(27c) Environmental Controls in Coal-Based Electrical Energy Production

Over the past half-century, the coal-fired electric power plant has evolved from a simple machine to a complex chemical process plant.  While the heart of the industry remains the same: turning turbines with coal-generated steam, the treatment of coal combustion emissions has grown considerably and more processes are under development.  There is a significant role for chemical engineers to play in meeting these current and future needs.  This tutorial will cover the environmental impacts and pollution control unit operations of coal-fired electric power plants, both current and future. The four main unit ops are selective catalytic reduction of NOx, electrostatic precipitation, fabric filtration (“baghouse”), and flue gas desulfurization (“scrubber”).  These incorporate a number of chemical engineering principles including separation processes and reactor design.  In addition, new compliance drivers are pushing additional pollution controls for mercury, which is typically done as an adsorption process.  Finally, concerns over global climate change have resulted in extensive research into carbon dioxide capture and sequestration using absorption processes.   Also water and wastewater impacts from the power plants will be covered.