Mercury Control Demonstrations

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C1.1 | Halogens and Sulfur in Coals and their Influence on Co-benefit Mercury Capture

Bernhard Vosteen | President, Vosteen Consulting Gmbh

Not only the range of the coal mercury content itself, but also the range of the native halogen and sulfur contents in coal are of great influence on co-benefit mercury capture, wet and dry. The specific role of different halogens is discussed with respect to many low chlorine coals worldwide, demonstrating that pre-combustion bromide addition to enhance mercury oxidation and co-benefit mercury capture will be needed not only in USA, but also in other countries (e.g. South Africa, China). The large scatter of coal sulfur contents is discussed, with respect to mercury reduction caused by sulfite and to mercury contamination of gypsum. Technologies are presented, how to prevent mercury reemissions and mercury contamination of by-products.

C1.2 | MHI Mercury Removal System with NH4Cl Injection

Shintaro Honjo | Lead Research Engineer, Mitsubishi Heavy Industries America, Inc.

MHI has developed and demonstrated an effective Mercury Removal System that is integrated with the SCR and FGD. This technology uses the injection of ammonium chloride (NH4Cl) into the ductwork, upstream of the SCR catalyst and provides NOx control and improved oxidation of elemental mercury. The downstream wet limestone FGD effectively removes the SO2 and the oxidized mercury with MHI ORP (Oxidation-Reduction-Potential) control technology. The results of several tests and a demonstration program have shown this halogen (NH4Cl) can result in much lower operating costs compared with Activated Carbon Injection (ACI). This technology also provides a benefit for the replacement of hazardous anhydrous ammonia injection and substitutes safer ammonium chloride injection. MHI has successfully completed collaborative testing and pilot-scale demonstrations of this Mercury Removal System with the Southern Company at the “Mercury Research Center” in Plant Crist, Pensacola, FL. With success of the demonstration, Southern Company and MHI will conduct full-scale demonstration testing for the NH4Cl injection and ORP control technologies at Alabama Power’s Plant Miller Unit 1 in early 2011. This report presents the demonstration results, including the vaporization, sublimation performance and effective emission control, and the future demonstration test plan.

C1.3 | Optimization of activated carbon addition and comparison of activated carbons in recent fullscale trial

Rob Nebergall | Business Manager, Norit Americas Inc.
Norit Americas Inc. is performing a full-scale field test at a coal fired power plant in the state of Illinois during the third quarter of 2010. The test program was developed in order to assist the plant in meeting the pending 2015 state mercury regulations in a cost effective and reliable manner. On January 1st, 2015, the State of Illinois requires a ninety percent reduction from coal base mercury or an output based emission standard of 0.008 lb of mercury per GW-hr on a plant-by-plant basis. Norit Americas Inc. will test several novel sorbents and compare the mercury removal efficiencies to that of DARCO® Hg-LH, The field test will last approximately eight weeks. EPA Method 30B will be used to determine the coal-to-stack mercury removal as well as the mercury stack emissions in lbs of mercury per GW-hr for each sorbent tested. In addition an economic analysis will be provided.

C1.4 | Evaluation of Sorbent-Based Strategies for Mercury Control at a Subbituminous Coal-Fired Plant

John Pavlish | Senior Research Advisor, Energy & Environmental Research Center of University of North Dakota
The Energy & Environmental Research Center has been investigating and developing sorbent-based strategies for mercury and trace metal control for well over a decade. At a midsized (400 MW) subbituminous power plant, two sorbent-based strategies were evaluated for mercury control, with some emphasis on evaluating balance-of-plant impacts. Testing included baseline measurement plus parametric and extended tests with sorbent-based strategies—commercial carbons and a suite of proprietary sorbents that were coupled with sorbent enhancement additives (SEAs). For comparison, noncarbon sorbents were also included with the SEAs. Trace metal data were captured by coal analysis, continuous mercury monitors, and sorbent traps. In addition, possible halogen impacts were evaluated using U.S. Environmental Protection Agency Method 26A. Electrostatic precipitator ash was analyzed to provide data on halogens, mercury, and loss-on-ignition changes as a result of using the technologies. Project results will be presented.

C1.5 | Behavior of various alloys in a steam boiler at the Ramat Hovav facility, using fuel oil spiked with bromide and chloride

Mira Freiberg | Head of Research, Israel Chemicals Ltd- Industrial Products
Inorganic Bromides such as NaBr, CaBr2, KBr, MgBr2 have advantages over chlorides for removal of mercury from flue gas produced in coal fired power plants. Bromine and bromine compounds are applied via different technologies to coal or flue gas for mercury control. This study evaluates the corrosion effects of adding bromides to coal fed to the boilers. It was designed to simulate the effect of addition of the bromides on the behavior of various alloys in the combustion atmosphere. Experiments were run in a steam boiler system at the Ramat Hovav plant, using fuel oil. The tests were carried out with chlorides, bromides and mixtures thereof. The results indicate similar behavior of the alloys in the different environments. The corrosion rate in all cases was at a safe level of less than 0.1 mm/year.

C1.6 |  Low Cost Multi-Pollutant Control Solutions

Tony Silva | Principal Engineer, Babcock & Wilcox

While dry sorbent injection (DSI) is not a new concept, it has taken on a new life in anticipation of regulations more stringent than CAIR. Field demonstrations have been ongoing in order to develop design and performance guidelines and comparative reagent economics for trona and hydrated lime. The impacts of a baghouse and/or ESP on reagent performance will also be discussed. The test results will not only address acid gas control but also the overall impact on multi-pollutants (including mercury) control. In addition, performance variables attributable to multi-pollutant control will be discussed.

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