IES73196B2 - Solvent purification - Google Patents
Solvent purificationInfo
- Publication number
- IES73196B2 IES73196B2 IES970142A IES73196B2 IE S73196 B2 IES73196 B2 IE S73196B2 IE S970142 A IES970142 A IE S970142A IE S73196 B2 IES73196 B2 IE S73196B2
- Authority
- IE
- Ireland
- Prior art keywords
- mixture
- acetonitrile
- amount
- phosphorus pentoxide
- containing impurities
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/32—Separation; Purification; Stabilisation; Use of additives
- C07C253/34—Separation; Purification
Abstract
An acetonitrile purification process comprises adding phosphorous pentoxide to a crude mixture in an amount of 0.125 to 0.625% by weight. Water is added to the mixture in an amount of at least 0.005% by volume. The mixture is distilled and purified acetonitrile is recovered.
Description
Solvent Purification
The invention relates to a purification process for purifying acetonitrile containing impurities such as allyl alcohol, acetone, water, oxazole, acrylonitrile, methacrylonitrile and/or propionitrile.
Acetonitrile was first produced commercially in 1952. It is widely used in liquid-liquid extraction, selective recrystallisation and extractive distillation. Because of its favourable dielectric, solvent and optical properties it is also widely used in analytical chemistry, particularly in high performance liquid chromatography (HPLC), DNA and peptide synthesis, residue analysis and in UV and DR spectroscopy.
In our UK-A-2249308 we have described a process for producing acetonitrile having a high level of purity in a cost efficient manner.
As modern chemical and biological process techniques become ever more sophisticated and new techniques are developed there is a need to provide an improved cost efficient process for producing acetonitrile with high levels of purity, especially with very low levels of water as impurity.
This invention is directed towards providing such an improved acetonitrile purification process.
According to the invention there is provided an acetonitrile purification process for the purification of an acetonitrile mixture containing impurities to produce $73 1 9β *
- 2 purified acetonitrile, the process comprising the steps of:
adding phosphorus pentoxide to the mixture in an amount of from 0.125% to 0.625% by weight of the mixture;
adding water to the mixture in an amount of at least 0.005% by volume of the mixture;
distilling the mixture in a distillation column;
recovering purified acetonitrile from the distillation column; and producing a first residue containing impurities and phosphorus pentoxide.
In one embodiment of the invention phosphorus pentoxide is added to the mixture in an amount of from 0.25% to 0.5% by weight of the mixture, especially approximately 0.375% by weight of the mixture.
In a preferred embodiment of the invention water is added to the mixture in an amount of at least 0.01% by volume of the mixture, especially in an amount of approximately 0.015% by volume of the mixture.
In one embodiment of the invention the process includes the step of adding an oxidising agent to the mixture prior to distillation. Preferably the oxidising agent is potassium permanganate which is preferably added in an amount of from 0.00625% to 0.0125% by weight of the mixture, especially approximately 0.00875% by weight of the mixture.
In a particularly preferred embodiment of the invention the process includes the steps of:
adding further acetonitrile containing impurities to the first mixture;
adding further phosphorus pentoxide and water to the mixture;
distilling the mixture;
recovering purified acetonitrile, and producing a second residue containing impurities and phosphorus pentoxide.
Preferably the process further includes the steps of:
adding further acetonitrile containing impurities to the second residue;
adding further phosphorus pentoxide to the mixture;
distilling the mixture;
recovering purified acetonitrile;
producing a third residue containing impurities and phosphorus pentoxide; and removing the third residue.
The invention also provides purified acetonitrile when produced by the purification process of the invention.
The invention will be more clearly understood from the following description thereof given by way of example only with reference to accompanying drawing which is a schematic diagram of a distillation apparatus used in the process of the invention.
Referring to the drawing there is illustrated a distillation apparatus used in the acetonitrile purification process of the invention. The apparatus comprises a distillation column 1 having a packing of raschig rings with from 30 to 40 theoretical plates. Feed acetonitrile containing impurities is added along an inlet line 2 to a reboiler 3 having a steam heating coil 4. The feed acetonitrile is then delivered into a boiling vessel 5. Vapour from the distillation column 1 is condensed by passing cooling water through a coil 7 in a condenser 8. Reflux is returned to the column through a reflux line 9. When the desired purity level of acetonitrile is reached the purified acetonitrile is delivered along an outlet line 10 through a molecular sieve 12 [?] to a collection vessel 13. Purified acetonitrile from the vessel 13 or residue from the boiling vessel 5 may be taken off along a delivery line 15.
EXAMPLE 1
Acetonitrile containing impurities is added to the boiling vessel 5. Water is added to the acetonitrile in an amount of approximately 15ml per 100 litres of acetonitrile. Phosphorus pentoxide is then added to the acetonitrile in an amount of approximately 300g per 100 litres of acetonitrile. The mixture is gently heated to reflux and refluxed for from 15 minutes to 30 minutes. Distillation is continued and the purified acetonitrile is delivered into the receiving vessel 13 and bottled. A first residue containing impurities and phosphorus pentoxide is produced.
Further acetonitrile containing impurities is introduced into the boiling vessel 5 and water in an amount of approximately 15ml per 100 litres of acetonitrile is added. Additional phosphorus pentoxide in an amount of approximately 250g per 100 litres of acetonitrile is added. The distillation process is repeated as above producing purified acetonitrile and a second residue which may be retained in the system.
Further acetonitrile containing impurities is introduced into the boiling vessel 5 and water in an amount of approximately 15ml per 100 litres of acetonitrile is added. Additional phosphorus pentoxide in an amount of approximately 200g per 100 litres of acetonitrile is added. The distillation process is repeated as above producing purified acetonitrile and a third residue which is cleaned from the system.
We have surprisingly found that very high purity levels, especially with regard to water, can be achieved using phosphorus pentoxide in the defined amounts in combination with water. In particular, the process may be operated to maximise the production of purified acetonitrile with minimum downtime required for cleaning out impurity residue products.
EXAMPLE 2
Example 1 above was repeated except that in this case in each stage an amount of approximately 7g per 100 litres of potassium permanganate is added to the mixture.
This further enhances the purity levels of the acetonitrile produced.
The invention is not limited to the embodiments hereinbefore described which may be varied in detail.
Claims (5)
1. An acetonitrile purification process for the purification of an acetonitrile mixture containing impurities to produce purified acetonitrile, the process comprising the steps of: adding phosphorus pentoxide to the mixture in an amount of from 0.125% to 0.625% by weight of the mixture; adding water to the mixture in an amount of at least 0.005% by volume of the mixture; distilling the mixture in a distillation column; recovering purified acetonitrile from the distillation column; and producing a first residue containing impurities and phosphorus pentoxide.
2. An acetonitrile purification process as claimed in claim 1 wherein phosphorus pentoxide is added to the mixture in an amount of from 0.025% to 0.5% by weight of the mixture, preferably the phosphorus pentoxide is added to the mixture in an amount of approximately 0.375% by weight of the mixture, preferably water is added to the mixture in an amount of at least 0.01% by volume of the mixture, preferably in an amount of approximately 0.015% by volume of the mixture.
3. An acetonitrile purification process as claimed in any preceding claim including the step of adding an oxidising agent to the mixture prior to distillation, preferably the oxidising agent is potassium permanganate, preferably potassium permanganate is added in an amount of from 0.00625% to 0.0125% by weight of the mixture, most preferably potassium permanganate is added in an amount of approximately 0.00875% by weight of the mixture.
4. An acetonitrile purification process as claimed in any preceding claim including the stages of:adding further acetonitrile containing impurities to the first mixture; adding further phosphorus pentoxide and water to the mixture; distilling the mixture; recovering purified acetonitrile, and producing a second residue containing impurities and phosphorus pentoxide, preferably the process includes the steps of:adding further acetonitrile containing impurities to the second residue; adding further phosphorus pentoxide to the mixture; distilling the mixture; recovering purified acetonitrile; producing a third residue containing impurities and phosphorus pentoxide; and removing the third residue.
5. 5. Purified acetonitrile whenever purified by a process as claimed in any preceding claim. CRUICKSHANK & CO.,
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IES970142 IES73196B2 (en) | 1997-03-03 | 1997-03-03 | Solvent purification |
GB9704816A GB2322856B (en) | 1997-03-03 | 1997-03-07 | Solvent purification |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IES970142 IES73196B2 (en) | 1997-03-03 | 1997-03-03 | Solvent purification |
GB9704816A GB2322856B (en) | 1997-03-03 | 1997-03-07 | Solvent purification |
Publications (1)
Publication Number | Publication Date |
---|---|
IES73196B2 true IES73196B2 (en) | 1997-05-07 |
Family
ID=26311143
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
IES970142 IES73196B2 (en) | 1997-03-03 | 1997-03-03 | Solvent purification |
Country Status (2)
Country | Link |
---|---|
GB (1) | GB2322856B (en) |
IE (1) | IES73196B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2435040B (en) * | 2006-02-08 | 2009-10-07 | G K Analytical Sciences Ltd | Acetonitrile purification by the addition of phosphorus pentoxide, then water, and subsequent distillation |
CN107935887B (en) * | 2017-12-21 | 2020-12-08 | 上海应用技术大学 | Preparation method of gradient acetonitrile |
-
1997
- 1997-03-03 IE IES970142 patent/IES73196B2/en not_active IP Right Cessation
- 1997-03-07 GB GB9704816A patent/GB2322856B/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
GB2322856A (en) | 1998-09-09 |
GB2322856B (en) | 2000-05-10 |
GB9704816D0 (en) | 1997-04-23 |
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