Process for the removal of carbon dioxide from 3,4-epoxy-1-butene process recycle streams
First Claim
1. Process for the removal of carbon dioxide from a butadiene epoxidation effluent recycle gas stream comprising about 3 to 15 mole percent butadiene, about 8 to 25 mole percent oxygen, about 55 to 88 mole percent inert diluent gas and about 0.5 to 10 mole percent carbon dioxide which comprises feeding the gas stream to an absorption vessel wherein the gas stream is intimately contacted with a liquid solution of an alkanolamine at a pressure of about 0.1 to 1 MPa and a temperature of about 20 to 65°
- C. to obtain;
(1) a vapor effluent comprising butadiene, oxygen, inert diluent gas and about 0.005 to 0.5 mole percent carbon dioxide from the upper section of the absorption vessel; and
(2) a liquid effluent comprising the alkanolamine solution and carbon dioxide-alkanolamine adduct from the lower section of the absorption vessel;
wherein butadiene is 1,3-butadiene.
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Accused Products
Abstract
Disclosed is a process for the efficient removal of carbon dioxide from a gas recycle system generated in an epoxidation process wherein 1,3-butadiene is selectively oxidized to 3,4-epoxy-1-butene. Carbon dioxide at low partial pressure is absorbed into an alkanolamine solution from a low pressure recycle gas stream containing high levels of oxygen. Also disclosed is a means for reclaiming the alkanolamine from a solution of a carbon dioxide-alkanolamine salt or adduct formed in the carbon dioxide removal process.
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Citations
24 Claims
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1. Process for the removal of carbon dioxide from a butadiene epoxidation effluent recycle gas stream comprising about 3 to 15 mole percent butadiene, about 8 to 25 mole percent oxygen, about 55 to 88 mole percent inert diluent gas and about 0.5 to 10 mole percent carbon dioxide which comprises feeding the gas stream to an absorption vessel wherein the gas stream is intimately contacted with a liquid solution of an alkanolamine at a pressure of about 0.1 to 1 MPa and a temperature of about 20 to 65°
- C. to obtain;
(1) a vapor effluent comprising butadiene, oxygen, inert diluent gas and about 0.005 to 0.5 mole percent carbon dioxide from the upper section of the absorption vessel; and
(2) a liquid effluent comprising the alkanolamine solution and carbon dioxide-alkanolamine adduct from the lower section of the absorption vessel;
wherein butadiene is 1,3-butadiene. - View Dependent Claims (2, 3)
- C. to obtain;
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4. Process for the removal of carbon dioxide from a butadiene epoxidation effluent recycle gas stream about 3 to 15 mole percent butadiene, about 8 to 25 mole percent oxygen, about 55 to 88 mole percent inert diluent gas and about 0.5 to 10 mole percent carbon dioxide which comprises the steps of:
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(I) feeding the gas stream to a first absorption vessel wherein the gas stream is intimately contacted with a liquid solution of an alkanolamine at a pressure of about 0.1 to 1 MPa (14.5 to 145 psia) and a temperature of about 20 to 65°
C. to obtain;
(i) a vapor effluent comprising butadiene, oxygen, inert diluent gas, about 0.005 to 0.5 mole percent carbon dioxide from the upper section of the absorption vessel, and about 20 to 2000 ppmv alkanolamine; and
(ii) a liquid effluent comprising the alkanolamine solution and carbon dioxide-alkanolamine adduct from the lower section of the first absorption vessel; and
(II) feeding vapor effluent (i) to a second absorption vessel wherein the gas stream is intimately contacted with a solvent at a pressure of about 0.1 to 1.1 MPa and a temperature of about 20 to 65°
C. to obtain;
(iii) a vapor effluent comprising butadiene, oxygen, inert diluent gas, about 0.005 to 0.5 mole percent carbon dioxide from the upper section of the absorption vessel, and less than 10 ppmv alkanolamine; and
(iv) a liquid effluent comprising solvent and absorbed alkanolamine from the lower section of the absorption vessel;
wherein butadiene is 1,3-butadiene.- View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. Process for the removal of carbon dioxide from a butadiene epoxidation effluent recycle gas stream comprising about 3 to 15 mole percent butadiene, about 8 to 25 mole percent oxygen, about 55 to 88 mole percent inert diluent gas and about 0.5 to 10 mole percent carbon dioxide which comprises the steps of:
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(I) feeding the gas stream to an absorption vessel wherein the gas stream is intimately contacted with a liquid solution of an alkanolamine at a pressure of about 0.1 to 1 MPa and a temperature of about 20 to 65°
C. to obtain;
(i) a vapor effluent comprising butadiene, oxygen, inert diluent gas and about 0.005 to 0.5 mole percent carbon dioxide from the upper section of the absorption vessel; and
(ii) a liquid effluent comprising the alkanolamine solution and carbon dioxide-alkanolamine adduct from the lower section of the absorption vessel; and
(II) subjecting liquid effluent (ii) to an alkanolamine reclamation process which comprises feeding liquid effluent (II) to the lower section of a column wherein the liquid is heated at a temperature of about 90 to 165°
C. to obtain;
(iii) a vapor effluent comprising carbon dioxide from the upper section of (iv) a liquid effluent comprising the alkanolamine solution substantially free of carbon dioxide-alkanolamine adduct from the lower section of the column;
wherein butadiene is 1,3-butadiene.- View Dependent Claims (23, 24)
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Specification