FI118007B - Procedure for separating sterols from pine pitch - Google Patents

Description

:, 118007

Method for separating sterols from pine oil lime

The present invention relates to a process for separating sterols from tall oil pitch according to the preamble of claim 1.

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Plant sterols have recently begun to be used as dietary supplements because they prevent the deposition of cholesterol in human blood vessels.

Sterols are created eg. wood, which is a by-product of the cellulosic industry.

10 Then they get into the pitch of tall oil when the fatty and resin acids are distilled off of tall oil. The tall oil pitch, referred to as TOP (tall oil oil pich), represents approximately 25% of the total tall oil recovered from the digestion of cellulose.

Sterols have molecular weights of the order of 415 and 280-300 of the fatty acids and the same of the resin acids. A typical tall oil pitch produced in Scandinavia and produced by Scandinavian processes has a composition of 70-85% of neutral substances, 5-2% of fatty acids and 12-18% of resin acids. Neutral materials contain 45 to 15% sterols, and since the pitch is further composed of other substances, 20 sterols are 11-17% overall. In Scandinavia, one third of the steroids are free • · ·; ··; * sterol and 2/3 are sterol resin and fatty acid esters.

• '. r • · * * · · · TOP also contains a large proportion of various dimers and trimers, wax alcohols,

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· · · · · · · · · · · · · · · · · · · Lignin derivatives, which are even higher in molecular weight than sterols! • · · 25

Different types of sterols have been proposed for the separation of sterols from tall oil, sapwood, or tall oil pitch> • · * · ·

•; j; and about 70 patents have been published. I

• · t «* * · · •" lir ..I "Typically the pitch of tall oil is treated with alkali, such as NaOH or KOH, to make acids • · · * * r

'···' 30 would be separated into salts in the water phase and so that the sterol esters S

Would be converted into hydrolysed free sterol alcohols. Usually at this point Saponification and alkaline hydrolysis is carried out by boiling tall oil pitch or tall oil for about 45-60 min in an alkaline alcohol mixture of 10% NaOH or 118007 KOH in lower alkanol such as methanol, ethanol or butanol. An example of the prior art is the solution disclosed in CZ 256092. When the resulting solution is neutralized by adjusting its pH to 6.9 to 5.8, a rapid phase separation is obtained, whereby the neutral substances remain in the upper organic phase and the 5 aqueous salts remain in the salts of fatty and resin acids.

A similar operation can also be accomplished without the use of an alcoholic solvent and even without acid neutralization, but the separation of the phases takes days. This is due to the good emulsifying ability of the resin and fatty acid soaps.

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Generally, sterols, along with other neutral substances, are separated by extraction with a hydrocarbon solvent (Hamunen US 6,770,767, Kutney US 5,770,749 Johansson US 4,044,031,

Holmbom U.S. Pat. No. 3,965,085, U.S. Pat. No. 4,495,094, etc.) When the acids have been removed with alkali and the mineral acid used to neutralize the mixture, a large amount of contaminated brine (usually Na 2 SO 4) is obtained which is difficult to handle and environmentally hazardous.

The extraction of neutral substances with solvents, in turn, requires continuous purification of the solvent by distillation.

• * • · · * y: * If and when the pitch has been treated with alkali, ie mainly NaOH / KOH, these must be removed • · * • ^ '#: very carefully washed, washed with water, etc. so that they do not undergo subsequent heat treatments • · ·. · J would cause problems. This means that the alkali salts * * * · ... · 25 of fatty acids and resin acids form highly viscous solutions in the hot state when further purification is performed by vacuum distillation. Further, if the sterol-depleted waste is incinerated encountering problems due to alkali, the ash which directs the boilers has a low melting point so that it adheres to the heat transfer tubes. . For example, Na2SO4 > m has a melting point of 884 ° C.

3o! • i::; To solve this distillation problem, e.g. the following solutions in patent litigation:; U.S. Patent No. 6,780,831 to Hamunen, U.S. Patent No. 3,800,797, proposes the addition of a plasticizer to reduce viscosity in distillation. One embodiment of the separation of sterols is by extraction of the neutral substances as a solvent and addition of a Ca salt which forms with the sterols a solvent-insoluble precipitate which is separated by filtration (CS 250645). The Ca salt is also added to lower the melting point of the Na-K fatty acid / resin acid salts so that distillation can be performed (WO 03/0520341,

Resitec)) Then a relatively small amount of Ca-Zn-Mg salts will lower the melting point of the Na / K fatty acid / resin acid salts. The hydrolysis is first performed with Na, K-alkali.

The problem with the separation of the sterols is the separation of the steps whenever water or solvent is used to remove some of the starting material.

When alkali is used for hydrolysis of sterol esters, separation of the aqueous phase by decantation is practically impossible, or it will take days, unless the alkalis are neutralized with acid to pH 6.9 to 5.8, whereby the organic acids are not yet separated. However, this causes a salt water problem and a waste problem, as even after further acidification, organic matter remains in the water and the yield is reduced. However, the phase separation is easy when the temperature is high enough> 150 ° C.

As water is released in the formation of esters, it is known that esters can also be hydrolyzed by addition of water. However, this requires a long time and a high temperature, * 150 ° C, namely 150-250 ° C, which corresponds to a pressure of 5 -40 bar. In U.S. Patent ··· 5,097,012, the salt is treated at a pressure of about 90 bar, at a temperature of about 300 ° C, where the sterol esters also appear to be hydrolyzed. U.S. Patent 4,524,024 hydrolyses • · ·. The sterol esters with hot water at 40-70 bar and distilling the water vapor by distillation and finally the sterols are purified by dissolving in the solvent, filtering and crystallizing.

• ♦: The methods described have quantities of chemicals used as a problem. In addition, j * · * • · * · ”* solutions have clarity problems that cause problems with yields, .. * · * because the differences are not sharp.

»· · 30 •; : A problem not addressed at all in the patents and other literature described is the handling and use of post-sterol separation material.

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4, 118007

If 100,000 tonnes / a of TOP feed is processed, 8-9,000 tonnes of pure sterol / stanol product and more than 90,000 tonnes / small pitch that could potentially be used as fuel are obtained. In known processes using alkali metal hydrolysis, the amount of ash doubles from what it was in the feedstock.

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Instead, in the process of the invention, which is described in more detail below, the amount of ash in the end product burner is reduced. If the ash contains mainly Na / K salts, they are formed into oxides and carbonates with a low melting point and high boiler slagging. For example, the melting point of Na 2 SO 4 is 884 ° C and the normal temperature of the flame 10 is generally 1800 to 1500 ° C when burning pitch.

It is an object of the present invention to provide a solution which provides for the separation of sterols / stanols from tall oil pitch, so that at least some of the major drawbacks can be avoided.

In almost all of the approximately 70 patents which deal with the separation of plant sterols from vegetable waste or tall oil or tall oil pitch, the water is at some point dried off from the organic product so that it can, for example, be dried. distillates under vacuum. Likewise, they are washed with water prior to drying to reduce alkali metal residues. The low alkali-20 metal content is justified by the fact that the bottom product has a high viscosity and distillation difficulty due to alkali metal soaps. For this reason, a few patents have added Ca Mg salts before distillation (WO 01/98444 A2, WO 031052034 A1) ♦ * · * ... * at a later stage to take the viscosity and melt point of the distillation base product ♦ ♦ • · ·

· * ·· · would be reduced to the point where the product does not decompose and the sterol fraction to be distilled (WO

* ··· * 25 031052034 / Recitec Industria Qhimica).

The present invention is based on the idea that the pitch of tall oil is mixed with an excess of water to form a mixture, the mixture is homogenized at 150-300 ° C and at an elevated temperature. under pressure to keep water in the barrier phase, the homogeneous mixture is recovered, the phases of the mixture are separated, the organic phase is recovered and the desired sterols are separated from the organic phase. According to the invention, sterol esters in tall oil * · · * · * · are efficiently hydrolyzed without the addition of alkali metal hydroxides and such bases.

More specifically, the method according to the invention is essentially characterized in what is set forth in the characterizing part of claim 1.

The invention provides considerable advantages. Thus, the invention enables the hydrolysis to be carried out without the addition of alkali metal salts. Excess water, which is not needed for hydrolysis, extracts the worst part of fatty and resin acids into water at the temperatures used, whereupon the organic acids are decanted from the water when the solution is cooled (this section of process diagrams 1, 2 and 3)

According to the diagram, the neutral substances do not dissolve at all in hot water, but the resin acids / fatty acids dissolve quite completely. When sufficient water is used at this stage, the decanting steps may also be used to wash the further fractions to be free of salts. These salts have already appeared in the separation of lust. If a small peak from sterol separation of about 70-75% of the TOP of the feed is used as a fuel, it is highly preferred that it contains a minimum amount of sodium / potassium salts. ;

No other salts have been added in the process of the invention.

Hydrolysis requires 5 to 7 h without homogenization (U.S. Patent 6,815,551 / Cognis *> · * ··· Deutschland GmbH). Homogenization can halve the time, especially when k *: · water is used so that the transfer surface is sufficient.

Thus, in the first step of the invention, the sterol esters contained in the immediate product «· * · ... · 25 are hydrolyzed using a sufficient amount of water and homogenization is continued until the bulk (over 50 mol%, especially 60-100 mol%) of sterol esters have been · · · · hydrolyzed to the corresponding free acids. The temperature of the homogenization is maintained at 170 ° C to 280 ° C, preferably 220 ° C to 280 ° C, and the pressure is high enough to maintain the water in the liquid phase (generally about 20-100 bar, especially about 25-70 bar). bar).

• · »30 •. 'f j * Add at least the amount of water to the tall oil pitch necessary to hydrolyze the sterol fraction and possibly other ester fractions, but preferably about four times the minimum, for phase separation. Even more preferably, about 20 times the amount of 6,118,007 is added, which represents about 60% of the amount of TOP fed, as this results in a high mass transfer area between the water phase and the organic phase to be hydrolyzed.

Another alternative is to use this much larger amount of water, namely 150%, preferably 150-1000%, by volume. Water is thus used in an amount that avoids the stepwise conversion of the pitch-water dispersion (less than 60% or more than 150%).

10 The product is fed into a homogenizer, with a small clearance rotating a multistage rotor within a multistage same-pole stator. Alternatively, the product may be homogenized as milk is first pumped over a high pressure drop to form small droplets The homogenizer "grinds" into insoluble organic phase droplets, then pumped and heated to about 15 220-280, e.g., about 250 ° C, to a temperature of 25 to 70 bar, e.g. about 40 bar,

for rapid hydrolysis. I

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The homogenization forms an emulsion. The average droplet size of the emulsified droplets is e.g. about 0.5 to 5 micrometers, preferably about 0.6 to 2 micrometers.

.V. According to our invention, the product is first clarified at an initial temperature of 220 to 280 ° C, ·· 1 to separate the aqueous phase with a relatively high content of fatty and resin acids (3 · · · · - 7%, temperature) and most of the dissolved salts. Now, by reducing the temperature in beaker 2 and • ♦ JJ · beaker 3 to about 95 ° C, fatty acids and resin acids • 1 · · ... 1 25 are separated and returned to the start of refining of the tall oil refinery. The same applies to beaker 3, which releases water and salts. The water stream of the decanter 3 is discharged completely, or at least partially, into the sewer to reduce salts in the process.

We now have a TOP product from which sterol esters have been hydrolyzed to free steryl alcohols and ··· 30 fatty acids and resin acids, and most of the fatty acids and resin acids have been removed by pressure water: extraction.

··· · • · · · 1 · • · 7 118007

Subsequently, the volatile components such as residual water and any decarboxylation products which are produced in small quantities at high hydrolysis temperature are distilled. The pressure is 0.1 to 1 mm Hg and the temperature is about 150 to 170 ° C. The distillates still contain fatty and resin acids as well as wax alcohols and oils derived therefrom.

The bottom product of this distillation is optionally further distilled before final sterol distillation at a pressure of 0.01 to 0.05 mmHg and at a temperature of 170 to 180 ° C to give a distillate containing fatty acids and resin acids already containing about 20-30% sterols. The distillate will be restored to the peak of refining of tall oil. The previous operation 10 is carried out in order to make the next distillate so pure that the purification by crystallization would be easy. At this stage, 5 to 15% of the feed is taken.

t

The bottom product of the previous distillation, i.e. the distillation residue, is distilled at a pressure of 2 x 10 -3 mbar and a temperature of 150-170 ° C, whereby 30-50% of the distillate is taken from the distillate.

The distillation residue from this distillation, which is well over half of the total feed, may optionally be incinerated or used for other purposes. Upon combustion, the organic material is now nearly ash free, containing about 0.05% Na 2 SO 4, as compared to 0.3% initially. Distillation- * * i •; · · · The residue may have uses other than incineration, as it can be a useful substitute for ·· * eg tar in wood surface treatment.

• · · · • · · '• · • · · ·! ·.' * * · · '·' ·· i ·. ·; According to our invention, sterols can be separated from tall oil pitch so that almost no waste water problem is developed. If the feed were 100,000 tons per year, all methods using NaOH / KOH hydrolysis and acidification would produce about 200,000 tons / s of saline, dirty waste water and waste 10,000 tons / a of NaOH. ** · Sulfuric acid of more than 12,000 tonnes / a. Also, the industrial incineration of the remaining 70,000 tonnes / a of waste ... ϊ is not a problem in the process according to our invention.

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In the following, the details of the process of the invention will be examined on the basis of the accompanying drawing * · * *. **. It should be noted that the water used must be at least RO-purified water.

: f 8 118007 TOP and the water is fed to the homogenizer 1, whereupon the mixture they form is pumped to a heat exchanger where the temperature of the mixture is raised to the desired level, that is, about 220 to 280 degrees, and a pressure so high that the water does not evaporate. Water is preferably supplied at about 60% by volume or alternatively more than 150%, but most preferably not between this range. Between 60 and 150% can lead to so-called. stepwise inversion, where clarity cannot be guaranteed within a reasonable time.

Preferably, the hydrolysis vessel 2 is a vertical pressure vessel having a filler pack, 10 continuously dividing the flow, and beginning to clarify the micrometer droplets obtained in the homogenizer into ever larger droplets, which are finally clarified in the beaker 3. separated into fatty acids and resin acids and returned to the start of the tall oil distillation process. ; 15

After cooling the beaker for 5 minutes, some water and salts are still separated from the neutral fraction / sterol fraction. This water phase is, as a rule, discharged into the sewer to remove the salts i from the process.

The neutral fraction is now led to thin film evaporation 6 where it is dried, distilled water and a small amount of fatty acids with water are returned to the start of the separation process. Distillation · -: V: is carried out at a pressure of about 0.1 to 1 mm Hg and at a temperature of 150 to 170 ° C, whereby ** condensation occurs at 100 to 110 ° C.

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This gives a hydrolyzed, dried, almost salt-free raw material, of which most j * · ·.

Fatty acids have been removed by dissolution in pressurized water. Preferably, from 5 to 15% of this feed is distilled in a short path evaporator, 5 to 15%, which in turn will contain about 20 to 30% sterols. The distillate is returned to the tall oil distillery for a small amount or to a process for small supply.

30 • · · - i

The bottom product of the previous evaporation is now the feed of the next evaporation 8. In this short path evaporation 8, distillate is taken at about 30% to about 50%, preferably at about 2 x pressure: *: '! · "· · · 9 118007 10" 3 mbar and preferably at 170-180 ° C, with a condensation temperature of about v 115-130 ° C;

The inside of evaporators 7 and 8 is formed by a water cooler.

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The bottom product is now a waste pitch that can be easily burned due to low ash content or used in polyurethane production or as an epoxy resin filler or ink binder.

The distillate is now a sterol fraction containing 55-70% beta-sitosterol. The distillate is dissolved in ethyl alcohol at 76-78 ° C 9, filtered 10 and crystallized 11 by lowering the temperature 4 and adding a small amount of pure water. The crystal is centrifuged after lowering the temperature to 15-20 ° C and washed in the centrifuge 12 with a small amount of 96% ethanol at 10 ° C. From the separator 12, the crystals go to drying and ethanol to distillation.

The crystallization may be carried out a second time to improve purity. 98-98.5% beta-sitosterol is obtained. ?

The bottom products of ethanol distillation can be returned to evaporation 7 or pumped directly to the waste pitch fraction.

* 1 • • 1 1 • • * 1 1 • 1 · · · · 1 · 1 · · · · 1 1 · 1 · 1 · 1 • • • • 1 • · 1 # 1 · • • • • • • • • • • • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · to · · · · · · · · · · ·: • ·

Claims (14)

A process for separating sterols from a tall oil order product, characterized in that the pitch of 5. tall oil is mixed with water to form a mixture, the water being added to at least as much as is necessary to hydrolyze the sterol fraction and possibly other ester fractions. and at elevated pressure to retain water in the liquid phase, 10. the homogeneous mixture is recovered, - the mixture steps are separated, - the organic phase is recovered, and - the desired sterols are separated from the organic phase, hydrolyzing the sterol esters in to the corresponding free acids. Process according to Claim 1, characterized in that the temperature of the homogenization is maintained at 170-280 ° C, preferably at 220-280 ° C. 20 The process according to any one of the preceding claims, characterized in that the amount of water is at least four times greater than that required for the small sterol esters and optionally the resin / fatty acid esters contained in tall oil. • J: for hydrolysis, preferably water up to 60% by volume of the supplied tall oil • 25 *. *. Method according to claim 1 or 2, characterized in that the amount of water is at least 150%, preferably 150-1000%, by volume. • · * * * * * · • * · • · *; * 30 The method according to any one of the preceding claims, characterized in that the homogenization of the * * *. *. * Emulsion produces an emulsion droplet having an average droplet size of about 0.5 to 5 micrometers, preferably about 0.6 to 2 micrometers. i Π 118007 A process according to any one of the preceding claims, characterized in that a) water is added to the tall oil pitch to at least the amount needed to hydrolyze the sterol esters and other esters, 5 b) the product is pumped through a homogenizer and heated to 170-280 ° C (c) decanting off the neutral fraction from the neutral fraction, containing a significant amount of fatty acids and resin acids, and recovering the organic phase; 10 d) cooling the two separated steps to below 100 ° C and decanting; further water steps are removed and fatty acids and resin acids are returned to the tall oil distillation process, e) the neutral fraction is dried to a drying process using e.g. a thin film evaporator, f) the vapor phase of the drying is recycled to the beginning of the process a) from 0.1 to 0.5 mmHg to about 5 to 15% of the amount of feed, and h) evaporating the base product of the preceding at 0.1 to 0.001 mmHg at 150-250 ° C, e.g., about 30 to 50% distillate consisting mainly of sterols and stanols which are recovered. 20 * * *: · *: Process according to claim 6, characterized in that the distillate obtained in (h) is dissolved in alcohol and crystallized and washed 1-2 times to give the pure sterol-stanol product. t · • · * ♦ · · • · «· *** * ... * 25 The process according to claim 6 or 7, characterized in that the mother liquor to be removed from the crystallization is distilled and the bottom product is added to the waste of step g. The process according to any one of the preceding claims, characterized in that the product and water are used to hydrolyze the sterol esters and other esters. is homogenized as such by a known multi-stage separator or homogenizer into a finely divided emulsion • · V ·: to accelerate the transfer of material. Method according to one of Claims 1 or 2, characterized in that; 1, 2 1 1 8007 water is used in an amount relative to the pitch volume of tall oil that no phase inversion of the dispersion can occur. I 10 1 18007 Process according to one of Claims 8 to 10, characterized in that thin film evaporators and / or short path evaporators are used as evaporators. Process according to one of Claims 8 to 11, characterized in that a short path evaporator is used in the final evaporation step of the process. Process according to one of the preceding claims, characterized in that the process is directly connected to a tall oil distillery and integrated into its hot oil and vacuum system. A process according to any one of the preceding claims, characterized in that the amount of water to be hydrolyzed is controlled by the instant forecast of tall oil distillation; from the bottom. • · • · · • · · ·; m; ** ··· 1 2 3 · * · ···. ' • ... • · 1 Φ • · · · * 1 • · · 1 ··· - ··· · * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · * · • «· · 1 • 1 1 2 • · • · · • • • 3. ··;.! • Ϊ „• · ·· 1. • · · · · · · · · ··· 13 1 1 8007