WO2014095703A1

WO2014095703A1 - Methods for extracting oil and oil compositions

Info

Publication number: WO2014095703A1
Application number: PCT/EP2013/076675
Authority: WO
Inventors: Michael Greenhill-Hooper; Andrew Robert LOCKIE; Philippe Maillard
Original assignee: Imerys Talc Europe
Current assignee: Imerys Talc Europe
Priority date: 2012-12-18
Filing date: 2013-12-16
Publication date: 2014-06-26
Anticipated expiration: 2015-06-18

Abstract

A method for extracting oil from a palm plant is provided. The method includes providing a portion of the palm plant, releasing crude palm oil from the portion of the palm plant, separating the crude palm oil from the remainder of the portion of the palm plant, contacting the portion of the palm plant, the crude palm oil, or both with an inorganic particulate material.

Description

METHODS FOR EXTRACTING OIL AND OIL COMPOSITIONS TECHNICAL FIELD The present invention is directed to methods for extracting palm oil or palm kernel oil, oil compositions, and use of inorganic particulate material as an adjuvant for palm oil extraction or palm kernel oil extraction.

BACKGROUND OF THE INVENTION

Palm oil is typically derived from the mesocarp (i.e., pulp) of the fruit of oil palms. Oil losses during palm oil milling vary from mill to mill, but can be around 10% based on the total oil yield, and preferably are in the range 4-6% based on the total oil yield ( about 1 .4% when expressed in terms of the fresh fruit bunch). A substantial fraction of these losses are from two sources. One source of palm oil losses can be in the palm oil mill effluent, which is the waste water phase recovered after decantation and centrifugation of the liquid coming from the pressing of the digested fruits. Another source of palm oil losses can be oil trapped in the nut and fibre rich press cake. Palm oil producers desire processes for extracting palm oil from the palm fruit that result in high yield (e.g., reduced oil losses during the extraction process) and improved oil quality. The extraction of palm kernel oil from the kernel of the palm fruits would also benefit from reduced oil losses and improved oil quality. Thus, it would be desirable to provide palm oil and palm kernel oil extraction processes with such desirable attributes.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is provided a method for extracting oil from a palm plant comprising providing a portion of the palm plant, releasing crude palm oil from the portion of the palm plant, separating the crude palm oil from the remainder of the portion of the palm plant, contacting the portion of the palm plant, the crude palm oil, or both with an inorganic particulate material. In certain embodiments, the contacting step may occur before, during, or after the step of releasing. In particular embodiments, the releasing step comprises digesting. In accordance with a second aspect of the present invention, there is provided a composition comprising crude palm oil or crude palm kernel oil, and inorganic particulate material. In accordance with a third aspect of the present invention, use of inorganic particulate material as an adjuvant in a palm oil extraction process or palm kernel oil extraction process is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagram showing one embodiment of the method of extracting oil from a palm plant of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Oil Extraction Method

In certain embodiments, the method of extracting oil from a palm plant may comprise the steps shown in Figure 1. In Figure 1 , palm fruit bunches are sterilised, stripped (and/or threshed to remove the empty fruit bunches), and fed into a digester. Within the digester, the strips of palm fruit mesocarp are disintegrated to release the individual oil cells and rupture the individual oil cells. Rupture of the oil cells releases the palm oil. The digestion may also include digesting the palm fruit with steam and/or diluting the digestion product (e.g., crude palm oil and remainder of the portion of the palm plant) with hot water. Examples of suitable digesters include, but are not limited to horizontal rapid digesters.

In certain embodiments, inorganic particulate material may be added to the palm fruit mesocarp before it is added to the digester and/or inorganic particulate material may be added directly to the digester. In other embodiments, the inorganic particulate material may be contacted with a portion of the palm plant (e.g., palm fruit or palm fruit bunch), the crude palm oil, or both during or after the step of releasing (e.g., digesting or other conditioning process). For example, the inorganic particulate material may be added to a digester after the start of the digestion process. In another embodiment, the inorganic particulate material may be contacted with the digestion product after digestion ends. In certain embodiments, the inorganic particulate material may be added to the digestion product coming from the digester before or during the separation of the crude oil from the remainder of the palm fruit. In other embodiments, the inorganic particulate material may be added to the crude oil before or during settling (e.g., in a settling tank), decanting, or centrifugation, whereby crude oil may separated from sludge and non-oily phase.

In certain embodiments, the inorganic particulate material is contacted with the portion of the palm plant, the crude palm oil, or both in an amount ranging from about 0.1 % to about 3% based on the weight of the portion of the palm plant. In other embodiments, the inorganic particulate material is contacted with the portion of the palm plant, the crude palm oil, or both in an amount ranging from about 1 % to about 2% based on the weight of the portion of the palm plant. In particular embodiments, the inorganic particulate material is contacted with the portion of the palm plant, the crude palm oil, or both in an amount of at least about 0.5%, or at least about 1.0%, or at least about 1 .5%, or at least about 2.0% based on the weight of the portion of the palm plant (e.g., palm fruit). The digested product may be pressed to separate crude palm oil from the remainder of the palm fruit fibers and nuts. For instance, a hydraulic press (e.g., with piston and cages) may be used to expel oils from the oil palm fruit. In certain embodiments, a press applying a pressure equivalent to at least about 25 Megatons may be used to expel the raw crude palm oil from the digested fruit.

From the press, the raw crude palm oil, which includes at least a portion of the inorganic particulate material may be screened and sent to a settling tank, where impurities such as sand may be separated from the raw crude palm oil. Further separation steps to purify the raw crude palm oil may be carried out, such as straining, de-sanding, centrifugation, vacuum drying, clarification, combinations thereof, and the like.

Without being bound by a particular theory, it is believed that the inorganic particulate material added to the process of extracting palm oil acts as a adjuvant which enhances, aids, or increases the extraction of palm oil from portions of the palm plants. As the extraction process is carried out in the presence of high levels of water, emulsions are prone to form. During the separation steps performed on the released crude palm oil, it is desirable to ensure that the oil is released from the palm fruit pulp in high yields and separates cleanly in the extracted oil. Without being bound by a particular theory, it is believed that addition of inorganic particulate material to the extract process enhances oil yields, which is desirable for maintaining good oil quality. Addition of inorganic particulate material before or during the separation step in the extraction process may result in a cleaner and more complete separation of the oil from the press liquid and less oil remaining in the sludge phase and effluent water stream. Also, inorganic particulate material addition may result in less oil being trapped in the press cake. In addition, use of an inorganic particulate material as an adjuvant in dry extraction processes such as the extraction of palm kernel oil equipment may be beneficial in reducing (e.g., expeller screw and/or agitator) wear and energy consumption. In certain embodiments, use of an inorganic particulate material as an adjuvant in the palm oil extraction process results in the extraction and recovery of at least an additional 0.5% of palm oil. In other embodiments, use of an inorganic particulate material as an adjuvant in the palm oil extraction process results in the extraction and recovery of at least an additional 1 % of palm oil, or at least an additional 10% or greater of palm oil. For instance, use of 1 % of inorganic particulate material based on the weight of the palm fruit as an adjuvant in the palm oil extraction process results in the extraction and recovery of at least an additional 2% of palm oil. In particular embodiments, use of an inorganic particulate material as an adjuvant in the palm oil extraction process results in the extraction and recovery of at least an additional 0.1 % of palm oil based on the weight of the palm fruit bunches.

In certain embodiments, the palm kernel recovered from the palm oil extraction process may be further processed to extract oil therefrom. For instance, the palm kernel may be dried and cracked to extract the palm kernel oil. The palm kernel and the extracted palm kernel oil could then be processed to recover the palm kernel oil in a manner analogous to the method described above for separating the palm oil from the palm fruit. In particular embodiments, the palm kernel oil may be separated from the palm kernel in the presence of inorganic particulate material. For instance, the inorganic particulate material may be added to the palm kernel before, during or after the palm kernel oil is expelled from the palm kernel (e.g., by an expeller screw). In certain embodiments, the inorganic particulate material is contacted with the portion of the palm kernel, the crude palm kernel oil, or both in an amount ranging from about 0.1 % to about 3% based on the weight of the palm kernel. In other embodiments, the inorganic particulate material is contacted with the palm kernel, the crude palm kernel oil, or both in an amount ranging from about 1 % to about 2% based on the weight of the palm kernel.

In certain embodiments, use of an inorganic particulate material as an adjuvant in the palm kernel oil extraction process results in the extraction and recovery of at least an additional 0.5% of palm oil. In other embodiments, use of an inorganic particulate material as an adjuvant in the palm kernel oil extraction process results in the extraction and recovery of at least an additional 0.5% of palm oil. For instance, use of 1 % of inorganic particulate material based on the weight of the palm kernel as an adjuvant in the palm kernel oil extraction process results in the extraction and recovery of at least an additional 2% of palm oil.

Inorganic particulate material adjuvant

In certain embodiments, the inorganic particulate material may comprise a mineral selected from the group consisting of talc, an alkaline earth metal carbonate or sulphate, such as calcium carbonate (natural ground or precipitated), magnesium carbonate, dolomite, gypsum, a hydrous kandite clay such as kaolin, halloysite or ball clay, an anhydrous (calcined) kandite clay such as metakaolin or fully calcined kaolin, mica, perlite, feldspars, nepheline syenite, wollastonite, diatomaceous earth, barite, glass, and natural or synthetic silica or silicates. The inorganic particulate material may be a natural or synthetic inorganic particulate material.

In particular embodiments, the inorganic particulate material may be a macro or microcrystalline talc. The individual platelet size, i.e. the median diameter as measured by the Sedigraph method, of an individual talc platelet (a few thousand elementary sheets) can vary from approximately 1 μηη to over 100 μηη, depending on the conditions of formation of the deposit. The individual platelet size determines the lamellarity of the talc. A highly lamellar talc will have large individual platelets, whereas a microcrystalline talc will have small platelets. Although all talcs may be termed lamellar, their platelet size differs from one deposit to another. Small crystals provide a compact, dense ore, known as microcrystalline talc. Large crystals come in papery layers, known as macrocrystalline talc. Known microcrystalline talc deposits are located in Montana (Yellowstone) and in Australia (Three Springs). In a microcrystalline structure, talc elementary particles are composed of small plates compared to macrocrystalline structures, which are composed of larger plates.

In other embodiments, the inorganic particulate material may be a chloritic talc.

In certain embodiments, the inorganic particulate material is a food grade inorganic particulate material.

In particular embodiments, the inorganic particulate material may be provided in the form of an agglomerate, pellet, or compacted composition.

The inorganic particulate material has d₅₀ of from about 0.5 to about 30 μηη and/or a d₉₀ of from about 15 to about 50 μηη and/or a d₉₅ of from about 15 to about 70 μηη. In certain embodiments, the inorganic particulate material composition has a d₅₀ of from about 0.5 to about 30 μηι, a d₉o of from about 15 to about 50 μηι, and a d₉5 of from about 15 to 70 μηι. The microcrystalline talc according to certain embodiments of the present invention may have a d₅₀ ranging from 0.5 to 10 μηη. For example, the d₅₀ of the microcrystalline talc may be ranging from 1.0 to 7.5 μηη, such as 1.0 to 5 μηη, or 3.0 to 4.5 μηη.

Unless otherwise stated, particle size properties referred to herein for the inorganic particulate materials are as measured in a well known manner by sedimentation of the particulate material in a fully dispersed condition in an aqueous medium using a Sedigraph 5100 machine as supplied by Micromeritics Instruments Corporation, Norcross, Georgia, USA (web-site: www.micromeritics.com), referred to herein as a "Micromeritics Sedigraph 5100 unit". Such a machine provides measurements and a plot of the cumulative percentage by weight of particles having a size, referred to in the art as the 'equivalent spherical diameter' (e.s.d), less than given e.s.d values. The mean particle size d₅₀ is the value determined in this way of the particle e.s.d at which there are 50% by weight of the particles which have an equivalent spherical diameter less than that d₅o value. In certain embodiments, the inorganic particulate material has a d of from about 0.5 to about 15 μηη, for example, from about 0.5 to about 12 μηη, or from about 0.5 to about 10 μηη, or from about 1 to about 15 μηη, or from about 1 to about 12 μηη, or from about 1 to about 10 μηη, or from about 3 to about 15 μηη, or from about 3 to about 12 μηη, or from about 3 to about 10 μηη, or from about 5 to about 15 μηη, or from about 5 to about 12 μηη, or from about 5 to about 10 μηη, or from about 7 to about 15 μηη, or from about 7 to about 12 μηη, or from about 7 to about 10 μηη.

In certain embodiments, the inorganic particulate material has a d₉₀ of from about 15 to about 50 μηη, for example, from about 15 to about 45 μηη, or from about 15 to about 40 μηι.

In certain embodiments, the inorganic particulate material has a d₉₅ of from about 15 to about 70 μηη, for example, from about 15 to about 60 μηη, or from about 15 to about 55 μηη, or from about 15 to about 50 μηη, or from about 15 to about 20 μηη, or from about 15 to about 18 μηη.

In certain embodiments, the inorganic particulate material has a d₀ of less than about 1 μηι, and/or a di₀ of less than about 4 μηι, and/or a d₅o of less than about 10 μηι, and/or a d₉₀ of less than about 20 μηη, and/or a d₉₅ of less than about 20 μηη. In certain embodiments, the inorganic particulate material has a d₀ of from about 0.4 to about 0.75 μηι, and/or a di₀ of from about 0.5 to about 2.75 μηι, and/or a d₅o of from about 1 to about 12 μηι, and/or a d₉5 of from about 15 to about 18 μηι. Furthermore, the inorganic particulate materials according to certain embodiments of the present invention may have a surface BET area in the range of 5 to 20 m²-g^"1, such as for example from 8 to 25 m²-g^"1, or from 10 to 15 m²-g^"1, or from 12 to 14 m²-g^"1. As used herein, the surface BET area is the specific surface area measured according to DIN ISO 9277.

In certain embodiments, the inorganic particulate material has a Hegman fineness of 3.0 or more, for example, from about 3.0 to about 4.5, or from about 3.0 to about 4.25, or from about 3.0 to about 4.0. In certain embodiments, the inorganic particulate material agglomerate composition has a Hegman fines of about 3.0, or about 3.25, or about 3.5, or about 3.75, or about 4.0, or about 4.25, or about 4.5. In certain embodiments, the inorganic particulate material has a Hegman fineness which is within the range of ± 1 of the Hegman fineness of the inorganic particulate material feed material from which the inorganic particulate material is prepared, for example, within the range of ± 0.5 or, for example, within the range of ± 0.25 of the Hegman fineness of the inorganic particulate material feed material. The test for measuring Hegman fineness is based on a ASTM D-1210-05 (2010). In a preferred method, 25 g of vegetable oil are provided. After adding 5 g sample, the mixture is kept stirring for 15 to 30 seconds. When no dry powder is visually present, mixing speed is increase to the highest reasonable speed without splashing the sample and mixing is continued for at least 2 minutes. Using a spatula or glass rod, the dispersion is stirred manually. A small amount of dispersed sample is placed in the deep end of the path of the Hegman fineness gage (Precision Gage & Tool Co., Dayton, Ohio). By using a steel draw-down blade/scraper, the material is then drawn down the length of the path toward the shallow end of the gage with a uniform, brisk motion. The fineness reading, in Hegman units (0-8) is obtained by observing the point where the material first shows a definite speckled pattern. Typical fineness patterns described in the ASTM D 1210-05 (2010) procedure can be used for comparison.

Compositions and uses As described above, certain embodiments of the method of the present invention produces a crude palm oil or crude palm kernel oil, each of which is devoid of or substantially devoid of talc inorganic particulate material. For instance, the crude palm oil has less than 0.1 % inorganic particulate material or no detectable inorganic particulate material. In some embodiments, the crude palm oil is devoid of or substantially devoid of inorganic particulate material. In certain embodiments, the crude palm kernel oil has less than 0.1 % inorganic particulate material, no detectable organic particulate material, is devoid of, or substantially devoid of inorganic particulate material. In certain embodiments, the crude palm oil including inorganic particulate material may be further purified to produce refined palm oil which is devoid of or substantially devoid of talc inorganic particulate material. In particular, the refined palm oil has less than 0.1 % inorganic particulate material or no detectable organic particulate material. In some embodiments, the crude palm kernel oil may be further purified to produce refined palm kernel oil which is devoid of or substantially devoid of inorganic particulate material.

Claims

1 . A method for extracting oil from a palm plant comprising:

a. providing a portion of the palm plant;

b. releasing crude palm oil from the portion of the palm plant;

c. separating the crude palm oil from the remainder of the portion of the palm plant

d. contacting the portion of the palm plant, the crude palm oil, or both with inorganic particulate material.

2. The method of claim 1 , wherein the inorganic particulate material is selected from the group consisting of talc, calcium carbonate, and kaolin.

3. The method of claim 1 or claim 2, wherein the contacting step may occur before, during, or after the step of releasing.

4. The method of any preceding claim, wherein the portion of the palm plant is selected from the group consisting of palm fruit, palm kernel, palm fiber, or combinations thereof.

5. The method of any preceding claim, wherein the releasing step comprises digesting.

6. The method of any preceding claim, wherein the separating step comprises pressing, settling, decanting, and/or centrifuging.

7. The method of any preceding claim, wherein the inorganic particulate material has a d₅o of from about 0.5 to about 30 μηι.

8. The method of any preceding claim, wherein the inorganic particulate material is contacted with the portion of the palm plant, the crude palm oil, or both in an amount ranging from about 0.1 % to about 3% of the portion of the palm plant.

9. The method of any preceding claim, wherein the inorganic particulate material has a d₉o of from about 15 to about 50 μηι.

10. The method of any preceding claim, wherein the inorganic particulate material has a Hegman value of about 3 or more.

1 1 . The method of any preceding claim, wherein the inorganic particulate material comprises microcrystalline talc.

12. The method of any preceding claim, wherein the inorganic particulate material has a surface BET area in the range of about 5 to about 20 m²-g^"1.