KR20100066401A - Method of improving oil compositions - Google Patents

Abstract

PURPOSE: An improving method of an oil composition is provided to improve the low temperature property of the oil composition including fatty acid alkyl ester induced from saturated fatty acid with the carbon number of 16~22. CONSTITUTION: An improving method of an oil composition containing fatty acid alkyl ester comprises a step of reacting the oil composition with more than one compound containing more than three nitrogen atoms. The compound containing more than three nitrogen atoms includes an imidazoline compound with polyalkylen polyamine, a polyalkyleneimine substituent, or more than one primary amine group. The polyalkylen polyamine contains more than five nitrogen atoms.

Description

Improvement of oil composition {METHOD OF IMPROVING OIL COMPOSITIONS}

The present invention relates to a method for improving the low temperature properties of oils derived from plant or animal materials.

Oils and fats derived from plant or animal materials are increasingly being used as partial or complete substitutes for fuels, more particularly for petroleum intermediate fractions such as diesel. Such fuels are generally known as "biofuels" or "biodiesel". Biofuels can be derived from a number of sources. The most common are esters of alkyl, often methyl, of fatty acids extracted from plants such as rapeseed, sunflower seeds and the like. This type of fuel is often referred to as Fatty acid methyl ester (FAME).

Since they are obtained from renewable sources, there is an environmental motivation to encourage the use of such fuels. There are also indications that biofuels produce less pollutants on combustion than comparable petroleum-based fuels.

Fuel oils derived from plant or animal materials may contain components such as methyl n-alkanoate, which tend to precipitate as spherulite or large platelet crystals of wax at low temperatures in a manner that forms a gel structure. In which the gel structure causes a decrease in fuel flow. The lowest temperature at which the fuel still flows is known as the pour point.

As the temperature of fuel drops and approaches the pour point, difficulties arise in transporting fuel through piping and pumps. In addition, wax crystals tend to clog fuel lines, screens, and filters even at temperatures above the pour point. These problems are well recognized in the art and various additives have been proposed, many of which are commercially available to lower the pour point of both fuel oils derived from petroleum sources and fuel oils derived from plant or animal materials, for example. Is being used. Similarly, other additives have been proposed and are in use commercially to reduce the shape and size of the wax crystals formed. Smaller sized crystals are preferred because they can lessen the filter. Certain additives suppress the tendency of the wax formed to crystallize into platelets and instead adopt the needle-like properties. The resulting needle is easier to pass through the filter or to form a porous crystal layer in the filter than in the platelet type. The additive may also have the effect of retaining the wax crystals in the suspension of the fuel, reducing the sedimentation and also assisting in containment prevention.

The low temperature properties of oils derived from plant or animal substances are mainly determined by the saturated fatty acid content of the oil, more specifically by the proportion of C ₁₆ -C ₂₂ saturated fatty acids present. Methyl and ethyl esters of these acids can be particularly problematic. It is difficult to transport and handle these oils below the temperature at which these species crystallize from mixtures of fatty acid esters. Oils that sometimes contain little saturated fatty acid esters can be successfully treated with conventional additives that improve their low temperature properties. However, oils containing relatively small amounts, especially esters derived from palmitic acid and stearic acid, have been found to be unreactive to conventional additives.

Notwithstanding the problems highlighted by Acer, it is preferred to use oils derived from plant or animal substances containing saturated fatty acids having from 16 to 22 carbon atoms. This is because they are obtained from relatively inexpensive and abundant sources. The present invention provides a solution to the cold transport and handling problems associated with such oils.

The present invention seeks to provide a new method for improving the low temperature properties of plant- or animal-derived oils comprising fatty acid alkyl esters derived from saturated fatty acids having from 16 to 22 carbon atoms.

According to the present invention, a fatty acid alkyl ester derived from a plant or animal material, wherein at least 5% by weight of the fatty acid alkyl ester improves the low temperature properties of oils derived from saturated fatty acids having 16 to 22 carbon atoms, Reacting at least a portion of the oil with one or more compounds having at least three nitrogen atoms, at least one of these nitrogen atoms being in the form of a primary amine group, wherein one containing said at least three nitrogen atoms Provided is a process wherein the above compounds comprise a polyalkylene polyamine, or an imidazoline compound having both a polyalkylene imine substituent and at least one primary amine group.

According to the invention, the invention improves the low temperature properties of oils comprising fatty acid alkyl esters derived from plant or animal substances.

In the present invention, the improvement in low temperature properties associated with oil may constitute an improvement in one or more of the pour point, cloud point, cold filter plugging point (CFPP) or other operational tests. Suitable tests will be known to those skilled in the art. Preferably, improvement in low temperature properties will constitute improvement in pour point and / or CFPP.

While not wishing to be bound by any theory, it is believed that the amidation of mixtures of fatty acid ester types that lead to poor low temperature properties provides an effective "additive" to improve the low temperature properties of oils in which the ester is present in significant amounts. . The "additives" are prepared in situ by directly reacting oils containing problematic saturated fatty acid-derived esters with compounds having at least three nitrogen atoms. As is known in the art, for example, it is easy to react the methyl ester with an amine to form an amide.

Preferably, the oil portion that reacts with the compound having three or more nitrogen atoms is 0.05 to 10% by weight, more preferably 0.05 to 2% by weight, for example 0.05 to 1% by weight of the oil.

Once reacted with a compound having three or more nitrogen atoms, the oil may be used on its own, for example as a pure bio-fuel, or mixed with any proportion of petroleum oil.

In a preferred embodiment, one or more fatty acids are additionally used. Preferably mixtures of fatty acids are used, for example mixtures of fatty acids obtained from plant or animal materials. The one or more fatty acids are co-reacted with or added to the oil and one or more compounds having three or more nitrogen atoms. The one or more fatty acids and one or more compounds having three or more nitrogen atoms may be added to the oil in any order.

By using one or more fatty acids, the low temperature properties of oils derived from plant or animal materials containing at least 5% by weight of fatty acid alkyl esters derived from saturated fatty acids having from 16 to 22 carbon atoms can be further improved.

It is expected that one (or more if present) of the primary amine groups of the compound having three or more nitrogen atoms will react with the fatty acid alkyl esters to form amides. As mentioned above, this reaction is predominant and can be facilitated by gentle heating. Other nitrogen atoms of the compounds may be secondary or tertiary amines, for example. Amide formation from these amine groups is somewhat less prevalent, so they are expected to remain unreacted in the presence of fatty acid alkyl esters. At present, it is contemplated that the addition of fatty acids may facilitate the formation of salts with one or more other nitrogen atoms.

Various features of the invention will be described in more detail below.

Mixture of fatty acid alkyl esters

At least 5% by weight of the mixture of fatty acid alkyl esters is derived from saturated fatty acids having 16 to 22 carbon atoms. Preferably at least 10%, more preferably at least 20% and even more preferably at least 30% of the mixture of fatty acid alkyl esters are derived from saturated fatty acids having 16 to 22 carbon atoms. Preference is given to methyl or ethyl esters, in particular methyl esters.

In a preferred embodiment, the fatty acid alkyl esters derived from saturated fatty acids having 16 to 22 carbon atoms include methyl palmitate, methyl stearate or mixtures thereof.

Preferably, the amount of the mixture of fatty acid alkyl esters derived from saturated fatty acids having from 16 to 22 carbon atoms does not exceed 60% by weight. Most of the rest of the mixture of fatty acid esters preferably include those derived from unsaturated fatty acids.

Non-limiting examples of suitable materials include palm oil methyl ester (PME), soybean oil methyl ester (SME) and rapeseed oil methyl ester (RME). Mixtures of materials obtained from different sources are also suitable, for example mixtures of PME and rapeseed oil methyl ester (RME) or other similar mixtures.

Compounds having three or more nitrogen atoms

The compound to react with the oil has three or more nitrogen atoms. At least one of these nitrogen atoms is in the form of a primary amine.

In one embodiment, the compound having three or more nitrogen atoms is (i) a polyalkylene polyamine.

Suitable amino acids include amino nitrogens linked by alkylene bridges, wherein the amino nitrogens may be primary, secondary and / or tertiary in nature and only one or more amino nitrogens are primary amine groups. The polyamine may be straight chain, wherein all amino groups will be primary or secondary groups, or the polyamine may contain cyclic or branched regions or both, in which case tertiary amino groups may be present, but only one or more amino nitrogens are primary amines. Must contribute. The alkylene groups in a single molecule can be the same or different. Preference is given to ethylene or propylene groups, in particular ethylene.

Non-limiting examples of suitable polyalkylene polyamines include di (ethylene) triamine (DETA), tri (ethylene) tetraamine (TETA), tetra (ethylene) pentaamine (TEPA), penta (ethylene) hexaamine (PEHA ) And similar homologues. Polyalkylene polyamines having five or more nitrogen atoms are generally preferred over those having up to four nitrogen atoms.

Mixtures of polyalkylene polyamines are also suitable. As is known in the art, such materials are readily available and include polyalkylene polyamines of various sizes. These are generally referred to as PAMs. These are defined by the average number of nitrogen atoms per component molecule, and may preferably have from 5 to 8.5, more preferably from 6.8 to 8, for example from 6.8 to 7.5 nitrogen atoms per molecule. Heavier substances called HPAMs, amine mixtures comprising polyamines having, for example, an average of 7 and 8 and optionally 9 nitrogen atoms per molecule, are suitable.

In other embodiments, the compound having three or more nitrogen atoms is an imidazoline compound having both (ii) a polyalkylene imine substituent and at least one primary amine group. Such compounds can be prepared, for example, by reacting fatty acids (eg, stearic or palmitic acid) or methyl esters of fatty acids with polyalkylene polyamines (eg, TETA, TEPA, PEHA, PAM, etc.). have.

fatty acid

Preferred fatty acids are unsaturated fatty acids having 16 to 20 carbon atoms. Particular preference is given to unsaturated acids having 18 carbon atoms, for example oleic acid, linoleic acid and linolenic acid. They can be used as pure components, but preference is given to using mixtures of fatty acids obtained from plant or animal materials. From rapeseed oil, tall oil, coriander oil, soybean oil, cottonseed oil, sunflower seed oil, castor oil, olive oil, peanut oil, corn oil, almond oil, palm kernel oil, coconut oil, mustard seed oil, jatropha oil, tallow oil, and fish oil Fatty acid mixture obtained. Further examples include oils derived from corn, jute, sesame seeds, cyanuts, peanuts and flax seeds, and may be derived from them by methods known in the art. Oils having a high proportion of unsaturated fatty acids of 18 carbon atoms, ie oils having more than 50% by weight unsaturated fatty acids of 18 carbon atoms, preferably those having more than 70% or more than 85% by weight unsaturated fatty acids. Fatty acids obtained from tall oil and rapeseed oil are particularly suitable.

One or more co-additives may be used in the present invention. Suitable co-additives are not only effective in improving the low temperature properties of fuel oils, but are also known in the art as additives that improve other properties of oils such as lubricating additives, antioxidants, dispersants, detergents and the like.

In a preferred embodiment, ethylene polymers can be used as co-additives. Examples of these are as follows.

Ethylene polymer

Each polymer may be a homopolymer of ethylene or a copolymer of ethylene and other unsaturated monomers.

Preferred co- equivalents are unsaturated esters or ether monomers, with ester monomers being more preferred. Preferred ethylenically unsaturated ester copolymers have units of formula (I) in addition to units derived from ethylene:

-CR ³ R ⁴ -CHR ^5-

Where

R ³ is hydrogen or methyl,

R ⁴ is COOR ⁶ , R ⁶ is an alkyl group having 1 to 12 carbon atoms, preferably 1 to 9 carbon atoms, and is linear or branched when having 3 or more carbon atoms.

R ⁴ is OOCR ⁷ , wherein R ⁷ is R ⁶ or H,

R ⁵ is H or COOR ⁶ .

These may include copolymers of ethylenically unsaturated esters and ethylene or derivatives thereof. Examples are copolymers of ethylene and esters of saturated alcohols and unsaturated carboxylic acids, but preferably the esters are esters of saturated carboxylic acids and unsaturated alcohols. Ethylene-vinyl ester copolymers are advantageous and include ethylene-vinyl acetate, ethylene-vinyl propionate, ethylene-vinyl hexanoate, ethylene-vinyl 2-ethylhexanoate, ethylene-vinyl octanoate or ethylene-vinyl versa Tate copolymers are preferred. Preferably, the copolymer comprises 5 to 40 weight percent vinyl ester, more preferably 10 to 35 weight percent vinyl ester. For example, as described in US Pat. No. 3,961,916, a mixture of two copolymers may be used. The Mn of the copolymer is advantageously 1,000 to 10,000. If desired, copolymers (eg terpolymers, quaternary polymers or more polymers) may contain units derived from additional comonomers, for example the added comonomers are isobutylene or diiso Butylene or further unsaturated esters.

Other suitable co-monomers include hydrocarbon monomers such as propylene, n- and iso-butylene, 1-hexene, 1-octene, methyl-1-pentene vinyl-cyclohexane and various alphas known in the art. -Olefins such as 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene and mixtures thereof.

The present invention will now be described by way of example only.

Example 1

Rapeseed oil methyl ester (RME), having a 6.2-wt% C16-22 saturate content, was reacted with 0.125 wt% Tetraethylene Pentamine (TEPA). The reaction was carried out at 140 ° C. for 4 hours under a blanket of nitrogen. The pour point of the untreated RME was -12 ° C. After reacting with TEPA, the pour point decreased to -42 ° C.

Example 2

By refluxing in xylene at 160 ° C., 1-2 moles of diethylene triamine (DETA) and 1 mole of stearic acid were reacted. After completion, excess amine was removed together with the solvent by vacuum distillation. 1-aminoethyl-2-heptadecyl-imidazoline was obtained as a product. Soybean oil methyl ester (SME) having a saturate content of 16 to 22 carbon atoms of 14.6% by weight was reacted with an imidazoline in an amount of 0.5% by weight. The reaction was carried out at 150 ° C. for 4 hours under a blanket of nitrogen gas. 0.6 wt% ethylene vinyl acetate (EVA) copolymer was added to the SME and the pour point was measured at -42 ° C. For comparison, the pour point of untreated SME comprising 0.6% EVA copolymer was measured at -6 ° C.

Example 3

Triethylene tetraamine (TETA) was reacted with the same proportion of stearic acid under the same reaction conditions as described in Example 2. 1- (N-aminoethyl-aminoethyl) -2-heptadecyl-imidazoline was obtained as a product. Soybean oil methyl ester (SME) having a saturate content of 14.6 wt% to 16 carbon atoms was reacted with imidazoline in an amount of 0.5 wt%. The reaction was carried out at 150 ° C. for 4 hours under a nitrogen gas blanket. 0.6 wt% ethylene vinyl acetate (EVA) copolymer was added to the SME and the pour point was measured at -51 ° C. For comparison, the pour point of unreacted SME comprising 0.6% EVA copolymer was -6 ° C.

Claims (9)

A fatty acid alkyl ester derived from a plant or animal material, wherein at least 5% by weight of the fatty acid alkyl ester improves the low temperature properties of oils derived from saturated fatty acids having from 16 to 22 carbon atoms. And reacting with at least one compound having at least three nitrogen atoms, at least one of which is in the form of a primary amine group, wherein at least one compound having at least three nitrogen atoms is a polyalkylene polyamine Or an imidazoline compound having both a polyalkylene imine substituent and at least one primary amine group. The method of claim 1, Wherein said polyalkylene polyamine has at least 5 nitrogen atoms. The method of claim 1, The said imidazoline compound is manufactured by making a polyalkylene polyamine and the fatty acid or the methyl ester of a fatty acid react. 4. The method according to any one of claims 1 to 3, Wherein the portion of the oil that reacts with the compound having at least three nitrogen atoms is from 0.05% to 10% by weight of the oil. The method according to any one of claims 1 to 4, The oil comprising fatty acid alkyl esters derived from plant or animal material consists essentially of methyl or ethyl esters, preferably methyl esters. 6. The method according to any one of claims 1 to 5, Wherein at least 5% by weight of the fatty acid alkyl esters derived from saturated fatty acids having from 16 to 22 carbon atoms comprise methyl palmitate, methyl stearate or mixtures thereof. 7. The method according to any one of claims 1 to 6, At least one fatty acid is co-reacted with or added to the oil and at least one compound having at least three nitrogen atoms. The method of claim 6, At least one fatty acid comprises a mixture of fatty acids obtained from an animal or plant material, preferably a mixture having more than 50% by weight of unsaturated fatty acids having 18 carbon atoms. 9. The method according to any one of claims 1 to 8, Further comprising adding an ethylene polymer to the oil.