JP2011511878A - Oxygenated gasoline composition with reduced RVP and method thereof - Google Patents

Abstract

  A composition of oxygenated gasoline comprising isobutanol is disclosed. This has a reduced vapor pressure compared to those containing a single oxygenate and no isobutanol. These compositions can be formed at refineries or terminals. A method of reducing the vapor pressure of oxygenated gasoline is disclosed, and a method of reducing vapor pressure constraints on refineries when producing oxygenated gasoline is disclosed. The basic properties of isobutanol are disclosed including IR spectral analysis. Also disclosed are processes and methods for blending and delivering these fuels.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of US Provisional Patent Application No. 61 / 027,969 (filed February 12, 2008), which is hereby incorporated by reference in its entirety. Incorporated.

  The present invention relates to fuel, and more particularly to oxygenated gasoline, including gasoline containing ethanol. The present invention provides an oxygenated gasoline that has a reduced lead vapor pressure (RVP), thereby allowing a high proportion of low boiling components to be blended into the gasoline without exceeding the RVP limit. . The present invention also provides a method for reducing the RVP of oxygenated gasoline.

Gasoline is suitable for use in spark ignition engines and generally has a number of boiling points as major components and typically boils at temperatures ranging from about 26 ° C. to about 225 ° C. under normal pressure. A fuel containing a mixture of hydrocarbons. This range is an approximation and can vary according to the actual mixture of hydrocarbon molecules present, additives or other components present (if any), and environmental conditions. Typically, the hydrocarbon component of _gasolines, including C 4 _{-C 10} hydrocarbons.

  Gasolines are typically required to meet certain physical and performance standards. Some characteristics may be met to properly operate an engine or other fuel combustion device. However, many physical and performance characteristics are set by national and regional regulations for other reasons such as environmental management. Examples of physical properties include RVP, sulfur content, oxygen content, aromatic hydrocarbon content, benzene content, olefin content, temperature at which 90% of the fuel is distilled (T-90), The temperature at which 50% is distilled (T-50), etc. are included. Performance characteristics can include octane number (also called antiknock index), combustion characteristics, and emission components.

  For example, the standard for gasoline sold in many United States states is shown in ASTM standard number D4814-01a ("ASTM 4814"). This is incorporated herein by reference. Additional federal and state regulations supplement this standard.

  The gasoline specifications shown in ASTM 4814 differ based on a number of parameters that affect volatility and flammability, such as weather, season, geographical location, and altitude. For this reason, gasoline produced according to ASTM 4814 is divided into volatile classifications AA, A, B, C, D, and E, and vapor lock prevention classifications 1, 2, 3, 4, 5, and 6. Each class has a set of standards that represent gasoline that meets the requirements of the individual class. This standard also indicates a test method for determining parameters within the standard.

For example, Class AA-2 gasoline blended for use during the summer driving season in a relatively warm climate has a maximum vapor pressure of 54 kPa and a maximum temperature for distilling 10 vol% of its components (“T ₁₀ ”). 70 ° C., temperature for distilling 50 vol% of its components (“T ₅₀ ”) 77 ° C. to 121 ° C., maximum temperature for distilling ₉₀ vol% of its components (“T ₉₀ ”) 190 ° C., distillation end point 190 ° C, distillation residue up to 2 vol%, maximum temperature of “Drivability Index” or “DI” 597 ° C., where DI is calculated as 1.5 × T ₁₀ + 3.0 × T ₅₀ + T ₉₀ , and Must have a maximum vapor / liquid ratio of 20 (test temperature 56 ° C.).

One physical property of gasoline described in ASTM 4814 and commonly regulated in many judicial administrations is RVP. RVP can be measured according to ASTM standard D 5191-04a ("D 5191"), which is incorporated herein by reference. The RVP standard is typically expressed as the maximum RVP limit that may be regulated to satisfy gasoline sold commercially in a particular judicial administration. These RVP limits substantially limit the hydrocarbon composition of the gasoline. This is because RVP increases as the proportion of lighter hydrocarbons increases. Typically, to produce gasoline with reduced RVP, the proportion of lighter hydrocarbons (eg, C ₄ hydrocarbons) is reduced. Reducing these lighter hydrocarbons can negatively affect gasoline properties. For example, a decrease in the amount of butane in gasoline fuel lowers the RVP of that fuel, but it also reduces the octane number.

  By constraining the gasoline composition, the RVP limit also places a burden on the refinery. In general, refineries adjust the composition of gasoline by controlling the ratio of the various refinery streams used to produce gasoline. For example, to produce higher boiling gasoline, a refinery may need to reduce the proportion of low boiling refinery streams used to produce gasoline. In order to produce gasoline that will meet applicable RVP limits, refineries typically reduce the proportion of lighter boiling hydrocarbons in gasoline. RVP is typically controlled or adjusted using empirically determined RVP blending values. The RVP blend value represents the contribution of a particular composition to the RVP of a particular mixture. One result of these RVP constraints on the refinery is that less gasoline is refined from each barrel of oil. This can substantially affect the supply of gasoline that can satisfy customer requirements.

  The impact of RVP limits is intensifying from the increasing use of oxygenates in gasoline. Oxygenated compounds are used in gasoline to increase the chemical oxygen content. Unfortunately, oxygenates have a non-linear effect on RVP when blended with fuel. Thus, the RVP blending value of the oxygenate is determined empirically for a specific concentration of a specific oxygenate in a specific fuel. Many judicial administrations have a requirement for oxygenated compounds to promote more complete combustion for gasoline. Methyl-t-butyl ether (MTBE) was an oxygenate commonly used as gasoline. However, many judicial administrations prohibit or strictly limit the use of MTBE and similar ethers.

  Due to restrictions on the use of MTBE, other oxygenates with less favorable RVP are typically used in gasoline. Ethanol is widely used as a gasoline oxygenate due to many factors. This includes tax credits provided by many judicial authorities for the use of 10 vol% or less of ethanol in gasoline. Patent Documents 1 and 2 discuss blending ethanol into gasoline. These are hereby incorporated by reference. Unfortunately, many oxygenates that are allowed to be blended into gasoline have significant drawbacks. This includes an affinity for water that causes transportation and handling difficulties, and an increase in gasoline RVP when blended with oxygenates. The affinity with water results in transportation and handling difficulties. As RVP increases, it becomes more difficult to produce gasoline within applicable RVP limits. Ethanol exhibits both effects described above.

  There is a need for compositions or methods that reduce the adverse effects that can result from blending oxygenates into gasoline. More specifically, it would be desirable to offset at least some of the RVP increase resulting from blending oxygenates with gasoline.

  The inventors have found that certain compounds exhibit unexpectedly low RVP blending values for blends with typical oxygenated gasolines. Surprisingly, in some cases, these compounds can even exhibit negative RVP blending values.

  The present invention reduces the RVP increase due to oxygenates blended with gasoline. This allows the refinery to use a high proportion of low boiling hydrocarbons in the gasoline blending material, thereby increasing the refinery's gasoline production capacity. The present invention can be used to reduce the RVP of oxygenated gasoline. In the specific case where oxygenated gasoline having an RVP exceeding the maximum applicable RVP limit is blended, the present invention can be used to adapt the oxygenated gasoline to the RVP limit.

US Pat. No. 6,258,987 (Schmidt et al.) US Pat. No. 6,540,797 (Scott et al.)

  The inventors have found that the use of isobutanol can have a surprising RVP reducing effect with respect to oxygenated gasoline. Isobutanol can interact with oxygenates to reduce the RVP increase expected from blending oxygenates with gasoline blends. In some cases, the effects of isobutanol are so dramatic that RVP reducing compounds exhibit negative RVP blending values.

  The present invention provides an oxygenated gasoline that can meet applicable RVP limits and still contain higher amounts of lighter components than would otherwise be possible. The present invention allows refineries to use higher proportions of crude oil for gasoline, thereby increasing gasoline supply. The present invention also provides a method for reducing the RVP of oxygenated gasoline. These reductions can be implemented at the terminal and can help reduce the need to obtain a waiver for gasoline that could otherwise have RVP beyond regulation. The present invention also provides a method for reducing RVP constraints on gasoline blends for oxygenated compounds blended in producing judicial government oxygenated gasoline having a maximum RVP limit.

  In one embodiment, the inventors provide a gasoline comprising a gasoline blend, a suitable oxygenate, and an effective amount of isobutanol. Preferably, the isobutanol has an RVP blend value of less than about 5.0 psi. More preferably less than about 3.0 psi, and most preferably less than about 0.0 psi. Optionally, the RVP value of the mixture of gasoline blend stock and a suitable oxygenate is at least about 6.9 psi. Preferably the suitable oxygenate is an alcohol. More preferred is ethanol. Preferably, more than 1 vol% of a suitable oxygenate is present. Preferably, less than 20 vol% isobutanol is present. Two or more oxygenated compounds can be used.

  In other embodiments, a method for reducing the RVP of oxygenated gasoline is provided. The method blends a gasoline blend material and one or more suitable oxygenates to produce an oxygenated gasoline, and mixes the oxygenated gasoline and isobutanol, where isobutanol is the RVP blend value. Including a step having less than about 5.0 psi, preferably less than about 3.0 psi, and most preferably less than about 0.0 psi. A suitable oxygenate can be an alcohol, preferably ethanol. Either or both blending or mixing steps can be performed at the terminal. Optionally, the blending step can be performed simultaneously with the mixing step. Preferably, more than 1 vol% of a suitable oxygenate is present. Preferably, less than 20 vol% RVP reducing compound is present.

  In other embodiments, a method is provided for reducing RVP constraints on gasoline blends when producing oxygenated gasoline having a predetermined maximum RVP limit. The method includes the steps of blending a gasoline blend material and one or more suitable oxygenates to produce an oxygenated gasoline having an RVP value greater than a predetermined maximum RVP limit, and an effective amount of an isoform. A step is included in which butanol is added to produce a gasoline having an RVP value below a predetermined maximum RVP limit. The blending step and the adding step can be performed simultaneously. A suitable oxygenate is preferably ethanol. Preferably, more than 1 vol% of a suitable oxygenate is present. Preferably, less than 20 vol% RVP reducing compound is present.

  Relative absorbance is a useful method for measuring the effectiveness of isobutanol in reducing RVP, as further described herein. Relative absorbance can also be used to identify oxygenated gasolines that are particularly suited to reducing RVP using isobutanol. In any embodiment, the gasoline blend material, one or more suitable oxygenates, and isobutanol is a mixture of the gasoline blend material, suitable oxygenates, and isobutanol with a normalized relative absorbance of less than about 0.045. Can be selected to have Preferably, the blend of gasoline blend material and a suitable oxygenate has a normalized relative absorbance of greater than about 0.05.

  Gasoline is well known in the art and generally comprises as a major component a mixture of hydrocarbons having different boiling points and boiling at temperatures ranging from about 26 ° C. to about 225 ° C. under normal pressure. . This range is approximate and can vary according to the actual mixture of hydrocarbon molecules present, the additives or other compounds present (if any), and the environmental conditions. Oxygenated gasoline is a blend of gasoline blend material and one or more oxygenated compounds.

  Gasoline blends can be made from a single component, such as a product from a refinery alkylator or other refinery stream. However, gasoline blends are more commonly blended using two or more components. Gasoline blends may be blended to meet desired physical and performance characteristics and to meet regulatory requirements and may include several components (eg, 3 or 4) or multiple components (eg, , 12 or more types).

  The gasoline and gasoline blending material may optionally include other chemicals or additives. For example, additives or other chemicals can adjust gasoline properties to meet regulatory requirements, add or enhance desired properties, reduce undesirable deleterious effects, The properties can be adjusted or added so that the properties of the gasoline are modified. Examples of these chemicals or additives include detergents, antioxidants, stability enhancers, demulsifiers, corrosion inhibitors, metal deactivators and the like. Two or more additives or chemicals can be used.

  Useful additives and chemicals are described in US Pat. No. 5,782,937 (Colucci et al.). This is incorporated herein by reference. These additives and chemicals are also described in US Pat. No. 6,083,228 (Wolf) and US Pat. No. 5,755,833 (Ishida et al.). Both are incorporated herein by reference. Gasoline and gasoline blending materials may also include a solvent or carrier solution. This is often used to add additives into the fuel. Examples of these solvents or carrier solutions include, without limitation, mineral oils, alcohols, carboxylic acids, synthetic oils, and many others known in the art.

  Gasoline blends suitable for the compositions of the present invention are typically blends useful for making gasoline for consumption in spark ignition engines or other engines that burn gasoline. Suitable gasoline blends include blends for gasolines that meet ASTM 4814 and blends for reformate gasoline. Suitable gasoline blends also include blends having a low sulfur content that may be desired to meet local requirements. For example, it has less than about 150 ppmv sulfur, more preferably less than about 100 ppmv sulfur, more preferably less than about 80 ppmv sulfur. These suitable gasoline blends also include blends with low aromatic content that may be desired to meet regulatory requirements. For example, having less than about 8000 ppmv benzene, more preferably less than about 7000 ppmv benzene. Or as a further example, it has a total aromatic content of less than about 35 vol%, more preferably a total aromatic content of less than about 25 vol%. As used herein, “total aromatic content” refers to the total amount of all aromatic species present.

As used herein, “oxygen compound” simply means a C ₂ -C ₈ compound containing carbon, hydrogen, and one or more oxygen atoms. For example, the oxygenate can be an alcohol, ketone, ester, aldehyde, carboxylic acid, ether, ether alcohol, ketone alcohol, and polyhydric alcohol. Ethanol is a preferred oxygenate for several reasons, including its wide availability. As used herein, “suitable oxygenate” means an oxygenate that has an RVP blend value of at least 6.5 psi and is soluble in the particular oxygenated gasoline produced. Preferably, more than about 2 vol% oxygenated compounds are present.

  “RVP blend value” or “blend RVP” is the effective RVP of the composition when blended into the fuel mixture. The blend RVP value represents the compositional contribution to the RVP of the mixture, and the RVP of the mixture is equal to the sum of (blend RVP of each component x volume fraction of that component). For example, for a fuel mixture of [A] and [B], RVP = (volume fraction of [A] blend RVP × [A]) + ([B] blend RVP × [B] volume fraction) It is.

  As used herein, a compound is soluble in a second compound if the mixture of compounds exhibits a single liquid phase at the desired concentration over the temperature range. This is from about −40 ° C. to the initial boiling point of the mixture, unless otherwise specified.

  Isobutanol is soluble in selected oxygenated gasolines and, when isobutanol is blended with selected oxygenated gasoline, reduces the RVP of selected oxygenated gasolines that do not contain any isobutanol. . An effective RVP reduction of isobutanol is an amount that reduces the RVP of oxygenated gasoline by at least 0.05 psi relative to the concentration of a particular RVP reducing compound. RVP can be determined according to ASTM D5191, which uses sufficient measurements to make a statistically significant determination. Preferably, the total concentration of isobutanol is less than about 20 vol%, more preferably less than about 10 vol%, and most preferably about 5 vol% or less. Isobutanol can be obtained from any suitable material. This includes those made from biomass. In addition to isobutanol, one or more additional RVP reducing compounds can be added to the mixture with the oxygenated gasoline.

  The particular usefulness of isobutanol for reducing the RVP of oxygenated gasoline is demonstrated by determining the normalized relative absorbance of a mixture of oxygenated gasoline and isobutanol. In addition, suitable oxygenates that are particularly compatible with these particularly effective RVP reductions can be identified by determining the normalized relative absorbance of oxygenated gasoline (no isobutanol).

  Without being limited to any particular theory, isobutanol interacts with oxygenated compounds in oxygenated gasoline, increasing the tendency of the oxygenated compounds to remain in the liquid phase, thereby reducing the RVP of the oxygenated gasoline. It is thought to be reduced. Relative absorbance is an analytical technique that can be used to identify appropriate oxygenates and isobutanol, and is particularly compatible with these interactions with isobutanol resulting in a synergistic reduction in RVP.

  Relative absorbance is measured by the ASTM standard method for the general technique of the two-point baseline method, the difference method, and the infrared quantitative analysis technique (infrared quantitative analysis standard E168-99 ("E168"), incorporated herein by reference). Is used).

The relative absorbance of the mixture containing isobutanol and oxygenated gasoline is determined using the difference spectrum obtained by subtracting the absorbance spectrum of oxygenated gasoline without any suitable oxygenated compound from the absorbance spectrum of the mixture, and It is determined using a two-point baseline method that calculates the ratio of (band 3680 cm ^{−1 to} 3550 cm ⁻¹ ) to (band 3680 cm ^{−1 to} 3100 cm ⁻¹ ). Using the differential spectrum described minimizes variations due to using different gasoline blends.

The relative absorbance of the oxygenated gasoline is determined using the difference spectrum obtained by subtracting the absorbance spectrum of the oxygenated gasoline without the appropriate oxygenated compound from the absorbance spectrum of the oxygenated gasoline and the band (3680 cm ⁻¹ to 3550 cm ⁻¹ ) to (bandwidth 3680 cm ^{−1 to} 3100 cm ⁻¹ ) is determined using a two-point baseline method.

  Table I below shows the relative absorbances of several oxygenated gasolines having different concentrations for one oxygenated compound in an alternative unleaded regular gasoline satisfying ASTM D4814.

  As shown in Table I, the relative absorbance varies with concentration. Table I also shows the non-linearity between relative absorbance and concentration. The relative absorbance will generally be determined empirically. For the particular unleaded regular gasoline used in Table I, ethanol would be a suitable oxygenate for this particular embodiment of the present invention.

  Table II shows the relative absorbances of several mixtures of isobutanol and oxygenated gasoline with the same replaceable unleaded regular gasoline used in Table I.

  As shown in Table 1, the addition of isobutanol to oxygenated gasoline has a significant effect on the relative absorbance of the mixture. The effect varies with different concentrations of isobutanol. However, these changes in relative absorbance indicate a synergistic interaction between the components that results in a surprising RVP reducing effect.

  In some embodiments, the normalized relative absorbance of the mixture comprising isobutanol and oxygenated gasoline is less than about 0.045, preferably less than 0.030. Preferably, the one or more suitable oxygenates are such that the standardized relative absorbance of the oxygenated gasoline comprising these suitable oxygenates (without isobutanol) is greater than about 0.05, preferably greater than about 0.1. Selected to be.

  The term “standardized relative absorbance” of a mixture comprising isobutanol and oxygenated gasoline refers to the mixture when isobutanol is present above about 0.5 wt% in a mixture of the desired concentration of the appropriate oxygenated compound. Defined as relative absorbance.

  The normalized relative absorbance of oxygenated gasoline (no isobutanol) is determined by calculating the relative absorbance when the appropriate oxygenated compound is present at about 1.0 wt% in the oxygenated gasoline.

  In other embodiments, the oxygenated gasoline includes a blend of a gasoline blend material, one or more suitable oxygenated compounds, and isobutanol. In yet another embodiment, the oxygenated gasoline is a blend of a gasoline blend stock, one or more suitable oxygenated compounds (including ethanol), and isobutanol.

  Some properties of mixtures of gasoline blends with oxygenates, isobutanol, or both do not vary linearly with the amount of each component used. In particular, the volatility related properties of these mixtures can differ from linear proportions with respect to the amount of each component used. This non-linear effect makes it particularly difficult to predict the actual impact of oxygenated compounds in gasoline on RVP. The actual RVP of oxygenated gasoline depends on the gasoline blending material used, the specific oxygenated compound used, and the specific concentration of oxygenated compound in the oxygenated gasoline. Because of this non-linear variation, the RVP of oxygenated gasoline is determined empirically. RVP data is typically collected empirically over the oxygenate concentration range and the gasoline blend stock range.

  The blend RVP of oxygenates is typically calculated by measuring the RVP of the fuel before and after the addition of these oxygenates. The oxygenate blend RVP values that can be calculated from these empirical data also show non-linear behavior with respect to the concentration of oxygenates in a particular oxygenated gasoline, making these blend RVP values difficult to predict. . Because of these non-linear effects on RVP, the calculated blend RVP value is specific to the concentration of a particular oxygenate added to a particular fuel.

  The isobutanol blend RVP as calculated as a function of the isobutanol volume fraction exhibits non-linear behavior, making it more difficult to predict the RVP of the resulting mixture. The isobutanol blend RVP is typically calculated by measuring the RVP of the fuel before and after the addition of isobutanol. The measured blend RVP is specific to the concentration of isobutanol added to a particular fuel, since isobutanol has a non-linear effect on RVP when added to the fuel.

  The inventors have surprisingly found that a combination of one or more suitable oxygenates and isobutanol can have a synergistic effect on the RVP value of the gasoline produced.

  In any embodiment, the gasoline blending material, a suitable oxygenate, and isobutanol can be blended in any order. For example, isobutanol can be added to a mixture comprising a gasoline blend and a suitable oxygenate. As another example, one or more suitable oxygenates and isobutanol can be added in several different locations or in multiple stages. For further examples, isobutanol is added with the appropriate oxygenate, added before the appropriate oxygenate, or blended with the appropriate oxygenate before being added to the gasoline blend. Can be done. In a preferred embodiment, isobutanol is added to the oxygenated gasoline. In other preferred embodiments, one or more suitable oxygenates and isobutanol are simultaneously blended into the gasoline blend.

  In any embodiment, two or more suitable oxygenates can be used in place of a single suitable oxygenate. Suitable oxygenates and isobutanol can be added at any point in the distribution chain. For example, a gasoline blend can be transported to the terminal, and then a suitable oxygenate and isobutanol can be blended with the gasoline blend at the terminal, individually or in combination. As a further example, a gasoline blend, one or more suitable oxygenates, and isobutanol can be combined at a refinery. Other ingredients or additives can be added at any point in the distribution chain.

  In yet another embodiment, a method is provided for reducing the RVP of oxygenated gasoline. The method can be implemented at a refinery, terminal, retail site, or any other suitable point in the distribution chain. Preferably, the method is performed at a terminal already designed for blending ethanol or some other oxygenate with a gasoline blending material or at a terminal that can be adapted to allow blending thereof. Is done.

  In accordance with other embodiments, the gasoline blending material is blended with ethanol, any other suitable oxygenate or combination of suitable oxygenates, and isobutanol, to an oxygenated gasoline that does not contain isobutanol. An oxygenated gasoline fuel with a low RVP is produced.

  The isobutanol blend RVP value is less than the RVP value of the remaining mixture. Preferably, the isobutanol blend RVP is no more than about 50% of the RVP of the remaining mixture. Alternatively, the isobutanol blend RVP is less than about 5.0 psi, more preferably less than about 3.0 psi, more preferably less than about 0.0 psi.

  Regulations on gasoline set limit values for various characteristics of fuel. This typically includes an upper limit for RVP. These RVP limits may vary by country, region, and season. These RVP limits impose restrictions on refinery products that can be used as gasoline. Typically, oxygenates when blended into a gasoline blend will increase the RVP of the resulting blend. Gasoline blends for blending oxygenates typically have an RVP well below any applicable upper limit that allows for the expected effect of oxygenates. This further constrains refinery products that can be used for gasoline. This is because fuel components that are not very volatile can be used in gasoline blends. These RVP constraints can limit the amount of gasoline available for consumption.

  In another embodiment, a method is provided for reducing RVP constraints on a refinery that produces a gasoline blend for blending oxygenated compounds. Because oxygenated gasoline that meets regulatory RVP limits can be made using gasoline blends that would otherwise not be available to produce RVP-compliant oxygenated gasoline, RVP constraints on refineries are Alleviated. Other embodiments provide oxygenated gasolines so that some oxygenated gasolines that would otherwise not meet regulatory RVP limits may be further blended to meet these regulatory RVP limits. A method for reducing RVP is provided.

  In yet other embodiments, oxygenated gasoline is produced by blending selected gasoline blend materials, selected appropriate oxygenated compounds, and isobutanol to form oxygenated gasoline. Isobutanol reduces the RVP value of oxygenated gasoline. For certain suitable oxygenates and certain gasoline blends, using isobutanol has a higher RVP value than is typically used to produce oxygenated gasoline that meets applicable RVP regulations. It may be possible to use a gasoline blend material.

  For a given maximum RVP value, a gasoline blend and a suitable oxygenate will produce gasoline, even if the RVP value of the mixture of gasoline blend and suitable oxygenate will exceed the maximum RVP value. The RVP value of the oxygenated gasoline mixture comprising the blend material, the appropriate oxygenated compound, and isobutanol is selected to be less than or equal to the maximum RVP value.

  Without limiting the scope, the following examples illustrate various embodiments of our invention. The following specific examples are discussed for unleaded gasoline fuels that meet the performance characteristics of ASTM D4814. However, those skilled in the art will appreciate that the invention is not limited to these fuels and can be used with any gasoline blend or fuel consistent with the description herein.

  An unleaded regular gasoline blend that satisfies the performance characteristics of ASTM D4814-01a was blended with 10 vol% of the appropriate oxygenate. Ethanol was used as a suitable oxygenate. The RVP of the resulting oxygenated gasoline was measured at 9.69 psi when measured according to ASTM D5191. Isobutanol (14 vol%) was blended with oxygenated gasoline and the resulting mixture had an RVP of 8.64 psi as measured according to ASTM D5191. The calculated blend RVP value for the 14 vol% blend was 2.19 psi.

  The above examples show how isobutanol can reduce the RVP of oxygenated gasoline. In areas with maximum RVP limits, refineries typically produce gasoline blend stocks that are significantly below these limits in anticipation of the increase in RVP by blending oxygenates. Because isobutanol can be used to reduce the RVP of oxygenated gasoline, refineries can apply with gasoline blends that would otherwise not be usable to produce RVP-compatible oxygenated gasoline. Oxygenated gasoline can be produced in line with possible RVP limits.

Claims (37)

(A) gasoline blend material,
A gasoline composition comprising (b) a suitable oxygenate, and (c) an amount of isobutanol effective to reduce the RVP of oxygenated gasoline that does not contain isobutanol.   The gasoline composition of claim 1, wherein the isobutanol has an RVP blend value of less than about 5.0 psi.   The gasoline composition of claim 2, wherein the isobutanol has an RVP blend value of less than about 0.0 psi.   3. A gasoline composition according to claim 1 or claim 2 wherein the RVP value of the mixture of gasoline blend stock and a suitable oxygenate is at least about 6.9 psi.   A gasoline composition according to claim 1 wherein the suitable oxygenate is an alcohol.   A gasoline composition according to claim 5 wherein the suitable oxygenate is ethanol.   The gasoline composition of claim 6, wherein the ethanol is present at least about 1 vol%.   The gasoline composition of claim 7, wherein the isobutanol is present at less than about 20 vol%.   9. The gasoline composition of claim 8, wherein ethanol is present at 20 vol% or less and isobutanol is present at about 1 vol% to about 20 vol%.   The gasoline composition of claim 1, wherein the blend of the gasoline blend material and a suitable oxygenate has a normalized relative absorbance of greater than about 0.05.   The gasoline composition of claim 10, wherein the mixture of gasoline blend, suitable oxygenate, and isobutanol has a normalized relative absorbance of less than about 0.045.   The gasoline composition of claim 11, wherein the isobutanol exhibits an RVP blend value of less than about 5.0 psi.   13. A gasoline composition according to claim 11 or claim 12, wherein the RVP value of the mixture of gasoline blend material and a suitable oxygenate is at least about 6.9.   A gasoline composition according to claim 10 wherein the suitable oxygenate is ethanol.   A method for reducing the RVP of oxygenated gasoline comprising the steps of blending a gasoline blending material, a suitable oxygenated compound, and an amount of isobutanol effective to reduce RVP. Method.   16. The method of claim 15, wherein the isobutanol has an RVP blend value of less than about 5.0 psi.   17. The method of claim 16, wherein the isobutanol has an RVP blend value of less than about 0.0 psi.   18. The method of claim 15 or claim 17, wherein the RVP value of the mixture of gasoline blend stock and a suitable oxygenate is at least about 6.9 psi.   The process according to claim 15, wherein the suitable oxygenate is ethanol.   20. The method of claim 19, wherein ethanol is present at 20 vol% or less and isobutanol is present at about 1 vol% to about 20 vol% in the resulting composition.   16. The method of claim 15, wherein at least one suitable oxygenate or isobutanol is blended at the terminal.   16. The method of claim 15, wherein a suitable oxygenate and isobutanol are simultaneously blended with the gasoline blending material.   16. The method of claim 15, wherein the mixture of gasoline blend material and a suitable oxygenate has a normalized relative absorbance of greater than about 0.05.   24. The method of claim 23, wherein the mixture comprising isobutanol, gasoline blending material, and a suitable oxygenate has a normalized relative absorbance of less than about 0.045.   A method for reducing RVP constraints on a gasoline blending material when producing oxygenated gasoline having a predetermined maximum RVP limit value, effective for reducing gasoline blending material, suitable oxygenated compounds, and RVP Blending a quantity of isobutanol, wherein the mixture of gasoline blending material and a suitable oxygenate has an RVP value above a predetermined maximum RVP limit value and the gasoline blending material A method for reducing RVP constraints, wherein a mixture of an oxygen-containing compound and isobutanol has an RVP value equal to or less than a predetermined maximum RVP limit value.   26. The method of claim 25, wherein a suitable oxygenate and isobutanol are simultaneously blended with the gasoline blending material.   26. The method of claim 25, wherein the isobutanol is blended with the gasoline blend material before a suitable oxygenate is blended with the gasoline blend material.   26. The method of claim 25, wherein at least one suitable oxygenate or isobutanol is blended with the gasoline blend at the terminal.   26. The method of claim 25, wherein the suitable oxygenate is ethanol.   30. The method of claim 29, wherein ethanol is present in the resulting composition at least 1 vol%.   32. The method of claim 30, wherein the isobutanol is present in the resulting composition at less than about 20 vol%.   32. The method of claim 31, wherein ethanol is present in the resulting composition from about 1 vol% to about 20 vol% and isobutanol is present from about 1 vol% to about 20 vol%.   26. The method of claim 25, wherein the oxygenated gasoline has a normalized relative absorbance of greater than about 0.05.   34. The method of claim 33, wherein the mixture of isobutanol and oxygenated gasoline has a normalized relative absorbance of less than about 0.045.   35. The method of claim 34, wherein in the resulting composition, a suitable oxygenate is present at greater than about 1 vol% and isobutanol is present at less than about 20 vol%.   26. The gasoline composition of claim 25, wherein the isobutanol exhibits an RVP blend value of less than about 5.0 psi.   38. The gasoline composition of claim 36, wherein the isobutanol exhibits an RVP blend value of less than about 0.0 psi.