BIO-BASED ADDITIVES FOR DIESEL

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The subject application claims priority to Canadian Patent Application No. 3,256,764 filed Nov. 1, 2024, the contents of which are incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention is directed to a composition for use as a fuel additive or fuel blend component, more specifically a composition comprising various esterified lignin depolymerization products.

BACKGROUND OF THE INVENTION

In recent years, numerous groups have been addressing the pressing need of partially or completely replacing petroleum-based fuels and related products in an attempt to solve the environmental challenges facing humanity.

Bio-fuels derived from renewable resources present an inherent benefit in terms of resource abundancy as well as having a neutral carbon footprint. Lignocellulosic biomass such as, but not limited to wood, grasses and other plant materials, contains three main components: cellulose fibers; lignin; and hemicelluloses. Pulping of lignocellulosic biomass has a primary goal to separate the fibers from the lignin. Lignin is a three-dimensional polymer which figuratively acts as a mortar to hold all the fibers together within the plant.

Lignin accounts for, in some biomass, up to 30 percent of the lignocellulose biomass, and has a great potential to replace at least a portion of the petroleum-based chemical products. However, it is still greatly underused as such an alternative. Lignin is the second most abundant organic natural material encountered in nature. However, approximately 98% of it is still simply burned to provide heat or used in the production of energy. Lignin is made up of various aromatic compounds and its complexity comes from the diversity and degree of crosslinking between the various monomeric units which comprises it. These are called lignols and fall under one of three main categories: coniferyl alcohol; sinapyl alcohol; and paracoumaryl alcohol.

Generally, biodiesel is produced from vegetable oils, yellow grease, used cooking oils, or animal fats. Biodiesel is produced by transesterification of waste oils or vegetable oils. It takes about 100 pounds of oil and 10 pounds of a short-chain alcohol in the presence of a catalyst (most commonly a hydroxide such as sodium hydroxide or potassium hydroxide) to generate 100 pounds of biodiesel.

Unprocessed raw or refined vegetable oil, or recycled greases do not constitute biodiesel and should not be used as fuel. The reason being that such oils are much more viscous than biodiesel and, if used as fuel, can cause long-term engine problems by deposits, gelling. These and other factors, are part of the limitations which have been plaguing the biodiesel industry.

There are numerous patents and patent applications which are directed to the production and purification of biodiesel using various vegetable-based oil as a starting point. For example, U.S. Pat. No. 7,528,272B2 teaches a process for yielding biodiesel, the process comprising: providing a feed stream, wherein the feed stream comprises mono-alkyl esters, glycerol, alcohol and salts; substantially separating alcohol of the feed stream to yield a first stream comprising mono-alkyl esters, glycerol and salts, wherein separation is by volatility; substantially separating salts of the first stream to yield a vapor stream comprising mono-alkyl esters and glycerol, wherein separation is by volatility; and substantially separating glycerol from the vapor stream to yield a biodiesel comprising mono-alkyl esters.

U.S. Pat. No. 7,321,052 B2 teaches a continuous process for the preparation of a composition useful as a fuel oil which comprises: (a) reacting in a first closed vessel containing a first solid acid catalyst, a triglyceride and a lower alkanol containing 1 to 6 carbon atoms at a first elevated temperature to produce a first mixture comprising glycerol, monoglycerides, diglycerides and triglycerides, lower alkanol, and transesterified fatty acid ester as a partial transesterification mixture; and (b) reacting in a second closed vessel above a second acid catalyst the partial transesterification mixture and additional of the alkanol, with an aldehyde, ketone containing 1 to 20 carbon atoms or a diether containing 2 to 20 carbon atoms below the second acid catalyst at a second elevated temperature with removal of excess alkanol, and aldehyde, ketone or diether from an upper portion of the second vessel, to form a mixture of the transesterified fatty acid ester and a glycerol acetal which is removed from a lower portion of the second closed vessel to thereby provide the composition.

US patent application no. 2004/0025417A1 discloses a diesel fuel composition comprises a major proportion of at least one diesel fuel and a minor proportion of at least one glycerol acetal carbonate.

PCT patent application WO2009/017958A1 discloses a process for preparing Renewable Diesel comprising the step of pyrolysis of oil of vegetable and/or animal origin followed by the step of esterification of residual carboxylic acid to yield diesel fuel according to either ASTM D396 or ASTM D975 or both.

U.S. Pat. No. 7,635,398 B2 teaches a method of purifying a crude biodiesel fuel, comprising: contacting said crude biodiesel fuel with at least one adsorbent material, wherein said at least one adsorbent material comprises magnesium silicate, and wherein said biodiesel fuel is a product of reacting triglycerides with an alcohol, thereby providing a purified biodiesel fuel which includes at least one monoalkyl fatty acid ester.

U.S. Pat. No. 10,030,205B2 teaches a catalyst system, such as a mixed catalyst composition, that can be used to make biofuel. In some embodiments, the mixed catalyst composition can comprise an inorganic catalyst and an organic catalyst, such as a cyclic organic catalyst. In particular disclosed embodiments, a mixed catalyst composition comprising, consisting essentially of, or consisting of an inorganic catalyst and an organic catalyst can be used to enhance the production of biofuel, such as biodiesel, by reducing the amount of time needed to make the biofuel as compared to that needed for the inorganic catalyst or the organic catalyst independently.

U.S. Pat. No. 5,525,126A teaches a process for producing esters from a feed stock utilizing a single catalyst without producing soap that includes a fat or an oil, comprising: mixing the feedstock with an alcohol and a catalyst, the catalyst comprising a mixture of calcium acetate and barium acetate to form a reaction mixture; and heating the reaction mixture at a temperature effective to form esters.

US patent application no. 2006/0074256A1 discloses a process for yielding biodiesel, the process comprising: providing a feed stream, wherein the feed stream comprises mono-alkyl esters, glycerol, alcohol and salts; substantially separating alcohol of the feed stream to yield a first stream comprising mono-alkyl esters, glycerol and salts, wherein separation is by volatility; substantially separating salts of the first stream to yield a vapor stream comprising mono-alkyl esters and glycerol, wherein separation is by volatility; and substantially separating mono-alkyl esters and glycerol of the vapor stream to yield a biodiesel.

PCT patent application WO2008/055676A1 discloses a method for purifying crude biodiesel, wherein said crude biodiesel is contacted with a clay material, said clay material having: a surface area of more than 120 m²/g: a total pore volume of more than 0.35 ml/g.

U.S. Pat. No. 5,053,169A teaches a sequential treatment process for decreasing the phospholipid content of and decolorizing wax esters, comprising first treating said wax ester by contacting with amorphous silica having an effective average pore diameter of about 20 to 5000 Angstroms and next treating the phospholipid-depleted wax ester with bleaching earth.

The paper entitled “Dry washing biodiesel purification using fumed silica sorbent” (2019) by Catarino et al. discloses that biodiesel, produced by soybean oil and waste frying oil methanolysis over a Ca-based catalyst was purified by dry washing using a commercial fumed silica sorbent. Another paper entitled “Activated bentonite clay-based dry-wash purification of waste cooking oil biodiesel in comparison with a wet washing process” (2022) explains that biodiesel obtained by transesterification of vegetable oils and fats is purified by dry washing with raw bentonite clay, sulfuric acid-activated bentonite clay, and calcinated bentonite clay.

The advent of biodiesel as part of a diesel fuel blend necessitates the use of fuel additives. Fuel refiners must adhere to the strict requirements of relevant diesel specifications depending on the location and time of year. This is typically achieved by the refinery processing, blending and/or the use of additives. It is conventionally understood that an additive represents no more 1% w/w (i.e. 10,000 mg/kg or 10,000 ppm) of the fuel to which it is added. Consequently, it is expected that an additive will not greatly affect the physical properties of a fuel including its density and viscosity.

Numerous additives are found to be used in diesel, these include the following groups: fuel handling and distribution additives: fuel stability additives: engine protection additives; and combustion additives. Contained in the fuel handling and distribution additives category are: low temperature operability additives which comprise: flow improvers: wax anti-settling additives: cloud point depressants; and de-icing additives. Other fuel handling additives include: antifoam additives: drag reducing additives: static dissipater additives: demulsifiers: corrosion inhibitors for fuel distribution system: marker dyes; and deodorants and re-odorants. Fuel stability additives include: antioxidants: stabilizers; and dispersants. Engine protection additives include: corrosion inhibitors for vehicle fuel system; and lubricity additives. Combustion additives include: ignition improver and combustion catalysts.

In light of the above state of the art, there still exists a need to develop fuel bio-based additives derived from lignin, rather than vegetable oils, which can provide in some cases, multiple advantages compared to known additives. Moreover, in some preferred cases, such a sustainable fuel additive is largely readily available after esterification of lignin degradation products.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided a composition useful as a fuel additive, said composition comprising:

• • aliphatic diesters:
  • esters of aromatic monomers; and
  • esters of short aromatic oligomers.

According to another aspect of the present invention, there is provided a composition useful as a fuel additive, said composition consisting of:

• • aliphatic diesters:
  • esters of aromatic monomers; and
  • esters of short aromatic oligomers.

According to a preferred embodiment of the present invention, said aliphatic diester compounds comprise: malonate diesters, succinate diesters; and maleate diesters. Preferably, said aliphatic diesters are selected from the group consisting of: dibutyl esters; dipropyl esters; diethyl esters; and combinations thereof. More preferably, said aliphatic esters are dibutyl esters.

According to a preferred embodiment of the present invention, said esters of aromatic monomers are esters of are selected from the group consisting of: oxidized derivatives of lignols. Preferably, said oxidized derivatives of lignols are selected from the group consisting of: oxidized derivatives of coniferyl alcohol (3-methoxy-4-hydroxyphenylpropane: oxidized derivatives of sinapyl alcohol (3,5-dimethoxy-4-hydroxyphenylpropane and oxidized derivatives of paracoumaryl alcohol (4-hydroxyphenylpropane). More preferably, said oxidized derivatives of lignols comprise ester moieties selected from the group consisting of: butyl esters: propyl esters: ethyl esters; and combinations thereof.

According to an aspect of the present invention, there is provided a composition useful as a fuel additive, said composition consisting of:

• • aliphatic diesters in an amount ranging from 10-90 wt %; and
  • esters of aromatic monomers esters in an amount ranging from 10-90 wt %, where the total does not exceed 100 wt %. Preferably, the fuel is selected from the group consisting of: diesel and marine diesel.

According to an aspect of the present invention, there is provided a composition useful as a fuel blend component, said composition consisting of dibutyl esters derived from the esterification of a lignin-hemicellulose depolymerized organics (LHDO) composition:

wherein said LHDO is obtained from the delignification of a lignocellulosic biomass using a modified Caro's acid composition and carried out at a temperature below 60° C.

According to a preferred embodiment of the present invention, said dibutyl ester is selected from the group consisting of: maleate dibutyl ester; malonic dibutyl ester: succinic dibutyl ester; and combinations thereof.

According to an aspect of the present invention, there is provided a process for the preparation of a fuel additive, said process comprising the steps of:

• • providing a light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition:
    wherein said light fraction of esterified LHDO composition is isolated via hexane or iso-octane extraction; wherein said light fraction of esterified LHDO composition comprises: aliphatic diesters; aromatic monomers; and oligomeric condensed aromatics:
  • admixing said said light fraction of esterified LHDO composition with a hydrocarbon selected from the group consisting of: toluene and alkanes (preferably, C₇-C₁₀), more preferably, C₆-alkane; C₇-alkane; C₈-alkane:
  • purifying the said light fraction of esterified LHDO composition by adding an adsorbent material to the admixture at room temperature and mixing for a period of time sufficient to allow for the adsorption of minerals and insoluble organic compounds to yield a fuel-miscible composition, wherein said fuel-miscible composition comprises 40-60 by wt. % of aliphatic diester compounds comprising: malonate diesters, succinate diesters; and maleate diesters and 40-60 by wt. % of aromatic monomers and short oligomeric condensed aromatics.

According to a preferred embodiment of the present invention, aliphatic diester compounds comprising: malonate diesters, succinate diesters; maleate diesters and oxalic diesters.

According to an aspect of the present invention, there is provided a process for the preparation of a fuel blend component, said process consisting of:

• • providing a light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition:
    wherein said light fraction of esterified LHDO composition is isolated via hexane or iso-octane extraction; wherein said light fraction of esterified LHDO composition comprises: aliphatic diesters; aromatic monomers; and oligomeric condensed aromatics:
  • admixing said said light fraction of esterified LHDO composition with a hydrocarbon selected from the group consisting of: toluene and alkanes (preferably, C₇-C₁₀), more preferably, C₆-alkane; C₇-alkane; C₈-alkane:
  • purifying the said light fraction of esterified LHDO composition by adding an adsorbent material to the admixture at room temperature and mixing for a period of time sufficient to allow for the adsorption of minerals and insoluble organic compounds and to yield a substantially aromatics-free composition, wherein said substantially aromatics-free composition comprises at least 90 by wt. % of aliphatic diester compounds comprising: malonate diesters, succinate diesters; and maleate diesters.

According to a preferred embodiment of the present invention, said adsorbent is selected from the group consisting of: silica; kaolin clay; bentonite clay, zeolites, and combinations thereof. Preferably, said adsorbent is selected from the group consisting of: kaolin clay; bentonite clay, zeolites, and combinations thereof.

According to a preferred embodiment of the present invention, said step of purifying is followed by a second step of purifying using an adsorbent different from the adsorbent used in said first step of purifying.

According to a preferred embodiment of the present invention, said esterified lignin-hemicellulose depolymerized organics composition (LHDO) is suspended in iso-octane at a 4:1 to 10:1 iso-octane:LHDO weight ratio.

According to a preferred embodiment of the present invention, said adsorbent is added at a 3:1 to 1:3 adsorbent:LHDO weight ratio, and the mixture was stirred vigorously resulting in a suspension. Preferably, to 1:3 adsorbent:LHDO weight ratio.

According to a preferred embodiment of the present invention, said suspension is filtered through a fritted filter and optionally rinsed with additional iso-octane.

According to another aspect of the present invention, there is provided a method for the preparation of a fuel additive component from a light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition, wherein said method comprising the steps of:

• • providing a first acidic composition having a pH of less than 1, said first acidic composition comprising:
    • an acid selected from the group consisting of: sulfuric acid: an alkylsulfonic acid: an arylsulfonic acid; and combinations thereof:
    • a source of peroxide:
    • an alcohol selected from the group consisting of C₁-C₅ linear alcohol; C₃-C₈ branched alcohol and mixtures thereof:
  • exposing said light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition to said first acidic composition for a period of time sufficient for said first acidic composition to react with said esterified LHDO and depolymerize it into lignin-derived material comprising:
    • condensed aromatics oligomers:
    • aromatic monomers; and
    • diester compounds:
  • admixing said lignin-derived material with a hydrocarbon selected from the group consisting of: toluene and alkanes (preferably, C₇-C₁₀), more preferably, C₆-alkane; C₇-alkane; C₈-alkane:
  • purifying said lignin-derived material by adding an adsorbent material to the admixture at room temperature and mixing for a period of time sufficient to allow for the adsorption of minerals and insoluble organic compounds thus yielding said fuel additive component.

According to another aspect of the present invention, there is provided a process for the preparation of a fuel blend component, said process comprising the steps of:

• • providing a light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition:
    wherein said light fraction of esterified LHDO composition is isolated via hexane or iso-octane extraction; wherein said light fraction of esterified LHDO composition comprises: aliphatic diesters; aromatic monomers; and short oligomeric condensed aromatics;
  • distilling the light fraction to yield:
    • a first stream of an aliphatic diester-rich cut comprising: malonate dialkyl esters; maleate dialkyl esters; and succinate dialkyl esters:
    • a second stream containing distillation residues comprised of esters of aromatic monomers; and esters of short aromatic oligomers; and
  • optionally, further purifying the first stream to increase the aliphatic diester content to a concentration above 90 wt. % of the total composition; and
  • purifying said second stream by adding an adsorbent material thereto at room temperature and mixing for a period of time sufficient to allow for the adsorption of minerals and insoluble organic compounds thus yielding a purified blend of condensed aromatics oligomers; aromatic monomers; and
  • combining said first stream with said purified blend of condensed aromatics oligomers; aromatic monomers to yield said fuel blend component.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

A preferred embodiment of the present invention is prepared by the following process comprising the steps of:

• • providing a light fraction of an esterified lignin-hemicellulose depolymerized organics (esterified LHDO) composition:
    wherein said light fraction of esterified LHDO composition is isolated via hexane or iso-octane extraction; wherein said light fraction of esterified LHDO composition comprises: aliphatic diesters; aromatic monomers; and oligomeric condensed aromatics:
  • admixing said said light fraction of esterified LHDO composition with a hydrocarbon selected from the group consisting of: toluene and alkanes (preferably, C₇-C₁₀), more preferably, Có-alkane; C₇-alkane; C₈-alkane:
  • purifying the said light fraction of esterified LHDO composition by adding an adsorbent material to the admixture at room temperature and mixing for a period of time sufficient to allow for the adsorption of minerals and insoluble organic compounds and to yield a substantially aromatics-free composition, wherein substantially said aromatics-free composition comprises at least 90 by wt. % of aliphatic diester compounds comprising: malonate diesters, succinate diesters; and maleate diesters.

According to a preferred embodiment of the present invention, there is provided a fuel-miscible composition prepared by a method which involves the conversion of a lignin-derived material into at least one esterified lignin derivative, said method comprising the steps of:

• • providing said lignin-derived material which comprises: lignin monomers (20 to 50 wt. % of said lignin-derived material); lignin depolymerization products (50 to 80 wt. % of said lignin-derived material):
  • providing an acidic composition having a pH of less than 1, said acidic composition comprising:
    • an acid selected from the group consisting of: sulfuric acid: an alkylsulfonic acid; and an arylsulfonic acid; and
    • an alcohol selected from the group consisting of C₁-C₅ linear alcohol and C₃-C₈ branched alcohol and mixtures thereof:
  • combining said lignin-derived material with said acidic composition into a reaction mixture:
  • heating up said mixture to a temperature ranging from 25° C. to 120° C.; and
  • allowing sufficient time of reaction to convert at least a portion of said lignin-derived material into said at least one esterified lignin derivative.

According to a preferred embodiment of the present invention, the esterified LHDO is added to a separatory funnel, followed by an equal mass of solvent such as iso-octane. The resulting mixture was shaken vigorously and then left to settle and separate. The undissolved esterified LHDO was drained out of the separatory funnel and the iso-octane solution was collected. The undissolved esterified LHDO was then added back into the separatory funnel, followed by a half-portion of fresh iso-octane. Again, the mixture was shaken vigorously and then left to separate. The undissolved esterified LHDO was drained and then the iso-octane solution was collected and combined with the first fraction. The solvent was then removed to yield a light fraction of the esterified LHDO which is used in some experiments listed below.

Esterification Reaction

LHDO obtained from a delignification of lignocellulosic biomass using a modified Caro's acid as described hereinabove added to pre-weighed round bottom flask containing magnetic stir bar. Material was concentrated on a rotavap (bath temperature 50° C., vacuum gradually decreased to 1 mbar) until all volatile solvent was removed. Residue was weighed, and then the required mass of alcohol solvent was added (1:1 alcohol:LHDO by weight). The mixture was placed in an oil bath on a heating stir plate, an air condenser was attached, and the bath temperature was set to 60° C. In the LHDO, the acid is present in a concentration ranging from 30-70%, more preferably from 40-65%. More preferably, the raw LHDO has an acid content of between 40-45%. Based on these numbers, acid concentration of the reaction mixture is expected to range from 3-35% depending on the dilution factor upon combining the LHDO with the alcohol.

The reaction mixture was then stirred at the desired temperature for 16 hours. After 16 hours, the reaction mixture was removed from the oil bath, left to cool, and then filtered through a medium fritted filter to remove precipitated solids. The solids were rinsed with additional alcohol, collected, dried overnight in a 45° C. oven, and then weighed. The filtrate was concentrated on a rotary evaporator and then transferred to a separatory funnel. Water and ethyl acetate were added, and the product was extracted into the ethyl acetate phase. The organic phase was collected, and the aqueous phase was extracted two additional times with fresh ethyl acetate. The organic phases were combined and transferred back into the separatory funnel, where they were washed with two portions of a pH 2 sulfate buffer solution. The organic phase was then dried over MgSO₄, filtered into a round bottom flask, and evaporated on a rotary evaporator to remove all volatiles. The residue was then weighed and the yield calculated.

Example #1: Separation of Esterified LHDO Light Fraction Using Silica Gel

An esterified LHDO light fraction was suspended in nonpolar solvent (hexanes or iso-octane) at a 5:1 solvent:LHDO weight ratio. Silica gel was then added to the suspension at a 3:1 silica:LHDO weight ratio, and the mixture was stirred vigorously for approximately 1 minute. The mixture was then filtered through a fritted funnel and rinsed with additional solvent. The filtrate was collected, solvent removed, and yield of iso-octane (or hexane) soluble LHDO was calculated.

A second fraction was then collected by resuspending the silica gel in toluene, stirring vigorously, and then filtering the mixture through a fritted filter. The silica gel was rinsed with additional toluene, and then the filtrate was collected, solvent removed, and the yield of toluene-soluble LHDO was calculated.

Finally, the silica gel was suspended in methanol and that mixture was filtered through a fritted filter to flush all remaining organics off the silica gel. The silica was rinsed with additional methanol until the filtrate ran through clear and colourless, and the silica was white. The filtrate was then collected, solvent removed, and yield of the methanol-soluble fraction calculated.

Example #2: Purification of Esterified LHDO by Exposure to Clay

An esterified LHDO light fraction was suspended in iso-octane at a 4:1 iso-octane:LHDO weight ratio. Clay (either kaolinite or bentonite) was then added at a 1:3 clay:LHDO ratio, and the mixture was stirred vigorously. The suspension was then filtered through a fritted filter and rinsed with additional iso-octane. The filtrate was collected, solvent removed, and the yield of clay-filtered esterified LHDO was calculated.

The remaining organic material absorbed by the clay was then flushed out using methanol. This flushing procedure involves the suspension of the clay in methanol and then stirring of the mixture vigorously, subsequent filtering through a fritted filter, and then rinsing with additional methanol until the filtrate becomes clear and colourless. The filtrate was collected, solvent removed, and the yield of methanol-soluble esterified LHDO portion was calculated.

Example #3: Whole Esterified LHDO

Esterified LHDO was added to a separatory funnel, followed by an equal mass of iso-octane. The mixture was shaken vigorously and then left to settle and separate. The undissolved LHDO was drained out of the separatory funnel and the iso-octane solution was collected. The undissolved LHDO was then added back into the separatory funnel, followed by a half-portion of fresh iso-octane. Again, the mixture was shaken vigorously and then left to separate. The undissolved LHDO was drained and then the iso-octane solution was collected and combined with the first fraction. A 50 g portion of the iso-octane solution was rotavapped to remove the solvent, and then the residue was weighed to determine the approximate concentration of LHDO dissolved in the iso-octane.

Using this value, clay (either kaolinite or bentonite) was added to the remaining iso-octane solution to obtain an approximately 3:1 weight ratio of LHDO:clay, and then the mixture was stirred. The mixture was then filtered through a fritted filter and rinsed with additional iso-octane. The filtrate was collected, solvent removed, and the yield of clay-filtered LHDO was calculated.

The remaining organic material absorbed by the clay was then flushed out using methanol. The clay was first suspended in methanol and then the mixture was stirred vigorously, filtered through a fritted filter, and then rinsed with additional methanol until the filtrate ran clear and colourless. The filtrate was collected, solvent removed, and the yield of methanol-soluble LHDO was calculated.

Experimental characterization tests were carried out to assess the impact of a number of preferred embodiments of the present invention in raw diesel (free from any additives) as well as commercial diesel (containing additives). Table 1 provides a list of various diesel additive parameters across several jurisdictions. Table 2 provides data obtained from experimental testing on the impact of a number of preferred embodiments of the present invention on raw diesel. Table 3 provides data obtained from experimental testing on the impact of a number of preferred embodiments of the present invention on commercial diesel.

TABLE 1
Various diesel additive parameters across several jurisdictions

			UAE/
Test	Unit	Canada	ADNOC	EU	UK	Japan

Flash Point	Deg C.	>40	>65	>55	>56	>45
Sediment & Water	vol %	0.02	0.05
(Centrifuge)
Kinematic Viscosity @	mm2/s	1.3 to 4.1	2 to 4.5	2 to 4.5		>1.7
40Deg C.
Ash Content	mass %	0.01	0.01
Sulfur Content	mg/kg	15	10	10	10	10
Copper Strip Corrosion	NA	Class 1	Class 1	Class 1
Density @ 15Deg C.	g/cm3		.820-.845	.820-.845	.820-.845
Cetane Index, Proc-A	NA
Cetane Index	NA	>40	>46	>46	>45	>45
Cloud Point	Deg C.			−22
Carbon Residue on 10% Dist	mass %	0.1	0.2	0.3		0.1
Electrical Conductivity	pS/m	25	150
Lubricity HFRR @ 60
Deg C.
Wear Scar Diameter	μm		460	460

TABLE 2
Parameters from raw diesel (blank) and raw diesel with an additive
according to a preferred embodiment of the present invention

							750 ppm	750 ppm
			2.5%	2.5%	1%	1%	HW	Date Palm
			HW	HW	Kaoline	Kaoline	Toluene	Kaoline
			Toluene	isooctane	Clay	Clay Date	Silica	Clay
Test	Unit	Blank	Silica	silica	Hardwood	Palm	Fraction	Fraction

Flash Point	Deg C.	50	49	55	56	55	57.5	52.5
Sediment &	vol %	<.01	<.01	<.01	<.01	<.01	<.01	<.01
Water
(Centrifuge)
Kinematic	mm2/s	2.449	2.442	2.435	2.454	2.459	2.454	2.45
Viscosity @
40Deg C.
Ash Content	mass %	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01
Sulfur Content	mg/kg	6.8	9.3	9.7	7.8	19	6.8	7.4
Copper Strip	NA	1a	1a	1a	1a	1a	1a	1a
Corrosion
Density @	g/cm3	0.851	0.8546	0.8543	0.8526	0.8529	0.8512	0.8511
15Deg C.
Cetane Index,	NA	43.7	42.4	42.3	43.2	43.1	43.4	43.5
Proc-A
Cetane Index	NA	44.99	43.64	43.59	44.52	44.35	44.85	44.86
Cloud Point	Deg C.	−25	−23	−23	−24	−20	−24	−23
Carbon Residue	mass %	<.01	0.161	0.064	0.1	0.1	<.01	<.01
on 10% Dist
Electrical	pS/m	<1	<1	<1	<1	46	<1	1
Conductivity
Lubricity
HFRR @ 60
Deg C.
Wear Scar	μm	570	260	300	240	220	520	340
Diameter

“2.5% HW Toluene Silica”—refers to esterified lignin derived from hardwood delignification which is then purified by admixing it with toluene and exposing to silica as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, toluene) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 2.5% to the diesel. Similarly, the sample labelled “2.5% HW Isooctane Silica”—refers to esterified lignin derived from hardwood delignification purified by admixing with iso-octane using silica as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 2.5% to the diesel. “1% Kaoline Clay HW”—refers to esterified lignin derived from a hardwood delignification purified by admixing with iso-octane using kaoline clay as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 1% to the diesel. “1% Kaoline Clay Date Palm”—refers to esterified lignin derived from a date palm delignification purified by admixing with iso-octane using kaoline clay as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 1% to the diesel

TABLE 3
Parameters from commercial diesel (blank) and commercial diesel with an
additive according to a preferred embodiment of the present invention

			1%	2.5%	1%	5%
			HW	HW	Kaoline	HW
			Isooctane	Isooctane	Clay	Isooctane
Test	Unit	Blank	silica	Silica	HW/DP	Silica

Flash Point	Deg C.	53	53	48	57	50
Sediment & Water	vol %	<.01	<.01	<.01	<.01	<.01
(Centrifuge)
Kinematic Viscosity @	mm2/s	2.35	2.346	2.339	2.361	2.336
40Deg C.
Ash Content	mass %	<0.01	<0.01	<0.01	<0.01	<0.01
Sulfur Content	mg/kg	7.5	8.9	9.9	15	13
Copper Strip Corrosion	NA	1a	1a	1a	1a	1a
Density @ 15Deg C.	g/cm3	0.8531	0.8544	0.8565	0.8549	0.8598
Cetane Index, Proc-A	NA	42.8	42.4	41.6	42.2	40.7
Cetane Index	NA	43.9	43.32	42.66	43.21	41.46
Cloud Point	Deg C.	−21	−21	−22	−21	−22
Carbon Residue on 10%	mass %	0.04	0.048	0.15	0.2	0.28
Dist
Electrical Conductivity	pS/m	1128	1640	1935	1840	>2000
Lubricity HFRR @ 60
Deg C.
Wear Scar Diameter	μm	300	290	160	220	160

“1% HW Isooctane silica”—refers to esterified lignin derived from hardwood delignification purified by admixing it with isooctane using silica as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 1% to the diesel. “2.5% HW Isooctane Silica”—refers to esterified lignin derived from hardwood delignification purified by admixing it with isooctane using silica as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 2.5% to the diesel. “1% Kaoline Clay HW/DP”—refers to esterified lignin derived from a mixture of hardwood and date palm delignification purified by admixing it with isooctane using kaoline clay as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 1% to the diesel. “5% HW Isooctane Silica”—refers to esterified lignin derived from hardwood delignification purified by admixing it with isooctane using silica as adsorbent material (as per the procedure described hereinabove). The solvent (in this case, iso-octane) is then removed after the purification step. The resulting purified esterified LHDO material is added in a proportion of 5% to the diesel.

The data indicates that the diesel additive according to a preferred embodiment of the present invention provides no improvement in electrical conductivity in the absence of a static dispersant, while commercial diesel which contains a static dispersant additive will generate a synergistic interaction which will boost electrical conductivity to high levels, exceeding the electrical conductivity thresholds set in various jurisdictions. The implications of this lead one to conclude that in the presence of an additive according to a preferred embodiment of the present invention one can safely reduce the loading of a anti-static component.

The data also indicates that the kinematic viscosity, density, cetane index, cloud point remain largely unaffected when a diesel additive according to a preferred embodiment of the present invention is added to either raw diesel or commercial diesel. This suggests that such an additive does not adversely impact the fuel.

Tables 4 and 5 relate data which was conducted by adding various composition according to preferred embodiments of the present invention in raw diesel.

The source from which the additive was derived is provided (hardwood, bagasse, bamboo, etc.) the filtration media used in the purification is also provided. Lastly, the concentration at which the additive is included in the diesel fuel is also indicated. The person skilled in the art will understand that an component added to a fuel is to be considered as an additive so long as its concentration in the fuel does not exceed 1% by volume. Above 1% (by volume), the component is considered to be a fuel blend component.

TABLE 4
Results of testing of various parameters in raw diesel of various additives and additive
concentrations according to a preferred embodiment of the present invention

			Wear Scar	Sulfur	Carbon	Electrical
	Filtration		Diameter	content	Residue	Conductivity
Feedstock	Media	Concentration	(um)	(mg/kg)	(mass %)	(pS/m)

Blank	N/A	N/A	570	6.8	<0.1	<1
Hardwood	Bentonite	1%	190	11.0	<0.1	23
Hardwood	Kaolinite	1%	240	7.8	0.1	7
Hardwood	Kaolinite	750 ppm	340	6.7	<0.1	<1
Hardwood	Bentonite	750 ppm	320	6.8	<0.1	<1
Hardwood	Bentonite	400 ppm	360	8.0	<0.1	5
Organosolv
Hardwood	Bentonite	400 ppm	400	7.0	<0.1	1

TABLE 5
Results of testing of wear scar diameter for various feedstocks
in raw diesel at a 1% additive concentration according
to a preferred embodiment of the present invention

			Wear Scar
			Diameter
Feedstock	Filtration Media	Concentration	(um)

Blank	N/A	N/A	570
Hardwood	Bentonite	1%	190
Hardwood	Kaolinite	1%	240
Date Palm	Bentonite	1%	210
Bagasse	Bentonite	1%	180
Bamboo	Bentonite	1%	200
Hardwood	Bentonite	1%	180
Organosolv

The data further indicates that the wear scar diameter is further improved in the presence of a diesel additive according to a preferred embodiment of the present invention. This data provides a reliable indication of the lubricity enhancement provided by the additive being tested.

According to a preferred embodiment of the present invention, the process for the preparation of a diesel fuel additive, can be tailored to yield specific types of compounds depending on the intended use of said compounds. Preferably, if the compounds sought are intended to increase the lubricity of the diesel compositions, the process will use a co-solvent such as iso-octane and kaolin clay to yield a composition comprising mainly larger aromatic compounds which are known for their lubricity when exposed to metal surfaces.

Preferably, if the compounds sought are intended to improve the combustion of diesel compositions, the process will use a co-solvent such as iso-octane and silica to yield a composition comprising mainly small diesters which are known to enhance combustion properties and reduce harmful emissions such as unburnt hydrocarbons and particulate matter by increasing the amount of oxygen in the fuel.

According to a preferred embodiment of the present invention, a first stream of aliphatic diesters as described herein may be blended with a purified second stream of condensed aromatics oligomers and aromatic monomers in a ratio which maximizes the lubricity of the additive while also maximizing the concentration of oxygenates. This allows the convenience of overcoming the hurdles posed by using the basic blend fraction (which is not distilled but rather only purified using an adsorbent as described herein) and also allows one to increase the loading of the blend component without adversely affecting the fuel parameters which are impacted by the presence of aromatics.

The embodiments described herein are to be understood to be exemplary and numerous modification and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the claims appended hereto, the invention may be practiced otherwise than as specifically disclosed herein.