Case Study

HAZOP Study for Green Hydrogen Plant

Last updated: May 20, 2025

Introduction

A Hazard and Operability (HAZOP) Study is a structured approach to identifying hazards and operability issues in chemical and energy systems. For green hydrogen plants where hydrogen is produced from water using solar-powered electrolysis the study plays a vital role in ensuring process safety. These facilities involve high-pressure hydrogen, electrolyzers, and power systems, requiring detailed risk assessment. The HAZOP study helps mitigate potential deviations, enhance operational safety, and support reliable, eco-friendly hydrogen production.

Methodology

The HAZOP study methodology includes the following steps:

  1. Node Selection: Divide the plant into logical sections or nodes using P&IDs.
  2. Parameter Identification: Define key process parameters (flow, pressure, temperature, etc.).
  3. Use of Guidewords: Apply standard guidewords like No, More, Less, Reverse to each parameter.
  4. Deviation Analysis: Identify potential deviations from design intent.
  5. Cause and Consequence Analysis: Analyze credible causes and resulting consequences.
  6. Safeguards Review: Assess existing controls and protection mechanisms.
  7. Recommendations: Suggest additional safeguards or actions if necessary.

This approach ensures comprehensive coverage of possible deviations and their impact.

Outcomes 

HAZOP study in green hydrogen plants help identify potential hazards such as leaks, overpressure, and operability issues. Key outcomes include:

  • Improved safety through better design and controls
  • Enhanced SOPs for leak detection, maintenance, and emergencies
  • Identification of critical equipment upgrades (e.g., NRVs, alarms)
  • Updated P&IDs and system documentation
  • Risk reduction to acceptable safety levels

These ensure safe, reliable, and efficient hydrogen production.

1. HAZOP Study for JSHL Green Hydrogen Plant

Introduction

Jindal Steel Hisar Limited (JSHL) commissioned a Green Hydrogen Plant at Hisar, Haryana, in collaboration with Hygenco India. This Plant aims to support decarbonization by replacing conventional hydrogen with green hydrogen produced from solar-powered electrolysis. The system is powered by a 2.8 MWp solar PV array installed on shed roofs and water bodies within the JSHL facility.

The facility includes the following major subsystems:

  • Renewable Energy System: 2.8 MWp solar PV system powering the Plant during daylight hours.
  • Electrolyzer: Produces hydrogen (99.0% to 99.8% purity) and oxygen from demineralized water using aqueous KOH as electrolyte.
  • Gas Liquid Separators: Remove moisture and lye from hydrogen and oxygen.
  • Purification System: Deoxo and dryer units that purify hydrogen to 99.999% purity and ensure -70°C dew point.
  • Buffer Tanks and Storage: Intermediate storage in buffer tanks and further distribution.
  • Utilities: DM water plant, cooling towers, nitrogen and instrument air systems.
  • Fire and Gas Safety Systems: Includes leak detection, fire alarm, MOEFA systems, extinguishers, and Novec-based gas suppression systems.

Project Insights

The HAZOP study covered the full lifecycle of hazard identification and operability analysis for the process systems of the green hydrogen facility. The scope included:

  • Reviewing PFDs and P&IDs for feed water system, electrolyzer unit, gas purification and storage sections.
  • Node identification and parameter deviation analysis using guidewords.
  • Identifying plausible failure scenarios, such as equipment malfunction, pressure surges, reverse flow, and gas leaks.
  • Analyzing causes and their consequences to personnel, plant integrity, and the environment.
  • Validating existing safeguards like pressure indicators, level alarms, trip systems, relief valves, SOPs, and interlocks.
  • Recommending improvements including instrumentation interlocks, tag corrections in P&IDs, addition of NRVs, and SOP updates.

The HAZOP was conducted by a multidisciplinary team using PHA-Pro 8.0 software. 

Conclusion

The HAZOP study for JSHL’s Green Hydrogen Project identified actionable recommendations aimed at improving safety and reducing operational risk. Noteworthy suggestions included updating SOPs to reflect regeneration cycles, ensuring proper venting and interlock configuration, and upgrading P&IDs. The study concluded that with the implementation of these recommendations, the risks associated with the hydrogen production and purification systems can be brought within tolerable limits.

This study plays a critical role in achieving the plant’s objectives of sustainable, safe, and uninterrupted hydrogen production, and sets a benchmark for future green hydrogen installations.