Method of purifying raw methanol
AssigneeAndritz Inc.
InventorJohan Olsson
Life of this patent
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Abstract
A method of purifying raw methanol obtained in chemical pulping, wherein heavy oil is admixed with the raw methanol to prevent precipitation, and the methanol mixture is distilled or evaporated to recover the methanol. The heavy oil is formed by mixing and heating raw methanol obtained from a side stream of chemical hardwood pulping with an acidic aqueous solution to vaporize low boiling point sulfurous compounds and provide acidified raw methanol. The acidified raw methanol is separated into a liquid top phase, a liquid aqueous middle phase, and a liquid bottom phase. The liquid bottom phase is extracted to obtain the heavy oil.
Claims15
A method to form a heavy oil from a raw methanol side stream from chemical hardwood pulping, wherein the method comprises:
- an acidification step comprising mixing the raw methanol side stream with an acidic aqueous solution, and heating the raw methanol mixed in the aqueous solution to vaporize low boiling point sulfurous compounds and provide acidified raw methanol;
- a separation step comprising separating from the acidified raw methanol a liquid top phase, a liquid aqueous middle phase, and a liquid bottom phase;
- and
- collecting the liquid bottom phase as the heavy oil having a density of about 1010 kg/m3 at 20° C.
A method comprising:
- providing a raw methanol side stream from hardwood pulping;
- an acidification step comprising mixing the raw methanol side stream with an acidic aqueous solution, and heating to vaporize low boiling point sulfurous compounds, to provide acidified raw methanol;
- a separation step comprising separating from the acidified raw methanol a liquid top phase, a liquid aqueous middle phase, and a liquid bottom phase;
- and
- collecting the bottom phase as a heavy oil having a density greater than a density of the raw methanol side stream.
A method of purifying raw methanol obtained in chemical pulping, the method comprising:
- providing raw methanol obtained as a by-product of chemical pulping;
- acidifying the raw methanol with an acidic aqueous solution to provide acidified methanol;
- admixing a heavy oil having a density of about 1010 kg/m3 with the acidified methanol to provide a methanol mixture;
- and
- distilling or evaporating the methanol mixture to recover methanol.
Dependencies are inferred from the claim text.