Synergistic effects of lanthanum and magnesium additive to H-ZSM-5 for ethanol conversion to propylene

Abstract

The direct conversion reaction of ethanol to propylene was investigated using lanthanum - and magnesium-co-modified H-ZSM-5 catalyst with Si/Al2 ratio of 80. Propylene selectivity of 30 % was obtained at 0.1 MPa, 550 °C. The ethylene and propylene selectivities were 44 % and 27 %, respectively, even after 50.2 h. The rapid increase in ethylene formation was also depressed, possibly because the catalyst modifications prevented reduction of performance by dealumination and coking. The deactivation of lanthanum - and magnesium-co-modified H-ZSM-5 with Si/Al2 ratio of 80 was slower than that of catalyst with Si/Al2 ratio of 150. Because more acid sites are left even if dealumination proceeds, higher effects on the propylene production and ethylene restraint might be maintained with Si/Al2 ratio of 80.