April 2015 - Power Air Quality Insights 205

The Hot Gas Decisions session at AFS yesterday zeroed in on key issues and options relative to selection and operation of filters and precipitators to capture a range of pollutants. As Tom Hart of AEP pointed out to the attendees, power plants must evaluate mercury, water and solid waste impacts along with any decision to reduce particulate. Tom contributed additional power points on the regulatory maze. These have been incorporated into the PPAQ decision orchard.

The first decision is whether to keep the existing precipitator or to replace it with a baghouse. The key factor is whether MATS particulate limits can be met where particulate is the surrogate for metal toxics. Mick Chambers of SEI presented a number of examples where precipitators are achieving efficiencies suitable to meet MATS.

A hot discussion was generated by the question of whether to use a precipitator or a baghouse for a new plant. Tom Hart unhesitatingly chose the baghouse. When challenged by Mick, Tom explained some of the operating problems he has seen at AEP plants. Maintaining efficiency in a baghouse is easier, in his opinion, due to the ability to easily replace bags. The same cannot be said for precipitator internals.

Steve Feeney of B&W said that the particulate decision is greatly influenced by the scrubber type selected. He believes that dry scrubbers are the better choice. Dry scrubber efficiency has improved over the years. This makes it a candidate for a range of coals. Steve also talked about successfully capturing and preventing re-emission of mercury in the wet scrubber. This also makes the wet scrubber option more attractive.

The scrubber now functions to capture a number of pollutants which results in what Tom Hart described as “scrubber soup”.

There was agreement regarding the difference between a 200 and a 500 SCA precipitator. The good news and bad news is as follows: the good news is that you can increase precipitator efficiency just by increasing the size. The bad news is that the cost rises proportionately. Also there is difficulty expanding the size of an existing precipitator.

This SCA sizing also impacts the capture of activated carbon laden with mercury. Some operators are finding higher mercury readings with sorbent traps than CEMS. The conclusion is that particulate mercury is captured in the sorbent trap but not measured by the CEMS. The further conclusion is that this could be a serious problem once EPA concludes that there is a big hole in the theory of just measuring gaseous mercury.

The opposite experience was communicated by Tom who says that their measurements may even show higher readings with CEMS than sorbent traps but acknowledged that they have large well operated precipitators with high total efficiency. But not all the power plants are operating in this highly efficient mode. As Tom, himself pointed out earlier, it is difficult to maintain precipitators except by shutting them down for repairs.

If a baghouse is chosen, a decision must be made on cleaning type. Reverse air and pulse jets are the options. Glass and synthetics are the common fiber options but ceramics and metals have suddenly joined the list.

Rich Miller of Solaft championed the use of extended surface area bags such as their star bag. He also recommended software to track bag life, predict change outs and manage operations. This was part of a theme addressed by many of the panel members. It is the maintenance and operation which determine performance. With the new continuous mass monitoring requirements the operator cannot operate for any length of time with broken bags without exceeding the limits.

The panel had proponents for membranes on glass and synthetics and proponents for non-woven felts including those with fiber blends by type and size e.g. nanofibers. Clint Scoble of Testori maintained that non-woven blends can meet MATS requirements. P84 fiber has a different shape than PPS. By blending the two the efficiency/pressure drop ratio can be improved.

Eddie Ricketts of Donaldson cited the efficiency and ease of cleaning associated with membranes. John McKenna of ETS agreed that membranes do provide the highest efficiency. Several of the panelists then discussed initial vs. long-term performance. If the membrane breaks, there is a problem. On the other hand, if the felt pressure drop builds up despite increased pulsing, there is also a problem.

John Eleftherakis of Filtration Group covered the extensive experience on glass furnaces, biomass boilers and incinerators with their ceramic hot gas element. When catalyst is embedded and dry sorbent injection is utilized results of less than 5 mg/Nm³, 90% SO₂ and even 90% NO_xremoval can be achieved.

Martin Schroter of Dürr provided insight into a unique combination of processes. Very finely powdered limestone is injected in the boiler with the fuel. A ceramic catalytic element follows the economizer. High SO₂ removal efficiency is obtained due to the contact time of the calcium particles on the filter element. The clean gas then enters a heat exchanger which can extract lots of valuable heat. Boiler efficiency is also enhanced by the lower volume of gas moved by the ID fan. This results in lower fan horsepower. Elimination of the rotary air heater also eliminates the extra flue gas volume created by air heater leakage.

John McKenna of ETS believes that combining nanofiber and catalyst technology could be a big step forward.

Pavlos Papadopoulos of Purolator displayed results showing that sintered metal fibers perform better than sintered powdered metal. Very high removal efficiencies are achieved at low pressure drop. Purolator has deep and varied experience on a range of applications including smelters. This technology may have some new uses in coal-fired boiler operation according to some new concepts offered by McIlvaine.

Coal flyash has been found to contain high percentages of rare earths in contrast to mined coal. China has concluded that flyash is, therefore, a top source for rare earth extraction. The process of capturing flyash is a beneficiation process. But what about refining this even further? What if there were two more particulate separation stages? If the rare earth percentage in one stage was much higher than in others, it could make the rare earth production from flyash even more attractive.

This hot gas session was a positive step toward improving the hot gas decisions program. We will keep updating the decision guide and the decision orchard. We welcome your input for both.

Thousands of Air Pollution Control Projects at Chinese Coal-fired Power Plants

China is no longer building one new 1000 MW coal-fired power plant per week. The program has slowed to only about 500 MW per week. However, tighter regulations are forcing upgrades at most power plants. Datang just announced that it will upgrade ten plants this year.

New national and local regulations are approaching and surpassing the stringency of regulations in the most advanced countries. The result is that there are thousands of individual projects underway. These projects are tracked in Chinese Utility Plans published by the McIlvaine Company. (www.mcilvainecompany.com)

Many of the projects involve reduction in particulate emissions. Ninety-five percent of the coal-fired boilers in China utilize dry electrostatic precipitators for capture of fine dust. Most will not meet the new standards. Options include:

Where a plant also has to remove more NO_x and SO₂, there are additional options:

· Combine a dry scrubber with a fabric filter to capture both dust and acid gases.

Plants in certain cities and provinces have to meet stringent limits on dust, SO₂, NO_x and mercury. Wet precipitators have been selected by several plants in these zones. Several are combining activated carbon injection and dry scrubbing.

More of the engineering and process design is being undertaken by Chinese companies. Only two large system suppliers are operating from foreign locations. Some international suppliers have very active Chinese subsidiaries which function as Chinese companies and even export air pollution control equipment to other countries in Asia.

Some home grown Chinese companies have developed enough expertise to export to other countries. The most notable activity has been the sale of hybrid precipitators to India. These units have precipitator fields and then filter bags. China has also developed the largest catalyst manufacturing capacity of any country.

The required investment for a 1000 MW FGD system is $200 million. If the unit must be retrofitted to an existing power plant, the investment could exceed $300 million, so orders for 10 large systems can make a $3 billion dollar difference in the market.

The history of the industry includes large peaks and valleys. The peaks come as one country passes regulations which generate a large short-term market. There may be an interval until there is another significant regulation somewhere else.

New FGD system yearly peaks have been over $15 billion and valleys as low as $2 billion. This activity has been tracked for more than 40 years in FGD Market and Strategies. McIlvaine analysts have experience dating back to the first commercial FGD system at Union Electric in 1968.

The future markets for systems will continue to fluctuate. However, the market for operating and maintenance, including repair, will continue to increase at a steady rate. Sales of reagents such as lime and limestone continue to expand at rates well above GDP.

Many of the systems in the U.S. and Europe are more than 30 years old. New components are required regularly. Slurry valves and pumps are examples. Due to the corrosive and abrasive nature of the process, major equipment replacements are also needed. System suppliers such as B&W have recognized the market opportunity and have built a substantial aftermarket business.

A large market is developing to upgrade systems to meet tighter limits. The EU, U.S. and China are all forcing operators to upgrade the efficiency of existing units.

New technology will also play a big role in the future FGD market. Here are some of the developments:

· Two stage HCl and SO₂ scrubbing with use of the HCl scrubber to leach rare earths and metals from the flyash.

· One stop shopping with catalytic filter and DSI to remove all pollutants at one point.

· Activated carbon injection ahead of and in the FGD scrubber to remove mercury, prevent re-emissions, and ensure that the gypsum is mercury free.

· Use of chemical fixation instead of gypsum production to lower system costs and provide encapsulation of toxic metals (eliminates costly wastewater treatment).

· Continuing penetration of dry scrubbing including circulating dry scrubbers, spray drier absorbers and direct sorbent injection.

Sempra U.S. Gas & Power announced it has acquired the Black Oak Getty wind project in Minnesota from Geronimo Energy, LLC, a utility-scale wind and solar energy developer. When the 78-megawatt (MW) Black Oak Getty is completed, Sempra U.S. Gas & Power, along with its affiliates and joint-venture partners, will have wind facilities in seven states totaling more than 1,200 MW of generating capacity.

Located in Stearns County, MN, the Black Oak Getty wind farm will generate enough renewable power for approximately 30,000 Minnesota homes. The project is expected to move into full construction in spring 2016.

The project is expected to employ about 250 workers at peak construction and be in commercial operation by late 2016. The entire power output from the wind farm has been sold to Minnesota Municipal Power Agency (MMPA) under a 20-year contract.

Trina Solar Signs Strategic Cooperation Framework Agreement with Hefei Xinzhan General Pilot Zone for 300 MW DG Solar Power Plant

Trina Solar Limited announced that it has signed a strategic cooperation framework agreement with the Administrative Committee of the Hefei Xinzhan General Pilot Zone to develop up to 300 MW of distributed generation (DG) solar power and related projects in Hefei, Anhui Province.

The first phase of the project consists of a 30 MW commercial rooftop project, on which the Company will start construction in the second quarter of 2015 and will be one of the largest single-unit commercial rooftop project in China once completed. The 300 MW project will be developed in Heifei City, a pioneer in promoting local DG solar power development and had a great amount of installed capacity of DG solar power in China as of the end of 2014. The Xinzhan General Pilot Zone is the primary area for PV industry development in Hefei, and will assist Trina Solar to gain local government support. In return, Trina Solar will use its leading technology, human resource, products, and industry leading position to help further develop DG solar power projects in Hefei.

Mississippi Power Announces Plans for Largest Utility Scale Solar Projects in the State

Mississippi Power is partnering with two solar businesses and the U.S. Navy to build utility-scale solar electric generating farms at two different locations in the company's service territory. With a combined total of approximately 53 megawatts, together these projects would represent the largest solar installations in Mississippi.

Mississippi Power and Strata Solar, a turn-key solar provider, are working to develop a 50 MW solar project located on 450 acres at Hattiesburg-Forrest County Industrial Park located near Hattiesburg.

In addition to the Strata solar project, Mississippi Power also is partnering with the U.S. Navy and Hannah Solar at the Naval Construction Battalion Center Gulfport on a 23-acre, 3-4 MW facility. The project is part of the Navy's efforts to meet the Secretary of the Navy's goal to produce or procure one gigawatt of renewable energy.

Blue Sphere Corporation Announces Second Closing This Year of Joint Venture for a 3.2 MW Biogas Generation Facility in Johnston, RI

Blue Sphere Corporation, a clean energy company that develops, manages and owns waste-to-energy projects, announced the closing of a joint venture with an affiliate of York Capital Management to develop, construct and operate a 3.2 MW biogas generation facility in Johnston, RI under the management of Entropy Investment Management.

Under the terms of the Joint Venture, Blue Sphere owns 22.75 percent of the project and received an initial payment of $1,481,900 in cash at the closing. Two payments of $562,500 each are expected to be paid later this year upon the Project achieving mechanical completion and commercial operation milestones.

Blue Sphere CEO Shlomi Palas noted that this is the second closing for the company in 2015, stating "we closed on a joint venture to develop a second significant food waste to energy facility in the United States, which, under the current construction timeline for the Project, is anticipated to commence production and sale of electricity during the fourth quarter of 2015. We booked our second round of revenue in the history of the company from the cash payment received at the closing of the Joint Venture, and upon successful completion of the project, expect to earn regular revenue from the sale of electricity, compost and feedstock tipping fees."

AES Energy Storage Announces 260 MW of Interconnected Global Projects in Construction or Late Stage Development

AES Energy Storage unveiled a portion of its deployment roadmap for AES Advancion^TM Energy Storage Solutions, which includes the addition of battery-based storage resources across the US, South America, and Europe. Projects in construction or late stage development are expected to deliver 260 MW of interconnected battery-based energy storage, equivalent to 520 MW of flexible power resource, 25 percent of which is expected to be on-line by mid-2016. These projects are in addition to the 86 MW of interconnected energy storage, equivalent to 172 MW of resource, AES currently has in operation.

· Judge upholds 50 Percent Sale of Coal-fired Power Plant in West Virginia

· TVA releases Draft Environmental Assessment for Steam Production at Johnsonville Plant

· New Study finds Caithness II Gas-fired Power Plant would produce significant Cost savings on Long Island and in New York State

· Follow-up to Carroll County Energy Project - Flexible Gas Power from GE

· Toshiba to supply Steam Turbines and Generators for Norte III Combined Cycle Power Plant in Mexico

· Noble Energy agrees to settle Colorado Oil Storage Tanks Emissions Violations

· Hot Gas Filtration and Gas Turbine Inlet High Level Discussions slated for Charlotte on the 28^th and 29^th

· Cement Industry will spend over $3.8 Billion on Air Pollution Control Equipment in 2015

The MACT decision process will pass from equipment selection to contractual agreements with suppliers of sorbents. Both equipment and sorbents will be addressed by three speakers:

Michael (Mike) Widico, Vice-President, Business Development, KC Cottrell, Inc. /Lodge Cottrell-Regional Office

Eric C.Van Rens, Vice-President, Sales & Marketing, Mississippi Lime Company

Two of our speakers will be addressing sorbent selection. However, important equipment decisions will continue to be made. We have one speaker on equipment and will explore a number of proactive options. Industrial plants are expanding due to the favorable economic conditions. There will be a need for more process steam and power. The final MACT activities can be combined with new investments to most economically provide the additional requirements.

One of the potential routes to more steam is the transfer of heat from the flue gas. The average stack exhaust is either at 300^oF and dry conditions or 160^oFand saturated. In either case, the potentially recovered heat is being lost. The saturated conditions involve not only lost heat but water as well.

By injecting sorbents ahead of the air heater, with use of high temperature filters and efficient tubular heat exchangers, the heat can be recovered and reused. The Hot Gas Filter Decision Guide was used as a foundation of discussion on this and other technologies on April 29 at the AFS in Charlotte. Quite a bit of discussion was focused on replacing the precip internals with bags. Upgrading precips with better electricals or bags will be ongoing. All the plants subject to MACT now have to worry about state initiatives to meet the ambient pm_2.5 limits. You can access this guide at Hot Gas Filtration Decision Guide, If you are a subscriber to the full decisions program you can view it all at 44I Power Plant Air Quality Decisions.

We will discuss the hot gas options and other decision guides relevant to MACT during the session. The use of alternative fuels in a co-combustion mode can reduce costs and greenhouse gas impacts. Industrial plants are more receptive to production of high value byproducts such as hydrochloric acid, sulfuric acid, or ammonium sulfate.

On Thursdays at 10:00 a.m. Central time, McIlvaine hosts a 90 minute web meeting on important energy and pollution control subjects. These Webinars are free of charge to owner/operators of the plants. They are also free to McIlvaine Subscribers of Power Plant Air Quality Decisions and Utility Tracking System. The cost for others is $300.00 per webinar.

See below for information on upcoming Hot Topic Hours. We welcome your input relative to suggested additions.

DATE	SUBJECT	DESCRIPTION
May 7, 2015	MACT Update	More Information
May 14, 2015	Wet Calcium FGD	More Information
May 21, 2015	Gas Turbine Intake Filters	More Information
May 28, 2015	No webinar but on-site interviews at Industrial Valve Summit in Bergamo, Italy
June 4, 2015	Power Plant Valves	More Information
June 11, 2015	SO3 Removal Options	More Information
June 18, 2015	Hot Gas Filtration	More Information
June 25, 2015	Mercury Removal Options	More Information