During the month of July 1983, the program objectives for Test G-21 were developed, recommending that the gasifier be operated at 500 psig with Illinois No. 6 coal instead of 750 psig. The purpose for reducing the pressure is to decrease or eliminate the char agglomeration occurring in Stage II of the gasifier. Details of the test program, theory on formation of agglomerates and changes in operating procedure are included in the Plant Operations section. Also included are a report and graph dealing with terminal velocity of char particles in the gasifier at operating pressures of 500 and 750 psig. 4 figures.