A Metal Hydride Compressor Concept using Hydrogen as a Heat Transfer Fluid

Abstract Metal hydride hydrogen compressors have been explored as an alternative to mechanical hydrogen compressors since the first patents were filed in the 1970s. As heat engines, their productivity significantly depends on the achievable heat transfer rate, which is inherently limited by the pressure-bearing walls separating the heat transfer fluid from the reactive metal hydride beds and their effective thermal conductivity. This work presents and analyzes a new metal hydride compressor system that uses hydrogen as heat transfer fluid in direct convective contact with the metal hydride material. Following this principle, we show how an integrated compressor can be designed and behaves on a system and metal hydride bed level. The achievable productivity surpasses what has been reported for experimental metal hydride compressors while showing good prospects for low electrical energy consumption.