Natural gas poetry

Natural gas in a broad sense refers to all natural gas, including gases formed by various natural processes in the atmosphere, hydrosphere, biosphere and lithosphere. The commonly used definition of "natural gas" for a long time is a narrow definition from the perspective of energy. Refers to the mixture of hydrocarbon and non-hydrocarbon gases naturally contained in the formation, mainly alkanes, of which methane accounts for the vast majority, and a small amount of ethane, propane and butane. In addition, there are generally hydrogen sulfide, carbon dioxide, nitrogen and water vapor and a small amount of inert gases, such as helium and argon. Under standard conditions, methane is converted into butane and exists in gaseous state. Liquid natural gas above pentane mainly exists in oilfield gas, gas field gas, coalbed methane, mud volcano gas and biogas, and a small amount comes from coal seam. Natural gas can be divided into associated gas and non-associated gas. The oilfield gas produced together with crude oil is called associated gas. Non-associated gas includes pure gas field natural gas and condensed gas field natural gas, both of which exist in the formation in gaseous state. After the natural gas in condensate gas field flows out of the wellhead from the formation, it is separated into gas phase and liquid phase with the decrease of pressure and temperature. The gas phase of condensate gas field is natural gas and the liquid phase is condensate oil, which is called condensate oil. Compared with coal, oil and other energy sources, natural gas produces very few substances that can affect the health of human respiratory system during combustion, and the carbon dioxide produced is only about 40% of that of coal, and the sulfur dioxide produced is also very small. Natural gas has no waste residue and waste water after combustion, and has the advantages of safe use, high calorific value and cleanliness. However, for the greenhouse effect, natural gas will produce carbon dioxide like coal and oil. Therefore, natural gas can't be stored in underground porous rocks as a new energy source. The main component is methane, with a specific gravity of about 0.65, which is lighter than air and has the characteristics of colorless, odorless and nontoxic. Natural gas companies all add odorant (tetrahydrothiophene) according to government regulations for users to smell. When the content of natural gas in the air reaches a certain level, it will suffocate people. If the concentration of natural gas in the air is in the range of 5% ~ 15%, it will explode when it meets an open flame, and this concentration range is the explosion limit of natural gas. The explosion instantly produces high pressure and high temperature, which is very destructive and dangerous. According to the state of natural gas, it can be divided into three types: structural natural gas, water-soluble natural gas and coal mine natural gas. Structured natural gas can be divided into wet natural gas produced from crude oil and dry natural gas without liquid components.