The report describes the sulfur capture potential during combustion of limestone copulverized with a high sulfur eastern bituminous coal, using Foster Wheeler's commercial Controlled-Flow/Split-Flame (CF/SF) low NOx, internally staged burner. Sulfur capture was optimized by using overfire air and two proprietary flame temperature control methods. Additionally, the effects of excess air changes, load changes, and different calcium/sulfur mole ratios (Ca/S) were evaluated. Two flame temperature reduction methods were used to reduce the flame temperature to minimize dead burning of limestone and thus enhance SO2 capture. Although the use of flame temperature reduction and overfire air improved the SO2 capture, the optimum SO2 capture of 29% at a Ca/S of 2.15 was low. Operation under optimum SO2 capture mode resulted in measured NOx emissions of 0.19 lb/million Btu; CO was less than 25 ppm at an excess oxygen level of 3.0%.