Turbocharged PFBC Power Plant Technical and Economic Assessments

Abstract

"Fluidized bed combustion (FBC) boilers are receiving considerable attention by the utility and industrial business sectors in the United States and other nations for several reasons.

The most significant of these are:

1. The FBC boiler can be designed to burn many solid fuels which are troublesome to burn in suspension (pulverized coal) firing systems. 2. The SOX removal process is integral with the combustion process rather than a separate system subject to upsets during combustion transients. 3. NOX production is low because of the lower combustion temperatures. 4. Waste is in a dry form.

Although the most attention is directed toward atmospheric fluidized bed combustion (AFBC) because of its simplicity, AFBC does not offer substantial improvement in operating economy over pulverized coal systems. Steam conditions are essentially the same, heat rate is a stand-off, and boiler size is little different. However, significant differences are apparent when pressurized fluidized bed combustion (PFBC) is considered. The combustion bed is about 1/5 the volume and the heat rate is substantially improved because the heat conversion process can become a combined Brayton/Rankine cycle."