FGD and DeNOx
NEWSLETTER       

                                                                                                                                     June 2007
                                                                                                                                        No. 350

Pump Hot Topics were Availability and Pump Materials

On April 5 pump experts provided alternative views on pump materials but did agree that there is a current supply problem. The first presentation was by George Jenkins of Idex. Handling ammonia in all its forms (anhydrous, aqueous and urea) is a challenge and one that Idex has successfully met.

The scrubber recycle pump was the focus of the remainder of the 90 minute recorded session. Jim Burke of Weir led off with insights based on a very large scrubber pump base. Steve Lindgren told the participants that GIW/KSB manufactures an all-metal pump and one with a ceramic/polymer lining. Allan Abbott indicated that Flowserve has met good success in China with their FGD pump. Mike Agosti of Lawrence related that the Düchting SIcast pump is being offered in North America. An order for Vectren for 20 pumps is presently being processed.

There was a very interesting exchange among the pump suppliers relative to availability of pumps. If you want to start up a scrubber in 2010 and haven’t ordered a pump yet, then you can eliminate several of the largest suppliers from your bidders list. Pumps are one of the first major components to be shipped to a site and can therefore precede startup by one or two years.

Rubber lining, hard metal, and ceramic lining all have been successfully applied. Conditions such as chloride levels are variables which may enter the decision making between one material and the other. Mechanical seals were another focus of discussion. The seals are to some extent the Achilles heel. Therefore proper design and selection is important.

Summaries of some of the company presentations follow. You can access the Hot Topic Hour presentations in the NO_x Decision Tree by following

Start►NOx Removal ► Physical ► Components ► Pumps ► Sources ► Index

and in the FGD Decision Tree by following

Start ►Scrub ► Physical ► Component Specification ► Pumps ► Sources

Idex (Corken) – George Jenkins, Speaker

Corken is the leading supplier of pumps to handle ammonia for SCR systems. Side Channel Pumps for anhydrous ammonia, aqueous ammonia, and urea are claimed to have the following advantages:

• Exceptional in light liquid transfer.

• Capable of pumping liquids containing up to 50 percent gas.

• Enclosed centrifugal impeller.

• Able to develop high pressures without pulsations.

• There is no metal-to-metal contact, so wear is minimized.

• Designed for continuous duty.

• Available in sealless magnetic drive design for leak proof integrity.

WEIR Slurry- Jim Burke

Jim gave a good overview of the recycle pump application and corrosion considerations. Weir formerly acquired both Warman and ASH. Warman has over 2500 large pumps installed on absorber recirculation duty worldwide. ASH has over 90 FGD installations and over 600 large frame absorber recycle pumps installed worldwide. Claims for the GSL series are as follows:

• High Efficiency - 90 percent,

• Lower power consumption,

• Maintainable installed efficiency throughout the life of the impeller,

• Same design features as the successful large "L" series pumps currently operating at 10 or more years life without maintenance,

• Reduced weight in casing and base support. The highly efficient alloy impeller with chrome alloy (28 percent) is specifically designed for FGD services. The high chrome matrix resists pitting corrosion, chloride and pH excursions.

 KSB / GIW – Steve Lindgren

KSB has traditionally offered its metal and ceramic/polymer lined pumps in Europe and the GIW rubber lined pumps in the U.S. but now is ready to introduce U.S. buyers to the full range of products. FGD plants around the world use more than 1000 KSB scrubber pumps and well over 2000 process pumps in secondary circuits, plus several thousand valves. KSB developed CeramikPolySiC to provide a highly durable ceramic/polymer composite material specially designed for FGD plants. KSB uses CeramikPolySiC for KWPK scrubber pump components in contact with the fluid. This material is highly wear resistant and completely corrosion proof, providing operators with considerably longer running times.

Flowserve – Allan Abbott

The Flowserve type M hard metal slurry pump is a horizontal, single stage, end suction design with a tangential discharge nozzle. The M pump is engineered to handle high concentrations of abrasive solids in suspension. Hard metal casing, made from abrasion and corrosion resistant high chrome iron, incorporates integrally cast straightening vanes in the suction nozzle to reduce pipe swirl and extend impeller life.

Pumps are available to handle

• Flows to 44,000 gpm (10,000 m³/h)

• Heads to 300 ft (90 m)

• Pressures to 10 bar (150 psi)

• Temperatures to 250°F (120°C)

• Solids from 2 to 70 percent by weight

• Specific gravities from 1.0 to 2.7

• Medium to large sized, sharp particle.

Lawrence Pumps – Mike Agosti

The unique SICcast^® FGD slurry pump technology developed by Düchting Pumpen GmbH is now available in North America through an exclusive alliance with Lawrence Pumps, Inc. Under this partnership, Lawrence Pumps will be the sole U.S. and Canadian resource for SICast^® FGD pumps, with direct responsibility for the sub-assembling and servicing of these highly-efficient, long-life systems.

Huntington 2 Wet Lime FGD System Achieves >95 Percent SO₂ Removal

Huntington Environmental Partners, a joint venture of Burns & McDonnell Engineering Co., Sentinel Constructors (a Zachry company) and Barton Malow Co. was awarded a turnkey contract to provide emissions control equipment to PacificCorp 475 MW Huntington 2. This equipment was started up in November 2006. Jeromy Jones of Burns & McDonnell talked about this project at the EUEC Conference Jan. 21-24, 2007.  This is the first wet lime FGD in the United States that is designed utilizing in-situ forced oxidation and capable of providing commercial grade gypsum. Preliminary performance testing showed an SO₂ removal efficiency greater than 95.6 percent with a pressure drop less than 5.6 inches.

Babcock Power provided the wet lime FGD system. Process equipment included two horizontal ball mill slakers with capacities of 11 ton/hr. The system was designed for 95.6 percent SO₂ removal or 0.08 lb/MMBtu with a single module open spray tower absorber, two stage mist eliminator (Munters), and  installed spare spray level and recycle pump (3 operating, 1 spare). The lower three spray levels used bi-directional spray nozzles. Weir supplied the spray pumps. The wet/dry interface was made of C-276, the absorber 2205 and the absorber outlet duct was clad C-276. Ekato supplied five agitators; Atlas Copco supplied oxidation blowers.  Primary dewatering was by Krebs hydroclones, two operating and two spare.

Where Will SO₂ Allowance Prices Go?

At EUEC in January 2007 both Power & Energy Analytic Resources Inc. (PEAR) and Element Markets LLC presented information about the United States emissions markets.  PEAR noted that SO₂ allowances were currently trading at about $450, but

• Actual low-sulfur coal premiums over the last six months (I assume of 2006) averaged nearly double that price,

• Announced FGD additions will temporarily reverse the steady decline in the allowance bank,

• Natural gas will continue to be volatile, and

• PEAR sees a gap between the about 70 GW of FGD systems announced and the 85 GW required by 2010.

PEAR thinks there are reasonable fundamentals supporting $800-950 SO₂ Allowances by 2010 considering the projected marginal cost of FGDs for 2009 startup are about $800 and applying a liquidity risk premium of 20 percent, PEAR can justify allowance prices of about $1000.

Randall Lack, managing director of Element Markets LLC, notes that SO₂ allowance prices were incredibly turbulent in 2006 and have fallen below the marginal cost of scrubbers. He also notes that the NO_x allowance market was down over $2000/ton in 2006, ending the year at $650/ton. At that time NO_x allowance prices were close to the cost of SCR controls.

Trona Duct Injection is a Good Choice for Moderate SO₂ Removal

Keith Day of O’Brien & Gere presented a paper at the EUEC Conference in January 2007 on duct injection of Trona for SO₂, SO₃, mercury and NO_x control. Factors favoring duct injection are

• Cost of low-sulfur coal,

• Requirements for moderate SO₂ removal,

• Low capital expenditure,

• Elimination of SO₃ plume,

• Enhanced ESP performance when injecting Trona, and

• Short design/build schedule.

Trona injected for SO₂ control is injected dry (no humidification), needs no backend modification, actually enhances ESP performance, gives 50 to 60 percent SO₂ removal at a capital cost of $15 to $25/kW and O&M costs of $700 to $1000/ton of SO₂ removed, and needs only six to nine months from design to commissioning. Demonstrations (compiled from several units with ESPs) showed

• 15 to 20 percent higher SO₂ reduction when the Trona was injected at 700^oF (Air Heater inlet) vs. at the Air Heater outlet,

• 15 to 20 percent higher SO₂ reduction using milled Trona (about 10 to 15 micron vs. 28 to 50 micron for unmilled),

• 10 to 20 percent NO_x reduction with Trona injection,

• 40 to 90 percent mercury reduction with Trona, and

• 80 to 90 percent HCl removal with Trona.

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