000 ml g􀀀1 h􀀀1. The reaction was found to obey first-order kinetics for the depletion of both of the reacting components; CH4 and CO2 on all the investigated catalysts. At the same temperature, CO2 had a higher reaction rate constant, k0, as compared to CH4 for all the catalysts. This was more pronounced for Rh/-alumina catalyst, which occupied the highest reaction rates. Activation Energies were calculated from the Arrhenius relation

International Journal of Energy Research

International Journal of Hydrogen Energy

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Journal of applied microbiology, Jan 19, 2018

Marine seaweeds (macroalgae) cause eutrophication problem and affects the touristic activities. T... more Marine seaweeds (macroalgae) cause eutrophication problem and affects the touristic activities. The success of the production of the third generation bioethanol from marine macroalgae depends mainly on the development of an ecofriendly and eco-feasible pretreatment (i.e. hydrolysis) technique, a highly effective saccharification step and finally an efficient bioethanol fermentation step. Therefore, this study aimed to investigate the potentiality of different marine macroalgal strains, collected from Egyptian coasts, for bioethanol production via different saccharification processes. Different marine macroalgal strains; red Jania rubens, green Ulva lactuca. and brown Sargassum latifolium, have been collected from Egyptian Mediterranean and Red Sea shores. Different hydrolysis processes were evaluated to maximize the extraction of fermentable sugars; thermo-chemical hydrolysis with diluted acids (HCl and H SO ) and base (NaOH), hydrothermal hydrolysis followed by saccharification wit...

World Applied Sciences Journal

Renewable Energy, 1994

The thermal performance of a laboratory-scale salt gradient solar pond has been modeled as a one-... more The thermal performance of a laboratory-scale salt gradient solar pond has been modeled as a one-dimensional unsteady conduction heat transfer problem with heat generation. The pond is assumed to be cut into horizontal slices and finite difference heat balance equations are solved simultaneously to predict the temperature of each slice at any time. The initial conditions were the temperature profile data. The boundary conditions were determined by studying the heat balance at the bottom of the pond and by assuming the pond surface temperature to be equal to the ambient temperature. Solar radiation attenuation is calculated by the Bryant and Colbeck formula. A computer program is constructed to perform the calculations. In addition, Kooi's model was compared with our model. Similarly the salinity behavior was studied by writing the one-dimensional differential mass balance equation over a small slice with the appropriate boundary and initial conditions. The resultant set of linear equations was solved simultaneously for the unknown new concentrations. A computer program has been constructed to perform the calculations. Fair agreement between experimental and predicted profiles was obtained.