The dynamic response of benzene alkylation process to a set of deviations is analyzed with Aspen Plus Dynamics. A quantitative risk assessment is developed through simulations of deviation scenarios. The process comprises a reactor and three distillation columns with a recycle stream. The simulation scenarios are determined according to lessons learnt from accidents. This study underlines the conditions that induce an overpressure or a flooding in a distillation column. Three scenarios are proposed: feed flowrate variations, coolant flowrate reduction and cooling of the reboiler steam. Thereafter, the results allow calculating a set of risk indexes related to flooding and overpressure phenomena. This study underlines the deviation propagation effects that can be expected in all the process equipment. Moreover, it represents a significant contribution to the definition of the process control strategy and the necessary safety barriers. (C) 2018 Elsevier Ltd. All rights reserved.