Multistage process for oxygenate conversion to hydrocarbons

A process for increasing the yield of liquid hydrocarbons from a C.sub.1 -C.sub.4 aliphatic oxygenate feestock comprising:

• contacting the feedstock under oxygenate conversion conditions in a primary fluidized bed reaction system with a crystalline medium pore shape selective zeolite catalyst;
• withdrawing an effluent comprising ethene and C.sub.3.sup.+ olefins;
• separating the effluent into a primary bottoms stream comprising C.sub.3 + olefins and a primary overhead stream comprising ethene;
• and
• contacting the primary overhead stream comprising ethene under high severity oligomerization conditions in a secondary fluidized bed reaction system with a crystalline medium pore shape selective zeolite catalyst.

A process for integrating catalyst flow in a multi-stage process comprising:

• maintaining a primary fluidized bed reactor stage at oxygenate conversion conditions, the reactor containing solid catalyst particles comprising medium pore shape selective crystalline siliceous zeolite;
• maintaining a secondary fluidized bed reactor stage at olefins oligomerization conditions, the reactor containing solid catalyst particles comprising medium pore shape selective crystalline aluminosilicate, said reactor being operatively connected to the primary reactor stage;
• withdrawing from the secondary fluidized bed reactor stage at least a portion of partially deactivated solid catalyst particles;
• and
• adding the partially deactivated solid catalyst particles to the primary fluidized bed reactor stage.

A process for preparing a feedstock for a fixed bed olefins conversion to gasoline and distillate reactor comprising:

• maintaining a reaction system comprising a lower section operatively connected to an upper section, the lower section comprising a secondary fluidized bed containing catalyst particles comprising shape selective medium pore crystalline metallosilicate catalyst and the upper section comprising a primary fluidized bed containing catalyst particles comprising shape selective medium pore crystalline metallosilicate catalyst;
• contacting a vapor stream comprising ethene with fluidized catalyst particles in the lower section to obtain an effluent comprising unreacted ethene and heavier hydrocarbons;
• withdrawing the effluent from the lower section;
• adding a stream comprising a C.sub.1 -C.sub.4 oxygenate or mixtures thereof to the upper section;
• and
• adding the lower section effluent with fluidized catalyst particles to the upper section to produce oligomerizable C.sub.3 + olefins

A continuous multistage fluidized bed catalytic process for converting a C.sub.1 -C.sub.4 aliphatic oxygenate feedstock to liquid hydrocarbon products comprising:

• maintaining a primary fluidized bed of finely divided acid medium pore zeolite catalyst particles in steady state equilibrium fluidized condition under oxygenate conversion reaction conditions, wherein the average catalyst particle acid value is maintained at a first predetermined value to optimize conversion of oxygenate feedstock to lower olefins comprising ethylene and C.sub.3 + olefins;
• contacting a C.sub.1 -C.sub.4 aliphatic oxygenate feedstock with acid zeolite catalyst particles in the primary fluidized bed to produce a lower olefin effluent;
• withdrawing the lower olefin effluent and separating the effluent to obtain a first effluent fraction rich in ethylene and a second effluent fraction rich in C.sub.3 + olefins;
• maintaining a secondary fluidized bed of finely divided acid medium pore zeolite catalyst particles in steady state equilibrium fluidized condition under reaction severity conditions sufficient to convert a major amount of ethylene, wherein the average catalyst particle acid value is maintained at a second predetermined acid value higher than said first value by addition of fresh acid medium pore zeolite catalyst particles to optimize conversion of ethylene to C.sub.5 + hydrocarbons;
• contacting the first effluent fraction rich in ethylene with acid zeolite catalyst particles in the secondary fluidized bed to obtain a C.sub.5 + hydrocarbon effluent;
• withdrawing acid catalyst particles from the secondary fluidized bed;
• adding a first portion of withdrawn secondary fluidized bed particles to the primary fluidized bed;
• adding a second portion of withdrawn secondary fluidized bed particles to a catalyst regeneration zone;
• withdrawing deactivated acid catalyst particles from the primary fluidized bed to maintain equilibrium conditions therein;
• adding withdrawn primary fluidized bed particles to the catalyst regeneration zone;
• oxidatively regenerating catalyst particles from said primary and secondary fluidized beds in the catalyst regeneration zone;
• withdrawing regenerated catalyst from the oxidative regeneration zone;
• and
• adding regenerated catalyst to at least the secondary fluidized bed.