http://103.99.128.19:8080/xmlui/handle/123456789/46 Thesis published in Dept. of M.E. 2026-09-13T19:50:54Z http://103.99.128.19:8080/xmlui/handle/123456789/570 Techno-Economic Feasibility Analysis of Integrated Heat Pump and Solar Cell Systems for Commercial Buildings NUPUR, SUROVI AKTAR As economic feasilibity is one of the utmost tonality in every single thing exclusively in energy disciplines, it is consequential assesing the techno-economic feasibility of integrated heat pump and solar cell systems for commercial buildings. This thesis investigates the techno-economic feasibility of heat pump and solar system for the i4Health building at UiA considering performance evaluation, cost effectiveness, and environmental impact and a potential analysis of cost effectiveness towards 2040. In the beginning, Coefficient of Performance (COP) has been evaluated for the Ground Source Heat Pumps (GSHPs) to analyze the performance and Solar System’s (SS) performance has been analyzed on the basis of Performance Ratio (PR) and Solar Ratio (SR). Secondly, Annual cost savings from GSHPs and SS as well as the contribution of GSHPs and SS to the building’s economy along with the Payback Periods (PPs) indicate cost-effectiveness. An estimation model is developed presenting cost effectiveness towards 2040. Lastly, reduction of CO2 gas by GSHPs and SS of i4Health building has been estimated for analyzing environmental impact. Performance evaluation, cost-effectiveness, and environmental impact estimations are conducted using Python Programming and the model presenting a future scenario of cost effectiveness of GSHPs and SS for i4Health building has been developed by Multiple Variable Linear Regression Model (MVLRM) using Jupyter Notebook. The findings present that COP varies around 4.98-5.7 per week in cold weather and around 3.26-4.43 per week in warm weather. PR of solar system is 96% in 2022 whereas 89% in 2023. Solar system has highest SR in week 23 of 2023. Heat pump saves costing at 1.899 NOK/kwh in 2022 with a highest value in week 50 and 1 NOK/kwh in 2023 with a highest value in week 48. Solar system saves costing NOK 355121.69 in 2022 with a highest value in week 35 and NOK 122414.82 in 2023 with a highest value in week 24. From the cost savings model, NOK 398233.09, NOK 1474462.2, NOK 2902506.45 and NOK 3976269.33 is saved for the year 2025, 2030, 2035 and 2040 chronologically by heat pump and, at the same time NOK 293277.4, NOK 1612463.33, NOK 3370724.8 and NOK 4686860.5 is saved by solar system. The contribution of heat pump is 54.4% and 65.3% for the year 2022 and 2023 whereas the contribution of solar system is 60.27% and 56.59% at the same time. Payback period for heat pump is 16.33 years, and 30.63 years for solar system. This research also finds that heat pump and solar system reduce 32.28 ton and 36.05 ton CO2 in 2022 and, 35.66 ton and 33.69 ton in 2023. The thesis creates significant futute work opportunities. A Master of Science (M.Sc) Thesis in Mechanical Engineering (ME) Department at Chittagong University of Engineering and Technology (CUET). 2024-09-10T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/569 Conceptual Design of a Coupling Process of Hydrodynamic Cavitation and Hydrothermal Separation for Extractives and Biopolymers Extraction AHMED, MD. BAYAZID Lignocellulosic biomass is an abundant and sustainable resource for producing biopolymers, chemicals, biofuels, and high-value-added compounds. The primary refining processes, which includes pretreatment, fractionation, and separation of components, as well as structural disconnection or partial structural change, are necessary to achieve high-value utilization of lignocellulosic materials. However, conventional pretreatment processes for biomass valorization aim to obtain high yields of cellulose without concern for utilizing other components. Focusing on a single component of lignocellulose is not only a waste of resources but also causes serious environmental pollution. This study proposed a novel and efficient biomass processing concept that, for the first time, couples two key technologies (hydrodynamic cavitation and hydrothermal separation) to enable almost all the biomass to be used for a range of high-valued products, including biopolymers and extractives. The conceptual design of coupling of hydrodynamic cavitation and hydrothermal separation was then modeled and simulated to evaluate the ease of coupling in terms of component yield and overall extraction efficiency and observed how the coupling process was affected by the process parameters with an optimal overall extraction efficiency. The simulation results showed that the coupling of the HC and HTS processes had a maximum of 25.5% higher overall extraction efficiency than the single HC process and 18.2% higher efficiency than the single HTS process for woodchips. The process parameters, including HTS temperature, HTS residence time, and S/L ratio affected component yield and overall extraction efficiency. The maximum overall extraction efficiency was predicted by the statistical approach of 80.20 ± 5.04% with a regression coefficient (R-sq) of 99.33% at optimal conditions (S/L ratio 10%, HC pressure 3 bar, HC temperature 60℃, HC residence time 20 min, HTS temperature 210 ℃, HTS residence time 25 min, and HTS pressure of 19.04 bar). The coupling of hydrodynamic cavitation and hydrothermal separation showed better biomass utilization than the conventional pretreatment processes. This coupled process focuses on more utilization of biomass rather than only one yield, which will reduce the waste with minimal environmental effect and increase the potential use of biomass from different perspectives. A Master of Science (M.Sc) Thesis in Mechanical Engineering (ME) Department at Chittagong University of Engineering and Technology (CUET). 2024-09-10T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/566 Synthesis and Characterization of Magnesium-Manganese Based Oxide on Nickel Foam for Electrochemical CO₂ Reduction to Formate JOY, ADITTYA CHOWDHURY The increasing levels of atmospheric CO₂ from industrial activities necessitate effective technologies to mitigate climate change. Electrochemical CO₂ reduction offers a promising route to convert CO₂ into valuable products like formate, but challenges such as high overpotential, low selectivity, and catalyst instability hinder its efficiency. Conventional catalysts, while effective, often suffer from low performance or high costs, driving the search for alternative materials. This research explores magnesium-manganese oxide-based catalysts on nickel foam, leveraging their synergistic effects, unique structural properties, and cost-effectiveness to enhance Electrochemical CO2 reduction efficiency. The catalysts were directly grown on nickel foam via immersion in a precursor solution followed by calcination at 600°C. Structural and compositional analysis through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed the formation of crystalline phases, including Ni₆MnO₈, NiO, and NiMnO₃, with magnesium likely incorporated into the manganese oxide lattice. SEM revealed coral reef-like morphology, while elemental analysis indicated a uniform distribution of magnesium (1.1%) and manganese (22.1%) within the porous nickel foam. The optimized catalyst, Mg1.1-Mn22.1-Ox/NiF, exhibited superior electrocatalytic performance, achieving a high current density of -63.24 mA cm⁻² at -0.85 V vs. RHE and a low onset potential of 0.07 V, indicating improved charge transfer capabilities. These findings highlight the structural and compositional advantages of magnesium integration, significantly enhancing catalytic activity and stability. This work provides valuable insights into the design of advanced electrocatalysts for efficient CO₂ reduction, paving the way for further optimization and exploration of magnesium-manganese-based oxides systems. A Master of Science (M.Sc) Thesis in Mechanical Engineering (ME) Department at Chittagong University of Engineering and Technology (CUET). 2025-03-19T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/565 Performance, Combustion and Emission Analysis of a Compression Ignition Engine Fueled with Advanced Biofuel Blends Ahmed, Minhaz; ID:, 22MME009 Third-generation microalgae are considered superior to other biodiesel feedstocks. Biomass to-liquid (BTL) diesel, a renewable fuel, has emerged as a promising alternative for transportation due to its unique properties that enhance engine performance and reduce NOx emissions compared to conventional biodiesel. This study presents a numerical investigation into the effects of neat BTL diesel and four BTL diesel-microalgae biodiesel blends, prepared by mixing 20, 40, 60, and 80 vol% microalgae biodiesel into BTL diesel on the performance of a single-cylinder diesel engine. The study employs the RK multi-zone combustion model to simulate engine behavior across five injection timings (ITs) and validated against reliable experimental data. Neat BTL diesel demonstrated improved engine performance and exhaust characteristics compared to conventional diesel, except for NOx emissions. The ignition delay, combustion duration, and premixed peak heat release rate for the microalgae-BTL blends increased by 11.04–67.24%, 0.66–13.03%, and 5.25–29.87%, respectively, while peak cylinder pressure decreased by 0.72–5.26% relative to pure BTL diesel. The microalgae-BTL blends caused brake-specific fuel consumption to rise by 2.14–7.51% across all ITs. Brake thermal efficiency decreased by 0.2–1.6% for ITs between 1° and 4° CA bTDC, but increased for ITs between 7° and 13° CA bTDC with higher biodiesel content in the blends. Additionally, the microalgae blends reduced CO2, particulate matter (PM), and smoke emissions; however, the increased NOx emissions compared to neat BTL diesel. The optimum IT is identified as 4° CA bTDC for improved performance and reduced PM and smoke with an acceptable NOₓ trade-off. A Master of Science (M.Sc) Thesis in Mechanical Engineering (ME) Department at Chittagong University of Engineering and Technology (CUET). 2025-03-12T00:00:00Z