ELECTRIC POWER CONFERENCE

At Electric Power in Baltimore, McIlvaine focused on three areas of fuel choices, air issues, and water issues.

Should U.S. Utilities rely on Gas as the Main Fuel?

The answer is yes if there is confidence in low gas prices or the economic life of the plant. The future price of gas in the U.S. will be determined by the future price of oil worldwide. It can be argued that the discovery of large shale gas reserves in China and Europe as well as the U.S. will drive down oil prices over the long term. This will discourage developers from building gas-to-liquids and LNG plants in the U.S. and make gas the fuel of choice for U.S. generators. But here are the concerns:

1. Chinese and European shale potential is unknown.
2. Chinese shale is deeper.
3. Europe has environmental hurdles.
4. Oil consumption could be large enough to keep prices high regardless of increased supply.

                                           Shale Gas Reserves (trillion m³)

The shale gas reserves are sufficient to supply the U.S. needs for 30 years. But we will need to conserve this resource. Conventional gas will disappear in the coming years so we will be relying on shale gas for all our needs. It will be wiser to plan on gas for residential uses for 50 years and find other fuels for power plants. However, the outlook for coal was deemed to be bleak by some of the speakers.

Block Andrews of Burns & McDonnell cited:

• Low demand growth (0.8%.yr)
• Low gas-to-coal prices
• Aging coal fleet
• Well-funded environmental groups
• Renewable energy standards
• Tightening environmental regulations.

AIR ISSUES

Clyde Bergemann Bachmann gas turbine exhaust systems and components include:

• Diffusers,
• Equalizers,
• Transitions,
• Diverters,
• Expansion Joints,
• Elbows,
• Blanking Guillotines and Plates,
• Duct Extensions,
• Bypass Stacks,
• Silencers,
• Stack Dampers,
• Louver Dampers,
• Flap Dampers,
• Guillotines

The Sealeze auxiliary exterior turbine brush seal is designed to resolve air in-leakage problems resulting from turbine housing gland seal wear. These seals restore output capacity and operating efficiency.

Southern Environmental and FLSmidth have teamed to provide fabric filters for coal-fired boilers. Here is the recent FLS experience.

Taggart Global offers solutions for material handling at power plants, from system design to start-up and commissioning. Recent projects include:

• AEP Clifty Creek Flue Gas Desulfurization Facility,
• GenON, Morgantown Generating Station coal blending and handling system and
• Capital Power Keephills Generating Plant.

Harco Temperature Sensor is used to measure discharge gas temperature in gas turbines. The unit features two isolated Type K thermocouple junctions that are enclosed in a nickel alloy sheath designed to enhance time response and reduce gas path blockage. Output via a hermetically sealed mil-spec connector with Type K thermocouple contacts ensures optimum accuracy.

Fike video smoke and flame detection has several advantages over traditional types of smoke detection. They are:  earlier detection, immediate situational awareness and fewer devices to install.

GE has upgraded three GE 9E gas turbines at Shenzhen Ninshan Power station with DLN 1 Low NO_x combustors. This reduced NO_x to 11 ppm which is well under the 25 ppm requirement.

EES recently demonstrated ClearChem 64-X on a large industrial power boiler in Pennsylvania. The operator was committed to reducing SO₂ emissions but had no room to install an FGD system. The objectives of this demonstration were to show SO₂ reductions of 40-50 percent and confirm what effects, if any, the additional particulate loading would have on ESP performance boiler deposits, ash handling, and combustion. With an average SO₂ reduction of 50 percent at a stoichiometric ratio of 1.3, no adverse impacts on flyash capture, flyash handling or furnace slag deposits were evident. A finely ground dispersion of calcium carbonate (less than 1 micron average particle size is injected in the boiler.

SCR Catalyst – Catalyst used in SCR systems operating on a coal-fired boiler is more subject to poisoning and slugging. One answer is large catalyst spacing. It is also necessary to understand boiler operations which affect the phosphorous chemistry.

Cindy Khalaf - Johnson Matthey

Bags should be replaced based on pressure drop and inefficiency. Broken bags are evident on inspection because of dust residue. Broken bag detectors are also effective; however the decision to replace bags can often be a judgment call.

Bill Geza and Patrick Paul - Dustex

Titan Fabricators has the skills and equipment for high pressure steam components such as HRSG units, headers and drums. It also has the ability to supply absorbers and process piping using high cost, high performance alloys. It built the 160’ high CFB absorber for the Dry Fork, Wyoming project.

Seawater scrubbing is a top choice in the Middle East, Chile, and India. One of the problems is to ensure that there is sufficient salinity in the water being utilized. When intakes are near fresh water discharges such as rivers the salinity can be greatly reduced.

Further insights on the value of Decisive Classification were provided in a conversation between Bob McIlvaine and Bill Siegfriedt of Sargent and Lundy. Bill has been involved with scrubbers for decades as has Bob but they have different nomenclature to classify the scrubber types. If two people who have shared much of the same knowledge over the years have differences in classification, then it is obvious that people in other countries using other languages and without the base knowledge are going to be challenged.

McIlvaine has recognized that the Flow-Pac scrubber by Alstom and the jet bubbling reactor by Chiyoda operate on the same principle. McIlvaine has called these sump scrubbers. Bill calls them frothing scrubbers. But both men agree that this is a distinct group as compared to spray and tray towers.  Lower L/G, size and many other unique differences make it highly desirable to define this group precisely.

Bill has some unique insights on dry and semi dry scrubbing. He needed to find a unit which would approach 100 percent SO₂ removal. The fluid bed scrubbers made by Lurgi, Wulff and others provide very high ratios of Lime to SO₂ based on the recirculation within the vessel. The N.I.D.  unit offered by Alstom and similar units offered by others provide recirculation only back from the collector. The reagent in the vessel is all moving through. Thus the potential lime/SO₂ ratio is inherently lower.

Two other dry or semi-dry technologies are the spray dryer and the dry sorbent injection or DSI. Each of the four technologies has different performance and physical parameters. It is therefore necessary to decisively classify them. Bill uses the term circulating dry scrubber or CDS just to cover the Lurgi/Wulff fluid approach. McIlvaine has been using CDS to cover both the fluid bed and the N.I.D. type approach.

It is highly desirable to standardize on the terms. McIlvaine will be querying the relevant parties and see if we can come to agreement on a “decisive classification” of scrubber types.  Once this is done, we will generate precise translations in Chinese and Spanish.

Bill Siegfriedt – Sargent & Lundy

There were a number of sorbent supplies who exhibited at the show. Novinda, NatronX, Calgon Carbon, and Solvay were among this group. The regulatory delay is causing a bigger problem for these suppliers than for the equipment suppliers. The utilities are proceeding with the equipment. But they are not going to start using sorbent until required to do so.

Yougen Kong - Solvay

Richard Sereni, Ramonda Fabian, Michael Dunseith – Allied Environmental Solutions

One of the CFB suppliers is Allied Environmental Solutions. They have just bagged two big orders and can talk about one of them. Empire District Electric Asbury Unit 1 has purchased a CFB scrubber and baghouse for PRB coal. Alberici and Stanley are the EPC consortia.

WATER

Sam Barnes, vice-president of power generation of Commonwealth Associates, addressed the question of what to do with wastewater when a coal ash pond closes. "Whether or not coal ash becomes classified as hazardous waste by the EPA, coal plant owners may be looking at converting their ash systems from wet to dry for any number of reasons," said Barnes. "But what does this do to the plant's water mass balance, and where will the process wastewater go?"

Here are specific steps that plants should take in preparation for possible closures of coal ash ponds due to regulatory changes:

• Start by characterizing the plant's wastewater flows for both quantity and quality. Future considerations that could add to or subtract from wastewater generation must be documented. 
• Once the amount and nature of wastewater is known, modifications (physical and operational changes) can be reviewed that will minimize the wastewater generated. 
• Once wastewater generation has been minimized, treatment before release to an outfall must be considered. 
• Finally, evaluate appropriate treatment options (configurations, technologies, flows, and effluent limits) and then choose the ones that balance compliance, project costs, and operating and maintenance costs. 

Barnes also addressed upcoming regulatory issues that will likely decide the extent of treatment necessary for wastewater from coal ash ponds:

• EPA's pending revisions to steam electric power generating effluent limitation guidelines (ELG).
• ELG constraints for direct dischargers to be implemented through National Pollutant Discharge Elimination Systems permits under the Clean Water Act.

Discharge limits for indirect dischargers that are likely to be implemented through a national pretreatment program.

Colleen Layman of Bechtel pointed out that chemistry programs for combined cycle gas turbines have their own demands and constraints that are distinct from those for water-tube boilers. She cautioned that plant chemistry needs to be based on the highest system pressure and that careful thought needs to be given to each plant's unique characteristics and operating parameters.

John Hall Christensen - Layne

Layne Membrane Bioreactors utilize Poreflon fibers made from PTFE (polytetrafluoroethylene). The PTFE fibers achieve superior filtration and are the strongest, most chemically-resistant, temperature-resistant and longest service MBR fibers available.

International Cooling Tower (ICT) has furnished towers for recent new coal-fired power plants including Prairie State and Sandow where the 22 cell counterflow unit is constructed of FRP and film filled. It is about 100 x 600 x 70 feet high.

C.I. Agent^® Hydrocarbon Flow Filter allows water to flow through as it removes and captures hydrocarbons including most volatile organic compounds, down to a non-detectable level.

Veolia Water Solutions & Technologies has developed an efficient, small-footprint treatment scheme for removal of metals and TSS from cooling tower blowdown to achieve new stringent discharge limitation currently impacting the Power Industry. The treatment scheme is based upon two technologies from Veolia Water - ACTIFLO^® Turbo and Hydrotech Discfilters – optimized by the use of Hydrex™ treatment chemicals.

Kai Rondum, Darcy Dauterive, Joseph Janeczko – Ashland

A West Coast independent power producer operates a combined cycle power plant which uses an Ashland performance-based monitoring and control technology architecture that optimizes the cooling water treatment program and results and improves overall plant reliability, availability and operating efficiency.

Bob Markoja - CIDRA

CIDRA’s SONARtrac Flow Monitoring System is a non-invasive flow measurement technology. By installing on existing process lines, SONARtrac clamp-on flow monitoring systems eliminate the process disruptions associated with installing other types of flowmeters.

Nalco Mobotec has demonstrated total mercury capture for air and water for coal-fired power plants. A demonstration project showed reduction of mercury air emission levels to less than or equal to 0.008 lb/GWh and wastewater treatment effluent mercury content of less than 200 ppt.