Carbon capture effects on water use at pulverized coal power plants

AbstractSignificant quantities of water are utilized in thermoelectric power plants, mostly for the purpose of cooling. Water is becoming critically important for low carbon power generation. To reduce greenhouse gas emissions from pulverized coal (PC) power plants, post-combustion carbon capture systems are receiving considerable attention. However, current systems require a significant amount of cooling, which puts further pressure on cooling water resource. This paper quantifies cooling water use and evaluates technical and economic effects of carbon capture on cooling systems at PC power plants. Included are recirculating systems with wet cooling towers and air-cooled condensers (ACCs) for dry cooling. For a wet cooling tower, water has to be provided to make up losses due mainly to evaporation and blowdown. Adding an amine-based carbon capture system to the plant would approximately double water use. When air-cooled condensers (ACCs) are used as the dry cooling system, in spite of the advantage in reducing water usage, the dry cooling system has a much larger capital cost than the wet cooling system, depending strongly on specific site and system characteristics