Deepak Fertilizers & Petrochemicals Corporation Limited (DFPCL) is a 42-year-old company engaged in manufacture and marketing of Ammonia/Phosphoric Acid/Sulphur based fertilizers, Formulated Nutrients based fertilizers, Ammonium Nitrate, Methanol, Propyl Alcohol (IPA) & other Industrial Chemicals & Petrochemical products. DFPCL is one of the largest producer of Weak and Concentrated Nitric Acid in India.
Liquid Ammonia is used as raw material for production of Nitric acid. Liquid Ammonia is received at site by road tankers. Liquid Ammonia unloading system will comprise of following main equipment’s
- Ammonia Road Tanker
- Ammonia storage Tanks
- Ammonia Compressor
- Adequate Instrumentation System, Piping & Valves
- Ammonia transfer Pump
Ammonia required is about 135 TPD for the production of desired Weak Nitric acid (WNA) of capacity 450 TPD. Liquid ammonia at site shall be supplied by road tankers. Liquid Ammonia will be stored in 4 number of pressurized storage tank (3 number of storage tank for current requirement & 1 number of storage tank as spare) with the provision of one future ammonia storage tank. The storage facility will be made to accommodate 5 number of ammonia storage tanks. For effective operations, Four Ammonia storage tanks each of capacity 230 m3 are considered.
Out of 4 number of ammonia storage tank 3 number of liquid ammonia will be in receiving from ammonia road tankers and same is to be supplying to Weak nitric acid plant. One ammonia storage tank will be kept as Stand-by to mitigate any eventuality.
DFPCL is planning a capacity expansion of the existing ammonia storage. The scope of work is to carry out the Quantitative Risk Assessment to assess which ammonia storage option is better from a risk perspective.
The additional Ammonia storage options are:
- Multiple Bullets (330 m3)
- Atmospheric Storage tanks (Maximum of 5000 MT)
The PHA research aims to lower the likelihood and effects of an incident that would have a negative impact on the workers, plant, properties, and environment while also assisting in controlling project risk through early identification of hazards.
The objectives of PHA study include:
- Identification of potential hazardous occurrences, both internal and external, that, if they occur, could endanger people, property, and the environment.
- Analyze qualitatively the dangerous effects and propensity for the specified hazard events to occur.
- Examine the safety measures advised for avoiding, reducing, and regulating the possibly harmful outcomes.
- Identification of the residual hazardous events that need to be further quantitatively assessed and analysed.
- Identification of health and environmental impacts associated with the Project.
These recommendations include:
- Implementing lightning arrestors and deluge systems
- Developing and implementing SOPs for vehicle movement during the construction phase
- Ensuring that an Emergency Management Plan is available for the construction phase
- Considering using megaphones during construction
- Providing temporary sheds and adequate drinking water/energy drinks for construction workers
- Extending medical facilities for construction workers
- Ensuring that a Manning/Operations Philosophy, Construction Philosophy, permit to Work, and Site Safety Construction Procedure are available
- Providing fall arrestor nets/lifelines and scaffolding with firm platforms
These recommendations are important for ensuring the safety of both workers and the facility during the construction phase and beyond. By implementing these recommendations, DFPCL can reduce the risk of accidents and incidents, and protect its employees and the environment.
In conclusion, the PHA study by iFluids Engineering provides valuable insights into the potential hazards associated with the capacity expansion of the ammonia storage facility at DFPCL, Dahej site. The 14 recommendations made by the study team are comprehensive and address a wide range of safety issues. By implementing these recommendations, DFPCL can significantly improve the safety and operability of the facility.
The most important objective of this study is to evaluate the potential risk levels for personnel due to accidental release of hazardous flammable and toxic materials from the failure scenarios of the facilities and to demonstrate that individual risks are within the broadly acceptable regions.
The Objectives of Quantitative Risk Assessment QRA are as follows:
- Identification of Hazards and Major Loss of Containment (LOC) events
- Calculation of physical effects of failure case scenarios which include Estimation of Jet Fire, Pool Fire heat radiation distances, Flammable gas dispersion distances, and overpressure explosion distances
- Failure Frequency evaluation
- Societal risk and Potential Loss of Life identification
- Based on the UK HSE risk acceptance criteria risk assessment is performed to confirm that risk can be reduced consistent with the ALARP principle.
- Provide recommendations to ensure that all risks are in ALARP or Acceptable region.
Findings of the site with Ammonia storage bullet
- Location Specific Individual Risk
The probability that in one year a person will become a victim to an accident if the person remains permanently and unprotected in a certain location. The individual risk varies for different locations at a plant. Among the Risk ranking locations considered, Washroom, WNA plant and ETP area lies in the ALARP region and all other risk ranking points lies in the ACCEPTABLE region.
- Individual Risk for the people
The Individual Risk (IR) is a measure of the risk at each location (in this case, each area, generally), independent of the population. The Individual risk results for the people is concerned the individual contour of 1E-06/Avg.Year, 1E-07/ Avg. Year, 1E-08/Avg.Year and 1E-09/Avg.Year extends up to 264m, 714m, 1617m and 2064m in radius from the center of the ammonia storage bullet, respectively. The Individual Risk Per Annum for the People at the risk ranking locations considered for the study- Washroom, WNA plant and ETP area lies in the ALARP region and all other risk ranking points lies in the ACCEPTABLE region.
- Societal Risk
The Societal Risk gives the relationship between frequency and the number of people suffering from a specified level of harm in a given population from the realization of specified hazards. It is concluded from the study that the societal risk for the overall population considered for the study falls broadly in the ACCEPTABLE region.
Findings of the site with Ammonia storage Tank
- Location Specific Individual Risk
Among the Risk ranking locations considered, all the risk ranking points lies in the ALARP region.
- Individual Risk for the people
The Individual risk results for the people is concerned the individual contour of 1E-06/Avg.Year, 1E-07/Avg.Year, 1E-08/Avg.Year and 1E-09/Avg.Year extends up to 2892.5, 4776.8m, 7667.4m and 10394m in radius from the center of the ammonia storage bullet, respectively. The Individual Risk Per Annum for the People at the risk ranking locations considered for the study all the risk ranking points lies in the ALARP region.
- Societal Risk
It is concluded from the study that the societal risk for the overall population considered for the study falls broadly in the ALARP region.
The PHA study identified 14 recommendations to improve the safety and operability of the ammonia storage facility at Deepak Fertilizer and Petrochemicals Corporation Limited (DFPCL), Dahej site.
Based on the observations and conclusions following are the recommendations of the study:
- Ensure ammonia gas detectors are provided within the site in order to facilitate leak monitoring and regular leakage checks.
- Each vehicle transporting ammonia in bulk except farm applicator vehicles shall carry a container of at least 5 gallons of water and shall be equipped with a full face mask.
- Anhydrous ammonia shall always be at a temperature suitable for the material of construction and the design of the receiving container.
- Pumps used for transferring ammonia shall be those manufactured for that purpose.
- Compressors used for transferring or refrigerating ammonia shall be recommended for ammonia service by the manufacturer.
- Storage areas shall be kept free of readily ignitable materials such as waste, weeds, and long dry grass.
- Ensure ammonia tanker is earthed prior to loading / unloading operations.
- Ensure wind sock is available at an elevated and visible position in ammonia storage facility.