(Presented in Session C1 and C5 at EUEC 2015: Feb 16, San Diego, CA)
C6.1 Demonstration & Installation of Novel Mercury Oxidation Technology
Sterling Gray, Business Development Manager, AECOM; Jim B. Jarvis, Steven W. Kosler Andrew Wang
The Utility MATS regulation requires power plants to reduce emissions of hazardous air pollutants (HAPs)
including mercury. Many mercury control technologies involve the oxidation of elemental mercury to
a form that is more readily captured by activated carbon or wet scrubbers. However, many of these
oxidation techniques, including the use of SCR catalyst or the addition of halogens to the boiler, may
have limited effectiveness, are costly, and can have significant balance of plant impacts. This paper
will describe a new novel approach to mercury oxidation that is based on the injection of a benign
non-hazardous liquid chemical at the boiler exit. Full-scale testing at a Midwestern power plant has
shown that the process is highly effective and can achieve up to 80% reduction in stack mercury
emissions. Based on these results, the technology will be commercially installed at the plant. This paper
will describe the patent-pending technology, present full-scale results, summarize economics for the
process, and describe the first commercial installation.
C6.2 From MATS Hg Demonstrations to Commercial Compliance Programs Installation Update & Demonstration Results for PRB & Lignite EGU
John Pavlish, Senior Vice President & CTO, Midwest Energy Emissions Corp; Marcus Sylvester, Jim Trettel
This presentation will discuss the path from Hg Capture Demonstration to commercial installation of the
Midwest Energy Emissions’ Corporation (ME2C) Mercury Control Technology using proprietary Sorbent
Enhancement Additive (SEATM) & proprietary sorbents for the EPA Hg MATS compliance on 3 EGUs.
In addition, ME2C will present additional Hg Capture Demonstration results & further testing of the
SEATM program. ME2C utilizes a 2-part tunable program designed to provide a cost effective Hg
capture program to the Electric Utility Industry. Performance Testing of the SEA™–sorbent technology
verified the results & economics; mercury removal performance is measured from coal pile to stack;
utilizing Stack CMMS, sorbent trap analysis, & coal analysis. Fly Ash sales were not impacted with
the implementation of the mercury removal program. This technology has been demonstrated in
over 35 full scale demonstrations & has proved it self to be a cost-effective mercury control strategy
when compared to other programs; with demonstrated Hg capture rates exceeding 94% with minimal
C6.3 Mercury Removal in Wet Scrubbers & Beneficial Use of Gypsum – A Contradiction?
Andreas Gruber-Waltl, Team Leader Process Development, Andritz Energy & Environment; Michael Kramer & Dr. Harald Reissne, Andritz Energy & Environment; Christian Patterer, Andritz Environmental Solutions
One of ANDRITZ’s solutions for flue gas desulfurization of coal fired boilers is the open spray tower wet
scrubber technology. The wet FGD is not only a very efficient way of separating SO2 or HCl from flue gas,
it is also highly efficient when it comes to mercury removal (oxidized species). However, inconsistencies
in the scrubber chemistry can be linked to reemission of mercury stabilized in the slurry matrix. There are
tools to avoid reemission from wet FGD slurry such as injection of PAC (powdered activated carbon)
or reemission inhibiting additives into the scrubber. If PAC injection is applied, the main mercury sink
in the process chain will be the FGD product – the gypsum. This is for two reasons unacceptable if
beneficial use of the FGD product is targeted. Firstly, it increases the mercury content in the gypsum
which could render the FGD product useless for the drywall industry. Secondly, the gypsum whiteness
will deteriorate and become unattractive for commercial use. If gypsum or gypsum slurry is disposed
(landfills, ponds) the hazardous impact of mercury on the environment must be considered. ANDRITZ
has developed a hydro clone technology that clearly separates the mercury loaded PAC from the
gypsum and minimizes the mercury content in the FGD product. The heavy metal rich slurry fraction
will be sent to a waste water treatment plant discharging only a small, mercury concentrated sludge
fraction. A controlled mercury sink is created and landfill highly reduced.
C6.4 Extended Trials of Novinda’s AS-HgX for EPA MATS Mercury Compliance
James Butz, VP of Product Management, Novinda Corporation; Clifton Brown, Jr.& Stephen Baloga
In cooperation with host utilities Novinda Corporation has completed testing of its Amended Silicates
products in several plants for periods of time exceeding 30 days. Results have shown consistent mercury
capture to reduce stack mercury emissions below the MATS standard & documented consistent
feed from permanent silo systems. Tests have been run at multiple locations, which will be discussed
in detail. Associated analyses of fly ash samples have been completed to confirm sequestration of
mercury in the fly ash to levels two orders of magnitude below EPA Method 1311 TCLP standards.
Other analyses via the new EPA Method 1313 protocol have shown that the use of Amended Silicates
has no negative impact & for some trace metals actually reduces leachability from fly ash. The
presentation will summarize mercury capture performance & highlight test results that document the
strong sequestration of mercury in the reaction product generated with the use of Amended Silicates.
C6.5 Installation of the Gore Mercury Control System at the Cayuga Power Plant
Jonas Klingspor, VP Business Development, AECOM; Jeff Kolde, W.L. Gore; Doug Roll, Cayuga Operating Company (presenter)
URS is installing a Gore Mercury Control System at the Cayuga Power located close to Ithaca in the
state of New York. The plant has to comply with the NY state mercury emission rule of 0.6 lb/TBtu. The
paper will provide: Overview of the Gore Mercury control system; Recent pilot plant results; Detail
presentation of the installation approach at Cayuga; Early operating results at Cayuga in terms of Hg
removal, pressure drop etc.
C6.6 Demonstrating Compliance with MATS
Bob Fraser, Partner, ERM; Mike Zebell
Most facilities have a viable plan in place to achieve MATS emission levels. Attention is now turning to the
details of what exactly needs to be done by when to ensure initial and continuous compliance starting
one year from now (or 2016 for plants that have been granted a 1-yr extension). The MATS Rule offers
numerous compliance demonstration alternatives to be weighed and evaluated on a boiler-by-boiler
basis. Should we go with quarterly stack testing and wait for more industry experience with HCl CEMS?
Can we combine MATS Method 5 with the Subpart 60 Method 5 we are already required to perform?
What happens to our existing CAM Plan? Are we better off using existing SO2 CEMs as a surrogate for
HCl? Would we be better off with PM CEMS, CPMS or quarterly stack testing and parametric monitoring?
Can we qualify for LEE status? What are the advantages/disadvantages of these various options for
our specific boilers? When do we have to submit a formal monitoring plan? How do we certify initial
compliance? How will we deal with startup, shutdown and malfunctions? What about missing data?
These are complex and vexing questions, particularly for utilities with a fleet of diverse fossil generators.
Corporate EHS may wish to provide guidance, a template or a targeted MATS workbook reference to
individual plant EHS Managers to ensure a robust and consistent approach to MATS Rule compliance
demonstration without having to reinvent a new program for each affected boiler.
C1.1 Scrubber Additives for Mercury Re-Emission Control
Noah Meeks, Research Engineer, Southern Company Services; Gary Blythe & Mandi Richardson, AECOM Corporation; Chuck Dene, Electric Power Research Institute
If the mercury re-emission phenomenon occurs in the scrubber, the oxidized mercury captured in the scrubber is reduced to elemental mercury by reacting with reducing species such as sulfite & re-emitted into the gas from the scrubber. This can result in the stack mercury emissions higher than the MATS limit of 1.2 lb/TBtu even when the mercury at the inlet of the scrubber is highly oxidized. To mitigate mercury re-emission, additives can be added directly to the scrubber slurry. The two common additives used are: 1) sulfides; & 2) activated carbon. Southern Company Services & EPRI have conducted fullscale tests of both additive types on large scrubbed coal-fired units. Results from these tests will be presented & discussed, including impacts on FGD operations, mercury emission & re-emission rates, gypsum quality, & FGD wastewater characteristics. The relative advantages & disadvantages of using these two additive types will also be presented & discussed.
C1.2 Modification & Testing of Feed Systems for Amended Silicates
Building upon previous work with CH2M Hill & Jenike & Johanson, Novinda has developed & implemented a simplified approach to feeding Amended Silicates from typical ACI injection systems. The methodology involves strategic placement of air injection pads along with a programmed firing sequence to fluidize the material in the silo cone & promote the approach to mass flow. The technique can be applied as a retrofit to silos that were designed for other materials such as powdered activated carbon. The approach can also be utilized on new equipment. The theory & design of the modification along with data generated in multiple field tests will be discussed & presented.
C1.3 Mercury Management across Wet Scrubbers for MATS Compliance: Where does the mercury go?
Bruce Keiser, Research Fellow, Nalco, an Ecolab Company; Jianwie Yua, Wayne M. Carlso & Angela Zagala
MATS mercury emission compliance is facilitated for electricity generating units (EGUs) by controlling mercury capture efficiency of wet flue gas desulfurizer scrubbers (WFGDs). Mercury management throughout the WFGD’s scrubber liquor handling system has been shown to effectively reduce mercury air emissions. The functionality of a unique, polymeric scrubber additive has been demonstrated to manage scrubber liquor mercury & control mercury emissions at numerous coal-fired EGUs. Further, a proactive control methodology to optimize chemical feed has also been proven. This mercury compliance strategy has also been shown to decrease the potential for corrosion in a 2205 Alloy scrubber. Due to the greatly increased mercury capture afforded by this strategic solution, the fundamental question regarding the fate of the captured mercury arises. Previous studies have attempted to answer this question for WFGDs operating without scrubber additives. Additionally, questions regarding balance of plant impact on other metal species, & the effect on the wastewater treatment process also are important going forward. This paper will present commercial scale experiences ranging from weeks to months relating to the effects of application of this mercury control strategy regarding the fate of captured mercury & other metal species by the WFGDs. The paper builds on previous studies examining gypsum & scrubber blow-down.
C1.4 Inorganic Scrubber Additive for Enhanced Capture of Elemental Hg
Charles Lockert, President, Breen Energy Solutions; Russ Evans, Owensboro Municipal Utilities
As the deadline nears for compliance with EPA’s MATS Regulations, many utilities are faced with increasing compliance vs cost dilemmas. Mercury capture technologies seem to be appearing for application in every corner of the power plant. Most of the widely discussed technologies seem to center on ways to improve overall oxidation of the metal for eventual capture in the wet FGD system. As the overall systems have evolved, increasing work has been spent on reducing the re-emission of previously oxidized mercury back into its elemental form within the scrubber liquid. Multiple approach have been brought to solve this issue with varying degrees of success and cost. However, to date, none of the these scrubber additives have been effective in capturing elemental Mercury. This paper will detail the chemistry behind a new, inorganic based, scrubber additive that has been demonstrated to capture between 50% and 75% of the elemental mercury within the wet FGD system in addition to being a cost effective re-emissions control method. Data will be presented from several full-scale utility demonstrations on plants from 180 MW to 750 MW in gross capacity.
C1.5 Measurement of Corrosion Rate associated with Halogen Use for Mercury Oxidation
Mandar Gadgil, AQCS Engineer, The Babcock &Wilcox Company PGG; Murray Abbott, Chem Mod LLC; Steven Feeney, Babcock & Wilcox Power Generation Group, Inc.
In the United States, mercury emissions from coal-fired power plants stacks are regulated by the Mercury and Air Toxics Standards (MATS) emissions rule. Multiple technologies are available for control of mercury emissions. One such technology is the addition of halogens for mercury oxidation. This technology is relatively low cost from both a capital and operating cost point of view. There can be balances of plant impacts associated with the use of halogen addition for mercury oxidation. For instance, increased cold-end air heater corrosion has been reported as a result of bromine addition. The paper will show data comparing the measured rates of corrosion due to the use of iodine and bromine at a Midwestern 80 MW plant firing PRB coal. The paper will also present corrosion data for different calcium bromide addition rates to the coal.
C1.6 Carbon Sorbent Properties for Optimal Mercury Reduction
Mercury control by injection of powdered activated carbon sorbents is the leading method for direct control of mercury from coal combustion gas streams. There are many PAC sorbent products on the market and the properties of these products vary. It can be difficult for PAC users to choose the properties which will produce the optimal mercury capture performance for their specific application. This presentation addresses the properties of PAC and how these relate to mercury capture. It also discusses the various metrics used for measurement of the internal surface area and absorption capacity of PAC and the advantages and disadvantages of these various metrics.