Advanced in-duct sorbent injection for SO{sub 2} control. Topical report No. 6, Task 5: Conceptual commercial process design and economic evaluation

Abstract

The objective of this research project i s the development of a second generation in-duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research focused on the Advanced Coolside Process, which has shown the potential of exceeding the performance targets of 90% SO, removal and 60% sorbent utilization. In Task 5, Conceptual Process Design and Economic Evaluation, the economics of the CONSOL Advanced Cool side Process as a Clean Air Act compliance option were evaluated.A conceptual process design for full -scale, coal -fired applications is described. Advanced Cool s i de i s compared t o convent i onal Limestone Forced Oxi dat i on (LSFO) wet FGD technology. The process economics f o r coal sulfur levels ranging from 1.0% t o 3.5% (as-received) and plant sizes ranging from 160 t o 512 gross MW were investigated.In addition, the economics of on-site versus o f f -s i t e lime hydration and the cost sensitivity t o delivered pebble lime and hydrate prices are investigated.Advanced in-duct sorbent injection enjoys a capital and level ized cost advantage relative t o LSFO i n a l l cases examined i n this study. As a result of t h i s study and others made during this contract, the following conclusions can be made:The capital cost of Advanced Coolside is 55% t o 60% less than t h a t of LSFO and varies s l i g h t l y depending on coal sulfur content and plant size.The t o t a l levelized SO, control cost advantage relative t o LSFO varies from 15% t o 35% over the range of coal sulfur contents and p l a n t sizes evaluated. This cost advantage i s sensitive t o sorbent transportation charges. As a result, the economics are site-specific.The experimental optimizations based on interim economic analyses were the key t o capital and levelized cost reductions.i i