| 摘要 |
Process of preparing light monoolefins by: (a) activating a hydrogen-exchanged aluminosilicate catalyst having a silica to alumina ratio of less than 12 and, optionally, containing added metal cations, by treating with steam at a temperature of at least 400 DEG C., preferably 450 DEG to 520 DEG C.; (b) contacting the steam-activated catalyst in a reaction zone, at a temperature of about 350 DEG to about 600 DEG C., preferably 450 DEG to 520 DEG C., with a gas stream consisting essentially of dimethyl ether or a mixture of methanol and dimethyl ether, as reactant, and sufficient water such that the mole ratio of water to ether in the reaction zone is at least 0.3; at a pressure of about 0.2 to about 30 atmospheres (about 20 to about 3000 kPa), preferably atmospheric pressure (100 kPa), and at a weight hourly space velocity (WHSV) of greater than about 0.5 h-1, preferably 1 to 150 h-1, to convert at least 85 wt % of the reactant to hydrocarbons comprising at least 50 wt % ethylene and propylene, said 85% conversion being achieved before the contacting has exceeded 1 g of reactant per g of catalyst, preferably before exceeding 0.3 g of reactant per g of catalyst, more preferably before exceeding 0.1 g of reactant per g of catalyst until the catalyst is spent; and (c) regenerating the spent catalyst with a mixture comprising steam and oxygen at a temperature of at least 400 DEG C., preferably 450 DEG to 520 DEG C. |
