Providing Services to the Energy Industry


Moxie Freedom is proposing to build a highly efficient combined cycle power plant in Salem Township.  Combined-cycle power plants operate at higher efficiencies than traditional fossil-fueled plants by capturing much of the energy contained in the hot exhaust from the natural gas combustion turbines to generate additional electricity.  Using that energy, which otherwise would be wasted up the stack as hot air, is a major benefit of the combined-cycle design.

Energy from the exhaust of each combustion turbine is captured by a heat recovery steam generator (HRSG).  The HRSGs are so efficient that exhaust leaving turbines at more than 1,100°F is reduced in temperature to below 200°F by the time the heat recovery process is completed.  The HRSGs will be equipped with state-of-the-art emissions control technology including Selective Catalytic Reduction (SCR) and an Oxidation Catalyst, to reduce air emissions of nitrogen oxides and carbon monoxide that are generated during the combustion process in the gas turbines.

HRSGs contain boiler tubes filled with ultrapure water.  Hot exhaust flows past these tubes, turning the water into steam.  The steam is piped to a steam turbine, which is also connected to a generator.  Steam enters the turbine at more than 1,000°F. The air-cooled condenser condenses the steam back into water using large diameter fans to circulate air past tubes containing the steam.  The water is then returned to the HRSG in a closed-loop cycle to be reused.

The process flow diagram below shows a single combustion turbine and single steam turbine.  The Moxie Freedom Generation Plant will utilize a second combustion turbine and HRSG combination to feed steam to a second steam turbine in what is known as a 2x2 configuration.

Double click thumbnail to enlarge image of Process Flow Diagram: