Getting methane from carbon dioxide is a process that requires laboratory conditions. So, in 2009, at the University of Pennsylvania (USA), methane was produced from water and carbon dioxide using nanotubes consisting of TiO 2 (titanium dioxide) and containing an admixture of nitrogen. To obtain methane, the researchers placed water (in a vapor state) and carbon dioxide inside metal containers, closed with a lid with nanotubes on the inside.
The process of obtaining methane is as follows - under the influence of the light of the Sun, particles appeared inside the tubes that carry an electric charge. Such particles separated water molecules into hydrogen ions (H, which then combine into hydrogen molecules H 2) and hydroxyl radicals (-OH particles). Further, in the process of obtaining methane, carbon dioxide was split into carbon monoxide (CO) and oxygen (O 2). Finally, the carbon monoxide reacts with hydrogen to produce water and methane.
The reverse reaction - the production of carbon dioxide occurs as a result of steam deformation of methane - at a temperature of 700-1100 ° C and a pressure of 0.3-2.5 MPa.
Farms annually face the problem of manure disposal. Considerable funds are wasted, which are required for organizing its removal and burial. But there is a way that allows you not only to save your money, but also to make this natural product serve you for the good.
Prudent owners have long been using eco-technology in practice, which makes it possible to obtain biogas from manure and use the result as fuel.
Therefore, in our material we will talk about the technology for producing biogas, we will also talk about how to build a bioenergy plant.
Determination of the required volume
The volume of the reactor is determined based on the daily amount of manure produced on the farm. It is also necessary to take into account the type of raw materials, temperature and fermentation time. In order for the installation to work fully, the container is filled to 85-90% of the volume, at least 10% must remain free for gas to escape.
The process of decomposition of organic matter in a mesophilic plant at an average temperature of 35 degrees lasts from 12 days, after which the fermented residues are removed and the reactor is filled with a new portion of the substrate. Since the waste is diluted with water up to 90% before being sent to the reactor, the amount of liquid must also be taken into account when determining the daily load.
Based on the given indicators, the volume of the reactor will be equal to the daily amount of the prepared substrate (manure with water) multiplied by 12 (time required for biomass decomposition) and increased by 10% (free volume of the tank).
Construction of an underground structure
Now let's talk about the simplest installation, which allows you to get at the lowest cost. Consider building an underground system. To make it, you need to dig a hole, its base and walls are poured with reinforced expanded clay concrete.
From opposite sides of the chamber, inlet and outlet openings are displayed, where inclined pipes are mounted for supplying the substrate and pumping out the waste mass.
The outlet pipe with a diameter of about 7 cm should be located almost at the very bottom of the bunker, its other end is mounted in a rectangular compensating container into which waste will be pumped out. The pipeline for supplying the substrate is located at a distance of approximately 50 cm from the bottom and has a diameter of 25-35 cm. The upper part of the pipe enters the compartment for receiving raw materials.
The reactor must be completely sealed. To exclude the possibility of air ingress, the container must be covered with a layer of bituminous waterproofing.
The upper part of the bunker is a gas holder having a dome or cone shape. It is made of metal sheets or roofing iron. It is also possible to complete the structure with brickwork, which is then upholstered with steel mesh and plastered. On top of the gas tank, you need to make a sealed hatch, remove the gas pipe passing through the water seal and install a valve to relieve gas pressure.
To mix the substrate, the unit can be equipped with a drainage system operating on the bubbling principle. To do this, vertically fasten plastic pipes inside the structure so that their upper edge is above the substrate layer. Poke a lot of holes in them. Gas under pressure will go down, and rising up, the gas bubbles will mix the biomass in the tank.
If you do not want to build a concrete bunker, you can buy a ready-made PVC container. To preserve heat, it must be overlaid around with a layer of thermal insulation - polystyrene foam. The bottom of the pit is filled with reinforced concrete with a layer of 10 cm. Polyvinyl chloride tanks can be used if the volume of the reactor does not exceed 3 m3.
Conclusions and useful video on the topic
How to make the simplest installation from an ordinary barrel, you will learn if you watch the video:
The simplest reactor can be made in a few days with your own hands, using available tools. If the farm is large, then it is best to buy a ready-made installation or contact specialists.
Formic acid, whose formula is HCOOH, is the simplest monocarboxylic acid. As it becomes clear from its name, the characteristic secretions of red ants became the source of its discovery. The acid in question is part of the poisonous substance secreted by stinging ants. It also contains a burning liquid, which is formed by the stinging caterpillars of the silkworm.
For the first time, a solution of formic acid was obtained during the experiments of the famous English scientist John Ray. At the end of the seventeenth century, he mixed water and red wood ants in a vessel. Next, the vessel was heated to a boil, and a jet of hot steam was passed through it. The result of the experiment was to obtain an aqueous solution, the distinguishing characteristic of which was a strongly acidic reaction.
In the middle of the eighteenth century, Andreas Sigismund Marggraf succeeded in obtaining pure formic acid. Anhydrous acid, which was obtained by the German chemist Justus Liebig, is considered the simplest and strongest carboxylic acid at the same time. According to modern nomenclature, it is called methanoic acid and is an extremely dangerous compound.
To date, obtaining the presented acid is carried out in several ways, including a number of successive stages. But it has been proven that hydrogen and carbon dioxide are able to turn into formic acid and return to their original state. The development of this theory was carried out by German scientists. The relevance of the topic was to minimize the release of carbon dioxide into the atmospheric air. This result can be achieved by its active use as the main source of carbon for the synthesis of organic substances.
The innovative technique developed by German specialists involves the implementation of catalytic hydrogenation with the formation of formic acid. According to it, carbon dioxide becomes both a base material and a solvent for separating the final product, since the reaction is carried out in supercritical CO2. Thanks to this integrated approach, one-step production of methane acid becomes a reality.
The process of hydrogenation of carbon dioxide with the formation of methane acid is currently one of the objects of active research. The main goal pursued by scientists is to obtain chemical compounds from waste products that are formed as a result of the combustion of fossil fuels. In addition to the wide distribution of formic acid in various industries, its participation in the storage of hydrogen should be noted. It is possible that the role of fuel for vehicles equipped with solar panels will be played by this acid, from which hydrogen can be extracted by catalytic reactions.
The formation of methane acid from carbon dioxide by homogeneous catalysis has been the subject of study by specialists since the 1970s. The main difficulty is the shift of equilibrium towards the starting materials, which is observed at the stage of the equilibrium reaction. To solve the problem, it is necessary to remove formic acid from the composition of the reaction mixture. But at the moment this can be achieved only if methane acid is converted into a salt or other compound. Therefore, pure acid can be obtained only if there is an additional stage, which consists in the destruction of this substance, which does not allow to achieve the organization of an uninterrupted process of formic acid formation.
However, a unique concept is becoming increasingly popular, which is being developed by scientists from the Walter Leitner group. They suggest that the integration of the stages of hydrogenation of carbon dioxide and the isolation of the product with their implementation within the same apparatus makes it possible to make the process of obtaining pure methane acid uninterrupted. How did scientists manage to achieve maximum efficiency? The reason for this was the use of a two-phase system, in which the mobile phase is represented by supercritical carbon dioxide, and the stationary phase is represented by an ionic liquid, liquid salt. It should be noted that the ionic liquid was used to dissolve both the catalyst and the base to stabilize the acid. The flow of carbon dioxide in conditions where the pressure and temperature exceed the critical figures, contributes to the removal of methane acid from the composition of the reaction mixture. It is important that the presence of supercritical carbon dioxide does not lead to the dissolution of ionic liquids, catalyst, base, ensuring the maximum purity of the resulting substance.
, explosive gases , greenhouse effect
This explosive gas is often referred to as "swamp gas". Everyone knows its specific smell, but in fact these are special additives "with the smell of gas" that are added in order to recognize it. When burned, it practically does not leave harmful products. Among other things, this gas is quite actively involved in the formation of the well-known greenhouse effect.
A gas usually associated with living organisms. When methane was discovered in the atmospheres of Mars and Titan, scientists had hope that life exists on these planets. There is not much methane on the Red Planet, but Titan is literally “filled” with it. And if not for Titan, then for Mars, biological sources of methane are just as likely as geological ones. There is a lot of methane on the giant planets - Jupiter, Saturn, Uranus and Neptune, where it originated as a product of chemical processing of the substance of the protosolar nebula. On Earth, it is rare: its content in the atmosphere of our planet is only 1750 parts per billion by volume (ppbv).
Sources and production of methane
Methane is the simplest hydrocarbon, a colorless, odorless gas. Its chemical formula is CH 4 . Slightly soluble in water, lighter than air. When used in everyday life, industry, odorants with a specific “gas smell” are usually added to methane. The main component of natural (77-99%), associated petroleum (31-90%), mine and swamp gases (hence the other names for methane - swamp or mine gas).
90–95% of methane is of biological origin. Herbivorous ungulates such as cows and goats give off a fifth of their annual methane emissions, produced by bacteria in their stomachs. Other important sources are termites, paddy rice, swamps, natural gas filtration (a product of past life), and plant photosynthesis. Volcanoes contribute less than 0.2% to the total balance of methane on Earth, but the organisms of past eras can also be the source of this gas. Industrial methane emissions are negligible. Thus, the detection of methane on a planet like Earth indicates the presence of life there.
Methane is formed during the thermal processing of oil and oil products (10-57% by volume), coking and hydrogenation of coal (24-34%). Laboratory methods of obtaining: fusion of sodium acetate with alkali, the action of water on methylmagnesium iodide or on aluminum carbide.
It is prepared in the laboratory by heating soda lime (a mixture of sodium and potassium hydroxides) or anhydrous sodium hydroxide with acetic acid. The absence of water is important for this reaction, which is why sodium hydroxide is used, since it is less hygroscopic.
Properties of methane
burning in the air bluish flame, while the energy of about 39 MJ per 1m 3 is released. Forms with air explosive mixtures. Of particular danger is methane released during underground mining of mineral deposits into mine workings, as well as at coal processing and briquette factories, at screening plants. So, at a content of up to 5-6% in air, methane burns near a heat source (ignition temperature 650-750 ° C), from 5-6% to 14-16% it explodes, more than 16% can burn with an influx of oxygen from outside. A decrease in the concentration of methane in this case can lead to an explosion. In addition, a significant increase in the concentration of methane in the air causes asphyxiation (for example, a methane concentration of 43% corresponds to 12% O 2).Explosive combustion spreads at a speed of 500-700 m/s; gas pressure during an explosion in a closed volume is 1 MN/m 2 . After contact with a heat source, the ignition of methane occurs with some delay. The creation of safety explosives and explosion-proof electrical equipment is based on this property. At sites that are dangerous due to the presence of methane (mainly coal mines), the so-called. gas mode.
At 150–200 °C and a pressure of 30–90 atm, methane is oxidized to formic acid.
Methane forms inclusion compounds - gas hydrates, widely distributed in nature.
Methane application
Methane is the most thermally stable saturated hydrocarbon. It is widely used as household and industrial fuel And How raw materials for industry. So, by chlorination of methane, methyl chloride, methylene chloride, chloroform, carbon tetrachloride are produced.
Incomplete combustion of methane produces soot, during catalytic oxidation - formaldehyde, when interacting with sulfur - carbon disulfide.
Thermal-oxidative cracking and electrocracking methane - important industrial methods for obtaining acetylene.
Catalytic oxidation of a mixture of methane and ammonia underlies industrial production hydrocyanic acid. Methane is used as source of hydrogen in the production of ammonia, as well as for the production of water gas (the so-called synthesis gas): CH 4 + H 2 O → CO + 3H 2, used for the industrial synthesis of hydrocarbons, alcohols, aldehydes, etc. An important derivative of methane is nitromethane.
Automotive fuel
Methane is widely used as a motor fuel for cars. However, the density of natural methane is a thousand times lower than the density of gasoline. Therefore, if you fill a car with methane at atmospheric pressure, then for an equal amount of fuel with gasoline, you will need a tank 1000 times larger. In order not to carry a huge trailer with fuel, it is necessary to increase the density of the gas. This can be achieved by compressing methane to 20-25 MPa (200-250 atmospheres). To store gas in this state, special cylinders are used, which are installed on cars.
Methane and the greenhouse effect
Methane is greenhouse gas. If the degree of carbon dioxide impact on the climate is conditionally taken as a unit, then the greenhouse activity of methane will be 23 units. The content of methane in the atmosphere has grown very rapidly over the past two centuries.
Now the average content of methane CH 4 in the modern atmosphere is estimated at 1.8 ppm ( parts per million, parts per million). And, although this is 200 times less than the content of carbon dioxide (CO 2) in it, per molecule of gas, the greenhouse effect of methane - that is, its contribution to the dissipation and retention of heat radiated by the Earth heated by the sun - is significantly higher than from CO 2 . In addition, methane absorbs the Earth's radiation in those "windows" of the spectrum that are transparent to other greenhouse gases. Without greenhouse gases - CO 2 , water vapor, methane and some other impurities, the average temperature on the Earth's surface would be only -23°C, and now it is about +15°C.
Methane seeps out at the bottom of the ocean through cracks in the earth's crust, and is released in considerable quantities during mining and when forests are burned. Recently, a new, completely unexpected source of methane has been discovered - higher plants, but the mechanisms of formation and the significance of this process for the plants themselves have not yet been elucidated.
Methane on Earth
Near Santa Barbara, methane, an active greenhouse gas, is emitted from the ocean floor in large volumes in the form of bubbles.
Methane is especially dangerous during mining operations.
Methane instead of gasoline? Easily
When methane was discovered in the atmosphere of Mars, scientists hoped to find traces of life on the planet.
Usage: obtaining hydrocarbons. Essence: 10-80% aqueous solution of heteropolyacids 2-18 of the H 6 series is heated to a temperature of 70-140 o C, then a lead or copper plate is immersed in the solution and wait 3-15 minutes before the start of the process of restoring the anionic complex 6- , after which solution at a pressure of 700-800 mm Hg. pass a gas mixture with a carbon dioxide concentration of not more than 60 vol.% and an oxygen concentration of at least 5 vol. % to obtain methane or one of the saturated hydrocarbons. EFFECT: production of methane from carbon dioxide in industrial volumes.
Description text in facsimile (see graphic part).
Claim
A method for producing methane and its derivatives, the main raw material for which is carbon dioxide, characterized in that a 10-80% aqueous solution of heteropoly acid 2-18 of the H 6 series is heated to a temperature of 70-140C, then a lead or copper plate is immersed in the solution and wait 3-15 minutes before the start of the process of reduction of the anionic complex 6- , then through the solution at a pressure of 700-800 mm Hg. a gas mixture with a carbon dioxide concentration of not more than 60 vol.% and an oxygen concentration of at least 5 vol.% is passed until one of the saturated hydrocarbons is obtained.
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The invention relates to petrochemistry, in particular to methods for purifying oil, gas condensate and oil products, as well as water-oil emulsions from hydrogen sulfide and / or low molecular weight mercaptans, and can be used in oil, gas, oil and gas processing, petrochemical and other industries
The invention relates to the complex processing of pyrocondensate high-temperature homogeneous pyrolysis of saturated hydrocarbons of composition C3-C5
The invention relates to methods for producing liquid hydrocarbon products from gases, in particular from carbon dioxide, and can be used in the oil refining and petrochemical industries
The invention relates to a method for producing methane from atmospheric carbon dioxide. The method is characterized by the use of a mechanical mixture of a thermally regenerated sorbent - a carbon dioxide absorber, which is potassium carbonate fixed in the pores of titanium dioxide, and has the composition: wt%: K2CO3 - 1-40, TiO2 - the rest up to 100, and a photocatalyst for methanation process or reduction of carbon dioxide released during regeneration of the composition: wt.%: Pt≈0.1-5 wt.%, CdS≈5-20 wt.%, TiO2 - the rest is up to 100, the content of the photocatalyst in the mixture is 10-50 wt.%. This method is an energy-efficient method for producing methane from carbon dioxide in the air, using alternative renewable energy for fuel synthesis. 4 w.p. f-ly, 4 pr., 1 ill.
The invention relates to a process for producing hydrocarbon products, comprising the steps: (a) providing synthesis gas containing hydrogen, carbon monoxide and carbon dioxide; (b) a reaction for converting synthesis gas into an oxygenate mixture containing methanol and dimethyl ether in the presence of one or more catalysts that co-catalyze the reaction for converting hydrogen and carbon monoxide into oxygenates at a pressure of at least 4 MPa; (c) removing from step (b) the oxygenate mixture containing the amounts of methanol, dimethyl ether, carbon dioxide and water together with unreacted synthesis gas, and introducing the entire amount of the oxygenate mixture without further treatment into the stage of catalytic conversion of oxygenates (d); (d) reacting the oxygenate mixture in the presence of a catalyst that is active in converting oxygenates to higher hydrocarbons; (e) recovering the effluent from step (d) and separating the effluent into tail gas containing carbon dioxide arising from synthesis gas and carbon dioxide formed in step (b), a liquid hydrocarbon phase containing those obtained in step (d) ) higher hydrocarbons, and a liquid aqueous phase, where the pressure applied in stages (c)-(e) is essentially the same as that used in stage (b), and part of the tail gas obtained in stage (e) is recycled to step (d), and the rest of the tail gas is diverted. The present process is a process in which there is no recirculation of unreacted synthesis gas to the oxygenate synthesis step and no cooling of the dimethyl ether to higher hydrocarbon conversion reaction. 1 n.p., 5 w.p. f-ly, 2 pr., 1 tab., 2 ill.
The present invention provides a process for the production of ethylene oxide, comprising: a. cracking the ethane-containing feedstock in a cracking zone under cracking conditions to produce olefins, including at least ethylene and hydrogen; b. converting the feed oxygenate in an oxygenate to olefin conversion (OTO) zone to produce olefins, including at least ethylene; c. directing at least a portion of the ethylene produced in step (a) and/or (b) to an ethylene oxidation zone together with an oxygen-containing feedstock and oxidizing the ethylene to produce at least ethylene oxide and carbon dioxide; and wherein at least a portion of the oxygenate feedstock is produced by directing the carbon dioxide produced in step (c) and the hydrogen-containing feedstock to an oxygenate synthesis zone and synthesizing oxygenates, wherein the hydrogen-containing feedstock comprises the hydrogen produced in step (a). In another aspect, the present invention provides an integrated system for the production of ethylene oxide. EFFECT: development of a process for the production of ethylene oxide and optionally monoethylene oxide by integrating the processes of ethane cracking and RTO, which makes it possible to reduce carbon dioxide emissions and the amount of synthesis gas required for the synthesis of oxygenates. 2 n. and 13 z.p. f-ly, 1 ill., 6 tab., 1 pr.
The invention relates to a process for converting carbon dioxide in an exhaust gas into natural gas using excess energy. Moreover, the method includes stages in which: 1) perform voltage transformation and rectification of excess energy, which is generated from a renewable energy source, and which is difficult to store or connect to power networks, direct excess energy into the electrolyte solution for electrolysis of water in it into H2 and O2 , and remove water from H2; 2) carrying out purification of the industrial off-gas to separate CO2 therefrom, and purification of the CO2 separated therefrom; 3) feeding the H2 generated in step 1) and the CO2 separated in step 2) into a synthesis equipment including at least two fixed bed reactors so that a high temperature gas mixture with the main components of CH4 and steam is obtained as a result of a highly exothermic methanation reactions between H2 and CO2, wherein the primary fixed bed reactor is maintained at an inlet temperature of 250-300°C, a reaction pressure of 3-4 MPa, and an outlet temperature of 600-700°C; the secondary fixed bed reactor is maintained at an inlet temperature of 250-300°C, a reaction pressure of 3-4 MPa, and an outlet temperature of 350-500°C; wherein a portion of the high temperature gas mixture from the primary fixed bed reactor is bypassed for cooling, dewatering, compression and heating, and then mixed with fresh H2 and CO2 to transport the gas mixture back to the primary fixed bed reactor after the volumetric CO2 content in it is 6-8%; 4) use the high temperature gas mixture generated in step 3) to conduct indirect heat exchange with process water to produce superheated steam; 5) supplying the superheated water vapor obtained in step 4) to a turbine for generating electric power, and returning electric power to step 1) for voltage transformation and current rectification, and for electrolysis of water; and 6) condense and dry the gas mixture in step 4), cooled by heat exchange, until a natural gas with CH4 content up to standard is obtained. The invention also relates to a device. The use of the present invention makes it possible to increase the yield of methane gas. 2 n. and 9 z.p. f-ly, 2 pr., 2 ill.
The invention relates to a method for producing methanol from a stream rich in carbon dioxide as a first feed stream and a stream rich in hydrocarbons as a second feed stream, as well as to a plant for its implementation. The method includes the following steps: supplying a first carbon dioxide-rich feed stream to at least one methanization stage and converting the first feed stream with hydrogen under methanization conditions into a methane-rich stream, supplying a methane-rich stream to at least one synthesis gas production stage and converting it, together with a second hydrocarbon-rich feed stream, into a synthesis gas stream containing carbon oxides and hydrogen, under syngas production conditions, feeding the synthesis gas stream to a methanol synthesis stage built into the synthesis loop and converting it into a methanol-containing product stream under methanol synthesis conditions, separating the methanol from the methanol containing product stream and optionally purifying the methanol to a methanol end product stream and recovering a purge stream containing carbon oxides and hydrogen from the methanol synthesis unit. The present invention makes it possible to utilize the greenhouse gas carbon dioxide to produce methanol using a simple technology. 2 n. and 13 z.p. f-ly, 4 ill.
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