We Energies’ Pleasant Prairie Power Plant: AQCS Retrofit Project

Abstract

We Energies’ Pleasant Prairie Power Plant (P4) is installing a wet flue gas desulfurization (WFGD) system on steam generating Units 1 and 2 for SO2 control and a selective catalytic reduction (SCR) system on steam generating Unit 1 for NOx control. Unit 2 already has a SCR system that was installed in 2002. This retrofit project also includes installation of a new chimney, limestone and gypsum handling equipment, and wastewater treatment equipment. This environmental improvement project, now under way at P4, is part of the Company’s plan for meeting current and pending air quality improvement commitments and environmental regulations. P4 consists of two 617 MW Riley PC subcritical boilers firing PRB coal. The two units currently share a common chimney. These units were commissioned in the early to mid 80s. When the current project is completed, P4 will have the lowest SO2 and NOx emission rates of any coal fired Wisconsin power plant. The new equipment will be capable of reducing SO2 emissions by up to 95 percent and NOx emissions by up to 90 percent. The current schedule has Unit 1’s WFGD and SCR system on line by December of 2006 and Unit 2’s WFGD system on line by May of 2007. This paper will outline the execution plan used to launch this multi-million dollar project and to maintain its schedule. The paper will also review the technical drivers that lead to the selection and performance specifications of the WFGD and an overview of the major equipment parameters including the materials of construction chosen for this project.