A rig was constructed to burn 100 to 125 lb of coal per hour at 4,000 deg. F in a cycline burner with oxygen-enriched air preheated to 1,500 deg. F to acertain the problems in the coal-fired mhd generation of power. Potassium carbonate was added to the coal at several concentrations up to 1.23 G-moles/kg of coal (17 lb k2co3/100 lb coal). Boiler-tube materials maintained at wall temperatures of 800 deg. to 1,500 deg. F were exposed to the combustion effluent of 1,800 deg. to 2,500 deg. F. Practically complete removal of sulfur dioxide from the stack gas was achieved with the seed addition. Nitric oxide formation followed theoretical expectations at combustion temperatures with some decomposition of the no occurring as the gas cooled flowing through the system. Nitrates in the fly ash were less than 1.7 percent of the total fixed nitrogen. With aqueous extraction of the fly ash a maximum recovery of 75 percent of the potassium was obtained. Haynes 25 was unattacked at a wall temperature of 1,500 deg. F in combustion gas at 2,500 deg. F; the stainless steels 310, 316, and 446 were resistant at a metal temperature of 1,100 deg. F in gas at 2,100 deg. F.