Process for preparing alkyl tert-alkyl ethers

Claim 2

A process for producing an alkyl tert-alkyl ether comprising: (a) reacting an olefin having a double bond at a tertiary carbon atom and a primary alcohol in the presence of a catalyst under conditions sufficient to effect a condensation reaction whereby a mixture of the alkyl tert-alkyl ether, unreacted alcohol and unreacted olefin is produced; (b) introducing the mixture into a first column of a plurality of adsorption columns containing an adsorbent each of the plurality of adsorption columns which undergoes the sequential steps of: (1) passing the mixture through the first adsorption column containing the adsorbent and selectively adsorbing the unreacted primary alcohol while discharging a stream comprising a mixture of the alkyl tert-alkyl ether and the unreacted olefin; (2) rinsing the adsorption column in a direction co-current to the direction of feed flow of step (1) with the primary alcohol whereby a mixture of residual alkyl tert-alkyl ether and unreacted olefin is displaced and withdrawn from the adsorption column; and (3) rinsing the adsorption column with the olefin and withdrawing a mixture of unreacted primary alcohol and unreacted olefin from the adsorption column; (c) recycling mixture of unreacted primary alcohol and unreacted olefin from step (b:3) by combining the mixture with the feedstream recited in step (a); and (d) separating the stream from step (b:1) by distillation to produce unreacted olefin product and the alkyl tert-ether.

Claim 3

The process according to claim 1 wherein the alcohol is selected from primary alcohols having from 1 to about 8 carbon atoms.

Claim 4

The process according to claim 2 wherein the primary alcohol is selected from methanol, ethanol, propanol, butanol and pentanol.

Claim 5

The process according to claim 1 wherein the olefin has from 4 to about 10 carbon atoms.

Claim 6

The process according to claim 4 wherein the olefin is selected from isobutylene and isopentene.

Claim 7

The process according to claim 1 wherein the liquid desorbent is a C 4 to C 5 olefin.

Claim 8

The process according to claim 1 wherein the alcohol is methanol and the olefin is isopentene.

Claim 9

The process according to claim 1 wherein the alcohol is ethanol and the olefin is isobutylene.

Claim 10

The process according to claim 1 wherein the adsorbent is a 4A zeolite.

Claim 11

The process according to claim 1 wherein the adsorber feedstock is compressed to a pressure ranging from about 10 to 150 psig.

Claim 12

A process for producing methyl tert-butyl ether comprising: (a) reacting a feedstream comprising isobutene and methanol in the presence of a catalyst under conditions sufficient to effect a condensation reaction whereby a mixture of the methyl tert-butyl ether, unreacted isobutene and unreacted methanol is produced; (b) introducing the mixture into a first column of a plurality of adsorption columns containing 4A zeolite adsorbent, each of the plurality of adsorption columns which undergoes the sequential steps of: (1) passing the mixture through the first adsorption column containing the 4A zeolite adsorbent and selectively adsorbing the unreacted methanol while discharging an enriched steam comprising a mixture of the methyl tert-butyl ether and the unreacted isobutene; (2) rinsing the adsorption column with methanol in a direction co-current to the direction of feed flow of step (b) (1) whereby a mixture of residual methyl tert-butyl ether and unreacted isobutene is displaced and withdrawn from the adsorption column; and (3) rinsing the adsorption column with isobutene and withdrawing a mixture of unreacted methanol and unreacted isobutene from the adsorption column; (c) recycling the mixture of unreacted methanol and unreacted isobutene recited in step (b:3) by combining the mixture with the feedstream recited in step (a); and (d) separating the enriched stream of step (b:1) comprising the mixture of methyl tert-butyl ether and unreacted isobutene by distillation to produce an isobutene product and the alkyl tert-ether.

Claim 13

A process for producing methyl tert-butyl ether comprising: (a) reacting a feedstream comprising isobutene and methanol in the presence of a catalyst under conditions sufficient to effect a condensation reaction whereby a mixture of the methyl tert-butyl ether, unreacted isobutene and unreacted methanol is produced; (b) introducing the mixture into a first column of a plurality of adsorption columns containing 4A zeolite adsorbent, each of the plurality of adsorption columns which undergoes the sequential steps of: (1) passing the mixture through the first adsorption column containing the 4A zeolite adsorbent and selectively adsorbing the unreacted methanol while discharging an enriched steam comprising a mixture of the methyl tert-butyl ether and the unreacted isobutene; (2) rinsing the adsorption column with methanol in a direction co-current to the direction of feed flow of step (b) (1) whereby a mixture of residual methyl tert-butyl ether and unreacted isobutene is displaced and withdrawn from the adsorption column; and (3) rinsing the adsorption column with isobutene and withdrawing a mixture of unreacted methanol and unreacted isobutene from the adsorption column; (c) recycling the mixture of unreacted methanol and unreacted isobutene recited in step (b:3) by combining the mixture with the feedstream recited in step (a); and (d) separating the enriched stream of step (b:1) comprising the mixture of methyl tert-butyl ether and unreacted isobutene by distillation to produce an isobutene product and the alkyl tert-ether.