The report is an updated assessment of dry flue gas desulfurization (FGD) systems that reviews current and recently completed research, development, and commercial activities in the U.S. since October 1979, including: (1) spray dryers with a fabric filter or an electrostatic precipitator (ESP), (2) dry injection of alkaline material into flue gas combined with particulate collection in an ESP or fabric filter, and (3) combustion of coal/alkali fuel mixtures. Spray drying remains the only commercially applied dry FGD process. Since the last survey, completed late in 1979, eight utility and two industrial spray drying systems have been sold. Nine of them use lime as the sorbent, and nine use a fabric filter for particulate collection. Removal guarantees for SO2 range from 62 to 85%, depending on coal sulfur content. Two full-scale industrial spray drying systems are currently operating. The first large utility system is scheduled for startup early in 1981. Several publicly and privately funded pilot-scale programs have been completed in the past year. EPA is currently funding three such programs (two spray drying and one dry injection), as well as development of two combustion modification processes for SO2 control (combustion of coal/limestone pellets and of a pulverized coal/alkali mixture in a low-NOx burner). The DoE and others are studying dry injection on a pilot scale.