Air Pollution Control Guide

Recent changes:

Added court-ordered deadline for ozone regulations, and preliminary findings from scientific council. May 15, 2014

Updated state of legal battles and rule-making for PM2.5. May 13, 2014

Added US Court of Appeals decision on Mercury and Air Toxics Standard. May 1, 2014

Added Supreme Court decision on Cross-State Air Pollution Rule. May 1, 2014

Added documents in nitrogen dioxide review. Feb. 25, 2014

Added documents from ozone review; details of petition against EPA; agency decision on 2,3,3,3-tetrafluoropropene. Feb. 25, 2014

Updated state of legal battles and rule-making for PM2.5. Feb. 25, 2014

Air Pollution Control at a Glance

Air emissions control is a crucial part of sustainability for companies in many industries. Firms are obligated under law to restrict emissions of a variety of substances, with regulations varying widely by sector and country; but some of the most commonly regulated emissions include carbon monoxide, nitrogen oxides, sulfur dioxide, lead, particulates, volatile organic compounds (VOCs), ammonia, mercury, metals and hydrogen chloride – and also ozone, which companies don’t emit directly, but which forms from gases they do emit. This issue of EL Insights will look at what companies from a variety of sectors can do to reduce their emissions of airborne pollutants, and at the state of the emissions control industry. Since we have covered and continue to address carbon dioxide emissions from a variety of angles, this report will avoid discussing carbon reductions, but we will address several other greenhouse gases.

Technologies and Applications

Source and process control

Perhaps the most effective way to prevent air pollution is at the source, reducing the amount of pollutants created by a particular process – rather than simply capturing or treating the resultant pollutants. Often companies must use emissions control technology as well, but source reductions are a good place to start. Such reductions fall into a few basic categories:

  • Reducing the amount of fuel used
  • Minimizing waste generation, or reusing byproducts
  • Reducing the amount of raw materials used[1]
  • Making material substitutions: For example, companies can use non- or low-VOC solvents and coatings to help reduce ozone creation.[2]
  • Maintenance: For example, by keeping combustion equipment properly maintained, companies can avoid using excess fuel. In chemical reactions, they can improve parameters such as temperature and mixing to reduce the amount of raw materials consumed and waste generated.[3] Engineers can help reduce nitrogen oxide formation from furnaces by changing the flame temperature, the time air remains in the combustion change, or the mixing rate of fuel and air.[4]

Emissions control equipment

Companies choose their control technology based on the type of pollutant, stationary source conditions, and control efficiency needed.[5] Pollutant profiles vary considerably by industry, and certain types of control equipment therefore tend to be used by certain sectors. For example, the biggest industrial emitters of VOCs are petroleum and related industries, solvent utilization, and storage & transportation (see chart, p.5).

Some of the most common types of air pollution control equipment are:

Bag houses/fabric filters: These devices feature filter bags, made from any number of materials (including paper, cotton, Nomex, polyester, fiberglass, Teflon, and spun stainless steels), hanging in a sturdy “house.” The bags remove particulate matter found in smoke, vapors, dust or mists. Particles stay on the filter and eventually form a dust cake that is disposed of or re-used in industrial processes. Fabric filters can collect over 99.9 percent of entering particulates, including fine particles, but bag and house wear can reduce their efficiency. The dust cake must be removed carefully to prevent airborne releases.[6] Some companies have equipped bag houses with catalytic bags, so the devices can perform two types of pollution control at the same time. Fabric filters and bag houses are used at asphalt batch plants, concrete batch kilns, steel mills, foundries and fertilizer plants, among other facilities.[7]

Scrubbers/wet collectors: This type of control device either passes a gas stream through liquid (usually water), or sprays the liquid onto the gas stream. The sprays may contain chemicals to help the water absorb gases. Scrubbers can also remove particles. For particles, wet scrubbers can have removal efficiencies of up to 99 percent, but for very small particles their efficiency can be much lower. In general, they are better than cyclones (see below) at removing particles, but unless they are operated at high power, they are not as effective as bag houses or electrostatic precipitators. Scrubbers can handle high-temperature gases and don’t suffer from the fire and explosion hazards of some dry collection systems. Absorption can be used to recover products, and scrubbers are useful for gas streams with high concentrations of water-soluble compounds. However, they create dirty water which must itself be cleaned, often using settling ponds and sludge handlers. The high-humidity air these devices release can cause local meteorological problems and driving hazards. Air pollution control guide 1 Scrubbers are common at asphalt and concrete batch plants, coal-burning power plants, and other facilities that emit sulfur oxides, hydrogen sulfide, hydrogen chloride and ammonia.[8],[9]

Adsorbers: These devices use sponge-like porous materials, such as activated carbon, silica gel and alumina oxide, to soak up gases. Once the adsorbent material is saturated, it must be either refreshed or disposed of. Companies often use activated carbon to control VOCs, solvents, toxic gases and gasoline vapors, as well as odors. If the gases contain particulates, however, the adsorbents can become clogged. Adsorbers are often used at soil remediation facilities, oil refineries, paint shops, steel mills and wastewater treatment plants. Popular uses also include degreasing, rubber processing and printing operations.[10], [11]

Cyclones: These devices spin dirty air in increasingly tighter circles, using centrifugal force to cause large particles to move toward the outside wall, where they bounce off and fall to the bottom for collection. Cyclones can remove either solid particles or liquid droplets. They can achieve efficiencies greater than 90 percent for particle sizes of 10 μm or greater. Groups of cyclones called multi-cyclones, meanwhile, are better at removing fine particulate matter. Companies often use cyclones as a pre-treatment, before more expensive equipment such as bag houses or electrostatic precipitators remove smaller particles. Cyclones have a low capital and operating cost, and can withstand acids, high heat and pressure. But they can get clogged or worn out from sticky, hard or sharp particles.[12] Particles can also recirculate from the hopper, and heavy dust at the cyclone inlet can plug the hopper. Cyclones are widely used at cotton gins, rock crushers, woodworking shops, cement plans, pharmaceutical makers, grain elevators, feed mills and other industrial processes that produce gas streams with relatively large particulates.

Vapor condensers: These devices cool gaseous vapors, turning them into liquid. Companies often use them as pre-cleaners to remove gas vapors before sending exhaust air to more expensive equipment such as incinerators or absorbers. The liquefied gases can also be reused, helping to cut costs. For example, dry cleaners often use condensers to return solvents to use.[13]

Electrostatic precipitators (ESPs): These devices use high voltage electrodes to negatively charge airborne particles of between 0.1 and 10 microns, which then collect on a metal surface to form a dust cake. A “rapper” strikes the plate periodically to drop the dust cake into a collection hopper. Companies can also configure ESPs as a series of collecting plates to improve overall efficiencies. ESPs are capable of efficiencies over 99 percent. They are generally better at collecting fine particles than scrubbers or cyclones, and they can handle hot gases from 350 to 1,300 degrees Fahrenheit. This makes them ideal for use at Portland cement plants, steel furnaces, and industrial boilers.[14] ESPs are used in many of the same sectors as bag houses, including power plants, paper mills, smelters and petroleum refineries.[15]

Flares: Industrial plants use combustion to dispose of intermittent or emergency releases of certain emissions, such as hydrocarbons, chlorine, fluorine and particulate matter. Refineries and chemical plants often use flaring as well, as do large commercial printing facilities. The process is designed to destroy substances with a minimum amount of smoke.[16]

Thermal oxidizers: Incinerators that do not burn solids are called thermal oxidizers. They are used to destroy odorous or toxic VOCs, and can achieve efficiencies of 99.99 percent. But reaching the needed temperatures (up to 2000°F) requires a lot of fuel, so costs can be high. Regenerative thermal oxidizers capture and reuse heat, achieving heat recoveries of up to 95 percent, which cuts fuel costs considerably.[17]

Catalytic reactors/selective catalytic reduction (SCR): SCR systems are used frequently to control NOx from the burning of fossil fuels. In these systems, ammonia and NOx react to form nitrogen and water. SCR can remove more than 90 percent of NOx. Catalytic reactors can also be used for other gases and VOCs.[18] These devices have much lower energy and operating costs than incinerators. They are commonly used at landfills, oil refineries, printing companies and paint shops.[19] However, particulate matter can coat the catalyst surface, and certain chemicals can deactivate the catalyst.[20]

Biofilters: These destroy VOCs, hydrogen sulfide, organic sulfides and odors through microbial oxidation. The polluted air passes through a wet bed, which supports bacteria that absorb and metabolize the pollutants. Biofilters can achieve efficiencies over 98 percent. They are commonly used at wastewater treatment plants as well as in industrial processes.[21]

Vendors and Products

The EPA’s Air Pollution Control Technology Center has verified technologies in several pollution control categories. These products and technologies are:

Baghouse filtration

Donaldson Company: Dura-Life #0701607 Filtration Media, Tetratex #6262 Filtration Media, Tetratex #6277 Filtration Media, Tetratex #6282 Filtration Media Sinoma Science & Technology Co.: FT-806 Filtration Media, FT-902 Filtration Media TTG Inc.: TG100 Filtration Media, TG800 Filtration Media W.L. Gore & Associates, Inc.: 5117 High Durability PPS Laminate Filtration Media

Nitrogen Oxide (NO x) control technologies for stationary sources

Catalytica Energy Systems, Inc.: Xonon Flameless Combustion System[22] Other companies in the air pollution control market include the following (many of these are listed in the buyers’ guide run by the Institute of Clean Air Companies):[23]

ADA Carbon Solutions ( Provides activated carbon products for mercury capture from flue gas streams.

Anguil Environmental Systems ( Offers thermal and catalytic oxidizers to control VOCs, hazardous air pollutants, process odors and nitrous oxides.

Cabot Norit Activated Carbon ( Offers mercury and odor control products.

Calgon Carbon Corporation ( Offers activated carbon injection, continuous emissions and opacity monitoring systems.

California Analytical Instruments ( Offers gas analyzer products and systems.

Clyde Bergemann Power Group Americas – Air Pollution Control Product Division ( Offers electrostatic precipitators, fabric filter systems, flue-gas desulfurization and dry scrubbing systems, dry sorbent storage and injection and mercury control systems.

Cormetech ( Offers SCR catalysts.

CRI/Criterion (; CRI/Criterion is the catalyst technology company of the Shell Group. It provides SCR technology for nitrogen oxides (NOx) and catalysts for the oxidation of VOCs and carbon monoxide.

Durag ( Makes environmental measurement products addressing dust concentration and opacity, mercury concentration and flue gas volume flow.

Durr Systems, Environ. & Energy Systems ( Offers absorption, adsorption, catalytic oxidation and thermal oxidation products.

Envirogen Technologies ( The company has launched a product using both biological and adsorption technologies to address VOCs, hazardous air pollutants and odors. It says initial applications for the product will be in refinery and chemical facilities.[24]

Environmental Systems Corporation ( Offers emissions monitoring software and data controllers.

FMC Corporation ( Offers technologies for SOx and NOx abatement, particularly for fossil fired-generation plants.

Fuel Tech ( Provides multi-pollutant emission control and advanced combustion technologies, including customized NOx control systems and proprietary urea-to-ammonia conversion technology, which can provide safe reagent for use in selective catalytic reduction systems.

Haldor Topsoe ( Offers pollution control, including SCR systems, for removal of nitrogen oxides, sulfurous compounds, carbon monoxide and VOCs.

Herr Industrial ( Specializes in the control of VOCs and particulates, focusing on the printing, flexographic, wood finishing, metal coating, painting and OSB/MDF mill industries. Offers dust collectors, bag houses and wet and dry electrostatic precipitators.

Hitachi Power Systems America ( Offers SCR systems, NOx catalysts, dry scrubbers, low-NOx burners, fabric filters and flue gas desulfurization.

Lechler ( Sells nozzles, lances and systems used in semi dry flue-gas desulphurization, wet flue-gas desulphurization, SCR and SNCR.

MKS Instruments ( Offers air and gas analysis products.

Novinda ( Offers a reagent for mercury emissions control.

Tiger Optics LLC ( Manufactures trace gas analyzers and ambient air monitors.

URS Corporation ( Offers coal-fired power plants technologies to reduce sulfur dioxide, sulfur trioxide, mercury and other particulates, including flue gas desulfurization systems, through its Advatech joint venture with Mitsubishi Heavy Industries (MHI). URS also provides sodium bisulphite injection technology that reduces sulfur trioxide emissions.

Benefits and Challenges


Compliance: Much pollution control is driven by the need to comply with regulations and avoid penalties. See Policies, below, for more information.

Slowing climate change: Carbon dioxide and nitrous oxides are greenhouse gases, which cause climate change, and direct industrial emissions accounted for about 20 percent of total US greenhouse gases in 2011. If indirect emissions from industry’s electricity use are included, industry’s share goes up to 28 percent, making it the biggest contributor of greenhouse gases.[25] A recent study concluded that black carbon – a common component of particulate matter – is the second largest man-made contributor to global warming, with a per-square meter warming effect about two-thirds that of carbon dioxide.[26]

Improving health: Many of the emissions also directly affect health, especially that of children, the elderly and those suffering from respiratory ailments. Particulates can decrease lung function even in healthy people, and studies estimate that thousands of elderly people die prematurely each year from exposure to fine particles.[27] Exposure to ozone causes coughing, wheezing and throat irritation.[28] The 188 substances classed as hazardous air pollutants (see Policies, below) are known or suspected to cause serious health effects including cancer, reproductive problems and birth defects.[29]

Visibility: Ozone is the main component in smog, and wind can transport ozone long distances. Companies don’t emit ozone directly, but emit its components, nitrogen oxides (NOx) and volatile organic compounds (VOCs).[30]

Plant and animal life: Many types of emissions have harmful effects on crops and other vegetation, on ecosystems and on animals.

Cost savings: Process changes aimed at reducing emissions can also save companies money, by reducing purchases of raw materials and fuels, for example.[31]


Costs: It is difficult to generalize about the costs of industrial air pollution controls. For a start, costs vary widely by type of equipment – for example, bag houses and electrostatic precipitators tend to be more expensive than cyclones; incinerators and adsorbers are usually more expensive than vapor condensers. Thermal oxidizers tend to be expensive because of their fuel use, but the addition of catalysts can reduce these costs[32], as can advanced systems with high heat recoveries. The operating costs of various thermal and catalytic oxidizers varies from $0.30 to $28.37 an hour at a 1 percent lower explosive limit (a measure of the flammability of gas).[33]

The EPA has estimated capital costs for wet electrostatic precipitators in the range of $300,000 to $450,000, depending on saturated volume and efficiency, though the estimates date from 1999.[34] The EPA and industry often publish wildly different estimates of regulation’s costs to business. Power companies have said they cannot bear the costs of new equipment to comply with the Cross-State Air Pollution Rule, estimated at $800 million annually from 2014.[35]

Meanwhile a study by National Economic Research Associates on behalf of the American Coalition for Clean Coal Electricity analyzed seven EPA regulations that affect coal-fueled electricity generation, including Mercury and Air Toxics Standards, regional haze, national ambient air quality standards (NAAQS) for ozone, SO2 NAAQS, PL 2.5 NAAQS, 316(b) and coal combustion residuals, and found that compliance costs for the electric sector could total between $198 billion and $220 billion from 2013 to 2034.[36]

Regulations: Much of air pollution control is driven by regulations, and the EPA is constantly reviewing and revising rules relating to air emissions. Companies must make sure that they stay up-to-date with actual and potential changes to avoid committing violations.

Disposal: Many types of emission control require careful cleaning and disposal to ensure that the pollutants don’t inadvertently enter the air or water.

Policies and Regulations

Industrial air pollutants are subject to a number of regulations in the US, as well as in other countries, and regulation is a key driver of pollution control adoption. Here we will focus on the major US regulations. This list is not exhaustive but touches on the major focus points of US regulations. The EPA divides regulated pollutants into two categories: criteria pollutants and hazardous air pollutants.

Criteria pollutants – NAAQSs

The Clean Air Act, last amended in 1990, requires the EPA to set National Ambient Air Quality Standards for pollutants considered harmful to the environment and public health. These fall into two categories: primary standards are designed to provide public health protection, while secondary standards are designed to provide public welfare protection, which includes protections for visibility, animals, crops, other vegetation and buildings.

The EPA has set NAAQSs for six principal pollutants, called “criteria” pollutants. The standards are as follows: (Units of measure are either parts per million (ppm) by volume, parts per billion (ppb) by volume, or micrograms per cubic meter of air (µg/m3).) Air pollution control guide 2 Carbon monoxide: Primary standards only: 9 ppm measured over 8 hours, and 35 ppm measured over 1 hour. These standards may not be exceeded more than once per year.[37] In August 2011 the EPA issued a decision to retain these standards, although it made some changes to monitoring requirements.[38], [39]

Lead: For primary and secondary standards: rolling 3-month average, 0.15 μg/m3. These standards may not be exceeded.[40] EPA issued findings that seven states missed Clean Air Act deadlines for submitting plans, or elements of plans, for implementing EPA’s 2008 national air quality standards for lead.[41] In June 2013, the EPA issued a final rule establishing a new Federal Reference Method for state and local air monitoring agencies to use as one of the approved methods for measuring lead in total suspended particulate matter.[42]

Nitrogen dioxide: Primary standard: 1-hour, 100 ppb; 98th percentile, averaged over 3 years. Primary and secondary: annual, 53 ppb;actual mean.[43] On February 6, 2014, the EPA released its Draft Integrated Review Plan for the Primary NAAQS for Nitrogen Dioxide. On November 22, 2013, the EPA released the Integrated Science Assessment for Oxides of Nitrogen – Health Criteria – First External Review Draft. On March 12 and 13, 2014, the EPA’s Clean Air Scientific Advisory Committee Oxides of Nitrogen Primary NAAQS Review Panel was scheduled to meet in Durham, N.C. to peer review these two documents.

(Updated Feb. 25, 2014)

Sulfur dioxide: Primary: 1-hour, 75 ppb;99th percentile of 1-hour daily maximum concentrations, averaged over 3 years. Secondary: 3-hour, 0.5 ppm; not to be exceeded more than once per year.[44]

Ozone: Primary and secondary standard: 8-hour, 0.075 ppm.[45] The Obama administration proposed in January 2010 to tighten the 8-hour primary standard to a level in the range of 0.06-0.07 ppm, and to establish a seasonal secondary standard in the range of 7-15 ppm-hours.[46] But businesses and Republicans in Congress objected over economic concerns, and in September 2011 the White House shelved the plans.[47]

On July 23, 2013, a federal court rejected arguments that the current primary standard is either too weak or too strong, but said the EPA would have to reconsider the secondary standard for the pollutant[48] – a review that was already underway.

In January 2014, the EPA took the next step in its review by publishing several documents:

(The Federal Register notice of these publications is here.)

The draft policy assessment repeats the 2010 recommendation to tighten the standard to between .06 and .07 ppm.

On April 30, 2014, the US District Court for the Northern District of California found in favor of a motion by the American Lung Association, Sierra Club, NRDC and EDF, ordering that the EPA issue draft regulations by December 1 of this year and a final rule by October 1, 2015. 

In May 2014, it emerged that the EPA’s Clean Air Scientific Advisory Committee had apparently reached consensus that the .075 ppm standard was too weak. The committee is tentatively backing the draft policy assessment’s finding that a new standard could be set as low as .06 ppm.

See the committee’s draft letter of recommendation here. 

The panel warns that the draft letter does not represent an official recommendation, but the document does suggest which way future work on the ozone standard may be headed.

The panel will reconvene May 28.

(Updated May 15, 2014; previously updated Feb. 25, 2014)

Ozone implementation: On May 29, 2013, the EPA published a draft rule to address implementation requirements for the ozone standard, proposing several approaches. The EPA says the proposed rule would provide states with flexibility and help in meeting their Clean Air Act requirements.[49]

On September 19, 2013, the EPA issued a final rule that identified 2,3,3,3-tetrafluoropropene (also known as HFO-1234yf) as a chemical compound that will no longer be regulated as a volatile organic compound (VOC) under the Clean Air Act for purposes of meeting the national ambient air quality standards for ozone.

(Updated Feb. 25, 2014)

Particle pollution, PM2.5: For primary standards: annual, 12 μg/m3,annual mean, averaged over 3 years. For secondary standards: annual, 15 μg/m3,annual mean, averaged over 3 years. For primary and secondary standards: 24-hour, 35 μg/m3,98th percentile, averaged over 3 years.[50]

In January 2013 the EPA strengthened the NAAQS for PM2.5 to 12 µg/m3, down from 15 µg/m3 set in 1997.[51] (This guide originally reported the action as taking place in December 2012. The EPA did send the rule to the White House for review in that month, but it published the final rule on January 15, 2013.)

The final rule is available here.

The National Association of Manufacturers, US Chamber of Commerce and other groups tried to vacate the EPA’s decision to tighten the NAAQS, but in May 2014 the DC Circuit Court found for the EPA. The court decision is available here.

On January 4, 2013, the DC Circuit Court issued a decision finding fault with how the EPA issued rules for PM2.5, but the EPA said this decision did not affect its strengthening of the standard.[52]

In response to the DC Circuit Court’s January decision, on November 15, 2013, EPA proposed a rule to clarify PM2.5 implementation requirements to the states for 1997 and 2006 nonattainment areas. EPA proposed to classify areas designated nonattainment for the 1997 and/or 2006 PM 2.5 standards as moderate and to set a deadline of December 31, 2014 for states to submit necessary SIP elements (including NSR provisions). A fact sheet is available here.

(Updated May 13, 2014; previous update Feb. 25, 2014)

Particle pollution, PM10: The standard for primary and secondary, in place since 1997, is 150 μg/m3 over 24 hours, not to be exceeded more than once per year on average over 3 years.[53] In its December 2012 rulemaking, the EPA retained the existing standards for PM10.[54]

Other rules on criteria pollutants

Cross-State Air Pollution Rule: The EPA finalized this rule, on pollutants that cross state lines, in July 2011.[55] An appeals court declared the rule invalid in August 2012,[56] following a challenge by 16 states and a number of power companies.[57] On April 29, 2014, the US Supreme Court upheld the rule in a 6-2 decision. Read the decision here.

(Updated May 1, 2014)

The rule sets limits on sulfur dioxide and nitrogen oxide emissions from coal-fired plants in 28 states. When introducing the rule, the EPA estimated that the regulations would prevent up to 34,000 premature deaths. But power companies said they could not meet the EPA’s timeframe, or bear new equipment costs estimated at $800 million annually from 2014.

Hazardous air pollutants

The EPA is working to reduce releases of 188 pollutants classed as HAPs. These pollutants are known or suspected to cause cancer, other serious health effects (such as reproductive problems or birth defects) or negative environmental effects. Examples include dioxins, asbestos, toluene, cadmium, mercury, chromium, lead compounds, benzene, perchlorethlyene and methylene chloride.[58]

EPA regulations cover over 80 categories of major industrial sources, such as chemical plants, oil refineries, aerospace manufacturers, and steel mills, as well as categories of smaller sources, such as dry cleaners, commercial sterilizers, secondary lead smelters, and chromium electroplating facilities. It projects that these standards will cut annual air toxics emissions by about 1.5 million tons.[59] The EPA has established national emission standards for hazardous air pollutants (NESHAPS) requiring the use of maximum achievable control technology (MACT) for a number of industries. [60]

Mercury and Air Toxics Standards: Finalized in April 2013, these are the first federal standards requiring power plants to limit their emissions of toxic air pollutants like mercury, arsenic and metals.[61] The rules apply to coal- and oil-fired plants. The rule sets mercury emissions at 0.003 pound/GWh. For new coal-fired plants, the agency sets the standard for filterable particulate matter emissions at 0.09 pound/MWh, hydrogen chloride at 0.01 pound/MWh, sulfur dioxide at 1.0 pound/MWh and lead at 0.02 pound/GWh.[62]

On April 15, 2014, the US Court of Appeals for the District of Columbia Circuit upheld MATS against a challenge by industry groups and some states, who said the rules were too stringent. Read the decision here. In a dissenting opinion, Judge Brett Kavanaugh said the EPA had not even considered the cost of the rules, which are estimated at $9.6 billion.

(Updated May 1, 2014)

Toxics Release Inventory: This EPA program tracks the management of over 650 toxic chemicals, most of which cause cancer or other chronic human health effects; significant acute human health effects; or significant environmental effects. Facilities that manufacture, process or otherwise use these chemicals in amounts above established levels must submit annual TRI reports indicating how much of each chemical is released and how much is managed through recycling, energy recovery and treatment.[63]

Companies must report if: they are in a specific industry sector, such as manufacturing, mining or electric power generation; have 10 or more full-time employees; and either a) manufacture or process more than 25,000 lbs. of a TRI-listed chemical per year or b) use more than 10,000 lb. of a listed chemical in a year.[64]

Cross-cutting regulations

The EPA has also issued rules that govern both criteria and hazardous air pollutants, within certain sectors. These include:

Portland Cement MACT standards: In December 2012, the EPA issued final amendments to the 2010 clean air standards for the cement manufacturing industry, including emissions of mercury, hydrochloric acid and particulate matter. The final air toxics rule retains emission limits for mercury, acid gases and total hydrocarbons from the 2010 rules, along with retaining requirements that kilns continuously monitor compliance with limits for mercury, total hydrocarbons and particulate matter.[65]

Boiler standards: In December 2012, the EPA released its final Clean Air Act standards for industrial boilers and incinerators, aimed at reducing toxic air pollution including mercury, sulfur dioxide, hydrogen chloride and particulates, but said these will apply to less than 1 percent of those machines. The standards now cover only the highest emitting boilers and incinerators, typically operating at refineries, chemical plants and other industrial facilities. The other 99 percent of the approximately 1.5 million boilers in the US either aren’t covered by the rules because they burn clean natural gas at area source facilities and emit little pollution, or can meet the new standards by conducting periodic maintenance or regular tune-ups, according to the EPA.

Standards and Certifications

The air pollution control market is driven mostly by regulations, not by voluntary standards. However, it’s worth noting that several of the pollutants discussed in this report are greenhouse gases, and subject to GHG reporting guidelines. For example, the Greenhouse Gas Protocol covers accounting and reporting of carbon dioxide, methane, nitrous oxide, hydroflurorocarbons, perfluorocarbons and sulfur hexafluoride.[66]

The protocol now requires nitrogen trifluoride (NF3) to be included in GHG inventories under the Corporate Standard, Value Chain (Scope 3) Standard and the Product Standard. NF3 is primarily produced in the manufacture of semiconductors and LCD panels, and certain types of solar panels and chemical lasers.[67] Air pollution control guide 3

Latest Developments in Air Pollution Controls

US and Global Markets

Air quality management in the US has improved considerably over the past several decades. Since 1970, industrial processes have found reductions in emissions of a number of pollutants, including carbon monoxide and sulfur dioxide (see chart, previous page).

VOC emissions have seen a few spikes but fallen significantly since 1970. PM10 has also seen a long-term reduction although it is up on 2000 levels. Nitrogen oxides, on the other hand, after an initial drop back in the early 1970s, have almost returned to 1970 levels. The EPA’s data on ammonia and PM2.5 doesn’t go back as far, but since 1990 industry has found significant reductions in these areas.

Looking specifically at the electricity sector, in 2011 power plant NOx and SO2 emissions were 70 percent and 72 percent lower than in 1990, when Congress passed major amendments to the Clean Air Act. But the emissions reductions are largely due to increased use of natural gas and growing reliance on renewable energy – rather than to emissions controls. To find these reductions and cope with regulatory pressures, companies are spending heavily on emissions control equipment.

The McIlvaine Company projects that the world market for air filtration and air pollution control will reach $44.39 billion this year, with the power sector spending the lion’s share at over $20 billion (see chart, next page).[68] China will be a major player, spending just under $19 billion on air pollution control systems, consumables and instrumentation this year.[69]

As of November 2012, power plants around the world had 968 air pollution control projects underway and due to be completed in 2013. Over half are in Asia.[70] The most popular control devices for new power plants are scrubbers, selective catalytic reduction systems and fabric filters, while older plants are being retrofitted with a variety of SO2, NOx, and mercury reduction controls.

Several other industries, including stone, metals, incinerators, steel, chemicals and wastewater, as well as the commercial sector, will spend over $1 billion each on air pollution control this year. McIlvaine notes that cement plants need expensive particulate control equipment, scrubbers and non-selective catalytic reduction equipment. Municipal wastewater plants, meanwhile, are buying activated carbon filters, biofilters and chemical scrubbers.[71] In 2013, McIlvaine expects the air and gas measurement market to reach $4.5 billion. This includes not just measurement of emissions into surrounding air, but also indoor air, process air and so on.[72] Air pollution control guide 4

Adoption by Businesses

Owens Corning: See Q&A.

Alcoa: The company says its In-Duct Scrubber, under construction as part of a commercial-scale demonstration project at the company’s baked anode and calcined coke facility in Lake Charles, La., will remove up to 90 percent of sulfur dioxide, particulate matter and hydrogen fluoride emissions at the plant. Alcoa expects commissioning and on-site testing of the project to be complete in August 2014.[73]

Doe Run: In preparation for EPA sulfur dioxide standards, the company’s Buick Resource Recycling Division began installing technology in 2011 that decreases SO2 emissions. Meanwhile, the company’s Primary Smelting Division has cut lead concentrations in ambient air around its Herculaneum, Mo., smelter. As of November 2011, the smelter reduced the rolling three-month average for ambient air lead concentration to below 0.6 micrograms per cubic meter of air – a 25 percent reduction from the 2011 average level.[74]

AEP: The power company reduced its total SO2 emissions by 52 percent between 2000 and 2011, from 1.1 million tons to just over half a million tons, primarily by adding scrubbers to approximately 7,900 MW of coal-fired generating capacity, according to a report by M.J. Bradley & Associates, sponsored by Ceres, NRDC, Entergy Corporation, Exelon, Pacific Gas and Electric Company, PSEG, Tenaska and Bank of America.[75]

Duke Energy: The company is spending $400 million to install two selective catalytic reduction units as well as dry sorbent injection systems at its coal-fired Cayuga power plant, on top of the roughly $500 million it spent on two scrubbers for the plant in 2008. The company is carrying out the SCR project to comply with the Mercury and Air Toxics Standard. Since 1990, Duke’s sulfur dioxide emissions have fallen more than 84 percent and nitrogen oxide more than 73 percent, through control equipment, use of low-sulfur fuel, and changes to the company’s fuel mix.[76] Air pollution control guide 5

The Future of Air Pollution Controls


Next year, The McIlvaine Company predicts a $48.9 billion world market for air pollution control, with the biggest portion – $11.7 billion – going into fabric filter bags and systems (see chart, above). Power plants will account for more than 50 percent of the total air pollution market, and the chemical, refinery, oil and gas, steel, mining and cement industries will also make pollution control purchases.

By 2020, McIlvaine expects China to have four times the coal-fired capacity of the US, driving huge growth in the selective catalytic converter market there. The country is also upgrading existing power plants to met NOx and particulate limits.

While the US industry spends millions of dollars on lawsuits to contest controls for about 50,000 MW, McIlvaine notes, “China is stepping up to the plate and committing to 1,100,000 MW of SCR over the same timeframe.”[77] India will be a strong pollution control market, as it is also building a sizeable number of new coal-fired power plants and is addressing pollution from steel mills, cement plants and refineries. Vietnam and Indonesia will also be major buyers in the market.[78]

Air Pollution Controls: What does all this mean?

Air emissions control is an essential component of sustainability and compliance for companies in many sectors. Control technology is evolving as governments push for tighter and tighter emissions limits. Companies must stay on top of evolving regulations to predict future emissions control needs, which could be expensive.

[1] CED Engineering, Selecting the Best Air Pollution Control Strategy.
[3] CED Engineering, Selecting the Best Air Pollution Control Strategy.
[5] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[7] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[8] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[10] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[15] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[17] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[19] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[21] Air and Waste Management Association, Fact Sheet: Air Pollution Emission Control Devices for Stationary Sources.
[31] CED Engineering, Selecting the Best Air Pollution Control Strategy.
[32] CED Engineering, Selecting the Best Air Pollution Control Strategy.
[33] Gene Anguil of Anguil Environmental Systems, Emission Control Technology. Updated chapter, originally from Odor and VOC Control Handbook, Harold J. Rafson, Ed.

Category: , Organizations: Companies: , , , , , , , , , , , , , , , , , , , , , , , , , Policies: