# Upgrade of Wet FGD Systems

A low-cost approach to upgrade your older wet FGD system to meet today’s performance requirements

• Above 98% SO 2 

## removal
• Above 90% oxidized Hg removal

• 70% particulate removal

• Uninterrupted operation between scheduled outages
• Dry byproduct for sale or landfill

• Zero liquid discharge operation 

# Process Technologies

## Industry Challenges
The power industry faces the challenge of increasingly stringent environmental regulations. As a result, existing FGD systems must operate at peak efficiency and reliability, and must provide maximum and sustainable performance to meet current and future emissions requirements. A large portion of the existing U.S. fleet of FGD systems were not designed to meet the emission standards currently being adopted or considered. In addition, these older systems often suffer from poor reliability and high O&M costs due to their age or design. In today’s competitive environment, performance, operating costs, maintenance requirements, and reliability all have a significant impact on the bottom line, or worse, the viability of an aging asset. Through a cost-effective upgrade project, the performance and reliability of an older FGD system can be improved to levels matching or exceeding new FGD systems, regardless of age and design. In addition, new dewatering, wastewater treatment and reagent preparation systems can be installed to lower operating costs and/or meet future regulatory requirements. 

## URS F GD E xper i en c e
URS has been an FGD industry leader for the past 35 years working with utilities to improve the operation and performance of their FGD systems. URS has worked with every FGD process and design, and worked at most of the FGD systems installed in North America. URS can and has applied our technology and know-how to all OEM’s designs and processes, having more than 52,000 MW of FGD upgrade experience. URS understands how to upgrade an older system and improve performance and reliability, in spite of the design and operating limitations inherent with the system. URS understands the capabilities and limitations of all FGD processes and designs. 

# FGD Solutions

URS is recognized as an FGD industry leader

• 35+ years of experience

• More than 52,000 MW

of upgrade experience

• More than 14 GW

of new and retrofit experience

• Installed more than

100 trays at 25 plants



## Bene fi ts T o Y our F GD S ystem

• Increase performance and reliability

• Provide even and uniform gas distribution

– No recirculation zones

– Improved performance through spray zone and mist

eliminator

• Create vigorous gas-liquid contact

– Increased removal performance

– Reduce or eliminate performance additives

• Provide stable and controlled chemistry

– Increase reagent use

– Improve byproduct quality

– Eliminate scaling

• Improve mist elimination

• Improve dewatering, reagent preparation, and

wastewater treatment operation



## Bene fi ts T o Y our Bottom Li ne

• Increase SO 2 removal efficiency

• Improve removal of other regulated pollutants

• Improve reliability and availability of scrubber

• Implement innovative and low-cost solutions

• Reduce or eliminate performance additives

• Allow switch to lower-cost, higher sulfur fuels

• Extend life of existing equipment

• Reduce operating and maintenance costs

• Improve byproduct quality and propertiesThe reasons why a utility may want to upgrade an existing FGD system generally fall into one of three categories: improved performance, improved reliability and operation, and rehabilita

tion and life extension of existing equipment. URS has the know-how to successfully meet all of your project objectives— with innovative and low-cost solutions. 

### FGD Upgrade Projects Below are examples of the types of projects URS has successfully completed.

• Increased SO 2 removal performance to meet a lower

emission limit, reduced scrubber operating costs by eliminating a costly performance additive, and reduced plant operating costs by firing a lower cost, higher sulfur fuel.

• Upgraded scrubbers to improve the removal of other

pollutants such as fine particulate and oxidized mercury.

• Improved scrubber controls and scrubber chemistry to

improve system reliability and performance and resolve process problems.

• Improved the performance of mist eliminators and mist

eliminator wash systems.

• Improved the performance of reagent preparation and

dewatering systems.

• Converted a system to forced oxidation to produce a saleable

gypsum byproduct.

• Designed and installed dewatering systems to eliminate liquid

disposal ponds.

• Designed and installed systems to treat FGD wastewater. CFD Gas Flow Modeling : Bottom figure shows improved distribution resulting from design upgrades. 

### Technologies to Improve Your System

• Liquid Distribution Rings

– Improve gas-liquid contact

– Reduce “gas sneakage” along

absorber walls and corners

– Protect absorber walls from spray

impingement

• Side-by-side Double Hollow Cone

Spray Nozzles

– Improved droplet interactions

(secondary atomization)

– Enhanced removal performance

• Dual-flow Sieve Trays

– Improved gas-liquid contact

– Improved gas distribution

– Reduced pump requirements

• CFD Modeling

– Improved gas distribution

– Improved mist eliminator

performance

– Improved oxidation air sparger

design

• Spray Coverage Design Tools

• Mist Eliminator Design Guidelines

• Material Selection Guidelines 

### SCOPE RESULT FGD performance upgrade and conversion to F.O. New dewatering system SO 2 removal increased from high 80% range to 97%. High quality saleable gypsum produced. Single hollow cone spray nozzles replaced with double hollow cone spray nozzles SO 2 removal efficiency increased from 91% to over 98%­ allowing plant to eliminate additive and use higher S fuel.

Absorber upgrade, new mist eliminators, and conversion to F.O. SO 2 removal efficiency increased from 89% to over 98%. High quality gypsum byproduct produced. Improved system reliability and operation Absorber upgrade with new headers, trays, LDR, recycle pumps and mist eliminators SO 2 removal increased from high 80% range to 99%.

Absorber upgrade with new headers, trays, and mist eliminators. Conversion to F.O. New dewatering, reagent preparation, and wastewater treatment system installed. SO 2 removal efficiency increased to over 98%. High quality gypsum byproduct produced. Improved system reliability and operation. New systems performed as expected. 

### Project SuccessURS Corporation is a leading provider of engineering, construction and technical services for public agencies and private sector companies worldwide. We offer a full range of program management; planning, design and engineering; systems engineering and technical assistance; information technology; construction and construction management; operations and maintenance; and decommissioning and closure services for federal, oil and gas, infrastructure, power and industrial projects. URS CORPORATION 600 Montgomery Street 26th Floor San Francisco, CA 94111

www.urs.com

2.7.13 Federal OI L & G A S i n f r a s tructure P o wer I NDU S TR I AL 

### For More Information Contact:

Gordon Maller Tel: 512.419.5045 gordon.maller@urs.com


### Jonas Klingspor Tel: 512.419.5439 jonas.klingspor@urs.com

P.O. Box 201088 Austin, TX 78720 For 35 years, URS has been recognized as a world leader in air pollution and FGD control technology—installing new units, upgrading existing units, and helping utilities effectively and efficiently operate their FGD systems. Since the days when the FGD industry began, URShas been at the forefront, performing laboratory, pilot-scale, and fullscale studies aimed at obtaining a deeper understanding of FGD processes and systems. URS offers an experienced team of FGD engineers and technologists to support our utility and industry clients in developing, evaluating, and implementing proven technology and solutions for their FGD systems. As a result of our broad experience and know-how, URS offers designs and approaches that are more innovative and cost-effective than our competitors.

© 2013 URS Corporation