Waste heat recovery is recognized as one of the methods to overcome this energy saving issue. In this paper, the Organic Rankine Cycle (ORC) system has been introduced for the waste heat recovery. The main objective of the study is to convert the unused heat into useful power, which could reduce the fuel consumption and also minimize the harmful exhaust transmission. A thermodynamic model of the waste heat recovery cycle is developed and validated. The eventual results depict a reasonable agreement for the ORC power output and its thermal performance, especially at higher turbine inlet pressure. Consequently, this ORC model is then connected to a turbofan engine. The performance analysis of the engine depicts that the lowest Thrust Specific Fuel Consumption (TSFC) is at 0.68 lbm/lbf.h with the thrust force of 7000 lbf, thus lower than the base cycle without ORC as waste heat recovery.

This study addresses the performance analysis of a subcritical and supercritical Organic Rankine Cycle (ORC) with the addition of a preheater or superheater integrated with a turbofan engine. This analysis will try to explore the heat transfer throughout the evaporator for the purpose of determining the ORC output power and thermal efficiency. A simplified numerical model of the ORC for waste heat recovery is presented. The model depicts the evaporator by using a distributed model, and includes parameters such as the effectiveness, heat capacity and inlet temperature of the waste heat and the organic fluid. For a given set of initial parameter values, the output power and thermal efficiency, as well as the mass flow rate of the working fluid are acquired by solving the system’s thermodynamic cycle with the aid of MATLAB software. The model is then verified by using data from an industrial waste heat recovery system. The connection between the turbofan engine and the ORC system was established and evaluated by means of Thrust-Specific Fuel Consumption (TSFC) as well as fuel burn. It was found that the supercritical ORC with a preheater and superheater exhibits lower TSFC than the subcritical ORC, whereas the impact of the ORC in terms of waste heat recovery in relation to the environment and sustainability indices is quite small, but still considerable depending on the engine’s weight.

The proper disposal of fibre waste products is a significant issue for the GFRP industries; as a result, the reuse and recycling of these waste products require sustainable solutions. Given that FRP materials, especially those created with thermosetting resins, cannot be reprocessed, so the majority of thermosetting FRP waste will be dumped in landfills. Innovative approaches are thus required to manage waste. This study investigates the performance of the FRP waste, known as Glass Fibre Reinforced Polymer (GFRP), that is ground to 0.15mm to 2.36mm in size and used to replace sand at 5%, 10%, 15%, 20%, and 25% by weight of the concrete composite. The experimental work starts with the grinding and sieving process, followed by preparing grade 45 concrete. Then the workability of concrete with GFRP was determined, followed by the compression, and split tensile strengths. The findings showed that adding up to 5% of GFRP waste as a partial replacement for fine aggregate improved the workability and compressive strength of the concrete mix. but decreases when more GFRP waste is added. While the split tensile strength shows increments in line with the increasing amount of GFRP waste replacement. It can be concluded that GFRP waste replacement has the potential to be used in the construction industry, however, the long-term performance must be determined first.