During the period 2/1/84 through 2/29/84 work was performed on the following tasks: Task No. 1 simplified models and Task No. 4 rigorous models (Area 1700-methanation, Area 4900-methanol synthesis,4376 ); and Task No. 2 review of existing gasifier models. The ASPEN simulation of the Methanation flowsheet, Section 1700 of the Great Plains'project, has been modified to use the physical property option set SYSOP4W in place of SYSOP3, which was originally used. The full component list was also added for overall consistency, which is necessary if this flowsheet is to be connected with Rectisol or Gas Compression. For the same conditions as in the original case presented in the referenced memo, this modification produced no significant changes in the results. The ASPEN simulation of the Methanol Synthesis flowsheet, Section 4900 of the Great Plains'project, has been modified to use the physical property option set SYSOP4W in place of SYSOP3, which was originally used. The full component list was also added for overall consistency, which is necessary if this flowsheet is to be connected with Rectisol of Methanation. For the same feed as in the original case presented in the referenced memo, this modification resulted in lower K-values for all components except methanol and water in the Methanol Condenser, EA-4903T (FLASH2). Consequently, more H/sub 2/, CO and CO/sub 2/ were dissolved in the methanol stream and more methanol was lost in the purge. The net effect was a 2.7 percent decrease in the amount of methanol returned to Rectisol. No other significant effects were produced.