Economic comparison of pulsed electrostatic precipitators and fabric filters in coal fired utility plants

Abstract

Electrostatic precipitators (ESP) and fabric filters (FF) are the main air pollution control systems utilized to clean dust laden fumes from utility boilers. The choice among these systems depends from the specific site conditions such as dust characteristics, required efficiency, gas flowrate and temperature. ESP are generally characterized by higher capital investments and lower operating charges, while the opposite may be said for baghouses. As a consequence, ESP present higher total costs when high specific collection areas are required, as happens in the case of low-sulfur high-resistivity dust. However, significant reductions in both capital investment and operating charges may be obtained with pulsed energization of precipitators working in severe back corona conditions. This possibility greatly enlarges the field of applications in which ESP are a lower cost option compared to fabric filters. In the paper an economic comparison of pulse energized ESP, with conventional ESP, reverse-air, shaker and pulse-jet baghouses is performed. A mapping of the operating conditions in which the adoption of each examined control technology is economically convenient is also defined.