Abdulwahab GIWA | Afe Babalola University, Ado-Ekiti (original) (raw)
Papers by Abdulwahab GIWA
International Journal of Engineering Research in Africa, 2019
This study has been carried out to demonstrate the control of a reactive distillation process in ... more This study has been carried out to demonstrate the control of a reactive distillation process in which the production of biodiesel was taken as the case study using an advanced control method, which is known as dynamic matrix control. The control was accomplished by employing the transfer function model of the reactive distillation process developed, using the System Identification Toolbox of MATLAB, from the dynamic data generated when the prototype plant of the process was simulated with the aid of ChemCAD process simulator. The results obtained from the dynamic matrix control were compared with those of a proportional-integral-derivative (PID) control system tuned with Ziegler-Nichols and Cohen-Coon methods, and it was discovered that the dynamic matrix control was able to perform best among the three (dynamic matrix control method, PID tuned with Ziegler-Nichols method and PID tuned with Cohen-Coon method) because it (the dynamic matrix control) was able to make the biodiesel mo...
Advances in Applied Science Research, 2015
This work has been carried out to study the dynamics of reactive distillation process used for th... more This work has been carried out to study the dynamics of reactive distillation process used for the production ofcis-2- butene and cis-2-hexene from the metathesis reaction of cis-2-pentene. The dynamics was investigated using the 2 x 2 transfer function model of the process developed, with the aid of System Identification Toolbox of MATLAB, from the data generated, through the use of Parametric Utility, by employing the prototype plant of the process modelled with the aid of Aspen HYSYS. The input parameters of the process transfer function model were reflux ratio and reboiler duty while the output parameters were top stage and bottom stage temperatures of the column, which were the temperatures of the products obtained from the reactive distillation column. In order to study the dynamics, step changes of 1 and 0.1 units were applied to the reflux ratio and the reboiler duty respectively, both separately and simultaneously, and the dynamic responses of the output variables were recorded and plotted. The results obtained revealed that both the top and the bottom stage temperatures were able to respond to the step changes applied to the input variables. The response given by the bottom stage temperature upon the application of a unit step change to the reflux ratio was found to be slower than that of the top stage temperature, but both of them were able to get to their steady states within the simulation time used. In addition, the two output variables were found to respond very well in a smooth manner to the simultaneous application of step changes to the input variables, indicating that the chosen input variables were actually having effects on the selected output variables
International Journal of Engineering Research in Africa, May 1, 2017
In the last years, the integration of reaction and distillation in one process, has gained more i... more In the last years, the integration of reaction and distillation in one process, has gained more interest. The mixing of these two operations is especially convenient and shows many advantages. The startup procedure of a conventional distillation column spends a lot of time and energy besides producing offspec products. In reactive distillation, this problem becomes worse once the product cannot be easily recycled, making the start-up procedure very costintensive. In this work, the dynamic simulation of reactive distillation columns is studied in order to analyze different startup procedures. Different strategies were implemented and simulated. Furthermore, an evaluation of uncertainties in model parameters on the startup time was carried out.
International journal of engineering research and technology, Jan 30, 2013
This work was carried out to optimize the esterification process, between myristic acid and isopr... more This work was carried out to optimize the esterification process, between myristic acid and isopropanol, used for the production of isopropyl myristate in a reaction integrated distillation column taking the bottom mole fraction of isopropyl myristate as the objective function and the reflux ratio, the feed ratio and the reboiler duty as the manipulated variables. The experimental setup was built in form of a model using HYSYS 3.2. Response Surface Methodology was used to design the experimental simulations that were carried out. The results of the experimental simulations in addition to the designed experimental parameters were used to develop the model for the bottom mole fraction of isopropyl myristate using Design-Expert 7.0.0. The developed model was theoretically simulated and optimized with the aid of MATLAB R2012a and the theoretical optimum parameters found were used to run the experimental setup. The results obtained showed that the theoretical optimum values obtained with the aid of MATLAB R2012a were valid because the experimental simulation with these values gave the bottom isopropyl myristate mole fraction of 0.9912 that compared very well with the theoretical simulation value of bottom isopropyl myristate mole fraction of 1.0000.
International journal of engineering research and technology, Jul 22, 2013
Methane steam reforming has been simulated, analyzed and optimized with the aid of Aspen Plus, in... more Methane steam reforming has been simulated, analyzed and optimized with the aid of Aspen Plus, in this work. The model of the steam reforming process used was developed using equilibrium reactor type. Both steam reforming process model with and without mixer were developed and simulated in Aspen Plus environment. The sensitivity analyses and the optimization of the process were accomplished using the Sensitivity and the Optimization sections of Model Analysis Tool of Aspen Plus. The results obtained revealed that the simulations with and without mixer gave the same mole fractions of the process components and that the simulation with liquid methane feed was able to produce highmole fraction of the desired product(hydrogen) at approximately atmospheric pressure. Furthermore, it was revealed from the sensitivity analyses of the process that optimization was necessary to obtain the operating variables that would yield hydrogen in very high and highest purity among the components involved in the process and the optimization was able to give a satisfactory value of 0.7432 as the mole fraction of hydrogen present in the top product of the reactor when the optimum reactor temperature, reactor pressure, volumetric flow rate of feed water and volumetric flow rate of feed methane were approximately 964.89 o C, 1 bar, 0.0172 L/min and 0.0353 L/min, respectively.
Advances in Applied Science Research, 2015
This research work has been carried out to investigate the effects of volumetric feed ratio of st... more This research work has been carried out to investigate the effects of volumetric feed ratio of stearic acid and methanol on the purity of the stearic acid methyl ester (SAME) obtained from a reactive distillation processaccomplished through an esterification reaction. The investigation was carried out by developing a model of the process with the aid of Aspen Plus using RadFrac column having 32 stages including the condenser and the reboiler. Wilson model was used as the property package of the simulation. The feeds (top-stearic acid and bottom-methanol) were passed into the column at a temperature and a pressure of 25 o C and 1 atm, respectively. The esterification reaction of the process was modelled as an equilibrium type, the equilibrium constant of which was estimated using Gibbs free energy. In the simulation of the developed Aspen Plus model of the reactive distillation process, the volumetric feed ratio of the column was varied from 3 to 11, and the results obtained showed that the trends of the mole fraction profiles of the components of the process were very similar to one another except those of the feed ratios of 9, 10 and 11 that were a little bit different from the others. Also obtained from the results was that increasing the volumetric feed ratio of the column made the mole fraction of the desired product, which was stearic acid methyl ester and also known as methyl stearate, to decrease. The results obtained have thus revealed that there was an inverseproportional, but not linear, relationship between the volumetric feed ratio of the process and the mole fraction of the desired product. Furthermore, it was discovered from the results that the feed ratio that gave the highest mole fraction of the desired product was 3.
International Journal of Engineering Research in Africa, Jul 1, 2017
The identification of a reactive distillation system for the production of n-butyl acetate from t... more The identification of a reactive distillation system for the production of n-butyl acetate from the esterification reaction between acetic acid and n-butanol has been carried out in this research work. In order to achieve the aim of the research work, a prototype plant of the process was developed using ChemCAD from which dynamics data were generated upon applications of step changes to the reboiler duty and the reflux ratio, which were the input variables of the system. Thereafter, the transfer function of the process, later represented in Simulink environment, was formulated using the dynamics data and with the aid of MATLAB. The simulation of the transfer function model of the system was also carried out for open loop by applying step changes unto the input variables using the developed Simulink model of the system. Thereafter, the closed-loop control system developed also in Simulink environment was simulated by applying step changes to the set-point variable, which was the bottom mole fraction of n-butyl acetate. The results obtained from the simulation of the prototype plant of the reactive distillation process showed ChemCAD to be a powerful tool for steady state and dynamics prototype plant development. Furthermore, good representation and stability were also observed to exist in the system from the formulation and the simulation of the transfer function model of the process, which were carried out with the aid of MATLAB/Simulink. Moreover, the selection of appropriate closed-loop time constant contained in the tuning parameter formulas of IMC-based control system showed that the value suggested by Rivera et al. [1] was very good for this system, compared to those of Chien and Fruehauf [2] and Skogestad [3], because it could give closed-loop dynamic response with comparatively very low values of integral squared error (ISE), integral absolute error (IAE) and integral time absolute error (ITAE) for both proportional-integral (PI) and proportional-integral-derivative (PID) control systems. In addition, the comparison made between the IMC-based tuning approach and other ones (Cohen-Coon, Tyreus-Luyben and Ziegler-Nichols) considered in this work made it known that IMC-based tuning technique was the best among all those considered because its ISE, IAE and ITAE were found to be the lowest for both PI-and PID-controlled cases simulated.
International Journal of Environmental Analytical Chemistry
The mathematical model of an evaporator, showing the dynamic behavior of liquid height and system... more The mathematical model of an evaporator, showing the dynamic behavior of liquid height and system temperature, has been developed. The model was used to investigate the dynamics of the system by simulating the obtained nonlinear differential equations using the ode45 command of MATLAB. Furthermore, using the realistic steady-state values obtained by solving the developed model with the aid of fsolve command of the same MATLAB, the system of transfer function model of the system was obtained via its state space form. Moreover, the Simulink model of the system was developed using the obtained transfer functions of the model. Thereafter, the dynamics of the system was investigated by simulating the Simulink model through the application of input steps to the liquid feed flow rate and the steam temperature of the system. The results obtained from the development of the transfer function models and the simulations carried out when steps were applied to the input variables of the system r...
Solid State Technology, Apr 5, 2021
Solid State Technology, Apr 5, 2021
International Journal of Engineering Research in Africa, 2021
In the recent time, there is increasing research in the area of alternative fuels as the exhausts... more In the recent time, there is increasing research in the area of alternative fuels as the exhausts of presently used petroleum-based fuels have been identified to have negative effects on the environment. Fuels produced from plant oils and animal fats have the tendencies of replacing petro fuels since they are renewable in nature. One of these renewable fuels is biodiesel. However, the homogenous catalyst used in biodiesel production has some drawbacks such as difficulty in separation from the fuel, soap formation and corrosiveness of the product mixture. In this work, the use of heterogeneous catalyst sourced from local raw materials (kaolin and eggshell) for the production of biodiesel from oil of desert date seed has been investigated. The kaolin obtained from Alkaleri Mining Site, Bauchi, was calcined in an oven at 800 °C for 3 h. The calcined kaolin was then chemically activated. Also, the eggshell-based catalyst was produced from raw eggshells after washing, drying, grinding, s...
In this work, the production of biodiesel via reactive distillation process has been modelled and... more In this work, the production of biodiesel via reactive distillation process has been modelled and simulated with the aid of ChemCAD for both steady state and dynamics. Also, the control of the process has been carried out using MATLAB/Simulink. In order to achieve the aim of the work, dynamics data showing the response of biodiesel mole fraction in the column bottoms (controlled variable) to a change in reboiler duty (manipulated variable) and reflux ratio (selected disturbance variable) were extracted from the ChemCAD dynamic simulation of the developed process model and used to obtain the first-order-plus-dead-time transfer function relation between biodiesel mole fraction in the column bottoms, reboiler duty and reflux ratio with the aid of MATLAB. The open loop simulation was done by applying steps to the input variables (reboiler duty and reflux ratio). Furthermore, the set-point tracking and disturbance rejection control of the system were carried out using a PID controller tu...
Bu calismada, tepkimeli dolgulu damitma kolonunun denetimi ayirimli model ongormeli kontrol algor... more Bu calismada, tepkimeli dolgulu damitma kolonunun denetimi ayirimli model ongormeli kontrol algoritmasi ile gerceklestirilmistir. Dolgulu tepkimeli damitma kolonunda asetik asit ve etanol’un tepkimeye girmesi sonucu etil asetat uretilmistir. Prosesin isletim parametreleri “HYSYS 3.2” yardimi ile optimizasyon teknigi kullanilarak belirlenmistir. Kolonun matematiksel modelleri gelistirilerek sayisal olarak “MATLAB” ortaminda cozulmustur. Benzetim sonuclari deneysel verilerle karsilastirilarak, modellerin gecerliligi gosterilmistir. Ayrica, deneysel dinamik veriler kullanilarak “Neural Network Toolbox” yardimiyla prosesin “Nonlinear AutoRegressive with eXogenous Inputs (NARX)” modelleri de gelistirilmistir. Gelistirilen yapay sinir agi modelleri ayirimli model ongormeli denetim algoritmasinin olusturulmasi icin kullanilmistir. Prosesin iletim fonksiyonlari “System Identification Toolbox” yardimiyla bulunmustur. Bu iletim fonksiyonlari ayirimcilarin (“decouplers”) hesaplanmasi icin kull...
International Journal of Engineering Research in Africa, 2020
Dispersion is one of the fate processes of oil spill. This research has been carried out on the n... more Dispersion is one of the fate processes of oil spill. This research has been carried out on the numerical simulation of the dispersion of crude oil using the model obtained from the work of Hamam (1987). The model was solved with the explicit, implicit and Crank-Nicolson methods of solution of partial differentiation equations with the aid of MATLAB, and the concentration of the crude oil dispersed in water was obtained. The results obtained revealed that the three methods could be used to study the process because the profiles given by all of them were very similar. Also discovered from the investigations carried out was that the concentration of crude oil was decreasing with time for a particular spatial point while, for a particular time, it was increasing along the length of the water body. It was also discovered that experiments would be very necessary in order for the validation of the results obtained from the simulations.
International Journal of Engineering Research in Africa, 2020
Pressure drop in a vertical or deviated borehole has been found to be due to hydrostatic changes ... more Pressure drop in a vertical or deviated borehole has been found to be due to hydrostatic changes and friction as a result of the produced fluids flowing to the surface. When oil flows upwards, the flowing pressure along the tubing string drops, and this makes gas to start liberating. Thus, multiphase flow forms in the tubing string. Hence, adequate modelling of vertical lift performance is required to predict the pressure drop and subsequently the wellbore pressure because many factors are involved [1]. In this work, sensitivity analysis of multiphase flow in a well has been carried out with the aid of PROSPER in which the most accurate correlation was chosen from twelve selected built-in correlations present in the program to predict the pressure drop via gradient matching. A sensitivity analysis of the well was further performed to investigate the parameters such as tubing diameter, gas-oil ratio and wellhead pressure that were affecting the vertical lift performance of a high wat...
Industrial Chemistry, 2018
This study examined the drying behaviour, optimum drying conditions and proximate analysis of Mor... more This study examined the drying behaviour, optimum drying conditions and proximate analysis of Moringa oleifera seeds in a tray dryer. Thirteen (13) experimental data sets were generated using Box-Behnken design of design expert at varying temperature, contact time and fan speed on response surface methodology. Data generated from the experiment were fitted into existing models to determine the best fit using Excel Solver. Experimental data was used to simulate mathematical model developed using Box-Behnken design with the objective of minimizing the moisture content of the moringa seed within the lower and upper bound of 25-50°C (drying temperature), 30-100 mins (contact time) and 0.5-2.5 m/secs (fan speed). It was shown that the moisture ratio decreases with increasing drying time in all the plots with equilibrium moisture content being achieved within the range of 60-90 minutes at different operating conditions. However, the experiments with temperature (50°C) and fan speed (2.5 m/s) exhibited lowest moisture ratio with varying time. Also, the drying rate decreased continuously throughout the drying period in all the graphs with no constant rate period at any of the operating conditions. Wang and Singh model best described the drying behaviour of the Moringa oleifera seeds in a tray dryer with R 2 and χ 2 values of 0.9991 and 0.00017 respectively at drying temperature of 50°C, fan speed of 0.5 m/s and contact time of 65 min. The moringa seeds that were dried at temperature 37.5°C, contact time 65 mins and fan speed of 1.5 m/s have moisture content of 17.71% with highest crude carbohydrate of 75.49%. A minimum moisture content of 16.7390% was obtained at drying temperature of 25°C, contact time of 75 mins and fan speed of 2.5 m/s using the developed optimization model that gives an excellent prediction with R 2 value of 0.9918.
International Journal of Engineering Research in Africa, 2017
The quality and accessibility of drinking water are of paramount importance to human health. Drin... more The quality and accessibility of drinking water are of paramount importance to human health. Drinking water may contain disease causing agents and toxic chemicals, and to control the risks to public health, systematic water quality monitoring and surveillance are required. Thousands of chemicals have been identified in drinking water supplies around the world and are considered potentially hazardous to human health at relatively high concentrations. Heavy metals are the most harmful of the chemical pollutants and are of concern due to their toxicities to humans. Moringa oleifera seed acts as a natural coagulant, adsorbent and antimicrobial agent while commercial activated carbon is known for its excellent heavy metal removal. It is believed that Moringa oleifera seed is an organic natural polymer. This work has been carried out to analyse the removal of some heavy metals (lead, nickel, iron, and zinc) from borehole water using moringa seed powder, activated carbon and a combination ...
International Journal of Engineering Research in Africa, 2017
Moringa oleifera seeds, being good sources of valuable nutrients, contain appreciable amounts of ... more Moringa oleifera seeds, being good sources of valuable nutrients, contain appreciable amounts of crude fat, crude fibre, carbohydrate, crude protein, moisture and ash. The seeds contribute significantly to the nutrient requirements and health management of man and should be recommended in diets. So, efforts need to be made to make the seeds be well preserved while still retaining the nutrients contained in them. In an attempt to contribute to that, this research work has been carried out to obtain the optimum values of the parameters required to appropriately make the seeds be dried without much loss in the nutrients. The optimization of the drying parameters has been carried out, in this work, using Box–Behnken design technique of response surface methodology. The technique was used to design a set of 13 experiments that were carried out. The input factors considered were contact time, temperature and fan speed while the response (output) chosen was the residual moisture content of...
International Journal of Engineering Research in Africa, 2019
This study has been carried out to demonstrate the control of a reactive distillation process in ... more This study has been carried out to demonstrate the control of a reactive distillation process in which the production of biodiesel was taken as the case study using an advanced control method, which is known as dynamic matrix control. The control was accomplished by employing the transfer function model of the reactive distillation process developed, using the System Identification Toolbox of MATLAB, from the dynamic data generated when the prototype plant of the process was simulated with the aid of ChemCAD process simulator. The results obtained from the dynamic matrix control were compared with those of a proportional-integral-derivative (PID) control system tuned with Ziegler-Nichols and Cohen-Coon methods, and it was discovered that the dynamic matrix control was able to perform best among the three (dynamic matrix control method, PID tuned with Ziegler-Nichols method and PID tuned with Cohen-Coon method) because it (the dynamic matrix control) was able to make the biodiesel mo...
Advances in Applied Science Research, 2015
This work has been carried out to study the dynamics of reactive distillation process used for th... more This work has been carried out to study the dynamics of reactive distillation process used for the production ofcis-2- butene and cis-2-hexene from the metathesis reaction of cis-2-pentene. The dynamics was investigated using the 2 x 2 transfer function model of the process developed, with the aid of System Identification Toolbox of MATLAB, from the data generated, through the use of Parametric Utility, by employing the prototype plant of the process modelled with the aid of Aspen HYSYS. The input parameters of the process transfer function model were reflux ratio and reboiler duty while the output parameters were top stage and bottom stage temperatures of the column, which were the temperatures of the products obtained from the reactive distillation column. In order to study the dynamics, step changes of 1 and 0.1 units were applied to the reflux ratio and the reboiler duty respectively, both separately and simultaneously, and the dynamic responses of the output variables were recorded and plotted. The results obtained revealed that both the top and the bottom stage temperatures were able to respond to the step changes applied to the input variables. The response given by the bottom stage temperature upon the application of a unit step change to the reflux ratio was found to be slower than that of the top stage temperature, but both of them were able to get to their steady states within the simulation time used. In addition, the two output variables were found to respond very well in a smooth manner to the simultaneous application of step changes to the input variables, indicating that the chosen input variables were actually having effects on the selected output variables
International Journal of Engineering Research in Africa, May 1, 2017
In the last years, the integration of reaction and distillation in one process, has gained more i... more In the last years, the integration of reaction and distillation in one process, has gained more interest. The mixing of these two operations is especially convenient and shows many advantages. The startup procedure of a conventional distillation column spends a lot of time and energy besides producing offspec products. In reactive distillation, this problem becomes worse once the product cannot be easily recycled, making the start-up procedure very costintensive. In this work, the dynamic simulation of reactive distillation columns is studied in order to analyze different startup procedures. Different strategies were implemented and simulated. Furthermore, an evaluation of uncertainties in model parameters on the startup time was carried out.
International journal of engineering research and technology, Jan 30, 2013
This work was carried out to optimize the esterification process, between myristic acid and isopr... more This work was carried out to optimize the esterification process, between myristic acid and isopropanol, used for the production of isopropyl myristate in a reaction integrated distillation column taking the bottom mole fraction of isopropyl myristate as the objective function and the reflux ratio, the feed ratio and the reboiler duty as the manipulated variables. The experimental setup was built in form of a model using HYSYS 3.2. Response Surface Methodology was used to design the experimental simulations that were carried out. The results of the experimental simulations in addition to the designed experimental parameters were used to develop the model for the bottom mole fraction of isopropyl myristate using Design-Expert 7.0.0. The developed model was theoretically simulated and optimized with the aid of MATLAB R2012a and the theoretical optimum parameters found were used to run the experimental setup. The results obtained showed that the theoretical optimum values obtained with the aid of MATLAB R2012a were valid because the experimental simulation with these values gave the bottom isopropyl myristate mole fraction of 0.9912 that compared very well with the theoretical simulation value of bottom isopropyl myristate mole fraction of 1.0000.
International journal of engineering research and technology, Jul 22, 2013
Methane steam reforming has been simulated, analyzed and optimized with the aid of Aspen Plus, in... more Methane steam reforming has been simulated, analyzed and optimized with the aid of Aspen Plus, in this work. The model of the steam reforming process used was developed using equilibrium reactor type. Both steam reforming process model with and without mixer were developed and simulated in Aspen Plus environment. The sensitivity analyses and the optimization of the process were accomplished using the Sensitivity and the Optimization sections of Model Analysis Tool of Aspen Plus. The results obtained revealed that the simulations with and without mixer gave the same mole fractions of the process components and that the simulation with liquid methane feed was able to produce highmole fraction of the desired product(hydrogen) at approximately atmospheric pressure. Furthermore, it was revealed from the sensitivity analyses of the process that optimization was necessary to obtain the operating variables that would yield hydrogen in very high and highest purity among the components involved in the process and the optimization was able to give a satisfactory value of 0.7432 as the mole fraction of hydrogen present in the top product of the reactor when the optimum reactor temperature, reactor pressure, volumetric flow rate of feed water and volumetric flow rate of feed methane were approximately 964.89 o C, 1 bar, 0.0172 L/min and 0.0353 L/min, respectively.
Advances in Applied Science Research, 2015
This research work has been carried out to investigate the effects of volumetric feed ratio of st... more This research work has been carried out to investigate the effects of volumetric feed ratio of stearic acid and methanol on the purity of the stearic acid methyl ester (SAME) obtained from a reactive distillation processaccomplished through an esterification reaction. The investigation was carried out by developing a model of the process with the aid of Aspen Plus using RadFrac column having 32 stages including the condenser and the reboiler. Wilson model was used as the property package of the simulation. The feeds (top-stearic acid and bottom-methanol) were passed into the column at a temperature and a pressure of 25 o C and 1 atm, respectively. The esterification reaction of the process was modelled as an equilibrium type, the equilibrium constant of which was estimated using Gibbs free energy. In the simulation of the developed Aspen Plus model of the reactive distillation process, the volumetric feed ratio of the column was varied from 3 to 11, and the results obtained showed that the trends of the mole fraction profiles of the components of the process were very similar to one another except those of the feed ratios of 9, 10 and 11 that were a little bit different from the others. Also obtained from the results was that increasing the volumetric feed ratio of the column made the mole fraction of the desired product, which was stearic acid methyl ester and also known as methyl stearate, to decrease. The results obtained have thus revealed that there was an inverseproportional, but not linear, relationship between the volumetric feed ratio of the process and the mole fraction of the desired product. Furthermore, it was discovered from the results that the feed ratio that gave the highest mole fraction of the desired product was 3.
International Journal of Engineering Research in Africa, Jul 1, 2017
The identification of a reactive distillation system for the production of n-butyl acetate from t... more The identification of a reactive distillation system for the production of n-butyl acetate from the esterification reaction between acetic acid and n-butanol has been carried out in this research work. In order to achieve the aim of the research work, a prototype plant of the process was developed using ChemCAD from which dynamics data were generated upon applications of step changes to the reboiler duty and the reflux ratio, which were the input variables of the system. Thereafter, the transfer function of the process, later represented in Simulink environment, was formulated using the dynamics data and with the aid of MATLAB. The simulation of the transfer function model of the system was also carried out for open loop by applying step changes unto the input variables using the developed Simulink model of the system. Thereafter, the closed-loop control system developed also in Simulink environment was simulated by applying step changes to the set-point variable, which was the bottom mole fraction of n-butyl acetate. The results obtained from the simulation of the prototype plant of the reactive distillation process showed ChemCAD to be a powerful tool for steady state and dynamics prototype plant development. Furthermore, good representation and stability were also observed to exist in the system from the formulation and the simulation of the transfer function model of the process, which were carried out with the aid of MATLAB/Simulink. Moreover, the selection of appropriate closed-loop time constant contained in the tuning parameter formulas of IMC-based control system showed that the value suggested by Rivera et al. [1] was very good for this system, compared to those of Chien and Fruehauf [2] and Skogestad [3], because it could give closed-loop dynamic response with comparatively very low values of integral squared error (ISE), integral absolute error (IAE) and integral time absolute error (ITAE) for both proportional-integral (PI) and proportional-integral-derivative (PID) control systems. In addition, the comparison made between the IMC-based tuning approach and other ones (Cohen-Coon, Tyreus-Luyben and Ziegler-Nichols) considered in this work made it known that IMC-based tuning technique was the best among all those considered because its ISE, IAE and ITAE were found to be the lowest for both PI-and PID-controlled cases simulated.
International Journal of Environmental Analytical Chemistry
The mathematical model of an evaporator, showing the dynamic behavior of liquid height and system... more The mathematical model of an evaporator, showing the dynamic behavior of liquid height and system temperature, has been developed. The model was used to investigate the dynamics of the system by simulating the obtained nonlinear differential equations using the ode45 command of MATLAB. Furthermore, using the realistic steady-state values obtained by solving the developed model with the aid of fsolve command of the same MATLAB, the system of transfer function model of the system was obtained via its state space form. Moreover, the Simulink model of the system was developed using the obtained transfer functions of the model. Thereafter, the dynamics of the system was investigated by simulating the Simulink model through the application of input steps to the liquid feed flow rate and the steam temperature of the system. The results obtained from the development of the transfer function models and the simulations carried out when steps were applied to the input variables of the system r...
Solid State Technology, Apr 5, 2021
Solid State Technology, Apr 5, 2021
International Journal of Engineering Research in Africa, 2021
In the recent time, there is increasing research in the area of alternative fuels as the exhausts... more In the recent time, there is increasing research in the area of alternative fuels as the exhausts of presently used petroleum-based fuels have been identified to have negative effects on the environment. Fuels produced from plant oils and animal fats have the tendencies of replacing petro fuels since they are renewable in nature. One of these renewable fuels is biodiesel. However, the homogenous catalyst used in biodiesel production has some drawbacks such as difficulty in separation from the fuel, soap formation and corrosiveness of the product mixture. In this work, the use of heterogeneous catalyst sourced from local raw materials (kaolin and eggshell) for the production of biodiesel from oil of desert date seed has been investigated. The kaolin obtained from Alkaleri Mining Site, Bauchi, was calcined in an oven at 800 °C for 3 h. The calcined kaolin was then chemically activated. Also, the eggshell-based catalyst was produced from raw eggshells after washing, drying, grinding, s...
In this work, the production of biodiesel via reactive distillation process has been modelled and... more In this work, the production of biodiesel via reactive distillation process has been modelled and simulated with the aid of ChemCAD for both steady state and dynamics. Also, the control of the process has been carried out using MATLAB/Simulink. In order to achieve the aim of the work, dynamics data showing the response of biodiesel mole fraction in the column bottoms (controlled variable) to a change in reboiler duty (manipulated variable) and reflux ratio (selected disturbance variable) were extracted from the ChemCAD dynamic simulation of the developed process model and used to obtain the first-order-plus-dead-time transfer function relation between biodiesel mole fraction in the column bottoms, reboiler duty and reflux ratio with the aid of MATLAB. The open loop simulation was done by applying steps to the input variables (reboiler duty and reflux ratio). Furthermore, the set-point tracking and disturbance rejection control of the system were carried out using a PID controller tu...
Bu calismada, tepkimeli dolgulu damitma kolonunun denetimi ayirimli model ongormeli kontrol algor... more Bu calismada, tepkimeli dolgulu damitma kolonunun denetimi ayirimli model ongormeli kontrol algoritmasi ile gerceklestirilmistir. Dolgulu tepkimeli damitma kolonunda asetik asit ve etanol’un tepkimeye girmesi sonucu etil asetat uretilmistir. Prosesin isletim parametreleri “HYSYS 3.2” yardimi ile optimizasyon teknigi kullanilarak belirlenmistir. Kolonun matematiksel modelleri gelistirilerek sayisal olarak “MATLAB” ortaminda cozulmustur. Benzetim sonuclari deneysel verilerle karsilastirilarak, modellerin gecerliligi gosterilmistir. Ayrica, deneysel dinamik veriler kullanilarak “Neural Network Toolbox” yardimiyla prosesin “Nonlinear AutoRegressive with eXogenous Inputs (NARX)” modelleri de gelistirilmistir. Gelistirilen yapay sinir agi modelleri ayirimli model ongormeli denetim algoritmasinin olusturulmasi icin kullanilmistir. Prosesin iletim fonksiyonlari “System Identification Toolbox” yardimiyla bulunmustur. Bu iletim fonksiyonlari ayirimcilarin (“decouplers”) hesaplanmasi icin kull...
International Journal of Engineering Research in Africa, 2020
Dispersion is one of the fate processes of oil spill. This research has been carried out on the n... more Dispersion is one of the fate processes of oil spill. This research has been carried out on the numerical simulation of the dispersion of crude oil using the model obtained from the work of Hamam (1987). The model was solved with the explicit, implicit and Crank-Nicolson methods of solution of partial differentiation equations with the aid of MATLAB, and the concentration of the crude oil dispersed in water was obtained. The results obtained revealed that the three methods could be used to study the process because the profiles given by all of them were very similar. Also discovered from the investigations carried out was that the concentration of crude oil was decreasing with time for a particular spatial point while, for a particular time, it was increasing along the length of the water body. It was also discovered that experiments would be very necessary in order for the validation of the results obtained from the simulations.
International Journal of Engineering Research in Africa, 2020
Pressure drop in a vertical or deviated borehole has been found to be due to hydrostatic changes ... more Pressure drop in a vertical or deviated borehole has been found to be due to hydrostatic changes and friction as a result of the produced fluids flowing to the surface. When oil flows upwards, the flowing pressure along the tubing string drops, and this makes gas to start liberating. Thus, multiphase flow forms in the tubing string. Hence, adequate modelling of vertical lift performance is required to predict the pressure drop and subsequently the wellbore pressure because many factors are involved [1]. In this work, sensitivity analysis of multiphase flow in a well has been carried out with the aid of PROSPER in which the most accurate correlation was chosen from twelve selected built-in correlations present in the program to predict the pressure drop via gradient matching. A sensitivity analysis of the well was further performed to investigate the parameters such as tubing diameter, gas-oil ratio and wellhead pressure that were affecting the vertical lift performance of a high wat...
Industrial Chemistry, 2018
This study examined the drying behaviour, optimum drying conditions and proximate analysis of Mor... more This study examined the drying behaviour, optimum drying conditions and proximate analysis of Moringa oleifera seeds in a tray dryer. Thirteen (13) experimental data sets were generated using Box-Behnken design of design expert at varying temperature, contact time and fan speed on response surface methodology. Data generated from the experiment were fitted into existing models to determine the best fit using Excel Solver. Experimental data was used to simulate mathematical model developed using Box-Behnken design with the objective of minimizing the moisture content of the moringa seed within the lower and upper bound of 25-50°C (drying temperature), 30-100 mins (contact time) and 0.5-2.5 m/secs (fan speed). It was shown that the moisture ratio decreases with increasing drying time in all the plots with equilibrium moisture content being achieved within the range of 60-90 minutes at different operating conditions. However, the experiments with temperature (50°C) and fan speed (2.5 m/s) exhibited lowest moisture ratio with varying time. Also, the drying rate decreased continuously throughout the drying period in all the graphs with no constant rate period at any of the operating conditions. Wang and Singh model best described the drying behaviour of the Moringa oleifera seeds in a tray dryer with R 2 and χ 2 values of 0.9991 and 0.00017 respectively at drying temperature of 50°C, fan speed of 0.5 m/s and contact time of 65 min. The moringa seeds that were dried at temperature 37.5°C, contact time 65 mins and fan speed of 1.5 m/s have moisture content of 17.71% with highest crude carbohydrate of 75.49%. A minimum moisture content of 16.7390% was obtained at drying temperature of 25°C, contact time of 75 mins and fan speed of 2.5 m/s using the developed optimization model that gives an excellent prediction with R 2 value of 0.9918.
International Journal of Engineering Research in Africa, 2017
The quality and accessibility of drinking water are of paramount importance to human health. Drin... more The quality and accessibility of drinking water are of paramount importance to human health. Drinking water may contain disease causing agents and toxic chemicals, and to control the risks to public health, systematic water quality monitoring and surveillance are required. Thousands of chemicals have been identified in drinking water supplies around the world and are considered potentially hazardous to human health at relatively high concentrations. Heavy metals are the most harmful of the chemical pollutants and are of concern due to their toxicities to humans. Moringa oleifera seed acts as a natural coagulant, adsorbent and antimicrobial agent while commercial activated carbon is known for its excellent heavy metal removal. It is believed that Moringa oleifera seed is an organic natural polymer. This work has been carried out to analyse the removal of some heavy metals (lead, nickel, iron, and zinc) from borehole water using moringa seed powder, activated carbon and a combination ...
International Journal of Engineering Research in Africa, 2017
Moringa oleifera seeds, being good sources of valuable nutrients, contain appreciable amounts of ... more Moringa oleifera seeds, being good sources of valuable nutrients, contain appreciable amounts of crude fat, crude fibre, carbohydrate, crude protein, moisture and ash. The seeds contribute significantly to the nutrient requirements and health management of man and should be recommended in diets. So, efforts need to be made to make the seeds be well preserved while still retaining the nutrients contained in them. In an attempt to contribute to that, this research work has been carried out to obtain the optimum values of the parameters required to appropriately make the seeds be dried without much loss in the nutrients. The optimization of the drying parameters has been carried out, in this work, using Box–Behnken design technique of response surface methodology. The technique was used to design a set of 13 experiments that were carried out. The input factors considered were contact time, temperature and fan speed while the response (output) chosen was the residual moisture content of...