HAZOP, QRA & ERDMP as per latest PNGRB guideline for IOCL bottling plant locations at Bhopal

Indian Oil Corporation set up an LPG Bottling Plant in the district of Bhopal in the year 1989. The LPG bottling plant of IOCL Bhopal is situated at Bakania Bhauri, Bhopal – 462030 Distt. Bhopal (M.P.) The main activities of the Plant are receipt of liquefied petroleum gas (LPG) through bulk Tank trucks and Railway wagons, stored in Horton spheres, filling of domestic as well as commercial LPG cylinders, and dispatch through Trucks.

Bulk LPG from tankers (Bulk TTs) is transferred through a pipeline to storage vessels as it is pumped to carousal (filling machine) for filling of empty cylinders. The filled-up cylinders after passing through quality control checks are stored in filled cylinder shed is dispatched to various indane distributors through stack trucks. Bulk LPG is received in tank trucks. LPG transported from refinery locations/ installations to bottling plants shall be unloaded using pressure differential method.

LPG compressors are used for pressurizing the vessels which are to be unloaded by taking the LPG vapour from receiving vessel and a liquid line will be connected to facilitate the transfer of liquid LPG.

LPG is stored in (4×650 MT) + (4 x 1400 MT) capacity horton spheres. In Differential Pressure method, When the compressor starts and the deferential pressure between Tank Trucks and storage vessel becomes 2kg/cm2, the LPG liquid starts flowing from bullet Trucks to LPG Vessels. Similar operation is implemented for Tank Wagon too.

LPG is delivered to customers as bottled LPG cylinders. IOCL LPG Plant plays a crucial role in  distribution of domestic as well as commercial cylinders to  districts of Bhopal.

Quantitative Risk Assessment (QRA)

The scope of work is to carry out QRA study for  IOCL LPG Bottling plant, Bhopal and this study covers the different sections, components, and equipment associated with this facility and process description.

Quantitative Risk Assessment aims to evaluate the risk levels for personnel due to the accidental release of hazardous components/materials due to loss of containment scenarios from the facilities and to analyze and exhibit that the individual risks lie within the broadly acceptable region. The main objective of the study is to evaluate the potential risk levels for personnel due to accidental release of hazardous materials and to exhibit that individual risks lie within the acceptable region.

The Objectives of QRA are as follows:

  •  To identify hazards and major loss of containment (LOC) scenarios.
  • To calculate the physical effects of failure case scenarios which include estimation of jet fire, pool fire heat radiation distances, flammable gas dispersion distances, BLEVE, and overpressure explosion impact distances.
  • Failure frequency evaluation.
  • To quantify societal risk around the particular facility.
  • Performs risk assessment to confirm that risk can be reduced consistently with the ALARP region/principle according to the UK HSE risk acceptance criteria.
  • Recommending measures to reduce risk and ensuring whether all risks are in ALARP or in acceptable region

This facility has been divided into 30 isolatable sections. As this facility handles LPG the major credible outcome events of jet fire, fireball, flash fire & overpressure explosion have been identified and their impacts/consequences for each scenario have been determined using DNV PHAST 8.22. And the risk analysis has been carried out with frequency outcome and frequency for the respective events using DNV SAFETI 8.22. From the results, most of the locations fall under acceptable region. To prevent the risk few safety practices have been provided as recommendations.

Recommendations

1. Ensure portable gas detectors are provided within the site to facilitate manual gas leak monitoring and regular leakage checks.

2. Plan for regular functional testing of the control equipment (Active / Monitor Regulator, MOV, ROV, TRV, control valves, etc.).

ERDMP

The scope of  Work is to develop an Emergency Response & Disaster Management Plan for the respective facility in line with PNGRB guidelines.

The main objective of this ERDMP is to identify emergencies which can arise during normal operations of IOCL LPG Bottling Plant Bhopal  and recommend mitigation measures to reduce and eliminate the risks related to a disaster, develop plans for actions when disaster or emergencies occur and keep prepared responses that mobilize  necessary emergency services including responders (I level, II level and III level) like Fire service, Police service, Medical service including ambulance, Government as well as non-governmental agencies. This also includes post disaster recovery measures with an aim to normalize the affected area.

Required Data had been collected from IOCL which was organized to prepare Report based on PNGRB guidelines.  

HAZOP

The scope of work is to carry out HAZOP study for Bhopal LPG Bottling plant of Indian Oil Corporation Ltd. (IOCL) in accordance with the applicable OISD and other relevant statutes as part of the Process Hazard Analysis (PHA).

The main objective of  HAZOP study is to manage project risks through early identification of potential hazards & operability problems and reduce the probability & consequences of an incident that would have a detrimental impact on living, assets and the environment.

The objectives of HAZOP are as follows:

  1. Identify  hazards inherent to the facility/process.
  2. To segregate various process into separate nodes and thorough analysis is carried out using Guide Words (No, Less, More, Reverse for parameters like Flow, Pressure, Temperature, Level, Leak) for each section.
  3. To identify all possible deviations from the way the design is expected to operate.
  4. Identify credible manual or equipment instrument failures (cause for the deviations) likely to lead to consequence associated with it (accident scenarios/hazards/operability problems).
  5. Qualitatively assess the risk and provide recommendations to prevent or overcome the hazards if required.
  6. In addition to these issues, HAZOP occasionally identifies items that could improve unit operations and efficiency of the process.

This Facility has been divided into 3 Nodes. Possible deviations for all the nodes, their respective cause and consequence were assessed, safeguard were found out for the respective consequences for reducing the likelihood of an hazardous event occurring or reducing the severity of the consequence. For certain case, available safeguards were inadequate to reduce the likelihood of hazard, so in order to mitigate the risk few safety practices have been provided as recommendation. The recommendation was ensuring whether gas detectors are available in the plant. Entire HAZOP study was conducted in PHA Pro software.