Study On Environmental Risk Assessment And Environmental Eemergency Management For Chemical Industrial Factories Based On Severity Order Coefficient Model

With the continuous development of the industrialization in China,emergency environmental accidents have occured frequently in recent years.The chemical industry is an industry with a high frequency of emergency environmental accidents.Therefore,it is of great importance to prejudge the possible environmental pollution incidents and to carry out related researches on the emergency management of typical chemical industrial factories,which could prevent pollution incidents and reduce environmental pollution accordingly.Based on the theoretical research on the accident risk analysis,the environmental risk assessment and the emergency management of emergency environmental accidents,this thesis developed the Severity Order Coefficient model to evaluate the maximum credible accident facing ambient air,and put forword the emergency management mode of STA(Scenarios—Task—Ability)which was validated by the chemical industrial factory.The results are as follows:1.The Severity Order Coefficient model was developed to evaluate the maximum credible accident facing ambient air.Based on the ARAMIS(Accidental Risk Assessment Methodology for Industries System),by simplifying the accident probability and the accident intensity,dimensionless treating on environmental hazards of accidents,this thesis developed the Severity Order Coefficient model:S=F×M.Thereinto,F is for the multiplication of the initial accident probability and the ratio of online and critical of typical equipment;M is for natural logarithm of area size of half lethal concentration after the accident.The problem of uncertainty of maximum credible accident in environmental risk assessment is better solved.2.The evaluation of maximum credible accident of chemical industrial factory was carried out.Taking YongNong BioSciences CO.,LTD as research object,the Severity Order Coefficient model on the six potential accidents was calculated.The severity order coefficients of leakage accident of liquid ammonia cylinder,leakage of chloromethane cylinder,leakage of acrolein tank,leakage accidents in hydrochloric storage tank,leakage of phosphorus trichloride tank,CO emission accident caused by explosion of distillation kettle were 1.59 × 10-4,9.68 × 10-5,7.98 ×10-5,7.01 × 10-5,2.37 × 10-5,2.34 × 10-5 respectively.Results showed that the maximum credible accident is the leakage accident of liquid ammonia cylinder.The result was consistent with the risk values based on fault tree model proposed by Guidelines(HJ/T 169-2004).3.The emergency management strategy of STA(Scenarios—Task—Ability)was put forward based on the Severity Order Coefficient model.Taking YongNong BioSciences CO.,LTD as research object,the important accident scenarios index of this company was calculated as 7.54×10-5 by using the Severity Order Coefficient model,illustrating that the company's emergency environmental accidents which are the priorities to be prevented are the leakage accident of liquid ammonia cylinder,of chloromethane cylinder,and of acrolein tank.In combination with the current emergency management situation,the detailed emergency lists of prevention,preparation,response and recovery were established and the suggestions for improving emergency capacity were put forward.