Introduction

There has been increasing interest worldwide to decrease atmospheric pollution, especially from coal. The primary pollutants associated with coal are carbon dioxide, sulfur oxides, and nitrogen oxides, in addition to particulate matter. Sulfur oxides and nitrogen oxides are associated with acid rain and smog, and carbon dioxide is associated with climate change. There are various methods to prevent these environmental consequences, by separating the carbon dioxide, sulfur compounds, and nitrogen compounds from the coal and flue gases at various stages. This chapter outlines the nature of the problem and the various overarching strategies for solving it. These strategies include precombustion and postcombustion methods for separating sulfur and carbon dioxide, including flue-gas scrubbers, integrated gasification and liquefaction cycles, and solid absorbents. The chapter outlines the need for these technologies, and discusses their applicability in the context of a modern coal-fired power facility.