US20080244960A1

US20080244960A1 - Fuel blends

Info

Publication number: US20080244960A1
Application number: US12/100,393
Authority: US
Inventors: Randall Fischer; Russell J. Barker; Bryan D. Johnson
Original assignee: ETHANOL EEX LLC
Current assignee: ETHANOL EEX LLC
Priority date: 2007-04-09
Filing date: 2008-04-09
Publication date: 2008-10-09
Also published as: WO2008124800A1

Abstract

The invention provides a vehicle fuel composition containing an alcohol, a lubricant and an ether. A preferred embodiment is a fuel blend containing ethanol, dimethyl ether and a distilled organic acid. These fuel blends are thoroughly blended to obtain a motor fuel having a higher energy content and a lower pollution profile compared to standard commercial motor fuels.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 60/910,721 filed Apr. 9, 2007, which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to fuel compositions that may be used as fuels and as fuel additives for enhancing and stabilizing alcohol fuels and alcohol fuel blends.

BACKGROUND OF THE INVENTION

Due to the non-renewable nature of hydrocarbon fuels, considerable attention has been focused on development of alternate fuel sources. Oxygenated fuels containing ethanol or anhydrous ethanol have gained wide technical acceptance. An oxygenated fuel is a fuel in which oxygen atoms are chemically bound within the fuel structure. The oxygen bond in the oxygenated fuel is energetic and provides chemical energy that results in no loss of efficiency during combustion. Unfortunately, alcohol attracts water and will separate from petroleum fuels in the presence of certain amounts of water condensation. Another problem is that alcohol and particularly ethanol is generally denatured using methanol or with liquid natural gas (2-5%), which exacerbates the problem of water separation and produces unacceptable solvency levels, such that ethanol/methanol/gasoline mixtures cannot be transported through existing pipelines. Transportation is a major factor in the cost and availability of alternative fuels (namely E10 and E85) to the consumer, and there is no current use of pipeline transportation of E10 or E85 for lack of technology that prevents ethanol/petroleum blends from separating in the midst of water and causing corrosion.
Another problem associated with using ethanol as an oxygenate is that ethanol, as well as methanol and other water-soluble alcohols, will not mix at all with less refined fossil fuels, such as diesel fuel. Diesel oil and anhydrous ethanol form solutions when blended but the presence of even a very low amount of water will cause a separation into a hydrocarbon phase and an ethanol/water phase. At lower temperatures, the tendency of phase separation increases. It is therefore important to maintain the fuel in a homogeneous liquid phase over the entire temperature range at which the fuel can be exposed.
Several methods of increasing the stability of a mixed fuel containing aqueous ethanol and hydrocarbons are known. For example, EP-A1-89 147 discloses a macroemulsion comprising liquid hydrocarbons, ethanol and water and as an emulsifier a polyetherpolystyrene block copolymer. However, the stability of such emulsions is limited and even minor separations may cause disturbances when starting or running an internal combustion engine, or causing increased emissions, for example of CO and organic substances, when burnt.
Similarly, EP-A1-475 620 discloses a microemulsion diesel fuel containing a hydrocarbon fraction, water and optionally also ethanol. In order to form a microemulsion between the water phase and the hydrocarbon fraction, a blend of a hydrophilic surfactant and a lipophilic surfactant is added, in particular a mixture of a sulfonate and an ethoxylate. This fuel needs large amounts of surfactants and is furthermore rather sensitive to temperature variations.
Thus, there remains a need for ethanol fuel blends that do not separate into different phases under typical operating conditions and can be pipelined in the presence of water that may condense in a pipeline or storage tank without separation. These blends must retain the combustion properties and renewable nature and favorable economics of alcohol fuels and the beneficial effect on emissions, which initially spurred the interest in hybrid fuels.

SUMMARY OF THE INVENTION

The present invention provides novel fuel compositions that may also be used as fuel additives for alcohol fuel blends. These fuel compositions are produced from renewable sources and can be pipelined directly or in any combination with an alcohol without water separation. These fuel compositions contain an ether and a lubricant component. These fuel blends may contain an alcohol, and particularly ethanol, in amounts representing from between 1% to greater than 99% of the fuel blend. These fuel blends may also include petroleum fuel products such as gasoline or diesel fuels. Preferred fuel blends of this invention can be used independently of any petroleum products with the same composition benefits, but with better emissions profiles due do the elimination of the high carbon petroleum components.
The fuel blends of this invention may be mixed with petroleum gasoline. In any ratio, this gas-alcohol fuel additive blend will burn with favorable emissions, better mileage and power and with no undesirable effects in non-flex fuel engines. In embodiments containing ethanol concentrations over about 60%, the vehicle merely requires a modification to the oxygen sensor. The ability of these fuel blends to be used in all existing automobiles, without engine or fuel system modifications, is a novel advantage of these fuel blends.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts a fractional distillation system that may be used to produce an organic oil lubricant of the present invention.

DESCRIPTION OF THE INVENTION

The present invention is drawn to ethanol fuel blends that enhance the combustion characteristics of the fuel while limiting the dryness and corrosiveness of the fuel. The fuel blends of the present invention will not separate under typical temperature and pressure conditions present in an automotive engine. The fuel blends of the present invention are formed by combining an alcohol, an ether component, and a lubricant.
The alcohol is preferably ethanol, but methanol, as well as alcohols of isomers of propane, butane, pentane, methoxypropane, hexane, heptane and octane are also contemplated in the fuel blends of the present invention. Hydrocarbon fuels having a carbon number greater than three (i.e. propane) may have a higher flash point requiring the use of larger amounts, by volume, in the fuel mixtures of the present invention. These larger hydrocarbons may also impose greater environmental toxicities.
The alcohol may have any source. Preferably, the alcohol source is largely free of water. The anhydrous ethanol may be obtained from a renewable biomass source or other related sources. Preferably, the ethanol is greater than 90% pure, more preferably more than 95% pure and even more preferably, more than 99% pure. The anhydrous methanol or anhydrous ethanol as added in this invention may be 1% to 15% by volume of the light hydrocarbon fraction, namely the pentane fraction. The percentage of the anhydrous methanol or anhydrous ethanol as added in this invention may be optionally adjusted depending upon the desired octane number.
The ether component of the fuel blends of the present invention lowers the vapor pressure for the fuel and thereby lowers the flash point of the fuel and acts as a primer to the combustion of the fuel. The ether component is preferably diethyl ether, dimethyl ether or a combination of these ethers. The ether component may be present in an amount between 1% and 90%, by weight, of the fuel blend. The amount of ether added to the fuel blends of the present invention may vary widely in response to the altitude and temperature in which the fuels will be used, as well as the amount and concentration of the lubricant present in the fuel. Preferably, the ether component of the fuel blends is diethyl ether present in an amount between 1% and 10%, by volume, of the fuel blend.
The lubricant component of the fuel blends of the present invention may be any lubricant effective to offset the corrosiveness and dryness of the ether and ethanol portions of the fuel blend, while increasing the energy content of the alcohol component of the fuel blend. The preferred lubricant is a mixture of hydrocarbons. Preferably, the hydrocarbons are recovered from distilled organic oils. Oils derived from any plant, seed, bean, fruit or vegetable that has an oil component may be distilled to produce the hydrocarbon blends that serve as lubricants in the fuel blends of the present invention. Used cooking oils can also be used in the process. Petroleum and synthetic petroleum products may also be used to produce the hydrocarbon mixture but these hydrocarbon components will separate from the fuel blends over time, requiring continuous mixing. The lubricant component may be present in an amount between 0.001% and 99%, by volume, of the fuel blend. The lubricant may be mixed with the alcohol in an amount between 0.008% and 0.02%, by volume, of the fuel blend. The lubricants may also be used as a primary component of a fuel, or used with the addition of only minor amounts of ether and ethanol as a bio-diesel fuel blend.
Thus, preferred fuel blends of the present invention contain an anhydrous alcohol containing between about 1% and about 10%, by volume, of an ether and between about 0.001% and about 0.1%, by volume, of a mixture of distilled hydrocarbons. Preferably, the fuel blend is an anhydrous ethanol containing between about 1% and about 10%, by volume, diethyl ether and between about 0.001% and about 0.02%, by volume, of a distilled organic oil.
The lubricant components used in making the fuel blends of the present invention may be formed by distillation processes. The distillation processes used are described below, but one of skill in the art will readily recognize that these processes may be scaled up to industrial distiallation production volumes as desired.
Hydrocarbon lubricants may be produced by common fractional distillation of an organic oil. Referring to FIG. 1, any organic oil is introduced to the round bottom flask (C) and an alcohol is introduced to the organic oil, preferably through a separatory flask (A) in connection with round bottom flask (C). The round bottom flask (C) is heated using a heat source (D) to a temperature in the range of between about 260° C. to about 380° C., as may be measured by thermometer (B). Temperatures above 380° C. may be used but the distillation produces excess quantities of natural gas at these temperatures while the production of the lubricant is reduced. Natural gas produced during the distillation is bled away from the distilled lubricant from the condensing column (E) through vacuum hose (J) to a natural gas containment vessel (L) under vacuum created by pump (K). Natural gas collected may be removed for uses outside the distillation procedures of the present invention or re-introduced to the heat source (D). Hydrocarbon lubricant is collected in collection flask (H) that is preferably cooled in an ice bath or other suitable cooling or refrigeration system (I). The condensing column is cooled by circulating a coolant through coolant inlet (G) and returned through coolant return line (F). Hydrocarbons collected in collection flask (H) may be further distilled to separate all fuel-grade hydrocarbons from any remaining glycerin.
The lubricant produced by common fractional distillation as described above can be further refined by common fractional distillation to remove additional alcohols present. The lubricant is re-introduced to a round bottom flask and heated to distill away any remaining alcohols. Preferably these additional alcohols are distilled through a fractionating column and natural gas produced during the distillation is bled away from the distilled lubricant and alcohol vapor from the condensing column through vacuum hose to a natural gas containment vessel under vacuum. Natural gas collected may be removed for uses outside the distillation procedures of the present invention or re-introduced as a heat source. A condensed and further refined lubricant is retained in the round bottom flask. The condensed lubricant retained in the round bottom flask may be mixed with an alcohol to form a lubricant—alcohol fuel blend suitable for the intended temperature and altitude at which the fuel will be used.
Diethyl ether may be produced by common fractional distillation of sulfuric acid and ethanol. Referring again to FIG. 1, sulfuric acid is introduced to the round bottom flask (C) and an alcohol is introduced to the sulfuric acid, preferably through a separatory flask (A) in connection with round bottom flask (C). The round bottom flask (C) is heated using a heat source (D) as measured by thermometer (B). Natural gas produced during the distillation is bled away from the distilled diethyl ether from the condensing column (E) through vacuum hose (J) to a containment vessel (L) under vacuum created by pump (K). Natural gas collected may be removed for uses outside the distillation procedures of the present invention or re-introduced to the heat source (D). The condensing column is cooled by circulating a coolant through coolant inlet (G) and returned through coolant return line (F). Diethyl ether is collected in collection flask (H) that is preferably cooled in an ice bath or other suitable cooling or refrigeration system (I).
The fuel blends of the invention may be used alone as a fuel or combined with gasoline or diesel or biodiesel fuels to improve the performance or decrease the pollution created by burning typical gasolines, diesels, biodiesels or blends thereof. Reference to “fuel” or “gasoline” herein is meant to encompass a fuel containing hydrocarbons boiling in the gasoline boiling point range of from 80° C. to 450° C., and preferably from about 90° C. to about 400° C. When combined with the fuel blends of the present invention, the gasoline or diesel fuels obtain a higher oxygenate content meaning that the amount of oxygenate in the fuel may be increased by at least about 5 volume percent, and preferably at least about 20 volume percent. The fuel blends of the present invention may be added to gasoline or biodiesel fuels to obtain an alcohol content in the final hydrocarbonaceous fuel blend of about 20 volume percent or higher. Fuel blends of the present invention may be added to gasoline for use in all vehicles without adverse effects. For example, the fuel may be formed to include the fuel blends of the present invention such that the ethanol content of the final fuel product is about 25 or about 50 or about 75 volume percent in the fuel. While there is no known upper limit on the alcohol (or any oxygenate) content in a fuel that will benefit from the present invention, ethanol contents above about 80 volume percent may have certain undesired corrosive effects. These fuel compositions composed of fuel blends of the present invention combined with gasoline, diesel, and/or biodiesel, do not undergo phase separation under typical fuel consumption operating conditions for periods of greater than 14 months. The lubricants used were found to be excellent stabilizers for the ethers and to impart a corrosion inhibiting property to the fuel blends.
The present invention also includes methods of improving the fuel economy and reducing the pollutants produced by an internal combustion engine. These methods include using the fuel blends of the present invention to fuel an internal combustion engine. These oxygenated fuels produce fewer pollutants than the same engine fueled with a standard commercial gasoline or diesel fuel. These enhanced fuels also have a higher energy content compared to standard commercial fuels, owing to the lubricant additives in the fuel blends of the present invention.
The present invention also provides a fuel production methodology and facility that substantially reduces dependence on products imported to the facility, other than the plant or animal feedstock used as a source of oil. The facility internally produces natural gases which are collected in the production process for use in the facility. The production process includes known processes of producing ethanol combined with the distillation processes described herein. Ethanol, diethyl ether, water, lubricant/diesel, natural gas, and glycerin are all derived from grain or celluosic feedstock or any other feedstock that can be utilized to produce all of these products. Ethanol is produced from the feedstock and introduced to an organic oil (also derived from the feedstock) and by distillation produces the lubricant as described above. A portion of the lubricant is mixed with ethanol and ether to produce a fuel blend of the present invention. Portions of the lubricant produced are also boiled down to produce a unique type of fuel similar to a diesel. Diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make specific quantities of diethyl ether. Vapor-phase dehydration of ethanol over some alumina catalysts can give a yield of up to 95%. Diethyl ether is also produced by the acid ether synthesis mixing sulfuric acid and ethanol. A nucleophollic oxygen atom of unprotonated ethanol displaces a water molecule from the protonated ethanol molecule, producing water, a hydrogen ion and diethyl ether. Water produced as by product may be reintroduced to facility operations. The glycerin that is collected is used as mass to collect, contain, and distribute the heat required in the facility, via systems similar to typical hydronic heat systems. The glycerin may be mixed with glycol or water to provide greater mass than typical glycol or water hydronic systems. Natural gas is produced as a byproduct of the primary processes of ethanol, lubricant, diesel, and diethyl ether, and collected for redistribution to energy production for the facility. The remaining feedstock may be used to provide bio-mass for energy. This type of bio-mass derives from celluosic or other feedstocks, which would otherwise not be used to feed livestock. Other sources of energy may be required to supplement the natural gas but alternate sources of energy such as solar, geothermal, photovoltaic technologies, and or other sources of methane may be applied to achieve a self sufficient processing facility or a processing facility which relies primarily on alternative energies.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiment described hereinabove is further intended to explain the best mode known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.

Claims

1. A fuel composition, comprising a homogeneous liquid phase comprising an alcohol, an ether and an organic oil.

2. The fuel composition of claim 1, wherein the alcohol is ethanol.

3. The fuel composition of claim 2, wherein the ethanol is anhydrous ethanol.

4. The fuel composition of claim 1, wherein the ether is selected from the group consisting of diethyl ether, dimethyl ether and combinations thereof.

5. The fuel composition of claim 1, wherein the organic oil is an oil distilled from a source selected from the group consisting of a plant, a seed, a bean a fruit and a vegetable.

6. The fuel composition of claim 1, wherein the organic oil is an oil distilled from used cooking oil.

7. A fuel composition, comprising a homogeneous liquid phase comprising:

at least about 80% by weight of an alcohol;

about 1-10%, by volume, of at least one ether selected from the group consisting of dimethyl ether and diethyl ether; and,

about 0.008-0.02%, by volume, of a distilled organic oil.

8. A method of producing a hydrocarbon fuel additive comprising:

mixing an organic oil with an alcohol to form an alcohol-oil mixture;

heating the alcohol-oil mixture to a temperature of between about 260° C. to about 380° C. to produce a hydrocarbon gas; and,

cooling the hydrocarbon gas to condense and capture a liquid hydrocarbon lubricant.

9. The method of claim 8, further comprising capturing natural gas emitted from the heated alcohol-oil mixture.

10. The method of claim 8, further comprising heating the liquid hydrocarbon lubricant to distill off additional alcohol.

11. A method of producing ether comprising:

mixing sulfuric acid with an alcohol to form an alcohol-acid mixture;

heating the alcohol-acid mixture to evaporate an ether gas; and,

cooling the ether gas to condense and capture a liquid ether.

12. The method of claim 11, further comprising capturing natural gas emitted from the heated alcohol-oil mixture.

13. A fuel composition, comprising a homogeneous liquid phase comprising

an alcohol,

an ether and a hydrocarbon lubricant formed by the process comprising:

mixing an organic oil with an alcohol to form an alcohol-oil mixture;

14. The fuel composition of claim 13, wherein the alcohol is ethanol.

15. The fuel composition of claim 13, wherein the ether is selected from the group consisting of diethyl ether, dimethyl ether and combinations thereof.

16. A fuel blend comprising a homogeneous liquid phase comprising:

a petroleum fuel selected from the group consisting of gasoline and diesel;

an alcohol;

an ether; and,

a hydrocarbon lubricant formed by the process comprising:

mixing an organic oil with an alcohol to form an alcohol-oil mixture;

17. The fuel blend of claim 16, wherein the alcohol content of the homogeneous liquid phase is between about 25 volume percent and about 75 volume percent.