Use of a reactor, methods, and device for quantitatively obtaining molecular hydrogen from substances

Abstract

The invention relates to the use of a reactor, methods, and devices for the quantitative recovery of molecular hydrogen from solid, liquid, or gaseous substances which contain hydrogen and which have heteroatoms, as well as to reactors. In this case, the reactors have material containing chromium. The subject matter of the invention also includes the use of the reactor, the method, and the device for the compound-specific or component-specific measurement of the isotope ratio (δ.sup.2H) of hydrogen using online apparatuses.

Claims

1. A method for the quantitative recovery of molecular hydrogen from a sample of solid, liquid, or gaseous substances which have heteroatoms, comprising: introducing the sample, via an inlet, into a pyrolysis reactor with material containing chromium; performing pyrolysis of the sample to form hydrogen, characterized in that a zone with temperatures above 1100° C. is generated in the pyrolysis reactor, in which a reactive chromium layer of the material containing chromium of the pyrolysis reactor is at least partially arranged within the zone and adjacent to a quartz layer; and providing the hydrogen via an outlet of the pyrolysis reactor, the reactive chromium layer of the material containing chromium arranged between the inlet and the quartz layer, and the quartz layer arranged between the chromium layer and the outlet of the pyrolysis reactor, the quartz layer including quartz wool, and a layer of chippings arranged next to the quartz layer, the layer of chippings including one or more of: quartz, ceramic, or glassy carbon.

2. The method according to claim 1, wherein the zone with temperatures above 1100° C. is generated in the reactor to pyrolize substance.

3. The method according to claim 2, characterized in that the pyrolysis of the substances is carried out using a carrier gas.

4. The method according to claim 3, characterized in that the reactor's material containing chromium ensures a flow of carrier gas of up to 10 mL/min.

5. The method according to claim 3, characterized in that the reactor's material containing chromium ensures a flow of carrier gas of up to 300 mL/min.

6. The method according to claim 3, characterized in that the reactor's material containing chromium ensures a flow of carrier gas of up to 1000 mL/min.

7. The method according to claim 2, characterized in that the reactor is positioned in an apparatus for high-temperature conversion (in HTC systems).

8. The method according to claim 2, characterized in that the reactor is positioned in an apparatus for elemental analysis.

9. The method according to claim 2, characterized in that the reactor is made at least partially of heat-resistant materials suitable for pyrolysis of inserted substances at temperatures≥1100° C., which do not allow the passage of molecular hydrogen from the inside or of air from the outside.

10. The method according to claim 1, characterized in that at least one section of a reactor inner wall is made of, at least on its inner side, material containing chromium, and/or at least one section of a reactor inner wall has a coating containing chromium, and/or a material containing chromium is embedded in at least one section of a reactor inner wall, at least on its inner side.

11. The method according to claim 1, characterized in that the reactor's material does not contain any hydrogen or do not react with molecular hydrogen above 1100° C.

12. The method according to claim 1, characterized in that silver wool is arranged in a first region of the reactor, as a halogen trap, where there is a temperature zone between 500° C. and 800° C. during pyrolysis due to the temperature zone generated above 1100° C.

13. The method according to claim 1, characterized in that the solid, liquid, or gaseous substances from which the molecular hydrogen will be recovered are separated into their components by means of gas chromatography prior to entry into the reactor.

14. The method according to claim 1, characterized in that the zone with temperatures above 1100° C. is only generated in a subvolume of the pyrolysis reactor which makes up at most 50% of the reactor volume.

15. The method according to claim 1, characterized in that the reactor has at least one reactor tube with material containing chromium, in that the zone with temperatures above 1100° C. is generated over at least 90% of the length of the reactor tube in the direction of the longitudinal axis of the reactor tube, and in that the reactor tube's material containing chromium is arranged in the reactor tube at least over the length of the zone with temperatures above 1100° C.

16. The method according to claim 15, characterized in that the reactor's material containing chromium extends over 40% to 60% of the length of the zone with temperatures above 1100° C., in the longitudinal direction of the reactor tube.

17. The method according to claim 15, characterized in that the longitudinal axis of the reactor tube is oriented vertically, and the reactor tube's material containing chromium is present as a layer constructed horizontally.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: First embodiment of a single-walled reactor with a packing containing chromium

(2) FIG. 2: A double-walled reactor with a packing containing chromium

(3) FIG. 3: Second embodiment of a single-walled reactor with a packing containing chromium

(4) FIG. 4: Byproduct measurement with the reactor according to FIG. 2 in an HTC system

(5) FIG. 5: Detection of mass 27 with the reactor according to FIG. 2 in an HTC system

(6) FIG. 6: Byproduct measurement with the reactor according to FIG. 2 in a Cr-EA system

(7) FIG. 7: Detection of mass 27 with the reactor according to FIG. 2 in a Cr-EA system

(8) FIG. 8: Byproduct measurement with the reactor according to FIG. 3 in a GC/HTC system

(9) FIG. 9: Detection of mass 27 with the reactor according to FIG. 3 in a GC/HTC system

(10) FIG. 10: Byproduct measurement with the reactor according to FIG. 3 in a GC-Cr system

(11) FIG. 11: Detection of mass 27 with the reactor according to FIG. 3 in a GC-Cr system

(12) FIG. 12: Byproduct measurement with the reactor according to FIG. 3 in a GC/HTC system

(13) FIG. 13: Detection of mass 35 to 38 with the reactor according to FIG. 3 in a GC/HTC system

(14) FIG. 14: Byproduct measurement with the reactor according to FIG. 3 in a GC-Cr system

(15) FIG. 15: Detection of mass 35 to 38 with the reactor according to FIG. 3 in a GC-Cr system

DETAILED DESCRIPTION OF EMBODIMENTS

(16) In the figures, reference numbers which are the same indicate the same features of the invention. The illustrations in FIGS. 1 to 3 show a certain ratio of the dimensions of the individual components of the reactor, to thereby illustrate one embodiment. In the following legends, other parameters are deliberately given for the components, to thereby describe a further embodiment of the reactor shown in the figures.

(17) Legend for FIGS. 1 and 2: 1 Reactor tube (ceramic); length: 450 mm 2 Inner reactor tube (glassy carbon); length of the packing: 220 mm 3 Chromium filling: chromium powder/particles with a diameter of 0.1 to 5 mm, length: 80 mm 4 Hottest zone 1100 to 1800° C. 5 Quartz wool: length: 10 mm 6 Quartz chips: length: 100 mm 7 Silver wool (optional); length: 20 mm (integrated into the quartz layer, the total length of which remains 100 mm) 8 Quartz wool: length: 20 mm

(18) Legend for FIG. 3: 1 Reactor tube (ceramic); length: 320 mm, outer diameter 1/16 inch, Inner diameter: 0.8 mm 3 Chromium filling: chromium powder/particles with a diameter of 0.25 mm, length: 240 mm 4 Hottest zone 1100 to 1500° C. 7 Silver wool (optional); length: 20 mm 8 Length of the quartz wool at the outlet: 20 mm 9 Length of the quartz wool at the inlet: 20 mm

Example 1

(19) Use example, based on caffeine, using a double-walled pyrolysis reactor according to FIG. 2:

(20) Solid samples are weighed in silver capsules. The silver capsules are placed in the autosampler of the analyzer (EA). From there, the samples drop individually into the pyrolysis reactor, wherein the silver capsule melts in the hot zone and the sample decomposes. The fluid reaction products are transported with the carrier gas helium through a gas chromatography column to the open split module. From there, the carrier gas stream including the H.sub.2 enters the isotope ratio mass spectrometer, wherein the ion streams of the masses are determined and compared to those of a calibrated reference gas.

(21) The reaction is carried out by means of a standard high-temperature conversion system for elemental analysis (HTC System; e.g. TC/EA from Thermo Fisher Scientific GmbH, Bremen, Germany, without chromium) and a high-temperature conversion system for elemental analysis (Cr-EA system) according to the invention.

(22) As can be seen in the attached FIGS. 4 and 5, the known HTC system leads to the formation of byproducts which limit the yield of molecular hydrogen to a maximum of 60-70%.

(23) FIGS. 6 and 7 show that a nearly 100% yield is achieved using the reactor and method according to the invention.

Example 2

(24) Use example, based on caffeine, using a pyrolysis reactor according to FIG. 3

(25) The fluid reaction products are transported with the carrier gas helium through a gas chromatography column to the open split module. From there, the carrier gas stream including the H.sub.2 enters the isotope ratio mass spectrometer, wherein the ion streams of the masses are determined and compared to those of a calibrated reference gas.

(26) The reaction is carried out by means of a standard high-temperature conversion system (GC/HTC System; e.g. standard TC/GC system, e.g. from Thermo Fisher Scientific GmbH, Bremen, Germany, without chromium) and a high-temperature conversion system (GC-Cr system) according to the invention. In this case, the caffeine has been divided into its components by means of gas chromatography prior to entry in the pyrolysis reactor.

(27) As can be seen in the attached FIGS. 8 and 9, the known GC/HTC system leads to the formation of byproducts which limit the yield of molecular hydrogen to a maximum of 60-70%.

(28) FIGS. 10 and 11 show that a nearly 100% yield is achieved using the reactor and method according to the invention.

(29) The results of the measurements in Examples 1 and 2 are explained in the following:

(30) FIGS. 4 and 5, as well as 8 and 9: Formation of byproducts containing hydrogen (HCN) during the conversion of the hydrogen in the molecule into molecular hydrogen in the HTC system, and the GC/HTC system:

(31) ##STR00001##

(32) FIGS. 6 and 7, as well as 10 and 11: no formation of byproducts during the conversion of the hydrogen in the molecule into molecular hydrogen in the Cr-EA system and the GC-Cr system:

(33) ##STR00002##

(34) FIGS. 4 and 5: Byproduct measurements with the HTC system, detection of the mass 27 (HCN) in the region of >1 mA, ˜10,000 times higher than in the Cr-EA system.

(35) FIGS. 6 and 7: Byproduct measurements with the Cr-EA system, no detection of the mass 27 is possible (HCN), air/water substrate in the region<0.1 μA.

(36) FIGS. 8 and 9: Byproduct measurements with the GC/HTC system, detection of the mass 27 (HCN) in the region>0.4 mA, ˜10,000 times higher than in the GC-Cr system.

(37) FIGS. 10 and 11: Byproduct measurements with the GC-Cr system, no detection of the mass 27 is possible (HCN), air/water substrate in the region<0.4 μA.

Example 3

(38) Use example, based on hexachlorocyclohexane, using a pyrolysis reactor according to FIG. 3:

(39) The fluid reaction products are transported with the carrier gas helium through a gas chromatography column to the open split module. From there, the carrier gas stream including the H.sub.2 enters the isotope ratio mass spectrometer, wherein the ion streams of the masses are determined and compared to those of a calibrated reference gas.

(40) The reaction is carried out by means of a standard high-temperature conversion system (GC/HTC System; e.g. standard TC/GC system, e.g. from Thermo Fisher Scientific GmbH, Bremen, Germany, without chromium) and a high-temperature conversion system (GC-Cr system) according to the invention. In this case, the hexachlorocyclohexane has been divided into its components by means of gas chromatography prior to entry in the pyrolysis reactor.

(41) FIGS. 12 and 13: Formation of byproducts containing hydrogen (HCl) during the conversion of the hydrogen in the molecule into molecular hydrogen in the GC/HTC system:

(42) ##STR00003##

(43) FIGS. 14 and 15: No formation of byproducts containing hydrogen (HCl) during the conversion of the hydrogen in the molecule into molecular hydrogen in the GC-Cr system

(44) ##STR00004##

(45) As can be seen in the attached FIGS. 12 and 13, the known GC/HTC system leads to the formation of byproducts which limit the yield of molecular hydrogen to a maximum of 60-70%.

(46) FIGS. 14 and 15 show that a nearly 100% yield is achieved using the reactor and method according to the invention.