Chemical Engineering

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Activation of the carbonaceous material from the pyrolysis of waste tires for wastewater treatment.
(Vaal University of Technology, 2017-07) Malise, Lucky; Seodigeng, T., Dr.; Rutto, H. L., Dr.
The generation of waste tires is one of the most serious environmental problems in the modern world due to the increased use of auto mobiles all over the world. Currently there is a problem with the disposal of waste tires generated since there are strict regulations concerning their disposal through landfill sites. Therefore, there is a need to find ways of disposing these waste tires which pose serious health and environmental problem. The pyrolysis of the waste tires has been recognised as the most promising method to dispose the waste tires because it can reduce the weight of the waste tires to 10% of its original weight and produce products such as pyrolysis oil, pyrolysis char, and pyrolysis char. These products can be further processed to produce value added products. The char produced from the pyrolysis of waste tires can be further activated to produce activated carbon. This study is based on the chemical activation of waste tire pyrolysis char to produce activated carbon for the removal of lead ions from aqueous solution. This was done by impregnating the waste tire pyrolysis char with Potassium hydroxide and activating it inside a tube furnace under inert conditions to produce waste tire activated carbon. Adsorbent characterisation techniques (SEM, FTIR, TGA, XRF, XRD, BET, and Proximate analysis) were performed on the waste tire pyrolysis char and the activated carbon produced to make a comparison between the two samples. The results showed that the waste tire activated carbon produced has better physical and chemical properties compared to the raw waste tire pyrolysis char. Adsorption results revealed that waste tire activated carbon achieves higher removal percentages of lead ions from aqueous solution compared to waste tire pyrolysis char. The results also showed the effect of various process variables on the adsorption process. Adsorption isotherms, kinetics, and thermodynamics were also studied. The adsorption of lead ions agreed with the Freundlich isotherm model for both the waste tire pyrolysis char and waste tire activated carbon. In terms of adsorption kinetics, the experimental data provided best fits for the pseudo-first order kinetic model for both the waste tire pyrolysis char and the waste tire activated carbon. The adsorption thermodynamics study revealed that the process is an exothermic process and spontaneous in nature. Response surface methodology was used to determine the combined effect of process variables on the adsorption of lead ions onto waste tire activated carbon and to optimise the process using numerical optimisation. The optimum conditions were found to be adsorbent dosage = 1g/100ml, pH = 7, contact time = 115.2 min, initial meta concentration = 100 mg/l, and temperature = 25°C to achieve a maximum adsorption capacity of 93.176 mg/l.
The adsorption of Cu(II) ions by polyaniline grafted chitosan beads.
(Vaal University of Technology, 2013-11-06) Igberase, Ephraim; Ofomaja, A., Dr; Osifo, P.O., Dr
This work investigates the possible use of chitosan beads and polyaniline grafted chitosan beads (PGCB) for the adsorption of copper ions from copper contaminated water. For this purpose chitosan flakes were converted to chitosan beads. However, a variable from a number of reaction variables (aniline concentration, chitosan concentration, temperature, acid concentration, reaction time and initiator concentration) was varied while others was kept constant, in an attempt to determine the best conditions for grafting of polyaniline onto chitosan beads. Percentage (%) grafting and % efficiency were key parameters used to determine such conditions. The chitosan beads and PGCB were characterized using physical techniques such as Fourier transformed infra red (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The beads were used as an adsorbent for copper ions removal. The effect of pH on the removal rate of copper (II) by PGCB was investigated on by varying the pH values from pH 3 to 8 at an initial concentration of 40 mg/l. The effect of contact time, initial concentration and temperature was also investigated. The Langmuir and Freundlich model were used to describe adsorption isotherms for chitosan beads and PGCB, with correlation coefficient (R2) as the determining factor of best fit model. The thermodynamics of adsorption of copper (II) onto PGCB was described by parameters such as standard Gibb’s free energy change (ΔGo), standard enthalpy change (ΔHo), and standard entropy change (ΔSo) while the pseudo first-order and pseudo second-order kinetic model was used to describe kinetic data for the PGCB, with R2 and chi- square test (  2) as the determinant factor of best fit model. From the desorption studies, the effect of eluants (HCl and HNO3) and contact time on percentage desorption of PGCB loaded copper (II) ion was investigated upon. In determining the reusability of the PGCB loaded copper (II) ion, three cycles of adsorption/desorption studies was carried out. The results obtained from determining the best conditions for grafting polyaniline onto chitosan beads revealed the following grafting conditions; [Aniline] 0.1 g/l, [temperature] 35oC, [chitosan] 0.45 g/l, [HCl] 0.4 g/l, [(NH4)2S2O8] 0.35 g/l, and [time] 1 h. These conditions were applied in the grafting of polyaniline onto chitosan beads. FTIR analysis showed increase intensity in the grafted beads which provided evidence of grafting, XRD measurement showed a decrease in crystallinity in the PGCB as against the partial crystalline nature of chitosan. In SEM analysis, evidence of grafting was revealed by the closed gap between the polysaccharide particles in the PGCB. From the investigation carried out on the effect of pH on the percentage removal of Cu(II) ions by PGCB, the optimal pH value was found to be pH 5 with a percentage removal of 100% and this value was used for all adsorption experiment. Also from the investigation performed on the effect of contact time and initial concentration, it was observed that there was a sharp increase in the amount of Cu(II) ions adsorbed by PGCB up until contact time of 30 min and thereafter, it increases gradually. From the experiment carried out on the effect of temperature on adsorption capacity, there was an increase in adsorption capacity with increase in temperature. Moreover, at temperatures of 25oC, 35 oC and 45oC the Langmuir model gave the best fit for the chitosan beads having R2 values that are equal and greater than 0.942 in contrast to Freundlich having R2 values that is equal and greater than 0.932. The maximum adsorption capacity (Qm) from Langmuir model at these temperatures were 30.3 mg/g, 47.6 mg/g and 52.6 mg/g respectively. Also, the Langmuir model gave the best fit for the PGCB having R2 values that are equal and greater than 0.956 in contrast to Freundlich model with R2 values that is equal and greater than 0.935. The Qm from Langmuir model at these temperatures were 80.3 mg/g, 90.9 mg/g and 100 mg/g respectively. The values of Qm for PGCB appears to be significantly higher when compared to that of chitosan beads and this makes PGCB a better adsorbent than chitosan beads. From the thermodynamic studies carried out on PGCB, the values of ΔGo were negative and this denotes that the adsorption of copper ions onto PGCB is favorable and spontaneous, the positive value of ΔHo shows the adsorption process is endothermic and the positive value of ΔSo illustrate increased randomness at the solid-liquid interface during the adsorption process. Also, from the kinetic studies carried out on the PGCB, the pseudo second-order kinetic model best described the kinetic data having R2 values that are equal and greater than 0.994 in contrast to the pseudo first-order kinetic model with R2 values that is equal and greater than 0.913. The  2 values for the pseudo first-order and pseudo second-order kinetic model were similar; however, there was a large difference for qe between the calculated (qeCal) values of the first-order kinetic model and experimental (qeExp) values. In the case of the pseudo second-order model, the calculated qe values agree very well with the experimental data. Desorption of the metal ions from PGCB was efficient. 0.5 M HCl was successfully used in desorbing the beads loaded with copper ions and a percentage desorption of 97.1% was achieved at contact time of 180 min. PGCB were successfully re-used for adsorption/desorption studies were a Qm of 83.3 mg/g, 83.3 mg/g and 76.9 mg/g was achieved in the first, second and third cycle respectively.
Application of neural network techniques to predict the heavy metals in acid mine drainage from South African mines
(Vaal University of Technology, 2022-04) Maliehe, Andani Valentia; Osifo, P., Prof.; Matjie, H., Dr.; Tshilenge, John Kabuba, Prof.
Acid mine drainage (AMD) refers to acidic water generated during mining activities and is characterised by a low pH, high salt content, and the presence of heavy metals. To treat water sources contaminated with AMD, sampling and laboratory analysis will have to be done for each water source to determine the concentrations of heavy metals. This process is time-consuming, high in cost and may involve human error or negligence. The application of neural network (NN) techniques to predict the heavy metals in AMD from South African mines has been presented. Four specific objectives were pursued in this dissertation. The first one was to identify AMD and analyse for heavy metals in the AMD. Heavy metals that were identified and found to be in high concentrations in the AMD sample from Sibanye Western Basin AMD Treatment Plant are Zn, Fe, Mn, Si, and Ni. The other objectives of the study were to determine the input, output, and hidden layers of the NN structure (application of NN); (2) to find the appropriate algorithm to train the NN, and to compare the NN results (outputs) with the measured concentrations of major heavy metals sampled (targets). The Backpropagation Neural Network (BPNN) model had three layers which included the input layer (pH, SO42−, and TDS), the hidden layer (five neurons) with a tangent sigmoid transfer function (tansig) and the output layer (Cu, Fe, Mn, and Zn) with linear transfer function (purelin). The predictions for heavy metals (Zn, Fe, Mn, Si, and Ni) using the NN method focusing on a BP forward pass (feed-forward backpropagation NN) with ten different algorithms were presented and compared with the measured data. The mean square error (MSE) value was calculated for ten algorithms and compared to identify the one that is most appropriate for the prediction process and the model by having the lowest value. It was determined that the Levenberg-Marquardt back-propagation (trainlm) algorithm resulted in the best fitting during training because it resulted in an MSE value of 0.00041, meaning the error was very low when this algorithm was used.
Application of nonwoven microfiltration membrane on activated sludge final effluent: improving wastewater quality for re-use
(Vaal University of Technology, 2022-04) Masala, Murendeni Shonisani; Topkin, James; Tshilenge, J. Kabuba, Prof.
Water scarcity is one of the biggest problems that South Africa is facing currently, as a results it limits economic and social development. The application of membrane technology in wastewater treatment for re-use is one of the alternatives to reduce the demand of water in domestic, agricultural and industrial sectors. The primary aim of this study was to improve effluent wastewater quality prior to disinfection for re-use. This was done by diverting biological nutrient removal (BNR) clarifier effluent to a pilot nonwoven membrane filtration unit. The physical barrier provided by this unit, together with the effect of aeration within this system, provided particulate, physicochemical, and microbial removal. Monitoring of water quality was attained from the BNR clarifier effluent, and the nonwoven membrane permeate. Water quality trends against the standards were analysed for compliance with a water use license (WUL), and the removal efficiency for the permeate was also determined. The Single Factor Pollution Index (Pi) was used to determine the extent of pollution in the BNR clarifier effluent and the permeate, while the Water Quality Index (WQI) was utilised to determine the suitability of water derived from the BNR clarifier effluent and the permeate for re-use. Water Use Licence standards were utilised to determine the Water Quality Index of the BNR clarifier effluent and the permeate. Results for the BNR clarifier effluent showed that the physicochemical water quality parameters comply with the limits however, electrical conductivity (EC) and microbial water quality Escherichia coli (E. coli) were exceeded. Permeate results indicated that physicochemical and microbial parameters were compliant with the limits of the WUL. E. coli reduction was the highest with a removal efficiency of 90%, followed by chemical oxygen demand (COD) at 25%, NH4N at 22%, NO3 at 12.6%, PO4 at 7.8%, suspended solids (SS) at 6.3%, and the lowest was EC at 5.2%. The Single Factor Pollution Index has revealed that the BNR clarifier effluent water quality is medium polluted and the permeate water quality is slightly polluted. The WQI results for the BNR clarifier effluent showed good water quality and the water can be re-used for domestic, irrigation, and industrial purposes, while permeate WQI results indicated excellent water quality and the water can be re-used for drinking, domestic, irrigation, and industrial purposes. Outstanding permeate water quality improvement was observed on E. coli counts improving from 4974.48 counts/L to 294.33 counts/L. The standard of E. coli according to the WUL at Waterval WCW is 500 counts/L. The results indicate that nonwoven membrane filtration can improve microbial contamination and decrease the demand of chlorine for disinfection of wastewater final effluent. The nonwoven membrane filtration can decrease the water scarcity gap in South Africa for direct water reclamation by improving effluent wastewater.
An application of reverse osmosis process on effluent treatment for the rubber industry
(2009-05) Ralengole, Galebone; Van der Merwe, H.; Modise, S. J.
The methods used to remove potassium sulphate (K2S04) and other impurities contained within Karbochem finishing plant effluent were investigated. Reverse osmosis was explored for this application. The study was conducted in two steps. The first step focuses mainly on the effluent treatment using BW30 flatsheet as well as BW30-2540 spiral-wound reverse osmosis membranes for the rejection of potassium and sulphate ions. The membranes were supplied by Filmtec. The second step reveals the possible use of potassium sulphate obtained from the brine stream in the fertiliser and fertigation industry by a literature search. Reverse osmosis study was conducted on a laboratory scale unit using flat sheet membranes and also on a pilot plant scale using spiral wound membrane modules. The tests were conducted at a feed pressure of 20 bar(g) with the membrane rejections being 98% and 99.1% on flat sheet membrane, and 96.9% and 99.4% on spiral wound membrane for potassium and sulphates respectively. The results show that both membranes have completely desalinated. Significant reduction in the concentrations of all problematic quality parameters, especially of potassium and the sulphate ions was noted. Granular activated carbon (GAC) bed treatment was recommended for pretreatment of the effluent prior to exposure of the membrane to avoid organic fouling of the membrane. GAC treatment was tested to illustrate its effectiveness to adsorb the COD's.
Biodiesel production and evaluation of heterogeneous catalyst using South African oil producing trees
(Vaal University of Technology, 2014-01) Modiba, Edward Magoma; Osifo, Peter, Prof.; Rutto, Hillary, Dr.
This study presents the use of sodium methoxide as a homogeneous catalyst and impregnated Perlite (potassium hydroxide/perlite) as heterogeneous catalyst for production of biodiesel using Baobab and Marula oil respectively. One factor at a time experimental design was used to study the effect of temperature, time, amount of catalyst and methanol to oil ratio on the transesterification of baobab oil using sodium methoxide as a catalyst. Response surface methodology was used to study the effect of temperature, time, amount of catalyst and methanol to oil ratio on the transesterification of marula oil using perlite as a catalyst. Biodiesel yield produced using sodium methoxide and baobab oil was 96% at 1 hr reaction time, 30 wt.% methanol to oil ratio, 1 gram of catalyst and 60°C reaction conditions. Biodiesel yield produced using perlite and marula oil was 91.38% at 3.55 hr reaction time, 29.86 wt.% methanol to oil ratio, 3.46 grams of catalyst and 70.41°C reaction conditions. Perlite catalyst was reusable for transesterification of marula oil while sodium methoxide was not reusable for transesterification of baobab oil. Baobab and Marula biodiesel fuel properties are comparable to American Society for Testing Materials standard (ASTM).
Biodiesel production using cellulose-supported calcium hydroxide heterogeneous catalyst. phosphate rock as a catalyst precursor
(Vaal University of Technology, 2022-06) Kiprono, Janet Jematia; Rutto, H. L., Prof.
Due to rising gasoline prices and growing worldwide worries about climate change and environmental pollution, the need for a clean, environmentally friendly fuel such as biodiesel has recently gained traction. This has demanded greater study into more efficient techniques to boost biodiesel production. The current study focuses on making and improving the efficiency of calcium hydroxide heterogeneous catalyst to be used in biodiesel manufacturing from waste cooking oil. Phosphate rock, a primary mineral mined in South Africa, containing the compound calcium carbonate in higher quantities, was used to prepare calcium nitrate, a useful compound in nature. Calcium nitrate was then reacted with cellulose nanoparticles and sodium hydroxide solution to obtain cellulose-supported calcium hydroxide catalyst through the co-precipitation method. Characterization techniques such as SEM and FTIR were used to confirm calcium hydroxide loading on the cellulose support material. The efficiency of the synthesized catalyst in the transesterification process was studied by varying the alcohol to oil ratio, amount of catalyst, the reaction temperature, reaction time, and the reusability cycles of the catalyst through one factor at a time method and response surface methodology. Artificial neuron network was later used in the prediction of biodiesel yield. High regression coefficient values were obtained, indicating the efficiency of artificial neuron network tool in the prediction of biodiesel. Calcined phosphate rock is also tested for use as a heterogeneous catalyst for biodiesel production. This is based on the fact that when calcium carbonate in the rock is subjected to extremely high temperatures, the carbonates undergo decomposition releasing carbon iv oxide gas thus forming calcium oxide. This oxide also proved to be an active catalyst for transesterification. The efficiency of this catalyst was also tested through one factor at a time and response surface methodology. Both cases obtained a higher biodiesel yield.
Biogas production from solid food waste and its use for electricity production
(Vaal University of Technology, 2021-10-15) Khune, Selebogo Mervyn; Ochieng, Aoyi, Prof.; Otieno, Benton, Dr.; Osifo, Peter, Prof.
An enormous amount of food waste (FW) is generated worldwide. Most of this waste is discarded in landfills, where it undergoes uncontrolled anaerobic digestion (AD) process, which emits excessive amounts of greenhouse gases, (methane and carbon dioxide), thereby contributing to global warming. A controlled AD of FW is key for organic waste management with a positive impact on the environment and economy. In South Africa (SA) there is little uptake of biogas technology for FW management due to little research on biogas potential at small to large scale. Furthermore, there is an over reliance on foreign data, which leads to misfit parameters to local raw materials; consequently, producing biogas of low quality and quantity with low degradation of waste. Biogas with poor quality reduces the efficiency of biogas conversion to energy and the low production rate makes the system less feasible. Considering the challenges faced with FW management and the little uptake of the AD technology in SA, this study aimed to treat FW through AD and convert the biogas produced to electricity. A complete-mix biogas pilot plant (VUT-1000C) was designed, constructed and commissioned. The materials used for constructing the pilot plant were sourced locally to prove the applicability of the AD technology in SA. The biodigester was operated at mesophilic temperature, 37 oC, aided by a solar system. A stand-alone 1 m3 plug-flow ambient biodigester (STH-1000A) was operated semi-continuously as well as a control. Cow dung (CD) was used to inoculate the biodigesters, which were then operated semi-continuously at their optimum organic loading rate (OLR). The STH-1000A digester was operated at 0.446 kgVS/m3/day OLR, according to the manufacturer’s specification, while for VUT-1000C, the OLR was determined. The highest biogas and methane yields obtained were 582 and 332 L/kgVS/m3, respectively, at the determined optimal OLR of 1.5 kgVS/m3/day for the VUT-1000C digester this was supported by the modified Gompertz model with an R2 value of 0.9836. VUT-1000C produced 1200 L/day while STH-1000A produced 150 L/day. VUT-1000C proved to be a more effective biodigester than STH-1000A owing to the digester design and operation at mesophilic conditions. The key design findings are higher reactor working volume and high digester temperature. From the 1000 L of biogas produced from VUT-1000C, 1.8 kW of electricity was generated, which is equivalent to powering 300 6W light bulbs for 1 hour. The energy balance of the pilot plant showed that only 10 percent of the energy output was required to operate the plant. These results show that SA has a 475 GWh energy potential based on the current FW figures. Furthermore, the study has shown that biogas technology is readily available for South Africans and that the designed biogas plant was very efficient in FW-to-energy conversion.
Chitosan modification with cellulose - gelatin to remove heavy oil from wastewater
(Vaal University of Technology, 2022-08-30) Fundji, Wato Nathan; Igberase, Ephraim, Dr.; Tshilenge, John Kabuba, Prof.
In this study, Chitosan was modified with cellulose and gelatin for the removal of Cu2+, Fe2+, and Pb2+ from oily wastewater. Membranes were prepared and characterized using Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X - Ray Diffraction (XRD). Their changes and permeabilities were studied and showed that pH values slightly changed. The effects of pH solution and conductivity were investigated. Adsorption study was performed to remove the heavy metals. The results revealed that the highest % removal of Cu2+ was 96.62 (pH = 7.52 and conductivity = -12 mV), of Fe2+ was 97.95 (pH = 6.30 and conductivity = +68 mV) and of Pb2+ was 98.86 (pH = 10.58 and conductivity = -170 mV) for the 12: 2: 2 ratio and for the other ratio, results were quite similar. To analyse the impacts of experimental factors, experiments were developed using Central Composite Design (CCD) based and the Response Surface Methodology (RSM). R2 values were 0.99, 0.99 and 0.98 correspondingly to the analysis of variances of Cu2+, Fe2+, and Pb2+, respectively while using the 12: 2: 2 ratio but for the other ratio, results were almost the same. In interpreting the experimental data, the quadratic models were significant and appropriate. For all models, the variations between experimental and predicted values of % Removal were insignificant. The resulting 3D response surface graphs allowed for a paired investigation of variable influences upon every response model. This study aimed to develop a new chitosan membrane as a film-forming material with a lower acid content and improved mechanical properties in order to remove heavy oil from wastewater.
Corrosion behaviour of ferrous and non-ferrous alloys exposed to sulphate - reducing bacteria in industrial heat exchangers
(Vaal University of Technology, 2018) Prithiraj, Alicia; Osifo, Prof. P. O.; Otunniyi, Prof. I. O.
Corrosion responses of some carbon steels, stainless steel and copper alloys in the presence of a culture of bacteria (referred to as SRB-Sulphate-reducing bacteria) found in industrial heat exchangers, was studied to recommend best alloys under this service condition, with techno-economic consideration. Water from cooling towers in three plants in a petrochemical processing complex were analysed for SRB presence. Two of the water samples showed positive indication of SRB presence. The mixed cultures obtained from plant one were grown in prepared media and incubated at 35 °C for 18 days. Potentiodynamic polarisation studies in anaerobic conditions were done on the selected alloys in aqueous media with and without the grown SRB. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were then used to study the corrosion morphology and corrosion products formation. The voltamograms show higher icorr for alloys under the SRB compared to the control media, indicating the SRB indeed increased the corrosion rates. The surface analysis showed pitting on steel alloy ASTM A106-B. Localised attack to the grain boundaries on a selective area, was seen on ASTM A516-70 dislodging the grains, and intergranular corrosion was seen throughout the exposed area of ASTM A179. Copper alloys showed pitting on ASTM B111 grade C71500 (70-30), and denickelification on ASTM B111 grade C70600 (90-10), and is a good alternative material for use apart from carbon steel alloys, recording a low corrosion rate of 0.05 mm/year. The EDS analysis supported the findings showing higher weight percent of iron and sulphur on surface of the alloys after exposure to the SRB media. This implies that the presence of the sulphur ion indeed increased the corrosion rate. ASTM A516-70 carbon steel was chosen as a suitable alternative material to the stainless steel in this environment. The Tafel plot recorded a corrosion rate of 1.08 mm/year for ASTM A516-70 when exposed to SRB media.
Desulfurization of waste tire pyrolytic oil (TPO) using adsorption and oxidation techniques
(2018-01) Mello, Moshe; Seodigeng, T; Rutto, H. L.
The presence of tires in open fields, households and landfills is a great threat to the wellbeing of the ecosystem around them. Tire creates an ideal breeding ground for disease carrying vermins and their possible ignition threatens the surrounding air quality due to the harmful gases produced during combustion. Pyrolysis of tires produces four valuable products namely; char, steel, tire pyrolytic oil (TPO) and noncondensable gases. TPO has been reported to have similar properties to commercial diesel fuel. The biggest challenge faced by TPO to be used directly in combustion engines is the available sulfur content of about 1.0% wt. Considering the stringent regulations globally for allowable sulfur content in liquid fuels, TPO therefore, requires deep desulfurization before commercialization. In this study, different desulfurization techniques were applied to reduce the sulfur content in TPO. A novel study on combination of adsorptive and air-assisted oxidative desulfurization (AAOD) was developed for desulfurization of TPO. Different carbon materials were employed as catalyst and/or adsorbent for the AAOD system. The effect of operating conditions; catalyst/adsorbent dosage, H2O2/HCOOH ratio, reaction time, temperature and air flowrate were studied. Oxidation equilibrium was reached at 80 °C for both commercial activated carbon (CAC) and activated tire char (ATC) at a reaction time of 50 min. With a total oil recovery of more than 90% and the initial sulfur content of 7767.7 ppmw, the presence of air at a flow rate of 60 l/hr increased oxidation from 59.2% to 64.2% and 47.4% to 53% for CAC and ATC, respectively. The use π-complexation sorbent was also applied to study the selectivity of such sorbents to organosulfur compounds (OSC) found in liquid fuels. The π-complexationbased adsorbent was obtained by ion exchanging Y-zeolite with Cu+ cation using liquid phase ion exchange (LPIE). Batch adsorption experiments were carried out in borosilicate beakers filled with modified Cu(I)-Y zeolite for both TPO and synthesized model fuels. For model fuels (MF), the selectivity for adsorption of sulfur compounds followed the order dibenzothiophene (DBT)> benzothiophene (BT)> Thiophene.
Desulphurization of diesel fuel using carbon-based metal oxide nanocomposites
(Vaal University of Technology, 2021-04) Cherubala, Rusumba Bienvenu; Rutho, L., Prof.; Tshilenge, J. K., Dr.
This thesis presents a slight on desulphurization process of the commercial diesel fuel using the carbon-based metal oxide nanocomposites such as graphene oxide, ZnO, rGO as a nano-adsorbent, activated carbon (PAC and AC) and charcoal Granular active carbon (GAC) to produce a fuel of less than 10 ppm sulphur content. Due to the high percentage of sulphur compounds in the fuel causing air pollution, acid rain and other problems related to combustion process. The synthesised of sorbents were achieved using incipient impregnation, microwaved-assisted and chemical exfoliation methods. The materials were characterized using Thermogrametric Analyzer (TGA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD), Brunauer, Emmett and Teller (BET). The examination effect of operating conditions on the adsorption capacity with DBT and Sulphur compounds adsorption, the isotherms and the adsorption kinetic models were evaluated. The experimental data for PAC and AC were well suited to Freundlich isotherm and pseudo second-order kinetic models. The results shown that the sulphur feed concentration, the space velocity and the functional groups of the adsorbents have a considerable effect on the adsorption. In addition, it was observed that the temperature in the range of 30 to 80oC has a significant effect on the adsorption of Sulphur compounds from diesel fuel using 20 wt.% of sorbents. The rGO substrate which contained abundant oxygen functional groups was confirmed to promote the dispersion metal oxide and increased the adsorption efficiency of sulphur compounds (H2S and SO2) by providing oxygen ions weakly bound to the sulphur molecules. For the desulfurization process by adsorption, PAC and AC exhibited a better affinity for 80% removal of sulphur compared to the GAC and GO. The effects of metal species such as zinc oxide (ZnO) and reduced graphite oxide (rGO) composite on the adsorption capacity of hydrogen sulphide (H2S) were investigated. It was found that depending on the copper load, the adsorption capacity of H2S increased up to 20 times compared to pure ZnO. To study the oxidation changes on copper and zinc oxides, crystallite analysis by XRD and chemical state analysis by XPS were performed.
Development of sulfonated chitosan membranes modified with inorganic nanofillers and organic materials for fuel cell applications
(Vaal University of Technology, 2021-07-06) Zungu, Nondumiso Petunia; Ofomaja, A., Prof.; Osifo, P. O., Prof.
Fuel cell technology is a promising clean energy source compared to internal combustion engines and electricity generating plants which are associated with high emissions of greenhouse gases. The aim of this study was to modify chitosan into polymer electrolyte membranes suitable for use in PEMFC and DMFC fuel cells. Chitosan modification was done with 2-aminoethanesulfonic acid (2-AESA), dimethylformamide (DMF) and silica nanoparticles. The effect of the modification on the properties of the developed chitosan membranes was studied using FTIR, XRD, SEM-EDS and TGA. The performance of the membrane electrode assemblies was investigated. The formation of electrostatic interactions in the developed sulfonated chitosan membranes was confirmed via the Fourier transform infrared (FTIR) analysis, indicating a shift in the wavenumber of the N-H bonds from 1581 cm-1 on the chitosan spectrum to a lower wavenumber of 1532 cm-1 in the FTIR spectra of the membranes and by the new peak at the wavenumber of ~1260 cm-1 attributed to the asymmetric O=S=O stretching vibrations of the sulphate groups and sulfonic acid groups from the cross-linking sulphuric acid solution and 2-aminoethanesulfonic acid incorporated on the chitosan polymer chain during the modification. Notably, the FTIR spectra of the developed sulfonated chitosan membranes lacked the peak at the wavenumber of ~1153 cm-1 attributed to the stretching of C-O-C bonds of the polysaccharide ring of chitosan. A reaction mechanism was proposed in this study illustrating the possible conversion of the polysaccharide rings of chitosan into a poly (cyclohexene-oxide) thermoplastic rings in the developed membranes. The TGA/DTGA results of the developed sulfonated chitosan membranes showed three degradation stages. The initial weight loss occurred at temperatures ˂100 °C due to the evaporation of volatile components and water molecules inside the membranes. The second degradation phase of the membranes occurred at 208 ℃ with a loss in weight of >30% resulting from the decomposition of cross-linking networks. The third degradation stage was associated with the decomposition of the main polymer backbone of the membranes and occurred at 263°C for the chitosan membranes modified with 2-aminoethanesulfonic acid and at 266 °C for the chitosan membrane modified with silica nanofiller. The TGA/DTGA curves of Nafion 117 showed a small loss in weight of ~ 5% before a sharp decomposition that occurred between 346–505 °C. The XRD diffractograms of the developed sulfonated chitosan membranes showed amorphous phases, the crystal peaks of chitosan at 2theta of 10° and 20° were flattened on the membranes. The SEM images showed a homogenous surface morphology for the sulfonated chitosan membrane with a higher weight percentage of 2-aminoethanesulfonic acid (13,6 wt.%). The SEM images performed on the surface of the sulfonated chitosan membrane modified silica nanoparticles showed a slight agglomeration associated with the migration of the unbonded silica to the surface. The methanol permeability coefficient of the developed sulfonated chitosan membrane modified with 2-aminoethanesulfonic acid was calculated to be 2.29x10-6 cm2/s. This value was close to the methanol permeability coefficient of 2.33x10-6 cm2/s associated with unfavourable depolarisation at the cathode in direct methanol fuel cells when using Nafion 117. The proton diffusion coefficient of Nafion 117 was calculated to be 1.64x10-5 cm2/s and that of the developed sulfonated chitosan membrane modified with 2-aminoethanesulfonic acid was found to be 6.56x10-6 cm2/s, respectively. The fuel cell performance of the developed sulfonated chitosan membrane modified with 2AESA was investigated in a hydrogen fuel cell (PEMFC) supplied with H2 and O2 directly from the electrolyser. The sulfonated chitosan membrane modified with 2-aminoethanesulfonic acid (13.6 wt.%) achieved an open-circuit voltage of ~0.9 V and a maximum power output of 64.7 mW/cm2 at a maximum current of 70 mA. The current produced by the developed chitosan membrane was applied into the load and was able to turn (power) the electric fan. The sulfonated chitosan membrane modified with silica nanoparticles (2 wt.%) yielded an open-circuit voltage of ~0.9 V and attained a maximum power output of 58 mW/cm2 at a maximum current output of 60 mA/cm2. The current generated by the membrane was also able to turn the electric fan. The Nafion 117 membrane was also investigated under similar conditions and obtained an open-circuit voltage of 0.6 V and a maximum power output of 130 mW/cm2 at the maximum current output of 308 mA. The current produced by Nafion 117 was supplied into the load and was able to turn the electric fan.
Electrocatalytic degradation of industrial wastewater using iron supported carbon-cloth electrode via Electro-Fenton oxidation process
(Vaal University of Technology, 2022-02) Emeji, Ikenna Chibuzor; Ama, O. M., Dr.; Osifo, P. O., Prof.
Human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) causes morbidity and mortality in infected patients. These epidemics are significantly reduced and treated globally with antiretroviral drugs (ARVDs). However, the eventual disposal of the ARVDs, either by excretion or otherwise, enables them to end up as emerging hazardous contaminants in our environment. Of all the available methods to remove ARVDs from our water bodies, electrochemical methods are reckoned to be one of the most effective. As a result, it is imperative to acknowledge the interactive behavior of these pharmaceuticals on the surface of the electrode. In this study, iron nano-particles were deposited on the carbon cloth electrode by electrodeposition using chronoamperometry techniques. The synthesized electrode was characterized using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), and x-ray photoelectron spectroscopy (XPS) microanalysis. The electrochemical characterization of the material was also carried out using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrode's electrocatalytic activity toward the generation of hydrogen peroxide (H2O2) through a two-electron oxygen reduction reaction was assessed. Furtherance to this is the electrochemical degradation of nevirapine (NVP), lamivudine (LVD), and zidovudine (ZVD) in wastewater as a pharmaceutical model compound for organic pollutants in 50 mM K2SO4 electrolyte at a pH of 3. The SEM and EDX analysis showed the formation of iron nanoparticles within the matrix structure of the carbon cloth (CC) electrode. The XPS enlightened the presence of oxygen functional groups in the electrode's structure. EIS results are indicative that the modified electrode has a decreased charge transfer resistance (Rct)value as compared to the bare CC electrode. On the other hand, the CV result fosters good conductivity, enhanced current and large surface area of the modified electrode. More active and anchor sites were discovered on the iron-supported CC electrode which resulted in higher catalytic activity for the generation and accumulation of H2O2. The concentrations of “in-situ” generated H2O2 were found to be related to the current density supplied to the device after quantification. Although the accumulated H2O2 concentration appears to be low, it's possible that side reactions depleted the amount of H2O2 produced. As a result, the oxygen reduction reaction (ORR) through 2e- has a higher electrocatalytic activity with the improved iron assisted CC electrode than bare CC electrode. The electrochemical degradation studies conducted with the modified CC electrode by electro-Fenton process show a decrease in the initial ARVDs concentration (20 mg/L) as compared with the bare electrode. Their rate constants were 1.52 x 10-3 mol-1min-1 for ZVD, 1.20 x 10-3 mol-1min-1 for NVP and 1.18 x 10-3 mol-1min-1 for LVD. The obtained removal efficiencies indicate that the iron nanoparticle in the synthesised improves the degradation efficiency.
Electroflocculation of river water using iron and aluminium electrodes
(2008-09) Mashamaite, Aubrey Nare; Van der Merwe, H. C.
A novel technology in the treatment of river water, which involves an electrochemical treatment technique to produce domestic or drinking water is being investigated using aluminium and iron electrodes in an electrochemical circuit. Coagulation and flocculation are traditional methods for the treatment of polluted water. Electrocoagulation presents a robust novel and innovative alternative in which a sacrificial metal anode treats water electrochemically. This has the major advantage of providing mainly active cations required for coagulation and flocculation, without increasing the salinity of the water. Electrocoagulation is a complex process with a multitude of mechanisms operating synergistically to remove pollutants from the water. A wide variety of opinions exist in the literature for key mechanisms. A lack of a systematic approach has resulted in a myriad of designs for electrocoagulation reactors without due consideration of the complexity of the system. A systematic, holistic approach is required to understand electrocoagulation and its controlling parameters. An electrocoagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium and/or iron electrodes. The water to be treated (river water) was subjected to coagulation, by Al(III) and Fe(II) ions dissolved from the electrodes, resulting in floes floating after being captured by hydrogen gas bubbles generated at the cathode surfaces. Apparent current efficiencies for AI and Fe dissolution as aqueous Al(III) and Fe(II) species at pH 6.5 and 7.8 were greater than unity. This was due to additional chemical reactions occurring parallel with electrochemical AI and Fe dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation plus reduction) currents at both anodes and cathodes. Investigation results illustrate the feasibility of ferrous and aluminium ion electrochemical treatment as being a successful method of water treatment. Better results were achieved under conditions of relatively high raw water alkalinity, relatively low raw water turbidity, and when high mixing energy conditions were available.
Flue gas desulphurization by spray dry scrubbing
(Vaal University of Technology, 2022-03) Koech, Lawrence; Everson, R. C., Prof.; Hattingh, B. B., Prof.; Neomagus, H. W. J. P., Prof.; Rutto, H. L., Prof.
Post combustion sulphur dioxide (SO2) emission is a major problem facing coal-based power plants. Increased awareness of the detrimental effects of SO2 on human health and the environment has prompted increased pressure to equip power plants with flue gas desulphurization (FGD) systems. FGD is a commercially proven technology for removal of SO2 from flue gas which is considered as a significant pollutant to the environment. Spray dry scrubbing (SDS) process represents a type of semi-dry FGD which is a low-cost retrofit SO2 control technology that could be used in already existing coal-fired power plants. This study explored the experimentation on the performance of a laboratory-scale spray dryer involving flue gas desulphurization (FGD). The experimentation involved test done to investigate the effects of spray characteristics i.e., inlet gas phase temperature, approach to saturation temperature, and calcium to sulphur ratio on SO2 removal efficiency using hydrated lime as a sorbent. Results indicated improved SO2 removal efficiency with increasing the stoichiometric ratio and decreasing the temperature and approach to saturation temperature. An absorption efficiency of SO2 beyond 90% was achieved at a stoichiometric ratio of 2.5. A high degree of conversion of calcium was realized at low stoichiometric ratios with a maximum utilization of 94% obtained at a stoichiometric ratio of 1.5. This study also investigated the interaction effects of independent variables on SO2 absorption using response surface methodology. By analyzing the influence of stoichiometric ratio, inlet gas phase temperature, slurry solid concentration and slurry pH, a predictive quadratic model was developed correlating the independent variables and SO2 removal efficiency. Although all independent variables had impact SO2 removal efficiency, stoichiometric ratio was found to have the largest influence. The recommended optimal conditions for SO2 absorption were inlet gas phase temperature of 140℃, stoichiometric ratio of 2, slurry solid concentration of 8% and slurry pH of 10 to achieve 90% SO2 removal efficiency. An investigation into performance of relevant spray dying FGD sorbents was carried by evaluating different sorbents namely: hydrated lime, limestone and trona. Results show that trona had better performance characteristics with the highest SO2 absorption efficiency when compared to hydrated lime and limestone under the same operating conditions. The analysis of the desulphurization product revealed that trona has better sorbent conversion and utilization in comparison with limestone and hydrated which contained high concentration of unreacted sorbent in the desulphurization product.
Hybrid light photocatalysis of aromatic wastes in a fluidized bed reactor
(Vaal University of Technology, 2022-08) Akach, John Willis Juma Pesa; Tshilenge, John Kabuba, Prof.; Aoyi, Ochieng, Prof.
The use of solar photocatalysis for the treatment of aromatic chemicals like phenol in wastewater has attracted significant attention due to the low cost of sunlight. However, sunlight is unreliable since its intensity fluctuates during the day. This drawback can be addressed by supplementing sunlight with artificial UV lamps when the solar intensity reduces. In this work, such a hybrid solar/UV lamp reactor, internally illuminated by the UV lamp and externally by sunlight, was designed. Phenol was used as the model pollutant and the nanophase Aeroxide P25 TiO2 was employed as the photocatalyst and fluidized by compressed air. The catalyst and bubble distribution in the reactor was analysed using computational fluid dynamics (CFD) while the Monte Carlo (MC) method was used to model the light distribution and reaction kinetics. Finally, a lamp controller was designed to specify the required UV lamp output as a function of the solar intensity. The CFD simulation using ANSYS CFX 17 showed that a fairly homogeneous distribution of the catalyst was achieved in the reactor. Consequently, accurate simulations of the light distribution could be achieved without considering the hydrodynamics. The MC models revealed that bubbles did not significantly influence light absorption at the optimum catalyst loading. This showed that air was a good medium for fluidization as it could provide good mixing and oxygen electron acceptor without negatively affecting light absorption. The forward scattering behaviour of the P25 TiO2 and the increase in light attenuation with catalyst loading was confirmed in this work. The optimum catalyst loading in the different reactor configurations was 0.15 g/L (tubular solar), 0.2 g/L (annular solar), 0.4 g/L (annular UV lamp), and 0.4 g/L (hybrid light). This resulted in experimental reaction rates of 0.337 mgL-1min-1 (tubular solar), 0.584 mgL-1min-1 (annular UV lamp), and 0.93 mgL-1min-1 (hybrid light). An analysis of the local volumetric rate of energy absorption (LVREA) and reaction rate profiles along the radial coordinate showed a non-uniformity which worsened with an increase in catalyst loading. The reaction order with respect to the volumetric rate of energy absorption (VREA) indicated that solar illumination resulted in a higher electron-hole recombination as compared to UV illumination. This, combined with the higher intensity of the UV lamp, resulted in a higher reaction rate under UV light as compared to sunlight, demonstrating that the UV lamp could be used to supplement sunlight. For a typical sunny day, a lamp controller was designed that could adjust the UV lamp output as a function of the solar intensity to maintain the reaction rate at a reference level while ensuring less energy consumption than an ON/OFF lamp controller. This work demonstrated the feasibility of hybrid solar/UV lamp photocatalysis reactor which could maintain the advantages of solar photocatalysis while mitigating its drawbacks.
Integrated anaerobic digestion and UV photocatalytic treatment of industrial wastewater in fluidized bed reactors
(Vaal University of Technology, 2017-03-28) Apollo, Seth Otieno; Onyango, Maurice S., Prof.; Aoyi, Ochieng, Prof.
Anaerobic digestion (AD) is usually applied in the treatment of distillery effluent due to the fact that it is effective in chemical oxygen demand (COD) reduction and bioenergy recovery. However, due to the presence of biorecalcitrant melanoidins present in distillery effluent, AD is ineffective in colour reduction. For this reason, ultraviolet (UV) photodegradation, which is effective in melanoidins’ degradation, can be integrated with AD to achieve high efficiency in colour and COD reduction. However, the UV process is energy intensive, majorly due to the electricity requirement of the UV lamp. In contrast, the AD process has high potential of renewable energy production in the form of biomethane, which can be transformed into electrical energy and applied to supplement the energy requirement of the UV process. The aim of this study was to evaluate the efficiency of a combined AD-UV system in colour and COD reduction for the treatment of distillery effluent in fluidised bed reactors. The potential of the application of the bioenergy produced by the AD process to supplement the energy intensive UV process was evaluated and modelled using response surface methodology. In the first place, the optimal hydrodynamic conditions of the fluidised bed reactors were determined using optical attenuation technique. The best homogeneity in the bioreactor, in which zeolite was used as microbial support, was found to be at a superficial liquid velocity of 0.6 cm/s while the best catalyst and gas hold up in the photoreactor were found to be 0.077 and 0.003, respectively. At these conditions, it was found that the initial biological step removed about 90% of COD and only about 50% of the colour while photodegradation post-treatment removed 98% of the remaining colour. Kinetic analysis of the bioreactor showed that ~ 9% of the feed total organic carbon (TOC) was non-biodegradable and this was attributed to the biorecalcitrant melanoidins. Photodegradation post-treatment mineralized the biorecalcitrant melanoidins via a reductive pathway as was indicated by the formation of NH4+ in large quantity compared to NO3-. Kinetic analysis further showed that the rate of substrate utilization in the bioreactor increased with an increase in organic loading rate and it was inversely proportional to the rate of photodegradation post-treatment. Modeling using response surface methodology (RSM) was applied to predict the effects of the operating parameters of the initial AD step on the performance of the photodegradation post-treatment process and the energy efficiency. Energy analysis of the integrated system showed that the AD process could produce 59 kWh/m3 of electricity which could supplement the electricity demand of the UV lamp by 30% leading to operation cost reduction of about USD 4.8/m3. This led to a presumed carbon dioxide emission reduction (CER) of 28.8 kg CO2e/m3.
Investigation of sorbent characteristics used in low temperature dry flue gas desulfurization
(Vaal University of Technology, 2022-04-22) Makomere, Robert Someo; Reynolds, Kelley, Dr.; Koech, Lawrence; Rutto, H. L., Prof.
Coal is an efficient raw material for generating electric power. However, coal-fired power stations generate a great deal of emissions in the form of exhaust gases from the combustion of coal. The exhaust gases known as flue gas contain a significant amount of greenhouse gases (CO2, SOX, HF, Hg and NOX) that have led to detrimental effects on the environment. Sulphur oxides (SO2 and SO3) present in the exhaust gas stream facilitate acid rain formation while ozone layer depletion is accelerated by the presence of excess carbon dioxide (CO2). Flue gas desulphurization (FGD) is a post-combustion technology used to mitigate specifically SOX emissions from coal power plants. This is per pollution regulations set by air quality regulators for instance the Environmental Protection Agency (EPA). Dry FGD (DFGD) is a current subset of FGD systems that can be easily retrofitted to SO2-generating units at lower capital expenditures compared to wet and semi-dry FGD. In this study, sorbent utilization was tested using a modified nano Ca(OH)2-diatomite sorbent. The reaction occurred in a simulated packed bed reactor consisting of sorbent balls. Cellulose nanocrystals were employed as the precipitating support for Ca(OH)2 formation while diatomite material was used as the siliceous additive. The final sorbent manifested superior scrubbing (𝑌1) and conversion (𝑌2) efficiencies compared to the commercial grade Ca(OH)2. The highest scrubbing and conversion responses were achieved when a diatomite ratio of 0.25 was used. This research also explored experimental modeling using Artificial Neural Networks (ANN), a deep learning MATLAB fitting tool that can be trained to estimate final responses. The learning network using Levenberg-Marquardt (LM) algorithm was statistically compared to the Response surface methodology (RSM) technique to assess performance reliability. ANN was more precise in mapping the predicted responses with the actual experimental values achieving higher R2 values (𝑌1=0.993 and 𝑌1=0.9986) as opposed to those from RSM (𝑌1=0.9753 and 𝑌2=0.9771). Error analysis using RMSE and MSE justified the superior efficacy of the ANN model. The final part of this study evaluated the algorithms present in ANN which can present more acute predicted metadata. Levenberg-Marquardt (LM) and Bayesian Regularization (BR) were chosen and investigated based on their iterations (epochs), validity tests, R2 values, RMSE and MSE. Although the BR algorithm took much more computing time, the predicted and actual values were correlated more effectively compared to the LM training tool. However, both algorithms were reliable in forecasting the sulfation and reagent utilization responses, and hence can be used to model DFGD.
Modelling of in-situ real-time monitoring of catalysed biodiesel production from sunflower oil using fourier transform infrared
(Vaal University of Technology, 2020-10) Mwenge, Pascal Kilunji; Rutto, H. L., Prof.; Seodigeng, T. G., Dr.
The industrialisation of the twenty-first century and the worldwide population growth led to the high demand for energy. Fossil fuels are the leading contributor to the global energy, and subsequently, there is a high demand of fuels. The decrease of global fossil fuels and the environmental air pollution caused by these fuels are concerning. Therefore, eco-friendly and renewable fuel such as biodiesel is one the leading alternative. Chromatography and Spectroscopy are the most used analytical methods and proven reliable but are time-consuming, requires qualified personal, extensive samples preparation, costly and do not provide in-situ real-time monitoring. Fourier Transform Infrared (FTIR) has mainly been used for qualitative analysis of biodiesel, but not much work has been reported in real-time monitoring. This study focused on the modelling of in-situ real-time monitoring of the biodiesel production from sunflower oil using FTIR (Fourier Transform Infrared). The first part of the study investigated the effect of catalyst ratio and methanol to oil ratio on biodiesel production by using central composite design (CCD). Biodiesel was produced by transesterification using Sodium Hydroxide as a homogeneous catalyst. A laboratory-scale reactor consisting of; flat bottom flask mounted with a reflux condenser, a hot plate as heating element equipped with temperature, timer and stirring rate regulator was used. Key parameters including, time, temperature and mixing rate, were kept constant at 60 minutes, 60 oC and 600 RPM, respectively. From the results obtained, it was observed that the biodiesel yield depends on catalyst ratio and methanol to oil ratio. The highest yield of 50.65 % was obtained at a catalyst ratio of 0.5 wt% and methanol to oil mole ratio 10.5. The analysis of variances of biodiesel yield showed the R2 value of 0.8387. A quadratic mathematical model was developed to predict the biodiesel yield in the specified parameters range. The same set-up was used to produce waste margarine biodiesel using a homogeneous catalyst, potassium hydroxide (KOH). The effects of four reaction parameters were studied, these were: methanol to oil ratio (3:1 to 15:1), catalyst ratio (0.3 to 1.5 wt. %), temperature (30 to 70 oC), time (20 to 80 minutes). The highest yield of 91.13 % was obtained at 60°C reaction temperature, 9:1 methanol to oil molar ratio, 0.9 wt. % catalyst ratio and 60 minutes. The important biodiesel fuel properties were found to be within specifications of the American Standard Test Method specifications (ASTM). It was concluded that waste margarine can be used to produce biodiesel as a low-cost feedstock. The core of the study was performed using EasyMax Mettler Toledo reactor equipped with a DiComp (Diamond) probe. The quantitative monitoring of the biodiesel production was performed by building a quantitative model with multivariate calibration using iC Quant module from iC IR 7.0 software. Fourteen samples of known concentrations were used for the modelling which were taken in duplicate for model calibration and cross-validation, data were pre-processed using mean centring and variance scale, spectrum math square root and solvent subtraction. These pre-processing methods improved the performance indexes from 7.98 to 0.0096, 11.2 to 3.41, 6.32 to 2.72, 0.9416 to 0.9999, RMSEC, RMSECV, RMSEP and R2Cum, respectively. The R2 values of 1 (training), 0.9918 (test), 0.9946 (cross-validation) indicated the fitness of the model built. The model was tested against the univariate model; small discrepancies were observed at low concentration due to unmodelled intermediates but were quite close at concentrations above 18%. The software eliminated the complexity of the Partial Least Square (PLS) chemometrics. It was concluded that the model obtained could be used to monitor transesterification of sunflower oil at industrial and lab scale. The model thus obtained, a batch reactor setup, EasyMax Mettler Toledodo reactor was used, the experiments were designed and monitored using iControl software. The results were recorded and quantified using iC IR software based on the biodiesel calibrated monitoring model built. The optimisation of the biodiesel was performed using three key parameters (methanol to oil ratio, catalyst ratio and temperature) while keeping time at 60 minutes and mixing rate at 150RPM. The highest yield of 97.85 % was obtained at 60 oC, 0.85 wt % catalyst ratio and 10.5 methanol to oil mole ratio. The analysis of variances of biodiesel production showed the values of 0.9847, 0.9674 and 0.8749, for R-squared, adjusted R-squared and predicted R-squared, respectively. A quadratic mathematical model was developed to predict the biodiesel conversion in the specified parameters ranges. Using the Arrhenius equation, activation energy (Ea) and frequency factor were found to be 41.279 kJ.mole-1 and 1.08 x10-4 M-1. s-1, respectively. The proposed kinetics model was a pseudo-first-order reaction. It was concluded that the model obtained can be used for industrial and laboratory-scale biodiesel production monitoring.

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