6. cement sector - envis centre on:cleaner productiongcpcenvis.nic.in/experts/cement sector.pdf ·...

Gujarat Cleaner Production Centre

CLEANER PRODUCTION

CEMENT MANUFACTURING

Gujarat Cleaner Production Centre - ENVIS Centre

CLEANER PRODUCTION OPPURTUNITIES

IN

MANUFACTURING SECTOR

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OPPURTUNITIES

SECTOR


Indian Scenario of Indian Scenario of Indian Scenario of Indian Scenario of Cement Manufacturing Industries: Cement Manufacturing Industries: Cement Manufacturing Industries: Cement Manufacturing Industries:

The Indian cement industry is the 2nd largest market after China accounting for about 7

8% of the total global production. It had a total capacity of about

financial year ended 2011-12. Cement is a cyclical commodity with a high cor

GDP, growing at around 1.2x of GDP growth rate. The

driver of cement, accounting for

consumers of cement include infrastructure (17%), commercial & institutional (13%) and

industrial segment (6%).

Cement, being a bulk commodity, is a freight intensive industry and transporting it over

long distances can prove to be uneconomical. This has resulted in cement being largely a

regional play with the industry divided into five main regions viz. north, south, west, east

and the central region. The Southern region of India has the highest install

about 120.1 mtpa.

An Indian Cement industry is:

Second Largest Cement Second Largest Cement Second Largest Cement Second Largest Cement

MarketMarketMarketMarket

Dominated by private playersDominated by private playersDominated by private playersDominated by private players

Higher share of large plantsHigher share of large plantsHigher share of large plantsHigher share of large plants

LargeLargeLargeLarge concentration in South concentration in South concentration in South concentration in South

and Westand Westand Westand West


Cement Manufacturing Industries: Cement Manufacturing Industries: Cement Manufacturing Industries: Cement Manufacturing Industries:

The Indian cement industry is the 2nd largest market after China accounting for about 7

8% of the total global production. It had a total capacity of about 330 m tonnes (MT)330 m tonnes (MT)330 m tonnes (MT)330 m tonnes (MT)

12. Cement is a cyclical commodity with a high cor

GDP, growing at around 1.2x of GDP growth rate. The housing sector is the biggest demand

driver of cement, accounting for about 64% of the total consumption. The other major



ng distances can prove to be uneconomical. This has resulted in cement being largely a


and the central region. The Southern region of India has the highest install

With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production

Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the

world world world world

Of the total capacity: 98 per cent lies with the private sector

and the rest with public sector

185 large cement plants together account for 97 per cent of

the total installed capacity, while 365 small plants account

for the rest

of the total 185 large cement plants in India, 77 are located

in the states of Andhra Pradesh, Rajasthan and Tamil Nadu

Source:Source:Source:Source: Planning Commission, Aramca Research 2012.

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The Indian cement industry is the 2nd largest market after China accounting for about 7-

330 m tonnes (MT)330 m tonnes (MT)330 m tonnes (MT)330 m tonnes (MT) as of

12. Cement is a cyclical commodity with a high correlation with

is the biggest demand

about 64% of the total consumption. The other major



ng distances can prove to be uneconomical. This has resulted in cement being largely a


and the central region. The Southern region of India has the highest installed capacity of

With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production With nearly 300 million tonne of Cement Production

Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the Capacity, India is the second largest cement producer in the

capacity: 98 per cent lies with the private sector

185 large cement plants together account for 97 per cent of

the total installed capacity, while 365 small plants account

of the total 185 large cement plants in India, 77 are located

in the states of Andhra Pradesh, Rajasthan and Tamil Nadu

Planning Commission, Aramca Research 2012.


General Description of Industry ActivitiesGeneral Description of Industry ActivitiesGeneral Description of Industry ActivitiesGeneral Description of Industry Activities

Cement production process involve quarrying and mining, grinding, and homogenizing raw

materials as illustrated in figure

opportunity for the use of belt conveyors, cement manufacturing is typically located

adjacent to the sources of raw materials and in proximity to product markets. Cement can

be economically distributed by trucks in a relatively small radius (around 100

from the plant), and if the plant is located on a water body, transport can be a

with barge or ships. A compact single production line (preheater

preheater [PH] kiln with 3,000 tons / day clinker production capacity) typically needs

around 400,000 m2 in a flat area, as well as an additional area [for exam

for future expansion. The typical project facility lifespan is at least 40 to 50 years. The size

of the plant is an important factor, as differences in production scale have a significant

impact on production costs and, consequently, on in

and control technologies. The same level of environmental performance can be achieved by

small plants at a higher cost per cement production than by large plants.

Cement Manufacturing: Cement Manufacturing: Cement Manufacturing: Cement Manufacturing:

Cement manufacturing uses energ

limestone (calcium carbonate, CaCO3), clay (aluminum silicates), sand (silica oxide), and

iron ore to produce clinker, which is ground with gypsum, limestone, etc to produce

cement.

After an initial preblending stage, the raw materials are mixed

a homogeneous blend with the required chemical composition (the raw meal). The

fineness and particle size distribution of the raw meal are important characteristics for the

burning process. Following mixing,

calcining the raw meal (e.g. decomposing CaCO3 at about 900°C), releasing carbon dioxide

(CO2) and leaving CaO. This is followed by the clinkering process, in which CaO reacts at a

high temperature (1,400°C to 1,500°C) with silica, alumina, and ferrous oxides. Other

constituents may be added in the raw material mix to meet the required composition (e.g.

silica sand, foundry sand, iron oxide, alumina residues, blast furnace slag, and gyp

residues). The temperature of the flame and produced gases is close to 2,000°C. The hot

clinker falls from the kiln onto the cooler, where it must be cooled as quickly as possible to

improve the clinker quality and to recover energy by heating secondar

are typically employed for this purpose (as opposed to the use of satellite coolers). The

cooled clinker is then ground with gypsum and limestone to produce portland cement and

ground with other additional constituents to produce compo

Cement is then stored in silos or bags. The blending constituents are materials with

hydraulic properties (e.g. natural pozzolane, fly ash, blast furnace slag, and occasionally


General Description of Industry ActivitiesGeneral Description of Industry ActivitiesGeneral Description of Industry ActivitiesGeneral Description of Industry Activities

involve quarrying and mining, grinding, and homogenizing raw

erials as illustrated in figure 1. To minimize transportation costs and allow the



be economically distributed by trucks in a relatively small radius (around 100

from the plant), and if the plant is located on a water body, transport can be a

with barge or ships. A compact single production line (preheater-precalciner [PHP],


around 400,000 m2 in a flat area, as well as an additional area [for example, 250,000 m2]



impact on production costs and, consequently, on investment costs for pollution abatement


small plants at a higher cost per cement production than by large plants.

Cement manufacturing uses energy to process raw materials consisting of mainly



ing stage, the raw materials are mixed together and ground to form



Following mixing, the production process continues in a rotary kiln by



h temperature (1,400°C to 1,500°C) with silica, alumina, and ferrous oxides. Other


silica sand, foundry sand, iron oxide, alumina residues, blast furnace slag, and gyp



improve the clinker quality and to recover energy by heating secondary air. Grate coolers



ground with other additional constituents to produce composite or blended cements.



3 | P a g e

involve quarrying and mining, grinding, and homogenizing raw

. To minimize transportation costs and allow the



be economically distributed by trucks in a relatively small radius (around 100–150 km

from the plant), and if the plant is located on a water body, transport can be accomplished

precalciner [PHP],


ple, 250,000 m2]



vestment costs for pollution abatement


y to process raw materials consisting of mainly



together and ground to form



process continues in a rotary kiln by



h temperature (1,400°C to 1,500°C) with silica, alumina, and ferrous oxides. Other


silica sand, foundry sand, iron oxide, alumina residues, blast furnace slag, and gypsum



y air. Grate coolers



site or blended cements.




bottom ash). In fly and bottom ashes, carbon residues

plants) should not be present. CaCO3 is sometimes added in small quantities as filler.

Figure 1: Cement Manufacturing Flow

Environmental issues in cement Environmental issues in cement Environmental issues in cement Environmental issues in cement

A. Air Emissions

B. Energy consumption and fuels

C. Wastewater

D. Solid waste generation

E. Noise


bottom ash). In fly and bottom ashes, carbon residues (typically from coal


Figure 1: Cement Manufacturing Flow-Chart

Environmental issues in cement Environmental issues in cement Environmental issues in cement Environmental issues in cement manufacturing:manufacturing:manufacturing:manufacturing:

Energy consumption and fuels

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(typically from coal-fired power



A.A.A.A. Air Emissions Air Emissions Air Emissions Air Emissions

Air emissions in cement manufacturing are generated by the handling and storage of

intermediate and final materials, and by the operation of kiln systems, clinker coolers, and

mills.

Several types of kilns are currently used in cement manufacturing (preheater

(PHP), preheater (PH), long-dry (LD), semidry, semiwet, and wet process kilns). PHP kilns

are generally preferred in terms of environmental performance. While shaft k

in operation, they are generally only economically viable for small plants and are being

phased out with the renewal of installations.

Air Air Air Air

EmissionEmissionEmissionEmission

SourceSourceSourceSource

Particulate Particulate Particulate Particulate

matter matter matter matter

Particulate matter (PM)

emissions are among the most

significant impacts of cement

manufacturing.

For PM emissions associated

with intermediate and final

materials handling and storage

(including crushing and

grinding of raw materials);

handling and stor

fuels; transportation of

materials (e.g. by trucks or

conveyor belts), and bagging

activities,




Several types of kilns are currently used in cement manufacturing (preheater

dry (LD), semidry, semiwet, and wet process kilns). PHP kilns

are generally preferred in terms of environmental performance. While shaft k


phased out with the renewal of installations.

SourceSourceSourceSource Cleaner Production TechniquesCleaner Production TechniquesCleaner Production TechniquesCleaner Production Techniques

Particulate matter (PM)

emissions are among the most

significant impacts of cement

For PM emissions associated

with intermediate and final

materials handling and storage

(including crushing and

grinding of raw materials);

handling and storage of solid

fuels; transportation of

materials (e.g. by trucks or

conveyor belts), and bagging

• Use of a simple, linear layout for

materials handling operations to

reduce the need for multiple transfer

points;

• Use of enclosed belt conveyors for

materials transportation and emission

controls at transfer points;

• Cleaning of return belts in the conveyor

belt systems;

• Storage of crushed and preblended raw

materials in covered or closed bays;

• Storage of pulverized

petroleum coke (pet–coke) in silos;

• Storage of waste-derived fuels in areas

protected from wind and other

weather elements;

• Storage of clinker in covered / closed

bays or silos with automatic dust

extraction;

• Storage of cements in silos with

automatic reclaiming and loading of

bulk tankers;

• Storage of screened sizes of burnt lime

in bunkers or silos and storage of fine

grades of hydrated lime in sealed silos;

• Implementation of routine plant

maintenance and good housekeeping

to keep small air leaks and spills to a

minimum;

• Conduct material handling (e.g.

5 | P a g e



Several types of kilns are currently used in cement manufacturing (preheater– precalciner

dry (LD), semidry, semiwet, and wet process kilns). PHP kilns

are generally preferred in terms of environmental performance. While shaft kilns are still


Cleaner Production TechniquesCleaner Production TechniquesCleaner Production TechniquesCleaner Production Techniques

Use of a simple, linear layout for

materials handling operations to

reduce the need for multiple transfer

Use of enclosed belt conveyors for

materials transportation and emission

controls at transfer points;

Cleaning of return belts in the conveyor

Storage of crushed and preblended raw

materials in covered or closed bays;

Storage of pulverized coal and

coke) in silos;

derived fuels in areas

protected from wind and other

Storage of clinker in covered / closed

bays or silos with automatic dust

Storage of cements in silos with

tomatic reclaiming and loading of

Storage of screened sizes of burnt lime

in bunkers or silos and storage of fine

grades of hydrated lime in sealed silos;

Implementation of routine plant

maintenance and good housekeeping

eaks and spills to a

Conduct material handling (e.g.


Nitrogen Nitrogen Nitrogen Nitrogen

OxidesOxidesOxidesOxides

Nitrogen Oxides

generated in high temperature

combustion process of the

cement kiln.


crushing operations, raw milling, and

clinker grinding) in enclosed systems

maintained under negative pressure by

exhaust fans. Collecting ventilation air

and removing dust using cyclones and

bag filters;

• Implementation of automatic bag filling

and handling systems to the extent

possible, including:

• Using a rotary bag filling machine with

automatic paper bag feeder and

fugitive emission control

• Using automatic weight control for

each bag during discharge

• Using conveyor belts for transporting

bags to a palletizing machine o Storing

the finished pallets in covered bays for

subsequent shipping

Nitrogen Oxides emissions are

generated in high temperature

combustion process of the

• Maintaining secondary air flow as low

as possible (e.g. oxygen reduction);

• Employing flame cooling by adding

water to the fuel or directly to the

flame (e.g. temperature decrease and

hydroxyl radical concentration

increase). The use of flame

have a negative impact on fuel

consumption, possibly resulting in a 2

3 percent increase, and a subsequent

proportional increase of carbon

dioxide (CO2) emissions;

• Using low NOX burners to avoid

localized emission hot spots;

• Developing a staged combustion

process, as applicable in preheater

precalciner (PHP) and preheater (PH)

kilns;

• Lime manufacturing: Nitrogen oxide

(NOX) production is generally lower in

lime manufacturing than in cement

manufacturing. Because limestone

burning usually takes place at lower

temperatures, NOX emissions from this

source are lower and can be controlled

using low NOX burners.

6 | P a g e

crushing operations, raw milling, and

clinker grinding) in enclosed systems

maintained under negative pressure by

exhaust fans. Collecting ventilation air

and removing dust using cyclones and

Implementation of automatic bag filling

and handling systems to the extent

Using a rotary bag filling machine with

automatic paper bag feeder and

fugitive emission control

Using automatic weight control for

g discharge

Using conveyor belts for transporting

bags to a palletizing machine o Storing

the finished pallets in covered bays for

Maintaining secondary air flow as low

as possible (e.g. oxygen reduction);

Employing flame cooling by adding

water to the fuel or directly to the

flame (e.g. temperature decrease and

hydroxyl radical concentration

increase). The use of flame cooling can

have a negative impact on fuel

consumption, possibly resulting in a 2–

3 percent increase, and a subsequent

proportional increase of carbon

dioxide (CO2) emissions;

Using low NOX burners to avoid

localized emission hot spots;

ged combustion

process, as applicable in preheater-

precalciner (PHP) and preheater (PH)

Lime manufacturing: Nitrogen oxide

(NOX) production is generally lower in

lime manufacturing than in cement

manufacturing. Because limestone

es place at lower

temperatures, NOX emissions from this

source are lower and can be controlled

using low NOX burners.


Sulfur Sulfur Sulfur Sulfur

Dioxides Dioxides Dioxides Dioxides

Sulfur dioxide (SO2) emissions

in cement manufacturing are

primarily associated with the

content of volatile or reacti

sulfur in the raw materials

although less important, with

the quality of fuels for power

generation.

Greenhouse Greenhouse Greenhouse Greenhouse

gasegasegasegases s s s

Greenhouse gas emissions,

especially carbon dioxide

(CO2), are mainly associated

with fuel combustion and with

the decarbonation of

limestone, which in its pure

form is 44 percent

weight.

Carbon monoxide (CO) makes

a minor contribution to

greenhouse gas emissions

(less than 0.5–

total emitted gases).

emissions are normally related

to the organic matter content

of the raw material.

Heavy Heavy Heavy Heavy

Metals and Metals and Metals and Metals and

Other Air Other Air Other Air Other Air

Pollutants Pollutants Pollutants Pollutants

Heavy metals (e.g. lead,

cadmium, and mercury) can be

significant emissions from

cement manufacturing, and are

generated from the use of raw

materials, fossil fuels, and

waste fuel. Nonvolatile metals

are mostly bound to the

particulate matter. Volatile

metal emissions, such as

mercury, are usually generated

from both the raw materials


Sulfur dioxide (SO2) emissions

in cement manufacturing are

primarily associated with the

content of volatile or reactive

in the raw materials and,

although less important, with

the quality of fuels for power

• Use of a vertical mill and gases passing

through the mill to recover energy and

to reduce the sulfur content in the gas.

In the mill, the gas containing sulfur

oxide mixes with the calcium carbonate

(CaCO3) of the raw meal and produces

calcium sulfate (gypsum);

• Selection of fuel source with lower

sulfur content;

• Injection of absorbents such as

hydrated lime (Ca(OH)2), calcium

oxide (CaO), or fly ashes with high CaO

content into the exhaust gas before

filters;

• Use of wet or dry scrubbers.

Greenhouse gas emissions,

specially carbon dioxide

are mainly associated

with fuel combustion and with

the decarbonation of

limestone, which in its pure

form is 44 percent CO2 by

Carbon monoxide (CO) makes

a minor contribution to

house gas emissions

–1 percent of

emitted gases). These

emissions are normally related

organic matter content

of the raw material.

• Production of blended cements, which

have the potential for significant

reduction in fuel consumption and

subsequent CO2 emissions per ton of

final product;

• Process selection and operation to

promote energy efficiency (dry/ pre

heater / pre-calciner);

• Selection of fuel with a lower ratio of

carbon content to calorific value (e.g.

natural gas, fuel oil, or some waste

fuel);

• Selection of raw materials with lower

organic matter content.

Heavy metals (e.g. lead,

cadmium, and mercury) can be

significant emissions from

cement manufacturing, and are

generated from the use of raw

materials, fossil fuels, and

waste fuel. Nonvolatile metals

are mostly bound to the

particulate matter. Volatile

tal emissions, such as

mercury, are usually generated

from both the raw materials

• Implement efficient dust / PM

abatement measures, as discussed

above, to capture bound metals. For

high concentrations of volatile heavy

metals (in particular mercury), use of

absorption on activated carbon may be

necessary. The resulting solid waste

should be managed as a hazardous

waste as described in the General EHS

Guidelines;

• Implement monitoring

the volatile heavy metal content in the

7 | P a g e

Use of a vertical mill and gases passing

through the mill to recover energy and

to reduce the sulfur content in the gas.

In the mill, the gas containing sulfur

oxide mixes with the calcium carbonate

(CaCO3) of the raw meal and produces

sum);

Selection of fuel source with lower

Injection of absorbents such as

hydrated lime (Ca(OH)2), calcium

oxide (CaO), or fly ashes with high CaO

content into the exhaust gas before

Use of wet or dry scrubbers.

Production of blended cements, which

have the potential for significant

reduction in fuel consumption and

subsequent CO2 emissions per ton of

Process selection and operation to

promote energy efficiency (dry/ pre-

lection of fuel with a lower ratio of

carbon content to calorific value (e.g.

natural gas, fuel oil, or some waste

Selection of raw materials with lower

Implement efficient dust / PM

abatement measures, as discussed

above, to capture bound metals. For

high concentrations of volatile heavy

metals (in particular mercury), use of

absorption on activated carbon may be

necessary. The resulting solid waste

should be managed as a hazardous

waste as described in the General EHS

and control of



and the waste fuels, and they

are not controlled through use

of filters.

Waste fuelsWaste fuelsWaste fuelsWaste fuels Cement kilns, due

strongly alkaline atmospheres

and high flame temperatures

(2000°C), are capable of using

high calorific value waste fuels

(e.g. used solvents, waste oil,

used tires, waste plastics, and

organic chemical waste

including polychlorinated

biphenyls [PCBs], obsolete

organochlorine pesticides, and

other chlorinated materials).

The use of waste fuel can lead

to emissions of volatile organic

compounds (VOCs),

polychlorinated

dibenzodioxins (PCDDs) and

dibenzofurans (PCDFs),

hydrogen fluoride (HF),

hydrogen chloride (HCl), and

toxic metals and their

compounds if not properly

controlled and operated.

Use of waste fuel or waste raw

material in cement

manufacturing requires a

specific permit from the local

authority. The permit should

specify the amounts and t

of waste that may be used

either as fuel or as raw

material, and it should also

include quality standards such


and the waste fuels, and they

are not controlled through use

input materials and waste fuels though

implementation of materials selection.

Depending on the type of volatile

metals present in the flue gas, control

options may include wet scrubbers and

activated carbon adsorption;

• Operate the kiln in a controlled and

steady manner to avoid emergency

shutoffs of the electrostatic

precipitators (if present in the facility);

• Waste fuel should not be used during

start up or shut down.

Cement kilns, due to their

strongly alkaline atmospheres

and high flame temperatures

(2000°C), are capable of using

high calorific value waste fuels

(e.g. used solvents, waste oil,

used tires, waste plastics, and

organic chemical waste

including polychlorinated

CBs], obsolete

organochlorine pesticides, and

other chlorinated materials).

The use of waste fuel can lead

to emissions of volatile organic

compounds (VOCs),

polychlorinated

dibenzodioxins (PCDDs) and

dibenzofurans (PCDFs),

hydrogen fluoride (HF),

chloride (HCl), and

toxic metals and their

compounds if not properly

controlled and operated.

Use of waste fuel or waste raw

material in cement

manufacturing requires a

specific permit from the local

authority. The permit should

specify the amounts and types

of waste that may be used

either as fuel or as raw

material, and it should also

include quality standards such

• Implement monitoring and control of




Depending on the type of volatile metals

present in the flue gas, control options

may include wet scru


• Directly injecting fuels that have volatile

metals or high VOC concentrations into

the main burner rather than via the

secondary burners;

• Avoiding the use of fuels with high

content of halogens during secondary

firing and during startup and shutdown

phases;

• Keeping kiln gas cooling times (from

500 to 200°C) to a minimum to avoid or

minimize the reformation of already

destroyed PCDDs and PCDFs12,13,14;

• Implementing proper storage and

handling practices for hazardous

nonhazardous waste to be used as

waste fuel or raw material, as described

in the General EHS Guidelines.

• Waste fuel and waste raw materials are

seldom used in lime manufacturing

because of product quality

requirements.

8 | P a g e



Depending on the type of volatile

metals present in the flue gas, control

options may include wet scrubbers and

carbon adsorption;

Operate the kiln in a controlled and

steady manner to avoid emergency

shutoffs of the electrostatic

precipitators (if present in the facility);

Waste fuel should not be used during

Implement monitoring and control of




Depending on the type of volatile metals

present in the flue gas, control options

may include wet scrubbers and


Directly injecting fuels that have volatile

metals or high VOC concentrations into

the main burner rather than via the

Avoiding the use of fuels with high

content of halogens during secondary

ng and during startup and shutdown

Keeping kiln gas cooling times (from

500 to 200°C) to a minimum to avoid or

minimize the reformation of already

destroyed PCDDs and PCDFs12,13,14;

Implementing proper storage and

handling practices for hazardous and

nonhazardous waste to be used as

waste fuel or raw material, as described

in the General EHS Guidelines.

Waste fuel and waste raw materials are

seldom used in lime manufacturing

because of product quality


as minimum calorific value and

maximum concentration levels

of specific pollutants, such as

PCB, chlorine, PAH, mercury,

and other heavy met

B.B.B.B. Energy Consumption and FEnergy Consumption and FEnergy Consumption and FEnergy Consumption and Fuels uels uels uels

Cement manufacturing are energy

represent 40–50 percent of total production costs.

Kilns Kilns Kilns Kilns

For new plants and major upgrades, good international practice for the production of

cement clinker involves the use of a dry process kiln with multistage preheating and

precalcination (PHP kilns). PHP kilns are the most common kiln used in the cement

manufacturing industry. They have the lowest heat consumption (due to the high heat

recovery from kiln gas in the cyclones, and the low kiln heat losses), and no water to

evaporate (compared to wet kiln which uses slurry), while also offering the highest

production capacity. PH kilns are also used widely due to their ease of operation. Heat

consumption for PH kilns is only slightly higher than for PHP

production capacity is significantly lower than PHP kilns. The remaining types of kilns

(long-dry [LD], semidry, semiwet, and wet process k

further improve energy efficiency, the heat from the cooler should be used as hot process

air, such as via a tertiary air duct in the precalciner.

Fuels: Fuels: Fuels: Fuels:

The most commonly used fuel in the cement industry is pulverized coal (Black Coal and

lignite), however the lower cost of petroleum cock (pet

of this fuel type. Coal and pet coke generate higher emissions of greenhouse g

than fuel oil and natural gas (e.g. approximately 65 percent higher emissions than with

gas). In addition, high sulfur contents in the fuel (characteristic of pet coke) may create

problems, including mainly sulfur buildup on rings in the kiln. U

alternative to trafitional fuel is increasingly common in the cement industry.

abatement measures may be necessary to ensure that no toxic emissions are generated

from the firing of waste in cements kilns.


as minimum calorific value and

maximum concentration levels

of specific pollutants, such as

PCB, chlorine, PAH, mercury,

and other heavy metals.

uels uels uels uels

Cement manufacturing are energy-intensive industries. Electric energy and fuel costs can

50 percent of total production costs.


volves the use of a dry process kiln with multistage preheating and



in the cyclones, and the low kiln heat losses), and no water to



kilns is only slightly higher than for PHP kilns;


dry [LD], semidry, semiwet, and wet process kilns) are considered obsolete.


air, such as via a tertiary air duct in the precalciner.


lignite), however the lower cost of petroleum cock (pet-coke) has resulted in increased use

of this fuel type. Coal and pet coke generate higher emissions of greenhouse g



problems, including mainly sulfur buildup on rings in the kiln. Use of waste fuel as an

alternative to trafitional fuel is increasingly common in the cement industry.


from the firing of waste in cements kilns.

9 | P a g e

intensive industries. Electric energy and fuel costs can


volves the use of a dry process kiln with multistage preheating and



in the cyclones, and the low kiln heat losses), and no water to



however their


ilns) are considered obsolete. To



coke) has resulted in increased use

of this fuel type. Coal and pet coke generate higher emissions of greenhouse gases (GHG)



se of waste fuel as an

alternative to trafitional fuel is increasingly common in the cement industry. Pollution



Figure: 2 Electrical and Thermal Energy flow in Cement industry


ctrical and Thermal Energy flow in Cement industry

10 | P a g e

ctrical and Thermal Energy flow in Cement industry


Energy savings measuresEnergy savings measuresEnergy savings measuresEnergy savings measures

Cement manufacturing is an energy intensive process consuming about 12

energy consumption. Therefore opportunities exist to identify areas where energy savings

measures can be applied so that energy can be saved along with the reduction of emi

pollution.


Cement manufacturing is an energy intensive process consuming about 12


measures can be applied so that energy can be saved along with the reduction of emi

11 | P a g e

Cement manufacturing is an energy intensive process consuming about 12–15% of total


measures can be applied so that energy can be saved along with the reduction of emission


Sr. Sr. Sr. Sr.

NoNoNoNo

Energy saving in raw material preparationEnergy saving in raw material preparationEnergy saving in raw material preparationEnergy saving in raw material preparation

1 Efficient transport systems for raw material preparation (Dry process)

2 Raw meal blending system (Dry process)

3 Raw meal process control for vertical mills (Dry Process)

4 Use roller mills (Dry Process)

5 High efficiency classifiers /separators (Dry Process)

6 Slurry blending and homogenizing (wet Process)

7 Wash mills with closed circuit classifier (wet Process)

8 Roller mills for fuel preparation

Energy saving in clinker operation Energy saving in clinker operation Energy saving in clinker operation Energy saving in clinker operation

1 Improved refractory for clinker making in all kilns

2 Energy management and process control systems for clinker making in all kilns

3 Adjustable speed driver for kiln fan for clinker making in all kilns

4 Installation or upgrading of a preheater to a preheater/precalciner kiln for clinker

making in rotary kilns.

5 Conversion of long dry kilns to preheater/precalciner kilns for clinker making in

rotary kilns

6 Dry process upgrade to multi

7 Increasing number of preheater stages in rotary kilns

8 Conversion to reciprocating grate cooler for clinker making in rotary kilns.

9 Kiln combustion system improvements for clinker making in rotary kilns

10 Indirect firing for clinker making in rotary kilns

11 Optimize heat recovery/upgrade clinker coolers for making in rotary kilns

12 Low temperature heat recovery for power generation for clinker making in rotary

kilns

13 Seal replacement for clinker

14 High temperature heat recovery for power generation for clinker making in rotary

kilns

15 Low pressure drop cyclones for suspension preheaters for clinker making in rotary

kilns

16 Efficient kiln drivers for clinker making in r

17 Replacing vertical shaft kilns with new suspension

18 Preheater / precalciner kilns for clinker making in vertical shaft kilns

Energy Energy Energy Energy savingsavingsavingsavingssss in finish grinding in finish grinding in finish grinding in finish grinding

1 Process control and management in grinding mills for finish grinding

2 Vertical roller mills for finish grinding

3 High pressure (hydraulic) roller press for finish grinding

4 Horizontal roller mills for finish grinding

5 High efficiency classifiers for finish grinding

6 Improved grinding media

7 General energy saving measures

8 High efficiency motors and drivers


Energy saving in raw material preparationEnergy saving in raw material preparationEnergy saving in raw material preparationEnergy saving in raw material preparation

Efficient transport systems for raw material preparation (Dry process)

Raw meal blending system (Dry process)

Raw meal process control for vertical mills (Dry Process)

roller mills (Dry Process)

High efficiency classifiers /separators (Dry Process)

Slurry blending and homogenizing (wet Process)

Wash mills with closed circuit classifier (wet Process)

Roller mills for fuel preparation

Energy saving in clinker operation Energy saving in clinker operation Energy saving in clinker operation Energy saving in clinker operation

Improved refractory for clinker making in all kilns

Energy management and process control systems for clinker making in all kilns

Adjustable speed driver for kiln fan for clinker making in all kilns

Installation or upgrading of a preheater to a preheater/precalciner kiln for clinker

Conversion of long dry kilns to preheater/precalciner kilns for clinker making in

Dry process upgrade to multi-stage preheater kiln for clinker making in rotary kilns

Increasing number of preheater stages in rotary kilns

Conversion to reciprocating grate cooler for clinker making in rotary kilns.

Kiln combustion system improvements for clinker making in rotary kilns

Indirect firing for clinker making in rotary kilns

Optimize heat recovery/upgrade clinker coolers for making in rotary kilns

Low temperature heat recovery for power generation for clinker making in rotary

Seal replacement for clinker making in rotary kilns

High temperature heat recovery for power generation for clinker making in rotary

Low pressure drop cyclones for suspension preheaters for clinker making in rotary

Efficient kiln drivers for clinker making in rotary kilns

Replacing vertical shaft kilns with new suspension

Preheater / precalciner kilns for clinker making in vertical shaft kilns

in finish grinding in finish grinding in finish grinding in finish grinding

Process control and management in grinding mills for finish grinding

Vertical roller mills for finish grinding

High pressure (hydraulic) roller press for finish grinding

Horizontal roller mills for finish grinding

High efficiency classifiers for finish grinding

Improved grinding media

measures

High efficiency motors and drivers

12 | P a g e

Efficient transport systems for raw material preparation (Dry process)

Energy management and process control systems for clinker making in all kilns

Installation or upgrading of a preheater to a preheater/precalciner kiln for clinker

Conversion of long dry kilns to preheater/precalciner kilns for clinker making in

kiln for clinker making in rotary kilns

Conversion to reciprocating grate cooler for clinker making in rotary kilns.

Kiln combustion system improvements for clinker making in rotary kilns

Optimize heat recovery/upgrade clinker coolers for making in rotary kilns

Low temperature heat recovery for power generation for clinker making in rotary

High temperature heat recovery for power generation for clinker making in rotary

Low pressure drop cyclones for suspension preheaters for clinker making in rotary


9 Adjustable or variable speed drivers

10 High efficiency fans

11 Reduce leaks in compressed air systems

12 Reducing the inlet air temperatures in compressed air systems

13 Compressor controls in compress

14 Sizing pipe diameter correctly in compressed air systems

15 Heat recovery for water preheating in air compressor systems

16 Lighting control for plant wide lighting

17 Replace mercury light by metal halide or high pressure sodium

lighting

18 Replace magnetic ballasts with electronic ballasts for plantwide lighting

C. C. C. C. Wastewater Wastewater Wastewater Wastewater

Industrial Process Wastewater Treatment Wastewater is generated mainly from utility

operations for cooling purposes in different

Process wastewater with high pH and suspended solids may be generated in some

operations. Techniques for treating industrial process wastewater in this sector include

flow and load equalization with pH adj

reduction using settling basins or clarifiers; multimedia filtration for reduction in

nonsettleable suspended solids. Through use of these technologies and good practice

techniques for wastewater management, faci

prescribed norms of CPCB.

Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption

Stormwater flowing through pet

open air may become contaminated. Stormwater should be prevented from contacting

stockpiles by covering or enclosing stockpiles and by installing run

prevention techniques for dust emissions from stockpiles of raw materials, clinker, coal,

and waste (as above) may also help to minimize contamination of stormwater. If

stormwater does contact stockpiles, soil and groundwater should be protected from

potential contamination by paving or otherwise lining the base of the stockpiles, installing

run-off controls around them and collecting the stormwater in a lined basin to allow

particulate matter to settle before separation, control, and recycling or disc


Adjustable or variable speed drivers

Reduce leaks in compressed air systems

Reducing the inlet air temperatures in compressed air systems

Compressor controls in compressed air systems

Sizing pipe diameter correctly in compressed air systems

Heat recovery for water preheating in air compressor systems

Lighting control for plant wide lighting

Replace mercury light by metal halide or high pressure sodium lights for plant wide

Replace magnetic ballasts with electronic ballasts for plantwide lighting


operations for cooling purposes in different phases of the process (e.g. bearings, kiln rings)



flow and load equalization with pH adjustment; sedimentation for suspended solids



techniques for wastewater management, facilities should meet wastewater discharge as

Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption Other Wastewater Streams & Water Consumption

Stormwater flowing through pet–coke, coal, and waste material stockpiles exposed to the


stockpiles by covering or enclosing stockpiles and by installing run-on controls.





off controls around them and collecting the stormwater in a lined basin to allow

particulate matter to settle before separation, control, and recycling or discharge.

13 | P a g e

lights for plant wide

Replace magnetic ballasts with electronic ballasts for plantwide lighting


phases of the process (e.g. bearings, kiln rings)



ustment; sedimentation for suspended solids



water discharge as

coke, coal, and waste material stockpiles exposed to the


on controls. Pollution





off controls around them and collecting the stormwater in a lined basin to allow

harge.


D. D. D. D. Solid Wastes Solid Wastes Solid Wastes Solid Wastes

Sources of solid waste in cement and lime manufacturing include clinker production waste,

mainly composed of spoil rocks, which are removed from the raw materials during the raw

meal preparation. Another potential waste s

bypass flow and the stack, if it is not recycled in the process.

Limited waste is generated from plant maintenance (e.g. used oil and scrap metal). Other

waste materials may include alkali or chloride / fluor

kiln.

E.E.E.E. Noise Noise Noise Noise

Noise pollution is related to several cement manufacturing phases, including raw material

extraction; grinding and storage; raw material, intermediate and final product handling and

transportation; and operation of exhaust fans.

Noise prevention and mitigation measures should be applied where predicted or measured

noise impacts from a project facility or operations exceed the applicable noise level

guideline at the most sensitive point of reception

noise from stationary sources is to implement noi

Methods for prevention and control of sources of noise emissions depend on the source

and proximity of receptors. Noise reduction optio

• Selecting equipment with lower sound power levels

• Installing silencers for fans

• Installing suitable mufflers on engine exhausts and compressor components

• Installing acoustic enclosures for equipment casing radiatin

• Improving the acoustic performance of constructed buildings, apply sound

insulation

• Installing acoustic barriers without gaps and with a continuous minimum surface

density of 10 kg/m2 in order to minimize the transmission of sound through the

barrier. Barriers should be located as close to the source or to the receptor location

to be effective.

• Installing vibration isolation for mechanical equipment

• Limiting the hours of operation for specific pieces of equipment or operations,

especially mobile sources operating through community areas

• Re-locating noise sources to less sensitive areas to take

shielding

• Sitting permanent facilities away from community areas if possible

• Taking advantage of the natural topography as a n

• Reducing project traffic routing through community areas wherever possible

• Developing a mechanism to record and respond to complaints

Reference:

http://www.ifc.org/wps/wcm/connect/Topics_Ext_Content/IFC_External_Corpo

ental,+Health,+and+Safety+Guidelines/




meal preparation. Another potential waste stream involves the kiln dust removed from the

bypass flow and the stack, if it is not recycled in the process.


waste materials may include alkali or chloride / fluoride containing dust buildup from the



and operation of exhaust fans.



guideline at the most sensitive point of reception. The preferred method for controlling

noise from stationary sources is to implement noise control measures at source.


and proximity of receptors. Noise reduction options that should be considered include:

Selecting equipment with lower sound power levels

Installing silencers for fans

Installing suitable mufflers on engine exhausts and compressor components

Installing acoustic enclosures for equipment casing radiating noise

Improving the acoustic performance of constructed buildings, apply sound

Installing acoustic barriers without gaps and with a continuous minimum surface


rier. Barriers should be located as close to the source or to the receptor location

Installing vibration isolation for mechanical equipment

Limiting the hours of operation for specific pieces of equipment or operations,

sources operating through community areas

locating noise sources to less sensitive areas to take advantage of distance and

permanent facilities away from community areas if possible

Taking advantage of the natural topography as a noise buffer during facility design

Reducing project traffic routing through community areas wherever possible

Developing a mechanism to record and respond to complaints

http://www.ifc.org/wps/wcm/connect/Topics_Ext_Content/IFC_External_Corporate_Site/IFC+Sustainability/Sustainability+Framework/Environm

14 | P a g e



tream involves the kiln dust removed from the


ide containing dust buildup from the





. The preferred method for controlling

se control measures at source.


ns that should be considered include:

Installing suitable mufflers on engine exhausts and compressor components

Improving the acoustic performance of constructed buildings, apply sound

Installing acoustic barriers without gaps and with a continuous minimum surface


rier. Barriers should be located as close to the source or to the receptor location

Limiting the hours of operation for specific pieces of equipment or operations,

advantage of distance and

oise buffer during facility design

Reducing project traffic routing through community areas wherever possible

rate_Site/IFC+Sustainability/Sustainability+Framework/Environm

6. cement sector - envis centre on:cleaner productiongcpcenvis.nic.in/experts/cement sector.pdf ·...

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