A preliminary design was made of the pressurized version of the tube reactor. The design will be finalized and the reactor constructed during the third quarter. Approximately 25 trial pyrolysis tests with the Montana Rosebud 200 x 270 mesh have been made in the high pressure reactor (HPR). Operation has been very satisfactory with material balances of 95 to 105% and reproducibility of gas yields within -10% for most experiments. An experiment was done at the same conditions used for a METC/AGC run (916/sup 0/C, 178 psig, 3.20s). The total yield of gas and the yields of gas and the yields of major gaseous species were similar. The yield of char was significantly lower in our experiment by an amount which corresponded to the amount of missing material. Much of the missing char was found in the upper part of the furnace and was presumably deposited by natural convection flows which are important at the low flow rates used for the long residence time experiments. We plan to transfer many of the lower temperature, long residence time runs to a second high pressure tube reactor with a very long hot zone to overcome this problem. The FT-IR diagnostic techniques were used to measure particle temperatures during pyrolysis of Montana Rosebud coal in the tube reactor. Additional experiments using the same technique were done in the tube reactor to measure optical properties of char prepared from the Montana Rosebud coal in the entrained flow reactor. During the course of these measurements, some problems with the FT-IR technique were encountered. Most of the quarter was spent identifying the source of these problems. The two major sources of error were identified as due to the presence of fines (primarily from particle breakup) and spurious reflection from particles back to the detector. These problems have been solved and previous measurements will be repeated where necessary. 2 refs., 2 figs., 2 tabs.