Process configurations/modeling

The objective of this research is to develop preliminary process designs and cost estimates for four different configurations of scrubbers which contact sulfur dioxide laden flue gas with a wet, densely packed bed of 1/4 inch limestone gravel. The four configurations include a fixed limestone bed (ii), cocurrent flow of limestone and flue gas ([number sign]2), counter-current flow (13), and a cross-flow moving bed configuration ([number sign]4). First principles models are used to predict the performance of the scrubbers. A standardized nomenclature has been developed and maintained during the year. A standardized set of physical property and transport correlations has been developed. A general set of material and energy balances based on a first principles analysis of the underlying chemical and physical processes has been generated. Detailed equations for process configurations 1 through 4 have been developed. The numerical solution algorithms for configurations 1 through 4 have been coded and debugged. The simulation programs for configurations 1 through 4 have been tested for the effects of varying numerical step size. Design study cases have been developed using two representative coals with 1.5 and 3.5 wt% sulfur and assuming two levels of sulfur dioxide removal, 90 and 98%. Cost equations formore » capital and operating expenses have been developed and coded for the reactors and associated sorbent handling equipment. Case studies which examine the effect of bed depth on the overall economics have been generated. The results to date have been largely as expected. The major goal of developing a systematic and computationally efficient simulation package which can model a variety of process configurations has been achieved.« less