The market for equipment and consumables to measure and remove mercury from stack gases will average over $2 billion/year over the next decade, according to a report by McIlvaine Company.

There are three immediate markets, all in the United States, including cement, utility boilers and industrial boilers. McIlvaine says hundreds of millions of dollars has already been spent by U.S. utilities to install mercury continuous emissions monitors. There are 100 systems to inject activated carbon into flue gases currently under construction or installed. Ultimately, 900 units will be challenged to meet mercury limits, which will reflect Maximum Achievable Control Technology (MACT).

A new development in the last few weeks is an initiative by 18 states to influence the U.S. Environmental Protection Agency to set the MACT limit much higher. This is based on potential water quality impairment considerations and not just air quality. With this new approach, McIlvaine says reductions as high as 98 percent may be needed to meet the Total Maximum Daily Load (TMDL) in the water bodies in the Northeast region of the United States. There was a limit set by the now redacted Clean Air Mercury Rule (CAMR). A replacement rule is being crafted based on the court guidance and testing at power plants, which is ongoing.

The utility MACT rule is likely to be promulgated in 2011, and compliance would be required by 2014. The rule will address not only mercury, but also HCl and other toxics, according to McIlvaine. The need to remove a range of toxics will impact the mercury removal decisions. One observation made by McIlvaine is that utilities will want to consider making commercial 30 percent hydrochloric acid. Benefits include high mercury removal and sequestration of the mercury separate from the flyash, wastewater or gypsum.

The cement MACT is likely to be promulgated in the next week or two. This rule will set the stage for both the utility and industrial boiler MACT rules, according to McIlvaine. Cement plants emit 15 tons of mercury per year compared to 50 tons of emissions for utilities. McIlvaine says any utility rule is likely to be at least as stringent as the cement rule. Investment costs to meet the cement rule are estimated at over $4 billion. Prior to 2014, 120 cement plants will need to install equipment. The cost justification of the rule is based on the use of activated carbon injection and a secondary fabric filter to follow the existing particulate collector.

Large amounts of activated carbon will be purchased to capture the mercury. The demand will be influenced by the reduction requirements and by the success of competing technologies. Wet scrubber and chemical additives offer a less expensive approach if the scrubbers are already in place. The need to remove HCl may force plants to install scrubbers, many of which would not have done so just for SO2 capture, according to McIlvaine.

One recent discovery is that activated carbon captures selenium as well as mercury, notes McIlvaine. Since utilities are facing big expenditures to remove selenium from the FGD wastewater, it is possible that both activated carbon and wet scrubbing will be utilized for mercury removal. One variation of this practiced by Evonik in Germany is to add activated carbon directly in the scrubber. The mercury containing carbon is separated from the sludge, so the drivers are water and sludge quality improvements as well as reduction in air emissions.

McIlvaine has analyzed and continues to analyze the planned expansion of activated carbon production facilities and to determine whether there will be an adequate supply. McIlvaine says power plants could potentially consume more activated carbon than is now produced and used in the United States for water treatment and all other purposes.

The markets outside the United States are presently small but will grow, according to McIlvaine. The Chinese cement industry emits seven times as much mercury as U.S. cement plants. The combination of the Chinese power and cement plants emit four times as much mercury as the U.S. plants. Mining operations can result in very large quantities of airborne mercury. McIlvaine believes Europe and Asia will follow suit in the coming years and enact their own mercury air regulations, according to McIlvaine.