ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 33, Number 1
JKCSEZ 33(1)
February 20, 1989 

Methyl tert-butyl ether(MTBE) was synthesized from vapor phase reaction of methanol with iso-butylene over HZSM-5 catalysts, and effects of SiO2/Al2O3 ratio in the HZSM-5 catalysts and reaction conditions on products distribution have been examined. Acid strength and acid type of each catalyst with different SiO2/Al2O3 ratio were measured using pyridine adsorption followed by temperature programmed desorption(TPD) and IR analysis. Reactants and products adsorption characteristics on different acid sites have also been examined. As the SiO2/Al2O3 ratio of HZSM-5 catalyst was increased, selectivity to MTBE was improved as a result of decrease in dimethylether(DME) formation at the strong acid sites. Conversion and selectivity to MTBE were also greatly enhanced as i-C4H8/CH3OH reactant ratio was increased, and overall about 80℃ was adequate for the MTBE synthesis. The properties of deposited coke on spent catalysts were examined by TG, DTA and IR spectrum analysis, indicating the amount of the coke deposit in the order of HY > H-Mordenite > HZSM-5. Even if the coke deposited on H-Mordenite was little more in amount than to that on HZSM-5, the former deactivated quickly due to its non-interconnected channel structure. For HY, owing to its lange pore size, significant i-C4H8 polymerization was occured, and rapid deactivation and severe coke formation has resulted within few hours.