ENVIRONMENTAL COMPANY OF SAO PAULO STATE – CETESB

REGIONAL CENTRE OF STOCKHOLM CONVENTION ON POPs FORLATIN AMERICA AND THE CARIBBEAN REGION

V INTERNATIONAL TRAINING PROGRAM ON ENVIRONMENTAL SOUND MANAGEMENT ON CHEMICALS AND WASTES, ESPECIALLY ON PERSISTENT

ORGANIC POLLUTANTS (POPs) AND MERCURY (Hg)

MANAGEMENT OF UNNTENTIONAL POPs AND ATMOSPHERIC EMISSIONS CEMENT KILNSEng. Maria Cristina Poli

2016

Sao Paulo – SP – Brazil

Cement Kilns

Stockholm ConventionAnnex C - Non-intentional production

Part II - Source Category

EVOLUTION OF CEMENT PRODUCTION IN LATIN AMERICAN (million tons)Countries 2003 2004 2005 2006 2007 2008 2009

Argentina 5.2 6.3 7.6 8.9 9.6 9.7 9.4

Brazil 35.1 36.0 38.7 41.9 46.5 52.0 51.7

Chile 3.6 3.8 4.0 4.1 4.4 4.6 3.9

Colombia 7.3 7.8 9.9 10.0 11.1 10.5 10.0

Mexico 31.9 33.4 35.4 38.4 39.2 37.7 35.4

Venezuela 4.4 5.0 5.8 7.2 9.0 7.7 8.0

LAT. AM. TOTAL

112.4 118.2 130.4 142.6 151.5 157.2 153.4

Sources: Cembureau, SNIC, Association of countries, Jefferies International

GROUPS, FACTORIES AND CAPACITIES INSTALLED IN VARIOUS COUNTRIES - 2011

Countries ProducingGroups

Factories InstalledCementCapacity(Mt)

Argentina 4 17 18.1Brazil 14 75 73.2Chile 4 11 7.1Colombia 5 20 20.5Costa Rica 2 3 2.4Mexico 5 34 58.7Paraguay 1 2 0.7Peru 5 7 11.0Uruguay 3 5 1.5Venezuela 3 10 9.9

Sources: Global Cement Report 9th Edition

Stockholm Convention Annex C -Part II

Category of industrial sources with relatively high potential for formation and liberation of

Dioxins and Furans (D&F)D&F are formed and released unintentionally

from heat processes, which have organic matter and chlorine, as a result of incomplete

combustion or chemical reactions.

Cement Kilns

The cement manufacture process consists of four main stages:

– Extraction and grinding of raw material– Homogenization of raw material – Clinker Production– Grinding of cement

Cement Production

Extraction ofraw material Grinding and

Homogenization

kiln

DispatchStorage silo

Storage siloMixing and grinding of cement

ESPSupply of raw material(Flour)

SystemClinker

gassolid

• The main raw materials are clay and limestone.

• The manufacture of the cement begins with calcination,which is the decomposition of the calcium carbonate(CaCO3) at 900 °C into calcium oxide (CaO) and carbondioxide (CO2).

• Next, the lime, at temperatures normally between 1,400and 1,500 ºC, reacts with the silica, alumina and ironoxide, forming "clinker".

• The clinker is ground together with gypsum (CaSO4) andother additives to produce cement

• There are four types of processes for the manufacture ofcement: dry processes, semi-dry processes, semi-wetprocesses and wet processes

Dry process

Chimney

Clinker Rotary kiln Cooling

Kiln gases

Drying silos

Supply and mixture of

raw material

“The burning of hazardous waste in cement kilns does not affect the formation of dioxins and furans;

dioxins and furans are formed after combustion”

Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT),

EPA

(Federal Register, 64 FR 52876, September 30, 1999).

Rotary KilnCyclone

Preheater

Clinker Cooler

«De-Novo-Synthesis»

550 [°C]720 [°C]

1200 [°C]2000 [°C]

850 [°C]

0 [sec] 8 [sec]

25 [sec]

Gas FlowMaterial Flow

800 [°C]

30 [°C]

1450 [°C]

900 [°C]

350 [°C]Range 400-800 [°C]

Temperature and retention time in a cement kiln with pre-heater

“Synthesis Again”

D&F emission factors for the production of cement

Type of process Emission factorsµg of D&F/t of cement

Vertical kilns 5.0Old wet process kilns, ESP with T >300°C 5.0Rotary kilns, ESP/fabric filter at 200-300°C 0.06

Wet process kilns, ESP/fabric filter with T< 200ºC

0.05

Dry kilns with pre-heater or precalciner with T<200ºC

0.05

Source: Toolkit 2003

Emission factors by type of source

Production of mineral products - Cement Kilnsμg TEQ/t of raw material or product

0,001

0,601

1,201

1,801

2,401

3,001

3,601

4,201

4,801

Wet kilns, ESP temperature >300 °C Wetkilns, ESP/FF temperature 200 to 300 °C Wet kilns, ESP/FF temperature <200 °C andall types of dry kilns

• All cement kilns must be equipped withelectrostatic precipitators or fabric filters,or both, for the control of particles.

• Pollution control equipment for acidgases are not used in cement kilns as theraw materials are highly alkaline andallow the control of acid gas

The unintentional formation of POPs may occur within the ESP at temperatures between

200ºC and 450ºC.

Lower D&F emission have been observed when the ESP/chimney is below

255 ºC

Fabric filters are also referred to as baghouses or bag filters. These devices for controlling

particulate matter can effectively remove

unintentional POPs that may be associated with the

particles and vapors that the particles adsorb in the escape

gas flow.Fabric filters are sensitive to acids and, therefore, they are normally used in conjunction with washers for removing

acid gases.

Factors that affect the formation of D&F in cement kilns

• Type of kiln• Burning condition

– Constance of fuel/waste supply– Constance of fuel/waste characteristics– Adequate oxygen content– CO monitoring in the chimney

• ESP operating temperature• Efficiency of the ESP or fabric filter• Temperature in the chimney• Minimize the consumption of energy by using pre-

heaters or precalciners

• The cement industry consumes largequantities of energy, which representsaround 40% of production costs

• The most common fuels are petcoke,carbon and various types of waste

STRUCTURE OF CONSUMPTION IN CEMENT

SECTOR (%)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

2004

OTHERS

PETROLEUMCOKE

CHARCOAL

ELECTRICITY

FUEL OIL

MINERAL COAL

Co-processing

The use of waste in industrial processes such as cement production or other industrial processes involving

combustion where the fuel or raw material is replaced by waste or a

waste mixture (blend)

State of São Paulo

• 02 industrial waste blend co-processingkilns

• 01 tire co-processing kilns• 02 kilns in licensing process for co-

processing tires• 01 kiln for co-processing tires +

agrotoxic packaging

General Co-processing Principals

• The management of waste must be respected• The emission levels must not be higher than those of

cement production with traditional fuel• The quality of the cement produced must not be altered• Staff, processes and systems that demonstrate

commitment to safety, protecting the environment and health must be provided

• They must be able to control inputs and parameters required for effective co-processing

• Good relations with the public and with the neighboring population must be maintained.

• Training for employees• Emergency plans

Reusing energy

• For waste to be used as a fuel substitutefor energy re-use purposes, its lowercalorific value, on a dry basis, must begreater than 2775 kcal/kg (5000 Btu/lb).

• Waste with a lower calorific value, on a dry basis of less than 2775 kcal/kg must be studied case by base.

Reuse as raw material substitute

• For waste to be used as a raw materialsubstitute, it must have a similar chemicalcomposition to that normally used in theproduction of clinker.

Co-processing is not considered

• Plant waste resulting from agricultural activity,such as sugarcane bagasse, rice straw, etc.

• Plant waste resulting from the food producttransformation industry, such as peel, citrus rind,citrus fruits used for the extraction of central oils,etc.

• Office waste (paper and cardboard)and personal protection equipment

(PPE) generated at the plant itself

Types of waste frequently used as fuel in cement kilns

• Used tires• Oil residues

• Industrial waste

Solid fuelSolid fuel

Supply of waste and raw material

Liquid fuel

Main burner

Calciner

Bucket elevator

Kiln

Co-processing tires

• Use of shredded or whole tires• Does not produce waste in addition to that

generated in the production of cement• Metals in their bodywork are incorporated

into the clinker, replacing the addition ofpart of the iron ore.

Typical Composition of Tires (%)

Material Passenger car tires Load vehicle tires

Natural rubber 14 27Synthetic rubber 27 14Carbon black 28 28Steel, textile fibers and glass 14.5 14.5Antidegradant tarp and curing accelerators

16.5 16.5

Source: Oswaldo Aly, Scrap tires, Alternatives to significant reduction of this liability

Burning Feasibility Study

Test Burn

Blank Test

Continuous monitoring

Emission limits Interlocking

Supply Rate

Licensing Stages

Emission LimitsBrazil São

PauloParticulate Matter mg/Nm3 at 11% O2 (a) 70 70

Kg/t of supplied flour - 0.15

Sulfur oxides (SOx) mg/Nm3 at 10% O2 (a) - 350

Hydrochloric acid (HCl) Kg/h 1.8 -mg/Nm3 at 10% O2 (a) - 10

Hydrofluoric acid (HF)mg/Nm3 at 7% O2 (a) 5 -mg/Nm3 at 10% O2 (a) - 4

Dioxins and Furans (b)ηg/Nm3 at 7% O2 (a) 0.5ηg/Nm3 at 11% O2 (a) - 0.1

Nitrogen Oxides (NOx) (c) mg/Nm3 at 10% O2 (a) - 800

(a) In normal conditions (0° and 1 atm), dry basis. (b) Expressed as 2,3,7,8-TCDD(c) Expressed as NO2.

Emission LimitsBrazil São Paulo

Lead (Pb)(mg/Nm3 at 7% O2) (a) 0.35 -

(mg/Nm3 at 10% O2) (a) - 0.275

Cadmium (Cd) (mg/Nm3 at 7% O2) (a) 0.1 -

Thallium (TL) (mg/Nm3 at 7% O2) (a) 0.1 -

Cd+TL (mg/Nm3 at 10% O2) (a) - 0.05

Mercury (Hg)(mg/Nm3 at 10% O2) (a) - 0.04

(mg/Nm3 at 7% O2) (a) 0.05 -

As+Be+Co+Ni+ Se+Te (mg/Nm3 at 7% O2) (a) 1.4 -

As+Be+Co+Ni+ Se+Te (mg/Nm3 at 10% O2) (a) - 1.0

As+Be+Co+Cr+ Cu+Mn+Ni+Pb+Sb+Se+Sn+ Te+Zn (mg/Nm3 at 7% O2) (a) 7.0 -

As+Be+Co+Cr+ Mn+Ni+Pb+Sb+Se+Sn+Te+ Zn (mg/Nm3 at 10% O2) (a) - 5

(a) In normal conditions (0° and 1 atm), dry basis.

Stockholm Convention, Co-processing

Does not establish limits for any sourcesof dioxins

Recommends that priority sources takemeasurements

Sampling in chimney -Brazil

– USEPA 23 Method– Type of collection: isokinetic– Absorption of compounds in XAD2 resin– Collection time: ± 3 hours/sample– Number of collections: 03 collections in

chimney and 03 field control + 01 travel control

– Analysis method: EPA 8290

Results of Dioxin and Furan Sampling in chimney at cement plants without waste

supply

ng/Nm3, expressed as 2,3,7,8-TCDD

Source: ABCP - Brazilian Portland Cement Association - 2005

Unit 1st collection

2nd collection

3rd collection

average

1 0.0024 0.0025 0.0018 0.00222 0.0016 0.0023 0.0021 0.00203 0.0071 0.0035 0.0025 0.00444 0.0010 0.0015 0.0010 0.00125 0.0075 0.0047 0.0027 0.0050

Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply

ng/Nm3, expressed as 2,3,7,8-TCDD

Smoke box: 10% shredded tires 0.0024 0.0040 0.0212 0.0092

Smoke box: 11% shredded tires 0.0018 0.0075 0.0040 0.0044

Smoke box: 10% shredded tires + SPL raw material 0.0168 0.0211 0.0209 0.0196

Smoke box: 14.1% shredded tires 12% blend 0.0207 0.0026 0.0224 0.0152

Smoke box: 30% shredded tires + rice husk 0.0598 0.0592 0.0406 0.0532

Source: ABCP - Brazilian Portland Cement Association - 2005

Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply

(Blend)

ng/Nm3, expressed as 2,3,7,8-TCDD

Heat replacement: 15.9% 0.1034 0.0990 0.0804 0.0943

Heat replacement: 18% 0.1624 0.1668 0.1676 0.1656

Heat replacement: 20% 0.0035 0.0039 0.0045 0.0040

Source: ABCP - Brazilian Portland Cement Association - 2005

Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply

(Blend)

ng/Nm3, expressed as 2,3,7,8-TCDD

Torch: 4.46% waste 0.0163 0.0128 0.0079 0.0123

Torch: 70% coke 30% waste 0.0543 0.0066 0.0792 0.0467

Torch: 70% oil 30% waste 0.0500 0.0724 0.1581 0.0935

Source: ABCP - Brazilian Portland Cement Association - 2005

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37

0

0,05

0,1

0,15

0,2

PCDD / F Emissions of the cement industry in Brazil(ng/Nm3, expressed as 2,3,78-TCDD)

Source: ABCP - Brazilian Portland Cement Association - 2005

D&F Emissions of the cement industry in Europe(ng/Nm3, expressed as 2,3,78-TCDD)

Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte

D&F Emissions of the cement industry in Germany in 2001(ng/Nm3, expressed as 2,3,78-TCDD)

Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte

Waste with high chlorine content

• Problems with kiln joining, causing damage to the kiln

Comparison of the D&F atmospheric emission results in kilns in Heidelberg with and without the

use of alternative fuel

(40% energy replacement)

Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte

(0.29)

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 20 40 60 80 100 120 140 160

Emis

sion

s in

ng

I-TEQ

/m3 Normal

fuel

With secondary fuel

With raw material replacement

D&F Sampling Research Institute of the German Cement

Industry

Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte

Hg Emissions

0.1 to 0.035 g/t of cement

• Resulting from:– Raw Material– Fuel– Co-processed industrial waste– Used of RDF (Refuse-Derived Fuel)

Hg Concentration in Raw Material

Hg Concentration in fuel

Hg Concentration in RDF

Hg Concentration in waste used as fuel in Brazil

• Minas Gerais ≤ 10mg/kg• Paraná ≤ 10 mg/kg• São Paulo 0.32 mg/kg

Hg emission limits in cement kilns with use of waste

Country Emission limit(mg/Nm3)

Observation

Mexico 0.07 at 7 % O2

El Salvador 0.05 at 10 % O2

Costa Rica 0.24 Sum of Hg and Cd at 10% O2

Colombia 0.05 at 11 % O2

Venezuela 0.05 at 10% O2

Chile 0.109 at 10% O2

USA 0.12 at 7% O2

Canada 0.15 at 10% O2

Indonesia 0.2 at 7% O2

Thailand 0.10 at 7% O2

Morocco 0.10 at 11% O2

Hg emissions at cement manufacturers across the world

Hg emission control in cement kiln

• Careful control of all substances entering the kiln• Good burning conditions

– Constance of fuel/waste supply– Constance of fuel/waste characteristics– Adequate oxygen content– CO monitoring in the chimney

• Periodic purging of waste of control equipment such asESP and fabric filter, recycled in the kiln.

• Addition of activated carbon before the fabric filter.• Do not use hazardous industrial waste with mercury in

kilns.

Other emissions

• ESP or fabric filter combined with good burning condition, expected PM emission should be 20 to 30 mg/Nm3

• Special care must be taken in relation to metals, observing the return of ashes from the ESP/fabric filter into the kiln. One control measure is to limit metal contents in the waste supply rate.

Continuous Monitoring

• The co-processing unit must keep thecontinuous monitors installed in thechimney calibrated and operating at thefollowing parameters:

CO, O2, THC and NOx.

• In kilns that use SNCR for controlling NOx,the EC requests the continuous monitoringof NH3

Waste Monitoring

All waste received by the waste mixing unit and/or by the co-processing unit should be analyzed previously in order to prove compliance with the requirements established in environmental licenses.

Waste MonitoringThe company must have a waste analysis plan, which must cover, at

least:

• The origin and characterization of the waste• Sampling methods used• The parameters that will be analyzed in each type of

waste, methods and frequency of analysis, and testingdetection limits

• Incompatibility with other wastes• Analysis recording (reports with signature of the

responsible person) and• Availability of counter-tests (site and length of storage,

amounts and form of packaging, traceability, etc.)

Monitoring Operational Parameters

In additional to the normal parameters of theproductive process, the co-processing unit mustmonitor the following parameters continuously:

• Supply of waste• Fuel consumption• Flour supply• Kiln temperature• Temperature at waste supply point• Operational parameters of the PCE

Environmental Monitoring

This monitoring is established case bycase, based on the Risk Analysis Study,Atmospheric Dispersion Study and on thecharacteristics of the area and itssurroundings, such as, proximity ofresidences, vegetation, agriculturalcultures, bodies of water, etc.)

Inspection and Maintenance• The co-processing unit must have a preventive

maintenance program• The maintenance program established must be duly

documented and those involved must be duly trained.• All measurement and monitoring equipment and EPS

must be included in the maintenance program.• Documented procedures must be established

determining the calibration actions needed for themeasurement and monitoring instruments to maintainthe measurement capacity required.

Thank you very much !

mcpoli@sp.gov.br