The HyS cycle was first proposed by Brecher and Wu [1] at Westinghouse Electric., where it
was developed in the 1970s and 1980s [2,3,4]. As a result, it has also come to be known as
the Westinghouse process [5]. HyS is one of the simplest thermochemical cycles,
comprising only two reaction steps and having only fluid reactants. The “hybrid”
designation acknowledges the electrochemical nature of one of the reaction steps, which
requires that electric as well as thermal energy be supplied to the process. It is a sulfur cycle
because it entails sulfur oxidation and reduction. In fact, sulfur is the only element in the
cycle other than H2 and oxygen (O2).
A simple schematic of the HyS cycle that