Water

Circulating fluid bed (CFB) dry scrubbing technologies provide distinct advantages over conventional spray dryer absorber scrubbers for removing SO₂ from flue gases. The CFB also competes well against wet limestone flue gas desulfurization processes typically favored for large boilers firing high-sulfur coals. With high SO₂ removal rates in a dry treatment process, the CFB scrubber appears to be the best of both technologies: a water-stingy scrubber with high SO₂ removal rates.

Ensuring the availability of water for power plants is a matter of both water quantity and quality. As freshwater becomes less available for power plant use, new supplies from marginal or impaired sources will require new cooling technologies. We look at cooling equipment options and how water availability and quality affect cooling system design and cost.

Shrinking water supplies will unquestionably constrain the development of future power plants. A hybrid system consisting of concentrated solar thermal power and desalination to produce water for a plant, integrated with a combined cycle or conventional steam plant, may be the simple solution.

River deltas experience extreme seasonal changes in water quality that perplex conventional water treatment systems. Industrial development in China, including new power plants, has spurred the development of desalination processes that have tamed these brackish water sources to provide a virtually unlimited supply of boiler-quality water.

Concentrated sulfuric acid is often used to prevent calcium-based scale formation on condenser and heat exchanger tube surfaces in power plant evaporative cooling water systems. Unfortunately, the chemical’s price has jumped more than 300% over the past three years. If the rising cost of water treatment has you under the budget gun, here are some alternative strategies that can reduce or even eliminate your sulfuric acid usage.

The U.S. Department of Energy’s National Energy Technology Laboratory is pursuing a new integrated energy-water R&D program that addresses water management issues relative to coal-fired power generation that takes into account the major impacts of CCS on water use. The goal of this research is to promote more efficient use of water in power plant operations and increase the availability of heretofore unusable waters for power plant use. Those practices can mitigate the impacts of CCS on power plant water use and allow for continued development of energy resources.

The atmospheric vortex engine exploits the natural energy content of the vortex produced during upward heat convection in the atmosphere. The heat source can be solar energy, warm sea water, warm humid air, or even waste heat rejected in a cooling tower. When mature, the technology — currently in the small-scale testing phase — promises to be an efficiency game-changer for fossil-fired power plants.

The race is on to claim the title of "most efficient coal-fired power plant" on the planet. However, it’s tricky identifying finalists because of the widespread misuse of the term "efficiency" and all those nagging assumptions. Let’s first establish clear definitions and then identify the title contenders.

There are a number of reasons why your plant might be looking at new water pretreatment equipment in the near future. One common reason is the addition of new generating capacity. Regardless of the type of new generation, you can be sure that it will require additional high-purity water for processes ranging from direct steam generation to power augmentation, NO_x control, and washing the blades of the combustion turbines.

One key area at the 800-MW Michoud power station where O&M excellence is evident is in maintaining plant water quality.