CA1088957A - Process for the purification of methanol obtained from kraft pulping condensates - Google Patents
Process for the purification of methanol obtained from kraft pulping condensatesInfo
- Publication number
- CA1088957A CA1088957A CA276,674A CA276674A CA1088957A CA 1088957 A CA1088957 A CA 1088957A CA 276674 A CA276674 A CA 276674A CA 1088957 A CA1088957 A CA 1088957A
- Authority
- CA
- Canada
- Prior art keywords
- methanol
- solution
- condensates
- separate
- purification
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
- C07C31/02—Monohydroxylic acyclic alcohols
- C07C31/04—Methanol
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
Abstract
ABSTRACT OF THE DISCLOSURE
A process for the purification of odorous methanol or an odorous methanol-water solution derived from condensates of a kraft pulping process in which the solution is treated with dilute acid. The methanol is concentrated from the treated solution and then treated with an oxidating agent under alkaline conditions after which purified methanol is recovered from the aqueous alkaline solution.
A process for the purification of odorous methanol or an odorous methanol-water solution derived from condensates of a kraft pulping process in which the solution is treated with dilute acid. The methanol is concentrated from the treated solution and then treated with an oxidating agent under alkaline conditions after which purified methanol is recovered from the aqueous alkaline solution.
Description
1(~8~9S'~
The present invention relates to a process whereby odorous methanol derived from four kraft pulping condensates can be purified. The methanol can equally well be applied directly to the odorous foul condensates. Such toxic and odorous conden-sates are formed at various stages in a kraft pulping process, - e.g., the foul condensate of batch cligesters, the foul condensate -from evaporation plant and the turpentine condensates.
A strong unpleasant odour originating from dissolved sulphur- and nitrogen compounds is typical for these condensates.
Further the condensates contain appreciable amounts of volatile compounds not containing sulphur of which the main component is methanol, other such components are acetone, ethanol and turpen-tine, etc.
Although constituting a very small part of the total waste water amount of a pulping industry these condensates are responsible for an appreciable part of the total BOD7-load of the factory. Different methods have been developed for the puri-fication of such condensates. The best BOD7-reduction is ob-tained in a method in which the volatile organic compounds are stripped by steam from the condensates as for instance in the condensate handling process by Rosenlew Oy. The purified con-densate can then be reused in the process. The odorous methanol separated by stem stripping can then be burned as normally is done. However, methanol is an important raw material for the chemical industry, the importance of which is continuously growing and the economics of the handling of condensates as well as the kraft process itself can be improved if the odorous methanol can be purified sufficiently to be used as an industrial raw mat-erial rather than simply as fuel.
Previous procedures for the chemical purification of methanol separated from a kraft process either simply employ the use of expensive catalysts as in Swedish Patent 55,998, in which methanol is purified from sulphur compounds by passing the methanol lQ~3~9St7 at high temperature through a cuprous oxide layer or the addition of expensive, and for the kraft industry, new chemicals, to the process as in German Patent 54,126 in which the waste liquor is treated with barium-, strontium- or calcium- hydroxide before the separation of the condensates.
In a technically feasible purification method for meth-anol environmental conditions in addition to the economic factors impose very stringent requirements on the chemicals to be used.
Requirements which have not been fullfilled in methods presented earlier.
In Swedish Patent 38,682, and supplement 42,374 a method for the purification of methanol by chemicals is described but in these patents no description is given of the chemicals to be used nor of how the purification should he done or of the results ob- ~
tainable by the method. ~outalals Puukemia (1936) describes a ;
method based on the above information for the purification of methanol from sulphur compounds by the addition of lead acetate which due to its toxicity and high price does not comply with the requirements of a technically feasible method.
The present method makes i* possible to combine from the environmental point of view the necessary separation of odorous methanol from the kraft condensates before these are discarded, with the purification of the foul smelling methanol to the level of technical grade methanol.
Further it is typical for the method that this purifi-cation is effected by chemicals already in use in the kraft process, a condition which is important from the point of view of the total chemical balance of the kraft process.
The new method comprises the following steps:
1. The separated foul smelling methanol solution or methanol ~/S-3~7~) B containing condensate is treated with dilute sulphuric acid1or with sodium sulphate containing spent acid from a tall oil splitt-ing process, or sulphur dioxide. At this stage, the terpenes i'7 which are insoluble in water form a separate phase which is drawn off and the odorous ammonium- and amine-compounds dissolved in the methanol solution precipitate as sulphate salts and can be separated by filtration. The volatile impurities can be removed by gas-stripping.
The present invention relates to a process whereby odorous methanol derived from four kraft pulping condensates can be purified. The methanol can equally well be applied directly to the odorous foul condensates. Such toxic and odorous conden-sates are formed at various stages in a kraft pulping process, - e.g., the foul condensate of batch cligesters, the foul condensate -from evaporation plant and the turpentine condensates.
A strong unpleasant odour originating from dissolved sulphur- and nitrogen compounds is typical for these condensates.
Further the condensates contain appreciable amounts of volatile compounds not containing sulphur of which the main component is methanol, other such components are acetone, ethanol and turpen-tine, etc.
Although constituting a very small part of the total waste water amount of a pulping industry these condensates are responsible for an appreciable part of the total BOD7-load of the factory. Different methods have been developed for the puri-fication of such condensates. The best BOD7-reduction is ob-tained in a method in which the volatile organic compounds are stripped by steam from the condensates as for instance in the condensate handling process by Rosenlew Oy. The purified con-densate can then be reused in the process. The odorous methanol separated by stem stripping can then be burned as normally is done. However, methanol is an important raw material for the chemical industry, the importance of which is continuously growing and the economics of the handling of condensates as well as the kraft process itself can be improved if the odorous methanol can be purified sufficiently to be used as an industrial raw mat-erial rather than simply as fuel.
Previous procedures for the chemical purification of methanol separated from a kraft process either simply employ the use of expensive catalysts as in Swedish Patent 55,998, in which methanol is purified from sulphur compounds by passing the methanol lQ~3~9St7 at high temperature through a cuprous oxide layer or the addition of expensive, and for the kraft industry, new chemicals, to the process as in German Patent 54,126 in which the waste liquor is treated with barium-, strontium- or calcium- hydroxide before the separation of the condensates.
In a technically feasible purification method for meth-anol environmental conditions in addition to the economic factors impose very stringent requirements on the chemicals to be used.
Requirements which have not been fullfilled in methods presented earlier.
In Swedish Patent 38,682, and supplement 42,374 a method for the purification of methanol by chemicals is described but in these patents no description is given of the chemicals to be used nor of how the purification should he done or of the results ob- ~
tainable by the method. ~outalals Puukemia (1936) describes a ;
method based on the above information for the purification of methanol from sulphur compounds by the addition of lead acetate which due to its toxicity and high price does not comply with the requirements of a technically feasible method.
The present method makes i* possible to combine from the environmental point of view the necessary separation of odorous methanol from the kraft condensates before these are discarded, with the purification of the foul smelling methanol to the level of technical grade methanol.
Further it is typical for the method that this purifi-cation is effected by chemicals already in use in the kraft process, a condition which is important from the point of view of the total chemical balance of the kraft process.
The new method comprises the following steps:
1. The separated foul smelling methanol solution or methanol ~/S-3~7~) B containing condensate is treated with dilute sulphuric acid1or with sodium sulphate containing spent acid from a tall oil splitt-ing process, or sulphur dioxide. At this stage, the terpenes i'7 which are insoluble in water form a separate phase which is drawn off and the odorous ammonium- and amine-compounds dissolved in the methanol solution precipitate as sulphate salts and can be separated by filtration. The volatile impurities can be removed by gas-stripping.
2. Remaining impurities mainly sulphur compounds are removed from the methanol in the second stage of the process in which the methanol solution is made alkaline with for example sodium hydro-xide or white liquor and then treated with an oxidating agent such as for example hydrogen peroxide or sodium hypochlorite.
When the solution is further distilled to concentrate the methanol, the oxidated sulphur compounds remain in the aqueous bottom product.
Specifically, the present invention relates to a process for the purification of methanol obtained from condensates of a kraft pulping process comprising the steps of:
A) Acidifying ~rude methanol or methanol containing condensate, B) separating the methanol from the resultant aqueous solution into a separate fraction;
C) treating the separate methanol fraction with an oxidating agent under alkaline conditions, and D) separating the methanol into a separate fraction from the resultant solution.
The following examples will further illustrate the invention:
EX~LE 1 To a 300 ml sample of methanol condensate 300 ml of 20% sulphuric acid was added. The~ -pinene, amounting to about 6% of the total methanol volume separating at the surface was removed, the methanol solution was filtrated to separate the solid sulphate precipitate. The weight of the removed precip-itate was approximately 31 g. The obtained methanol solution s~
was distilled to concentrate the methanol and further made alkaline (pH 10-11) by adding to the methanol 100 ml of a mixture of the following composition: 2 g sodium hydroxide 100 ml water and 50 ml 30~ hydrogen peroxide. The solution was distilled and the separated methanol was analysed. The analysis confirmed that the treated methanol was free from nitrogen and sulphur compounds.
EXAMPL~ 2.
A 3 1, sample of crude methanol separated from kraft condensates was acidified (ph~ 1) by adding 700 g. about 30%
sulphuric acid, 30 ml of~ -pinene separated as a lower layer.
A white precipitate (270 g) precipitated from the solution. After distillation the methanol was made alkali by adding a mixture -which contained 5 g of sodium hydroxide, 150 g of water and 100 g 30~ hydrogen peroxide. After this the solution was distilled again to concentrate the methanol. By analysis it was confirmed that the treated methanol was free from nitrogen and sulphur compounds. ~ `
EXAI~L~E 3.
To a 2 1, sample of methanol condensate a total amount of 80 1, of SO2-gas was passed at constant flow rate (2 Q./min).
150 ml of water was added to the solution. The formed precipitate (230 g) was filtered off. 200 ml of water was added to the filtrate and it was heated. After cooling 21 ml turpentine was separated from the bottom of the solution and the solution was distilled in order to concentrate the methanol. It was noted that the odour of the distillate had diminished considerably. The obtained distillate was treated further as in Examples 1 and 2.
EXAMPLÆ 4.
To 3 1, crude methanol separated from kraft condensates 727 g of spent acid was added the composition of which was: 180 g sodium sulphate, 230 g H2SO4, 315 g of water. The formed precip-.
~(3~ 7 itate (app. 400 g) was separated by filtration and an additional300 g of water was added to the solution in order to separate the ~-pinene. The separated aqueous methanol solution was distilled in order to concentrate the methanol. The obtained distillate was treated by alkaline oxidation in a similar way as in the previous examples and further concentrated by distillation (Ex-ample 2). By analysis it was confirmed that the treated methanol was free from nitrogen and sulphur compounds.
EXAMPLE 5.
Crude methanol was treated with sulphuric acid according to Example 2, the formed precipitate was separated and the solu-tion concentrated by distillation. To 50 ml of the obtained methanol distillate 0,5 g NaOH and 60 ml of l-N NaC10 was added.
The solution was allowed to clarify after which thec~-pinene was separated and the solution concentrated by distillation. The final purification of the concentrated methanol was done by filtration through alkaline alumina. By analysis it was confirmed that the methanol treated in this way was free from nitrogen and sulphur compounds.
When the solution is further distilled to concentrate the methanol, the oxidated sulphur compounds remain in the aqueous bottom product.
Specifically, the present invention relates to a process for the purification of methanol obtained from condensates of a kraft pulping process comprising the steps of:
A) Acidifying ~rude methanol or methanol containing condensate, B) separating the methanol from the resultant aqueous solution into a separate fraction;
C) treating the separate methanol fraction with an oxidating agent under alkaline conditions, and D) separating the methanol into a separate fraction from the resultant solution.
The following examples will further illustrate the invention:
EX~LE 1 To a 300 ml sample of methanol condensate 300 ml of 20% sulphuric acid was added. The~ -pinene, amounting to about 6% of the total methanol volume separating at the surface was removed, the methanol solution was filtrated to separate the solid sulphate precipitate. The weight of the removed precip-itate was approximately 31 g. The obtained methanol solution s~
was distilled to concentrate the methanol and further made alkaline (pH 10-11) by adding to the methanol 100 ml of a mixture of the following composition: 2 g sodium hydroxide 100 ml water and 50 ml 30~ hydrogen peroxide. The solution was distilled and the separated methanol was analysed. The analysis confirmed that the treated methanol was free from nitrogen and sulphur compounds.
EXAMPL~ 2.
A 3 1, sample of crude methanol separated from kraft condensates was acidified (ph~ 1) by adding 700 g. about 30%
sulphuric acid, 30 ml of~ -pinene separated as a lower layer.
A white precipitate (270 g) precipitated from the solution. After distillation the methanol was made alkali by adding a mixture -which contained 5 g of sodium hydroxide, 150 g of water and 100 g 30~ hydrogen peroxide. After this the solution was distilled again to concentrate the methanol. By analysis it was confirmed that the treated methanol was free from nitrogen and sulphur compounds. ~ `
EXAI~L~E 3.
To a 2 1, sample of methanol condensate a total amount of 80 1, of SO2-gas was passed at constant flow rate (2 Q./min).
150 ml of water was added to the solution. The formed precipitate (230 g) was filtered off. 200 ml of water was added to the filtrate and it was heated. After cooling 21 ml turpentine was separated from the bottom of the solution and the solution was distilled in order to concentrate the methanol. It was noted that the odour of the distillate had diminished considerably. The obtained distillate was treated further as in Examples 1 and 2.
EXAMPLÆ 4.
To 3 1, crude methanol separated from kraft condensates 727 g of spent acid was added the composition of which was: 180 g sodium sulphate, 230 g H2SO4, 315 g of water. The formed precip-.
~(3~ 7 itate (app. 400 g) was separated by filtration and an additional300 g of water was added to the solution in order to separate the ~-pinene. The separated aqueous methanol solution was distilled in order to concentrate the methanol. The obtained distillate was treated by alkaline oxidation in a similar way as in the previous examples and further concentrated by distillation (Ex-ample 2). By analysis it was confirmed that the treated methanol was free from nitrogen and sulphur compounds.
EXAMPLE 5.
Crude methanol was treated with sulphuric acid according to Example 2, the formed precipitate was separated and the solu-tion concentrated by distillation. To 50 ml of the obtained methanol distillate 0,5 g NaOH and 60 ml of l-N NaC10 was added.
The solution was allowed to clarify after which thec~-pinene was separated and the solution concentrated by distillation. The final purification of the concentrated methanol was done by filtration through alkaline alumina. By analysis it was confirmed that the methanol treated in this way was free from nitrogen and sulphur compounds.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the purification of methanol ob-tained from condensates of a kraft pulping process comprising the steps of:
A) acidifying crude methanol or methanol containing con-densate using an acid selected from the group consisting of 15 -30% sulphuric acid, spent acid from tall oil splitting and sulphur dioxide;
B) separating the methanol from the resultant aqueous solution into a separate fraction by distillation or steam strip-ping;
C) treating the separate methanol fraction with an oxidat-ing agent under alkaline conditions, and D) separating the methanol into a separate fraction from the resultant solution.
A) acidifying crude methanol or methanol containing con-densate using an acid selected from the group consisting of 15 -30% sulphuric acid, spent acid from tall oil splitting and sulphur dioxide;
B) separating the methanol from the resultant aqueous solution into a separate fraction by distillation or steam strip-ping;
C) treating the separate methanol fraction with an oxidat-ing agent under alkaline conditions, and D) separating the methanol into a separate fraction from the resultant solution.
2. A process as claimed in claim 1, wherein the aqueous methanol containing solution obtained in step (A) is filtered to separate precipitated (NH4)2SO4.
3. A process as claimed in claim 1, wherein the methanol fraction obtained in step (B) is made alkaline with sodium hydroxide or white liquor and treated with an oxidating agent selected from the group consisting of hydrogen peroxide and sodium hypochlorite.
4. A process as claimed in claim 1, wherein mixing in step (A) is effected by passing gas through the solution to speed the removal of gaseous impurities.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI761096A FI52710C (en) | 1976-04-22 | 1976-04-22 | Process for the purification of methanol separated from the condensates of the sulphate process. |
| FI761096 | 1976-04-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1088957A true CA1088957A (en) | 1980-11-04 |
Family
ID=8509936
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA276,674A Expired CA1088957A (en) | 1976-04-22 | 1977-04-21 | Process for the purification of methanol obtained from kraft pulping condensates |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS52156804A (en) |
| BR (1) | BR7702535A (en) |
| CA (1) | CA1088957A (en) |
| FI (1) | FI52710C (en) |
| NO (1) | NO146135C (en) |
| SE (1) | SE430411B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4961918A (en) * | 1988-10-11 | 1990-10-09 | Eka Nobel Ab | Process for production of chlorine dioxide |
| WO2009059920A2 (en) * | 2007-11-09 | 2009-05-14 | Upm-Kymmene Oyj | Use of methanol in the production of hydrogen and fuel, processes and plants for the production of hydrogen and fuel |
| WO2010091492A1 (en) * | 2009-02-12 | 2010-08-19 | A.H Lundberg Systems Limited | Methanol purification method and apparatus |
| US10160706B2 (en) | 2013-10-11 | 2018-12-25 | Andritz Oy | Process for removal of sulphur from raw methanol |
| WO2019240654A1 (en) * | 2018-06-11 | 2019-12-19 | Valmet Ab | A method and a system for obtaining methanol from foul condensate of a pulping process |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0657603B2 (en) * | 1990-04-05 | 1994-08-03 | エカ ノーベル アクチェボラーグ | Chlorine dioxide production method |
| FI127304B (en) | 2011-02-03 | 2018-03-15 | Stora Enso Oyj | A process for preparing purified methanol from a condensate of sulphate pulp cooking |
| FI126459B (en) * | 2011-02-03 | 2016-12-15 | Stora Enso Oyj | Process for the preparation of dimethyl sulfone |
| US9394220B2 (en) * | 2013-06-19 | 2016-07-19 | Fpinnovations | Method for producing bio-methanol at pulp mills |
-
1976
- 1976-04-22 FI FI761096A patent/FI52710C/en not_active IP Right Cessation
-
1977
- 1977-04-21 JP JP4520977A patent/JPS52156804A/en active Pending
- 1977-04-21 NO NO771384A patent/NO146135C/en unknown
- 1977-04-21 CA CA276,674A patent/CA1088957A/en not_active Expired
- 1977-04-21 SE SE7704558A patent/SE430411B/en unknown
- 1977-04-22 BR BR7702535A patent/BR7702535A/en unknown
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4961918A (en) * | 1988-10-11 | 1990-10-09 | Eka Nobel Ab | Process for production of chlorine dioxide |
| US10407304B2 (en) | 2007-11-09 | 2019-09-10 | Upm-Kymmene Oyj | Use of methanol in the production of hydrogen and fuel, processes and plants for the production of hydrogen and fuel |
| WO2009059920A2 (en) * | 2007-11-09 | 2009-05-14 | Upm-Kymmene Oyj | Use of methanol in the production of hydrogen and fuel, processes and plants for the production of hydrogen and fuel |
| WO2009059920A3 (en) * | 2007-11-09 | 2009-11-05 | Upm-Kymmene Oyj | Use of methanol in the production of hydrogen and fuel, processes and plants for the production of hydrogen and fuel |
| WO2010091492A1 (en) * | 2009-02-12 | 2010-08-19 | A.H Lundberg Systems Limited | Methanol purification method and apparatus |
| EA020038B1 (en) * | 2009-02-12 | 2014-08-29 | А.Х. Лундберг Системз Лимитед | Methanol purification method and apparatus |
| US9320986B2 (en) | 2009-02-12 | 2016-04-26 | A.H. Lundberg Systems Limited | Methanol purification method and apparatus |
| US9938216B2 (en) | 2009-02-12 | 2018-04-10 | A.H. Lundberg Systems Limited | Methanol purification method and apparatus |
| AU2009339923B2 (en) * | 2009-02-12 | 2014-04-24 | A.H Lundberg Systems Limited | Methanol purification method and apparatus |
| US10160706B2 (en) | 2013-10-11 | 2018-12-25 | Andritz Oy | Process for removal of sulphur from raw methanol |
| WO2019240654A1 (en) * | 2018-06-11 | 2019-12-19 | Valmet Ab | A method and a system for obtaining methanol from foul condensate of a pulping process |
| CN112262241A (en) * | 2018-06-11 | 2021-01-22 | 维美德公司 | Method and system for obtaining methanol from a foul condensate of a pulping process |
| CN112262241B (en) * | 2018-06-11 | 2022-09-30 | 维美德公司 | Method and system for obtaining methanol from a foul condensate of a pulping process |
| US11898309B2 (en) | 2018-06-11 | 2024-02-13 | Valmet Ab | Method and a system for obtaining methanol from foul condensate of a pulping process |
Also Published As
| Publication number | Publication date |
|---|---|
| SE7704558L (en) | 1977-10-23 |
| NO146135C (en) | 1982-08-04 |
| JPS52156804A (en) | 1977-12-27 |
| BR7702535A (en) | 1978-03-21 |
| NO146135B (en) | 1982-04-26 |
| NO771384L (en) | 1977-10-25 |
| FI52710C (en) | 1977-11-10 |
| SE430411B (en) | 1983-11-14 |
| FI52710B (en) | 1977-08-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 19971104 |