miolo sho2009_indices v8 - Departamento de Produção e Sistemas ...

SAFETY EVALUATION AND IMPROVEMENT IN ANETHYLENE OXIDE REACTORRochim B. Cahyono a , Yeni Cristiani b , Mohammad Shahriari ca,b,c Department of Product and Production Development, Chalmers University of Tech., Swedena Department of Chemical Engineering, Gadjah Mada University, Indonesiaa rochim@student.chalmers.se, b yeni@student.chalmers.se, c mohammad.shahriari@chalmers.seSho2009ABSTRACTEthylene Oxide (EO) is one of the essential chemicals in industrial processes. At ambienttemperature, EO is an uncoloured gas with a somewhat sweet odour. The market value of EO isvery high since its field of application is large. Above all, EO is used as input component in theproduction of many different chemical products, i.e. bromide fluid, cosmetic and anti-freezingmedium in engines.Handling EO is very complicated because of its flammability. It is very dangerous in many ways.If released uncontrollably it is very likely that a powerful explosion will take place. Exposure toEO may also result in health problems. EO is toxic, carcinogenic, caustic and allergenic.The first stage of EO production is direct oxidation of ethylene, which takes place in a reactorunder high pressure and temperature. The reaction is exothermic and has a high potential ofrunaway followed by an explosion. Therefore, the design, operation and maintenanceprocedures require proper safety concern.The objective of this project is to identify all possible hazards in the process of EO reactor andto introduce some safety actions in order to minimize the risk of potential accidents. Thus,guideline to improve the safety of EO reactor can be proposed.In this study, some risk assessment tools such as HAZOP and FMEA are used to identify themost hazardous scenarios concerning the reaction phase of the process. Operating conditionhazards is evaluated using HAZOP, while equipment hazards and failures are analyzed usingFMEA. The results of the study in terms of safeguards and suggestions can be used to improvethe EO reactor safety.Colóquio internacional sobre segurança e higiene ocupacionaisKeywords: ethylene oxide, EO reactor, safety evaluation, HAZOP, FMEAINTRODUCTIONThe world total production of Ethylene Oxide (EO) has been around 16 million tons in 2003. It isidentified as one of the essential chemicals in process industries [1]. EO can be used directly inseveral chemical manufactures such as cosmetics, bromide fluid, and anti-freezing agent. Asintermediate products, EO is used for producing of ethylene glycol and polyethylene glycolwhich are useful as softeners, solvents, plasticizers, disinfectants, etc.EO has some dangerous characteristics. It is highly reactive, flammable, explosive withpossibility of polymerization and decomposition. When EO uncontrollably releases to theenvironment, it is very likely that a powerful explosion takes place due to its reactivity andflammability properties. It is direct effects on human health will be headaches, nausea, lethargy,and memory loss to reproductive effects, genetic changes and even cancer.The most common method to produce EO in industry is direct oxidation process with either pureoxygen or air. EO reaction occurs in fixed-bed catalytic reactor with operating condition 200-260 o C and 10-30 atm [1]. The reaction is highly exothermic and has high potential of runawayfollowed by an explosion. The potential of explosion might increase with cooling system failureand pipeline plugging due to decomposition and polymerization. Several accidents haveoccurred and caused loss of human and properties. For instance on 24 th of June 1997, oneperson was killed and fifty-nine persons were injured in Elkhart, Indiana, USA due to anethylene oxide pressurized container (a sterilizer used in hospital) is exploded [3, 4]. Anotheraccident in the EO production and derivative plant has occurred in 1962 when EO vapor cloudexploded due to contamination of aqueous ammonia in EO storage tank. The explosion caused101