Seeking information on methanation! !

Methane is the simplest substance among hydrocarbon molecules, with the chemical formula CH4. Methane is a colorless and odorless gas; it is slightly soluble in water and soluble in alcohol and ether. Density (at standard conditions): 0.717 grams per liter; boiling point: -161.5°C; melting point: -182.48°C. Heat of combustion (kJ/mol): 889.5, Critical temperature (°C): -82.6, Critical pressure (MPA): 4.59. Flash point (°C): -188, Ignition temperature (°C): 538. Under certain conditions, methane can undergo halogenation reactions (with Cl2, Br2) and thermal decomposition (into C, H2, C2H2, etc.). The flame appears blue-white when methane burns. The main component of biogas, landfill gas, and natural gas is methane. Methane in natural gas is liquefied through low temperature and high pressure, and can be transported across oceans using special ships. Chemical properties of methane: Methane is stable in nature and does not react with acidic KMnO4 solutions or bromine water. Igniting a mixture of methane and air can cause an explosion. The explosive limit of methane in air is 5.3–14.0% (by volume), while its explosive limit in oxygen is 5.4–59.2% (by volume). Precautions for transporting methane: When using steel cylinders for transportation, it is necessary to wear the safety caps on those cylinders. Gas cylinders should generally be placed flat, with their openings facing in the same direction; they must not be crossed ； The height must not exceed the vehicle’s guardrail, and it should be secured with wooden blocks to prevent it from rolling. Transport vehicles should be equipped with fire-fighting equipment of the appropriate type and quantity during transportation. The exhaust pipes of the vehicles used to transport this item must be equipped with flame arrestors, and the use of mechanical equipment and tools that may generate sparks for loading and unloading is prohibited. Mixing or transporting it together with oxidizers and similar substances is strictly prohibited. During summer, transportation should take place in the morning and evening to avoid exposure to sunlight. When making stops en route, stay away from sources of fire and heat. When transporting by road, follow the designated routes and do not stop in residential areas or densely populated zones. Sliding is prohibited during railway transportation. Hazardity-Health risks: Methane is essentially non-toxic to humans, but at high concentrations it significantly reduces the oxygen level in the air, leading to suffocation. When methane levels in the air reach 25%–30%, it can cause headaches, dizziness, fatigue, difficulty concentrating, accelerated breathing and heartbeat, and ataxia. If not removed in time, it can lead to death from asphyxiation. Skin contact with the liquefied product can cause frostbite.

Is it data on synthetic methane in coal-to-natural gas?

O(∩_∩)O~ One character too few, hehe

Synthetic methane is classified information; it’s very difficult to come by

Raw gas methanization purification is a process in which (CO+CO2) in the gas phase reacts with H2 under the action of a catalyst to be converted into CH4, thereby purifying the gas. It was a traditional gas purification method used in early nitrogen fertilizer production; in recent years, it has gained attention in small and medium-sized nitrogen fertilizer plants due to the development of advanced desulfurization technologies. Methanation gas purification technology is considered more advanced and rational than copper washing, and it is itself a mature technology. The methanation reaction is a highly exothermic reaction: 3H2 + CO = CH4 + H2O + 206.37 kJ; 4H2 + CO2 = CH4 + 2H2O + 165.35 kJ. For methanation, the CO content in the feedstock must be < 0.3%, (CO + CO2)

Well, methanation in the coal-to-gas process

Using high-pressure methanol methanation is excellent; it produces methanol along with purified gases, and the carbon monoxide level at the inlet of the methanation reactor is below 500 ppm.

Is there a more detailed introduction to 8# wgtwm? It also allows me to learn more*

1 Principles, Application Status, and Development Trends of Methanation Reactions 1.1 Principles The synthesis of methane from carbon monoxide via hydrogenation is a multiphase catalytic gas-phase reaction. The basic reaction equation is: CO + 3H2 = CH4 + H2O, with ΔH = –206.4 kJ/kmol (1). This reaction employs catalysts containing cobalt or nickel; at temperatures between 200 and 350 °C, carbon monoxide is catalytically hydrogenated to form methane. It represents a special case of the F-T process for hydrocarbon synthesis. The methanation reaction is equivalent to a fuel conversion process, which allows the energy density to increase from 11.28 MJ/m3 to 35.9 MJ/m3 before and after the reaction. 1.2 Application status Methanation technology is typically used in the following two situations: ① To remove small amounts of CO and CO2 from process gases (such as purified H2 or raw materials for ammonia synthesis) ； ② CO in city gas is detoxified through methanation. During the 1970s and 1980s, the United States and Europe used methanation reactions to produce SNG from coal-based syngas in order to ensure a long-term supply of natural gas. Great Plains Synthetic Fuels Company originated from the energy crisis in the United States in the 1970s; construction began in 1981, and SNG was produced in 1984. The plant consumes 6 million tons of raw coal per year. It utilizes 14 Lurgi fluidized bed gasifiers (with 2 as spares), and can produce 1,200 tons per day of anhydrous ammonia as a by-product, as well as 5,000 tons per day of high-purity CO2, which is supplied to oil fields in Canada for enhanced oil recovery (EOR). 1.3 Development trends Due to the limitations of large-scale gasification technology, as well as the discovery of substantial natural gas resources not long after, the development of this technology remained at the demonstration stage and was not widely applied. But now, as natural gas prices continue to rise, some companies that rely on natural gas as a raw material are unable to bear the price risks and are seeking new alternatives. Furthermore, the second-generation fluidized bed gasification technology, represented typically by companies such as Texaco and Shell, has been widely adopted in industry, ensuring the large-scale comprehensive utilization of coal. Current coal-to-SNG projects under consideration at home and abroad include: ① GE’s Texaco gasifier and Danish company Haldor Topsoe’s methanization technology, which will be used in Power Holding’s gasification plant in Illinois to produce SNG. Construction began in January 2007, and the coal-to-natural gas project is expected to be completed by 2010, with the capacity to process 4 million to 4.5 million tons of coal per year. ② The American company Steelhead Energy plans to start construction in 2008 of an SNG-electric combined plant with a coal input capacity of 10,000 tons per day, an electricity generation capacity of 600 MW, and an SNG production volume of 2.69 million cubic meters per day ； The installation of the E-gas gasifier and two 200 MW Siemens W501FD gas turbines fueled by medium- and low-calorific-value gas will be completed in 2011. ③ The Datang International Keshiketeng coal-to-natural gas project utilizes the abundant lignite reserves in the area as well as the local water resources to produce natural gas and other by-products, with commissioning expected in the second half of 2010.

Process simulation of the coal-based SNG system at the pit entrance. The process flow for coal-based SNG is shown in Figure 1. The quenched syngas from the gasifier is fed into the water-gas shift reactor to adjust the hydrogen-to-carbon ratio required for methane synthesis ； It then enters the desulfurization and decarburization units to collect high-purity CO2, which is subsequently recovered as elemental sulfur through Claus/SCOT units ； Clean syngas is fed into the methanation reactor to produce SNG, while a small portion of the syngas is used as fuel for drying coal ； The large amount of heat released during the methanation process is used to generate high-pressure steam, which drives steam turbines to produce electricity.