DEPARTMENT OF CHEMICAL ENGINEERING

This study investigates the optimization of biobutanol production from cassava bagasse through simultaneous saccharification and fermentation (SSF) using Clostridium acetobutylicum. Cassava bagasse, sourced from Uselu market, Benin City, was compositionally characterized, revealing 53.33% cellulose, 16.67% hemicellulose, and 3.00% lignin. Alkaline pretreatment using 2% NaOH at 121°C for 60 minutes effectively disrupted the lignocellulosic structure, as confirmed by FTIR spectroscopy showing reduced lignin and enhanced cellulose accessibility. Response Surface Methodology based on Central Composite Design was employed to optimize three critical SSF parameters: pH (4.5-6.5), inoculum size (5-15% v/v), and temperature (30-40°C). The quadratic model developed demonstrated excellent predictive accuracy (R² = 0.9624, adjusted R² = 0.9286) with pH and inoculum size identified as the most significant factors. Parametric validation studies confirmed maximum butanol production of 15.13 g/L at pH 6.0 and 15.45 g/L at 13% v/v inoculum size. Kinetic models were successfully developed describing the relationships between process parameters and butanol concentration, with second-order polynomials achieving R² values exceeding 0.98. The final optimal conditions identified were pH 6.0, inoculum size 12% v/v, and temperature 36°C, yielding a predicted butanol concentration of 15.4 g/L. This research establishes cassava bagasse as a viable, sustainable feedstock for biobutanol production, offering environmental waste valorization, economic opportunities for cassava-processing regions, and contribution to Nigeria's renewable energy security. The developed optimization framework and kinetic models provide a foundation for industrial-scale implementation of lignocellulosic biobutanol production

This study investigates the optimization of biobutanol production from cassava bagasse through simultaneous saccharification and fermentation (SSF) using Clostridium acetobutylicum. Cassava bagasse, sourced from Uselu market, Benin City, was compositionally characterized, revealing 53.33% cellulose, 16.67% hemicellulose, and 3.00% lignin. Alkaline pretreatment using 2% NaOH at 121°C for 60 minutes effectively disrupted the lignocellulosic structure, as confirmed by FTIR spectroscopy showing reduced lignin and enhanced cellulose accessibility. Response Surface Methodology based on Central Composite Design was employed to optimize three critical SSF parameters: pH (4.5-6.5), inoculum size (5-15% v/v), and temperature (30-40°C). The quadratic model developed demonstrated excellent predictive accuracy (R² = 0.9624, adjusted R² = 0.9286) with pH and inoculum size identified as the most significant factors. Parametric validation studies confirmed maximum butanol production of 15.13 g/L at pH 6.0 and 15.45 g/L at 13% v/v inoculum size. Kinetic models were successfully developed describing the relationships between process parameters and butanol concentration, with second-order polynomials achieving R² values exceeding 0.98. The final optimal conditions identified were pH 6.0, inoculum size 12% v/v, and temperature 36°C, yielding a predicted butanol concentration of 15.4 g/L. This research establishes cassava bagasse as a viable, sustainable feedstock for biobutanol production, offering environmental waste valorization, economic opportunities for cassava-processing regions, and contribution to Nigeria's renewable energy security. The developed optimization framework and kinetic models provide a foundation for industrial-scale implementation of lignocellulosic biobutanol production

The discharge of untreated textile wastewater containing synthetic dyes poses significant environmental and public health risks due to its toxicity and resistance to conventional degradation processes. This research explores a sustainable and cost-effective solution by developing and evaluating a novel activated carbon (AC) adsorbent derived from a blend of two abundant agricultural wastes: Palm Kernel Shell (PKS) and Coconut Shell (CS).This study aimed to treat synthetic wastewater contaminated with Methyl Red dye. The PKS and CS were individually carbonized and chemically activated using potassium hydroxide (KOH). The resulting activated carbons were blended in a 1:1 ratio to create a composite adsorbent (PKS-CS AC). The adsorbent was extensively characterized using Brunauer-Emmett-Teller (BET) analysis, which revealed a specific surface area of 275.762 m²/g and a well-developed microporous and mesoporous structure, complemented by Fourier-Transform Infrared Spectroscopy (FTIR) that identified key functional groups (O-H, C=O, C-O) crucial for adsorption.A series of batch adsorption experiments were conducted, and the process was optimized using Response Surface Methodology (RSM) based on a Central Composite Design (CCD). The influence of critical operational parameters—adsorbent dosage (PKS-AC and CS-AC), contact time, and initial dye concentration—on Methyl Red removal efficiency was investigated. The ANOVA of the quadratic model confirmed its high significance, with an R² value of 0.9501, indicating the model accurately represented the experimental data. The optimization results identified the optimal conditions as 1.65 g/L of CS-AC, 6.13 g/L of PKS-AC, a contact time of 70.75 minutes, and an initial dye concentration of 328.1 mg/L, achieving a predicted dye removal efficiency of 93.75%

The aim of this study is to evaluate the effect of blending ratios of Jatropha biodiesel with fossil diesel on compression ignition engines. The main goal is to compare the physical and chemical properties of Jatropha biodiesel and fossil diesel and evaluate engine performance,such as power output,torque,and fuel consumption,for different blend ratios and also examine the emissions characteristics (TVOC, CO, PM) that arise from various blend compositions. Physiochemical analysis confirms the suitability of esterified Jatropha oil for industrial applications. Engine performance tests reveal favourable metrics for biodiesel blends, with varying emissions characteristics across blends. Operational assessment indicates blenddependent differences in construction time, emissions, and particulate matter. Cost-benefit analysis shows economic feasibility and environmental benefits of Jatropha biodiesel. The optimal blending ratio considering performance, emissions, and economic factors suggested B30 and B40 blends for specialized applications and B10 for general use.

Chromium is one of the most notorious heavy metals released by various industries such as tanning and leather industries, manufacturing industries, catalyst and pigments, fungicides, ceramics, crafts, glass, photography, electroplating industry and corrosion control application. This study was aimed at sorption of chromium(VI) ion from aqueous solution by adsorbent derived from used tyres. Waste tyre was collected from Uwelu spare part market in Edo state. The collected tire was washed and rinsed with distilled water to remove debris, oven dried for 3hours at 180oC and ground into powder. This dried powder was carbonized and activated by charging into a muffle furnace for 2hrs at 500oC and then treated with 4M nitric acid. The efficacy of chromium removal of the adsorbent is determined by investigating the various parameters such as adsorbent dose, agitation time and shaking speed. The adsorbent was characterized by Scanning Electron Microscopy (SEM), Energy dispersive X-ray (EDX) and Fourier Transform Infra-Red (FTIR) spectroscopy. The total pore volume of the adsorbent was observed to bet P/P0=0.988646762:0.624668 cm3/g. The percentage of C and O was found to be 30.50% and 20.23%. Analysis of Variance for the response surface quadratic model showed that the Model F-value of 75.25 implies that the model is significant. The Lack of Fit F-value of 0.9763 implies that the Lack of Fit is not significant relative to the pure error. The high R-square value (coefficient of determination) of 0.9898 indicates that the fitted model predicts the metal ion removal with reasonable precision

This study explored the optimization of the microwave aided biodiesel production from waste cooking oil using a bio-waste catalyst derived from clamshell and cocoa pods via the Taguchi Optimization Approach.The bio-waste catalyst was synthesized by the carbonization and sulphuration of cocoa pods to produce an acid precursor, while clam shells was calcined and treated with KOH to create the basic precursor. Both precursors were then impregnated using the wet-impregnation method. The bi-functional catalyst produced was characterized using standard techniques to establish its catalytic potency.Characterization involved SEM,EDXRF,XRD,FTIR,BET/BJH techniques and GCMS for the oil and biodiesel .Also, a model was developed to simulate the process and examine the interactive effect of process input variables on Waste cooking oil(WCB)yield using the Taguchi L16 approach. A reusability test was used to evaluate the catalyst's commercial viability by analyzing its effects on WCB yield and Acid Value. This test was carried out over five consecutive runs with the catalyst cleaned using methanol and reused, based on the optimal circumstances. The BET analysis showed the catalyst to have a BET surface area of 393.3 m2/g, Pore volume and diameter 0.02349 cm3/g and 2.421 nm, respectively and the average micropore size calculated to be 5.520 nm in width and 0.1785 cc/g in volume, while the micropore surface area found to be 502.1 m2/g. From the XRF result it is seen that calcium oxide has 68.431% followed by phosphorous pentoxide which contains 13.527% .The best combination of the input variables determined for the process is a heating power of 600W, methanol:WCO of 15:1, time of 5 min,v reaction speed of 1000rpm and Catalyst loading of 2 wt% with an optimum WCB yield of 92.737 wt.% and AV of 0.408 mg KOH/g. It was shown that the WCB yield was significantly influenced by the reaction time, reaction speed,power of the reaction and the methanol to oil molar ratio but the catalystloading, reaction speed, power of reaction and reaction time were the factors that had the biggest influence on the AV of the WCB.The WCB produced met standard specifications for biodiesel according to ASTM D6751 and EN 14214 requirements.Applying a microwave to the WCO transesterification helped to speed up the reaction's completion.The study found that clam shells and cocoa pods are viable feedstock for low-cost, environmentally friendly biodiesel manufacturing

This study explored the optimization of the microwave aided biodiesel production from neem oil with a bio-waste catalyst derived from cow bones and rice bran using central composite design, an experiment analysis on response surface model. The bio-waste catalyst was synthesized by the carbonization and sulphonation of rice bran to produce an acid precursor, while cow bones was calcined and treated with KOH to create the basic precursor. Both precursors were then impregnated using the wet-impregnation method. Also, a model was developed to simulate the process and examine the interactive effect of process input variables on neem oil biodiesel yield using the central composite approach. These inputs generated about 50 runs to be carried out with the catalyst using methanol under optimal conditions. In this study, we aimed to optimize biodiesel production from neem oil using a microwave- assisted process with a bifunctional heterogeneous catalyst synthesized from cow bones and rice bran. Oil characterization was carried out according to the ASTM standards, the catalyst failed to facilitate the transesterification reaction resulting in no biodiesel formation. Biodiesel production was carried out using sodium hydroxide which proved the viability of the oil and this outcome underscores the critical importance of proper catalyst synthesis and activation in biodiesel production. Additionally, the presence of impurities or moisture during catalyst preparation could have led to deactivation, further inhibiting the reaction. Fresh catalyst samples have been impregnated and are awaiting analysis results

This research aimed to develop a sustainable and efficient method for making biodiesel from a mix of neem and yellow oleander oils, using a catalyst made from chicken bones. The oils' properties were examined, created and tested the catalyst, optimized the transesterification process, and checked that the biodiesel meets ASTM D6751 and EN14214 standards. The oil analysis looked at free fatty acids (FFA), viscosity, density, iodine value, and fatty acid profiles. Neem oil had an FFA of 5.2%, viscosity of 5.93 mm²/s, and an iodine value of 76.4; yellow oleander oil had an FFA of 3.8%, viscosity of 4.02 mm²/s, and iodine value of 73.86. The catalyst was prepared by calcining chicken bones at 800°C for 3 hours, resulting in calcium oxide with a surface area of 154 m²/g. Tests with SEM, XRD, XRF, FTIR, and BET confirmed it was effective and stable. By optimizing the transesterification process through Response Surface Methodology (RSM), a biodiesel yield of 88.46% was achieved. The optimal conditions identified were a methanol-to- oil ratio of 14:1, a reaction duration of 180 minutes, a catalyst loading of 6% by weight, all maintained at a steady temperature of 65°C

The influence of dye concentration, adsorbent dosage, and contact time on the % removal of methylene blue dye (textile effluent) from aqueous solution was optimized and evaluated using a three-variable Box-Behnken design (BBD) in combination with response surface methodology (RSM). Coconut shell was utilized to make the adsorbent, which was then activated with H3PO4 after being carbonized at 600°C for an hour. Three variables dye concentration (50–200 mg/l), adsorbent dosage (g/100 ml), and contact time (10–60 mins), were varied to treat the dye solution. The responses of the linear and quadratic models that were developed for % dye removal from aqueous solution were significantly influenced by all three parameters, according to a statistical analysis of the data with p < 0.0001, the models were significant and demonstrated a strong fit with the experimental data. The adsorbent dosage and contact time had a positive impact on the percentage of dye removal. The process was optimized, and the maximum dye removal of 82% was attained at optimum dye concentration, adsorbent dosage, and contact time of 125 mg/l, 0.55 g/100 ml, and 35 min

Climate change driven by increasing atmospheric CO₂ concentrations calls for urgent implementation of atmospheric CO2 reduction. However, adsorbents are mostly expensive and energy-intensive, especially for developing nations. Agricultural wastes, especially corn cobs, are a sustainable alternative due to their lignocellulosic composition, natural porosity,
and abundance as underutilized biomass. This study investigated the CO₂ adsorption potential of chemically activated corn cob-derived adsorbent through packed bed column experiments. Corn cobs were collected, processed, and activated using potassium hydroxide (KOH) at temperatures between 400-600°C. CO₂ gas was generated in-situ via CaCO₃-HCl reaction and
passed through glass columns (2.1 cm diameter, 5 cm bed height) at flow rates of 0.5-2.0 L/min. Four particle size ranges (100, 250, 500, and above 500 μm) were evaluated over 60- minute contact periods at ambient temperature (29±2°C).
Characterization via SEM-EDS revealed highly porous morphology with 90.05% carbon content and oxygen-containing functional groups favorable for CO₂ binding. The 100 μm particle size achieved the highest equilibrium adsorption capacity of 5,459 ppm·L/g, while 250 μm particles demonstrated optimal removal efficiency of 48.0%. Breakthrough analysis indicated that smaller particles delayed saturation, with 100 μm maintaining effectiveness beyond 45 minutes compared to 25 minutes for above 500 μm particles. Flow rate influenced performance, with reduced rates (0.5 L/min) compensating for larger particle sizes by increasing contact time. These findings reveal that corn bobs are a viable solution for carbon capture.