CASE STUDY

HAZOP Analysis for BPCL’s HGU Utilities Offsite BDT, COT, and SPM Units: A Case Study in Safety Management

Introduction

The case study on the HAZOP study for the HGU (Hydrocracking Unit) utilities offsite BDT (Bottoms Depressant Tank), COT (Cooling Oil Tank), and SPM (Single Point Mooring) units at BPCL (Bharat Petroleum Corporation Limited) is a detailed examination of safety and operational efficiency in a petrochemical facility

  • Bina Refinery (BR) of Bharat Petroleum Corporation Limited, Situated in Bina, Madhya Pradesh runs a 7.8 MMTPA refinery.
  • The refinery was commissioned in 2011 with crude oil processing capacity of 6.0 MMTPA, which was subsequently debottlenecked to 7.8 MMTPA in year 2018-19.
  • To source crude up to refinery, there is a Single Point Mooring (SPM) system, Crude Oil Terminal (COT) and a cross country 937 kms pipeline from Vadinar, Gujarat to Bina, Madhya Pradesh.
  • Oil is sourced mainly from the Middle East in tankers and is unloaded at the SPM, stored in COT and then transported to Bina via pipeline.
  • Very large crude carriers can be received by the SPM (VLCCs).
  • The refinery complex at Bina produces various petroleum fuels such as LPG, Naphtha, Kerosene, Aviation Turbine Fuel/Jet Fuel, Motor Spirit (BS VI), Diesel (BS VI), Pet coke and Sulphur.

SCOPE of HAZOP STUDY

Scope of Work (SOW) is to carry out HAZOP study of –HGU, Utilities, Offsite, BDT & COT-SPM units at BPCL -Bina Refinery in accordance with applicable regulations and standards to identify hazards, design deficiencies, and operability issues within the specified units.

Objective of HAZOP Study:

  • Conduct a comprehensive study to:
    • Identify potential hazards.
    • Assess the implications of these hazards.
    • Propose actionable recommendations for Risk mitigation.

What is HAZOP (Hazard and Operability Study):

A design review technique focused on Identifying hazards in industrial processes and detecting design deficiencies that could lead to operability problems.

Primary Use Cases for HAZOP:

  • Systems that handle hazardous materials.
  • Processes that transmit or process dangerous substances or activities.

Importance of HAZOP:

  • Prevents risks that could lead to:
    • Harm to people.
    • Damage to property.
    • Environmental impact.

Repercussions of Not Controlling Identified Risks:

  • Serious consequences if risks are not mitigated, including:
    • Human injuries or fatalities.
    • Property damage.
    • Environmental hazards.

The main objective of HAZOP study is to identify hazard scenarios that would eliminate or reduce the Risk in Operation.

  • To identify deviations from the design intent & applicable standards.
  • To recognize possible risks and problems with operation
  • To make suggestions for mitigating the issues found.

As part of the comprehensive HAZOP study for BPCL’s Hydrocracking Unit (HGU) and its associated utilities, offsite, and terminal units, the following nodes were systematically examined to identify potential risks and hazards:

Bina Dispatch Terminal

  • Total Nodes Studied: 10 nodes

Offsites

  • Total Nodes Studied: 25 nodes

Crude Oil Terminal

  • Total Nodes Studied: 7 nodes

Hydrogen Generation Unit

  • Total Nodes Studied: 21 nodes

Utilities

  1. Condensate Polishing Unit:
    • Total Nodes Studied: 6 nodes
  2. Emergency Diesel Generator:
    • Total Nodes Studied: 6 nodes
  3. Effluent Treatment Plant (ETP):
    • Total Nodes Studied: 22 nodes
  4. Nitrogen Unit:
    • Total Nodes Studied: 6 nodes
  5. RO-DM Plant:
    • Total Nodes Studied: 15 nodes
  6. Raw Water Treatment Plant (RWTP):
    • Total Nodes Studied: 8 nodes

HAZOP Methodology

  • The study analysed possible deviations for all nodes, their respective causes, and consequences. Safeguards were identified to reduce the likelihood of hazardous events occurring or to minimize their severity.
  • In cases where existing safeguards were deemed inadequate, recommendations were provided to mitigate risks. The HAZOP study was conducted using PHA Pro software, ensuring a comprehensive analysis of the units.
The image is a flowchart illustrating the process of conducting a HAZOP Hazard and Operability HAZOP study flowchart detailing step-by-step analysis for identifying and mitigating risks in process design. The process starts with explaining the overall design, followed by selecting a node and agreeing on the design intent. Key elements and characteristics are identified, and guide words are applied to analyze deviations. Each deviation is checked for credibility. The study investigates the causes, consequences, protections, or indications of potential hazards. The process repeats for all elements until every part has been examined, concluding with the documentation of findings

Key Recommendations for Safety and Risk Mitigation

To enhance operational safety and mitigate risks, the following key recommendations were proposed:

  1. Development of Standard Operating Procedures (SOPs):
    • Create SOPs to ensure the following safety protocols:
      • Proper decontamination of unloading hoses after each use.
      • Ensuring the correct material of construction (MOC) and maintaining cleanliness for unloading hoses.
  2. Decontamination of Dead Legs on Pipelines:
    • Implement SOPs for decontaminating or eliminating dead legs on hydrogen peroxide (H₂O₂) pipelines to prevent accumulation of hazardous materials.
  3. Installation of H₂S Detectors:
    • Install hydrogen sulfide (H₂S) gas detectors near the sour water storage tank to monitor and detect potential gas leaks, enhancing worker safety.
  4. Emergency Pressure Release Provisions for Tanks:
    • Consider installing tank top emergency pressure release hatches to manage pressure build-ups in emergency situations.
  5. N₂ Blanket System for Tanks:
    • Explore the feasibility of installing a nitrogen (N₂) blanket system on storage tanks to prevent air from contacting volatile substances, thereby reducing fire and explosion risks.
  6. Gas Detectors for Sump Areas:
    • Install both H₂S and hydrocarbon (HC) gas detectors near the Oily Water Separator (OWS) and Contaminated Rainwater Sump (CRWS) to enhance early leak detection and response.
  7. Additional Piping Arrangements:
    • Study and implement additional piping arrangements downstream from HV-2951 to EE-1035 to eliminate stagnant cold liquids and maintain the normal operating temperature in the system.
  8. Pressure Transmitters and Remote Emergency Valves:
    • Provide pressure transmitters (PT) and install remote-operated valves for emergency closures, aimed at preventing loss of containment (LOC) in critical scenarios.
  9. Alternative Dosing Points:
    • Collaborate with vendors to identify alternative dosing points on low-pressure and low-temperature sites to improve dosing efficiency and safety.

CONCLUSION:

The HAZOP study of HGU, Utilities, Offsite, BDT & COT-SPM units at BPCL – Bina Refinery identified potential hazards, deviations, and operability issues, and provided actionable recommendations to mitigate risks and enhance operational safety. By implementing these recommendations, BPCL can further strengthen its commitment to process safety and ensure the smooth and secure functioning of its refinery operations.