Speaker
Description
Paris agreement was adopted by consensus on 12th December 2015, then went into effect on 4th November 2016. The necessity to reduce the emission of greenhouse gas is growing on a world scale. We have to consider the substitute energy source of fossil fuel. One of the prospective solutions is hydrogen. In Japan, the concept “CO2 Free Hydrogen Chain” is promoted. The concept is that massive hydrogen produced by electrolysis using renewable energy, or gasification of abundant unused energy such as brown coal (generated CO2 is captured and stored) in foreign country is liquefied to transport effectively, imported into Japan by liquefied hydrogen cargo carrier. In this concept, the technology of storage and transportation of massive liquefied hydrogen is essential. Based on the concept of large tank for liquefied hydrogen, we measured outgas rate from various materials which constitute the vacuum jacket, such as tank, thermal insulation, and support structure. We studied the mechanism of reaction from the data of the outgassing rate for each material, diffusion controlled reaction or the reaction limited at the surface of the material. We treated the material by baking or coating at the surface to reduce the outgas rate, and confirmed the effect comparing with that of untreated materials. We made an analysis of the component of the outgas from the materials and discussed the effect for vacuum degree during the storage of liquefied hydrogen.