Water-Conserving Steam Ammonia Power Cycle

79186S Fresh water is growing scarcer and costlier. Power production is the second largest user of fresh water, accounting for 130 billion gallons daily. Unfortunately, current approaches to reducing the water used in power production increase the cost of power and reduce the efficiency. Cycle improvements are needed which will enable power to be produced from coal with reduced water usage but without economic or efficiency penalty. This project will develop a new power cycle, the Steam Ammonia Power Cycle (SAPC), which avoids the penalties normally encountered in air-cooled power cycles. The SAPC condenser operates above atmospheric pressure (100-250 psia), allowing "dry" or "damp" cooling with finned tube heat exchangers, greatly reducing the quantity of water required (60% reduction with damp cooling). Also, because the SAPC cycle closely matches the temperature glide of the heat available from the power plant, it will be from 5% to 15% more energy efficient than the conventional steam cycle. Phase I will analyze and optimize the SAPC cycle for three specific power generation applications, which cover the gamut of coal-fired application to power production: coal direct, coal derived gas in a combined cycle, and coal derived liquid in a combustion turbine. For each, the benefits of reduced water consumption and reduced fuel use will be quantified, and the change in capital cost will be estimated. Commercial Applications and other Benefits as described by the awardee: Applications should include integrated coal gasification combined cycle power plants, coal-fired power plants, and other cycles which incorporate a steam vacuum condenser. With a 25% penetration of this technology, fresh water consumption would be reduced by 22 billion gallons per day, and fuel consumption by 0.35 quads per year.