Evaluation of advanced separation techniques for application to flue gas cleanup processes for the simultaneous removal of sulfur dioxide and nitrogen oxides

Thirteen advanced separation techniques were reviewed in detail for application to flue gas cleanup processes. Of these, the three most promising for application to systems for simultaneous removal of sulfur dioxide and nitrogen oxides from flue gas are solvent extraction, electrodialysis, and inverse thermal phase separation. Gas separation membranes would also be promising if a membrane could be developed that would be selective for SO/sub 2/ and NO/sub x/. Specific utility or industrial systems incorporating some of these processes are suggested. Preliminary estimates of annual revenue requirements for three gas-separation-membrane flue gas cleanup systems and an electrodialysis system are compared with an estimate for a limestone system with selective catalytic reduction. In addition, fourteen wet simultaneous SO/sub 2//NO/sub x/ flue gas cleanup processes that have progressed beyond bench scale were reviewed for possible modification to incorporate advanced separation techniques. It appeared that in processes where modifications were possible, either such modification would result in marginal improvement, or the process would no longer be recognizable. 147 refs., 10 figs., 9 tabs.