Ethanol conversion to light olefins using mordenite catalysts

Abstract

Natural mordenite was dealuminated with acid and then modified with metal loading to prepare MD/metal catalysts. The single and mixed metals were loaded onto mordenite using solid state ion exchange and impregnation methods which were characterized by FT-IF, XRF, XRD and TGA techniques. They were used as catalyst for conversion of ethanol and aqueous ethanol to light olefins. Various parameters influencing reaction such as temperature, addition of water into feed, method of metal loading, addition of diluent (alumina) and amount of catalyst were studies. It was found that at 350 ํC, 1 h, 10% EtOH, WHSV 1 h[superscript -1] and catalyst weight of 1 g, all DM/metal catalysts produced mainly ethylene. At low temperature (350 ํC) they showed higher selectivity to ethylene than at high temperature (550 ํC). When diluting ethanol with water to make 10% EtOH, it gave higher selectivity to ethylene. Both seem to give similar product distribution. Among DM/mixed metal catalysts tested, DM/Ag-Zn which prepared by impregnation method gave the highest selectivity to ethylene (98.0%). All DM/mixed metals (DM/Ag-Zn, DM/Mn-Zn, DM/Co-Zn and DM/Fe-Zn) showed a higher ethylene selectivity than DM/single metal (DM/Zn, MD/Rh, DM/Co, MD/Mn, DM/Cu, DM/Fe, DM/Ag and DM/Ni). Amount of catalyst can be reduced by diluting it with alumina. It was found that selectivity to ethylene was slightly decreased. For DM/1%Ni, it showed higher selectivity to ethane due to its hydrogenation ability. Increasing amount of catalysts increased selectivity to methane. The DM/metal catalysts investigated in this work show comparable activity to ZSM-5. In addition, it was shown that the catalysts can be reused