Functional, economic and environmental comparison of biofuels produced in a proposed cycle of power, heat and cooling production

This article proposes a three-effect system based on diesel engine to increase efficiency and reduce environmental pollution. An organic Rankine cycle to produce power, an ejector refrigeration cycle to produce cold and a heat exchanger to produce heat. 12 biofuels are produced based on vegetable oils and compared with the performance of pure diesel. Mass, energy, exergy, economic and environmental analyzes are performed for the produced biofuels. In this regard, canola biofuel B20 has been selected as the best fuel for the designed system, which has a net power of 7468 kW with an exergy efficiency of 37.96%, an environmental sustainability index of 1.611 and an environmental impact index of 1.635 at an engine speed of 1700 rpm and load. It provides 100 percent. The exergy efficiency of the engine is influenced by the engine load, while the exergy efficiency of the proposed system is influenced by the engine speed. Also, the exergy efficiency of the system and the unit product cost are 37.96% and 11.196 $/GJ, respectively, in the optimal state.