Chevron U.s.a. Inc.

Laura C Boudreau

Michael Sean Driver

William L Schinski

Curtis Lee Munson

Daniel Chinn

De Q Vu

Curt Munson

A process and method for separating COfrom a gaseous stream such as natural gas. An ionic liquid comprising an anion having a carboxylate function and an effective amount of water is used as an adsorbent to selectively complex the COyielding a gaseous stream with a greatly reduced COcontent. The ionic liquid can then be readily be regenerated and recycled.

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Methods for separating di-olefins from mono-olefins, and olefins from non-olefins such as paraffins, oxygenates and aromatics; are provided. The methods use metal salts which complex both mono-olefins and di-olefins, but which selectively complex di-olefins in the presence of mono-olefins. The metal salts are dissolved or suspended in ionic liquids, which tend to have virtually no vapor pressure. Preferred salts are Group IB salts, more preferably silver and copper salts. A preferred silver salt is silver tetrafluoroborate. A preferred copper salt is silver CuOTf. Preferred ionic liquids are those which form stable solutions, suspensions or dispersions of the metal salts, which do not dissolve unwanted non-olefins, and which do not isomerize the mono- or di-olefins. The equivalents of the metal salt can be adjusted so that di-olefins are selectively adsorbed from mixtures of mono- and di-olefins. Alternatively, both mono- and di-olefins can be adsorbed, and the mono-olefins selectively desorbed. The latter approach can be preferred when non-olefins are also to be separated. The mono- and di-olefin-containing mixture can be in the gas phase or in the liquid phase. The flow of mono- and di-olefin-containing mixture over/through the ionic liquid can be, for example, co-current, counter-current, or staged in stirred tanks, with countercurrent being preferred.

Separation of dienes from olefins using ionic liquids

Methods for separating olefins from non-olefins, such as paraffins, including cycloparaffins, oxygenates and aromatics, are provided. The methods use metal salts to complex olefins, allowing the non-olefins to be separated by a variety of methods, including decantation and distillation. The metal salts are dissolved in ionic liquids, which tend to have virtually no vapor pressure, and which poorly solubilize the non-olefins. Accordingly, the non-olefins phase separate well, and can be distilled without carrying over any of the ionic liquid into the distillate. Preferred salts are Group IB salts, more preferably silver salts. A preferred silver salt is silver tetrafluoroborate. Preferred ionic liquids are those which form stable solutions or dispersions of the metal salts, and which do not dissolve the non-olefins. Further, if the olefins are subject to isomerization, the ionic liquid is preferably relatively non-acidic. The methods involve forming a solution of a suitable olefin-complexing salt in an appropriate ionic liquid. An olefin-containing mixture is contacted with the ionic liquid/salt solution, and the olefins are adsorbed. After the paraffins are removed, the olefins can be isolated by desorption. The olefin-containing mixture can be in the gas phase, or in the liquid phase. The flow of olefin-containing mixtures over/through the ionic liquid can be, for example, co-current, counter-current, or staged in stirred tanks. Countercurrent is preferred as it is the most efficient. The methods can be optimized using combinatorial chemistry.

Separation of olefins from paraffins using ionic liquid solutions

Methods for separating olefins from non-olefins, such as parafins, including cycloparaffins, oxygenates and aromatics, are provided. The methods use metal salts to complex olefins, allowing the non-olefins to be separated by a variety of methods, including decantation and distillation. The metal salts are dissolved in ionic liquids, which tend to have virtually no vapor pressure, and which poorly solubilize the non-olefins. Accordingly, the non-olefins phase separate well, and can be distilled without carrying over any of the ionic liquid into the distillate. Preferred salts are Group IB salts, more preferably silver salts. A preferred silver salt is silver tetrafluoroborate. Preferred ionic liquids are those which form stable solutions or dispersions of the metal salts, and which do not dissolve the non-olefins. Further, if the olefins are subject to isomerization, the ionic liquid is preferably relatively non-acidic. The methods involve forming a solution of a suitable olefin-complexing salt in an appropriate ionic liquid. An olefin-containing mixture is contacted with the ionic liquid/salt solution, and the olefins are adsorbed. After the paraffins are removed, the olefins can be isolated by desorption. The olefin-containing mixture can be in the gas phase, or in the liquid phase. The flow of olefin-containing mixtures over/through the ionic liquid can be, for example, co-current, counter-current, or staged in stirred tanks. Countcrcurrent is preferred as it is the most efficient. The methods can be optimized using combinatorial chemistry.

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Houston, TX, United States of America

Laura C Boudreau