KR101061708B1 - Cleaner Combustion Diesel Engine - Google Patents

Abstract

The present invention relates, in particular, to improved diesel fuel formulations comprising biodiesel and ultra-low sulfur diesel fuels of low aromatic content together with fuel additives containing concentrates containing fuel borne catalyst (FBC). The catalyst preferably comprises platinum and / or cerium and / or iron and the ultra low sulfur diesel fuel will preferably contain less than 10% aromatics. Biodiesel is typically used in amounts of about 20% relative to the formulation.

Description

Cleaner Combustion Diesel Engine {CLEANER BURNING DIESEL FUEL}

The present invention provides improved diesel fuels based on blends of biodiesel and ultra-low sulfur diesel fuels of low aromatic content, especially with concentrate containing fuel additives containing fuel borne catalyst (FBC).

US patent application Ser. No. 10 / 290,798 describes low emission diesel fuel, including Jet A and FBC.

US patent application Ser. No. 10 / 357,027 describes low emissions diesel fuel, including emulsions of Jet A and FBC.

US Patent Application No. 10 / 401,367 describes low emission diesel fuel, including Jet A, biodiesel and FBC.

While these fuels are effective, there is a continuing need for additional diesel fuels that provide further reduction in pollutant production, in particular NO _x and particulate emissions.

Summary of the Invention

It is an object of the present invention to provide an improved diesel fuel that reduces emissions of unburned hydrocarbons, carbon monoxide, particulates and NO _x .

Another object of the present invention is to provide a fuel using renewable raw materials having a desirable balance ratio of hydrogen to carbon, thereby reducing the carbon dioxide emissions by this means and also the economics of the fuel as emissions of non-toxic pollutants. To control.

The above and other problems are achieved by the present invention, in particular with improved diesel fuels based on ultradiesel diesel fuel blends of biodiesel and low aromatic content, in combination with fuel additives containing concentrates containing fuel borne catalysts. .

Many preferred embodiments of the invention will be described below.

The present invention improves on ultra-low sulfur diesel fuel formulations based on biodiesel and low aromatic content, in particular with fuel additives containing concentrates containing fuel borne catalysts (FBCs). Supplied diesel fuel.

As the main component of the fuel blend of the present invention, there is provided an ultralow sulfur diesel (ULSD) fuel of low aromatic (LA) content. The term "low aromatics content" as used herein means that the components of the fuel herein will have an aromatic content in the range of less than 10% by volume, preferably 1 to 8% by volume, in particular 2 to 5% by volume. In the table below, in addition to the preferred formulations according to the invention (LA ULSD containing FBC and 20% biodiesel), 2 Typical results of diesel and low aromatics ultra low sulfur diesel fuel LA ULSD are described. Equivalents having the same essential function and varying in composition up to 50%, preferably below 20%, for example up to 10%, can also be used.

Another major component of the low emission diesel fuel of the present invention is what is referred to in the art as "biodiesel". Biodiesel will comprise a minor percentage of the fuel blend, typically about 1 to 35%, for example on the order of 15 to 25%. The blend will typically contain about 20% biodiesel, wherein the biologically derived fuel component is a "mono-alkyl ester based oxygenated fuel", ie preferably soybean oil, canola oil and / or tallow. And fatty acid esters from fatty acids derived from triglycerides such as The term "fatty acid ester" as used herein is intended to include any compound in which the alcohol moiety, including polyols and substituted alcohols, etc., is readily removed, but preferably volatile alcohols, such as C ₁ -C ₄ alcohols. (Preferably methyl) esters, 2-methoxy ethyl, and benzyl esters of fatty acids containing about 8 or more (eg 8 to 22) carbon atoms, and mixtures of the esters described above. Volatile alcohols are very preferred. Methyl esters are very preferred ester reactants. Suitable ester reactants may be prepared by the reaction of diazoalkanes with fatty acids, or may be derived by alcoholysis from fatty acids naturally occurring in fats and oils.

Suitable fatty acid esters can be derived from synthetic or natural, saturated or unsaturated fatty acids, including positional and geometric isomers. Suitable preferred saturated fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, isomilistic acid, isomargaric acid, and anteisoarakidic acid. Included. Suitable preferred unsaturated fatty acids include myristic oleic acid, palmitoleic acid, lysine oleic acid, linoleic acid, oleic acid, oleic acid, linolenic acid, ellasteric acid, arachidonic acid, erucic acid and erythrogenic acid. Mixtures of fatty acids derived from soybean oil, palm oil, safflower oil, rapeseed oil, canola (low erucic acid) and corn oil are particularly preferred for use herein. Fatty acids can be used by themselves and / or after hydrogenation, and / or after isomerization, and / or purification. For example, rapeseed seeds provide a good source of C ₂₂ fatty acids; C ₁₆ -C ₂₈ fatty acids may be provided by tallow, soybean oil or cottonseed oil; Short-chain fatty acids may be provided by coconut, palm kernel or babassu oil. Lard, olive oil, peanut oil, sesame seed oil, and safflower seed oil are examples of other natural sources of fatty acids.

Preferred esters included in the biodiesel are lower alkyl esters, for example methyl, ethyl, propyl and butyl, in particular methyl esters of soybean and / or tallow fatty acids. Specifications for biodiesel (B100) set by the National Biodiesel Board in December 2001, used for clarity and definition of the invention, are described below. Accordingly, biodiesel is defined as mono alkyl esters of long chain fatty acids derived from vegetable oils or animal fats for use in compression-ignition (diesel) engines. This specification is for pure (100%) biodiesel before blending with diesel fuel or prior to use. In the United States, 20% biodiesel blends and 80% diesel fuel (B20) are used empirically. Biodiesel (B100) may be used, however, a combination of diesel fuel and more than 20% biodiesel should be evaluated on a case-by-case basis until further experience is available. Equivalents having equivalent essential functions and varying compositionally up to 25%, preferably less than 10%, may also be used. In some cases, very small amounts of biodiesel, such as 2%, may be used with a blend of 98% diesel fuel of distillate origin.

¹ : In order to meet special operating conditions, individual restrictions may be modified with the agreement of the purchaser, seller and manufacturer.

One product of this type is available under the trade name BioDiesel by members of the National Biodiesel Commission, which is identified as "Methyl Soyate, Rapeseed Methyl Ester (RME), Methyl Tallowate". The manufacturer also calls this fuel "mono-alkyl ester based oxygenated fuel", which is made from vegetable oils or animal fats. The fuel generally contains 11% by weight of oxygen. Their products are described as methyl esters from a lipid source, CAS No. 67784-80-9.

The fuel borne catalyst (FBC) will comprise fuel soluble platinum and / or cerium and / or iron. Cerium and / or iron are typically used at concentrations of 2 to 25 ppm, platinum is used at concentrations of 0.05 to 2 ppm, and preferred levels of cerium or iron are 2 to 10 ppm, for example 3 to 8 ppm. And platinum is used at a level of 0.1 to 0.5 ppm, for example 0.15 ppm. The preferred ratio of cerium and / or iron to platinum is from 75: 1 to 10: 1. The LA ULSD component will typically be used at a volume ratio of fatty acid ester of about 2: 1 to about 5: 1, for example 4: 1. The full range of formulations advantageously extends from 50: 1 to 1:50. The LA ULSD fuel component of the blend preferably contains 50 to 1500 ppm of detergent, up to about 500 ppm of lubricating additive, and 0.1 to 1 ppm of platinum COD and 5 to 20 ppm of cerium oleate or octoate. It is an advantage of the present invention that the fatty acid esters provide lubricity to the LA ULSD and the need for independent lubricating additives is reduced.

The catalyzed combinations of the present invention are effective in reducing the controlled emissions of contaminants, especially NO _x , particulates, hydrocarbons and carbon monoxide. Preferably the fuel will simultaneously reduce NO _x and particulates, and new combinations. Preferred combinations are no. It will be effective to reduce NO _x to at least 4% or more and reduce particulates to at least 25% relative to the baseline of two diesel fuels. More preferred levels are No _x reduction of 5-25% and particulate reduction of 20-60%. Higher reduction of particulates can be achieved by using the fuel in an engine with a diesel particulate capture filter or diesel oxidation catalyst. Such a reduction is preferably obtained without reducing or increasing the NO ₂ emissions.

Preferred detergents that can be used include polyolefin amide alkyleneamine (about 65-80%) and residual amounts of petroleum distillate. Equivalents with the same essential function may also be used. One preferred form is available from Texaco as TFA-4690-C used at a concentration of about 50 to 300 pm, more narrowly 75 to 150 ppm, for example about 100 ppm, the analysis for this product in the table below. The results are listed:

Preferred lubricating additives that can be used include tall oil fatty acids commercially available as a mixture of fatty acids including oleic acid, linoleic acid and the like. Equivalents with the same essential function may be used. One preferred form is available from Texaco as TFA-4769 used at a concentration of about 25 to 500 pm, for example about 150 to 250 ppm, the results of analysis of this product are described in the table below. :

Among the specific cerium compounds are the following: cerium III acetylacetonate, cerium III naphthenate, and cerium octoate, cerium oleate and other soaps such as stearate, neodecanoate and octoate (2-ethyl Hexoate). Most of the cerium compounds are trivalent compounds that satisfy the formula Ce (OOCR) ₃ , wherein R = hydrocarbons, preferably C ₂ to C ₂₂ , including aliphatic, cycloaliphatic, aryl and alkylaryl . Cerium is preferably used at a concentration of 2 to 15 ppm cerium w / v for the fuel. Preferably, cerium is supplied as cerium hydroxy oleate propionate complex (40% cerium by weight). The lower end of the range is the preferred level.

Among the specific iron compounds are: ferrocene, ferric and ferrous acetyl-acetonate, iron soaps such as octoate and stearate (commonly marketed as iron (III) compounds), iron pentacarbonyl Fe ( CO) ₅ , iron naphthenate and iron talate.

Of the platinum group metal compositions described in US Pat. No. 4,891,050 to Bowers et al., US Pat. No. 5,034,020 to Epperly et al. And US Pat. Any, for example 1,5-cyclooctadiene platinum diphenyl (platinum COD) may be used as the platinum source. Other suitable platinum group metal catalyst compositions include fatty acid soaps of commercially or easily synthesized platinum group metal acetylacetonates, platinum group metal dibenzylidene acetonates, and tetramine platinum metal complexes, such as tetramine platinum oleate. Include. Preference is given to platinum at a concentration of 0.1 to 2.0 ppm platinum w / v (mg per liter) of the fuel. Increasing levels toward the lower end of this range, for example 0.15 to 0.5 ppm, are preferred. Platinum COD is a preferred form of platinum for addition to the fuel. Cerium or iron is typically used at concentrations to provide metals of 2 to 25 ppm, platinum is used at concentrations of 0.005 to 2 ppm, preferably cerium or iron is 5 to 10 ppm, for example 7.5 ppm And platinum is used at the level of 0.1 to 0.5 ppm, for example 0.15 ppm. The preferred ratio of cerium and / or iron to platinum is from 75: 1 to 10: 1.

In addition to using the low emission fuel according to the present invention, delaying the engine timing to, for example, 2 to 6 ° can further reduce NO _x , and the use of diesel particulate filters and / or diesel oxidation catalysts results in carbon monoxide. Unburned hydrocarbons and particulates can be further reduced.

Low-emission fuels according to the invention can be used as emulsions with water, in which the oil phase is emulsified with water, where water is contained in an amount of 1 to 30% by weight of aviation kerosene. In a preferred form, the emulsion will be predominantly water-in-oil type and will preferably contain surfactants, lubricating additives and / or corrosion inhibitors in addition to the other components mentioned above. A discussion of suitable emulsion forms and additives is found in US Pat. No. 5,743,922. Water-in-oil emulsions typically provide a NO _x reduction of about 1% for each added 1% water. Combining technologies will provide more emissions reductions than if used alone. Platinum / cerium fuel borne catalysts or other catalysts are preferred but optional. If desired, a combination of fatty acid esters and aviation kerosene can be used to obtain good effects without the fuel borne catalyst. The fuel formed in any one of the above embodiments may be used with a timing changer, EGR, oxidation catalyst or soot capture filter for improved emission control.

The term “diesel particulate collection filter” is intended to refer to such an apparatus known in the art as an exhaust gas filter that reduces particulate emissions by trapping some of the particulates in the internal structure of the complex. The filter must be regenerated or replaced as the deposit accumulates. The fuel borne catalysts described above, when used with the base fuels described above which form the fuel of the present invention, also allow for very reduced emissions in the operation of the improved particulate filter.

The term “diesel oxidation catalyst” refers to such a device known in the art as an exhaust gas treatment catalyst that reduces particulate, hydrocarbon and carbon monoxide emissions by bringing it into contact with the catalyzed surface instead of particulate capture made in a diesel particulate filter. Intended to. The fuel borne catalysts described above allow for very reduced emissions in the operation of improved oxidation catalysts when forming the fuels of the invention and also when used with the base fuels described above.

An engine timing delay of, for example, about 2 to about 6 ° is a known process for reducing NO _x , which, unfortunately, will generate pollutants due to poor combustion when used alone. This problem makes the technique difficult, because in this case emissions control becomes important. An advantage of the present invention is that reduction of both NO _x and other contaminants can be achieved by using the fuel of the present invention in combination with exhaust gas circulation and / or one or more of the techniques in which a portion of the exhaust gas is mixed with combustion air. Can be.

When operating the present invention in one preferred form as described in US Pat. No. 6,003,303 and the references cited therein, FBCs are provided.

The present invention is particularly useful for the operation of a fleet vehicle that is moved to a central position at regular intervals, for example for daily fuel supply.

The concentration of FBC catalyst in the fuel is preferably maintained at 4 to 10 ppm in the examples.

The following examples are provided to further illustrate and illustrate the invention and are not intended to limit the invention in any way. Unless otherwise stated, all parts and percentages are by weight.

Example  One

Cleaner combustion biodiesel fuel formulations containing Platinum Plus ^® fuel borne catalyst (FBC) (added at 0.15 ppm Pt as Pt COD) and weakly catalyzed (3 to 5 g Pt) diesel oxidation catalyst (DOC) Standard No. An emission reduction of 51% particulate matter (PM) and 9% NO _x was obtained compared to baseline emissions from 2D fuel. This blend represents a reduction of more than 100 lbs per year of controlled pollutants from a typical school bus and a reduction of more than 200 lbs per year for local transport vehicles. Conventional biodiesel blends can increase NO _x by 2-4%.

Tests were conducted over three federal interim test cycles on the 1995 Navistar DT-466 engine, which is commonly used for school buses, beverages, and regional transportation vehicles. The fuels used are listed in the table below.

In the first of two test sequences, a blend of 20% biodiesel is combined with low aromatics ultra low sulfur diesel (LA ULSD) and Platinum Plus ^® FBC (0.15% ppm Pt as Pt COD) and weakly catalyzed in the engine (3-5 g / ft ³ ) DOC was equipped. In this case, the overall emission reduction rate is about 66% HC, was 63% for CO, 9% for NO _x, it was for the PM 51%, 95% for SO _x. To the reduction rate of more than 60% doeeotneun again confirmed in the exhaust gas in the NO ₂ fraction, the NO ₂ may be increased if after a conventional over-catalyst with a strong lung irritant screen used in conjunction with the processing apparatus. In the test procedure, a weakly catalyzed DOC was used to reduce the cost and minimize the formation of NO ₂ .

From the first test in the test carried out on engines from Cummins and Detroit Diesel, Platinum Plus ^® FBC and No. Cleaner burnable biodiesel formulations made of 1D or ULSD have been demonstrated to have the ability to consistently reduce NO _x and PM emissions.

The foregoing description is intended to teach those skilled in the art how to practice the invention, and does not describe all possible changes and modifications that will be apparent to those skilled in the art upon reading this specification. However, all such modifications and variations are included in the scope of the present invention as defined by the following claims. The claims, unless specifically stated to the contrary context, include the elements and steps indicated, in any arrangement or order effective to meet the intended purpose for the present invention.

Claims (4)

As an improved, catalyzed diesel fuel blend for use with a catalyzed exhaust treatment apparatus, The fuel blend comprises less than 1-35% fatty acid ester biodiesel combined with a low aromatic content ultra-low sulfur diesel fuel having an aromatic content less than 10%, The fuel blend further comprises 4 to 10 ppm of fuel borne catalyst comprising platinum and at least one of iron and cerium, wherein the platinum content is within the range of 0.1 to 0.5 ppm Wherein the ratio of at least one of the platinum to the iron and cerium is in the range of 1:75 to 1:10, An improved, catalyzed diesel fuel blend for use with the catalyzed exhaust treatment apparatus. The diesel fuel blend of claim 1, comprising from 15 to 25% biodiesel and platinum. delete delete