MEMORANDUM

From: The Office of Air Qu ality Planning and Standards U.S. Environmental Protection Agency

To: EGU NSPS Docket (EPA-HQ-OAR-2011-0044)

Date: March, 2011

Subject: Multi-pollutant Control Technologies

Introduction

In addition to single pollutant co ntrols, several emerging multi-pol lutant technologies in various stages of commercial development are available to reduce emissions. These include technologies that offer the potential for improved environmenta l performance at lower costs than traditional technologies. The following is a brief summary of some of the mu lti-pollutant control technologies, including propriety technologies. This summary is not intended to be a comprehensive list of available technologies. The perfor mance values given here are thos e that have been provided by the technology provider in publically av ailable sources. Inclusion of a technology in this summary is
not intended to be an endorsement of that technology by the US EPA the US Government

Multi-pollutant Control Technologies

Airborne Process TM

The Airborne ProcessTM employs a proprietary method of sodium bicarbona te regeneration that involves dry sodium bicarbonate in jection, wet sodium scrubbing, and staging with oxidants. The sodium sulfate by-product (the e nd product after scrubbing of flue gas emissions has occurred) is regenerated into two end products. The first pr oduct is sodium bicarbona te for re-use in the scrubbing process, and the second is a salable fertilizer that is generated using a granulation process. It is projected to pr ovide 99.5% removal of SO 2 , 98% removal of SO 3 (sulfuric acid mist precursor),
98% removal of NO X , and 90% removal of Hg from plant emissions.

APTECH CST LLC (Clean Stack Technologies)

The APTECH CST process uses a slu rry-injection technology to reduce SO 2 , SO 3 , NO X , mercury, chlorides, and prevent slagging with less than 0.4% parasitic power required. The technology is expected to achieve emissions reduc tions of greater than 70% for SO 2 and NO X , close to 100% for

SO 3 and HCl, and potentially greater than 60% for Hg.

CEFCO

The CEFCO Process integrates tw o technologies to selectively capture and remove flue gas pollutants and CO 2 and then convert these captured polluta nts into salable end- products or readily disposable waste streams. The first technology component (Ewan' s shockwave "free- jet collision" scrubbing) applies a sequence of re actors and aero-coalescers to st rip flue gas of metals, fineparticulates, SO X , NO X , and CO 2 , and capture them as segregated products. The second technology component (the "Cooper Process") is a chemical process which uses chem ical reagents for the selective conversion of each polluta nt in succession, into concentrated forms of recovered metals, potassium sulfate fertilizer, pota ssium nitrate fertilizer, pure CO 2 , or readily disposable waste streams. As an integrated process, the CEFCO Pr ocess is designed to remove greater than 90% of

CO 2 and over 99% of all other pollutants from gas streams with less than 10% energy penalty or parasitic load burden.

COMPLY 2000

The COMPLY 2000 process is a patented ozone-bas ed technology designed to remove flue gas pollutants. As the flue gas exit s the boiler, it passes through the O 3 aspirator where the flue gas is
mixed with O 3 (Ozone) to convert NO to NO 2 , which, as a result, become s water soluble. As the gas then enters the unit, it blends with the firs t fog field where a full ga s–to–liquid contact takes place. The fogging process floods the product of combustion (POC) and fog mix with condensation nuclei, encouraging acid vapor forming hydrolysis reactions. The fogging spray is mixed with a hydrogen peroxide solution to provide SO 2 conversion to sulfuric acid.

As the mixed moist gas passes through the cooling coil, the condensing coils extract heat and the captured pollutants run off of the finned coil to th e drain. The treated gas then passes through the second fog field where the moisture levels are elevat ed and the cooling coil is cleaned of any dirt or soot. From the second fog field, the clean gas passes through the condensing coil where any other heat is extracted, and the clean ga s is cooled to lower temperatures . From the condensing coil, the clean cool gas is directed to the outside air. Th e wastewater enters the ho lding tank to be treated (acids to be neutralized). After treatment, it is recycled back to the high-pressure pumps for use in the foggers. The COMPLY 2000 process is designe d to remove up to 98% of combustion emission pollutants such as NO X , SO 2 , Hg, and PM 2.5 , and capture up to 25% of the CO 2

.

Copper-Oxide (CuO)

The Copper-Oxide (CuO) proces s is designed to remove SO 2 and NO X from coal-fired boiler’s flue gas streams. The SO 2 is absorbed on alumina spheres that are impregnated with copper. The reaction forms copper sulfate, which then ac ts as a selective reduction catalyst of NO X in the presence of NH 3 . The process consists of an absorber, re generator, solids heater, and combustor. When the flue gas stream enters the absorber the SO 2 is adsorbed by a sorbent and NO X is reduced by injecting NH 3 . The spent sorbent is transported to the solids heater where the sorbent is regenerated by contacting combustion gas from the natural gas combustor. The sorbent then is transported back to the adsorber for reuse. Cu rrent tests have shown the CuO process to remove
90% of SO 2 and NO X

.
Electro-Catalytic Oxidation (ECO®)

The Electro-Catalytic Oxidation (ECO) process rem oves flue gas emissions in a single adsorber
vessel and the utilization of an integral WESP. The system phases are a gas converter stage, condensing WESP, and acid recovery system. The gas converter provides electrical oxidation of

SO 2 , NO X , and Hg. The oxidized molecules then fo rm particulates that, along with any SO 2 and

NO 2 that were not converted to acids, are remove d by the WESP. The ECO process is designed to remove up to 90% of NO X , 98% of SO 2 , 70% of Hg, 88% of HCl, and 90% of PM 2.5 for a coal-fired power plant.Electron Beam Process (E-Beam)

The Electron Beam Process (E-Beam) process removes NO X and SO 2 through a series of steps set up after the particulate matter contro l. The system consists of an evaporative spray cooler to cool the flue gas to 140-150°F. Gaseous ammonia is inje cted into the flue gas before the main process vessel. In the main process vessel, the flue gas is irradiated by a beam of high-energy electrons,
while water is added as a coolant to counter the temperature rise. In this process, hydroxyl radicals and oxygen atoms are formed and oxidize SO 2 and NO X , which mix with water from the flue gas to
form sulfuric and nitric acids. The sulf uric and nitric acid s are neutralized by NH 3 and the products
are ammonium sulfate and ammonium sulfate-nitrate, which are collected in the PM control device. The projected emission removal efficiencies are up to 90% for NO X and up to 95% for SO 2

.

Indigo Multi Air Pollutant System (MAPSystemTM)

The Indigo Multi Air Pollutant System (MAPSystem) was designed to reduce SO 2 , NO X , PM, and Hg emissions through chemical, fluidic and elect rostatic processes. Reagants oxidze the NO X and enable the removal of mercury, while sorbents remove acidic compounds. The fluidic process provides mixing to enhance removal efficiency. Th e flue gas then proceeds to the ESP or bag house. Projected removal efficiencies are up to 94% for Hg, up to 97% for SO 2 , and up to 54% for

NO X

.

Nalco Mobotec techology

This process involves three technological com ponents. T he addition of ROTAMIX technology for the injection of ammonia or urea lowers NO X emissions, while furnace sorbent injection (FSI) systems can be applied effectively to reduce SO 2 and mercury emissions. FSI systems coupled with ROFA technology increase the co ntact/interface between sorbent a nd flue gas. This improved mixing reduces sorbent usage while maintaining de sired emission levels. The combination of the ROFA, FSI, and ROTAMIX systems can reduce SO 2 up to 98% and NO X up to 95% at relatively low auxiliary power requirements.

NOXSO

THE NOXSO process is a dry, regenerabl e system capable of removing both SO 2 and NO X in flue gas from coal-fired utility boilers burning medium-t o-high sulfur coals. The flue gas passes through
a fluidized-bed adsorber downstr eam of a precipitator. The SO 2 and NO X are adsorbed by the
sorbent. The NO X is desorbed and recycled to the boiler. The sulfur is regenera ted and reacted with methane to produce an off-gas with a high SO 2 concentration. This gas is used to produce elemental sulfur. The projected removal efficiencies for SO 2 are up to 98% and for NO X are up to 90%.

Pahlman Process TM

The Pahlman Process TM uses the Pahlmanite TM sorbent mineral powder to adsorb SO X , NO X , and Hg. The technology can remove multiple pollutants by a single, dual or multi stage dry process and does not require NH3. The process creates end produc ts that can be used to make detergents, fertilizers, and food preservatives. Remova l efficiencies of greater than 99% for SO

x and NO

x and greater than 65% for Hg have been reported.ReACT TM

The ReACTTM process controls SO 2 , NO X , Hg and PM in a multistage regenerative process that produces salable byproduct. A moving bed ad sorber provides contact between flue gas (downstream of a primary particulate control devi ce, typically an electro static precipitator) and activated coke pellets, where SO 2 , SO 3 , NO X , and Hg are adsorbed onto the carbon surfaces. Ammonia is injected upstream in order to promote the SO 2 and NO X reactions. The moving bed acts as a particulate collection step as the impinge nt of the flue gas on th e activated coke pellets provides "polishing" cont rol of particulate.

Activated coke from the adsorber is then proces sed in a regenerator vess el which completes the
reduction of NO X to N 2 , and drives off SO X in a concentrated sulfur rich gas stream. Adsorbed mercury is retained in the activated coke in a region of the regenerator where temperature conditions allow the mercury to accumulate. Rege nerated activated coke is screened to remove
fines and returned to the absorber. Sulfur rich gas is then processed us ing conventional technology to produce salable sulfuric acid.

This completely dry process does not evaporate an y water into the gas stream. It can reduce SO 2 and SO 3 emissions to greater than 98%, NO X capture can be in the range of 30 to 60%, mercury capture is in the range of 90%, and a net reduction of par ticulate in the range of 50% is expected.

SkyMine®

Skyonic’s SkyMine® technology is a post-combustion syst em that reacts flue effluent with sodium hydroxide and pulls CO 2 out to form sodium bicarbonate (" better-than-food-grade baking soda") while also removing heavy metals and acid gases. The process uses energy in the form of waste heat from the plant. In additi on to capturing and mineralizing CO 2 , the process cleans SO X and NO 2 from the flue gas, and removes heavy metals such as mercury. The process is reported to permit the removal of up to 99% of the CO 2 and virtually all of the SO 2 , NO 2 , Hg, and other heavy metals.

SNOX TM

The SNOX process is a catalytic fl ue gas cleaning process. The process generates no secondary sources of pollution, such as waste water, slurries or solids. It consumes no water or materials, except for ammonia for the catalytic NO X reduction. The principal SNOX process steps are dust removal in ESP (or bag filter); heating of the flue gas to about 400°C; catalytic reduction of NOx by

NH 3 added to the gas upstream of the DeNOx-reactor; catalytic oxidation of SO 2 to SO 3 in the subsequent oxidation reactor; coolin g of the gas to about 260°C; and, further cooling of the gas to about 100°C in the "WSA Condenser", a falling film condenser and concentrator with vertical glass tubes, whereby the SO 3 and H 2 SO 4 vapor is condensed and separated as concentrated sulfuric acid
from the bottom chamber of the condenser.

SNOX removes up to 99% of SO 2 and SO 3 and up to 96% of the NO X in flue gases. The sulfur is
recovered as 94 – 96% concentrated sulfuric acid of high purity. NO X is catalytically reduced by ammonia to nitrogen and water. Essentially all dust and particulates are rem oved from the flue gas. The heat produced in the process and by cooling of the flue gas to 100°C is recovered as steam and preheating of combustion air, thus increasing boiler thermal effici ency and gross power production.The process is in particular su ited for boilers burning high sulfur refinery residues, such as petroleum coke (petcoke), orimulsion, h eavy oils and tars and sour gases.

SOx-NOx-Rox Box

The SOx-NOx-Rox Box (SNRBTM) involves two t echnological components. High-temperature filter bags and circular monolith ca talyst developments enable multiple emission controls in a single component with a low plan-area sp ace requirement. The high-tem perature bag provides a clean, high-temperature environment compatible with eff ective SCR operation, and a surface for enhanced

SO 2 /sorbent contact. SO 2 removal is accomplished using either calcium- or sodium-based sorbent injected into the flue gas. The NO X removal is accomplished by injecting ammonia (NH 3 ) to selectively reduce NO X in the presence of a selective catalytic reduction (SCR) catalyst. Particulate removal is accomplished by high-temperature fibe r bag filters. The SNRB TM can achieve greater
than 70% SO 2 removal and 90% or higher reduction in NO X emissions while maintaining particulate emissions below 0.03 lb/MMBtu.