Ali Shawabkeh - Academia.edu (original) (raw)
Papers by Ali Shawabkeh
Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated b... more Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated by means of tracer techniques. Gas mixing was studied by injecting gaseous CO2 into the CFB unit, and gas samples were continuously collected and analyzed. For solids mixing solid CO2 (dry ice) was injected, and gas concentrations and temperatures were measured. The experiments were performed in a cold model CFB riser with a rectangular cross section of 0.3 m 1.0 m and a height of 8.5 m. Quartz sand with a surface mean diameter of 150 µm was used as the bed material. The unit was operated at superficial gas velocities between 2.6 and 3.8 m/s with the riser pressure drop ranging from 7,000 to 10,000 Pa.
De-NOx and De-SOx for the treatment of exhaust gas such as from the power plants and blast furnac... more De-NOx and De-SOx for the treatment of exhaust gas such as from the power plants and blast furnaces, so far have been carried out separately. It is highly expected that m uch effective and advantageous t echniques w ould be developed.
Journal of Solid Waste Technology and Management
Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes we... more Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes were prepared by mixing dried fly ash ground to particles smaller than 63 µm (derived from a pressurized fluidized-bed combustor, PFBC) with water at different water to solid weight ratios in a 170-rpm agitated vessel for 5 min. The paste was cast into a rectangular mold before being placed in a humidity-controlled chamber for curing. The curing conditions were kept at 80°C, and 80% relative humidity for 3 days. The effect of the addition of 10, 20 and 30 wt% of car-window glass fragments to the paste was also investigated. Measurements of the density, thermal conductivity and mechanical properties of the resulting brick were used for the evaluation of its suitability as a thermal insulator. The insulators prepared from water to solid weight ratio (W/S) of 0.5 showed good specifications in terms of low density and thermal conductivity, and high mechanical strengths. The addition of 10-wt% glass to the ash during slurrying enhanced the mechanical properties of the insulating material produced but had no significant effect on its density and thermal conductivity.
Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated b... more Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated by means of tracer techniques. Gas mixing was studied by injecting gaseous CO2 into the CFB unit, and gas samples were continuously collected and analyzed. For solids mixing solid CO2 (dry ice) was injected, and gas concentrations and temperatures were measured. The experiments were performed in a cold model CFB riser with a rectangular cross section of 0.3 m 1.0 m and a height of 8.5 m. Quartz sand with a surface mean diameter of 150 µm was used as the bed material. The unit was operated at superficial gas velocities between 2.6 and 3.8 m/s with the riser pressure drop ranging from 7,000 to 10,000 Pa.
Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes we... more Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes were prepared by mixing dried fly ash ground to particles smaller than 63 µm (derived from a pressurized fluidized-bed combustor, PFBC) with water at different water to solid weight ratios in a 170-rpm agitated vessel for 5 min. The paste was cast into a rectangular mold before being placed in a humidity-controlled chamber for curing. The curing conditions were kept at 80°C, and 80% relative humidity for 3 days. The effect of the addition of 10, 20 and 30 wt% of car-window glass fragments to the paste was also investigated. Measurements of the density, thermal conductivity and mechanical properties of the resulting brick were used for the evaluation of its suitability as a thermal insulator. The insulators prepared from water to solid weight ratio (W/S) of 0.5 showed good specifications in terms of low density and thermal conductivity, and high mechanical strengths. The addition of 10-wt% glass to the ash during slurrying enhanced the mechanical properties of the insulating material produced but had no significant effect on its density and thermal conductivity.
Six types of coal slags were tested for H2S retention in a TGA reactor under conditions simulatin... more Six types of coal slags were tested for H2S retention in a TGA reactor under conditions simulating modern coal gasifiers (850-1000C and 0.7-1.1vol% H2S). Results based on analysis from XRD and SEM/EDS showed that the iron contained in the slag was responsible for the removal of H2S in the form of FeS1.1. The reactivity of slag for H2S removal achieved at 850C and 1.1% H2S varied between 7 and 30%. This was found to increase with increasing iron content in slag. Slag reactivity with H2S could be enhanced by decreasing the slag particle size and/or raising the sulfidation reaction temperature.
The effect of the SLES (sodium lauryl ether sulphate) concentration on the apparent viscosity of ... more The effect of the SLES (sodium lauryl ether sulphate) concentration on the apparent viscosity of a dish washing liquid detergent (Hypex), manufactured in a Jordanian industry, was investigated using a Brookfield viscometer. Keeping the active matter of the detergent (the total concentration of surfactants) fixed at 21%, five formulations (Hypex 1, Hypex 2, Hypex 3, Hypex 4, and Hypex 5) were prepared with different SLES-LABSA ratio of 0.50, 0.68, 0.92, 1.25 and 1.57, respectively. The apparent viscosities of these five formulations were examined at different shear rates ranging from 5 to 325 s −1 under both forward and backward shearing at constant 25°C. The Hypex detergents were found to be shear thinning liquids (pseudoplastic) and time independent. The Hypex of higher SLES concentration could exhibit higher apparent viscosity values. These measured values were satisfactorily modeled using ---11/22---21/22-
Beni-Suef University Journal of Basic and Applied Sciences, 2013
Metallic membrane a b s t r a c t Powder of metallic materials composed of Fe, Ni was proposed fo... more Metallic membrane a b s t r a c t Powder of metallic materials composed of Fe, Ni was proposed for membrane applications such as microfiltration devices. The powder was synthesized using thermal route of simultaneously sinteringereduction techniques. The resulting powder has specific porous structure and can be deposited on steel substrate. The formed phases were identified by X-ray phase analysis. The produced powder was characterized by reflected light microscope and scanning electron microscope along with energy-dispersive X-ray spectroscopy (EDX). The reduction behavior of metal oxides was followed up by thermogravimetric techniques. The kinetics data obtained from reduction process were used to elucidate the reduction mechanism under isothermal condition. The microstructure changes accompanying sinteringereduction processes were investigated under different experimental parameters such as temperature, holding time and gas composition. The results show that pure Fe 0.64 Ni 0.36 with relatively high porosity can be fabricated via reduction route. The presence of NiO plays a significant role in the reduction of iron oxide as well as in the structural changes accompanying the reduction processes. The particle size distribution of the produced metallic materials is being controlled under the different operation conditions to get a homogenous porous metallic structure with well defined porosity. The main advantage of using porous ferroalloy materials is their narrow size distribution leading to a well defined pore size distribution after sintering and reduction.
Advances in Chemical Engineering and Science, 2015
A clay catalyst (montmorillonite and kaolinite) was prepared and used to degrade three phenolic c... more A clay catalyst (montmorillonite and kaolinite) was prepared and used to degrade three phenolic compounds: hydroquinone, resorcinol and catechol obtained from the treatment the Olive Mill Wastewater (OMW) generated in the production of olive oil. The operating conditions of the degradation of these compounds are optimized by the response surface methodology (RSM) which is an experimental design used in process optimization studies. The results obtained by the catalytic tests and analyses performed by different techniques showed that the modified montmorillonites have very interesting catalytic, structural and textural properties; they are more effective for the catalytic phenolic compound degradation, they present the highest specific surface and they may support iron ions. We also determined the optimal degradation conditions by tracing the response surfaces of each compound; for example, for the catechol, the optimal conditions of degradation at pH 4 are obtained after 120 min at a concentration of H2O2 equal to 0.3 M. Of the three phenolic compounds, the kinetic degradation study revealed that the hydroquinone is the most degraded compound in the least amount of time. Finally, the rate of the catalyst iron ions release in the reaction is lower when the Fe-modified montmorillonites are used.
KAGAKU KOGAKU RONBUNSHU, 1996
Energy Conversion and Management, 1997
Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated b... more Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated by means of tracer techniques. Gas mixing was studied by injecting gaseous CO2 into the CFB unit, and gas samples were continuously collected and analyzed. For solids mixing solid CO2 (dry ice) was injected, and gas concentrations and temperatures were measured. The experiments were performed in a cold model CFB riser with a rectangular cross section of 0.3 m 1.0 m and a height of 8.5 m. Quartz sand with a surface mean diameter of 150 µm was used as the bed material. The unit was operated at superficial gas velocities between 2.6 and 3.8 m/s with the riser pressure drop ranging from 7,000 to 10,000 Pa.
De-NOx and De-SOx for the treatment of exhaust gas such as from the power plants and blast furnac... more De-NOx and De-SOx for the treatment of exhaust gas such as from the power plants and blast furnaces, so far have been carried out separately. It is highly expected that m uch effective and advantageous t echniques w ould be developed.
Journal of Solid Waste Technology and Management
Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes we... more Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes were prepared by mixing dried fly ash ground to particles smaller than 63 µm (derived from a pressurized fluidized-bed combustor, PFBC) with water at different water to solid weight ratios in a 170-rpm agitated vessel for 5 min. The paste was cast into a rectangular mold before being placed in a humidity-controlled chamber for curing. The curing conditions were kept at 80°C, and 80% relative humidity for 3 days. The effect of the addition of 10, 20 and 30 wt% of car-window glass fragments to the paste was also investigated. Measurements of the density, thermal conductivity and mechanical properties of the resulting brick were used for the evaluation of its suitability as a thermal insulator. The insulators prepared from water to solid weight ratio (W/S) of 0.5 showed good specifications in terms of low density and thermal conductivity, and high mechanical strengths. The addition of 10-wt% glass to the ash during slurrying enhanced the mechanical properties of the insulating material produced but had no significant effect on its density and thermal conductivity.
Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated b... more Gas and solids mixing in the bottom zone of a circulating fluidized bed (CFB) were investigated by means of tracer techniques. Gas mixing was studied by injecting gaseous CO2 into the CFB unit, and gas samples were continuously collected and analyzed. For solids mixing solid CO2 (dry ice) was injected, and gas concentrations and temperatures were measured. The experiments were performed in a cold model CFB riser with a rectangular cross section of 0.3 m 1.0 m and a height of 8.5 m. Quartz sand with a surface mean diameter of 150 µm was used as the bed material. The unit was operated at superficial gas velocities between 2.6 and 3.8 m/s with the riser pressure drop ranging from 7,000 to 10,000 Pa.
Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes we... more Cost-effective thermal insulating bricks were produced from treated fly ash pastes. The pastes were prepared by mixing dried fly ash ground to particles smaller than 63 µm (derived from a pressurized fluidized-bed combustor, PFBC) with water at different water to solid weight ratios in a 170-rpm agitated vessel for 5 min. The paste was cast into a rectangular mold before being placed in a humidity-controlled chamber for curing. The curing conditions were kept at 80°C, and 80% relative humidity for 3 days. The effect of the addition of 10, 20 and 30 wt% of car-window glass fragments to the paste was also investigated. Measurements of the density, thermal conductivity and mechanical properties of the resulting brick were used for the evaluation of its suitability as a thermal insulator. The insulators prepared from water to solid weight ratio (W/S) of 0.5 showed good specifications in terms of low density and thermal conductivity, and high mechanical strengths. The addition of 10-wt% glass to the ash during slurrying enhanced the mechanical properties of the insulating material produced but had no significant effect on its density and thermal conductivity.
Six types of coal slags were tested for H2S retention in a TGA reactor under conditions simulatin... more Six types of coal slags were tested for H2S retention in a TGA reactor under conditions simulating modern coal gasifiers (850-1000C and 0.7-1.1vol% H2S). Results based on analysis from XRD and SEM/EDS showed that the iron contained in the slag was responsible for the removal of H2S in the form of FeS1.1. The reactivity of slag for H2S removal achieved at 850C and 1.1% H2S varied between 7 and 30%. This was found to increase with increasing iron content in slag. Slag reactivity with H2S could be enhanced by decreasing the slag particle size and/or raising the sulfidation reaction temperature.
The effect of the SLES (sodium lauryl ether sulphate) concentration on the apparent viscosity of ... more The effect of the SLES (sodium lauryl ether sulphate) concentration on the apparent viscosity of a dish washing liquid detergent (Hypex), manufactured in a Jordanian industry, was investigated using a Brookfield viscometer. Keeping the active matter of the detergent (the total concentration of surfactants) fixed at 21%, five formulations (Hypex 1, Hypex 2, Hypex 3, Hypex 4, and Hypex 5) were prepared with different SLES-LABSA ratio of 0.50, 0.68, 0.92, 1.25 and 1.57, respectively. The apparent viscosities of these five formulations were examined at different shear rates ranging from 5 to 325 s −1 under both forward and backward shearing at constant 25°C. The Hypex detergents were found to be shear thinning liquids (pseudoplastic) and time independent. The Hypex of higher SLES concentration could exhibit higher apparent viscosity values. These measured values were satisfactorily modeled using ---11/22---21/22-
Beni-Suef University Journal of Basic and Applied Sciences, 2013
Metallic membrane a b s t r a c t Powder of metallic materials composed of Fe, Ni was proposed fo... more Metallic membrane a b s t r a c t Powder of metallic materials composed of Fe, Ni was proposed for membrane applications such as microfiltration devices. The powder was synthesized using thermal route of simultaneously sinteringereduction techniques. The resulting powder has specific porous structure and can be deposited on steel substrate. The formed phases were identified by X-ray phase analysis. The produced powder was characterized by reflected light microscope and scanning electron microscope along with energy-dispersive X-ray spectroscopy (EDX). The reduction behavior of metal oxides was followed up by thermogravimetric techniques. The kinetics data obtained from reduction process were used to elucidate the reduction mechanism under isothermal condition. The microstructure changes accompanying sinteringereduction processes were investigated under different experimental parameters such as temperature, holding time and gas composition. The results show that pure Fe 0.64 Ni 0.36 with relatively high porosity can be fabricated via reduction route. The presence of NiO plays a significant role in the reduction of iron oxide as well as in the structural changes accompanying the reduction processes. The particle size distribution of the produced metallic materials is being controlled under the different operation conditions to get a homogenous porous metallic structure with well defined porosity. The main advantage of using porous ferroalloy materials is their narrow size distribution leading to a well defined pore size distribution after sintering and reduction.
Advances in Chemical Engineering and Science, 2015
A clay catalyst (montmorillonite and kaolinite) was prepared and used to degrade three phenolic c... more A clay catalyst (montmorillonite and kaolinite) was prepared and used to degrade three phenolic compounds: hydroquinone, resorcinol and catechol obtained from the treatment the Olive Mill Wastewater (OMW) generated in the production of olive oil. The operating conditions of the degradation of these compounds are optimized by the response surface methodology (RSM) which is an experimental design used in process optimization studies. The results obtained by the catalytic tests and analyses performed by different techniques showed that the modified montmorillonites have very interesting catalytic, structural and textural properties; they are more effective for the catalytic phenolic compound degradation, they present the highest specific surface and they may support iron ions. We also determined the optimal degradation conditions by tracing the response surfaces of each compound; for example, for the catechol, the optimal conditions of degradation at pH 4 are obtained after 120 min at a concentration of H2O2 equal to 0.3 M. Of the three phenolic compounds, the kinetic degradation study revealed that the hydroquinone is the most degraded compound in the least amount of time. Finally, the rate of the catalyst iron ions release in the reaction is lower when the Fe-modified montmorillonites are used.
KAGAKU KOGAKU RONBUNSHU, 1996
Energy Conversion and Management, 1997