A High-Efficiency Power Cycle in Which Hydrogen Is Compressed by Absorption in Metal Hydrides

Abstract

A high-efficiency power cycle is proposed in which molecular hydrogen gas is used as a working fluid in a regenerative closed Brayton cycle. The hydrogen gas is compressed by an absorption-desorption cycle on metal hydride (FeTiH_x) beds. Low-temperature solar or geothermal heat (temperature about 100°C) is used for the compression process, and high-temperature fossil fuel or nuclear heat (temperature about 700°C) supplies the expansion work in the turbine. Typically, about 90 percent of the high-temperature heat input is converted to electricity, while about 3 kilowatts of low-temperature heat is required per kilowatt of electrical output.