PL240039B1 - Method for the catalytic conversion of carbon monoxide or dioxide to methane and a catalyst bed for carrying out the method - Google Patents

Description

Description of the invention

The subject of the invention is a method of catalytic conversion of carbon monoxide or dioxide into methane, in combination with water sorption, based on nanoparticles of the active phase (ruthenium Ru, rhenium Re, palladium Pd) deposited on nickel (Ni) grains. It has been shown that such a reaction system can run with CO2 or CO conversion up to 100%, with full selectivity of methane synthesis at a temperature only slightly above the boiling point of water, i.e. 130 ° C.

Coal is a key element of human life and civilization. In particular, increasing concerns about the anthropogenic effects of climate change have brought the present inventors' attention to the delicate environmental balance of carbon dioxide. On the one hand, CO2 production poses a threat to the security of energy supply, due to the potential need to significantly reduce the level of energy exhaust emissions. On the other hand, the availability of CO2 is an opportunity for the development of new environmentally friendly, sustainable technologies based on this raw material [Z. W. Seh, J Kibsgaard, C. F. Dickens, I. Chorkendorff, J. K. N0rskov, T. F. Jaramillo, Science 355 (2017) 1-12]. Consequently, CO2 can be an attractive, renewable, safe and low-cost component Ci for fuel engineering or organic chemistry. However, this potential is limited by the high thermodynamic stability of the CO2 molecule, and therefore both new chemistry (new solutions that go beyond the hitherto accepted patterns of thought) and technology are required for economically efficient processing of CO2. Methanation, a process in which CO2 is reacted with hydrogen to form methane and water, is a model example of managing the surplus of this raw material. In fact, methane is an important mass product that is in demand in chemistry and energy. Moreover, the methanation process has been suggested as a method of storing energy, in particular renewable energy, in the so-called method of converting energy into gas [M. Gotz, J. Lefebvre, F. Mors, A. McDaniel Koch, F. Graf, S. Bajohr, R. Reimert, T. Kolb, Renewable Energy 85 (2016) 1371-1390]. This explains why, despite the controversial unfavorable economy clearly hampering technological progress in this field, the potential of CO2 methanation has attracted a lot of attention, especially in the field of environmental catalysis. Methanation processes are complex multi-stage processes involving various mechanisms [B. Miao, S.S. Khine Ma, X. Wang, H. Su, S. H. Chan, Catal. Sci. Technol. 6 (2016) 4048-4058]. For example, a detailed study of Ni-catalyzed methanation [C. W. Hu, J. Yao, H. Q. Yang, Y. Chen, A. M. Tian, J. Catal. 166 (1997) 1-7] disclose at least six steps of carbon formation and carbon methanation [S. J. Choe, H. J. Kang, S. J. Kim, S. B. Park, D. H. Park, D. S. Huh, Bull. Korean Chem. Soc., 26 (2005) 1682-1688]. It is worth noting that temperature plays a role in the reaction mechanisms and then in their thermodynamics and kinetics. Accordingly, at a fundamental level, the thermodynamics of methanation is much more favorable at low temperatures, where methanation dominates the reverse process of the water-gas shift reaction (WGSR) [J. Gao, Q. Liu, F. Gu, B. Liu, Z. Zhongc, F. Su., RSC Adv., 5 (2015) 22759-22776]. Various metals, for example Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt, usually active at 300-400 ° C, have been discovered as useful methanation catalysts [A. L. Kustov, A. M. Frey, K. E. Larsen, T. Johannessen, J. K. Norskov, C. H. Christensen, Appl. Catal. A 320 (2007) 98-104 and F. Solymosi, A. Erdohelyi, M. Kocsis, J. Chem. Soc., Faraday Trans. 77 (1981) 1003-1012 and A. Erdohelyi, M. Pasztor, F. Solymosi, J. Catal. 98 (1986) 166-177 and Z. Zhang, A. Kladi, X. E. Verykios, J. Catal. 148 (1994) 737-747]. In turn, the engineering of various metal oxide-based catalysts, as well as the mechanisms of their activity, are discussed in detail in the publicly available literature [J. Jia, C. Qian, Y. Dong, Y. F. Li, H. Wang, M. Ghoussoub, K. T. Butler, A. Walsh, G, A. Ozin, Chem. Soc. Rev. 46 (2017) 4631-4644]. In particular, it describes the significance of the disadvantages of the oxide structures. In practice, the lowest operating temperature for catalytic methanation was recorded for the Ru catalyst, namely the Ru / TiO2 system, in which Ru nanoparticles were mounted on a support using the polygonal barrel-sputtering method with an initial operating temperature of 160 ° C. At the same time, the analogous Ru / TiO2 catalyst produced by the wet method required a reaction temperature higher by about 100 ° C, i.e. about 260 ° C [T. Abe, M. Tanizawa, K. Watanabe, A. Taguchi, Energy Environ. Sci. 2 (2009) 315-321]. On the other hand, Ru nanoparticles passivated with oxide on SiO2 or Ni supports can be an efficient methanation catalyst at the initial reaction temperature of about 150 ° C [J. Polański, T. Siudyga, P. Bartczak, M. Kapkowski, W. Ambrożkiewicz, A. Nobis, R. Sitko, J. Klimontko, J. Szade, J. Lelątko, Appl. Catal., B 206 (2017) 16- 23].

On a technical level, temperature is an important parameter that determines the potential for using the exothermic heat of the methanation process, as well as for cracking or sintering the catalyst.

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Catalytic methanation reactors typically operate in the temperature range of 200-550 ° C and pressures in the range of 1-100 bar [M. Gotz, J. Lefebvre, F. Mors, A. McDaniel Koch, F. Graf, S. Bajohr, R. Reimert, T. Kolb, Renewable Energy 85 (2016) 1371-1390]. Catalyst deactivation involves a variety of processes, including poisoning, coking and sintering, generally intensifying with increasing process temperature [M. Gotz, J. Lefebvre, F. Mors, A. McDaniel Koch, F. Graf, S. Bajohr, R. Reimert, T. Kolb, Renewable Energy 85 (2016) 1371-1390, and A.L. Roes, M.K. Patel, J. Clean. Prod. 19 (2011) 1659-1667]. The deposition of the carbon deposit can begin at temperatures as low as 200-450 ° C [J. Engbaek, O. Lytken, J. H. Nielsen, I. Chorkendorff, Surf. Sci. 602 (2008) 733-743], for example, specific forms of carbon formed on the surface of Ni-AEOs at about 220 ° C were investigated by McCarty et al., [J. G. McCarty and H. Wise, J. Catal. 1979,57,406-416]. The sintering of the metal, in turn, turned out to be a further complication causing the deactivation of the Ni-based catalyst, which can proceed at a relatively low temperature of 230 ° C. These processes may involve complex mechanisms, for example migration of Ni carbonyls [M. Agnelli, H. M. Swaan, C. Marquez-Alvarez, G. A. Martin, C. Mirodatos, J. Catal. 175 (1998) 117-128].

Accordingly, an effective low temperature methanation catalyst is critical to maintaining favorable thermodynamics as well as minimizing catalyst deactivation. Lower temperatures prevent stresses and sintering of the catalyst grains with active centers. In current industrial practice, catalysts are designed to operate at temperatures below 320 ° C, where by-products of the reverse water-gas shift (RWGS) reaction appear [X. Xu, J. Moulijn, Energy Fuels 10 (1996) 305-325]. High porosity and uniform dispersion of active centers on a support with a large specific surface area were indicated among the most key technical issues determining the successful construction of low-temperature catalysts. In the context of these considerations, it should be mentioned that the use of a metal-organic backbone with a very large surface area (2961 m ² g ^-1 ) as a potential Ni carrier has been recently tested. The selectivity of CH4 was 100%, and the catalyst was tested in the temperature range of 200-300 ° C, while the conversion at 300 ° C reached about 75% [W. Zhen, B. Li, G. Lu, J. Maa, Chem. Commun. 51 (2015) 1728-1731]. Water sorption, which accompanies the production of methane as a by-product of the reaction of CO2 with H2, is another idea for improving the reaction. The developed catalytic systems allowed to achieve 100% conversion at a temperature of 250-350 ° C in Ni / zeolite systems [A. Borgschulte, N. Gallandat, B. Probst, R. Suter, E. Callini, D. Ferri, Y. Arroyo, R. Erni, H. Geerlings, A. Zuttel, Phys. Chem. Chem. Phys. 15 (2013) 9620-9625].

In the patent description EP0044740A1 [W. J. Ball, D. G. Stewart, 1980] describes silicate-based catalysts containing one or more metals: cobalt, iron, manganese, nickel, ruthenium, palladium, zinc, chromium and copper in the production of C1-C4 light hydrocarbons or their oxidized derivatives (methanol, ethanol). The products are prepared by passing synthesis gas (CO: H 2 = 1: 2 molar) through a flow reactor in the temperature range 150-450 ° C at 1-700 bar, achieving a CO conversion in the range 4-22%.

The foreign patent literature also describes the process of enriching synthesis gas with hydrogen by converting carbon monoxide and water vapor on a catalyst containing spinel structures consisting mainly of zinc and aluminum oxides and promoters (Na, K, Rb, Cs, Cu, Ti, Zr, rare earth elements and mixtures thereof). The catalysts were tested in the temperature range of 300-400 ° C in the pressure range of 2.3-6.5 MPa, in which the synthesis gas has an oxygen to carbon molar ratio of 1.69 to 2.25. The dry gas composition was approximately 15% CO, 10% CO2, 72% H2 and 3% Ar. The steam / gas mole ratio (S / G) was 0.07, corresponding to an oxygen / carbon mole ratio (O / C) of 1.69. [N.C. Schi0dt, WO2010000387A1,2008].

Also disclosed is a solution relating to catalysts and their precursors for the selective conversion of carbon oxides to methane and / or other hydrocarbons. The catalyst precursors include one or more refractory oxides selected from the group consisting of rare earth oxides (Tb, Er, Pr, Sm, Y, Yb, La, Dy, Ce, Eu, Ho, Lu, Tm, Gd) and perovskites containing Rare earth metals, the precursor containing mainly nickel or nickel cations or other metals (Fe, Co, Ni, Ru, Rh, Pt, Mg, Ca, Ba, Ti, Zr, V, Nb, Ta, Cr, Mo, Mn , Al, Ga, In) sufficient to provide a catalyst by reducing the precursor to be able to at least partially reduce the carbon monoxide to a hydrocarbon product. Methods for making such catalysts and catalyst precursors are also disclosed, as are processes for converting carbon oxides to methane and / or other hydrocarbons. The catalysts were tested in the temperature range of 250-550 ° C under atmospheric pressure, obtaining 21 to 58% methane in the gas mixture [K.E. Henville, G.J. Millar, J. A. Alarco, WO2000016901A1, 1998].

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In the patent specification US2019151825A1 [H. Kim, B.K. Kim, H.W. Lee, J.H. Lee, J.W. Son, K.J. YOON, S. J. CHOI, S.M. Choi, 2017] also describes a metal / support catalyst for the conversion of carbon dioxide to methane. In this solution, the metal is an element from the group of transition metals (Ni, Ti, V, Cr, Mn, Le, Co, Cu and Zn), while the support contains a perovskite type oxide (ABO3 type) on which the active metal is deposited. Perovskite (ABO3 type) is made of zirconates or Ba, Sr ceramics or their compositions doped with Y, Nd, Sm, Yt, In, Eu, Gd. The metal / carrier catalyst allows the conversion of carbon dioxide into methane by increasing the catalytic activity in the Sabatier reaction to as a result of promoting the formation of hydroxide ions and formate, which is an intermediate product in the conversion of carbon dioxide to methane. In the solution, no noble metals mentioned from the group: Ru, Rh, Pd, Ag, Ir, Pt and Au were used as the active metal. The Sabatier reaction was carried out in the temperature range of 300-600 ° C, obtaining a CO2 conversion to methane in the range of 40-100%.

In another patent specification US2017056861A1 [M. Landau, M. Herskowitz, R. Vidruk, 2013] also disclosed a catalyst having a spinel structure of formula [Le ²⁺ (Le ³⁺ yAl ³⁺ 1-y) 2O4] with the possibility of its application in the hydrogenation reaction of a gas containing carbon dioxide. For example, for the Fe2O3-Fe-Al-O-spinel catalyst with the content of up to 40% of the Fe2O3 (hematite) phase, about 52% conversion of CO2 to CH4 was obtained at the temperature of 300 ° C, pressure of 10 atm. and the ratio of H2 / CO2 = 4.

Polish patent description No. 220538 describes a method of obtaining nickel methanation catalysts in the process of continuous precipitation, calcination, reduction and passivation. It is characterized in that a catalyst precursor containing, expressed as oxides, more than 75 wt. % nickel, 10-20 wt. % of aluminum, 1-5%, preferably 1.5-3.5% by weight. cerium and / or lanthanum and not more than 0.5%, preferably 0.1% by weight. alkali metals having a hydrotalcite structure of at least 70%, preferably more than 90%, which is calcined. Then it is mixed with active aluminum hydroxide and the resulting mixture containing 50-88% aluminum hydroxide is formed into extrudates and dried or mixed with aluminum oxide and aluminum cement, and the resulting mixture containing 10-80% aluminum oxide and 10-30% aluminum cement is formed into is balled by the disc granulation method, seasoned in an atmosphere of water vapor and dried.

Polish patent description No. 220558 describes a method of obtaining nickel methanation catalysts of small amounts of carbon oxides, promoted by the addition of cerium and / or lanthanum, characterized in that the starting material is a catalyst precursor containing, calculated as oxides, more than 75% of nickel , 10-20% aluminum, 1-5% cerium and / or lanthanum and less than 0.5% alkali metals, hydrotalcite structure more than 70%, preferably 90%, mixed with technical aluminum hydroxide and calcined at a temperature of up to 900 ° C within 10 s or the catalyst precursor is calcined at temperatures of 350-450 ° C and mixed with active alumina, then the powder mixture containing 66-83% alumina is formed into spheres using the disc granulation method, seasoned in a water vapor atmosphere and dries to obtain the finished product.

The Polish patent specification No. 207 415 describes a catalyst for the conversion of carbon monoxide in the temperature range 300-480 ° C, containing iron, chromium and copper oxides, which is characterized by the fact that it consists of iron oxide in an amount from 50% to 82%, chromium oxide from 5% to 10%, copper oxide from 1% to 3% as essential ingredients and aluminum oxide and / or lanthanum oxide and / or cerium oxide and / or cobalt oxide from 0.2% to 5% as factors improving the activity, insensitivity to long-term exposure to elevated temperature and catalyst strength.

Polish patent specification No. 206,338 describes a catalyst for the conversion of carbon monoxide obtained in the process of continuous precipitation of the catalyst precursor in a circulation system, simultaneously dosing the circulating suspension of the precursor with a temperature of 50 to 100 ° C and a pH of 7 to 8.5, acid solution of nitrates copper and zinc at a concentration of 150-250 g / dm ³ and an alkaline solution of sodium or potassium aluminate and possibly sodium or potassium carbonate at a concentration of 5-20 g Al / dm ³ and a weight ratio of sodium or potassium carbonate to sodium or potassium hydroxide from 0 to 20. Precipitation of the precursor is carried out under a turbulent flow of the suspension while maintaining the Reynolds number of 105 <Re <106 and a constant volume ratio of the circulation stream to the metered streams in the range from 10 to 100. The precipitated precursor is aged by optionally mixing with dust graphite at a temperature of 50-115 ° C for a period of at least 1 h, after which it is repeatedly filtered and washed with water, and the last filtration is carried out using water or optionally a solution of cesium and / or potassium salt and / or hydroxide. After drying, the precursor is granulated and molded, and then the formed precursor is calcined to obtain

The finished product or crushes, tablets and calcines to obtain the finished product, or calcines, crushes and pellets to obtain the finished product, it contains 30-60% by weight of CuO, 10-30% by weight of Al2O3 and optionally 0.3-2% by weight of CS2O and / or K2O, and no more than 0.1% by weight of Na2O.

Polish patent description No. 177557 describes a catalyst for low-temperature conversion of carbon monoxide with steam in the form of a monolithic block composed of electrochemically etched aluminum foils covered with a catalytically active layer. The catalytic layer consists of: 25-65% by weight of CuO, 22-45% by weight of ZnO and 13-30% by weight of Al2O3. The subject of the invention is also a method of producing a catalyst, which consists in the fact that a mixture of co-precipitated oxides of copper, zinc and aluminum is ground to a grain diameter of less than 0.12 mm and dissolved at 25-120 ° C in 25-80% in acid lemon at a concentration of 0.6-0.8 g / ml. The resulting solution is applied to the etched aluminum foils by impregnating or coating the surface of the support by known methods. After drying, the aluminum foil is rolled into a monolith and fired at 400 ° C for 3 hours.

The Polish patent specification No. 206854 describes a method of obtaining a catalyst for high-temperature conversion of carbon monoxide, consisting in preparing a solution of a soluble iron (II) salt and a soluble copper (II) salt and sodium dichromate (VI) at a temperature of 55-90 ° C and introducing it into at 55-90 ° C to a sodium hydroxide solution prepared in such an amount that the final pH of the mixture is between 9 and 12. The resulting precipitate is filtered off, dried and, after adding the lubricant, formed into the desired catalyst shapes.

The known solutions in the field of methane methane of carbon oxides are carried out at high temperatures, which results from the low activity of the catalysts used. Most often, the process is carried out at temperatures above 250 ° C, even up to 600 ° C. Tests conducted at temperatures around 150 ° C are known, but low conversion rates are usually achieved. The method of carrying out the reaction at high temperature affects the economy of the process and introduces inconveniences related to intensive heating of the catalytic bed. Contrary to the known solutions, the present invention allows these drawbacks to be significantly reduced by carrying out the reaction at a much lower temperature.

Known methods of catalytic methanation are usually carried out at relatively high temperatures, which adversely affects the economics of the process. The aim of the present inventors was to develop a catalytic bed and a method for catalytic conversion of carbon monoxide or dioxide to methane using this bed, which will allow for effective methanation of the above-mentioned oxides in a low-temperature process.

The solution according to the present invention presents the results of research on the low-temperature methanation potential of carbon monoxide or carbon dioxide in combination with water sorption based on Re, Ru, Pd nanoparticles, passivated with their oxide deposited on Ni grains. It has been shown that this reaction system can run with CO / CO 2 conversion up to 100% with full methane synthesis selectivity at a temperature only slightly above the boiling point of water, i.e. at 130 ° C.

The essence of the invention is a process for the catalytic conversion of carbon monoxide or dioxide to methane, consisting in a gas stream in the form of CO + H2 in the proportions from 0.5: 3 to 2: 3, preferably 1: 3, or a gas stream in the form of CO2 + H2 in proportions from 0.5: 4 to 2: 4, preferably 1: 4, are passed with a flow rate ranging from 0.5 to 10 dm ³ / h, preferably 3 dm ³ / h, through at least one an adsorption layer with a catalytic bed in the form of a nickel catalytic support in the form of a powder with a grain size of 2 to 170 μm, preferably 50 μm, on which an active phase is deposited in the form of nanoparticles of transition metals from groups 7-11 of the periodic table selected from: Re , Ru, Pd, with nanoparticle sizes from 1 to 100 nm, preferably below 20 nm, most preferably <10 nm, the content of nanoparticles of the active phase on the surface of the catalytic support is from 0.5% to 2% m / m, and the process is carried out by from -20 ° C to 350 ° C, preferably at a temperature above 90 ° C, and after lowering the activity of the catalytic bed, it is preferable to prepare the system for the next cycle by carrying out a regeneration process consisting in removing reaction residues adsorbed on the catalyst, especially water, by passing - at a temperature above 105 ° C, preferably above 130 ° C - through the catalytic bed of the hydrogen stream.

Preferably, the catalyst adsorption layer is made of aluminosilicates, including halloysite and zeolites, especially molecular sieves, most preferably 4A molecular sieves.

Preferably, the ratio of the catalytic bed layer to the adsorption layer is in the range of 1: 0.1 parts. wt. up to 1: 10 pcs. wt., preferably 1: 2 pts. wt.

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Preferably, the process is carried out continuously in a system of at least two reactors connected in parallel, equipped with reaction byproduct removal nodes within the reaction zone, in such a way that alternately, while an oxide or dioxide conversion reaction is carried out in one reactor. coal to methane, the catalytic bed regeneration process is carried out in the second reactor in parallel, and the heat recovered in the bed regeneration process is used to preheat the reactant stream in the reactor in the methane production phase.

The essence of the invention is also a catalytic bed for the catalytic conversion of carbon monoxide or dioxide into methane, characterized in that it is in the form of a nickel catalytic support in the form of a powder with grain sizes from 2 to 170 μm, preferably 50 μm, on which is deposited an active phase in transition metal nanoparticle forms from groups 7-11 of the periodic table selected from: Re, Ru and Pd, with nanoparticle sizes from 1 to 100 nm, preferably below 20 nm, most preferably <10 nm, the content of nanoparticles of the active phase on the surface of the catalytic support is from 0.5% to 2% m / m.

The main advantages of the solution according to the invention are:

- low energy consumption of the process resulting from the course of the reaction at low temperatures, compared to known solutions in the field; conducting the process in such conditions also significantly reduces investment costs and safety of its implementation;

- in the conversion process according to the invention, the residual enthalpy of gases containing carbon monoxide and carbon dioxide is used, which allows to reduce the energy consumption at the stage of conversion and regeneration of the catalytic bed;

- low catalyst production costs, resulting from the low content of active metals on the support surface;

- ease of catalyst regeneration without the need to remove the bed from the reactor; the regeneration can be carried out automatically on the basis of the achieved conversion rates measured in the gases leaving the catalytic reactor.

The subject of the invention is presented in the following examples of implementation and in the drawing, in which Fig. 1 shows a diagram of a system that takes into account the use of a bifunctional catalyst with sorption layers, enabling the simultaneous conduct of methanation reaction with water sorption as well as catalyst regeneration.

P r z k ł a d 1

In a 7.5 mm diameter flow reactor with a fixed bed, 200 mg of the catalyst in the form of Ru nanoparticles with sizes ranging from 1-100 nm, mainly 10 nm, were placed on Ni powder with a grain size of 50 μm, maintaining the ratio of 1% Ru / Ni . The catalyst is arranged in the form of two layers of 100 mg, each of them is placed on the adsorption layer (4A molecular sieves) absorbing water vapor, in the amount of 200 mg each adsorption layer. The flow reactor was fed with a stream of CO + H2 gases in a volume ratio of 1: 3 with a constant flow rate of 2 dm ³ / h.

In the gas stream flowing out of the reactor, the methane content was analyzed using a flow gas analyzer. Carrying out the process at a temperature of 100 ° C, after a few milliseconds, a CO conversion level of 27.1% was achieved. During the 10-hour test, no decrease in catalyst activity was observed. After the conversion process was completed, the catalyst was regenerated by passing a stream of hydrogen through the catalytic bed at the temperature of 135 ° C for 1 hour.

P r z k ł a d 2

In a flow reactor with a diameter of 7.5 mm with a fixed catalyst bed, 200 mg of the catalyst in the form of Ru nanoparticles with sizes in the range 1-100 nm, mainly 10 nm, were placed on Ni powder with a grain size of 50 μm (maintaining the ratio of 1% Ru / Ni). The catalyst was arranged in the form of five layers of 40 mg, and each of them was placed on an adsorption layer (4A molecular sieves) absorbing water vapor, 80 mg each for each adsorption layer. The flow-through reactor was fed with a stream of CO2 + H2 gases in a volume ratio of 1: 4 with a constant flow rate of 2 dm ³ / h. In the gas stream flowing out of the reactor, the methane content was analyzed using a flow gas analyzer. Carrying out the process at 135 ° C, a CO2 conversion level of 97.9% was achieved after a few milliseconds. After the adsorption layer is saturated

A decrease in CO2 conversion was observed, and at a conversion level of 70%, the catalyst regeneration process was carried out by passing a stream of hydrogen through the catalytic bed at 135 ° C for 1 hour.

P r z k ł a d 3

In a flow reactor with a diameter of 7.5 mm with a fixed catalyst bed, 200 mg of catalyst in the form of Pd nanoparticles with sizes in the range 1-100 nm, mainly about 8 nm, were placed on Ni powder with a grain size of 5 μm (maintaining the proportions 1.5 % Pd / Ni). The catalyst was arranged in the form of three layers, 66.7 mg each, and each of them is placed on an adsorption layer (zeolite type ZSM-5) absorbing water vapor, 133.4 mg each adsorption layer. The flow-through reactor was fed with a stream of CO2 + H2 gases in a volume ratio of 1: 4 with a constant flow rate of 3 dm ³ / h.

In the gas stream flowing out of the reactor, the methane content was analyzed using a flow gas analyzer. Carrying out the process at a temperature of 197 ° C, after a few milliseconds, a CO2 conversion level of 34.4% was achieved. During the 12-hour test, no decrease in catalyst activity was observed. After the conversion process was completed, the catalyst was regenerated by passing a stream of hydrogen through the catalytic bed at the temperature of 142 ° C for 1 hour.

P r z k ł a d 4

In a flow reactor with a diameter of 7.5 mm with a fixed catalyst bed, 200 mg of catalyst in the form of nanoparticles Re with sizes in the range 1-100 nm, mainly about 5 nm, were placed on Ni powder with a grain size of 150 μm (maintaining the proportions 0.8 % Re / Ni). The catalyst is arranged in the form of four layers of 50 mg, each of them is placed on the adsorption layer (halloysite) absorbing water vapor, in the amount of 100 mg each adsorption layer. The flow reactor was fed with a stream of CO + H2 gases in a volume ratio of 1: 3 with a constant flow rate of 3 dm ³ / h.

In the gas stream flowing out of the reactor, the methane content was analyzed using a flow gas analyzer. Conducting the process at a temperature of 229 ° C, after a few milliseconds, a CO conversion level of 72.0% was achieved. During the 10-hour test, no decrease in catalyst activity was observed. After the conversion process was completed, the catalyst was regenerated by passing a stream of hydrogen through the catalytic bed at the temperature of 133 ° C for 1 hour.

P r z k ł a d 5

In a 7.5 mm diameter flow reactor with a fixed bed, 200 mg of the catalyst in the form of Ru nanoparticles with sizes ranging from 1-100 nm, mainly 10 nm, were placed on Ni powder with a grain size of 50 μm, maintaining the ratio of 1% Ru / Ni . The catalyst was arranged in the form of three layers, 66.7 mg each, and each of them is placed on the adsorption layer (4A molecular sieves) absorbing water vapor, 133.4 mg each adsorption layer. The flow-through reactor was fed with a stream of CO + H2 gases in a volume ratio of 1: 3 with a constant flow rate of 1.5 dm ³ / h.

In the gas stream flowing out of the reactor, the methane content was analyzed using a flow gas analyzer. Conducting the process at -7 ° C, after a few milliseconds, a CO conversion level of 1.2% was achieved. During the 10-hour test, no decrease in catalyst activity was observed. After the conversion process was completed, the catalyst was regenerated by passing a stream of hydrogen through the catalytic bed at the temperature of 135 ° C for 1 hour.

Claims (5)

A method of catalytic conversion of carbon monoxide or dioxide to methane, characterized in that the gas stream in the form of CO + H2 in the proportions from 0.5: 3 to 2: 3, preferably 1: 3, or the gas stream in the form of CO2 + H2 in the proportions 0.5: 4 to 2: 4, preferably 1: 4, is passed with a flow rate ranging from 0.5 to 10 dm ³ / h, preferably 3 dm ³ / h, through at least one adsorption layer placed in the reactor with a catalytic bed in the form of a nickel catalytic support in the form of a powder with grain sizes PL 240 039 B1 from 2 to 170 μm, preferably 50 μm, on which the active phase is deposited in the form of nanoparticles of transition metals from groups 7-11 of the periodic table selected from: Re, Ru, Pd, with nanoparticle sizes from 1 to 100 nm, preferably below 20 nm, most preferably <10 nm, the content of nanoparticles of the active phase on the surface of the catalytic support is from 0.5% to 2% m / m, and the process is carried out at a temperature of -20 ° C to 350 ° C, preferably at a temperature above 90 ° C, and after lowering the activity of the catalytic bed, it is preferable to prepare the system for the next cycle by carrying out the process of its regeneration consisting in removing reaction residues adsorbed on the catalyst, especially water, by passing - at a temperature above 105 ° C, preferably above 130 ° C - through the catalytic bed of the hydrogen stream. 2. The method according to p. The method of claim 1, characterized in that the catalyst adsorption layer is made of aluminosilicates, including halloysite and zeolites, especially molecular sieves, most preferably 4A molecular sieves. 3. The method according to p. The process of claim 1, wherein the ratio of the catalytic bed layer to the adsorption layer is in the range of 1: 0.1 part. wt. up to 1: 10 pcs. wt., preferably 1: 2 pts. wt. 4. The method according to p. Process according to claim 1, characterized in that the process is carried out continuously in a system of at least two reactors connected in parallel, equipped with reaction byproduct removal nodes within the reaction zone, in such a way that the reaction is performed alternately in one reactor. the conversion of carbon monoxide or dioxide to methane, the catalytic bed regeneration process is carried out in the second reactor in parallel, and the heat recovered in the bed regeneration process is used to preheat the reactant stream in the reactor in the methane production phase. 5. Catalytic bed for the catalytic conversion of carbon monoxide or dioxide to methane, characterized in that it is in the form of a nickel catalytic support in the form of a powder with a grain size of 2 to 170 μm, preferably 50 μm, on which an active phase in the form of metal nanoparticles is deposited transients from groups 7-11 of the periodic table selected from: Re, Ru and Pd, with a nanoparticle size from 1 to 100 nm, preferably below 20 nm, most preferably <10 nm, with the content of active phase nanoparticles on the surface of the catalytic support is from 0, 5% to 2% m / m.