Assessment of circulating atmospheric fluidized-bed combustion technology for utility applications

The primary objectives of this study was to develop a current evaluation of circulating atmospheric fluidized-bed combustion (AFBC) technology applied to a 200-MW boiler. This report presents process descriptions, drawings, and cost comparisons for 200-MW circulating AFBC and pulverized coal (PC) plants for four different coals. The circulating AFBC boil and immediate auxiliaries are based on technical and cost information obtained from two circulating AFBC suppliers. All plants were designed to meet New Source Performance Standards. In assessing the two technologies, it was found that circulating AFBC requires less plant space than PC. It was also found that for the coals evaluated, circulating AFBC has approximately the same boiler efficiency, requires more limestone (except for Wyoming coal case) and uses less water than PC with FGD. The net result of the relationships discussed above is that the levelized cost of fuel plus consumables for circulating AFBC ranges from 2.3% less (Wyom.) to 5.8% more (Ill.) than PC. The total levelized cost of the circulating AFBC cases ranged from 6.0% less to 4.6% more than the respective PC cases. Further, the circulating AFBC capital costs ranged from 8.4% less than PC to 8.6% more than PC. The overall cost differentials betweenmore » all circulating AFBC and PC cases are within the accuracy of the estimate ({plus minus}25 percent). However, the conclusion can be drawn that circulating AFBC can be competitive with PC at the 200-MW size. In general terms, it was found that circulating AFBC is the most competitive (shows the greatest potential cost benefits) for high sulfur coals (Illinois and West Virginia), and exhibits less cost benefit for low sulfur coals (Wyoming and Texas).« less