Fractionation of crude tall oil

Abstract

The present invention is directed to the fractionation of crude tall oil originating from Kraft black liquor. In the process according to the invention, at least two strong base anion exchange resins are used to efficiently separate fractions from crude tall oil.

Description

[Technical Field]

[0001] The present invention is directed to the fractionation of crude tall oil originating from Kraft black liquor. In the process according to the invention, at least two strong base anion exchange resins are used to efficiently separate fractions from crude tall oil. [Background technology]

[0002] During the production of kraft pulp, black liquor is formed and removed from the produced pulp. The removed black liquor contains soap, which must be separated from the black liquor because the soap contains valuable raw materials. The water from the black liquor is then evaporated, and the black liquor soap is skimmed and acidified to produce crude tall oil (CTO). Another reason for separating the soap from the black liquor is that the soap can cause problems during subsequent processing steps of the black liquor.

[0003] The separated soap contains extractives, water, lignin, inorganic compounds, fiber, and some black liquor. The fatty acids and rosin acids of crude tall oil (CTO) are in the form of sodium salts in the soap. The amount of each component in the soap depends on the raw materials and their seasonal variations, the pulping method used, and the process by which the soap is separated from the black liquor, i.e., the soap skimming method. CTO is primarily composed of fatty acids (TOFA), rosin acids (TOR), and unsaponifiable matter.

[0004] CTO is a valuable raw material and it is important to recover as much of it as possible from the soap. CTO can be used as a raw material for a variety of chemicals and other products, such as biodiesel or detergents.

[0005] CTO can be isolated from soap by adding acid to the soap at a certain temperature. After mixing the soap with the added acid, tall oil is formed, which then separates into three main phases due to differences in phase density: CTO phase, lignin phase, and spent acid phase, also called brine. The lignin and spent acid phases are waste products during CTO production, and they need to be adequately separated from the CTO phase during CTO recovery.

[0006] The amount of acid needed to separate the optimum amount of CTO from the soap is determined based on the quality of the soap, e.g., CTO content, water content, fiber content, lignin content, and / or black liquor content. Currently, it is common to measure the density of the soap, as well as the pH and density of the spent acid, as a guide to the amount of acid and water that needs to be added to separate the optimum amount of CTO from the soap. These measurements are made online, and the amount of acid and water needed is then adjusted, i.e., feedback controlled.

[0007] Traditionally, CTO is fractionated into fractions such as heads (low-boiling compounds), fatty acids, rosin acids, and pitch (distillation residue) using vacuum distillation. Furthermore, because the boiling points of fatty acids and rosin acids are similar, intermediate fractions can be collected to prevent contamination of the fatty acid fraction with the rosin acid fraction. During the distillation of CTO at high temperatures, alcohols are esterified with carboxylic acids, resulting in a decrease in the yield of the free acid fraction and an increase in the low-value pitch fraction. Furthermore, thermal decomposition of compounds can occur during high-temperature distillation.

[0008] As mentioned above, CTO can be used to produce several different products. Alternatively, CTO can be first separated into unsaponifiable matter and high acid value tall oil. The high acid value tall oil can be further separated into rosin acids and fatty acids. The unsaponifiable matter fraction contains, among other things, phytosterols.

[0009] Phytosterols have multiple uses, including as food additives and as precursors to steroids. Several methods have been reported for the isolation of sterols from tall oil soap, including extraction of the neat soap with various organic solvents.

[0010] Currently, phytosterols are commercially produced, for example, from tall oil pitch. If the production of free phytosterols is the goal, the phytosterol esters must be hydrolyzed because esters are formed during distillation, which requires an additional processing step.

[0011] There is a need for an easier and more efficient process for producing phytosterols, preferably also high acid value tall oil, from crude tall oil. Summary of the Invention

[0012] Surprisingly, it has been found that the method according to the present invention can be used to more efficiently separate CTO into a neutral fraction and a neutral-depleted fraction. The neutral fraction mainly contains components commonly referred to as unsaponifiable matter. The neutral-depleted fraction mainly contains components such as sodium salts of fatty acids and sodium salts of rosin acids.

[0013] Therefore, the present invention provides a) providing a mixture comprising crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol; b) contacting the mixture from step a) with a strong base anion exchange resin; c) collecting at least a first fraction and a second fraction, each fraction comprising at least one component; d) contacting the first fraction recovered in step c) with a second strongly basic anion exchange resin; e) recovering the neutral fraction and the neutral-depleted fraction; The present invention relates to a method for separating components from crude tall oil, the method comprising:

[0014] The present invention is also directed to the fraction recovered in step c) of the process of the present invention. In particular, the present invention is directed to a composition comprising a sodium salt of a fatty acid and a sodium salt of a rosin acid, as well as a composition comprising phytosterols. After additional processing steps, a composition comprising high acid value tall oil can be obtained. [Brief explanation of the drawings]

[0015] [Figure 1]

[0013] Figure 1 is a schematic diagram of a process for separating components from crude tall oil. The diagram illustrates providing a mixture (1) containing crude tall oil and alcohol, contacting the mixture (1) with a strong base anion exchange resin (2), recovering a first fraction (3) and a second fraction (7), contacting the first fraction (3) with a second strong base anion exchange resin (4), and recovering a neutral fraction (5) and a neutral-depleted fraction (6). The neutral-depleted fraction (6) can be combined with the second fraction (7) if desired. DETAILED DESCRIPTION OF THE INVENTION

[0016] During the production of kraft pulp, black liquor is formed and removed from the produced pulp. The removed black liquor contains soap, which must be separated from the black liquor because the soap contains the valuable raw materials. The water from the black liquor is then evaporated, and the black liquor soap is skimmed and acidified to produce tall oil. Crude tall oil can therefore originate from the pulping of softwoods, hardwoods, or a mixture thereof.

[0017] The mixture (1) used in step a) preferably comprises at least 1 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, based on the total weight of the mixture. The alcohol is a solvent in which the tall oil is soluble and which also allows the strongly basic anion exchange resin to function. More preferably, the mixture used in step a) comprises at least 5 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, such as at least 10 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, or at least 15 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, or at least 20 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, or at least 25 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, based on the total weight of the mixture. Preferably, the mixture used in step a) comprises less than 75 wt. % of an alcohol selected from methanol, ethanol, and / or isopropanol, based on the total weight of the mixture. More preferably, the mixture used in step a) comprises less than 60% by weight of an alcohol selected from methanol, ethanol and / or isopropanol, such as less than 50% by weight of an alcohol selected from methanol, ethanol and / or isopropanol, based on the total weight of the mixture. The mixture used in step a) may comprise other components than crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol. However, the mixture used in step a) preferably comprises at least 40% by weight of crude tall oil, based on the total weight of the mixture. More preferably, the mixture comprises at least 50% by weight of crude tall oil, such as at least 60% by weight of crude tall oil, or at least 70% by weight of crude tall oil, at least 80% by weight of crude tall oil, or at least 90% by weight of crude tall oil, or at least 95% by weight of crude tall oil, based on the total weight of the mixture. Preferably, the alcohol used in the mixture used in step a) is methanol.

[0018] In one embodiment, the mixture used in step a) was prepared by mixing crude tall oil with an alcohol selected from methanol, ethanol and / or isopropanol. In one embodiment of the present invention, the mixture of crude tall oil with an alcohol selected from methanol, ethanol and / or isopropanol was contacted with a strongly acidic cation exchange resin before step b). The advantage of carrying out such a strongly acidic cation exchange step before step b) is that alkali metal salts can be removed from the mixture and residual soaps can be converted to at least some extent to a neutral form before step b), thereby leading to high yields and purity of the components in the first and second fractions.

[0019] The strongly basic anion exchange resin (2) used in step b) is preferably an anion exchange resin having quaternary ammonium groups incorporated into the polymer backbone.

[0020] In step b), the mixture (1) from step a) is contacted with a strong base anion exchange resin (2) in a column. In step b), the mixture from step a) is added to the strong base anion exchange resin. During the passage through the strong base anion exchange resin, the acidic components of the mixture adhere to the resin, while the neutral components of the mixture flow off the resin and are recovered as a first fraction (3). The flow rate through the strong base anion exchange resin is preferably 4 to 15 bed volumes per hour, such as 5 to 10 bed volumes per hour or 5 to 8 bed volumes per hour. The amount of CTO loaded onto the resin is based on the capacity of the strong base anion exchange resin, and is preferably 0.5 to 1 acid equivalent. The temperature used in step b) is preferably in the range of 10°C to 80°C, more preferably 20°C to 60°C, such as 30°C to 60°C, such as 40°C to 60°C or 30°C to 50°C.

[0021] During step c), a first fraction (3) is collected. Additional alcohol selected from methanol, ethanol, and / or isopropanol, optionally mixed with water, is optionally added to the column after the mixture of step b) to elute the remaining neutral components collected as first fraction (3). The flow rate through the column is preferably 4 to 15 bed volumes per hour, such as 5 to 10 bed volumes per hour or 5 to 8 bed volumes per hour. Preferably, the additional alcohol added is methanol.

[0022] Subsequently, as part of step c), the acidic components attached to the strongly basic anion exchange resin are released from the strongly basic anion exchange resin by the addition of a mixture preferably containing sodium hydroxide and an alcohol selected from methanol, ethanol, and / or isopropanol. The concentration of sodium hydroxide in the mixture is preferably 0.05M to 6.0M. The mixture of sodium hydroxide and an alcohol selected from methanol, ethanol, and / or isopropanol optionally contains 0% to 25% by weight of water, such as 0% to 10% by weight, 1% to 10% by weight, or 5% to 10% by weight of water. Preferably, the alcohol is methanol.

[0023] As the acidic components attached to the strong base anion exchange resin are released from the strong base anion exchange resin, they are recovered as a second fraction (7) that is depleted in neutral compounds.

[0024] After the second fraction is recovered, the strong base anion exchange resin is preferably regenerated using methods known in the art before repeating step b). Typically, the strong base anion exchange resin is regenerated simultaneously with the release of acidic components from the strong base anion exchange resin. When the acidic components are released from the strong base anion exchange resin, excess alkali can be removed from the strong base anion exchange resin by adding a pure alcohol selected from methanol, ethanol, and / or isopropanol. Preferably, the alcohol is methanol. When regenerating the second strong base anion exchange resin in step e), excess alkali can be collected and reused, thereby maximizing alkali usage.

[0025] The second strongly basic anion exchange resin (4) used in step d) is preferably an anion exchange resin having quaternary ammonium groups incorporated into the polymer backbone.

[0026] In step d), the first fraction (3) recovered in step c) is loaded onto a second strongly basic anion exchange resin (4). In step d), the first fraction recovered in step c) is preferably contacted with the second strongly basic anion exchange resin in a column. During passage through the second strongly basic anion exchange resin, the remaining acidic components of the first fraction adhere to the resin, while the remaining neutral components of the mixture flow off the resin and are recovered as a neutral fraction (5), thereby maximizing the yield and purity of phytosterols and improving the purity of the second fraction and the neutral-depleted fraction. The flow rate through the second strongly basic anion exchange resin is preferably between 4 and 15 bed volumes per hour, such as between 5 and 10 bed volumes per hour, between 5 and 8 bed volumes per hour, etc. The amount of the first fraction loaded onto the second resin is based on the capacity of the second strongly basic anion exchange resin and is preferably 0.1 to 1 acid equivalent. The temperature used in step d) is preferably in the range of 10°C to 80°C, more preferably in the range of 20°C to 60°C, such as 30°C to 60°C, such as 40°C to 60°C or 30°C to 50°C.

[0027] In step e), a neutral fraction (5) is collected. Additional alcohol selected from methanol, ethanol, and / or isopropanol, optionally mixed with water, is optionally added to the column after the mixture of step d) to elute the remaining neutral components collected as neutral fraction (5). The flow rate through the column is preferably 4 to 15 bed volumes per hour, such as 5 to 10 bed volumes per hour or 5 to 8 bed volumes per hour. Preferably, the additional alcohol added is methanol.

[0028] As part of step e), the acidic components attached to the strongly basic anion exchange resin are released from the strongly basic anion exchange resin by the addition of a mixture preferably containing sodium hydroxide and an alcohol selected from methanol, ethanol, and / or isopropanol. The concentration of sodium hydroxide in the mixture is preferably 0.05M to 6.0M. The mixture of sodium hydroxide and an alcohol selected from methanol, ethanol, and / or isopropanol optionally contains 0% to 25% water by weight, such as 0% to 10% or 1% to 10% water by weight, or 5% to 10% water by weight. Preferably, the alcohol is methanol.

[0029] As the acidic components attached to the second strong base anion exchange resin are released from the strong base anion exchange resin, they are collected as neutral-depleted fraction (6) and can be combined with fraction (7) if desired.

[0030] After step e), the second strong base anion exchange resin is preferably regenerated in the same way as the first strong base anion exchange resin is regenerated.

[0031] Therefore, the method according to the invention comprises the following steps: - providing a mixture (1) comprising crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol; - optionally contacting a mixture comprising crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol with a strongly acidic cation exchange resin; - contacting a mixture comprising crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol with a strongly basic anion exchange resin (2); recovering at least a first fraction comprising at least one component; - releasing the acidic components attached to the strongly basic anion exchange resin from the strongly basic anion exchange resin, preferably by adding a mixture comprising sodium hydroxide and an alcohol selected from methanol, ethanol and / or isopropanol; recovering a second fraction (7) comprising the at least one component and depleted in neutral compounds; - contacting the first fraction (3) with a second strongly basic anion exchange resin (4); recovering the neutral fraction (5); - releasing the acidic components attached to the second strongly basic anion exchange resin from the second strongly basic anion exchange resin, preferably by adding a mixture comprising sodium hydroxide and an alcohol selected from methanol, ethanol and / or isopropanol; recovering the neutral depleted fraction (6), which can be combined with a second fraction (7) if desired; Includes:

[0032] The first fraction (3) is the first fraction emerging from the first strongly basic ion exchange resin. The first fraction is partially acid-deficient. The first fraction contains components commonly referred to as unsaponifiable matter, including fatty acids, rosin acids, and solvents. The first fraction also contains phytosterols.

[0033] The first fraction is contacted with a second strongly basic anion exchange resin (4).

[0034] After contacting the first fraction (3) with a second strongly basic anion exchange resin (4), a neutral fraction (5) and a neutral-depleted fraction (6) are recovered.

[0035] From the neutral fraction (5), phytosterols are preferably separated from other neutral compounds. Surprisingly, it has been found that phytosterols can spontaneously crystallize in the neutral fraction. Advantageously, the obtained phytosterols are not esterified, as is typical for prior art processes. If such spontaneous crystallization cannot be achieved, the phytosterols can be separated from other neutral compounds by crystallization, such as evaporation crystallization, static crystallization, or cooling crystallization, essentially using methods known in the art. The alcohol selected from methanol, ethanol, and / or isopropanol can be distilled off, or alternatively, it can be part of the precipitation / crystallization solvent system. The alcohol selected from methanol, ethanol, and / or isopropanol is preferably recycled in the process according to the present invention. The precipitate / crystals produced can be further purified by vacuum distillation or recrystallization, or a combination thereof, and, if necessary, can be subsequently washed and dried.

[0036] The first fraction (3) is contacted with a second strongly basic anion exchange resin to maximize the yield and purity of the phytosterols.

[0037] One aspect of the invention is a composition comprising phytosterols, the composition comprising less than 0.5% by weight of tall oil, the composition comprising less than 1% by weight of esterified phytosterols.

[0038] The recovered neutral-depleted fraction (6) is a soap fraction. The neutral-depleted fraction (6) can be combined with the second fraction (7) recovered from the first strong base ion exchange resin (2). The neutral-depleted fraction (6), optionally combined with the second fraction (7), contains components such as sodium salts of fatty acids and sodium salts of rosin acids. Surprisingly, it has been found that the acid salts can spontaneously crystallize / precipitate as white precipitates / crystals in the neutral-depleted fraction. Surprisingly, it has been found that a color tint remains in the liquid phase. The crystallized / precipitated material can be purified by subsequent recrystallization, if desired.

[0039] The neutral-depleted fraction (6) combined with the second fraction (7) can be dried, if desired, by evaporation of an alcohol selected from methanol, ethanol, and / or isopropanol using methods known in the art to produce a dry mixture of fatty acid salts and rosin acid salts. The dried material can be washed or reslurried, for example, with water, to remove excess sodium hydroxide from the dried material. Preferably, washing is with water, and the temperature of the water is preferably in the range of 20°C to 80°C, such as 40°C to 60°C. Preferably, once the wash liquid is removed from the slurry, the slurry has a temperature in the range of 15°C to 25°C. The removed sodium hydroxide can be recycled in the process.

[0040] The mixture of fatty acid salts and rosin acid salts can be further fractionated, for example, using precipitation / crystallization methods, or converted to high-quality tall oil using methods known in the art. High-quality tall oil can be further fractionated into tall oil fatty acids and tall oil rosin acids using either a chromatography system or by standard vacuum distillation. In one embodiment, high acid value tall oil is first converted to a mixture of fatty acid methyl esters and rosin acids by esterification. The fatty acid methyl esters and rosin acids can subsequently be separated from each other using methods known in the art.

[0041] One aspect of the present invention is a composition comprising tall oil having an acid number of at least 175, the composition comprising less than 0.5 wt.% phytosterols, based on the total weight of the composition. The composition preferably has a Gardner color index of less than 14, more preferably less than 9, as measured according to ASTM D1544-04.

[0042] The tall oil acid number can be measured using methods known in the art. One way to evaluate the quality of tall oil is to describe its acid number, which is the amount of potassium hydroxide in milligrams required to neutralize 1 g of CTO. As used herein, the term "high acid number tall oil" means tall oil having an acid number of at least 175, such as at least 180, or at least 185, or at least 188.

[0043] The term "phytosterol" is intended to mean sterols derived from plants, including all plant sterols and saturated forms of these phytosterols (i.e., phytostanols). Plant sterols fall into one of three categories: 4-desmethylsterols (lacking a methyl group); 4-monomethylsterols (one methyl group); and 4,4-dimethylsterols (two methyl groups), including, but not limited to, sitosterols (e.g., [alpha] and [beta] sitosterol), campesterol, stigmasterol, taraxasterol, and brassicasterol. The term "phytostanol" is intended to mean saturated phytosterols, including, but not limited to, sitostanols (e.g., [alpha] and [beta] sitostanol), campestanol, stigmastanol, clionastanol, and brassicasterol. Phytosterols isolated as described herein can be quantified by any means known in the art.

[0044] Crystallization of phytosterols can be carried out using methods known in the art, including cooling, concentration by removing part of the solvent by distillation, evaporation to dryness, followed by the introduction of a solvent or solvent mixture that dissolves only phytosterols at elevated temperatures, followed by cooling, or by seeding with phytosterol crystals, or by adding an anti-solvent. After the evaporation step, such as by distilling off some or all of the solvent, precipitation or crystallization can occur. Alternatively, another solvent, such as an anti-solvent, can be added, optionally in combination with seeding, to facilitate precipitation or crystallization of phytosterols.

[0045] The method according to the present invention can be carried out as a batch process. However, by using more than one strong base anion exchange column, the process can be carried out continuously by switching the flow of the mixture of step a) from the first strong base anion exchange column to the second strong base anion exchange column. In such a continuous process, the mixture of step a) is passed through the first strong base anion exchange column, while the first fraction is recovered from the first strong base anion exchange column. When the flow of the mixture of step a) is switched to the second strong base anion exchange column, the second fraction can be recovered from the first strong base anion exchange column. This allows the process steps a) to c) to be carried out continuously. Similarly, steps d) and e) can be carried out continuously.

[0046] Preferably, the crude tall oil is pre-treated before being subjected to strong base anion exchange. Pre-treatment preferably involves the removal of fiber and any other components that may cause clogging of the strong base anion exchange column system. [Example]

[0047] material A small-scale preparative column of IX (ion exchange) resin was constructed with a Biotage ISOLUTE Single frit reservoir using standard Luer fittings. Solutions were pumped using a syringe pump (Harvard Apparatus 11S).

[0048] Preparation of solutions The 1.75 M aqueous sodium hydroxide solution used for activation of the ion exchange resin was prepared by dissolving solid sodium hydroxide (70 g / L) in a 4 / 1 mixture of methanol and deionized water at room temperature.

[0049] 0.67 M sodium hydroxide in methanol was prepared by dissolving solid sodium hydroxide (26.8 g / L) in methanol at room temperature.

[0050] A 75 wt% CTO solution in methanol was prepared by mixing crude tall oil (217 g) with methanol (72 g). The resulting solution (289 g) was used for each separation cycle.

[0051] 1.5 M sodium hydroxide in methanol was prepared in a 1 L volumetric flask by dissolving sodium hydroxide (60 g) in methanol at room temperature.

[0052] 0.67 M sodium hydroxide in methanol was prepared in a 1 L volumetric flask by diluting aqueous sodium hydroxide (53.6 g, 50 wt % aqueous solution) with methanol at room temperature.

[0053] A 50 wt% CTO solution in methanol was prepared by dissolving crude tall oil (100 g) in methanol (100 g). The resulting solution is dark in color.

[0054] Preparation of Strong Acid Cation Exchange Resin (SAC) Purolite PPC100H (22 mL) was loaded into a cartridge (Φ22 mm, length 65 mm) between 10 μm polyethylene filter discs and swollen overnight in methanol. The methanol was drained, and fresh methanol (50 mL) was pumped through the resin bed (upflow, 45 mL / h). Sulfuric acid (70 mL, 4 vol% in water) was pumped through the resin bed (upflow, 100 mL / h), followed by demineralized water (150 mL, 45 mL / h). The SAC resin was then flushed with methanol (50 mL, 45 mL / h).

[0055] Desalination of 75 wt% CTO in methanol using SAC resin CTO solution (200 mL, 182 g of 75 wt% in MeOH) was pumped (upstream, 20 mL / h) through the SAC resin bed and the demineralized product was collected. ICP was used to analyze the metal content of the samples before and after demineralization. Data are the average of three separate samples. TIFF2026501191000002.tif27170

[0056] Small-scale separation experiment Preparation of Strongly Basic Anion Exchange Resin (SBA) Purolite A500OHPlus (12.4 g / 20 mL) was loaded into a cartridge (Φ22 mm, length 65 mm) between 10 μm polyethylene filter discs and swollen overnight in methanol. The SBA resin was drained, and sodium hydroxide (20 mL, 1.75 M in a 4 / 1 mixture of methanol and water) was pumped through the resin bed (upflow, 40 mL / h). The SBA resin was then flushed with methanol (110 mL) until the conductivity was less than 10 μS / cm.

[0057] Isolation of sterols using 50 or 75 wt% CTO in methanol CTO solution (10 mL, 8.74 g of 50 wt% in MeOH or 6.66 mL, 6.05 g of 75 wt% in MeOH) was added to the SBA resin (upstream 10–40 mL / h), followed by methanol (50 mL, 40 mL / h). Crystallization of a white solid occurred in the early fraction (0.4–1.0 bed volumes), consisting primarily of sterols. Cooling the early fraction to 4 °C afforded a large yield of crystalline material.

[0058] Isolation of fatty acid salts and rosinate salts and regeneration of IX resin. A solution of sodium hydroxide in methanol (1.5 M, 40 mL) was added to the SBA resin, followed by methanol (120 mL, flowing at 40 mL / h) until the conductivity was less than 10 μS / cm. Precipitation of the soap as a white solid occurred in the early fractions (0.4-1.4 bed volumes) at ambient temperature. Cooling to 4°C caused the precipitation of a large amount of white material.

[0059] Large-scale separation experiment Preparation of Strongly Basic Anion Exchange Resin (SBA) Purolite A500OHPlus resin (620 g) was loaded into a jacketed stainless steel column (ID 50 mm, length 500 mm, volume 1 L) between 10 μm polyethylene filter discs, and the column was sealed at both ends with end caps with inlet and outlet ports connected to Teflon tubing for injection and collection. Demineralized water was added from the top, and the resin was allowed to swell overnight. The water was drained, and sodium hydroxide (2 L, 1.5 M in water) was pumped through the resin bed (downward flow, 2 L / h). The IX resin was then washed first with demineralized water (4 L) and then with methanol (1 L) until the conductivity was below 10 μS / cm.

[0060] First column Isolation of the first fraction (3) using 75 wt% CTO in methanol The resin column was heated to 50°C using a hot water circulating bath through the heating jacket of the column, and the temperature was maintained throughout the separation process.

[0061] A CTO solution (1,289 g of 75 wt% in MeOH) was loaded onto an IX resin column (133 mL / h, 8 BV / h). Neutral compounds were eluted with methanol (1 L, 133 mL / h, 8 BV / h) and collected as the first fraction (3). The collected fractions were kept at 50°C to prevent precipitation.

[0062] Isolation of the second fraction (7) and regeneration of IX resin The acidic compounds were eluted from the IX resin column using a solution of sodium hydroxide in methanol (0.67 M, 1.0 L, 133 mL / min, 8 BV / hr) and collected as the second fraction (7). The IX resin was then regenerated using a solution of sodium hydroxide in methanol (0.67 M, 1.0 L, 133 mL / min, 8 BV / hr), and the eluate was collected and used as the eluent for the acidic compounds in the second column described below.

[0063] The second fraction (7) can be combined with the neutral-depleted fraction (6) described below, if desired. The combined soap-containing fractions were evaporated to dryness under reduced pressure, and the evaporated methanol was collected for solvent recovery, if desired.

[0064] Using procedures known in the literature using concentrated H2SO4 and water, the isolated dried Na soap can be directly converted into neutral deficient high acid value tall oil to give a brown oil with improved acid value.

[0065] Preparation of IX resin column After elution and regeneration of the resin column using sodium hydroxide in methanol, the column was flushed with methanol (1.5 L, 133 mL / min, 8 BV / h). The methanol was collected for solvent recovery as needed, and the IX resin column was now conditioned for a new separation cycle.

[0066] Second column Isolation of the neutral fraction (5) The second resin column was heated to 50°C using a hot water circulating bath through the heating jacket of the column and the temperature was maintained throughout the separation process.

[0067] The first fraction (3) collected from the first column was loaded onto the resin column at 50°C (133 mL / min, 8 BV / h). Neutral compounds were eluted with methanol (1 L, 133 mL / h, 8 BV / h) and collected as neutral fraction (5). The neutral fraction was cooled to 4°C, and the solid material precipitated and isolated by filtration. The filter cake was washed with cold methanol (50 mL) and dried under reduced pressure to obtain crude phytosterols as a pale yellow solid.

[0068] Isolation of neutral-depleted fraction (6) and regeneration of IX resin. The acidic compounds were eluted from the IX resin column, along with some residual soap from the first column, using the regeneration eluent of the first column, which was a solution of sodium hydroxide in methanol (<0.67 M, 1.0 L, 133 mL / min, 8 BV / hr), and collected as neutral-depleted fraction (6). The IX resin was then regenerated using a solution of sodium hydroxide in methanol (0.67 M, 1.0 L, 133 mL / min, 8 BV / hr), and the eluate was collected and used as the eluent for acidic compounds in the first column during the next cycle. The neutral-depleted fraction (6) can be combined with the second fraction (7) above, or, if desired, proceeded separately as described for the second fraction, to obtain neutral-depleted high acid value tall oil.

[0069] Preparation of IX resin column After elution and regeneration of the resin column using sodium hydroxide in methanol, the column was flushed with methanol (1.5 L, 133 mL / min, 8 BV / h). The methanol was collected for solvent recovery as needed, and the IX resin column was now conditioned for a new separation cycle.

[0070] Analysis method Silylation in pyridine with BSTFA, N,O-bis(trimethylsilyl)trifluoroacetamide, followed by GC / FID, or derivatization in deuterated chloroform / pyridine with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphosphorane according to known procedures. 31 P-NMR was used to determine the identity and purity of individual components or the type of component.

[0071] Other modifications and variations will be apparent to those skilled in the art in view of the above detailed description of the invention, and it will be apparent, however, that such other modifications and variations can be made without departing from the spirit and scope of the invention.

Claims

1. 1. A process for separating components from crude tall oil, comprising the steps of: a) providing a mixture comprising crude tall oil and an alcohol selected from methanol, ethanol and / or isopropanol; b) contacting the mixture from step a) with a strong base anion exchange resin; c) collecting at least a first fraction and a second fraction, each fraction comprising at least one component; d) contacting the first fraction recovered in step c) with a second strongly basic anion exchange resin; e) recovering the neutral fraction and the neutral-depleted fraction; 1. A method for separating components from crude tall oil, comprising:

2. 2. The method of claim 1, wherein one of the fractions is a fraction containing primarily unsaponifiable matter.

3. 3. The method according to claim 1 or 2, wherein one of the fractions is a fraction containing mainly sodium salts of fatty acids and sodium salts of rosin acids.

4. 4. The process according to claim 1, wherein the alcohol used in step a) is methanol.

5. 5. The method of claim 1, wherein the phytosterols are isolated from the neutral fraction.

6. 6. The method according to any one of claims 1 to 5, wherein step b) is carried out at a temperature of from 30°C to 60°C.

7. 5. The method of claim 4, wherein the amount of methanol in the mixture of step a) is at least 10 wt. %, based on the total weight of the mixture of step a).

8. 8. The method of any one of claims 1-2 or 4-7, wherein the phytosterols spontaneously crystallize in the neutral fraction.

9. 9. The method of claim 8, wherein the naturally crystallized phytosterols consist primarily of beta-sitosterol.

10. 8. The method of any one of claims 1 or 3 to 7, wherein tall oil having an acid number of at least 175 is produced from the neutral depleted fraction.

11. 11. A fraction separated and recovered according to the method of any one of claims 1 to 10.

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