Reason For The Short Running Period Of MTBE And Solution

MTBE is one of the petrochemical products most rapidly developed in the recent twenty years. It is widely used in the blending of gasoline. Even though the addition of MTBE in gasoline have been prohibited in many countries, including USA, Japan and Denmark, because the leakage of the underground oil tanks leads to the pollution of water sources. by estimation, but the demand of MTBE in the Asian-Pacific areas and North European areas will not decline, and get rise in a rather long period of time.For the short lifetime of the catalyst in a 20,000 metric ton per year MTBE unit, combined the principle and mechanism of losing activity of catalyst with the analysis data of the non-active catalyst and the macroscopic pHenomena in the reactor running, the paper gave the reasons as follows:First, the activity losing of etherification catalyst in the MTBE unit is a diffusing one, not the pushing one. Second, the main reason of the short lifetime of catalyst is the high content of small molecular amine, alkali or sodium ion and water in the raw material of C4 fraction.To solve the above problems, several measures had been taken in the paper. These measures are, first, removing the small molecular amine and alkali or sodium ion by washing the LPG, second, separating the free water in the liquid gas by using the filter and tank sedimentation and third, decreasing the water content of material C4 fraction by adjusting the top pressure, top temperature, reflux amount and reflux temperature of the rectifying tower in gas fractionation unit. These measures double the use lifetime of the catalyst to 16 months in continuous process, reaching the high internal level with the same MTBE unit, significantly improving the catalyst lifetime in the MTBE plant.