Showing papers by "Faisal Khan published in 2004"

Integrated inherent safety index (I2SI): A tool for inherent safety evaluation

Abstract: Inherent safety is a proactive approach for loss prevention and risk management. Considering the lifetime costs of a process and its operation, an inherent safety approach can lead to a cost-optimal option. Inherent safety may be achieved at any stage of process design; however, its application at the early stages of process design yields the best results. Despite being an attractive and cost-effective approach, the inherent safety methodology is not widely used. Many reasons have been attributed to this lack of widespread use; the nonavailability of systematic tools for the application of inherent safety principles is perhaps the most important reason. This paper presents a conceptual framework of an integrated inherent safety index (I2SI). It is called an integrated index because the procedure, when fully developed, is intended to consider the life cycle of the process with economic evaluation and hazard potential identification for each option. The I2SI is composed of subindices which account for hazard potential, inherent safety potential, and add-on control requirements. An application of the I2SI is also discussed. © 2004 American Institute of Chemical Engineers Process Saf Prog 23: 136–148, 2004

Risk-based maintenance (RBM): A new approach for process plant inspection and maintenance†

Abstract: This paper discusses recently proposed methodology for the design of an optimum maintenance management program. The methodology is based on integrating a reliability approach and a risk assessment strategy to obtain an optimum maintenance schedule. The method is called risk-based maintenance (RBM). First, the likely equipment failure scenarios are formulated. Out of the many likely failure scenarios, the ones that are most credible are subjected to a detailed study. Detailed consequence analysis is done for the selected scenarios. Subsequently, a fault tree analysis is performed to determine the probability of failure. Finally, risk is computed by combining the consequence analysis and the probability analysis results. The calculated risk is compared against known acceptable criteria. The frequency of maintenance tasks is obtained by minimizing the estimated risk. The proposed methodology is used to answer two questions: Which equipment should be included in a scheduled maintenance program? When should the maintenance be scheduled? Offshore oil and gas process facilities involve hazardous chemicals (highly flammable and toxic) at extreme conditions of temperature and pressure. Proper maintenance of process equipment is one of the important activities to ensure safe and continuous operation of the facility. RBM methodology has been used to develop a detailed maintenance plan for safe and fault free operation of the facility. © 2004 American Institute of Chemical Engineers Process Saf Prog, 2004

An inherent safety–based incident investigation methodology

Abstract: A methodology has been developed to enable the explicit use of the principles of inherent safety in an incident investigation protocol. The usefulness of this approach is demonstrated by application to the Westray coal mine explosion that occurred in Nova Scotia in 1992. This process-related disaster resulted in the deaths of 26 workers, destruction of the underground workings, and bankruptcy of the parent company. The purpose in presenting this case study is twofold: to validate the methodology and to identify the inherent safety considerations that could have prevented the incident. These findings have application beyond the realm of coal mining, extending well into the world of the chemical process industries. © 2004 American Institute of Chemical Engineers Process Saf Prog 23:197–205, 2004

Evaluation of Inherent Safety Potential in Offshore Oil and Gas Activities

Abstract: The inherent safety approach is the best option for hazard/risk management in offshore oil and gas activities. Some of the main drivers for inherent safety in the offshore industry are to reduce manning levels and provide minimum facilities installations, encourage the use of compact and simple technology, and reduce the need for operators to be present. Though this approach is comparatively mature and has been widely accepted in onshore process industries, its applications in offshore industries are still limited. A recent pilot study to assess the extent to which the concept and principles of inherent safety are being applied in the development and design of offshore oil and gas installations revealed that the term inherent safety is only just beginning to be recognized in the industry, mainly as a result of its inclusion in the Design Safety Case Guidance, and the UKOOA Fire and Explosion Hazard Management Guide. There appears to be a number of subtle but significant differences of opinion as to what inherent safety is, including ‘hazard avoidance’, ‘hazard prevention’, ‘risk minimization’, and ‘good engineering’. While all of these may form part of an inherently safer strategy, they do not encompass a full understanding of the role of inherent safety. This paper discusses inherent safety in offshore oil and gas activities and presents methods to evaluate inherent safety potential. It also highlights areas for further research.Copyright © 2004 by ASME

Air dispersion modelling in coastal areas with rough terrain, using calpuff prime

Abstract: To study the effects of exit temperature, exit velocity, and stack height on contaminant dispersion and concentration, the revised version of the CALPUFF air dispersion model was used to predict the dispersion of total suspended particulates (TSP) and sulphur dioxide (SO2) emissions released from an industrial source in a coastal region with rough terrain. The CALPUFF model accounts for the influence that large water bodies have on atmospheric pollutant dispersion, accounts for plume rise and flow around building obstacles, and is suitable for use in areas with complex terrain. This study shows that stack heights and exit velocity are controlling factors in pollutant dispersion. An increase in the stack height and exit velocity, resulted in a decrease in maximum pollutant concentrations. When the height of the stack is increased, the effective plume rise is enhanced and this promotes buoyancy induced dispersion. An increase in exit velocity increases plume momentum leading to higher mixing and turbulent dispersion. An increase in exit temperature did not have a significant effect on concentrations near the source, but did result in a decrease in pollutant concentrations at a distance from the source due to the thermal buoyancy effect.