BRPI0614026A2 - petrol composition and rvp reduction methods of a hydrogen peroxide and rvp construction over in gasoline mixture stock in the production of peroxide having a predetermined maximum limit of rvp - Google Patents

Abstract

GASOLINE COMPOSITION AND METHODS OF REDUCING THE RVP OF AN OXYGENED GASOLINE AND THE CONSTRICTION OF RVP ON A GASOLINE MIXTURE STOCK IN THE PRODUCTION OF OXYGENED GASOLINES WITH A PREDETERMINATED MAXIMUM LIMIT. Oxygenated gasoline compositions are disclosed that have reduced vapor pressure compared to those containing a single oxygen and no RVP reducing compound. Such compositions can be formed at a refinery or at a terminal. Methods of reducing the vapor pressure of an oxygenated gasoline are disclosed and methods of reducing vapor pressure constraints in a refinery in the production of oxygenated gasoline are revealed. The fundamental properties of RVP reduction compound are revealed, including the analysis of IR spectra. Processes and methods of mixing and distributing these fuels are also disclosed.

Description

'Gasoline Composition and RVP Reduction Methods of a

Oxygenated Gasoline and RVP Constriction on a Gasoline Mixing Stock in the Production of Oxygenated Gasolines

Having a Default Maximum RVP Limit "^ 5 Descriptive Report

Background of the Invention

This invention relates to fuels, particularly oxygenated gasolines including ethanol-containing gasolines. This invention provides an oxygenated gasoline having a pres-

Reid Vapor (RVP), thus allowing a higher proportion of low boiling components to be mixed in gasoline without exceeding the RVP limits. This invention also provides a method of reducing the RVP of oxygenated gasolines.

Gasolines are fuels which are suitable for use in a spark ignition engine and which generally contain as a primary component a mixture of numerous hydrocarbons having different boiling points and typically boiling at a temperature in the range from about 8 ° C. from 26 ° C to about 225 ° C under atmospheric pressure. This range is approximate and may vary depending on the actual mixture of hydrocarbon molecules present, additives or other compounds present (if any) and environmental conditions. Typically, the hydrocarbon gasoline component contains C4 to C10 hydrocarbons.

Gasolines are typically required to meet certain physical and performance standards. Some features may be implemented for proper operation of engines or other fuel combustion equipment. However, many physical and performance characteristics are shaped by national or regional regulations for other reasons such as environmental stewardship. Examples of physical characteristics include RVP, sulfur content, oxygen content, aromatic hydrocarbon content, benzene content, olefin content, temperature at which 90 percent of the fuel is distilled (T-90), temperature at which 50 percent of the fuel is distilled (T-50) and others. Performance characteristics may include octane rating (also called anti-detonating index), combustion properties and emission components.

For example, standards for gasolines for sale within many of the United States are generally described in ASTM Standard Specification Number D 4814-Ola ("ASTM 4814") which is incorporated herein by reference. Additional federal and state regulations supplement this standard.

The specifications for gasolines described in ASTM 4814 vary based on various parameters that affect volatility and combustion, such as time, season, geographical location and height. For this reason, gasolines produced in accordance with ASTM 4814 are divided into AA, A, B, C, D and E volatility categories and 1, 2, 3, 4, 5 and 6 vapor block protection categories. , each category having a set of specifications describing the gasolines meeting the requirements of the respective classes. This specification also describes test methods for determining the parameters in the specification.

For example, a blended Class AA-2 gasoline for use during the summer driving season in relatively hot climates should have a maximum vapor pressure of 54 kPa, a maximum distillation temperature of 10% of the volume of its components. ("Uncle") of 10 0C, a distillation temperature range of 50% of the volume of its components (at ftT50 ") between 77 ° C and 121 ° C, a maximum distillation temperature of 90% of the volume of its components (the "Tgo") of 190 ° C, a distillation endpoint of 190 ° C, a maximum distillation residue of 2% by volume, a "Conductivity Index" or a maximum temperature ftDI " 597 ° C, where D1 is calculated as 1.5 times Tio plus 3.0 times T5O plus T9o, and a maximum vapor to liquid ratio of 20 at a test temperature of 56 ° C.

A physical feature of gasolines that is addressed in ASTM 4814 and is generally regulated in many jurisdictions is RVP. RVP may be measured in accordance with ASTM Standard Specification D 5191-04a ("D 519Γ) which is incorporated herein by reference. RVP standards are typically expressed as an upper limit of RVP that gasolines commercially sold in a particular jurisdiction may be. This RVP limit significantly constrains the hydrocarbon composition in gasolines because RVP increases as the proportion of lighter hydrocarbons increases.Typically, to produce reduced RVP gasolines, Lighter hydrocarbons, for example C4 hydrocarbons, are reduced Reducing these lighter hydrocarbons can negatively impact gasoline characteristics For example, decreasing the amount of butane in a gasoline fuel lowers the RVP of that fuel, but also reduces the rating. of octane.

Constraining gasoline composition, RVP limits also impose a burden on refineries. Generally, refineries adjust the composition of gasolines by controlling the proportions of various refinery streams that are used to produce the gasolines. For example, to produce gasoline with a higher boiling point, a refinery may need to reduce the proportion of low boiling refinery streams used to produce gasoline. To produce gasolines that meet applicable RVP limits, refineries typically reduce the proportion of higher boiling hydrocarbons in gasolines. RVP is typically controlled or adjusted using empirically determined RVP mix values. An RVP blend value represents the contribution of a particular composition to the RVP of a particular blend. One consequence of these RVP constraints on refineries is that less gasoline can be refined from each barrel of oil. This can significantly impact the supply of gasoline available to meet consumer demand.

The impact of RVP limits has intensified due to the increasing use of oxygenates in gasolines. Oxygenates are used in gasolines to increase chemical oxygen content. Unfortunately, oxygenates have a nonlinear effect on RVP when mixed into a fuel. Therefore, the RVP mixture values of oxygenates are determined empirically for a particular concentration of a particular oxygenate in a particular fuel. Many restrictions have oxygenate requirements for gasolines to promote more complete combustion. Methyl tert-butyl ether (MTBE) was generally used as a gasoline oxygenate. However, many jurisdictions prohibit or severely limit the use of MTBE and similar ethers.

Due to restrictions on the use of MTBE, they are typically

Other oxygenates with less favorable RVP are often used in gasolines. Ethanol is widely used as a gasoline oxygenate due to several factors including tax credits offered by many jurisdictions for use of up to 10% by volume of ethanol in gasoline. Schmidt et al. U.S. Patent Nos. 6,258,987 and 6,540,797 to Scott et al., Which are incorporated herein by reference, discuss the mixture of ethanol in gasolines. Unfortunately, many of the oxygenates that are allowed to be mixed in gasolines have significant detriments including an affinity for water that causes transport and handling difficulties and an increase in RVP of a gasoline when mixed with oxygenate. An affinity for water causes transport and handling difficulties. Increasing RVP increases the difficulty of producing gasoline within applicable RVP limits. Ethanol exhibits both preceding effects. There is a need for a composition or method for

mitigate the detrimental effects that may result from mixing oxygenates in gasolines. In particular, it would be desirable to count at least some of the increases in RVP attributable to the mixing of oxygenates in gallins.

We have found that certain compounds may exhibit mixture values.

unexpectedly low RVP rates for mixing with typical oxygenated gasolines. Surprisingly, in some cases, these Mi compounds

may even display negative RVP mix values.

This invention decreases the increase in RVP attributable to oxygenate blending in gasolines, which allows refineries to use a higher proportion of low boiling hydrocarbons in gasoline blending stocks, thereby increasing refining capacity. refinery gas station. This invention can be used to reduce the RVP of an oxygenated gasoline. In certain instances where an oxygenated gasoline having an RVP value exceeding the applicable RVP limit is mixed, this invention may be used to make the oxygenated gasoline meet the RVP limit.

Summary of the Invention

We have found that the use of RVP-reducing compounds, as best described herein, may have a surprising RVP-reducing effect on oxygenated gasolines. These RVP reducing compounds can interact with an oxygenate to lower the expected RVP increase from mixing the oxygenate with a gasoline blend stock. In some cases, the effect of the RVP reducing compound is so drastic that the RVP reducing compound exhibits a negative RVP mix value.

This invention provides an oxygenated gasoline which contains

It therefore meets an applicable RVP limit and may also include more lighter components than would otherwise be possible. This invention allows a refinery to use a higher proportion of crude gasoline to thereby increase its gasoline supply. This invention also provides a method of reducing the RVP of an oxygenated gasoline. This reduction can be accomplished at a terminal and can help reduce the need for gasoline waivers that may otherwise have an RVP that exceeds regulations. This invention also provides a method of reducing the RVP constraint on gasoline blending stocks of oxigen blends in the production of oxygenated gasolines for jurisdictions that have a maximum RVP limit. In one embodiment, we provide a gasoline containing a gasoline blend stock, a suitable oxygenate and an effective amount of an RVP reducing compound. Preferably, the RVP reducing compound has an RVP blend value of less than about 21 kPa, more preferably less than more or less than 0.0 kPa. Optionally, the RVP value of a mixture of the gasoline mixture stock and the appropriate oxygenate is at least approximately 47.5 kPa. Preferably, the suitable oxygenate is an alcohol, more preferably ethanol. The RVP reducing compound may be selected from a group consisting of 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1,3-propanediol, 2,3-butanediol, acetic acid and combinations of the following. same. Preferably more than 2 vol% suitable oxygenates are present. Preferably less than 15% by volume of RVP reducing compounds are present. More than one suitable oxygenate may be used. More than one RVP reduction compound may be used.

In another embodiment, a method of reducing the RVP of an oxygenated gasoline is provided. The method includes a step of mixing a gasoline mixture stock and one or more suitable oxygenates to form an oxygenated gasoline and the step of mixing the oxygenated gasoline and one or more RVP reducing compounds wherein at least one RVP reducing compound has an RVP blend value of less than approximately 21 kPa, preferably less than about 0.0 kPa. Suitable oxygen may be an alcohol, preferably ethanol, and the RVP reducing compound may be selected from the group consisting of 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1,3- propanediol, 2,3-butanediol, acetic acid and combinations thereof. One or both of the mixing steps may be performed at one terminal. Optionally, the mixing step may be carried out contemporaneously with the mixing step. Preferably, more than 2 vol% suitable oxygenates are present. Preferably less than 15% by volume of RVP reducing compounds.

are present.

In another embodiment, a method of reducing RVP constraint on a gasoline mixture stock in the production of oxygenated gasolines with a predetermined maximum RVP limit is provided. The method includes the step of mixing a gasoline blending stock and one or more suitable oxygenates to form an oxygenated gasoline having an RVP value greater than the predetermined upper limit of RVP and the step of adding an effective amount of one or more. RVP reduction compounds to form a gasoline having an RVP value less than or equal to the predetermined maximum RVP limit. The mixing step and the addition step can be performed at the same time. Suitable oxygenates are preferably ethanol. The RVP reducing compound may be selected from the group consisting of 2-propanol, 1-butanol, 2-butanoyl, tert-butanol, 1,3-propanediol, 2,3 butanediol, acetic acid and combinations thereof. Preferably more than 2 vol% suitable oxygenates are present. Preferably less than 15% by volume of RVP reducing compounds are present.

Relative absorbance, as best described herein, is a useful way to identify particularly effective RVP reducing compounds. Relative absorbance can also be used to identify oxygenated gasolines that are particularly receptive to RVP reduction using an RVP reduction compound. In either embodiment, a gasoline blending stock, one or more suitable oxygenates and one or more RVP reducing compounds may be selected such that a mixture of the gasoline blending stock, suitable oxygen (s) and PVR compound (s) has a normalized relative absorbance of less than about 0.045. Preferably, a mixture of the appropriate gasoline and oxygenate mixture (s) stock has a normalized relative absorbance greater than about 0.05.

Brief Description of the Drawing Figure 1 is a graph representing the relative absorbance Hb

oxygenated gasoline having two different oxygenates as a function of the weight percentage. Figure 2 is a bar graph of the relative absorbance of an oxygenated gasoline with various RVP reducing compounds. Figure 3 is a graph depicting the RVP of a unleaded regular gasoline having a base RVP of 42 kPa as a function of the volume percent of ethanol in that gasoline.

Description of Preferred Mode (s)

Gasolines are well known in the art and generally contain as a primary component a mixture of hydrocarbons having different boiling points and typically boiling at a temperature in the range of about 26 ° C to about 225 ° C under atmospheric pressure. . This range is approximate and may vary depending on the actual mix of hydrocarbon molecules present, additives or other compounds present (if any) and environmental conditions. Oxygenated gasolines are a mixture of a gasoline mixture stock and one or more oxygenates.

Gasoline blending stocks may be produced from a single component, such as the product from a refinery alkylation unit or other refinery streams. However, gasoline blending stocks are more generally blended using more than one component. Gasoline blend stocks are mixed to meet desired physical and performance characteristics and to meet regulatory requirements and may involve some components, for example three or four, or may involve many components, for example twelve. or more.

Gasolines and optionally gasoline mixing stocks may include other chemicals or additives. For example, additives or other chemicals may be added to adjust the properties of a gasoline to meet regulatory requirements, to add or enhance the desired properties, to reduce undesirable effects, to adjust performance characteristics.

30 or otherwise modify the characteristics of gasoline. Examples of such chemicals or additives include detergents, antioxidants, stability enhancers, demulsifiers, corrosion inhibitors, metal deactivators and others. More than one additive or chemical may be used.

Useful additives and chemicals are described in US Patent 5,782,937 to Colucci et al., Which is incorporated herein by reference. Such additives and chemicals are also described in US Patent 6,083,228 to Wolf and US Patent 5,755,833 to Ishida and co-workers, both of which are incorporated herein by reference. Gasoline and gasoline mixture stocks may also contain solvent or carrier solutions that are often used to release additives into a fuel. Examples of such solvent or carrier solutions include, but are not limited to, mineral oil, alcohols, carboxylic acids, synthetic oils, and numerous others known in the art.

Gasoline blending stocks suitable for the composition of this invention are typically blending stocks usable for making gasolines for consumption in spark ignition engines or other gasoline combustion engines. Suitable gasoline blending stocks include gasoline blending stocks that satisfy ASTM 4814 and reformulated gasoline blending stocks. Suitable gasoline mixing stocks also include mixing stocks having low sulfur content that may be desired to meet regional requirements, for example having less than about 150 ppmv sulfur, more preferably less than about 100. ppmv sulfur, more preferably less than about 80 ppmv sulfur. Such suitable gasoline blending stocks also include blending stocks having low aromatic content that may be desirable to meet regulatory requirements, for example, having less than about 8,000 ppmv benzene content, more preferably less than 10% ppmv. approximately 7,000 ppmv benzene or, as an additional example, having less than about 35% by volume of aromatics, more preferably less than about 25% by volume of aromatic content. As used herein, "total aromatic content" refers to the total amount of all aromatic species present.

"Oxygenate" as used herein means a C2 to Ce compound containing only carbon, hydrogen and one or more oxygen atoms. For example, the oxygenates may be alcohols, ketones, esters, aldehydes, carboxylic acids, ethers, ether alcohols, ketone alcohols and polyalcohols. Ethanol is a preferred oxygenate for several reasons including its widespread availability. "Suitable oxygen" as used herein means an oxygenate which has an RVP blend value of at least 44.8 kPa and is soluble in the particular oxygenated gasoline being produced. Preferably, more than about 2 vol% oxygen is present.

"RVP Blend Value" or "RVP Blend" is the effective RVP of a composition when blended into a fuel blend. A mixed RVP value represents the composition's contribution to the RVP of a mixture such that the RVP for the mixture equals the addition of each RVP of the component mixture multiplied by that volume fraction of the component. For example, for a fuel mixture of [A] and [Β], RVP = (RVP of the mixture of [A] χ volume fraction of [A]) + (RVP of the mixture of [Β] χ fraction volume [B]).

As used herein, a compound is soluble in a second compound if a mixture of the compounds exhibits a single liquid phase at the desired concentrations in the temperature range of interest which, unless otherwise stated, is from about -40 ° C to the initial boiling point of the mixture.

"RVP reducing compound" as used herein means a C2 to Cs compound that includes only carbon and hydrogen and a 43 W

or more heteroatoms, each of which is selected from the group consisting of oxygen and nitrogen, which is soluble in the selected oxygenated gasoline and which reduces the RVP of the selected oxygenated gas when mixed into the selected oxygenated gasoline. An effective amount of an RVP reducing compound is an amount that reduces the RVP of oxygenated gas by at least 0.34 kPa for the concentration of the particular RVP reducing compound. RVP can be determined according to ASTM D 5191 using sufficient measures for a statistically significant determination. Preferably, the total concentration of the RVP reducing compound is less than about 15% by volume, more preferably less than about 10% by volume, more preferably no greater than about 5% by volume. in volume.

RVP reducing compounds may be alcohols, ketones, esters, carboxylic acids, ethers, ether alcohols, ketone alcohols, polyalcohols, amines, amine alcohols and combinations thereof. Examples of RVP reducing compounds include 2-propanol, 1-butanol, 2-butanol, tert-butanol, 2 butanone, 3-methyl-2-butanone, 4-methyl-2-pentanone, ethyl, butyl acetate, acetic acid, diisopropyl ether, methyl tert-butyl ether, 2-ethoxy ethanol, 4-methyl-4-hydroxy-2-pentanone, 1,3-propanediol, 2,3-butanediol, 2- ethylhexanol, triethyl amine and combinations thereof.

RVP reducing compounds that are especially effective in reducing the RVP of oxygenated gasolines can be identified by determining the normalized relative absorbance of a mixture of oxygenated gasoline and the RVP reducing compound. In addition, suitable oxygenates that are particularly receptive to this especially effective RVP reduction can be identified by determining the normalized relative absorbance of oxygenated gasoline (without the RVP reduction compound).

Without being bound by any particular theory, it is believed that RVP reducing compounds interact with oxygenates in an oxygenated gasoline and increase the propensity of oxygenate to remain in the liquid phase, thereby reducing the RVP of oxygenated gasoline. Relative absorbance is an analytical technique that can be used to identify suitable oxygenates and RVP reducing compounds that are particularly receptive to those interactions that produce a synergistic reduction of RVP.

Relative absorbance employs the two-point baseline method, the difference method, and infrared quantitative analysis techniques as described in ASTM Standard Practicesfor General Techniques of Jnfrared Quantitative Analysis Specification E 168-99 ("E 168") , which is incorporated herein by reference.

The relative absorbance of a mixture containing an RVP reduction compound and an oxygenated gasoline is determined using the difference spectrum obtained by subtracting the absorbance spectrum of the oxygenated gasoline without any suitable oxygenates from the absorbance spectrum of the mixture. and using the two-point baseline method to calculate the ratio of the banding area from 3,680 cm -1 to 3550 cm -1 to the banding area 3680 cm -1 to 3100 cm -1. The difference spectrum as described minimizes the variability due to the use of different gasoline blend stocks.

The relative absorbance of an oxygenated gasoline is determined using the difference spectrum obtained by subtracting the absorbance spectrum of oxygenated gas without the appropriate oxygenate from the absorbed spectrum of oxygenated gas and using the base line method. of two points to calculate the ratio of the banner area from 3,680 cm-1 to 3,550 cm-1 to the range of 3,680 cm1 to 3,100 cm-1.

Table I below shows the relative absorbance of various oxygenated gasins having different concentrations of two oxygenates in a fungible regular unleaded gasoline that meets ASTM D 4814. Figure 1 shows a representation of these data. Table I

Relative Absorbance of Oxygenate Compounds at Varied Concentrations in a Lead-Free Regular Gasoline

Concentration Compound Absorbance Oxygenate% Weight Relative Ethanol 1.05 0.104 Ethanol 2.11 0.049 Ethanol 5.27 0.009 2-Butanol 0.938 0.211 2-Butanol 1.88 0.174 2-Butanol 4.69 0.047

As shown in Table I and Figure 1, relative absorbance varies by compound and by concentrations. Table I also demonstrates the nonlinearity between absorbance and relative concentration. Relative absorbance will generally be determined empirically. For the particular unleaded regular gasoline used in Table I, both ethanol and 2-butanol would be oxygenate compounds for this particular embodiment of the invention.

Table II shows the relative absorbance of various mixtures of RVP reducing compounds and an oxygenated gasoline with the same regular, unlithable unleaded gasoline used for Table I. Figure 2 is a graph of the data. SjL

Table II

Relative Absorbance of RVP Reduction Compounds in an Oxygenated Gasoline (2% by Weight Ethanol) Concentration Compound Absorbance RVP Reduction Relative Weight% none 0.049 2-butanol 2.0 0.019 methyl ethyl ketone 2.0 0.015 butyl acetate 3, 0 0.027 triethyl amine 3.0 0.037

As shown in Table I and Figure 2, the addition of RVP reducing compound to oxygenated gasoline has a significant impact on the relative absorbance of the mixture. Impact varies with different PVR reduction compounds, but this change in relative absorbance indicates a synergistic interaction between components, resulting in a surprising PVR reduction effect.

In some embodiments, an RVP reducing compound is selected such that the normalized relative absorbance of a mixture containing one or more RVP reducing compounds and an oxygenated gasoline is less than about 0.045, preferably less than about 0.030. Preferably one or more suitable oxygenates are selected such that the normalized relative absorbance of an oxygenated gasoline containing such suitable oxygenate (s) (without the RVP reducing compound) is greater than approximately 0 0.05, preferably greater than about 0.1.

The normalized relative absorbance of a mixture containing an RVP reducing compound and an oxygenated gasoline is defined as the relative absorbance of the mixture when the RVP reducing compound is present in more than approximately 0.5% by weight of the mixture in the mixture. desired concentration of the appropriate oxygenate.

The normalized relative absorbance of an oxygenated gasoline (without an RVP reducing compound) is determined by calculating the relative absorbance when the appropriate oxygenate is present at approximately 1.0% by weight in an oxygenated gasoline.

Preferably, the RVP reducing compound is 2-propanol, 1-butanol, 2-butanol, tert-butanol, 1,3-propanediol, 2,3-butanediol or acetic acid. More preferably, the suitable RVP reducing compound is 1-butanol, 2-butanol or tert-butanol. Other examples of RVP reducing compounds include triethyl amine, octyl tertiary amine.

In another embodiment, the oxygenated gasoline includes a gasoline mixture stock mixture, one or more suitable oxygenates and one or more RVP reducing compounds including 1-butanol. In yet another embodiment, oxygenated gasoline is a gasoline blend stock mixture, one or more suitable oxygenates including ethanol and one or more RVP reducing compounds including 1-butanol.

Some properties of gasoline-oxygenate mixture stock mixtures, RVP reducing compounds, or both do not vary linearly with the amount of each component used. In particular, the related volatility characteristics of these mixtures may differ from the linear proportionality with respect to the quantity of each component used. Figure 3 illustrates how the RVP of a gasoline varies with respect to the volume percentage of ethanol in the fuel. Figure 3 represents the RVP of a unleaded regular gasoline having a base RVP of 42 kPa as a function of volume percent ethanol in that gasoline. As shown in Figure 3, there is a nonlinear relationship between ethanol volume percent and RVP. This nonlinear effect makes it particularly difficult to predict the actual impact on oxygen PVR of gasoline. The actual RVP of an oxygenated gasoline varies with the gasoline mixture stock used, the particular oxygen used, and the specific oxygen concentration in the oxygenated gasoline. Because of this nonlinear variability, the RVP of an oxygenated gasoline is determined empirically. RVP data are typically empirically collected over a range of oxygenate concentrations and a range of gasoline mixture stocks.

The RVP mixture of an oxygenate is typically calculated by measuring the RVP of a fuel before the addition of this oxygenate and after the addition of this oxygenate. The RVP values of the oxygenate mix that can be calculated from these empirical data also exhibit nonlinear behavior with respect to the oxygenate concentration in the particular oxygenated gasoline, making these mixture's RVP values difficult to predict. Because of these nonlinear effects on RVP, the calculated RVP value of the mixture is particular for the concentration of a particular oxygen added to a particular fuel.

The RVP of the RVP reduction compound mixture, when calculated as a function of the volume fraction of this RVP reduction compound, exhibits nonlinear behavior, making it more difficult to predict the RVP of the resulting mixture. The RVP of the mixture of a suitable RVP reducing compound is typically calculated by measuring the RVP of a fuel prior to the addition of that RVP reducing compound and after the addition of that RVP reducing compound. Since RVP reduction compounds exhibit a nonlinear effect on RVP when added to a fuel, the measured RVP of the mixture is particular for the concentration of RVP reduction compound added to the particular fuel.

Surprisingly, we find that the combination of one or more suitable oxygenates and one or more RVP reducing compounds can have a synergistic effect on the RVP value of the gasoline being produced.

In either embodiment, the gasoline blending stock, suitable oxygenates and RVP reducing compounds may be mixed in any order. For example, RVP reducing compounds may be added to a mixture including a suitable gasoline and oxygenate mixture stock. As another example, one or more suitable oxygenates and one or more RVP reducing compounds may be added at several different locations or in multiple phases. For additional examples, the RVP reducing compounds may be added with the appropriate oxygenates, added before the appropriate oxygenates or mixed with the appropriate oxygenates before being added to a gasoline blending stock. In a preferred embodiment, one or more RVP reducing compounds are added to oxygenated gasoline. In another preferred embodiment, one or more suitable oxygenates and one or more RVP reducing compounds are contemporaneously mixed in a gasoline mixture stock.

In either embodiment, more than one suitable oxygenate may be used in place of a single suitable oxygenate, and optionally, more than one RVP reducing compound may be used instead of just one reducing oxygen compound. RVP. Suitable oxygenates and RVP reducing compounds may be added at any point within the distribution chain. For example, a gasoline mixture stock may be transported to a terminal and then suitable oxygenates and RVP reduction compounds may be mixed to the petrol mixture stock, either individually or in combination, at the terminal. . As a further example, a gasoline blending stock, one or more suitable oxygenates and one or more RVP reducing compounds may be combined in a refinery. Other components or additives may be added at any point in the distribution chain.

In yet another embodiment, a reduction method <56 is provided.

. - of the RVP of an oxygenated gasoline. The method can be practiced in a

refinery, terminal, retail location or any other suitable point in the distribution chain. Preferably, the method is practiced on a terminal already designed for blending ethanol or some other oxygenate to a gasoline blending stock or a terminal that can be adapted to accommodate such blending.

According to another embodiment, a gasoline blending stock is blended with ethanol, another suitable oxygenate or combination of suitable oxygenates and an RVP reducing compound φ 10 OR combination of RVP reducing compounds to produce a fuel. oxygenated gasoline having a lower RVP than oxygenated gasoline without the RVP reducing compound.

The particular RVP reducing compound used in any embodiment depends on the particular gasoline mixture stock used and the particular suitable oxygenate used. Preferably, an RVP reducing compound is chosen such that the RVP value of the mixture of the RVP reducing compound is less than the RVP value of the remaining mixture. More preferably, an RVP reducing compound is selected such that the RVP mixture of the RVP reducing compound is at most about 50% of the RVP of the remaining mixture. Alternatively, an RVP reducing compound may be selected such that the RVP of the RVP reducing compound mixture is less than approximately 31 kPa, more preferably less than about 21 kPa, more preferably less than that about 0.0 kPa.

Gasoline regulations set limits on various fuel properties, typically including an upper limit on RVP. These RVP limits may vary by country, region and season. These RVP limits put a constraint on the refinery product that can be used as gasoline. Typically, oxygenates, when mixed in a gasoline mixture stock, will increase the RVP of the resulting mixture. 5Ύ mixing stocks

10

20

*

30

Oxygenate blending gasolines typically have a RVP sufficiently below any applicable upper limits to account for the anticipated effect of oxygenate. This further constrains the refinery product that can be used for gasolines, as lower high volatility fuel components can be used for gasoline blending stocks. This RVP constraint may limit the amount of gasoline available for consumption.

In another embodiment, a method of reducing RVP constraint on the refinery for the production of gasoline blending stock for oxygen blending is provided. RVP constraint in a refinery is lessened because oxygenated gasoline that meets regulatory RVP limits can be produced using a gasoline blend stock that otherwise could not be usable to produce corresponding RVP oxygenated gasoline. . Another embodiment provides a method of reducing the RVP of an oxygenated gasoline such that some oxygenated gasoline that otherwise could not meet regulatory RVP limits could be further mixed to meet these regulatory RVP limits.

In still another embodiment, an oxygenated gasoline is produced by mixing a selected gasoline blend stock, a suitable suitable oxygenate and a selected RVP reducing compound to form an oxygenated gasoline. RVP Reduction Compound reduces the RVP value of hydrogen peroxide. For a particular suitable oxigenate and particular gasoline mixture stock, the use of an RVP reducing compound may allow the use of a higher RVP gasoline mixing range than could typically be used. to produce an oxygenated gasoline that meets applicable RVP regulations.

For a given maximum RVP value, a gasoline mixture stock, a suitable oxygenate and an RVP reduction compound are selected, so that while the RVP value of the gasoline mixture stock mixture and the appropriate oxygenate exceeded the

Maximum RVP value means the RVP value of the oxygenated gasoline mixture containing the gasoline mixture stock, the appropriate oxygenate and the RVP reduction compound is less than or equal to the maximum RVP value.

Without limiting the scope, the following examples illustrate various embodiments of our invention. The specific examples below are examined in the context of a unleaded gasoline fuel that meets the performance characteristics of ASTM D4814, but it will be appreciated by those of skill in the art that the invention is not limited to that fuel and may be used with any gasoline or fuel mixture stock consistent with this description.

Comparative Example A

Several oxygenates were tested for solubility in a regular unleaded gasoline mixture meeting the performance characteristics of ASTM D 4814-01 A. Solubility was determined at 1% by volume of the oxygenate compound and at 10%. % by volume of oxygenate compound. The results are shown in Table III below. TABLE III - Solubility in Unleaded Regular Gasoline

1% Compound 10% Oxygenate 2-propanol S S 1-butanol S S 2-butanol S S 1,3-propanediol I I 2,3-butanediol I Glycerol I I acetic acid S S ethanol S S

S = soluble I = insoluble

From the results shown in Table III above, 1,3-propanediol, 2,3-butanediol and glycerol are insoluble and therefore not suitable oxygenates for the particular unleaded gasoline product.

Comparative Example B

Suitable oxygenates from Comparative Example A were tested to determine the RVP blending value of each compound for blending with the unleaded regular gasoline blending stock of Comparative Example A. The RVP of the gasoline blending stock was 59.5 kPa as measured according to ASTM D5191. Each oxygenate was mixed with the gasoline mixture stock at the indicated volume percentage and the resulting oxygenated gasoline RVP was measured in the same manner. The particular compounds tested and the percentage by volume of materials used are detailed in Table II below. The RVP mixture value of the oxygenates for the indicated volume concentration was then calculated and the results described in Table IV.

TABLE IV - RVP Mixing Values (psi)

Oxygenate 1% 5% 10% 2-propanol 33,63 15,23 11,93 1-butanol 12,63 4,03 5,03 2-butanol 8,63 4,03 5,83 1,3-propanediol 5, 63 4.23 5.63 2,3-butanediol (not tested) 31.03 19.83

As can be seen from the results in Table IV, the RVP values of the mixture do not correlate linearly with the volume percent of these suitable oxygen compounds. Suitable oxygenates exhibit an effect on RVP that is nonlinear with respect to the volume percentage of the oxygenate compound. The results in Table IV also illustrate that increasing the concentration of different oxygenates may have a different effect on the RVP value of the particular oxygenate mixture. Increasing the concentration of each of 1-butanol, 2-butanol and acetic acid from 5% by volume to 10% by volume increased the RVP value of the oxygenate mixture. However, the same concentration increase for each of 2-propanol and ethanol resulted in a decrease in the RVP value of the oxygenate mixture.

Example X

The gasoline mixture stock of Comparative Example A above was mixed with 5% by volume of suitable oxygenates. Ethanol was used as a suitable oxygenate. The PVR of oxygenated gasoline results was measured as 67.2 kPa when measured according to ASTM D5191. Several potential RVP reducing compounds were mixed with oxygenated gasoline to determine if the compounds were soluble and to determine the RVP value of the mixture. The RVP value of the mixture was calculated for 1% by volume and 5% by volume mixtures by measuring the RVP of the resulting gasolines according to ASTM D5191. Results are shown in Table V below.

TABLE V - RVP Mixing Values (psi) 5% Ethanol Unleaded Regular Gasoline 1% 5% 2-propanol -0.25 2.15 1-butanol -11.25 -2.25 2-butanol -6.25 -1.25 1,3-propanediol I 2,3-butanediol -8,25 I glycerol I I Acetic acid -16,25 -4,45

I = Insoluble

Table V illustrates the unpredictable nature of mixing oxygenates and RVP reducing compounds with gasoline mixing stocks. The 1,3-propanediol and glycerol which were insoluble in this particular gasoline mixture stock (see Comparative Example A) were also not soluble in the oxygenated gasoline mixture of this Example and therefore are not RVP reducing compounds for this. particular mix. 2,3-Butanediol was insoluble in this mixture stock of,

ν- "

particular gasolines (see Comparative Example A), however, was and is a 1% by volume RVP reduction compound when mixed with this particular gasoline mixture stock and 5% by volume of ethanol. 2,3 Butanediol was not soluble and is not a 5% by volume RVP reducing compound when mixed with this particular stock of gasoline mixture and 5% by volume ethanol.

The results described in Table V reveal that, surprisingly, some RVP reducing compounds exhibit negative mixed RVP values. These drastically low RVP blend values indicate RVP reducing compounds that have a significant reducing effect on oxygenated gasoline RVP.

Example 2

The gasoline mixture stock of Comparative Example A above was mixed with 10% by volume of a suitable oxygenate. Ethanol was used as a suitable oxygenate. The RVP of the resulting oxygenated gasoline was measured to be 67.2 kPa when measured according to ASTM D5191. Several potential RVP reduction compounds were mixed with the oxygenated gasoline and the RPV value of the mixture was calculated for 1% by volume and 5% by volume mixtures by measuring the RVP of the resulting mixture according to ASTM D5191. Results are shown in Table Vl below. TABLE VI - RVP Mixing Values (psi)

Potential RVP Reduction Compound

2-propanol

1-butanol

2-butanol 1,3-propanediol 2,3-butanediol

glycerol acetic acid

Unleaded Regular Gasoline with 10% Ethanol

1%

-5.25 -8.25 -6.25 -9.25 -3.25 I

-8.25

5%

1.35 0.15 0.15 I

1.95 I

-1.25

I = Insoluble

Table V1 further illustrates the unpredictable nature of the mixture.

of oxlgenates and RVP reduction compounds with mixing stocks

Gasoline 1,3-propanediol was not an RVP reducing compound

suitable for the oxygenated gasoline mixture of Example i but is

a suitable RVP reduction compound at P / 0 by volume for the mixture of oxygenated gasolines of this Example Q

2,3-butanediol was not a suitable 5% RVP reduction compound

by volume in the mixture of oxygenated gasolines of Example 1, but it is a

RVP reduction compound suitable at 5 ° / 0 by volume for the oxygenated gasoline mixture of this example.

The results in Table V1 also reveal that these 1% by volume RVP reduction compounds exhibited negative values for RVP mixing. Even at 3% by volume concentration, RVP reducing compounds exhibited RVP mixture values below 13 8

ESSCS Values of RVP mixture indicate significant RVP reduction effect.

The above examples show how RVP reducing compounds can reduce the RVP of an oxygenated gasoline. In regions that have a maximum RVP Hmite, refineries typically produce gasoline blend stocks significantly below this limit in anticipation of an increase in RVP from the oxygenate mix. As a suitable RVP reduction compound can be used to To reduce the RVP of an oxygenated gasoline, refiners may use gasoline blending stocks to produce oxygenated gasolines that meet the applicable RVP limits where gasoline blending stocks could not otherwise be used to produce oxygenated gasoline. Corresponding RVP.

Claims (18)

"Gasoline Composition and RVP Reduction Methods of an Oxygenated Gasoline and RVP Constriction Over a Gasoline Mixture Stock in the Production of Oxygenated Gasolines Having a Predetermined Maximum RVP Limit" Claims 1. Gasoline composition, characterized in that it comprises: (a) a gasoline mixture stock; (b) a suitable oxygenate wherein a mixture of the gasoline mixture stock and the appropriate oxygenate has an RVP value of at least 47.5 kPa; and (c) an effective amount of an RVP reducing compound wherein the RVP reducing compound has an RVP mixture value of less than 21 kPa. 2. Gasoline composition according to Claim 1, characterized in that the RVP reducing compound has an RVP mixture value of less than about 0.0 kPa. 3. Gasoline composition according to Claim 1, characterized in that the suitable oxygenate is an alcohol. 4. Gasoline composition according to Claim 1, characterized in that the RVP reducing compound is selected from a group consisting of 2-propanol, 1-butanol, 2-butanol, tert-butanol. 1,3-propanediol, 2,3-butanediol, acetic acid and combinations thereof. Gasoline composition according to any one of Claims 1 to 4, characterized in that the suitable oxygenate is present at a maximum of 10% by volume and the RVP reducing compound is present at about 1%. by volume up to about 5% by volume. Gasoline composition according to any one of Claims 1 to 5, characterized in that a mixture of the gasoline, suitable oxygenate and RVP compound mixture stock has a normalized relative absorbance of less than about 0.045. 7. Gasoline composition according to Claim 6, characterized in that a mixture of the gasoline mixture stock and the appropriate oxygenate has a normalized relative absorbance greater than approximately 0.05. 8. The RVP Reduction Method of an Oxygenated Gasoline, characterized in that it comprises mixing a gasoline mixture stock, a suitable oxygenate and an effective amount of an RVP reduction compound in which a mixture of the gasoline mixture stock is mixed. and the suitable oxygenate has an RVP value of at least 47.5 kPa and the RVP reducing compound has an RVP mixture value of less than 21 kPa. 9. The RVP reduction method of an oxygenated gasoline according to claim 8, characterized in that the RVP reduction compound has an RVP mixture value of less than about 0.0 kPa. 10. The RVP reduction method of an oxygenated gasoline according to Claim 8, characterized in that the RVP reducing compound is selected from the group consisting of 2-20 propanol, 1-butanol, 2-butanol, tert-butanol, 1,3-propanediol, 2,3-butanediol, acetic acid and combinations thereof. 11. The RVP reduction method of an oxygenated gasoline according to any one of claims 8-10, characterized in that ethanol is present at most 10% by volume and the RVP reduction compound is present from about 1% by volume to about 5% by volume. 12. An oxygenated gasoline RVP reduction method according to any one of claims 8-11, characterized in that at least one of the suitable oxygenate or RVP reduction compound is mixed at one terminal. An oxygenated gasoline RVP reduction method according to any of Claims 8-12, characterized in that the appropriate oxygenate and RVP reduction compound are contemporaneously mixed with the gasoline mixture stock. 14. An oxygenated gasoline RVP reduction method according to any of claims 8-13, characterized in that the mixture comprising the RVP reducing compound, the gasoline mixture stock and the appropriate oxygenate has a normalized relative absorbance less than about 0.045. 15. The method of reducing the RVP of an Oxygenated Gasoline according to Claim 14, wherein the gasoline blending mixture and the appropriate oxygenate have a normalized relative absorbance greater than or less. 0.05. 16. - RVP Constriction Reduction Method Over a Gasoline Mixture Stock in the Production of Oxygenated Gasolines Having a Predetermined Maximum RVP Limit, characterized in that it comprises mixing a gasoline blend stock, an appropriate oxygenate and an effective amount of RVP reduction compound in which a mixture of the gasoline mixture stock and the appropriate oxygenate has an RVP value greater than the predetermined upper limit of RVP and a mixture of the gasoline mixture stock, the appropriate oxygenate. - and the RVP reduction compound has an RVP value less than or equal to the predetermined maximum RVP limit. 17. A method of reducing the RVP constriction over a gasoline mixture stock in the production of oxygenated gasolines having a predetermined maximum RVP limit according to claim 16, wherein the mixture comprising the reducing compound. PVR and oxygenated gasoline have a standardized relative absorbance of less than about 0.045. A method of reducing the RVP constriction on a gasoline mixture stock in the production of oxygenated gasolines having a predetermined upper limit of RVP according to claim 17, wherein the oxygenated gasoline has an absorbance. relative ratio greater than about 0.05.