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Wet flue gas desulfurization (WFGD) Systems and the associated wastewater treatment (WWT) plants are typically designed separately with little or no direct communication of design conditions between vendors. In the current economic climate the emphasis on cost reductions thru improved design conditions and innovative design approaches is essential. The basic design factors for the purge stream are the volumetric rates of the purge stream, the chlorides concentration, and the weight percent solids. These factors have significant impacts to the costs of both the WFGD system and the downstream WWT system. The optimization of these design factors will minimize the overall design costs of project. This paper will examine the process and cost impacts of designs from five projects that have both a Siemens WFGD and a Siemens WWT system and provide design recommendations for future systems.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Siemens Energy, FGD, Air Quality, USA
The electrical generating community is aware of the U.S. EPA-proposed first-time nationwide regulations for handling and disposal of coal ash residuals (CCRs) including fly ash, bottom ash, and flue gas desulfurization (FGD) byproducts. Option one (Subtitle C) makes CCRs subject to hazardous waste requirements under the Resource Conservation and Recovery Act (RCRA). Option two (Subtitle D) establishes stringent requirements under non-hazardous classification similar to municipal solid waste rules, also under RCRA. The industry is buzzing with speculation regarding the form of the final rule, timing, litigation and how to influence change. The critical question is “what is this going to cost?” Timely budget planning, decisions, and actions are necessary to prepare for minimum requirements common to both options, with sufficient flexibility to adapt should the more stringent classification be approved. In addition to new dry disposal requirements, existing wet ash and FGD handling systems may be phased out entirely, requiring conversion of equipment, addition of dewatering systems, and closure of ash ponds. Some states already have similar disposal requirements; others have no such regulations. Using the combined resources of detailed cost analysis for specific sites, adjustments from municipal and hazardous waste regulations and costs, trade and association summaries, existing regulations, local economic conditions, computer models, and 30 years of disposal records for other wastes help to develop high confidence level cost estimates. This paper presents an up-to-the moment rule status summary, key points of the CCR proposal and discusses optional engineering solutions available for compliance along with associated costs using the Total Cost Accounting approach. Potential impacts on beneficial uses (recycling) of CCRs are difficult to predict but must be factored into the financial decision making process.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Sargent & Lundy, Wastewater Treatment System, Wastewater, USA
This paper will take a brief look back at the history of SO3/H2SO4 concerns, from the “pseudo” particulate issues of the 1970s, current mitigation techniques, a review and comparison of extractive SO3 test methodology and the current need for real-time SO3 monitoring. The concern over SO3/H2SO4 formation in back-end coal fired boiler emissions has increased with the introduction of Selective Catalytic Reduction (SCR) units to control NOX emissions. Prior to SCR usage, it has been the corrosive nature of SO3/H2SO4 and its’ affect on downstream equipment and ductwork, that has fueled efforts to understand its’ formation and the means to control or mitigate its’ affects. In addition, SO3 emissions can cause opacity accidences, interfere with activated carbon control of mercury emissions and bias particulate test results. Wet chemistry test methods do not provide real-time data often needed to minimize additive fuel rates used to control SO3 emissions. To both lower opacity levels while maintaining ESP fly ash conditioning, a facility will undertake a series of process control modifications; additive feed rates, and even comparison of different additives. These operations are time consuming and costly. The use of a real-time SO3 monitor allows sources to make these changes and receive feedback in a timely and cost effective manner. A comparison of the Controlled Condensate wet method and real time monitor test results will also be provided. The benefits of a real-time SO3 analyzer (vs the CCM approach) will also be discussed as they pertain to ease of set-up and operation, results by method, cost, and the ability of each method to provide information in a timely manner.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, EES, Monitoring, Air Quality, USA
As new regulations become more stringent and inclusive of additional requirements, utilities are being forced to modify the operation of their plants. Many are looking to their SCR catalyst to help meet these challenges. Choosing the optimum catalyst is an increasingly important decision because it not only ensures that utilities will comply with current regulations but it can also give utilities the flexibility to meet those that follow. Catalyst manufacturers continue to develop new catalysts that enhance the performance of the SCR, providing low cost solutions that give the required flexibility while minimizing the operational impact to the unit. This presentation will review the various factors that are part of the catalyst design and selection process including the catalyst performance requirements and the anticipated operating conditions. Discussion topics will include low load / low temperature operational impacts, SO2 to SO3 conversion minimization, mercury oxidation promotion on low halogen fuels, handling of large particle ash, and more. Finally, the operational and economic impacts of catalyst management programs will be reviewed.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Hitachi Power Systems America, Selective Catalytic Reduction, Air Quality, USA
The City Utilities of Springfield, MO - Southwest Power Station is comprised on one (1) operational generating unit (Unit 1), and one (1) new generating unit which is currently under construction (Unit 2). Unit 1 is a 203 MW Riley Wall Fired Unit utilizing PRB coal that has been retrofitted with an SCR System for NOx Control. The SCR reagent feed system is a urea based NH3 generation system provided by Fuel Tech, Inc under the trade name NOxOUT ULTRA™. The ULTRA technology is an on-line urea thermal decomposition process which provides the reagent feed to SCR systems. The ULTRA System for Unit 1 is sized at 240 PPH and Unit 2 is sized at 225 PPH of SCR reagent feed. The CUS Unit 1 SCR and reagent system was placed into commercial operation in January 2009 and has been operating successfully for approximately sixteen (16) months. The presentation will review the system layout, operational record, and maintenance issues over this time period. Also discussed will be some of the reasoning for selection on this technology and latest improvements.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Fuel Tech, Selective Catalytic Reduction, Air Quality, USA
Ameren has been a leader in lowering NOx emissions. In 1990 AmerenUE, now Ameren Missouri, an Ameren subsidiary, implemented a long term emission reduction program. Based on NOx emission rates in 2009, Ameren had 13 of the top 20 plants nation-wide including the top 4 for T-fired coal units without SCRs. These reductions can be attributed to the addition of OFA, boiler tuning, utilization of combustion optimization software, and Ameren’s dedication to reducing NOx emissions by maintaining a group of combustion engineers. Ameren will discuss recent advances in this area.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Ameren Services, Selective Catalytic Reduction, Air Quality, USA
Power facilities and others relying on water as a means of cooling may be facing the need to make significant changes to their intake system to be compliant with the pending 316(b) ruling. This ruling is promoting safer fish handling, among other environmental aspects, and the EPA is planning to identify the Best Technology Available (BTA), which may be a variety of solutions, cooling towers or closed loop systems at the top. Solutions Some groups propose that closed loop cooling systems are the best solution for 316(b) compliance and ultimately the most environmental friendly. While this may seem like a sustainable solution, for the plant it can require major construction to retrofit the facility to accommodate a closed loop system. This construction can be costly and require the plant to stop production for some time, or worse, close the plant down. Many of these facilities are facing very tight budgets and making the most economical decision is important. The decision must be made carefully, considering the risk of costing the community jobs, impacting the local economy and ecology. A large portion of the market affected by the most up to date 316(b) rulings are currently utilizing Once Through Cooling rather than Closed Loop Systems. If given the chance to implement alternative water screening and handling technology, power generators and others using cooling water must evaluate more effective and affordable solutions while still meeting the core requirements of 316(b). There are solutions that may satisfy the demands of environmentalist, the EPA, and power plants. During this discussion, a fair comparison on these alternative technologies will be presented, along with our best available EPA 316(b) ruling update.
Revision Date: 5/12/2011
Tags: 221112 - Fossil Fuel 化石燃料, Superior Water Screen, Wastewater Treatment System, Wastewater, USA
Based on a Federal Court decision the US EPA has agreed to propose the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Coal- and Oil-Fired Electric Utility Steam Generating Units. This NESHAP is to be proposed by March 16, 2011 and promulgated by November 16th, 2011. This NESHAP, and the associated requirements for MACT (Maximum Achievable Control Technology), are expected to be very similar in form to the Industrial Boiler MACT. The MACT floor, based on EPA regulations, cannot be less stringent than the average emission limitation achieved by the best performing 12% of existing sources for subcategories with 30 or more sources, or the best-performing 5 sources for subcategories with fewer than 30 sources. Accordingly at least 90% of the Utility industry will be affected by the emission standards promulgated under this MACT. The MACT requirements will require upgrades and modifications to existing emissions control equipment and the installation of new control systems to limit emissions of mercury, the other criteria metals, acid gases such as HCl, and organics. This presentation will address the potential impacts on existing Utility Assets and discuss the implications and limitations of existing control technology to control the air pollutants addressed by this NESHAP.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Sargent & Lundy, Air Quality, MACT, USA
The NID Dry Scrubber System is an advanced dry scrubber process that was developed by Alstom starting in the late 80's with commercial units in operation since 1996. The system allows for SO2 removal rates greater than 98% with the ability to operate with high Sulfur fuels that would be beyond the capabilities of traditional SDA dry scrubber systems. This presentation will provide on overview of the NID system, highlight recent developments in the technology, and introduce several NID reference units within the U.S. and Europe as well as a few new projects currently in execution.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Alstom, Absorber, Spray Dryer, Air Quality, USA
An air pollution control system was installed at Dominion Generation’s Chesterfiled Plant in April 2008. The air pollution control system includes limestone injection, fabric filter, and a single absorber module to control emissions from the Chesterfiled plant’s number 6 boiler unit. The unit burns medium to high sulfur eastern bituminous coal. For sites such as this, a dry electrostatic precipitator has typically been used to control particulate emission. Recently, however, fabric filters have been installed at several installations to control particulate emissions under these conditions. With this type of emission control arrangement, ash loadings to the FGD are generally much lower than a typical dry ESP / Wet FGD arrangement. The are several advantages of operating a Wet FGD system with low ash loadings. Under this operating scenario, equilibrium inert / ash concentrations of the scrubber will remain quite low (usually under wt 2%) and absorber solids concentrations is mostly gypsum. Low concentrations of ash minimizes the potentialal of Wet FGD chemistry issues, such as aluminum fluoride blinding. Chemical analysis of the absorber slurries that are equipped with Fabric Filters upstream indicates lower concentrations of some dissolved metals, such as Selenium that is an important regulatory species. The low ash content of the FGD also results in very low gypsum moistures values (5% - 8%) to while operating with a typical hydroclone, vacuum filter system. Additionally, equipment wear is lessened as highly abrasive ash particles are not present in high quantities. SESS will present photos of absorber equipment from the most recent outage (September) 2010 at Chesterfield 6.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Siemens Energy, FGD, Fabric Filter, Air Quality, USA
Study was conducted at a 5-MW equivalent slipstream facility of Gulf Power’s Plant Crist Unit 5 located in Pensacola, FL. The facility is also commonly referred to as Mercury Research Center (MRC). During the trials lasting 10 days, the effect of a range of process variables was studied. The variables included flue gas temperature, air-to-cloth ratios, interval between cleaning, and the effect of removing some of the fly ash by an ESP upstream of baghouse, etc. GE tested a novel membrane-based filtration media formed as pleated elements. Data will be presented that shows that by using GE’s novel filtration elements, Mercury capture as high as 98% can be achieved by inherent fly ash alone (without needing to inject powdered activated carbon). This was true in spite of majority (about 80%) of Mercury being in elemental form in the flue gas. Traditional round filter bags are typically known to capture around 30 to 40% of Mercury in the flue gas by inherent fly ash. Data was also collected with injection of activated carbon upstream of baghouse. It was found that by using these novel filtration elements, if a plant is already using powdered activated carbon the consumption of activated carbon can be reduced by as much as 85%. Data will be reviewed along with the proposal of mechanisms about how this novel filtration element works in achieving such high Mercury captures, as compared to traditional round bags.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, GE Energy, Fabric Filter, Air Quality, USA
Over the past several years, a significant number of FGD systems have been placed in operation. At each site, absorber materials of construction have varied based on plant preferences and industry experience. A portion of absorber vessels were constructed of solids alloy material such as 6% moly stainless steel, alloy 255, alloy 2205, and 317 LMN. Other vessels were built out of carbon steel, lined with flakeglass or rubber. Also some FGD units were constructed of concrete that is lined with ceramic tile. This paper will examine several SESS installations that have utilized ceramic tile lined absorber vessels. The discussion will include design experience, general arrangement considerations, construction issues, and schedule limitations that must be considered with this absorber arrangement. In addition, internal inspection observation will be presented from several sites, including Dominion Chesterfield 6 , PPL Montour, PPL Brunner Island, and Constellation Brandon Shores.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Siemens Environmental Systems & Services, FGD, Air Quality, USA
Dry Sorbent Injection (DSI) is being considered more frequently as a cost effective means of mitigating emissions of acid gases (SO2, SO3, HCl), heavy metals (Hg), and toxic organic compounds (dioxins and furans) from coal-fired boilers. A variety of dry sorbents are being considered, including sodium based compounds such as trona and sodium bicarbonate, calcium based compounds such as hydrated lime, and various activated carbons. Many existing power plants are equipped with electrostatic precipitators for controlling particulate emissions. Electrostatic precipitators can be very sensitive to operating conditions such as flow rate, temperature and to the quantity and chemistry of the particulate matter entering the ESP. Injection of sorbents upstream of an existing ESP changes both the quantity and the chemistry of the particulate entering the collector. This can change the performance of the ESP. When deciding whether to employ Dry Sorbent Injection, operators need to know what effect it will have on their existing equipment. Can they meet the required particulate emissions with existing equipment or will they need to upgrade their ESPs or even replace them with fabric filters? This paper will review several case studies wherein a variety of dry sorbents are injected upstream of an existing ESP. As will be discussed, the effects vary, depending on the design of the existing collector and on the amount and type of sorbent injected. The paper will also discuss mitigation options to enhance the performance of ESPs with dry sorbent injection.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Lodge Cottrell, Sorbent Injection, Electrostatic Precipitator, Air Quality, USA
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Babcock & Wilcox, Electrostatic Precipitator, Air Quality, USA
Draft U.S. Environmental Protection Agency hazardous air pollutant regulations for coal-fired utilities are anticipated by March 2011, and the expectation is that very high emission reductions (90% or greater) will be required for mercury control. Activated carbon injection (ACI) is expected to be a key tool for achieving these reductions; however, typical performance data with ACI suggest that in-flight mercury capture becomes exponentially more difficult at high reduction levels. Because of this decreasing sensitivity of mercury capture to carbon injection rate, ACI parameters will need to be optimized in order to consistently achieve high reduction targets. Unfortunately, optimization data may not exist for a number of plants since existing site-specific data may have been collected with outdated mercury capture targets in mind, and the ultimate capture potential or its sensitivity to plant operations was not thoroughly examined. To add to this dilemma, optimizing the maximum mercury reduction with ACI is not a trivial matter since there are number of potential bottlenecks that can limit overall capture. These restrictions range from insufficient sorbent distribution and contact time in the flue gas, to one of many kinetic limitations that arise under the conditions encountered in flue gas. This presentation will discuss the common mechanisms that limit mercury capture with ACI, as identified through fundamental study of mercury–carbon interactions and analysis of pilot and field data. Recognizing the typical trends with mercury capture can assist in the selection of ACI parameters that are most likely to achieve high reductions that may be mandated in the near future.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, Energy & Environmental Research Center, Activated Carbon Injection System, Air Quality, USA
Dry injection of sodium sorbents (trona and sodium bicarbonate) has been proven as an important multi-pollutant control technology due to (a) its low capital cost, (b) small installation, © easiness to operate, and (d) flexibility to fuel changes. Trona has been used as the main sodium sorbent due to its relatively low price. However, for some power plants where higher SO2 removal rates are desired and amount of generated fly ash need to be minimized, sodium bicarbonate (NaHCO3) offers a good alternative. For these reasons, a power plant that has been using trona since Fall 2005 tested conversion from trona to sodium bicarbonate on a 100 MW boiler. Trona or sodium bicarbonate was injected upstream of a hot-side ESP. The flue gas temperature at the injection point was around 600 oF. For 80% of SO2 removal, the normalized stoichemetric ratio (NSR) with trona was 2.5. With milled sodium bicarbonate, the required NSR for the same SO2 removal rate was decreased to 1.0. Over 97% of HCl was also removed. As a result, less sorbent was needed and significant savings in the sorbent was achieved. Furthermore, less fly ash was produced due to the sorbent change, and resulted in lower fly ash disposal cost. Same as trona, the sodium bicarbonate was able to keep the stack opacity below the limit since both sodium sorbents were able to lower the fly ash resistivity and thus enhance the ESP performance.
Revision Date: 5/11/2011
Tags: 221112 - Fossil Fuel 化石燃料, SOLVAir Solutions, Sorbent Injection, Air Quality, USA
Electric Power Conference, Chicago, Illinois, May 10-12, 2011 / Exhibitors
A number of air pollution system and coal fired boiler component suppliers, as well as some water oriented companies, will be exhibiting.
Revision Date: 3/9/2011
Tags: 221112 - Fossil Fuel 化石燃料, NeuCo, Metso, NWL Transformers, Nalco Mobotec, Milton Roy, Layne Christensen, KSB, Oak Park Chimney, KE Burgmann, Siemens Energy, Johnson Matthey, Horn Industrial Services, Kiewit Power Engineers, Paragon Airheater Technologies, Pennsylvania Crusher, Praxair, Roberts & Schaefer, CoaLogix, SOLVAir Solutions, SPX Flow Technology, Zachry, Veolia ES / Special Services, Swan Analytical Instruments, Hitachi Power Systems America, Hadek, Curtiss-Wright, International Chimney, Ovivo USA, Whiting Corporation, Vector Construction, Pentair Flow Technologies, Titan Fabrication, Sulzer Turbo Services, Pullman Energy Services, Nickel Systems, National Steel Erection, Air - Cure, Masaba Mining Equipment, National Steel City, Heyl & Patterson, FMC Corporation, East Jordan Iron Works, Degremont Technologies, Day & Zimmermann, Cambria Contracting, Burns & McDonnell, BRUKS Rockwood, Babcock & Wilcox, Grindex Pumps, Clyde Bergemann, Allied Environmental Solutions, Fujikin, Fuel Tech, FLSmidth, Everlasting Valve, Endress + Hauser, Eaton, DustMASTER Enviro Systems, Dustex, Donaldson, Graycor, Infilco Degremont, GE Energy, Chemco Systems, Calgon Carbon, Blome International, Barnhart Crane & Rigging, Apollo Valves, Atlas Copco, USA