FGD technology has made considerable progress in terms of SO2 removal efficiency, reliability, and capital/operating costs over this last decade – as SO2 emission regulations have become more stringent throughout the world. The regulations have been based generally on the best available technology. This report examines the performance and experience of state-of-the-art FGD systems available commercially, with special emphasis on the advanced wet limestone scrubber. It also focuses on how electric utilities have complied with stringent regulations. Reliability of FGD systems has been currently improved to over 99% through a better understanding of FGD chemistry and engineering. Capital and operating costs of the wet limestone scrubber have been reduced by 20-30% this decade – mainly as a result of simplification of the system configuration. This has also brought a considerable reduction in power consumption. The retrofit difficulty factor is important in assessing the costs of retroftting an existing power plant. A medium retrofit factor of 1.3 means the capital costs of retrofitting an FGD system are higher by 30% compared with the ease of installing it during the first stage of power plant construction. This report also reviews the applicability, performance and cost-effectiveness of the alternative FGD systems such as spray dry scrubbers, sorbent injection, regenerable and combined SO2/NOx removal processes. These are used mainly for relatively small to medium capacity power plants using low to medium sulphur coal or where the available land is too limited for storage of reagent and for disposal of the waste product. However, the market share for these FGD systems is small. The brief case studies aim to demonstrate selection of the most suitable FGD system for each individual power plant, depending on site-specific conditions.
Title: FGD performance and experience on coal-fired plants, IEACR/58
Author(s): Mitsuru Takeshita
ISBN: ISBN: 92-9029-217-2
Publication Date: 01/07/1993