Patent Application
20080086933
By “volatility agent” herein is meant any fuel soluble and combustible component or additive that can be shown to partition differentially such that its presence is enriched in the combustion chamber during starting or other operations requiring a higher concentration of ignitable material to provide improved startability.
Accordingly, in one example herein is provided a fuel composition comprising, or in another embodiment consisting essentially of, gasoline, ethanol and at least one volatility agent, said volatility agent being selected from the group consisting of methyloxirane and other oxiranes, peroxides, alkyl nitrates, C1-C8 aliphatic hydrocarbons, ketones, butylene oxides, propylene oxides, ethylene oxides, epoxides, butane, pentane, nitrous oxide, nitromethane, xylene, diethyl ether, monoesters, diesters, ethers, diethers, polyethers, glymes, and glycols. In another embodiment, the fuel composition is free of or essentially free of gasoline, except for any gasoline or gasoline component used as the denaturant for the ethanol.
In another example is provided a fuel composition comprising an alcohol and a hydrocarbon volatility agent and optionally a hydrocarbon component. In yet another embodiment the alcohol is selected from the group consisting of ethanol, propanol, butanol and blends thereof. In a further embodiment the volatility agent has a Reid Vapor Pressure greater than 7.0. Still another example provides a fuel composition with an alcohol and a hydrocarbon volatility agent wherein the alcohol is ethanol and the hydrocarbon is a gasoline having a Reid vapor pressure greater than 7.0. In another example the alcohol is ethanol, the volatility agent is butane and the hydrocarbon component is gasoline.
The fuel compositions disclosed herein can further comprises a fuel additive selected from the group consisting of lubricity additives, combustion improvers, detergents, dispersants, cold flow improvers, dehazers, demulsifiers, cetane improvers, antioxidants, scavengers, and pollution suppressants.
In one embodiment, the ethanol content of the fuel composition is from about 74% to about 85%. In another embodiment of the disclosure herein the ethanol content of the fuel composition is from about 50% to about 74%.
Also provided herein is a method of improving the cold start performance of an engine combusting a fuel composition containing a hydrocarbon and an alcohol or mixture of alcohols, said method comprising combining the fuel and an additive selected from the group consisting of volatility enhancing materials that include monoesters, diesters, ketones, ethers, diethers, polyethers, glymes, and glycols, wherein the cold start of said engine is improved relative the cold start of the engine combusting a gasoline fuel without ethanol.
The present disclosure provides in one embodiment a fuel composition comprising ethanol and a hydrocarbon component with a Reid Vapor Pressure of greater than 7.0. In another embodiment the hydrocarbon component is a volatility agent. In yet another embodiment the fuel composition is essentially free of gasoline.
The formulation and methods presently disclosed will improve the cold start performance of engines combusting the fuel compositions described herein. Cold start performance is directly related to volatility of the fuel and/or the volatility of at least one combustible component thereof. Thus, cold start, as measured by the time required to achieve positive torque or disengaging the starter motor, can be evaluated to show enhanced performance in engines combusting fuel containing gasoline and 10% to about 90% of an alcohol, such as but not limited to ethanol, plus at least one of the volatility additives described herein. These additives can also provide enhanced performance after cold start by improving volatility or partition of combustible components into the combustion chamber during normal vehicle operation. Many of the volatility agents disclosed herein have been utilized in gasoline to achieve other benefits, but it is not known to the present inventors that these materials have been used in gasoline/ethanol blended fuels for their volatility attributes.
The volatility agents described herein can be useful in the range of from about 0.1 to about 15.0 weight percent of the finished fuel formulation.
The present disclosure also provides a volatility agent for ethanol, propanol and butanol or combinations of these alcohols or ethanol-gasoline, propanol-gasoline, and butanol-gasoline blends or blends of these alcohol-gasoline combinations where the agent is selected from the group consisting of one or more C1-C8 aliphatic hydrocarbon components, such as methane, ethane, propane, butane, isobutane, pentane, isopentane, hexane, heptane and octane and isomers thereof and mixtures thereof.
In another embodiment is provided a fuel composition comprising ethanol, gasoline and up to about 15% by weight pentane, or in another embodiment 10% by weight pentane, and in yet another embodiment 5% by weight pentane.
The following examples further illustrate aspects of the present disclosure but do not limit the present disclosure.
A fuel formulation can be prepared by blending commercial gasoline and ethanol (which by U.S. law will contain a denaturant, often gasoline or kerosene) in a ratio to achieve 85% ethanol (aka E85). To this fuel blend can be added 1.0% by weight of dimethyl ether as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and ethanol in a ratio to achieve 85% ethanol (aka E85). To this fuel blend can be added 3.0% by weight of isobutane as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and ethanol in a ratio to achieve 85% ethanol (aka E85). To this fuel blend can be added 10.0% by weight of petroleum ether as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and ethanol in a ratio to achieve 85% ethanol (aka E85). To this fuel blend can be added 5.0% by weight of nitrous oxide as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and ethanol in a ratio to achieve 85% ethanol (aka E85). To this fuel blend can be added 10.0% by weight of nitromethane as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
To an E100 fuel can be added 8.0% by weight of nitrous oxide as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
To an E100 fuel can be added 4.0% by weight of dimethyl ether as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
To an E100 fuel can be added 15.0% by weight of isobutane as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
To an E100 fuel can be added 1.0% by weight of petroleum ether as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
To an E100 fuel can be added 10.0% by weight of nitromethane as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and butanol in a ratio to achieve 85% alcohol. To this fuel blend can be added 5.0% by weight of butane as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
A fuel formulation can be prepared by blending commercial gasoline and butanol in a ratio to achieve 85% alcohol. To this fuel blend can be added 5.0% by weight of nitrous oxide as a volatility agent. The fuel can then be supplied to an internal combustion engine (spark ignited or compression ignited) and combusted in the engine. The volatility agent will decrease the time needed to achieve positive torque or disengaging the starter motor in the engine relative to the time needed to achieve positive torque or disengaging the starter motor in the same engine when combusting a comparable fuel of gasoline and ethanol but without the volatility agent. By this method the cold start performance of the engine is improved.
Volatility agents can be used herein to blend with an alcohol fuel, such as but not limited to E85 to adjust the vapor pressure and thus improve the fuel properties and the engine performance. Examples of such volatility agents, including ethers and alkanes, are listed in Table 1.
Table 2 is a graph of the results from ASTM D86 test which shows the percent of fuel blend that is evaporated at various temperatures. A fuel blend in a beaker is evaporated and the percentage is measured at each temperature. To achieve better or improved low temperature start or ignition in an engine, one desires a higher percentage of evaporation at constant temperature, or a lower temperature of equivalent evaporation. Thus, Table 2 shows that the E85 blend began its evaporation at 126° F., while the E85 blend with 5 weight percent pentane (C5) had initial evaporation at 114° F. The E85 blend containing 10 weight percent pentane (C5) had evaporation at 106° F., a significant reduction of temperature and improvement in cold start performance. The raw data is presented in Table 4 and shows that the temperatures to achieve 10% evaporation for E85, E85+5% C5 and E-85+10% C5 were, respectively, 150° F., 148.9° F. and 138.2° F.
Table 3 shows vapor pressure measurements above a fuel according to ASTM D5191. It is readily apparent that the E85+10% C5 had an RVP of 8.56, while the E85+5% C5 has an RVP of 7.36, and the E85 without a volatility agent had an RVP of 6.03. By the present invention, fuel blends with RVP above 7.0 are possible.
Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. As used throughout the specification and claims, “a” and/or “an” may refer to one or more than one. Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, percent, ratio, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
