DEPARTMENT OF CHEMICAL ENGINEERING

Escalating anthropogenic carbon dioxide (CO₂) emissions necessitate the development of sustainable and cost-effective capture technologies. This research investigates the valorization of corn cobs, an abundant agricultural waste, as a precursor for producing activated carbon (AC) for CO₂ capture via adsorption. The activated carbon was synthesized from corn cobs, sourced from Benin City, Nigeria, using a chemical activation method with potassium hydroxide (KOH). The resulting adsorbent was characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Thermogravimetric Analysis (TGA). Adsorption experiments were conducted in a packed column to evaluate CO₂ capture performance. The study systematically assessed the effects of key operational parameters, including contact time, adsorbent dosage, gas flow rate (0.5 and 2.0 L/min), and particle size (100, 250, 500, and >500 µm). Characterization confirmed the synthesis of a porous, carbon-rich material. SEM revealed a rough, heterogeneous surface with significant porosity ideal for adsorption, while EDS confirmed carbon as the predominant element (90.05% atomic concentration). TGA demonstrated high thermal stability, indicating suitability for regeneration cycles. Adsorption studies showed rapid CO₂ uptake, reaching equilibrium in approximately 50-60 minutes. Particle size was identified as a critical factor influencing performance. The 250 µm particle size achieved the highest CO₂ removal efficiency at 48.0%. However, the 100 µm particles exhibited the highest equilibrium adsorption capacity (qₑ) of 2,939 ppm·L/g, attributed to their greater specific surface area. Breakthrough analysis further confirmed that smaller particle sizes (<100 µm) significantly prolonged bed saturation time (approx. 45 minutes) compared to larger particles.This study concludes that corn cob-derived activated carbon is an effective, low-cost, and sustainable adsorbent for CO₂ capture. The 250 µm particle size offers an optimal balance between removal efficiency and practical operational handling. This wasteto-value approach supports circular economy principles and presents a viable pathway for mitigating CO₂ emissions using locally available agricultural residues.

Textile wastewater poses a significant environmental threat due to its recalcitrant nature and toxic pollutants. This study explores the potential of snail shell and floor tiles as sustainable adsorbents for the oxidative degradation of textile wastewater. The adsorbents were characterized using FTIR,SEM,BET and XRF analyses. The effects of contact time, adsorbent dosage, and initial concentration on the degradation efficiency were investigated. The Snail Shell And Floor tiles were purchased separately, processed and characterized to evaluate its suitability as an adsorbent. Batch adsorption studies were carried out by varying parameters such as adsorbent dosage, contact time, temperature ,pH and initial dye concentration.The adsorption mechanism was predicted by some kinetic models such as pseudo-first-order, pseudo-second-order, intra particle diffusion model and Elovich model.The results of batch adsorption study showed that for unactivated and activated snail shell and floor tiles increasing the adsorbent dosage and contact time resulted in increased percentage dye removal while increasing the pH and initial dye concentration resulted in decrease in percentage dye removal. The optimum conditions for maximum percentage dye removal for unmodified and modified bio adsorbent are 2.5g adsorbent dosage, 75minutes contact time, and 25mg/l initial dye concentration. The best percentage dye removal were 268.59 % and 251.61% using unactivated and activated bio adsorbent. The sorption kinetics for the adsorption processes were found to be best represented by the pseudo-second-order kinetic equation, as its R2 values were greater than 0.98. and the qe experimental and qe calculated are virtually equal. The Elovich model also showed a significant fitting to the kinetics of the adsorption process as its R2 values were also high. This suggests that chemisorption with heterogeneous sorption mechanism is likely responsible for congo red dye uptake

The process of enzymatic hydrolysis of cassava bagasse is a potentially effective method of producing biofuel, as cellulase and pectinase are essential for the conversion of biomass. The goal of this work was to compare the hydrolysis effectiveness of cellulase in isolation and in combination with pectinase over a range of time periods (6 and 24 hours). Separately, under controlled conditions, cassava bagasse was used to incubate both cellulase alone and the cellulasepectinase combo. The yield of fermentable sugars was determined by analyzing the resultant hydrolysates, which gave information about how well each combination of enzymes worked. In the first six hours, the yields of cellulase by itself were higher than those of the cellulasepectinase combination. This is explained by the greater starting activity of cellulase in hydrolyzing cellulose, the main ingredient in cassava bagasse. But compared to cellulase alone, the cellulasepectinase combination showed better hydrolysis efficiency over the longer 24-hour period, producing more fermentable sugars. Pectinase was added to help break down pectin barriers, which improved cellulase access to cellulose fibers and eventually raised hydrolysis efficiency. These findings emphasize the significance of reaction time and enzyme synergy in biomass conversion processes. The combination of pectinase and cellulase maximizes the yield of fermentable sugars from cassava bagasse over extended periods of time, despite the fact that cellulase alone may produce larger initial yields. By providing insightful information on how to best utilize enzymatic hydrolysis processes for producing biofuel, this work advances the creation of efficient and sustainable bioenergy technology.

Crude oil emulsions pose significant operational and environmental problems due to high viscosity, corrosion, and the toxicity of synthetic demulsifiers currently used. This research aims to investigate Lemon Peel Extract (LPE), a promising green, biodegradable alternative, by evaluating its performance kinetics against a stable crude oil emulsion. The study focused on determining the optimal LPE dosage required for achieving maximum water separation, supporting the industry's shift towards sustainable fluid processing. The methodology centered on the standard bottle test procedure, with the process optimized using a Central Composite Design (CCD) of experiments, testing Demulsifier Dosage, Temperature, and Time. A stable W/O emulsion was prepared at (50:50 v/v) and treated with LPE across a concentration range up to 127.6ppm. The vials were thoroughly shaken and placed in a thermostatically controlled water bath (operating between 30°C and 80°C) to enhance kinetics. Performance was monitored by measuring the volume of separated water at defined time intervals. The experimental results confirmed that the LPE is a highly effective demulsifier. The LPE successfully achieved its maximum water separation efficiency of 93.68%. This optimal performance was recorded at a dosage of 127.6ppm and a temperature of 55°C, with the separation being substantially complete within 75minutes. Response Surface Methodology confirmed a strong synergistic interaction between Dosage and Time (AC = +3.83), indicating that optimal performance requires sufficient LPE concentration paired with adequate contact time. These findings demonstrate that the LPE is a technically iv viable, fast-acting, and environmentally friendly green demulsifier for sustainable crude oil treatment operations.

This study investigates a plant-based surfactant alternative as a result of the growing need for Surfactants that are both economical and ecologically friendly for enhanced oil recovery. These research project comprises the study of enhance oil recovery with it crucial application of Natural surfactant from bitter leaf extract , while using alkaline from calcined corn cob ash to form basic medium . Corn cobs were calcined for 3 hours at 750°C to produce the alkali, which was then extracted using distilled water to produce the alkaline for the medium, the extraction process for the bitter leaf to extract the saponin content to produce the surfactant The extraction process was carried out according to the experimental design with 19 runs with independent variables of extraction time (30-300 minutes) ,mass of bitterleaf (1-10grams) and temperature
(50-90 degree census),and a constant volume of 100 ml of methanol with a single response yield (%), Alkaline surfactant was also produced using alkaline hydrolysis of the saponin was carried out to form the surfactant and75ml of the saponin was mixed with 25ml of the ash solution. Various Physical characteristics was carried out in the process such as forth test where 2.0 gms portion of the powdered sample was boiled into 20ml of distilled water in a test tube in boiling water bath and filtered , 10ml of the filtrate was mixed with 5ml of distilled water and shaken vigorously to foam, Total Saponin Content Quantitative Analysis where a quantity ,1.0 gms of the powdered sample was weighed using electric weighing balance into 25ml beaker and soaked with 100 ml of 20% Methanol for 3 minutes and heated for 3 hours at 55 degree
census for proper extraction then filtered and lastly . The volume and stability of the emulsion was observed and the emulsion index was calculated.

With Nigeria generating over 42 million tonnes of waste annually, improper disposal poses significant risks to soil health, groundwater, and public health. This study examines the contamination levels of heavy metals and the physicochemical properties of soil at a solid waste disposal site in Ovia Northeast, Edo State, Nigeria. Soil samples were collected at varying depths (10, 20, 30, and 40 cm) from a dumpsite and a control site, focusing on lead (Pb), iron (Fe), copper (Cu), and manganese (Mn), alongside properties such as pH, bulk density, porosity, organic matter, and electrical conductivity (EC). Results revealed elevated levels of heavy metals at the dumpsite compared to the control site, particularly in the top 10 cm of soil. For example, Pb concentrations reached 12.31 mg/kg at the dumpsite, nearly three times higher than the 4.24 mg/kg observed at the control. Similarly, copper (Cu) levels at the dumpsite peaked at 74.22 mg/kg, significantly higher than the control site’s 57.47 mg/kg. Physicochemical properties demonstrated a strong influence on metal mobility: soil pH at the dumpsite ranged from 7.12 to 7.62, slightly higher than the control’s 6.86 to 6.12. Organic matter content decreased with depth, from 8.74% at the surface to 3.15% at 40 cm in the dumpsite, compared to 9.07% to 2.54% in the control. EC values were markedly higher
at the dumpsite (252–290 µS/cm) compared to the control (144–168 µS/cm), reflecting leachate infiltration and ion enrichment. The findings underscore the environmental risks posed by heavy metal contamination, including soil degradation, reduced fertility, and potential bioaccumulation in the food chain. Elevated
metal concentrations exceeded WHO permissible limits, necessitating immediate remediation actions. Recommendations include the implementation of sustainable waste management
practices, soil remediation techniques such as phytoremediation, and ongoing monitoring to mitigate long-term environmental impacts.

The increasing demand for sustainable energy sources has driven the exploration of biodiesel as a viable alternative to fossil fuels. This study focuses on the development of biomass-derived catalysts for the production of biodiesel using a blend of non-edible oils: neem, shea, and jatropha. The research aims to address the challenges associated with conventional catalytic processes, such as high costs, environmental impact, and inefficiencies, by utilizing agricultural waste products to create sustainable and cost-effective catalysts.
The project involved the synthesis of biomass-derived catalysts from plantain peels and coconut husks, which were characterized for their physical and chemical properties. The transesterification process was optimized using the Box-Behnken Design (BBD) to determine the effects of reaction temperature, reaction time, catalyst load, and methanol-to-oil mole ratio on biodiesel yield. The results indicated that the optimal conditions for biodiesel production were a reaction temperature of 60°C, a reaction time of 90 minutes, a catalyst load of 5.5 wt%, and a methanol-to-oil mole ratio of 6.5:1, yielding a maximum biodiesel yield of 92.37%.
The biodiesel produced from the oil blend was characterized according to ASTM standards, and the results showed that the physical and chemical properties, including density, viscosity, flash point, and acid value, were within acceptable limits for biodiesel. The study demonstrated that biomass-derived catalysts are effective in producing high-quality biodiesel from non-edible oil blends, offering a sustainable and economically viable alternative to conventional catalysts. This research contributes to the advancement of renewable energy technologies by providing a framework for the utilization of locally sourced agricultural waste in biodiesel production. The findings highlight the potential of biomass-derived catalysts to enhance biodiesel yield and qualitywhile reducing environmental impact, thereby supporting the transition to sustainable energy
solution.

The growing demand for renewable and sustainable fuels has led to increased research into biodiesel production from non-edible oils. This study aims to evaluate the techno economic feasibility of biodiesel production from a ternary blend of neem oil, castor oil, and waste vegetable oil. The research focuses on analyzing the economic viability through Aspen Plus simulation, with an emphasis on optimizing reaction parameters to achieve a high biodiesel yield while maintaining
cost-effectiveness. In this study, the acid values of the feedstocks were first determined through titration, revealing the need for pre-treatment via esterification before transesterification. The Aspen Plus process simulation was employed to model the transesterification reaction, incorporating key factors such as methanol-to-oil ratio, reaction temperature, and the flowrate. A techno-economic analysis was
conducted to determine capital investment, operating costs, net present value (NPV), internal rate of return (IRR), and payback period, providing insights into the financial viability of the biodiesel production process. The results indicate that biodiesel production from the ternary blend is economically feasible.
The total capital investment for the project was $7,020,220 (₦10,603,000,000), with an annual operating cost of $1,793,070 (₦2,710,000,000). The total revenue generated was $15,678,800 (₦23,678,000,000) per year, leading to an NPV of $78,295,380 (₦118,180,000,000) at a 10% interest rate. The internal rate of return (IRR) was 28.2%, demonstrating strong investment potential, while the payback period was approximately 0.51 years (~6 months), indicating rapid cost recovery. Additionally, the profit margin was 88.56%, confirming the economic viability of
the process

This study investigates a plant-based surfactant alternative as a result of the growing need for surfactants that are both economical and ecologically friendly for enhanced oil recovery. Using alkali from corn cobs, this study explores the synthesis of a natural surfactant from Aloe vera for possible use in enhanced oil recovery (EOR). Corn cobs were calcined for eight hours at 450°C to produce the alkali, which was then extracted using distilled water. Aloe vera leaves were macerated with 62.5% ethanol to extract saponins, which were then filtered and the
solvent evaporated. To create the surfactant, the isolated saponins were mixed with the alkali solution that had been created under controlled conditions.
Several tests were carried out to assess the surfactant's effectiveness. Tests for emulsification and foam stability were carried out to evaluate the characteristics. The surfactant's functional groups were also compared to those of the synthetic surfactant Tween 80 using Fourier Transform Infrared Spectroscopy (FTIR). Response surface methodology (RSM) was employed using Box-Behnken Design to optimize the experimental variables and produce surfactant.
The research results showed that the aloe vera-derived surfactant proved a viable alternative for conventional synthetic surfactants due to its foaming ability and emulsion formation. The existence of functional groups typical of surfactants was confirmed by the FTIR analysis which was similar to that of tween 80. The surfactant produced had an optimum volume of emulsion of 2.52 ml which was achieved with saponin concentration of 0.0587 g/ml, 0.0186g/ml alkaline concentration at the duration of 53 mins. The RSM model was seen to be quite effective in
optimizing surfactant production because of the R2 of 0.9719. This study demonstrates the viability of using agricultural waste (corn cobs) with locally produced aloe vera to create an affordable and sustainable surfactant, supporting environmentally friendly industrial processes.

The components of bio-waste are particularly abundant in essential minerals like calcium and potassium, which are essential for the manufacture of effective biocatalysts for biodiesel. This study evaluated the potential of bio-based heterogeneous catalyst of fused cockle shells and watermelon peels for the transesterification of waste vegetable oil. At 900°C and 500℃, the waste materials were dried, calcined, and carbonized, respectively. In order to evaluate the compositional, morphological, structural, and thermal features of both the catalyst and the precursor materials, they were both characterized. The Box-Behnken design was utilized to generate 29 experimental runs to examine the impact of operational parameters such catalyst loading, temperature, methanol-to-oil molar ratio, and reaction time. The presence of basic (calcium and potassium) and acidic oxides (silicon and nickel) demonstrated that the catalyst was bi-functional. The catalyst's surface area (105.35 m2/g) and pore volume (0.60 cm3/g) obtained from the BET analysis contributed to a 91.77% biodiesel yield at 63.34 °C reaction temperature, 149.41 min reaction time, 1.05wt% catalyst loading, and a 14.45:1 methanol to oil ratio. The physicochemical parameters of the biodiesel produced were measured and determined to be acceptable according to the European National (EN) and American Society for Testing of Materials (ASTM) quality standards, demonstrating the product's suitability for use as fuel