Integrated etherification and oxygenates to gasoline process

Claim 2

An integrated once through process for the production of ether-rich liquid fuels, comprising; (a) reacting a fresh mixture of excess methanol in a hydrocarbon feedstock containing C 4 + isoalkenes in the presence of acidic etherification catalyst under etherification conditions whereby an etherification effluent stream containing methyl tertiary alkyl ethers is produced; (b) separating said etherification effluent stream to provide a first stream comprising ether-rich gasoline and a second stream comprising unreacted methanol and olefinic hydrocarbons; and (c) contacting said second stream with an acidic metallosilicate catalyst under olefinic and oxygenates conversion conditions at elevated temperature whereby C 6 + gasoline is produced.

Claim 3

The process of claim 1 comprising the further step of mixing step (b) second stream with an auxiliary feedstock comprising C 2 -C 5 alkenes before contacting with the acid metallosilicate catalyst in step (c).

Claim 4

The process of claim 1 wherein said step (b) second stream comprises an azeotropic mixture of lower alkyl alcohol and olefinic hydrocarbons and said first stream comprises C 5 + ether-rich gasoline.

Claim 5

The process of claim 2 wherein said C 2 -C 5 alkene auxiliary feedstock and step (a) hydrocarbon feedstock contain light inert components whereby the exothermic temperature rise of step (c) conversion conditions is diluted.

Claim 6

The process of claim 1 wherein the etherification conditions comprise up to 100% stoichiometric excess of said methanol over C 4 + isoalkenes whereby the etherification reaction equilibrium is shifted substantially toward the formation of C 5 + ethers.

Claim 7

The process of claim 5 wherein said stoichiometric excess of lower alkyl alcohol is about 50 percent.

Claim 8

The process of claim 1 wherein said methyl tertiary alkyl ethers comprise MTBE and TAME.

Claim 9

The process of claim 1 wherein said metallosilicate catalyst comprises a crystalline, medium pore, acid aluminosilicate zeolite-type catalyst.

Claim 10

The process of claim 1 wherein step (b) first stream comprises C 5 + ether-rich gasoline having high motor octane and research octane values.

Claim 11

An integrated continuous process for producing tertiary alkyl ethers and gasoline range hydrocarbons comprising the steps of: (a) contacting a first liquid reaction mixture in a single pass with an acid etherification catalyst under etherification conditions, said first reaction mixture comprising C 4 -C 9 hydrocarbons containing C 4 -C 7 isoalkene components and C 6 + gasoline range non-etherifiable aliphatic components, and a lower alkyl alcohol reactant, said alcohol being present in more than 30% stoichiometric excess of the isoalkene component; (b) recovering an etherification reaction effluent containing C 5 + tertiary alkyl ether, gasoline range hydrocarbons, unreacted alcohol and light olefinic hydrocarbons; (c) distilling the etherification reaction effluent to provide a first product stream comprising a liquid mixture of C 5 + ether and gasoline range hydrocarbons, and a second volatile low molecular weight reaction mixture comprising unreacted alcohol and light olefinic hydrocarbons; and (d) contacting the second reaction mixture with an acid medium pore metallosilicate zeolite catalyst at elevated temperature to convert the alcohol and light olefinic hydrocarbons to a second product stream having average molecular weight greater than the second reaction mixture.

Claim 12

An integrated continuous process for producing tertiary alkyl ethers and gasoline range hydrocarbons comprising the steps of: (a) contacting a first liquid reaction mixture in a single pass with an acid etherification catalyst under etherification conditions, said first reaction mixture comprising C 4 -C 9 hydrocarbons containing C 4 -C 7 isoalkene components and C 6 + gasoline range non-etherifiable aliphatic components, and a lower alkyl alcohol reactant, said alcohol being present in more than 30% stoichiometric excess of the isoalkene component; (b) recovering an etherification reaction effluent containing C 5 + tertiary alkyl ether, gasoline range hydrocarbons, unreacted alcohol and light olefinic hydrocarbons; (c) distilling the etherification reaction effluent to provide a first product stream comprising a liquid mixture of C 5 + ether and gasoline range hydrocarbons, and a second volatile low molecular weight reaction mixture comprising unreacted alcohol and light olefinic hydrocarbons; and (d) contacting the second reaction mixture with an acid medium pore metallosilicate zeolite catalyst at elevated temperature to convert the alcohol and light olefinic hydrocarbons to a second product stream having average molecular weight greater than the second reaction mixture.

Claim 13

The process of claim 10 wherein the first reaction mixture consists essentially of a mixture of butenes rich in iso-olefins, light olefinic naptha and methanol, and methanol being present in at least 1/3 stoichiometric excess of the isoalkene components; wherein the second reaction mixture comprises unreacted methanol and butylenes; and wherein the zeolite catalyst comprises aluminosilicate having the structure of ZSM-5.

Claim 14

The process of claim 11 wherein the second reaction mixture is supplemented with an added C 2 -C 5 olefin stream.

Claim 15

The process of claim 11 wherein the first product stream comprises MTBE, TAME and unreacted naphtha.

Claim 16

An integrated, once through reactor system for iso-olefin etherification to MTBE and TAME and conversion of oxygenates and olefins to gasoline, comprising in combination: first reactor means for containing etherification catalyst under etherification conditions; first fluid handling means for passing lower alkyl alcohol to said first reactor means; second fluid handling means for passing C 4 + hydrocarbons to said first reactor means; separator means operatively connected to said first reactor means for separating effluent therefrom; second reactor means for conversion of oxygenates and olefins operatively connected to said separator to receive unreacted and hydrocarbon overhead vapor therefrom; third fluid handling means for optionally passing auxiliary feedstream to said second reactor.

Claim 17

An integrated, once through reactor system for iso-olefin etherification to MTBE and TAME and conversion of oxygenates and olefins to gasoline, comprising in combination: first reactor means for containing etherification catalyst under etherification conditions; first fluid handling means for passing lower alkyl alcohol to said first reactor means; second fluid handling means for passing C 4 + hydrocarbons to said first reactor means; separator means operatively connected to said first reactor means for separating effluent therefrom; second reactor means for conversion of oxygenates and olefins operatively connected to said separator to receive unreacted and hydrocarbon overhead vapor therefrom; third fluid handling means for optionally passing auxiliary feedstream to said second reactor.