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Title:
REACTOR FOR SPECTROSCOPIC STUDIES
Document Type and Number:
WIPO Patent Application WO/2018/143832
Kind Code:
A1
Abstract:
The invention relates to a reactor for spectroscopic studies, operating in transmission mode, comprising a reaction chamber (1 ), which includes a cylindrical tube, from which at least two connectors (21, 22, 23) extend perpendicularly, delivering a gaseous working medium to a reaction zone in the reaction chamber (1), where the tested sample (6) is placed, at least two optical windows (17), located at the ends of the reaction chamber's (1 ) cylindrical tube, pressed to the reaction chamber (1) and sealed with it by a window seal (16), heating and cooling system supported directly by the reaction chamber (1) and placed basically around the reaction zone, at least two reactor fastenings (14) fixing the opposite ends of the reaction chamber (1), with the reactor fastening (14) including a cooling agent duct (20), having an internal surface constituting the external surface of the reaction chamber (1), the cooling agent duct (20) being sealed from the side of the heating and cooling system and from the vacuum side by a hydraulic seal (19), being in direct contact with the reaction chamber (1).

Inventors:
TARACH KAROLINA (PL)
GÓRA-MAREK KINGA (PL)
BUDZIOCH JANUSZ (PL)
Application Number:
PCT/PL2018/050003
Publication Date:
August 09, 2018
Filing Date:
February 04, 2018
Export Citation:
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Assignee:
UNIV JAGIELLONSKI (PL)
International Classes:
G01N21/03
Foreign References:
JPS6031040A1985-02-16
PL173291B11998-02-27
Other References:
RYCZKOWSKI J. ET AL.: "Adsorbenty i katalizatory. Wybrane technologie a srodowisko", UNIWERSYTET RZESZOWSKI 2012, pages 175 - 203, ISBN: 978-83-931292-8-7
Attorney, Agent or Firm:
WITEK, Andrzej (PL)
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Claims:
Claims

1. A reactor for spectroscopic studies comprising a reaction chamber (1 ), which includes a cylindrical tube, from which at least two connectors (21 , 22, 23) extend perpendicularly, delivering a gaseous working medium to a reaction zone in the reaction chamber (1 ), where the tested sample (6) is placed, at least two optical windows (17), located at the ends of the reaction chamber's (1 ) cylindrical tube, pressed to the reaction chamber (1 ) and sealed with it by a window seal (16), heating and cooling system supported directly by the reaction chamber (1 ) and placed basically around the reaction zone, at least two reactor fastenings (14) fixing the opposite ends of the reaction chamber (1 ), characterised in that the reactor fastening (14) includes a cooling agent duct (20), having an internal surface constituting the external surface of the reaction chamber (1 ), the cooling agent duct (20) being sealed from the side of the heating and cooling system and from the vacuum side by a hydraulic seal (19), being in direct contact with the reaction chamber (1 ).

2. The reactor according to claim 1 , characterised in that the whole reaction chamber (1 ) is made of quartz.

3. The reactor according to claim 1 or 2, characterised in that the reaction chamber (1 ) comprises a third connector (22), preferably perpendicular to the two connectors (21 , 23) delivering the gaseous working medium, and perpendicular to the reaction chamber's (1 ) cylindrical tube, through which a thermocouple (5) is introduced into the vicinity of the sample (6), preferably in a plugged quartz pipe, preferably the thermocouple being coupled with the heating and cooling system.

4. The reactor according to any of the claims from 1 to 3, characterised in that fillings (12), preferably quartz, with a cylindrical coaxial longitudinal hole, are inserted into the reaction chamber's cylindrical tube (1 ), preferably from two opposite ends, each filling having a length smaller than half of the length of the reaction chamber's (1 ) cylindrical tube.

5. The reactor according to any of the claims from 1 to 4, characterised in that the reactor fastenings (14) are supported on a common frame (8).

6. The reactor according to any of the claims from 1 to 5, characterised in that heating and cooling system comprises a heater (2), surrounding the reaction chamber at least partially (1 ) in the sample placement zone (6), and a cooling chamber (11 ), defined by an external shield (4) and preferably a thermal shield (3), with coolant, preferably liquid nitrogen, being introduced into the cooling chamber (1 1 ) by supply pipes (10).

7. The reactor according to any of the claims from 1 to 6, characterised in that a reactor seal (15) is introduced between the reactor fastening (14) and the window seal (16), sealed with the reactor fastening (14) via a vacuum seal (18), remaining in a direct contact with the external surface of the reaction chamber (1 ).

8. The reactor according to claim 7, characterised in that the reactor seal (15) is connected with the window seal (16) using bolts, preferably three bolts.

9. The reactor according to any of the claims from 1 to 8, characterised in that a vacuum seal (18) is placed between the optical window (17) and the window seal (16).

10. The reactor according to any of the claims from 1 to 9, characterised in that the vacuum seals (18) and/or the hydraulic seals (19) constitute o-ring type seals, made of a polymer, preferably an elastomer, preferably Viton.

Description:
Reactor for spectroscopic studies

The invention relates to a reactor for spectroscopic studies, enabling measurements in transmission mode and investigation of reaction products by research techniques, particularly such as IR spectroscopy, mass spectroscopy, or chromatography.

Infrared (IR) spectroscopy is commonly applied for analyses of samples in various aggregation states, because it is a universal method used for identification of molecular structure. IR spectroscopic studies yield an IR spectrum, which is a source of much useful information. The least complicated analytical methods include transmission spectroscopy, which consists in measuring of the light transmitted through the tested sample. In this case, scatter and absorption mechanisms occur, identified in the obtained spectrum, and due to a proper analysis, they allows for determining important physicochemical properties of the tested sample.

A scientific publication by I. Malpartida ef a/., "CO and NO adsorption for the IR characterization of Fe 2+ cations in ferrierite: An efficient catalyst for NO x SCR with NH 3 as studied by operando IR spectroscopy," Catalysis Today, Vol. 149, Iss. 3-4, January 30 th , 2010, discloses an IR reactor for spectroscopic studies of catalysis. The presented reactor comprises a steel cylinder with a toroidal sample holder inside, in which a tested sample is placed, having a form of a wafer. In the vicinity of the sample, a thermocouple is placed, introduced through a proper cylinder duct. A heater, providing a temperature of 723 K (approx. 450°C) in the reactor, is placed around the cylinder, in the area of the sample holder and the thermocouple. The IR reactor is installed in air-cooled holders, which provide maintaining a temperature below 573 K (approx. 300°C) at the chamber ends. Thereby, by using a Kalrez o-ring between the terminal windows and the chamber ends, it is possible to achieve a tightness reaching 30 bar. Application of a chamber filling in the form of KBr windows reduces the dead zone (the remaining space between the sample surfaces and the windows) to 0.12 cm 3 , and the optical path to below 3 mm.

From a scientific publication by H. Arakawa et al., "Novel high-pressure FT-IR spectroscopic system combined with specially designed in situ IR cell for studying heterogeneous catalytic reactions," Appl Spectrosc Volume 40, Issue 6, 1986, a reactor is known used in IR spectroscopy intended for studies on catalytic reactions. In general, the design of the IR reactor has a basically cylindrical body, having a sample placed in its central area. A gas inlet duct extends perpendicularly from the cylindrical body in the sample area, and a gas outlet duct extends in the opposite direction. A thermocouple is introduced over the sample through the gas inlet. A heater is placed around the cylindrical body. KBr poles are placed in the cylindrical body to reduce the gaseous volume around the sample. CaF 2 windows are placed at the ends of the cylindrical body, sealed using Viton o-rings. Water cooling channels are used in the areas of the ends of the cylindrical body.

Then, in a scientific publication by Wei Zheng Weng et al., "Mechanistic study of partial oxidation of methane to synthesis gas over supported rhodium and ruthenium catalysts using in situ time-resolved FTIR spectroscopy," Catalysis Today, Vol. 63, Iss. 2-4, Dec. 25 th , 2000, a high-temperature IR cell with a quartz insert and CaF 2 windows was applied for studies on catalytic phenomena. The design of the IR cell allows for heating the chamber from room temperature to 700°C. Also, a spot for a thermocouple placed at a distance from the sample, is planned in the design of the IR cell. Moreover, cooling water ports may be distinguished in the high-temperature cell, one of them being located near the end of the IR chamber body. The IR windows are placed on both sides of the cylindrical body and pressed down by the Kalrez o-ring so that it has no contact with the process gas. Also, gas ports connected to gas lines or to a vacuum system are present in the cited IR cell.

The technical problem faced by the present invention is providing such a reactor for spectroscopic studies, which is configured for tests in transmission mode, provides a wide stabilised range of sample activation temperatures, particularly from room temperature to approx. 1000 K, provides simultaneously a wide stabilised range of reaction course measurement temperatures, particularly from 100 K to 1000 K. It is also desirable for the reactor for spectroscopic studies that it would enable measurements under vacuum conditions, as well as under a gas flow, and simultaneously would protect from the contact of the gaseous medium with metal and polymer components of the reactor, while minimising the influence of the reaction chamber temperature on the operation of the polymer components, particularly sealing components, and gas desorption from such polymer components during studies at high temperatures. Surprisingly, the mentioned technical problems were solved by the present invention.

The invention relates to a reactor for spectroscopic studies, operating in transmission mode, comprising a reaction chamber, which includes a cylindrical tube, from which at least two connectors extend perpendicularly, delivering a gaseous working medium to a reaction zone in the reaction chamber, where the tested sample is placed, at least two optical windows, located at the ends of the reaction chamber's cylindrical tube, pressed to the reaction chamber and sealed with it by a window seal, heating and cooling system supported directly by the reaction chamber and placed basically around the reaction zone, at least two reactor fastenings fixing the opposite ends of the reaction chamber, characterised in that the reactor fastening includes a cooling agent duct, having an internal surface constituting the external surface of the reaction chamber, the cooling agent duct being sealed from the side of the heating and cooling system and from the vacuum side by a hydraulic seal, being in direct contact with the reaction chamber.

In a preferable embodiment of the invention, the whole reaction chamber is made of quartz.

In another preferable embodiment of the invention, the reaction chamber comprises a third connector, preferably perpendicular to the two connectors delivering the gaseous working medium, and perpendicular to the reaction chamber's cylindrical tube, through which a thermocouple is introduced into the vicinity of the sample, preferably in a plugged quartz pipe, preferably the thermocouple being coupled with the heating and cooling system.

In a further preferable embodiment of the invention, fillings, preferably quartz, with a cylindrical coaxial longitudinal hole, are inserted into the reaction chamber's cylindrical tube, preferably from two opposite ends, each filling having a length smaller than half of the length of the reaction chamber's cylindrical tube.

Preferably, the reactor fastenings are supported on a common frame.

Equally preferably, the heating and cooling system comprises a heater, surrounding the reaction chamber at least partially in the sample placement zone, and a cooling chamber, defined by an external shield and preferably a thermal shield, with coolant, preferably liquid nitrogen, being introduced into the cooling chamber by supply pipes.

In a preferable embodiment of the invention, a reactor seal is introduced between the reactor fastening and the window seal, sealed with the reactor fastening via a vacuum seal, remaining in a direct contact with the external surface of the reaction chamber.

In another preferable embodiment of the invention, the reactor seal is connected with the window seal using bolts, preferably three bolts.

In a further preferable embodiment of the invention, a vacuum seal is placed between the optical window and the window seal.

Preferably, the vacuum seals and/or the hydraulic seals constitute o-ring type seals, made of a polymer, preferably an elastomer, preferably Viton.

Due to its design, the reactor for spectroscopic studies according to the present invention, provides transmission-mode operation and enables application of various research techniques, such as IR spectroscopy, mass spectroscopy, or chromatography. Application of a reaction chamber constructed entirely of quartz, and a cooling system in the reactor fastenings to the frame, as well as a cooling-heating system, located in the central part of the reaction chamber and supported directly on the chamber, allowed for obtaining a broad range of sample activation temperatures from room temperature to a temperature of approx. 1000 K, as well as a broad range of reaction course measurement temperatures from 100 K to approx. 1000 K. Moreover, application of a thermocouple placed just above the sample, coupled with the cooling-heating system allowed for stabilising the operational temperature of the subject reactor for spectroscopic studies. In turn, use of quartz inserts placed in the reaction chamber's cylindrical tube enabled an effective reduction of the reaction zone volume in the reactor. Placement of the optical windows outside of the reaction chamber, with a sealing in the form of an externally applied vacuum seal with a clamp, allowed for obtaining a perfect tightness of the system, enabling measurements both under vacuum, and in a gaseous flow. Besides, thanks to this design, contact of metal components as well as polymer components (particularly elastomeric seals) of the reactor for spectroscopic studies with a hot working medium was avoided, thereby, the influence of the chemical character of the measurement chamber on the reaction course and the changes in composition of the reaction products analysed by a given research technique were avoided. Moreover, the coolant liquid ducts used in the reactor fastenings are sealed with a pair of o-ring type seals, which are cooled simultaneously by the coolant liquid introduced to the cooling duct, ensuring also cooling of terminal areas of the reaction chamber, and thereby the vacuum seals, without affecting the temperature in the reaction zone of the reactor for spectroscopic studies according to the present invention. Additionally, the design of the cooling ducts provides a direct contact of the coolant liquid with the heated reaction chamber, without intermediate components, which increases the cooling efficiency significantly.

Exemplary embodiments of the invention are shown in the drawing, wherein Fig. 1 shows an axonometric view of the reactor for spectroscopic studies according to one embodiment of the present invention, fig. 2 shows a front view of the reactor for spectroscopic studies of Fig. 1 , Fig. 3 shows a cross-section of the reactor for spectroscopic studies of Fig. 1 along the B- B plane marked in Fig. 2, Fig. 4 shows a side view of the reactor for spectroscopic studies of Fig. 1 , Fig. 5 shows a longitudinal section of the reactor for spectroscopic studies of Fig. 1 along the A-A plane marked in Fig. 4, Fig. 6 shows a magnification of the detail A of a holder of the reactor for spectroscopic studies marked in Fig. 5, Fig. 7 shows an axonometric view of the reaction chamber constituting a part of the reactor for spectroscopic studies illustrated in Fig. 1 , Fig. 8 shows a front view of the reaction chamber of Fig. 7, and Fig. 9 shows a cross-section of the reaction chamber of Fig. 7, along the A-A plane illustrated in Fig. 8. Example

A reactor for spectroscopic studies according to one embodiment of the present invention is shown in Figs 1-9. The main part of the reactor for spectroscopic studies is constituted by a reaction chamber 1 , made entirely of quartz, in the form of a tube with three quartz connectors 21 , 22, 23 welded-in inside it, as shown in Figs. 7-9. In this embodiment, the reaction chamber 1 consists of a quartz cylindrical tube with a diameter of 20 mm, into which the quartz connectors 21 , 22, 23 are welded in the form of cylindrical pipes with diameters providing minimisation of the system's volume and a good flow of the tested medium. The quartz connector 22 has a larger diameter, so that a possibility to introduce a plugged quartz pipe with a thermocouple 5 exists, which is shown in detail in the cross-section of the reactor for spectroscopic studies of Fig. 5. In the cross-section of the reactor for spectroscopic studies shown in Fig. 3, the quartz connectors 21 , 23 are connected to an inlet and an outlet of working gases 7.

The reaction chamber 1 is plugged using two optical windows 17, with optical parameters are selected depending on the type of the experiment carried out. In the cross-section of the reaction chamber 1 , presented in Fig. 9, the locations of the optical windows 17 in relation to the reaction chamber 1 is shown schematically, wherein the said optical windows 17 are in a direct contact with the reaction chamber 1. The sealing of the optical windows 16 in relation to the reaction chamber 1 is shown in the longitudinal section of the reactor for spectroscopic studies in Fig. 5, and in the magnification of the detail A, shown in Fig. 6.

Because of use of both high, and low temperatures and rapid temperature changes, the heating and cooling system is installed in the central part of the reaction chamber 1 and supported only on the chamber (as shown in Fig. 5). Such a solution provides a heat transfer between the heating and cooling system, and the fastening holders 14 and sealing of the reactor 15 only via the quartz reaction chamber 1 . A possibility to cool the quartz reaction chamber 1 to the temperature of the coolant liquid by cooling ducts 20, as shown in Fig. 6, is an additional advantage. The cooling ducts 20 are sealed from the side of the heating and cooling system by hydraulically sealing o-rings 19, and from the vacuum side by hydraulically sealing o-rings 19 and by vacuum-sealing o-rings 18. The coolant liquid supply to the cooling ducts 20 is realised via the coolant liquid couplings 9. The so-assembled system is Ieakproof in relation to the flowing coolant liquid, as well as airproof from the terminal side of the quartz reaction chamber 1 , and thereby provides a proper cooling of the quartz reaction chamber 1 in the area of the seals 19. The vacuum sealing o-rings 18 operate at a temperature stabilised by the coolant liquid. The heating and cooling system is fixed only to the quartz reaction chamber 1 and it consists of a heater 2 with a low thermal capacity, an external shield 4 enabling both application of a thermal shield 3, and introduction of the coolant, e.g. in the form of liquid nitrogen, into the cooling chamber 1 1 via pipes 10, which enable rapid cooling of the reaction chamber 1.

The reaction chamber 1 is fixed to the frame 8 using two fastening-sealing systems 15 and 16. Connection of these components is realised using bolts, namely three bolts per connection (visible, among others, in Fig. 4). The temperature of the reactor for spectroscopic studies according to the present invention may be controlled by the thermocouple 5 in a quartz casing placed just above the sample 6. In this case, the thermocouple 5 jest is fixed to the system by thermocouple fastening 13. In an alternative embodiment of the present invention, the temperature of the reactor for spectroscopic studies may be controlled also by a thermocouple integrated with the heater 2.

To minimise the volume of the reaction chamber 1 while maintaining a proper light transmission, quartz fillers 12 with proper longitudinal holes are used. The sample 6 is introduced to the reaction chamber 1 by inserting the first filler 12 to the cylindrical quartz tube at first, then the sample 6 and another filler 12 to an operating position. After mounting the optical windows 17, the optical windows seal 16 is introduced in the form of a clamp with a vacuum-sealing o-ring 18 (Viton o-ring), and then the assembly is tightened up using three bolts. As a result of clamping the vacuum-sealing o-ring 18, a tightness of the system is obtained with a seepage below l O^ mbar-l/s measured using a helium leak detector. All vacuum seals 18 operate at a temperature close to that of the liquid cooling the system, and thus, exceptionally favourable operating conditions of the elastomers used are obtained.

The presented solution provides a high tightness, a broad operating temperature range of the system and zero contact of the hot working medium with metal components, thereby eliminating a possible influence of the reaction of stainless steel and elastomers with the reagents. Because of the limitation of the impact of the hot tested gaseous medium forming during chemical reactions in the reactor according to the present invention, a concurrent application of other research methods is also possible, e.g. mass spectroscopy etc.