Method for producing hydrogen from gaseous hydrocarbons by organizing glow discharge in axisymmetric supersonic flow

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to a method for producing hydrogen from gaseous hydrocarbons by organizing a glow discharge in an axisymmetric supersonic flow in a Laval nozzle, which functions as an anode, with a central body, which functions as a cathode. The method consists of a glow discharge with a high degree of nonequilibrium being localized in the expanding region of a supersonic Laval nozzle with a central body, whereas in the highly nonequilibrium plasma, high-energy electrons break up molecules of gaseous hydrocarbons, and the resulting hydrogen atoms combine into hydrogen molecules and carbon atoms combine into carbon compounds.EFFECT: obtaining hydrogen from hydrocarbons with the simultaneous production of carbon nanostructures without the need for heating and the use of special catalysts, which increases the efficiency and environmental friendliness of the hydrogen production process.1 cl, 1 dwg

Description

[0001] The invention relates to devices for producing hydrogen from gaseous hydrocarbons.

[0002] A known method of producing hydrogen [USSR Patent No. 331648, class C01B 1 / 16, 1969 (Method of producing hydrogen, Akhmatov I.G., Gushchin A.D., Semenov V.P., Kharlamov V.V)] from hydrocarbons by two-stage conversion: steam and oxygen, followed by purification of the converted gas from carbon oxides, in which, in order to increase the product yield, steam conversion is carried out to a conversion degree of 50%, and the gas is first purified from carbon dioxide, then from carbon monoxide by combustion, followed by the use of combustion heat to carry out steam conversion. The disadvantage of this method is the presence of two stages of the technological process, which reduces the speed of processing, the need to use additional chemical reagents, which increases the cost of processing, the need to heat the reaction mixture to high temperatures, which reduces the energy efficiency of the processing.

[0003] A known method for the simultaneous production of hydrogen and a carbon-containing product involves introducing hydrocarbons into a reaction space and, in the presence of carbon-enriched granulate, subjecting them to thermal destruction into carbon and hydrogen. Part of the thermal energy required for the destruction of the hydrocarbons is provided by one or more gaseous heat carriers, wherein the thermal energy is generated outside the reaction space, and then the heated gaseous heat carrier is introduced into the reaction space. The gaseous heat carrier for the hydrocarbon destruction reaction is an inert gas or hydrogen, has a temperature in the range of 800 to 2200°C, preferably from 1000 to 1800°C, and transfers its heat to the reactant or reactants in the reaction space.The disadvantage of this method is the need to preheat the gaseous coolant to enormous temperatures, which reduces the energy efficiency of the method and can also be explosive if oxygen enters the reaction volume.

[0004] A method for producing hydrogen by dissociation of water is known [Russian Patent No. 2436729, cl. C25B1 / 04, 2008 (CARBON-FREE DISSOCIATION OF WATER AND CONCOMITANT PRODUCTION OF HYDROGEN AND OXYGEN, EVANS John W. (US), COYLE Edward L. (US))]. To implement this method, a plasma generator suitable for creating a zone of high-temperature, high-energy plasma is used. When producing hydrogen, as well as oxygen, by this method, the dissociation of water occurs at a very high temperature (usually over 9000°C) in a plasma environment. In addition to elemental hydrogen and oxygen, the product stream also contains any material used to facilitate the involvement of raw materials in the arc, such as water vapor or inert gases. The disadvantages of this method include the risk of explosion, as the process produces oxyhydrogen gas at temperatures exceeding 9000°C, as well as impurities in materials used to facilitate the involvement of raw materials in the arc, such as water vapor or inert gases.

[0005] A method for producing hydrogen is known [Russian Patent No. 2415072, cl. C01B3 / 061, 2008 (APPARATUS FOR PRODUCING HYDROGEN GASES USING A COMPOSITION INTENDED FOR PRODUCING HYDROGEN GASES, AND A COMPOSITION FOR PRODUCING HYDROGEN GASES, Dzung-Tae PARK (KR))] using an apparatus for producing hydrogen gas using a composition intended for producing hydrogen gas, which produces hydrogen gas (H2) from water (H2O) by performing a spontaneous thermochemical oxidation reaction using water at room temperature without supplying electricity. The composition required to carry out this method for producing hydrogen gas consists of 40-70 wt.% calcium oxide powder (CaO), 2-20 wt.% calcium chloride powder (CaCl2), magnesium chloride (MgCl2) or sodium bicarbonate (NaHCO3), 6.7-30 wt.% aluminum powder or aluminum oxide (Al2O3) and 0.001-10 wt.% iron or magnesium powder.In this method, the hydrogen gas production mixture reacts immediately and rapidly with water as soon as water is added, producing hydrogen gas (H2) and steam in a mixed state. Therefore, to remove impurities such as steam and oxygen from the resulting hydrogen gas and thereby obtain highly pure hydrogen gas, water removal devices, oxygen removal devices, and hydrogen gas drying devices are required. The disadvantages of this method include the need for a special reagent composition and the need for subsequent purification from water vapor and oxygen using filtration systems, which increases the duration and cost of the hydrogen production process and complicates its technology.

[0006] The technical result that the proposed method is aimed at achieving is the possibility of obtaining hydrogen from hydrocarbons with the simultaneous production of carbon nanostructures without the need for heating and the use of special catalysts, which increases the efficiency and environmental friendliness of the hydrogen production process.

[0007] The proposed method for producing hydrogen from gaseous hydrocarbons by generating a glow discharge in an axisymmetric supersonic flow is implemented in an axisymmetric supersonic Laval nozzle with a central body (Fig. 1). The gaseous hydrocarbons to be processed are fed into the confuser section 1 of the Laval nozzle and, in the critical section 4 of the Laval nozzle, acquire the speed of sound. As the gas continues to move along the diffuser, it expands adiabatically, decreasing its temperature and pressure, and increasing its flow velocity. A glow discharge is ignited in the diffuser section 2 of the Laval nozzle between the central body (cathode) and the Laval nozzle (anode). Electrons of the glow discharge, accelerated by the electric field, collide with molecules and break the molecular bonds of the hydrocarbons, resulting in the formation of carbon and hydrogen atoms.When hydrogen atoms collide with each other, they transform into hydrogen molecules, while carbon atoms combine into various nanostructures, such as fullerenes, graphene flakes, and soot nanoparticles. Acetylene can also form in small concentrations. These fusion reactions are facilitated by the presence of a gas of free atoms and low temperatures. In braking confuser 5, the subsonic flow is restored, also forming hydrogen molecules and carbon nanostructures.

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