Abstract: A method of heating a fluid stream for a power plant comprises diverting a portion of a main flow of flue gas from a power plant at a first pressure (P1), flowing the diverted flue gas through a heat exchanger, flowing an auxiliary fluid stream through the heat exchanger, and transferring heat from the diverted flue gas into the auxiliary fluid stream in the heat exchanger to raise a temperature of the auxiliary fluid stream from a first temperature (T3) to a second temperature (T4), while lowering a first temperature of the diverted flue gas (T1) to a second temperature (T2). The diverted flue gas is then returned to the main flow of flue gas in the power plant at a second pressure (P2). The method of flue gas flow through the heat exchanger may be accomplished by adding a self-contained flow path from a boiler higher pressure (P1) zone to a lower pressure (P2) zone.