Production of fuel components
AssigneeFortum Oil Oy
InventorsMatti Koskinen, Petri Lindqvist, Harri Jarvelin
Life of this patent
Estimating the term…
Abstract
A process for producing alkyl ethers, by etherification of tertiary C4-7 olefins with an alkanol, comprising carrying out the etherification in reactor train system primarily configured for dimerization of isoolefins. In the etherification, the ratio of alkanol-to-olefin is 0.5 to 2, calculated from the amount of tertiary C4-7 olefins of the fresh feedstock. The invention makes it possible to change the product of the process from dimer to ether and vice versa merely by adjusting specific flows within the process. The present kind of process is therefore readily adaptable to fluctuating market demands for various gasoline octane-boosters (isooctane or MTBE).
Claims20
A process for producing gasoline fuel components from an olefinic feed in a reactor train system including
- at least one primary reaction zone with an olefin inlet and an effluent outlet,
- at least one primary distillation zone connected to the effluent outlet of the primary reaction zone, said distillation zone having an overhead draw,
- at least one secondary reaction zone connected to the overhead draw of the distillation zone and having an effluent outlet, and
- at least one secondary distillation zone connected to the effluent outlet of the secondary reaction zone, said process being capable of a dimerization step for producing dimers during a first period of time and an etherifiction step for producing alkyl ether during a second period of time in the same reactor train system.
A process for etherifying isoolefins, comprising
- feeding a fresh olefinic hydrocarbon feedstock, containing at least one isoolefin selected from the group of tertiary C4-7 olefins, to a reactor train system including
- at least one primary reaction zone,
- at least one primary distillation zone connected to an effluent outlet of the primary reaction zone,
- at least one secondary reaction zone connected to an overhead draw of the distillation zone, and
- at least one secondary distillation zone connected to an effluent outlet of the secondary reaction zone,
- contacting said olefinic hydrocarbon feedstock in the primary reaction zone with an acidic catalyst in the presence of alkanol, the ratio of alkanol-to-olefin being 0.5 to 2, calculated from the amount of tertiary C4-7 olefins of the fresh feedstock, at conditions in which at least a part of the olefins are etherified to produce a first reaction mixture containing etherified isoolefins, unreacted olefins and alkanol,
- conducting an effluent comprising said first reaction mixture from said primary reaction zone to said primary distillation zone, where at least a part of the etherified isoolefins is separated from said effluent,
- withdrawing at least one flow comprising unreacted olefins and alkanol from the side of the primary distillation zone and circulating said flow from said distillation zone back to the primary reaction zone,
- conducting the overhead of the primary distillation zone, comprising unreacted isoolefins, to the secondary reaction zone,
- contacting said unreacted isoolefins in the secondary reaction zone with an acidic catalyst in the presence of an alkanol at conditions in which at least a part of the isoolefins are etherified to produce a second reaction mixture containing etherified isoolefins,
- conducting an effluent comprising said second reaction mixture from the second reaction zone to the secondary distillation zone, where at leat a part of the etherified isoolefins are separated from said effluent, and
- recovering etherified isoolefins.
A method of converting a dimerization process of isoolefins carried out in the presence of an oxygenate to an etherification process of isoolefins, which process is performed in a reaction train comprising a primary reaction zone and a first distillation zone connected to the outlet of the primary reaction zone, a sidedraw being circulated from the distillation zone to the reaction zone to recycle unreacted olefins and oxygenate, comprising increasing the molar proportion of the alkanol to olefin in the first reaction zone to more than 0.7 to favour the formation of alkyl ether instead of dimer and by conducting the overhead of the first distillation zone to a second reaction zone, wherein the unreacted components of the feedstock, including alkanol and olefinic hydrocarbons, are subjected to a second etherification reaction.
Dependencies are inferred from the claim text.