FGD and Acid Gas Separation Webinar June 16, 2016

Program Details

Issues and options for SO₂ and other acid gas separation from coal-fired power, cement, steel, and waste incineration plants will be the focus June 16 at 10:00 a.m. central standard time.  

A collaborative format will be used to discuss decision guides on acid gas removal for coal-fired power, cement, steel, waste-to-energy, and glass plants. The decision guides already prepared on these subjects will be updated and briefly displayed during the meeting. We are inviting you to provide data on any new developments which should be incorporated.  Discussion will revolve around controversial issues such as

          General

• How do you determine the lowest total cost of ownership LTCO?
• Can U.S. and European suppliers leverage knowledge of the LTCO to penetrate markets in developing countries?
• How does the need to remove NO_x, PM, and mercury shape the decision on which acid gas removal system should be chosen?
• What efficiency improvements e.g. flue gas heat recovery are possible and how will that shape the acid gas decision?
• How do the needs differ between coal-fired power, cement, steel, and waste-to-energy?

          Dry Scrubbing

• How efficient is DSI?
• Where is sodium a better choice than calcium?
• What improvements are achieved by using special high reactivity hydrated lime?
• How widely will DSI be used in terms of which industries and which geographies?
• Is McIlvaine on the right track recommending an analysis of FIFO/LIFO to ensure that the first sorbent on the cake is pulsed and not the fresh unreacted sorbent?
• For medium sulfur coals, can a combination of DSI and a spray drier be competitive with circulating dry scrubbers?
• How much progress is being made on using DSI solid waste and converting it into bricks and building materials?
• Should every power plant using high sulfur coal consider DSI ahead of the air heater to reduce SO₃ and to be combined with an air heater upgrade to further reduce gas temperature?
• Can DSI with ceramic catalytic filters replace all the other APC devices?

          Wet Scrubbing

• What about the European approach in waste-to-energy which includes two scrubber stages including one to capture hydrogen chloride and make 30 percent hydrochloric acid?
• Why not leach out rare earths with the acid?
• The Chinese are touting a technology similar to the rod deck scrubber for wet limestone SO₂ removal. How do rod decks and trays compare to spray towers in terms of lowest total cost of ownership?
• Can lime be competitive with limestone as a reagent based on lower capital cost and higher efficiency?
• Can lime or other reagents be used along with limestone?
• Is the double alkali approach worth considering particularly if you have a high magnesium lime and can make magnesium hydroxide?
• Where are the ammonium sulfate and sulfuric acid options attractive?
• Should powdered  limestone replace ball mills  (this is popular in china)
• How efficient should mist eliminators be?

Components

• Wet: Agitators, oxidation blowers, pumps, valves, fans, hydrocyclones are all subject to severe service. How should these be designed to provide LTCO?
• Dry:  Rotary atomizers, two fluid nozzles, slakers, dust valves are all in severe service. What selections provide the LTCO? How site specific is this in terms of coal type and sulfur percentages?

Materials

• Should linings or high alloys be used for scrubber shells?  How dependent is this on lining skills and site specific conditions

• Where should weld overlays and hard coatings be applied to pumps and valves?

Consumables

• What is the quality and availability of lime and limestone in each country?
• Should membrane or nonwoven bags be selected?
• What is the role of treatment chemicals in the fuel, flue gas and wastewater?

Click here for more information and to register

Acid Gas Removal Market Shifts to Existing Power Plants

Over the last twenty years, more than $150 billion has been invested in systems to remove acid gases from the stacks of coal-fired power, waste-to-energy, cement, steel, mining and other industrial plants.  Much of this money was spent on retrofitting existing power plants with systems to remove SO₂ and HCl.  The other major segment was new coal-fired boilers which have been equipped with flue gas desulfurization (FGD) equipment.

The market is now shifting in several ways.  First of all the new power plant activity will be in developing countries.  The percentage of acid gas removal investment for new power plants in Europe and the U.S. will be less than 20 percent of the investment in the rest of the world.  The ratio of new acid gas system investment to the investment in maintaining and operating existing systems has fallen substantially.

This is bad news for system designers whose only focus is new systems. However, there are many suppliers who will benefit from these market developments. There are equipment, component, controls and consumables beneficiaries.

·       Equipment

§  Upgrades to meet more stringent emission limits

§  Revisions to capture multiple pollutants

§  Addition of solid waste or wastewater treatment technologies

§  Replacement of failed systems due to corrosion, erosion and obsolescence.

·       Components

§  Flow control products such as fans, compressors, pumps, valves and blowers

§  Scrubber internals such as mist eliminators, nozzles, packing

§  Sub system components such as hydrocyclones, pneumatic conveyors, static mixers,  rotary atomizers, agitators, ball mills and belt filters

§  Materials such as linings and coatings

·       Consumables including lime, trona, limestone, water treatment chemicals, seals and bags

·       Monitoring and instrumentation including continuous emissions monitors and process control systems

Concern about greenhouse gases creates retrofit opportunities.  Injection of sorbents ahead of the air/air heat exchanger allows greater extraction of the flue gas heat and higher boiler efficiency.

The need to meet more stringent regulations at existing power plants creates challenges due to space limitations.  Multi pollutant solutions where dust, NO_x and acid gases are removed in the same device are both available and economically attractive.

These options will be discussed in a free webinar to be held on June 16, 2016. (Click here for more information and to register)

The market analyses for acid gas removal from coal-fired power plants is covered in N027 FGD Market and Strategies.

The market analysis for acid gas removal from cement, steel and other industrial plans is covered in N008 Scrubber/Adsorber/Biofilter World Markets.

Complex Unintended Consequences Obscure the Path Forward for Air Pollution Control

A small Ohio town no longer exists thanks to the unintended consequences of air pollution control. A nearby power plant spent hundreds of millions of dollars to reduce NO_x. The catalyst not only reduced the NO_x it converted SO₂ to sulfuric acid. Within a few days, the acid deposition did such great damage to the buildings in the town that the utility agreed to buy the complete town and pay for relocations. In the ensuing decade, catalyst suppliers have redesigned their product to eliminate this problem.

New mercury regulations have such low emission limits that the instrument just to measure gaseous mercury can cost hundreds of thousands of dollars. Prior to issuing the regulation, EPA tested a number of stacks and found that all the mercury existed in gaseous form. Therefore, the regulations only required measurement of gaseous mercury. In response to the regulation requirements, power plants, cement plants and waste-to-energy plants embraced a two-step solution.

Step one was to convert the gaseous mercury to particulate mercury. Step two was to remove the particulate mercury. The end result is that if step one is very efficient and step two is not, there is lots of particulate mercury being emitted. Another unintended consequence is that particulate mercury will not travel far, whereas gaseous mercury can transverse the globe. Even though this problem has been evident for a few years, there is still no proposed change in the regulations.

The recent regulation of many pollutants combined with new technology which makes it possible to remove all the pollutants in one device has greatly increased the use of fabric filters. However, there has not been a recognition of what McIlvaine describes as “The importance of FIFO vs. LIFO in Dust Cake creation.”

Direct sorbent injection (DSI) and embedded catalyst dictate a new approach to bag cleaning. In addition to discrete particle capture, bag filters are being tasked with:

• Mercury removal
• Acid gas absorption
• Dioxin destruction or capture
• NO_x reduction

The importance of the method of bag cleaning can be illustrated by use of the accounting approach to inventory. Two options are first in first out (FIFO) and last in first out (LIFO). If the price paid stays the same, the choice between the two accounting methods makes no difference. But, if the cost of recent inventory is greatly different than the past, then the accounting method makes a big impact on profits.

The capture of discrete particles is the equivalent of price parity. Let’s say that when you pulse a bag you are always discharging the latest particles to arrive and the remaining cake consists of the earliest. Since the ability of a matrix of dust particles to act as a filtration medium does not change, it does not matter which particles remain. In fact, maintaining a somewhat permanent layer of cake protects the fabric from wear. Also a more permanent cake provides higher dust capture. It has been shown that on-line cleaning results in some re-deposit of dust particles. But this is does not impact discrete particle capture efficiency.

The new paradigm with DSI is a big price difference. The newly arrived lime particle has the capability to absorb acid gases. The lime particle deposited earlier is already converted to calcium sulfate and provides no additional absorption capability. The semi-permanent cake layer is very undesirable for acid gas capture. Mercury re-emission is also a risk for an activated carbon cake which is semi-permanent. So it is very important to adopt FIFO and not LIFO.

This leads to the obvious question as to which are the best cleaning methods to achieve LIFO?  The long running debate about surface filtration vs. depth filtration needs to be reviewed in light of FIFO. Also, the pulsing method itself needs to be reviewed. Do some methods result in more re-entrainment of particles in the previous cake than do others?  Should more of the cake be removed with each pulsing?

It could be argued that the reaction takes place in the ductwork and not on the bag. But the big difference in performance of bag filters vs. precipitators with DSI proves that the cake absorption is substantial.

There may be lots of research on this subject but if so, McIlvaine would appreciate feedback on it. If there is not, it is an area deserving lots of attention.

Bag cleaning is also made more challenging by the increasing use of ceramic filter elements. The advantage of these elements is the ability to remove dust at 850°F. The older generation rigid ceramic has been replaced by ceramic fiber media which can be pulsed. However, this media cannot necessarily be pulsed with the identical system used for synthetic bags. An alumina refinery in Australia was having cleaning problems with a ceramic filter. Pentair Goyen analyzed the situation and provided a more robust pulsing system. This solved the problem.

Ceramic, glass and even synthetic media are incorporating catalyst in the media to reduce NO_x or oxidize dioxins. Do these designs require a different cleaning approach?  The catalyst in the Clear Edge design is not on the surface. So, the dust cake will not affect performance except if it causes maldistribution of the gas. If more gas flows through one area than another, the reactivity of the system is reduced.

A broader subject is the whole approach to cleaning. High pressure/low volume is the most popular option. Does capture of these other pollutants open the door for high volume /medium pressure or even for reverse air cleaning? 

The potential for the one-stop shopping is great. Costs of pollution control can be reduced for new installations. The small footprint makes a big difference in the cost of upgrading existing plants to meet new air pollution rules. It is, therefore, important to understand and then maximize FIFO potential. McIlvaine will be interviewing experts in the various niches to shed more light on this. The results will be published in:

1ABC Fabric Filter

3ABC FGD and DeNOx Knowledge Systems

44I Power Plant Air Quality Decisions (Power Plant Decisions Orchard)

Industrial Air Plants and Projects

Total Solutions is the Best Path for International Air Pollution Control Equipment Suppliers

The number of regulated air pollutants, stringency of regulations and technology are all changing rapidly. No one would have predicted that direct sorbent injection would be a success twenty years ago. In the preceding decade, lots of research money had been spent in the U.S. on the assumption that 60 percent SO₂ removal would be sufficient. When the regulators ultimately opted for 90 percent efficiency, dry sorbent injection (DSI) was taken off the table. Now, with new hydrated lime technology and the willingness of power plants to spend lots of money for sorbent to avoid capital investments, the outlook for DSI is very promising.

Today, plant owners must consider technologies that remove particulate, acid gases, mercury, CO, CO₂, NO_X and organics. Some technologies create new air and water pollutants which must also be addressed.

Various industries have unique challenges. They also have many identical needs. Cement plants should pay attention to developments in the coal-fired power sector and vice versa. McIlvaine just hosted a webinar which concluded that ionic liquid impregnated pellets designed for natural gas mercury removal could have wide applicability in power, waste-to-energy and other industries.

McIlvaine publishes a number of specific market reports and databases on each technology and industry. It also publishes 5AB Air Pollution Management to guide executives making strategic decisions for their companies. One of the recommendations is to be a “Solutions Provider” whether you are selling complete systems or just a component.

Let’s take an example. A typical valve controlling compressed air is a commodity product. One application involves pulsing air to clean filter bags. Pentair has become the world leader in this specialty niche by understanding the dust collection cleaning process and the variations needed for different industries. Pentair supplies not only the valves but the headers and the controls to optimize the cleaning process.

W.L. Gore has developed a number of innovative solutions based on process and industry knowledge. Most power plants have wet flue gas desulfurization (FGD) systems. There are new rules to reduce mercury. Wet FGD systems will remove most of this mercury with the right treatment chemicals. The conventional solution to remove the remainder of the mercury is to use activated carbon upstream. The problem is that any mercury removed by carbon reduces the amount captured in the scrubber. W.L. Gore developed a module that can be installed after the scrubber and efficiently remove remaining mercury.

This technology fits particularly well into the processes employed at sewage sludge incinerators and power plants. It is less attractive in some other industries. The reasons have to do with the sub processes, processes and the specific industries. The air pollution control solutions provider who understands all these aspects is in a position to offer the product with the lowest total cost of ownership (LTCO). This knowledge is the key to success in the international market. In fact, owners and operators in developing countries are in greater need of these insights than those in developed countries.

For more information on 5AB Air Pollution Management, click on: 
http://home.mcilvainecompany.com/index.php/markets/2-uncategorised/100-5ab

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Bob McIlvaine
President
847-784-0012 ext 112
rmcilvaine@mcilvainecompany.com
www.mcilvainecompany.com