Investigation and development of a novel solar-biomass integrated energy system for clean electricity and liquid hydrogen production

Abstract

In the present work, an innovative power generation system based on solar and biomass energy resources is proposed. Energy and exergy methods are applied to analyze and model the system. Also, to evaluate the system's performance during the year, the values of solar radiation and ambient temperature as a transient are studied for a case study in Khuzestan province. The system consists of a biomass unit, a solar unit, a waste heat recovery unit, and a hydrogen liquefaction unit. The power is generated by two gas turbines and two Rankine cycles. Furthermore, the system produces liquid hydrogen with a Linde-Hampson hydrogen liquefaction process and a proton exchange membrane electrolyzer, and hot water with a water heater. A gasifier is utilized to convert biomass to syngas, and a heliostat field is employed to harness solar energy. For solar energy storage, molten salt is used. The system’s power output is 7967 kW, while the exergy efficiency is 11.06%. Also, the production rates of liquid hydrogen and hot water are found to be 10.74 kg/h and 7 kg/s, respectively. To gain a deeper understanding of the impact of using solar energy, a comparison of biomass, solar-biomass, and solar-biomass with waste-heat recovery is made. The results show that solar energy with waste-heat recovery reduces CO2 emissions by 30.5% while increasing the system's electrical power output by 44% as compared to scenario 1 in which only biomass fuel was used. In addition, the highest component cost rate is attributed to the solar power system, accounting for 51% of the capital investment cost.