Integrated cement plants are recognised as a source of undesirable airborne emissions. In an attempt to moderate the effects of these on the environment and local populations, local, regional and national governments legislate maximum permissable limits for a multitude of emission types. As with many other aspects of cement manufacturing, there are variations between jurisdictions and even individual plants. Here, Global Cement attempts to untangle the web of emissions regulations for four key pollutant categories: sulphur dioxide (SO2), nitrogen oxides (NOx), mercury (Hg) and dust / particulate matter (PM).
As in other industries, the latter part of the 20th Century saw cement plants start to consider their effects on the environment and local populations far more than before. The motivating factors for this include: pressure from local population groups; internal sustainability policies; rising costs of fuels and/or raw materials and; direct legislation from governments.
A cynic might point out that it is ultimately legislation that drives down emissions of key pollutants in the cement industry. This is not to say that some plants don't voluntarily reduce emissions. Indeed, more and more cement producers are trying to stay ahead of the legislation curve. However, such actions can frequently be traced back to concern for public opinion and/or anxiety over future regulations.
In the global cement news we often hear of different cement plants preparing for or bemoaning new emissions limits. However, looking for concise emissions limits online leaves a very complicated picture. Emissions in the EU, for example, are governed centrally, unless a particular country has a permit to exceed the limit for a given type of emission or decides nationally to have harsher limits on some emissions classes. On top of this there may be additional restrictions for individual plants based on their unique circumstances. Elsewhere, there are differences depending on fuels, kiln type, raw materials, plant age, plant size and other factors. What follows is Global Cement's attempt to see through the smog.
Sulphur dioxide - SO2
Formula: | SO2 |
Molecular weight: | 64.61g/mol |
Melting point: | -72°C |
Boiling point: | -10°C |
Sulphur dioxide - Introduction
Airborne SO2 reacts with water vapour to form sulphuric acid (H2SO4). This contributes to acid rain, negatively affecting water sources, forests and crops. SO2 is also a potent greenhouse gas.
SO2 is emitted from cement plants via two main processes: 1. Sulphite impurities in the limestone and other raw materials; 2. Elemental sulphur contained in fuels, particularly coal and some alternative fuels.
SO2 emissions have risen significantly since the onset of the Industrial Revolution.2 In 2014, 73% of the emissions come from conventional coal power plants, with the remainder emitted from other industrial processes, including the cement industry.3
Although more developed economies have reduced their emissions of SO2 in recent years in line with concerns over acid rain, emissions from Europe, the (former) Soviet Union and North America have been more than replaced by those from other parts of the world.2 These are mainly East Asia (predominantly China) and India. It is possible that, with China now taking a more environmentally-conscious stance, growth in SO2 emissions from that country will tail off. Emissions levels from other emerging economies will determine whether or not global SO2 emissions rise or fall in the coming decades.
Sulphur dioxide - Emissions limits
A summary of SO2 emissions limits from cement plants can be seen in Table 1. Across the countries that information has been received for, most national limits for SO2 are in the region of 200 - 500mg/Nm3. However, there are some significantly higher limits in developing nations. Particularly high levels are permitted in Nigeria (2000mg/Nm3) and Pakistan (1700mg/Nm3). India has some state-level limits for this pollutant but given its high permitted levels for PM and NOx it is unlikely that these are particularly stringent.
Most of the lowest limits for SO2 emissions are seen in mature economies where environmental pressures have come to bear on industrial activities. The highly-advanced German cement inudstry has the lowest permitted limit for SO2 at 50mg/Nm3, a factor of 40 lower than is permitted in Nigeria. Norway (400-500mg/Nm3) and Austria (350mg/Nm3) have moderately stringent limits. Other nations with relatively low emissions standards for SO2 include Egypt (400mg/Nm3), Colombia (200-550mg/Nm3 depending on fuel type) and South Africa (50 - 250mg/Nm3).
An example of an EU member state legally exceeding EU emissions limits can be seen in the case of the UK, which has high limits of 600 - 2500mg/Nm3 in cases where there are unavoidably high levels of sulphate or sulphur in the kiln feed. This is higher than the permitted level in Pakistan.
China's limit for SO2 emissions from cement plants is a relatively stringent 200mg/Nm3. This certainly flies in the face of the stereotypical image of Chinese industrial facilities as being highly-polluting. The limit, imposed only since 2008, was the direct result of top-down influence from the Chinese government to shut down the most highly-polluting facilities in all types of industry. The new emissions standard for Chinese cement SO2 emissions limits for the period after 1 March 2014 is not yet known.
The USA is the only country to regulate its emissions limits in non-SI units, with its Portland Cement Maximum Achievable Control Technology (PC MACT) regulations stating a limit of 0.4lb/ton of clinker produced. This is proposed for implementation on 9 September 2015. This approximately corresponds to 0.2kg/t of clinker. Without knowing the total amount of gas emitted from the stacks, a parameter that will change depending on the weather, the fuel, the clinker factor and the type of kiln being used, it is not possible to transfer this into a mg/Nm3 rate as used in other jurisdictions.
US cement plants' SO2 emissions are currently limited by the Clean Air Act, which covers many sources of air pollution in the US. In reality, many cement producers in the United States are already preparing for the PC MACT SO2 regulations, having been planning for more stringent limits that were being discussed previously.
COUNTRY / REGION | SO2 LIMIT (mg/Nm3) | |
Australia (New South Wales, AF)1 | 50 | |
Australia (Victoria)1 | 250g/min | |
Austria4 | 350 | |
Bolivia5 | 600 | |
Brazil6 | By state | |
Canada7 | By province | |
Chile (AF plants only)8 | None | |
China (2008 regs.)9 | 200 | |
Colombia (Conventional fuels)10 | 550 | |
Colombia (Non-hazardous AF)10 | 200 | |
Colombia (Hazardous AF)10 | 500 | |
Egypt11 | 400 | |
European Union (EU)12 | <50 - 400 | |
Germany (Current)13 | 50 | |
Germany (From 1 Jan 2016)13 | 50 | |
India14 | Some State limits | |
Indonesia (Proposed)15 | 800 (400) | |
Lebanon (as SOx)16 | 850 (old) / 800 (new) | |
Nigeria (New plants)17 | 2000 | |
Nigeria (Existing plants)17 | 2000 | |
Norway (Norcem Brevik)18 | 500 | |
Norway (Norcem Kjøpsvik)18 | 400 | |
Pakistan19 | 1700 | |
Russia20 | By plant | |
Saudi Arabia21 | 365 | |
S Africa (AF, Built post-2004)22 | 50 | |
S Africa (AF, Built pre-2004)22 | 250 | |
S Africa (Built post-2004)22 | 250 | |
S Africa (Built pre-2004)22 | 250 | |
Switzerland23 | 500 | |
Trinidad & Tobago (Proposed)24 | 1000 | |
Turkey (Conventional fuel)25 | 300 | |
UAE26 | 125μg/Nm3 * | |
UK27 | 200 (600 - 2500 for High S) | |
UK (One particular plant)28 | 1760 (400 proposed) | |
USA (From 9 September 2015)29 | 0.4lb/ton (clinker) |
Above - Table 1: Selected current and future SO2 emission standards by country. Most limits are in the range of around 500mg/Nm3. Limits normalised to dry exhaust gas at 1atm pressure, 273K with 10% O2 as a reference unless stated otherwise.
AF = Alternative fuels.
Notes: Australian limits are set at state level.
Canadian limits are by province and were unavailable prior to publication. Only plants using AF are regulated in Chile and all plants use some form of AF.
Colombian limits for plants burning non-hazardous AF are more stringent than for those burning hazardous AF. The country uses 11% O2 in its reference criteria instead of 10%.
Indonesian regulations are currently under discussion.
Saudi Arabian regulations were related to all industrial plants.
South African plants are regulated differently according to date of construction and fuel type.
Russia operates on a plant-by-plant basis.
*UAE data as supplied by cement producer. Global Cement is of the opinion that this is limit could infact be 125mg/Nm3.
UK regulations permit higher levels due to high levels of sulphites in the raw material and/or high levels of sulphur in fuels.
Source: Local cement producers and associations.
Sulphur dioxide - Future trends
It is likely that, as other economies develop, there will be increased pressure on cement plants (and other industrial sites) to reduce SO2 emissions in these regions. As well as lower and lower limits in European countries, China is reducing its SO2 limits. Other countries will follow as local populations become more vocal against emissions. For abatement technology specialists there are considerable opportunities in India and parts of Africa, as well as in the United States.
Sulphur dioxide - Abatement methods
Amid ever-decreasing SO2 emissions limits, cement plants can employ a number of processing and technical measures to reduce their emissions. Firstly, producers can move to low-sulphur coal sources or move away from using coal as a primary fuel. Some alternative fuels, for example tyres, can also include high levels of sulphur impurities. Some limestone sources can also contain high levels of sulphite impurities, which convert to sulphates in the presence of oxygen and heat. Coal cleaning technologies, including sulphate adsorbtion and absorbtion, are also possible ways to reduce ingoing sulphur-based impurities but can be expensive to run.
If sulphurous inputs are unavoidable, two main abatement technologies are available, which both come under the heading of flue-gas desulphurisation: limestone forced oxidation scrubbers and lime spray dryer scrubbers. These create gypsum as a byproduct, which can be used as an onsite source of gypsum for the preparation of final cement blends.
Nitrogen oxides - NOx
Formula: | NO / NO2 (represented as NOx) |
Molecular weight: | 30.01g/mol / 46.00g/mol |
Boiling point: | -152°C / 21.2°C |
Nitrogen oxides - Introduction
In the atmosphere, nitric oxide (NO) and nitrogen dioxide (NO2) are in equilibrium via a reaction involving ozone (O3). As such they are both ozone depleters. Both gases are precursor compounds to nitric acid (HNO3), which contributes to acid rain, negatively affecting water sources, forests and crops.
NOx results from the combustion of nitrogen in oxygen at high temperatures and from nitrogen bound to fuels used. As such, it is not unique to cement production.
NOx emissions have been on the rise in most world regions in recent decades, rising by around 60% since 1970 from ~75Mt/yr to ~120Mt/yr in 2005. The main historic source (~2Mt/yr) was North America (mainly the US), although China has now risen to parity. Trade is also a major NOx source (~17Mt/yr), because it is emitted from ships and aircraft.
The Americas, Africa and Europe generally had the same combined NOx emissions in 2005 as in 1975 (47-48Mt/yr). As well as China, much of the recent additional NOx emissions have come from the rest of Asia, India, the Middle East and from shipping.
Nitrogen oxides - Emissions limits
A summary of NOx emissions limits from cement plants can be seen in Table 2. Across the countries that information has been received for, most national limits for this pollutant are in the region of 500 - 1000mg/Nm3.
NOx is the least stringently limited pollutant among those analysed here. The range of maximum permissable emissions is broad, stretching from 200mg/Nm3 for some sets of conditions within the EU, to 2500mg/Nm3 for older Lebanese plants, a factor of 12.5.
Again, the United States bucks the SI-unit trend with a limit of 1.5lb/ton of clinker (~0.75kg/t), which, like the incoming SO2 limit will start on 9 September 2015. Brazil has no limit for NOx emissions from cement plants (or for SO2 emissions). Other administations with relatively low NOx limits include new plants in China (400mg/Nm3) and certain types of kiln/fuel combination in Pakistan (400mg/Nm3).
COUNTRY / REGION | NOx LIMIT (mg/Nm3) |
Australia (New South Wales, AF) | 800 |
Australia (Victoria) | 3600g/min |
Austria | 500 |
Bolivia | 1800 |
Brazil | By state |
Canada | By province |
Chile (AF plants only) | None |
China (2008 regs.) | 800 |
China (2013 regs., Existing plants) | 400 |
China (2013 regs., New plants) | 400 |
Colombia (Conventional fuels) | 800 |
Colombia (Non-hazardous AF) | 200 |
Colombia (Hazardous AF) | 550 |
Egypt | 600 |
European Union (EU) | 200 - 450 |
Germany (Current) | 500 |
Germany (From 1 June 2018) | 200 |
India (Proposed by industry) | 1200 (existing), 800 (new) |
India (Proposed by authorities) | 1000 (existing), 600 (new) |
Indonesia | 1000 |
Indonesia (Proposed) | 800 |
Lebanon | 2500 (old), 1500 (new) |
Nigeria (New plants) | 600 - 800 (fuel dep.) |
Nigeria (Existing plants) | 1200 (old or wet) |
Norway (Norcem Brevik) | 800 |
Norway (Norcem Kjøpsvik) | 800 |
Pakistan | 400 - 1200 (fuel dep.) |
Russia | By plant |
Saudi Arabia | 600 (1hr average) |
S Africa (AF, Built post-2004) | 2000 |
S Africa (AF, Built pre-2004) | 1200 |
S Africa (Built post-2004) | 1500 |
S Africa (Built pre-2004) | 2000 |
Switzerland | 800 |
Trinidad & Tobago (Proposed) | 500 (as NO2) |
Turkey | 1200 |
Turkey (From 2015) | 400 |
UAE | 400 |
UK | 900 |
UK (One particular plant) | 800 (500 future) |
USA (from 9 September 2015) |
1.5lb/ton clinker |
Above - Table 2: Selected current and future emissions standards for NOx by country. The limits typically fall in the 400 - 800mg/Nm3 band. Limits normalised to dry exhaust gas at 1atm pressure, 273K with 10% O2 as a reference unless stated otherwise.
Notes: Australian limits are set at state level.
Canadian limits are by province and were unavailable prior to publication.
Only plants using AF are regulated in Chile and all plants use some form of AF.
Colombian limits for plants burning non-hazardous AF are more stringent than for those burning hazardous AF. The country uses 11% O2 in its reference criteria instead of 10%.
Indian cement producers are in discussion with environmental authorities regarding future NOx limits, which will vary depending on the ages of the plant. Global Cement infers that the split between 'existing' and 'new' plants will be made when limits are set.
Indonesian regulations are currently under discussion.
Pakistan's NOx limits are dependent on fuel type:
Gas = 400mg/Nm3,
Oil = 600mg/Nm3,
Coal = 1200mg/Nm3.
Russia operates on a plant-by-plant basis.
Saudi Arabian regulations were related to all industrial plants.
South African plants are regulated differently according to date of construction and fuel type.
Source: Local cement producers and associations.
Nitrogen oxides - Future trends
In 2018, Germany will go to a NOx limit of just 200mg/Nm3. There is also discussion in Trinidad & Tobago regarding the introduction of its NOx limit (it currently has none), but at a higher level (500mg/Nm3). Meanwhile, Turkey will limit its cement industry to a maximum of 400mg/Nm3 NOx from 2015.
While India currently has no NOx emission limits for its industry, there is ongoing discussion regarding these. Industry and enforcement authorities are in disagreement over the levels that NOx emissions should be set at, with a 200mg/Nm3 disparity between what the authorities want and the level that the industry is currently happy to be bound to. It is possible that these discussions will come to agreement at some point in 2014.
Going forward, the onset of new regulations for NOx in the jurisdictions mentioned above are a sign of the continued drive towards lower limits across the world. With Germany often a leader in terms of environmental awareness in the industry, it is possible that its 2018 reduction to 200mg/Nm3 will trigger a new round of reductions in other regions towards the latter half of the current decade. The reality is that most European plants are already operating well within the limits imposed for NOx. This will increasingly be reflected in the regulations of the future.
Nitrogen oxides - Abatement methods
With respect to NOx abatement, there are two main technologies available: Selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). Both of these involve the injection of ammonia (NH3) into the waste gas. In the presence (SCR) or absence (SNCR) of a catalyst, the NOx is selectively reduced to nitrogen (N2) as well as water (H2O). It is not really feasible to reduce NOx emissions by selection of input materials as these are rarely the source of emissions.
Mercury - Hg
Formula: | Hg |
Molecular weight: | 200.59 g/mol |
Melting point: | -39°C |
Boiling point: | 357°C |
Mercury - Introduction
The only metal that is a liquid at room temperature and pressure, mercury and many of its compounds are extremely toxic. This is in part due to its inherent chemistry as a heavy metal and is also due to it being a liquid. Methyl-mercury is a persistent and very toxic bio-accumulator, particularly in aquatic life forms and can pass into the human populace with extremely damaging consequences.
Mercury enters the cement production process via: 1. Impurities in the limestone raw material; 2. Minor impurities in fuel sources like coal and selected alternative fuels. Mercury becomes concentrated within cement plants but a portion is constantly emitted. Spikes in emissions occur upon start-up and shutdown, especially when the shutdown is unexpected.
Anthropogenic atmospheric mercury emissions have been on an inexorable rise since the start of the modern industrial era, although natural peaks from volcanic eruptions have occurred throughout the millenia. In 2010 it is estmated that around 1960t of mercury entered the atmosphere.
East and Southeast Asia accounted for 40% (777t) of the global total, with China contributing about three quarters of these emissions. This represents around a third of all emissions. Sub-Saharan Africa was the second most-prolific emitter, partly due to artisanal gold smelting, giving rise to 16% (316t) of mercury emissions in 2010. South America was third (13%, 245t), South Asia fourth (7.9%, 154t), with Europe and CIS fifth (6%, 115t).
This bias towards higher emissions from developing regions is a result of their higher populations and rapidly-growing industrial activity as well as a strong emphasis on mercury emission abatement from environmental action groups in more mature markets.
Mercury - Emissions limits
Similarly to NOx and SO2 emissions limits, more developed nations generally have more stringent emissions than developing economies. With a couple of notable exceptions, mercury emissions from cement plants are regulated at 0.05-0.10mg/Nm3 (in those jurisdictions where they are restricted). This range applies to emissions from cement plants in places as diverse as Europe, Egypt, Brazil, Nigeria, Australia, Chile and South Africa (See Table 3).
Pakistan (10mg/Nm3), Colombia (0.03mg/Nm3) and Germany (0.03mg/Nm3) represent the extremes in mercury emissions limits. However, there are many countries that have no limit for mercury emissions at all. These include the major markets of China, India, Turkey (for non-AF burning plants), the UAE, Saudi Arabia and Lebanon. China is in the process of implementing new regulations, effective 1 March 2014.
COUNTRY / REGION | Hg LIMIT (mg/Nm3) |
Australia (New South Wales) | 0.10 |
Australia (New South Wales, AF) | 0.05 |
Australia (Victoria) | 0.25g/min |
Austria | 0.05 |
Bolivia | None |
Brazil | 0.05 |
Canada | By province |
Chile (AF plants only) | 0.10 |
China | None |
Colombia (Conventional fuels) | None |
Colombia (Non-hazardous AF) | 0.03 |
Colombia (Hazardous AF) | 0.05 |
Egypt | 0.05 |
European Union (EU) | 0.05 |
Germany (Current) | 0.03 |
Germany (From 1 June 2018) | 0.02 |
India | None |
Indonesia (AF plants only) | By plant |
Lebanon | None |
Nigeria | 0.05 |
Norway | 0.05 |
Pakistan | 10.0 |
Russia | By plant |
Saudi Arabia | None |
South Africa | 0.05 |
Switzerland | 0.10 |
Trinidad & Tobago (Proposed) | 0.05 |
Turkey | None |
Turkey (AF) | 0.05 |
UAE | None |
UK | 0.05 |
USA (from 9 September 2015) | 55lb/Mt (old) / 21lb/Mt (new) |
Above - Table 3: Selected current and future emissions standards for mercury by country. Most limits fall into a range of 0.05 - 0.1mg/Nm3. Limits normalised to dry exhaust gas at 1atm pressure, 273K with 10% O2 as a reference unless stated otherwise.
AF = Alternative fuels.
Notes: Several countries have different mercury emissions limits depending on whether or not a plant uses alternative fuels. This is seen in the case of Australia and Colombia, which are more stringent for AF than for conventional fuels. Colombia uses 11% O2 in its reference criteria instead of 10%.
Brazil uses 7% O2 in its reference criteria for mercury.
Source: Local cement producers and associations.
Mercury - Future trends
As with the other emissions classes in this review, limits for mercury emissions from cement plants are on a downward trend.
From 1 January 2016 Germany will reduce its legal limit for mercury emissions from cement plants down to 0.02mg/Nm3. This will make it the most stringent regulator of mercury emissions in the global cement industry. As has been the case in other environmental areas, it is possible that this shift in Germany could spread across Europe. The standard 0.05mg/Nm3 limit could suddenly look old when the new German requirement is introduced.
Mercury - Abatement methods
In the face of increasing limits on mercury emissions, cement plants can take two approaches to reduce their mercury emissions. Firstly, careful selection of input materials, specifically limestone and fuels, can reduce the quantities entering the system. Secondly mercury vapour and compounds can be absorbed onto carbon dust in the stack. The dust is collected in an electrostatic precipitator prior to processing.
Dust / Particulate matter - Introduction
Dust is emitted from storage, crushing, grinding and pyroprocessing in cement plants. It is the industry's most obvious pollutant, since you can actually see it. It can cause respiratory problems. Some of the earliest cement plant emission regulations were for dust. The German Cement Association (VDZ) set up a dust committee as early as the 1930s.
As well as being the first emission type that was targeted by those outside the industry, cement companies in developing markets often target dust as their first pollutant to remove from the gas stream. Abatement technologies are well developed for dust, which often allows rapid installations. There is the potential to rapidly reduce emissions.
The term particulate matter (PM) describes solid material that is suspended in the air, regardless of its origin. Covering a very wide diameter range, from less than 0.01μm (eg: virus, tobacco smoke) to 10-100μm (dust, soot, ash), PM is broken down into classes by diameter.
The two classes of PM of most relevance to the cement industry are PM2.5 (a diameter lower than 2.5μm and PM10 (a diameter lower than 10μm). PM10 accumulates in the lungs and PM2.5 can enter the blood-stream. Both classes are potential carcinogens. Cement plants emit PM due to ash formation and may also emit salts and heavy metal PM.
Some diameters of cement dust particle can be classed as PM10, meaning that PM and dust limits frequently overlap in the cement industry.
Dust and particulate matter - Emissions standards
Dust and PM emissions are not as frequently regulated as SO2, NOx or mercury. It is possible that this is because cement plants are dustier than other industrial installations of a similar size and therefore cannot be easily covered under more general industrial regulations. Cement-specific regulations appear to trail behind more general ones.
As cement dust is essentially large particulate matter, different jurisdictions often combine them as a single formal pollutant class or legislate formally against just one as a proxy for the other. In Bolivia the two are mandated together under the term 'total solid particles.'
Most of the countries in this research for which there are cement-specific limits for dust are <100mg/Nm3, with Nigeria and Oman at the top of this range (See Table 4). However, Bolivian (300mg/Nm3 (for total solid particles), old Lebanese (250mg/Nm3) and some Turkish (<120mg/Nm3) facilities are limited less strongly. These countries have dust emissions limits around 10-30 times higher than those with the lowest permitted levels of dust. Austrian and German plants are both restricted to 20mg/Nm3 and plants in the UAE are limited to just 15mg/Nm3.
Most PM limits are <100mg/Nm3 although there are some substantially higher permitted levels in India (200 - 400mg/Nm3), Pakistan (300mg/Nm3) and for some Colombian plants (<250mg/Nm3). The lowest limits found are also in Colombia, for plants that burn non-hazardous alternative fuels (10mg/Nm3) and Egypt (10mg/Nm3). Other relatively low limits are set in New South Wales, Australia (30mg/Nm3), Chile (50mg/Nm3), China (50mg/Nm3) and for South African cement plants built after 2004.
Australia has an interesting methodology for dust emissions limits. It stipulates that no more than four grammes of dust must settle on a given square metre at the plant boundary in any given month. This is presumably aimed at developing dust limits that more closely relate to the perceptions of local residents and may therefore not include airborne emissions that are carried far from the plant. It is unfortunately not possible to convert the Victoria, Australia or US PM limits into mg/Nm3 levels without first knowing the mass of gas evolved from the plant(s) being regulated.
There are several countries for which no dust emission limits could be found, as evidenced by the number of countries not included in Table 4 compared to the other tables. Countries for which a lack of limit was positively identified are all in developing regions: South and Central America (Trinidad & Tobago, Colombia and Chile); Asia (Pakistan) and; Africa (South Africa).
COUNTRY / REGION | DUST LIMIT (mg/Nm3) |
Australia (New South Wales, AF) | 4g/m2/month at the plant boundary |
Australia (Victoria) |
4g/m2/month at the plant boundary |
Austria | 20 |
Bolivia | 300 (Total solid particles) |
Chile | None |
China | None |
Colombia | None |
Egypt | 100 (old), 50 (new) |
Germany | 20 (10 from 1 January 2016) |
Indonesia | 80 (50 Proposed) |
Lebanon | 250 (old), 50 (new) |
Nigeria | 100 |
Norway | 30 |
Oman | 100 |
Pakistan | None |
Russia | By plant |
South Africa | None |
Switzerland | 20 |
Trinidad & Tobago (Proposed) | None |
Turkey | 50 - 120 |
UAE | 15 |
UK | 30 |
UK (One particular plant) | 30 (10 - 20 Proposed) |
Above - Table 4: Selected current and future emissions standards for dust by country. Limits normalised to dry exhaust gas at 1atm pressure, 273K with 10% O2 as a reference unless stated otherwise.
AF = Alternative fuels.
Notes: Australia regulates the rate of dust deposited at the plant boundary.
Bolivia includes dust and particulate matter together under the classification 'total solid particles.'
The cut-off date between 'old' and 'new' Egyptian and Libyan plants is unclear.
Germany will have the lowest dust emissions limits for cement plants in 2016.
Russia operates on a plant-by-plant basis.
In Turkey dust emissions are limited according to the type of abatement system used:
ESP (pre-1993) = 120mg/Nm3;
Filters (pre-1993) = 75mg/Nm3;
Post 1993 = 50mg/Nm3.
Source: Local cement producers and associations.
COUNTRY / REGION | PM LIMIT (mg/Nm3) | |
Australia (New South Wales) | 95 | |
Australia (New South Wales, AF) | 30 | |
Australia (Victoria) | 1155g/min | |
Bolivia | 300 (Total solid particles) | |
Brazil | 70 | |
Canada | By province | |
Chile (AF plants only) | 50 | |
China | 50 | |
Colombia (Conventional fuels) | 150-250 (wet) / 150 (dry) | |
Colombia (Non-hazardous AF) | 10 | |
Colombia (Hazardous AF) | 50 | |
Egypt | 10 | |
India (<200t day) | 400 | |
India (>200t/day) | 250 | |
Indonesia (AF) | By plant | |
Lebanon | None | |
Nigeria | 50 (old) / 100 (new) | |
Pakistan | 300 | |
Russia | By plant | |
Saudi Arabia (PM10) | 340 | |
S Africa (AF, Built post-2004) | 30 | |
S Africa (AF, Built pre-2004) | 80 | |
S Africa (Built post-2004) | 50 | |
S Africa (Build pre-2004) | 100 | |
Trinidad & Tobago (Proposed) | 100 | |
Turkey | 100 | |
UAE | 100μg/Nm3 | |
USA | 0.07lb/ton of clinker |
Above - Table 5: Selected current and future emissions standards for PM by country. Limits normalised to dry exhaust gas at 1atm pressure, 273K with 10% O2 as a reference unless stated otherwise.
AF = Alternative fuels.
Notes: Australia regulates by State and fuel type.
Bolivia includes PM and dust together under the classification 'total solid particles.'
Brazil uses 11% O2 in its reference criteria for this emission class.
Canada regulates PM by Province.
Colombia regulates PM by kiln type and fuel type, with hazardous AF-using plants regulated less stringently than non-hazardous AF-using plants. The country uses 11% O2 in its reference criteria instead of 10%.
India regulates on plant size.
The date of the switch-over between 'old' and 'new Nigerian plants is unclear.
Saudi Arabia legislates PM10 emissions. Limit seen is for general industrial installations.
Russia operates on a plant-by-plant basis.
Source: Local cement producers and associations.
Dust and particulate matter - Future trends
As with other limits seen in this research, dust emission limits are on a downward trend. On 1 January 2016 Germany will lower its 20mg/Nm3 limit to just 10mg/Nm3 to have the lowest dust limit for cement producing facilities in the world. As EU legislators have looked to Germany in the past, it is possible that this trend may repeat in the future.
Elsewhere, discussions are ongoing in India regarding applying emission limits in principle in 2014 and Indonesia is targeting a reduction from 80mg/Nm3 to 50mg/Nm3, although its changes are currently at the proposal stage. Countries that have a split between emissions limits for older and newer facilities will see the effective dust emission load reduce with time as a result of the decommissioning of older capacity.
No evidence of cement-specific dust emission limits in China prior to 1 March 2014 were found. In a country that has placed such emphasis on macro-scale emission reduction efforts and places such a strong emphasis on PM emission monitoring, it is likely to be only a matter of time before these are included.
While PM currently gets a 'bad press' in the popular media, especially with reference to Chinese smog pollution, in the US and Europe PM levels are on the decline. In addition, industrial plants are rarely a major source of these types of emissions compared to sources like fossil fuel-burning power stations, agriculture and transportation. Cement plants make up a relatively small proportion of industrial installations, giving the industry somewhat lower impetus to legislate against PM by itself, rather than including PM emissions in general dust legislation.
With the EU and legislation 'front-runner' Germany including PM along with dust limits, there are actually relatively few countries considering changes to PM limits for the cement industry compared to other pollutants in this study. Colombian authorities are discussing the implementation of new regulations that will bring a more coherent picture for PM regulations with respect to the gulf between limits for conventional fuels and alternative fuels. While it is possible that this will result in an increase in the PM restrictions for plants using non-hazardous fuels, it is possible that the limits for plants using conventional fuels could head in the other direction. It is not known whether India and Brazil will introduce PM-only legislation for their growing cement industies.
Dust and particulate matter - Abatement methods
Cement plants can use two main dust and PM abatement technologies to help them meet emissions limits: 1. Electrostatic precipitators (ESP); 2. Filter bags.
ESPs use an induced electrostatic charge to attract dust to charged surfaces. While efficient on start-up and mechanically-reliable, ESPs become less effective as dust builds up on the charged surfaces, causing time lost to maintenance and cleaning and potentially causing emissions to rise above permitted levels.
Filter bags, housed in 'baghouses,' use natural or synthetic fibre-based bags to physically remove dust from the gas-stream. With typically four to 12 bags working in parallel, baghouses maintain steady operation for longer than ESPs, although care must be taken with respect to the potential for damaged bags. If a bag breaks mid-operation, the potential exists for a massive emission of dust. This can have severe adverse effects for local residents, water courses and may involve financial penalties for the producer.
Currently, the majority of upgrade projects conducted with respect to dust reduction see ESPs being replaced with baghouses. Particulate matter (PM) is also removed using these technologies.
Summary
By looking at the four pollutant classes in this review it is possible to draw some conclusions from the hard numbers in Tables 1-5. The most fundamental of these is that all four classes are seeing a gradual reduction in permitted emissions levels. This is the result of growing environmental awareness in developed markets from both cement producers and local residents. On top of this, countries that have a split between emissions limits for older and newer facilities will see the effective emission loads reduce with time as a result of the decommissioning of older capacity.
The most stringent regulations covered here are in the EU, specifically in Germany and Austria. Both countries are leaders in overall environmental awareness and have cement industries of sufficient size to act as plausible models for future production regimes elsewhere in the world. Producers in this region have been fairly proactive with respect to hitting limits (and exceeding them).
Comparisons with North America are hard due to a lack of data from Canada and a predisposition to non-SI-units in the US that does not easily permit conversion of its forthcoming limits. Producers in this region have previously warned of the highly-damaging effects of new regulations, so much so that they have successfully added five years to their implementation deadlines.
Central and South America is a continent of extremes. Brazil, the largest cement producer on the continent, does not have particularly strong limits and cement industry contacts were unable to provide NOx and SO2 emissions limits, which are mandated by state. Chile and Colombia appear to be aspiring to EU-level emissions limits, with relatively worse-off Bolivia somewhat more lax. Trinidad & Tobago is targeting slightly less stringent restrictions.
Areas that have had little legislation relating to cement plant emissions in the past include Africa and the Middle East. India only has some state-based limits for some pollutants, although commitments are expected in 2014 for other types of emissions.
Australia and Canada, both developed countries with sparse populations, implement limits on a regional basis, often for one plant (or even zero plants).
While the global cement news is full of stories as to how stringent limits put domestic industries at risk (see for example US producer concern over mercury limits or Australian concerns over CO2 taxation), countries with less stringent regulations (or indeed no regulations) relating to this area are catching up. This is evidenced by discussions in India, Trinidad & Tobago, Indonesia and others regarding stronger limits. While we have not been able to access the new
Chinese limits (except for NOx) it is clear that a country that is removing cement capacity wholesale in some regions is finally taking action over long-held environmental grievances. This desire to improve air quality will hopefully extend to other countries in the coming years and decades, benefiting local populations and the environments in the immediate vicinity of cement plants.
Complication risks complacency
A further general trend in global cement emissions limits appears to be that, as more stringent regulations come in, the more 'tailored' emissions limits become. This is certainly the case in the EU, the UK and the US, where individual plants are granted higher limits for given pollutants. This raises the prospect for more individual plants in more jurisdictions in the future. However, there is a risk that, as more jurisdictions go down the route of issuing exemptions, that national (and potentially future international) limits may become less and less relevant. If every plant has a special limit, then what is the point of a headline limit for that country?
In this hypothetical situation, it may be possible that exemptions could virtually invalidate overarching regulations. It is controversial but, faced with overcapacity, perhaps some European countries could do worse than employing a top-down approach, implementing future emissions changes with overall national emissions in mind.
Global cement emissions standards by country
Australia
Australian States have different regulations for cement plant emissions.1 The only regulations that could be collected prior to publication were for New South Wales and Victoria. In both cases these related to individual cement plants, which, despite belonging to the same operator, were regulated in different units using different measurement regimes.
Canada
Canadian Provinces have different regulations for cement plant emissions. This is likely confused by plant-by-plant variations due to local conditions in this relatively environmentally-conscious country. The limits are complicated to the point that that the country's cement association was unable to collate the standards in time for publication.
China
The world's largest cement player, China has been cleaning up its environmental act so far in the 21st Century. New emissions limits, effective 1 March 2014 have brought allowances into line with European norms. With a top-down attitude, the government has started a wholesale capacity reduction drive, targeting the most polluting plants. It targets regional emission reductions and has no qualms when taking the necessary steps.
USA
In the US, the Environmental Protection Agency sets PC MACT regulations for 'non-hazardous' pollutants and NESHAP regulations for hazardous pollutants such as mercury. Following dispute from industry in the 2010s, the most stringent regulations are now on hold until 9 September 2015, with cement plants currently implementing emission reduction strategies.
India
India has few emissions limits, for the second-largest cement industry in the world. There are some state limits for NOx and SO2 but no national policy for these, for mercury or dust. There is currently discussion between the national associations and authorities regarding the potential implementation of national standards for these pollutant classes, which could conclude in 2014.
Colombia
Colombia has fairly strong emissions limits for cement plants but they seem to have been put together in a strange order. The limits are lower for plants burning non-hazardous alternative fuels than they are for plants burning hazardous alternative fuels. Discussion is ongoing regarding changes to this situation. Could this result in an increase in permitted limits for those burning non-hazardous alternative fuels? This would certainly be an unusual situation if it occurs.
European Union (EU)
Richard Leese of the UK Mineral Products Association explains EU emissions limits: "Limits for European cement plants are enshrined in the Industrial Emissions Directive and best available techniques associated emission levels (BAT AELs). This means that, in theory, all plants in Europe will have the same emission limits. There will be exception cases where derogations from the limits are necessary. These have to be justified at plant level."
References
1. Environmental Manager, Boral Cement, Australia.
2. Smith, S.J.; van Aardenne, J.; Klimont, Z.; Andres, R.J.; Volke, A. & Delgado Arias, S.: Atmos. Chem. Phys., 11. 1101-1116, 2011. http://www.atmos-chem-phys.org/11/1101/2011/acp-11-1101-2011.pdf
3. Environmental Protection Agency (US) website, 'Sulfur Dioxide,' http://www.epa.gov/air/sulfurdioxide.
4. Plant Manager, Lafarge Mannersdorf, Austria.
5. Social Responsibility Manager, SOBOCE, Bolivia.
6. Representative of InterCement, Brazil.
7. Representative of Cement Canada, Canada.
8. Press Manager, Cementos Bío Bío, Chile.
9. Ministry of Environmental Protection (China) website, 'Emission Standard of Air Pollutants for Cement Industry,' http://www.mep.gov.cn/image20010518/5315.pdf.; News stories on Global Cement website.
10. Environmental Technical Manager, Cementos Argos, Colombia.
11. Technical/Government Affairs Director, Arabian Cement, Egypt.
12. EU.
13. VDZ website, 'Activity Report 2009-2012,' http://www.vdz-online.de/fileadmin/gruppen/vdz/3LiteraturRecherche/TaeB09-12/Taeb_09-12_eng.pdf. VDZ website, 'Environmental Data of the German Cement Industry,' http://www.vdz-online.de/fileadmin/gruppen/vdz/3LiteraturRecherche/Umweltdaten/Umweltdaten_E_2011.pdf
14. CMA India website, 'Annual Report 2012-2013,' http://www.cmaindia.org/pdf_files/annual%20report-2012-13.pdf.
15. Senior Environment Manager, Lafarge Cement Indonesia, Indonesia.
16. Analyst based in Lebanon.
17. Analyst based in Nigeria.
18. Process Manager, Norcem, Norway.
19. CEO, Thatta Cement Company Limited, Pakistan.
20. Press Secretary, BaselCement LLC, Russia.
21. Presidency of Metrology and Environment (Saudi Arabia), 'Environmental Standards - Ambient Air Quality,' http://www.pme.gov.sa/en/En_EnvStand19.pdf.
22. Environment.co.za website, 'National Environmental Management: Air Quality Act (39/2004) – List of activities which result in atmospheric emissions which have or may have a significant detrimental effect on the environment, including health, social, economic, ecological conditions,' 2 March 2011. http://www.environment.co.za/environmental-laws-and-legislation-in-south-africa/south-africa-national-environmental-management-air-quality-act-392004-list-of-activities-which-result-in-atmospheric-emissions-which-have-significant-detrimental-effect-on-the-environment-including-he.html.
23. Director, CemSuisse, Switzerland.
24. Business Development Specialist, Trinidad Cement Limited, Trinidad & Tobago.
25. Head of Environment and Climate Change Issues, TCMA, Turkey.
26. Production Manager, Union Cement Norcem, Ras Al Khaimah, UAE.
27. Environment Agency (UK), 'How to comply with your environmental permit. Additional guidance for The Cement Industry (EPR 3.01a),' http://www.environment-agency.gov.uk/static/documents/Business/How_to_Comply_-_Cement_EPR3_01a.pdf.
28. Correspondence with UK cement plant.
29. News stories on Global Cement website.