Method for producing methyl tert-butyl ether and fuel composition containing the same

Claim 1

A method for preparing a fuel composition for internal combustion engines comprising the steps of: (A) allowing isobutylene and methyl alcohol to react with each other by continuously passing an isobutylene-containing hydrocarbon mixture and methyl alcohol through a fixed bed filled with strongly acidic cation-exchange resin particles of 0.2 to 10 mm in mean grain diameter, at a temperature of 0° to 100° C., a pressure of 1 to 50 atmospheres and a liquid space velocity of 0.1 to 50 (1/hr), the molar ratio of isobutylene in said mixture to said methyl alcohol being in the range of 1:0.6 to 1:1.4; (B) dividing the effluent from the reaction of step (A) into first and second parts in which the weight ratio of said first part to said second part is in the range from 1:3 to 1:15; (C) recycling said second part to the fixed bed in step (A); (D) passing said first part through a fixed bed filled with a water-insoluble, solid, particulate acid-neutralizing agent of 0.1 to 10 mm in mean grain diameter, at 0° to 100° C.; (E) introducing the neutralized first part into a flashing tower to flash-remove unreacted hydrocarbon and to recover a methyl tert-butyl ether containing mixture from the bottom of said flashing tower; and, (F) mixing 2 to 30% by volume of said methyl tert-butyl ether containing mixture with internal combustion fuel.

Claim 2

A method for preparing a fuel composition for internal combustion engines comprising the steps of: (A) allowing isobutylene and methyl alcohol to react with each other by continuously passing an isobutylene-containing hydrocarbon mixture and methyl alcohol through a fixed bed filled with strongly acidic cation-exchange resin particles of 0.2 to 10 mm in mean grain diameter, at a temperature of 0° to 100° C., a pressure of 1 to 50 atmospheres and a liquid space velocity of 0.1 to 50 (1/hr), the molar ratio of isobutylene in said mixture to said methyl alcohol being in the range of 1:0.6 to 1:1.4; (B) dividing the effluent from the reaction of step (A) into first and second parts in which the weight ratio of said first part to said second part is in the range from 1:3 to 1:15; (C) recycling said second part to the fixed bed in step (A); (D) passing said first part through a fixed bed filled with a water-insoluble, solid, particulate acid-neutralizing agent of 0.1 to 10 mm in mean grain diameter, at 0° to 100° C.; (E) introducing the neutralized first part into a flashing tower to flash-remove unreacted hydrocarbon and to recover a methyl tert-butyl ether containing mixture from the bottom of said flashing tower; and, (F) mixing 2 to 30% by volume of said methyl tert-butyl ether containing mixture with internal combustion fuel.

Claim 3

A method for preparing a fuel composition for internal combustion engines comprising the steps of: (A) allowing isobutylene and methyl alcohol to react with each other by continuously passing an isobutylene-containing hydrocarbon mixture and methyl alcohol through a fixed bed filled with strongly acidic cation-exchange resin particles of 0.2 to 10 mm in mean grain diameter, at a temperature of 0° to 100° C., a pressure of 1 to 50 atmospheres and a liquid space velocity of 0.1 to 50 (1/hr), the molar ratio of isobutylene in said mixture to said methyl alcohol being in the range of 1:0.6 to 1:1.4; (B) dividing the effluent from the reaction step (A) into first and second parts in which the weight ratio of said first part to said second part is in the range from 1:3 to 1:15; (C) recycling said second part to the fixed bed in step (A); (D) passing said first part through a fixed bed filled with a water-insoluble, solid, particulate acid-neutralizing agent of 0.1 to 10 mm in mean grain diameter, at 0° to 10° C.; (E) introducing the neutralized first part into a flashing tower to flash-remove unreacted hydrocarbon and to recover a methyl tert-butyl ether containing mixture from the bottom of said flashing tower; (F) distilling said methyl tert-butyl ether-containing mixture with a multistage distillation column to remove an azeotropic mixture of methyl tert-butyl ether and methyl alcohol from the top of said distillation column and to recycle said azeotropic mixture for reuse in step (A), thereby obtaining methyl tert-butyl ether from the bottom of said distillation column; and (G) mixing 2 to 30% by volume of said methyl tert-butyl ether containing mixture with internal combustion fuel.

Claim 4

A method for preparing a fuel composition for internal combustion engines comprising the steps of: (A) allowing isobutylene and methyl alcohol to react with each other by continuously passing an isobutylene-containing hydrocarbon mixture and methyl alcohol through a fixed bed filled with strongly acidic cation-exchange resin particles of 0.2 to 10 mm in mean grain diameter, at a temperature of 0° to 100° C., a pressure of 1 to 50 atmospheres and a liquid space velocity of 0.1 to 50 (1/hr), the molar ratio of isobutylene in said mixture to said methyl alcohol being in the range of 1:0.6 to 1:1.4; (B) dividing the effluent from the reaction step (A) into first and second parts in which the weight ratio of said first part to said second part is in the range from 1:3 to 1:15; (C) recycling said second part to the fixed bed in step (A); (D) passing said first part through a fixed bed filled with a water-insoluble, solid, particulate acid-neutralizing agent of 0.1 to 10 mm in mean grain diameter, at 0° to 10° C.; (E) introducing the neutralized first part into a flashing tower to flash-remove unreacted hydrocarbon and to recover a methyl tert-butyl ether containing mixture from the bottom of said flashing tower; (F) distilling said methyl tert-butyl ether-containing mixture with a multistage distillation column to remove an azeotropic mixture of methyl tert-butyl ether and methyl alcohol from the top of said distillation column and to recycle said azeotropic mixture for reuse in step (A), thereby obtaining methyl tert-butyl ether from the bottom of said distillation column; and (G) mixing 2 to 30% by volume of said methyl tert-butyl ether containing mixture with internal combustion fuel.

Claim 5

The method for preparing a fuel composition as defined in claims 1 or 2, wherein said internal combustion fuel is at least one member selected from the group consisting of alcohols having 1 to 4 carbon atoms, ethers having 4 to 8 carbon atoms and hydrocarbons boiling in the gasoline range.