In amine-based post-combustion CO 2 capture, solvent loss contribute to process operation problem... more In amine-based post-combustion CO 2 capture, solvent loss contribute to process operation problems like corrosion, fouling, foaming as well as is responsible for economic deficit. In this work, thermal degradation of blended 3.2 m DEA and 0.8 m was investigated at 135 • C, simulating the stripper temperature. CO 2 loading of the system was varied from 0.0 to 0.4 mole CO 2 /mole alkalinity to explore its effect on degradation of the blended system. Experiments were conducted in 316 stainless steel cylinders, fitted with Swagelok ® endcaps made of 316 stainless steel, which were kept in convection ovens. Degraded samples were analyzed by using gas chromatography (GC) for final concentration and identification of the degradation products. Thermal loss of PZ was high in the PZ/DEA blend than other investigated blends of PZ like PZ/MDEA, PZ/AMP, and PZ/MEA under similar experimental conditions. CO 2 loading increased the rate of degradation of both PZ and DEA; however, rate of degradation of PZ was higher at high CO 2 loading and increased abruptly than that of DEA. Concentration of PZ approached to zero within 300 h of experiment at high CO 2 loading. Mechanism for the formation of major degradation products is proposed in the study. An empirical rate law is articulated to determine the loss of PZ. Results of model are in good agreement with experimental results.
Increasing global carbon dioxide (CO 2) emissions are a rising concern for the global climate cha... more Increasing global carbon dioxide (CO 2) emissions are a rising concern for the global climate change. Amine-based post-combustion CO 2 capture (PCC) technology is one of the mature options to contribute to the mitigation of these emissions. The technology is approaching toward its commercialization. However , there are two important problems, which should properly be addressed, solvent management and the amine-based PCC emissions. Major losses in amines are due to the oxidative and thermal degradation. Concentration of oxygen (O 2) is the driving force for the oxidation. Temperature, CO 2 loading and amine concentration affect both thermal and oxidative degradation. This manuscript reviews solvent selection, thermal and oxidative degradation of amines used for CO 2 capture. Furthermore, amine-based PCC emissions have also been highlighted, with some of their concerns. Based on literature reviewed and discussions provided, conclusions are made. In addition, some of the future work is also directed in form of suggestions.
ABSTRACT The effect of a new biofuel source derived from waste palm oil mill effluent (POME) addi... more ABSTRACT The effect of a new biofuel source derived from waste palm oil mill effluent (POME) addition to diesel on engine performance, emissions, and combustion characteristics was investigated in a single-cylinder diesel engine under six different speed operations and at full load conditions. The experimental results suggested that there are some penalties in engine torque, brake power, brake specific fuel consumption (BSFC), and brake specific nitrogen oxide (BSNOx) with the presence of Biopro Diesel™ fuel in the blend. Moreover, there is an improvement in exhaust emissions with lower brake specific hydrocarbons (BSHC), brake specific carbon monoxide (BSCO) and smoke emissions by using Biopro Diesel™ fuel blends across all engine speeds. Besides, the tip surfaces of the injectors running with Biopro Diesel™ blends were found to be cleaner than that of an injector running with fossil diesel. Moreover, there is an improvement in the combustion process with a shorter total burning angle for Biopro Diesel™ fuel blends than that of diesel at all engine speeds. Overall, the results suggested that biofuel derived from waste POME blended with fossil diesel can be used satisfactorily in an unmodified diesel engine.
Gasification in dual fluidized bed gasifiers (DFBGs)has beenproven itself as one of a promising t... more Gasification in dual fluidized bed gasifiers (DFBGs)has beenproven itself as one of a promising technologies. In DFBGs, the bubbling fluidized bed (BFB) act as a gasifier and a riser applied as combustor is coupled, with provision of solid transfer between them.Fundamentally, the performance of these reactors is a function of the fluid dynamics in the reactor.Axial solid holdup or solid fraction in the riser is a very important fluid dynamic parameter since it greatly influences and characterizes the mass transfer as well as heat transfer properties. Various types of models have been discussed in literaturesand they have profoundly predicted the solid holdup distribution in the riser. Among them, semi-empirical models are easier to construct and significantly aid in design and scale up.In this paper a model that satisfactorilypredicts the axial solid holdup profile according to different heights of the riseris developed. Thedecay factor required to obtain model results has been corr...
Carbon dioxide (CO2) emissions are a rising concern for the climate change and global warming. Po... more Carbon dioxide (CO2) emissions are a rising concern for the climate change and global warming. Postcombustion CO2 capture using amine-base solvents seems to be a viable technology. Concentrated, aqueous Piperazine (PZ) is an advanced solvent that has promising characteristics to capture CO2. Experimental, thermal degradation kinetics data of concentrated, aqueous PZ, loaded with CO2 was regressed using MATLAB ® . Data is fitted to first and second order rate laws, by linear and nonlinear regression methods. Six different types of expressions were used to describe the trend of thermal degradation of CO2 loaded aqueous PZ. The findings revealed that the thermal degradation data followed both first order and second order kinetics. Current model exhibited that rate constants (k1 and k2) can be predicted by making use of six different expressions (1-6). Expression 3 and 5 are the most appropriate expressions for predicting the thermal degradation kinetics for the first order and second o...
Journal of Petroleum Science and Engineering, 2015
ABSTRACT This paper presents an optimization of a lightweight biopolymer drilling fluid for under... more ABSTRACT This paper presents an optimization of a lightweight biopolymer drilling fluid for underbalanced drilling (UBD) using Response Surface Methodology (RSM). Concentrations of four raw materials (glass bubbles, clay, xanthan gum and starch) were varied to analyze their effects on three vital responses: density, plastic viscosity (PV) and yield point (YP) of the fluid. Based on the results, the optimum condition was achieved at concentrations of glass bubbles, clay, xanthan gum and starch of 24.46% w/v, 0.63% w/v, 0.21% w/v and 2.41% w/v respectively. The results showed that it is possible to predict the three response parameters using models generated by RSM since the experimental values were found to be in good agreement with the predicted values (error<1.0, standard deviation<0.5 and accuracy>98.5%).
Postcombustion carbon dioxide (CO2) capture using amine scrubbing is an emerging technology to mi... more Postcombustion carbon dioxide (CO2) capture using amine scrubbing is an emerging technology to mitigate CO2 emissions. Benchmark amines used in this technology are monoethanolamine (MEA), methyldiethanolamine (MDEA), and diethanolamine (DEA). Amines undergo irreversible reactions, resulting degradation of the solvent under process operating conditions. Degradation of solvent may create environmental concerns, increased costs as well as corrosion in the process equipment. Piperazine (PZ) has been investigated as a novel amine solvent for CO2 capture. It has high CO2 capture capacity and absorption rate with thermal and oxidative degradation resistance. This study discusses the thermal and oxidative degradation of PZ under process operating conditions. A critical review of various parameters, such as the effect of temperature, amine concentration, CO2 loading (α), partial pressure of oxygen (O2) and presence of metal ions on rate of degradation has been reported. Chemistry of degradation products and mechanisms of degradation of PZ are reported for better understanding of PZ degradation kinetics. In addition, degradation of PZ blends, structural analogs, and diamines is focused, and behavior of their degradation is highlighted. Furthermore, kinetics of formation and degradation of nitrosamines through PZ is also discussed.
In amine-based post-combustion CO 2 capture, solvent loss contribute to process operation problem... more In amine-based post-combustion CO 2 capture, solvent loss contribute to process operation problems like corrosion, fouling, foaming as well as is responsible for economic deficit. In this work, thermal degradation of blended 3.2 m DEA and 0.8 m was investigated at 135 • C, simulating the stripper temperature. CO 2 loading of the system was varied from 0.0 to 0.4 mole CO 2 /mole alkalinity to explore its effect on degradation of the blended system. Experiments were conducted in 316 stainless steel cylinders, fitted with Swagelok ® endcaps made of 316 stainless steel, which were kept in convection ovens. Degraded samples were analyzed by using gas chromatography (GC) for final concentration and identification of the degradation products. Thermal loss of PZ was high in the PZ/DEA blend than other investigated blends of PZ like PZ/MDEA, PZ/AMP, and PZ/MEA under similar experimental conditions. CO 2 loading increased the rate of degradation of both PZ and DEA; however, rate of degradation of PZ was higher at high CO 2 loading and increased abruptly than that of DEA. Concentration of PZ approached to zero within 300 h of experiment at high CO 2 loading. Mechanism for the formation of major degradation products is proposed in the study. An empirical rate law is articulated to determine the loss of PZ. Results of model are in good agreement with experimental results.
Increasing global carbon dioxide (CO 2) emissions are a rising concern for the global climate cha... more Increasing global carbon dioxide (CO 2) emissions are a rising concern for the global climate change. Amine-based post-combustion CO 2 capture (PCC) technology is one of the mature options to contribute to the mitigation of these emissions. The technology is approaching toward its commercialization. However , there are two important problems, which should properly be addressed, solvent management and the amine-based PCC emissions. Major losses in amines are due to the oxidative and thermal degradation. Concentration of oxygen (O 2) is the driving force for the oxidation. Temperature, CO 2 loading and amine concentration affect both thermal and oxidative degradation. This manuscript reviews solvent selection, thermal and oxidative degradation of amines used for CO 2 capture. Furthermore, amine-based PCC emissions have also been highlighted, with some of their concerns. Based on literature reviewed and discussions provided, conclusions are made. In addition, some of the future work is also directed in form of suggestions.
ABSTRACT The effect of a new biofuel source derived from waste palm oil mill effluent (POME) addi... more ABSTRACT The effect of a new biofuel source derived from waste palm oil mill effluent (POME) addition to diesel on engine performance, emissions, and combustion characteristics was investigated in a single-cylinder diesel engine under six different speed operations and at full load conditions. The experimental results suggested that there are some penalties in engine torque, brake power, brake specific fuel consumption (BSFC), and brake specific nitrogen oxide (BSNOx) with the presence of Biopro Diesel™ fuel in the blend. Moreover, there is an improvement in exhaust emissions with lower brake specific hydrocarbons (BSHC), brake specific carbon monoxide (BSCO) and smoke emissions by using Biopro Diesel™ fuel blends across all engine speeds. Besides, the tip surfaces of the injectors running with Biopro Diesel™ blends were found to be cleaner than that of an injector running with fossil diesel. Moreover, there is an improvement in the combustion process with a shorter total burning angle for Biopro Diesel™ fuel blends than that of diesel at all engine speeds. Overall, the results suggested that biofuel derived from waste POME blended with fossil diesel can be used satisfactorily in an unmodified diesel engine.
Gasification in dual fluidized bed gasifiers (DFBGs)has beenproven itself as one of a promising t... more Gasification in dual fluidized bed gasifiers (DFBGs)has beenproven itself as one of a promising technologies. In DFBGs, the bubbling fluidized bed (BFB) act as a gasifier and a riser applied as combustor is coupled, with provision of solid transfer between them.Fundamentally, the performance of these reactors is a function of the fluid dynamics in the reactor.Axial solid holdup or solid fraction in the riser is a very important fluid dynamic parameter since it greatly influences and characterizes the mass transfer as well as heat transfer properties. Various types of models have been discussed in literaturesand they have profoundly predicted the solid holdup distribution in the riser. Among them, semi-empirical models are easier to construct and significantly aid in design and scale up.In this paper a model that satisfactorilypredicts the axial solid holdup profile according to different heights of the riseris developed. Thedecay factor required to obtain model results has been corr...
Carbon dioxide (CO2) emissions are a rising concern for the climate change and global warming. Po... more Carbon dioxide (CO2) emissions are a rising concern for the climate change and global warming. Postcombustion CO2 capture using amine-base solvents seems to be a viable technology. Concentrated, aqueous Piperazine (PZ) is an advanced solvent that has promising characteristics to capture CO2. Experimental, thermal degradation kinetics data of concentrated, aqueous PZ, loaded with CO2 was regressed using MATLAB ® . Data is fitted to first and second order rate laws, by linear and nonlinear regression methods. Six different types of expressions were used to describe the trend of thermal degradation of CO2 loaded aqueous PZ. The findings revealed that the thermal degradation data followed both first order and second order kinetics. Current model exhibited that rate constants (k1 and k2) can be predicted by making use of six different expressions (1-6). Expression 3 and 5 are the most appropriate expressions for predicting the thermal degradation kinetics for the first order and second o...
Journal of Petroleum Science and Engineering, 2015
ABSTRACT This paper presents an optimization of a lightweight biopolymer drilling fluid for under... more ABSTRACT This paper presents an optimization of a lightweight biopolymer drilling fluid for underbalanced drilling (UBD) using Response Surface Methodology (RSM). Concentrations of four raw materials (glass bubbles, clay, xanthan gum and starch) were varied to analyze their effects on three vital responses: density, plastic viscosity (PV) and yield point (YP) of the fluid. Based on the results, the optimum condition was achieved at concentrations of glass bubbles, clay, xanthan gum and starch of 24.46% w/v, 0.63% w/v, 0.21% w/v and 2.41% w/v respectively. The results showed that it is possible to predict the three response parameters using models generated by RSM since the experimental values were found to be in good agreement with the predicted values (error<1.0, standard deviation<0.5 and accuracy>98.5%).
Postcombustion carbon dioxide (CO2) capture using amine scrubbing is an emerging technology to mi... more Postcombustion carbon dioxide (CO2) capture using amine scrubbing is an emerging technology to mitigate CO2 emissions. Benchmark amines used in this technology are monoethanolamine (MEA), methyldiethanolamine (MDEA), and diethanolamine (DEA). Amines undergo irreversible reactions, resulting degradation of the solvent under process operating conditions. Degradation of solvent may create environmental concerns, increased costs as well as corrosion in the process equipment. Piperazine (PZ) has been investigated as a novel amine solvent for CO2 capture. It has high CO2 capture capacity and absorption rate with thermal and oxidative degradation resistance. This study discusses the thermal and oxidative degradation of PZ under process operating conditions. A critical review of various parameters, such as the effect of temperature, amine concentration, CO2 loading (α), partial pressure of oxygen (O2) and presence of metal ions on rate of degradation has been reported. Chemistry of degradation products and mechanisms of degradation of PZ are reported for better understanding of PZ degradation kinetics. In addition, degradation of PZ blends, structural analogs, and diamines is focused, and behavior of their degradation is highlighted. Furthermore, kinetics of formation and degradation of nitrosamines through PZ is also discussed.
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Papers by Brahim Si Ali