ABSTRACT
Nomenclature .............................................................................................................................. 147 References ..................................................................................................................................... 147
5.1.1 Principle of Thermochemical Processes
As described in Section 3.2, not only heat but also work input is required to obtain hydrogen when the heat of lower than Td (4310 K) is input to the direct decomposition of water at 1 atm. However, incorporation of chemical reactions to the decomposition process can lower the temperature threshold of the heat to be required. Figures 5.1 through 5.3 explain the concept. The reactions in Figure 5.1 satisfy these enthalpy/entropy balances.
