Pollution Control Workshop Agenda

8:00 am - 8:30 am	Registration and Continental Breakfast
8:30 am - 9:30 am	Control of SO2 - Bill Downs, Instructor
9:30 am - 10:30 am	Control of NOx - Scott Rutherford, Instructor
10:30 am - 10:45 am	Break
10:45 am - 11:45 am	Control of Mercury Emissions - Bill Downs, Instructor
11:45 am - 12:45 pm	LUNCH
12:45 pm - 1:45 pm	CO2 Capture in Power Plant Applications - Jim Neathery, Instructor
1:45 pm - 2:00 pm	Break
2:00 pm - 3:00 pm	Tour of Buffalo Trace Distillery

Who should attend?

• Utilities
• Regulators
• R&D groups
• Industries with heavy energy consumption

Presenter Abstracts

Control of SO2 - Bill Downs

The emphasis of this presentation will be on the fundamentals involved in flue gas desulfurization by wet scrubbing with limestone as the reagent. Limestone preparation and limestone reactivity will be described. The consequences of impurities on limestone reactivity and process design will be discussed. The pertinent chemistry that takes place in the gas-liquid contact zone and in the absorber reaction tank will be described. The contribution of buffers, both natural and imposed of the absorption capacity will be described. The importance of crystallization on the operation of a wet scrubber will be shown to be pivotal to satisfactory operation. Also, the reasons why open spray/tray towers were selected over the more conventional packed tower will be shown. The reasons why forced oxidation of calcium sulfite to gypsum is the most significant improvement in flue gas desulfurization over the past 20 years will be discussed. Finally, the fate of mercury that is captured in a wet scrubber will be described.

Control of Mercury Emissions - Bill Downs

This presentation will be in two parts. The first will cover the case for regulation of mercury - both the right reasons and some inappropriate regulation. We will show the amount of mercury that cycles through the bio-cycle has increased over time since the industrial revolution. We will discuss the means for sequestration of mercury by both natural and engineered means and the mechanisms by which it can be transformed into lethal organic mercury. In the second part, we will discuss the primary principles used to capture and sequester mercury from point sources. We will update the main players and approaches being used commercially for mercury control from power plants. We will discuss the relative costs of capture by the different approaches including activated carbon absorption, inorganic additive injection for direct adsorption, schemes for oxidation upstream of a wet scrubber or dust collector, and the effectiveness of capture by amalgamation. Finally, the extent of fixation of the captured mercury by different techniques will be discussed to make the point that capture of mercury from a smoke stack does not necessarily imply that it is permanently separated from the bio-cycle.

Control of NOx - Scott Rutherford

The following will be covered during this section of the workshop:

• a brief chemistry regarding NOx reduction - low NOx burner, SNCR and SCR;
• the comparison among three approaches;
• history of SCR development;
• current development on SCR catalyst - such as low SO3 conversion and mercury oxidization;
• catalyst management.

CO2 Capture in Power Plant Applications - Jim Neathery and Kunlei Liu

Scrubbing of carbon dioxide from process gas streams in the chemical industry has been in practice for over half a century. In general, aqueous solutions of weak bases such as amines (e.g. monoethanolamine (MEA) or diethanolamine (DEA)) or potassium carbonate, are used as an absorbent under high pressures with concentrated inlet streams. For example, basic solutions such as aqueous MEA or aqueous potassium carbonate can neutralize CO2 into bicarbonate ion (HCO3-). Since CO2 is a weakly acidic gas and MEA is rather weak base, it will re-release CO2 when the scrubbing solution is heated. Accordingly, the amine or potassium carbonate solution is recycled through a regeneration unit or stripper which heats the solution from the scrubber unit to release the slightly acidic CO2 gas into a concentrated stream. The regenerated amine solution is recycled to the scrubber tower for reuse.

Applying these chemical industry technologies for utility boiler flue gas will be most challenging. Flue gas from a typical coal-fired pilot plant is nearly at atmospheric pressure and the concentration of CO2 is relatively dilute (less than 12 vol%) as compared to process syngas. Accordingly, this will necessitate the use massive scrubber vessels of similar scale to that used in FGD scrubbers. The prime concern for any CO2 scrubber technology will be the added energy needed to regenerate the scrubber solution that is "rich" in dissolved CO2 . In this lecture, we will outline the basics of these and other CO2 capture technologies that can be applied to conventional power plants.