Removal of sulfate from meg streams using calcium chloride
AssigneeCameron International Corporation
InventorBrian Edward Messenger
Life of this patent
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Abstract
A MEG recovery process is described, in which a MEG stream is processed by performing a divalent treatment to reduce dissolved divalent cations in the portion of the stream; performing a sulfate treatment to reduce dissolved sulfate ions in the stream, the sulfate treatment comprising adding an underdose of one or more calcium halides, one or more lower calcium carboxylates, or a mixture thereof to a treatment stream; and precipitating calcium sulfate from the treatment stream; performing a solids removal treatment to reduce solids in the stream; and returning the treated stream, depleted in divalent cations, sulfate ions, and solids, to the MEG recovery process.
Claims20
A method of MEG recovery, comprising:
- withdrawing a portion of a recycle of a MEG vaporization unit;
- performing a divalent treatment on the portion of the recycle to reduce dissolved divalent cations in the portion of the recycle;
- performing a sulfate treatment to reduce dissolved sulfate ions in the portion of the recycle, the sulfate treatment comprising:
- adding an underdose of one or more calcium halides, one or more lower calcium carboxylates, or a mixture thereof, to a treatment stream;
- and
- precipitating calcium sulfate from the treatment stream;
- performing a solids removal treatment to reduce solids in the portion of the recycle;
- and
- returning the portion of the recycle, depleted in divalent cations, sulfate ions, and solids, to the MEG vaporization unit.
A method of MEG recovery, comprising:
- withdrawing a portion of a recycle of a MEG vaporization unit;
- performing a divalent treatment to reduce dissolved divalent cations in the portion of the recycle;
- performing a sulfate treatment to reduce dissolved sulfate ions in the portion of the recycle, the sulfate treatment comprising:
- adding an underdose of one or more calcium halides to a treatment stream;
- and
- precipitating calcium sulfate from the treatment stream;
- performing a solids removal treatment to reduce solids in the portion of the recycle;
- measuring a first parameter that represents concentration of calcium ions in the MEG vaporization unit;
- measuring a second parameter that represents concentration of sulfate ions in the MEG vaporization unit;
- controlling the sulfate treatment based on the second parameter;
- controlling the divalent treatment based on the first parameter;
- and
- returning the portion of the recycle, depleted in divalent cations, sulfate ions, and solids, to the MEG vaporization unit.
A method of MEG recovery, comprising:
- treating a MEG stream in a divalent treatment unit to yield precipitated solids in a divalent treated stream;
- performing a solids removal process on the divalent treated stream to form a divalent depleted stream;
- vaporizing MEG from the divalent depleted stream in a vaporization unit having a heated recycle line;
- withdrawing a fluid from the heated recycle line as a treatment stream;
- performing a sulfate treatment to reduce sulfate ions in the treatment stream, the sulfate treatment comprising:
- adding calcium chloride to the treatment stream;
- and
- precipitating calcium sulfate from the treatment stream to form a sulfate treated stream;
- and
- returning the sulfate treated stream to the divalent treatment unit.
Dependencies are inferred from the claim text.