In this blog, Marmon Industrial Water takes a look at how water conservation efforts can be stepped up with significant financial benefits, using the Graver Powdex® Precoat Filter Demineralizer in power generation steam condensation loops. Result: Benefits to bottom line and achieve sustainability goals
Power generation uses more water than any other industrial process, and water-dependent thermal plants use steam to generate more than 81% of the world’s electricity. As demand for electricity drives demand for water, in a time when water scarcity is rising quickly as a global threat, power outages caused by water shortages are happening with greater frequency. Also on the rise are regulatory requirements for water reuse and conservation, particularly in water-stressed areas. Power plants and other industrial plants that generate steam electricity stand to invest in technology that conserves and makes the greatest use of water.
Contaminated condensate, and the high cost of blowdowns
Condensate that results from a steam turbine operation represents a significant opportunity for conservation. It can be reused, but over time it becomes increasingly contaminated, which can damage boilers, steam generators, reactors and turbines with impingement of abrasive particulate material transported with the steam or by deposition on soluble material (like silica and copper) on the turbine blades. Tube pitting, tube rupture and drum pitting are also possible consequences of contamination.
To remove system contamination, plants typically engage in blowdowns – or purging all the water from the condensate loop at once and replacing it with fresh water. This process represents enormous costs:
- The cost of replacement water (on the rise): 0.30-0.50/1,000 gallons
- Cost to prepare the water for heating (clarifying, filtration, softening, dealkalizing, reverse osmosis and deionization): 0.34-.50/1,000 gallons
- Cost of chemical treatment (neutralizing amines): 1,000 gallons
- Cost to heat the water (reusing condensate preserves water temperature; with a blowdown the new 55oF water must be heated up to 200oF): $5-$10/1,000 gallons
- Wastewater treatment of purged water: $2-$4/1,000 gallons
Total cost of a blowdown: $7.80-$15.15/1,000 gallons!
Benefits of recovering and reusing condensate using Powdex®
Marmon Industrial Water offers a viable solution to minimizing blowdowns: the Graver Powdex® Precoat Filter Demineralizer, available in both permanent and mobile (mPowdex®) units. This condensate polisher removes contaminants from condensate while preserving the heat, allowing it to return to the process clean and warm.
A precoat filter demineralizer is a special type of condensate polisher that remove steam loop contaminants in two ways: It removes suspended solids by filtration and reduces ionized impurities to parts per billion (in some cases, part per trillion) levels, using ion exchange. Precoat filter demineralizers remove soluble and suspended iron, copper, silica, activated corrosion products and salts. While their foundational technology is not new, recent advancements include precoating techniques, high energy air scouring during backwash for enhanced septa cleaning and other operational efficiencies.
Powdex® delivers a long list of benefits, starting with water conservation. By avoiding blowdowns, plants can save millions of gallons of water per year and helping companies with regulatory compliance goals. Especially in water-stressed areas, plants are facing increased pressure to reduce water waste, and even plants where water scarcity isn’t an issue today should be preparing now for this eventuality.
Water scarcity and conservation have quickly emerged as global megatrends
While the cost of fresh water is among the smaller pieces of the total cost of makeup water, this is changing. According to data compiled by Barclays, the average price of water increased by 60% in the 30 largest U.S. cities between 2010 and 2019, and California Water Futures have regularly jumped as much as 300% in recent years. For economic and sustainability goals, all industries must re-strategize their water use.
For more information, please visit marmonindustrialwater.com/mpowdex