Semi Quantitative Risk Assessment of a Hydrogen Production Unit
The safety of hydrogen generation facilities is the main concern in their process operation. This study was conducted to identify the hazards and evaluate the risks of a hydrogen generation plant. For this purpose, PrHA (Process Hazard Analysis) was applied for hazard identification while LOPA (Layer of Protection Analysis) was used for risk assessment. The study was conducted in the hydrogen production unit of Behshahr Industrial Complex, Iran in 2011 and 2012. In the process of risk assessment, the records of the accidents and plant flow diagrams were studied. Then, the knowledge of the experts and operators were used through brainstorming prior to the application of LOPA technique. LOPA standard template was applied using PHA-Pro6 software. The initiating events, consequences, independent protection layers and probability of failure were determined for 16 scenarios in 7 nodes. The results showed that without the application of IPLs, the risks of 2 scenarios needed immediate action, 9 scenarios required action at next opportunity and 5 scenarios were operational. The application of IPLs would significantly decrease the risks. The study concluded that LOPA has sufficient credibility for semi quantitative risk assessment of high potentially hazardous plants.
US Department of Energy. Hydrogen Incident Reporting and Lessons Learned. Available online in: http://www.h2incident.org, (2011).
Center for Chemical Process Safety (CCPS). Layer of Protection Analysis-Simplified Process Risk Assessment, American Institute of Chemical Engineers (AIChE), New York, US, (2001)
Shojaei S. Analysis of the protective layer (LOPA) for nitroglycerin production units. MA thesis, Chemical Engineering Process Design trends, Sharif University of Technology, Tehran, Iran, 2009, Pages: 68-54 and 95-100.
Shirzadian K. Smart Event tree modeling and genetic algorithm for risk assessment in the boiler, desalination unit, Cheshmekhosh (oil and gas companies to exploit west). 2010, http://www.betsa.ir
Dowell AM, Dennis C. Simplified risk analysis-Layer of protection analysis (LOPA). National Meeting of AIChE, 2002, Indianapolis
Sanders RE. Practicing chemical process safety: a look at the layers of protection, Journal of Hazardous Material 2004; 115: 141-147
Schupp BA, Hale AN, Pasman HA, Lemkovitz BS, Goossens LO. Design support for the systematic integration of risk reduction into early chemical process design. Safety Science 2006; 44: 34-54.
Fang JS, Mannan MS, Ford DM, Logan J, Summers A. Value at risk perspective on Layers of Protection Analysis. Trans IChem E, Part B 2007; Vol 85 (B1): 81-87.
Wei C, William J, Mannan S.M. Layer of Protection Analysis for reactive chemical risk assessment. Journal of Hazardous Material, 2008; 159: 19-24.
Markowski A, Mannan S. Fuzzy logic for piping risk assessment (pfLOPA). Journal of Loss Prevention in the Process Industries 2009; 22: 921-927.
Markowski A, Mannan S. ExSys-LOPA for the chemical process industry. Journal of Loss Prevention in the Process Industries 2010; 23: 688-696.
Markowski A, Kotynia A. Bow-tie model in layer of protection analysis. Journal of Process Safety and Environmental Protection 2011; 89 (4): 205-213.
Markowski A, Mannan S, Kotynia A, Pawlak H. Application of fuzzy logic to explosion risk assessment. Journal of Loss Prevention in the Process Industries 2011, 11: 1-11.
Gowland R. The accident risk assessment methodology for industries (ARAMIS) / LOPA methodology: A step forward towards convergent practices in risk assessment? Journal of Hazardous Material 2006; 130: 307-310.
Mohammad Fam I. Safety Techniques (PrHA). Fanavaran publisher, 2003, Pages: 10-3. Tehran
Frederickson A. The Layers of Protection Analysis (LOPA) method, Look for best practices and guidelines on how to use the LOPA method as an alternative to mitigate risks. Safety Users Group Network, 2002
Jafari MJ, Gharari N, Sheikhi HR. The Reliability of a Tunnel Boring Machine, IJOH 2009; 1: 19-24.
Zarei E. Quantitative Risk Assessment of a Hydrogen Plant in Tehran. MSc thesis, supervised by MJ Jafari, Occupational Health Eng Dept, Faculty of Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran, 2012.
Jafari MJ, Zarei E, Badri N, Quantitative Risk Assessment of a Hydrogen Generation Unit. International Journal of Hydrogen Energy 2012., Oct, (in Press)
Rosyid O. System–analytic Safety Evaluation of the Hydrogen Cycle for Energetic Utilization [thesis]: Germany: university of Magdeburg; 2006.
Li Zhiyong PX, Jianxin MA. Quantitative risk assessment on 2010 Expo hydrogen station, International Journal of Hydrogen Energy 2011; 36: 4079- 4086.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.