It should be noted that hydrocarbons are widespread in nature. Most organic substances are obtained from natural sources. In the synthesis of organic compounds, natural and associated gases, coal and lignite, oil, oil shale, peat, and animal and vegetable products are used as raw materials.
Natural sources of hydrocarbons: natural gases.
Natural gases are natural mixtures of hydrocarbons of various structures and certain gas impurities (hydrogen sulfide, hydrogen, carbon dioxide) that fill rock formations in the earth's crust. These compounds are formed as a result of the hydrolysis of organic substances at great depths in the thickness of the Earth. They are found in the free state in the form of huge accumulations - gas, gas condensate and oil and gas fields.
The main structural component of combustible natural gases is CH₄ (methane - 98%), ₂₆ (ethane - 4.5%), propane (₃₈ - 1.7%), butane (₄₁₀ - 0.8%), pentane (₅₁₂- 0 , 6%). Concomitant petroleum gas is included in the oil in a dissolved state and is released from it due to a decrease in pressure when lifting oil to the surface. In gas and oil fields, one ton of oil contains from 30 to 300 square meters. m of gas. Natural sources of hydrocarbon are a valuable fuel and raw material for the organic synthesis industry. Gas is supplied to gas processing plants where it can be processed (oil, low-temperature adsorption, condensation and rectification). It is divided into individual components, each of which is used for specific purposes. For example, hydrogen, synthesis gas, which is the basic raw material for the production of other hydrocarbons, acetylene, methanol, methanal, and chloroform, is obtained from methane.
Natural sources of hydrocarbons: oil.
Oil is a complex mixture, which consists mainly of naphthenic, paraffinic and aromatic hydrocarbons. The composition of the oil includes asphalt-resinous substances, naphthenic acids, mono- and disulfides, mercaptans, thiophene, thiophan, hydrogen sulfide, piperidine, pyridine and its homologues, as well as other substances. Based on petroleum refined products using petrochemical synthesis methods, more than 3,000 different products are obtained, including ethylene, benzene, propylene, dichloroethane, vinyl chloride, styrene, ethanol, isopropanol, butylenes, a variety of plastics, chemical fibers, dyes, detergents, medicines, explosives, etc.
Natural sources of hydrocarbons: peat.
Peat is a sedimentary rock of plant origin. This substance is used as fuel (mainly for thermal power plants), chemical raw materials (for the synthesis of many organic substances), antiseptic litter on farms, especially in poultry farms, and a fertilizer component for gardening and field cultivation.
Natural sources of hydrocarbons: xylem or wood.
Xylem is the tissue of higher plants, through which water and dissolved nutrients come from the rhizome of the system to the leaves and other organs of the plant. It consists of cells with a stiff membrane, which have a vascular conduction system. Depending on the type of wood, it contains a different amount of pectin substances and mineral compounds (mainly calcium salts), lipids and essential oils. Wood is used as fuel, from it you can synthesize methyl alcohol, acetate acid, cellulose, as well as other substances. From some types of wood, dyes (sandalwood, campus tree), tannins (oak), resins and balsams (cedar, pine, spruce), alkaloids (plants of the nightshade, poppy, buttercup, umbrella family) are obtained. Some alkaloids are used as medicines (chitin, caffeine), herbicides (anabazine), insecticides (nicotine).