Hazard Identification and Risk Asssment by N.C.Nigam,A.K.Maheshwari & N.P.Rao .
INTRODUCTION
For any industry to be successful, it has become esntial to identify the Hazards ,to asss the associated risks and to bring the risks to tolerable level. Recognising this, IFFCO-AONLA is continuously putting efforts for controlling the risks which are arising from various Hazards such that loss to Human life and property is negligible or zero. Its continuous best efforts to identify the Hazards and to bring the risk levels to tolerable level in the organization are recognid by veral Government and safety regulating bodies. This paper describes briefly about various types of Hazards and their associated risks, how they are being controlled effectively through risk analysis at IFFCO – Aonla unit
In all plants, hazards and risk are identified time to time by using modern techniques. IFFCO Aonla unit is OHSAS –18001 certified company. So in all departments /ction risk and hazards are find out by proper risk asssments. During this verity at various levels matched with probability level. And find out the ca of intolerable, substantial, moderate and tolerable risk. Accordingly control measures at the place checked. Documentation done and records are maintained. .
At IFFCO Aonla unit, HAZOP, HAZAN study, Dow index, Risk Analysis, FMIA, Fault Tree Analysis are c
arried out at its inception level..At IFFCO Aonla unit, various risk asssment procedures are followed. This has been done by Dow Index method and Conquences methods. At the same time when any process modification done/needed, then also proper HAZOP studies and any other risk analysis studies are carried out to asss the risk due to the effect of modification.
Now as IFFCO Aonla unit is OHSAS –18001 certified company, in all ctions/plants proper hazard and risk asssment procedures and documentation done. Time to time, plant/ction updates of this done and audited by other ctional persons. And again compliance incorporated.
1.0.0 To effectively implement the safety systems , a structured approach has been drawn out to minimize
the hazards and risks . This involves the following :
¾ REPORTING/INVESTIGATING/ANALYSIS OF ACCIDENTS, DANGEROUS
OCCURRENCES AND NEAR MISSES.
When any accident occurred in plant premi, the concern area shifts in-charge informed his higher officers as well as fire and safety ction regarding this. Immediately accident/dangerous occurrence
investigation committee consisting of nior officers from affected area, fire and safety ction, factory safety officer and medical person t up. This committee starts immediately investigation without delay. It also prerves all facts and finding and reports of for future reference.
IFFCO AONLA UNIT
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1
31.05.200008.06.200231.12.200222.08.200415.02.2006
Accident Free Man days Accident Free Period
026.10.1997-31.05.2000
02.06.2000-08.06.2002
01.09.2002-31.12.2002
inflation01.01.2003-22.08.2004
28.08.2004-15.02.2006
2
4681012
141615.06
12.27
1.9
7.83
13.00Y-AXIS ACCIDENT FREE MILLION HOURS X-AXIS ACCIDENT FREE PERIOD
31.05.2000
08.06.200231.12.200222.08.200415.02.2006
Accident Free Million Man hours Accident Free Period IFFCO AONLA UNIT
Now we e what type of risks and how they are being handled through some models of risk analysis in IFFCO –AONLA unit.
¾
PROCESS & SAFETY–RELATED DATA FOR INDIVIDUAL PROCESS STAGES :
Physical and Health Occupational Hazards in any large scale Chemical /Hydrocarbon Processing Industry (CPI/HPI) like our can be broadly classified into the following categories:
i. Mechanical Risks ii. Electrical Risks iii. Fire/Explosion Risks iv. High /low Temperature Exposure Risks v. Toxic/Carcinogenic Chemicals Exposure Risks vi. Corrosive/Reactive/Radioactive Chemicals Exposure Risks
奥运会足球比赛赛程The first two types of risks are of universal nature associated with any industrial activity and not specific to a particular plant or process. Mechanical risks which are generally encountered are injuries to the head, Limbs, eyes, etc usually as a results of negligence on the part of operating/maintenance personnel in the u of improper tools, bypassing prescribed safety procedures neglect of personal protective wear and risks associated with rotating machinery as well as risks associated with high-energy relea from compresd gas. Electrical risks which result in shock and/or burns are most often a conquence of poor maintenance, ingress of dust or moisture, handling by unauthorized personnel and u of improper/substandard hardware.
Other categories of risks associated with specific plants are detailed here under.
Ammonia Plant :
The manufacture of anhydrous liquid ammonia involves processing of hydrocarbons under high temperature, high pressure conditions in the prence of various catalysts, chemicals etc. Typical risks are as follows:
Fire /Explosion
¾ Glands/al leaks in valves, pumps, compressors handling hydrogen, natural gas, naphtha, synthesis gas etc.
¾ Ho/pipe failure, leakage from flanged joints carrying combustible
gas, vapours, liquids.
¾ Fire box explosions in furnaces.
High/Low Temp.
Exposure Risks
Toxic Chemicals
Exposure Risks
¾ Burns due to contact with hot surfaces of pipelines, equipments, etc. or leaking steam lines, process fluids at high temperature. ¾ Frost bite due to contact with anhydrous liquid ammonia at -33 deg. C ¾ Burns due to contact with pyrophoric catalyst. ¾ Asphyxia due to inhalation of simple asphyxiants like CO2 , N2, H2, CH4, naphtha etc. and chemical asphyxiants like CO, NH3, Nickel carbonyl, V2O5, Hydrazine, NOx, SOx, H2S etc. ¾ Acute toxicity due to inhalation of catalyst dusts containing heavy metals like Ni, Cr, CO, Mo, Fe, Zn, Alumina etc. and silica gel molecular sieves, insulation fibers/dusts.
1000020060080026.10.1997-31.05.200002.06.2000-08.06.200201.09.2002-31.12.200201.01.2003-22.08.200428.08.2004-15.02.2006
947400737122
700Y-AXIS –ACCIDENT FREE MAN DAYS
X-AXIS ACCDIENT FREE PERIOD 910
Urea Plant
The manufacture of urea involves reaction of Ammonia and Carbon dioxide under high temperature & pressure and subquent recovery and concentration of the solution at various pressure stages. Typical risks are as follows :
Fire / Explosion Risks
出pool
¾ Ammonia leaks from glands / als Risks involves, pumps or
flanged joints piping resulting in formation explosive mixtures in air.
Accumulation of H2 may take place in HP Section in ca CO2 purity from Ammonia Plant is not within allowable limits. Ignition of this accumulated H2 can occur due to dissipation of static charge.
High / Low Temperature Exposure Risks
¾ Refer to risks in Ammonia Plant Toxic Chemicals Exposure Risks ¾ Asphyxia due to inhalation of simple Exposure Risks asphyxiants like CO2 and N2 and chemical asphyxiant, NH3. Solution of Urea, Ammonium carbamate and ammonium carbonate
containing high NH3 content.
¾ Irritation due to inhalation of urea dust.
Corrosive / Radioactive Chemicals Exposure Risks
¾ Severe burns, damage to eyes, skin and body tissues due to contact with anhydrous ammonia, conc. Urea and Ammonium carbamate solutions.
好听的英文歌曲网站Power Plant
The captive Power Plant involves generation of steam in N.G./Naphtha-fired boilers and utilizing the steam in Urea and Ammonia plants. Typical risks are as follows :
Fire / Explosion Risks ¾ Explosion and fire risks associated with storage and handling of B Class (Naphtha) and Natural gas handling pipelines (Refer
off site Facilities).
¾ Fire Box explosion in Boiler
Flammable Material Lower Upper Temp. °C High / Low Temp. Exposure Risks ¾ Burns due to conta
ct with hot surfaces of pipelines, equipments, etc. or leaking steam lines. Toxic Chemical Exposure Risk
¾ Asphyxia due to inhalation of SOX and Nox.
¾ Irritation due to inflammation caud by inhalation of Natural gas and the Naphtha vapors.
The permissible exposure limits for cyclohexylamine coal dust / fly-ash are given below :
neglect
Offsite Facilities
The offsite facilities, as already described at the very outt, consist of integrated units for water and effluent treatment, inert gas generation, cooling towers, storage of petroleum products and ammonia, supply / distribution of utilities like compresd air, water, etc. Potential risks in the above offsite facilities are esntially on account of handling of corrosive, toxic and reactive chemicals as well as inflammable petroleum products.
Fire / Explosion Risks ¾ Gland / Seal leaks in valves, pumps, compressor, handling naphtha,
N.G., ammonia hydrogen, syngas etc.
¾ Ho / pipe failure, leakage from flanged joints in pipes conveying petroleum products, ammonia, hydrogen, syngas, etc.
¾ Leakage of petroleum products during tanker unloading operations. ¾ Overflow from storage tanks.
¾ Overheating / pressurization of storage tanks.
¾ Improper earthing / lightning protection of storage tanks and pipelines.
¾ Improper aling of floating roof tanks.
¾ In adequate / improper breather valves leading to tank failures. ¾ Fire Box Explosion in cracker Furnace.
Critical data for flammable materials stored / handled in off sites has already been furnished under Ammonia Plant and Power Plant.
High / Low Temp. Exposure Risks ¾ Burns due to contact with hot surfaces of pipe lines, equipments, etc or leaking steam lines.
¾ Heat radiation burns from high intensity flames from the flare stack. ¾ Frost bite due to contact with anhydrous liquid ammonia at – 33 °C
Toxic Chemicals Exposure Risks ¾ Asphyxia due to inhalation of simple asphyxiants like N2, H2, Naphtha, etc. and Chemical asphyxiants like Cl2, NH3, NOx, Sox,
etc.
¾ Toxicity due to inhalation of catalyst dust containing heavy metals like Ni, Pd, Alumina etc. and perlite / insulation fibers, silica gel dust.
poolData on Threshold Limit Values Limits for most of the above toxic Chemicals and dusts encountered in off sites has already been furnished under Ammonia Plant. Data for Cl2 are as follows :
Corrosive Chemicals Exposure Risks ¾ Severe burners, damage to eyes, skin & body tissues due to contact with corrosive chemicals like anhydrous liquid
Ammonia, Sulphuric acid, Hydrochloric acid, etc.
Bagging Plant
The bagging plant encompass storage, packing, loading and dispatch activities for product urea via road or rail. Typical risks in this plant are as follows :
Fire Risks
¾ Fire hazards due to storage of bulk quantity of polyethylene – lined jute bags or HDPE bags which are easily combustible. Chemicals Exposure Risks ¾ Irritation due to inhalation of urea dust and jute fibers.
S.No Name of Chemical Form under normal condition Expected form of
Chemical under abnormal condition
1. 2. 3. 4. 5. 6.
Ammonia
moore
Chlorine
Naphtha
Hydrochloric Acid
Sulphuric Acid
Natural Gas
Liquid state at – 33 °C temp. & atmospheric pressure.
Liquid at ambient temp. & 17.0 Kg/cm² pressure.
Liquid at ambient temp. & pressure.
Liquid at ambient temp. & pressure.
Liquid at ambient temp. & pressure.
Gaous at ambient temp &
Pressure
Vapour / Gaous form.
Vapour / Gaous form.
Vapour Acid fumes Acid fumes Gaous Form
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INFORMATION ON THE PRELIMINARY HAZARD ANALYSIS
Types of Accident
It is clear that during the cour of Urea manufacture, furnaces, reactors, moving machineries, material handling, cranes, chain, pulley blocks, wire ropes, chemicals, Rail wagons, etc. are involved. Past reportable accidents are related to the agencies.
climate changeType of personnel injuries indicates burn, cut, bone fracture burn injury etc. A brief resume of types of accidents may happen are as follows ;-
1. Burn injury due to handling cleaning of burners in furnaces.
2. Fire accidents in furnaces leading to property damage.
3. Burn injury accident due to attending electrical faults.
4. Burn injury accidents due to handling of acids / alkalies.
5.
Hit / cut type accidents due to various maintenance jobs. For reference purpos and internal report titled “Safety Performance at a glance” is enclod as Annexure 5.
System Elements or Events that can lead to a major Accident
All the ction / plants of IFFCO Aonla unit are constructed and designed taking care of all relevant safety measures possible. However the system elements such as Ammonia storage, Naphtha storage, Chlorine tonners, Ammonia Plant area, Urea Plant HP ction are some of them which can lead to a major accident.
hauntedfaceAlthough, Fire, explosion and relea / leakage of toxic chemicals may lead to major accident, all necessary safety measures have been duly incorporated in the plant design and regular up gradation of safety appliances is carries out.
Hazards Urea manufacturing process involves many chemicals such as NG, as feed stock, Ammonia as an
intermediate product and chlorine, hydrochloric / sulfuric acids, as water treatment chemicals.
Furnaces, High pressure vesls, Reactors, pipe lines, storage tanks are also involved in the
cour of Urea and Ammonia manufacturing. Handling and storage of the Hazardous chemicals and their u in the process may leak to a hazardous situation.
Failure Mode Analysis
There are various modes in which flammable and toxic chemicals can leak into atmosphere causing adver affects. It may be small leaks from gaskets of the flanged joints, or guillotine failure of a pipeline of even catastrophic failure of the storage tank. Some typical modes of failures and their possible caus are discusd below :
S.No. Failure Mode Probable Cau Remarks
1. Flange / Gasket failure Incorrect gasket Incorrect installation. Attention to be paid during lection
and installation of gaskets. 2
Weld failure
It is normally due to poor quality of welds Welding to be done by certified
welders with right quality of welding
rods. Inspection and radiography must also be done.
3 Pipe corrosion erosion or failure due to stress Some times fabrication or installation leaves stress in the pipes. Erosion or corrosion also are sometimes the cau. Pipes material of construction
should be lected correctly. Design should take care of erosion
effects. And installation of pipes should not leave any stress.
