Five measures to control risks in the production, use, and storage of butadiene and eliminate major hazards
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This post was last edited by Desert Fish on 2022-8-24 08:48. It is particularly important to control the risks associated with the production, use, and storage of butadiene in order to prevent accidents. In line with the spirit of recent relevant documents, the safety risks associated with butadiene have been analyzed. It is recommended to take measures in the following areas to prevent major risks and eliminate potential hazards. First, improve the intrinsic safety level of the facilities. First, optimize the process design to avoid dead zones. By properly designing the gas and liquid phase distribution and flow rates within the tower, as well as the design of the tray and downcomer structures, dead zones within the tower can be avoided ； In the design of the heat exchanger, butadiene is used in the tube side to prevent the formation of dead zones ； The piping is designed with an incline to reduce dead zones in horizontal sections, as well as blind ends such as drain lines and protrusions. Backflushing facilities are installed in areas of the high-purity butadiene system where accumulation is likely, to prevent the deposition of polymers ； Add a burst disc in front of the safety valve. Second, design measures such as emergency addition of inhibitors and emergency release. In areas where the purity of butadiene is high, such as the butadiene intermediate tank, an additional emergency dosing system for polymerization inhibitors is designed to enable the urgent injection of these inhibitors in case of abnormalities, thereby preventing self-polymerization reactions and facilitating emergency venting, and thus avoiding explosion accidents caused by self-polymerization. Third, in the design of the equipment, efforts should be made to minimize the residence time of high-concentration butadiene; for example, the butadiene residence time in the reflux tank can be reduced through proper design, and product batch tanks can be eliminated.
Second, improve the level of automated control of the equipment. Based on the results of the HAZOP analysis, and in accordance with the requirements for controlling hazardous processes that require close monitoring, automated control systems and interlocks are installed for reaction systems such as oxidation and polymerization processes. In addition, emergency shutdown systems, systems for introducing inert gas urgently, and safety relief systems are also established ； Strictly control parameters such as distillation temperature, pressure, flow rate, system oxygen content, and cooling water flow rate. Establish interlock relationships between temperature, pressure, butadiene inlet and outlet flow rates, cooling water flow rate, and heat transfer valve settings, in order to prevent overheating in heating equipment such as reboilers ； Based on the analysis and assessment, temperature and pressure monitoring is implemented at areas where self-polymerization may occur, thereby enhancing the ability to monitor key process parameters of the facility in real time. In particular, closer monitoring is carried out on high-purity butadiene storage tanks and intermediate tanks that do not contain inhibitors, so that alerts can be issued and appropriate actions taken promptly in case of abnormal changes in temperature or pressure. In situations where temperature or pressure rises sharply, the system is designed to shut down automatically and relieve pressure.
Third, strengthen the safety control during the operation of the equipment’s processes. During the production and use of butadiene, the polymerization inhibitors must be added to the system in accordance with the specified type, concentration, amount, method, and location, to ensure that their concentration meets the required levels ； Install an online detector to strictly control the oxygen content in the system ； Reduce the temperature of the butadiene material – the temperature of the butadiene being discharged from the plant should not exceed 27°C, in accordance with safety requirements. Lower the levels of iron ions and other substances in the system. Leak detection alarms should be installed in areas where butadiene is produced, used, or stored, and explosion-proof ventilation systems and equipment should be employed ； Butadiene sampling should employ a closed-loop sampling system ； When opening and maintaining equipment and pipelines involving butadiene, they must be purged and replaced to meet the required standards.
Third, strengthen the safety control during the operation of the equipment’s processes. During the production and use of butadiene, the polymerization inhibitors must be added to the system in accordance with the specified type, concentration, amount, method, and location, to ensure that their concentration meets the required levels ； Install an online detector to strictly control the oxygen content in the system ； Reduce the temperature of the butadiene material – the temperature of the butadiene being discharged from the plant should not exceed 27°C, in accordance with safety requirements. Lower the levels of iron ions and other substances in the system. Leak detection alarms should be installed in areas where butadiene is produced, used, or stored, and explosion-proof ventilation systems and equipment should be employed ； Butadiene sampling should employ a closed-loop sampling system ； When opening and maintaining equipment and pipelines involving butadiene, they must be purged and replaced to meet the required standards.
Fifth, conduct regular risk assessment and control. Conduct process safety risk analysis throughout the entire process and lifecycle. By considering the operation and maintenance status of the facilities, an assessment is made of the likelihood and locations where diborne polymers may be generated in units such as dehydrogenation, butadiene extraction, cis-butyl rubber, and styrene-butadiene rubber production; the discharge capacity is determined scientifically, and various preventive and control measures are reviewed to ensure their effectiveness. Establish and improve a monitoring and early-warning mechanism for production abnormalities. Record any abnormalities and the actions taken to address them in a timely manner. Regularly analyze and assess the trends in the process parameters across the entire system, and take prompt action to address any signs of potential accidents.
The focus is on design, process design, and safety design