One means of reducing SO2 air pollution from fuel combustion involves the injection of limestone directly into a furnace to effect vapor phase calcination and sulfation reactions. The report reviews this process and its basic objective to provide an independent assessment of the status of the Dry Limestone Process Technology and to up-date the design bases to reflect any additional process information. All available information was reviewed on the Fry Limestone Injection Process and pertinent correlations and equipment design recommendations were derived wherever possible. The emphasis was placed on the evaluation of data from in situ calcination-sulfation studies taken in flow reactors designed to simulate commercial boilers. The correlation approach was developed for a 'shrinking core' model, i.e., where SO2 gas must diffuse through a reaction product layer (CaSO4) to reach the shrinking inner core of available reactant (CaO). Attempts were made to test the reaction system model against data obtained in other flow reactor studies. Efforts were also made to compare the model with some initial test data. Available information was reviewed for the obvious important equipment performance parameters, e.g., effect of additives on slagging characteristics, efficiency of dust removal equipment, and sluice water quality control.