risk assessment -...
TRANSCRIPT
RISK ASSESSMENT
(QRA)
At
DEEPAK NITRITE LIMITED
(APL DIVISION) PLOT NO. 1 TO 7 & 26 TO 31, MIDC DHATAV,
DIST.:- RAIGAD, MAHARASHTRA, INDIA.
JANUARY 2017
2
CONTENTS SECTION DESCRIPTION PAGE NO.
1. EXECUTIVE SUMMARY. 03
2. HAZARD IDENTIFICATION. 23
2.1 Site Overview. 23
2.2 Process Description. 23
2.3 List Of Materials. 23
2.3.1 Finished Products. 23
2.3.2 Raw Materials. 23
2.4 Inventory Analysis. 23
2.5 Classification Of Hazardous Chemicals. 23
2.6 MSDS. (Highlights). 24
2.7 Mond Index Assessment. 27
2.8 Dow F & E Index. 54
2.9 Preliminary Hazard Analysis. 64
2.10 HAZOP Study. (Report enclosed separately). 64
3. FAILURE FREQUENCY ANALYSIS. 65
3.1 Failure Frequency. 65
3.2 Event Tree Analysis. 66
4. CONSEQUENCE ANALYSIS. 67
4.1 Introduction. 67
4.2 Accidental release of BTF. 68
4.3 Accidental release of Cumene 69
4.4 Accidental release of Furnace oil 70
4.5 Accidental release of HSD 72
4.6 Accidental release of Hydrogen Bromide 74
4.7 Accidental release of Hydrogen 75
4.8 Accidental release of MEK 77
4.9 Accidental release of Nitric acid
4.10 Accidental release of Nitrogen oxide
4.11 Accidental release of Toluene.
5. IMPACT ASSESSMENT (PROBIT). 78
5.1 Thermal Radiation Impact. 78
5.2 Over Pressure Impact. 79
5.3 Toxicity Impact. 80
6. RISK ESTIMATION. 81
6.1 Individual Risk Isopleths. 81
6.2 Societal Risk (F – N Curve). 82
7 RISK MITIGATION MEASURES. 82
LIST OF ANNEXURE SECTION DESCRIPTION PAGE NO.
1. GLOSSARY. 83
2. ABBRIVATIONS. 86
3. REFERENCES. 87
3
SECTION 1: EXECUTIVE SUMMARY
1.1 INTRODUCTION
1.1.1 M/s. Deepak Nitrite Ltd., is existing manufacturing facility located at Plot No.
1 to 7 & 26 to 31, MIDC Dhatav, Roha, District: Raigad, Maharashtra.
1.1.2 There is proposal for rationalizing the product mix is as follows;
TABLE NO. 1.1: LIST OF PRODUCTS FOR ENVIRONMENTAL
CLEARANCE
SN NAME OF THE PRODUCT
Product Capacity MT/M
Existing Addition/
Deletion Final
1.1 Para Cumidine(PC)
OR
200 200
1.2 2 Ethyl Hexy Nitrite
OR
200 -200
1.3 3 Amino BenzotriFlouride (3ABTF) - +200 200
2.1 Ortho Anisidine(OA)
OR
75 -25 50
2.2 Tri Methyl Hydro Quinine(TMHQ 75 -25 50
3.1 2,4 Xylidine and 2,6 Xylidine
OR
250 250
3.2 Nitrobenzene
OR
250 -250
3.3 2,3 Xylidine and 3,4 Xylidine
OR
250 250
3.4 2,5 Xylidine and 2,3 xylenol , 2,4 and
2,5 Xylenol
+250 250
4.1 Meta Cholro Aniline
OR
50 -50
4.2 Diphenyl Amine Derivatives 50 50
5.1 Crystal Diethyl Meta Amino Phenol(
DEMAP) OR
55 -15 40
5.2 Dibutyl Para Phenylene Di amine (DBPPDA
) OR
50 -10 40
5.3 3 NAP (3 Nitro AcetoPhenone)/
OR
+40 40
5.4 3AAP(3Amino AcetoPhenone)
OR
+40 40
4
5.5 3 HAP (3 HydroxyAcetoPhenone) +40 40
6.1 TFMAP(3-(trifloromethyl)acetophenon 55 +25 80
6.2 MePPDA Sulphate (2 Methyl P-
phenyleneDiamine Sulphate) OR
50 +10 60
6.3 1,3 CHD(1,3 Cyclohexane dione)
OR
22 +38 60
6.4 4-NAX (Benenamine,N-(1-ethyloropy)-3-
4-dimethyl)
10 -10 10
7.1 Pilot Plant Products 1,3 CHD(1,3
Cyclohexane dione) OR
5 -5
7.2 SMIA(synMethoximino(2 furanyl)acetic acid 5 -5
8.1 Pilot Plant Products ( synthetic Organic
Chemicals)
+10 10
TOTAL 822 -82 740
BYPRODUCTS
Sr.
no.
Name of the
by Product
By Product
from the
product
byproduct Capacity
MT/M
Existing
Addition
/deletion
Final
1 Ortho Nitro Cumene p- cumidiene 150 150
2 PPO (Poly phenylene
Oxide)
tri methyl
hydro quinine
201 -66 135
3 2 NBTF(2 Nitro BTF)
or
3 Amino BTF +41 41
4 2 ABTF(2 Amino BTF)
or
3 Amino BTF +41 41
5 4 ABTF (4 Amino BTF) 3 Amino BTF +41 41
6 Ortho Toluidine(OT) 2 MePPDA
Sulfate
20 +5 25
7 OHBTF
or
TFMAP +20 20
8 OA BTF TFMAP +20 20
Total 371 371
1.2 THE ASSIGNMENT
1.2.1 In compliance to the TOR for synthetic organic chemicals, this QRA report is
prepared.
1.2.2 Mr. Subhash Bonde of M/s. Bonde Technical Services, Thane is “EIA
Functional Expert – Risk Assessment and Hazard Management (RH)”
5
undertook this study in compliance with requirements of EIA report
preparation which is prepared by M/s. Goldfinch Engineering Systems Private
Limited, Thane.
1.3 SCOPE OF WORK
The scope of the report covers the proposed site activities of manufacturing. The
battery limits of this study are restricted to the installations indicated over the
proposed site plan.
1.4 METHODOLOGY
Methodology followed in preparation of this report is as per Technical EIA Guidance
Manual for Synthetic Organic Chemicals, prepared for the Ministry of Environment
and Forests Government of India.
The major steps are as outlined below;
Hazard Identification.
Failure Frequency Analysis.
Consequence Analysis.
Impact Assessment.
Protective System & Hazard Analysis.
Risk Mitigation Measures.
DMP.
FIGURE NO. 1.1: RISK ASSESSMENT METHODOLOGY.
6
1.5 HAZARD IDENTIFICATION
PRODUCT WISE RAW MATERIALS
S.n. RM NAME ↓ \ product no. → 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
1 2,3 xylidine √
2 2,5 xylidine √
3 3 AAP ( 3- amino acetophonone ) √ √
4 3 NAP √
S.n. RM NAME ↓ \ product no. → 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
5 3 –nitro BTF ( 3- Nitro Benzotrifluoride )
√
6 Acetaldoxime √
7 Acetic acid √ √
8 Acetophonone √
9 Acretanilide √
10 Ammonia Soln √
11 Anisole √
12 BTF √
13 Butanol √
14 catalyst √ √ √ √ √ √ √ √ √ √
15 Charcoal √ √
16 MEK √
17 PNA √
18 Copper sulphate √
19 Cumene √
20 Cuprous chloride √
21 Di methyl sulfate (DMS) √
22 DOST √
23 Ethyl acetate √
24 Sodium di thionite √ √ √
7
25 Hydrochloric acid √ √
26 Hydrogen √ √ √ √ √ √ √ √
27 Hydrogen bromide √
28 Hydrogen peroxide 50% √
29 2,4 xylidine √
30 Hyposupercell √ √
31 Iodine √
32 Iron powder √
33 M cresol √
34 Methanol √ √ √ √ √
35 MIBK √ √
36 M-Xylene √
37 Nitric acid 72% √ √ √ √ √
38 Nitric acid 98% √ √
39 Ortho Xylene √
40 P xylene √
41 PNC √
42 Potassium hydroxide √
43 Resorcinol √
44 Soda Soln √ √ √ √ √ √ √
45 Sodium bicarbonate √ √
46 Sodium bromide 36% √
47 Sodium hydro sulfate √
48 Sodium hydroxide /Caustic soda √ √ √
49 Sodium nitrite √ √ √ √ √
50 Sulfamic acid √
51 Sulfuric acid 98% √ √ √ √ √ √ √ √ √ √ √ √ √ √
52 TMP 80% √
53 Toluene √ √ √ √
54 Water √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √
Where product no.s are as pre following table . Sr.no. product no. Sr.no. product no.
1 3 AAP ( 3- amino acetophonone ) 10 P cumidine
2 3 HAP 3- hydroxyl acetophonone ) 11 2,4 Xylenol
3
3 NAP ( 3- nitro acetophonone )
12 2 MePPDA sulfate ( 2 methyl p- phylene di amine
sulphate
4 3 –ABTF ( 3- Amino BENZOTRIFLUORIDE ) 13 MMDPA ( 4 methyl di phenyl Amine
5 Cyclohexadione ( 1,3 CHD ) 14 Ortho anisidine
6 2,3 Xylenol 15 2,3 xylididene and 3,4 xylidene
7 2,4 xylidine & 2,6 xylidine 16 3‟ ( trifluoromethyl ) –acetophenone 9 TFMAP)
8 2,5 Xylenol 17 TMHQ
9 2,5 xylidine 18 DBPPDA (Di-Dibutyl para phenylene Diamine)
1.5.4 INVENTORY
No. Material location Existing Addition
proposed
Final Mode of
storage
1 MEK ‟A‟ Class Tank farm 24 24 Storage tank
2 Methanol* ‟A‟ Class Tank farm 10 10 Storage tank
3 Toluene* ‟A‟ Class Tank farm 10 10 Storage tank
4 BTF ‟B‟ Class Tank farm 100 100 Storage tank
5 Cumene* ‟B‟ Class Tank farm 60 60 Storage tank
6 M-Xylene* ‟B‟ Class Tank farm 100 100 Storage tank
7 Ortho Xylene* ‟B‟ Class Tank farm 90 90 Storage tank
8 PNC Column Tank farm 25 25 Storage tank
9 Nitric acid *72% Cont. Nitration Tank 50 50 Storage tank
8
farm
10 Nitric acid* 98%
Cont. Nitration Tank
farm
40 40 Storage tank
11 Acetaldoxime
DEMAP plant Tank
Farm 16
29 45 Storage tank
12 Sulfuric acid *98% DEMAP Tank farm 50 50 Storage tank
13
3-nitro BTF (3-
NitroBenzotrifluoride ) HP Tank farm
50
50
Storage tank
14 Hydrogen * Hydrogenation plant
1500
Nm3
1500
Nm3
Cylinder
Trolley
15 Di methyl sulfate (DMS)
MMDPA plant Tank
farm
35 35 Storage tank
16
Sodium hydroxide* /Caustic
soda
MMDPA plant Tank
farm
16 16 Storage tank
17 Hydrochloric acid*
ONA plant Tank
farm
16 16 Storage tank
18 2,3 xylidine * Ware house 5 5 Drum
19 2,5 xylidine * Ware house 5 5 Drum
20
3 AAP ( 3- amino acetophonone
)
Ware house
10 10 Bags
21 3 NAP Ware house 10 10 Bags
22 Acetic acid * Ware house 1 1 Drums
23 Acetophonone (50%) Ware house 1 1 Bags
24 Acretanilide Ware house
10
10 Bags
25 Ammonia Soln. Ware house 5 5 Drum
26 Butanol Ware house 4 4 Drum
27 catalyst Ware house 0.01 0.01 Drum
28 Charcoal Ware house 0.01 0.01 Drum
29 PNA Ware house 10 10 Bags
30 Copper sulphate* Ware house 1 1 Bags
31 Cuprous chloride * Ware house 1 1 Bags
32 DOST ( Catalyst ) Ware house 0.01 0.01 Drum
INVENTORY
Sr. No.
Material Existing Addition
Final Mode of storage
33 Ethyl acetate * Ware house 1 1 Drum
34 Hydrogen bromide* (36%) Ware house 9 9 Drums
35 Sodium dithionite Ware house 0.025 0.025 Bags
36 Hyposupercell Ware house 0.025 0.025 Bags
37 Iodine * Ware house 0.1 0.1 Bags
38 Iron powder Ware house 0.05 0.05 Bags
39 M cresol Ware house 16 16 Drums
40 MIBK * Ware house 0.24 0.24 Drums
41 P xylene * Ware house 5 5 Drums
42 Potassium hydroxide* Ware house 5 5 Bags
43 Resorcinol Ware house 5 5 Bags
44 Soda Ash Ware house 16 16 Bags
45 Sodium bicarbonate Ware house 1 1 Bags
46 Sodium bromide Ware house 2 2 Bags
47 Sodium hydro sulfate Ware house 1 1 Bags
48 Sodium nitrite Ware house 10 10 Bags
49 Sulfamic acid Ware house 0.1 0.1 Bags
9
50 TMP 80% Ware house 5 5 Bags
1.5.5. SAFETY PROPERTIES part I
Sr.
No.
NAME CAS LEL UEL F.P B.P.
NFPA
HAZARD
INDEX
N h Nf Nr MF
1 Acetic acid 64-19-7 5.4 16 39 118 2 2 0 10
2 Ammonium hydroxide 1336-21-6 - - 3 1 0 4
3
Acetaldoxime tech. solid 107-29-9
<22 115
dec.
2 3 0 16
4 BTF 98-08-8 12 101 3 3 1 16
5
Coal *
355
0
1 1 0
4
6 Cumene 0.9 6.5 36 152 2 3 1 16
7
Diesel 68476-34-
6
0.6 7.5 32 -
62
>150 0 2 0 10
8 DMS 4 2 0 10
9 Ethyl acetate 141-78-6 1 3 0 16
10
Furnace oil HC Mixture 0.7 5 >65 175-
325
1 2 0 10
11 Hydrochloric acid 7647-01-0 - 53 3 0 1 14
12 Hydrogen 1333-74-0 4 76 Gas - 0 4 0 21
13
Hydrogen bromide 10035-10-
6
- - - - 3 0 0 1
14 Hydrogen chloride 7647-01-0 -85 3 0 1 14
15 Hydrogen peroxide 50% 7722-84-1 - 141 2 0 3 29
16 Iodine 7553-56-2 - - - 184 - - - -
17 Methanol 67-56-1 6 36 11 64.7 1 3 0 16
18 MIBK 108-10-1 1.4 7.5 14 117-118 2 3 0 16
19 Nitric acid 98% 7697-37-2 - 121 4 0 1 14
20 Ortho Xylene 95-47-6 1 7 32 144 2 3 0 16
Sr.
No.
NAME CAS LEL UEL F.P B.P.
NFPA
HAZARD
INDEX
N h Nf Nr MF
21 Potassium hydroxide 1310-58-3 - - - - 3 0 1 14
22 Sodium hydroxide 1310-73-2 - - - - 3 0 1 14
23 Sodium Sulphide 1313-82-2 3 1 1 14
24 Sulfuric acid 98% 7664-93-9 - - - 340 3 0 2 24
25 Toluene 108-88-3 1.2 7 12.7 110.4 2 3 0 16
10
26 m Xylene 108-38-3 1.1 7 27 139 2 3 0 16
27
Xylidine (mix isomer ) 1300-73-8 1.5 - 96 213-
226
28
Xylinol (mix isomer ) 1300-71-6 145 - 61-95 203-
225
* Explode able conc. 0.140 g/l ;CAS 3,4Xylinol ( 95-65-8) , 2,5 Xylinol ( 95-87-4) , 2,4 Xylinol ( 105-67-9), 2,3 Xylinol (526-75-0) 2,6Xylinol ( 576-26-1)
1.5.5. SAFETY PROPERTIES part II
Sr.
No. NAME CAS
tlv stel idlh
toxicity
oral
lD50
dermal
lD50
inhalation
LC50
Ppm ppm ppm mg/kg. ml/kg. mg/m3
1 Acetic acid 64-19-7 10 15 3310 1.06gm 5620
2
Ammonium
hydroxide
1336-21-6
0.35 250ug -
3
Acetaldoxime
tech.(s)
107-29-9
4 BTF 98-08-8
5 Coal 0.1mg/m3
6 Cumene
7 Diesel 68476-34-6 5 10-15 - 7.5 - -
8 DMS
9 Ethyl acetate 141-78-6
10 Furnace oil HC Mix 200 >500
11 Hydrochloric acid 7647-01-0 5 50 3124 900
12 Hydrogen 1333-74-0 asphyxiant SA - SA
13 Hydrogen bromide 10035-10-6 3 PEL 10 2858
14 Hydrogen chloride 7647-01-0 5 5 2810
15
Hydrogen peroxide
50%
7722-84-1
16 Iodine 7553-56-2 0.1
17 Methanol 67-56-1 250
18 MIBK 108-10-1 100 300
19 Nitric acid 98% 7697-37-2 2 0.430 244
20 Ortho Xylene 95-47-6 150
21 Potassium hydroxide 1310-58-3 2mg/m3
22 Sodium hydroxide 1310-73-2 2mg/m3
23 Sodium Sulphide 1313-82-2
24 Sulfuric acid 98% 7664-93-9 1mg/m3 3mg/m3 100-330mg/m3
25 Toluene 108-88-3 50 150
26 m Xylene 108-38-3 100 150
27
Xylidine(mix isomer
)
1300-73-8 0.5
28 Xylinol (mix isomer ) 1300-71-6 -
1.5.6 HAZARDOUS CHEMICALS
Chemicals stored or handled at site are Hazardous chemicals which
satisfies; any of the following criteria.
11
1. Criteria laid down in part I or is listed in Column 2 of Part II Schedule I
appended to “Manufacture Storage and Import of Hazardous Chemicals
Rules, 1989” and
2. Criteria laid down in part I or is listed in Column 2 of Part II Schedule I
appended to “The Maharashtra Factories (Control of Industrial Major
Accident Hazards) Rules, 2003” or
3. Listed in Column 2 of Schedule 2 appended to these rules or
4. Listed in Column 2 of “The Second Schedule appended to the Factories
Act, 1948”.
5. “The Hazardous Waste (Management and Handling) Rules, 1989”
Amended 2000 and 2003.
1.5.7 MSDS
MSDS of BTF, Hydrogen and Toluene are enclosed in Section No. 2
and MSDS for others are maintained at site.
1.5.8 CLASSIFICATION OF HAZARDOUS CHEMICALS
TABLE NO. 1.3: HAZARDOUS CHEMICALS CLASSIFICATION
Sr.
No.
Location Material Max.
Storage
capacity
Group Thres
hold Qty.
Mt. for
MAH
(Sch. 2)*
1 Hydrogen
shed
Hydrogen <1 T 3 Highly reactive chemicals 2
2 A class Methanol 10 Kl 5.3 Very Highly Flammable
Liquids.
1500 T.
Tank Toluene 10 Kl 5.3 Very Highly Flammable
Liquids.
farm MEK 24 Kl 5.3 Very Highly Flammable
Liquids.
BTF 100 T 5.3 Very Highly Flammable
Liquids.
3 B class M-Xylene 100 T 5.5 Highly Flammable Liquids. 2500 T
Tank O-Xylene 100 T 5.5 Highly Flammable Liquids.
farm Cumene 150 T 5.5 Highly Flammable Liquids.
4 FO Tank
farm
Furnace
oil
50 Kl 5.6 Flammable Liquids. 5000 T
*Criteria used: “Manufacture Storage and Import of Hazardous
Chemicals Rules, 1989”
12
1.5.9 The inventory of hazardous chemicals does not exceeds the threshold
quantity to qualify as Major Accident Hazards installation
(MAH).There is no change in the status due to the proposed addition.
1.6 DOW F&E INDEX
Identification of hazardous units and segments of plants and storage units based on
“relative ranking technique,” such as Fire and Explosion Index. F & EI, is a method
universally adopted for classifying/ categorizing/ indexing of chemicals based on their
reactivity and instability. The more widely used hazard index is the F & EI developed
by DOW Chemical Company. Dow Fire and Explosion Index (F&EI) serve as a guide
to the selection of fire protection methods. Methodology adopted is described in
Section No. 2.8.
TABLE NO. 1.5: DOW F & E INDEX
Sr.
No.
Installation DOW
F&E
Index
The
Degree
Of
Hazard
Radius
Of
Exposure
(m)
Damage
Factor
Area Of
Exposure
(m2)
Toxicity
Index
Toxicity
Category
1 Hydrochloric
acid
2 Light - - - 7.3 II
2 Hydrogen 59 Light 15 0.58 706 - -
3 Toluene 38 Light 9.7 0.35 295 4.4 I
4 Cumene 38.6 Light 9.7 0.35 295 4.38 I
5 Furnace oil 19.2 Light 4.91 0.15 76 - -
6 O xylene 41.3 Light 10.5 0.37 346 4.48 I
1.7 MOND INDEX ASSESSMENT
1.7.1 The MOND Index is a rapid hazard assessment method for use on chemical
plant or in plant design. The use of this technique puts the hazard of a plant on
a numerical scale, where the comparative pictures of all subdivisions of the
plant form emerge. The assessment is carried out as per MOND INDEX
Manual 1993. Methodology adopted is described in Section No. 2.7.
TABLE NO. 1.4: MOND INDEX ASSESSMENT
SR. NO. MATERIAL EQUIVALENT
DOW INDEX
FIRE INDEX INTERNAL
EXPLOSION INDEX
AERIAL
EXPLOSION INDEX
OVER ALL
HAZARD RATING
1 Cumene 143 3.7 3.25 32.43 1197
13
Low Moderate Moderate High Group II
2 Furnace oil 65 7.5
Moderate
2.85
Moderate
9.4
Light
380
Moderate
3 HSD 71 2.25
Low
2.6
Moderate
0.3
Light
102
Moderate
4 Hydrogen 173 0.35
Light
5.02
High
11.17
Low
518
High Group I
5 O xylene 155 4.35
Low
3.6
Moderate
26.47
Low
1354
High Group II
6 Toluene 159 0.54
Light
3.6
Moderate
5.31
Light
352 Moderate
1.7.2 It is reasonable to assume that a unit assessed at this level can be operated in a
satisfactory manner by providing adequate off setting measures, giving full
regard to the hazards indicated by the assessment provided adequate depends
heavily upon the maintenance of the hardware and of the management
procedures; neglect of either will lead to loss of protection and the rating will
rise.
1.8 COMPATIBILITY/ REACTIVITY HAZARD
TABLE NO. 1.6: COMPATABILITY /REACTIVITY HAZARD MATRIX
Chemicals Mixing
With → Ethyl
Acetate
Hydrobromic
Acid, Solution
Hydrogen
Peroxide
Iodine Potassium
Hydroxide
Sodium
Sulfide
1 Ethyl Acetate
2 Hydrobromic
Acid, Solution N
3 Hydrogen
Peroxide N N
4 Iodine C C C
5 Potassium
Hydroxide N N N C
CHART LEGEND
Y Compatible - No hazardous reactivity issues expected
N Incompatible - Hazardous reactivity issues expected
C Caution - May be hazardous under certain conditions
SR Self reactive - Potentially self reactive e.g. polimerizable
1.9 HAZOP STUDY
(Enclosed separately).
1.9.1 Identification of hazards by HAZOP study is carried out, the thrust area being
the environmental issues in the proposed activities. The report is “Enclosed
separately”. The methodology adopted is described in the report.
1.9.2 HAZOP COMMITTEE
14
HAZOP committee was formed under the chairmanship of Project Proponent
with members of the project team and Mr. Subhash Bonde as Moderator.
1.9.3 UNIT PROCESS AND UNIT OPERATIONS
TABLE NO. 1.7: PRODUCT WISE UNIT PROCESSES & OPERATIONS
S
r
.
N
o
.
Unit
Processes/
Unit
Operations
Product number in which the corresponding
process/operation is used.
1 2 3 4 5 6 7 8 9 1
0
1
1
1
2
1
3
1
4
1
5
1
6
1
7
1
8
1
Centrifugin
g
√ √ √ √ √ √ √
2
Charcoal
treatment
√ √
3
Condensati
on
√
4 Coupling √
5
Crystallizat
ion
√ √ √ √ √ √
6
Decarboxyl
ation
7
Diazotizati
on
√ √ √ √ √
8 Dissolution √ √ √ √ √ √ √
9 Distillation √ √ √ √ √ √ √ √ √ √ √ √ √ √
10 Drying √ √ √ √ √ √ √
11 Filtration √ √ √ √ √ √ √ √ √
12 Fulfation √
15
13
Halogenatio
n
√
14
Hydrogenat
ion
√ √ √ √ √ √ √ √ √
15 Hydrolysis √ √ √ √ √ √
16
Isolation
by acid
√
17
Methylatio
n
√
18 Mixing √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √
19 Nitration √ √ √ √ √ √
20 Oxidation √
21 Quenching √
22
23
Reduction
iron acid
√
24 Settling √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √
25
Solvent
recovery
√ √ √ √ √ √ √ √ √
26 Washing √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √ √
Reaction Exotherm.
Critical To Control Moderate Mild
1.9.4 NODES
TABLE NO. 1.7: NODES FOR HAZOP STUDY
Node 1 Tank farm.
Node 2 Nitration
Node 3 Halogenation
Node 4 Hydrogenation
Node 5 Oxidation
Node 6 Hydrolysis
Node 7 Condensation
Node 8 Reduction
Node 9 Solvent Recovery
Node 10 Effluent Treatment Plant.
16
Node 11 All Other Unit Processes And Operations.
1.9.5 MODES
Mode of operation is batch wise.
1.9.6 IDENTIFICATION OF HAZARDS
1.9.6.1 HAZARD RATING
Probability of each hazard according to its likelihood of
occurrence and the severity of each hazard according to its
potential for harm was estimated on 1 to 5 scale. By
multiplying these two factors i.e. probability and severity, a
range of risk ratings between 1 to 25 is obtained.
1.9.6.2 Identified hazards/ events having risk rating in 16 to 25 range
summezised as follows;
STORAGE AND HANDLING
Solvent handling Toxicity hazard
Fire/ explosion /toxicity hazard at tank farm.
Reactivity/ compatibility hazards at warehouse.
PROCESS OPERATIONS
Fire /Explosion hazard at reactor due to uncontrolled
exothermic reactions.
Health hazard due to vapors emissions at work place.
Toxic gas release at vent in case of scrubber failure.
Fire explosion hazard due to Static charge as source of
ignition in handling of solvents.
1.9.6.3 Following accident scenario is considered for Consequence
Analysis.
Accidental Release of solvent followed by
fire/explosion/toxicity hazard
Accidental Release of Hydrogen followed by fire/explosion
Release of NOx at vent of the scrubber
1.10 CONSEQUENCE ANALYSIS
1.10.1 The potential consequences from the hazardous scenarios identified are
determined and the impact zones modeled using ALOHA and PHAST
software tools. The primary consequence types are pressure wave, thermal
radiations and toxic gas release. The stable atmospheric stability conditions
17
and ambient temperature of 30 oC, wind speed was 1.5 m/s. and humidity
(50%) used for Consequence Analysis.
1.10.2 RESULTS
TABLE NO. 1.9: CONSEQUENCE ANALYSIS RESULTS
Downwind Affect Distance (m)
Sr.
No
.
Accident
Scenario Toxic vapor cloud
Flammable
vapor cloud
LEL
Blast Over
Pressure psi
Thermal
radiation
(KW/m2)
ERPG
3
ERPG
2
ERPG
1 IDLH 60 % 10 % 8 3.5 1.0 10 5 2
1 BTF 32 94 486 - <10 11 - - - 16 25 41
2 Cumene 10 10 27 10 10 10 - - - 43 62 98
3 Furnace oil - - - - - - - - - 9 13 18
4 HSD 11 12 13.
5
5 Hydrogen
Bromide
PAC 3
21
PAC 2
45
PAC 1
379 - - - - - - - - -
6 Hydrogen
Jet fire
- - - - - - - - - <10 <10 <10
7 Hydrogen
line leak
- - - - 30 73 24 27 45 18 25 38
8 MEK PAC 3
<10
PAC 2
<10
PAC 1
<10 13 <10 <10 - <10 11 <10 <10 <10
9 Nitric acid <10 25 64 13
10 Nitrogen
oxide
54 75 305 66
11 Toluene
pool fire
<10 <10 <10 <10 <10 <10 - - - 10 13 17
DISPERSION POOL FIRE EXPLOSION. TOXIC GAS RELEASE.
BTF TOLUENE. HYDROGEN. NITRIC ACID
1.11 FREQUENCY ASSESSMENT
1.11.1 Event trees begin with an initiating event and work toward a final result. This
approach is inductive. The method provides information on how a failure can
occur and the probability of occurrence.
18
1.11.2 Frequency of the incident is estimated by Event Tree.
S.N. EVENT EVENT FREQUENCY/ YR
1. Release of flammable solvent
followed by pool fire.
1.0 × 10-4
2. Hydrogen gas accidental fire/
explosion
4.4 × 10-3
3. Toxic gas release at scrubber vent. 1 × 10-3
1.12 IMPACT ASSESSMENT
1.12.1 Effect models are used to determine how people are injured by exposure to
heat, overpressure and toxic load. Effect models make use of a probit function.
In probit function a link exists between the load and percentage of people
exposed who suffer particular type of injury.
1.12.2 RESULTS
TABLE NO. 1.10: PROBIT CORRELATION RESULTS
Event Level Of Concern Affect
Distance
Impact Probit Correlation *Fatality
%
Toluene Pool Fire. 10.0 KW/m2 10 m Thermal Radiations. Pr = –14.9+ 2.56 ln [(t×I4/3)] 0
Toluene evaporating Pool 1000 ppm -ERPG3 <10m Toxicity. Pr = –6.794 + 0.408 [ln (C 2.5×T)] 0
Hydrogen Explosion. Over pres. 3.5 psi 27 m Lung Hemorrhage. Pr = –77 + 6.91 ln (Po) 54
Hydrogen Explosion. Over pres. 3.5 psi 27 m Ear Drum Rupture. Pr = –15.6 + 1.93 ln (Po) 5
Hydrogen Explosion. Over pres. 3.5 psi 27 m Fatality. Pr = –46.1 + 4.82 ln (Po) 0
Hydrogen Fire 10.0 KW/m2 18 m Thermal radiations. Pr = –14.9+ 2.56 ln [(t×I4/3)] 0
Furnace Oil. 10.0 KW/m2 9 m Thermal radiations. Pr = –14.9+ 2.56 ln [(t×I4/3)] 0
Cumene Pool Fire. 10.0 KW/m2 43 m Thermal Radiations. Pr = –14.9+ 2.56 ln [(t×I4/3)] 0
Nitrogen di oxide IDLH 20 ppm 66m Toxicity. Pr = –13.79 + 1.4 [ln (C2.0×T)] 0
* Assuming escape time from fire to safe place exceeds 90 seconds and for toxic gas 10 minutes.
1.13 RISK ESTIMATION
1.13.1 VULNERABLE ZONE
19
Contour No.
Chemical Color Code
Level Of Concern Impact
1 Nitric acid IDLH concentration Toxicity
2 Toluene. 10 KW/m2 - Thermal Radiations. Thermal Radiations.
3 Hydrogen. 3.5 psi Overpressure
4 Hydrogen. 10 KW/m2 - Thermal Radiations. Thermal Radiations.
5 Hydrogen. DOW damage 35% damage
6 O Xylene DOW damage 37% damage
7 Cumene DOW damage 35% damage
8 Cumene DOW damage 35% damage
9 BTF 10 KW/m2 - Thermal Radiations. Thermal Radiations.
10 Furnace Oil. DOW damage 15% damage
1.13.2 INDIVIDUAL RISK
INDIVIDUAL RISK - FATALITY CRITERIA. Individual Fatality Individual Fatality Criteria
1 × 10-4 per yr This contour remains on-site.
1 × 10-5 per yr This contour extends into industrial developments only.
1 × 10-6 per yr This contour extends into commercial and industrial developments only.
INDIVIDUAL FATALITY QRA RESULTS. Individual Fatality Downwind
Affect
Distance (M)
Remarks
4.4 × 10-4 per yr. 35 This contour remains on-site.
4.4 × 10-5 per yr. 58 This contour extends in to notified industrial area only.
4.4 × 10-6 per yr. 70 This contour extends in to notified industrial area only.
20
1.13.3 SITE SURROUNDING : MIDC - NOTIFIED AREA
CONTOUR NO. RISK LEVEL
1 4.4 × 10-4 per yr.
2 4.4 × 10-5 per yr.
3 4.4 × 10-6 per yr.
1.13.5 SITE SURROUNDING POPULATION
SITE SURROUNDING.POPULATION
Sr.
No.
Name of
Village
Distance
(km)
Population Sr.
No.
Name of
Village
Distance
(km)
Population
1 Asthami 6 79 5 Talaghar 6.4 1207
2 Dhatav 1.5 2817 6 Warse 1.8 1909
3 Kholad 6.4 1836 7 Udavanne 1.3 778
4 Killha 2.65 2571
1.13.6 SITE SURROUNDING STATUS
Google image Wind rose
21
1.13.7 Societal risk
QRA RESULTS. F – N CURVE.
R.
NO. EVENT
EVENT FREQUENCY
PER YR
NO. OF
FATALITY
CUMULATIVE
FREQUENCY
1. Hydrogen Gas Fire/
Explosion.
4.4 10-4 1 4.4 10-4
2 Solvent Tank Pool
Fire.
1.0 10-3 0 5.4 10-4
1.14 RISK MITIGATION MEASURES SUGGESTED.
6. Provide Dyke for accidental spill containment for above ground storage
tanks.
7. Provide mobile pump arrangement to transfer the accidental spill
contained in Dyke to emergency spare tank.
8. Store chemicals considering the compatibility and reactivity hazards at
store/ warehouse.
11. Provide Hydrogen gas leak detectors and alarm at hydrogen trolley
location and hydrogenation plant
13. Provide wind direction socks.
14. Provide smoke detector at warehouses.
15. Provide suitable arrangement at storm drain to avoid any organic
contaminated water/ spill/ fire water going out of the site.
22
16. Revise “DMP” based on MCLS Analysis for the site with dove tailing data
for offsite disaster control plan.
A Hydrogen leak detector
B Hydrogen chloride leak detector
1.16 We thank the staff and the management for positive approach shown and excellent co-
operation extended throughout the studies to complete the studies in scheduled time
frame.
23
SECTION 2: HAZARD IDENTIFICATION
2.1 SITE OVERVIEW
2.1.1 M/S.
2.1.2 Products for environmental clearance
Refer Table No. 1.1 in Section No. 1.
2.1.2 LIST OF PRODUCTS FOR ENVIRONMENTAL CLEARANCE
Refer Table No. 1.1 in Section No. 1.
2.2 PROCESS DESCRIPTION
Refer HAZOP Study report for process, flow chart, material balance and plant
equipment details.
2.3 LIST OF MATERIALS
2.3.1 FINISHED PRODUCTS
Refer Table No. 1.1 in Section No. 1.
2.3.2 RAW MATERIALS
Refer Table No. 1.2 in Section No. 1.
2.4 INVENTORY ANALYSIS
HAZARDOUS CHEMICALS
Chemicals stored or handled at site are Hazardous chemicals which satisfies; any of
the following criteria.
1. Criteria laid down in part I or is listed in Column 2 of Part II
Schedule I appended to “Manufacture Storage and Import of
Hazardous Chemicals Rules, 1989” and
2. Criteria laid down in part I or is listed in Column 2 of Part II
Schedule I appended to “The Maharashtra Factories (Control of
Industrial Major Accident Hazards) Rules, 2003” or
3. Listed in Column 2 of Schedule 2 appended to these rules OR
4. Listed in Column 2 of “The Second Schedule appended to the
Factories Act, 1948”.
5. “The Hazardous Waste (Management and Handling) Rules, 1989”
Amended 2000 and 2003.
24
Properties of the chemicals are checked to classify the hazardous chemicals.
Refer Table No. 1.3 in Section No. 1.
2.5 CLASSIFICATION OF HAZARDOUS CHEMICALS
Refer Table No. 1.5 in Section No. 1.
25
2.6 MSDS
BTF
26
27
28
2.7 MOND INDEX ASSESSMENT
2.7.1 METHODOLOGY
The MOND Index is a rapid hazard
assessment method for use on
chemical plant or in plant design.
The use of this technique puts the
hazard of a plant on a numerical
scale, where form the comparative
pictures of all subdivisions of the
plant emerges. (For details refer
MOND INDEX Manual 1993). The
plant installations having significant
inventory of flammable/
combustible materials are
considered and plant is sub divided
accordingly. MOND INDEX
ASSESSMENT (without offsetting) for
these installations is summerised. FIGURE NO. 2.1:
THE MOND INDEX PROCEDURE.
FIRE INDEX (F):
The Index concentrates on the amount of flammable material in the unit, its energy
release potential and the area of the unit. The expression is;
N
KBF
And descriptive categories can be derived from the table below.
TABLE NO. 2.4: FIRE INDEX CATEGORY.
FIRE INDEX CATEGORY
0 – 2 Light.
2 – 5 Low.
5 – 10 Moderate.
10 – 20 High.
20 – 50 Very High.
50 – 100 Intensive.
100 – 250 Extreme.
29
> 250 Very Extreme.
EXPLOSION INDICES (E):
Separate indices have been developed to indicate the potential of the unit for an
internal explosion an aerial (vapor cloud) explosion.
Internal Explosion Index (E) this is expressed as follows,
1001
SPME
And gives a measure of the potential for explosion within the unit. Corresponding
descriptive categories are given below.
TABLE NO. 2.5: INTERNAL EXPLOSION INDEX CATEGORY.
INTERNAL EXPLOSION INDEX CATEGORY
0.0 – 1.5 Light.
1.5 – 2.5 Low.
2.5 – 4.0 Moderate.
4.0 – 6.0 High.
Above 6.0 Very High.
AERIAL EXPLOSION INDEX (A):
Important features in assessing aerial explosion risk include the quantity of material
available and its heat of combustion, the likelihood of release, the rate and height of
release and the mixing characteristics of the gas. All of these factors have been
considered to give an aerial explosion index according to the expression. Where, B is
material factor, characteristic of the material.
ptQHEm
BA
1
300
273
10001001
Corresponding descriptive categories are given below;
TABLE NO. 2.6: AERIAL EXPLOSION INDEX CATEGORY.
AERIAL EXPLOSION INDEX CATEGORY
0 – 10 Light.
10 – 30 Low.
30 – 100 Moderate.
100 – 400 High.
400 – 1700 Very High.
30
Above 1700 Extreme.
OVERALL HAZARD RATING (R):
As it is often necessary to compare units having different types of hazard, an overall
hazard index has been developed based upon the indices described above. The
combination adopted is, with the descriptive categories as given below.
AFEDR 2.01
TABLE NO. 2.7: OVERALL HAZARD RATING CATEGORY.
OVERALL HAZARD RATING CATEGORY
0 – 20 Mild.
20 – 100 Low.
100 – 500 Moderate.
500 – 1100 High (Group 1).
1100 – 2500 High (Group 2).
2500 – 12,500 Very High.
12500 – 65,000 Extreme.
Above 65,000 Very Extreme.
EQUIVALENT DOW INDEX:
1001
1001
1001
TLQSPMBD
2.7.2 SUB – DIVISION OF PLANT IN UNITS
Storage tank installations.
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
2.8 DOW F & E INDEX
HAZARDS IDENTIFICATION BY USE OF DOW INDEX:
By Dow's Fire and Explosion Index Method:
Fire and Explosion Index, F & EI, is a method universally adopted for classifying/
categorizing/ indexing of chemicals based on their reactivity and instability. The more
widely used hazard index is the F & EI developed by DOW Chemical Company.
1. Identification of equipment within a process plant that would contribute to the
initiation or escalation of an incident.
2. Qualification of the expected damage potential of fire and explosion incident
in realistic terms.
3. Determination of area of exposure surrounding the process unit.
The quantitative methodology relies on the analysis based on historical loss
data, the energy potential of the material under study and the extent to which
loss prevention measures are already taken.
F & EI = MF F3
Where,
MF = Material factor which represents in flammability and Reactivity of substance.
F3 = Hazard Factor.
= F1 × F 2
Where,
F1 = Process Hazard.
F2 = Special Process Hazard.
Deviation of MF
MF is a measure of intrinsic rate of potential energy release from fire or explosion
produced by combustion or any other chemical reaction. The National Fire Protection
Agency of U.S.A. (N.F.P.A.) has specified standard values of MF for many
substances. It is calculated from Flammability (Nf) and Reactivity (Nr) indices
provided in NFPA 325 M or NFPA-49. Knowing Flash Point (FP) and Boiling (B.P.)
Flammability can be determined.
50
General Process Hazard (F1)
Six operations, process units or processing conditions which contributes to a
significant enhancement of potential for fire and explosion have been identified and
numerical values of penalties to be added for obtaining the values of F1 are given.
These includes exothermicity and endothermicity of reactions, method of handling,
accessibility and facilities to drainage and spill control.
Special Process Hazards (F2) are factors that contribute primarily to the probability of
occurrence of a loss accident.
Evaluation of F & EI
The degree of hazard potential is identified based on the numerical value of F & E as
per the criteria given below:
TABLE NO. 2.8: F&EI RANGE & DEGREE OF HAZARD.
F & EI Range Degree of Hazard
0 – 60. Light.
61 – 96. Moderate.
97 – 127. Intermediate.
128 – 158. Heavy.
159 – and above. Severe.
51
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: FURNACE OIL tank farm
MATERIALS AND PROCESS: FURNACE OIL.
MATERIAL FACTOR: 10.
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 0.0
B. Endothermic Process. 0.20 to 0.40 0.0
C. Material Handling & Transfer. 0.25 to 1.05 0.2
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 0.0
E. Access. 0.20 to 0.35 0.0
F. Drainage and Spill Control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). 1.2
2. SPECIAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.0
B. Sub – Atmospheric Pressure. 0.50 0.0
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 –
3. Always in Flammable Range. – 0.0
D. Dust Explosion. 0.25 to 2.0 0.0
E. Pressure Operating atmospheric; – 0.0
F. Low Temperature. 0.20 to 0.50 0.0
G. Quantity of Flammable/ Unstable Material Quantity
50 T., Hc = 18.7 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – 0.4
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 0.0
K. Hot Oil Heat Exchange system > 210 ft. 0.15 to 1.15 0.0
L. Rotating Equipment. 0.5 0.0
Special Process Hazards Factor (F2) 1.6
Unit Hazards Factor (F1 F2 = F3). 1.92
Fire and Explosion Index (F3 MF) (F & IE). 19.2
THE DEGREE OF HAZARD LIGHT.
RADIUS OF EXPOSURE 4.91 meter.
DAMAGE FACTOR 0.15
AREA OF EXPOSURE 76 m2
52
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: Tank farm
MATERIALS AND PROCESS: HYDROCHLORIC ACID.
MATERIAL FACTOR: 1
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 00
B. Endothermic Process. 0.20 to 0.40 00
C. Material Handling & Transfer. 0.25 to 1.05 0.0
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 00
E. Access. 0.20 to 0.35 00
F. Drainage and spill control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). – 1.0
2. SPECIAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.6
B. Sub – Atmospheric Pressure. 0.50 00
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 –
3. Always in Flammable Range. – –
D. Dust Explosion. 0.25 to 2.0 00
E. Pressure Operating atmospheric; Relief Setting - – 00
F. Low Temperature. 0.20 to 0.50 00
G. Quantity of Flammable/ Unstable Material Quantity;
10 Mt., Hc = 0 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – –
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 00
K. Hot Oil Heat Exchange system 0.15 to 1.15 00
L. Rotating Equipment. 0.5 00
Special Process Hazards Factor (F2) – 1.8
Unit Hazards Factor (F1 F2 = F3). 1.8
Fire and Explosion Index (F3 MF) (F & IE). 2
THE DEGREE OF HAZARD. LIGHT
RADIUS OF EXPOSURE. –
DAMAGE FACTOR. –
AREA OF EXPOSURE. –
Th 250 + 125 (1 + 1 + 1.8) = 725. T 7.3 Cat II.
53
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: HYDROGEN CYLINDER SHED.
MATERIALS AND PROCESS: HYDROGEN.
MATERIAL FACTOR: 21
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 00
B. Endothermic Process. 0.20 to 0.40 00
C. Material Handling & Transfer. 0.25 to 1.05 0.5
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 00
E. Access. 0.20 to 0.35 00
F. Drainage and Spill Control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). 1.5
2. SPECIAL PROCESS HAZARDS
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.0
B. Sub – Atmospheric Pressure. 0.50 00
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 0.3
3. Always in Flammable Range. – –
D. Dust Explosion. 0.25 to 2.0 00
E. Pressure Operating 75 psig; Relief Setting + 10 %. – 0.39
F. Low Temperature. 0.20 to 0.50 00
G. Quantity of Flammable/ Unstable Material Quantity
80 cylinders, Hc 51.6 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – < 0.1
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 00
K. Hot Oil Heat Exchange system > 210 ft. 0.15 to 1.15 00
L. Rotating Equipment. 0.5 00
Special Process Hazards Factor (F2) 1.89
Unit Hazards Factor (F1 F2 = F3). 2.84
Fire and Explosion Index (F3 MF) (F & IE). 59
THE DEGREE OF HAZARD MODERATE
RADIUS OF EXPOSURE 15 meter
DAMAGE FACTOR 0.58
AREA OF EXPOSURE 706 m2
54
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: TANK FARM.
MATERIALS AND PROCESS: Cumene
MATERIAL FACTOR: 16
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 00
B. Endothermic Process. 0.20 to 0.40 00
C. Material Handling & Transfer. 0.25 to 1.05 0.25
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 00
E. Access. 0.20 to 0.35 00
F. Drainage and Spill Control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). – 1.25
2. SPECIAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.4
B. Sub – Atmospheric Pressure. 0.50 00
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 –
3. Always in Flammable Range. – –
D. Dust Explosion. 0.25 to 2.0 00
E. Pressure Operating atmospheric; Relief Setting. 00
F. Low Temperature. 0.20 to 0.50 00
G. Quantity of Flammable/ Unstable Material Quantity
75 t ., Hc = 18 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – 0.33
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 00
K. Hot Oil Heat Exchange system > 210 ft. 0.15 to 1.15 00
L. Rotating Equipment. 0.5 00
Special Process Hazards Factor (F2) – 1.93
Unit Hazards Factor (F1 F2 = F3). 2.41
Fire and Explosion Index (F3 MF) (F & IE). 38.56
THE DEGREE OF HAZARD. LIGHT
RADIUS OF EXPOSURE. 9.7 meter
DAMAGE FACTOR. 0.35
AREA OF EXPOSURE. 295 m2
T = {125+75×(1 + 1.25 + 1.93)}/100 = 4.38 T Category I
55
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: TANK FARM.
MATERIALS AND PROCESS: O –xylene
MATERIAL FACTOR: 16
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 00
B. Endothermic Process. 0.20 to 0.40 00
C. Material Handling & Transfer. 0.25 to 1.05 0.25
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 00
E. Access. 0.20 to 0.35 00
F. Drainage and Spill Control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). – 1.25
2. SPECIAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.4
B. Sub – Atmospheric Pressure. 0.50 00
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 –
3. Always in Flammable Range. – –
D. Dust Explosion. 0.25 to 2.0 00
E. Pressure Operating atmospheric; Relief Setting. 00
F. Low Temperature. 0.20 to 0.50 00
G. Quantity of Flammable/ Unstable Material Quantity
100 T ., Hc = 17.6 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – 0.46
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 00
K. Hot Oil Heat Exchange system > 210 ft. 0.15 to 1.15 00
L. Rotating Equipment. 0.5 00
Special Process Hazards Factor (F2) – 2.06
Unit Hazards Factor (F1 F2 = F3). 2.58
Fire and Explosion Index (F3 MF) (F & IE). 41.28
THE DEGREE OF HAZARD. LIGHT
RADIUS OF EXPOSURE. 10.5 meter
DAMAGE FACTOR. 0.37
AREA OF EXPOSURE. 346 m2
T = {125+75×(1 + 1.25 + 2.06)}/100 = 4.48 T Category I
56
DOW FIRE & EXPLOSION INDEX WORKSHEET.
PLANT: TANK FARM.
MATERIALS AND PROCESS: Toluene
MATERIAL FACTOR: 16
PENALTY FACTOR
RANGE PENALTY FACTOR USED
1. GENERAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Exothermic Chemical Reactions. 0.30 to 1.25 00
B. Endothermic Process. 0.20 to 0.40 00
C. Material Handling & Transfer. 0.25 to 1.05 0.25
D. Enclosed or Indoor Process Unit. 0.25 to 0.90 00
E. Access. 0.20 to 0.35 00
F. Drainage and Spill Control. 0.25 to 0.50 0.0
General Process Hazards Factor (F1). – 1.25
2. SPECIAL PROCESS HAZARDS.
Base Factor. 1.0 1.0
A. Toxic Materials. 0.20 to 0.80 0.4
B. Sub – Atmospheric Pressure. 0.50 00
C. Operation in or Near Flammable Range Inerted. – –
1. Tank Farm Storage Flammable Liquids. 0.0 –
2. Process Upset or Purge Failure. 0.3 –
3. Always in Flammable Range. – –
D. Dust Explosion. 0.25 to 2.0 00
E. Pressure Operating atmospheric; Relief Setting. 00
F. Low Temperature. 0.20 to 0.50 00
G. Quantity of Flammable/ Unstable Material Quantity
10 kl ., Hc = 17.4 103 BTU/Lb.
– –
1. Liquid or Gases in Process. – –
2. Liquid or gases in Storage. – 0.31
3. Combustible Solids in Storage. – –
H. Corrosion and Erosion. 0.10 to 0.75 0.1
I. Leakage – Joint and packing. 0.10 to 1.50 0.1
J. Use of fired heaters. – 00
K. Hot Oil Heat Exchange system > 210 ft. 0.15 to 1.15 00
L. Rotating Equipment. 0.5 00
Special Process Hazards Factor (F2) – 1.91
Unit Hazards Factor (F1 F2 = F3). 2.38
Fire and Explosion Index (F3 MF) (F & IE). 38
THE DEGREE OF HAZARD. LIGHT
RADIUS OF EXPOSURE. 9.7 meter
DAMAGE FACTOR. 0.35
AREA OF EXPOSURE. 295 m2
T = {125+75×(1 + 1.25 + 1.95)}/100 = 4.40 T Category I
57
HAZOP STUDY
“Report Enclosed Separately”
PROPOSED EXPANSION PROJECT
At
DEEPAK NITRITE LTD.
(APL DIVISION ) PLOT NO.1TO 7,26TO 31, MIDC DHATAV ,
DIST.:- RAIGAD, MAHARASHTRA , INDIA.
JANUARY 2017
58
SECTION 3: FAILURE FREQUENCY ANALYSIS
3.1 FAILURE FREQUENCY
The frequency assessment stage of the analysis involved defining the potential release sources and
subsequently determining the likelihood (frequency) of the various releases. The failure frequencies
were determined using failure item counts for each of the failure items identified and publicly available
historical failure rate data. Ignition probability data was used to estimate the probability of a release
subsequently being ignited.
3.1.1 Flange gasket failure/ gland failure. An accident/ event for gasket leakage/ failure can be
termed as “quite probable”. The hole size in a gasket failure may be that due to complete
section between bolt holes or something much smaller. The hole size for a complete section
failure of a gasket is usually calculated.
3.1.2 Failure of transfer line. The possible route of hazardous material going out of containment in
open atmosphere is the rupture of a transfer line. The case of guillotine type failure of tanker
unloading hose / transfer line or bottom nozzle undergoing guillotine type of failure also are
rather low. Failure frequency as per published literature for such lines is low and such events
can be considered, “foreseeable”.
3.1.3 Accidental spill of flammable solvent and uncontrolled spreading pool followed by fire is
considered as Worst Possible Scenario. It is to be noted that loss caused due to this event is
very high but the probability is low; however, in case of neglect of maintenance or natural
calamities such as earthquake the possibility exists. Such events are unlikely to happen and are
not credible. Failure frequency of catastrophic rupture of such pressure vessel is very low i.e.
3 per million per year.
3.2 EVENT TREE ANALYSIS
HYDROGEN GAS RELEASE
Fire/ Explosion frequency = 0.004 + 0.0004 = 0.0044, R = 0.9936, MTBF, 155 yrs.
*0.5 if distance to 50 % LFL falls within plant (with control of company) and
59
HYDROGEN GAS RELEASE
P = 0.0008 + 0.00072 = 0.00152, R = 0.99848, MTBF 657 yrs.
0.1 if distance to 50 % LFL falls inside electrically classified area.
FLAMMABLE SOLVENT RELEASE
Pool fire frequency = 0.0001 *0.1 if distance to 50 % LFL falls inside electrically classified area.
60
SECTION 4: CONSEQUENCE ANALYSIS
4.1 INTRODUCTION
4.1.1 LIKELY ACCIDENT SCENARIOS
TABLE NO. 4.1: LIKELY ACCIDENT SCENARIOS.
1 BTF release
2 Cumene release
3 Furnace oil release
4 HSD release
5 Hydrogen Bromide release
6 Hydrogen release
7 MEK release
8 Nitric acid release
9 Nitrogen oxide release
10 Toluene release
These accident scenarios are divided in two categories considering the consequence
seriousness and occurrence frequency.
MAXIMUM CREDIBLE LOSS SCENARIO (MCLS).
WORST POSSIBLE SCENARIO.
4.1.2 MAXIMUM CREDIBLE LOSS SCENARIO (MCLS)
Maximum Credible Loss Scenario (MCLS) is one of the methodologies
evolved to access the events in realistic and practical way. An MCLS can be
described as the worst “credible” accident or as an accident with a maximum
damage distance, which is still believed to be probable. The analysis, however,
does not include a quantification of the probability of occurrence of an
accident.
The MCLS aims at identifying undesirable and hazardous events causing the
Maximum damage to human beings environment around the industry under
the consideration.
Leak from hose/ piping failure are quite probable events. Accidental release of
flammable material e.g BTF is considered as MCLS.
4.1.3 WORST POSSIBLE SCENARIO
Worst Case Scenario/ MCA (Maximum Credible Accident) Accident Scenario
accidental release of Hydrogen gas and uncontrolled spreading followed by
fire/ explosion is considered as Worst Case Scenario/ MCA (Maximum
61
Credible Accident).
4.2 CONSEQUENCE ANALYSIS
ACCIDENT SCENARIO NO. 1: ACCIDENTAL SPILL OF BENZOTRIFLUORIDE
CHEMICAL NAME: BENZOTRIFLUORIDE
Mole Weight Ambient B.P. 102 oC VP. at ambient temp 0.063 atm
PAC -1 19 gm/cum PAC -2 220 gm/cum PAC -3 1300 gm/cum
LEL 16000 ppm UEL 84000 ppm
Ambient Saturation Concentration: 63,510 ppm or 6.35%
SOURCE STRENGTH
100 m3 tank Evaporating Puddle of Puddle dia : 4.4 meter, Max Average Sustained Release Rate: 1.11
kilograms/min
ACCIDENT SCENARIO NO. 1.1
THREAT ZONE:
Model Run: Heavy Gas
62
THREAT ZONE
Red PAC -3 1300 mg/(cu m) 32 meters.
Orange PAC -2 220 mg/(cu m) 94 meters.
Yellow PAC -1 19 mg/(cu m) 486 meters.
ACCIDENT SCENARIO NO. 1.2
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
THREAT ZONE
Red 9600 ppm = 60% LEL = Flame Pockets. < 10 meters.
Yellow 1600 ppm = 10% LEL. 11 meters.
ACCIDENT SCENARIO NO. 1.3
THREAT MODELED: OVER PRESSURE (BLAST FORCE), VCE
No explosion: no part of the cloud is above the LEL at any time.
ACCIDENT SCENARIO NO. 6.4: POOL FIRE
THERMAL RADIATION FROM POOL.
63
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/sq.m (potentially lethal within 60 sec). 16 meters.
2. Distance to 5.0 KW/sq.m (2nd degree burns within 60 sec). 25 meters.
3. Distance to 2.0 KW/sq.m (pain within 60 sec). 41 meters.
ACCIDENT SCENARIO NO. 2: ACCIDENTAL SPILL OF CUMENE
CHEMICAL NAME: CUMENE
Mole Weight 120.19 g/mol Ambient B.P. 152.3 oC VP. at ambient temp 0.0081 atm
AEGL-1 (60
min): 50 ppm AEGL-1 (60
min): 300 ppm AEGL-3 (60 min): 730 ppm
IDLH 900 ppm LEL 8800 ppm UEL 65000 ppm
Ambient Saturation Concentration: 8,156 ppm or 0.82%
SOURCE STRENGTH
100 m3 tank Evaporating Puddle
ACCIDENT SCENARIO NO. 2.1
THREAT ZONE:
Model Run: Heavy Gas
THREAT ZONE
Red PAC -3 730 ppm 10 meters.
Orange PAC -2 300 ppm 10 meters.
Yellow PAC -1 50 ppm 27 meters.
IDLH 900 ppm 10 meters.
ACCIDENT SCENARIO NO. 2.2
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
THREAT ZONE
Red 5280 ppm = 60% LEL = Flame Pockets. 10 meters.
Yellow 880 ppm = 10% LEL. 10 meters.
ACCIDENT SCENARIO NO. 2.3
64
THREAT MODELED: OVER PRESSURE (BLAST FORCE), VCE
No explosion: no part of the cloud is above the LEL at any time.
ACCIDENT SCENARIO NO. 2.4: POOL FIRE
THERMAL RADIATION FROM POOL.
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/sq.m (potentially lethal within 60 sec). 43 meters.
2. Distance to 5.0 KW/sq.m (2nd degree burns within 60 sec). 62 meters.
3. Distance to 2.0 KW/sq.m (pain within 60 sec). 98 meters.
ACCIDENT SCENARIO NO. 3: ACCIDENTAL SPILL OF FURNACE OIL
Continuous release of Furnace Oil due to failure a pipe line having diameters of 40 mm at
storage tank in dyke.
THREAT MODELED: THERMAL RADIATION FROM POOL FIRE.
SR. NO. THERMAL RADIATION LEVEL EFFECT DISTANCE
1 10.0 KW/M2 (potentially lethal within 60 sec.). 9 meters.
2 5.0 KW/M2 (2nd degree burns within 60 sec.). 13 meters.
3 2.0 KW/M2 (pain within 60 sec.). 18 meters.
65
ACCIDENT SCENARIO NO. 4: HSD RELEASE
Continuous release of Diesel due to failure if drum.
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. 10.0 KW/M2 (potentially lethal within 60 sec.). 11 meters.
2. 5.0 KW/M2 (2nd degree burns within 60 sec.). 12 meters.
3. 2.0 KW/M2 (pain within 60 sec.). 13.5 meters.
ACCIDENT SCENARIO NO. 5:HYDROGEN BROMIDE
RELEASE
CHEMICAL NAME: HYDROGEN BROMIDE 10035-10-6
Mole Weight 80.91 g/mol Ambient B.P. -66.7 oC VP. at ambient temp. >1atm
PAC -1 1 ppm PAC -2 40 ppm PAC -3 120 ppm
IDLH 30 ppm
Ambient Saturation Concentration: 1,000,000 ppm or 100.0%
SOURCE STRENGTH
Sustained release rate =0.1 kilograms/min
Model Run: Gaussian
ACCIDENT SCENARIO NO. 5.1
Flammable chemical escaping from storage tank (not burning).
THREAT MODELED: TOXIC AREA OF VAPOR CLOUD
PAC IDLH
THREAT ZONE
Red PAC – 3. 120 ppm. 379 meters.
66
Orange PAC – 2. 40 ppm. 45 meters.
Yellow pac -1. 1 ppm. 21 meters.
IDLH 30 ppm. 53 meters.
ACCIDENT SCENARIO NO. 6: ACCIDENTAL RELEASE OF HYDROGEN
CHEMICAL NAME: HYDROGEN.
Mole Weight 2.02 g/mol Ambient B.P. - 252.8 oC VP. at ambient temp > 1 atm.
TEEL-1 145000 ppm TEEL -2 280000 ppm TEEL -3 500000ppm
LEL 40000 ppm UEL 75000 ppm
Ambient Saturation Concentration: 1,000,000 ppm or 100.0 %.
ACCIDENT SCENARIO NO. 6.1 (MCLS)
Hydrogen gas escaping from pipe (not burning), through pipe.
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
Red 24,000 ppm = 60% LEL = Flame Pockets. 30 meters.
Yellow 4,000 ppm = 10% LEL. 73 meters.
ACCIDENT SCENARIO NO. 6.2 (MCLS)
THREAT MODELED: OVER PRESSURE (BLAST FORCE), VCE
67
OVER PRESSURE (BLAST FORCE), VCE
Red. 8.0 psi: Destruction of buildings. 24 meters.
Orange. 3.5 psi: Serious injury likely. 27 meters.
Yellow. 1.0 psi: Shatters glass. 45 meters.
ACCIDENT SCENARIO NO. 6.3
Flammable gas is burning as it escapes from pipe.
THREAT MODELED : JET FIRE MODEL
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/m2 (potentially lethal within 60 sec). < 10 meters.
2. Distance to 05.0 KW/m2 (2nd degree burns within 60 sec). < 10 meters.
3. Distance to 02.0 KW/m2 (pain within 60 sec). < 10 meters.
ACCIDENT SCENARIO NO. 6.4 (MCA).
Hydrogen cylinder rupture (involved in fire).
THREAT MODELED: FIRE BALL MODEL
68
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/m2 (potentially lethal within 60 sec). 18 meter.
2. Distance to 05.0 KW/m2 (2nd degree burns within 60 sec). 25 meter.
3. Distance to 02.0 KW/m2 (pain within 60 sec). 38 meter.
ACCIDENT SCENARIO NO. 7: RELEASE OF MEK
CHEMICAL NAME: ETHYL METHYL KETONE/ MEK.
Mole
Weight
72.11
g/mol
Ambient
B.P.
79.6 oC VP. at
ambient temp
0.15
atm.
PAC-3 4000 ppm PAC-2 2700
ppm
PAC-1 200
ppm
IDLH 3000 ppm LEL 18000
ppm
UEL 110000
ppm
Ambient Saturation Concentration: 153,584 ppm or 15.4 %.
Accidental MEK 180 liters release due to /transfer hose failure will form liquid pool in the
curb wall/ dyke of 1.5 sq.m. area.
ACCIDENT SCENARIO NO. 7.1: EVAPORATING POOL MODEL.
Model Run: Gaussian.
Max average sustained release rate: 374 grams/min
(averaged over a minute or more)
69
Total amount released: 17.2 kilograms
THREAT MODELED: TOXIC AREA OF VAPOR CLOUD
THREAT ZONE
Red PAC - 3 4000 ppm. < 10 meters.
Orange PAC - 2 2700 ppm. < 10 meters.
Yellow PAC - 1 200 ppm. 13 meters.
IDLH 2000 ppm. < 10 meters.
ACCIDENT SCENARIO NO. 7.2: FLAMMABLE AREA OF VAPOR CLOUD
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
THREAT ZONE
Red 10800 ppm = 60% LEL = Flame Pockets. < 10 meters.
Yellow 1800 ppm = 10% LEL. < 10 meters.
ACCIDENT SCENARIO NO. 7.3: VAPOR CLOUD EXPLOSION
THREAT MODELED: OVER PRESSURE (BLAST FORCE)
VAPOR CLOUD EXPLOSION
No explosion: no part of the cloud is above the LEL at any time.
ACCIDENT SCENARIO NO. 7.4: BURNING POOL – POOL FIRE MODEL.
POOL FIRE MODEL
Burn Rate = 5.17 Kg/min. Flame Height = 3 meters.
THREAT MODELED:
THERMAL RADIATION FROM POOL FIRE
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/sq.m (potentially lethal within 60 sec). < 10 meters.
2. Distance to 5.0 KW/sq.m (2nd degree burns within 60 sec). < 10 meters.
3. Distance to 2.0 KW/sq.m (pain within 60 sec). < 10 meters.
70
ACCIDENT SCENARIO NO. 7.5: EVAPORATING POOL.
Whether F1 category likely in winter nights. Worst Possible Scenario.
THREAT MODELED: OVER PRESSURE (BLAST FORCE)
VAPOR CLOUD EXPLOSION
Red. 8.0 psi: Destruction of buildings. -
Orange. 3.5 psi: Serious injury likely. < 10 meters.
Yellow. 1.0 psi: Shatters glass. 11 meters.
ACCIDENT SCENARIO NO.8: NITRIC ACID RELEASE
CHEMICAL NAME: NITRIC ACID 98%.
Mole Weight 63.01 g/mol Ambient B.P. 90.5 oC VP. at ambient temp 0.087atm
ERPG-1 1 ppm ERPG -2 6 ppm ERPG -3 78 ppm
IDLH 25 ppm
Ambient Saturation Concentration: 87,311 ppm or 8.73%.
SOURCE STRENGTH
Evaporating Puddle (0.6 m dia.). Max Average Sustained Release Rate: 35.6 grams/min.
Warning: NITRIC ACID can react with water and/or water vapor. This can affect the evaporation rate and downwind dispersion. ALOHA cannot accurately predict the air hazard if this substance comes in contact with water.
ACCIDENT SCENARIO NO. 8.1
71
THREAT MODELED: TOXIC AREA OF VAPOR CLOUD
THREAT ZONE
Red ERPG – 3: 78 ppm. < 10 meters.
Orange ERPG – 2: 6 ppm. 25 meters.
Yellow ERPG – 1: 1 ppm. 64 meters.
IDLH 25 ppm. 13 meters.
Note: Threat zone was not drawn because effects of near-field patchiness make dispersion
predictions less reliable for short distances.
ACCIDENT SCENARIO NO.9: NITROGEN OXIDE RELEASE
CHEMICAL NAME: NITROGEN DIOXIDE.
Mole Weight 46.01 g/mol Ambient B.P. 21 oC VP. at ambient temp >1 atm
ERPG-1 1 ppm ERPG -2 15 ppm ERPG -3 30 ppm
AEGL-1(60 min) 0.5 ppm AEGL-2
(60 min)
12 ppm AEGL-3(60 min) 20 ppm
IDLH 20 ppm
Ambient Saturation Concentration: 1,000,000 ppm or 100.0%
Maximum average sustained release rate = 0.00375 kilograms/sec
ACCIDENT SCENARIO NO. 9.1 (MCA)
Nitrogen Di Oxide gas escaping from scrubber vent.
THREAT MODELED: TOXIC AREA OF VAPOR CLOUD
72
ERPG IDLH
TOXIC AREA OF VAPOR CLOUD.
THREAT ZONE
1. ERPG – 3 (30 ppm): Red. 54 meters.
2. ERPG – 2 (15 ppm): Orange. 75 meters.
3. ERPG – 1 (1 ppm): Yellow. 305 meters.
4. IDLH - 20 ppm 66 meters.
ACCIDENT SCENARIO NO.10: ACCIDENTAL SPILL OF TOLUENE
CHEMICAL NAME: TOLUENE.
Mole Weight 92.14 g/mol Ambient B.P. 110.5 oC VP. at ambient temp 0.048 atm
ERPG-1 50 ppm ERPG -2 300 ppm ERPG -3 1000 ppm
IDLH 500 ppm LEL 12000 ppm UEL 71000 ppm
Ambient Saturation Concentration: 48,470 ppm or 4.85%.
SOURCE STRENGTH
Evaporating Puddle of Puddle Area: 1 square meter.
ACCIDENT SCENARIO NO. 10.1
THREAT ZONE
Red ERPG -3 1000 ppm. < 10 meters.
Orange ERPG -2 300 ppm. < 10 meters.
Yellow ERPG -1 50 ppm. < 10 meters.
IDLH 2000 ppm. < 10 meters.
73
ACCIDENT SCENARIO NO. 10.2
THREAT MODELED: FLAMMABLE AREA OF VAPOR CLOUD
THREAT ZONE
Red 6600 ppm = 60% LEL = Flame Pockets. < 10 meters.
Yellow 1100 ppm = 10% LEL. < 10 meters.
ACCIDENT SCENARIO NO. 10.3
THREAT MODELED: OVER PRESSURE (BLAST FORCE), VCE
No explosion: no part of the cloud is above the LEL at any time.
ACCIDENT SCENARIO NO. 10.4: POOL FIRE AT PIT.
THERMAL RADIATION FROM POOL.
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/sq.m (potentially lethal within 60 sec). < 10 meters.
2. Distance to 5.0 KW/sq.m (2nd degree burns within 60 sec). < 10 meters.
3. Distance to 2.0 KW/sq.m (pain within 60 sec). < 10 meters.
ACCIDENT SCENARIO NO. 10.5 : POOL FIRE OF 3 M DIA.
THERMAL RADIATION FROM POOL FIRE.
74
THERMAL RADIATION FROM POOL.
S. N. THERMAL RADIATION LEVEL EFFECT DISTANCE
1. Distance to 10.0 KW/sq.m (potentially lethal within 60 sec). 10 meters.
2. Distance to 5.0 KW/sq.m (2nd degree burns within 60 sec). 13 meters.
3. Distance to 2.0 KW/sq.m (pain within 60 sec). 17 meters.
4. Distance to 4.0 KW/sq.m (emergency action ). 13.5 meters.
75
SECTION 5: IMPACT ASSESSMENT
Effect models are used for the impact analysis. These models used to determine how people
are injured by exposure to heat, overpressure and toxic load. Effect models make use of a
probit function. In probit function a link exists between the load and percentage of people
exposed who suffer particular type of injury.
5.1 THERMAL RADIATION IMPACT
The effect of human exposure to a fire is a function of both the intensity of heat
radiation and the duration of exposure. The harmful effect can be characterized by a
thermal dose that is defined by the function
3
4
It .
Where,
Y = probit value,
I = heat radiation intensity, and
t = exposure duration.
The probit equation utilized is the Eisenberg equation.
3
4
ln56.29.14 ItY
A probit function has been used to evaluate the likelihood of fatality for different heat
flux exposures.
A radiation level of 12.5 KW/m2 will give 1 % fatalities for short exposure periods of
30 seconds and 50 % fatalities for exposures of over 80 seconds.
TABLE NO. 5.1: FATAL THERMAL RADIATION EXPOSURE LEVELS.
RADIATION LEVEL
KW/m2
SECONDS EXPOSURE FOR A % FATALITY LEVELS
1 % 50 % 99 %
1.6 500 1300 3200
4.0 150 370 930
12.5 30 80 200
37.5 8 20 50
76
TABLE NO. 5.2: EFFECTS OF THERMAL RADIATION ON UNPROTECTED SKIN.
RADIATION LEVEL
(KW/m2)
DURATION PERIOD SECONDS BEFORE
Pain is Felt Blistering Starts
22 02.0 03.0
18 02.5 04.3
11 05.0 08.5
08 08.0 13.5
05 16.0 25.0
2.5 40.0 65.0
Below 2.5 Prolonged exposure can. be tolerated.
Continued exposure to heat flux of 4.0 KW/m2 is considered sufficient to cause
injury. Hence, injury risk was assessed based on exposure to this level of heat flux or
greater. It is estimated that heat flux of 10.0 KW/m2 is likely up to 10 m distance from
the centre of the Toluene pool fire. It is assumed that any person near fire can take
shelter within 90 seconds.
5.2 OVER PRESSURE IMPACT
TABLE NO. 5.3: EFFECT OF BLAST PRESSURE WAVE.
OVER PRESSURE (bar) EFFECTS
0.01 Shattering of glass windows. Failure of panels.
0.03 Shattering of asbestos siding.
0.1 Collapse of steel framing panels.
0.3 Shearing of brick walls (8-12 inches).
5.2.1 Lung Hemorrhage
o
r PP ln91.677
Where,
Po is the Peak Over Pressure (Pa).
= 5.1 corresponds to 54 %.
5.2.2 Ear Drum Rupture
o
r PP ln93.16.15
Where,
Po is the Peak Over Pressure (Pa).
= 4.0 corresponds to 15 %.
77
5.2.3 Fatality Due To Impact
o
r PP ln82.41.46
Where,
Po is the Peak Over Pressure (Pa).
= 2.3 corresponds to 0 %.
5.2.4 However over pressure of 3.5 psi zone at tank farm persons are likely to take
safe shelter quickly avoiding any fatality.
5.3 TOXICITY IMPACT
5.3.1 HYDROGEN BROMIDE
HEALTH EFFECTS OF HYDROGEN BROMIDE EXPOSURE.
CONCENTRATION CONCENTRATION SYMPTOMS OF EXPOSURE
NOTE: Exposure to concentrations in excess of 1300 ppm may cause laryngeal spasms, resulting in death.
5.3.3 TOLUENE
Harmful if inhaled or absorbed through skin. Vapor harmful. Flammable liquid and vapor. May
affect liver, kidneys, blood system, or central nervous system. Causes irritation to skin, eyes
and respiratory tract.
78
SECTION 6: RISK ESTIMATION
6.1 INDIVIDUAL RISK ISOPLETH
6.1.1 Individual risk is defined by AIChE/ CCPS as risk to a person in the vicinity
of a hazard. This includes the nature of the injury to the individual, the
likelihood of the injury occurring and the time period over which the injury
might occur. Individual risk can be estimated for the most exposed individual,
for groups of individuals at particular places or for an average individual in an
effect zone. For a given incident or set of incidents, these individual risk
measures have different values.
6.1.2 Individual Risk due to incidence „I‟ at a geographical location x, y is given as;
iyxyx IR
NIR ,,,
1
Where,
N is number of persons in the affect zone.
Continued exposure to heat flux of 4.0 KW/m2 is considered sufficient to
cause injury. Hence, injury risk was assessed based on exposure to this level
of heat flux or greater.
6.1.3 RISK ISOPLETH
Average individual risk (exposed hours/worked hours) individual risk of
fatality at Assembly point is estimated. A broadly acceptable level of
individual risk as per the ALARP (As low as reasonably practicable) concept
of HSE, UK 10-6
/year.
6.2 SOCIETAL RISK (F-N CURVE)
Societal risk criteria are generally presented as curves on F – N plots. Mathematically,
the equation for an F – N criterion curve may be presented as; [Ball 19981].
aNkF
Where,
F = the cumulative frequency of N or more fatalities.
N = the number of fatalities.
a = aversion factor (often between 1 and 2).
k = constant.
79
The slope of the societal risk criterion (when plotted on a log – log basis) is equal to
„–a‟ and represents the degree of aversion to multi-fatality events embodied in the
criterion.
When the F – N curve slope is equal to -1, the risk criterion is termed „risk neutral‟. A
risk criterion for which the curve slope is more negative than -1 is said to be more risk
averse.
An anchor point along the curve (e.g. N=10 fatalities, F=10-3
/year) and a slope (e.g. -
1) is usually enough information to plot a risk criterion F – N curve. If any portion of
the calculated F – N curve exceeds the criterion line, the societal risk is said to exceed
that risk criterion.
In the present case any fatality unlikely in the surroundings and there is no situation
point above the criterion line indicating insignificant societal risk.
QRA RESULTS.
EVENT EVENT FREQUENCY
PER YR NO. OF FATALITY CUMULATIVE FREQUENCY
Hydrogen gas fire /explosion 4.4 10-4 1 4.4 10-4
Pool Fire of Solvent 1.0 × 10-4 0 5.4 10-4
F-N Curve
Refer Section 1.13.7
SECTION 7: RISK MITIGATION MEASURES
Refer Section 1.15
80
ANNEXURE 1: GLOSSARY
Acceptance
Criteria
(Risk).
: Defines the level of risk to which an individual is
exposed, as either tolerable (negligible risk), intolerable
or within the ALARP region.
Consequence : This is the severity associated with an event in terms
of toxic doses, fire or explosion etc., i.e. the potential
effects of a hazardous event.
ERPG : The Emergency Response Planning Guidelines.
ERPG 1: The maximum airborne concentration below
which it is believed that nearly all individuals could be
exposed for up to 1 hour without experiencing other
than mild transient adverse health effects or perceiving
a clearly defined, objectionable odor.
ERPG 2: The maximum airborne concentration below
which it is believed that nearly all individuals could be
exposed for up to 1 hour without experiencing or
developing irreversible or other serious health effects or
symptoms which could impair an individual's ability to
take protective action.
ERPG 3: The maximum airborne concentration below
which it is believed that nearly all individuals could be
exposed for up to 1 hour without experiencing or
developing life-threatening health effects.
Frequency : This is the number of occurrences of an event
expressed per unit time. It is usually expressed as the
81
likelihood of an event occurring within one year.
Hazard : A physical situation with the potential for human
injury, damage to property, damage to the
environment or some combination of these.
Hazardous
Scenario
: The identified isolatable sections and/or those which
have been broken down into scenarios for specific items
of equipment.
IDLH : Immediately Dangerous To Life And Health.
The maximum concentration would not cause any
escape imparting symptoms or irreversible health
effects to a person exposed for 30 minutes.
Individual
Risk
: The frequency at which an individual may be expected
to sustain a given level of harm from the realization of
specified hazards.
Individual
Risk
Contours.
: As IR (Individual Risk) is calculated at a point,
calculating the IR at many points allows the plotting
of IR contours, these being lines that indicate constant
levels of risk. Most commonly used are the 1 chance
per million-year contour and the 10 chances per
million-year contour.
82
Individual
Risk
Of Fatality.
: Individual risk with “harm” measured in terms of
fatality. It is calculated at a particular point for a
stationary, unprotected person for 24 hours per day,
365 days per year. Normally measured in chances of
fatality per million years.
Individual
Risk
Of Injury.
: Similar to individual risk of fatality, however with
“harm” measured in terms of injury.
Isolatable
Section.
: A system of pipes or vessels containing the hazardous
materials that are bounded by specific isolation points.
Isolation
Point.
: A point in the process, which can be used to isolate
one part of the process from the rest of the system.
LEL. : Lower Flammability Limit.
Expressed as % by volume of flammable gas in air. This
is the minimum concentration of gas in air mixture
which can ignite. Gas air mixtures below this
concentration do not ignite.
Probability. : The expression for the likelihood of an occurrence of an
event or an event sequence or the likelihood of the
success or failure of an event on test or demand. By
definition, probability must be expressed as a number
between 0 and 1.
Quantitative
Risk
: A risk assessment undertaken by combining quantitative
evaluations of event frequency and consequence.
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Assessment.
Risk. : The combination of frequency and consequences, the
chance of an event happening that can cause specific
consequences.
Risk
Reduction.
: The process of risk assessment coupled to a systematic
consideration of potential control measures and a
judgment on whether they are reasonably practicable to
implement.
TEEL : Temporary Emergency Exposure Limits.
TEEL-1: Maximum concentration in air below which it
is believed nearly all individuals could be exposed
without experiencing other than mild transient health
effects or perceiving a clearly defined objectionable
odor.
TEEL-2: Maximum concentration in air below which it
is believed nearly all individuals could be exposed
without experiencing or developing irreversible or other
serious health effects or symptoms that could impair
their abilities to take protective action.
TEEL-3: Maximum concentration in air below which it
is believed nearly all individuals could be exposed
without experiencing or developing life-threatening
health effects.
UFL : Upper Flammability Limit.
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Expressed as % by volume of flammable gas in air. This
is the maximum concentration of gas in air mixture
which can ignite. Gas air mixtures above this
concentration do not ignite.
Vapor Cloud
Explosion
: An accidental release of flammable liquid or gas, there
is possibility that it may form a cloud which can spread
along the wind direction. Delayed ignition of the cloud
away from the source of release results in Vapor cloud
explosion (flash back) and associated blast/ over
pressure effects.
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ANNEXURE 2: ABBREVIATIONS
AIChE. American Institute Of Chemical Engineers.
ALARP. As Low As Reasonably Practicable.
BTU. British Thermal Unit.
CCPS. Centre For Chemical Process Safety.
DMP. Disaster Management Plan
ECC. Emergency Control Centre.
EIA. Environmental Impact Assessment.
EMP. Environment Management Plan.
F & E I. Fire And Explosion Index.
HAZOP. Hazard Operability.
HSD. High Speed Diesel.
IDLH. Immediately Dangerous To Life And Health.
IPL. Independent Protection Layer.
KCal. Kilocalories.
lb. Pound.
LOC. Level Of Concentration.
LOPA. Layers Of Protection Analysis.
MCA. Maximum Credible Accident.
MF. Material Factor.
MIDC. Maharashtra Industrial Development Corporation.
MoEF. Ministry Of Environment And Forests.
MSDS. Material Safety Data Sheet.
MT. Metric Ton.
NFPA. National Fire Protection Association.
PFD. Probability Of Failure On Demand.
PHA. Preliminary Hazard Analysis.
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QRA. Quantative Risk Assessment.
RH. Risk Assessment And Hazard Management.
SIF. Safety Integrated Function.
TEEL. Temporary Emergency Exposure Limits.
UK. United Kingdom.
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ANNEXURE 3: REFERENCES
1. Technical EIA Guidance Manual for Synthetic Organic Chemicals,
prepared for the Ministry of Environment and Forests Government of
India.
2. MOND INDEX Manual 1993.
3. “TNO Yellow Book”. Method for calculation of the Physical Effects of
the escape of Dangerous Material (Liquid & Gases) Published by the
Directorate General of Labour, Ministry of Social affair, Netherlands
(1979).
4. Frank P. Lees – Loss Prevention in the Process Industries – Volume I.
5. Risk Assessment for Process Industries, Loss Prevention News April -
June 2001.
6. Techniques for assessing Industrial Hazards (World Bank Technical
Paper, ISSN 0253; No. 55).
7. Ref. Table 3.8 – Vapor Pressure of Organic Compounds, R. H. Perry,
C.C., Chemical Engineers Handbook, 5th Edition (1969) McGrow – Hill
Book co. (New York, London).
8. Guideline for Quantitative Risk Assessment “Purple Book”.