Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B11/00—Recovery or refining of other fatty substances, e.g. lanolin or waxes
  • C11B11/005—Lanolin; Woolfat
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/74—Recovery of fats, fatty oils, fatty acids or other fatty substances, e.g. lanolin or waxes

Definitions

• Lanolin is recovered from spent alkaline scouring liqor, preferably after removal by centrifuging of the major portion of its original lanolin content, by mixing spent alkaline scouring liquor having a pH between about 7.5 and 10, and preferably of between 8.0 and 9.5, and being free of solvents for lanolin, with an alcohol having between 6 and 8 carbon atoms per molecule.
• the alcohol is admixed in an amount greater than that which is soluble in the spent alkaline scouring liquor from which lanolin is to be removed, and equals between 1 and 25%, preferably between 1 and 10% of the volume of the alkaline scouring liquor, whereby the thus-formed mixture will separate into a heavier, aqueous, substantially lanolinfree phase, and a lighter lanolin-containing alcoholic phase from which lanolin may be recovered.
• the present invention relates to a method of treating wool scouring liquors and, more particularly, the present invention is concerned with a method of recovering lanolin from alkaline, aqueous scouring liquors which have been used for the washing of raw wool and which broadly consist of an alkaline aqueous solution of soap and/or detergents which is free of solvents for lanolin.
• lanolin is obtained as an important raw material for further processing and simultaneously the disposal of the spent scouring liquor is facilitated due to the removal of lanolin therefrom.
• the raw or greasy wool Prior to further processing, the raw or greasy wool must be freed of suint (wool sweat), wool wax (lanolin), dirt and dust. This is conventionally carried out by washing the raw wool in a suitable apparatus, for instance of the type known as Leviathan. Since lanolin is insoluble in water but soluble in some organic solvents, the removal of lanolin from the raw wool may be carried out by two difierent methods, namely either by converting the lanolin into an aqueous emulsion by means of a soap or detergent, or by including suitable solvent in the washing liquid.
• the methods of washing raw or greasy wool can be divided into two groups, depending on the type of washing agents which are employed.
• the raw wool is washed with an alkaline, aqueous liquid containing as the washing agent either a soap or a synthetic detergent or a combination of both.
• the other group of methods is concerned with the washing of raw wool with a washing liquid consisting of one or more solvents or with an aqueous soap or detergents-containing, washing liquid to which an organic sol' vent has been added.
• Solvents which may be used in connection with the last-mentioned method of washing raw wool include, on the one hand, hydrocarbons such as benzene, hexane and the like and, on the other hand, water-soluble alcohols such as methanol, ethanol and propanol, or partially wa- 3,458,543 Patented July 29, 1969 ter-miscible higher alcohols, for instance butanol or amyl alcohol.
• the wool obtained by washing raw wool in an alkaline aqueous liquor containing soap or synthetic detergents is of high quality, however, it is rather difiicult to separate lanolin from the spent washing liquor. Due to the fact that the impurities which are transferred from the wool to the Washing liquid amount to up to one-half of the weight of the raw wool, it is obvious that the spent washing liquid contains a very high concentration of impurities. From an economic point of view, it is important to achieve as complete as possible a separation of lanolin from the spent washing or scouring liquor because the lanolin per se is a valuable raw material and because it is rather difficult to biologically degrade lanolin and, consequently, waste waters containing significant amounts of lanolin are diflicult to dispose of.
• the methods which have been suggested for removing lanolin from the spent scouring liquor obtained in the washing of raw wool with an aqueous, soap or synthetic detergents-containing liquid include the following:
• the present invention contemplates a method of removing lanolin from spent alkaline scouring liquor obtained by scouring of raw wool with an aqueous, alkaline solution of soap or detergents, comprising the steps of mixing the spent liquor with an alcohol having between six and eight carbon atoms per molecule, the alcohol being admixed in an amount sufficient to cause separation of the thus formed mixture into a heavier, aqueous, substantially lanolin-free phase and a lighter lanolin-containing alcoholic phase, and separating the phases from each other.
• the scouring liquor which is free of solvents for lanolin may include sodium carbonate and have a pH of between 7.5 and 10, and furthermore, the spent alkaline scouring liquor, prior to mixing with the alcohol is subjected to centrifuging so as to remove a major portion of its original lanolin content therefi'om, and the alcohol which is admixed to the scouring liquor is n-hexanol and is admixed in an amount equal to between about 1.5 and 2.5% of the volume of the thus-formed mixture.
• the lanolin is then recovered from the thus-formed lanolin-containing alcoholic phase and the simultaneously separated alcohol of the alcoholic phase is recycled and may be admixed to subsequent portions of spent alkaline aqueous scouring liquor for removal of lanolin therefrom.
• the present invention is concerned with the recovery of lanolin from spent scouring liquor obtaining the scouring of raw wool with an aqueous, alkaline, soap or synthetic detergent solution which preferably contains sodium carbonate, i.e. an alkaline solution having a pH which generally will be within the range of between 7.5 and 10.0 but most frequently between about 8.0 and 9.5.
• the thus-obtained spent scouring liquor will contain substances which had been washed out of the wool such as suint, solid impurities of different specific weight and size, and wool grease, i.e. lanolin and also chemical agents added in order to separate the wool grease from the raw wool, such as washing agents, either soap or anionic or non-ionic detergents, and sodium carbonate.
• the spent scouring liquor will be free of solvents for lanolin.
• the amount of suint, and of the chemical agents which are to be added, will depend on the specific technological conditions of the raw wool scouring process.
• the amount of solidimpurities in the spent scouring liquor will depend on the type of raw wool which is scoured, and on any pretreatment of the spent scouring liquor, i.e. whether or not the same has been subjected to centrifuging and thereby solid impurities and a considerable portion of the lanolin content of the spent scouring liquor have been removed prior to subjecting the same to the process of the present invention.
• aliphatic alcohols with between 6 and 8 carbon atoms per molecule, although it is also possible to carry out the process of the present invention with aromatic alcohols of between 6- and 8 carbon atoms per molecule, however, at a somewhat lower efiiciency.
• aromatic alcohols of between 6- and 8 carbon atoms per molecule, however, at a somewhat lower efiiciency.
• n-hexanol as the alcohol which is to be admixed to the spent alkaline scouring liquor.
• the lanolin is recovered from the spent scouring liquor obtained by the washing of raw wool with alkaline aqueous soap and/ or synthetic detergent-containing washing liquors, either directly or after first removing solid impurities and a portion of the lanolin by centrifuging, by admixing a relatively small proportion of an alcohol containing between 6 and 8 carbon atoms per molecule to the spent scouring liquor whereby it will be accomplished that the lanolin which is emulsified and dispersed in the spent scouring liquor will separate into an alcoholic layer.
• This process can be, and preferably is, carried out without changing the pH of the alkaline, aqueous spent scouring liquor.
• two separate phases are obtained, either by allowing the mixture to stand and thereby to separate into two phases or by centrifuging, namely an upper layer or phase of lower specific gravity consisting of alcohol, lanolin and possibly a small proportion of water, and a lower layer or phase of higher specific gravity consisting essentially of water and being substantially, but generally not completely, free of lanolin, and also containing the washing agents such as soap or detergents, wool sweat salts and the like as Well as a portion of the alcohol corresponding to its solubility in the aqueous phase.
• the heavier aqueous phase is then freed of dissolved alcohol by boiling and may either be directly recycled for use in the subsequent washing of raw wool or first subjected to purification.
• the regenerated alcohol may be recycled and reused for admixture to subsequent portions of spent alkaline aqueous scouring liquor for the purpose of separating lanolin therefrom.
• the lanolin which is contained in the alcoholic phase of lower specific gravity is separated from the alcoholic phase by centrifuging at a temperature which should be higher than 40 C. and up to 80 C., or is obtained as distillation residue after steam distillation or direct heat distillation of the alcohol, the latter distillation preferably being carried out under reduced pressure in a manner known to those skilled in the art.
• the thus-obtained regenerated alcohol may then be reused for admixture to subsequent portions of spent alkaline aqueous scouring liquor.
• the separation of lanolin which is present in emulsified condition in the spent alkaline aqueous scouring liquor does not require changing the alkalinity of the spent liquor which generally is within the range of pH 7.5-10.
• the pH value of the scouring liquor and thus also of the spent scouring liquor will vary dependent on whether the scouring liquor contains soap or synthetic detergents. If the scouring liquor contains soap, the pH generally will be somewhat higher, such as between 8.5 and 10.0. On the other hand, if synthetic detergents and no soap are incorporated in the scouring liquor, then the pH will be somewhat lower, namely between about 7.5 and 8.5.
• the incorporation of sodium carbonate in the scouring liquor is generally desirable and the proportion thereof and thus the alkalinity of the scouring liquor will to some extent depend on the type of raw wool which is to be scoured.
• the sodium carbonate demand will be higher.
• the composition of alkaline aqueous scouring liquors containing soap and/or detergent are well known to those skilled in the art and, per se, do not form part of the present invention.
• the minimum pH which is desired for the removal of lanolin from the spent scouring liquor in accordance with the present invention will be about 7.5 and since generally sodium carbonate will be one of the constituents of the scouring liquor, the pH of the same always will be at least that high. An excessively high pH value, higher than 10, would not affect the method of the present invention, but would not be desirable because it would lower the quality of the wool which is scoured.
• the scouring of the wool by means of an aqueous soap or synthetic detergentcontaining liquor is always carried out in an at least slightly alkaline medium, while the scouring processes which are performed in a neutral medium require the use of solvents for lanolin which solvents are not included in the type of spent scouring liquor which is treated according to the present invention.
• Lanolin is only slightly soluble in alcohols having between 6 and 8 carbon atoms per molecule and thus the lanolin in the alcoholic phase obtained as described above it not in dissolved condition.
• the admixture of alcohol to the spent scouring liquor containing either its initial lanolin content or (as generally will be the case) only the residual portion thereof which could not be removed by centrifuging will cause a change of the polar forces in the spent alkaline aqueous scouring liquor which will cause the emulsified lanolin of the spent scouring liquor to pass in the form of a dispersion of lanolin into the alcoholic phase, from which the dispersed lanolin can be separated by centrifuging or distillation.
• the lighter phase i.e. the lanolin in alcohol dispersion
• the lighter phase may be split by centrifuging whereby the relatively small difference between the specific weights of lanolin and of the above-described alcohols will require a relatively powerful centrifugal field and a relatively long period of centrifugation.
• the temperature during centrifuging should exceed 40 C., in order to be safely above the solidification point of lanolin which is at 39 C.
• distillation may be used as the method for separating the alcohol from the lanolin of the alcoholic phase, whereby care should be taken only not to overheat the lanolin, i.e. not to expose the lanolin to a temperature above C., since at this temperature and higher temperatures the quality of the lanolin might suffer. Since the boiling point of the alcohols containing between 6 and 8 carbon atoms per molecule is higher than 120 C., it is therefore desirable, in fact practically necessary, to carry out the distillation under a partial vacuum.
• the method of steam-stripping will be useful only for the separation of some of the mentioned alcohols, such as aliphatic alcohols with between 6 and 8 carbon atoms per molecule, from the lanolin-containing alcoholic phase.
• alcohols such as aliphatic alcohols with between 6 and 8 carbon atoms per molecule
• the alcohols will be separated as an azeotropic mixture having a boiling point below 100 C.
• the required addition of alcohol will be equal to between about 1 and 10% of the volume of scouring liquor which is to be treated, and the optimum proportion will be between 1.5 and 2.5% by volume thereof.
• the effectiveness of the lanolin separation remains practically unchanged so that a slight excess of alcohol has no disadvantageous results.
• Suitable alcohols which may be admixed to the spent alkaline aqueous scouring liquor for the purpose of separatink lanolin therefrom, in accordance with the present invention, include the following hydrocarbyl alcohols: nhexanol, secondary hexanol, teritiary hexanol, cyclohexanol, benzyl alcohol, n-heptanol, n-octanol, secondary octanol, tertiary octanol, iso-octanol, or mixtures of the same.
• the best effect is achieved with aliphatic hexanols. If the alcohols with between 6 and 8 carbon atoms per molecule are replaced with alcohols having between 1 and carbon atoms per molecule or alcohols having 9 or more carbon atoms per molecule, it is not possible to destroy the lanolin emulsion in the spent scouring liquor without changing the pH of the spent scouring liquor, and thus, it is not possible in the simple and effective manner of the present invention to form an alcoholic phase having dispersed therein the lanolin which prior thereto has formed an emulsion in the spent scouring liquor.
• n-hexanol Upon the addition of, for instance, n-hexanol to the spent alkaline aqueous scouring liquor, it will sufiice to simply permit the mixture to rest or to subject the same to centrifuging, in order to obtain two separate phases, namely an upper more viscous phase of lower-specific gravity consisting of lanolin and the excess amount of solvent beyond the amount thereof which has been dissolved in the aqueous phase.
• This upper lanolin-containing layer may be equal to about 15% of the total volume of the mixture while the lower layer may amount, for instance, to about 85% of the volume of the mixture of alcohol and spent scouring liquor and will consist of a clear, brown-colored aqueous liquid.
• the method of the present invention can be carried out irrespective of whether a portion of the original lanolin content of the spent alkaline aqueous scoured liquor has been previously separated, for instance by centrifuging, or whether the spent scouring liquor which is subjected to the treatment according to the present invention still contains its entire original lanolin content.
• the proportion of lanolin in the spent scouring liquor which is treated according to the. present invention rises then, with increasing concentration of the lanolin, also the residual lanolin concentration in the aqueous phase of the spent scouring liquor treated in accordance with the present invention will increase.
• the spent scouring liquors obtained by the washing of raw wool with aqueous or synthetic detergent solutions which generally contain sodium carbonate can be worked up with high effectiveness so as to obtain substantially the entire lanolin content thereof in a relatively pure form, so that the thus recovered lanolin can be easily further processed, including the portion of the lanolin of the scouring liquor which up to now apparently could no be effectively recovered.
• the separation of the lanolin can be carried out without changing the pH of the spent scouring liquor.
• the use of chemical agents for changing the pH and the generally required rather complicated devices for dosing such chemical agents and for controlling the pH of the solution can be dispensed with.
• the natural composition of the lanolin is maintained according to the present invention while this composition is usually changed and impaired during changes in the pH of the spent scouring liquor.
• the amount of alcohol which is to be used in accordance with the present invention may vary within a rather wide range without changing the effectiveness of the process, it is possible to admix the alcohol by means of very simple dosing devices or the like.
• the possibility of using a relatively small proportion of alcohol of the type described for separating lanolin from the spent aqueous scouring liquor, and the high yield in which lanolin is thus separated results in a highly economical process.
• the spent scouring liquor from which lanolin has been removed in accordance with the present invention can be easily further purified by conventional biological methods.
• Example I A sample of spent scouring liquor obtained from scouring of a lower grade raw wool blend in an alkaline soap and sodium carbonate solution was taken after the spent scouring liquor had been pretreated by centrifuging in the first step centrifuge (type QX 210-79 B De Laval) of the conventional lanolin station, i.e. after the spent scouring liquor had been relieved of the major part of centrifugally separable lanolin and of solid impurities.
• This spent liquor had a pH value of 9.8 and contained 14.2 grams per liter of emulsified lanolin.
• the lanolin content was determined in a Soxhlet apparatus as etherical extract from dry matter obtained by steam-stripping of a precise volume of spent liquor acidified by means of phosphoric acid causing slightly acid reaction, and the dry matter was displaced from the steaming vessel quantitatively into an extractional shell by means of sea sand.
• the ether was steam-stripped from the extract and the residue, after drying to constant weight, weighed as lanolin at 105 C.
• a measured amount of the sample was introduced into a separating vessel, 1.5% by vol. of n-hexanol was added at 20 C. and the content of the vessel was shaken manually five to ten times.
• the mixture of the alcohol and the spent scouring liquor was put into cells of a laboratory cell-centrifuge. After min. centrifuging two distinctly separated phases were obtained-besides a small volume of bottom sludge sediment-the upper one, specifically lighter, consisting of the wool grease or lanolin, of the added alcohol minus the part thereof dissolved in the aqueous phase, and of a small amount of water; the lower, specifically heavier phase was a brown coloured clear liquor consisting mainly of water substantially free of lanolin.
• the lighter phase was separated from the so treated spent liquor.
• the grease residue remaining in the thus treated spent liquor was recovered and found to be equal to 354 milligrams per liter, so that the yield from one liter of the so treated liquor was 13.85 grams of lanolin.
• the lighter phase was poured into a flask with ground neck provided with a steam pipe discharging at the bottom of the flask and with an outlet for steam leading to a condenser.
• n-hexonal was expelled as an azeotropic mixture.
• Two phases remained in the flask, the lower one consisting of steam condensate pollute-d by suint, detergents and the like from the wool grease, and the upper one consisting of alcohol-free grease recovered.
• Example II A sample of spent liquor from scouring Australian raw wool with an alkaline aqueous scouring liquor containing a non-ionic detergent (Slovapon) and sodium carbonate, was taken after pretreating of the same on the first step centrifuge (type Nozzle Separator SVK 4 De Laval) in the lanolin station, i.e. after the spent liquor was relieved of a portion of the centrifugally separable lanolin component.
• This spent liquor had pH value of 8.8 and contained 17.0 grams per liter of lanolin determined as described in Example I.
• Example II After 10 min. centrifuging, similarly as in Example I, two separated phases were obtained; the lower aqueous phase contained substantially the same amount of wool grease residue. Alcohol was separated from the upper lighter phase in the same manner as in Example I.
• Example III A sample of a non-centrifuged spent alkaline, aqueous scouring liquor obtained by scouring Australian raw wool with an aqueous solution of sodium carbonate and of a non-ionic detergent (Slovapon) was taken.
• This spent liquor had a pH value of 8.8 and contained 24.2 grams per liter of lanolin determined as in Example I.
• To measured amounts of the sample in two separating vessels, 2% and 5% by vol., respectively, of n-hexanol were added at 20 C. After shaking, both samples were centrifuged or allowed to stand.
• the wool grease residue in the first sample was 2.38 grams per liter, and in the second sample 2.39 grams per liter. Thus the difference was negligible and the yield was 21.82 grams of lanolin from one liter, which corresponds to an efiiciency of 90.25%.
• Example IV A sample of spent liquor similar to that described in Example II was mixed at 20 C. with 2% by vol. of cyclohexanol and after manually shaking (five to ten times) it was centrifuged or let stand as in Example II.
• a typical scouring liquor which, after having been used for the washing of raw wool, may be freed of lanolin in accordance with the present invention, may have the following composition:
• a method of recovering lanolin from spent alkaline scouring liquor obtained by scouring of raw wool with an aqueous, alkaline solution of soap or detergents comprising the steps of mixing a spent alkaline scouring liquor, which is free of solvents for lanolin and has a pH of between 7.5 and about 10, with a hydrocarbyl alcohol having between 6 and 8 carbon atoms per molecule, said alcohol being admixed in a proportion above that which is soluble in said spent alkaline scouring liquor and which is at least equal to about 1% and below 25% of the volume of said alkaline scouring liquor, so as to cause separation of the thus-formed mixture into a heavier, aqueous, substantially lanolin-free phase and a lighter lanolin-containing alcoholic phase; and separating said phases from each other.

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• Chemical Kinetics & Catalysis (AREA)
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• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Detergent Compositions (AREA)
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• 1966
  • 1966-03-17 DE DE1617012A patent/DE1617012C3/de not_active Expired
  • 1966-03-21 BE BE678188D patent/BE678188A/xx unknown
  • 1966-03-22 US US3458543D patent/US3458543A/en not_active Expired - Lifetime
  • 1966-03-22 GB GB1246466A patent/GB1112596A/en not_active Expired
  • 1966-03-22 DK DK147366A patent/DK118517B/da unknown
  • 1966-03-23 SE SE383966A patent/SE327488B/xx unknown
  • 1966-03-24 BR BR17814866A patent/BR6678148D0/pt unknown

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