Ammonia scrubbing and production of phosphate fertilizer has promise, under certain conditions, as a method for recovering sulfur oxides from stack gases. The main economic factors are product volume (depending on power plant size and S content of coal), net sales revenue, and basis of financing. Private industry participation in financing and operation appears unlikely because of the high projected cash flow necessary to attract capital. There is a net profit for plants about 500 mw and larger but it is not large enough to attract investment except perhaps under special conditions. The situation is improved if there is supplemental income in the form of a payment for the service of sulfur oxide control; in this case the larger product volumes (e.g., 1000 mw at 3.5% S in coal or 500 mw at 5% S) give a projected total income adequate for financing. The economics under power industry financing are more promising. For plants 500-600 mw and larger in size the recovery method is favored over limestone - wet scrubbing because there is less deficit passed on to the power consumer after payment to investors of the regulated return on investment. Only a few recovery installations of this type can be accommodated by the fertilizer market. (Author)

"TV-29233A." Bibliography: p. 131-139.