Discussed is the continuing development of a molten carbonate process to remove sulfur oxides from power plant stack gases. In this process, the sulfur oxides are absorbed in a molten mixture of lithium, sodium, and potassium carbonates. The resulting carbonate-sulfite mixture is then regenerated chemically. This part of the summary report describes the plant analysis results achieved through October 28, 1968. The operating and capital costs for treating the stack gases of a 60 Mwe and an 800 Mwe power plant were estimated and evaluated. Several important observations from the 800 Mwe plant analysis are summarized below: The reduction step using hydrogen as the reducing agent contributes 47% of the total overall process cost; The cost of natural gas as the raw material for hydrogen production is an important contributor in the overall cost of the process; Carbon (fluidized coke) as the reducing agent offers the highest potential for lowering the overall cost; The overall costs can be reduced by 0.07 mils/kwh if a reducing mixture of 75/25 hydrogen/carbon monoxide can be effectively utilized; and Unless nearly all of the fly ash is removed (more than 99%) from the gas stream before it enters the scrubber, the carbonate melt must be recovered from the melt-ash filter cake for economic operation. (Author)