Ethylene oxide purification
AssigneesPetron Scientech, Inc., Scientech Associates Inc.
InventorBrian J. Ozero
Life of this patent
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Abstract
An improved process for the recovery of high-purity ethylene-oxide water feed streams to EO purification and MEG reaction units when both are operating in EO plants that incorporate EO Stripper bypass technology, by installing a second lights stripper to exclusively degasify the diluted EO feed to the MEG reactor, thus permitting the use of additional bypassed (gasified) EO absorbate as the diluent and resulting in a substantial increase in the total amount of EO absorbate that can bypass the EO Stripper.
Claims9
An apparatus for producing purified ethylene oxide (EO) and monoethylene glycol (MEG) from a quenched and alkaline treated and water washed vaporous reaction stream, wherein the quenched and alkaline treated and water washed vaporous reaction stream comprises EO, CO2, formaldehyde, and acetaldehyde, the apparatus comprising:
- a) an EO absorber configured and arranged to contact the quenched and alkaline treated and water washed vaporous reaction stream with water to produce a first absorbate stream having a first EO concentration in water;
- b) a first series of conduits configured and arranged to divide the first absorbate stream into a first portion of the first absorbate stream, a second portion of the first absorbate stream, and a third portion of the first absorbate stream;
- c) an EO stripper configured and arranged to contact the first portion of the first absorbate stream with steam to produce a vaporous EO stream;
- d) an EO reabsorber configured and arranged to contact the vaporous EO stream with the second portion of the first absorbate stream to form a reabsorber bottoms stream, wherein the reabsorber bottoms stream has a second EO concentration in water that is higher than the first EO concentration in water;
- e) a second series of conduits configured and arranged to divide the reabsorber bottoms stream into a first portion of the reabsorber bottoms stream and a second portion of the reabsorber bottoms stream;
- f) a first lights stripper configured and arranged to contact the first portion of the reabsorber bottoms stream with steam to produce a first lights stripper bottoms, wherein the first lights stripper bottoms has a third EO concentration in water that is higher than the first EO concentration in water;
- g) a high purity ethylene oxide distillation column configured and arranged to produce purified EO from the first lights stripper bottoms;
- h) a series of conduits configured and arranged to combine the second portion of the reabsorber bottoms stream and the third portion of the first absorbate stream to produce a second lights stripper feed;
- i) a second lights stripper configured and arranged to contact the second lights stripper feed with steam to produce a second lights stripper bottom stream, wherein the second lights stripper bottom stream has a fourth EO concentration in water that is lower than the third EO concentration in water;
- and
- j) a glycol reactor configured and arranged to produce MEG from the second lights stripper bottom stream.
Dependencies are inferred from the claim text.