### Environmental, Health, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DIS TILLATION

D ECEMBER 10

, 2007 1 WORLD BANK GROUP 

# Environmental, Health and Safety Guidelines for Large Volume Inorganic Compounds Manufa c t uring and Coal Tar Distillation
In troduction
The Environmental, Health, and Safety (EHS) Guidelines are technical reference documents with general and industry

speci fic examples of Good International Industry Practice (GIIP) 1

. When one or more members of the World Bank Group are involved in a project, these EHS Guidelines are applied as required by their respective policies and standards. These i n dustry sector EHS gui delines are designed to be used together with the General EHS Guidelines document, which provides gui d

ance to users on common EHS issues potentially applicable to all industry sectors. For complex projects, use of multiple i n dustry

- sector guidelines may be

necessary. A complete list of indu

s try

- sector guidelines can be found at: www.ifc.org/ifcext/enviro.nsf/Content/EnvironmentalGuidelines
The EHS Guidelines contain the pe rformance levels and

mea s ures that are generally considered to be achievable in new facil i ties by existing technology at reasonable costs. A p plication of the EHS Guidelines to existing facilities may involve the esta b lishment of site

- specific targets, with an appr o priate timetable for achieving them.
The applicability of the EHS Guidelines should be tailored to the hazards and risks established for each pr o ject on the basis of

1 Defined as the exercise of professional skill, diligence, prudence and foresight that would be reasonably expected from skilled and experienced professionals engaged in the same type of undertaking under the same or similar cir cu m stances globally. The circumstances that skilled and experienced professionals may find when evaluating the range of pollution prevention and control tec h niques available to a project may include, but are not limited to, varying levels of environmental degradation and environmental assimilative capacity as well as varying levels of financial and technical feasibility. the results of an environmental asses s ment in which site

specific variables, suc

h as host country context, assimil a tive capacity of the environment, and other project factors, are taken into account. The applicability of specific technical recommend

a tions should be based on the profe s sional opinion of qualified and experienced persons

. When host country regulations differ from the levels and measures presented in the EHS Guidelines, projects are expected to achieve whichever is more stringent. If less stringent levels or measures than those provided in these EHS Guidelines are appropri ate, in view of specific project ci r

cumstances, a full and detailed justification for any proposed alternatives is needed as part of the site

- specific environmental assessment. This justification should demonstrate that the choice for any alternate perform ance levels is protective of h u man health and the environment. 

# Applicability

This EHS Guideline includes information relevant to c hemical manufacturing projects and facilities, and covers the production of large volume inorganic compounds (LVIC), including

a mmonia, a cids (nitric, hydrochloric, sulfuric, hydrofluoric, phosphoric a cid), c

hlor

- a lkali (e.g. chl o

rine, caustic soda, soda ash, etc.), c

arbon b lack , and c oal t ar d istillation (naphthalene, phenanthrene, anthr

a cene)

. This document is

o r ganized accord i ng to the following sections:

Section 1.0

—

Industry

- Specific Impacts and Management Section 2.0

—

Performance Indicators and Monitoring Section 3.0

—

References and Additional Sources Annex A

—

General Description of Industry Activities

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 2 WORLD BANK GROUP 

# 1.0 Industry

- Specific Impacts and Manag e ment
The following section provides a summary o f EHS i ssue s associated with facilities

manufacturing large volume inorganic compounds ( LVIC)

and for coal tar distillation , which occur during the operational phase, along with reco mmendations for their management.
Recommendations for the management of EHS impacts

co m mon to most large industrial facilities during the constru c tion and decommissioning phase s are provided in the Ge

n eral EHS Guid e line s

. 

## 1.1 Environmental
Typical e nviro

nmental issues associated with LVIC manufacturing include the following:

• Air emissions

• Liquid effluents

• Generation of solid waste

• Hazardous materials management

• Noise

• Odors

• Deco m

missioning



### Air Emissions T he manufacture and use of inorganic chemicals and c hemical products typically generate s large volume of emissions; however, current technology allows for closed system operations , thus significant

ly reducing e mission releases to the environment.
Emission sources from chemical processes include process t ail gases, heaters and boilers; valves, flanges, pumps, and compressors; storage and transfer of raw materials, products and intermediates; waste water handling; flares; and emergency vents.
Although chemical manufacturing emissions vary depending on the specific process and related feedstok, the most common pollutants that may be emitted from point or fugitive sources dur ing routine operations, include: carbon dioxide (CO 2 )
, nitrogen oxides (NO X )
, sulfur oxides (SO X ), ammonia (NH 3

)
, acids and acid mists

, chlorine gas, and dust

. Volatile organic compounds and tar fume are emitted from carbon black and coal tar distillation plants.

The gaseous emissions from the chemical manufacturing industry can be typically controlled by adsorption or absorption. Parti culate emissions

, usually less than 10 mi crons in aerodynamic diameter, are controlled by h ighly efficient systems such as bag filters, electrostatic precipitators, etc.

Chemical manufacturing facilities are large consumer of energy. Exhaust gas emissions produced by the combustion of gas or other fuels in turbines, boilers, compressors, pumps and other engines for power and heat generation, are a signi ficant source of mainly CO

2 and NO

X
. Guidance for the management of small combustion source emissions wi th a capacity of up to 50 megawatt hours thermal (MWth), including air emission standards for exhaust emissions, is provided in the General EHS Guidelines

. Guidance for the management of combustion source emissions from larger sources of power generation is provided in the EHS Guidelines for Thermal Power.



### Greenhouse Gases

(GHG s ) The LVIC manufacturing industry is a significant emitter of greenhouse gases, especially carbon dioxide (CO 2 ). GHGs are generated from the process as well as during the producti on of its highly demanding energy needs. Measures to increase

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 3 WORLD BANK GROUP energy efficiency and installation of Low NO X burners should be adopted since they will contribute to reduce CO 2 gener a tion.

A ttempts should be made to maximize energy efficiency and design faci lities for lowest energy use. R ecommendations on energy efficiency are addressed in the General EHS Guidelines

. 

### Fugitive Emissions Fugitive emiss

ions are associated with leaks from pipes , valves, connections, flanges, packings, open

- ended lines, floating roof storage tank and pump seals, gas conveyance systems, compressor seals, pressure relief valves, tanks or open pits / containments, and loading and unloading operations of products. Due to the presence of hazardous products in LVIC manufacturing facili ties ( i.e. NH 3 and chlorine) , methods for controlling and preventing fugitive emissions should be considered and implemented in the ir design, operation, a nd maintenance . The selection of appropriate valves, flanges, fittings, seals, and packings should be based on their capacity to reduce gas leaks and fugitive emissions.
Use of open vents in tank roofs should be avoided by installing pressure relief valves. S torages and unloading stations should be provided with vapor recovery units. Vapor processing syste ms may consist of different methods , such as carbon adsorption, refrigeration, recycling collecting and burning.
Examples of measures for reducing the generation of fugitve emissions include:

• Rig o rous maintenance

programs, particularly in stuffing boxes on valve stems and seats on relief valves, to reduce or eliminate accidental releases;

• Selection of appropriate valves, flanges, fittings;

• Well designed , constructed, operat ed and maintained installations; • Implementation of leak detection and repair progra ms ;

• Installation of continuous m onitoring in all sensitive a r

eas

. 

### Venting and Flaring Venting and flaring are important safety measure s used in chemical manufacturing facilities to ensure gas is safely disposed of

during process start up and shut down or i n the event of an emergency, power or equipment failure, or other plant upset conditions.
Recommended methods to prevent, minimize, and control air emissions from venting and flaring include:

• Use best practices and new technologies to minimize

r e leases a nd potential impacts from venting and flaring ( e.g., efficient flare tips, reliable pilot ignition system, minimization

of liquid carry over, control of odor and visible smoke emissions

, and locating flare at a safe di s tance from potential human and enviro nmental rece p tors

);

• Estimate flaring

volumes and develop flaring targets for new facilities

, and record volumes of ga

s flared for all fla r ing events;

• Divert gas emissions from emergency or upset cond i tions to an efficient flare gas system. Emergency ven t in g may be acceptable under specific conditions where flaring of the gas stream is not possible, on the basis of a risk analysis. Justification for no gas flaring system should be fully doc u mented before an emergency gas venting facility is consi d ered.



### Proce ss Air Emissions

–

Ammonia Ma nufa

c turing Process air emissions from ammonia plants consist mainly of hydrogen (H 2

), carbon dioxide (CO 2 ), carbon monoxide (CO), and ammonia (NH 3

)

. Concentrated carbon dioxide emissions are generated from CO 2 removal i n these

facilities. Fugitive emissions of NH 3

(e.g. from storage tanks, valves, flanges, and

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 4 WORLD BANK GROUP tubing) may also occur, especially during tran s port or transfer. Non

- routine emissions associated with process u p sets or accidents may contain natural gas, CO, H 2 , CO 2 , v olatile organic compounds (VOCs), nitrogen oxides (NO X ) and NH 3 .
Recommended e mission prevention and control measures i n clude the fo l lowing:

• Use synthesis

NH 3 purge gas treatment to recover NH 3 and H 2 before combustion of the remainder in the primary

r e f ormer;

• Increase the residence time for off

- gas in the high

te m perature zone;

• Connect ammonia emissions from relief valves or pre

s sure control devices from vessels or tanks to a flare or to a

w a ter scrubber;

• Combine ammonia

and urea facilities to reduce ( through reuse in urea plant) ammonia process

- generated CO 2 emissions

2

. Another industrial alternative is to combine with methanol production . It is noted that, in methanol pr o duction facilities, hydrogen is produced from natural gas, by means of a steam reforming unit followed by a methanol unit. This process , therefore, does not fully eliminate CO

2 emissions because of the energy used to run the hydrogen production and methanol sy n thesis units.



### Process Air Emissions

– Acid Manufactu r ing Process emission

s fr om acid plants include the following:

• Nitrous oxide (N 2

O) and NO

X from nitric acid manufacturing plants , particularly from tail gas emissions 3 ;

2 Ammonia process

-

derived CO

2 can be almost totally consumed if the produced ammonia is transformed into urea (1t NH 3 - 1 .5 t urea)

. 3 Th e lowest NO

X emission levels currently achieved in a modern plant without added pollution abatement are between1,000 to 2,000 ppmv for medium pressure absorption and 100 to 200 ppmv for high pressure absorption. For new plants in normal operating condition s the NO

X emission level (excluding N 2 O) • SO 2 resulting from incomplete oxidation and SO 3 resulting from incomplete absorption and droplets of sulfuri c acid (H 2 SO 4 ) from sulfuric acid manufacturing plants;

• Gaseous fluorides and dust from phosphoric / hydrofluoric acid plants ;

• Hydrochloric acid (

HCl ) gas, chlorine, and chlorinated organic compounds result

ing primarily from gases exiting the HCl purificat

ion system in HCl production;

• Fluorine, hydrofluoric acid (HF), and silicon tetr a fluoride (SiF 4 ) from digestion of phosphate rock and dust from handling of phosphate rock in HF production

. Particulate matter is emitted during handling and drying of the fl uo r spar. I n hydrofluoric acid facilities fluorine emissions present in the final vents are typically very low following the required treatment

.
Recommended e mission prevention and control measures include the following:

• The plant should be

equipped with pre

- condenser s that

r e move water vapor and sulfuric acid mist, and with conden s ers, acid scru b

ber s , and water scrubbers that minimize the release

of HF, SiF 4

, SO 2 , and CO

2 from t he tail

- gas;

• Use high

- pressure adsorption process for nitric acid pr o duction to minimize the concentration of NO X in the tail gas ;

• Treat the off

- gases from nitric acid plants using cat a lytic NO X removal ;

• Consider using double absorption process for H 2

SO 4 plants. P lants operating on a single absorption process shouild consider impl ementation of the following:

o C esium catalyst in the last bed

can be at 100 ppmv, which is equivalent to 0.65kg NO X (expressed as NO 2 ) per ton of 100% nitric acid produced.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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o SO

2 abatement by scrubbi ng with a neutralizing compound

o SO

2 abatement with hydrogen peroxide (H 2 O 2 )

• Control dust emissions from the flue

- gases of directly heated dryers and/or from pneumatic conv eying g ases using cy clones and filters;

• Recover the fluorine as fluosilicic acid; a dilute solution of fluosilicic acid should be used as the scrubbing liquid. Fluorine, released during the digestion of phosphate rock and during the concentration of phosp horic acid, should be removed by scrubbing systems;

• Control e missions of HF by the condensing, scrubbing, and absorption equipment used in the recovery and purification of the hydrofluoric and hexafluorosilicic acid products;

• Minimize HF emissions , maintai ning a slight negative pressure in the kiln during normal operations;

• Install caustic scrubber s t o reduce the levels of pollutants in the HF tail

- gas, as needed;

• Control d ust emissions by bag filters at the fluorspar silos and drying kilns. Collect dust f rom the gas streams exiting the kiln in HF production and return the dust to the kiln for fu r ther processing

;

• Control dust emissions from fluorspar handling and storage with flexible coverings and chemical additive s , and

• Control d ust emissions from phospha te rock

during transport, handling and storage , using enclosed systems and bag filters

. 

### Process Air Emissions

– Chlor

- Alkali Plants The princip

al chlor

- alkali processes are mercury, diaphragm,

a nd membrane cell electrolysis. The most significant emi s sion s from all three processes are both fugitive and point source chl o rine gas emissions. Sources of potential signif i cant chlorine emissions are normally associated with the chlorine destruction unit where emissions from non

- condensable gases remaining from liq uefaction (H 2 , O 2 , N 2 , CO 2 ) having a chlorine content from 1

- 8% of the raw chlorine gas produced are treated. Other emissions from chlor

- alkali plants are linked to the brine purific a tion. Air emissions from mercury cell technology include mercury v a pors, emitted as fugitive emissions from the cells (e.g. cell room ventilation gas )

. Principal air emissions from soda ash manufacturing are pro c ess carbon dioxide and particulate emissions from ore calciners, soda ash coolers and dryers, ore crushing, screen ing, and transportation operations, product handling and shipping oper a tions. Emissions of products of combustion, such as carbon monoxide, nitrogen oxides, and sulfur dioxide, occur from direct

- fired process heating units such as ore calcining kilns and s oda ash dryers. Ammonia may also be emitted. Nitrogen oxides

are produced in small quantities i n side the kiln by the oxidation of nitrogen contained in the air used in the combustion process, and sulfur oxides by the oxidation of compounds containing su l f

u r in the limestone.

Recommended e mission prevention and control measures i n clude the fo l lowing:

• Discontinue use of m

ercury and diaphragm cell pro c esses, where possible, and adopt new membrane cell process

. Alternatively, install i mp

roved cell part materia

ls (e.g. d i mensionally stable anodes (DSA®), modified diaphragm), as needed;

• Prepare

mercury mass balances to ac c ount for all mercury

use ;

• Optimize

process to keep the cells as close as possible ;

• Install mercury

distillation units to recover mercury ;

• E nsu re that

that the mercury cell end boxes and caustic boxes are properly sealed, thus eliminating fugitive releases ;

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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• Design t

he chlorine absorption unit with a treatment capa c ity sufficient to absorb the full cell

- room production and prevent emissions of chl orine gas in the event of a process upset until the plant can be shut down. The

a b sorption unit should be designed to lower the chlorine content in the emitted gas to less than 5 mg/m 3 in the worst

case sc e nario;

• Direct a ll chlorine

- containing waste gas st reams to the chlorine absorption unit

and ensure that the system is gas tight ;

• Install c

hlorine gas detectors in areas with a potential risk of chlorine leaks to allow for immediate leakage detection;

• Use c arbon tetrachloride

- free chlorine liquefaction and pur i fication processes

. The use of carbon tetrachloride (CCl 4 ), for removal of nitrogen trichloride (NCl 3 ) and for absorption of tail gas

, should be avoided

and discontinued ;

• In soda ash facilities

, control particulate emissions from ore and product han

dling operations by either venturi

scru b bers, or baghouse filters, electrostatic precipit a tors, and/or cyclones

and recycle the collected partic u lates

. 

### Process Air Emissions

– Carbon Black Manufactu r ing An important potential source of emission to air is the tail gas coming from the reactor after carbon black separation, which is a low calorific gas with a high moisture content due to the quench water vapor. The tail

- gas composition may vary consi d erably according to the grade of carbon black being pr o du ced and the feedstock used. It may contain H 2 , CO, CO

2 , reduced sulfur compounds (H 2 S, CS 2 and COS), SO

2 , nitrogen

co m pounds (N 2

, NO X , HCN and NH 3

), VOCs such as ethane and acetylene, and carbon black particles that are not captured by product separ

a tion b ag filter s.

Recommended e mission prevention and control measures i n clude the following: • Use primary feedstock with a sulfur content in the range of 0.5

- 1.5 percent

4 ;

• Preheat process air in heat exchangers using the hot gases (containing carbon black) leaving the furnace black

rea c tor;

• Install and maintain high

- performance bag filters to e n sure high carbon black collection efficiency and minimum pro d uct losses of the residual carbon black in the filtered tail gas;

• Utilize the energy content of the tail gas (by burning the gas and using the energy

produced );

• Primary NO

X reduction techniques

should be applied to reduce the NO

X content in flue

- gas originating from tail

- gas combustion in energy producing systems 5 ;

• Install fabric

filters for the air conveying system, vent colle c tion system, and dryer purge gas 6 ;

• V ent un

- combusted tail

- gas only during emergencies , start

up and shut

- down periods, and during periods of grade change.



### Process Air Emissions

– Coal Tar Distill a tion Although coal tar distillation emi ssions occur in normal ope r ating conditions, the key emissions from these pro c esses that warrant control are those consisting of tar fume, odor, polycyclic

ar o matic hydrocarbons (PAH), and particulate ma t ter, which may originate from facility processes inc luding delive

r ing, storing, heating, mixing

, and cooling tar.

Recommended e mission prevention and control measures i n clude the fo l lowing:

4 Specific emission levels of 10

– 50 kg SO

X (as SO

2 ) per tonne of rubber grade carbon black produced ar

e possible, as a yearly average

. 5 Plants emission levels associated with use of BAT are less than 0.6 g NO X /Nm 3 as an hourly average at 3 % O 2 during normal production. 6 For the low temperature air conveying and vent collector systems, assoc i ated emissi on levels are 10 to 30 mg/Nm 3 as a half

- hour ave r age. For the dryer purge filter, associated emission levels are from less than 20 to 30 mg/Nm 3 as a half

hour average

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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• Use ground

- based pumps and other methods to opt i mize tar deliveries to reduce emissions of tar fume and odor;

• Site st

orage tanks downwind of potential nearby rece p tors, control temperature of stored materials 7 , and implement careful handling procedures to prevent odor nuisance;

• Implement overfill prevention methods for bulk sto r

age tanks , such as high

- level alarms or vol ume indicators;

• Used local exhaust ventilation adequate to collect and treat VOC emissions

from mixing tanks and other processing equipment

. 

### Liquid Effluents Liquid effluents include process and cooling water, storm w a ter , and other specific discharge s ( e. g. hydrotesting and cleaning , mainly during facility start up and turnaround). 8 Process water discharges from LVIC

manufacturing plants may include the acid wash from scheduled cleaning activities and purges, which are part of daily operation. Additional potential sources of effl u ents may include scrubbers, if used as air emission control sy s tems. Accide n tal releases or leaks from product storage tanks such as refrigerated ammonia and acid storage may also pr o duce effluents. Other sources include acidic a nd caustic effl u ents from the boiler feed water preparation for the different steam sy s tems. Cooling water and storm water management

are a d dressed in the General EHS Guidelines

. Effluents and control specific to different types of c hemicals manufactu ring

plants are described below.



### Effluents

– Ammonia Manufacturing Plant discharges, during normal operation, may occur due to process condensates or due to the scrubbing of waste gases containing ammonia and other products. In partial oxidation,

7 The rate of fume emission doubles for approximately every 11oC rise in te m perature. 8 F a cility turnarounds are usually limited to once every three to four years and last a few weeks. soot and ash removal may impact water discharged, if not pro p erly handled.
Recommended measures to prevent, minimize, and control

e f fluents from ammonia plants include:

• Recover ammonia

absorbed from purge and flash gases in a closed loop system so that no aqueous ammon ia emi s sions occur

;

• Recover soot

from gasification in partial oxidation pro c esses and recycle the recovered material to the process.


### Effluents

– Acids Manufacturing Effluents from nitric acid plants may be contaminated with nitr o gen compounds . Effluents f

rom hydrochloric acid plants can vary depending on manufacturing processes from traces of HCl when r

e acting H 2 with Cl, to mineral salt (Na 2 SO 4 ) when the acid is produced by reac t

ing sodium chloride with sulfuric acid.
Liquid releases from phosphoric acid plants mainly consist of the liquid effluents originating from vacuum cooler conden s ers and gas scrubbing systems used for condensation and cleaning of the vapors that evolve in the various process stages. These condensed acidic vapors contain mainly flu o rine and small amounts of phosphoric acid. The fluorine released from the

r e actor and evaporators can be recovered as a commercial by

product (fluo

ro silicic acid 20

- 25 percent

).
Recommended measures to prevent, minimize, and control

e f fluents from acid pl ants include:

• Use closed

- loop reactors and evaporators to elim i nate process wastewater;

• Recirculate t

he water used for the transport of phosphogypsum into the process after settling ;

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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• Treat scrubber effluent with lime or limestone or use

se a water as a scrub

bing liquid to precipitate fluorine as

ca l ci um fluoride;

• Install a separator to remove phosphoric acid droplets from vacuum flash coolers and vacuum evaporators emissions before scrubbing t

o minimize contamination of the scrubber effluent with phosphorous pento x ide ( P 2 O 5 ) ;

• Recover fluorosilicic

acid ( H 2 SiF 6 ) from treatment of tail gases from hydrofluoric units for use as a feed material or for the manufacture of fluorides or silicofluorides

. H 2 SiF 6 can also be chemically combined to produce CaF 2 and si l ica

. 

### Effluents

– Chlor

- Alkali Plants Brine is one of key waste streams of the chlor

- alkali industry. Membrane cells may use recycled brine requiring dechlorin a tion. Sp e cifically for membrane technology, brine purification is of critical importance to long memb rane life and high eff i ciency. The m

ain components in brine purification wastes are sulfate, chloride, free oxidants, chlorate , bromate , and carbon tetrachl

o ride.
The main sources of liquid effluent from the soda ash pro c ess are typically waste water from the distillation and brine purific a tion and cooling waters. The effluents are characte r ized by high levels of suspended solids 9 . Another significant i

s sue is the potential discharge of heavy metals present in the main raw

m a terials 10

.
Recommended measures to prevent, minimize, and control

e f fluents from chlor

- alkali plants include:

9 Loads of suspended solids discharged with waste waters are generally si g nificant and range from 90 to 700 kg/t soda ash, with an average value est i mated at 24

0 kg/t soda ash. 10 For a soda ash plant with a capacity of around 600 kt/year, 10 to n nes per year can be reached. • Purify b rine by pH adjustment, pr

e cipitation, flocculation and filtration to keep impurities at acceptable levels. The consumption of chemicals which are employed to purify the b rine varies from plant to plant depending on the impurities of the brine

;

• Recycle brine in membrane technology, removing impur i ties by ion exchange resin units . R egeneration of resins requires caustic soda and acid was h ing ;

• Minimize consumption and discha rge of sulfuric acid by means of on

- site re

- concentration in closed loop evapor a tors. The spent acid should be used to control pH in pro c ess and waste water streams; r e sold to a user that accepts this quality of acid; or returned to a sulfuric acid manufa c turer for re

- concentration;

• Use fixed bed catalytic redu c tion, chemical reduction, or other equally effective method to minimize discharge of free oxidants 11 ;

• Adopt c

arbon tetrachloride

- free chlorine liquefac tion and purification processes;

• Use acid condit

ions in the anolyte (pH 1

- 2) to min i mize the formation of chlorate (ClO 3

) and bromate (BrO 3 ), and chl o rate destruction in the brine circuit to remove chlorate b e fore purging

in membrane plants 12

. 

### Effluents

– Carbon Black / Coal Tar Distill a tion
Waste water effluents are of relatively limited significance for the

ca r bon black industry and in coal tar distillation units.

A zero discharge to water is possible for some types of ca r bon black plants. However, the production of some rubber black and nearly all spe cialty black grades require clean quench water. S uspended solids (mainly carbon black) should be filtered

11 The emission level of free oxidants to water associated with implementation of best available technuiques is less than 10 mg/l. 12 The chlora te level associated with best available techniques in the brine circuit is 1

- 5 g/l and the associated bromate level is 2

- 10 mg/l , and depends o

n the bromide level in the salt

.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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b e fore discharge (or re

- use) to levels less than 20 mg/l. After filtr a tion, process streams can be reused.
Suspended solids, BOD and PAH concentrati ons should be monitored in effluents from coal tar distillation units. 

### Hydrostatic Testing Water Hydrostatic testing of equipment and pipelines usually need s significant amount of water (

e.g., NH 3 tanks may have

c a pacities of more than 20

- 30 ,000 m 3 ). Chemi cal additives (typically a co

r rosion inhibitor, an oxygen scavenger, and a dye) are often added to the water to prevent internal corr o sion.
In managing hydrotest waters, pollution prevention and co n trol measures should be considered including: optimizing w a ter consumption and optimum dosage and careful selection of needed chemicals.
If discharge of hydrotest waters to the sea or to surface water is the only feasible alternative , a hydrotest w

a ter d is posal plan should be prepared. The plan should include , a t a min i mum , characteristics of the discharge point ( s ) rate of di s charge, chemical use and dispersion, env i ronmental risk, and required monitoring.
Hydrotest water disposal into shallow coastal w a ters should be avoided.



### Wastes Well

- managed c

hemicals manuf

acturing plants

should not generate significant quantities of solid wastes during normal operation. Typical wastes ge ne rated include waste oils, spent catalysts, sludge from wastewater treatment units, collected dust from bag houses, bottom ashes from boil ers, muds and cakes from filtration units, etc. Recommended management strategies for spent catalysts include the following:

• Proper on

- site management, including submerging pyrophoric spent catalysts in water during temporary storage and transport until th ey reach the final point of treatment to avoid uncontrolled exothermic reactions;

• Off

- site management

by specialized companies that can recover and reclycle heavy metals (or precious metals from nitric acid plant catalysts) whenever possible

. Storage and handling of hazardous and non

- hazardous wastes should be conducted in a way consistent with good EHS practice for waste management, as described in the EHS General Guidelines

.


### Waste

– Ammonia Manufacturing
A mmonia manufacturing processes should not produce significant solid wastes 13

. Spent catalysts and mol

ecular sieves management should be conducted as specified above

. 

### Waste

– Acids Manufacturing Phosphog ypsum is the most significant by

- product in wet pho s phoric acid production 14

. Phospho gypsum contains a w

ide range of impur

i ties, some of which are considered a potential hazard to the enviro

n ment and public health

. 15 , 16

13 Spent catalysts and other solid waste should be less than 0.2kg per ton of pro duct. 14 Around 4

-

5 tons of phosphogypsum (princ i pally calcium sulfate, CaSO4) are produced for every ton of phosphoric acid pr o duced 15 The impurities contained in the phosphate rock are distri b uted between the phosphoric acid produced and the calcium sul fate (gypsum); mercury, lead and radioactive components, where present, end up mainly in the gy p sum, while arsenic and the other heavy metals such as ca d mium end up mainly in the acid

. The radioactivity of phosphate rock is mainly from radionuclides from t he radi o active decay series of uranium

- 238. 16 Phosphate rock, phosphogypsum, and the effluents produced from a pho s phoric acid plant have generally a lower radioactivity than the exem p tion values given in the relevant international regulations and guidelin es ( for example, EU Directive 96/26/EURATOM)

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 10 WORLD BANK GROUP Calcium sulfate (anhydrite) is produced as a by

- product of h y drofluoric acid (HF) manufacturing
, contain ing between 0.2 to 2.0 % of unreacted CaF 2

and less than 1.0 % H 2

SO 4 . It also contains the majority of the trace impurities contained in the fluorspar 17

. Recommended measures to prevent or minimize solid waste generation and to manage solid waste from acid plants i n clude:

• Disposal of phosphogy psum in land facilities d

e signed to prevent leaching to groundwater or surface water

. Any

e f fort should be made in order to reduce the impact of phosphogypsum disposal and possibly improve the quality of the gypsum, for its reuse. D isposal to sea is consi dered non acceptable ;

• Refinement and sale of calcium sulfate anhydrite from HF production for use in other products (e.g. cement ), if possible.



### Waste

– Chlor

- Alkali Plants Brine sludges are one of the largest waste stream s of the chlor

alkali industry. The

quantity of brine filtration sludges mainly d e pends on the incoming salt characteristics

, used for the purification of the brine

. The precipitated salts are removed from the brine through decantation/clarification and filtration

. The sludge may be

removed discontinuously by flushing with a weak hydrochloric acid solution. The acid causes the precip i tate to dissolve and the relatively harmless solution can be di s charged with liquid effluent. Wastes are generated during the secondary brine pur i fication and c

onsist of used materials such as precoat and body feed material made of cellulose. The precoat filter sludge from the brine softener consists mainly of alpha

cellulose, contam

i nated with iron hydroxide and silica 18 . Ion

17 About 3.7 tonnes of anhydrite per tonne of HF are pr o duced as by

- product. 18 Membrane cell plants report a figure of 600 g/t for sludge from brine softe n ing. exchange resins for secondary brine p urification are rarely changed 19 . Spent me m

branes 20 and gaskets from membrane cells are other waste streams.

The main solid waste s

from soda ash unit are fines of lim e stone (30

– 300 kg/t soda ash) and n on recycled grits at slaker (10

– 120 kg/t soda ash)

. Recommended measures to prevent, minimize solid waste ge n eration and to manage solid waste from chlor

- alkali plants i n clude:

• Attempt to find reuse

options for waste solids from the pur i fication of salt brine

; if the waste must be disposed of,

co n sider th e use of natural repositories, such brine cavities ;

• Select limestone

with high CaCO

3 content , appropr i ate physical characteristics , and limited content of heavy

me t als and other impurities

.


### Waste

– Carbon Black / Coal Tar Distillation Carbon black process

es generate very limited amount of ha z ardous waste (oil residues). Coal

- tar pitch is a black solid

res i due from the distillation of coal tar. The recovery of tar chemicals leaves residual oils, including heavy naphtha, dephenolated carbolic oil, naphthalen e drained oil, wash oil, strained anthracene oil, and heavy oil.
Recommended measures to prevent, minimize solid waste ge n eration and to manage solid waste include:

• R euse spent oil , oil sludge, and coal tar distillation res i dues as feedstock or fuel , if po

ssible;

• Recycle o ff

- spec ification carbon black back into the process.

19 Resins are regenerated about 30 times per year. 20 The membranes have a lifetime of b e tween 2 and 4 years.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 11 WORLD BANK GROUP 

### Hazardous Materials Management Chemical manufacturing

plants are required to a

s sess the risks associated with the use and handling of hazardous m

a terials and implement practices to preve nt and minimized such risks. As indicated in the General EHS Guidelines , the application of these management practices should be doc u mented in a written Hazardous Materials Manag e ment Plan 21

. The purpose of

this plan is to establish

and impl e ment

a systema tic set of preventive actions against accidental releases of substances that can cause serious harm to the public and the environment from short

- term exposures and to mitigate the severity of releases that do o c cur.
Industry

- specific pollution prevention a nd control practices include the following:

• Accidental releases

of fluids through should be prevented trough inspections and maintenance of storage and conveyance systems, including stuffing boxes on pumps and valves and other potential leakage points

. Sp illages of dangerous intermediates and product should be contained and recovered or neutralized as quick as possible;

• Secondary containment for the storage tanks storing liquid s (i.e, ammonia , acid

s, etc.) and spare capacity for dangerous products like

chlorine should be installed as discussed in the General EHS Guidelines ;

• Maintain good housekeeping practices, including conducting product transfer activities over paved areas and prompt collection of small spills

. 

### Noise In chemical manufacturing

facilit ies, significant noise sources include large size rotating machines, such as compressors and turbines, pumps, elect

ric motors, air coolers

, and fired heaters.

21 See IFC Hazardous Waste Management Manual. During emergency depressurization, high noise levels can be generated due to high pre

s sure gases to flare and/or steam release into the atmosphere.
Noise prevention and abatement strategies i n clude:

• O ptimization of

plant layout

s in order to use the larger buil d ings as noise barriers and locating noise sources as far as possible from existing rece p tor s;

• U se of

low noise generation equi p ment;

• I nstallation

of acoustic insulating barriers and silen c ers.
Noise abatement and control measures are similar to other large industries and are addressed in the General EHS Guidelines

. 

### Odors Odor s from fugitive vapo

r releases or from wastewater treatment plants may be generated in the LVIC manufacturing processes. Adequate controls to eliminate leaks should be implemented to minimize fugitive releases and prevent odor nuisances.



### Decom m issioning Chemical manufacturi ng facilities may have important quant i ties of solid and liquid hazardous materials such as CO 2 r e moval solutions, liquid ammonia, chlorine, soda, acids and products in process and storage systems, off spec products, spent cat a lysts , and mercury from mercu ry cell chlor

- alkali plants.
Recommended management practices of decommissioning

a c tivities include the follo

w ing:

• In the case of mercury cell chlor

- alkali plants, car

e fully plan all decommissioning steps to minimize r e leases of mercury and other hazardo

us substances (including dioxins and f u rans if graphite anodes were used) and to protect worker

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 12 WORLD BANK GROUP health and safety, and plan for dispos i tion of the remaining mercury;

• Collect CO

2 removal solutions

in the ammonia plants and all dangerous products for further handling and di s

posal as a hazardous waste material;

• Remove spent catalysts from NH 3 and HNO

3 plants for fu r ther management as described in the solid waste section above;

• Recover and further manage NH 3 , Cl 2 , a cids, and all other products from the synthesi s section and storage tanks as well as all products and intermediates from the storage tanks according to hazardous materials management gui d ance from the

General EHS Guid e lines.
General guidance on decommissioning and contaminated land remediation is prov ided in the General EHS Guid e lines

. 

## 1.2 Occupational Health and Safety
The occupational health and safety issues that may occur during the construction and decommissioning of LVIC facilities are similar to those of other industrial facilities, and their

ma nagement is discussed in the General EHS Guidelines

. Facility

- specific occupational health and safety issues should be identified based on job safety analysis or comprehensive hazard or risk assessment, using established methodologies such as a hazard iden tification study [HAZID], hazard and operability study [HAZOP], or a quantitative risk assessment [QRA]. As a general approach, health and safety management planning should include the adoption of a systematic and structured approach for prevention and con trol of physical, chemical, biological, and radiological health and safety hazards described in the General EHS Guidelines

.
In addition, o

ccupational health and safety issues for spe cific consideration in chemical

operations i n

clude: • Chemical hazards due t o a cute and chronic exposure to toxic gases and other hazardous compounds ;

• Major hazards, including f ires and explosions

. Major hazards should be managed according to international regulations and best practices (e.g., OECD Recommendations 22

, EU Seveso II D irective 23 and USA EPA Risk Management Program Rule 24 ).



### Chemical Hazards The industry is characterized by the presence of toxic

co m pounds , including chlorine gas, ammonia, acids , caustic soda, amines, components of coal tar (e.g. mononuclear and pol y cyclic a romatic h

y drocarbons, phenols, and pyridine bases )
, which can be toxic when ingested, inhaled, or a b sorbed through the skin. The main health hazard usually a s sociated with coal tar and its products is carcinogenicity due to long

- term, conti n ued exposure of

the skin to finely divided solid pitch (dust).
Recommendations to prevent, minimize, or control occup a tional health impacts from exposure to toxic substances at these facil i ties include:

• Assess and minimize t he concentrations of toxic

su b stances in worki ng areas in both normal and emergency condi tions

. Rigorous workplace monitoring protocols ought to be in place as part of the overall occupational and health and safety management system

. Protective clothing, i n

cluding eye protection and PVC gloves, shoul d

be worn, suitable respirators be available, and regular medical checkups be carried out on all person nel, as needed ;

22 OECD, Guiding Principles for Chemical Accident Prevention, Preparedness and Response, Second Edition (2003). 23 EU Council Directive 96/82/EC
, so

- called S eveso II Directive, extended by the Directive 2003/105/EC. 24 EPA, 40 CFR Part 68, 1996

- Chemical accident prevention provisions

.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 13 WORLD BANK GROUP

• Install g

as detectors

in hazard areas, wherever poss i ble

. For example, c

hlorine detectors should be placed in areas of potential risk of

chlorine leaks

, giving immediate indication of the pre

s ence and location of any lea k age;

• Ensure effective ventilation, w here the lower boiling pro d ucts are han

dled;

• Provide

and use b arrier creams

formulated against

ar o matic hydrocarbons

. 

### Major Hazards
T he most significant safety impacts are related to the ha n dling and storage of NH 3

(volatile and poisonous in high concentr a tions), chlorine (highly poisonous), caustic soda, nitric, hydr o chloric, sulfuric, hydrofluoric, phosphoric acids and o r ganic compoun ds and combu

s tible gases such as natural gas, CO, and H 2 and other process chemicals. These impacts may i n clude significant acute exposures to workers and, potentially, to surrounding co

m munities, depending on the quantities and types of accidentally relea sed chemicals and the conditions for reactive or catastrophic events, such as fire and explosion.
LVIC manufacturing

facilities may generate or process large quantities of combustible gases, such as natural gas, H 2 , CO, and other process chemicals. Syn t hetic Gas (

SynGas; contai n ing H 2

and CO

25 ) generated at ammonia plants may cause “Jet Fires” if ignited in the release section, or give rise to Vapor Cloud Explosion, “Fireballs , ” or “Flash Fires

, ” d e pending on the quantity of flammable material involved, t he degree of confin e ment of the cloud , and the congestion of the area interested by the flammable cloud.

The risk of fire, explosion and other major hazards should be minimized through the follo

w ing measures:

25 Hydrogen and carbon monoxide have autoignition te m peratures of 500°C and 609°C, respe

c tively; therefore in some points of th e SynGas generation unit, where gas temperature is higher, potential gas r e leases may self ignite without the need of i g nition sources. • E stablishing a plant layout to reduce the fre quency of pro d uct transfers and the likelihood of accidental releases, as well as to facilitate the collection of accidental r e leases ;

• Early detection

of the release;

• Limiting the inventory which may be released by isol a tion of the installation from large inventories and isolation and blow

- down of pressurized flammable gases inventories

. P rocess areas, storage areas, utility areas, and safe areas should be segregated, preferably by adoption of safety di s tances. These distances can be derived from safety

an al y ses specific for the facility, considering the occurrence of the hazards or from appl i cable standards or guidelines (e.g., API, NFPA);

• Removing

potential ignition sources;

• Removing or diluting

the release and limiting the area

a f fected by the loss of co

n tainment.

R ecommended industry specific measures to minimize the above me n tioned risks include:

• Mi nimize the liquid chlorine inventory and the length of pipeline containing liquid chlorine ;

• Design a tmospheric ammonia storage tanks (

- 33°C) with dual walls and an external concrete wall with the roof

res t ing on the outer wall , and using an adequate margin b e tween operating and relief pressure

. Refri g erated storage should be preferred for storage of large quantities of liquid ammonia, since the initial releas e of ammonia in the case of a line or tank failure is slower than with pres surized a m

monia storage systems;

• Design c

hlorine storage

tanks based on a specific analysis of major failure or acc i dent risks and consequences, and accounting on the po

s sibility to safely recover and handle any product spills

— consider low

- temperature storage (

- 34°C) for large storage capacities, and provision of at least

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 14 WORLD BANK GROUP one empty tank equal in capacity to the largest chlorine storage tank as an emergency spare ;

• Given their highly

corrosive and toxic nature, special atte n tion should be given to the handling and storage of acids including prevention of leaks or spills to effluent waters by provision of secondary containment; separ a tion from critical drainage channels; and continuous monitoring and alarm detection systems (such as aut o matic pH monitoring) of at

- risk containment and drainage ne t works;

• Avoid p

ressurizing for unloading

large quantities of n i tric acid

. The recommended material for tanks, vessels and accessories is low ca rbon au s tenitic stainless steel;

• Only use specially

trained and certified staff or contra c tors for deliveries and transfer of all process chemicals, inclu d ing chemicals used in the CO 2 r e moval unit of the ammonia plant

. 

## 1.3 Community Health and Safety

Com munity health and safety impacts during the construction are common to those of most industrial facilities, and are di s cussed in the General EHS Guideline . These impacts i n clude, among other things, dust, noise, and vibration from construction vehicle tran

sit, and communicable disease

a s sociated with the influx of temporary co n struction labor.
The most significant community health and safety hazards du r ing th e operation of chemical

facilities are r

e lated to:

• Handling and storage

of hazardous materials incl u d ing raw materials, intermediaries, products and wastes near pop u lated areas;

• S hipping of hazardous pro d ucts (ammonia, chlorine, acids, carbon black), with possibility of accide n tal lea k of toxic and flammable gases;

• Disposal of solid waste (phosphogypsum , sludge). The design should include safeguards to minimize and co n trol hazards to the community, through the fo l lowing :

• Identifying reasonable design leak cases;

• Assessing the effects of the potential leaks on the

su r rounding areas, including groundwater and soil poll u tion;

• Properly selecting the plant location in respect to the inha b ited areas, meteorological conditions (e.g. prevailing wind directions), and water resources (e.g., groundwater vulne r ability) and identifying safe distances b e tween the plan t area and the community a r eas; and

• Identifying the prevention and mitigation measures r e quired to avoid or minimize the hazards.
If the facilities are located on the shore, the ship traffic

assoc i ated with the facilities should be considered in the

asses s ment, analyzing the p

o tential impact of the traffic on the local marine traffic and activities and the potential impacts of li q uids leaks from the unloading or offloading oper a tions. Measures to avoid accidental impacts and minimize distu r bance to other ma rine activities in the area should be a s sessed. Risk analysis and emergency planning should include, at a minimum, the preparation of an Emergency Manag e ment Plan, prepared with the participation of local authorities and potentially affected

commun i ties. O ther community health and safety hazards are common to those of most large i n dustrial facilities, and are discussed in the General EHS Guid e line

. Community health and safety impacts during the decommissio

n ing are common to those of most large industrial f acil i ties, and are discussed in the Ge n eral EHS Guideline

. These impacts include, among other things, transport safety, disposal of dem

o lition waste that may include hazardous materials, and other impacts related to physical conditions and the presence of ha z ardous materials after site aba n donment.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 15 WORLD BANK GROUP Guidance for the management of these issues at chemical plants is presented under Section 1.2 and in rel e vant sections of the General EHS Guidelines inclu d ing “ Planning, Siting, and Design ” , and “ Emergency Prepar edness and R e

sponse ”

. 

# 2.0 Performance Indicators and Monitoring
2.1 Environment
Emissions and Effluent Guidelines Tables 1 and 2 present emission and effluent guidelines for this sector. Guideline values for process emissions and effluents in this sector a re indicative of good international industry practice as reflected in relevant standards of countries with recognized regulatory frameworks. These levels should be achieved, without dilution, at least 95 percent of the time that the plant or unit is operat

ing, to be calculated as a proportion of annual operating hours. Deviation from these levels in consideration of specific, local project conditions should be justified in the environmental assessment.
Effluent guidelines are applicable for direct discharg es of treated effluents to surface waters for general use. Site

- specific di s charge levels may be established based on the avai l ability and conditions in the use of publicly operated sewage collection and treatment systems or, if discharged directly to surf ace waters, on the receiving water use classification as described in the General EHS Guideline

. Emissions guidelines are applicable to process emissions. Combustion source emissions guidelines associated with steam and power generation activities from so urces with a c

a pacity equal to or lower than 50 thermal megawatts are addressed in the General EHS Guideline with larger power source emissions addressed in the EHS Guidelines for Thermal Power

. Guidance on ambient considerations based on the total load of emissions is provided in the General EHS Guideline

.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 16 WORLD BANK GROUP



### Table 1. Air Emissions Levels Pollutant Units Guid e line Value Ammonia Plants NH 3 mg/Nm 3 50 NO X mg/Nm 3 300 Particulate Matter mg/Nm 3 50 Nitric Acid Plants NO X mg/Nm 3 300 N 2 O mg/Nm 3 800 NH 3 mg /Nm 3 10 Sulfuric Acid Plants SO 2 mg/Nm 3 450

(2 kg/t acid) SO 3 mg/Nm 3 60

(0.075 kg/t acid) H 2 S mg/Nm 3 5 NO X mg/Nm 3 200 Phosphoric / Hydrofl u oric Acids Plants Fluorides (gas e

ous) as HF mg/Nm 3 5
Particulate Matter/CaF 2 mg/Nm 3 50

(0.10 kg/t pho

s phate rock) Chlor

- alkali / Hydrochl o ric Acid Plants Cl 2 mg/Nm 3 1 (partial liquefa c tion) 3 (complete liqu

e fa c tion HCl ppmv 20
Hg mg/Nm 3 0.2

( a nnual average emission of 1 g/t chlorine) Soda Ash Plants NH 3 mg/Nm 3 50 H 2 S mg/Nm 3 5 NO x mg/Nm 3 200 Particulate Matter mg/Nm 3 50 Carbon Black SO 2 mg/Nm 3 850 NO X mg/Nm 3 600 CO mg/Nm 3 500 Particulate Matter mg/Nm 3 30 VOC mg/Nm 3 50 Coal Tar Distill a tion Tar fume mg/Nm 3 10 VOC mg/Nm 3 50 Particulate Matter mg/Nm 3 50 

### Ta ble 2. Effluent Levels

Pollutant Unit s Guid e

line Value pH S.U. 6

- 9 Temperature I n

crease °C <3 Ammonia Plants NH 3 mg /l 10

(0.1 kg/t) 1 TSS mg /l 30 Nitric Acid Plants NH 3 mg /l 10 Nitrates g/t 25 TSS mg /l 30 Sulfuric Acid Plants Phosphorus mg /l 5 Fluoride mg /l 20 TSS mg /l 30 Phospho ric Acid Plants Phosphorus mg /l 5 Fluoride mg /l 20 TSS mg /l 30 Hydrofluoric Acid Plants

Fluorides kg/tonne HF 1 kg/tonne HF 1 Suspended Solids mg /l 30 Chlor

- alkali /Hydrochloric Acid Plant TSS mg /l 20 2 COD mg /l 150 2 AOX mg /l 0.5 2 Sulfides mg /l 1 Chlorin e mg /l 0.2 2 Mercury

-- 0.05 mg/l 0.1 g/t chlorine Toxicity to Fish Eggs T F 2 Soda Ash Plants Suspended solids kg/t 270 Phosphorus kg/t 0.2 TSS mg /l 30 Ammonia (as N) mg /l 10 Carbon Black Plants COD mg/l 100 S uspended Solids mg/l 20 C oal Tar Distill a tion Plants BOD 5 mg/l 35 (monthly ave r age) 90 (daily max i

mum) TSS mg/l 50 (monthly ave r age) 160 (daily max i

mum) Anthracene, Naphthalene and Phenanthrene (each) μg /l 20 (monthly ave

r age) 60 (daily max i

mum) Notes: 1. Load based guideline: 0 .1 kg/t of product 2. Non

- asbestos diaphragm plants

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 17 WORLD BANK GROUP 

### Resource Use

, Energy Consumption , Emission and Waste Gener a

tion Table s 3 and 4 provide

examples of resource consumption and waste generation benchmarks in this sector. Industry benchmark values are provided for comparative pu r

poses only and individual projects should target continual i m prov e ment in these areas.


### Table 3. Resource and Energy Consumption

Product Unit Industry Benchmark
Ammonia GJ lower heating value

(LHV)/tonne NH

3 28.8 to 31.5 (1) Tonne phosphate rock/tonne P 2 O 5 2.6

- 3.5 (1)

KWh/ tonne P 2 O 5 120

- 180 (1) Phosphori c Acid

m 3 cooling water/tonne P 2 O 5 100

- 150 (1)
Tonne CaF 2l

/ tonne HF 2.1

- 2.2 (4)
Tonne H

2 SO 4 / tonne HF 2.6

- 2.7 (4) Hydrofluoric Acid

KWh/

tonne HF 150

- 300 (4)
KWh/ tonne Cl 2 3000 without Cl liquefaction 3200 with Cl liquefaction / evaporation

(3)
Tonne NaCl/

tonne Cl 2 1.750 (3) Chlor

- Alkali

g Hg/

tonne of chlorine capacity (mercury cell plants) 0.2

- 0.5 (3)

GJ/ tonne soda ash 9.7

- 13.6 (2)
Tonne limestone/tonne soda ash 1.09

- 1.82 (2)

Tonne NaCl/tonne soda ash 1.53

- 1.80 (2) Soda Ash

m 3 cooling water/tonne soda ash 50

- 100 (2)

KWh/ tonne carbon black 430

- 550 (2) Carbon Black

GJ/

tonne carbon black 1.55

- 2 (2) Notes:

1. European Fertilizer Manufacturers Association (EFMA). 2000. 2. EU IPPC

-

Reference Document on Best Available Techniques in Large Volume Ino

r ganic Chemicals

-

Solid and Others industry. December 2006. 3. EU IPPC

-

Reference Document on Best Available Techniques in the Chlor

- Alkali Man u facturing industry December 2001. 4. EU I PPC

-

Reference Document on Best Available Techniques in Large Volume Inorganic Chemicals

– Ammonia, Acids and Fertilizers Industries. Oct o ber 2006.



### Table 4. Emissions, Effluents and Waste

Generation

Parameter Unit Industry Benchmark
Ammonia Plants CO 2 from process tonne/tonne NH 3 1.15

- 1.3 (1) NO X (advanced conventional refor m ing processes and processes with reduced primary reforming) kg/tonne NH 3 0.29

– 0.32

NO X (heat exchange autothermal reforming) kg/tonne NH 3 0.175

Nitric Acid Plants N 2 O kg/to nne 100% HNO 3 0.15

- 0.6 (4)

NO X ppmv 5

- 75 (4) Sulfuric Acid Plants SO 2 (Sulfur burning, double contact/double a

b sorption) mg/Nm 3 30

- 350 (1)(4)

SO 2 (Single contact/single absor p tion) mg/Nm 3 100

- 450 (4)
Phosphoric / Hydrofluoric Acid Plants Fluorides mg/ Nm 3 0.6

- 5 (4) SO 2 kg/tonne HF 0.001

– 0.01 (4) Solid Waste (phosphogypsum) tonne/tonne P 2 O 5 4

- 5 (1) Anhydrite (CaSO

4 ) tonne/tonne HF 3.7 (4) Chlor Alkali Plants Cl 2 (partial liquefaction) mg/Nm 3 <1 (3) Cl 2 (total liquefaction) mg/Nm 3 <3 (3) Chlorates (brine circuit) g/l 1

- 5 (3) Bromates (brine circuit) mg/l 2

- 10 (3) Soda Ash Plants CO 2 Kg/tonne soda ash 200

- 400 (2) Cl Kg/tonne soda ash 850

- 1100 (2)

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 18 WORLD BANK GROUP

Ca Kg/tonne soda ash 340

- 400 (2) Na Kg/tonne soda ash 160

- 220 (2) Waste water/suspended solids m 3 /tonne/ tonne soda ash 8.5

- 10.7 / 0.09

- 024 (2) Carbon Black Plants

SO 2 kg/tonne of ru b ber grade carbon black 10

- 50 (2)

NO X mg/Nm 3 <600 (2)
VOC mg/Nm 3 <50 (2) Table 4 Notes : 1. European Fertilizer Manufacturers Associa tion (EFMA). 2000; 2. EU IPPC

-

Refere nce Document on Best Available Techniques in Large Volume Ino

r ganic Chemi

cals

- Solid and Other Industries. Dec, 2006. ; 3. EC IPPC

-

Reference Document on Best Available Techniques in the Chlor

- Alkali Man u facturing industr

y December 2001; 4. EC IPPC

-

Referenc e Document on Best Available Techniques in Large Volume Inorganic Chemicals

– Ammonia, Acids and Fertilizers Industries. Oct, 2006.


### Environmental Monitoring Environmental monitoring programs for this sector should be implemented to address all activities that have been ident

i fied to have potentially significant impacts on the enviro n ment, during normal operations and upset conditions. Enviro n mental monitoring activities should be based on direct or ind i rect indicators of emissions, effluents, and resour ce use a p plicable to the particular project.
Monitoring frequency should be sufficient to provide represe n tative data for the parameter being monitored. Monitoring should be conducted by trained individuals following monito r ing and record

- keeping procedu res and using properly cal i brated and maintained equipment. Monitoring data should be analyzed and reviewed at regular intervals and compared with the operating standards so that any necessary corrective

a c tions can be taken. Additional guidance on applica ble

sa m pling and analytical methods for emi s sions and effluents is provided in the General EHS Guidelines

. 

## 2.2 Occupational Health and Safety Performance Occupational Health and Safety Guidelines Occupational health and safety performance should be eval u at ed against internationally published exposure guidelines, of which examples include the Threshold Limit Value (TLV®) occupational exposure guidelines and Biological Exposure Indices (BEIs®) published by American Conference of Go v ernmental Industrial H y

gien ists (ACGIH), 26

the United States National Institute for Occupational Health and Safety (NIOSH), 27 Permissible Exposure Li m

its (PELs) published by the Occupational Safety and Health Administration of the United States (OSHA), 28

Indicative Occupational Expos ure Limit Values published by European Union me m ber states, 29

or other similar sources. 

### Accident and Fatality Rates Projects should try to reduce the number of accidents among project workers (whether d i rectly employed or subcontracted) to a rate of zero, especially accidents that could result in lost work time, different levels of disability, or even fatalities. Faci l ity rates may be benchmarked against the performance of facilities in this sector in developed countries through consu l tation with published sources (e.g. US Bureau of Labor Stati s tics and UK Health and Safety E x ecutive) 30

. 

### Occupational Health and Safety Monitoring The working environment should be monitored for occup a tional hazards relevant to the specific project. Monitoring should be

26 Available at: http://www.acgih.org/TLV/ 27 Available at: http://www.cdc.gov/niosh/npg/ 28 Available at: http://www.osha. gov/pls/oshaweb/owadisp.show_document?p_table=STANDAR DS&p_id=9992 29 Available at: http://europe.osha.eu.int/good_practice/risks/ds/oel/ 30 Available at: http://www.bls.gov/iif/ and http://www.hse.gov.uk/statistics/index.htm

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 19 WORLD BANK GROUP
d e signed and impl e mented by accredited professionals 31 as part of an occupational health and safety monitoring program. Facilities should also maintain a record of occupational

acc i dents and diseases and dangerous occurrences and

acc i dents. Additional guidance on o ccupational health and safety monitoring programs is provided in the General EHS Guid e lines

.

31 Accredited

professionals may include Certified Industrial Hygienists, Re g istered Occupational Hygienists, or Certified Safety Professionals or their equiv a lent.

### Environmental, Health, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DIS TILLATION

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# 3.0 References

Australian Government, Department of the Environment and Heritage. 2004. Emission Estimation Technique Manual for Inorganic Chemicals Manufactu r ing

. Version 2.0. Canberra, Australia
European Integrated Pollution Prevention and Control Bureau (EIPPCB) . 2001. Integrated Pollution Prevention and Control (IPPC ) Reference Doc u ment on Best Available Techniques in the Chlor

- Alkali Manufacturing Industry. D e cember 2001 . Sevilla, Spain

EIPPCB . 2006 a . Integrated Pollution Prevention and Control (IPPC) Refe r ence Document on Best Available Techniques in Large Volume Inorganic Chemicals

- Solids and Others Indu

s try. October 2006

. Sevilla, Spain

EIPPCB . 2006 b . Inte grated Pollution Prevention and Control (IPPC) Refe r ence Doc u ment on Best Available Techniques in Large Volume Inorganic Chemicals

– Ammonia, Acids and Fertilisers. Decembe r 2006. Sevilla, Spain
European Fertilizer Manufacturers Association (EFMA). 2000a. Best Avai l able Techniques for Pollution Prevention and Control in the European Fertilizer I n dustry. “Produ

c tion of Ammonia,” Booklet No. 1. Brussels, Belgium
EFMA. 2000b. Best Available Techniques for Pollution Prevention and Co n trol in the European Fertil izer Industry. “Production of Nitric Acid,” Booklet No. 2. Bru s sels, Belgium
EFMA. 2000c. Best Available Techniques for Pollution Prevention and Co n trol in the European Fertilizer Industry. “Production of Sulphuric Acid,” Boo k let No. 3. Brussels, Belgium

E FMA. 2000d. Best Available Techniques for Pollution Prevention and Co n trol in the European Ferti l izer Industry. “Production of Phosphoric Acid,” Booklet No. 4. Brussels, Be l gium

German Federal Government. 2002. First General Admini s trative Regulation Perta ining the Federal Immission Control Act (Technical Instructions on Air Qua l ity Control

– TA Luft). Berlin, Germany
German Federal Ministry for the Environment, Nature Co n servation and Nuclear Safety. 2004. Promulgation of the New Version of the Ordinance on Requir e ments for the Discharge of Waste W a ter into Waters (Waste Water Ordinance

-

AbwV) of 17. June 2004. Berlin, Germany

Helsinki Commission. 2002. Helcom Recommendation 23/6. Reduction of Emi s sions and Discharges of Mercury from Chl o ralkali Industry. Helsinki, Finland.
Intergovernmental Panel on Climate Change (IPCC). 2006. Special Report, Ca r bon Dioxide Capture and Storage, March 2006. Geneva, Switzerland

Kirk

- Othmer, R.E. 2006. Encyclopedia of Chemical Techno l ogy. 5 th Edition. John Wiley and Sons Lt

d., New York, NY National Fire Protection Association ( NFPA ). 2000. Standard 850: Reco m mended Practice for Fire Protection for Ele c tric Generating Plants and High Voltage Direct Current Converter Stations

. 2000 Edition

. Quincy, Massach u setts

NFPA . 2004. St

andard 120: Standard for Fire Prevention and Control in Coal Mines

. 2004

Edition

. Quincy, Massachusetts

Paris Commission. 1990. Parcom Decision 90/3 of 14 June 1990 on Redu c ing Atmospheric Emi s

sions from Existing Chlor

- Alkali Plants. Paris, France

UK Envi ronmental Agency. 1999a. IPC Guidance Note Series 2 (S2) Chem i cal Industry Sector. S2 4.03: Inorganic A c ids and Halogens. Bristol, UK
UK Environmental Agency. 1999b. IPC Guidance Note Series 2 (S2) Chem i cal Industry Sector. S2 4.04: Inorganic Chem i cals. Br istol, UK
UK Environmental Agency. 2004a. Sector Guidance Note IPPC S4.03. Gui d ance for the Inorganic Chemicals Sector. Bristol, UK
UK Environmental Agency. 2004b. Process Guidance Note 6/42 (04). Secr e tary of State's Guidance for Bitumen and Tar Processes . Bristol, UK
US Environmental Protection Agency (EPA). Office of Co m pliance. 1995. Sector Notebook Project. Profile of the Inorganic Chemical Industry. Was h ington, DC

US EPA . 40 CFR Part 60, Standards of Performance for New and Existing St a tionary Sources : Su

b part G

— Standards of Performance for Nitric Acid Plants . Washington, DC . Available at http://www.gpoaccess.gov/cfr/index.html (a c cessed on Oct

o ber 2006)

US EPA. 40 CFR Part 60, Standards of Perfo rmance for New and Existing St a tionary Sources: Su

b part H

— Standards of Performance for Sulfuric Acid Plants. Washington, DC . Available at http://www.gpoaccess.gov/cfr/index.html (a c cessed on Oct

o ber 2006)
US EPA. 40 CFR Part 60, Standards of Performance for New and Existing St a tionary Sources: Subpart T

— Standards of Performance for the Phosphate Ferti l izer Industry: Wet

- Process Phosphoric Acid Plants. Washington, DC

. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on O

c tober 2006)

US EPA. 40 CFR Part 63, National Emission Standards for Hazardous Air Po l lutants for Source Categories: Subpart AA

— National Emission Standards for Hazard ous Air Pollutants From Phosphoric Acid Manufacturing Plants. Washin g ton, DC . Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct

o ber 2006)

US EPA. 40 CFR Part 63, National Emission Standards for Hazardous Air Po l lutants for Source Categories: Subpart IIIII

— National Emission Standards for Hazardous Air Pollutants: Mercury Emi s sions From Mercury Cell Chlor

- Alkali Plants. Washington, DC . Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct

o ber 2006)

US EPA. 40 CFR Part 63, National Emission Standards for Hazardous Air Po l lutants for Source Categories: Subpart NNNNN

— National Emission Standards for Hazardous Air Pol lutants: Hydrochloric Acid Production.

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

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Washington, DC . Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct

o ber 2006)

US EPA. 40 CFR Part 414

. Subpart G

—

Bulk Organic Chemicals

. Washi n g ton, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 414. Subpart I

— Direct Discharge Point Sources That Use End

- of

- Pipe Biolog i

cal Treatment. Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 414. Subpart J

— Direct Discharge Point Sources That Do Not Use End

-

of

- Pipe Biologic al Treatment. Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 415. Subpart F

— Chlor

- alkali Subcat

e gory (Chlorine and Sodium or Potas

sium Hydroxide Production). Washington, DC. Avai l able at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 415. Subpart H

— Hydrofluoric Acid Production Subcat e gory . Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 418. Subpart A

— Phosphate Subcategory. Washin g ton, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)
US EPA. 40 CFR Part 418. Subpart B

— Ammonia Subcat

e gory. Washington, DC. Available at http: //www.gpoaccess.gov/cfr/index.html (accessed on O c tober 2006)

US EPA. 40 CFR Part 418. Subpart E

— Nitric Acid Subcategory

. Washin g ton, DC. Available at http://www.gpoaccess.gov/cfr/index.html (access ed on Oct o ber 2006)

US EPA. 40 CFR Part 422

. Subpart D

— Defluorinated Phosphate Rock Su b category. Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)

US EPA . 40 CFR Part 422. Subpart E

— Defluorinated Phosphoric Acid Su b category. Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)

US EPA. 40 CFR Part 458. Subpar t A

— Carbon Black Furnace Process Su b category. Washington, DC. Available at http://www.gpoaccess.gov/cfr/index.html (accessed on Oct o ber 2006)

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# Annex A : General Description of Industry A c tivit ies

Th is EHS Guideline for Large Volume Inorganic Compound (LVIC) Manufacturing and Coal Tar Distillation includes Amm o nia ; Chlor

- Alkali (i.e., chlorine, caustic soda, soda ash, etc.) ; Acids (Nitric, Hydrochlodric, Sulfuric, Hydrofluodric, Phosphoric) ; Carbon Bl ack

; and Coal Tar Distillation (naphthalene, phenanthrene, anthracene) sectors. It covers the production of

major intermediates and products for the downstream industry covering many diversified sectors ranging from fertilizers to plastics. It is character ized by large volume productions, which can reach up to million ton per year and be manufactured in large facilities.


## Ammonia 32
About 80 % of ammonia (NH 3 ) is currently used as the nitrogen source in fertilizers, with the remaining 20 % applied

in severa l industrial applications, such as the manufacture of plastics, fibres, explosives, hydrazine, amines, amides, nitriles and other organic nitrogen compounds which serve as intermediates in dyes and pharmaceuticals manufacturing. Important inorganic product s manufactured from ammonia include nitric acid, urea and sodium cyanide. Liquid ammonia is an important solvent and is also used as a refrigerant.

Ammonia plants may be built as stand

- alone or integrated with other plants at a site, typically with urea p roduction . H owever recent trends include combined ammonia with methanol production. Hydrogen and / or carbon monoxide production can also be integrated with ammonia plants. An ammonia plant typically produces around 2,000 tonnes per day, but plants that

c an produce up to 3,400 tonnes per day have been built.

32 EIPPCB. 2006b; EFMA. 2000a The natural gas reforming with steam and air is the simplest and most efficient way of ammonia synthesis gas production and is today the most used.
Ammonia is produced by an exot h ermic reaction of hy drogen and nitrogen. This reaction is carried out in the presence of metal oxide catalysts at elevated pressure. Catalysts used in the process may contain cobalt, molybdenum, nickel, iron oxide / chromium oxide, copper oxide / zinc oxide, and iron. The

am monia product, in liqu

e fied form, is stored either in large atmospheric tanks at temperature of

– 33 degrees centigrade or in large spheres at pressures up to 20 atmospheres at ambient temperature. The raw material source of nitrogen is atmospheric air and it may be used in its natural state as compressed air or as pure nitrogen from an air liquefaction plant. Hydrogen is available from a variety of sources such as natural gas, crude oil, naphtha, or off gases from processes such as coke oven or refineries.
Ammonia production from natural gas includes the following process steps: removal of trace quantities of sulfur in the feedstock; primary and secondary reforming; carbon monoxide shift conversion, removal of carbon dioxide, methanation, compression, ammon

ia synthesis, and ammonia product refrigeration. Carbon is removed in the form of concentrated CO 2 , which should preferably be used for urea manufacture or other industrial purposes to reduce its release to the atmosphere.
Two other non conventional proce ss routes include: (1) the addition of extra process air to the secondary reformer with cryogenic removal of the excess nitrogen, and (2) heat

exchange autothermal reforming. The second process route has

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some environmental advantage because of the reduced need for firing in the primary reformer and the potential to lower energy consumption. It is a recent technology and, to date, built for a capacity of about 500 tonnes NH 3 per day.
Liquefied ammonia from production plants is either used directly in downs tream plants or transferred to storage tanks. From storage the ammonia can be shipped to users, through road tankers, rail tank cars or ships. Ammonia is usually stored by using one or other of three methods:

• Fully refrigerated storage in large tanks with a typical capacity of 10,000 to 30,000 tonnes (up to 50,000)

• Pressurized storage

spheres or cylinders with a capacity up to about 1,700 tonnes

• Semi

- refrigerated

tanks

. There are several storage types for refrigerated liquid products. The most important typ

es are:

• Single containment

: a single

- wall insulated tank, usually with a containment bund around it;

• Double containment

: tanks with two vertical walls, both designed to contain the stored liquid and withstand its hydrostatic pressure. The roof rests on the inner wall; and

• Full containment

: closed storage tanks with two walls, as for double containment, but with the roof resting on the outer wall and using an adequate margin between operating and relief pressure.


## Nitric Acid 33
The production stages for nitric acid manufacture include the following: vaporizing liquid ammonia; mixing the vapor with air

33 EIPPCB. 2006b; EFMA. 2000b. and burning the mixture over a platinum / rhodium catalyst; cooling the resultant nitric oxide (NO) and oxidizing it to nitrogen dioxide (NO

2 ) with residual oxyge n; and absorbing the nitrogen dioxide in water in an absorption column to react into nitric acid. Large

- capacity plants normally have dual

- pressure design ( e.g. medium

- pressure combustion and high

- pre ssure absorption), while small plants may have combustio n and absorption conducted at the same pressure. High pressure in the absorption column reduces the nitrogen oxides (NO X ) emissions. Generation of NO X and nitrous oxide (N 2

O), which is a greenhouse gas, in ni tric acid plants is significant; however catalyt ic conversion techniques can reduce the emission level by more than 80 percent.

The recommended material for tanks, vessels and accessories is low carbon austenitic stainless steel. Transfer to transport vessels is typically via

pumping or by gravity. Pre ssurizing for unloading large quantities should be avoided. Nitric acid is transported using rail tank cars, road tankers and less frequently, ships.
The typical capacity of modern plants for producing nitric acid

is

a pproximately

1,000 tons per day.


## Sulf uric Acid 34 The most important use of sulfuric acid (H 2 SO 4 ) is in the phosphate fertilizer industry. Sul f uric acid is manufactured from sul f ur dioxide (SO 2

) produced by combustion of elemental sulfur. Liquid sulfur is a product of the desulfurization of na tural gas or the cleaning of coal flue

- gas; another possible route is the melting of naturally occurring solid sul f ur. S ul f ur dioxide is also produced by the metals industry, through roasting and smelting processes generating

off

- gases with a sufficiently high

34 EIPPCB. 2006b; EFMA. 2000c.

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concentration of SO 2 to allow direct processing to H 2 SO 4 . The thermal oxidizing process of spent acids used as raw materials is another route to produce SO 2 and H 2 SO 4 . The exothermic oxidation of sulfur dioxide over several layers of a suitable cataly st (i.e., vanadium pentoxide) to produ c e sulfur trioxide (SO 3 ) is the process used today in almost all sulfuric acid manufacturing plants. Modern plants can be designed to be very efficient in terms of sulfur dioxide conversion (more than 99%) and energy r

ecovery.
Sulfuric acid is obtained from the absorption of SO 3 and water into H 2 SO 4 (with a concentration of at least 98%). SO 3 is absorbed in an intermediate absorber installed after the second or third catalyst layer in a double contact process, where th e gases are then conveyed to the final catalyst layer(s) and the SO 3 formed here is absorbed in a final absorber. The final absorber is installed after the last catalyst layer in a single contact process. The warm acid produced is sparged with air in a col umn or in a tower to collect the remaining SO 2 in the acid; the SO 2 laden air is returned to the process. 

## Phosphoric Acid 35
Phosphoric acid (H 3

PO 4 ) is primarily used in the manufacture of phosphate salts (fertilizers and animal feed supplements). Two diffe rent processes can be used in the manufacture of phosphoric acid. In the first process, known as the ther mal process, elemental phosphor us is produced from phosphate rock, coke and silica in an electrical resistance furnace and is then oxidized and hydrate d to form the acid. Thermal

- generated acid is considerably pure, but also expensive, and hence produced in small quantities, mainly for the manufacture of industrial phosphates.

35 EIPPCB. 2006b; EFMA. 2000d The second types of processes, known as wet processes, are those digesting pho

sphate rocks with an acid (i.e. sulfuric, nitric or hydrochloric acid). The wet digestion of phosphate rock with sulfuric acid is the preferred process in term of volume. The tri

calcium phosphate from the phosphate rock reacts with

conce n trated sulfuric a cid to produce phosphoric acid and calcium su l fate that is an insoluble salt. The operating conditions are generally selected so that the calcium sulfate is precipitated as the dihydrate (DH) or hemihydrate (HH) form.
The main production steps are the fo llowing: grinding of phosphate rock; reaction with sulfuric acid in a series of separate agitated reactors at a temperature of 70

- 80 °C; and filtration to separate the phosphoric acid from the calcium sulfate.
Phosphoric acid is most commonly stored in r ubber

- lined steel tanks, although stainless steel, polyester and polyethylene

- lined concrete are also used. Storage tanks are normally equipped with some means of keeping the solids in suspension to avoid costly cleaning of the tank. 

## Hydrofluoric Acid 36
Hyd rogen fluoride (HF) is produced in two forms, as anh y drous hydrogen fluoride and as aqueous hydrofluoric acid. The pr e dominant form manufactured is hydrogen fluoride, a colorless liquid or gas that fumes when in contact with air and is water

- soluble. Hydro

gen fluoride is also a fortuitous by

- product in the manufacture of superphosphate fertilizers. Hydrofluoric acid is used in glass etching and polishing, p e troleum alkylation, and stainless steel pickling. Hydrofluoric acid is also used to produce fluoroca rbons for the manufacture of resins, solvents, stain r e movers, surfactants, and pharmaceuticals.

36 E IPPCB. 2006b

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Hydrofluoric acid is

manufactured by the reaction of acid

- grade fluorspar (CaF 2

) with sulfuric acid (H 2

SO 4 ). The end o thermic reaction is conducted in horizonta l rotary kilns exte r nally heated to 200 to 250°C. Dry fluorspar and a slight e x cess of sulfuric acid are fed continuously to the front end of a stationary pre

reactor for mixing or directly to the kiln by a screw conveyor. Calcium sulfate (CaSO 4

) is remove

d through an air lock at the opposite end of the kiln.
The gaseous reaction products

- hydrogen fluoride and e

x cess H 2 SO 4 from the primary reaction, and silicon tetr a fluoride (SiF 4

), sulfur dioxide (SO 2

), carbon dioxide (CO 2 ), and water vapor pr o duced in s econdary reactions

-

are r e moved from the front end of the kiln along with entrained particulate matter. The partic u late matter is then removed from the gas stream and returned to the kiln. Sulfuric acid and w a ter are removed in a pre

- condenser. Hydrogen f luoride vapors are subsequently

co n densed in refrigerant co

n densers forming crude HF, which is sent to intermediate storage tanks. The remaining gas stream passes through a sulfuric acid absorption tower or acid

scru b ber, removing most of the remaining hyd rogen fluoride and some residual sulfuric acid, which are also sent to intermediate storage. The gases exiting the acid scrubber are treated in

w a ter scrubbers, where both SiF 4 and remaining HF are recovered as hexafluor

o silicic acid (H 2

SiF 6 ). The water sc

rubber tail

- gases are passed through a caustic scrubber before being emitted to the atmosphere. The hydrogen fluoride and sulfuric acid are d e livered from intermediate storage tanks to distillation

co l umns, where the hydrofluoric acid is extracted at 99.98 pe r cent purity. A final dilution step with water is needed to pr o duce weaker concentrations (typically 70 to 80 pe r cent).
Anhydrous HF is a liquid

which boils at 19.5 °C. The liquid HF is kept at low temperature, preferably below 15 °C, by cooling or by t he installation of condensers in vent storage pipelines which condense the evaporating HF. Liquid HF is normally stored at atmospheric pressure in carbon steel tanks, where a thin prote c tive layer of FeF 2

is formed, preventing the tank walls from fu r ther c orrosion. Liquid velocity in the pipelines should be below 1 m/s to avoid erosion of the FeF 2 layer. Hydrofluoric acid with a concentration of at least 70 % is also stored in carbon steel tanks, whereas acid with concentrations of less than 70 % is stored in lined steel tanks or alternatively in polyethylene tanks. 

## Hydrochloric Acid 37 Hydrochloric acid (HCl) is a versatile chemical used in a variety of chemical processes, including hydrometallurgical processing , chlorine dioxide syntheses, hydrogen productio n, and miscellaneous cleaning and etching operations. It is also a common ingredient in many chemical reactions, and a commonly used

acid for cataly z ing organic processes.

The acid is manufactured by several different processes

. commonly applied product

ion processes consist of

reacting sodium chloride with sulfuric acid , or more recently , the acid is generated as a by

- product of the chlorination reaction process (e.g., production of chlorinated solvents and organics)

. 

## Chlor

- alkali 38

The chlor

- alkali ind us try

produces chlorine (Cl 2

) and alkali (i.e., caustic soda or sodium hydroxide (NaOH) and potassium hydroxide (KOH)), by electrolysis of a salt solution, mainly using sodium chloride (NaCl) as feed or potassium chloride (KCl) for the production of potassiu m hydroxide. The chlor

- alkali process is an important consumer

of electrical energy.

37 Australian Government, Department of the Environment and Heritage. 2004. 38 EIPPCB. 2001.

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The main chlor

- alkali manufacturing technologies are mercury, diaphragm and membrane cell electro lysis. In the chlorine process, chlorine gas leaving the electrolyzers is at approximately 80

- 90 oC and saturated with water vapor. It also contains impurities such as brine mist, nitrogen, hydrogen, oxygen, carbon dioxide and traces of chlorinated hydrocarbons. After direct or indirect cooling and impurities removal, chlorine is passed to the drying towers for drying with concentrated sulfuric acid. The gas is then compressed and liquefied at different pressure and temperature levels. Liqu e fied chlorine is stored in bulk tanks at ambient or low temperature.

The membrane cell process has environmental advantages over the two older processes, in addition to be currently the most economically advantageous process. The anode and cathode are separated by a water

- impermeable ion

- conducting membrane. Brine solution flows through the anode compartment where chloride ions are oxidized to chlorine gas. The sodium ions migrate through the membrane to the cathode compartment which contains caustic soda solution. The demineralized water added to the catholyte circuit is hydrolyzed, and rel eases hydrogen gas and hydroxide ions. The sodium and hydroxide ions combine to produce caustic soda which is typically brought to a concentration of 32

- 35% by recirculating the solution before discharge from the cell. Higher concentrations are produced co ncentrating the caustic liquor by steam evaporation. The output of caustic soda is proportional to that of chlorine (1.128 tonnes of caustic soda (100%) are produced by electrolysis per tonne of chlorine). Because of the membrane, the caustic soda soluti on contain a very limited amount of salt due to migration of chloride, as in the diaphragm cell process. Depleted brine is discharged from the anode compartment and resaturated with salt. The cathode material used in membrane cells is either stainless stee l or nickel and the anodes used are metal. The cathodes are often coated with a catalyst that increases surface area and reduces over

- voltage. Coating materials include Ni

- S, Ni

- Al, and Ni

- NiO mixtures, as well as mixtures of nickel and platinum group meta ls. The membranes used in the chlor

- alkali industry are commonly made of perfluorinated polymers.

C hlorine is often

produced near consumers. Storage and transport of chlorine requires proper handling and use of best practice to minimize potential hazards

. Chlorine is transported by pipe, road and rail.
Hydrogen is a co

- product of the electrolysis of brine (28 kg for 1 tonne of chlorine) and is generally used on

- site as a combustible , sent as a fuel to other companies , or sold and transported as chemical . It

can be used on integrated sites for certain applications because of its high purity, including synthesis of ammonia, methanol, hydrochloric acid, hydrogen peroxide, etc.

In addition to cell electrolysis , there are processing steps which are common to all technologies and include: salt unloading and storage, brine purification and resaturation, chlorine, caustic soda, and hydrogen processing.
The brine purification process consists of a primary system for the mercury and diaphragm technologies and an additi onal secondary system for membrane technology. This operation is needed to eliminate i m

purities (sulfate anions, cations of calcium, magnesium

, barium and metals) that can affect the electrolytic process.
The primary brine purification uses sodium carbonat e and sodium hydroxide to precipitate calcium and magnesium ions as calcium carbonate (CaCO 3 ) and magnesium hydroxide

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, 2007 27 WORLD BANK GROUP (Mg(OH) 2 ). Metals may also precipitate as hydroxide during this operation. Sodium sulfate may be controlled by adding calcium chloride (Ca Cl 2

) or barium salts

(which however may represent a hazard due to their toxicity) to remove sulfate anions by precipitation of calcium sulfate (CaSO 4 ) or barium sulfate (BaSO 4 ). After precipitation, impurities are removed by sedimentation, filtration or a combination of both. Other possibilities to remove sulfates include ultra

- filtration and brine purging.
The secondary brine purification consists of a polish filtration step and brine softening in an ion exchange unit generally with filters in order to su fficiently reduce the suspension matter and protect the ion

- exchange resin from damage. The ion exchange chelating resin treatment is designed to decrease the alkaline earth metals to trace levels. The resin is periodically regenerated with high purity hy drochloric acid and sodium hydroxide solutions.
Instead of diluting the remaining gases after partial condensation of the chlorine gas, the hydrogen is removed by means of a reaction with chlorine gas in a column. This step produces gaseous hydrochloric a cid, which can be recovered in a hydrochloric acid unit.


## Soda Ash

39
Sodium carbonate (Na 2

CO 3 ) or s oda ash is a fundamental raw material to the glass, soaps and detergent s, and chemical

s industries. Soda ash (calcined soda) is manufactured in two grades: ‘li ght soda ash’ and ‘dense soda ash’. Dense soda ash is mainly use

d in the glass industry and for economic transportation over long distances. The light form is used mainly for the detergent market and certain chemical intermediates.

39 EIPPCB. 2006a. Soda ash is generally ma nufactured by large, highly integrated production units, with a plant capacity ranging from 1 5 0 to 1,200 kt per year.

The Solvay process

(ammonia soda process) involves saturation of brine with ammonia and carbon dioxide gas. The process uses salt brine (NaCl) and limestone (CaCO 3 ) as raw materials. Ammonia is almost totally regenerated and recycled. The main advantage of this process is the widespread availability of the relatively pure raw materials, which allow operating production units relatively clo se to the market.
The Solvay process produces ‘light soda ash’, with a pouring density of about 500 kg/m 3 . ‘Light soda ash’ is transformed by recrystallization first to sodium carbonate monohydrate, and then to ‘dense soda ash’ after drying (dehydration). Dense soda ash has a pouring density of about 1,000 kg/m 3 . Dense soda ash can also be produced by compaction.


## Carbon Black

40

Carbon black is produced

by partial oxidation or thermal d e composition of hydrocarbons. About 65

– 70 % of the world’s consumption o f carbon black is used in the production of tires and tire products for automobiles and other vehicles. Roughly 25

- 30% is used for other rubber products and a small pe r cent is used in plastics, printing ink, paint, paper and misce l laneous applications.

C arbon black differs from other carbon

- based materials in many respects, especially in bulk density. Mixtures of gaseous or li q uid hydrocarbons represent the raw materials preferable for i n dustrial production with preference to ar o matic hydrocarbons for be tter yields.

40 EIPPCB. 2006a.

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The processes are divided into two groups: those employing incomplete or partial co m

bustion and those based on thermal cracking. In the partial combustion processes, air is used to burn part of the feedstock, producing the energy required to carry out the pyrolysis, whereas in the thermal cracking pro c ess, heat is generated externally and introduced into the process.
The furnace black process is currently the most important pr o duction process. It accounts for more than 95% of the t o tal worldwi de production. It is a continuous process and its adva n tages are its great flexibility and its better economy compared to other process. The typical production rate is

a p proximately 2,000 kg/h for a modern furnace black reactor. In furnace black, a heavy a romatic feedstock is injected by atomization into a high speed stream of combustion gases and partially burned and mostly cracked (45

– 65%) to produce carbon black and hydr

o gen at a te m

perature ranging from 1200 to 1700° C. After quenching with water, car bon black is recovered by cyclones and bag filters, pellettized, dried and delivered to storage (silos) or shipped.


## Coal Tar Distillation

Coal tar is currently

almost totally distilled mainly in continuous stills that have daily capacities of 100

– 700 t ons

. It is a conde n sation product obtained by cooling the gas evolved in coal distillation (pyrolysis or carbonization of coal). Coal tar is a black viscous liquid denser than water. Coal

- tar pitch is a black very viscous, semisolid, or solid residue from the distillation of coal tar.

The coal tar product

, which distills up to about 400 ° C at atmospheric pressure , is primarily a complex mixture of mono

and polycyclic aromatic hydrocarbons, a proportion of which are substituted with alkyl, hydroxyl , amine and/ or hydro sulfide groups, and to a lesser extent their sulfur

- , nitrogen

- , and oxygen

- containing analogues . T ars produced at the lower coal carbonization temperatures also contain hydroaromatics, alkanes, and alkenes. T he residue from the distillation is a t least 50% of the coal tar products by high temperat ure carbonization and consists

of a continuation of the sequence of polynuclear aromatic, aromatic, and heterocyclic compounds, up to molecules containing 20 to 30 rings.

M etal corrosion

associated to c

ontinuous coal tar distillation is a typical issue to be considered in plant management . The ammonium salts

( mainly ammonium chloride

) , associated with the entrained liquor remain in the tar after dehydration, tend to dissociate with the production of hydr ochloric acid . This acid may deteriorate any equipment part s in which these vapors and steam are present above 240°C , including the c ondensers on the dehydration and fractionation columns. Corrosion is controlled by the addition of alkali (either sodium c arbonate solution or caustic soda) to the tar.
A primary distillation product pattern at a tar

- processing plant can give only one fraction, naphthalene oil taken between 180 and 240 ° C, or two fractions, light creosote or middle oil (230

– 300 ° C) and heavy cr

eosote or heavy oil (above 300 ° C) between the naphthalene oil and pitch.
The higher boiling cresylic acids are mixtures of cresols or xylenols with higher boiling phenols. Their main uses are in phenol

- formaldehyde resins, solvents for wire

- coating enamels , metal degreasing agents, froth

- flotation agents, and synthetic tanning agents.
Naphthalene is the principal component of coke

- oven tars and the only component that can be concentrated to a reasonably

### Environmental, Hea lth, and Safety Guidelines LARGE VOLUME INORGANIC COMPOUNDS MANUFACTURING AND COAL TAR DISTILLATION

D ECEMBER 10

, 2007 29 WORLD BANK GROUP
high content on primary distillation 41

. Naphthalene oil s can be further upgraded by several methods, mainly based on crystallization of the primary naphthalene oil to upgrade to phthalic grade quality or to convert the latter into the purer chemical grade anthracene oils. Naphthalene has been traditionally

us ed for the production of phthalic anhydride , ß

naphthol and dye stuff intermediates. More recently, naphthalene has been used in condensation products from naphthalene sulfonic acids, utilizing formaldehyde as additives to improve the flow properties of concrete. Another application is the product

io n of diisopropylnaphthalenes.

Crude anthracene is isolated from coke

- oven anthracene oils. W here the anthracene oil gives only a limited residue at 360°C, the oil is diluted using naphthalene drained oil or a light wash oil and this blend is cooled to 35°C . The resulting solid

– liquid slurry is filtered or centrifuged to give a crude anthracene oil containing 40

– 45% anthracene.
The recovery of tar chemicals leaves residual oils, including heavy naphtha, dephenolated carbolic oil, naphthalene drained oil, was h oil, strained anthracene oil, and heavy oil. These are blended to give creosote oils, which have been used as timber preservatives Coal

- tar creosote is also a feedstock for carbon black manufacture. Other smaller markets for creosote are for fluxing coa l tar, pitch, and bitumen.

41 Naphthalene oils from coke

- oven tars generally contain 60

– 65% of naphthalene.