(457e) Dependence of S-I Thermochemical Decomposition Process Configuration and Efficiency on Property Models

Using both a model-free analysis described previously^a,b, and Aspen Plus flowsheeting, several property model methods have been applied to obtain and compare the effects on the energy and entropy flows for selected S-I processes, including fully integrated plants. It has been found that, although the differences in properties among the modeling approaches appear to be small, their use leads to significant changes in overall efficiency and irreversibility estimates; stream flows; process unit configuration; and even flowsheet convergence. In addition, a survey of the literature shows that different workers do not use the same input and output conditions. These variations suggest that appropriate comparisons among different programs can be problematic.

The presentation will show examples of the analyses and raise questions about how to standardize process formulation and results to provide maximum communication effectiveness and reliable foundations for selecting among, and improving, proposed alternative processes.

^a AIChE Annual Meeting, Cincinnati, OH, November 2005

^b AIChE Annual Meeting, San Francisco, CA, November 2006