阅读说明：本技术 生产游离脂肪酸的方法 (Method for producing free fatty acid ) 是由 尤卡-佩卡·帕萨宁 安妮卡·马尔姆 拉米·皮洛拉 于 2018-12-17 设计创作，主要内容包括：公开了从包含叶绿素的油中生产游离脂肪酸的方法。本发明基于将包含叶绿素的油与脂肪共混,然后进行5次水解和蒸馏。(A method for producing free fatty acids from chlorophyll-containing oils is disclosed. The invention is based on blending an oil containing chlorophyll with a fat, followed by 5 hydrolyses and distillations.)

1. A method of producing free fatty acids, the method comprising the steps of:

a. providing a feedstock comprising a blend of algal oil and fat, wherein the feedstock contains less than 50% w/w algal oil;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. distilling the oil phase to recover the free fatty acids contained therein.

2. The method of claim 1, wherein the total content of free fatty acids, monoglycerides, diglycerides and triglycerides in the algal oil as analyzed by ISO 15304M-2002 is below 90% w/w.

3. The method of claim 1 or 2, wherein the fat is an animal fat, a vegetable oil, or a mixture thereof.

4. A process according to claim 3, wherein the feedstock contains 1-45% w/w algal oil, preferably 5-45% w/w, more preferably 5-35% w/w, and most preferably 5-15% w/w.

5. The process of any one of claims 1-4, wherein hydrolysis is carried out at a temperature selected from the range of 220 to 280 ℃.

6. The method of any one of claims 1-5, wherein step c further comprises separating the aqueous phase and the solid phase.

7. Process according to any one of claims 1-6, wherein in step d, the distillation is carried out at a temperature selected from the range of 220 to 300 ℃ and a pressure, given as absolute pressure, selected from the range of 0.01 to 50kPa to recover a fraction comprising free fatty acids.

8. A process according to any one of claims 1 to 7, wherein the feedstock comprises at least 1000ppm total chlorophyll.

9. The method of any one of claims 1 to 8, wherein the feedstock comprises at least 1000ppm phosphorus.

10. A free fatty acid fraction obtained according to the method of claims 1-9 comprising at least 95% of free fatty acids having a carbon number of C14-C28.

11. A method of producing a renewable fuel comprising the steps of:

a. providing a feedstock comprising a blend of algal oil and fat, and wherein the feedstock comprises less than 50% w/w algal oil;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase;

d. distilling the oil phase to recover free fatty acids contained therein; and

e. chemically reacting the recovered free fatty acids to produce hydrocarbons or alkyl esters of fatty acids, wherein the free fatty acids optionally serve as: co-feed in fuel production, sole feed in fuel production, and/or blending a fuel obtained from the free fatty acids with another fuel;

thereby producing a renewable fuel.

12. The method of claim 11, wherein the total content of free fatty acids, monoglycerides, diglycerides, and triglycerides in the algal oil as analyzed by ISO 15304M-2002 is below 90% w/w.

13. A method of removing chlorophyll from a feedstock comprising:

a. providing a feedstock comprising a blend of algal oil and fat, wherein the feedstock contains less than 50% w/w algal oil;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. distilling the oil phase.

Technical Field

The present invention relates to the treatment of oil containing chlorophyll. In particular, the present invention relates to the production of free fatty acids free of impurities from chlorophyll-containing oils, such as algal oil.

Background

Chlorophyll-containing oils, such as algal oil, are a promising source of renewable hydrocarbons. Algal oil differs from many vegetable oils and animal fats because it contains a large amount of chlorophyll. In addition, algae oils typically contain significant amounts of chlorine, metals, and phosphorus. It was found that most of the nitrogen in algal oil is present in chlorophyll, as opposed to the nitrogen present in typical vegetable oils, where nitrogen is mainly present in amino acids. Chlorophyll consists of a highly stable and high molecular weight quaternary porphyrin ring. Since high molecular weight chlorophyll, or its degradation products, still has a high molecular weight, it is known to cause plugging of catalyst or adsorbent pores and coking of catalyst surfaces, thereby causing catalyst deactivation. Thus, when chlorophyll-rich oils are used in industrial processes, such as fuel production, removal of chlorophyll is required prior to catalytic treatment.

Previous techniques for chlorophyll removal include adsorption treatment with different clays, enzymatic hydrolysis of the chlorophyll ring structure, strong acid treatment and membrane filtration. These techniques are typically designed to remove chlorophyll from vegetable oils, which contain much lower chlorophyll than algal oil. These prior techniques are not feasible for chlorophyll removal on an industrial scale due to the high chlorophyll content of algal oil, due to increased cost and processing difficulties. Thus, for example, analytical methods sometimes used for processing and analyzing algal oil are not useful in industrial-scale production.

Lipolysis and distillation are known techniques for treating fats and oils in the production of free fatty acids. In this process, triglycerides are treated with water at elevated temperatures, resulting in the splitting (decomposition) of the triglycerides into free fatty acids and glycerol. The resulting oil phase can be separated from the water-glycerol phase, and the free fatty acids can be separated from the oil phase by distillation.

The inventors have now found that when a feedstock comprising an oil with a high chlorophyll content is used in the fat splitting and distillation process, the resulting water-glycerol phase and free fatty acid phase are not sufficiently separated after the splitting step, and the resulting product is an emulsion that is difficult to break.

To prevent the formation of emulsions when processing oils containing large amounts of chlorophyll, previous techniques have used pre-treatment of oils to prepare and isolate free fatty acids. Previous pretreatment methods for separating the oil phase from the water-glycerol phase include: degumming to remove emulsified components prior to hydrolysis, acidic conditions and/or demulsifying salts during hydrolysis, and using organic solvents after hydrolysis. However, these solutions are not feasible on an industrial scale, since they involve the use of environmentally harmful chemicals and may corrode equipment used in the process. Furthermore, it has now been found that they do not sufficiently improve the phase separation from oils comprising large amounts of chlorophyll.

It is an object of the present invention to provide a process for the treatment of oils comprising large amounts of chlorophyll, which can be used to obtain free fatty acids, while purifying said free fatty acids so that their further treatment is possible, and without the need for expensive or complicated treatment steps.

Disclosure of Invention

According to a first aspect, there is provided a process for producing free fatty acids, the process comprising the steps of:

a. providing a feedstock comprising a blend of algal oil and fat, wherein the feedstock comprises less than 50% w/w algal oil;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. the oil phase is distilled to recover the free fatty acids contained therein.

According to one aspect, there is provided a process for producing free fatty acids, the process comprising the steps of:

a. providing a feedstock comprising a blend of oil and fat containing chlorophyll;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. the oil phase is distilled to recover the free fatty acids contained therein.

The invention has the advantage of realizing effective hydrolysis and simple recovery of the oil phase. As shown in the examples, the hydrolysis step alone has not been effective in removing chlorophyll or its degradation products that still have an intact porphyrin ring structure. The present invention effectively separates and recovers the oil phase, which is then treated by distillation to produce free fatty acids of high quality and purity. In the recovered free fatty acids, the chlorophyll content, its degradation products and elemental impurities are all significantly reduced.

Furthermore, as shown in the examples, the present invention achieves simultaneous formation of free fatty acids and removal of elemental impurities from the oil phase during the hydrolysis step if there is no pretreatment like degumming prior to hydrolysis. Without being bound by theory, this purification results from the simultaneous washing of the oil phase with water and glycerol and/or thermal effects.

According to a second aspect, there is provided a free fatty acid fraction obtained by the present process, the fraction comprising at least 95% free fatty acids having a carbon number of C14-C28.

According to a third aspect, there is provided a method of producing a renewable fuel comprising the steps of:

a. providing a feedstock comprising a blend of algal oil and fat,

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase;

d. distilling the oil phase to recover free fatty acids contained therein; and

e. chemically reacting the recovered free fatty acids to produce hydrocarbons or alkyl esters of fatty acids, wherein the free fatty acids optionally serve as: co-feed in fuel production, sole feed in fuel production, and/or blending a fuel obtained from the free fatty acids with another fuel;

thereby producing a renewable fuel.

According to another aspect, there is provided a method of producing a renewable fuel, comprising the steps of:

a. providing a feedstock comprising a blend of chlorophyll-containing oils and fats;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase;

d. distilling the oil phase to recover free fatty acids contained therein, and

e. chemically reacting the recovered free fatty acids to produce hydrocarbons or alkyl esters of fatty acids, wherein the free fatty acids optionally serve as: co-feed in fuel production, sole feed in fuel production, and/or blending a fuel obtained from free fatty acids with another fuel;

thereby producing a renewable fuel.

In one embodiment of the present process and method, the total content of free fatty acids, monoglycerides, diglycerides and triglycerides in chlorophyll-containing oils (such as algal oil) as analyzed by ISO 15304M-2002 is below 90% w/w;

the advantage of this process is that it efficiently and economically utilizes an oil comprising large amounts of chlorophyll as a source of renewable raw materials. With the present process, catalytic conversion of free fatty acids is possible due to the high quality and purity of the obtained product. Thus, problems associated with catalyst plugging and deactivation can be avoided.

According to a fourth aspect, there is provided a method of removing chlorophyll from a feedstock, the method comprising:

a. providing a feedstock comprising a blend of algal oil and fat, wherein the feedstock comprises less than 50% w/w algal oil;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. distilling the oil phase.

According to another aspect, there is provided a method of removing chlorophyll from a feedstock, the method comprising:

a. providing a feedstock comprising a blend of chlorophyll-containing oils and fats;

b. hydrolyzing the feedstock to obtain at least one oil phase;

c. recovering the oil phase; and

d. distilling the oil phase.

In one embodiment, the steps of the above-described method and process are performed in the order shown starting with step a.

Detailed Description

As used herein, the term "comprising" includes "including", "containing" and "containing" in their broad sense, as well as expressions in the narrow sense of "consisting of … …" and "consisting of … … only".

In one embodiment, at least one component of the composition of the present invention has a different chemical, structural or physical property than the corresponding natural component from which it is derived. In one embodiment, the characteristic is at least one of: more uniform size or molecular weight, more uniform dispersion or solution, higher purity.

If the raw material to be hydrolyzed contains only an oil having a high chlorophyll content (such as algal oil) without blending with fats, phase separation after hydrolysis cannot be efficiently performed, and an emulsion is obtained instead of a separated phase. The resulting emulsion is difficult to further process on an industrial scale, for example due to its high viscosity. Therefore, the emulsion cannot be separated without using impractical methods used in the prior art, such as organic solvents or extensive centrifugation. When vegetable oils and animal fats are typically subjected to lipolysis, these emulsification problems are typically addressed by removing phospholipids from the feed by degumming and/or bleaching. However, it has now been found that for oils with a high chlorophyll content (such as algal oil), these conventional pre-treatment methods are ineffective in preventing the formation of emulsions, even for algal oils with low phosphorus, and therefore a low phospholipid content also leads to the formation of emulsions. Without being bound by any theory, it is believed that the tendency of even pre-treated (i.e. degummed and/or bleached) algal oil to cause emulsification problems is due to the presence of non-triglyceride components in such oils with high chlorophyll content.

Further, the inventors have found that previous processes for isolating FFA from, for example, animal fats and oils or from vegetable oils are not suitable for treating algae oil containing feedstocks.

In one embodiment, the algal oil is not pre-treated with acid.

In one embodiment, the oil phase recovered in the process is distilled without additional purification and/or separation methods. In contrast to prior art methods, in the present invention, such purification/separation methods are not required in the processing of algal oil.

The present process has the advantage of efficiently producing free fatty acids from oils containing high purity chlorophyll relative to metals, chlorophyll and chlorophyll degradation products. During the manufacturing process, the oil phase is effectively separated from the aqueous phase containing glycerol. Further, with the present process, it is possible to form a solid phase during lipolysis and to effectively remove the solid phase after lipolysis.

In the hydrolysis step, the oil phase containing the hydrophobic component may be washed. The combination of hydrolysis and distillation according to the invention further enables the processing of chlorophyll-containing oils into fatty acid streams that are substantially free of chlorophyll and chlorophyll degradation products containing intact porphyrin ring structures. By using the present invention, the resulting free fatty acids also contain small amounts of other impurities, such as elemental impurities. In one embodiment, the fat used in the blend with the chlorophyll-containing oil comprises or consists essentially of an animal fat, a vegetable oil, or a mixture thereof.

In one embodiment, the total free fatty acid, monoglyceride, diglyceride and triglyceride content of the fat as analyzed by ISO 15304M-2002 is at the level of typical vegetable oils and animal fats, i.e. > 90% w/w, and more preferably > 95% w/w.

As shown in the examples, pretreatment prior to the hydrolysis step, such as degumming, generally does not improve the phase separation after hydrolysis when treating algae oil.

Thus, in one embodiment, a process is provided that does not involve pretreatment of the feedstock prior to hydrolysis. In another embodiment, the process does not involve degumming. In another embodiment, the process does not involve acid treatment. The omission of the pre-treatment stage is advantageous because it simplifies the process and makes it more economical.

As shown in the examples, even though the process does not involve pretreatment before hydrolysis, free fatty acids can be formed and elemental impurities removed from the oil phase simultaneously in the hydrolysis step. Without being bound by theory, this purification results from the simultaneous washing of the oil phase with water and glycerol and/or thermal effects.

In one embodiment, the chlorophyll-containing oil comprises or consists of algal oil.

Algal oil is characterized by a total content of free fatty acids, monoglycerides, diglycerides and triglycerides lower than typical vegetable oils and animal fats, i.e. < 90% w/w, as analyzed by ISO 15304M-2002.

In one embodiment, the unsaponifiable residue of the chlorophyll-containing oil as analyzed by ISO 18609-2000 is > 1% w/w, and more preferably > 5% w/w. In another embodiment, the chlorophyll-containing oil is algal oil, and it contains at least 0.5, 1, 2, 3, 4, 5, 6, or 7% w/w unsaponifiable residue. The advantage of the present process is that it allows the use of raw materials with such a high content of unsaponifiable residues, which, when treated by methods known in the art, cause the above-mentioned phase separation problems.

In one embodiment, the fat comprises or consists essentially of animal fat, vegetable oil, or mixtures thereof. This is advantageous in the present process as it is not limited to a single source of fat.

In another embodiment, the fat comprises or consists essentially of a vegetable oil.

In one embodiment, the feedstock is comprised of oils containing chlorophyll and fats, such as algal oils and fats.

In another embodiment, the blend has 200-2000ppm, preferably 220-2000ppm, phosphorus.

In one embodiment, the phosphorus is calculated as elemental phosphorus.

In one embodiment, the total content of free fatty acids, monoglycerides, diglycerides and triglycerides in the chlorophyll-comprising oil as analyzed by ISO 15304M-2002 is below 90% w/w.

In one embodiment, the fat is an animal fat, a vegetable oil, or a mixture thereof.

In one embodiment, the feedstock contains less than 50% w/w oil comprising chlorophyll, preferably algal oil. The remainder of the feedstock may comprise fat, or another source of fat and hydrocarbons such as oil.

In one embodiment, the feedstock contains 1-45% w/w, preferably 5-45% w/w, more preferably 5-35% w/w, or 5-15% w/w of an oil comprising chlorophyll, preferably algal oil. The remainder of the feedstock may comprise fat, or another source of fat and hydrocarbons such as oil.

In one embodiment, the feedstock contains about 10% w/w oil comprising chlorophyll, preferably algal oil. In one embodiment, the feedstock contains 15% w/w, 25% w/w, 35% w/w, 45% w/w, 10-35% w/w, 10-25% w/w or 10-15% w/w of an oil comprising chlorophyll, preferably algal oil. Preferably this amount is such as to obtain a rapid separation of the oil phase by sedimentation. The remainder of the feedstock may comprise fat, or another source of fat and hydrocarbons such as oil.

In one embodiment the feedstock contains at least 90%, 85%, 75%, 65% or 55% w/w fat.

In one embodiment, the blend contains 50% w/w or less of the oil comprising chlorophyll and 50% w/w or more of the fat. Preferably, the blend contains 10-45% w/w of the chlorophyll-containing oil and 90-55% w/w of the fat, more preferably 10-35% w/w of the chlorophyll-containing oil and 90-65% w/w of the fat, even more preferably 10-15% w/w of the chlorophyll-containing oil and 90-75% w/w of the fat, and most preferably 10-15% w/w of the chlorophyll-containing oil and 90-85% w/w of the fat.

In one embodiment, the feedstock consists of a blend as defined above. In this particular embodiment, the feedstock does not contain significant amounts of other sources of free fatty acids.

In one embodiment, the hydrolysis step is performed under typical lipolytic conditions, such as at a temperature selected in the range between 220 and 280 ℃. In one embodiment, a residence time of 1 to 90 minutes is used. In another embodiment, the amount of water ranges from 10 to 60 wt-%. In yet another embodiment, an emulsifier or an acidic catalyst is used in the hydrolysis step.

In one embodiment, the hydrolysis is performed at a temperature selected in the range between 220 and 280 ℃.

In one embodiment, step c further comprises separating the aqueous phase and the solid phase.

In one embodiment, step c comprises isolating about 5% w/w of the solid as a solid phase.

It is therefore an advantage of the present invention that impurities can be removed simply by removing the solid phase, thereby forming an oil phase that is directly suitable for distillation. Specifically, phosphate can be removed as magnesium phosphate by removing the solid phase.

In one embodiment, the oil phase recovered in step c contains less than 10% metals, preferably less than about 5% metals, compared to the feedstock prior to hydrolysis. In one embodiment, the oil phase recovered in step c contains less than 5% phosphorus, preferably less than about 1% phosphorus, compared to the feedstock prior to hydrolysis. In another embodiment, the oil phase recovered in step c contains less than 10% chloride, preferably less than about 6% chloride, compared to the feedstock prior to hydrolysis.

In one embodiment, the oil phase contains less than 500ppm chlorophyll.

In one embodiment, the oil phase contains less than 50ppm phosphorus.

In one embodiment, in step d, the distillation is carried out under conditions known in the art, wherein the temperature is between 180 ℃ and 280 ℃ and the pressure is between 0.1kPa and 1.0kPa, to recover a fraction comprising free fatty acids.

In one embodiment, in step d, the distillation is carried out at a temperature selected from the range between 220 and 300 ℃ and a pressure selected from the range between 0.01 and 50kPa (given as absolute pressure) to recover a fraction comprising free fatty acids.

In one embodiment, the distillation is performed to separate different algal oil free fatty acid fractions, i.e., fractions containing a significant amount of polyunsaturated fatty acids such as C16:4, C18:3, and C20:5, which are typical of algal oils using methods known in the art.

The above distillation conditions are advantageous because they reduce the amount of total chlorophyll and metals remaining in the FFA fraction as shown in table 4 below.

In one embodiment, the feedstock comprises at least 1000ppm total chlorophyll.

In one embodiment, the feedstock comprises at least 1500ppm, 2000ppm, 5000ppm or 10000ppm total chlorophyll.

In an embodiment, the feedstock comprises at least 500ppm total chlorophyll, preferably at least or about 600ppm, 700ppm, 800ppm, 900ppm, 1000ppm, 1100ppm, 1200ppm, 1300ppm, 1400ppm, 1500ppm, 2000ppm, 5000ppm or 10000 ppm. These embodiments are advantageous because the present process can be used with feedstocks containing varying amounts of chlorophyll. Thus, the present process allows for variation in the amount of chlorophyll in the feedstock and is still successful in the production of FFA.

In one embodiment, the feedstock comprises at least 1000ppm phosphorus.

In one embodiment, the feedstock comprises at least or about 800ppm phosphorus, preferably at least 900ppm, 1000ppm, 1100ppm, 1200ppm, 1300ppm, 1400ppm, or 1500 ppm.

In one embodiment, the feedstock comprises at least 1000ppm total chlorophyll and at least 1000ppm phosphorus.

In one embodiment, in step c, the recovery is performed by separating the oil phase from the aqueous phase and optionally from the solid phase. In one embodiment, the phases are separated from each other by settling. It should be noted that when the algal oil is otherwise treated according to the present invention but not blended with fat, these phases do not separate by settling after hydrolysis.

In another embodiment, the phases are separated by centrifugation. Centrifugation may be advantageous if more rapid phase separation is desired.

In one embodiment, the solid phase is also separated from the oil and water phases. In this case, after hydrolysis, the reaction system comprises three phases: an aqueous phase, an oil phase and a solid phase. Solid phase separation is advantageous and indicates the removal of elemental impurities. When these components are removed from the oil phase, impurities that may be detrimental to the performance of the catalyst, for example in subsequent processing, are removed. It is therefore an advantage of the present invention that metal sensitive catalysts can be used to treat the obtained free fatty acids.

In one embodiment, the hydrolyzed algae oil is washed during hydrolysis and settling.

In one embodiment, at least 90% w/w of the metals, phosphorus and chloride are removed in the wash. In a preferred embodiment, the washing is performed during hydrolysis and separation of the oil phase from the aqueous and solid phases.

In one embodiment, the aqueous phase contains glycerol.

In one embodiment, the distillation is performed to obtain a fraction containing free fatty acids, which is substantially free of chlorophyll, preferably containing less than 10ppm chlorophyll. In another embodiment, the free fatty acid fraction contains less than 10ppm of metals, or it does not contain one or more metals.

In one embodiment, after distillation, the free fatty acid phase has a color that varies from yellow to dark orange. This color indicates the removal of impurities such as chlorophyll.

In one embodiment, the process is a batch process.

In one embodiment, the process is a continuous process.

In one embodiment, the free fatty acid fraction obtained after distillation contains < 10ppm total chlorophyll, < 10ppm metals and < 10ppm phosphorus. In one embodiment, it further contains <200ppm of sulfur.

In one embodiment, the free fatty acid fraction obtained after distillation is used to make renewable fuels by hydrotreating the free fatty acids themselves or blending with triglycerides into normal paraffins, followed by optional catalytic conversion into branched paraffins (isoparaffins).

In one embodiment, the free fatty acid fraction is used in the manufacture of chemicals.