Novel hybrid system of pulsed HHO generator/TEG waste heat recovery for CO reduction of a gasoline engine

Environmental crisis requires using cleaner energy sources for different sectors including the transportation. Hydrogen can support the transition of the automotive industry from petrol and diesel into a sustainable fuel. It could be the main source of energy or the auxiliary fuel in vehicles. As an auxiliary fuel, it has recently been considered in hydroxyl (HHO) form for reducing the emissions from transportation fleet. In this study, an HHO generator with the optimum power consumption was utilised for HHO injection into the intake manifold of a petrol engine as the case study. High concentration of CO is expected to be produced during idling, so the experiments were designed to inject ultra-low HHO for reducing CO emissions. The results were very promising, and it was shown that the CO emission could be reduced by about 98%. Furthermore, a novel design was developed based on the concept of waste heat recovery (WHR) for powering the HHO unit. Engine was simulated in AVL software to design a thermo-electric generators (TEG) for running the HHO unit. Based on the results, TEG can provide the energy required for HHO unit as the energy output of the TEG was between 91 kJ and 169 kJ for the case study while the energy consumption of the proposed HHO generator was just about 22.5 kJ. The results of this study are recommending a practical solution for bringing HHO injection from laboratory research into the real practice.