Method for determining a standardised sooting tendency of a substance mixture

Abstract

The invention relates to a method for determining sooting tendency by means of a gas chromatography component analysis of hydrocarbon types and oxygenates of a substance mixture, in particular a fuel (F) or an additive (B), by means of a reformulyzer analysis. According to the invention, a normalisable total sooting tendency index (YSItotal) of substance mixtures is determined according to the equation (1) YSItotal = ∑YSIi ∙ Vi / 100, wherein the percentage by volume (Vi) of each reformulyzer subgroup (i) is multiplied by the sooting tendency index (YSIi) associated with the reformulyzer subgroup (i), after which the values determined are added up to give the total sooting tendency index (YSItotal). The invention also relates to a procedure for determining a sooting tendency index (YSIi-M) that represents the sooting tendency index (YSIi) associated with the subgroups (i).

Description

[0001] Description

[0002] Method for determining a standardized soot formation tendency of a mixture of substances

[0003] The invention relates to a method for determining the soot formation tendency by means of a gas chromatographic component analysis of hydrocarbon types and oxygenates of a substance mixture.

[0004] The issue of soot particle formation in fuels is of paramount importance today, as emissions and soot particle formation from motor vehicles are to be continually reduced. This is particularly due to the tightening of guidelines in connection with the EU-7 reform. The new guidelines must be met for motor vehicles and fuels, and a wide range of different fuels must be tested. Furthermore, the existing effectiveness, for example for city fuels, must be reviewed. The YSI (Yield Sooting Index) provides a good basis for describing the tendency to soot formation. The YSI is known in German as the Rußbildungsneigungs-Index (Rußformationsneigungs-Index). This index is currently complicated to determine. It is then possible to determine the soot formation tendency index using an individual component analysis of a fuel.The disadvantage is that a single-component analysis must be performed to determine the soot formation index. This analysis involves a large amount of data and is very time-consuming and costly. Furthermore, there is the problem that not all components can be assigned with this method and are listed as unknowns. This ultimately leads to adverse deviations in the calculation.

[0005] DE 68927 133 T2 is known from the prior art. It proposes a method for determining the aromatic carbon content of a hydrocarbon-containing solution containing more than one aromatic compound, which proceeds as follows: (a) The solution is separated into fractions by liquid chromatography, (b) Each fraction is separately irradiated with UV light in a wavelength range, at least a portion of which lies in the range from 200 nm to 400 nm, (c) The absorption of the UV light by the aromatic hydrocarbons in each fraction is measured, (d) The integral of the absorption is then determined as a function of the photon energy over the energy corresponding to the wavelength range, (e) Finally, the aromatic carbon content is determined from the absorption integral.The document EP 1 953 545 A1 discloses a method for the quantitative analysis of a mixture of molecular compounds by two-dimensional gas chromatography, in which a two-dimensional chromatogram (CHR) is generated from a chromatographic signal (SB) and chromatographic peaks are selected at the polygon aid.

[0006] The method comprises the following steps for at least one polygon: fitting a polygon by identifying portions of the chromatographic signal contained in the polygon, with the following further steps: (a) determining start times, end times and maximum chromatographic peaks present on the portions, (b) adjusting the polygon by shifting intersection points between the polygon and the portions as a function of the start times, end times and maximum chromatographic peaks, (c) determining an amount of at least one molecular compound by calculating the area of ​​the thus fitted polygon.

[0007] Document WO 1997 / 01142 A1 describes a method for predicting physical, perceptual, performance, or chemical properties of a complex hydrocarbon mixture, comprising: (a) selecting at least one property of the hydrocarbon mixture, (b) selecting reference samples, the reference samples containing characteristic compound types present in the complex hydrocarbon mixture and having known values ​​of the property or properties selected in step (a), (c) creating a sample set by the steps of: (1) injecting each reference sample into a gas chromatograph connected to a mass spectrometer, thereby causing at least partial separation of the hydrocarbon mixture into chemical constituents, (2) introducing the chemical constituents of each reference sample into the mass spectrometer under dynamic flow conditions.(3) Obtain a series of time-resolved mass chromatograms for each reference sample. (4) Calibrate the mass chromatograms to correct the retention times. (5) Select a series of corrected retention time windows. (6) Select a series of molecular and / or fragment ions within each retention time window, the ions being representative of characteristic compounds or classes of molecules expected within the retention time window. (7) Record the total amount of each characteristic compound or group of compounds selected in step c(6). (8) Form the data from steps c(6) and c(7) into an X-block matrix. (9) Form the data selected in (a) for reference samples selected in (b) into a Y-block matrix.

[0008] (10) Analyzing the data from steps c (8) and c (9) by multivariate correlation techniques including partial least squares, principal component regression or ridge regression to generate a series of coefficients, (d) Subjecting an unknown hydrocarbon mixture to steps c (1) to c (3) in the same manner as the reference sample to generate a series of time-resolved mass chromatograms.

[0009] (e) repeating steps c (4) to c (8) for each mass chromatogram of step (d) and

[0010] (f) multiplying the matrix from step (e) by the coefficients from step c (10) to produce a predicted value of the property or properties.

[0011] In summary, the prior art according to document DE 68927 133 T2 proposes a (molecular) group formation, while document EP 1 953 545 A1 provides for the determination in peak groups, and finally document WO 1997 / 01142 A1 discloses the selection of molecular and / or fragment ions in order to analyze hydrocarbon mixtures.

[0012] The invention is based on the object of developing a simplified method for determining a soot formation tendency index for a substance mixture which consists of a plurality of individual components which differ in terms of material and percentage volume, in particular hydrocarbon types and oxygenates, wherein the method result should be suitable for incorporating the soot formation tendency of substance mixtures to be compared into the standardization in the form of a soot formation tendency index assigned to the substance mixtures.

[0013] The starting point of the method according to the invention is the standard ISO 22854:2016 entitled “Liquid petroleum products - Determination of hydrocarbon types and oxygenates in automotive gasoline and in ethanol (E85) - Multidimensional gas chromatography method”.

[0014] For most fuels encountered today, a reformulyzer analysis according to ISO 22854 is available. This means that in most cases there is no single component analysis, but a reformulyzer analysis according to the ISO 22854 standard. Gas chromatography is carried out according to ISO 22854. The result is then presented as a so-called reformulyzer in a so-called reformulyzer output. In the reformulyzer analysis according to ISO 22854, the individual components are divided into functional supergroups and reformulyzer groups, whereby the reformulyzer analysis contains the reformulyzer groups i, which are differentiated according to the number of carbon atoms. The reformulyzer groups i, which are divided according to the number of carbon atoms, are also referred to as reformulyzer subgroups. In multidimensional gas chromatography, the percentage volumetric

[0015] Proportion V; of the respective reformulyzer subgroup i is determined.

[0016] To determine the soot formation tendency by means of a gas chromatographic component analysis of hydrocarbon types and oxygenates of a mixture of substances, in particular a fuel (F) or an additive (B) by means of a reformulyzer analysis, the following steps are provided:

[0017] (I) Classification of the hydrocarbon types and oxygenates of the mixture determined within the component analysis into functional reform ulyzer supergroups,

[0018] (II) Classification of the specific hydrocarbon types and oxygenates according to the number of carbon atoms into reformulyzer subgroups (i), which are assigned to the functional reformulyzer supergroups,

[0019] (III) Determining the percentage volumetric fraction (Vj) of the respective reformulyzer subgroup (i) of the total volume of the mixture.

[0020] According to the invention, further steps are provided,

[0021] (IV) Assigning a soot formation tendency index (YSh) to each reformulyzer subgroup (i) and the

[0022] (V) Determining an overall soot formation tendency index (YSItotal) according to the equation (1) YSIcesamt = £ YSh ■ V / 100, wherein the volumetric proportion (Vj) of each reformulyzer subgroup (i) is multiplied by the soot formation tendency index (YSh) assigned to the reformulyzer subgroup (i), after which the determined values ​​are summed up to form the overall soot formation tendency index (YSItotal).

[0023] Preferred embodiments of the method are explained in the subclaims and in the description.

[0024] The invention is explained below with reference to the accompanying drawings. They show:

[0025] Figure 1 shows a basic procedure in a schematic

[0026] Overview and

[0027] Figure 2 shows a reformulyzer analysis carried out according to ISO 22854. Figure 1 shows the basic procedure in a schematic overview.

[0028] By means of the method according to the invention, gasoline engine fuels F or additives B produced on the basis of hydrocarbons, so-called blends, which are mostly added to gasoline engine fuels F as additives, are investigated for their tendency to form soot.

[0029] Within the process, a reformulyzer analysis carried out according to ISO 22854, as explained and illustrated in Figures 1 and 2, provides a classification of the individual components into functional reformulyzer main groups and reformulyzer subgroups i, whereby within the reformulyzer analysis according to ISO 22854 the percentage volumetric fraction V; of the respective reformulyzer subgroup i is determined and thus available for further development of the process.

[0030] The functional reformulyzer groups are naphthenes, paraffins, cyclic olefins, olefins, aromatics and oxygenates.

[0031] The reformulyzer subgroups i are assigned to the respective functional supergroups according to Figure 2 and sorted by number of carbon atoms with the reference symbol V; (V = volumetric fraction in % of the total volume and i = number of carbon atoms).

[0032] According to the invention, each of these reformulyzer subgroups i is assigned a soot formation tendency index, which is referred to below as YSh and provided with the reference symbol YSh. One could thus also speak of a subgroup YSh.

[0033] In the reformulyzer analysis according to ISO 22854, only the group classification i and the percentage volumetric content V; are available for the individual components, but not the soot formation tendency index of the individual components, so that ultimately no value for YSh of a reformulyzer subgroup i can be calculated.

[0034] The method according to the invention overcomes this disadvantage as follows:

[0035] The YSh of the respective reformulyzer subgroup i will be taken from a database available for this purpose, which the applicant has created by evaluating the individual components belonging to the respective reformulyzer subgroup i. In other words, the database comprises the individual components belonging to a reformulyzer subgroup i with the respective YSh of the respective individual components, wherein, according to the invention, the YSh for the respective reformulyzer subgroup i is determined within the database.

[0036] This YSh, assigned to the respective reformulyzer subgroup i, is valid in the database independently of the percentage volumetric fraction V; of the total volume of the substance mixture under investigation, whereby the percentage volumetric fraction V; is advantageously provided by the reformulyzer analysis according to ISO 22854.

[0037] The applicant recorded the YSh values ​​of the individual components of the respective reformulyzer subgroups i from its own DHA analyses of the individual components of the respective reformulyzer subgroups i and from databases outside the applicant.

[0038] For example, an arithmetic mean is calculated from the database-side YSh values ​​of the individual components of the respective reformulyzer subgroup i, which is assigned to the reformulyzer subgroup i as a representative YSh-M, which is used in the calculation of the total soot formation tendency index YSItotal as YSh in equation 1 explained below.

[0039] The subject of this patent application is the simplified basic method for determining a standardized soot formation tendency of a fuel F or an additive B or an overall soot formation tendency index with the reference symbol YSItotal for a fuel F or an additive B.

[0040] As an example, Figure 2 shows the percentage volumetric fraction Vj of the respective reformulyzer subgroup i, which is used to calculate the overall soot formation tendency index with the reference symbol YSItotal according to equation 1.

[0041] (Eq. 1) YSI Total — z YSh ' V / 100

[0042] YSIcesamt ■> Total soot formation index of the fuel F or additive B YSh ■> the YSh of the respective subgroup i

[0043] V is the determined volume fraction V; in percent of the respective subgroup i

[0044] Different fuels F and / or additives B can be compared more easily than before using the overall soot formation tendency index YSItotal, whereby a higher value of the overall YSI indicates a fuel F or additive B with a greater tendency to soot formation.

[0045] The simplification of this procedure lies in the fact that for a fuel F or an additive B, no conventional, complex DHA evaluation (DHA = Detailed Hydrocarbon Analysis) of all individual components (number > 350) of the respective mixture of substances, in particular of a fuel F and / or an additive B, has to be determined anymore.

[0046] Advantageously, this procedure no longer requires summation over all > 350 individual components, but only the summation of the subgroups i taking into account the percentage volumetric share Vi of the respective reformulyzer subgroup i is necessary.

[0047] In addition, by using the reformulyzer or the output of the reformulyzer analysis as the basis for the evaluation, the problem of the many unknowns, as explained above, no longer occurs.

[0048] Ultimately, this allows for a more robust determination, with the result being achieved with significantly less effort, as is clear from the previous description.

[0049] The method has preferred embodiments.

[0050] In a first variant, it is planned to additionally combine functional reformulyzer supergroups. For example, the functional reformulyzer supergroups of olefins and cyclic olefins are combined into one functional reformulyzer supergroup. This reduces the amount of data that needs to be summed in the final step of the process, summing.

[0051] In a second embodiment, closely located reformulyzer subgroups i, whose values ​​differ by less than five volume percent, are combined within a functional reformulyzer supergroup.

[0052] For example, within one of the functional reformulyzer supergroups, the reformulyzer subgroups i, such as C7 and C8, can be combined into a single reformulyzer subgroup. This reduces the amount of data that needs to be summed in the final step of the procedure, summing.

[0053] In a third embodiment, closely spaced reformulyzer subgroups i, whose values ​​differ by less than five percent by volume, are combined from multiple functional reformulyzer supergroups. Thus, reformulyzer subgroups i across multiple functional reformulyzer supergroups, for example, C7 and C8 can be combined to form C(7+8) of the reformulyzer supergroups, into one reformulyzer subgroup i. This reduces the need for summation in the final step of the process, the summation.

[0054] In a fourth embodiment, closely spaced reformulyzer subgroups i, whose values ​​differ by less than five percent by volume, of all functional reformulyzer supergroups are combined. For example, across all functional reformulyzer supergroups, for example, C7 and C8 can be combined to form O(7+8) of all reformulyzer supergroups into one reformulyzer subgroup i. This reduces the need to sum data in the final step of the process, summing.

[0055] The first embodiment variant can advantageously be combined with at least one of the second to fourth embodiment variants.

[0056] Advantageously, the “summarization” according to the explained embodiments reduces the effort of calculating the overall soot formation tendency index YSItotal depending on the selected embodiment YSItotal.

[0057] The advantages of the method are that the costs for determining the total soot formation tendency index YSItotal are reduced, since no

[0058] Single component analysis must be carried out and existing standards (ISO 22854) can be used. Since there are no longer any unknowns when using the results of the reformed lyzer analysis, another advantage of the method is that it achieves a significantly more robust result that is not frustrated by unknown input variables, so that the result can always be determined. A standardized determination of the overall soot formation tendency index YSItotal also advantageously leads to a standardized and standardizable statement on the soot formation tendency for each fuel F or additive B. This means that using the overall soot formation tendency index YSItotal, a comparison of the overall soot formation tendency indices YSItotal of various fuels F and additives B can advantageously be carried out and standardized in a standard.

[0059] Finally, the invention provides that all fuels for which the soot formation tendency must be predicted can be examined and evaluated, in particular standardized, using this method. The method can advantageously be applied both in the development of new fuels (F) or additives (B) and in the testing of existing fuels.

[0060] During vehicle operation, the invention allows the overall soot formation tendency index YSItotal to be transmitted either automatically (e.g., wirelessly) or manually to a receiving unit, in particular a control unit with the vehicle's receiving unit. If such a value is available in the engine control unit, the soot formation tendency index YSItotal can be used to more precisely determine the control of the operating parameters of the internal combustion engine and / or the exhaust system. The soot formation tendency index YSItotal can also be displayed to the user via the HMI, providing the user with standardized information about whether they are using a fuel F or an additive B that is prone to high or low soot formation.

Claims

Patent claims 1. Method for determining the tendency to form soot by means of a gas chromatographic component analysis of hydrocarbon types and oxygenates of a mixture of substances, in particular a fuel (F) or an additive (B) by means of a reformulyzer analysis comprising the steps: (I) Classifying the hydrocarbon types and oxygenates of the mixture identified within the component analysis into functional reformulyzer subgroups, (II) Classification of the specific hydrocarbon types and oxygenates according to the number of carbon atoms into reformulyzer subgroups (i) which are assigned to the functional reformulyzer supergroups, (III) Determining the percentage volumetric fraction (Vj) of the respective Reform ulyzer subgroup (i) of the total volume of the mixture, characterized by the steps: (IV) Assigning a soot formation tendency index (YSh) to each reformulyzer subgroup (i), (V) Determining an overall soot formation propensity index (YSItotal) according to equation (1) YSIceamt = £ YS ■ Vj / 100, where the volumetric fraction (Vj) of each Reformulyzer subgroup (i) is multiplied by the soot formation propensity index (YSh) assigned to the Reformulyzer subgroup (i), after which the determined values ​​are summed to obtain the overall soot formation propensity index (YSItotal).

2. Method according to claim 1, characterized in that the soot formation tendency index (YSh) assigned to the respective reformulyzer subgroup (i) is taken from a database, wherein the value of the soot formation tendency index (YSh) of the respective reformulyzer subgroup (i) is provided on the basis of the respective individual components of a reformulyzer subgroup (i) present in the database.

3. Method according to claim 1, characterized in that, prior to determining the total soot formation tendency index (YSItotal), at least two or more functional reformulyzer supergroups are combined into one functional reformulyzer supergroup. A method according to claim 1, characterized in that, prior to determining the total carbon black formation index (YSItotal), closely related reformulyzer subgroups (i) within a functional reformulyzer supergroup, whose values ​​differ by less than five volume percent, are grouped together. A method according to claim 1, characterized in that, prior to determining the total carbon black formation index (YSItotal), closely related reformulyzer subgroups (i) of several functional reformulyzer supergroups, whose values ​​differ by less than five volume percent, are grouped together. A method according to claim 1, characterized in that, prior to determining the total carbon black formation index (YSItotal), closely related reformulyzer subgroups (i) of all functional reformulyzer supergroups, whose values ​​differ by less than five volume percent, are grouped together.A method according to claim 3, characterized in that the grouping of functional reformulyzer supergroups into a functional reformulyzer supergroup is combined with the grouping of closely related reformulyzer subgroups (i) whose values ​​differ by less than five volume percent, according to at least one of claims 4 to 6. A method according to claim 1, characterized in that the total soot formation tendency index (YSItotal) is transmitted either automatically or manually to a receiving unit of a vehicle. A method according to claim 8, characterized in that the soot formation tendency index (YSItotal) is used as an additional input variable for a more precise determination of the control of the operating parameters of an internal combustion engine and / or an exhaust system of the vehicle.Method according to claim 1, characterized in that the total soot formation tendency index (YSItotal) is used for normalization with regard to the soot formation tendency of several, at least two, different mixtures of substances investigated within the method, in particular fuels (F) or additives (B).

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