Patent ID: 7732650

Claim:
A process for producing light olefins from an oxygenate-containing feedstock including at least a quantity of methanol, the process comprising: contacting the oxygenate-containing feedstock in an oxygenate conversion reactor with an oxygenate conversion catalyst and at reaction conditions effective to convert the oxygenate-containing feedstock to an oxygenate conversion effluent stream comprising light olefins and C4+ hydrocarbons, wherein the light olefins comprise ethylene and the C4+ hydrocarbons comprise a quantity of butenes including a quantity of 1-butenes and a quantity of isobutene; treating the oxygenate conversion effluent stream and forming a first process stream comprising at least a portion of the butenes including a quantity of isobutenes and a quantity of 1-butenes from the oxygenate conversion effluent stream; converting at least a portion of quantity of isobutenes from the first process stream in an isobutene conversion zone to form a second process stream including a quantity of 1-butenes and a third process stream including a conversion product; isomerizing at least a portion of the 1-butenes from the second process stream in an isomerization zone to form an isomerized stream comprising a quantity of 2-butenes; contacting at least a portion of the quantity of 2-butenes from the isomerized stream with ethylene in a metathesis zone comprising a reaction distillation column containing a fixed bed of the metathesis catalyst and wherein upon contact with the metathesis catalyst at least a portion of the quantity of 2-butenes from the isomerized stream is metathesized with ethylene in the fixed bed to produce the metathesis effluent stream comprising propylene and a metathesis bottoms stream; recycling at least a portion of the metathesis bottoms stream to the oxygenate conversion zone; and recovering propylene from the metathesis effluent stream.