Study On The Commonality Safety Function Requirements Of Coke Oven Gas-methanol Plant

The coke oven gas methanol plant,as a direct means of recovering coke oven gas and improving the efficiency of the coal coking enterprises,a history of over 10 years in China.Coke oven gas to methanol process is a dangerous chemical process with emphasis regulation——Oxidation process,which is characterized by high temperature,high pressure,inflammable and explosive.Once an accident happens,the consequences will be very serious.However,due to the lack of experience in design and operation and the lack of risk analysis,there are many problems in most enterprises,such as unreasonable interlock design,lack of interlock protection and low interlock investment rate.For example,when X Co.Ltd designs the coke oven gas to Methanol,it assumed that the security function is in the DCS system.Through the DCS system,functions like realizing real-time control to complete the data acquisition,information processing,safety interlock,emergency stop achieved.There is no scientific confirmation of the security function of the necessary safety instrument system,and there is no clear test cycle and other safety requirements for the safety instrument system process.This design lacks the control of the systematic failure of the safety instrument system and the risk of simultaneous failure of the DCS and the security instrument system.In order to promote the standardization of safety management of chemical industry safety instrument system,the State Administration for Safety Control issued No.116 on 2014,it has a clear demand that safety instrumented systems need to be established independently of process control system(such as distributed control system),and also demands that safety requirements,design intent and basis of the safety instrumented system process should be clear,as well as compiling safety requirements of technical documents of safety instrument system.And there is no systematic research on the technical documents of safety requirements for methanol unit coke oven gas meter system now.This research based on the risk characteristics of coke oven gas to methanol,focuses on the technological hazards analysis and layer of protection analysis,the safety function of the safety instrumented system and the integrity of the safety instrumented system.It makes clear of the safety instrument system security requirements,design intent and basis,and uses Aspen Plus V8.4 software on the condition of high risk to carry out the process simulation,to determine the interlocking part of SIF loop set points and response time for safety,to draft coke oven gas to methanol system safety instrument system specification(SRS),safety instrument system,to standardize the management of enterprises,and to improve the level of safety management of enterprises.At the same time,it provides reference for the design,installation,maintenance and management of the safety instrument system in the same industry.