Safety HAZOP analysis

New systems or processes may also need to be qualified from an operational safety perspective. This is particularly relevant in the case of chemical synthesis involving exothermic reactions. Critical safety aspects are usually identified using hazard operability or HAZOP assessments and studies. For example, a HAZOP analysis of an exothermic reaction vessel would involve consideration of the consequence of failure of the motors for mixers or circulation pumps for cooling water. Thus, the qualification of such a system would involve checks and assessment to ensure that the system/process can be operated safely and that pressure relief valves or other emergency measures are adequate and functional. 

At this phase no technical hurdles are anticipated. Future actions include conducting a safety design review (HazOps analysis), establishing an activity-based target date for a critical design review, and generating a system level functional specification document which will help define the research boundaries for this project. 

Hazard operability (HAZOP) analysis. The process is analyzed purely from an equipment versus safety angle. Every single operation involved in the process is discussed by the cross functional team (CFT) for potential safety issues that could arise out of operations and any unexpected equipment failure. If any such condition is identified, the GET identifies a remedy and implements it before scale-up. 

A strategy that makes easier for the team to handle with large nodes was proposed and the main initiating events identified during the Petrobras coke drums HAZOP analysis were presented. Some LOPA results were commented in order to provide the reader the type of answers this approach allows. These results include the identification of the logics that need to be defined as safety instrumented functions and the required target SIL to achieve a tolerable frequency of occurrence for a specific hazard scenario. 

Layer of protection analysis (LOPA) LOPA is a systematic and structured way of quantification of risk reduction and safety integrity level (SIL) determination. Usually, it starts its work on the data developed in HAZOP analysis. For each documented undesired event with an initiating cause, it provides an independent protection layer (IPL), which will mitigate or prevent the hazard. Then, the total amount of risk can be determined. If safety instrumented function is necessary, LOPA methodology can be used to determine SIL also. From ISA 84 transaction it is found that LOPA is a simplified risk assignment tool used to evaluate the effectiveness of IPLs that are designed to reduce the likelihood or severity of an undesirable event. Quantitative PHA LOPA deals with single cause consequence pairs. Detailed documentation is possible and can be applied for continuous process. 

Out of all the team members, the team leader and scribe (secretary) are required to possess experience in HAZOP and excellent communication skills. Generally, for plant HAZOP analysis the team is formed from people with a technical background. In most of the plants dealing with hazardous materials, and/or any other hazardous situation, a person from the HSE department is made a team member. In some countries it is mandatory to keep one person from HSE. Since in most plants, control instrumentation plays a great role in ensuring plant safety through interlock and protection, it is better to keep one person from process, operation/production... 

R.N. Liin, L. Morten, J. Niels, J.S. Bay, A goal based methodology for HAZOP analysis. Nuclear Safety and Simulation 1 (2) (June 2010). 

The HAZOP analysis and the probabilistic safety assessment of the plant have been... 

Risk assessment system for verifying the safety guards system based on the HAZOP analysis information... 

HAZOP analysis is a technique to identify hazard by using deviation from the design intent. HAZOP used in the preliminary safety assessment of new plant or modification to existing ones. HazopNavi was developed to clarify the operation, behavior of the chemical plant (Kawamura et al. 2008). 

After the HAZOP analysis including safety measures, the information of a safety measures... 

Hussey, A. HAZOP Analysis of Formal Models of Safety-Critical Interactive Systems. In Koomneef, F., van der Meulen, M.J.P. (eds.) SAFECOMP 2000. LNCS, vol. 1943, pp. 371-381. Springer, Heidelberg (2000)... 

The remainder of the paper is structured as follows Section 2 gives an overview of relevant parts of the standards VDE 0832 and EN 50556, respectively. Section 3 presents a hazard analysis using HAZOP analysis. Section 4, in turn, introduces the embedded system platform architecture derived from the safety and domain specific requirements. In addition. Section 5 proves the architecture by going through a typical use-case. The main steps within the architecture are highlighted. Finally, Section 6 concludes by summarizing the key facts of the work carried out. 

Using the simulated biodiesel production process as case study, basically Jeerawongsuntom and team (2011) integrated the human-machine interface with HAZOP analysis for safety protection. Safety instmmented system was developed to create interlocks such as automatic shutdown to prevent the system from being exposed to extreme or... 

Cocchiara, M., Bartolozzi, V., Picciotto, A., Galluzzo, M. Integration of interlock system analysis with automated HAZOP analysis. Reliability Engineering and System Safety 74 (2001) 99-105. 

Jeerawongsuntom, C., Sainyamsatif N., Srinophakun, T. Integration of safety instrumented system with automated HAZOP analysis An application for continuous biodiesel production. Journal of Loss Prevention in the Process Industries 24 (2011) 412-4-19. 

Methods for performing hazard analysis and risk assessment include safety review, checkhsts, Dow Fire and Explosion Index, what-if analysis, hazard and operabihty analysis (HAZOP), failure modes and effects analysis (FMEA), fault tree analysis, and event tree analysis. Other methods are also available, but those given are used most often. 

Process Hazards Analysis. Analysis of processes for unrecogni2ed or inadequately controUed ha2ards (see Hazard analysis and risk assessment) is required by OSHA (36). The principal methods of analysis, in an approximate ascending order of intensity, are what-if checklist failure modes and effects ha2ard and operabiHty (HAZOP) and fault-tree analysis. Other complementary methods include human error prediction and cost/benefit analysis. The HAZOP method is the most popular as of 1995 because it can be used to identify ha2ards, pinpoint their causes and consequences, and disclose the need for protective systems. Fault-tree analysis is the method to be used if a quantitative evaluation of operational safety is needed to justify the implementation of process improvements. 

Perform a HAZOP study on the laboratory process of Problem 1. Consider the intention reactant flow to reactor for your analysis. What specific recommendations can you make to improve the safety of this experiment ... 

Another widely used safety analysis method in process industry is the Hazard and Operability Analysis, better known as Hazop (Kletz, 1992). The conventional Hazop is developed to identify probable process disturbances when complete process and instrumentation diagrams are available. Therefore it is not very applicable to conceptual process design. Kletz has also mentioned a Hazop of a flowsheet, which can be used in preliminary process design, but it is not widely used. More usable method in preliminary process design is PIIS (Edwards and Lawrence, 1993), which has been developed to select safe process routes. 

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