Eighteen of the runs outlined in the test plan for the high pressure reactor (HPR) using Montana Rosebud coal were done during the fourth quarter, bringing the total number completed to 40. These were all pyrolysis runs and included excursions in temperature, pressure, heating rate, residence time, and particle size. Additional work during the fourth quarter included devising plans for the gas mixing station so that pyrolysis or gasification runs can be done with helium, oxygen, or CO/sub 2/ mixed with nitrogen or argon. During the fourth quarter, pyrolysis studies were done at 30 K/min (0.5 K/s) in a combined thermogravimetric analyzer/evolved gas analyzer (TGA/EGA) with Montana Rosebud 200 x 270 mesh coal. We have tried to simultaneously fit kinetic data on two coals (North Dakota lignite and Montana Rosebud) from the TGA/EGA (0.5 K/s) and the heated tube reactor in order to optimize the set of kinetic rates and the coal composition parameters in the Functional Group model. The North Dakota lignite experiments in the heated tube reactor (HTR) and TGA/EGA and the optimization studies were done under our other METC contract. In general, the agreement of the model and the data from the two reactors was good for both coals. We have continued to do measurements of active site area, determined by oxygen chemisorption, surface area, determined by CO/sub 2/ absorption, and char reactivity, determined by the time for 50% burnoff in air on chars generated in this program. A comparison was made between our data and predictions by the regression model developed at METC for pyrolysis data from the AGC. In general, there was not good agreement when the METC model was extrapolated outside the range of conditions used in the AGC. 2 refs., 3 figs.