EP0646162A4 - Process for reducing contaminants in glyceride oils. - Google Patents

Process for reducing contaminants in glyceride oils.

Info

Publication number
EP0646162A4
EP0646162A4 EP94912793A EP94912793A EP0646162A4 EP 0646162 A4 EP0646162 A4 EP 0646162A4 EP 94912793 A EP94912793 A EP 94912793A EP 94912793 A EP94912793 A EP 94912793A EP 0646162 A4 EP0646162 A4 EP 0646162A4
Authority
EP
European Patent Office
Prior art keywords
oil
sodium
ffa
oils
metasilicate pentahydrate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94912793A
Other languages
English (en)
Other versions
EP0646162A1 (de
Inventor
Carlos E. Canessa
Jed C. Seybold
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PQ Corp
Original Assignee
PQ Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by PQ Corp filed Critical PQ Corp
Publication of EP0646162A1 publication Critical patent/EP0646162A1/de
Publication of EP0646162A4 publication Critical patent/EP0646162A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
    • C11B3/00—Refining fats or fatty oils
    • C11B3/008—Refining fats or fatty oils by filtration, e.g. including ultra filtration, dialysis
    • C—CHEMISTRY; METALLURGY
    • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
    • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
    • C11B3/00—Refining fats or fatty oils
    • C11B3/10—Refining fats or fatty oils by adsorption

Definitions

  • the present invention pertains to a composition and method for treating edible glyceride oils to remove contaminants, chiefly free-fatty acids (FFA) .
  • the composition and process may be applied either to rejuvenation of used oils or refining of crude edible glyceride oils.
  • Edible glyceride oils at various stages of their production and use, contain variable amounts of non-glyceride impurities.
  • these impurities In refining crude edible oils, these impurities must be removed through the refining process.
  • used glyceride oils these impurities build up as the oil is used, and if removed will increase the useable life of the oil.
  • these impurities influence both the way the oil responds in the various processing steps employed to produce a finished product, and the yield of finished oil.
  • an increase in impurities can degrade the oil, which can adversely affect its taste and shelf-life and may increase its ability to be absorbed by foods. Accordingly, it is desirable to remove these impurities at whatever stage of oil production and use they occur, whenever possible.
  • Table 1 shows some of the impurities contained in crude glyceride oils, which can be removed by the refining process.
  • the oils are treated with caustic soda in the primary steps.
  • the caustic soda forms a flocculant precipitate of soaps which settle out as "foots.”
  • the addition of an alkali solution to crude or crude degummed oil results in chemical reactions and physical changes.
  • the alkali combines with free-fatty acids in the oil to form soaps.
  • the phosphatides and gums absorb alkali and are coagulated through hydra ion or degradation. Much of the coloring matter is degraded and absorbed by the gums, or made water soluble by the alkali. The insoluble matter is entrained with the other coagulated material.
  • the soap-oil mixture is then heated to about 160-180°F (75- 82°C) and fed through a centrifuge for separation into light and heavy density phases.
  • the light phase comprises chiefly refined oils including traces of moisture and soap.
  • the heavy phase is primarily soap, insoluble matter, free caustic, phosphatides, and 5-9% of neutral oil.
  • the refined oil (light phase) is discharged from the centrifuge, heated to 190°F (88°C) and mixed with soft water that has been heated to 200°F (93°C).
  • the water-oil mixture passes through a high-speed shear mixer to obtain intimate contact between the oil and water phases for maximum soap transfer from the oil to the water.
  • the mixture next passes through a second centrifuge where the phases are separated.
  • the water- washed oil is discharged as the light phase, and the soapy water as the heavy phase.
  • the water-washing process removes about 90% of the soap content of the refined oil. The remainder of the soap is removed by a subsequent bleaching process.
  • adsorbents In conjunction with the refining process, many different adsorbents have been used, including: silica hydrogel (U.S. Patent 4,629,588); silica hydrogel treated with an organic acid (U.S. Patent 4,734,226); high surface area amorphous silica treated with a strong acid (U.S. Patent 4,781,864); partially dried silica gel (U.S. Patent 4,880,574); bleaching absorbent and phosphoric acid (U.S. Patent 3,895,042); silicon dioxide, aluminum oxide or mixtures thereof (U.S. Patent 3,955,004); activated carbon impregnated with MgO (U.S. Patent 4,125,482 and U.S.
  • Patent 4,150,045 bleaching clay and an alkaline earth metal, lanthanide, or transition metal exchange zeolite Y
  • U.S. Patent 4,443,379 silica gel and silicic acid
  • U.S. Patent 4,874,629 metal oxide silica absorbent
  • sodium silicate solution combined with phosphoric acid USSR patents 992,564-A, 1,386,642-A, 1,148,861-A, and 806,750-B
  • the present invention provides a composition and method for treating edible glyceride oils to remove contaminants therefrom.
  • the composition can be added directly to crude oil, degummed oil, or used oil to reduce FFA, color bodies, trace metals, and other impurities.
  • the composition comprises solid hydrous alkali metal silicates, particularly sodium metasilicate pentahydrate and hydrous sodium polysilicate. This material is added to oil containing contaminants, in an amount approximately equal to the amount of FFA present in the oil after a small amount of water is added to the oil.
  • the oil may then be heated and agitated.
  • the oil is then filtered or centrifuged to remove the solid hydrous sodium silicate, and vacuum dried, if appropriate, to remove residual water.
  • the type and levels of contaminants present in glyceride oils depend on a number of factors, including whether the oil is crude, whether it has been degummed, and if used, what foods were fried in the oil. Some crude oils, like soybean for example, can have only about 0.7% FFA, while other oils like palm oil, have around 5.0% FFA. Accordingly, in removing FFA, the amount of treating agent (solid hydrous sodium silicate) used should depend upon the amount of contaminants in the oil. It is preferred to use a 1:1 ratio of solid hydrous sodium silicate to the FFA content of the oil on a weight basis. Thus for 100 gms. of palm oil with 5.0% FFA, 5 gms. of solid hydrous sodium silicate would be used as a treating agent.
  • the oil and solid hydrous sodium silicate should react at elevated temperature.
  • the oil may be heated before (or after) the addition of the solid hydrous sodium silicate.
  • the temperature to which the oil should be heated will depend upon the processing that the oil has previously received. Crude oils tend to discolor when heated to temperatures over 220°F because of color reactions and phospholipids. Once color bodies are removed, higher temperatures may be used without adversely affecting the oil. For instance, refined oil must have the ability to be heated to 350° or higher in order to withstand the temperatures needed to fry foods.
  • the temperature to which the oil is heated also depends on what treating agent is used.
  • Sodium metasilicate pentahydrate has a melting point around 162°F (although experiments indicate it is stable in oil at temperatures as high as 220°F) . Therefore oils treated with sodium metasilicate pentahydrate should be heated to a lower temperature than oils treated with hydrous sodium polysilicate, which has a much higher melting point.
  • Table 3 shows the effect of varying the temperature of the oil on FFA removal when using hydrous sodium polysilicate and sodium metasilicate pentahydrate.
  • hydrous sodium polysilicate is not as effective at removing FFA at low temperatures as sodium metasilicate pentahydrate.
  • hydrous sodium polysilicate is useful and effective for removing FFA at temperatures well above the melting point of sodium metasilicate pentahydrate. Therefore, sodium metasilicate pentahydrate is recommended for refining where the oil begins cold and must be heated, since sodium metasilicate pentahydrate allows processing at lower temperature, thereby effecting a cost savings in heating the oil.
  • Hydrous sodium polysilicate is useful in removing contaminants from used oils, since they are usually at an elevated temperature at which sodium metasilicate pentahydrate would melt.
  • the hydrous sodium polysilicate does not require cooling the used oil and possibly reheating the oil for use after cleaning.
  • Sodium silicates in general are combinations of sodium oxide (Na2 ⁇ ) and silicon dioxide (Si ⁇ 2) . They may or may not have water chemically bound within them.
  • Sodium polysilicate for instance, has the formula (Na2 ⁇ ) x (Si ⁇ 2)y*zH2 ⁇ where the weight ratio y:x is greater than 2.0 but less than 2.40. The material is generally about 17.5% water on a weight basis when it is hydrous.
  • BRITESIL ® C20 BRITESIL is a registered trademark and BRITESIL products are available through the PQ Corporation, P.O. Box 840, Valley Forge, Pennsylvania 19482).
  • BRITESIL ® C20 has a Si0 2 :Na 2 0 ratio of 2.00.
  • BRITESIL ® C20 sodium polysilicate is amorphous, has a bulk density of 50 lb/ft 3 (.80 g/cm 3 ) , and is 17.5% H 2 0 by weight.
  • the sodium metasilicate evaluated for performance in removal of contaminants from edible glyceride oils had the general formula
  • the traditional refining process for edible glyceride oils generally begins with a preheating step to heat the oil to treatment temperature. Once hot, the oil is treated with H3PO4 and centrifuged. This treatment turns non-hydratable (unreactive with alkali) phospholipids to hydratable, so they can be removed by the refining process. This treatment is referred to as degumming. As previously described, once the oil has been degummed, diluted caustic (NaOH) is added to neutralize or remove FFA from the oil. The FFA react with the sodium hydroxide to form soaps. The sodium hydroxide is a solution in water, and soaps are contained in the aqueous phase.
  • NaOH diluted caustic
  • the caustic step in the refining process may be eliminated.
  • water is added to the oil in an amount based upon the FFA level.
  • water should be added in an amount of between l.7 and 2.1 times the weight of FFA present in the oil.
  • a ratio of water:FFA of 1.9 is preferred. If too much water is used, the soaps which form will be thin, and will therefore absorb more oil, leading to higher oil losses. Conversely, if too little water is added, the soaps formed will be too thick, making separation difficult.
  • Solid alkaline hydrous sodium silicate is then added to the oil.
  • the oil may be heated and agitated.
  • the oil may then be centrifuged or filtered, depending upon the amount of sodium silicate added to the oil. When greater amounts of sodium silicate are added, filtering becomes increasingly slow. Therefore if large amounts of sodium silicate are to be added, centrifugation is the preferred method of separation.
  • the oil may then be washed with water a second time, separated, and vacuum dried to remove residual water.
  • oils like olive and almond oils have a low phosphorus content.
  • the step of adding phosphoric acid in order to remove phospholipids from the oil can be eliminated since the sodium silicates will remove some phospholipids.
  • the remainder of the refining process is the same, and this process is improved by using solid alkaline hydrous sodium silicate instead of a solution of caustic in that the amount of water added to the oil is reduced.
  • a treating agent is generally added directly to the used cooking oil in the fryer or a separate treatment vessel.
  • the oil is then filtered to remove the treating agent and returned to the fryer to be used. Generally this operation is performed while the oil is hot.
  • the hydrous alkali metal silicate described and claimed herein is useful as such a treatment agent for used cooking oils, either alone or in combination with other rejuvenating compounds.
  • hydrous sodium polysilicate is generally more useful than sodium metasilicate pentahydrate.
  • the sodium metasilicate pentahydrate used in the tests conducted for this invention has a melting point of about 162°F (72.2°C), although this sodium metasilicate did not melt in oil until the temperature rose to about 240°F. Nevertheless, oil in fryers is generally at a temperature of around 350°F. This temperature is too high for sodium metasilicate pentahydrate to be useful, since it would melt upon contact with the oil. Therefore, hydrous sodium polysilicate with a higher melting point is more useful for used cooking oil rejuvenation.
  • the sodium metasilicate pentahydrate, while effective in removing contaminants, would require the cooling of the oil prior to treatment. This is generally undesirable in that it involves an additional processing step.
  • Crude 1 Crude 2, Crude 3, Crude 4, Crude 5, Crude 6, Crude Olive, and Crude Walnut.
  • the METSO PENTABEAD 20 (sodium metasilicate pentahydrate) performed better with higher contact times, higher temperatures, and larger doses. This was expected, as each factor allows greater contact between oil and treatment agent. The exception to this general observation was sample 9 where METSO PENTABEAD 20 appeared to perform slightly worse with an increase in temperature from 200 to 220°F. Only one sample was tried at this higher temperature. The METSO PENTABEAD 20 even performed well where the initial FFA content was in excess of 5% (see samples 75, 77, 87, and 88) .
  • METSO Fluorine
  • METSO Medium
  • METSO Granular
  • METSO Oversized
  • samples 50-74 in table 4 these sizes of sodium metasilicate pentahydrate were effective in removing FFA from the oils.
  • Table 4 also shows that BRITESIL C20 was effective in removing FFA from the oils. This may be seen from samples 47-53, 76, and 78. It does not appear from these experiments that filtering or centrifuging the oil made any difference in the performance of the treatment agents. In real life, the time required to filter large amounts of oil may increase the contact time between the oil and treatment agent, thereby increasing the performance of the treatment agent.
  • ⁇ -Filtration time was > 15 minutes.
  • Sodium metasilicate pentahydrate and hydrous sodium polysilicate were tested to gauge performance as compared to treatment with a solution of 10% sodium hydroxide, traditionally used to treat oil to remove FFA.
  • the sodium hydroxide was added in an amount of .3% of the weight of the oil to be treated. The results of these tests are shown in Table 8.
  • Ratio Color Pigments wt trtmt Red Yellow Chlorophyll FFA Soap
  • both the sodium metasilicate pentahydrate and hydrous sodium polysilicate performed comparably to the sodium hydroxide in both crude and degummed oil, whether or not the oil was bleached.
  • the use of these treatment agents does not sacrifice the quality of the oil produced.
  • an advantage of these treatment agents is that, compared to caustic refining, less soap remains in the oil and less neutral oil is lost in the soap stock. For example, a caustic treated oil was found to contain 319 ppm residual soap and yielded a soap stock that weighed 5.0% of the untreated oil weight. The same oil treated by sodium metasilicate pentahydrate gave 228 ppm and 2.1%.
  • Palm oil refined with METSO PENTABEAD 20 was also compared to oil refined in the traditional manner described previously. The results of this comparison are shown in Table 9. As may be seen, refining with METSO PENTABEAD 20 is comparable to refining in the traditional manner.
  • Dosage is 1:1 ratio of METSO PENTABEAD 20:FFA on a weight basis.
  • METSO PENTABEAD 20 sodium metasilicate pentahydrate was also tested to determine the amount of oil absorbed by the treatment agent. The results of this test are shown in Table 10.
  • Oil absorbed is a weight percentage based on the weight of treatment agent used.
  • sodium metasilicate pentahydrate absorbed only 30 to 40% of its weight of oil, indicating low losses of oil in this type of treatment.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Microbiology (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Fats And Perfumes (AREA)
  • Edible Oils And Fats (AREA)
  • Detergent Compositions (AREA)
EP94912793A 1993-03-18 1994-03-17 Process for reducing contaminants in glyceride oils. Withdrawn EP0646162A4 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US3296793A 1993-03-18 1993-03-18
US32967 1993-03-18
PCT/US1994/002848 WO1994021765A1 (en) 1993-03-18 1994-03-17 Process for reducing contaminants in glyceride oils

Publications (2)

Publication Number Publication Date
EP0646162A1 EP0646162A1 (de) 1995-04-05
EP0646162A4 true EP0646162A4 (en) 1995-04-19

Family

ID=21867835

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94912793A Withdrawn EP0646162A4 (en) 1993-03-18 1994-03-17 Process for reducing contaminants in glyceride oils.

Country Status (5)

Country Link
EP (1) EP0646162A4 (de)
JP (1) JPH07507100A (de)
KR (1) KR950701676A (de)
CA (1) CA2136018C (de)
WO (1) WO1994021765A1 (de)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9408865D0 (en) * 1994-05-04 1994-06-22 Unilever Plc Process for refining glyceride oil
US6248911B1 (en) * 1998-08-14 2001-06-19 Pq Corporation Process and composition for refining oils using metal-substituted silica xerogels
US6376689B1 (en) 1999-09-02 2002-04-23 Cargill, Incorporated Removal of gum and chlorophyll-type compounds from vegetable oils
PE20070482A1 (es) 2005-08-26 2007-06-08 Ocean Nutrition Canada Ltd Metodo para remover y/o reducir esteroles a partir de aceites
US7977498B2 (en) 2005-08-26 2011-07-12 Ocean Nutrition Canada Limited Reduction of sterols and other compounds from oils
DE102006061604A1 (de) * 2006-12-27 2008-07-03 Alois Dotzer Verfahren zur Herstellung eines Kraftstoffs aus Pflanzenöl
DE102009043418A1 (de) 2009-09-29 2011-04-07 Süd-Chemie AG Alumosilikat-basierte Adsorbentien zur Aufreinigung von Triglyceriden
DE102014210662A1 (de) 2014-06-04 2015-12-17 Gea Westfalia Separator Group Gmbh Vorrichtung und Verfahren zur Gewinnung von Glycoglycerolipiden und Glycosphingolipiden aus lipoiden Phasen
EP3098293A1 (de) 2015-05-27 2016-11-30 Evonik Degussa GmbH Verfahren zur entfernung von metall aus einem metallhaltigen glyceridöl mit einer behandlung aus basischem quaternärem ammoniumsalz
EP3098292A1 (de) 2015-05-27 2016-11-30 Evonik Degussa GmbH Verfahren zum raffinieren von glyceridöl mit einer behandlung mit basischem quaternärem ammoniumsalz
GB2538758A (en) 2015-05-27 2016-11-30 Green Lizard Tech Ltd Process for removing chloropropanols and/or glycidol
EP3483237A1 (de) 2017-11-10 2019-05-15 Evonik Degussa GmbH Verfahren zur extraktion von fettsäuren aus triglyceridölen
MY176002A (en) * 2018-04-25 2020-07-21 Sime Darby Plantation Intellectual Property Sdn Bhd Process for producing crude palm fruit oil
GR1009852B (el) * 2019-01-23 2020-10-29 Pinchas Or Ελαιολαδο ψυχρης εκθλιψης με περιεκτικοτητα ελευθερων λιπαρων οξεων μικροτερη του 0,1%
EP3858958A1 (de) * 2020-01-28 2021-08-04 Or, Pinhas Kaltgepresstes olivenöl mit einem gehalt an freien fettsäuren von weniger als 0,1 %

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2006729A (en) * 1977-09-14 1979-05-10 Johns Manville Fast flow rate coarse synthetic hydrous calcium silicate.
EP0304115A2 (de) * 1987-08-05 1989-02-22 Unilever N.V. Seeöl-Pflanzenöl-Mischung und daraus hergestellte Produkte

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3557008A (en) * 1967-05-08 1971-01-19 Jennings Dev Corp Animal fat cleaning composition and method
ATE69975T1 (de) * 1986-11-24 1991-12-15 Unilever Nv Metall-oxid-siliziumdioxid enthaltendes sorbentmittel und dessen verwendung zur oelraffinierung.

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2006729A (en) * 1977-09-14 1979-05-10 Johns Manville Fast flow rate coarse synthetic hydrous calcium silicate.
EP0304115A2 (de) * 1987-08-05 1989-02-22 Unilever N.V. Seeöl-Pflanzenöl-Mischung und daraus hergestellte Produkte

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9421765A1 *

Also Published As

Publication number Publication date
JPH07507100A (ja) 1995-08-03
KR950701676A (ko) 1995-04-28
CA2136018C (en) 2005-02-01
WO1994021765A1 (en) 1994-09-29
EP0646162A1 (de) 1995-04-05
CA2136018A1 (en) 1994-09-29

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