Monroe Units 1, 2, 3 and 4
Wet Flue Gas Desulfurization System

Detroit Edison
Monroe, Michigan

Contract Order

Units 3 & 4: 2006
Units 1 & 2: 2010

Commercial Operation

Units 3 & 4: 2009
Unit 1: 2013
Unit 2: 2014


The wet flue gas desulfurization (FGD) system from Babcock & Wilcox (B&W) features a combination of design components to provide a high level of reliability and removal efficiencies. These include B&W’s signature tray tower design that provides excellent gas-to-liquid contact and uniform flow distribution through the absorber spray zones; its patented inlet awning; interspatial spray headers to reduce absorber height, pump power requirements, and internal support costs; forced oxidation system; and advanced mist eliminators.

Boiler/Plant Information

  • (PRB)/bituminous coal blend
  • Design fuel: Powder River Basin
  • Boiler type: Pulverized coal
  • 4 x 825 MW (3,300 MW total)
Project Summary

B&W provided engineering, procurement and construction of the wet FGD system. The system is designed to remove 97% of the entering sulfur dioxide (SO2) without organic acid addition, at an optimal combination of reduced absorber liquor recirculation (L/G) versus tray pressure drop. The system utilizes limestone reagent with forced oxidation to a gypsum byproduct. There is one absorber per unit.

BWCC Construction Services

BWCC provided construction services for all B&W supplied wet FGD system equipment at the Monroe power plant.

 B&W Scope

  • Four (4) wet FGD absorbers (1 per boiler), concrete tower with Stebbins tile construction and 2205 internals
  • Three (3) limestone milling systems (2 operating, 1 spare) Gypsum dewatering system that includes three (3) horizontal
  • table filters (2 operating, 1 spare) Six (6) oxidation air blowers (2 operating, 1 spare for each set of 2 absorbers)
  • Construction of B&W supplied equipment by Babcock & Wilcox Construction Co., Inc. (BWCC), a subsidiary of B&W


  • Units 3 & 4 – The contract for units 3 & 4 was released in April 2006 with startup in June 2009 (Unit 4) and November 2009 (Unit 3)
  • Units 1 & 2 – Units 1 & 2 were awarded in March 2010 with operation scheduled for December 2013 (Unit 1) and May 2014 (Unit 2)


  • Both commissioned units (Units 3 and 4) have met performance guarantees
  • Achieved mechanical and substantial completion on schedule

Computer generated three-dimensional projection of absorber modules at Monroe.

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.