PL243340B1 - Additive for diesel fuel, especially containing methyl esters of higher fatty acids - Google Patents

Abstract

The subject of the application is an enriching additive for diesel fuel, especially containing methyl esters of higher fatty acids, which consists of dicyclopentadienyl iron in the amount of 20 to 30% by weight, isooctyldicyclopentadienyl iron in the amount of 20 to 30% by weight, an aromatic solvent obtained from the distillation of the reforming product catalytic gasoline with a boiling point range of 160 - 215°C and a density at 15°C of 0.873 - 0.892g/cm³ and a detergent being a product of polyisobutylene synthesis with a molecular weight of about 1000g/mol with fatty acid methyl esters (FAME) and maleic anhydride (MA) at the temperature of 140°C, in a slight excess of FAME and MA in relation to the stoichiometry, and then acylation with the obtained polyethylene polyamine intermediate in a ratio close to the stoichiometric ratio, at the temperature of 160 - 180°C in the amount of 15 up to 35% by weight.

Description

The subject of the invention is an enriching additive for diesel fuel, especially containing methyl esters of higher fatty acids. The invention relates to an additive to fuels for self-ignition engines - diesel oils of petroleum origin and diesel oils composed with methyl esters of higher fatty acids.

Modern compression-ignition engines, in principle, function similarly to all such internal combustion engines. A portion of fuel in a single or several doses is introduced under high pressure into the combustion chamber filled with compressed, hot air. The fuel introduced through the injector nozzle is atomized and in this form penetrates the air in the combustion chamber. The stream of sprayed diesel fuel evaporates in contact with hot air, its vapors mix with the air and begin to undergo oxidation reactions. If the mixture is under a sufficiently high pressure and temperature, after a certain reaction time, the fuel ignites itself (J. B. Heywood Internal combustion engines fundamentals, McGraw-Hill Inc. 1988). As a result of combustion, gases and heat are released, which causes an increase in pressure and further evaporation of the remaining part of the injected fuel. Each subsequent part of the diesel dose undergoes the same transformations, i.e. atomization, evaporation, mixing with air, oxidation and combustion, which causes a further increase in pressure in the combustion chamber. Thus, it can be concluded that fuel combustion in a compression ignition engine is a multi-stage, complex process of physical and chemical transformations.

The effective operation of a diesel engine requires the simultaneous fulfillment of many conditions, such as: a properly designed combustion chamber, an efficient fuel supply system, proper engine control and high-quality fuel - diesel oil. The fuel should ensure the achievement of the designed power of the drive unit, the possibly low content of toxic components in the combustion products and long-term, economic operation of the engine (W.W. Pulkrabek Engineering Fundamentals of the Internal Combustion Engine, Prentice Hall, New Jersey).

High-quality diesel fuel designed to power modern high-speed engines must meet a whole range of requirements. The basic parameter of fuel quality, determining the smooth operation of the engine, is the cetane number, the value of which results from the chemical composition of the diesel fuel. Other important features are: high chemical stability in the conditions of fuel transport and storage, and the ability to keep the fuel supply system and combustion chamber clean. In addition, good lubricating properties, necessary to protect against wear of precision high-pressure pumps, and varied, adequate to the season, low-temperature properties. From the point of view of the quality of the fuel stream sprayed in the combustion chamber, fuel viscosity and surface tension are important. These requirements are met by mixtures of refined petroleum fractions, synthetic hydrocarbon components, oxygen components and necessary enriching additives.

Chemists, technologists of petroleum products and tribologists strive to improve fuels in order to obtain better and better engine operation as well as lower emission of toxic components in engine exhaust gases. Practice shows that the effective, full combustion of diesel fuel determines the low content of toxins, primarily products of incomplete fuel combustion. In industrial practice, there are basically two ways to improve the quality of motor fuels, including diesel oil.

The first direction is the change in the quality of the main components of the fuel, and so: the total sulfur content is reduced by deepening the refining processes of diesel oil fractions, derived both from the distillation of crude oil and from thermal and catalytic decomposition processes (visbreaking, cracking, coking, hydrocracking of gudron), reducing content of aromatic hydrocarbons by deep hydrogenation (hydrotreating) of diesel oil fractions, hydrocracking of oil raw materials - vacuum distillates and deasphaltisates from crude oil separation. As components from renewable raw materials, methyl esters of higher fatty acids, hydrogenated and processed vegetable oils and components obtained from waste raw materials as well as components obtained from thermolysis of waste plastics are used. Hydrocarbon fractions obtained as a result of the Fischer-Tropsch synthesis from syngas obtained from the gasification of coal, petroleum residues and biomass are also used as components of diesel oils.

The changes in the quality and technology of diesel oil components are complemented by the improvement of quality and the introduction of new enriching additives. According to the legal definition, additives are substances introduced into the fuel in a concentration not exceeding 0.2% m/m; substances or mixtures added in larger amounts are fuel components. Diesel fuel additives are used to strengthen certain physicochemical and operational properties of the fuel or to impart completely new functional characteristics. The most important properties of fuel for compression-ignition engines, which determine the combustion process, include: a sufficiently high cetane number and detergent properties. Precise fuel dosing, complete evaporation and complete combustion result in high efficiency of conversion of fuel chemical energy into work, as well as no or minimal concentration of toxic exhaust components, such as: carbon monoxide, unburnt hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs), and above all - solid particles. The latter are created by mineral impurities and mainly by soot particles. The harmfulness of particulate matter up to 10 μm (PM 10) and even more so 2.5 μm (PM 2.5) results from the possibility of penetrating organisms through the lungs and introducing carcinogenic polycyclic aromatic hydrocarbons into the blood, which adsorb on the surface of the particles. In view of the proven impact of particulate matter emissions on human health, environmental protection authorities, health services, administrative authorities and social organizations demand profound changes to reduce the harmfulness of diesel engines or even eliminate them from use.

In response to legitimate demands to reduce the adverse impact of diesel engines on the environment and human health, there are changes in the design of engines, the method of fuel supply and exhaust gas purification or filtration. The quality of the fuel has a great influence on the reduction of the emission of toxic exhaust components from the diesel engine. Detergent additives remove deposits and keep the engine's fuel supply system clean, which has a decisive influence on the volume of the fuel dose directed to combustion, on the characteristics of the injected fuel stream - the distribution of the size of the dots, and, consequently, on full evaporation and complete combustion of the fuel in excess air. The method of combustion and pressure build-up in the cylinder depends mainly on the chemical composition of the diesel fuel, which determines its cetane number. Natural, resulting from the chemical composition of the fuel, the cetane number can be increased to a certain extent by introducing an appropriate additive, the so-called cetane additive. However, even gradual combustion with an appropriate auto-ignition delay does not guarantee complete combustion. Combustion processes in the diesel engine chamber occur in many stages, which always results in some emission of unburned components. These are unburned hydrocarbons, including the most difficult to burn PAHs and carbon particles - soot. The analysis of the catalytic effect of various chemical compounds on the combustion of diesel oil components leads to justification for the use of various types of additives, including metal compounds with variable valence, such as: manganese, cobalt or iron. And although the addition of these types of substances, which themselves do not undergo ashless combustion, may result in contamination of the fuel dosing system, and above all - the combustion chamber and then the exhaust system, the benefits of their use far outweigh the possible risks. For example, on diesel particulate filters that collect soot together with PAHs, after reaching a sufficiently high exhaust gas temperature or forcing it by feeding excess fuel and transferring combustion outside the combustion chamber, carbon (soot) and PAHs are burned out, which reduces the emission of these toxins from vehicle. Appropriate substances, including iron compounds, are added to the fuel in order to reduce the temperature at which deposits burn on the filters.

There are many different solutions, including patented ones. For example, the European patent EP2129751A1(B1) describes a highly concentrated iron-containing polymer for dissolving in fuel, with great suitability for regeneration of Fuel Borne Catalyst (FBC) filters. Likewise, the platinum-containing multi-component diesel combustion and oxidation catalyst (FBC) known from WO2006078762A1 reduces emissions.

In order to improve diesel fuel combustion processes, additives have been tested and used for many years, which are to catalyze individual stages of the process. The first developed and patented solutions concerned the introduction of small amounts of metal compounds soluble in hydrocarbons, such as: manganese, cobalt, lead, cerium, chromium, along with the fuel. Patent CN101148618A describes a diesel fuel additive containing cerium and manganese compounds; another solution recommends the use of a platinum group additive in a concentration of up to 1 ppm in diesel engine fuel - publication WO9628524A1. Modulation of the fuel combustion rate using nanoparticles of oxides, hydroxides, hydrates or carbonates Al, Sb, Mg, Fe, Mo, Zn, Sn, B, Bi, Ca, Li, Na, K, Ba, Mn, Cu, Cd, Co, Ni, Cr, Ti, Ce and V are disclosed in patent CN102224223A.

For over twenty years, in the area of additives catalysing the combustion process on the surface of the particulate filter (soot combustion), but also in the volume of the combustion chamber, iron compounds, including dicyclopentadienyl iron and its derivatives, have dominated. One of the older solutions, disclosed in the application GB1175203A, describes a concentrate of iron compounds, such as dicyclopentadienyl iron, iron phenate and cresolate, containing a total of about 100 g of iron per liter of additive which is diluted in the fuel. Patents CN105503964 (B) and CN108912181A (B) describe the use and preparation of an additive that catalyzes the combustion of diesel oil and other liquid petroleum fuels due to the content of dicyclopentadienyl iron and its alkyl derivatives, for example 4-octyl- and 3-octyl-dicyclopentadienyl iron. The use of a solution of dicyclopentadienyl iron in xylene and methanol as a co-solvent is described in patent CN107987894A. Due to the limited solubility of dicyclopentadienyl iron in petroleum fuels and hydrocarbon solvents, recent patents describe a number of methods for obtaining and isolating alkyl derivatives of this compound, which significantly increase the solubility (concentration) of iron in additive concentrates. An example may be application KR20150059407A describing the method of synthesis and the method of isolating mono alkyl derivatives of dicyclopentadienyl iron.

Numerous solutions patented in recent years concern the use of additives that catalyze combustion, but contain alcohols, also as components, and emulsion fuels, most often in the form of microemulsions with different water content. However, it is a separate branch of technology covering the production and application of emulsion fuels.

Due to the extremely complex mechanism of diesel oil combustion in a compression ignition engine, there are constantly perceived shortcomings both in engine operation and in terms of emissions of substances harmful to health and the environment. The widespread introduction of FAME (Fatty Acid Methyl Esters) as a fuel component additionally complicates the individual stages of diesel oil combustion in a compression-ignition engine. FAMEs have a much higher viscosity compared to petroleum diesel, which affects the size of the droplets of the fuel stream injected into the combustion chamber. The lower thermo-oxidative stability of FAME results in the earlier appearance of aging products, including particulate matter, in diesel fuel. They form deposits in the fuel supply systems of diesel engines and contribute to incomplete combustion and thus increase the emission of toxins. Such fuels, especially those used in modern engines with high-pressure diesel fuel injection, create additional problems for both engine designers and motor fuel producers.

Unexpectedly, it turned out that there are possibilities to improve combustion efficiency and thus - exhaust gas purity and reduce fuel consumption through the use of a comprehensive combustion catalysing additive used in a minimum proportion to diesel oil with biocomponent (B7) as well as to biodiesel as self fuel diesel engine (B100).

The multifunctional additive according to the invention consists of dicyclopentadienyl iron and its alkyl derivative isooctyldicyclopentadienyl iron as a catalyst for the combustion of hydrocarbons, soot and carbon monoxide, a polymeric surfactant as a detergent with the ability to wash resinous substances, asphaltenes and sodium soaps and zinc higher fatty acids from metal surfaces and solubilize them in fuel and solvent. The detergent used in the composition of the additive, marked as DETERG, is a product of the synthesis of polyisobutylene (PIB) with a molecular weight of about 1000 g/mol with fatty acid methyl esters (FAME) and male anhydride (MA) at 140°C, in a slight excess of FAME and MA in relation to stoichiometry, and then acylation with the obtained polyethylene polyamine intermediate in a ratio close to stoichiometric, at a temperature of 160-180°C. The product is effective in keeping clean and cleaning the elements of the fuel supply system of a diesel engine from resin compounds, asphaltene and soaps of higher fatty acids. The iron compounds contained in the additive composition show a much higher efficiency of burning soot and solid organic substances in the presence of an effective detergent, which has the characteristics of a synergy effect. This is particularly evident in relation to FAME as biodiesel, where a four-fold reduction in particulate emissions is observed. The additive contains DETERG detergent in the amount of 15 to 35% by weight, dicyclopentadienyl iron in the amount of 20 to 30% by weight, isooctyldicyclopentadienyl iron in the amount of 20 to 30% by weight and an aromatic solvent obtained from the distillation of the product of the catalytic reforming of gasolines with a boiling point 160-215°C and density at 15°C 0.873-0.892 g/ ^cm3 . Preferably, one of the two fractions from the distillation of the catalytic reforming product of gasolines is used as a solvent - with a boiling range of 160-180°C and a density at 15°C of 0.873 g/ ^cm3 or with a boiling range of 180-215°C and a density at temperature of 15°C 0.892 g/cm ³ The additive is used for diesel oil type B7 (7% by volume of FAME in a mixture with diesel oil of petroleum origin) or B100 (100% FAME) in a concentration of 2 to 1500 ppm m/m, preferably from 5 to 750 ppm m/m, most preferably 10 to 250 ppm m/m.

It was found that the composition of the additive has a synergistic effect in relation to the properties of the individual components, as evidenced by the following examples.

Example 1

B7 fuel, meeting the PN-EN 590+A1:2017-06 standard, was tested to determine the performance characteristics of the Perkins 1104C-44T engine. As part of the test, concentrations of toxic exhaust components were measured, on the basis of which specific emissions of toxic exhaust components were obtained in accordance with the ISO 8178 standard. The engine qualified for category C1 of the ISO 8178 standard and was tested in accordance with the 11-phase test. The concentrations of CO2, CO, unburnt hydrocarbons (THC) and nitrogen oxides NOX in the engine exhaust gases were measured using the CEBII exhaust gas analyzer by AVL. A 415 PM opacimeter by AVL was used to measure particulate matter. For comparison, an identical fuel supplemented with the additive according to the invention was tested in the proportion of 2 g of the additive per 10 kg of fuel (200 ppm m/m). A mixture of: dicyclopentadienyl iron 25% by weight, isooctyldicyclopentadienyl iron 25% by weight, detergent DETERG 30% by weight and an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines, with a boiling point range of 160-180°C and a density of 0.873 g/ cm ³ in the amount of 20% by weight. The concentration of unburned hydrocarbons (THC) in engine exhaust is significantly reduced; at 1400 revolutions per minute, corresponding to the maximum engine torque, the additive reduces the concentration of THC by 40%. The calculated specific emissions from the fuel enriched with the additive according to the invention are reduced compared to the emissions during combustion of the B7 fuel: carbon monoxide by 11%, unburned hydrocarbons by 17%, nitrogen oxides by 3% and particulate matter by 7%.

Example 2

In the manner as in Example 1, the combustion of B100 fuel was compared with B100 fuel with the additive according to the invention, as in Example 1, at a concentration of 200 ppm m/m. All indicators of engine operation indicated a beneficial effect of the additive according to the invention on the combustion of B100 fuel. The calculated specific emissions indicate a 25% reduction in carbon monoxide emissions, a 40% reduction in unburnt hydrocarbon emissions, a four-fold reduction in particulate emissions (75%) and a slight increase in nitrogen oxide emissions - 8%. Comparative example 3

In the manner described in example 1, the study of the influence of the type of detergent on the combustion of B7 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. A mixture of: dicyclopentadienyl iron 25% by weight, isooctyldicyclopentadienyl iron 25% by weight, classical detergent PIBSI (poly isobutylene succinic imide) in the amount of 30% by weight and an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines, with a temperature range of boiling point 160-180°C and density 0.873 g/cm ³ in the amount of 20% by weight. The reduction of carbon monoxide by 4%, unburned hydrocarbons by 6% and particulate matter by 2% was observed.

Example 4

In the manner described in example 1, the study of the effect of the proportion of iron compounds on the combustion of B7 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. The catalyst used was a mixture of: dicyclopentadienyl iron in the amount of 30% by weight, isooctyldicyclopentadienyl iron in the amount of 20% by weight, detergent DETERG in the amount of 30% by weight and an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines, with a boiling range of 160-180° C and a density of 0.873 g/cm ³ in an amount of 20% by weight. The reduction of carbon monoxide by 7%, unburnt hydrocarbons by 10% and particulate matter by 4% was observed. Comparative example 5

In the manner described in example 1, the study of the influence of the type of detergent on the combustion of B100 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. As a catalyst, a mixture was used: dicyclopentadienyl iron in the amount of 25% by weight, isooctyldicyclopentadienyl iron in the amount of 25% by weight, the classical detergent PIBSI (poly isobutylene succinic imide) in the amount of 30% by weight and an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines , with a boiling range of 160-180°C and a density of 0.873 g/cm ³ in the amount of 20% by weight. The reduction of carbon monoxide by 7%, unburned hydrocarbons by 16% and particulate matter by 6% was observed.

Example 6

In the manner described in example 1, the study of the influence of the proportion of iron compounds on the combustion of B100 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. The catalyst used was a mixture consisting of: dicyclopentadienyl iron in the amount of 30% by weight, isooctyldicyclopentadienyl iron in the amount of 20% by weight, detergent DETERG 30% and an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines, with a boiling range of 160-180°C and density of 0.873 g/cm ³ by weight. A reduction of 9% in carbon monoxide, 22% in unburned hydrocarbons and 12% in particulate matter was observed.

Example 7

In the manner described in example 1, the effect of the catalyst, as in example 1, at a concentration of 2 ppm m/m on the combustion of B7 diesel oil was tested. A 2% reduction in carbon monoxide, 2% reduction in unburned hydrocarbons and 1% reduction in particulate matter was observed. Example 8

In the manner described in example 1, the study of the effect of the catalyst, as in example 1, at a concentration of 1500 ppm m/m on the combustion of diesel oil B7 was carried out.

A 12% reduction in carbon monoxide, 18% reduction in unburnt hydrocarbons and 8% reduction in particulate matter was observed.

Example 9

In the manner as in example 1, the combustion of B100 fuel was compared with the B100 fuel with the additive, as in example 1, at a concentration of 2 ppm m/m. The calculated specific emissions indicate a 2% reduction in carbon monoxide emissions, a 2% reduction in unburnt hydrocarbon emissions, and a 2% reduction in particulate matter emissions. Example 1 0

In the manner as in example 1, the combustion of B100 fuel was compared with the B100 fuel with the additive, as in example 1, at a concentration of 1500 ppm m/m. The calculated specific emissions indicate a reduction in carbon monoxide emissions by 26%, unburned hydrocarbons by 42%, and particulate emissions by 77%. Comparative example 11

In the manner described in example 1, the study of the effect of the type of catalyst on the combustion of B7 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. A commercial product containing iron compounds in a mixture of C3 to C5 aliphatic alcohols in the amount of 50% by weight, DETERG detergent in the amount of 30% by weight and an aromatic solvent, obtained from the distillation of the product of catalytic reforming of gasolines, with a boiling range of 160-180°C, was used as a catalyst. and a density of 0.873 g/ ^cm3 in an amount of 20% by weight. A reduction of 2% in carbon monoxide, 2% in unburned hydrocarbons and 2% in particulate matter was observed.

Comparative example 12

In the manner described in example 1, the study of the effect of the type of catalyst on the combustion of B100 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. A commercial product containing iron compounds in a mixture of C3 to C5 aliphatic alcohols in the amount of 50% by weight, DETERG detergent in the amount of 30% by weight and an aromatic solvent obtained from the distillation of the product of catalytic reforming of gasolines, with a boiling range of 160-180°C and density 0.873 g/cm ³ in the amount of 20% by weight. A reduction of 2% in carbon monoxide, 3% in unburnt hydrocarbons and 2% in particulate matter was observed.

Comparative example 13

In the manner described in example 1, the study of the effect of the type of solvent on the combustion of B7 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. A mixture of: dicyclopentadienyl iron 25% by weight, isooctyldicyclopentadienyl iron 25% by weight, detergent DETERG 30% by weight and an aromatic solvent, obtained from the distillation of the catalytic reforming product of gasolines, with a boiling point range of 180-215°C and a density of 0.892 g/ cm ³ in the amount of 20% by weight. The reduction of carbon monoxide by 11%, unburned hydrocarbons by 17% and particulate matter by 7% was observed. Comparative example 14

In the manner described in example 1, the study of the effect of the type of solvent on the combustion of B100 diesel oil with the addition of a catalyst at a concentration of 200 ppm m/m was carried out. A mixture of: dicyclopentadienyl iron 25% by weight, isooctyldicyclopentadienyl iron 25% by weight, detergent DETERG 30% by weight and an aromatic solvent, obtained from the distillation of the catalytic reforming product of gasolines, with a boiling point range of 180-215°C and a density of 0.892 g/ cm ³ in the amount of 20% by weight. The reduction of carbon monoxide by 25%, unburned hydrocarbons by 40% and particulate matter by 75% was observed.

The additive according to the invention reduces the degree of coking of the injector tips in the test in accordance with the CEC PF-023 procedure on the XUD9 engine and the nozzle flow test according to the ISO 4010 standard. resulted in more than 2% less reduction at 0.1mm needle lift. This means an improvement in the efficiency of the additive, which results in a more even flow of fuel from the holes of the injector tips. Traditionally used detergents in diesel fuel, such as polybutylene succinimides (PIBSI), leave some coke deposits in fuel injector nozzles. As a result of impeding the outflow of liquid fuel, the jet is deformed, in which there are particles of carbon deposits detached from the surface of the injector tips. Each improvement in fuel properties reduces the amount of highly carbonated, condensed soot particles in the fuel jet injected into the combustion chamber, more complete vaporization, better mixture homogenization and more complete combustion. The above-mentioned physicochemical factors result in a greater degree of conversion of hydrocarbons and carbon into carbon dioxide, which reduces fuel consumption to obtain the same engine power and means an increase in its overall efficiency.

Claims (6)

1. An additive for diesel fuel, especially containing methyl esters of higher fatty acids, containing an iron compound, a detergent and an organic solvent, characterized in that it consists of dicyclopentadienyl iron in the amount of 20 to 30% by weight, isooctyldicyclopentadienyl iron in the amount of 20 to 30% by weight , an aromatic solvent obtained from the distillation of the catalytic reforming product of gasolines with a boiling point range of 160-215°C and a density at 15°C of 0.873-0.892 g/cm ³ and a detergent being a product of polyisobutylene synthesis with a molecular weight of about 1000 g/mol with fatty acid methyl esters (FAME) and maleic anhydride (MA) at the temperature of 140°C, in a slight excess of FAME and MA in relation to the stoichiometry, and then acylation with the obtained polyethylene polyamine intermediate in a ratio close to the stoichiometric ratio, at the temperature of 160-180° c 2. An additive according to claim 1, characterized in that it is added to diesel fuel in a concentration of 2 to 1500 ppm m/m 3. An additive according to claim 2, characterized in that it is added to diesel fuel in an amount of 5 to 750 ppm m/m. 4. An additive according to claim 3, characterized in that it is added to diesel fuel in an amount of 10 to 250 ppm m/m. 5. An additive according to claim 1, characterized in that the organic solvent is an aromatic solvent obtained from the distillation of the product of the catalytic reforming of gasolines, with a boiling range of 160-180°C and a density at 15°C of 0.873 g/cm ³ . 6. An additive according to claim 1, characterized in that the organic solvent is an aromatic solvent obtained from the distillation of the product of the catalytic reforming of gasolines, with a boiling range of 180-215°C and a density at 15°C of 0.892 g/cm ³ .