CS233100B1 - Gasoline with reduced susceptibility to ice formation in petrol engine carburetors - Google Patents

Abstract

The invention describes gasolines characterized by a reduced susceptibility to ice formation in carburetors of spark-ignition engines and giving reduced concentrations of toxic substances in exhaust gases during combustion. These properties are achieved by adding a mixture of Cg - C^g aliphatic alcohols, diols and ethers, preferably hydrogenated products of oxosynthesis consisting mainly of r- and i-butanol and 2-ethylhexanol

Description

(54) Motor gasolines with reduced susceptibility to ice formation in carburetors of gasoline engines

The invention describes motor gasolines characterized by a reduced susceptibility to ice formation in carburetors of spark-ignition engines and giving reduced concentrations of toxic substances in exhaust gases during combustion. These properties are achieved by adding a mixture of Cg - C^g aliphatic alcohols, diols and ethers, preferably hydrogenated products of oxosynthesis consisting mainly of r- and i-butanol and 2-ethylhexanol.

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The invention relates to gasolines additived with precipitates of i-alkanoic alcohols, ethers and diols resulting from the processing of hydrogenated products of oxosynthesis, thereby reducing the susceptibility of the product to ice formation in carburetors and the toxicity of exhaust gases from engines during their combustion.

Motor gasolines are consistently one of the most important products of oil processing and their properties are constantly being improved. In addition to hydrocarbons of various types, other chemical compounds are already being added to them to improve some of the desired properties.

The most serious of these is the toxicity of exhaust gases produced during the combustion of gasoline, especially the reduction of the CO, CxHy and NOx content. This reduction is achieved in many ways, some of which consist in fuel treatment, others in the combustion in engines. In addition to a number of others, chemical compounds are added to gasolines that reduce their susceptibility to ice formation in carburetors during gasification of gasoline. This reduction reduces the formation of ice in carburetor nozzles at idle, or at high speeds, if the air humidity is high and the temperature is relatively low (below 10 °C). The ice that forms from the co-intake air clogs the fuel and air nozzles, so that a mixture rich in hydrocarbons is burned and CO and CxHy escape with the combustion products.

- 2 233 100 □There are two types of additives known that reduce the mentioned susceptibility to ice formation. They are surfactants that adsorb to the surface of the nozzles and prevent the growth of ice crystals. They are used in concentrations of several hundredths of a percent and are complex chemicals with polar and non-polar parts of the molecule. Alcohols with one or more OH groups in the molecule are simpler. Their action has a different mechanism: they dissolve the formed ice more and release the permeability of the nozzles, thereby ensuring the set ratio between fuel and air. They are used in concentrations hundreds of times higher. The addition of oxygen compounds also allows to increase the amount of moisture in the fuel, thus enabling better engine operation. A number of alcohols and ethers and many other similar oxygen compounds are described. Their availability is usually limited and their production is complicated.

The invention provides a new solution that describes the composition of motor gasolines with increased susceptibility to ice formation in carburetors and thus to reduce the concentration of pollutants in exhaust gases from spark-ignition engines. To a mixture of hydrocarbons boiling in the range of 30 to 210 °C containing 90 to 99.9 wt. % hydrocarbons 8 at least 20 wt. % aromatics C _g - Ο^θ and 0.1 to 0.4 g Pb/l in the form of alkyl ee are added 0.1 to 10 wt. mixtures of aliphatic alcohols and ethers with up to carbons in the molecule. The weight ratio between alcohols and ethers is 200:1 and between alcohols and diols 10:1 to 3:1. The said mixture of alcohols and ethers preferably consists of C _g of alcohols, ethers and diols, which are removed during the redistillation of the product of hydrogenation of oxoaldehydes obtained by the reaction of propylene with a mixture of hydrogen and carbon monoxide. In this mixture, n-butanol, i-butanol and 2-ethylhexanol predominate among the aliphatic alcohols and their concentration is 30 to 90% of the mixture of hydrogenated oxo products.

The definition of the new product shows the advantages of the new composition and the effects during use can be inferred. The good solubility of oxo products in motor gasolines is ensured by the aromatics present. The concentration range includes ranges of higher effect (1 to 10%) and lower effect (0.1 to 0.1.0%).

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The following example characterizes the effect of the invention.

Example

The production of C^ and Cg oxoalcohols results in a mixture of oily fractions (hereinafter referred to as OPS). OPS consist of both light and heavy fractions from the distillation of hydrogenated and Οθ aldehydes and also of oils from wastewater stripping. OPS mainly contain

amount of C^ ethers and other oxygenated organic compounds. A detailed analysis of the individual compounds in the mixture is not known, but oxygenated compounds with straight chains predominate from the individual streams that form it. During ©xosynthesis from propylene, n-butyraldehyde is mainly formed, and after hydrogenation, n-butanol. 2-ethylhexanol formed from the dimer is also relatively unbranched. The effects of the individual compounds on hydrocarbon gasolines are not described in the literature or in the available patents. According to general rules, a slight improvement in the solubility of water against hydrocarbons and testing of antiknock characteristics could be expected (e.g. n-butanol itself has an octane number VM of around 60 units).

The mixture of oxoproducts was added to gasoline, the characteristics of which are given in Table 2. A slightly cloudy solution was obtained, which completely cleared after several hours of standing. The characteristics of the solution were determined in comparison with the original gasoline, and its values, which could have been affected by the admixture, were measured. From the comparison in Table 3, it is clear that the addition of OPS did not have an adverse effect on the purity of the gasoline or on the anti-knock characteristics. This implies that OPS have a higher mixed octane number (around 90) than the majority of the compounds forming them in the presence of alkyl lead compounds. For the OPS sample itself, the measured octane number VM was only 75 with 0.4 g Fb/1 (TEO)

The susceptibility to ice formation in carburetors changed both indirectly in the laboratory according to the amount of water that could be

- 4 233 100 saturate gasoline and sample β with 1% OPS. It was found that the above addition allowed 2.5 times more water to be dissolved in gasoline, which proportionally reduces the susceptibility to ice formation in car carburetors (Table 3). The effect of 1% OPS is almost the same as the addition of 0.5% by volume of synthetic ethyl alcohol, which is about ten times more expensive.

During the operational test in a SKODA car, the number of engine stops decreased by 50% (90% air humidity, 5°C) and the CO and CxHy content in the exhaust gases decreased by 15 to 20% at idle speed. Here too, the OPS were comparable to the addition of 0.5% ethyl alcohol.

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Table 1

Characteristics of OPS (mixed oxo products)

^day 20 0.830 chromatographic analysis (typical): distillation curve °C alcohols C^ 44% by weight beginning 83 alcohols Οθ 13 10% vol. 91 diols Οθ+θΐ2 21 50% vol. 128 ethers 3 90% vol. 223 toluene 1 end of distillation 243/98 other org. substances 15+ ⁾

water 3

+) esters, aldehydes, acetates

Table 2 Characteristics of gasoline for blending ^day 20 0.726 OCVM 90 distillation curve C OCVM 84 beginning 40 Pb g/1 (TEO) 0.36 10% vol. 52 50% vol. 85 95% vol. 177 end of distillation 194/98

Table 3

Effect of 1% OPS addition on the quality of motor gasoline

sample no. 1 2 characteristic clean gasoline gasoline with ^d 20 distillation curve C 0.726 0.727 95% vol. 177 177 end of distillation 189 192 residue mg/100 ml 5.8 ’ 6.0 resin mg/100 ml 1 1 oxidation stability 100°C, min. over 360 over 360 dissolved water ppm wt. 199 534 OCVM with 0.4 g Pb/1 90 89.8

+) when shaken with water 1:1 v/v and after phase separation at 20°C

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-6OBJECT OF THE INVENTION

Claims (3)

1 «Gasoline with reduced susceptibility to ice formation in spark ignition engine carburetors, providing a lower concentration of pollutants during combustion in spark ignition engines by the addition of alcohols, ethers and diols to the hydrocarbon mixture 8, boiling in the range of 30 to 210 ° C; 90 to 99.9 wt. uhlovodlků _(in which at least 20 wt.% C _g to C _1Q aromatic types, and from 0.1 to 10 wt.% mixture of aliphatic alcoholic strength, ethers, and diols of C ₃ to C _g atoms per molecule, the weight ratio of alcohols and ethers are from 200: 1 to 20: 1 and between alcohols and diols from 10: 1 to 3: 1 and from 0.1 to 0.4 g of Pb / l in the form of alkylols. Second gasolines according to claim 1 _(wherein, in said mixture of aliphatic alcohols, ethers and diols as main components _C4 and _Cg alcohols, ethers, and diols which arises during the redistillation oxoaldehydů hydrogenation products obtained by reacting propylene with a mixture of hydrogen and carbon monoxide. 3. The gasoline according to claim 1 ₍ characterized in that the aliphatic alcohols predominate n-butanol, i-butanol and 2-ethylhexanol at a concentration of 30 to 90% per mixture of hydrogenated oxo products. Printed by Moravian Printing Works, plant 12, Leninova 21, Olomouc