WO2009145674A1

WO2009145674A1 - Agent for increasing the octane number of a gasoline automobile fuel

Info

Publication number: WO2009145674A1
Application number: PCT/RU2009/000266
Authority: WO
Inventors: Сергей Дмитриевич ВАРФОЛОМЕЕВ; Григорий Алексеевич НИКИФОРОВ; Виолетта Борисовна ВОЛЬЕВА; Геннадий Григорьевич МАКАРОВ; Лев Ильич ТРУСОВ
Original assignee: Учреждение Российской Академии Наук Институт Биохимической Физики Им. Н.М. Эмануэля Ран (Ибхф Ран)
Priority date: 2008-05-28
Filing date: 2009-05-27
Publication date: 2009-12-03
Also published as: EA201001729A1; US20110154725A1; EP2298851A1; EP2298851A4; EA018090B1; EP2298851B1

Abstract

The invention relates to an agent for increasing the octane number of a gasoline automobile fuel, which agent is a combination of alcohol and a product of reaction between a carbonyl compound and a compound containing at least two hydroxyl groups enabling to form cycles with carbonyl compounds, or is the mixtures of the above mentioned products. In the preferred variant, mono- or oligosaccharides or diatomic, triatomic or polyatomic alcohols are used as the compounds containing at least two hydroxyl groups enabling to form cycles with carbonyl compounds. Pentoses, preferably xylose or arabinose or hexose, substantially glucose, and the mixtures thereof are used as the monosaccharides. Glycols, for example, ethylene glycol are used as diatomic alcohols, glycerin is used as triatomic alcohols and erythritols, for example, pentaerythritol are used as polyatomic alcohols. The compound relating to lower aldehydes or lower ketones, for example, formaldehyde, acetaldehyde, acetone, methylethylketone, diethylketone or cyclohexane are used as a carbonyl compound. The alcohols are in the form of aliphatic alcohols containing up to five carbon atoms, substantially ethanol. The inventive gasoline automobile fuel means a gasoline or an alcohol-gasoline composition.

Description

MEANS FOR INCREASING THE OCTAN NUMBER OF PETROL

CAR FUEL

Technical field

The invention relates to means that increase the octane number of gasoline automobile fuel, including alcohol-containing gasoline automobile fuel, and can be used to improve consumer characteristics of these types of automobile fuel.

State of the art

Progress in the design of automotive engines and increased requirements for environmental performance of automotive fuel determine the ever-increasing need for high-octane gasoline, which ensures the level of toxicity of exhaust gases that meets modern standards. An increase in the share of production of high-octane gasolines is impossible without the widespread use of antiknock additives, which increase the detonation resistance of gasoline fuel.

Currently, oxygenates are used as antiknock agents, including a wide range of oxygen-containing compounds. As a rule, it is difficult to control in composition mixtures containing alcohols, simple and complex alkyl ethers, carbonyl compounds, and products of their interaction. Most of them, under the influence of atmospheric oxygen, are capable of being converted to peroxides, which lead to a decrease in the chemical stability of the fuel and accumulation of carboxylic acids, which cause corrosion of the engine and fuel storage tanks. A serious drawback of methyl tert-butyl ether, which is currently widely used, is its noticeable toxicity and low degradability, which leads to the spread and accumulation of toxic products in soil and water bodies.

It is known that cyclic ketals obtained by the interaction of glycols with carbonyl compounds (1,3-dioxolanes) in the composition of fuel compositions contribute to improving the environmental performance of automobile engines. For example, they reduce the content of particulate matter and toxic products of incomplete combustion in the exhaust gases of diesel engines [US 2004025417, publ. 02/12/2004, FR 2833607, publ. 06/20/2003, AT 311428T, publ. 12/15/2005, JP 7331262, publ. 12/19/1995], improve ecological characteristics of biodiesel [US 2006199970, publ. 09/07/2006, WO

2006084048, publ. 08/10/2006] and gasoline [US 4390345, publ. 06/28/1983, WO 8903242, publ. 04/20/1989].

In the invention protected by patent CA 2530219, publ. 02/03/2005, describes a method for producing oxygenate and its use as an additive that increases the ability of gasoline to ignite and reduces the content of harmful emissions into the atmosphere. Oxygenate is the product of the interaction of glycerol with a carbonyl compound, for example acetone, alkylated with a tertiary olefin. The need for alkylation is associated with the insufficient solubility of 1,3-dioxolanes having a free hydroxyl group in hydrocarbon fuel. This circumstance is a significant limitation for the use of glycerol-based 1,3-dioxolanes as an additive to gasoline.

The above documents do not contain information on the ability of 1,3-dioxolanes to exhibit antiknock properties with respect to gasoline.

The alkylation of glycerol with isobutylene is described in order to obtain glycerol polyalkyl esters as an additive to gasoline [DE 4445635, publ. 06.27.1996, EP 0718270, publ. 06/26/1996]. If acetone is used as the solvent, the reaction mixture is a mixture of tert-butyl esters of glycerol with varying degrees of substitution mixed with free glycerol, and also additionally contains cyclic ketal - 2,2-dimethyl-4-tert-butoxymethyl-l, 3-dioxolane and an admixture of 2,2-dimethyl-4-hydroxymethyl-l, 3-dioxolane containing free hydroxyl. It is shown that these reaction mixtures, when added to gasoline, exhibit the properties of effective octane enhancing additives. To ensure phase compatibility, it is necessary to alkylate the free hydroxyl groups of glycerol, which is associated with additional labor and energy costs. However, the presence of monoalkylated glycerol in the mixture, as well as impurities of free glycerol and unalkylated 4-hydroxymethyl-l, 3-dioxolane, increases the likelihood of delamination of the gasoline composition comprising this additive. The complex variable composition of the additive, depending on the reaction conditions in a multicomponent system, causes the variability and unpredictability of its antiknock properties.

Known multifunctional additive for gasoline based on ethyl alcohol, providing an increase in octane number (OCh), lowering the temperature turbidity, reduction of toxicity of emissions, containing, along with ethyl alcohol, N-methylaniline, acetic aldehyde, crotonic aldehyde, ethyl ether, multifunctional additive AUTOMAT [RU 2148077, publ. 04/27/2000].

Known additive to gasoline based on ethyl alcohol [RU 2068871, Cl, publ. 10.11.1996], containing as a stabilizer co-solvent, which is a waste of the hydrolysis production of ethyl alcohol from wood raw materials, the so-called "Aldehyde-ether-alcohol fraction" in the amount of 8 to 80 mass. % The introduction of this additive in gasoline in an amount of 2 to 20 mass. % allows you to increase the octane number and get automotive fuel, not stratified at low temperatures. The hydrolysis production waste included in the additive is a mixture of C ₃ -C ₅ aliphatic alcohols, methyl and ethyl alcohols and formic and acetic acids, furfural and other organic compounds.

Known additive for gasoline based on stabilized ethyl alcohol, including N-methylaniline, ferrocene and / or its derivatives, and to stabilize ethyl alcohol use lower aliphatic alcohols, esters or aldehyde-alcohol fraction obtained from waste products from the production of ethyl alcohol from wood raw materials [RU 2129141, publ. 04/20/1999].

The objective of the present invention is to provide a universal tool for gasoline automobile fuel with a higher octane-increasing ability, which can easily be obtained from available chemical products or from waste or intermediate products of processing carbohydrate-containing raw materials.

Disclosure of invention

As a result of the studies, it was found that the combination of alcohol with the product of the interaction of the carbonyl compound with a compound containing at least two hydroxy groups, which allow the formation of cycles with carbonyl compounds, or mixtures of these products, allows to increase the octane number of gasoline much more efficiently than each of these components individually, showing a synergistic effect.

In addition, the problem of phase incompatibility with gasoline fuel, which arises due to the presence of a free hydroxyl group in the reaction products of a carbonyl compound with a compound containing at least two hydroxy groups allowing the formation of rings with carbonyl compounds.

Thus, the aforementioned problem is solved in that, as a means for increasing the octane number of gasoline automobile fuel, a combination of alcohol and a reaction product of a carbonyl compound with a compound containing at least two hydroxy groups allowing the formation of cycles with carbonyl compounds, or mixtures of these products.

Preferably, saccharides or dihydric, trihydric and polyhydric alcohols are used as compounds containing at least two hydroxy groups allowing the formation of rings with carbonyl compounds.

Preferably, said saccharides are monosaccharides, however, oligosaccharides that are converted into monosaccharides by reaction with carbonyl compounds can also be used.

As monosaccharides, pentoses or hexoses can be used, as well as mixtures thereof, which can be obtained by mixing individual monosaccharides, or in technological processes for processing carbohydrate-containing raw materials.

As pentoses, xylose or arabinose is mainly used, and glucose is used as hexose.

Glycols, for example, ethylene glycol, are used as dihydric alcohols, glycerin is used as trihydric alcohols, erythrites, for example, pentaerythritol, are used as polyhydric alcohols.

As the carbonyl compound, a compound relating to lower aldehydes or lower ketones is used, for example, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone.

Aliphatic alcohols containing up to five carbon atoms, mainly ethanol, are used as alcohol.

Gasoline automobile fuel in the context of the present invention means gasoline or in the alcohol-gasoline composition.

The presence in the inventive tool for increasing the octane number of gasoline automobile fuel alcohol in combination with the reaction products of a carbonyl compound with a compound containing at least two hydroxy groups capable of forming cycles with carbonyl compounds, or mixtures of these products is an essential condition necessary to ensure high octane-raising ability. So, alcohols themselves are not sufficiently effective antiknock: according to our data, as well as according to [US 4541836, publ. September 17, 1985], the introduction of anhydrous ethyl alcohol into gasoline in an amount up to 10% increases the octane number of fuel by 2-4 units.

The study of the octane enhancing ability of cyclic ketals of monosaccharides, which is one example of the product of the interaction of a carbonyl compound with a compound containing at least two hydroxy groups, allowing the formation of cycles with carbonyl compounds, on a standard model hydrocarbon mixture showed that pure ketals formed by monosaccharides and acetone practically do not increase the octane number of hydrocarbons. For example, the introduction of ketal acetone and arabinose into the model mixture of isooctane - n-heptane (4: 1) in an amount of about 8 weight. % practically does not affect its octane number. A similar picture holds for ketals based on trihydric alcohols: at a 10% content in gasoline of the cyclic ketal of glycerol and acetone, the increase in the octane number is 1.4 units, for the ketal of glycerol and methyl ethyl ketone - 0.9 units, for other ketals the increase in the octane number does not exceed the measurement error.

The addition of ethanol to the system leads to an increase in the octane number of the model mixture: by 10.4 units. in the case of ketal arabinose and acetone (weight ratio ketal: ethanol 0.75: 1.0), by 13.1 units. - in the case of ketal xylose and acetone (weight ratio ketal: ethanol 0.75: 1.0), by 12.6 units. - in the case of ketal glycerol and acetone (weight ratio ketal: ethanol 1.0: 1.0). This indicates the synergistic effect of the pair "alcohol - cyclic ketal", providing high octane-increasing ability of the claimed funds.

Of particular note is the fact that the order of introduction of the alcohol and the product of the interaction of the carbonyl compound with the compound containing at least two hydroxy groups that allow the formation of cycles with carbonyl compounds does not affect the achievement of the octane-raising effect of the claimed agent. The only significant thing is the presence of a combination of these components, regardless of whether they were mixed before being introduced into automotive gasoline fuel or whether this mixing occurred in automobile gasoline fuel itself. In this regard, the tool exhibits octane enhancing effect both in the case of gasoline and in the case of alcohol-containing gasoline compositions.

The presence of alcohol in the additive eliminates the problem of phase compatibility with gasoline of cyclic ketals and acetals having free hydroxyl groups. In the presence of alcohol, these compounds, regardless of the nature of the alkyl substituents, form a single-phase stable system with gasoline.

It is known that cyclic ketals based on glycerol increase the phase stability of alcohol-containing gasoline [GB 811406, publ. 04/02/1959, US 4390344, publ. 06/28/1983]. This fully applies to cyclic ketals based on monosaccharides. For example, the addition of cyclic ketals or mixtures of cyclic ketals based on monosaccharides in an amount of 3 to 8 weight. % to a two-phase system containing gasoline and 10 vol.% of watered ethanol, leads to a homogeneous system. Thus, the presence of these ketals stabilizes the phase uniformity of gasoline, making it possible to increase the threshold concentration of water, beyond which it is expelled into a separate phase. Therefore, to compound hydrocarbon and alcohol, it becomes possible to use not only dry ethanol, but also a rectified product containing 3.6% water and waterlogged alcohol containing up to 5% water.

Embodiments of the invention

The product of the interaction of a carbonyl compound with a compound containing at least two hydroxy groups, allowing the formation of cycles with carbonyl compounds, necessary for the implementation of the invention can be obtained as follows.

One group of compounds containing at least two hydroxy groups allowing the formation of rings with carbonyl compounds are saccharides.

As saccharides, both individual monosaccharides and mixtures thereof, for example, the pentose fraction obtained as described below, from plant materials are used.

As a source of a mixture of saccharides to obtain products used in the composition of the claimed funds, it is advisable to use cheap agricultural waste that does not have food and feed value, for example, cereal straw and other grain processing waste used to produce bioethanol. The feedstock is subjected to pre-treatment, including grinding with the formation of particles with a size of 2.0 - 0.5 mm, the chemical separation of related components (waxes, fats, terpenes, soluble pectins, proteins, lignins, inorganic substances) by extraction with ethanol-benzene, followed by acid hydrolysis and separation of the carbohydrate fraction by known methods [Yu.I. Holtin, “Technology of hydrolysis production)), M., Forestry, 1989]. The result is a mixture of monosaccharides in an amount of 25-30% of the weight of the feedstock, which is the so-called “pentose fraction)), containing mainly xylose and arabinose mixed with glucose.

In the table. 1 shows the composition of the products of pre-treatment and hydrolysis of raw materials of various kinds.

Table 1

The composition of the products of pre-treatment and hydrolysis of raw materials of various kinds.

Products are obtained by the interaction of these substances with carbonyl compounds under conditions of acid catalysis with the removal of water formed by one of the known methods [Under. ed. N.K. Kochetkova “Methods of the chemistry of carbohydrates)), Mir, M., 1967, p. 165]. To separate from side products poorly soluble in hydrocarbons, the reaction mixture is extracted with benzene or another suitable solvent, the extract is evaporated and used in the composition to increase the octane number. Di- and oligosaccharides that hydrolyze in the course of reaction with carbonyl compounds and also produce mixtures of the corresponding products can also be used. Lower aldehydes or ketones can be used as carbonyl compounds. In the first case, the reaction is an acetalization reaction, and the reaction products are cyclic acetals, and in the second case, the reaction is a ketalization reaction, and the reaction products are cyclic ketals. .

Since these monosaccharides contain at least two pairs of hydroxy groups capable of forming cycles when reacted with carbonyl compounds, derivatives containing one or two cyclic groups per one monosaccharide molecule can be obtained. In order to obtain the maximum octane enhancing effect, the reaction is carried out in the presence of an excess of carbonyl compound, which provides the maximum conversion depth with the formation of products containing two oxygen-containing cycles. As an example, in table. 2 shows the physicochemical characteristics of the products of the interaction of saccharides (individual monosaccharides, disaccharides, mixtures of monosaccharides) with acetone.

table 2

Physico-chemical characteristics of cyclic products obtained by the interaction of monosaccharides and acetone

Given in the table. 2 cyclic diketals of monosaccharides and acetone are solid at room temperature or viscous liquid products soluble in alcohol, their mixtures with alcohol are soluble in gasoline.

When using a pentose fraction isolated from a hydrolyzate of a carbohydrate-containing raw material, the yield of a mixture of cyclic diketals is 57–70%, depending on which raw material the pentose fraction is obtained from. Dried stalks of Mescanthus are a promising raw material for obtaining the claimed additives, since they are richest in pentoses and provide the highest yield of a mixture of cyclic diketals. In the table. Figure 3 shows the weight composition of the mixture obtained by ketalization with acetone of the pentose fraction isolated from dry stalks of mescanthus.

Table 3

The composition of the mixture obtained by ketalization with acetone of the pentose fraction isolated from the dry stems of mescanthus

Monosaccharide ketalization products are non-toxic. In experiments on laboratory mice of the SHK line (Stolbovaya nursery), it was shown that preparations of cyclic diketals based on arabinose and glucose in olive oil, administered to animals in doses from 100 to 6000 mg / kg, are well tolerated upon observation for 30 days animals and do not cause any changes in their condition.

Cyclic diketals of monosaccharides are stable in the composition for increasing the octane number, while they are capable of hydrolytic cleavage with the formation of non-toxic products, which is their significant advantage over toxic, non-degradable alkyl esters, in particular methyl tert-butyl ether, which is widely used in oxygenates . Another group of compounds containing at least two hydroxy groups allowing the formation of rings with carbonyl compounds are di-, tri- and polyhydric alcohols.

The products of the interaction of di-, tri- and polyhydric alcohols with carbonyl compounds — cyclic acetals and ketals — are obtained by a single-stage synthesis from available large-capacity industrial products (glycerin, ethylene glycol, pentaerythritol, paraform, acetaldehyde, acetone, etc.) by known methods under conditions acid catalysis with azeotropic distillation of reaction water [A. Thorne, “Combined Methods of Organic Chemistry, vol. 2, M.: Mir, 1981, p. 20]. In the case when the azeotropic distillation of the reaction water is carried out in the presence of methyl ethyl ketone, the reaction product is a mixture of the corresponding cyclic compounds, which can also be used as part of the inventive octane-raising agent.

Cyclic acetals and ketals of di- and trihydric alcohols are liquids that are highly soluble in alcohol, their mixtures with alcohol are highly soluble in gasoline.

Another example of cyclic acetal, which can be used in the composition of the claimed means to increase the octane number, is the pentaerythritol formal, which is the product of the interaction of pentaerythritol with formaldehyde. Pentaerythritol is an available large-capacity chemical product and is a branched polyhydric alcohol containing four hydroxy groups that pairwise react with formaldehyde to form two dioxane rings. Pentaerythritolformal is a solid soluble in alcohol.

Octane-increasing ability of the claimed funds, investigated on n-heptane and model hydrocarbon mixtures of isooctane - n-heptane 1: 1 and 4: 1. Measurements are carried out by the standard method in accordance with GOST 8226-82 “Fuel for engines. The research method for determining the octane number ”(method 1), and the express method (method 2), giving results close to standard methods. The express method uses a gas detonation resistance meter Oktanometr OK-2m (PLUS PLADIO manufacturer), used to quickly determine the octane number of gasolines during process control manufacturing, during research work, while taking gasoline by the consumer. The principle of operation of the 0K-2m Octanometer is based on measuring the reaction parameters of the cold flame oxidation of gasolines with subsequent determination of the detonation resistance from them, equivalent to motor and research methods. In this case, the parameters of the reactions of cold flame oxidation of control fuels made according to GOST 511-92 are used as reference standards.

Tables 4 and 5 show examples illustrating the octane enhancing effect of agents containing various individual cyclic ketals and acetals and various aliphatic alcohols with respect to n-heptane and to model isooctane-n-heptane hydrocarbon mixtures.

Table 4

Octane enhancing ability of cyclic ketal glycerol and acetone in the presence of alcohols of various structures with respect to n-heptane

Table 5

Octane-increasing ability of agents, including various individual cyclic acetals and ketals and various alcohols, in relation to model mixtures of isooctane - n-heptane of various compositions

The data in tables 4 and 5 confirm the well-known fact that the lower the octane number of the initial hydrocarbon mixture, the greater the effect of the introduction of an octane-raising agent. The magnitude of the octane enhancing effect in the studied concentration range is approximately proportional to the weight content of the agent in the mixture. In addition, these data show that the synergistic octane-enhancing effect of cyclic ketals and acetals is manifested in the presence of alcohols of various structures.

Table 6 shows the octane-enhancing ability of ethanol-containing products in combination with mixtures of cyclic ketals of various structures. Table 6

Octane-increasing ability of ethanol-containing agents, including mixtures of cyclic ketals, in relation to the model hydrocarbon mixture isooctane-n-heptane 4: 1 (data obtained by method 1)

For a number of octane enhancing agents, tests were carried out on gasoline and straight-run gasoline fraction.

Table 7 shows examples showing the octane enhancing effect of the claimed monosaccharide-based products in relation to motor gasoline. Table 7

Octane-increasing ability of products containing cyclic ketals and ethanol in relation to motor gasoline with 04 = 77.6 (data obtained by method 1)

the results were obtained on commercial gasoline AI-80 Table 8 shows the test results of several options for fuel compositions, including straight-run gasoline fraction and octane-raising agents containing cyclic ketals based on glycerol and ethylene glycol and ethanol.

Table 8

Test results of various variants of octane enhancing agents containing cyclic ketals based on glycerol and ethylene glycol and ethanol in the gasoline fraction.

If a ready-made alcohol-gasoline composition (SBC) is used as automobile gasoline fuel, then a cyclic ketal or a mixture of cyclic ketals is added in the required amount directly to the alcohol-gasoline composition.

The data in tables 9 and 10 show the effect of cyclic ketals on the octane characteristics of SBC.

Table 9

The effect of cyclic diketals based on monosaccharides on the octane characteristics of SBC containing 10 vol. % ethanol

Table 10.

The influence of cyclic ketals based on ethylene glycol and glycerol on the change in the octane number of SBC

The phase stability of alcohol-gasoline compositions quantitatively characterized by the stratification temperature is measured in accordance with GOST 5066-91 on a KRIO VT low-temperature thermostat (manufacturer TERMEX-P). The data in Table 11 shows the effect of cyclic ketals based on glycerol and ethylene glycol on the phase stability of alcohol-gasoline compositions at low temperatures.

Table 11

The stabilizing ability of cyclic ketals in relation to SBC

Thus, the results show that the claimed means exhibit a pronounced octane-enhancing and stabilizing effect with respect to alcohol-containing gasoline fuel.

Studies on model systems have shown that the octane enhancing agents of the invention have a low tendency to gum formation. So, under the norm established by GOST, allowing the actual resin content to 6.0 mg / 100 cm of fuel, the actual gumming of the agent containing 10% cyclic ketal of acetone and glycerol was 0.6 mg / 100 cm of fuel, and at a content of 30% - 3 , 0 mg / SOS. Given the known influence of these funds on reducing the content of harmful products in exhaust gases, it can be argued that they can have a comprehensive positive effect on engine performance.

Claims

CLAIM

1. A means for increasing the octane number of gasoline automobile fuel, which is a combination of alcohol and the product of the interaction of a carbonyl compound with a compound containing at least two hydroxy groups, allowing the formation of cycles with carbonyl compounds, or mixtures of these products.

2. The tool according to claim 1, characterized in that saccharides or dihydric alcohols or trihydric alcohols or polyhydric alcohols are used as a compound containing at least two hydroxy groups allowing to form rings with carbonyl compounds.

3. The tool according to claim 2, characterized in that monosaccharides and oligosaccharides are used as saccharides.

4. The tool according to claim 3, characterized in that pentoses, preferably xylose or arabinose, or hexoses, preferably glucose, and also mixtures thereof are used as monosaccharides.

5. The tool according to claim 2, characterized in that glycols, for example, ethylene glycol, are used as dihydric alcohols.

6. The tool according to p. 2, characterized in that glycerol is used as trihydric alcohols.

7. The tool according to p. 2, characterized in that as polyhydric alcohols use erythritol, for example, pentaerythritol.

8. The tool according to claim 1, characterized in that the carbonyl compound is a compound related to lower aldehydes or lower ketones, preferably formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, diethyl ketone or cyclohexanone.

9. The tool according to claim 1, characterized in that aliphatic alcohols containing up to five carbon atoms, mainly ethanol, are used as the alcohol.

10. The tool according to claim 1, characterized in that gasoline is used as gasoline automobile fuel.

11. The tool according to claim 1, characterized in that an alcohol-gasoline composition is used as a gasoline automobile fuel.