Multi-scale assessment and multi-objective optimization of a novel solid oxide fuel cell hybrid power system fed by bio-syngas

Nowadays, thermal power generation using fossil fuels is still the main way for electricity supply, resulting in serious environmental pollution and energy consumption. The research on new power generation and alternative energy is urgently needed to conduct. In this paper, a new power supply system combined biomass and fuel cell with waste heat recovery is proposed and analyzed. The system uses agricultural waste as energy source, providing gas fuel for solid oxide fuel cell through the biomass gasification. In addition, the homogeneous charge compression ignition engine can utilize unreacted fuel, and the waste heat energy in flue gas is recovered by the combination of supercritical carbon dioxide cycle and absorption refrigeration cycle. Under selecting working condition, the engine and bottom cycles brings an improvement of 11.10% in thermal efficiency, and the total fuel efficiency can reach 59.35%. Besides, the payback time of this system is nearly 60% shorter than the traditional system, with a minimum of 1.77 years. The whole system realizes the energy cascade utilization, being more efficient and cleaner, and has satisfactory performance.