FACULTYOFENGINEERING

Comparative Performance analysis of Selected Working Fluids in a low temperature organic RankineCycle forWasteHeatrecoveryApplication. The global imperative to improve energy efficiency necessitates the effective recovery of low- gradewast heat,achallengeperfectlyaddressedbytheorganicRankineCycle (ORC)technology. This project undertakes a comprehensive comparative analysis of selected candidate organic
working fluids – including Ethanol, Toluene, Cyclopentane, R245fa, R1233zd(E) and R152a, drawn fromthe categories ofdry,wet andisentropic fluids,withina low temperatureORCsystem designed for industrial waste heat recovery. The primary goal isto identify the optimal fluid that maximizesthermodynamic performance under a specified heatsource temperature (e.g 206 0Cto 123.70C). A thermodynamic model was developed to simulate the cycle’s performance. The selected fluids areevaluatedagainstkeymetricssuchasnetworkandthermal efficiency. Initial simulation results reveal significant variability in cycle performance, depending on the fluid’s criticaltemperature,boilingpointandcondensationtemperatures andpressures. The findings provide a data driven basisforselecting aworking fluid that not only achieves higher power generation but also minimizes system’s complexity and investment cost, thereby acceleratingthedeploymentofsustainablelowtemperaturewasteheatrecoverysystems

This study examined the comparative quality of borehole water, sachet water, and bottled water consumed in Ikhueniro Community, Benin City, Edo State, Nigeria. The research adopted an investigative and analytical approach to evaluate the safety and suitability of the major drinking water sources used by residents. In response to increasing public health concerns associated with waterborne diseases and the widespread availability of inadequately regulated water sources, the study provided a scientific basis for water quality assessment and proposed recommendations for enhanced water safety and regulatory control. The primary objective of the study was to compare the microbiological and physicochemical quality of borehole, sachet, and bottled water and to determine their compliance with established drinking water standards. Specifically, the study assessed the physical, chemical, and microbiological parameters of the three water sources; evaluated their quality using national and international guidelines provided by the World Health Organization (WHO), National Agency for Food and Drug Administration and Control (NAFDAC), Standards Organisation of Nigeria (SON), and Nigerian Standard for Drinking Water Quality (NSDWQ); computed the Water Quality Index (WQI) for each source to facilitate interpretation; and identified potential contaminants as well as the effectiveness of treatment and purification methods. Both field and laboratory methods were employed in the study. Physicochemical parameters analyzed included pH, electrical conductivity, total dissolved solids, total alkalinity, temperature, and concentrations of selected heavy metals such as lead, iron, magnesium, and cadmium.

Electronic waste is an emerging issue posing serious pollution problems to human and the environment. The specific objectives of this work are to determine the physical properties of crushed e-waste materials, granite and aggregates, to design a concrete mix incorporating e-waste and granite as the coarse aggregate, to investigate the strength development of e-waste concrete at 7, 14 and 28 days, under standard curing method, to determine the effect of e-waste replacement on the compressive and flexural strength of concrete, and to analyse the result and ascertain the benefits of e- waste in the production of concrete. The research methodology will involve performing a comprehensive literature reviewand laboratory investigation of compressive strength and flexural test. Before that, several series of test would be carried out which includes specific gravity test, sieve analysis test, mix design, slump test, and casting of concrete test cubes. The results showed that adding e-waste as a partial replacement for coarse aggregate increased workability but reduced strength. Slump values rose from 27mm in the control mix to 61 mm at 20% replacement, indicating greater fluidity due to the smooth, non-absorbent surface of e-waste particles. In contrast, compressive strength dropped from 20.09 N/mm² to 10.43 N/mm², and flexural strength from5.25 N/mm² to 0.38 N/mm² as e-waste content increased. The mix with 5% e-waste achieved 18.12N/mm², close to the control, showing that small replacements maintain acceptable performance. Overall, e-waste improved workability but reduced strength, with 5% replacement identified as the optimum level for structural use. Using e-waste as a partial replacement for coarse aggregate is feasible up to 5%, giving the best compressive and flexural strength. Higher replacements (above 10%) reduce strength significantly. Further studies are recommended under real site conditions, for longer
curing periods, and in combination with other waste materials to improve performance.