Lansing Generating Station, Unit 4

Alliant Energy
Lansing, Iowa, USA

Plant Description

  • Pre-retrofit equipment
  • 270 MW boiler
  • Hot-side electrostatic precipitator (ESP)
  • Selective catalytic reduction (SCR)
  • Powdered activated carbon (PAC)
  • Fabric filter

Contract Order: 2012

Commercial Operation: 2015

B&W Project Description

Babcock & Wilcox (B&W) integrated a circulating dry scrubber (CDS) system upstream of an existing fabric filter to control SO2, H2SO4, HCl, HF, mercury, and particulate matter emissions. The CDS system was designed to control emissions from burning either Powder River Basin (PRB) coal alone or with a blend of bituminous coal, achieving SO2 removal efficiency up to 98%.

The new CDS system was integrated into the existing flue work structure in approximately 6 months, while Babcock & Wilcox Construction Co., Inc., a subsidiary of B&W, completed the tie-in outage in less than 6 weeks. After approximately 3 months of operation, the system was performance tested and passed all guarantees (emissions and consumables) and completed the reliability demonstration shortly thereafter.


  • Design, supply, erection, training and commissioning
  • Circulating dry scrubber; 6 venturi design
  • By product solids recirculation system; 6 solids injection locations (below the venturis)
  • Hydrated lime feed system
  • Humidification water system; 6 water injection lances (above the venturis)
  • Gas recirculation system
  • Fabric filter upgrades
  • Byproduct handling equipment

B&W CDS Technology Benefits

B&W optimizes its circulating dry scrubber design for each application. This approach provides the end user with an optimized system to reduce long-term power and lime consumption, while providing reliable operation across wide load and fuel ranges. Plant owners benefit from lower operation and maintenance costs.

The compact CDS absorber module is ideal for plant locations with limited space.



A circulating dry scrubber is integrated with a fabric filter for effective SOx, H2SO4, HCl, HF, mercury, and particulate emissions control. Hover and click on the numbered image shown below to learn more!

Fabric Filter

ID Fan

Clean Gas Recirculation Flue

Circulating Dry Scrubber Absorber

Absorbent Storage Silo

New Build

We consistently demonstrate the ability to successfully execute innovative solutions for our customers, from new equipment to large, complex full-scope engineering and construction projects.

Upgrades / Retrofits

Modifying, improving and maintaining existing equipment are vital considerations for the long-term viability and profitability of all operations.

Parts / Services

An extensive network of worldwide regional service centers, field service engineers and technical support personnel are available to provide the customized service and aftermarket solutions for your requirements.