The primary purpose of this research work was to provide METC with computer software to simulate various fossil fuel process configurations. In particular, software to simulate mass and energy transfer for various fossil fuel reactions was required. To these ends the code MSRS was installed and tested at METC and then enhanced into an engineering modeling code useable by METC scientists and engineers. The enhancements consisted of adding reaction capabilities which grew out of XELAMP, improved input capabilities which made the code easier to use, and increased output media such as graphics. The input and output capabilities were patterned after the XELAMP system. Validation and consistency of the work can be checked using the LFER code; output from LFER can be input to MSRS and the corresponding temperatures can be compared. 3 refs., 1 fig.