2.4.2 Bottoming cycle
In a bottoming cycle, the primary fuel produces high temperature thermal energy and the heat
rejected from the process is used to generate power through a recovery boiler and a turbine
generator. Bottoming cycles are suitable for manufacturing processes that require heat at high
temperature in furnaces and kilns, and reject heat at significantly high temperatures. Typical
areas of application include cement, steel, ceramic, gas and petrochemical industries.
Bottoming cycle plants are much less common than topping cycle plants. Figure 9 illustrates the bottoming cycle where fuel is burnt in a furnace to produce synthetic rutile. The waste
gases coming out of the furnace is utilized in a boiler to generate steam, which drives the
turbine to produce electricity.