This project replaces the cooling tower in a fossil fired power plant with an innovative diffusion driven desalination (DDD) plant that will render the power plant a net producer of fresh water. The energy required to drive the desalination process comes from the main condenser cooling water, which would otherwise be discharged. Saline water is used to condense the low pressure steam exiting the turbine. The hot, saline water exiting the condenser is sprayed into the top of a diffusion tower. The diffusion tower is filled with high surface area packing material such as that used in air stripping towers to enhance the water/air surface area. Air is blown through the bottom of the tower and becomes humidified. The humidified air goes to a direct-contact condenser where the fresh water is condensed. This process has an advantage over conventional desalination technology in that it may be driven by waste heat with very low thermodynamic availability. Also, cold air is a byproduct of this process which can be used to cool buildings.

A main feed pump (1) draws water from a large body of seawater. The water is pumped through (3) two regenerative heat exchangers. The purpose of these heat exchangers is to recover thermal energy from the brine and condenser cooling water and transfer it to the incoming seawater, thus improving the efficiency of the process. The seawater is then heated in a primary heater (4), which may be the heat from low pressure condensing steam in the main condenser of a fossil-fired power plant. After the feed water is heated in the primary heater, it is sprayed into the top of the diffusion tower (5)

On the bottom of the diffusion tower, low humidity air is pumped in using a forced draft blower (8). The water falls concurrently to the airflow through the diffusion tower by the action of gravity. The diffusion tower should be designed such that the air/water vapor mixture leaving the diffusion tower should be fully saturated with water vapor. The water not evaporated in the diffusion tower will be collected at the bottom as brine and pumped through the regeneration heater using a brine pump (7). The air/water mixture enters a condensing tower where the water vapor is condensed into fresh liquid water that is collected in the sump of the condenser. The condenser is cooled with seawater that is drawn from a large depth beneath the surface using a circulating pump (2). A condensate pump (9) pumps the fresh water from the condenser sump for storage or consumption.