Power Water Insights No

				Power Water Insights No. 3 January 13, 2012

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· Regulatory Initiatives Should Encourage Co-location of Power and Municipal Wastewater Treatment Plants

· Denmark Combines Power Plant, Biomass Refinery and Municipal Water Treatment.

· Wedeco Ozone Replaces Biocides and Chlorine at Hoescht due to Need to Minimize Adsorbable Halogens and COD

Regulatory Initiatives Should Encourage Co-location of Power and Municipal Wastewater Treatment Plants

“It is often said that an economy runs on oil, but it could also be said it runs on water. Simply put, electricity is needed to power the economy, however in most cases power cannot be generated without water. Conversely, electricity is needed to treat water. It is therefore critical that we consider the nexus between water and power. In a world where water is an increasingly scarce resource, policies supporting the conservation and recycling of water for power generation must become an urgent international priority. This observation was made by Heiner Markhoff, president and CEO of GE Water & Process Technologies “

Markhoff went on to say that “Incentives to collocate municipal wastewater treatment plants and power generation plants in the future would go a long way towards providing innovative sources of water, reducing freshwater withdrawal and energy consumption. However, while advanced water reclamation technologies already exist, the motivation to deploy them often does not”. Today, it is often less expensive for plant operators to pull water from a river or a well, or even to draw potable water from a municipal system, than to treat and reuse it.

“Barriers to water reuse and water recycling systems come in many forms: technological, financial, and regulatory. In fact, regulations intended to protect the public or programs providing services to the community may have the unintended effect of discouraging or even preventing voluntary water reuse.”

Denmark Combines Power Plant, Biomass Refinery and Municipal Water Treatment

At the Asnæs Power Station, Dong Energy co-located the Inbicon Biomass Refinery and integrated it with the power station.

The new biomass refinery became the ninth major company in the Industrial Symbiosis of Kalundborg, where energy and byproducts are exchanged in over 20 mutually beneficial ways. Waste steam from the power station cooks straw to prepare it for conversion into cellulosic ethanol. The process also produces a lignin powder that power plants can use without additional treatment to replace coal. This energy exchange dramatically increases the efficiency and shrinks the carbon footprint of both operations.

The Asnæs Power Station also sends steam to the Statoil Refinery and Nova Nordisk (Novozymes); heat to the municipal water treatment facility and a fish farm; and fly ash offsite to the concrete and cement industry. In removing sulfur dioxide from its flue gas, the power station produces about 110,000 tons of gypsum, which another Kalundborg company turns into plasterboard for the construction industry. This reduces the amount of natural gypsum the company needs to import, and it gives the power station a valuable product made from flue gas.

We are conducting a collaborative discussion on silca scale. In preparation for the meeting we are posting papers which would be relevant to the discussion. If you have a paper to post, please send it to us before the 25th. The papers are being posted in our Global Knowledge Orchard. You can access them under “other subjects” and then “silica scale.”

Join us on Wednesday, January 25 at 10 a.m. (central time) to hear and participate in a discussion of silica scale issues and answers for the power industry.

Wedeco Ozone Replaces Biocides and Chlorine at Hoescht due to Need to Minimize Adsorbable Halogens and COD

Infraserv Höchst is a leading company for operating large scale industrial and chemical production complexes. Infraserv is a complete service provider offering different services (purchasing, engineering, facility management, etc.) and full supply of commodities as compressed air, steam, energy, cooling water, purified water, technical gases and energy.

In Frankfurt/Main Infraserv Höchst is operating one of the largest production and research site for the chemical industry in Europe.

In the early 90s, WEDECO in collaboration with Hoechst and Messer investigated in detail the use of ozone for different applications. Soon, the use of ozone to prevent biological growth in industrial cooling systems was recognized as one of the most promising applications. After scale pilot testing including a thorough investigation of all relevant water parameters, corrosion measurements, evaluation of safety and ease of operation, Hoechst decided to change the former biocide treatment (organic biocides, chlorine gas, and hypochlorite) to ozone treatment. The formerly already used inhibitor treatment to prevent scaling or corrosion was further used with only minor adoptions.

Between 1995 and 2007 a total of sixteen (16) ozone systems were delivered by WEDECO which are operating successfully to prevent biofilm formation inside the single cooling loop systems. The different cooling loops consist of air cooled cooling towers that provide chilled water for all different consumers as chemical production facilities, air separation plants for oxygen and nitrogen supply and power plants. The different cooling loops have circulation rates from 1.000 – 16.000 m³/h. The WEDECO ozone systems are using technical oxygen available on site or dried compressed air to produce between 700 – 4.000 g/h.

The introduction of small dosages of ozone into the recirculated cooling water prevents biological growth inside the cooling systems and process heat exchangers. The cleaner cooling system saves energy due to better heat transfer, reduces maintenance work significantly and increases the lifetime of components and piping. Since no additional salts are introduced into the cooling loop, less make-up water is consumed, higher concentration cycles can be achieved and thus less inhibitors are needed.

Main motivation beside the prevention of biological growth was the safe compliance with governmental thresholds for AOX (adsorbable halogens) of < 500 μg/m³ and COD (chemical oxygen demand) of 40 mg/l in the blowdown (discharge) of the cooling loop and the safe control of Legionella. Due to the permanent urge for higher degrees of automation needing lesser and lesser manpower to operate complex systems, the fully automatic operation of the ozone system and the lowest need for maintenance was of special and growing importance for our client.

Seven of the WEDECO EFFIZON SMO/SMA systems installed on site produce ozone from technical oxygen at typical ozone concentrations of 10 wt% while one unit uses dried and filtered air as feed gas at ozone concentrations of 2.3 wt%. The systems are complete and operate automatically from remote on/off. The single systems consist of: ozone generator, side stream pump-injection system, ozone analyzers for the gas phase, ambient air ozone detection unit and complete process control based on Siemens S5 / S7. Some of the ozone systems are completely containerized including all relevant safety features, while there are also skid-mounted units installed in the premises of the client. ITT WEDECO was considered as the right partner for Infraserv especially due to its extensive experience in cooling water treatment, broad installation basis and most reliable and efficient ozone technology.

On January 19 at 10 a.m. central time, McIlvaine editors will initiate discussions of some novel ways to make coal plants green as well as review some of the technologies which are better known. The newest concept is co-location of municipal wastewater treatment power plants and coal power plants. Why send the sludge to the power plant by truck and send the treated wastewater by pipe. It makes more sense to co-locate the two and use the low pressure steam from the power plant to improve the sewage treatment operations. This can be combined with liquid manure delivered in the same piping from surrounding farms.

Article:	An evaluation of silica scale control additives for industrial water systems
Article:	BASF introduces new silica scale inhibitor
Article:	Effective use of recycled water in cooling towers with new green technology
Article:	Electronic treatment removes silica scale in power and semiconductor applications
Article:	Flue Gas Injection Control of Silica in Cooling Towers
Article:	Preventions and Solutions for the Scale Problem at the Geothermal Power Plant and CDM Study in Indonesia
Article:	Silica Scale Management: Lowering Operating Costs through Improved Scale Control, and Adding Value by Extracting Marketable By-Products
Article:	Silica Scale problems Occur in Western U.S., Southern Europe and Pacific Rim
Article:	Western Water Technologies has a Polymer for Control of Silica Deposition