Environment Safety Risk Footprint Assessment Of Chemical Processes

Due to the production scale expansion in chemical industry,complicated and largescale production facilities will cause potential environmental pollution to the surrounding environment of the chemical plant.Moreover,the production process with the features of being flammable and explosive,toxic,high temperature and pressure accelerates such potential environmental pollution.Therefore,it is the prerequisite to conduct environment safety risk analysis and assessment of chemical processes so as to ensure the normal operation of the plant.Aiming at the environment safety risk problem in chemical processes,this thesis proposes the method of environment safety risk footprint analysis according to the accident evolution process pattern and the whole life cycle of chemical process.From the three scales of reaction routine,process unit,and engineering control measures,an environment safety risk footprint index system is proposed.The corresponding environment safety risk footprint assessment model is presented for each scale.To systematically investigate and evaluate the risk footprint of a chemical process,a detailed procedure for environment safety risk footprint assessment is proposed,which is divided into three main stages.They are as follows.(1)Environmental safety risk footprint for reaction routines(FPR).Based on reaction uncontrolled and physical property data(e.g.,the flash point and explosion limit)of the reaction path,the environmental safety risk footprint for reaction routines(FPR)is proposed.FPR can be used as the index for the risk difficulty degree of the reaction routine.Using the fuzzy logic method,FPR value for each reaction routine is obtained.Then,the inherent safe reaction routine can be selected according the comparison of the FPR values.(2)Environmental safety risk footprint for process units(FPE).To characterize the risk footprint of unit equipment in the production process,we establish FPE indicators based on the probability of unit equipment leakage during operation and the amount of chemicals residence in the equipment.The probability of unit equipment leakage obeys the Weibull distribution.(3)Environmental safety risk footprint for engineering controls(FPC).FPC is related to engineering control and Environmental safety risk footprint for process units of the previous stage.The implementation of engineering control measures is conducive to reducing the FPE value of the process unit equipment risk footprint and weakening the risks of the chemical processes.Targeted engineering control measures are supposed to be imposed.Through the assessment of the environment safety risk footprint in the chemical processes,the existence of the process of accidents and the subsequent environmental pollution risks are recognized.The proposed environmental safety risk footprint can give some guidance to further strength the risk management of chemical plants.