Multistage process for converting oxygenates to hydrocarbons

Claim 2

A continuous multi-stage catalytic system for converting oxygenated feedstock to liquid hydrocarbons comprising primary stage catalytic means containing dehydration catalyst for converting oxygenate to olefinic and aromatic hydrocarbons; interstage separation means for recovering water from the primary stage effluent stream; means for pressurizing and heating primary stage hydrocarbon effluent stream rich in C 3 + components; secondary stage catalytic oligomerization reactor means containing medium pore shape selective zeolite oligomerization catalyst for converting said olefinic hydrocarbons in the primary stage effluent stream to liquid hydrocarbons comprising a major amount of distillate in the presence of aromatic hydrocarbons; fractionation means for separating secondary stage effluent into a light hydrocarbon stream rich in C 3 -C 4 aliphatic hydrocarbons, a C 5 + gasoline stream and distillate range stream; means for recycling at least a portion of the C 5 + gasoline stream to the secondary stage for combining with substantially the entire primary stage C 3 + hydrocarbon stream; and hydrotreating reactor means for catalytically hydrogenating olefinic and aromatic components of the distillate stream to provide a stabilized distillate product.

Claim 3

An integrated continuous system for converting oxygenated organic feedstock to liquid hydrocarbons comprising: first reactor means for contacting feedstock with at least one primary stage acidic zeolite conversion catalyst at elevated temperature and moderate pressure to convert at least a portion of the feedstock to hydrocarbons containing a major fraction of C 2 -C 14 olefins and a minor fraction containing C 5 + heavy hydrocarbons; means for cooling and separating reactor effluent from the primary stage to provide an aqueous liquid stream, a heavy hydrocarbon liquid stream and a light hydrocarbon vapor stream rich in C 2 -C 4 olefins; means for pressurizing and heating at least a portion of the olefinic light hydrocarbon stream and substantially all of the heavy hydrocarbon liquid stream to form a secondary stage olefinic feedstream; second reactor means for contacting the olefinic feedstream in a secondary stage with oligomerization catalyst comprising medium-pore shape selective acidic zeolite at substantially increased pressure and moderate temperature to convert olefins to a heavier liquid hydrocarbon effluent stream comprising olefinic gasoline and distillate range liquids; separation means for fractionating the liquid hydrocarbon effluent stream from the secondary stage to obtain an olefinic distillate stream, olefinic gasoline stream and lighter hydrocarbon stream; means for recycling at least a portion of the olefinic gasoline stream to the second reactor means; and

Claim 4

An integrated continuous system for converting oxygenated organic feedstock to liquid hydrocarbons comprising: first reactor means for contacting feedstock with at least one primary stage acidic zeolite conversion catalyst at elevated temperature and moderate pressure to convert at least a portion of the feedstock to hydrocarbons containing a major fraction of C 2 -C 14 olefins and a minor fraction containing C 5 + heavy hydrocarbons; means for cooling and separating reactor effluent from the primary stage to provide an aqueous liquid stream, a heavy hydrocarbon liquid stream and a light hydrocarbon vapor stream rich in C 2 -C 4 olefins; means for pressurizing and heating at least a portion of the olefinic light hydrocarbon stream and substantially all of the heavy hydrocarbon liquid stream to form a secondary stage olefinic feedstream; second reactor means for contacting the olefinic feedstream in a secondary stage with oligomerization catalyst comprising medium-pore shape selective acidic zeolite at substantially increased pressure and moderate temperature to convert olefins to a heavier liquid hydrocarbon effluent stream comprising olefinic gasoline and distillate range liquids; separation means for fractionating the liquid hydrocarbon effluent stream from the secondary stage to obtain an olefinic distillate stream, olefinic gasoline stream and lighter hydrocarbon stream; means for recycling at least a portion of the olefinic gasoline stream to the second reactor means; and

Claim 5

third reactor means for catalytically hydrogenating the olefinic distillate to provide a stabilized distillate product.

Claim 6

third reactor means for catalytically hydrogenating the olefinic distillate to provide a stabilized distillate product.

Claim 7

The system of claim 2 further comprising means for fractionating hydrocarbon dehydration effluent to recover an ethene-rich gas stream and an olefinic stream rich in C 3 + olefins.

Claim 8

The system of claim 2 wherein the oligomerization catalyst comprises ZSM-5 type zeolite.

Claim 9

The system of claim 4 wherein the primary stage and secondary stage catalysts consist essentially of HZSM-5.

Claim 10

The system of claim 2 further comprising means for cooling the primary stage reactor effluent under process pressure; means for compressing light hydrocarbon vapors to form a second liquid hydrocarbon stream to be fed under process pressure to the secondary stage.

Claim 11

The system of claim 2 further comprising means for compressing and fractionating light hydrocarbon vapor separated from the primary stage reactor effluent.

Claim 12

The system of claim 2 comprising a fixed bed primary stage having means for maintaining a pressure range of about 170 to 800 kPa and weight hourly space velocity range of about 0.5 to 1.0, whereby ethene production is optimized.

Claim 13

The system of claim 2 comprising means for recovering and recycling primary stage water diluent for cofeeding with feedstock in a molar ratio of about 0.1:1 to 5:1.

Claim 14

Apparatus for converting a lower aliphatic alcohol or derivative thereof to liquid hydrocarbon product comprising a primary stage reactor containing zeolite dehydration conversion catalyst and means for maintaining said reactor conditions for producing lower olefins, a minor amount of liquid hydrocarbons and byproduct water; phase separation means for cooling and recovering water, liquid hydrocarbons and light olefinic hydrocarbon vapor from the primary stage effluent; pump means for pressurizing and passing substantially all of said liquid hydrocarbons from the primary stage to a secondary stage oligomerization reactor containing a shape selective medium pore acid zeolite catalyst; compressor means for pressurizing and passing at least a portion of light olefinic hydrocarbons from the phase separation means to the secondary stage reactor; means for heating said pressurized stream to second stage oligomerization temperature under conditions for producing a major amount of olefinic distillate range hydrocarbons; means for fractionating second stage effluent to recover gasoline range olefinic liquid, distillate range olefinic liquid and light gas; pump means for recycling at least a portion of the gasoline liquid to the secondary stage reactor, and a final stage hydrotreating reactor containing hydrogenation catalyst for mild hydrotreating of the olefinic distillate to produce a paraffinic distillate product.

Claim 15

Apparatus for converting a lower aliphatic alcohol or derivative thereof to liquid hydrocarbon product comprising a primary stage reactor containing zeolite dehydration conversion catalyst and means for maintaining said reactor conditions for producing lower olefins, a minor amount of liquid hydrocarbons and byproduct water; phase separation means for cooling and recovering water, liquid hydrocarbons and light olefinic hydrocarbon vapor from the primary stage effluent; pump means for pressurizing and passing substantially all of said liquid hydrocarbons from the primary stage to a secondary stage oligomerization reactor containing a shape selective medium pore acid zeolite catalyst; compressor means for pressurizing and passing at least a portion of light olefinic hydrocarbons from the phase separation means to the secondary stage reactor; means for heating said pressurized stream to second stage oligomerization temperature under conditions for producing a major amount of olefinic distillate range hydrocarbons; means for fractionating second stage effluent to recover gasoline range olefinic liquid, distillate range olefinic liquid and light gas; pump means for recycling at least a portion of the gasoline liquid to the secondary stage reactor, and a final stage hydrotreating reactor containing hydrogenation catalyst for mild hydrotreating of the olefinic distillate to produce a paraffinic distillate product.