Thermodynamic Simulation And Optimization Of A Compression Ignition Engine Fueled With Oil Derived From Mixed Plastic Waste

In recent years, waste-to-energy systems have gained significant attention due to their dual benefits of reducing environmental pollution and decreasing reliance on fossil fuels.Owing to its high calorific value and abundant availability, plastic waste has emerged as a promising energy resource.Mixed plastic feedstock can be rapidly pyrolyzed to produce Waste Plastic Oil (WPO), which serves as a potential alternative fuel for internal combustion engines.In the present study, oil derived from mixed plastic waste was evaluated through thermodynamic simulation using Diesel-RK software on a four-stroke, single-cylinder, direct injection CI engine.Simulation results revealed that WPO produced 14.4% higher brake power, increasing from 4.04 kW (diesel) to 4.62 kW (WPO), along with a 7.4% lower specific fuel consumption (SFC) compared to diesel, indicating improved thermal efficiency.However, higher in-cylinder temperatures led to a notable increase in nitrogen oxide (NO) emissions.To address this, Exhaust Gas Recirculation (EGR) was introduced at rates of 5%, 10%, and 15%.While performance metrics such as brake power and thermal efficiency slightly declined under EGR conditions, NO emissions were significantly reduced from 2529.6 ppm to 831.34 ppm.Further optimization was conducted using 1D and 2D scanning techniques to fine-tune compression ratio and injection timing both independently and simultaneously.Finally, a 3D multi-variable optimization was carried out by simultaneously controlling compression ratio, injection timing, and EGR using four search algorithms.The Rosenbrock method yielded the best result, achieving the lowest Summary of Emissions (SE = 1.6189) at CR = 15.104,SOI = 17.212CA BTDC, and EGR = 17.457%Index Terms -Waste plastic oil,