Overview
Deepak Chem Tech Limited has undertaken a comprehensive Quantitative Risk Assessment (QRA) for its Nitric Acid Plant in Nandesari, Vadodara. This assessment aims to systematically evaluate potential hazards associated with the plant’s operations, ensuring safety and compliance with industry standards.
Purpose of the Study
The primary objective of this study is to methodically and quantitatively assess potential risks related to the Nitric Acid Plant’s operations. By employing both qualitative and quantitative risk assessment methodologies, the study provides a clear understanding of possible hazards, facilitating informed decision-making and effective risk management.
Objectives of QRA
The Quantitative Risk Assessment focuses on
- Involves assessing and quantifying pitfalls in colourful scripts through the use of numerical data and analysis.
- Facilitates educated decision-making by furnishing options.
- Offer stakeholders a clear and unprejudiced means of entering information about risks.
- Gives risks numerical values so that they can be compared and prioritized.
- Quantification of societal risk and calculation of potential loss of life.
Risk Assessment Procedure
A methodical approach to assessing the risks connected to industrial systems and processes is called Quantitative Risk Assessment, or QRA.
The Quantitative Risk Assessment (QRA) process involves:
- Systematic Identification: Analyzing relevant processes, units, and activities within the Nitric Acid Plant.
- Loss of Containment (LoC) Scenarios: Developing hypothetical situations where hazardous materials might escape containment.
- Consequence Analysis: Evaluating potential impacts and damages for each LoC scenario.
- Frequency Analysis: Determining the likelihood of each scenario using probabilistic methods and historical data.
- Risk Estimation and Presentation: Utilizing metrics such as societal risk f-N curves and individual risk contours to represent risk levels.
- Risk Evaluation: Assessing the acceptability of identified risks and determining necessary mitigation measures.
Comprehensive Risk Assessment for Loss of Containment (LoC)
- Establish contingency plans for loss of containment (LoCs).
- Analyse each LoC’s repercussions, including damages and effects.
- Ascertain the likelihoods and frequencies of failure for each LOC.
- Determine and display risk measures, such as societal risk f-N curves, individual risk contours, and so on.
- Assess and examine the risk.
Identification of Hazard
Depending on taking into account variables including the fluids’ physical and chemical characteristics, equipment configuration, maintenance and operation guidelines, process conditions, external risks like outside influence, and harsh environmental circumstances,
Consequence Analysis
The next stage after identifying the scenarios is to evaluate the possible outcomes of each one. Several kinds of effects can have consequences, including:
- Employee safety involves evaluating the risk of harm or death to employees.
- Assessing the degree of harm to machinery, buildings, or the environment is known as asset damage.
- Examining the consequences for soil, water, air, and ecosystems is known as environmental impact.
- Impact on business: evaluating the monetary and operational ramifications, such as production loss, downtime, and reputational harm.
Risk Analysis
Estimating the frequency or possibility of each possible scenario happening comes next after they have been recognized as potential scenarios. To determine the likelihood of occurrences occurring within a specified time frame, this entails taking into account several aspects, including expert judgment, probabilistic modeling, historical data, and analysis of pertinent data.
To calculate the overall risk, a risk estimate combines the likelihood and effects of each event. Techniques like risk matrices, risk curves, and probabilistic risk assessment (PRA) procedures are frequently used for this. As a consequence, there is a numerical representation of risk that is frequently described as estimated annual loss (EAL), individual risk (IR), or society risk (SR).
After risks are measured, they are compared to predefined risk or tolerance standards to see if they can be tolerated or if additional mitigation is needed. This entails contrasting the determined risk levels with established risk acceptability standards, legal mandates, and social norms.
Risk Communication
The public, regulators, and decision-makers are among the stakeholders to whom the risk analysis’s findings are finally conveyed. To make sure that the implications of the analysis are fully understood and that the necessary risk management measures are put in place, clear and open communication is crucial.
Risk Overview
Liquid ammonia from storage tanks is processed by the Nitric Acid Plant (DCTL) by feeding it into an ammonia feed vessel and pumping it to the necessary pressure. Using cold and cooling water, ammonia is vaporized in two phases. Any leftover ammonia and water mixture is then treated in an ammonia stripper. After being superheated and filtered, the ammonia gas is combined with air. In the air mixer, ammonia and compressed air are mixed by a steam turbine and tail gas. Oxidation on catalyst gauzes produces high-pressure steam. After cooling the process gas, the water that was created during combustion condenses into weak nitric acid, which is subsequently concentrated using secondary air in an absorption tower. After more heating and processing, the resultant nitric acid is stored, along with tail gas.
Conclusion
The nitric acid plant had been divided into nine isolatable sections. Using DNV PHAST, the major plausible end events of the following scenarios have been identified: jet fire, pool fire, flash fire, overpressure explosion, and toxic dispersion. Their impacts and consequences have been calculated for each scenario. DNV SAFETI was used for the risk analysis, yielding risk results in the form of F-N curves and LSIR contours. The analysis concludes that the societal risk for the entire population under consideration is within the ALARP zone.
Learn how our Qualitative & Quantitative Risk Assessment (QRA) helped identify hazards, assess risks, and implement proactive safety measures for a safer, more compliant industrial environment.
✅ Ensure regulatory compliance
✅ Minimize operational risks
✅ Protect your workforce & assets
Need a risk assessment for your facility? Contact us today!”