Proximity risk assessment for two sensitive chemical plants based on the accident scenario consequence analysis

Abstract

Petrochemical complexes include high risk interconnected plants processing large quantities of dangerous/flammable substances, complex reactors of high thermal sensitivity operated under severe conditions of high productivity and associated equipment, vessels or separation units operating at intense temperature and pressures. Such plant design/operation problems contribute quite frequently to the occurrence of small incidents or rare major accidents including domino effects. The study applies classical boiling liquid expanding vapour explosion fire and toxic puff release models to evaluate the effects and consequences of different accident scenarios involving two neighbouring risk plants, with exemplifications for the aniline and maleic anhydride synthesis plants. A proposed joint probability index of human casualties, related to thermal radiation doses and toxic material released around plants, points out the influence of production capacity and plant proximity on the severity of accident consequences and domino‐effect occurrence. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.

The Reactor Size Influence on the Optimal Operating Setpoint Choice for a Fixed-Bed Multi-Tubular Catalytic Reactor

“…The right choice of the tolerable safety limit of the failure probability P f in the reactor design/operation calculus depends, as proved by Dan and Maria (2012), on the reactor type/characteristics, process hazard, and of the magnitude of consequences of a reactor runaway [11]. For instance, this limit is of 3-4 % for a tubular catalytic reactor used for butane oxidation [2], of 0.5-2% for the same tubular catalytic reactor but used for benzene oxidation (this study), or of 3-6 % for a semi-batch reactor used for the catalytic acetoacetylation of pyrrole with diketene in homogeneous liquid phase [2].…”

“…The runaway probability P f2 appears as a result of random fluctuations in the control variables and/or operating parameters, thus determining the running point to enter in the risky runaway limit confidence region. In other words, by considering normally distributed variables , this risk index reflects the probability that: (11) [see [2,3,9] for computational details].…”

“…ix)The operating alternatives can be drastically reduced if a supplementar y criterion is considered during optimization (of economic or environmental nature, e.g. costs of the accident consequences using simulated failure scenarios; [7,11] ).…”

Derivation of Pareto Optimal Operating Policies Based on Safety Indices for a Catalytic Multi-tubular Reactor Used for Nitrobenzene Hydrogenation

“…7,8 It should be mentioned that the entire plant productivity depends on accident frequency and their effects/consequence magnitude. 5,8,9 -Consider various sources of uncertainties when solving the mentioned multi-objective optimization problem, e.g. uncertainty in the control vari-able runaway boundaries, and the inherent random disturbances of the control variable setpoint.…”

“…uncertainty in the control vari-able runaway boundaries, and the inherent random disturbances of the control variable setpoint. 5,8,9,[32][33][34][35][36] On the other hand, the plant optimal operating policy should be considered as a trade-off between economic, environmental, and safety objectives. By using a new "safe operation criterion" introduced by Maria and Dan,[10][11][12][13][14] based on the sum of two failure probability indices related to uncertainty in the reactor runaway boundaries and random disturbances in the operating parameters, a multi-objective optimization can be formulated by defining the sustainability by simultaneously considering technological, economic, and safety constraints.…”