A substantial effort has been in the area of sulfur dioxide capture by limestones in fluidized bed combustors. Before the group's research revealed the importance of thermally induced fractures to the efficiency of sulfur capture, limestones were inappropriately specified on the basis of calcium carbonate content. Recent work has shown the importance of grain size in controlling particle attrition, another important aspect of sorbent performance. Details of a multifuel demonstration boiler at the East Campus Steam Plant. Recent results point to the importance of the dissolution rate of the limestone in the slurry solution to the overall performance of the unit.
Ongoing work is aimed at understanding the limestone properties that control dissolution rate.
In the area of nitrogen oxide formation and control, the group used 15N NMR spectroscopy to establish the importance of pyrrolic nitrogen in the coal structure as a source of nitrogen oxide. Previous to this pioneering work, pyrindinic nitrogen was thought to be the dominant source. With industrial partnerships, low NOx burners have been designed and tested and are now being produced commercially. In addition, the performance of industrial burners has been predicted computationally, and the group has established the importance of flame structure to combustion efficiency and NOx emissions. Publications N. Hu and A. W. Scaroni.