POWER-GEN International 2012 hosted its first live webcast Wednesday from behind the delegate luncheon area, featuring a subject that is applicable to many in the power generation industry.
Associate Editor Lindsay Morris moderated the webcast titled “Emissions Controls: Understanding Your Options.” The speakers had one common theme running through their presentations: The options to comply with federal regulations are presently available, and there are some that can be installed without breaking the company’s bank.
The webcast started off with Diane Fischer, Air Quality Control Systems (AQCS) Area Leader with Black & Veatch, giving an overview of what challenges power producers are facing now and in the future when it comes to regulations and potential future builds of power plants.
Fischer said some current drivers of AQCS projects are the Mercury and Air Toxics Standard (MATS), local consent decrees and regional haze regulations. But, Fischer warned that power producers will also have to start thinking about future regulations.
“The National Air and Ambient Quality Standard (NAAQS) is one regulation that producers will have to begin planning for,” Fischer said. “There is also the Boiler MACT (Most Available Maximum Achievable Control Technology) rule that will be finalized sometime in the near future, and, even though it was vacated, the Cross State Air Pollution Rule (CSAPR) will more than likely be reissued.”
With many regulations either already in place or just over the horizon, what is available for power producers to use to comply? Fischer said there are many options already available on the market for different types of projects.
“There are options for the front-end projects, such as fuel changes; in situ projects, like retrofitting existing emissions control systems and even add-ons to consider at power plants,” Fischer said.
Some of those add-ons include boiler and flue gas desulfurization, or scrubbers, additives to remove mercury, and low NOx burners and selective non-catalytic reduction systems for the removal of nitrogen oxides (NOx), said Robert Nicolo, Director of AQCS Products with Hitachi. For SOx, HCl and acid gases, power producers can consider fuel switching and dry and wet scrubbers. To remove metals, Nicolo suggested fuel switching, retrofitting existing electrostatic precipitators, or adding particulate controls to power plants.
“Something else you may want to begin to consider is carbon capture,” Nicolo said. Some of those options included post combustion using amine and oxy-combustion with carbon dioxide capture.
Another technology that is available is sodium dry sorbent injection (DSI), which Mike Wood, Business Manager with Solvay, spoke about. The “unsung hero” of emissions controls, as Wood called it, has been used for more than 20 years at coal-fired power plants. Wood touted DSI for its ability to capture multiple emissions, such as sulfur dioxide (SO2) and hydrogen chloride (HCl) without the need to spend excess amounts of money.
“DSI enables power plants to meet today’s regulations and also control SO2 for MATS,” Wood said. “It can’t help but to catch SO2 while removing HCl.”
DSI is generally used for Activated Carbon Injection, Wood said, but if used with trona or sodium bicarbonate, it can also be a cost-effective way of controlling HCl, SO2 and SO3 emissions.
“Most power plants with emissions controls are also using DSI to comply with CSAPR,” Wood said. “It is also effective over a wide temperature range and helps to meet HCl limits for MATS.”
However, not all technologies suit every plant, Nicolo said.
“It’s a case-by-case scenario,” he said. “It’s not a one box fits all case.”
Unfortunately for utilities and power plant operators, many regulations end up stuck in courts after lawsuits are brought against them, and they are not finalized for years, leaving plants operators stuck in limbo about whether they should move forward with projects or not. Add in relatively low natural gas prices, the slowed U.S. economy, NAAQS area designations and uncertainty about greenhouse gas regulations, and there are many unanswered questions remaining.
Regardless, air quality control projects should continue to move forward.
“We must consider all regulations today to make decisions for the future,” Nicolo said.
Fischer said there are several ways to plan for future projects.
“We need to figure out our options, starting with performing several scenarios and cost assessments for different types of projects,” Black & Veatch’s Fischer said. “Don’t box yourself in with construction plans, identify and monitor key economic indicators and plan a response to them, and develop contingency plans.”
Nicolo said that though it seems like there are an overwhelming amount of current and upcoming emissions regulations, the power generation industry can handle the challenge.
“Even with the next generation of regulations, we feel like we’re ready,” Nicolo said. “The technology is currently here to meet the requirements.”