Sakineh A. Abbasi

Techniques and methodologies for risk analysis in chemical process industries

This paper presents a state-of-art-review of the available techniques and methodologies for carrying out risk analysis in chemical process industries. It also presents a set of methodologies developed by the authors to conduct risk analysis effectively and optimally.

Safety Weighted Hazard Index (SWeHI): A New, User-friendly Tool for Swift yet Comprehensive Hazard Identification and Safety Evaluation in Chemical Process Industrie

Indices are extensively used for ranking various units of a chemical process industry on the basis of the hazards they pose of accidental fires, explosions and/or toxic release. This type of ranking enables the professionals to identify the more hazardous units from the less hazardous ones so that greater attention can be paid to the former. The available indices—including the well-known Dow and Mond indices, and the authors HIRA (hazard identification and ranking analysis, Khan and Abbasi, 1 )—rank chemical process units mainly in terms of the hazardous substances and operating conditions associated with the concerned units. Dow and Mond indices do consider some factors (‘off setting index values’ in the case of the Mond Index and ‘credits factor’ in the case of the Dow index) to account for the safety measures existing or planned in the unit, but much greater rigour, accuracy, and precision are needed in quantifying the impact of safety measures on the values of the hazard indices. In this context, an attempt has been made to develop a new index, named here the Safety Weighted Hazard Index (SWeHI). The details are presented in this paper.

A new method for assessing domino effect in chemical process industry

A new methodology is presented with which the likely impact of accident in one process unit of an industry on other process units can be forecast and assessed. The methodology is based on Monte Carlo Simulation and overcomes the limitations of analytical methods, used hitherto, which were inherently limited in their ability to handle the uncertainty and the complexity associated with domino effect phenomena. The methodology has been validated and its applicability has been demonstrated with two case studies.

MAXCRED – a new software package for rapid risk assessment in chemical process industries

Abstract A new software package for conducting rapid risk assessment (RRA) in chemical process industries and the system of methodologies on which it is based are described. The objectives behind the development of the package are to achieve greater breadth and depth, sophistication, and user-friendliness in conducting RRA. In pursuit of these objectives we have incorporated in the package state-of-the-art models for generating accident scenarios and assessing their consequences. The package has been coded in C++ using the concepts of object-oriented programming to enhance the tools speed of execution and ease of use. The paper also demonstrates the applicability of MAXCRED with an illustrative example of a RRA conducted with its assistance.

Accident Hazard Index: A Multi-Attribute Method for Process Industry Hazard Rating

Traditionally, the severity of accidents in the chemical process industries has been gauged on the basis of the human lives lost1-5. However, factors such as loss of assets, contamination of the surroundings, and the resultant trauma also contribute to a very large extent towards the adverse impacts of such accidents. We have developed Accident Hazard Index (AHI) as a new system for a comprehensive yet rapid assessment of the damage caused by accidents in the chemical process industries. The index can also be used to assess the impacts of accidents likely in a yet-to-be-commissioned industry on the basis of site characteristics and the industry’ s process and operational details; the index thus enables one to choose between possible sites for setting up a new industry.

Inherently safer design based on rapid risk analysis

Abstract The importance of inherently safer design (ISD) as a strategy to minimize risk of accidents in chemical process industries is being repeatedly stressed in recent years. The increasing number, frequency, and extents of damage caused by such accidents across the world have contributed to this thinking. However even as the need for ISD is being underscored, there are very few reports on precise methods to implement this concept. Significant recent reports are by Berge (1993 Berge, 1995) who has suggested a scenariobased design procedure in which construction of accident scenarios in a structured manner is made the basis of ISD. We have been developing and applying the concept of rapid risk analysis ( Khan & Abbasi, 1995 , Khan & Abbasi, 1996 , Khan & Abbasi, 1997a , Khan & Abbasi, 1997b , Khan & Abbasi, 1998a , Khan & Abbasi, 1998b ). In this paper we present an approach to ISD utilizing this concept. We believe, as detailed in this paper, that this approach is a significant improvement upon Berges procedure in terms of ease, speed, and effectiveness.

A scheme for the classification of explosions in the chemical process industry.

All process industry accidents fall under three broad categories-fire, explosion, and toxic release. Of these fire is the most common, followed by explosions. Within these broad categories occur a large number of sub-categories, each depicting a specific sub-type of a fire/explosion/toxic release. But whereas clear and self-consistent sub-classifications exist for fires and toxic releases, the situation is not as clear vis a vis explosions. In this paper the inconsistencies and/or shortcomings associated with the classification of different types of explosions, which are seen even in otherwise highly authentic and useful reference books on process safety, are reviewed. In its context a new classification is attempted which may, hopefully, provide a frame-of-reference for the future.