DE102013011642B4 - Process for the determination of carbochemically relevant parameters of lignite by means of fluorescence photometry - Google Patents

Abstract

Process for the photometric determination of carbochemically important components in lignite, such as bitumen content, carbon tar yield or the amount of lignite-derived liquid hydrocarbons, characterized by the following features: a) The luminescence of a pulverulent lignite sample is determined monochromatically by means of a photomultiplier (SEV) and / or spectrometer b) The luminescence measurement integrally registers the entire image field using a low-magnification optical system. c) The measurement results are related to a defined fluorescence standard with monochromatic emission characteristics.

Description

The invention relates to a monochromatic, standard-related, optical measuring method for luminescence photometric parameter determination in carbochemistry. It is used primarily for the quantification of lignite constituents containing hydrocarbons and thermal hydrocarbon products of lignite.

Relative spectral and monochromatic measuring methods are known for luminescence-photometric parameter determination of luminescent substances in sediments, soils, rotting products, petroleum parent rock and lignite [1 - 8]. In the monochromatic range, these are based on the comparison of a particle emission shielded from the sample environment with suitable luminescence standards (reference). The latter are technical glasses with high long-term constancy of the emission (fading-free), the emission intensity of which is reduced by partial masking and is therefore of the same order of magnitude as the measured carbon particle. The spectral measurement of the emission is also carried out on isolated particles in the microscopic range. The luminescent microcomponents to be measured are shielded from the environment by defined diaphragm arrangements, or the influence of the environment is compensated for using mathematical algorithms (background compensation).

These methods are not suitable for determining the parameters of luminescent substances by means of integral measurement in the sense of the method described, since it is always a point-like recording of the emission intensity carried out in the micrometer range, in which, in order to avoid the effects of fluorescence from the environment, aperture arrangements narrowing the measuring field are used, which are used in the case of integral Measurement within the meaning of the invention would further reduce the already low luminescence intensity of the sample. DD 208 416 B1 is devoted to a similar set of problems, but using an arrangement that differs significantly from the present invention, is not standard-related and non-monochromatic, ie, is characterized by the spectral susceptibility of the individual components of the optical system.

The state of the art in contaminated site exploration is the ROSTTM system (Rapid Optical Screening Tool) for examining hydrocarbon contamination in sediments and soils via the registration of the emissions generated by means of pulsed laser-induced fluorescence [9]. A reference-dependent quantification of the signal in relation to the amount of contaminants is not the subject of the technology. Use of ROSTTM within the meaning of the claims for use of the present invention is not relevant.

Out U.S. 4,959,549 A a method is known which is said to be suitable for determining properties of coal.

To date, there are no reference-related methods based on luminescence photometry for determining the tar yield or the bitumen content of lignite.

The object of the invention is to create a method for measuring luminescence photometric parameters of weakly luminescent substances, which enables the determination of the tar yield or the bitumen content of lignite in particular by optical means.

According to the invention, the object is achieved by comparing the luminescence measured at a defined wavelength of the dust-fine, homogenized sample material and a luminescence standard without a diaphragm arrangement, monochromatically and using low-magnification lens systems as an integral measurement of all fluorescent carbon components, with amplification being necessary to quantify the signal and, according to the invention, the luminescence emissions of the sample material and of the luminescence standard are measured in the region of the highest susceptibility of the photomultiplier / spectrometer.

This enables a direct comparison of the luminescence emissions from the sample and the standard. It is irrelevant whether the emission of the luminescence standard is of the same order of magnitude as the measured sample, or whether its intensity exceeds the luminescence emission of the sample material many times over.

The method makes it possible to determine the corresponding parameters on very weakly luminescent substances such as lignite. The method also has the advantage that the tar yield or bitumen content of lignite can be determined in a very short time, without drying and chemical analysis, for a specific seam or site.

The invention is to be illustrated using the following exemplary embodiment:

For clarification, in the structure of a luminescence-photometric measuring arrangement is shown. The measuring arrangement preferably used to ensure the process-specific, measurable luminescence effect consists of a reflected light luminescence microscope 1 better known Design, or a comparable optical arrangement, equipped with a filter arrangement which is used to excite luminescence and is mainly permeable in the ultraviolet and short-wave blue range 2 and a dichromatic splitter mirror 3 , as well as a blocking filter combination to eliminate stray short-wave excitation radiation (UV / blue) 4th . To ensure sufficient excitation energy and for the integral measurement according to the invention of larger sample areas, the beam path is to be designed free of any diaphragm arrangement.

In a first step, the system is calibrated - analogous to the algorithm described below for the sample measurement.

The substance-specific luminescence emission emanating from the pulverulent lignite dust preparation (grain size 0-0.2mm) 5 is generated via low-magnification lens systems 6th excited by UV / short-wave blue light (integral large-field measurement), the emission is recorded in the same way and a defined, very limited wavelength range is monochromatic in the photomultiplier / spectrometer (SPECTRO / SEV) 7th , the evaluation units 8th of a known type are registered. The photocurrent that can be measured in the multiplier / spectrometer is thus a measure of the luminescence emission of the sample and the standard that can be recorded as a function of the susceptibility of the measuring device.

Since there are naturally close relationships between the luminescence intensity of lignite and carbochemically relevant parameters, such as the carbonization tar yield, the bitumen content or the gain in liquid product in the hydrogenation, the relative surface luminescence emission intensities obtained in the manner described for the largely homogenized lignite samples are compared with the In a known manner, certain carbochemical parameters are compiled in calibration diagrams by means of chemical analysis. With sufficient compression of the value pairs, the determination of carbochemically relevant lignite parameters is possible in a simple and fast way by means of luminescence photometric measurement without further complex chemical analysis for specific seams and deposits (area).

Literature:

1. [1] Jacob, H .: “Microscope photometry of organic matter in soils. II. Fluorescence photometry of forest and agricultural rotting products. ”- Bodenkultur, 24, S.1-40, Vienna 1973 ;
2. [2] Jacob, H .: "Fluorescence microscopy and photometry of the organic matter of sediments and soils." - In: Freund, H .: Handbook of microscopy in technology. 4, 2, pp. 369-391, Umschau Verlag Frankfurt a. M. 1973 ;
3. [3] Ottenjann, K., Teichmüller, M. & M. Wolf: “Spectral fluorescence measurements on sporinites with incident light excitation, a microscopic method for determining the degree of carbonization of slightly carbonized coals.” - Progress. Geol. Rheinld. and Westf. 24, pp. 1-36, Krefeld 1974 ;
4. [4] Ottenjann, K., Teichmüller, M. & M. Wolf: "Spectral fluorescence of sporinites in reflected light and their applicability for coalification studies." - In: Alpern, B. (Eds.): Petrographie organique et potentiel petrolier, p. 49-65, published by CNRS Paris 1975 ;
5. [5] Jacob, H .: "The application of microphotometry in organic petrology." - Leitz Mitteilungen für Wissenschaft und Technik 7, 7, pp. 209-216, Wetzlar 1980 ;
6. [6] Ottenjann, K .: “Spectral fluorescence microphotometry of coal and oil shale.” - Leitz Mitteilungen für Wissenschaft und Technik 7, 7, pp. 262-273, Wetzlar 1980 ;
7. [7] Ottenjann, K .: “Improvements in microscopic photometric fluorescence measurement on carbon maceral.” - Zeiss Information, 26, 93, pp. 40-46, Oberkochen 1982; International Commission for Coal Petrology [ICCP]: “International Lexicon for Coal Petrology.” - 1st & 2nd edition with additions, Verlag CRNS Paris 1963, 1965, 1973, 1975 ;
8. [8th] Martinez, L., Pradier, B. & Ph. Bertrand: “La microspectrofluorimetrie en petrologie organique. Methodology and application à l'etude de la maturation des algues fossils du Toarcien du bassin de Paris. ”- CR Acad. Sc., T. 304, III / 9, pp. 441-446, Paris 1987) ;
9. [9] Neuhaus, M. & N. Ehle: "Investigation of hydrocarbon contamination with the help of pressure probes." - WLB Wasser, Luft und Boden, 10, pp. 69-71, Stuttgart 2000) ;

List of reference symbols

1

Incident light luminescence microscope

2

Filter arrangement

3

dichromatic splitter mirror

4th

Blocking filter combination

5

pulverulent lignite dust preparation (grain size 0-0.2mm)

6th

low magnification lens systems

7th

Photomultiplier / Spectrometer (SPECTRO / SEV)

8th

Evaluation units

Claims (1)

Process for the photometric determination of carbochemically important components in lignite, such as bitumen content, coal tar yield or the amount of lignite-derived liquid hydrocarbons, characterized by the following features: a) The luminescence of a pulverulent lignite sample is determined in a monochromatic way using a photomultiplier (SEV) and / or spectrometer . b) The luminescence measurement integrally registers the entire image field using a low-magnification optical system. c) The measurement results are related to a defined fluorescence standard with monochromatic emission characteristics.

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