QUANTITATIVE RISK ASSESSMENT OF FCC UNIT OF A PETROCHEMICAL PLANT

Abstract

Risk Assessment is a well-established methodology for assessing developments with a high degree of uncertainty and potentially high significance of impacts. The aim of the risk assessment process is to remove a hazard or reduce the level of its risk by adding precautions or control measures, as necessary. Over the past four decades, risk assessment has matured into a powerful analytical tool to evaluate hazards. Risk assessment typically involves the identification of hazards, and potency or effects of those hazards Quantitative risk assessment requires calculations of two components of risk, the magnitude of the potential loss and the probability that the loss will occur. Here provide the general guidelines and steps on how to develop a quantitative risk assessment for a fluid catalytic cracking unit in refinery, and how to use it and interpret the results. The main inputs and key elements of the quantitative risk assessment are plant maintenance history, component failure data, human errors, operation and engineering experience, and plant design documentation such as operating manuals, process flow diagrams (PFD) and piping and instrumentation diagrams (P&ID). In order to carry out the HAZOP studies, a visit to the Panipat Refinery was made. A thorough study of the plant and its P & PIDs was done to prepare the HAZOP Report and also to form the basis of basic Fault trees of the FCC unit. The visit gave an apposite insight of the plant operation and processes. It includes the Quantitative Risk assessment of fluid catalytic cracking unit, for that firstly made the HAZOP study which gives the idea about the exposure which will take place in plant. Secondly for calculating the frequency of hazard, here the fault tree analysis of the whole unit was discussed. Which give the approximate value of top event probability (TEP). From that value calculate the risk for a unit by putting the TEP value in the various risk acceptance criteria of various countries.