RO137755A2 - METHOD AND INSTALLATION FOR THE PRODUCTION, SEPARATION AND STORAGE of 13CO2 FOR USE AS A PRECURSOR IN THE SYNTHESIS OF 13C-LABELED COMPOUNDS - Google Patents

Abstract

The invention relates to a method and a plant for producing, separating and storing 13C-labelled carbon dioxide, to be applied mainly as a precursor in the synthesis of 13C-labelled compounds, where 13CO2 can be obtained by the reaction between 13CO (gas) and O2 (gas) at atmospheric pressure and temperature, in the presence of a catalyst. According to the invention, the method comprises the following steps: a. catalyst activation in hydrogen flow, at 350°C and conversion of 13CO into 13CO2, at a temperature of 250°C, in a tubular reactor, b. separating 13CO2 from the reaction mixture, at a temperature of -140...-155°C, and storing it under pressure in a stainless steel collecting cylinder, c. collecting the non-reacted O2 and He and d. directly using the 13CO2 as a precursor in the synthesis of 13C-labelled compounds. The plant, as claimed by the invention, consists of cylinders (1, 2 and 3) with reaction gases of 13C, O2 and He, respectively, provided with electronic flowmeters (DE) for the control of gas flow, a gas premixing vessel (4), a tubular quartz reactor (5) with catalyst bed (7) for the conversion of 13CO to 13CO2, an electric oven (6), a gas chromatograph (8) for analysis of gases coming out of the reactor (5), a collecting cylinder (9) for separating and storing 13CO2 provided with a pressure gauge (M) and a collecting cylinder (11) for non-reacted O2 and He.

Description

METHOD AND PLANT FOR THE PRODUCTION, SEPARATION AND STORAGE ^{OF 13} CO ₂ FOR USE AS A PRECURSOR IN THE SYNTHESIS OF ¹³ C LABELED COMPOUNDS

The invention relates to a method and an installation for the production, separation and storage of carbon dioxide labeled with ¹³ C, with the main application as a precursor in the synthesis of compounds 1Ț 1Ț 1Ț labeled with C. CO ₂ can be obtained by the reaction between CO (gas) and O ₂ (gas) at atmospheric temperature and pressure, in the presence of a catalyst:

catalyst ¹³ CO + l/2O2 --------------> ¹³ CO2

T°C, p atm

Through the documentation we have identified this reaction as being studied for the oxidation of unlabeled CO to CO ₂ with direct application in environmental pollution control [S. Day, GC Dhal, "Catalytic conversion of carbon monoxide into carbon dioxide over spinel catalysts: An overview", Materials Science and Energy Technologies 2019, 2(3):575-588], or in elucidating the mechanism of heterogeneous catalytic reactions [R. Kopelent, A. Tereshchenko, A. Guda, G. Smolentsev, Luca Artiglia, VL Sushkevich, A. Bugaev, LI. Sadykov, T. Baidya, M. Bodnarchuk, JA van Bokhoven, M. Nachtegaal, OV Safonova, "Enhanced reducibility of the ceria-tin oxide solid solution modifies the CO oxidation mechanism at the platinum-oxide interface", ACS Catalysis 2021, ll (15):9435-9449], but no facility for the production, separation and storage of ¹³ CO ₂ has been identified.

The technical problem that the proposed invention solves is related to the yield of the process, because the mandatory condition in reactions involving isotopically labeled compounds (in the present case CO) is precisely the high yield in a single pass of the reactants through the reactor, considering that they are valuable and any loss as by-products increases the cost of the whole process.

Another advantage of the proposed method and facility is the relatively low costs considering that a single catalytic reactor is used and a single reaction product is obtained, easily separated and stored.

in the installation proposed in the present invention, ¹³ CO ₂ can be produced starting from ¹³ CO with

τ

The installation for the production, separation and storage of CO2 is shown schematically in Figure 1 and has three main modules: (i) the part for cutting and pre-mixing the working gases, (ii) the thermo-catalytic conversion part of CO to CO2 consisting of -a tubular quartz reactor and (iii) the CO2 capture and separation part consisting of a stainless steel cylinder, filled with stainless steel wire (or chip), equipped with an inert gas jacket.

A concrete example of the invention is given below. in the tubular quartz reactor 5 (fig. 1), having an inner diameter of 10 mm, a catalytic bed 7 having a length of 30 mm, consisting of catalyst (for example, N1/AI2O3 granules 0.1-0.2 mm) mixed with quartz granules (0.2-0.3 mm) with a role in canceling the pressure drop in the reactor. The reactor is placed in the electric furnace 6 and the three cylinders with reaction gases are connected: ¹³ CO (cylinder 1), O2 (cylinder 2) and He (cylinder 3) to the gas pre-mixing vessel 4. Helium acts as a gas carrier ensuring a constant flow through the catalytic bed. The gas chromatograph reactor 8 (GC-2010 Shimadzu), equipped with a HID detector (Helium lonisation Detector), is connected. before starting the CO to CO2 conversion reaction, the catalyst is activated in a hydrogen flow of 15 ml/min, at 350°C for 2 h, then it is switched to a helium flow of 80 ml/min and the temperature in the electric furnace 6 it is reduced to 250°C, the temperature at which the conversion of ¹³ CO to ¹³ CO2 takes place. When the temperature has reached 250°C, helium is admitted into the installation until the pressure in the capture bottle ¹³ CO2 9 (emptied beforehand) reaches the value of 1 bar, and the temperature inside it reaches the value of -110°C, using a Dewar 10 vessel with liquid nitrogen as a cooling agent. Once these conditions are met, CO is allowed in the installation with a flow rate of 25 ml/min and O2 with a flow rate of 20 ml/min, flows controlled with the help of DE electronic flow meters. The conversion of CO to CO2 is immediate, its formation, as well as the excess oxygen, are analyzed online in the gas chromatograph 8. The gases leaving the reactor are continuously collected in the capture bottle 9, thermostated at -140 + 155°C, temperature at which CO2 condenses, and unreacted oxygen and carrier gas (He) leave this product cylinder, in continuous flow, being collected in cylinder 11.

To determine the global yield, necessary for the validation of the method for the production of ¹³ CO2, 4.214 L of ¹³ CO were oxidized, from which 4.018 L of ¹³ CO2 were obtained, the obtained chemical yield being 95.3%.

Considering that the catalytic system does not contain carbon sources, the isotopic balance does not undergo changes during the oxidation, i.e. no isotopic dilutions can be observed. This is also confirmed by the results obtained by the isotopic analysis of the ¹³ CO2 product, carried out with a

mass spectrometer ISOPRIME 100, starting from ¹³ CO labeled with ¹³ C 2.07 ± 0.02 % at. CO2 was obtained with an isotopic concentration of 2.02 ± 0.02 % at., the observed difference is due to the errors of the isotopic analyses.

The installation proposed in this patent has a production capacity of 100 sl. CO2 per month.

Claims (2)

demand 1. Method for the production, separation and storage of carbon dioxide marked with C, characterized in that it will include the following steps: activation of the catalyst in a hydrogen flow at 350°C and conversion ^{of 13} CO to ¹³ CO2 at a temperature of 250°C in a tubular reactor; separating ¹³ CO2 from the reaction mixture at a temperature of -140 -155°C and storing it under pressure in a stainless steel capture cylinder; collection of unreacted O2 and He; direct use of CO2 as a precursor in the synthesis of C-labelled compounds. 2. Installation for applying the method according to claim 1, characterized in that it consists of: cylinders with reaction (working) gases - CO (1), O2 (2) and He (3), electronic flow meters for controlling the flow of gases (DE), gas premix vessel 4, tubular quartz reactor (5), equipped with a catalyst bed (7) for the conversion of CO to CO2, electric furnace (6), gas chromatograph 8 for analyzing the gases leaving the reactor, cylinder capture (9) for the separation and storage of CO2 equipped with manometer (M), cylinder (11) for the collection of unreacted O2 and He.