Design and comparison study of a novel linear Fresnel reflector solar ORC-driven hydrogen production system using different working fluids

This paper presents a novel linear Fresnel reflector solar organic Rankine cycle-driven hydrogen production system consisting of thermal energy storage system, organic Rankine cycle and proton exchange membrane hydrogen production device. By using Ebsilon software, operation, exergy and economic performances of the proposed hydrogen production system using seven different organic working fluids are evaluated and compared, including cyclohexane, propane, toluene, hexane, R123, R11 and R143A. The analysis results show that when hexane is used as the organic working fluid, the proposed system has the largest net output power, highest cycle efficiency and largest hydrogen production rate (2325.3 kW, 20.8 % and 36.0 kg·h-1), showing the best operation performance. In addition, the proposed system using hexane has the smallest overall exergy loss (19.58 MW) and highest overall exergy efficiency (18.4 %), while the system using R11 has the largest overall exergy loss (21.78 MW) and lowest overall exergy efficiency (9.24 %). Furthermore, the proposed system using hexane has the lowest levelized cost of hydrogen, smallest payback period and largest net present value (4.97 $·kg-1, 4.7 years and 47.8 million USD), showing the best economic performance. In general, compared with other six organic working fluids, the proposed hydrogen production system using hexane has the best operation, exergy and economic performances.