Uncontrolled Reaction in a Storage Tank

摘要

1996 a storage tank ruptured in BASF AG in Ludwigshafen and considerable damage to property arose. The stored compound was Cyano-Ethyl Ethanolamine "CEEA". The synthesis of CEEA by addition of Ethanolamin to Acrylnitril worked out in the laboratory didn't show any unusual features. Destination, storage, handling and further processing of the substance proceeded straightforwardly. It did not give any reference to instability from the literature below the onset-temperature of 180°C determined by means of DTA. Thorough examinations after the accident showed the following facts: Already at the low storage temperature of 50°C, CEEA decomposes at a very small rate, as a consequence of autocatalytic behaviour, into a large number of cyclic compounds with the cyclic 1,3-Oxazol structure as bottom constituent. As a result one gets a compound which is able to polymerise. The energy for the endothermic reaction steps was delivered by the heating device of the storage tank. After CEEA was changed largely, the quota of the reactions which consume energy reduced itself. As a consequence a positive heat development arose. The mixture heated itself and finally a runaway-reaction took place under ring opening, polymerisation and decomposition. The details of the examinations will be discussed.