Alloy selection for dual stage metal-hydride hydrogen compressor: Using a thermodynamic model to identify metal-hydride pairs

Metal-hydrides offer a potentially competitive method for compressing hydrogen, particularly where waste heat is available. Metal hydrides are metal alloys or intermetallic compounds that react reversibly with H2. They readily absorb low-pressure H2 at low temperature, and then release higher pressure when the temperature raised. The high released above expected from standard press-temperature relations. absorption desorption pressures of determined by their thermodynamic properties (enthalpy entropy). To achieve compression ratios about 10, more than one stage typically required. challenge to find alloy pairs can work together effectively desired heating/cooling Previously, model has been proposed identifying suitable be paired compression. This paper describes methods used previously in literature select pairs, applies current an example selection 33 potential hydrogen application aims compress stream 10 350 bar using range 30–150 °C, however theory could adapted different ranges. For specific evaluated none were able meet target, however, modification parameters (heating/cooling availability) resolve this issue.