Method of separating ethyl tertiobutyl ether from mixtures with ethanol

Claim 1

A method of separating ethyl tertiobutyl ether from mixtures which it forms with ethanol, wherein a charge chiefly comprising ethyl tertiobutyl ether (ETBE) and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; the charge is introduced at a temperature of about 50° to 80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60° to 95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ethyl tertiobutyl ether and a minor proportion of ethanol; a liquid reflux of a composition close to that of a ternary azeotrope at pressure p1 is produced at the top of the first column at a temperature of about 60° to 70° C., by passing appropriate proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60° to 70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure pl by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100° to 120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120° to 150° C.; the distillate from the second column is depressurized to pressure p1 then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ethyl tertiobutyl ether from the bottom of the second column.

Claim 2

A method of separating ethyl tertiobutyl ether from mixtures which it forms with ethanol, wherein a charge chiefly comprising ethyl tertiobutyl ether (ETBE) and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; the charge is introduced at a temperature of about 50° to 80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60° to 95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ethyl tertiobutyl ether and a minor proportion of ethanol; a liquid reflux of a composition close to that of a ternary azeotrope at pressure p1 is produced at the top of the first column at a temperature of about 60° to 70° C., by passing appropriate proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60° to 70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure pl by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100° to 120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120° to 150° C.; the distillate from the second column is depressurized to pressure p1 then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ethyl tertiobutyl ether from the bottom of the second column.

Claim 9

A method of preparing ethyl tertiobutyl ether (ETBE) through etherification with ethanol of isobutene contained in a C 4 cut from steam cracking, catalytic cracking or dehydrogenation of isobutane, wherein, in a reaction zone A, ethanol and the C 4 cut are put into contact under reaction conditions; the product discharged from the reaction zone A, chiefly containing ETBE, ethanol, C 4 -hydrocarbons other than isobutene, and non-reacted isobutene, is passed into a distillation zone B, where the C 4 -hydrocarbons including non-reacted isobutene are separated at the top and a mixture of ETBE and ethanol at the bottom; and said mixture is passed into a separating zone C; and wherein in said separating zone C, said mixture of ETBE and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; said mixture is introduced at a temperature of about 50°-80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60°-95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ETBE and a minor proportion of ethanol; a liquid reflux of a composition of substantially that of a ternary azeotrope of ETBE, ethanol, and water at pressure p1 is produced at the top of the first column at a temperature of about 60°-70° C., by passing sufficient proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60°-70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure p1 by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100°-120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120°-150° C.; the distillate from the second column is depressurized to pressure p1, then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column.

Claim 10

A method of preparing ethyl tertiobutyl ether (ETBE) through etherification with ethanol of isobutene contained in a C 4 cut from steam cracking, catalytic cracking or dehydrogenation of isobutane, wherein, in a reaction zone A, ethanol and the C 4 cut are put into contact under reaction conditions; the product discharged from the reaction zone A, chiefly containing ETBE, ethanol, C 4 -hydrocarbons other than isobutene, and non-reacted isobutene, is passed into a distillation zone B, where the C 4 -hydrocarbons including non-reacted isobutene are separated at the top and a mixture of ETBE and ethanol at the bottom; and said mixture is passed into a separating zone C; and wherein in said separating zone C, said mixture of ETBE and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; said mixture is introduced at a temperature of about 50°-80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60°-95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ETBE and a minor proportion of ethanol; a liquid reflux of a composition of substantially that of a ternary azeotrope of ETBE, ethanol, and water at pressure p1 is produced at the top of the first column at a temperature of about 60°-70° C., by passing sufficient proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60°-70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure p1 by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100°-120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120°-150° C.; the distillate from the second column is depressurized to pressure p1, then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column.

Claim 15

A method of preparing ethyl tertiobutyl ether (ETBE) through etherification with ethanol of isobutene contained in a C 4 cut from steam cracking, catalystic cracking or dehydrogenation of isobutane, wherein, in a reaction zone A, ethanol and the C 4 cut are put into contact under reaction conditions; the product discharged from the reaction zone A, chiefly containing ETBE, ethanol, C 4 -hydrocarbons other than isobutene, and non-reacted isobutene, is passed into a reactive distillation zone B', passing additional ethanol into said reactive distillation zone B' to remove the non-reacted isobutene, separating the C 4 -hydrocarbons at the top of the reactive distillation zone B', and separating a mixture of ETBE and ethanol at the bottom of the reactive distillation zone B'; and said mixture is passed into a separating zone C; and wherein in said separating zone C, said mixture of ETBE and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; said mixture is introduced at a temperature of about 50°-80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60°-95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ETBE and a minor proportion of ethanol; a liquid reflux of a composition of substantially that of a ternary azeotrope of ETBE, ethanol, and water at pressure p1 is produced at the top of the first column at a temperature of about 60°-70° C., by passing sufficient proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60°-70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure p1 by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100°-120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120°-150° C.; the distillate from the second column is depressurized to pressure p1, then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column.

Claim 16

A method of preparing ethyl tertiobutyl ether (ETBE) through etherification with ethanol of isobutene contained in a C 4 cut from steam cracking, catalystic cracking or dehydrogenation of isobutane, wherein, in a reaction zone A, ethanol and the C 4 cut are put into contact under reaction conditions; the product discharged from the reaction zone A, chiefly containing ETBE, ethanol, C 4 -hydrocarbons other than isobutene, and non-reacted isobutene, is passed into a reactive distillation zone B', passing additional ethanol into said reactive distillation zone B' to remove the non-reacted isobutene, separating the C 4 -hydrocarbons at the top of the reactive distillation zone B', and separating a mixture of ETBE and ethanol at the bottom of the reactive distillation zone B'; and said mixture is passed into a separating zone C; and wherein in said separating zone C, said mixture of ETBE and ethanol is treated continuously in an installation comprising two distillation columns connected overhead to a decanter; said mixture is introduced at a temperature of about 50°-80° C. into the upper part of the first column, which operates at a pressure p1 of 0.05 to 0.2 MPa, said first column being heated to a bottom temperature of about 60°-95° C.; distillate from the first column is mixed with distillate from the second column and the mixture thus formed is condensed; the condensate obtained is decanted into a lower phase with a major proportion of water and a minor proportion of ethanol, and an upper phase with a major proportion of ETBE and a minor proportion of ethanol; a liquid reflux of a composition of substantially that of a ternary azeotrope of ETBE, ethanol, and water at pressure p1 is produced at the top of the first column at a temperature of about 60°-70° C., by passing sufficient proportions of a first stream of upper phase and of a stream of lower phase to the top of the first column at a temperature of about 60°-70° C.; a second stream of upper phase, brought to a pressure p2, which is higher than pressure p1 by a value Δp of 0.4 to 1 MPa, and heated to a temperature of about 100°-120° C., is fed to the upper part of the second column, which operates at pressure p2 and which is heated to a bottom temperature of about 120°-150° C.; the distillate from the second column is depressurized to pressure p1, then mixed with the distillate from the first column; and purified ethanol is collected from the bottom of the first column and purified ETBE from the bottom of the second column.