Temperature and Pressure Dependence of Anomalous Heat Generation Occurring in Hydrogen Gas Absorption by Metal Powder

As reported in previous papers, anomalous heat generation occurs when nickel or palladium powder is exposed to hydrogen or deuterium gas, while there is also a chemical effect that occurs when hydrogen (or deuterium) gas is absorbed by mixed oxides of Pd and Zr. Many experiments were previously conducted while increasing either initial temperature or pressure in the reaction chamber. In this report, we conducted fundamental experiments of hydrogen gas absorption by metal powder, while increasing both temperature and pressure simultaneously. The experiments were conducted in conditions up to 244°C and 0.5 MPa, using a small constant-volume reaction system developed by us. As a result, about 4 K of temperature rise was observed in the experiment using nickel powder, and about 10 K was observed in the experiment using Pd-Ni-Zr composite powder. In these experimental results, there are positive correlations between the temperature rise and both the initial temperature and loaded gas pressure. This result may show that the temperature rise is assisted by not only preheating but also gas absorption under higher pressure.