pollution control in refineries and fertilizer industries

7/28/2019 Pollution Control in Refineries and Fertilizer Industries

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PRESENTED BY,

NIGHILA V PAUL

S2 MTECH,GEC THRISSUR



INTRDUCTION Population increase->More fertilizers & chemicals

Heavy pollution caused by factories near residential

areas. Pollution due to petroleum industries-> 3 stages

-crude oil production

-transportation

-refining operation

Refineries also cause thermal pollution of water bodies



POLLUTION CONTROL IN

FERTILIZER INDUSTRIES



FERTILIZER INDUSTRIES• Ammonia plant

• Conversion to urea, ammonium sulphate,nitro lime etc

NITROGENOUSFERTILIZERS

• Nitric acid, phosphoric acid, sulphuricacid plants

• Nitrohosphate production

PHOSPHATICFERTILIZERS

• All the above mentioned processesNP OR NPK(COMPLEX)



FERTILIZER INDUSTRY CLASSIFICATION

Classification(5 types)

1.Ammonia & urea plants

2.Ammonia, urea, & ammonium nitrate

plants3. Ammonia, urea, phosphoric acid &

complex fertilizers.

4. Ammonia, urea, ammonium sulphate

& H2so4.

5. Ammonia, urea, phosphoric acid,

nitric acid, sulphuric acid and complex

fertilizer plant

POLLUTANTS PLANT CATEGORY

1 2 3 4 5

pH X X X X X

AMMONIACAL N2 X X X X X

FLUORIDES X X X

SUSPENDEDSOLIDS

X X X

CHROMIUM X X X X X



EFFLUENTS FROM FERTILIZER INDUSTRY

POLLUTANT AvgConc. in waste

source Effects

Ammonia 732 NH3 & urea plants Toxicity to aquatic life,eutrophication

Urea 614 Urea plants Toxicity of NH3 afterhydrolysis, eutrophication

Arsenic 1.6 Gas purification Plant Poison, black foot disease,affects plants & crops

Oil NA Gas compressorhouses

Prevents o2 dissolution, floats& forms slicks in water

Phosphate 77 Phosphoric acid andcomplex plants

Causes algal blooms

Fluoride 15 Scrubber effluents in

phosphoric acidmanufacture

Dental & skeletal fluorisis,

effects fish hatching



PLANTS CONSIDERED• AMMONIA PLANT

• AMMONIUM SULPHATE

•PHOSPHORIC ACID

•COMPLEX FERTILIZER PLANT



I. AMMONIA PLANT EFFLUENTS

1. REMOVAL OF CARBON

Carbon formed by scrubbing the soot particles with water

Effects –choking of pipelines-blocks sunlight & o2 supply in water & disturbs

aquatic life

Treatment-mixing with oil & separation by gravity

-pelletization-vaccum filtration



Vacuum filtration method

Vaccum filter

pumppump Vaccumpump

condensor

receiver

Carbon cake



2.OIL REMOVAL

Oil seperator followed by adsorption by coke->oil content<10mg/l

3.HYDROGEN SULPHIDE REMOVAL

a) combustion of H2

S ->SO2

->sulphuric acid

b) Converted to sulphur by claus process

4.NITROGEN-WASH TAIL GAS REMOVAL

a)Flare the gas

b) Catalytic reduction of Nox

c) For low presure steam generation & heating



AMMONIUM SULPHATE AND PHOSPHORIC

ACID PLANT EFFLUENTS

1. SOLID EFFLUENT

Important solid product->gypsum

But Gypsum may contain fluorineBy hemi-hydrate dihydrate/ dihydrate- hemihydrate

process -> pure gypsum->

uses of gypsum->cement industry

->as soil conditioner

phospho-gypsum can also be used to make sulphuric

acid by mueller- Kuehne process



2.GASEOUS EFFLUENTS

INDUSTRIAL PLANT ALLOWABLE LIMIT

Single super phosphate plants 500mg/m3

Triple super phosphsate plants 4kg/tonne

Urea palnts(existing) 6kg/tonne

Urea plants(new) 2kg/tonne

•Causes mist formation in sulphuric acid plants•Mist eliminated by mist eliminator(Two Stages)•Other methods of separation of dust->

2.1) PARTICULATE MATTER



Other methods of separation of dust->

Gravity settling

Traps

impingement separators

louvres Cyclone Separators

Wet collectors

Packed towers

Gravity scrubbers Floating Bed Scrubbing

Electrostatic precipitators

pollution control in refineries and fertilizer industries

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